fs/btrfs/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/bio.h>
   8 #include <linux/file.h>
   9 #include <linux/fs.h>
  10 #include <linux/fsnotify.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/highmem.h>
  13 #include <linux/time.h>
  14 #include <linux/string.h>
  15 #include <linux/backing-dev.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <linux/writeback.h>
  19 #include <linux/compat.h>
  20 #include <linux/security.h>
  21 #include <linux/xattr.h>
  22 #include <linux/mm.h>
  23 #include <linux/slab.h>
  24 #include <linux/blkdev.h>
  25 #include <linux/uuid.h>
  26 #include <linux/btrfs.h>
  27 #include <linux/uaccess.h>
  28 #include <linux/iversion.h>
  29 #include "ctree.h"
  30 #include "disk-io.h"
  31 #include "transaction.h"
  32 #include "btrfs_inode.h"
  33 #include "print-tree.h"
  34 #include "volumes.h"
  35 #include "locking.h"
  36 #include "inode-map.h"
  37 #include "backref.h"
  38 #include "rcu-string.h"
  39 #include "send.h"
  40 #include "dev-replace.h"
  41 #include "props.h"
  42 #include "sysfs.h"
  43 #include "qgroup.h"
  44 #include "tree-log.h"
  45 #include "compression.h"
  46
  47 #ifdef CONFIG_64BIT
  48 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  49  * structures are incorrect, as the timespec structure from userspace
  50  * is 4 bytes too small. We define these alternatives here to teach
  51  * the kernel about the 32-bit struct packing.
  52  */
  53 struct btrfs_ioctl_timespec_32 {
  54         __u64 sec;
  55         __u32 nsec;
  56 } __attribute__ ((__packed__));
  57
  58 struct btrfs_ioctl_received_subvol_args_32 {
  59         char    uuid[BTRFS_UUID_SIZE];  /* in */
  60         __u64   stransid;               /* in */
  61         __u64   rtransid;               /* out */
  62         struct btrfs_ioctl_timespec_32 stime; /* in */
  63         struct btrfs_ioctl_timespec_32 rtime; /* out */
  64         __u64   flags;                  /* in */
  65         __u64   reserved[16];           /* in */
  66 } __attribute__ ((__packed__));
  67
  68 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  69                                 struct btrfs_ioctl_received_subvol_args_32)
  70 #endif
  71
  72 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  73 struct btrfs_ioctl_send_args_32 {
  74         __s64 send_fd;                  /* in */
  75         __u64 clone_sources_count;      /* in */
  76         compat_uptr_t clone_sources;    /* in */
  77         __u64 parent_root;              /* in */
  78         __u64 flags;                    /* in */
  79         __u64 reserved[4];              /* in */
  80 } __attribute__ ((__packed__));
  81
  82 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
  83                                struct btrfs_ioctl_send_args_32)
  84 #endif
  85
  86 static int btrfs_clone(struct inode *src, struct inode *inode,
  87                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  88                        int no_time_update);
  89
  90 /* Mask out flags that are inappropriate for the given type of inode. */
  91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
  92                 unsigned int flags)
  93 {
  94         if (S_ISDIR(inode->i_mode))
  95                 return flags;
  96         else if (S_ISREG(inode->i_mode))
  97                 return flags & ~FS_DIRSYNC_FL;
  98         else
  99                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 100 }
 101
 102 /*
 103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 104  * ioctl.
 105  */
 106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
 107 {
 108         unsigned int iflags = 0;
 109
 110         if (flags & BTRFS_INODE_SYNC)
 111                 iflags |= FS_SYNC_FL;
 112         if (flags & BTRFS_INODE_IMMUTABLE)
 113                 iflags |= FS_IMMUTABLE_FL;
 114         if (flags & BTRFS_INODE_APPEND)
 115                 iflags |= FS_APPEND_FL;
 116         if (flags & BTRFS_INODE_NODUMP)
 117                 iflags |= FS_NODUMP_FL;
 118         if (flags & BTRFS_INODE_NOATIME)
 119                 iflags |= FS_NOATIME_FL;
 120         if (flags & BTRFS_INODE_DIRSYNC)
 121                 iflags |= FS_DIRSYNC_FL;
 122         if (flags & BTRFS_INODE_NODATACOW)
 123                 iflags |= FS_NOCOW_FL;
 124
 125         if (flags & BTRFS_INODE_NOCOMPRESS)
 126                 iflags |= FS_NOCOMP_FL;
 127         else if (flags & BTRFS_INODE_COMPRESS)
 128                 iflags |= FS_COMPR_FL;
 129
 130         return iflags;
 131 }
 132
 133 /*
 134  * Update inode->i_flags based on the btrfs internal flags.
 135  */
 136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 137 {
 138         struct btrfs_inode *binode = BTRFS_I(inode);
 139         unsigned int new_fl = 0;
 140
 141         if (binode->flags & BTRFS_INODE_SYNC)
 142                 new_fl |= S_SYNC;
 143         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 144                 new_fl |= S_IMMUTABLE;
 145         if (binode->flags & BTRFS_INODE_APPEND)
 146                 new_fl |= S_APPEND;
 147         if (binode->flags & BTRFS_INODE_NOATIME)
 148                 new_fl |= S_NOATIME;
 149         if (binode->flags & BTRFS_INODE_DIRSYNC)
 150                 new_fl |= S_DIRSYNC;
 151
 152         set_mask_bits(&inode->i_flags,
 153                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 154                       new_fl);
 155 }
 156
 157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 158 {
 159         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 160         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
 161
 162         if (copy_to_user(arg, &flags, sizeof(flags)))
 163                 return -EFAULT;
 164         return 0;
 165 }
 166
 167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
 168 static int check_fsflags(unsigned int flags)
 169 {
 170         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 171                       FS_NOATIME_FL | FS_NODUMP_FL | \
 172                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 173                       FS_NOCOMP_FL | FS_COMPR_FL |
 174                       FS_NOCOW_FL))
 175                 return -EOPNOTSUPP;
 176
 177         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 178                 return -EINVAL;
 179
 180         return 0;
 181 }
 182
 183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 184 {
 185         struct inode *inode = file_inode(file);
 186         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 187         struct btrfs_inode *binode = BTRFS_I(inode);
 188         struct btrfs_root *root = binode->root;
 189         struct btrfs_trans_handle *trans;
 190         unsigned int fsflags, old_fsflags;
 191         int ret;
 192         u64 old_flags;
 193         unsigned int old_i_flags;
 194         umode_t mode;
 195
 196         if (!inode_owner_or_capable(inode))
 197                 return -EPERM;
 198
 199         if (btrfs_root_readonly(root))
 200                 return -EROFS;
 201
 202         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
 203                 return -EFAULT;
 204
 205         ret = check_fsflags(fsflags);
 206         if (ret)
 207                 return ret;
 208
 209         ret = mnt_want_write_file(file);
 210         if (ret)
 211                 return ret;
 212
 213         inode_lock(inode);
 214
 215         old_flags = binode->flags;
 216         old_i_flags = inode->i_flags;
 217         mode = inode->i_mode;
 218
 219         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
 220         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
 221         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 222                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 223                         ret = -EPERM;
 224                         goto out_unlock;
 225                 }
 226         }
 227
 228         if (fsflags & FS_SYNC_FL)
 229                 binode->flags |= BTRFS_INODE_SYNC;
 230         else
 231                 binode->flags &= ~BTRFS_INODE_SYNC;
 232         if (fsflags & FS_IMMUTABLE_FL)
 233                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 234         else
 235                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 236         if (fsflags & FS_APPEND_FL)
 237                 binode->flags |= BTRFS_INODE_APPEND;
 238         else
 239                 binode->flags &= ~BTRFS_INODE_APPEND;
 240         if (fsflags & FS_NODUMP_FL)
 241                 binode->flags |= BTRFS_INODE_NODUMP;
 242         else
 243                 binode->flags &= ~BTRFS_INODE_NODUMP;
 244         if (fsflags & FS_NOATIME_FL)
 245                 binode->flags |= BTRFS_INODE_NOATIME;
 246         else
 247                 binode->flags &= ~BTRFS_INODE_NOATIME;
 248         if (fsflags & FS_DIRSYNC_FL)
 249                 binode->flags |= BTRFS_INODE_DIRSYNC;
 250         else
 251                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
 252         if (fsflags & FS_NOCOW_FL) {
 253                 if (S_ISREG(mode)) {
 254                         /*
 255                          * It's safe to turn csums off here, no extents exist.
 256                          * Otherwise we want the flag to reflect the real COW
 257                          * status of the file and will not set it.
 258                          */
 259                         if (inode->i_size == 0)
 260                                 binode->flags |= BTRFS_INODE_NODATACOW
 261                                               | BTRFS_INODE_NODATASUM;
 262                 } else {
 263                         binode->flags |= BTRFS_INODE_NODATACOW;
 264                 }
 265         } else {
 266                 /*
 267                  * Revert back under same assumptions as above
 268                  */
 269                 if (S_ISREG(mode)) {
 270                         if (inode->i_size == 0)
 271                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
 272                                              | BTRFS_INODE_NODATASUM);
 273                 } else {
 274                         binode->flags &= ~BTRFS_INODE_NODATACOW;
 275                 }
 276         }
 277
 278         /*
 279          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 280          * flag may be changed automatically if compression code won't make
 281          * things smaller.
 282          */
 283         if (fsflags & FS_NOCOMP_FL) {
 284                 binode->flags &= ~BTRFS_INODE_COMPRESS;
 285                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
 286
 287                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 288                 if (ret && ret != -ENODATA)
 289                         goto out_drop;
 290         } else if (fsflags & FS_COMPR_FL) {
 291                 const char *comp;
 292
 293                 binode->flags |= BTRFS_INODE_COMPRESS;
 294                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
 295
 296                 comp = btrfs_compress_type2str(fs_info->compress_type);
 297                 if (!comp || comp[0] == 0)
 298                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 299
 300                 ret = btrfs_set_prop(inode, "btrfs.compression",
 301                                      comp, strlen(comp), 0);
 302                 if (ret)
 303                         goto out_drop;
 304
 305         } else {
 306                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 307                 if (ret && ret != -ENODATA)
 308                         goto out_drop;
 309                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 310         }
 311
 312         trans = btrfs_start_transaction(root, 1);
 313         if (IS_ERR(trans)) {
 314                 ret = PTR_ERR(trans);
 315                 goto out_drop;
 316         }
 317
 318         btrfs_sync_inode_flags_to_i_flags(inode);
 319         inode_inc_iversion(inode);
 320         inode->i_ctime = current_time(inode);
 321         ret = btrfs_update_inode(trans, root, inode);
 322
 323         btrfs_end_transaction(trans);
 324  out_drop:
 325         if (ret) {
 326                 binode->flags = old_flags;
 327                 inode->i_flags = old_i_flags;
 328         }
 329
 330  out_unlock:
 331         inode_unlock(inode);
 332         mnt_drop_write_file(file);
 333         return ret;
 334 }
 335
 336 /*
 337  * Translate btrfs internal inode flags to xflags as expected by the
 338  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
 339  * silently dropped.
 340  */
 341 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
 342 {
 343         unsigned int xflags = 0;
 344
 345         if (flags & BTRFS_INODE_APPEND)
 346                 xflags |= FS_XFLAG_APPEND;
 347         if (flags & BTRFS_INODE_IMMUTABLE)
 348                 xflags |= FS_XFLAG_IMMUTABLE;
 349         if (flags & BTRFS_INODE_NOATIME)
 350                 xflags |= FS_XFLAG_NOATIME;
 351         if (flags & BTRFS_INODE_NODUMP)
 352                 xflags |= FS_XFLAG_NODUMP;
 353         if (flags & BTRFS_INODE_SYNC)
 354                 xflags |= FS_XFLAG_SYNC;
 355
 356         return xflags;
 357 }
 358
 359 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
 360 static int check_xflags(unsigned int flags)
 361 {
 362         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
 363                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
 364                 return -EOPNOTSUPP;
 365         return 0;
 366 }
 367
 368 /*
 369  * Set the xflags from the internal inode flags. The remaining items of fsxattr
 370  * are zeroed.
 371  */
 372 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
 373 {
 374         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
 375         struct fsxattr fa;
 376
 377         memset(&fa, 0, sizeof(fa));
 378         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
 379
 380         if (copy_to_user(arg, &fa, sizeof(fa)))
 381                 return -EFAULT;
 382
 383         return 0;
 384 }
 385
 386 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
 387 {
 388         struct inode *inode = file_inode(file);
 389         struct btrfs_inode *binode = BTRFS_I(inode);
 390         struct btrfs_root *root = binode->root;
 391         struct btrfs_trans_handle *trans;
 392         struct fsxattr fa;
 393         unsigned old_flags;
 394         unsigned old_i_flags;
 395         int ret = 0;
 396
 397         if (!inode_owner_or_capable(inode))
 398                 return -EPERM;
 399
 400         if (btrfs_root_readonly(root))
 401                 return -EROFS;
 402
 403         memset(&fa, 0, sizeof(fa));
 404         if (copy_from_user(&fa, arg, sizeof(fa)))
 405                 return -EFAULT;
 406
 407         ret = check_xflags(fa.fsx_xflags);
 408         if (ret)
 409                 return ret;
 410
 411         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
 412                 return -EOPNOTSUPP;
 413
 414         ret = mnt_want_write_file(file);
 415         if (ret)
 416                 return ret;
 417
 418         inode_lock(inode);
 419
 420         old_flags = binode->flags;
 421         old_i_flags = inode->i_flags;
 422
 423         /* We need the capabilities to change append-only or immutable inode */
 424         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
 425              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
 426             !capable(CAP_LINUX_IMMUTABLE)) {
 427                 ret = -EPERM;
 428                 goto out_unlock;
 429         }
 430
 431         if (fa.fsx_xflags & FS_XFLAG_SYNC)
 432                 binode->flags |= BTRFS_INODE_SYNC;
 433         else
 434                 binode->flags &= ~BTRFS_INODE_SYNC;
 435         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
 436                 binode->flags |= BTRFS_INODE_IMMUTABLE;
 437         else
 438                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
 439         if (fa.fsx_xflags & FS_XFLAG_APPEND)
 440                 binode->flags |= BTRFS_INODE_APPEND;
 441         else
 442                 binode->flags &= ~BTRFS_INODE_APPEND;
 443         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
 444                 binode->flags |= BTRFS_INODE_NODUMP;
 445         else
 446                 binode->flags &= ~BTRFS_INODE_NODUMP;
 447         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
 448                 binode->flags |= BTRFS_INODE_NOATIME;
 449         else
 450                 binode->flags &= ~BTRFS_INODE_NOATIME;
 451
 452         /* 1 item for the inode */
 453         trans = btrfs_start_transaction(root, 1);
 454         if (IS_ERR(trans)) {
 455                 ret = PTR_ERR(trans);
 456                 goto out_unlock;
 457         }
 458
 459         btrfs_sync_inode_flags_to_i_flags(inode);
 460         inode_inc_iversion(inode);
 461         inode->i_ctime = current_time(inode);
 462         ret = btrfs_update_inode(trans, root, inode);
 463
 464         btrfs_end_transaction(trans);
 465
 466 out_unlock:
 467         if (ret) {
 468                 binode->flags = old_flags;
 469                 inode->i_flags = old_i_flags;
 470         }
 471
 472         inode_unlock(inode);
 473         mnt_drop_write_file(file);
 474
 475         return ret;
 476 }
 477
 478 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 479 {
 480         struct inode *inode = file_inode(file);
 481
 482         return put_user(inode->i_generation, arg);
 483 }
 484
 485 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 486 {
 487         struct inode *inode = file_inode(file);
 488         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 489         struct btrfs_device *device;
 490         struct request_queue *q;
 491         struct fstrim_range range;
 492         u64 minlen = ULLONG_MAX;
 493         u64 num_devices = 0;
 494         int ret;
 495
 496         if (!capable(CAP_SYS_ADMIN))
 497                 return -EPERM;
 498
 499         rcu_read_lock();
 500         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 501                                 dev_list) {
 502                 if (!device->bdev)
 503                         continue;
 504                 q = bdev_get_queue(device->bdev);
 505                 if (blk_queue_discard(q)) {
 506                         num_devices++;
 507                         minlen = min_t(u64, q->limits.discard_granularity,
 508                                      minlen);
 509                 }
 510         }
 511         rcu_read_unlock();
 512
 513         if (!num_devices)
 514                 return -EOPNOTSUPP;
 515         if (copy_from_user(&range, arg, sizeof(range)))
 516                 return -EFAULT;
 517
 518         /*
 519          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 520          * block group is in the logical address space, which can be any
 521          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 522          */
 523         if (range.len < fs_info->sb->s_blocksize)
 524                 return -EINVAL;
 525
 526         range.minlen = max(range.minlen, minlen);
 527         ret = btrfs_trim_fs(fs_info, &range);
 528         if (ret < 0)
 529                 return ret;
 530
 531         if (copy_to_user(arg, &range, sizeof(range)))
 532                 return -EFAULT;
 533
 534         return 0;
 535 }
 536
 537 int btrfs_is_empty_uuid(u8 *uuid)
 538 {
 539         int i;
 540
 541         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 542                 if (uuid[i])
 543                         return 0;
 544         }
 545         return 1;
 546 }
 547
 548 static noinline int create_subvol(struct inode *dir,
 549                                   struct dentry *dentry,
 550                                   const char *name, int namelen,
 551                                   u64 *async_transid,
 552                                   struct btrfs_qgroup_inherit *inherit)
 553 {
 554         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 555         struct btrfs_trans_handle *trans;
 556         struct btrfs_key key;
 557         struct btrfs_root_item *root_item;
 558         struct btrfs_inode_item *inode_item;
 559         struct extent_buffer *leaf;
 560         struct btrfs_root *root = BTRFS_I(dir)->root;
 561         struct btrfs_root *new_root;
 562         struct btrfs_block_rsv block_rsv;
 563         struct timespec64 cur_time = current_time(dir);
 564         struct inode *inode;
 565         int ret;
 566         int err;
 567         u64 objectid;
 568         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 569         u64 index = 0;
 570         uuid_le new_uuid;
 571
 572         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 573         if (!root_item)
 574                 return -ENOMEM;
 575
 576         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
 577         if (ret)
 578                 goto fail_free;
 579
 580         /*
 581          * Don't create subvolume whose level is not zero. Or qgroup will be
 582          * screwed up since it assumes subvolume qgroup's level to be 0.
 583          */
 584         if (btrfs_qgroup_level(objectid)) {
 585                 ret = -ENOSPC;
 586                 goto fail_free;
 587         }
 588
 589         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 590         /*
 591          * The same as the snapshot creation, please see the comment
 592          * of create_snapshot().
 593          */
 594         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
 595         if (ret)
 596                 goto fail_free;
 597
 598         trans = btrfs_start_transaction(root, 0);
 599         if (IS_ERR(trans)) {
 600                 ret = PTR_ERR(trans);
 601                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 602                 goto fail_free;
 603         }
 604         trans->block_rsv = &block_rsv;
 605         trans->bytes_reserved = block_rsv.size;
 606
 607         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 608         if (ret)
 609                 goto fail;
 610
 611         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 612         if (IS_ERR(leaf)) {
 613                 ret = PTR_ERR(leaf);
 614                 goto fail;
 615         }
 616
 617         btrfs_mark_buffer_dirty(leaf);
 618
 619         inode_item = &root_item->inode;
 620         btrfs_set_stack_inode_generation(inode_item, 1);
 621         btrfs_set_stack_inode_size(inode_item, 3);
 622         btrfs_set_stack_inode_nlink(inode_item, 1);
 623         btrfs_set_stack_inode_nbytes(inode_item,
 624                                      fs_info->nodesize);
 625         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 626
 627         btrfs_set_root_flags(root_item, 0);
 628         btrfs_set_root_limit(root_item, 0);
 629         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 630
 631         btrfs_set_root_bytenr(root_item, leaf->start);
 632         btrfs_set_root_generation(root_item, trans->transid);
 633         btrfs_set_root_level(root_item, 0);
 634         btrfs_set_root_refs(root_item, 1);
 635         btrfs_set_root_used(root_item, leaf->len);
 636         btrfs_set_root_last_snapshot(root_item, 0);
 637
 638         btrfs_set_root_generation_v2(root_item,
 639                         btrfs_root_generation(root_item));
 640         uuid_le_gen(&new_uuid);
 641         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 642         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 643         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 644         root_item->ctime = root_item->otime;
 645         btrfs_set_root_ctransid(root_item, trans->transid);
 646         btrfs_set_root_otransid(root_item, trans->transid);
 647
 648         btrfs_tree_unlock(leaf);
 649         free_extent_buffer(leaf);
 650         leaf = NULL;
 651
 652         btrfs_set_root_dirid(root_item, new_dirid);
 653
 654         key.objectid = objectid;
 655         key.offset = 0;
 656         key.type = BTRFS_ROOT_ITEM_KEY;
 657         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 658                                 root_item);
 659         if (ret)
 660                 goto fail;
 661
 662         key.offset = (u64)-1;
 663         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
 664         if (IS_ERR(new_root)) {
 665                 ret = PTR_ERR(new_root);
 666                 btrfs_abort_transaction(trans, ret);
 667                 goto fail;
 668         }
 669
 670         btrfs_record_root_in_trans(trans, new_root);
 671
 672         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 673         if (ret) {
 674                 /* We potentially lose an unused inode item here */
 675                 btrfs_abort_transaction(trans, ret);
 676                 goto fail;
 677         }
 678
 679         mutex_lock(&new_root->objectid_mutex);
 680         new_root->highest_objectid = new_dirid;
 681         mutex_unlock(&new_root->objectid_mutex);
 682
 683         /*
 684          * insert the directory item
 685          */
 686         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
 687         if (ret) {
 688                 btrfs_abort_transaction(trans, ret);
 689                 goto fail;
 690         }
 691
 692         ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
 693                                     BTRFS_FT_DIR, index);
 694         if (ret) {
 695                 btrfs_abort_transaction(trans, ret);
 696                 goto fail;
 697         }
 698
 699         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
 700         ret = btrfs_update_inode(trans, root, dir);
 701         BUG_ON(ret);
 702
 703         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
 704                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
 705         BUG_ON(ret);
 706
 707         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 708                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 709         if (ret)
 710                 btrfs_abort_transaction(trans, ret);
 711
 712 fail:
 713         kfree(root_item);
 714         trans->block_rsv = NULL;
 715         trans->bytes_reserved = 0;
 716         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
 717
 718         if (async_transid) {
 719                 *async_transid = trans->transid;
 720                 err = btrfs_commit_transaction_async(trans, 1);
 721                 if (err)
 722                         err = btrfs_commit_transaction(trans);
 723         } else {
 724                 err = btrfs_commit_transaction(trans);
 725         }
 726         if (err && !ret)
 727                 ret = err;
 728
 729         if (!ret) {
 730                 inode = btrfs_lookup_dentry(dir, dentry);
 731                 if (IS_ERR(inode))
 732                         return PTR_ERR(inode);
 733                 d_instantiate(dentry, inode);
 734         }
 735         return ret;
 736
 737 fail_free:
 738         kfree(root_item);
 739         return ret;
 740 }
 741
 742 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 743                            struct dentry *dentry,
 744                            u64 *async_transid, bool readonly,
 745                            struct btrfs_qgroup_inherit *inherit)
 746 {
 747         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 748         struct inode *inode;
 749         struct btrfs_pending_snapshot *pending_snapshot;
 750         struct btrfs_trans_handle *trans;
 751         int ret;
 752         bool snapshot_force_cow = false;
 753
 754         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 755                 return -EINVAL;
 756
 757         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 758         if (!pending_snapshot)
 759                 return -ENOMEM;
 760
 761         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 762                         GFP_KERNEL);
 763         pending_snapshot->path = btrfs_alloc_path();
 764         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 765                 ret = -ENOMEM;
 766                 goto free_pending;
 767         }
 768
 769         /*
 770          * Force new buffered writes to reserve space even when NOCOW is
 771          * possible. This is to avoid later writeback (running dealloc) to
 772          * fallback to COW mode and unexpectedly fail with ENOSPC.
 773          */
 774         atomic_inc(&root->will_be_snapshotted);
 775         smp_mb__after_atomic();
 776         /* wait for no snapshot writes */
 777         wait_event(root->subv_writers->wait,
 778                    percpu_counter_sum(&root->subv_writers->counter) == 0);
 779
 780         ret = btrfs_start_delalloc_inodes(root);
 781         if (ret)
 782                 goto dec_and_free;
 783
 784         /*
 785          * All previous writes have started writeback in NOCOW mode, so now
 786          * we force future writes to fallback to COW mode during snapshot
 787          * creation.
 788          */
 789         atomic_inc(&root->snapshot_force_cow);
 790         snapshot_force_cow = true;
 791
 792         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
 793
 794         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 795                              BTRFS_BLOCK_RSV_TEMP);
 796         /*
 797          * 1 - parent dir inode
 798          * 2 - dir entries
 799          * 1 - root item
 800          * 2 - root ref/backref
 801          * 1 - root of snapshot
 802          * 1 - UUID item
 803          */
 804         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 805                                         &pending_snapshot->block_rsv, 8,
 806                                         false);
 807         if (ret)
 808                 goto dec_and_free;
 809
 810         pending_snapshot->dentry = dentry;
 811         pending_snapshot->root = root;
 812         pending_snapshot->readonly = readonly;
 813         pending_snapshot->dir = dir;
 814         pending_snapshot->inherit = inherit;
 815
 816         trans = btrfs_start_transaction(root, 0);
 817         if (IS_ERR(trans)) {
 818                 ret = PTR_ERR(trans);
 819                 goto fail;
 820         }
 821
 822         spin_lock(&fs_info->trans_lock);
 823         list_add(&pending_snapshot->list,
 824                  &trans->transaction->pending_snapshots);
 825         spin_unlock(&fs_info->trans_lock);
 826         if (async_transid) {
 827                 *async_transid = trans->transid;
 828                 ret = btrfs_commit_transaction_async(trans, 1);
 829                 if (ret)
 830                         ret = btrfs_commit_transaction(trans);
 831         } else {
 832                 ret = btrfs_commit_transaction(trans);
 833         }
 834         if (ret)
 835                 goto fail;
 836
 837         ret = pending_snapshot->error;
 838         if (ret)
 839                 goto fail;
 840
 841         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 842         if (ret)
 843                 goto fail;
 844
 845         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 846         if (IS_ERR(inode)) {
 847                 ret = PTR_ERR(inode);
 848                 goto fail;
 849         }
 850
 851         d_instantiate(dentry, inode);
 852         ret = 0;
 853 fail:
 854         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
 855 dec_and_free:
 856         if (snapshot_force_cow)
 857                 atomic_dec(&root->snapshot_force_cow);
 858         if (atomic_dec_and_test(&root->will_be_snapshotted))
 859                 wake_up_var(&root->will_be_snapshotted);
 860 free_pending:
 861         kfree(pending_snapshot->root_item);
 862         btrfs_free_path(pending_snapshot->path);
 863         kfree(pending_snapshot);
 864
 865         return ret;
 866 }
 867
 868 /*  copy of may_delete in fs/namei.c()
 869  *      Check whether we can remove a link victim from directory dir, check
 870  *  whether the type of victim is right.
 871  *  1. We can't do it if dir is read-only (done in permission())
 872  *  2. We should have write and exec permissions on dir
 873  *  3. We can't remove anything from append-only dir
 874  *  4. We can't do anything with immutable dir (done in permission())
 875  *  5. If the sticky bit on dir is set we should either
 876  *      a. be owner of dir, or
 877  *      b. be owner of victim, or
 878  *      c. have CAP_FOWNER capability
 879  *  6. If the victim is append-only or immutable we can't do anything with
 880  *     links pointing to it.
 881  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 882  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 883  *  9. We can't remove a root or mountpoint.
 884  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 885  *     nfs_async_unlink().
 886  */
 887
 888 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 889 {
 890         int error;
 891
 892         if (d_really_is_negative(victim))
 893                 return -ENOENT;
 894
 895         BUG_ON(d_inode(victim->d_parent) != dir);
 896         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 897
 898         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 899         if (error)
 900                 return error;
 901         if (IS_APPEND(dir))
 902                 return -EPERM;
 903         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 904             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 905                 return -EPERM;
 906         if (isdir) {
 907                 if (!d_is_dir(victim))
 908                         return -ENOTDIR;
 909                 if (IS_ROOT(victim))
 910                         return -EBUSY;
 911         } else if (d_is_dir(victim))
 912                 return -EISDIR;
 913         if (IS_DEADDIR(dir))
 914                 return -ENOENT;
 915         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 916                 return -EBUSY;
 917         return 0;
 918 }
 919
 920 /* copy of may_create in fs/namei.c() */
 921 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 922 {
 923         if (d_really_is_positive(child))
 924                 return -EEXIST;
 925         if (IS_DEADDIR(dir))
 926                 return -ENOENT;
 927         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 928 }
 929
 930 /*
 931  * Create a new subvolume below @parent.  This is largely modeled after
 932  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 933  * inside this filesystem so it's quite a bit simpler.
 934  */
 935 static noinline int btrfs_mksubvol(const struct path *parent,
 936                                    const char *name, int namelen,
 937                                    struct btrfs_root *snap_src,
 938                                    u64 *async_transid, bool readonly,
 939                                    struct btrfs_qgroup_inherit *inherit)
 940 {
 941         struct inode *dir = d_inode(parent->dentry);
 942         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 943         struct dentry *dentry;
 944         int error;
 945
 946         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 947         if (error == -EINTR)
 948                 return error;
 949
 950         dentry = lookup_one_len(name, parent->dentry, namelen);
 951         error = PTR_ERR(dentry);
 952         if (IS_ERR(dentry))
 953                 goto out_unlock;
 954
 955         error = btrfs_may_create(dir, dentry);
 956         if (error)
 957                 goto out_dput;
 958
 959         /*
 960          * even if this name doesn't exist, we may get hash collisions.
 961          * check for them now when we can safely fail
 962          */
 963         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 964                                                dir->i_ino, name,
 965                                                namelen);
 966         if (error)
 967                 goto out_dput;
 968
 969         down_read(&fs_info->subvol_sem);
 970
 971         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 972                 goto out_up_read;
 973
 974         if (snap_src) {
 975                 error = create_snapshot(snap_src, dir, dentry,
 976                                         async_transid, readonly, inherit);
 977         } else {
 978                 error = create_subvol(dir, dentry, name, namelen,
 979                                       async_transid, inherit);
 980         }
 981         if (!error)
 982                 fsnotify_mkdir(dir, dentry);
 983 out_up_read:
 984         up_read(&fs_info->subvol_sem);
 985 out_dput:
 986         dput(dentry);
 987 out_unlock:
 988         inode_unlock(dir);
 989         return error;
 990 }
 991
 992 /*
 993  * When we're defragging a range, we don't want to kick it off again
 994  * if it is really just waiting for delalloc to send it down.
 995  * If we find a nice big extent or delalloc range for the bytes in the
 996  * file you want to defrag, we return 0 to let you know to skip this
 997  * part of the file
 998  */
 999 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1000 {
1001         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1002         struct extent_map *em = NULL;
1003         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1004         u64 end;
1005
1006         read_lock(&em_tree->lock);
1007         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1008         read_unlock(&em_tree->lock);
1009
1010         if (em) {
1011                 end = extent_map_end(em);
1012                 free_extent_map(em);
1013                 if (end - offset > thresh)
1014                         return 0;
1015         }
1016         /* if we already have a nice delalloc here, just stop */
1017         thresh /= 2;
1018         end = count_range_bits(io_tree, &offset, offset + thresh,
1019                                thresh, EXTENT_DELALLOC, 1);
1020         if (end >= thresh)
1021                 return 0;
1022         return 1;
1023 }
1024
1025 /*
1026  * helper function to walk through a file and find extents
1027  * newer than a specific transid, and smaller than thresh.
1028  *
1029  * This is used by the defragging code to find new and small
1030  * extents
1031  */
1032 static int find_new_extents(struct btrfs_root *root,
1033                             struct inode *inode, u64 newer_than,
1034                             u64 *off, u32 thresh)
1035 {
1036         struct btrfs_path *path;
1037         struct btrfs_key min_key;
1038         struct extent_buffer *leaf;
1039         struct btrfs_file_extent_item *extent;
1040         int type;
1041         int ret;
1042         u64 ino = btrfs_ino(BTRFS_I(inode));
1043
1044         path = btrfs_alloc_path();
1045         if (!path)
1046                 return -ENOMEM;
1047
1048         min_key.objectid = ino;
1049         min_key.type = BTRFS_EXTENT_DATA_KEY;
1050         min_key.offset = *off;
1051
1052         while (1) {
1053                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1054                 if (ret != 0)
1055                         goto none;
1056 process_slot:
1057                 if (min_key.objectid != ino)
1058                         goto none;
1059                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1060                         goto none;
1061
1062                 leaf = path->nodes[0];
1063                 extent = btrfs_item_ptr(leaf, path->slots[0],
1064                                         struct btrfs_file_extent_item);
1065
1066                 type = btrfs_file_extent_type(leaf, extent);
1067                 if (type == BTRFS_FILE_EXTENT_REG &&
1068                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1069                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1070                         *off = min_key.offset;
1071                         btrfs_free_path(path);
1072                         return 0;
1073                 }
1074
1075                 path->slots[0]++;
1076                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1077                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1078                         goto process_slot;
1079                 }
1080
1081                 if (min_key.offset == (u64)-1)
1082                         goto none;
1083
1084                 min_key.offset++;
1085                 btrfs_release_path(path);
1086         }
1087 none:
1088         btrfs_free_path(path);
1089         return -ENOENT;
1090 }
1091
1092 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1093 {
1094         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1095         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1096         struct extent_map *em;
1097         u64 len = PAGE_SIZE;
1098
1099         /*
1100          * hopefully we have this extent in the tree already, try without
1101          * the full extent lock
1102          */
1103         read_lock(&em_tree->lock);
1104         em = lookup_extent_mapping(em_tree, start, len);
1105         read_unlock(&em_tree->lock);
1106
1107         if (!em) {
1108                 struct extent_state *cached = NULL;
1109                 u64 end = start + len - 1;
1110
1111                 /* get the big lock and read metadata off disk */
1112                 lock_extent_bits(io_tree, start, end, &cached);
1113                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1114                 unlock_extent_cached(io_tree, start, end, &cached);
1115
1116                 if (IS_ERR(em))
1117                         return NULL;
1118         }
1119
1120         return em;
1121 }
1122
1123 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1124 {
1125         struct extent_map *next;
1126         bool ret = true;
1127
1128         /* this is the last extent */
1129         if (em->start + em->len >= i_size_read(inode))
1130                 return false;
1131
1132         next = defrag_lookup_extent(inode, em->start + em->len);
1133         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1134                 ret = false;
1135         else if ((em->block_start + em->block_len == next->block_start) &&
1136                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1137                 ret = false;
1138
1139         free_extent_map(next);
1140         return ret;
1141 }
1142
1143 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1144                                u64 *last_len, u64 *skip, u64 *defrag_end,
1145                                int compress)
1146 {
1147         struct extent_map *em;
1148         int ret = 1;
1149         bool next_mergeable = true;
1150         bool prev_mergeable = true;
1151
1152         /*
1153          * make sure that once we start defragging an extent, we keep on
1154          * defragging it
1155          */
1156         if (start < *defrag_end)
1157                 return 1;
1158
1159         *skip = 0;
1160
1161         em = defrag_lookup_extent(inode, start);
1162         if (!em)
1163                 return 0;
1164
1165         /* this will cover holes, and inline extents */
1166         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1167                 ret = 0;
1168                 goto out;
1169         }
1170
1171         if (!*defrag_end)
1172                 prev_mergeable = false;
1173
1174         next_mergeable = defrag_check_next_extent(inode, em);
1175         /*
1176          * we hit a real extent, if it is big or the next extent is not a
1177          * real extent, don't bother defragging it
1178          */
1179         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1180             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1181                 ret = 0;
1182 out:
1183         /*
1184          * last_len ends up being a counter of how many bytes we've defragged.
1185          * every time we choose not to defrag an extent, we reset *last_len
1186          * so that the next tiny extent will force a defrag.
1187          *
1188          * The end result of this is that tiny extents before a single big
1189          * extent will force at least part of that big extent to be defragged.
1190          */
1191         if (ret) {
1192                 *defrag_end = extent_map_end(em);
1193         } else {
1194                 *last_len = 0;
1195                 *skip = extent_map_end(em);
1196                 *defrag_end = 0;
1197         }
1198
1199         free_extent_map(em);
1200         return ret;
1201 }
1202
1203 /*
1204  * it doesn't do much good to defrag one or two pages
1205  * at a time.  This pulls in a nice chunk of pages
1206  * to COW and defrag.
1207  *
1208  * It also makes sure the delalloc code has enough
1209  * dirty data to avoid making new small extents as part
1210  * of the defrag
1211  *
1212  * It's a good idea to start RA on this range
1213  * before calling this.
1214  */
1215 static int cluster_pages_for_defrag(struct inode *inode,
1216                                     struct page **pages,
1217                                     unsigned long start_index,
1218                                     unsigned long num_pages)
1219 {
1220         unsigned long file_end;
1221         u64 isize = i_size_read(inode);
1222         u64 page_start;
1223         u64 page_end;
1224         u64 page_cnt;
1225         int ret;
1226         int i;
1227         int i_done;
1228         struct btrfs_ordered_extent *ordered;
1229         struct extent_state *cached_state = NULL;
1230         struct extent_io_tree *tree;
1231         struct extent_changeset *data_reserved = NULL;
1232         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1233
1234         file_end = (isize - 1) >> PAGE_SHIFT;
1235         if (!isize || start_index > file_end)
1236                 return 0;
1237
1238         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1239
1240         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1241                         start_index << PAGE_SHIFT,
1242                         page_cnt << PAGE_SHIFT);
1243         if (ret)
1244                 return ret;
1245         i_done = 0;
1246         tree = &BTRFS_I(inode)->io_tree;
1247
1248         /* step one, lock all the pages */
1249         for (i = 0; i < page_cnt; i++) {
1250                 struct page *page;
1251 again:
1252                 page = find_or_create_page(inode->i_mapping,
1253                                            start_index + i, mask);
1254                 if (!page)
1255                         break;
1256
1257                 page_start = page_offset(page);
1258                 page_end = page_start + PAGE_SIZE - 1;
1259                 while (1) {
1260                         lock_extent_bits(tree, page_start, page_end,
1261                                          &cached_state);
1262                         ordered = btrfs_lookup_ordered_extent(inode,
1263                                                               page_start);
1264                         unlock_extent_cached(tree, page_start, page_end,
1265                                              &cached_state);
1266                         if (!ordered)
1267                                 break;
1268
1269                         unlock_page(page);
1270                         btrfs_start_ordered_extent(inode, ordered, 1);
1271                         btrfs_put_ordered_extent(ordered);
1272                         lock_page(page);
1273                         /*
1274                          * we unlocked the page above, so we need check if
1275                          * it was released or not.
1276                          */
1277                         if (page->mapping != inode->i_mapping) {
1278                                 unlock_page(page);
1279                                 put_page(page);
1280                                 goto again;
1281                         }
1282                 }
1283
1284                 if (!PageUptodate(page)) {
1285                         btrfs_readpage(NULL, page);
1286                         lock_page(page);
1287                         if (!PageUptodate(page)) {
1288                                 unlock_page(page);
1289                                 put_page(page);
1290                                 ret = -EIO;
1291                                 break;
1292                         }
1293                 }
1294
1295                 if (page->mapping != inode->i_mapping) {
1296                         unlock_page(page);
1297                         put_page(page);
1298                         goto again;
1299                 }
1300
1301                 pages[i] = page;
1302                 i_done++;
1303         }
1304         if (!i_done || ret)
1305                 goto out;
1306
1307         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1308                 goto out;
1309
1310         /*
1311          * so now we have a nice long stream of locked
1312          * and up to date pages, lets wait on them
1313          */
1314         for (i = 0; i < i_done; i++)
1315                 wait_on_page_writeback(pages[i]);
1316
1317         page_start = page_offset(pages[0]);
1318         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1319
1320         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1321                          page_start, page_end - 1, &cached_state);
1322         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1323                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1324                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1325                           &cached_state);
1326
1327         if (i_done != page_cnt) {
1328                 spin_lock(&BTRFS_I(inode)->lock);
1329                 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1330                 spin_unlock(&BTRFS_I(inode)->lock);
1331                 btrfs_delalloc_release_space(inode, data_reserved,
1332                                 start_index << PAGE_SHIFT,
1333                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1334         }
1335
1336
1337         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1338                           &cached_state);
1339
1340         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1341                              page_start, page_end - 1, &cached_state);
1342
1343         for (i = 0; i < i_done; i++) {
1344                 clear_page_dirty_for_io(pages[i]);
1345                 ClearPageChecked(pages[i]);
1346                 set_page_extent_mapped(pages[i]);
1347                 set_page_dirty(pages[i]);
1348                 unlock_page(pages[i]);
1349                 put_page(pages[i]);
1350         }
1351         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1352                                        false);
1353         extent_changeset_free(data_reserved);
1354         return i_done;
1355 out:
1356         for (i = 0; i < i_done; i++) {
1357                 unlock_page(pages[i]);
1358                 put_page(pages[i]);
1359         }
1360         btrfs_delalloc_release_space(inode, data_reserved,
1361                         start_index << PAGE_SHIFT,
1362                         page_cnt << PAGE_SHIFT, true);
1363         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1364                                        true);
1365         extent_changeset_free(data_reserved);
1366         return ret;
1367
1368 }
1369
1370 int btrfs_defrag_file(struct inode *inode, struct file *file,
1371                       struct btrfs_ioctl_defrag_range_args *range,
1372                       u64 newer_than, unsigned long max_to_defrag)
1373 {
1374         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1375         struct btrfs_root *root = BTRFS_I(inode)->root;
1376         struct file_ra_state *ra = NULL;
1377         unsigned long last_index;
1378         u64 isize = i_size_read(inode);
1379         u64 last_len = 0;
1380         u64 skip = 0;
1381         u64 defrag_end = 0;
1382         u64 newer_off = range->start;
1383         unsigned long i;
1384         unsigned long ra_index = 0;
1385         int ret;
1386         int defrag_count = 0;
1387         int compress_type = BTRFS_COMPRESS_ZLIB;
1388         u32 extent_thresh = range->extent_thresh;
1389         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1390         unsigned long cluster = max_cluster;
1391         u64 new_align = ~((u64)SZ_128K - 1);
1392         struct page **pages = NULL;
1393         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1394
1395         if (isize == 0)
1396                 return 0;
1397
1398         if (range->start >= isize)
1399                 return -EINVAL;
1400
1401         if (do_compress) {
1402                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1403                         return -EINVAL;
1404                 if (range->compress_type)
1405                         compress_type = range->compress_type;
1406         }
1407
1408         if (extent_thresh == 0)
1409                 extent_thresh = SZ_256K;
1410
1411         /*
1412          * If we were not given a file, allocate a readahead context. As
1413          * readahead is just an optimization, defrag will work without it so
1414          * we don't error out.
1415          */
1416         if (!file) {
1417                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1418                 if (ra)
1419                         file_ra_state_init(ra, inode->i_mapping);
1420         } else {
1421                 ra = &file->f_ra;
1422         }
1423
1424         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1425         if (!pages) {
1426                 ret = -ENOMEM;
1427                 goto out_ra;
1428         }
1429
1430         /* find the last page to defrag */
1431         if (range->start + range->len > range->start) {
1432                 last_index = min_t(u64, isize - 1,
1433                          range->start + range->len - 1) >> PAGE_SHIFT;
1434         } else {
1435                 last_index = (isize - 1) >> PAGE_SHIFT;
1436         }
1437
1438         if (newer_than) {
1439                 ret = find_new_extents(root, inode, newer_than,
1440                                        &newer_off, SZ_64K);
1441                 if (!ret) {
1442                         range->start = newer_off;
1443                         /*
1444                          * we always align our defrag to help keep
1445                          * the extents in the file evenly spaced
1446                          */
1447                         i = (newer_off & new_align) >> PAGE_SHIFT;
1448                 } else
1449                         goto out_ra;
1450         } else {
1451                 i = range->start >> PAGE_SHIFT;
1452         }
1453         if (!max_to_defrag)
1454                 max_to_defrag = last_index - i + 1;
1455
1456         /*
1457          * make writeback starts from i, so the defrag range can be
1458          * written sequentially.
1459          */
1460         if (i < inode->i_mapping->writeback_index)
1461                 inode->i_mapping->writeback_index = i;
1462
1463         while (i <= last_index && defrag_count < max_to_defrag &&
1464                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1465                 /*
1466                  * make sure we stop running if someone unmounts
1467                  * the FS
1468                  */
1469                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1470                         break;
1471
1472                 if (btrfs_defrag_cancelled(fs_info)) {
1473                         btrfs_debug(fs_info, "defrag_file cancelled");
1474                         ret = -EAGAIN;
1475                         break;
1476                 }
1477
1478                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1479                                          extent_thresh, &last_len, &skip,
1480                                          &defrag_end, do_compress)){
1481                         unsigned long next;
1482                         /*
1483                          * the should_defrag function tells us how much to skip
1484                          * bump our counter by the suggested amount
1485                          */
1486                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1487                         i = max(i + 1, next);
1488                         continue;
1489                 }
1490
1491                 if (!newer_than) {
1492                         cluster = (PAGE_ALIGN(defrag_end) >>
1493                                    PAGE_SHIFT) - i;
1494                         cluster = min(cluster, max_cluster);
1495                 } else {
1496                         cluster = max_cluster;
1497                 }
1498
1499                 if (i + cluster > ra_index) {
1500                         ra_index = max(i, ra_index);
1501                         if (ra)
1502                                 page_cache_sync_readahead(inode->i_mapping, ra,
1503                                                 file, ra_index, cluster);
1504                         ra_index += cluster;
1505                 }
1506
1507                 inode_lock(inode);
1508                 if (do_compress)
1509                         BTRFS_I(inode)->defrag_compress = compress_type;
1510                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1511                 if (ret < 0) {
1512                         inode_unlock(inode);
1513                         goto out_ra;
1514                 }
1515
1516                 defrag_count += ret;
1517                 balance_dirty_pages_ratelimited(inode->i_mapping);
1518                 inode_unlock(inode);
1519
1520                 if (newer_than) {
1521                         if (newer_off == (u64)-1)
1522                                 break;
1523
1524                         if (ret > 0)
1525                                 i += ret;
1526
1527                         newer_off = max(newer_off + 1,
1528                                         (u64)i << PAGE_SHIFT);
1529
1530                         ret = find_new_extents(root, inode, newer_than,
1531                                                &newer_off, SZ_64K);
1532                         if (!ret) {
1533                                 range->start = newer_off;
1534                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1535                         } else {
1536                                 break;
1537                         }
1538                 } else {
1539                         if (ret > 0) {
1540                                 i += ret;
1541                                 last_len += ret << PAGE_SHIFT;
1542                         } else {
1543                                 i++;
1544                                 last_len = 0;
1545                         }
1546                 }
1547         }
1548
1549         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1550                 filemap_flush(inode->i_mapping);
1551                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1552                              &BTRFS_I(inode)->runtime_flags))
1553                         filemap_flush(inode->i_mapping);
1554         }
1555
1556         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1557                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1558         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1559                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1560         }
1561
1562         ret = defrag_count;
1563
1564 out_ra:
1565         if (do_compress) {
1566                 inode_lock(inode);
1567                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1568                 inode_unlock(inode);
1569         }
1570         if (!file)
1571                 kfree(ra);
1572         kfree(pages);
1573         return ret;
1574 }
1575
1576 static noinline int btrfs_ioctl_resize(struct file *file,
1577                                         void __user *arg)
1578 {
1579         struct inode *inode = file_inode(file);
1580         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1581         u64 new_size;
1582         u64 old_size;
1583         u64 devid = 1;
1584         struct btrfs_root *root = BTRFS_I(inode)->root;
1585         struct btrfs_ioctl_vol_args *vol_args;
1586         struct btrfs_trans_handle *trans;
1587         struct btrfs_device *device = NULL;
1588         char *sizestr;
1589         char *retptr;
1590         char *devstr = NULL;
1591         int ret = 0;
1592         int mod = 0;
1593
1594         if (!capable(CAP_SYS_ADMIN))
1595                 return -EPERM;
1596
1597         ret = mnt_want_write_file(file);
1598         if (ret)
1599                 return ret;
1600
1601         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1602                 mnt_drop_write_file(file);
1603                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1604         }
1605
1606         vol_args = memdup_user(arg, sizeof(*vol_args));
1607         if (IS_ERR(vol_args)) {
1608                 ret = PTR_ERR(vol_args);
1609                 goto out;
1610         }
1611
1612         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1613
1614         sizestr = vol_args->name;
1615         devstr = strchr(sizestr, ':');
1616         if (devstr) {
1617                 sizestr = devstr + 1;
1618                 *devstr = '\0';
1619                 devstr = vol_args->name;
1620                 ret = kstrtoull(devstr, 10, &devid);
1621                 if (ret)
1622                         goto out_free;
1623                 if (!devid) {
1624                         ret = -EINVAL;
1625                         goto out_free;
1626                 }
1627                 btrfs_info(fs_info, "resizing devid %llu", devid);
1628         }
1629
1630         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1631         if (!device) {
1632                 btrfs_info(fs_info, "resizer unable to find device %llu",
1633                            devid);
1634                 ret = -ENODEV;
1635                 goto out_free;
1636         }
1637
1638         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1639                 btrfs_info(fs_info,
1640                            "resizer unable to apply on readonly device %llu",
1641                        devid);
1642                 ret = -EPERM;
1643                 goto out_free;
1644         }
1645
1646         if (!strcmp(sizestr, "max"))
1647                 new_size = device->bdev->bd_inode->i_size;
1648         else {
1649                 if (sizestr[0] == '-') {
1650                         mod = -1;
1651                         sizestr++;
1652                 } else if (sizestr[0] == '+') {
1653                         mod = 1;
1654                         sizestr++;
1655                 }
1656                 new_size = memparse(sizestr, &retptr);
1657                 if (*retptr != '\0' || new_size == 0) {
1658                         ret = -EINVAL;
1659                         goto out_free;
1660                 }
1661         }
1662
1663         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1664                 ret = -EPERM;
1665                 goto out_free;
1666         }
1667
1668         old_size = btrfs_device_get_total_bytes(device);
1669
1670         if (mod < 0) {
1671                 if (new_size > old_size) {
1672                         ret = -EINVAL;
1673                         goto out_free;
1674                 }
1675                 new_size = old_size - new_size;
1676         } else if (mod > 0) {
1677                 if (new_size > ULLONG_MAX - old_size) {
1678                         ret = -ERANGE;
1679                         goto out_free;
1680                 }
1681                 new_size = old_size + new_size;
1682         }
1683
1684         if (new_size < SZ_256M) {
1685                 ret = -EINVAL;
1686                 goto out_free;
1687         }
1688         if (new_size > device->bdev->bd_inode->i_size) {
1689                 ret = -EFBIG;
1690                 goto out_free;
1691         }
1692
1693         new_size = round_down(new_size, fs_info->sectorsize);
1694
1695         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1696                           rcu_str_deref(device->name), new_size);
1697
1698         if (new_size > old_size) {
1699                 trans = btrfs_start_transaction(root, 0);
1700                 if (IS_ERR(trans)) {
1701                         ret = PTR_ERR(trans);
1702                         goto out_free;
1703                 }
1704                 ret = btrfs_grow_device(trans, device, new_size);
1705                 btrfs_commit_transaction(trans);
1706         } else if (new_size < old_size) {
1707                 ret = btrfs_shrink_device(device, new_size);
1708         } /* equal, nothing need to do */
1709
1710 out_free:
1711         kfree(vol_args);
1712 out:
1713         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1714         mnt_drop_write_file(file);
1715         return ret;
1716 }
1717
1718 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1719                                 const char *name, unsigned long fd, int subvol,
1720                                 u64 *transid, bool readonly,
1721                                 struct btrfs_qgroup_inherit *inherit)
1722 {
1723         int namelen;
1724         int ret = 0;
1725
1726         if (!S_ISDIR(file_inode(file)->i_mode))
1727                 return -ENOTDIR;
1728
1729         ret = mnt_want_write_file(file);
1730         if (ret)
1731                 goto out;
1732
1733         namelen = strlen(name);
1734         if (strchr(name, '/')) {
1735                 ret = -EINVAL;
1736                 goto out_drop_write;
1737         }
1738
1739         if (name[0] == '.' &&
1740            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1741                 ret = -EEXIST;
1742                 goto out_drop_write;
1743         }
1744
1745         if (subvol) {
1746                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1747                                      NULL, transid, readonly, inherit);
1748         } else {
1749                 struct fd src = fdget(fd);
1750                 struct inode *src_inode;
1751                 if (!src.file) {
1752                         ret = -EINVAL;
1753                         goto out_drop_write;
1754                 }
1755
1756                 src_inode = file_inode(src.file);
1757                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1758                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1759                                    "Snapshot src from another FS");
1760                         ret = -EXDEV;
1761                 } else if (!inode_owner_or_capable(src_inode)) {
1762                         /*
1763                          * Subvolume creation is not restricted, but snapshots
1764                          * are limited to own subvolumes only
1765                          */
1766                         ret = -EPERM;
1767                 } else {
1768                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1769                                              BTRFS_I(src_inode)->root,
1770                                              transid, readonly, inherit);
1771                 }
1772                 fdput(src);
1773         }
1774 out_drop_write:
1775         mnt_drop_write_file(file);
1776 out:
1777         return ret;
1778 }
1779
1780 static noinline int btrfs_ioctl_snap_create(struct file *file,
1781                                             void __user *arg, int subvol)
1782 {
1783         struct btrfs_ioctl_vol_args *vol_args;
1784         int ret;
1785
1786         if (!S_ISDIR(file_inode(file)->i_mode))
1787                 return -ENOTDIR;
1788
1789         vol_args = memdup_user(arg, sizeof(*vol_args));
1790         if (IS_ERR(vol_args))
1791                 return PTR_ERR(vol_args);
1792         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1793
1794         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1795                                               vol_args->fd, subvol,
1796                                               NULL, false, NULL);
1797
1798         kfree(vol_args);
1799         return ret;
1800 }
1801
1802 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1803                                                void __user *arg, int subvol)
1804 {
1805         struct btrfs_ioctl_vol_args_v2 *vol_args;
1806         int ret;
1807         u64 transid = 0;
1808         u64 *ptr = NULL;
1809         bool readonly = false;
1810         struct btrfs_qgroup_inherit *inherit = NULL;
1811
1812         if (!S_ISDIR(file_inode(file)->i_mode))
1813                 return -ENOTDIR;
1814
1815         vol_args = memdup_user(arg, sizeof(*vol_args));
1816         if (IS_ERR(vol_args))
1817                 return PTR_ERR(vol_args);
1818         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1819
1820         if (vol_args->flags &
1821             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1822               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1823                 ret = -EOPNOTSUPP;
1824                 goto free_args;
1825         }
1826
1827         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1828                 ptr = &transid;
1829         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1830                 readonly = true;
1831         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1832                 if (vol_args->size > PAGE_SIZE) {
1833                         ret = -EINVAL;
1834                         goto free_args;
1835                 }
1836                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1837                 if (IS_ERR(inherit)) {
1838                         ret = PTR_ERR(inherit);
1839                         goto free_args;
1840                 }
1841         }
1842
1843         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1844                                               vol_args->fd, subvol, ptr,
1845                                               readonly, inherit);
1846         if (ret)
1847                 goto free_inherit;
1848
1849         if (ptr && copy_to_user(arg +
1850                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1851                                         transid),
1852                                 ptr, sizeof(*ptr)))
1853                 ret = -EFAULT;
1854
1855 free_inherit:
1856         kfree(inherit);
1857 free_args:
1858         kfree(vol_args);
1859         return ret;
1860 }
1861
1862 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1863                                                 void __user *arg)
1864 {
1865         struct inode *inode = file_inode(file);
1866         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1867         struct btrfs_root *root = BTRFS_I(inode)->root;
1868         int ret = 0;
1869         u64 flags = 0;
1870
1871         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1872                 return -EINVAL;
1873
1874         down_read(&fs_info->subvol_sem);
1875         if (btrfs_root_readonly(root))
1876                 flags |= BTRFS_SUBVOL_RDONLY;
1877         up_read(&fs_info->subvol_sem);
1878
1879         if (copy_to_user(arg, &flags, sizeof(flags)))
1880                 ret = -EFAULT;
1881
1882         return ret;
1883 }
1884
1885 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1886                                               void __user *arg)
1887 {
1888         struct inode *inode = file_inode(file);
1889         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1890         struct btrfs_root *root = BTRFS_I(inode)->root;
1891         struct btrfs_trans_handle *trans;
1892         u64 root_flags;
1893         u64 flags;
1894         int ret = 0;
1895
1896         if (!inode_owner_or_capable(inode))
1897                 return -EPERM;
1898
1899         ret = mnt_want_write_file(file);
1900         if (ret)
1901                 goto out;
1902
1903         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1904                 ret = -EINVAL;
1905                 goto out_drop_write;
1906         }
1907
1908         if (copy_from_user(&flags, arg, sizeof(flags))) {
1909                 ret = -EFAULT;
1910                 goto out_drop_write;
1911         }
1912
1913         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1914                 ret = -EINVAL;
1915                 goto out_drop_write;
1916         }
1917
1918         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1919                 ret = -EOPNOTSUPP;
1920                 goto out_drop_write;
1921         }
1922
1923         down_write(&fs_info->subvol_sem);
1924
1925         /* nothing to do */
1926         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1927                 goto out_drop_sem;
1928
1929         root_flags = btrfs_root_flags(&root->root_item);
1930         if (flags & BTRFS_SUBVOL_RDONLY) {
1931                 btrfs_set_root_flags(&root->root_item,
1932                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1933         } else {
1934                 /*
1935                  * Block RO -> RW transition if this subvolume is involved in
1936                  * send
1937                  */
1938                 spin_lock(&root->root_item_lock);
1939                 if (root->send_in_progress == 0) {
1940                         btrfs_set_root_flags(&root->root_item,
1941                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1942                         spin_unlock(&root->root_item_lock);
1943                 } else {
1944                         spin_unlock(&root->root_item_lock);
1945                         btrfs_warn(fs_info,
1946                                    "Attempt to set subvolume %llu read-write during send",
1947                                    root->root_key.objectid);
1948                         ret = -EPERM;
1949                         goto out_drop_sem;
1950                 }
1951         }
1952
1953         trans = btrfs_start_transaction(root, 1);
1954         if (IS_ERR(trans)) {
1955                 ret = PTR_ERR(trans);
1956                 goto out_reset;
1957         }
1958
1959         ret = btrfs_update_root(trans, fs_info->tree_root,
1960                                 &root->root_key, &root->root_item);
1961         if (ret < 0) {
1962                 btrfs_end_transaction(trans);
1963                 goto out_reset;
1964         }
1965
1966         ret = btrfs_commit_transaction(trans);
1967
1968 out_reset:
1969         if (ret)
1970                 btrfs_set_root_flags(&root->root_item, root_flags);
1971 out_drop_sem:
1972         up_write(&fs_info->subvol_sem);
1973 out_drop_write:
1974         mnt_drop_write_file(file);
1975 out:
1976         return ret;
1977 }
1978
1979 static noinline int key_in_sk(struct btrfs_key *key,
1980                               struct btrfs_ioctl_search_key *sk)
1981 {
1982         struct btrfs_key test;
1983         int ret;
1984
1985         test.objectid = sk->min_objectid;
1986         test.type = sk->min_type;
1987         test.offset = sk->min_offset;
1988
1989         ret = btrfs_comp_cpu_keys(key, &test);
1990         if (ret < 0)
1991                 return 0;
1992
1993         test.objectid = sk->max_objectid;
1994         test.type = sk->max_type;
1995         test.offset = sk->max_offset;
1996
1997         ret = btrfs_comp_cpu_keys(key, &test);
1998         if (ret > 0)
1999                 return 0;
2000         return 1;
2001 }
2002
2003 static noinline int copy_to_sk(struct btrfs_path *path,
2004                                struct btrfs_key *key,
2005                                struct btrfs_ioctl_search_key *sk,
2006                                size_t *buf_size,
2007                                char __user *ubuf,
2008                                unsigned long *sk_offset,
2009                                int *num_found)
2010 {
2011         u64 found_transid;
2012         struct extent_buffer *leaf;
2013         struct btrfs_ioctl_search_header sh;
2014         struct btrfs_key test;
2015         unsigned long item_off;
2016         unsigned long item_len;
2017         int nritems;
2018         int i;
2019         int slot;
2020         int ret = 0;
2021
2022         leaf = path->nodes[0];
2023         slot = path->slots[0];
2024         nritems = btrfs_header_nritems(leaf);
2025
2026         if (btrfs_header_generation(leaf) > sk->max_transid) {
2027                 i = nritems;
2028                 goto advance_key;
2029         }
2030         found_transid = btrfs_header_generation(leaf);
2031
2032         for (i = slot; i < nritems; i++) {
2033                 item_off = btrfs_item_ptr_offset(leaf, i);
2034                 item_len = btrfs_item_size_nr(leaf, i);
2035
2036                 btrfs_item_key_to_cpu(leaf, key, i);
2037                 if (!key_in_sk(key, sk))
2038                         continue;
2039
2040                 if (sizeof(sh) + item_len > *buf_size) {
2041                         if (*num_found) {
2042                                 ret = 1;
2043                                 goto out;
2044                         }
2045
2046                         /*
2047                          * return one empty item back for v1, which does not
2048                          * handle -EOVERFLOW
2049                          */
2050
2051                         *buf_size = sizeof(sh) + item_len;
2052                         item_len = 0;
2053                         ret = -EOVERFLOW;
2054                 }
2055
2056                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2057                         ret = 1;
2058                         goto out;
2059                 }
2060
2061                 sh.objectid = key->objectid;
2062                 sh.offset = key->offset;
2063                 sh.type = key->type;
2064                 sh.len = item_len;
2065                 sh.transid = found_transid;
2066
2067                 /* copy search result header */
2068                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2069                         ret = -EFAULT;
2070                         goto out;
2071                 }
2072
2073                 *sk_offset += sizeof(sh);
2074
2075                 if (item_len) {
2076                         char __user *up = ubuf + *sk_offset;
2077                         /* copy the item */
2078                         if (read_extent_buffer_to_user(leaf, up,
2079                                                        item_off, item_len)) {
2080                                 ret = -EFAULT;
2081                                 goto out;
2082                         }
2083
2084                         *sk_offset += item_len;
2085                 }
2086                 (*num_found)++;
2087
2088                 if (ret) /* -EOVERFLOW from above */
2089                         goto out;
2090
2091                 if (*num_found >= sk->nr_items) {
2092                         ret = 1;
2093                         goto out;
2094                 }
2095         }
2096 advance_key:
2097         ret = 0;
2098         test.objectid = sk->max_objectid;
2099         test.type = sk->max_type;
2100         test.offset = sk->max_offset;
2101         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2102                 ret = 1;
2103         else if (key->offset < (u64)-1)
2104                 key->offset++;
2105         else if (key->type < (u8)-1) {
2106                 key->offset = 0;
2107                 key->type++;
2108         } else if (key->objectid < (u64)-1) {
2109                 key->offset = 0;
2110                 key->type = 0;
2111                 key->objectid++;
2112         } else
2113                 ret = 1;
2114 out:
2115         /*
2116          *  0: all items from this leaf copied, continue with next
2117          *  1: * more items can be copied, but unused buffer is too small
2118          *     * all items were found
2119          *     Either way, it will stops the loop which iterates to the next
2120          *     leaf
2121          *  -EOVERFLOW: item was to large for buffer
2122          *  -EFAULT: could not copy extent buffer back to userspace
2123          */
2124         return ret;
2125 }
2126
2127 static noinline int search_ioctl(struct inode *inode,
2128                                  struct btrfs_ioctl_search_key *sk,
2129                                  size_t *buf_size,
2130                                  char __user *ubuf)
2131 {
2132         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2133         struct btrfs_root *root;
2134         struct btrfs_key key;
2135         struct btrfs_path *path;
2136         int ret;
2137         int num_found = 0;
2138         unsigned long sk_offset = 0;
2139
2140         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2141                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2142                 return -EOVERFLOW;
2143         }
2144
2145         path = btrfs_alloc_path();
2146         if (!path)
2147                 return -ENOMEM;
2148
2149         if (sk->tree_id == 0) {
2150                 /* search the root of the inode that was passed */
2151                 root = BTRFS_I(inode)->root;
2152         } else {
2153                 key.objectid = sk->tree_id;
2154                 key.type = BTRFS_ROOT_ITEM_KEY;
2155                 key.offset = (u64)-1;
2156                 root = btrfs_read_fs_root_no_name(info, &key);
2157                 if (IS_ERR(root)) {
2158                         btrfs_free_path(path);
2159                         return PTR_ERR(root);
2160                 }
2161         }
2162
2163         key.objectid = sk->min_objectid;
2164         key.type = sk->min_type;
2165         key.offset = sk->min_offset;
2166
2167         while (1) {
2168                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2169                 if (ret != 0) {
2170                         if (ret > 0)
2171                                 ret = 0;
2172                         goto err;
2173                 }
2174                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2175                                  &sk_offset, &num_found);
2176                 btrfs_release_path(path);
2177                 if (ret)
2178                         break;
2179
2180         }
2181         if (ret > 0)
2182                 ret = 0;
2183 err:
2184         sk->nr_items = num_found;
2185         btrfs_free_path(path);
2186         return ret;
2187 }
2188
2189 static noinline int btrfs_ioctl_tree_search(struct file *file,
2190                                            void __user *argp)
2191 {
2192         struct btrfs_ioctl_search_args __user *uargs;
2193         struct btrfs_ioctl_search_key sk;
2194         struct inode *inode;
2195         int ret;
2196         size_t buf_size;
2197
2198         if (!capable(CAP_SYS_ADMIN))
2199                 return -EPERM;
2200
2201         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2202
2203         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2204                 return -EFAULT;
2205
2206         buf_size = sizeof(uargs->buf);
2207
2208         inode = file_inode(file);
2209         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2210
2211         /*
2212          * In the origin implementation an overflow is handled by returning a
2213          * search header with a len of zero, so reset ret.
2214          */
2215         if (ret == -EOVERFLOW)
2216                 ret = 0;
2217
2218         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2219                 ret = -EFAULT;
2220         return ret;
2221 }
2222
2223 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2224                                                void __user *argp)
2225 {
2226         struct btrfs_ioctl_search_args_v2 __user *uarg;
2227         struct btrfs_ioctl_search_args_v2 args;
2228         struct inode *inode;
2229         int ret;
2230         size_t buf_size;
2231         const size_t buf_limit = SZ_16M;
2232
2233         if (!capable(CAP_SYS_ADMIN))
2234                 return -EPERM;
2235
2236         /* copy search header and buffer size */
2237         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2238         if (copy_from_user(&args, uarg, sizeof(args)))
2239                 return -EFAULT;
2240
2241         buf_size = args.buf_size;
2242
2243         /* limit result size to 16MB */
2244         if (buf_size > buf_limit)
2245                 buf_size = buf_limit;
2246
2247         inode = file_inode(file);
2248         ret = search_ioctl(inode, &args.key, &buf_size,
2249                            (char __user *)(&uarg->buf[0]));
2250         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2251                 ret = -EFAULT;
2252         else if (ret == -EOVERFLOW &&
2253                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2254                 ret = -EFAULT;
2255
2256         return ret;
2257 }
2258
2259 /*
2260  * Search INODE_REFs to identify path name of 'dirid' directory
2261  * in a 'tree_id' tree. and sets path name to 'name'.
2262  */
2263 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2264                                 u64 tree_id, u64 dirid, char *name)
2265 {
2266         struct btrfs_root *root;
2267         struct btrfs_key key;
2268         char *ptr;
2269         int ret = -1;
2270         int slot;
2271         int len;
2272         int total_len = 0;
2273         struct btrfs_inode_ref *iref;
2274         struct extent_buffer *l;
2275         struct btrfs_path *path;
2276
2277         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2278                 name[0]='\0';
2279                 return 0;
2280         }
2281
2282         path = btrfs_alloc_path();
2283         if (!path)
2284                 return -ENOMEM;
2285
2286         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2287
2288         key.objectid = tree_id;
2289         key.type = BTRFS_ROOT_ITEM_KEY;
2290         key.offset = (u64)-1;
2291         root = btrfs_read_fs_root_no_name(info, &key);
2292         if (IS_ERR(root)) {
2293                 ret = PTR_ERR(root);
2294                 goto out;
2295         }
2296
2297         key.objectid = dirid;
2298         key.type = BTRFS_INODE_REF_KEY;
2299         key.offset = (u64)-1;
2300
2301         while (1) {
2302                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2303                 if (ret < 0)
2304                         goto out;
2305                 else if (ret > 0) {
2306                         ret = btrfs_previous_item(root, path, dirid,
2307                                                   BTRFS_INODE_REF_KEY);
2308                         if (ret < 0)
2309                                 goto out;
2310                         else if (ret > 0) {
2311                                 ret = -ENOENT;
2312                                 goto out;
2313                         }
2314                 }
2315
2316                 l = path->nodes[0];
2317                 slot = path->slots[0];
2318                 btrfs_item_key_to_cpu(l, &key, slot);
2319
2320                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2321                 len = btrfs_inode_ref_name_len(l, iref);
2322                 ptr -= len + 1;
2323                 total_len += len + 1;
2324                 if (ptr < name) {
2325                         ret = -ENAMETOOLONG;
2326                         goto out;
2327                 }
2328
2329                 *(ptr + len) = '/';
2330                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2331
2332                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2333                         break;
2334
2335                 btrfs_release_path(path);
2336                 key.objectid = key.offset;
2337                 key.offset = (u64)-1;
2338                 dirid = key.objectid;
2339         }
2340         memmove(name, ptr, total_len);
2341         name[total_len] = '\0';
2342         ret = 0;
2343 out:
2344         btrfs_free_path(path);
2345         return ret;
2346 }
2347
2348 static int btrfs_search_path_in_tree_user(struct inode *inode,
2349                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2350 {
2351         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2352         struct super_block *sb = inode->i_sb;
2353         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2354         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2355         u64 dirid = args->dirid;
2356         unsigned long item_off;
2357         unsigned long item_len;
2358         struct btrfs_inode_ref *iref;
2359         struct btrfs_root_ref *rref;
2360         struct btrfs_root *root;
2361         struct btrfs_path *path;
2362         struct btrfs_key key, key2;
2363         struct extent_buffer *leaf;
2364         struct inode *temp_inode;
2365         char *ptr;
2366         int slot;
2367         int len;
2368         int total_len = 0;
2369         int ret;
2370
2371         path = btrfs_alloc_path();
2372         if (!path)
2373                 return -ENOMEM;
2374
2375         /*
2376          * If the bottom subvolume does not exist directly under upper_limit,
2377          * construct the path in from the bottom up.
2378          */
2379         if (dirid != upper_limit.objectid) {
2380                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2381
2382                 key.objectid = treeid;
2383                 key.type = BTRFS_ROOT_ITEM_KEY;
2384                 key.offset = (u64)-1;
2385                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2386                 if (IS_ERR(root)) {
2387                         ret = PTR_ERR(root);
2388                         goto out;
2389                 }
2390
2391                 key.objectid = dirid;
2392                 key.type = BTRFS_INODE_REF_KEY;
2393                 key.offset = (u64)-1;
2394                 while (1) {
2395                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2396                         if (ret < 0) {
2397                                 goto out;
2398                         } else if (ret > 0) {
2399                                 ret = btrfs_previous_item(root, path, dirid,
2400                                                           BTRFS_INODE_REF_KEY);
2401                                 if (ret < 0) {
2402                                         goto out;
2403                                 } else if (ret > 0) {
2404                                         ret = -ENOENT;
2405                                         goto out;
2406                                 }
2407                         }
2408
2409                         leaf = path->nodes[0];
2410                         slot = path->slots[0];
2411                         btrfs_item_key_to_cpu(leaf, &key, slot);
2412
2413                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2414                         len = btrfs_inode_ref_name_len(leaf, iref);
2415                         ptr -= len + 1;
2416                         total_len += len + 1;
2417                         if (ptr < args->path) {
2418                                 ret = -ENAMETOOLONG;
2419                                 goto out;
2420                         }
2421
2422                         *(ptr + len) = '/';
2423                         read_extent_buffer(leaf, ptr,
2424                                         (unsigned long)(iref + 1), len);
2425
2426                         /* Check the read+exec permission of this directory */
2427                         ret = btrfs_previous_item(root, path, dirid,
2428                                                   BTRFS_INODE_ITEM_KEY);
2429                         if (ret < 0) {
2430                                 goto out;
2431                         } else if (ret > 0) {
2432                                 ret = -ENOENT;
2433                                 goto out;
2434                         }
2435
2436                         leaf = path->nodes[0];
2437                         slot = path->slots[0];
2438                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2439                         if (key2.objectid != dirid) {
2440                                 ret = -ENOENT;
2441                                 goto out;
2442                         }
2443
2444                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2445                         if (IS_ERR(temp_inode)) {
2446                                 ret = PTR_ERR(temp_inode);
2447                                 goto out;
2448                         }
2449                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2450                         iput(temp_inode);
2451                         if (ret) {
2452                                 ret = -EACCES;
2453                                 goto out;
2454                         }
2455
2456                         if (key.offset == upper_limit.objectid)
2457                                 break;
2458                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2459                                 ret = -EACCES;
2460                                 goto out;
2461                         }
2462
2463                         btrfs_release_path(path);
2464                         key.objectid = key.offset;
2465                         key.offset = (u64)-1;
2466                         dirid = key.objectid;
2467                 }
2468
2469                 memmove(args->path, ptr, total_len);
2470                 args->path[total_len] = '\0';
2471                 btrfs_release_path(path);
2472         }
2473
2474         /* Get the bottom subvolume's name from ROOT_REF */
2475         root = fs_info->tree_root;
2476         key.objectid = treeid;
2477         key.type = BTRFS_ROOT_REF_KEY;
2478         key.offset = args->treeid;
2479         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2480         if (ret < 0) {
2481                 goto out;
2482         } else if (ret > 0) {
2483                 ret = -ENOENT;
2484                 goto out;
2485         }
2486
2487         leaf = path->nodes[0];
2488         slot = path->slots[0];
2489         btrfs_item_key_to_cpu(leaf, &key, slot);
2490
2491         item_off = btrfs_item_ptr_offset(leaf, slot);
2492         item_len = btrfs_item_size_nr(leaf, slot);
2493         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2494         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2495         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2496                 ret = -EINVAL;
2497                 goto out;
2498         }
2499
2500         /* Copy subvolume's name */
2501         item_off += sizeof(struct btrfs_root_ref);
2502         item_len -= sizeof(struct btrfs_root_ref);
2503         read_extent_buffer(leaf, args->name, item_off, item_len);
2504         args->name[item_len] = 0;
2505
2506 out:
2507         btrfs_free_path(path);
2508         return ret;
2509 }
2510
2511 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2512                                            void __user *argp)
2513 {
2514         struct btrfs_ioctl_ino_lookup_args *args;
2515         struct inode *inode;
2516         int ret = 0;
2517
2518         args = memdup_user(argp, sizeof(*args));
2519         if (IS_ERR(args))
2520                 return PTR_ERR(args);
2521
2522         inode = file_inode(file);
2523
2524         /*
2525          * Unprivileged query to obtain the containing subvolume root id. The
2526          * path is reset so it's consistent with btrfs_search_path_in_tree.
2527          */
2528         if (args->treeid == 0)
2529                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2530
2531         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2532                 args->name[0] = 0;
2533                 goto out;
2534         }
2535
2536         if (!capable(CAP_SYS_ADMIN)) {
2537                 ret = -EPERM;
2538                 goto out;
2539         }
2540
2541         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2542                                         args->treeid, args->objectid,
2543                                         args->name);
2544
2545 out:
2546         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2547                 ret = -EFAULT;
2548
2549         kfree(args);
2550         return ret;
2551 }
2552
2553 /*
2554  * Version of ino_lookup ioctl (unprivileged)
2555  *
2556  * The main differences from ino_lookup ioctl are:
2557  *
2558  *   1. Read + Exec permission will be checked using inode_permission() during
2559  *      path construction. -EACCES will be returned in case of failure.
2560  *   2. Path construction will be stopped at the inode number which corresponds
2561  *      to the fd with which this ioctl is called. If constructed path does not
2562  *      exist under fd's inode, -EACCES will be returned.
2563  *   3. The name of bottom subvolume is also searched and filled.
2564  */
2565 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2566 {
2567         struct btrfs_ioctl_ino_lookup_user_args *args;
2568         struct inode *inode;
2569         int ret;
2570
2571         args = memdup_user(argp, sizeof(*args));
2572         if (IS_ERR(args))
2573                 return PTR_ERR(args);
2574
2575         inode = file_inode(file);
2576
2577         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2578             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2579                 /*
2580                  * The subvolume does not exist under fd with which this is
2581                  * called
2582                  */
2583                 kfree(args);
2584                 return -EACCES;
2585         }
2586
2587         ret = btrfs_search_path_in_tree_user(inode, args);
2588
2589         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2590                 ret = -EFAULT;
2591
2592         kfree(args);
2593         return ret;
2594 }
2595
2596 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2597 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2598 {
2599         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2600         struct btrfs_fs_info *fs_info;
2601         struct btrfs_root *root;
2602         struct btrfs_path *path;
2603         struct btrfs_key key;
2604         struct btrfs_root_item *root_item;
2605         struct btrfs_root_ref *rref;
2606         struct extent_buffer *leaf;
2607         unsigned long item_off;
2608         unsigned long item_len;
2609         struct inode *inode;
2610         int slot;
2611         int ret = 0;
2612
2613         path = btrfs_alloc_path();
2614         if (!path)
2615                 return -ENOMEM;
2616
2617         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2618         if (!subvol_info) {
2619                 btrfs_free_path(path);
2620                 return -ENOMEM;
2621         }
2622
2623         inode = file_inode(file);
2624         fs_info = BTRFS_I(inode)->root->fs_info;
2625
2626         /* Get root_item of inode's subvolume */
2627         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2628         key.type = BTRFS_ROOT_ITEM_KEY;
2629         key.offset = (u64)-1;
2630         root = btrfs_read_fs_root_no_name(fs_info, &key);
2631         if (IS_ERR(root)) {
2632                 ret = PTR_ERR(root);
2633                 goto out;
2634         }
2635         root_item = &root->root_item;
2636
2637         subvol_info->treeid = key.objectid;
2638
2639         subvol_info->generation = btrfs_root_generation(root_item);
2640         subvol_info->flags = btrfs_root_flags(root_item);
2641
2642         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2643         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2644                                                     BTRFS_UUID_SIZE);
2645         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2646                                                     BTRFS_UUID_SIZE);
2647
2648         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2649         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2650         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2651
2652         subvol_info->otransid = btrfs_root_otransid(root_item);
2653         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2654         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2655
2656         subvol_info->stransid = btrfs_root_stransid(root_item);
2657         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2658         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2659
2660         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2661         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2662         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2663
2664         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2665                 /* Search root tree for ROOT_BACKREF of this subvolume */
2666                 root = fs_info->tree_root;
2667
2668                 key.type = BTRFS_ROOT_BACKREF_KEY;
2669                 key.offset = 0;
2670                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2671                 if (ret < 0) {
2672                         goto out;
2673                 } else if (path->slots[0] >=
2674                            btrfs_header_nritems(path->nodes[0])) {
2675                         ret = btrfs_next_leaf(root, path);
2676                         if (ret < 0) {
2677                                 goto out;
2678                         } else if (ret > 0) {
2679                                 ret = -EUCLEAN;
2680                                 goto out;
2681                         }
2682                 }
2683
2684                 leaf = path->nodes[0];
2685                 slot = path->slots[0];
2686                 btrfs_item_key_to_cpu(leaf, &key, slot);
2687                 if (key.objectid == subvol_info->treeid &&
2688                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2689                         subvol_info->parent_id = key.offset;
2690
2691                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2692                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2693
2694                         item_off = btrfs_item_ptr_offset(leaf, slot)
2695                                         + sizeof(struct btrfs_root_ref);
2696                         item_len = btrfs_item_size_nr(leaf, slot)
2697                                         - sizeof(struct btrfs_root_ref);
2698                         read_extent_buffer(leaf, subvol_info->name,
2699                                            item_off, item_len);
2700                 } else {
2701                         ret = -ENOENT;
2702                         goto out;
2703                 }
2704         }
2705
2706         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2707                 ret = -EFAULT;
2708
2709 out:
2710         btrfs_free_path(path);
2711         kzfree(subvol_info);
2712         return ret;
2713 }
2714
2715 /*
2716  * Return ROOT_REF information of the subvolume containing this inode
2717  * except the subvolume name.
2718  */
2719 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2720 {
2721         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2722         struct btrfs_root_ref *rref;
2723         struct btrfs_root *root;
2724         struct btrfs_path *path;
2725         struct btrfs_key key;
2726         struct extent_buffer *leaf;
2727         struct inode *inode;
2728         u64 objectid;
2729         int slot;
2730         int ret;
2731         u8 found;
2732
2733         path = btrfs_alloc_path();
2734         if (!path)
2735                 return -ENOMEM;
2736
2737         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2738         if (IS_ERR(rootrefs)) {
2739                 btrfs_free_path(path);
2740                 return PTR_ERR(rootrefs);
2741         }
2742
2743         inode = file_inode(file);
2744         root = BTRFS_I(inode)->root->fs_info->tree_root;
2745         objectid = BTRFS_I(inode)->root->root_key.objectid;
2746
2747         key.objectid = objectid;
2748         key.type = BTRFS_ROOT_REF_KEY;
2749         key.offset = rootrefs->min_treeid;
2750         found = 0;
2751
2752         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2753         if (ret < 0) {
2754                 goto out;
2755         } else if (path->slots[0] >=
2756                    btrfs_header_nritems(path->nodes[0])) {
2757                 ret = btrfs_next_leaf(root, path);
2758                 if (ret < 0) {
2759                         goto out;
2760                 } else if (ret > 0) {
2761                         ret = -EUCLEAN;
2762                         goto out;
2763                 }
2764         }
2765         while (1) {
2766                 leaf = path->nodes[0];
2767                 slot = path->slots[0];
2768
2769                 btrfs_item_key_to_cpu(leaf, &key, slot);
2770                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2771                         ret = 0;
2772                         goto out;
2773                 }
2774
2775                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2776                         ret = -EOVERFLOW;
2777                         goto out;
2778                 }
2779
2780                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2781                 rootrefs->rootref[found].treeid = key.offset;
2782                 rootrefs->rootref[found].dirid =
2783                                   btrfs_root_ref_dirid(leaf, rref);
2784                 found++;
2785
2786                 ret = btrfs_next_item(root, path);
2787                 if (ret < 0) {
2788                         goto out;
2789                 } else if (ret > 0) {
2790                         ret = -EUCLEAN;
2791                         goto out;
2792                 }
2793         }
2794
2795 out:
2796         if (!ret || ret == -EOVERFLOW) {
2797                 rootrefs->num_items = found;
2798                 /* update min_treeid for next search */
2799                 if (found)
2800                         rootrefs->min_treeid =
2801                                 rootrefs->rootref[found - 1].treeid + 1;
2802                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2803                         ret = -EFAULT;
2804         }
2805
2806         kfree(rootrefs);
2807         btrfs_free_path(path);
2808
2809         return ret;
2810 }
2811
2812 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2813                                              void __user *arg)
2814 {
2815         struct dentry *parent = file->f_path.dentry;
2816         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2817         struct dentry *dentry;
2818         struct inode *dir = d_inode(parent);
2819         struct inode *inode;
2820         struct btrfs_root *root = BTRFS_I(dir)->root;
2821         struct btrfs_root *dest = NULL;
2822         struct btrfs_ioctl_vol_args *vol_args;
2823         int namelen;
2824         int err = 0;
2825
2826         if (!S_ISDIR(dir->i_mode))
2827                 return -ENOTDIR;
2828
2829         vol_args = memdup_user(arg, sizeof(*vol_args));
2830         if (IS_ERR(vol_args))
2831                 return PTR_ERR(vol_args);
2832
2833         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2834         namelen = strlen(vol_args->name);
2835         if (strchr(vol_args->name, '/') ||
2836             strncmp(vol_args->name, "..", namelen) == 0) {
2837                 err = -EINVAL;
2838                 goto out;
2839         }
2840
2841         err = mnt_want_write_file(file);
2842         if (err)
2843                 goto out;
2844
2845
2846         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2847         if (err == -EINTR)
2848                 goto out_drop_write;
2849         dentry = lookup_one_len(vol_args->name, parent, namelen);
2850         if (IS_ERR(dentry)) {
2851                 err = PTR_ERR(dentry);
2852                 goto out_unlock_dir;
2853         }
2854
2855         if (d_really_is_negative(dentry)) {
2856                 err = -ENOENT;
2857                 goto out_dput;
2858         }
2859
2860         inode = d_inode(dentry);
2861         dest = BTRFS_I(inode)->root;
2862         if (!capable(CAP_SYS_ADMIN)) {
2863                 /*
2864                  * Regular user.  Only allow this with a special mount
2865                  * option, when the user has write+exec access to the
2866                  * subvol root, and when rmdir(2) would have been
2867                  * allowed.
2868                  *
2869                  * Note that this is _not_ check that the subvol is
2870                  * empty or doesn't contain data that we wouldn't
2871                  * otherwise be able to delete.
2872                  *
2873                  * Users who want to delete empty subvols should try
2874                  * rmdir(2).
2875                  */
2876                 err = -EPERM;
2877                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2878                         goto out_dput;
2879
2880                 /*
2881                  * Do not allow deletion if the parent dir is the same
2882                  * as the dir to be deleted.  That means the ioctl
2883                  * must be called on the dentry referencing the root
2884                  * of the subvol, not a random directory contained
2885                  * within it.
2886                  */
2887                 err = -EINVAL;
2888                 if (root == dest)
2889                         goto out_dput;
2890
2891                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2892                 if (err)
2893                         goto out_dput;
2894         }
2895
2896         /* check if subvolume may be deleted by a user */
2897         err = btrfs_may_delete(dir, dentry, 1);
2898         if (err)
2899                 goto out_dput;
2900
2901         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2902                 err = -EINVAL;
2903                 goto out_dput;
2904         }
2905
2906         inode_lock(inode);
2907         err = btrfs_delete_subvolume(dir, dentry);
2908         inode_unlock(inode);
2909         if (!err)
2910                 d_delete(dentry);
2911
2912 out_dput:
2913         dput(dentry);
2914 out_unlock_dir:
2915         inode_unlock(dir);
2916 out_drop_write:
2917         mnt_drop_write_file(file);
2918 out:
2919         kfree(vol_args);
2920         return err;
2921 }
2922
2923 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2924 {
2925         struct inode *inode = file_inode(file);
2926         struct btrfs_root *root = BTRFS_I(inode)->root;
2927         struct btrfs_ioctl_defrag_range_args *range;
2928         int ret;
2929
2930         ret = mnt_want_write_file(file);
2931         if (ret)
2932                 return ret;
2933
2934         if (btrfs_root_readonly(root)) {
2935                 ret = -EROFS;
2936                 goto out;
2937         }
2938
2939         switch (inode->i_mode & S_IFMT) {
2940         case S_IFDIR:
2941                 if (!capable(CAP_SYS_ADMIN)) {
2942                         ret = -EPERM;
2943                         goto out;
2944                 }
2945                 ret = btrfs_defrag_root(root);
2946                 break;
2947         case S_IFREG:
2948                 /*
2949                  * Note that this does not check the file descriptor for write
2950                  * access. This prevents defragmenting executables that are
2951                  * running and allows defrag on files open in read-only mode.
2952                  */
2953                 if (!capable(CAP_SYS_ADMIN) &&
2954                     inode_permission(inode, MAY_WRITE)) {
2955                         ret = -EPERM;
2956                         goto out;
2957                 }
2958
2959                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2960                 if (!range) {
2961                         ret = -ENOMEM;
2962                         goto out;
2963                 }
2964
2965                 if (argp) {
2966                         if (copy_from_user(range, argp,
2967                                            sizeof(*range))) {
2968                                 ret = -EFAULT;
2969                                 kfree(range);
2970                                 goto out;
2971                         }
2972                         /* compression requires us to start the IO */
2973                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2974                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2975                                 range->extent_thresh = (u32)-1;
2976                         }
2977                 } else {
2978                         /* the rest are all set to zero by kzalloc */
2979                         range->len = (u64)-1;
2980                 }
2981                 ret = btrfs_defrag_file(file_inode(file), file,
2982                                         range, BTRFS_OLDEST_GENERATION, 0);
2983                 if (ret > 0)
2984                         ret = 0;
2985                 kfree(range);
2986                 break;
2987         default:
2988                 ret = -EINVAL;
2989         }
2990 out:
2991         mnt_drop_write_file(file);
2992         return ret;
2993 }
2994
2995 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2996 {
2997         struct btrfs_ioctl_vol_args *vol_args;
2998         int ret;
2999
3000         if (!capable(CAP_SYS_ADMIN))
3001                 return -EPERM;
3002
3003         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3004                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3005
3006         vol_args = memdup_user(arg, sizeof(*vol_args));
3007         if (IS_ERR(vol_args)) {
3008                 ret = PTR_ERR(vol_args);
3009                 goto out;
3010         }
3011
3012         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3013         ret = btrfs_init_new_device(fs_info, vol_args->name);
3014
3015         if (!ret)
3016                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3017
3018         kfree(vol_args);
3019 out:
3020         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3021         return ret;
3022 }
3023
3024 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3025 {
3026         struct inode *inode = file_inode(file);
3027         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3028         struct btrfs_ioctl_vol_args_v2 *vol_args;
3029         int ret;
3030
3031         if (!capable(CAP_SYS_ADMIN))
3032                 return -EPERM;
3033
3034         ret = mnt_want_write_file(file);
3035         if (ret)
3036                 return ret;
3037
3038         vol_args = memdup_user(arg, sizeof(*vol_args));
3039         if (IS_ERR(vol_args)) {
3040                 ret = PTR_ERR(vol_args);
3041                 goto err_drop;
3042         }
3043
3044         /* Check for compatibility reject unknown flags */
3045         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3046                 ret = -EOPNOTSUPP;
3047                 goto out;
3048         }
3049
3050         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3051                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3052                 goto out;
3053         }
3054
3055         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3056                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3057         } else {
3058                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3059                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3060         }
3061         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3062
3063         if (!ret) {
3064                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3065                         btrfs_info(fs_info, "device deleted: id %llu",
3066                                         vol_args->devid);
3067                 else
3068                         btrfs_info(fs_info, "device deleted: %s",
3069                                         vol_args->name);
3070         }
3071 out:
3072         kfree(vol_args);
3073 err_drop:
3074         mnt_drop_write_file(file);
3075         return ret;
3076 }
3077
3078 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3079 {
3080         struct inode *inode = file_inode(file);
3081         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3082         struct btrfs_ioctl_vol_args *vol_args;
3083         int ret;
3084
3085         if (!capable(CAP_SYS_ADMIN))
3086                 return -EPERM;
3087
3088         ret = mnt_want_write_file(file);
3089         if (ret)
3090                 return ret;
3091
3092         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3093                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3094                 goto out_drop_write;
3095         }
3096
3097         vol_args = memdup_user(arg, sizeof(*vol_args));
3098         if (IS_ERR(vol_args)) {
3099                 ret = PTR_ERR(vol_args);
3100                 goto out;
3101         }
3102
3103         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3104         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3105
3106         if (!ret)
3107                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3108         kfree(vol_args);
3109 out:
3110         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3111 out_drop_write:
3112         mnt_drop_write_file(file);
3113
3114         return ret;
3115 }
3116
3117 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3118                                 void __user *arg)
3119 {
3120         struct btrfs_ioctl_fs_info_args *fi_args;
3121         struct btrfs_device *device;
3122         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3123         int ret = 0;
3124
3125         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3126         if (!fi_args)
3127                 return -ENOMEM;
3128
3129         rcu_read_lock();
3130         fi_args->num_devices = fs_devices->num_devices;
3131
3132         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3133                 if (device->devid > fi_args->max_id)
3134                         fi_args->max_id = device->devid;
3135         }
3136         rcu_read_unlock();
3137
3138         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
3139         fi_args->nodesize = fs_info->nodesize;
3140         fi_args->sectorsize = fs_info->sectorsize;
3141         fi_args->clone_alignment = fs_info->sectorsize;
3142
3143         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3144                 ret = -EFAULT;
3145
3146         kfree(fi_args);
3147         return ret;
3148 }
3149
3150 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3151                                  void __user *arg)
3152 {
3153         struct btrfs_ioctl_dev_info_args *di_args;
3154         struct btrfs_device *dev;
3155         int ret = 0;
3156         char *s_uuid = NULL;
3157
3158         di_args = memdup_user(arg, sizeof(*di_args));
3159         if (IS_ERR(di_args))
3160                 return PTR_ERR(di_args);
3161
3162         if (!btrfs_is_empty_uuid(di_args->uuid))
3163                 s_uuid = di_args->uuid;
3164
3165         rcu_read_lock();
3166         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3167
3168         if (!dev) {
3169                 ret = -ENODEV;
3170                 goto out;
3171         }
3172
3173         di_args->devid = dev->devid;
3174         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3175         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3176         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3177         if (dev->name) {
3178                 strncpy(di_args->path, rcu_str_deref(dev->name),
3179                                 sizeof(di_args->path) - 1);
3180                 di_args->path[sizeof(di_args->path) - 1] = 0;
3181         } else {
3182                 di_args->path[0] = '\0';
3183         }
3184
3185 out:
3186         rcu_read_unlock();
3187         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3188                 ret = -EFAULT;
3189
3190         kfree(di_args);
3191         return ret;
3192 }
3193
3194 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
3195 {
3196         struct page *page;
3197
3198         page = grab_cache_page(inode->i_mapping, index);
3199         if (!page)
3200                 return ERR_PTR(-ENOMEM);
3201
3202         if (!PageUptodate(page)) {
3203                 int ret;
3204
3205                 ret = btrfs_readpage(NULL, page);
3206                 if (ret)
3207                         return ERR_PTR(ret);
3208                 lock_page(page);
3209                 if (!PageUptodate(page)) {
3210                         unlock_page(page);
3211                         put_page(page);
3212                         return ERR_PTR(-EIO);
3213                 }
3214                 if (page->mapping != inode->i_mapping) {
3215                         unlock_page(page);
3216                         put_page(page);
3217                         return ERR_PTR(-EAGAIN);
3218                 }
3219         }
3220
3221         return page;
3222 }
3223
3224 static int gather_extent_pages(struct inode *inode, struct page **pages,
3225                                int num_pages, u64 off)
3226 {
3227         int i;
3228         pgoff_t index = off >> PAGE_SHIFT;
3229
3230         for (i = 0; i < num_pages; i++) {
3231 again:
3232                 pages[i] = extent_same_get_page(inode, index + i);
3233                 if (IS_ERR(pages[i])) {
3234                         int err = PTR_ERR(pages[i]);
3235
3236                         if (err == -EAGAIN)
3237                                 goto again;
3238                         pages[i] = NULL;
3239                         return err;
3240                 }
3241         }
3242         return 0;
3243 }
3244
3245 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
3246                              bool retry_range_locking)
3247 {
3248         /*
3249          * Do any pending delalloc/csum calculations on inode, one way or
3250          * another, and lock file content.
3251          * The locking order is:
3252          *
3253          *   1) pages
3254          *   2) range in the inode's io tree
3255          */
3256         while (1) {
3257                 struct btrfs_ordered_extent *ordered;
3258                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3259                 ordered = btrfs_lookup_first_ordered_extent(inode,
3260                                                             off + len - 1);
3261                 if ((!ordered ||
3262                      ordered->file_offset + ordered->len <= off ||
3263                      ordered->file_offset >= off + len) &&
3264                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
3265                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
3266                         if (ordered)
3267                                 btrfs_put_ordered_extent(ordered);
3268                         break;
3269                 }
3270                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3271                 if (ordered)
3272                         btrfs_put_ordered_extent(ordered);
3273                 if (!retry_range_locking)
3274                         return -EAGAIN;
3275                 btrfs_wait_ordered_range(inode, off, len);
3276         }
3277         return 0;
3278 }
3279
3280 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3281 {
3282         inode_unlock(inode1);
3283         inode_unlock(inode2);
3284 }
3285
3286 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3287 {
3288         if (inode1 < inode2)
3289                 swap(inode1, inode2);
3290
3291         inode_lock_nested(inode1, I_MUTEX_PARENT);
3292         inode_lock_nested(inode2, I_MUTEX_CHILD);
3293 }
3294
3295 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3296                                       struct inode *inode2, u64 loff2, u64 len)
3297 {
3298         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3299         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3300 }
3301
3302 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3303                                     struct inode *inode2, u64 loff2, u64 len,
3304                                     bool retry_range_locking)
3305 {
3306         int ret;
3307
3308         if (inode1 < inode2) {
3309                 swap(inode1, inode2);
3310                 swap(loff1, loff2);
3311         }
3312         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
3313         if (ret)
3314                 return ret;
3315         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
3316         if (ret)
3317                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
3318                               loff1 + len - 1);
3319         return ret;
3320 }
3321
3322 struct cmp_pages {
3323         int             num_pages;
3324         struct page     **src_pages;
3325         struct page     **dst_pages;
3326 };
3327
3328 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3329 {
3330         int i;
3331         struct page *pg;
3332
3333         for (i = 0; i < cmp->num_pages; i++) {
3334                 pg = cmp->src_pages[i];
3335                 if (pg) {
3336                         unlock_page(pg);
3337                         put_page(pg);
3338                         cmp->src_pages[i] = NULL;
3339                 }
3340                 pg = cmp->dst_pages[i];
3341                 if (pg) {
3342                         unlock_page(pg);
3343                         put_page(pg);
3344                         cmp->dst_pages[i] = NULL;
3345                 }
3346         }
3347 }
3348
3349 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3350                                   struct inode *dst, u64 dst_loff,
3351                                   u64 len, struct cmp_pages *cmp)
3352 {
3353         int ret;
3354         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3355
3356         cmp->num_pages = num_pages;
3357
3358         ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
3359         if (ret)
3360                 goto out;
3361
3362         ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
3363
3364 out:
3365         if (ret)
3366                 btrfs_cmp_data_free(cmp);
3367         return ret;
3368 }
3369
3370 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3371 {
3372         int ret = 0;
3373         int i;
3374         struct page *src_page, *dst_page;
3375         unsigned int cmp_len = PAGE_SIZE;
3376         void *addr, *dst_addr;
3377
3378         i = 0;
3379         while (len) {
3380                 if (len < PAGE_SIZE)
3381                         cmp_len = len;
3382
3383                 BUG_ON(i >= cmp->num_pages);
3384
3385                 src_page = cmp->src_pages[i];
3386                 dst_page = cmp->dst_pages[i];
3387                 ASSERT(PageLocked(src_page));
3388                 ASSERT(PageLocked(dst_page));
3389
3390                 addr = kmap_atomic(src_page);
3391                 dst_addr = kmap_atomic(dst_page);
3392
3393                 flush_dcache_page(src_page);
3394                 flush_dcache_page(dst_page);
3395
3396                 if (memcmp(addr, dst_addr, cmp_len))
3397                         ret = -EBADE;
3398
3399                 kunmap_atomic(addr);
3400                 kunmap_atomic(dst_addr);
3401
3402                 if (ret)
3403                         break;
3404
3405                 len -= cmp_len;
3406                 i++;
3407         }
3408
3409         return ret;
3410 }
3411
3412 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3413                                      u64 olen)
3414 {
3415         u64 len = *plen;
3416         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3417
3418         if (off + olen > inode->i_size || off + olen < off)
3419                 return -EINVAL;
3420
3421         /* if we extend to eof, continue to block boundary */
3422         if (off + len == inode->i_size)
3423                 *plen = len = ALIGN(inode->i_size, bs) - off;
3424
3425         /* Check that we are block aligned - btrfs_clone() requires this */
3426         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3427                 return -EINVAL;
3428
3429         return 0;
3430 }
3431
3432 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3433                                    struct inode *dst, u64 dst_loff,
3434                                    struct cmp_pages *cmp)
3435 {
3436         int ret;
3437         u64 len = olen;
3438         bool same_inode = (src == dst);
3439         u64 same_lock_start = 0;
3440         u64 same_lock_len = 0;
3441
3442         ret = extent_same_check_offsets(src, loff, &len, olen);
3443         if (ret)
3444                 return ret;
3445
3446         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3447         if (ret)
3448                 return ret;
3449
3450         if (same_inode) {
3451                 /*
3452                  * Single inode case wants the same checks, except we
3453                  * don't want our length pushed out past i_size as
3454                  * comparing that data range makes no sense.
3455                  *
3456                  * extent_same_check_offsets() will do this for an
3457                  * unaligned length at i_size, so catch it here and
3458                  * reject the request.
3459                  *
3460                  * This effectively means we require aligned extents
3461                  * for the single-inode case, whereas the other cases
3462                  * allow an unaligned length so long as it ends at
3463                  * i_size.
3464                  */
3465                 if (len != olen)
3466                         return -EINVAL;
3467
3468                 /* Check for overlapping ranges */
3469                 if (dst_loff + len > loff && dst_loff < loff + len)
3470                         return -EINVAL;
3471
3472                 same_lock_start = min_t(u64, loff, dst_loff);
3473                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3474         } else {
3475                 /*
3476                  * If the source and destination inodes are different, the
3477                  * source's range end offset matches the source's i_size, that
3478                  * i_size is not a multiple of the sector size, and the
3479                  * destination range does not go past the destination's i_size,
3480                  * we must round down the length to the nearest sector size
3481                  * multiple. If we don't do this adjustment we end replacing
3482                  * with zeroes the bytes in the range that starts at the
3483                  * deduplication range's end offset and ends at the next sector
3484                  * size multiple.
3485                  */
3486                 if (loff + olen == i_size_read(src) &&
3487                     dst_loff + len < i_size_read(dst)) {
3488                         const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize;
3489
3490                         len = round_down(i_size_read(src), sz) - loff;
3491                         if (len == 0)
3492                                 return 0;
3493                         olen = len;
3494                 }
3495         }
3496
3497 again:
3498         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
3499         if (ret)
3500                 return ret;
3501
3502         if (same_inode)
3503                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3504                                         false);
3505         else
3506                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3507                                                false);
3508         /*
3509          * If one of the inodes has dirty pages in the respective range or
3510          * ordered extents, we need to flush dellaloc and wait for all ordered
3511          * extents in the range. We must unlock the pages and the ranges in the
3512          * io trees to avoid deadlocks when flushing delalloc (requires locking
3513          * pages) and when waiting for ordered extents to complete (they require
3514          * range locking).
3515          */
3516         if (ret == -EAGAIN) {
3517                 /*
3518                  * Ranges in the io trees already unlocked. Now unlock all
3519                  * pages before waiting for all IO to complete.
3520                  */
3521                 btrfs_cmp_data_free(cmp);
3522                 if (same_inode) {
3523                         btrfs_wait_ordered_range(src, same_lock_start,
3524                                                  same_lock_len);
3525                 } else {
3526                         btrfs_wait_ordered_range(src, loff, len);
3527                         btrfs_wait_ordered_range(dst, dst_loff, len);
3528                 }
3529                 goto again;
3530         }
3531         ASSERT(ret == 0);
3532         if (WARN_ON(ret)) {
3533                 /* ranges in the io trees already unlocked */
3534                 btrfs_cmp_data_free(cmp);
3535                 return ret;
3536         }
3537
3538         /* pass original length for comparison so we stay within i_size */
3539         ret = btrfs_cmp_data(olen, cmp);
3540         if (ret == 0)
3541                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3542
3543         if (same_inode)
3544                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3545                               same_lock_start + same_lock_len - 1);
3546         else
3547                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3548
3549         btrfs_cmp_data_free(cmp);
3550
3551         return ret;
3552 }
3553
3554 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3555
3556 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3557                              struct inode *dst, u64 dst_loff)
3558 {
3559         int ret;
3560         struct cmp_pages cmp;
3561         int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3562         bool same_inode = (src == dst);
3563         u64 i, tail_len, chunk_count;
3564
3565         if (olen == 0)
3566                 return 0;
3567
3568         if (same_inode)
3569                 inode_lock(src);
3570         else
3571                 btrfs_double_inode_lock(src, dst);
3572
3573         /* don't make the dst file partly checksummed */
3574         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3575             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3576                 ret = -EINVAL;
3577                 goto out_unlock;
3578         }
3579
3580         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3581         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3582         if (chunk_count == 0)
3583                 num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3584
3585         /*
3586          * If deduping ranges in the same inode, locking rules make it
3587          * mandatory to always lock pages in ascending order to avoid deadlocks
3588          * with concurrent tasks (such as starting writeback/delalloc).
3589          */
3590         if (same_inode && dst_loff < loff)
3591                 swap(loff, dst_loff);
3592
3593         /*
3594          * We must gather up all the pages before we initiate our extent
3595          * locking. We use an array for the page pointers. Size of the array is
3596          * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
3597          */
3598         cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3599                                        GFP_KERNEL | __GFP_ZERO);
3600         cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3601                                        GFP_KERNEL | __GFP_ZERO);
3602         if (!cmp.src_pages || !cmp.dst_pages) {
3603                 ret = -ENOMEM;
3604                 goto out_free;
3605         }
3606
3607         for (i = 0; i < chunk_count; i++) {
3608                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3609                                               dst, dst_loff, &cmp);
3610                 if (ret)
3611                         goto out_free;
3612
3613                 loff += BTRFS_MAX_DEDUPE_LEN;
3614                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3615         }
3616
3617         if (tail_len > 0)
3618                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3619                                               dst_loff, &cmp);
3620
3621 out_free:
3622         kvfree(cmp.src_pages);
3623         kvfree(cmp.dst_pages);
3624
3625 out_unlock:
3626         if (same_inode)
3627                 inode_unlock(src);
3628         else
3629                 btrfs_double_inode_unlock(src, dst);
3630
3631         return ret;
3632 }
3633
3634 int btrfs_dedupe_file_range(struct file *src_file, loff_t src_loff,
3635                             struct file *dst_file, loff_t dst_loff,
3636                             u64 olen)
3637 {
3638         struct inode *src = file_inode(src_file);
3639         struct inode *dst = file_inode(dst_file);
3640         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3641
3642         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3643                 /*
3644                  * Btrfs does not support blocksize < page_size. As a
3645                  * result, btrfs_cmp_data() won't correctly handle
3646                  * this situation without an update.
3647                  */
3648                 return -EINVAL;
3649         }
3650
3651         return btrfs_extent_same(src, src_loff, olen, dst, dst_loff);
3652 }
3653
3654 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3655                                      struct inode *inode,
3656                                      u64 endoff,
3657                                      const u64 destoff,
3658                                      const u64 olen,
3659                                      int no_time_update)
3660 {
3661         struct btrfs_root *root = BTRFS_I(inode)->root;
3662         int ret;
3663
3664         inode_inc_iversion(inode);
3665         if (!no_time_update)
3666                 inode->i_mtime = inode->i_ctime = current_time(inode);
3667         /*
3668          * We round up to the block size at eof when determining which
3669          * extents to clone above, but shouldn't round up the file size.
3670          */
3671         if (endoff > destoff + olen)
3672                 endoff = destoff + olen;
3673         if (endoff > inode->i_size)
3674                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3675
3676         ret = btrfs_update_inode(trans, root, inode);
3677         if (ret) {
3678                 btrfs_abort_transaction(trans, ret);
3679                 btrfs_end_transaction(trans);
3680                 goto out;
3681         }
3682         ret = btrfs_end_transaction(trans);
3683 out:
3684         return ret;
3685 }
3686
3687 static void clone_update_extent_map(struct btrfs_inode *inode,
3688                                     const struct btrfs_trans_handle *trans,
3689                                     const struct btrfs_path *path,
3690                                     const u64 hole_offset,
3691                                     const u64 hole_len)
3692 {
3693         struct extent_map_tree *em_tree = &inode->extent_tree;
3694         struct extent_map *em;
3695         int ret;
3696
3697         em = alloc_extent_map();
3698         if (!em) {
3699                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3700                 return;
3701         }
3702
3703         if (path) {
3704                 struct btrfs_file_extent_item *fi;
3705
3706                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3707                                     struct btrfs_file_extent_item);
3708                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3709                 em->generation = -1;
3710                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3711                     BTRFS_FILE_EXTENT_INLINE)
3712                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3713                                         &inode->runtime_flags);
3714         } else {
3715                 em->start = hole_offset;
3716                 em->len = hole_len;
3717                 em->ram_bytes = em->len;
3718                 em->orig_start = hole_offset;
3719                 em->block_start = EXTENT_MAP_HOLE;
3720                 em->block_len = 0;
3721                 em->orig_block_len = 0;
3722                 em->compress_type = BTRFS_COMPRESS_NONE;
3723                 em->generation = trans->transid;
3724         }
3725
3726         while (1) {
3727                 write_lock(&em_tree->lock);
3728                 ret = add_extent_mapping(em_tree, em, 1);
3729                 write_unlock(&em_tree->lock);
3730                 if (ret != -EEXIST) {
3731                         free_extent_map(em);
3732                         break;
3733                 }
3734                 btrfs_drop_extent_cache(inode, em->start,
3735                                         em->start + em->len - 1, 0);
3736         }
3737
3738         if (ret)
3739                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3740 }
3741
3742 /*
3743  * Make sure we do not end up inserting an inline extent into a file that has
3744  * already other (non-inline) extents. If a file has an inline extent it can
3745  * not have any other extents and the (single) inline extent must start at the
3746  * file offset 0. Failing to respect these rules will lead to file corruption,
3747  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3748  *
3749  * We can have extents that have been already written to disk or we can have
3750  * dirty ranges still in delalloc, in which case the extent maps and items are
3751  * created only when we run delalloc, and the delalloc ranges might fall outside
3752  * the range we are currently locking in the inode's io tree. So we check the
3753  * inode's i_size because of that (i_size updates are done while holding the
3754  * i_mutex, which we are holding here).
3755  * We also check to see if the inode has a size not greater than "datal" but has
3756  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3757  * protected against such concurrent fallocate calls by the i_mutex).
3758  *
3759  * If the file has no extents but a size greater than datal, do not allow the
3760  * copy because we would need turn the inline extent into a non-inline one (even
3761  * with NO_HOLES enabled). If we find our destination inode only has one inline
3762  * extent, just overwrite it with the source inline extent if its size is less
3763  * than the source extent's size, or we could copy the source inline extent's
3764  * data into the destination inode's inline extent if the later is greater then
3765  * the former.
3766  */
3767 static int clone_copy_inline_extent(struct inode *dst,
3768                                     struct btrfs_trans_handle *trans,
3769                                     struct btrfs_path *path,
3770                                     struct btrfs_key *new_key,
3771                                     const u64 drop_start,
3772                                     const u64 datal,
3773                                     const u64 skip,
3774                                     const u64 size,
3775                                     char *inline_data)
3776 {
3777         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3778         struct btrfs_root *root = BTRFS_I(dst)->root;
3779         const u64 aligned_end = ALIGN(new_key->offset + datal,
3780                                       fs_info->sectorsize);
3781         int ret;
3782         struct btrfs_key key;
3783
3784         if (new_key->offset > 0)
3785                 return -EOPNOTSUPP;
3786
3787         key.objectid = btrfs_ino(BTRFS_I(dst));
3788         key.type = BTRFS_EXTENT_DATA_KEY;
3789         key.offset = 0;
3790         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3791         if (ret < 0) {
3792                 return ret;
3793         } else if (ret > 0) {
3794                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3795                         ret = btrfs_next_leaf(root, path);
3796                         if (ret < 0)
3797                                 return ret;
3798                         else if (ret > 0)
3799                                 goto copy_inline_extent;
3800                 }
3801                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3802                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3803                     key.type == BTRFS_EXTENT_DATA_KEY) {
3804                         ASSERT(key.offset > 0);
3805                         return -EOPNOTSUPP;
3806                 }
3807         } else if (i_size_read(dst) <= datal) {
3808                 struct btrfs_file_extent_item *ei;
3809                 u64 ext_len;
3810
3811                 /*
3812                  * If the file size is <= datal, make sure there are no other
3813                  * extents following (can happen do to an fallocate call with
3814                  * the flag FALLOC_FL_KEEP_SIZE).
3815                  */
3816                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3817                                     struct btrfs_file_extent_item);
3818                 /*
3819                  * If it's an inline extent, it can not have other extents
3820                  * following it.
3821                  */
3822                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3823                     BTRFS_FILE_EXTENT_INLINE)
3824                         goto copy_inline_extent;
3825
3826                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3827                 if (ext_len > aligned_end)
3828                         return -EOPNOTSUPP;
3829
3830                 ret = btrfs_next_item(root, path);
3831                 if (ret < 0) {
3832                         return ret;
3833                 } else if (ret == 0) {
3834                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3835                                               path->slots[0]);
3836                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3837                             key.type == BTRFS_EXTENT_DATA_KEY)
3838                                 return -EOPNOTSUPP;
3839                 }
3840         }
3841
3842 copy_inline_extent:
3843         /*
3844          * We have no extent items, or we have an extent at offset 0 which may
3845          * or may not be inlined. All these cases are dealt the same way.
3846          */
3847         if (i_size_read(dst) > datal) {
3848                 /*
3849                  * If the destination inode has an inline extent...
3850                  * This would require copying the data from the source inline
3851                  * extent into the beginning of the destination's inline extent.
3852                  * But this is really complex, both extents can be compressed
3853                  * or just one of them, which would require decompressing and
3854                  * re-compressing data (which could increase the new compressed
3855                  * size, not allowing the compressed data to fit anymore in an
3856                  * inline extent).
3857                  * So just don't support this case for now (it should be rare,
3858                  * we are not really saving space when cloning inline extents).
3859                  */
3860                 return -EOPNOTSUPP;
3861         }
3862
3863         btrfs_release_path(path);
3864         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3865         if (ret)
3866                 return ret;
3867         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3868         if (ret)
3869                 return ret;
3870
3871         if (skip) {
3872                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3873
3874                 memmove(inline_data + start, inline_data + start + skip, datal);
3875         }
3876
3877         write_extent_buffer(path->nodes[0], inline_data,
3878                             btrfs_item_ptr_offset(path->nodes[0],
3879                                                   path->slots[0]),
3880                             size);
3881         inode_add_bytes(dst, datal);
3882
3883         return 0;
3884 }
3885
3886 /**
3887  * btrfs_clone() - clone a range from inode file to another
3888  *
3889  * @src: Inode to clone from
3890  * @inode: Inode to clone to
3891  * @off: Offset within source to start clone from
3892  * @olen: Original length, passed by user, of range to clone
3893  * @olen_aligned: Block-aligned value of olen
3894  * @destoff: Offset within @inode to start clone
3895  * @no_time_update: Whether to update mtime/ctime on the target inode
3896  */
3897 static int btrfs_clone(struct inode *src, struct inode *inode,
3898                        const u64 off, const u64 olen, const u64 olen_aligned,
3899                        const u64 destoff, int no_time_update)
3900 {
3901         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3902         struct btrfs_root *root = BTRFS_I(inode)->root;
3903         struct btrfs_path *path = NULL;
3904         struct extent_buffer *leaf;
3905         struct btrfs_trans_handle *trans;
3906         char *buf = NULL;
3907         struct btrfs_key key;
3908         u32 nritems;
3909         int slot;
3910         int ret;
3911         const u64 len = olen_aligned;
3912         u64 last_dest_end = destoff;
3913
3914         ret = -ENOMEM;
3915         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3916         if (!buf)
3917                 return ret;
3918
3919         path = btrfs_alloc_path();
3920         if (!path) {
3921                 kvfree(buf);
3922                 return ret;
3923         }
3924
3925         path->reada = READA_FORWARD;
3926         /* clone data */
3927         key.objectid = btrfs_ino(BTRFS_I(src));
3928         key.type = BTRFS_EXTENT_DATA_KEY;
3929         key.offset = off;
3930
3931         while (1) {
3932                 u64 next_key_min_offset = key.offset + 1;
3933
3934                 /*
3935                  * note the key will change type as we walk through the
3936                  * tree.
3937                  */
3938                 path->leave_spinning = 1;
3939                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3940                                 0, 0);
3941                 if (ret < 0)
3942                         goto out;
3943                 /*
3944                  * First search, if no extent item that starts at offset off was
3945                  * found but the previous item is an extent item, it's possible
3946                  * it might overlap our target range, therefore process it.
3947                  */
3948                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3949                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3950                                               path->slots[0] - 1);
3951                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3952                                 path->slots[0]--;
3953                 }
3954
3955                 nritems = btrfs_header_nritems(path->nodes[0]);
3956 process_slot:
3957                 if (path->slots[0] >= nritems) {
3958                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3959                         if (ret < 0)
3960                                 goto out;
3961                         if (ret > 0)
3962                                 break;
3963                         nritems = btrfs_header_nritems(path->nodes[0]);
3964                 }
3965                 leaf = path->nodes[0];
3966                 slot = path->slots[0];
3967
3968                 btrfs_item_key_to_cpu(leaf, &key, slot);
3969                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3970                     key.objectid != btrfs_ino(BTRFS_I(src)))
3971                         break;
3972
3973                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3974                         struct btrfs_file_extent_item *extent;
3975                         int type;
3976                         u32 size;
3977                         struct btrfs_key new_key;
3978                         u64 disko = 0, diskl = 0;
3979                         u64 datao = 0, datal = 0;
3980                         u8 comp;
3981                         u64 drop_start;
3982
3983                         extent = btrfs_item_ptr(leaf, slot,
3984                                                 struct btrfs_file_extent_item);
3985                         comp = btrfs_file_extent_compression(leaf, extent);
3986                         type = btrfs_file_extent_type(leaf, extent);
3987                         if (type == BTRFS_FILE_EXTENT_REG ||
3988                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3989                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3990                                                                       extent);
3991                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3992                                                                  extent);
3993                                 datao = btrfs_file_extent_offset(leaf, extent);
3994                                 datal = btrfs_file_extent_num_bytes(leaf,
3995                                                                     extent);
3996                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3997                                 /* take upper bound, may be compressed */
3998                                 datal = btrfs_file_extent_ram_bytes(leaf,
3999                                                                     extent);
4000                         }
4001
4002                         /*
4003                          * The first search might have left us at an extent
4004                          * item that ends before our target range's start, can
4005                          * happen if we have holes and NO_HOLES feature enabled.
4006                          */
4007                         if (key.offset + datal <= off) {
4008                                 path->slots[0]++;
4009                                 goto process_slot;
4010                         } else if (key.offset >= off + len) {
4011                                 break;
4012                         }
4013                         next_key_min_offset = key.offset + datal;
4014                         size = btrfs_item_size_nr(leaf, slot);
4015                         read_extent_buffer(leaf, buf,
4016                                            btrfs_item_ptr_offset(leaf, slot),
4017                                            size);
4018
4019                         btrfs_release_path(path);
4020                         path->leave_spinning = 0;
4021
4022                         memcpy(&new_key, &key, sizeof(new_key));
4023                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
4024                         if (off <= key.offset)
4025                                 new_key.offset = key.offset + destoff - off;
4026                         else
4027                                 new_key.offset = destoff;
4028
4029                         /*
4030                          * Deal with a hole that doesn't have an extent item
4031                          * that represents it (NO_HOLES feature enabled).
4032                          * This hole is either in the middle of the cloning
4033                          * range or at the beginning (fully overlaps it or
4034                          * partially overlaps it).
4035                          */
4036                         if (new_key.offset != last_dest_end)
4037                                 drop_start = last_dest_end;
4038                         else
4039                                 drop_start = new_key.offset;
4040
4041                         /*
4042                          * 1 - adjusting old extent (we may have to split it)
4043                          * 1 - add new extent
4044                          * 1 - inode update
4045                          */
4046                         trans = btrfs_start_transaction(root, 3);
4047                         if (IS_ERR(trans)) {
4048                                 ret = PTR_ERR(trans);
4049                                 goto out;
4050                         }
4051
4052                         if (type == BTRFS_FILE_EXTENT_REG ||
4053                             type == BTRFS_FILE_EXTENT_PREALLOC) {
4054                                 /*
4055                                  *    a  | --- range to clone ---|  b
4056                                  * | ------------- extent ------------- |
4057                                  */
4058
4059                                 /* subtract range b */
4060                                 if (key.offset + datal > off + len)
4061                                         datal = off + len - key.offset;
4062
4063                                 /* subtract range a */
4064                                 if (off > key.offset) {
4065                                         datao += off - key.offset;
4066                                         datal -= off - key.offset;
4067                                 }
4068
4069                                 ret = btrfs_drop_extents(trans, root, inode,
4070                                                          drop_start,
4071                                                          new_key.offset + datal,
4072                                                          1);
4073                                 if (ret) {
4074                                         if (ret != -EOPNOTSUPP)
4075                                                 btrfs_abort_transaction(trans,
4076                                                                         ret);
4077                                         btrfs_end_transaction(trans);
4078                                         goto out;
4079                                 }
4080
4081                                 ret = btrfs_insert_empty_item(trans, root, path,
4082                                                               &new_key, size);
4083                                 if (ret) {
4084                                         btrfs_abort_transaction(trans, ret);
4085                                         btrfs_end_transaction(trans);
4086                                         goto out;
4087                                 }
4088
4089                                 leaf = path->nodes[0];
4090                                 slot = path->slots[0];
4091                                 write_extent_buffer(leaf, buf,
4092                                             btrfs_item_ptr_offset(leaf, slot),
4093                                             size);
4094
4095                                 extent = btrfs_item_ptr(leaf, slot,
4096                                                 struct btrfs_file_extent_item);
4097
4098                                 /* disko == 0 means it's a hole */
4099                                 if (!disko)
4100                                         datao = 0;
4101
4102                                 btrfs_set_file_extent_offset(leaf, extent,
4103                                                              datao);
4104                                 btrfs_set_file_extent_num_bytes(leaf, extent,
4105                                                                 datal);
4106
4107                                 if (disko) {
4108                                         inode_add_bytes(inode, datal);
4109                                         ret = btrfs_inc_extent_ref(trans,
4110                                                         root,
4111                                                         disko, diskl, 0,
4112                                                         root->root_key.objectid,
4113                                                         btrfs_ino(BTRFS_I(inode)),
4114                                                         new_key.offset - datao);
4115                                         if (ret) {
4116                                                 btrfs_abort_transaction(trans,
4117                                                                         ret);
4118                                                 btrfs_end_transaction(trans);
4119                                                 goto out;
4120
4121                                         }
4122                                 }
4123                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
4124                                 u64 skip = 0;
4125                                 u64 trim = 0;
4126
4127                                 if (off > key.offset) {
4128                                         skip = off - key.offset;
4129                                         new_key.offset += skip;
4130                                 }
4131
4132                                 if (key.offset + datal > off + len)
4133                                         trim = key.offset + datal - (off + len);
4134
4135                                 if (comp && (skip || trim)) {
4136                                         ret = -EINVAL;
4137                                         btrfs_end_transaction(trans);
4138                                         goto out;
4139                                 }
4140                                 size -= skip + trim;
4141                                 datal -= skip + trim;
4142
4143                                 ret = clone_copy_inline_extent(inode,
4144                                                                trans, path,
4145                                                                &new_key,
4146                                                                drop_start,
4147                                                                datal,
4148                                                                skip, size, buf);
4149                                 if (ret) {
4150                                         if (ret != -EOPNOTSUPP)
4151                                                 btrfs_abort_transaction(trans,
4152                                                                         ret);
4153                                         btrfs_end_transaction(trans);
4154                                         goto out;
4155                                 }
4156                                 leaf = path->nodes[0];
4157                                 slot = path->slots[0];
4158                         }
4159
4160                         /* If we have an implicit hole (NO_HOLES feature). */
4161                         if (drop_start < new_key.offset)
4162                                 clone_update_extent_map(BTRFS_I(inode), trans,
4163                                                 NULL, drop_start,
4164                                                 new_key.offset - drop_start);
4165
4166                         clone_update_extent_map(BTRFS_I(inode), trans,
4167                                         path, 0, 0);
4168
4169                         btrfs_mark_buffer_dirty(leaf);
4170                         btrfs_release_path(path);
4171
4172                         last_dest_end = ALIGN(new_key.offset + datal,
4173                                               fs_info->sectorsize);
4174                         ret = clone_finish_inode_update(trans, inode,
4175                                                         last_dest_end,
4176                                                         destoff, olen,
4177                                                         no_time_update);
4178                         if (ret)
4179                                 goto out;
4180                         if (new_key.offset + datal >= destoff + len)
4181                                 break;
4182                 }
4183                 btrfs_release_path(path);
4184                 key.offset = next_key_min_offset;
4185
4186                 if (fatal_signal_pending(current)) {
4187                         ret = -EINTR;
4188                         goto out;
4189                 }
4190         }
4191         ret = 0;
4192
4193         if (last_dest_end < destoff + len) {
4194                 /*
4195                  * We have an implicit hole (NO_HOLES feature is enabled) that
4196                  * fully or partially overlaps our cloning range at its end.
4197                  */
4198                 btrfs_release_path(path);
4199
4200                 /*
4201                  * 1 - remove extent(s)
4202                  * 1 - inode update
4203                  */
4204                 trans = btrfs_start_transaction(root, 2);
4205                 if (IS_ERR(trans)) {
4206                         ret = PTR_ERR(trans);
4207                         goto out;
4208                 }
4209                 ret = btrfs_drop_extents(trans, root, inode,
4210                                          last_dest_end, destoff + len, 1);
4211                 if (ret) {
4212                         if (ret != -EOPNOTSUPP)
4213                                 btrfs_abort_transaction(trans, ret);
4214                         btrfs_end_transaction(trans);
4215                         goto out;
4216                 }
4217                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
4218                                 last_dest_end,
4219                                 destoff + len - last_dest_end);
4220                 ret = clone_finish_inode_update(trans, inode, destoff + len,
4221                                                 destoff, olen, no_time_update);
4222         }
4223
4224 out:
4225         btrfs_free_path(path);
4226         kvfree(buf);
4227         return ret;
4228 }
4229
4230 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
4231                                         u64 off, u64 olen, u64 destoff)
4232 {
4233         struct inode *inode = file_inode(file);
4234         struct inode *src = file_inode(file_src);
4235         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4236         struct btrfs_root *root = BTRFS_I(inode)->root;
4237         int ret;
4238         u64 len = olen;
4239         u64 bs = fs_info->sb->s_blocksize;
4240         int same_inode = src == inode;
4241
4242         /*
4243          * TODO:
4244          * - split compressed inline extents.  annoying: we need to
4245          *   decompress into destination's address_space (the file offset
4246          *   may change, so source mapping won't do), then recompress (or
4247          *   otherwise reinsert) a subrange.
4248          *
4249          * - split destination inode's inline extents.  The inline extents can
4250          *   be either compressed or non-compressed.
4251          */
4252
4253         if (btrfs_root_readonly(root))
4254                 return -EROFS;
4255
4256         if (file_src->f_path.mnt != file->f_path.mnt ||
4257             src->i_sb != inode->i_sb)
4258                 return -EXDEV;
4259
4260         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
4261                 return -EISDIR;
4262
4263         if (!same_inode) {
4264                 btrfs_double_inode_lock(src, inode);
4265         } else {
4266                 inode_lock(src);
4267         }
4268
4269         /* don't make the dst file partly checksummed */
4270         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
4271             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
4272                 ret = -EINVAL;
4273                 goto out_unlock;
4274         }
4275
4276         /* determine range to clone */
4277         ret = -EINVAL;
4278         if (off + len > src->i_size || off + len < off)
4279                 goto out_unlock;
4280         if (len == 0)
4281                 olen = len = src->i_size - off;
4282         /*
4283          * If we extend to eof, continue to block boundary if and only if the
4284          * destination end offset matches the destination file's size, otherwise
4285          * we would be corrupting data by placing the eof block into the middle
4286          * of a file.
4287          */
4288         if (off + len == src->i_size) {
4289                 if (!IS_ALIGNED(len, bs) && destoff + len < inode->i_size)
4290                         goto out_unlock;
4291                 len = ALIGN(src->i_size, bs) - off;
4292         }
4293
4294         if (len == 0) {
4295                 ret = 0;
4296                 goto out_unlock;
4297         }
4298
4299         /* verify the end result is block aligned */
4300         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
4301             !IS_ALIGNED(destoff, bs))
4302                 goto out_unlock;
4303
4304         /* verify if ranges are overlapped within the same file */
4305         if (same_inode) {
4306                 if (destoff + len > off && destoff < off + len)
4307                         goto out_unlock;
4308         }
4309
4310         if (destoff > inode->i_size) {
4311                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
4312                 if (ret)
4313                         goto out_unlock;
4314         }
4315
4316         /*
4317          * Lock the target range too. Right after we replace the file extent
4318          * items in the fs tree (which now point to the cloned data), we might
4319          * have a worker replace them with extent items relative to a write
4320          * operation that was issued before this clone operation (i.e. confront
4321          * with inode.c:btrfs_finish_ordered_io).
4322          */
4323         if (same_inode) {
4324                 u64 lock_start = min_t(u64, off, destoff);
4325                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
4326
4327                 ret = lock_extent_range(src, lock_start, lock_len, true);
4328         } else {
4329                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
4330                                                true);
4331         }
4332         ASSERT(ret == 0);
4333         if (WARN_ON(ret)) {
4334                 /* ranges in the io trees already unlocked */
4335                 goto out_unlock;
4336         }
4337
4338         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
4339
4340         if (same_inode) {
4341                 u64 lock_start = min_t(u64, off, destoff);
4342                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
4343
4344                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
4345         } else {
4346                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
4347         }
4348         /*
4349          * Truncate page cache pages so that future reads will see the cloned
4350          * data immediately and not the previous data.
4351          */
4352         truncate_inode_pages_range(&inode->i_data,
4353                                 round_down(destoff, PAGE_SIZE),
4354                                 round_up(destoff + len, PAGE_SIZE) - 1);
4355 out_unlock:
4356         if (!same_inode)
4357                 btrfs_double_inode_unlock(src, inode);
4358         else
4359                 inode_unlock(src);
4360         return ret;
4361 }
4362
4363 int btrfs_clone_file_range(struct file *src_file, loff_t off,
4364                 struct file *dst_file, loff_t destoff, u64 len)
4365 {
4366         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
4367 }
4368
4369 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4370 {
4371         struct inode *inode = file_inode(file);
4372         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4373         struct btrfs_root *root = BTRFS_I(inode)->root;
4374         struct btrfs_root *new_root;
4375         struct btrfs_dir_item *di;
4376         struct btrfs_trans_handle *trans;
4377         struct btrfs_path *path;
4378         struct btrfs_key location;
4379         struct btrfs_disk_key disk_key;
4380         u64 objectid = 0;
4381         u64 dir_id;
4382         int ret;
4383
4384         if (!capable(CAP_SYS_ADMIN))
4385                 return -EPERM;
4386
4387         ret = mnt_want_write_file(file);
4388         if (ret)
4389                 return ret;
4390
4391         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4392                 ret = -EFAULT;
4393                 goto out;
4394         }
4395
4396         if (!objectid)
4397                 objectid = BTRFS_FS_TREE_OBJECTID;
4398
4399         location.objectid = objectid;
4400         location.type = BTRFS_ROOT_ITEM_KEY;
4401         location.offset = (u64)-1;
4402
4403         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4404         if (IS_ERR(new_root)) {
4405                 ret = PTR_ERR(new_root);
4406                 goto out;
4407         }
4408         if (!is_fstree(new_root->root_key.objectid)) {
4409                 ret = -ENOENT;
4410                 goto out;
4411         }
4412
4413         path = btrfs_alloc_path();
4414         if (!path) {
4415                 ret = -ENOMEM;
4416                 goto out;
4417         }
4418         path->leave_spinning = 1;
4419
4420         trans = btrfs_start_transaction(root, 1);
4421         if (IS_ERR(trans)) {
4422                 btrfs_free_path(path);
4423                 ret = PTR_ERR(trans);
4424                 goto out;
4425         }
4426
4427         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4428         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4429                                    dir_id, "default", 7, 1);
4430         if (IS_ERR_OR_NULL(di)) {
4431                 btrfs_free_path(path);
4432                 btrfs_end_transaction(trans);
4433                 btrfs_err(fs_info,
4434                           "Umm, you don't have the default diritem, this isn't going to work");
4435                 ret = -ENOENT;
4436                 goto out;
4437         }
4438
4439         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4440         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4441         btrfs_mark_buffer_dirty(path->nodes[0]);
4442         btrfs_free_path(path);
4443
4444         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4445         btrfs_end_transaction(trans);
4446 out:
4447         mnt_drop_write_file(file);
4448         return ret;
4449 }
4450
4451 static void get_block_group_info(struct list_head *groups_list,
4452                                  struct btrfs_ioctl_space_info *space)
4453 {
4454         struct btrfs_block_group_cache *block_group;
4455
4456         space->total_bytes = 0;
4457         space->used_bytes = 0;
4458         space->flags = 0;
4459         list_for_each_entry(block_group, groups_list, list) {
4460                 space->flags = block_group->flags;
4461                 space->total_bytes += block_group->key.offset;
4462                 space->used_bytes +=
4463                         btrfs_block_group_used(&block_group->item);
4464         }
4465 }
4466
4467 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4468                                    void __user *arg)
4469 {
4470         struct btrfs_ioctl_space_args space_args;
4471         struct btrfs_ioctl_space_info space;
4472         struct btrfs_ioctl_space_info *dest;
4473         struct btrfs_ioctl_space_info *dest_orig;
4474         struct btrfs_ioctl_space_info __user *user_dest;
4475         struct btrfs_space_info *info;
4476         static const u64 types[] = {
4477                 BTRFS_BLOCK_GROUP_DATA,
4478                 BTRFS_BLOCK_GROUP_SYSTEM,
4479                 BTRFS_BLOCK_GROUP_METADATA,
4480                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4481         };
4482         int num_types = 4;
4483         int alloc_size;
4484         int ret = 0;
4485         u64 slot_count = 0;
4486         int i, c;
4487
4488         if (copy_from_user(&space_args,
4489                            (struct btrfs_ioctl_space_args __user *)arg,
4490                            sizeof(space_args)))
4491                 return -EFAULT;
4492
4493         for (i = 0; i < num_types; i++) {
4494                 struct btrfs_space_info *tmp;
4495
4496                 info = NULL;
4497                 rcu_read_lock();
4498                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4499                                         list) {
4500                         if (tmp->flags == types[i]) {
4501                                 info = tmp;
4502                                 break;
4503                         }
4504                 }
4505                 rcu_read_unlock();
4506
4507                 if (!info)
4508                         continue;
4509
4510                 down_read(&info->groups_sem);
4511                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4512                         if (!list_empty(&info->block_groups[c]))
4513                                 slot_count++;
4514                 }
4515                 up_read(&info->groups_sem);
4516         }
4517
4518         /*
4519          * Global block reserve, exported as a space_info
4520          */
4521         slot_count++;
4522
4523         /* space_slots == 0 means they are asking for a count */
4524         if (space_args.space_slots == 0) {
4525                 space_args.total_spaces = slot_count;
4526                 goto out;
4527         }
4528
4529         slot_count = min_t(u64, space_args.space_slots, slot_count);
4530
4531         alloc_size = sizeof(*dest) * slot_count;
4532
4533         /* we generally have at most 6 or so space infos, one for each raid
4534          * level.  So, a whole page should be more than enough for everyone
4535          */
4536         if (alloc_size > PAGE_SIZE)
4537                 return -ENOMEM;
4538
4539         space_args.total_spaces = 0;
4540         dest = kmalloc(alloc_size, GFP_KERNEL);
4541         if (!dest)
4542                 return -ENOMEM;
4543         dest_orig = dest;
4544
4545         /* now we have a buffer to copy into */
4546         for (i = 0; i < num_types; i++) {
4547                 struct btrfs_space_info *tmp;
4548
4549                 if (!slot_count)
4550                         break;
4551
4552                 info = NULL;
4553                 rcu_read_lock();
4554                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4555                                         list) {
4556                         if (tmp->flags == types[i]) {
4557                                 info = tmp;
4558                                 break;
4559                         }
4560                 }
4561                 rcu_read_unlock();
4562
4563                 if (!info)
4564                         continue;
4565                 down_read(&info->groups_sem);
4566                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4567                         if (!list_empty(&info->block_groups[c])) {
4568                                 get_block_group_info(&info->block_groups[c],
4569                                                      &space);
4570                                 memcpy(dest, &space, sizeof(space));
4571                                 dest++;
4572                                 space_args.total_spaces++;
4573                                 slot_count--;
4574                         }
4575                         if (!slot_count)
4576                                 break;
4577                 }
4578                 up_read(&info->groups_sem);
4579         }
4580
4581         /*
4582          * Add global block reserve
4583          */
4584         if (slot_count) {
4585                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4586
4587                 spin_lock(&block_rsv->lock);
4588                 space.total_bytes = block_rsv->size;
4589                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4590                 spin_unlock(&block_rsv->lock);
4591                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4592                 memcpy(dest, &space, sizeof(space));
4593                 space_args.total_spaces++;
4594         }
4595
4596         user_dest = (struct btrfs_ioctl_space_info __user *)
4597                 (arg + sizeof(struct btrfs_ioctl_space_args));
4598
4599         if (copy_to_user(user_dest, dest_orig, alloc_size))
4600                 ret = -EFAULT;
4601
4602         kfree(dest_orig);
4603 out:
4604         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4605                 ret = -EFAULT;
4606
4607         return ret;
4608 }
4609
4610 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4611                                             void __user *argp)
4612 {
4613         struct btrfs_trans_handle *trans;
4614         u64 transid;
4615         int ret;
4616
4617         trans = btrfs_attach_transaction_barrier(root);
4618         if (IS_ERR(trans)) {
4619                 if (PTR_ERR(trans) != -ENOENT)
4620                         return PTR_ERR(trans);
4621
4622                 /* No running transaction, don't bother */
4623                 transid = root->fs_info->last_trans_committed;
4624                 goto out;
4625         }
4626         transid = trans->transid;
4627         ret = btrfs_commit_transaction_async(trans, 0);
4628         if (ret) {
4629                 btrfs_end_transaction(trans);
4630                 return ret;
4631         }
4632 out:
4633         if (argp)
4634                 if (copy_to_user(argp, &transid, sizeof(transid)))
4635                         return -EFAULT;
4636         return 0;
4637 }
4638
4639 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4640                                            void __user *argp)
4641 {
4642         u64 transid;
4643
4644         if (argp) {
4645                 if (copy_from_user(&transid, argp, sizeof(transid)))
4646                         return -EFAULT;
4647         } else {
4648                 transid = 0;  /* current trans */
4649         }
4650         return btrfs_wait_for_commit(fs_info, transid);
4651 }
4652
4653 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4654 {
4655         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4656         struct btrfs_ioctl_scrub_args *sa;
4657         int ret;
4658
4659         if (!capable(CAP_SYS_ADMIN))
4660                 return -EPERM;
4661
4662         sa = memdup_user(arg, sizeof(*sa));
4663         if (IS_ERR(sa))
4664                 return PTR_ERR(sa);
4665
4666         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4667                 ret = mnt_want_write_file(file);
4668                 if (ret)
4669                         goto out;
4670         }
4671
4672         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4673                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4674                               0);
4675
4676         if (copy_to_user(arg, sa, sizeof(*sa)))
4677                 ret = -EFAULT;
4678
4679         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4680                 mnt_drop_write_file(file);
4681 out:
4682         kfree(sa);
4683         return ret;
4684 }
4685
4686 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4687 {
4688         if (!capable(CAP_SYS_ADMIN))
4689                 return -EPERM;
4690
4691         return btrfs_scrub_cancel(fs_info);
4692 }
4693
4694 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4695                                        void __user *arg)
4696 {
4697         struct btrfs_ioctl_scrub_args *sa;
4698         int ret;
4699
4700         if (!capable(CAP_SYS_ADMIN))
4701                 return -EPERM;
4702
4703         sa = memdup_user(arg, sizeof(*sa));
4704         if (IS_ERR(sa))
4705                 return PTR_ERR(sa);
4706
4707         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4708
4709         if (copy_to_user(arg, sa, sizeof(*sa)))
4710                 ret = -EFAULT;
4711
4712         kfree(sa);
4713         return ret;
4714 }
4715
4716 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4717                                       void __user *arg)
4718 {
4719         struct btrfs_ioctl_get_dev_stats *sa;
4720         int ret;
4721
4722         sa = memdup_user(arg, sizeof(*sa));
4723         if (IS_ERR(sa))
4724                 return PTR_ERR(sa);
4725
4726         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4727                 kfree(sa);
4728                 return -EPERM;
4729         }
4730
4731         ret = btrfs_get_dev_stats(fs_info, sa);
4732
4733         if (copy_to_user(arg, sa, sizeof(*sa)))
4734                 ret = -EFAULT;
4735
4736         kfree(sa);
4737         return ret;
4738 }
4739
4740 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4741                                     void __user *arg)
4742 {
4743         struct btrfs_ioctl_dev_replace_args *p;
4744         int ret;
4745
4746         if (!capable(CAP_SYS_ADMIN))
4747                 return -EPERM;
4748
4749         p = memdup_user(arg, sizeof(*p));
4750         if (IS_ERR(p))
4751                 return PTR_ERR(p);
4752
4753         switch (p->cmd) {
4754         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4755                 if (sb_rdonly(fs_info->sb)) {
4756                         ret = -EROFS;
4757                         goto out;
4758                 }
4759                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4760                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4761                 } else {
4762                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4763                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4764                 }
4765                 break;
4766         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4767                 btrfs_dev_replace_status(fs_info, p);
4768                 ret = 0;
4769                 break;
4770         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4771                 p->result = btrfs_dev_replace_cancel(fs_info);
4772                 ret = 0;
4773                 break;
4774         default:
4775                 ret = -EINVAL;
4776                 break;
4777         }
4778
4779         if (copy_to_user(arg, p, sizeof(*p)))
4780                 ret = -EFAULT;
4781 out:
4782         kfree(p);
4783         return ret;
4784 }
4785
4786 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4787 {
4788         int ret = 0;
4789         int i;
4790         u64 rel_ptr;
4791         int size;
4792         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4793         struct inode_fs_paths *ipath = NULL;
4794         struct btrfs_path *path;
4795
4796         if (!capable(CAP_DAC_READ_SEARCH))
4797                 return -EPERM;
4798
4799         path = btrfs_alloc_path();
4800         if (!path) {
4801                 ret = -ENOMEM;
4802                 goto out;
4803         }
4804
4805         ipa = memdup_user(arg, sizeof(*ipa));
4806         if (IS_ERR(ipa)) {
4807                 ret = PTR_ERR(ipa);
4808                 ipa = NULL;
4809                 goto out;
4810         }
4811
4812         size = min_t(u32, ipa->size, 4096);
4813         ipath = init_ipath(size, root, path);
4814         if (IS_ERR(ipath)) {
4815                 ret = PTR_ERR(ipath);
4816                 ipath = NULL;
4817                 goto out;
4818         }
4819
4820         ret = paths_from_inode(ipa->inum, ipath);
4821         if (ret < 0)
4822                 goto out;
4823
4824         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4825                 rel_ptr = ipath->fspath->val[i] -
4826                           (u64)(unsigned long)ipath->fspath->val;
4827                 ipath->fspath->val[i] = rel_ptr;
4828         }
4829
4830         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4831                            ipath->fspath, size);
4832         if (ret) {
4833                 ret = -EFAULT;
4834                 goto out;
4835         }
4836
4837 out:
4838         btrfs_free_path(path);
4839         free_ipath(ipath);
4840         kfree(ipa);
4841
4842         return ret;
4843 }
4844
4845 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4846 {
4847         struct btrfs_data_container *inodes = ctx;
4848         const size_t c = 3 * sizeof(u64);
4849
4850         if (inodes->bytes_left >= c) {
4851                 inodes->bytes_left -= c;
4852                 inodes->val[inodes->elem_cnt] = inum;
4853                 inodes->val[inodes->elem_cnt + 1] = offset;
4854                 inodes->val[inodes->elem_cnt + 2] = root;
4855                 inodes->elem_cnt += 3;
4856         } else {
4857                 inodes->bytes_missing += c - inodes->bytes_left;
4858                 inodes->bytes_left = 0;
4859                 inodes->elem_missed += 3;
4860         }
4861
4862         return 0;
4863 }
4864
4865 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4866                                         void __user *arg, int version)
4867 {
4868         int ret = 0;
4869         int size;
4870         struct btrfs_ioctl_logical_ino_args *loi;
4871         struct btrfs_data_container *inodes = NULL;
4872         struct btrfs_path *path = NULL;
4873         bool ignore_offset;
4874
4875         if (!capable(CAP_SYS_ADMIN))
4876                 return -EPERM;
4877
4878         loi = memdup_user(arg, sizeof(*loi));
4879         if (IS_ERR(loi))
4880                 return PTR_ERR(loi);
4881
4882         if (version == 1) {
4883                 ignore_offset = false;
4884                 size = min_t(u32, loi->size, SZ_64K);
4885         } else {
4886                 /* All reserved bits must be 0 for now */
4887                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4888                         ret = -EINVAL;
4889                         goto out_loi;
4890                 }
4891                 /* Only accept flags we have defined so far */
4892                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4893                         ret = -EINVAL;
4894                         goto out_loi;
4895                 }
4896                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4897                 size = min_t(u32, loi->size, SZ_16M);
4898         }
4899
4900         path = btrfs_alloc_path();
4901         if (!path) {
4902                 ret = -ENOMEM;
4903                 goto out;
4904         }
4905
4906         inodes = init_data_container(size);
4907         if (IS_ERR(inodes)) {
4908                 ret = PTR_ERR(inodes);
4909                 inodes = NULL;
4910                 goto out;
4911         }
4912
4913         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4914                                           build_ino_list, inodes, ignore_offset);
4915         if (ret == -EINVAL)
4916                 ret = -ENOENT;
4917         if (ret < 0)
4918                 goto out;
4919
4920         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4921                            size);
4922         if (ret)
4923                 ret = -EFAULT;
4924
4925 out:
4926         btrfs_free_path(path);
4927         kvfree(inodes);
4928 out_loi:
4929         kfree(loi);
4930
4931         return ret;
4932 }
4933
4934 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4935                                struct btrfs_ioctl_balance_args *bargs)
4936 {
4937         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4938
4939         bargs->flags = bctl->flags;
4940
4941         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4942                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4943         if (atomic_read(&fs_info->balance_pause_req))
4944                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4945         if (atomic_read(&fs_info->balance_cancel_req))
4946                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4947
4948         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4949         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4950         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4951
4952         spin_lock(&fs_info->balance_lock);
4953         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4954         spin_unlock(&fs_info->balance_lock);
4955 }
4956
4957 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4958 {
4959         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4960         struct btrfs_fs_info *fs_info = root->fs_info;
4961         struct btrfs_ioctl_balance_args *bargs;
4962         struct btrfs_balance_control *bctl;
4963         bool need_unlock; /* for mut. excl. ops lock */
4964         int ret;
4965
4966         if (!capable(CAP_SYS_ADMIN))
4967                 return -EPERM;
4968
4969         ret = mnt_want_write_file(file);
4970         if (ret)
4971                 return ret;
4972
4973 again:
4974         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4975                 mutex_lock(&fs_info->balance_mutex);
4976                 need_unlock = true;
4977                 goto locked;
4978         }
4979
4980         /*
4981          * mut. excl. ops lock is locked.  Three possibilities:
4982          *   (1) some other op is running
4983          *   (2) balance is running
4984          *   (3) balance is paused -- special case (think resume)
4985          */
4986         mutex_lock(&fs_info->balance_mutex);
4987         if (fs_info->balance_ctl) {
4988                 /* this is either (2) or (3) */
4989                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4990                         mutex_unlock(&fs_info->balance_mutex);
4991                         /*
4992                          * Lock released to allow other waiters to continue,
4993                          * we'll reexamine the status again.
4994                          */
4995                         mutex_lock(&fs_info->balance_mutex);
4996
4997                         if (fs_info->balance_ctl &&
4998                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4999                                 /* this is (3) */
5000                                 need_unlock = false;
5001                                 goto locked;
5002                         }
5003
5004                         mutex_unlock(&fs_info->balance_mutex);
5005                         goto again;
5006                 } else {
5007                         /* this is (2) */
5008                         mutex_unlock(&fs_info->balance_mutex);
5009                         ret = -EINPROGRESS;
5010                         goto out;
5011                 }
5012         } else {
5013                 /* this is (1) */
5014                 mutex_unlock(&fs_info->balance_mutex);
5015                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
5016                 goto out;
5017         }
5018
5019 locked:
5020         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
5021
5022         if (arg) {
5023                 bargs = memdup_user(arg, sizeof(*bargs));
5024                 if (IS_ERR(bargs)) {
5025                         ret = PTR_ERR(bargs);
5026                         goto out_unlock;
5027                 }
5028
5029                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
5030                         if (!fs_info->balance_ctl) {
5031                                 ret = -ENOTCONN;
5032                                 goto out_bargs;
5033                         }
5034
5035                         bctl = fs_info->balance_ctl;
5036                         spin_lock(&fs_info->balance_lock);
5037                         bctl->flags |= BTRFS_BALANCE_RESUME;
5038                         spin_unlock(&fs_info->balance_lock);
5039
5040                         goto do_balance;
5041                 }
5042         } else {
5043                 bargs = NULL;
5044         }
5045
5046         if (fs_info->balance_ctl) {
5047                 ret = -EINPROGRESS;
5048                 goto out_bargs;
5049         }
5050
5051         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
5052         if (!bctl) {
5053                 ret = -ENOMEM;
5054                 goto out_bargs;
5055         }
5056
5057         if (arg) {
5058                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
5059                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
5060                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
5061
5062                 bctl->flags = bargs->flags;
5063         } else {
5064                 /* balance everything - no filters */
5065                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
5066         }
5067
5068         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
5069                 ret = -EINVAL;
5070                 goto out_bctl;
5071         }
5072
5073 do_balance:
5074         /*
5075          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
5076          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
5077          * restriper was paused all the way until unmount, in free_fs_info.
5078          * The flag should be cleared after reset_balance_state.
5079          */
5080         need_unlock = false;
5081
5082         ret = btrfs_balance(fs_info, bctl, bargs);
5083         bctl = NULL;
5084
5085         if (arg) {
5086                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
5087                         ret = -EFAULT;
5088         }
5089
5090 out_bctl:
5091         kfree(bctl);
5092 out_bargs:
5093         kfree(bargs);
5094 out_unlock:
5095         mutex_unlock(&fs_info->balance_mutex);
5096         if (need_unlock)
5097                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
5098 out:
5099         mnt_drop_write_file(file);
5100         return ret;
5101 }
5102
5103 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
5104 {
5105         if (!capable(CAP_SYS_ADMIN))
5106                 return -EPERM;
5107
5108         switch (cmd) {
5109         case BTRFS_BALANCE_CTL_PAUSE:
5110                 return btrfs_pause_balance(fs_info);
5111         case BTRFS_BALANCE_CTL_CANCEL:
5112                 return btrfs_cancel_balance(fs_info);
5113         }
5114
5115         return -EINVAL;
5116 }
5117
5118 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
5119                                          void __user *arg)
5120 {
5121         struct btrfs_ioctl_balance_args *bargs;
5122         int ret = 0;
5123
5124         if (!capable(CAP_SYS_ADMIN))
5125                 return -EPERM;
5126
5127         mutex_lock(&fs_info->balance_mutex);
5128         if (!fs_info->balance_ctl) {
5129                 ret = -ENOTCONN;
5130                 goto out;
5131         }
5132
5133         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
5134         if (!bargs) {
5135                 ret = -ENOMEM;
5136                 goto out;
5137         }
5138
5139         btrfs_update_ioctl_balance_args(fs_info, bargs);
5140
5141         if (copy_to_user(arg, bargs, sizeof(*bargs)))
5142                 ret = -EFAULT;
5143
5144         kfree(bargs);
5145 out:
5146         mutex_unlock(&fs_info->balance_mutex);
5147         return ret;
5148 }
5149
5150 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
5151 {
5152         struct inode *inode = file_inode(file);
5153         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5154         struct btrfs_ioctl_quota_ctl_args *sa;
5155         int ret;
5156
5157         if (!capable(CAP_SYS_ADMIN))
5158                 return -EPERM;
5159
5160         ret = mnt_want_write_file(file);
5161         if (ret)
5162                 return ret;
5163
5164         sa = memdup_user(arg, sizeof(*sa));
5165         if (IS_ERR(sa)) {
5166                 ret = PTR_ERR(sa);
5167                 goto drop_write;
5168         }
5169
5170         down_write(&fs_info->subvol_sem);
5171
5172         switch (sa->cmd) {
5173         case BTRFS_QUOTA_CTL_ENABLE:
5174                 ret = btrfs_quota_enable(fs_info);
5175                 break;
5176         case BTRFS_QUOTA_CTL_DISABLE:
5177                 ret = btrfs_quota_disable(fs_info);
5178                 break;
5179         default:
5180                 ret = -EINVAL;
5181                 break;
5182         }
5183
5184         kfree(sa);
5185         up_write(&fs_info->subvol_sem);
5186 drop_write:
5187         mnt_drop_write_file(file);
5188         return ret;
5189 }
5190
5191 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
5192 {
5193         struct inode *inode = file_inode(file);
5194         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5195         struct btrfs_root *root = BTRFS_I(inode)->root;
5196         struct btrfs_ioctl_qgroup_assign_args *sa;
5197         struct btrfs_trans_handle *trans;
5198         int ret;
5199         int err;
5200
5201         if (!capable(CAP_SYS_ADMIN))
5202                 return -EPERM;
5203
5204         ret = mnt_want_write_file(file);
5205         if (ret)
5206                 return ret;
5207
5208         sa = memdup_user(arg, sizeof(*sa));
5209         if (IS_ERR(sa)) {
5210                 ret = PTR_ERR(sa);
5211                 goto drop_write;
5212         }
5213
5214         trans = btrfs_join_transaction(root);
5215         if (IS_ERR(trans)) {
5216                 ret = PTR_ERR(trans);
5217                 goto out;
5218         }
5219
5220         if (sa->assign) {
5221                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
5222         } else {
5223                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
5224         }
5225
5226         /* update qgroup status and info */
5227         err = btrfs_run_qgroups(trans);
5228         if (err < 0)
5229                 btrfs_handle_fs_error(fs_info, err,
5230                                       "failed to update qgroup status and info");
5231         err = btrfs_end_transaction(trans);
5232         if (err && !ret)
5233                 ret = err;
5234
5235 out:
5236         kfree(sa);
5237 drop_write:
5238         mnt_drop_write_file(file);
5239         return ret;
5240 }
5241
5242 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
5243 {
5244         struct inode *inode = file_inode(file);
5245         struct btrfs_root *root = BTRFS_I(inode)->root;
5246         struct btrfs_ioctl_qgroup_create_args *sa;
5247         struct btrfs_trans_handle *trans;
5248         int ret;
5249         int err;
5250
5251         if (!capable(CAP_SYS_ADMIN))
5252                 return -EPERM;
5253
5254         ret = mnt_want_write_file(file);
5255         if (ret)
5256                 return ret;
5257
5258         sa = memdup_user(arg, sizeof(*sa));
5259         if (IS_ERR(sa)) {
5260                 ret = PTR_ERR(sa);
5261                 goto drop_write;
5262         }
5263
5264         if (!sa->qgroupid) {
5265                 ret = -EINVAL;
5266                 goto out;
5267         }
5268
5269         trans = btrfs_join_transaction(root);
5270         if (IS_ERR(trans)) {
5271                 ret = PTR_ERR(trans);
5272                 goto out;
5273         }
5274
5275         if (sa->create) {
5276                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
5277         } else {
5278                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
5279         }
5280
5281         err = btrfs_end_transaction(trans);
5282         if (err && !ret)
5283                 ret = err;
5284
5285 out:
5286         kfree(sa);
5287 drop_write:
5288         mnt_drop_write_file(file);
5289         return ret;
5290 }
5291
5292 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
5293 {
5294         struct inode *inode = file_inode(file);
5295         struct btrfs_root *root = BTRFS_I(inode)->root;
5296         struct btrfs_ioctl_qgroup_limit_args *sa;
5297         struct btrfs_trans_handle *trans;
5298         int ret;
5299         int err;
5300         u64 qgroupid;
5301
5302         if (!capable(CAP_SYS_ADMIN))
5303                 return -EPERM;
5304
5305         ret = mnt_want_write_file(file);
5306         if (ret)
5307                 return ret;
5308
5309         sa = memdup_user(arg, sizeof(*sa));
5310         if (IS_ERR(sa)) {
5311                 ret = PTR_ERR(sa);
5312                 goto drop_write;
5313         }
5314
5315         trans = btrfs_join_transaction(root);
5316         if (IS_ERR(trans)) {
5317                 ret = PTR_ERR(trans);
5318                 goto out;
5319         }
5320
5321         qgroupid = sa->qgroupid;
5322         if (!qgroupid) {
5323                 /* take the current subvol as qgroup */
5324                 qgroupid = root->root_key.objectid;
5325         }
5326
5327         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
5328
5329         err = btrfs_end_transaction(trans);
5330         if (err && !ret)
5331                 ret = err;
5332
5333 out:
5334         kfree(sa);
5335 drop_write:
5336         mnt_drop_write_file(file);
5337         return ret;
5338 }
5339
5340 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5341 {
5342         struct inode *inode = file_inode(file);
5343         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5344         struct btrfs_ioctl_quota_rescan_args *qsa;
5345         int ret;
5346
5347         if (!capable(CAP_SYS_ADMIN))
5348                 return -EPERM;
5349
5350         ret = mnt_want_write_file(file);
5351         if (ret)
5352                 return ret;
5353
5354         qsa = memdup_user(arg, sizeof(*qsa));
5355         if (IS_ERR(qsa)) {
5356                 ret = PTR_ERR(qsa);
5357                 goto drop_write;
5358         }
5359
5360         if (qsa->flags) {
5361                 ret = -EINVAL;
5362                 goto out;
5363         }
5364
5365         ret = btrfs_qgroup_rescan(fs_info);
5366
5367 out:
5368         kfree(qsa);
5369 drop_write:
5370         mnt_drop_write_file(file);
5371         return ret;
5372 }
5373
5374 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5375 {
5376         struct inode *inode = file_inode(file);
5377         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5378         struct btrfs_ioctl_quota_rescan_args *qsa;
5379         int ret = 0;
5380
5381         if (!capable(CAP_SYS_ADMIN))
5382                 return -EPERM;
5383
5384         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5385         if (!qsa)
5386                 return -ENOMEM;
5387
5388         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5389                 qsa->flags = 1;
5390                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5391         }
5392
5393         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5394                 ret = -EFAULT;
5395
5396         kfree(qsa);
5397         return ret;
5398 }
5399
5400 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5401 {
5402         struct inode *inode = file_inode(file);
5403         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5404
5405         if (!capable(CAP_SYS_ADMIN))
5406                 return -EPERM;
5407
5408         return btrfs_qgroup_wait_for_completion(fs_info, true);
5409 }
5410
5411 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5412                                             struct btrfs_ioctl_received_subvol_args *sa)
5413 {
5414         struct inode *inode = file_inode(file);
5415         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5416         struct btrfs_root *root = BTRFS_I(inode)->root;
5417         struct btrfs_root_item *root_item = &root->root_item;
5418         struct btrfs_trans_handle *trans;
5419         struct timespec64 ct = current_time(inode);
5420         int ret = 0;
5421         int received_uuid_changed;
5422
5423         if (!inode_owner_or_capable(inode))
5424                 return -EPERM;
5425
5426         ret = mnt_want_write_file(file);
5427         if (ret < 0)
5428                 return ret;
5429
5430         down_write(&fs_info->subvol_sem);
5431
5432         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5433                 ret = -EINVAL;
5434                 goto out;
5435         }
5436
5437         if (btrfs_root_readonly(root)) {
5438                 ret = -EROFS;
5439                 goto out;
5440         }
5441
5442         /*
5443          * 1 - root item
5444          * 2 - uuid items (received uuid + subvol uuid)
5445          */
5446         trans = btrfs_start_transaction(root, 3);
5447         if (IS_ERR(trans)) {
5448                 ret = PTR_ERR(trans);
5449                 trans = NULL;
5450                 goto out;
5451         }
5452
5453         sa->rtransid = trans->transid;
5454         sa->rtime.sec = ct.tv_sec;
5455         sa->rtime.nsec = ct.tv_nsec;
5456
5457         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5458                                        BTRFS_UUID_SIZE);
5459         if (received_uuid_changed &&
5460             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5461                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5462                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5463                                           root->root_key.objectid);
5464                 if (ret && ret != -ENOENT) {
5465                         btrfs_abort_transaction(trans, ret);
5466                         btrfs_end_transaction(trans);
5467                         goto out;
5468                 }
5469         }
5470         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5471         btrfs_set_root_stransid(root_item, sa->stransid);
5472         btrfs_set_root_rtransid(root_item, sa->rtransid);
5473         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5474         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5475         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5476         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5477
5478         ret = btrfs_update_root(trans, fs_info->tree_root,
5479                                 &root->root_key, &root->root_item);
5480         if (ret < 0) {
5481                 btrfs_end_transaction(trans);
5482                 goto out;
5483         }
5484         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5485                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5486                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5487                                           root->root_key.objectid);
5488                 if (ret < 0 && ret != -EEXIST) {
5489                         btrfs_abort_transaction(trans, ret);
5490                         btrfs_end_transaction(trans);
5491                         goto out;
5492                 }
5493         }
5494         ret = btrfs_commit_transaction(trans);
5495 out:
5496         up_write(&fs_info->subvol_sem);
5497         mnt_drop_write_file(file);
5498         return ret;
5499 }
5500
5501 #ifdef CONFIG_64BIT
5502 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5503                                                 void __user *arg)
5504 {
5505         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5506         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5507         int ret = 0;
5508
5509         args32 = memdup_user(arg, sizeof(*args32));
5510         if (IS_ERR(args32))
5511                 return PTR_ERR(args32);
5512
5513         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5514         if (!args64) {
5515                 ret = -ENOMEM;
5516                 goto out;
5517         }
5518
5519         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5520         args64->stransid = args32->stransid;
5521         args64->rtransid = args32->rtransid;
5522         args64->stime.sec = args32->stime.sec;
5523         args64->stime.nsec = args32->stime.nsec;
5524         args64->rtime.sec = args32->rtime.sec;
5525         args64->rtime.nsec = args32->rtime.nsec;
5526         args64->flags = args32->flags;
5527
5528         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5529         if (ret)
5530                 goto out;
5531
5532         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5533         args32->stransid = args64->stransid;
5534         args32->rtransid = args64->rtransid;
5535         args32->stime.sec = args64->stime.sec;
5536         args32->stime.nsec = args64->stime.nsec;
5537         args32->rtime.sec = args64->rtime.sec;
5538         args32->rtime.nsec = args64->rtime.nsec;
5539         args32->flags = args64->flags;
5540
5541         ret = copy_to_user(arg, args32, sizeof(*args32));
5542         if (ret)
5543                 ret = -EFAULT;
5544
5545 out:
5546         kfree(args32);
5547         kfree(args64);
5548         return ret;
5549 }
5550 #endif
5551
5552 static long btrfs_ioctl_set_received_subvol(struct file *file,
5553                                             void __user *arg)
5554 {
5555         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5556         int ret = 0;
5557
5558         sa = memdup_user(arg, sizeof(*sa));
5559         if (IS_ERR(sa))
5560                 return PTR_ERR(sa);
5561
5562         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5563
5564         if (ret)
5565                 goto out;
5566
5567         ret = copy_to_user(arg, sa, sizeof(*sa));
5568         if (ret)
5569                 ret = -EFAULT;
5570
5571 out:
5572         kfree(sa);
5573         return ret;
5574 }
5575
5576 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5577 {
5578         struct inode *inode = file_inode(file);
5579         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5580         size_t len;
5581         int ret;
5582         char label[BTRFS_LABEL_SIZE];
5583
5584         spin_lock(&fs_info->super_lock);
5585         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5586         spin_unlock(&fs_info->super_lock);
5587
5588         len = strnlen(label, BTRFS_LABEL_SIZE);
5589
5590         if (len == BTRFS_LABEL_SIZE) {
5591                 btrfs_warn(fs_info,
5592                            "label is too long, return the first %zu bytes",
5593                            --len);
5594         }
5595
5596         ret = copy_to_user(arg, label, len);
5597
5598         return ret ? -EFAULT : 0;
5599 }
5600
5601 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5602 {
5603         struct inode *inode = file_inode(file);
5604         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5605         struct btrfs_root *root = BTRFS_I(inode)->root;
5606         struct btrfs_super_block *super_block = fs_info->super_copy;
5607         struct btrfs_trans_handle *trans;
5608         char label[BTRFS_LABEL_SIZE];
5609         int ret;
5610
5611         if (!capable(CAP_SYS_ADMIN))
5612                 return -EPERM;
5613
5614         if (copy_from_user(label, arg, sizeof(label)))
5615                 return -EFAULT;
5616
5617         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5618                 btrfs_err(fs_info,
5619                           "unable to set label with more than %d bytes",
5620                           BTRFS_LABEL_SIZE - 1);
5621                 return -EINVAL;
5622         }
5623
5624         ret = mnt_want_write_file(file);
5625         if (ret)
5626                 return ret;
5627
5628         trans = btrfs_start_transaction(root, 0);
5629         if (IS_ERR(trans)) {
5630                 ret = PTR_ERR(trans);
5631                 goto out_unlock;
5632         }
5633
5634         spin_lock(&fs_info->super_lock);
5635         strcpy(super_block->label, label);
5636         spin_unlock(&fs_info->super_lock);
5637         ret = btrfs_commit_transaction(trans);
5638
5639 out_unlock:
5640         mnt_drop_write_file(file);
5641         return ret;
5642 }
5643
5644 #define INIT_FEATURE_FLAGS(suffix) \
5645         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5646           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5647           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5648
5649 int btrfs_ioctl_get_supported_features(void __user *arg)
5650 {
5651         static const struct btrfs_ioctl_feature_flags features[3] = {
5652                 INIT_FEATURE_FLAGS(SUPP),
5653                 INIT_FEATURE_FLAGS(SAFE_SET),
5654                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5655         };
5656
5657         if (copy_to_user(arg, &features, sizeof(features)))
5658                 return -EFAULT;
5659
5660         return 0;
5661 }
5662
5663 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5664 {
5665         struct inode *inode = file_inode(file);
5666         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5667         struct btrfs_super_block *super_block = fs_info->super_copy;
5668         struct btrfs_ioctl_feature_flags features;
5669
5670         features.compat_flags = btrfs_super_compat_flags(super_block);
5671         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5672         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5673
5674         if (copy_to_user(arg, &features, sizeof(features)))
5675                 return -EFAULT;
5676
5677         return 0;
5678 }
5679
5680 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5681                               enum btrfs_feature_set set,
5682                               u64 change_mask, u64 flags, u64 supported_flags,
5683                               u64 safe_set, u64 safe_clear)
5684 {
5685         const char *type = btrfs_feature_set_names[set];
5686         char *names;
5687         u64 disallowed, unsupported;
5688         u64 set_mask = flags & change_mask;
5689         u64 clear_mask = ~flags & change_mask;
5690
5691         unsupported = set_mask & ~supported_flags;
5692         if (unsupported) {
5693                 names = btrfs_printable_features(set, unsupported);
5694                 if (names) {
5695                         btrfs_warn(fs_info,
5696                                    "this kernel does not support the %s feature bit%s",
5697                                    names, strchr(names, ',') ? "s" : "");
5698                         kfree(names);
5699                 } else
5700                         btrfs_warn(fs_info,
5701                                    "this kernel does not support %s bits 0x%llx",
5702                                    type, unsupported);
5703                 return -EOPNOTSUPP;
5704         }
5705
5706         disallowed = set_mask & ~safe_set;
5707         if (disallowed) {
5708                 names = btrfs_printable_features(set, disallowed);
5709                 if (names) {
5710                         btrfs_warn(fs_info,
5711                                    "can't set the %s feature bit%s while mounted",
5712                                    names, strchr(names, ',') ? "s" : "");
5713                         kfree(names);
5714                 } else
5715                         btrfs_warn(fs_info,
5716                                    "can't set %s bits 0x%llx while mounted",
5717                                    type, disallowed);
5718                 return -EPERM;
5719         }
5720
5721         disallowed = clear_mask & ~safe_clear;
5722         if (disallowed) {
5723                 names = btrfs_printable_features(set, disallowed);
5724                 if (names) {
5725                         btrfs_warn(fs_info,
5726                                    "can't clear the %s feature bit%s while mounted",
5727                                    names, strchr(names, ',') ? "s" : "");
5728                         kfree(names);
5729                 } else
5730                         btrfs_warn(fs_info,
5731                                    "can't clear %s bits 0x%llx while mounted",
5732                                    type, disallowed);
5733                 return -EPERM;
5734         }
5735
5736         return 0;
5737 }
5738
5739 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5740 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5741                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5742                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5743                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5744
5745 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5746 {
5747         struct inode *inode = file_inode(file);
5748         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5749         struct btrfs_root *root = BTRFS_I(inode)->root;
5750         struct btrfs_super_block *super_block = fs_info->super_copy;
5751         struct btrfs_ioctl_feature_flags flags[2];
5752         struct btrfs_trans_handle *trans;
5753         u64 newflags;
5754         int ret;
5755
5756         if (!capable(CAP_SYS_ADMIN))
5757                 return -EPERM;
5758
5759         if (copy_from_user(flags, arg, sizeof(flags)))
5760                 return -EFAULT;
5761
5762         /* Nothing to do */
5763         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5764             !flags[0].incompat_flags)
5765                 return 0;
5766
5767         ret = check_feature(fs_info, flags[0].compat_flags,
5768                             flags[1].compat_flags, COMPAT);
5769         if (ret)
5770                 return ret;
5771
5772         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5773                             flags[1].compat_ro_flags, COMPAT_RO);
5774         if (ret)
5775                 return ret;
5776
5777         ret = check_feature(fs_info, flags[0].incompat_flags,
5778                             flags[1].incompat_flags, INCOMPAT);
5779         if (ret)
5780                 return ret;
5781
5782         ret = mnt_want_write_file(file);
5783         if (ret)
5784                 return ret;
5785
5786         trans = btrfs_start_transaction(root, 0);
5787         if (IS_ERR(trans)) {
5788                 ret = PTR_ERR(trans);
5789                 goto out_drop_write;
5790         }
5791
5792         spin_lock(&fs_info->super_lock);
5793         newflags = btrfs_super_compat_flags(super_block);
5794         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5795         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5796         btrfs_set_super_compat_flags(super_block, newflags);
5797
5798         newflags = btrfs_super_compat_ro_flags(super_block);
5799         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5800         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5801         btrfs_set_super_compat_ro_flags(super_block, newflags);
5802
5803         newflags = btrfs_super_incompat_flags(super_block);
5804         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5805         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5806         btrfs_set_super_incompat_flags(super_block, newflags);
5807         spin_unlock(&fs_info->super_lock);
5808
5809         ret = btrfs_commit_transaction(trans);
5810 out_drop_write:
5811         mnt_drop_write_file(file);
5812
5813         return ret;
5814 }
5815
5816 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5817 {
5818         struct btrfs_ioctl_send_args *arg;
5819         int ret;
5820
5821         if (compat) {
5822 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5823                 struct btrfs_ioctl_send_args_32 args32;
5824
5825                 ret = copy_from_user(&args32, argp, sizeof(args32));
5826                 if (ret)
5827                         return -EFAULT;
5828                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5829                 if (!arg)
5830                         return -ENOMEM;
5831                 arg->send_fd = args32.send_fd;
5832                 arg->clone_sources_count = args32.clone_sources_count;
5833                 arg->clone_sources = compat_ptr(args32.clone_sources);
5834                 arg->parent_root = args32.parent_root;
5835                 arg->flags = args32.flags;
5836                 memcpy(arg->reserved, args32.reserved,
5837                        sizeof(args32.reserved));
5838 #else
5839                 return -ENOTTY;
5840 #endif
5841         } else {
5842                 arg = memdup_user(argp, sizeof(*arg));
5843                 if (IS_ERR(arg))
5844                         return PTR_ERR(arg);
5845         }
5846         ret = btrfs_ioctl_send(file, arg);
5847         kfree(arg);
5848         return ret;
5849 }
5850
5851 long btrfs_ioctl(struct file *file, unsigned int
5852                 cmd, unsigned long arg)
5853 {
5854         struct inode *inode = file_inode(file);
5855         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5856         struct btrfs_root *root = BTRFS_I(inode)->root;
5857         void __user *argp = (void __user *)arg;
5858
5859         switch (cmd) {
5860         case FS_IOC_GETFLAGS:
5861                 return btrfs_ioctl_getflags(file, argp);
5862         case FS_IOC_SETFLAGS:
5863                 return btrfs_ioctl_setflags(file, argp);
5864         case FS_IOC_GETVERSION:
5865                 return btrfs_ioctl_getversion(file, argp);
5866         case FITRIM:
5867                 return btrfs_ioctl_fitrim(file, argp);
5868         case BTRFS_IOC_SNAP_CREATE:
5869                 return btrfs_ioctl_snap_create(file, argp, 0);
5870         case BTRFS_IOC_SNAP_CREATE_V2:
5871                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5872         case BTRFS_IOC_SUBVOL_CREATE:
5873                 return btrfs_ioctl_snap_create(file, argp, 1);
5874         case BTRFS_IOC_SUBVOL_CREATE_V2:
5875                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5876         case BTRFS_IOC_SNAP_DESTROY:
5877                 return btrfs_ioctl_snap_destroy(file, argp);
5878         case BTRFS_IOC_SUBVOL_GETFLAGS:
5879                 return btrfs_ioctl_subvol_getflags(file, argp);
5880         case BTRFS_IOC_SUBVOL_SETFLAGS:
5881                 return btrfs_ioctl_subvol_setflags(file, argp);
5882         case BTRFS_IOC_DEFAULT_SUBVOL:
5883                 return btrfs_ioctl_default_subvol(file, argp);
5884         case BTRFS_IOC_DEFRAG:
5885                 return btrfs_ioctl_defrag(file, NULL);
5886         case BTRFS_IOC_DEFRAG_RANGE:
5887                 return btrfs_ioctl_defrag(file, argp);
5888         case BTRFS_IOC_RESIZE:
5889                 return btrfs_ioctl_resize(file, argp);
5890         case BTRFS_IOC_ADD_DEV:
5891                 return btrfs_ioctl_add_dev(fs_info, argp);
5892         case BTRFS_IOC_RM_DEV:
5893                 return btrfs_ioctl_rm_dev(file, argp);
5894         case BTRFS_IOC_RM_DEV_V2:
5895                 return btrfs_ioctl_rm_dev_v2(file, argp);
5896         case BTRFS_IOC_FS_INFO:
5897                 return btrfs_ioctl_fs_info(fs_info, argp);
5898         case BTRFS_IOC_DEV_INFO:
5899                 return btrfs_ioctl_dev_info(fs_info, argp);
5900         case BTRFS_IOC_BALANCE:
5901                 return btrfs_ioctl_balance(file, NULL);
5902         case BTRFS_IOC_TREE_SEARCH:
5903                 return btrfs_ioctl_tree_search(file, argp);
5904         case BTRFS_IOC_TREE_SEARCH_V2:
5905                 return btrfs_ioctl_tree_search_v2(file, argp);
5906         case BTRFS_IOC_INO_LOOKUP:
5907                 return btrfs_ioctl_ino_lookup(file, argp);
5908         case BTRFS_IOC_INO_PATHS:
5909                 return btrfs_ioctl_ino_to_path(root, argp);
5910         case BTRFS_IOC_LOGICAL_INO:
5911                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5912         case BTRFS_IOC_LOGICAL_INO_V2:
5913                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5914         case BTRFS_IOC_SPACE_INFO:
5915                 return btrfs_ioctl_space_info(fs_info, argp);
5916         case BTRFS_IOC_SYNC: {
5917                 int ret;
5918
5919                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5920                 if (ret)
5921                         return ret;
5922                 ret = btrfs_sync_fs(inode->i_sb, 1);
5923                 /*
5924                  * The transaction thread may want to do more work,
5925                  * namely it pokes the cleaner kthread that will start
5926                  * processing uncleaned subvols.
5927                  */
5928                 wake_up_process(fs_info->transaction_kthread);
5929                 return ret;
5930         }
5931         case BTRFS_IOC_START_SYNC:
5932                 return btrfs_ioctl_start_sync(root, argp);
5933         case BTRFS_IOC_WAIT_SYNC:
5934                 return btrfs_ioctl_wait_sync(fs_info, argp);
5935         case BTRFS_IOC_SCRUB:
5936                 return btrfs_ioctl_scrub(file, argp);
5937         case BTRFS_IOC_SCRUB_CANCEL:
5938                 return btrfs_ioctl_scrub_cancel(fs_info);
5939         case BTRFS_IOC_SCRUB_PROGRESS:
5940                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5941         case BTRFS_IOC_BALANCE_V2:
5942                 return btrfs_ioctl_balance(file, argp);
5943         case BTRFS_IOC_BALANCE_CTL:
5944                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5945         case BTRFS_IOC_BALANCE_PROGRESS:
5946                 return btrfs_ioctl_balance_progress(fs_info, argp);
5947         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5948                 return btrfs_ioctl_set_received_subvol(file, argp);
5949 #ifdef CONFIG_64BIT
5950         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5951                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5952 #endif
5953         case BTRFS_IOC_SEND:
5954                 return _btrfs_ioctl_send(file, argp, false);
5955 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5956         case BTRFS_IOC_SEND_32:
5957                 return _btrfs_ioctl_send(file, argp, true);
5958 #endif
5959         case BTRFS_IOC_GET_DEV_STATS:
5960                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5961         case BTRFS_IOC_QUOTA_CTL:
5962                 return btrfs_ioctl_quota_ctl(file, argp);
5963         case BTRFS_IOC_QGROUP_ASSIGN:
5964                 return btrfs_ioctl_qgroup_assign(file, argp);
5965         case BTRFS_IOC_QGROUP_CREATE:
5966                 return btrfs_ioctl_qgroup_create(file, argp);
5967         case BTRFS_IOC_QGROUP_LIMIT:
5968                 return btrfs_ioctl_qgroup_limit(file, argp);
5969         case BTRFS_IOC_QUOTA_RESCAN:
5970                 return btrfs_ioctl_quota_rescan(file, argp);
5971         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5972                 return btrfs_ioctl_quota_rescan_status(file, argp);
5973         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5974                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5975         case BTRFS_IOC_DEV_REPLACE:
5976                 return btrfs_ioctl_dev_replace(fs_info, argp);
5977         case BTRFS_IOC_GET_FSLABEL:
5978                 return btrfs_ioctl_get_fslabel(file, argp);
5979         case BTRFS_IOC_SET_FSLABEL:
5980                 return btrfs_ioctl_set_fslabel(file, argp);
5981         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5982                 return btrfs_ioctl_get_supported_features(argp);
5983         case BTRFS_IOC_GET_FEATURES:
5984                 return btrfs_ioctl_get_features(file, argp);
5985         case BTRFS_IOC_SET_FEATURES:
5986                 return btrfs_ioctl_set_features(file, argp);
5987         case FS_IOC_FSGETXATTR:
5988                 return btrfs_ioctl_fsgetxattr(file, argp);
5989         case FS_IOC_FSSETXATTR:
5990                 return btrfs_ioctl_fssetxattr(file, argp);
5991         case BTRFS_IOC_GET_SUBVOL_INFO:
5992                 return btrfs_ioctl_get_subvol_info(file, argp);
5993         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5994                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5995         case BTRFS_IOC_INO_LOOKUP_USER:
5996                 return btrfs_ioctl_ino_lookup_user(file, argp);
5997         }
5998
5999         return -ENOTTY;
6000 }
6001
6002 #ifdef CONFIG_COMPAT
6003 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
6004 {
6005         /*
6006          * These all access 32-bit values anyway so no further
6007          * handling is necessary.
6008          */
6009         switch (cmd) {
6010         case FS_IOC32_GETFLAGS:
6011                 cmd = FS_IOC_GETFLAGS;
6012                 break;
6013         case FS_IOC32_SETFLAGS:
6014                 cmd = FS_IOC_SETFLAGS;
6015                 break;
6016         case FS_IOC32_GETVERSION:
6017                 cmd = FS_IOC_GETVERSION;
6018                 break;
6019         }
6020
6021         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
6022 }
6023 #endif