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 <linux/fileattr.h>
  30 #include <linux/fsverity.h>
  31 #include <linux/sched/xacct.h>
  32 #include "ctree.h"
  33 #include "disk-io.h"
  34 #include "export.h"
  35 #include "transaction.h"
  36 #include "btrfs_inode.h"
  37 #include "print-tree.h"
  38 #include "volumes.h"
  39 #include "locking.h"
  40 #include "backref.h"
  41 #include "rcu-string.h"
  42 #include "send.h"
  43 #include "dev-replace.h"
  44 #include "props.h"
  45 #include "sysfs.h"
  46 #include "qgroup.h"
  47 #include "tree-log.h"
  48 #include "compression.h"
  49 #include "space-info.h"
  50 #include "delalloc-space.h"
  51 #include "block-group.h"
  52 #include "subpage.h"
  53 #include "fs.h"
  54 #include "accessors.h"
  55 #include "extent-tree.h"
  56 #include "root-tree.h"
  57 #include "defrag.h"
  58 #include "dir-item.h"
  59 #include "uuid-tree.h"
  60 #include "ioctl.h"
  61 #include "file.h"
  62 #include "scrub.h"
  63 #include "super.h"
  64
  65 #ifdef CONFIG_64BIT
  66 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
  67  * structures are incorrect, as the timespec structure from userspace
  68  * is 4 bytes too small. We define these alternatives here to teach
  69  * the kernel about the 32-bit struct packing.
  70  */
  71 struct btrfs_ioctl_timespec_32 {
  72         __u64 sec;
  73         __u32 nsec;
  74 } __attribute__ ((__packed__));
  75
  76 struct btrfs_ioctl_received_subvol_args_32 {
  77         char    uuid[BTRFS_UUID_SIZE];  /* in */
  78         __u64   stransid;               /* in */
  79         __u64   rtransid;               /* out */
  80         struct btrfs_ioctl_timespec_32 stime; /* in */
  81         struct btrfs_ioctl_timespec_32 rtime; /* out */
  82         __u64   flags;                  /* in */
  83         __u64   reserved[16];           /* in */
  84 } __attribute__ ((__packed__));
  85
  86 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
  87                                 struct btrfs_ioctl_received_subvol_args_32)
  88 #endif
  89
  90 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
  91 struct btrfs_ioctl_send_args_32 {
  92         __s64 send_fd;                  /* in */
  93         __u64 clone_sources_count;      /* in */
  94         compat_uptr_t clone_sources;    /* in */
  95         __u64 parent_root;              /* in */
  96         __u64 flags;                    /* in */
  97         __u32 version;                  /* in */
  98         __u8  reserved[28];             /* in */
  99 } __attribute__ ((__packed__));
 100
 101 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
 102                                struct btrfs_ioctl_send_args_32)
 103
 104 struct btrfs_ioctl_encoded_io_args_32 {
 105         compat_uptr_t iov;
 106         compat_ulong_t iovcnt;
 107         __s64 offset;
 108         __u64 flags;
 109         __u64 len;
 110         __u64 unencoded_len;
 111         __u64 unencoded_offset;
 112         __u32 compression;
 113         __u32 encryption;
 114         __u8 reserved[64];
 115 };
 116
 117 #define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
 118                                        struct btrfs_ioctl_encoded_io_args_32)
 119 #define BTRFS_IOC_ENCODED_WRITE_32 _IOW(BTRFS_IOCTL_MAGIC, 64, \
 120                                         struct btrfs_ioctl_encoded_io_args_32)
 121 #endif
 122
 123 /* Mask out flags that are inappropriate for the given type of inode. */
 124 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
 125                 unsigned int flags)
 126 {
 127         if (S_ISDIR(inode->i_mode))
 128                 return flags;
 129         else if (S_ISREG(inode->i_mode))
 130                 return flags & ~FS_DIRSYNC_FL;
 131         else
 132                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 133 }
 134
 135 /*
 136  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
 137  * ioctl.
 138  */
 139 static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
 140 {
 141         unsigned int iflags = 0;
 142         u32 flags = binode->flags;
 143         u32 ro_flags = binode->ro_flags;
 144
 145         if (flags & BTRFS_INODE_SYNC)
 146                 iflags |= FS_SYNC_FL;
 147         if (flags & BTRFS_INODE_IMMUTABLE)
 148                 iflags |= FS_IMMUTABLE_FL;
 149         if (flags & BTRFS_INODE_APPEND)
 150                 iflags |= FS_APPEND_FL;
 151         if (flags & BTRFS_INODE_NODUMP)
 152                 iflags |= FS_NODUMP_FL;
 153         if (flags & BTRFS_INODE_NOATIME)
 154                 iflags |= FS_NOATIME_FL;
 155         if (flags & BTRFS_INODE_DIRSYNC)
 156                 iflags |= FS_DIRSYNC_FL;
 157         if (flags & BTRFS_INODE_NODATACOW)
 158                 iflags |= FS_NOCOW_FL;
 159         if (ro_flags & BTRFS_INODE_RO_VERITY)
 160                 iflags |= FS_VERITY_FL;
 161
 162         if (flags & BTRFS_INODE_NOCOMPRESS)
 163                 iflags |= FS_NOCOMP_FL;
 164         else if (flags & BTRFS_INODE_COMPRESS)
 165                 iflags |= FS_COMPR_FL;
 166
 167         return iflags;
 168 }
 169
 170 /*
 171  * Update inode->i_flags based on the btrfs internal flags.
 172  */
 173 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
 174 {
 175         struct btrfs_inode *binode = BTRFS_I(inode);
 176         unsigned int new_fl = 0;
 177
 178         if (binode->flags & BTRFS_INODE_SYNC)
 179                 new_fl |= S_SYNC;
 180         if (binode->flags & BTRFS_INODE_IMMUTABLE)
 181                 new_fl |= S_IMMUTABLE;
 182         if (binode->flags & BTRFS_INODE_APPEND)
 183                 new_fl |= S_APPEND;
 184         if (binode->flags & BTRFS_INODE_NOATIME)
 185                 new_fl |= S_NOATIME;
 186         if (binode->flags & BTRFS_INODE_DIRSYNC)
 187                 new_fl |= S_DIRSYNC;
 188         if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
 189                 new_fl |= S_VERITY;
 190
 191         set_mask_bits(&inode->i_flags,
 192                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
 193                       S_VERITY, new_fl);
 194 }
 195
 196 /*
 197  * Check if @flags are a supported and valid set of FS_*_FL flags and that
 198  * the old and new flags are not conflicting
 199  */
 200 static int check_fsflags(unsigned int old_flags, unsigned int flags)
 201 {
 202         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 203                       FS_NOATIME_FL | FS_NODUMP_FL | \
 204                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 205                       FS_NOCOMP_FL | FS_COMPR_FL |
 206                       FS_NOCOW_FL))
 207                 return -EOPNOTSUPP;
 208
 209         /* COMPR and NOCOMP on new/old are valid */
 210         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 211                 return -EINVAL;
 212
 213         if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
 214                 return -EINVAL;
 215
 216         /* NOCOW and compression options are mutually exclusive */
 217         if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 218                 return -EINVAL;
 219         if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
 220                 return -EINVAL;
 221
 222         return 0;
 223 }
 224
 225 static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
 226                                     unsigned int flags)
 227 {
 228         if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
 229                 return -EPERM;
 230
 231         return 0;
 232 }
 233
 234 /*
 235  * Set flags/xflags from the internal inode flags. The remaining items of
 236  * fsxattr are zeroed.
 237  */
 238 int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
 239 {
 240         struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
 241
 242         fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
 243         return 0;
 244 }
 245
 246 int btrfs_fileattr_set(struct mnt_idmap *idmap,
 247                        struct dentry *dentry, struct fileattr *fa)
 248 {
 249         struct inode *inode = d_inode(dentry);
 250         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 251         struct btrfs_inode *binode = BTRFS_I(inode);
 252         struct btrfs_root *root = binode->root;
 253         struct btrfs_trans_handle *trans;
 254         unsigned int fsflags, old_fsflags;
 255         int ret;
 256         const char *comp = NULL;
 257         u32 binode_flags;
 258
 259         if (btrfs_root_readonly(root))
 260                 return -EROFS;
 261
 262         if (fileattr_has_fsx(fa))
 263                 return -EOPNOTSUPP;
 264
 265         fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
 266         old_fsflags = btrfs_inode_flags_to_fsflags(binode);
 267         ret = check_fsflags(old_fsflags, fsflags);
 268         if (ret)
 269                 return ret;
 270
 271         ret = check_fsflags_compatible(fs_info, fsflags);
 272         if (ret)
 273                 return ret;
 274
 275         binode_flags = binode->flags;
 276         if (fsflags & FS_SYNC_FL)
 277                 binode_flags |= BTRFS_INODE_SYNC;
 278         else
 279                 binode_flags &= ~BTRFS_INODE_SYNC;
 280         if (fsflags & FS_IMMUTABLE_FL)
 281                 binode_flags |= BTRFS_INODE_IMMUTABLE;
 282         else
 283                 binode_flags &= ~BTRFS_INODE_IMMUTABLE;
 284         if (fsflags & FS_APPEND_FL)
 285                 binode_flags |= BTRFS_INODE_APPEND;
 286         else
 287                 binode_flags &= ~BTRFS_INODE_APPEND;
 288         if (fsflags & FS_NODUMP_FL)
 289                 binode_flags |= BTRFS_INODE_NODUMP;
 290         else
 291                 binode_flags &= ~BTRFS_INODE_NODUMP;
 292         if (fsflags & FS_NOATIME_FL)
 293                 binode_flags |= BTRFS_INODE_NOATIME;
 294         else
 295                 binode_flags &= ~BTRFS_INODE_NOATIME;
 296
 297         /* If coming from FS_IOC_FSSETXATTR then skip unconverted flags */
 298         if (!fa->flags_valid) {
 299                 /* 1 item for the inode */
 300                 trans = btrfs_start_transaction(root, 1);
 301                 if (IS_ERR(trans))
 302                         return PTR_ERR(trans);
 303                 goto update_flags;
 304         }
 305
 306         if (fsflags & FS_DIRSYNC_FL)
 307                 binode_flags |= BTRFS_INODE_DIRSYNC;
 308         else
 309                 binode_flags &= ~BTRFS_INODE_DIRSYNC;
 310         if (fsflags & FS_NOCOW_FL) {
 311                 if (S_ISREG(inode->i_mode)) {
 312                         /*
 313                          * It's safe to turn csums off here, no extents exist.
 314                          * Otherwise we want the flag to reflect the real COW
 315                          * status of the file and will not set it.
 316                          */
 317                         if (inode->i_size == 0)
 318                                 binode_flags |= BTRFS_INODE_NODATACOW |
 319                                                 BTRFS_INODE_NODATASUM;
 320                 } else {
 321                         binode_flags |= BTRFS_INODE_NODATACOW;
 322                 }
 323         } else {
 324                 /*
 325                  * Revert back under same assumptions as above
 326                  */
 327                 if (S_ISREG(inode->i_mode)) {
 328                         if (inode->i_size == 0)
 329                                 binode_flags &= ~(BTRFS_INODE_NODATACOW |
 330                                                   BTRFS_INODE_NODATASUM);
 331                 } else {
 332                         binode_flags &= ~BTRFS_INODE_NODATACOW;
 333                 }
 334         }
 335
 336         /*
 337          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 338          * flag may be changed automatically if compression code won't make
 339          * things smaller.
 340          */
 341         if (fsflags & FS_NOCOMP_FL) {
 342                 binode_flags &= ~BTRFS_INODE_COMPRESS;
 343                 binode_flags |= BTRFS_INODE_NOCOMPRESS;
 344         } else if (fsflags & FS_COMPR_FL) {
 345
 346                 if (IS_SWAPFILE(inode))
 347                         return -ETXTBSY;
 348
 349                 binode_flags |= BTRFS_INODE_COMPRESS;
 350                 binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
 351
 352                 comp = btrfs_compress_type2str(fs_info->compress_type);
 353                 if (!comp || comp[0] == 0)
 354                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
 355         } else {
 356                 binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 357         }
 358
 359         /*
 360          * 1 for inode item
 361          * 2 for properties
 362          */
 363         trans = btrfs_start_transaction(root, 3);
 364         if (IS_ERR(trans))
 365                 return PTR_ERR(trans);
 366
 367         if (comp) {
 368                 ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
 369                                      strlen(comp), 0);
 370                 if (ret) {
 371                         btrfs_abort_transaction(trans, ret);
 372                         goto out_end_trans;
 373                 }
 374         } else {
 375                 ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
 376                                      0, 0);
 377                 if (ret && ret != -ENODATA) {
 378                         btrfs_abort_transaction(trans, ret);
 379                         goto out_end_trans;
 380                 }
 381         }
 382
 383 update_flags:
 384         binode->flags = binode_flags;
 385         btrfs_sync_inode_flags_to_i_flags(inode);
 386         inode_inc_iversion(inode);
 387         inode->i_ctime = current_time(inode);
 388         ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
 389
 390  out_end_trans:
 391         btrfs_end_transaction(trans);
 392         return ret;
 393 }
 394
 395 /*
 396  * Start exclusive operation @type, return true on success
 397  */
 398 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
 399                         enum btrfs_exclusive_operation type)
 400 {
 401         bool ret = false;
 402
 403         spin_lock(&fs_info->super_lock);
 404         if (fs_info->exclusive_operation == BTRFS_EXCLOP_NONE) {
 405                 fs_info->exclusive_operation = type;
 406                 ret = true;
 407         }
 408         spin_unlock(&fs_info->super_lock);
 409
 410         return ret;
 411 }
 412
 413 /*
 414  * Conditionally allow to enter the exclusive operation in case it's compatible
 415  * with the running one.  This must be paired with btrfs_exclop_start_unlock and
 416  * btrfs_exclop_finish.
 417  *
 418  * Compatibility:
 419  * - the same type is already running
 420  * - when trying to add a device and balance has been paused
 421  * - not BTRFS_EXCLOP_NONE - this is intentionally incompatible and the caller
 422  *   must check the condition first that would allow none -> @type
 423  */
 424 bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
 425                                  enum btrfs_exclusive_operation type)
 426 {
 427         spin_lock(&fs_info->super_lock);
 428         if (fs_info->exclusive_operation == type ||
 429             (fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED &&
 430              type == BTRFS_EXCLOP_DEV_ADD))
 431                 return true;
 432
 433         spin_unlock(&fs_info->super_lock);
 434         return false;
 435 }
 436
 437 void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info)
 438 {
 439         spin_unlock(&fs_info->super_lock);
 440 }
 441
 442 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
 443 {
 444         spin_lock(&fs_info->super_lock);
 445         WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
 446         spin_unlock(&fs_info->super_lock);
 447         sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
 448 }
 449
 450 void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
 451                           enum btrfs_exclusive_operation op)
 452 {
 453         switch (op) {
 454         case BTRFS_EXCLOP_BALANCE_PAUSED:
 455                 spin_lock(&fs_info->super_lock);
 456                 ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
 457                        fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD);
 458                 fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE_PAUSED;
 459                 spin_unlock(&fs_info->super_lock);
 460                 break;
 461         case BTRFS_EXCLOP_BALANCE:
 462                 spin_lock(&fs_info->super_lock);
 463                 ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED);
 464                 fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE;
 465                 spin_unlock(&fs_info->super_lock);
 466                 break;
 467         default:
 468                 btrfs_warn(fs_info,
 469                         "invalid exclop balance operation %d requested", op);
 470         }
 471 }
 472
 473 static int btrfs_ioctl_getversion(struct inode *inode, int __user *arg)
 474 {
 475         return put_user(inode->i_generation, arg);
 476 }
 477
 478 static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
 479                                         void __user *arg)
 480 {
 481         struct btrfs_device *device;
 482         struct fstrim_range range;
 483         u64 minlen = ULLONG_MAX;
 484         u64 num_devices = 0;
 485         int ret;
 486
 487         if (!capable(CAP_SYS_ADMIN))
 488                 return -EPERM;
 489
 490         /*
 491          * btrfs_trim_block_group() depends on space cache, which is not
 492          * available in zoned filesystem. So, disallow fitrim on a zoned
 493          * filesystem for now.
 494          */
 495         if (btrfs_is_zoned(fs_info))
 496                 return -EOPNOTSUPP;
 497
 498         /*
 499          * If the fs is mounted with nologreplay, which requires it to be
 500          * mounted in RO mode as well, we can not allow discard on free space
 501          * inside block groups, because log trees refer to extents that are not
 502          * pinned in a block group's free space cache (pinning the extents is
 503          * precisely the first phase of replaying a log tree).
 504          */
 505         if (btrfs_test_opt(fs_info, NOLOGREPLAY))
 506                 return -EROFS;
 507
 508         rcu_read_lock();
 509         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 510                                 dev_list) {
 511                 if (!device->bdev || !bdev_max_discard_sectors(device->bdev))
 512                         continue;
 513                 num_devices++;
 514                 minlen = min_t(u64, bdev_discard_granularity(device->bdev),
 515                                     minlen);
 516         }
 517         rcu_read_unlock();
 518
 519         if (!num_devices)
 520                 return -EOPNOTSUPP;
 521         if (copy_from_user(&range, arg, sizeof(range)))
 522                 return -EFAULT;
 523
 524         /*
 525          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
 526          * block group is in the logical address space, which can be any
 527          * sectorsize aligned bytenr in  the range [0, U64_MAX].
 528          */
 529         if (range.len < fs_info->sb->s_blocksize)
 530                 return -EINVAL;
 531
 532         range.minlen = max(range.minlen, minlen);
 533         ret = btrfs_trim_fs(fs_info, &range);
 534         if (ret < 0)
 535                 return ret;
 536
 537         if (copy_to_user(arg, &range, sizeof(range)))
 538                 return -EFAULT;
 539
 540         return 0;
 541 }
 542
 543 int __pure btrfs_is_empty_uuid(u8 *uuid)
 544 {
 545         int i;
 546
 547         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 548                 if (uuid[i])
 549                         return 0;
 550         }
 551         return 1;
 552 }
 553
 554 /*
 555  * Calculate the number of transaction items to reserve for creating a subvolume
 556  * or snapshot, not including the inode, directory entries, or parent directory.
 557  */
 558 static unsigned int create_subvol_num_items(struct btrfs_qgroup_inherit *inherit)
 559 {
 560         /*
 561          * 1 to add root block
 562          * 1 to add root item
 563          * 1 to add root ref
 564          * 1 to add root backref
 565          * 1 to add UUID item
 566          * 1 to add qgroup info
 567          * 1 to add qgroup limit
 568          *
 569          * Ideally the last two would only be accounted if qgroups are enabled,
 570          * but that can change between now and the time we would insert them.
 571          */
 572         unsigned int num_items = 7;
 573
 574         if (inherit) {
 575                 /* 2 to add qgroup relations for each inherited qgroup */
 576                 num_items += 2 * inherit->num_qgroups;
 577         }
 578         return num_items;
 579 }
 580
 581 static noinline int create_subvol(struct mnt_idmap *idmap,
 582                                   struct inode *dir, struct dentry *dentry,
 583                                   struct btrfs_qgroup_inherit *inherit)
 584 {
 585         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 586         struct btrfs_trans_handle *trans;
 587         struct btrfs_key key;
 588         struct btrfs_root_item *root_item;
 589         struct btrfs_inode_item *inode_item;
 590         struct extent_buffer *leaf;
 591         struct btrfs_root *root = BTRFS_I(dir)->root;
 592         struct btrfs_root *new_root;
 593         struct btrfs_block_rsv block_rsv;
 594         struct timespec64 cur_time = current_time(dir);
 595         struct btrfs_new_inode_args new_inode_args = {
 596                 .dir = dir,
 597                 .dentry = dentry,
 598                 .subvol = true,
 599         };
 600         unsigned int trans_num_items;
 601         int ret;
 602         dev_t anon_dev;
 603         u64 objectid;
 604
 605         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 606         if (!root_item)
 607                 return -ENOMEM;
 608
 609         ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
 610         if (ret)
 611                 goto out_root_item;
 612
 613         /*
 614          * Don't create subvolume whose level is not zero. Or qgroup will be
 615          * screwed up since it assumes subvolume qgroup's level to be 0.
 616          */
 617         if (btrfs_qgroup_level(objectid)) {
 618                 ret = -ENOSPC;
 619                 goto out_root_item;
 620         }
 621
 622         ret = get_anon_bdev(&anon_dev);
 623         if (ret < 0)
 624                 goto out_root_item;
 625
 626         new_inode_args.inode = btrfs_new_subvol_inode(idmap, dir);
 627         if (!new_inode_args.inode) {
 628                 ret = -ENOMEM;
 629                 goto out_anon_dev;
 630         }
 631         ret = btrfs_new_inode_prepare(&new_inode_args, &trans_num_items);
 632         if (ret)
 633                 goto out_inode;
 634         trans_num_items += create_subvol_num_items(inherit);
 635
 636         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 637         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 638                                                trans_num_items, false);
 639         if (ret)
 640                 goto out_new_inode_args;
 641
 642         trans = btrfs_start_transaction(root, 0);
 643         if (IS_ERR(trans)) {
 644                 ret = PTR_ERR(trans);
 645                 btrfs_subvolume_release_metadata(root, &block_rsv);
 646                 goto out_new_inode_args;
 647         }
 648         trans->block_rsv = &block_rsv;
 649         trans->bytes_reserved = block_rsv.size;
 650
 651         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
 652         if (ret)
 653                 goto out;
 654
 655         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
 656                                       BTRFS_NESTING_NORMAL);
 657         if (IS_ERR(leaf)) {
 658                 ret = PTR_ERR(leaf);
 659                 goto out;
 660         }
 661
 662         btrfs_mark_buffer_dirty(leaf);
 663
 664         inode_item = &root_item->inode;
 665         btrfs_set_stack_inode_generation(inode_item, 1);
 666         btrfs_set_stack_inode_size(inode_item, 3);
 667         btrfs_set_stack_inode_nlink(inode_item, 1);
 668         btrfs_set_stack_inode_nbytes(inode_item,
 669                                      fs_info->nodesize);
 670         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 671
 672         btrfs_set_root_flags(root_item, 0);
 673         btrfs_set_root_limit(root_item, 0);
 674         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 675
 676         btrfs_set_root_bytenr(root_item, leaf->start);
 677         btrfs_set_root_generation(root_item, trans->transid);
 678         btrfs_set_root_level(root_item, 0);
 679         btrfs_set_root_refs(root_item, 1);
 680         btrfs_set_root_used(root_item, leaf->len);
 681         btrfs_set_root_last_snapshot(root_item, 0);
 682
 683         btrfs_set_root_generation_v2(root_item,
 684                         btrfs_root_generation(root_item));
 685         generate_random_guid(root_item->uuid);
 686         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 687         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 688         root_item->ctime = root_item->otime;
 689         btrfs_set_root_ctransid(root_item, trans->transid);
 690         btrfs_set_root_otransid(root_item, trans->transid);
 691
 692         btrfs_tree_unlock(leaf);
 693
 694         btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
 695
 696         key.objectid = objectid;
 697         key.offset = 0;
 698         key.type = BTRFS_ROOT_ITEM_KEY;
 699         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
 700                                 root_item);
 701         if (ret) {
 702                 /*
 703                  * Since we don't abort the transaction in this case, free the
 704                  * tree block so that we don't leak space and leave the
 705                  * filesystem in an inconsistent state (an extent item in the
 706                  * extent tree with a backreference for a root that does not
 707                  * exists).
 708                  */
 709                 btrfs_tree_lock(leaf);
 710                 btrfs_clear_buffer_dirty(trans, leaf);
 711                 btrfs_tree_unlock(leaf);
 712                 btrfs_free_tree_block(trans, objectid, leaf, 0, 1);
 713                 free_extent_buffer(leaf);
 714                 goto out;
 715         }
 716
 717         free_extent_buffer(leaf);
 718         leaf = NULL;
 719
 720         new_root = btrfs_get_new_fs_root(fs_info, objectid, anon_dev);
 721         if (IS_ERR(new_root)) {
 722                 ret = PTR_ERR(new_root);
 723                 btrfs_abort_transaction(trans, ret);
 724                 goto out;
 725         }
 726         /* anon_dev is owned by new_root now. */
 727         anon_dev = 0;
 728         BTRFS_I(new_inode_args.inode)->root = new_root;
 729         /* ... and new_root is owned by new_inode_args.inode now. */
 730
 731         ret = btrfs_record_root_in_trans(trans, new_root);
 732         if (ret) {
 733                 btrfs_abort_transaction(trans, ret);
 734                 goto out;
 735         }
 736
 737         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
 738                                   BTRFS_UUID_KEY_SUBVOL, objectid);
 739         if (ret) {
 740                 btrfs_abort_transaction(trans, ret);
 741                 goto out;
 742         }
 743
 744         ret = btrfs_create_new_inode(trans, &new_inode_args);
 745         if (ret) {
 746                 btrfs_abort_transaction(trans, ret);
 747                 goto out;
 748         }
 749
 750         d_instantiate_new(dentry, new_inode_args.inode);
 751         new_inode_args.inode = NULL;
 752
 753 out:
 754         trans->block_rsv = NULL;
 755         trans->bytes_reserved = 0;
 756         btrfs_subvolume_release_metadata(root, &block_rsv);
 757
 758         if (ret)
 759                 btrfs_end_transaction(trans);
 760         else
 761                 ret = btrfs_commit_transaction(trans);
 762 out_new_inode_args:
 763         btrfs_new_inode_args_destroy(&new_inode_args);
 764 out_inode:
 765         iput(new_inode_args.inode);
 766 out_anon_dev:
 767         if (anon_dev)
 768                 free_anon_bdev(anon_dev);
 769 out_root_item:
 770         kfree(root_item);
 771         return ret;
 772 }
 773
 774 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 775                            struct dentry *dentry, bool readonly,
 776                            struct btrfs_qgroup_inherit *inherit)
 777 {
 778         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 779         struct inode *inode;
 780         struct btrfs_pending_snapshot *pending_snapshot;
 781         unsigned int trans_num_items;
 782         struct btrfs_trans_handle *trans;
 783         int ret;
 784
 785         /* We do not support snapshotting right now. */
 786         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
 787                 btrfs_warn(fs_info,
 788                            "extent tree v2 doesn't support snapshotting yet");
 789                 return -EOPNOTSUPP;
 790         }
 791
 792         if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
 793                 return -EINVAL;
 794
 795         if (atomic_read(&root->nr_swapfiles)) {
 796                 btrfs_warn(fs_info,
 797                            "cannot snapshot subvolume with active swapfile");
 798                 return -ETXTBSY;
 799         }
 800
 801         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
 802         if (!pending_snapshot)
 803                 return -ENOMEM;
 804
 805         ret = get_anon_bdev(&pending_snapshot->anon_dev);
 806         if (ret < 0)
 807                 goto free_pending;
 808         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 809                         GFP_KERNEL);
 810         pending_snapshot->path = btrfs_alloc_path();
 811         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 812                 ret = -ENOMEM;
 813                 goto free_pending;
 814         }
 815
 816         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 817                              BTRFS_BLOCK_RSV_TEMP);
 818         /*
 819          * 1 to add dir item
 820          * 1 to add dir index
 821          * 1 to update parent inode item
 822          */
 823         trans_num_items = create_subvol_num_items(inherit) + 3;
 824         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 825                                                &pending_snapshot->block_rsv,
 826                                                trans_num_items, false);
 827         if (ret)
 828                 goto free_pending;
 829
 830         pending_snapshot->dentry = dentry;
 831         pending_snapshot->root = root;
 832         pending_snapshot->readonly = readonly;
 833         pending_snapshot->dir = dir;
 834         pending_snapshot->inherit = inherit;
 835
 836         trans = btrfs_start_transaction(root, 0);
 837         if (IS_ERR(trans)) {
 838                 ret = PTR_ERR(trans);
 839                 goto fail;
 840         }
 841
 842         trans->pending_snapshot = pending_snapshot;
 843
 844         ret = btrfs_commit_transaction(trans);
 845         if (ret)
 846                 goto fail;
 847
 848         ret = pending_snapshot->error;
 849         if (ret)
 850                 goto fail;
 851
 852         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 853         if (ret)
 854                 goto fail;
 855
 856         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 857         if (IS_ERR(inode)) {
 858                 ret = PTR_ERR(inode);
 859                 goto fail;
 860         }
 861
 862         d_instantiate(dentry, inode);
 863         ret = 0;
 864         pending_snapshot->anon_dev = 0;
 865 fail:
 866         /* Prevent double freeing of anon_dev */
 867         if (ret && pending_snapshot->snap)
 868                 pending_snapshot->snap->anon_dev = 0;
 869         btrfs_put_root(pending_snapshot->snap);
 870         btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv);
 871 free_pending:
 872         if (pending_snapshot->anon_dev)
 873                 free_anon_bdev(pending_snapshot->anon_dev);
 874         kfree(pending_snapshot->root_item);
 875         btrfs_free_path(pending_snapshot->path);
 876         kfree(pending_snapshot);
 877
 878         return ret;
 879 }
 880
 881 /*  copy of may_delete in fs/namei.c()
 882  *      Check whether we can remove a link victim from directory dir, check
 883  *  whether the type of victim is right.
 884  *  1. We can't do it if dir is read-only (done in permission())
 885  *  2. We should have write and exec permissions on dir
 886  *  3. We can't remove anything from append-only dir
 887  *  4. We can't do anything with immutable dir (done in permission())
 888  *  5. If the sticky bit on dir is set we should either
 889  *      a. be owner of dir, or
 890  *      b. be owner of victim, or
 891  *      c. have CAP_FOWNER capability
 892  *  6. If the victim is append-only or immutable we can't do anything with
 893  *     links pointing to it.
 894  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 895  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 896  *  9. We can't remove a root or mountpoint.
 897  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 898  *     nfs_async_unlink().
 899  */
 900
 901 static int btrfs_may_delete(struct mnt_idmap *idmap,
 902                             struct inode *dir, struct dentry *victim, int isdir)
 903 {
 904         int error;
 905
 906         if (d_really_is_negative(victim))
 907                 return -ENOENT;
 908
 909         BUG_ON(d_inode(victim->d_parent) != dir);
 910         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 911
 912         error = inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 913         if (error)
 914                 return error;
 915         if (IS_APPEND(dir))
 916                 return -EPERM;
 917         if (check_sticky(idmap, dir, d_inode(victim)) ||
 918             IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
 919             IS_SWAPFILE(d_inode(victim)))
 920                 return -EPERM;
 921         if (isdir) {
 922                 if (!d_is_dir(victim))
 923                         return -ENOTDIR;
 924                 if (IS_ROOT(victim))
 925                         return -EBUSY;
 926         } else if (d_is_dir(victim))
 927                 return -EISDIR;
 928         if (IS_DEADDIR(dir))
 929                 return -ENOENT;
 930         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 931                 return -EBUSY;
 932         return 0;
 933 }
 934
 935 /* copy of may_create in fs/namei.c() */
 936 static inline int btrfs_may_create(struct mnt_idmap *idmap,
 937                                    struct inode *dir, struct dentry *child)
 938 {
 939         if (d_really_is_positive(child))
 940                 return -EEXIST;
 941         if (IS_DEADDIR(dir))
 942                 return -ENOENT;
 943         if (!fsuidgid_has_mapping(dir->i_sb, idmap))
 944                 return -EOVERFLOW;
 945         return inode_permission(idmap, dir, MAY_WRITE | MAY_EXEC);
 946 }
 947
 948 /*
 949  * Create a new subvolume below @parent.  This is largely modeled after
 950  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 951  * inside this filesystem so it's quite a bit simpler.
 952  */
 953 static noinline int btrfs_mksubvol(const struct path *parent,
 954                                    struct mnt_idmap *idmap,
 955                                    const char *name, int namelen,
 956                                    struct btrfs_root *snap_src,
 957                                    bool readonly,
 958                                    struct btrfs_qgroup_inherit *inherit)
 959 {
 960         struct inode *dir = d_inode(parent->dentry);
 961         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 962         struct dentry *dentry;
 963         struct fscrypt_str name_str = FSTR_INIT((char *)name, namelen);
 964         int error;
 965
 966         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 967         if (error == -EINTR)
 968                 return error;
 969
 970         dentry = lookup_one(idmap, name, parent->dentry, namelen);
 971         error = PTR_ERR(dentry);
 972         if (IS_ERR(dentry))
 973                 goto out_unlock;
 974
 975         error = btrfs_may_create(idmap, dir, dentry);
 976         if (error)
 977                 goto out_dput;
 978
 979         /*
 980          * even if this name doesn't exist, we may get hash collisions.
 981          * check for them now when we can safely fail
 982          */
 983         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 984                                                dir->i_ino, &name_str);
 985         if (error)
 986                 goto out_dput;
 987
 988         down_read(&fs_info->subvol_sem);
 989
 990         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 991                 goto out_up_read;
 992
 993         if (snap_src)
 994                 error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
 995         else
 996                 error = create_subvol(idmap, dir, dentry, inherit);
 997
 998         if (!error)
 999                 fsnotify_mkdir(dir, dentry);
1000 out_up_read:
1001         up_read(&fs_info->subvol_sem);
1002 out_dput:
1003         dput(dentry);
1004 out_unlock:
1005         btrfs_inode_unlock(BTRFS_I(dir), 0);
1006         return error;
1007 }
1008
1009 static noinline int btrfs_mksnapshot(const struct path *parent,
1010                                    struct mnt_idmap *idmap,
1011                                    const char *name, int namelen,
1012                                    struct btrfs_root *root,
1013                                    bool readonly,
1014                                    struct btrfs_qgroup_inherit *inherit)
1015 {
1016         int ret;
1017         bool snapshot_force_cow = false;
1018
1019         /*
1020          * Force new buffered writes to reserve space even when NOCOW is
1021          * possible. This is to avoid later writeback (running dealloc) to
1022          * fallback to COW mode and unexpectedly fail with ENOSPC.
1023          */
1024         btrfs_drew_read_lock(&root->snapshot_lock);
1025
1026         ret = btrfs_start_delalloc_snapshot(root, false);
1027         if (ret)
1028                 goto out;
1029
1030         /*
1031          * All previous writes have started writeback in NOCOW mode, so now
1032          * we force future writes to fallback to COW mode during snapshot
1033          * creation.
1034          */
1035         atomic_inc(&root->snapshot_force_cow);
1036         snapshot_force_cow = true;
1037
1038         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
1039
1040         ret = btrfs_mksubvol(parent, idmap, name, namelen,
1041                              root, readonly, inherit);
1042 out:
1043         if (snapshot_force_cow)
1044                 atomic_dec(&root->snapshot_force_cow);
1045         btrfs_drew_read_unlock(&root->snapshot_lock);
1046         return ret;
1047 }
1048
1049 /*
1050  * Try to start exclusive operation @type or cancel it if it's running.
1051  *
1052  * Return:
1053  *   0        - normal mode, newly claimed op started
1054  *  >0        - normal mode, something else is running,
1055  *              return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space
1056  * ECANCELED  - cancel mode, successful cancel
1057  * ENOTCONN   - cancel mode, operation not running anymore
1058  */
1059 static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info,
1060                         enum btrfs_exclusive_operation type, bool cancel)
1061 {
1062         if (!cancel) {
1063                 /* Start normal op */
1064                 if (!btrfs_exclop_start(fs_info, type))
1065                         return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1066                 /* Exclusive operation is now claimed */
1067                 return 0;
1068         }
1069
1070         /* Cancel running op */
1071         if (btrfs_exclop_start_try_lock(fs_info, type)) {
1072                 /*
1073                  * This blocks any exclop finish from setting it to NONE, so we
1074                  * request cancellation. Either it runs and we will wait for it,
1075                  * or it has finished and no waiting will happen.
1076                  */
1077                 atomic_inc(&fs_info->reloc_cancel_req);
1078                 btrfs_exclop_start_unlock(fs_info);
1079
1080                 if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags))
1081                         wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING,
1082                                     TASK_INTERRUPTIBLE);
1083
1084                 return -ECANCELED;
1085         }
1086
1087         /* Something else is running or none */
1088         return -ENOTCONN;
1089 }
1090
1091 static noinline int btrfs_ioctl_resize(struct file *file,
1092                                         void __user *arg)
1093 {
1094         BTRFS_DEV_LOOKUP_ARGS(args);
1095         struct inode *inode = file_inode(file);
1096         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1097         u64 new_size;
1098         u64 old_size;
1099         u64 devid = 1;
1100         struct btrfs_root *root = BTRFS_I(inode)->root;
1101         struct btrfs_ioctl_vol_args *vol_args;
1102         struct btrfs_trans_handle *trans;
1103         struct btrfs_device *device = NULL;
1104         char *sizestr;
1105         char *retptr;
1106         char *devstr = NULL;
1107         int ret = 0;
1108         int mod = 0;
1109         bool cancel;
1110
1111         if (!capable(CAP_SYS_ADMIN))
1112                 return -EPERM;
1113
1114         ret = mnt_want_write_file(file);
1115         if (ret)
1116                 return ret;
1117
1118         /*
1119          * Read the arguments before checking exclusivity to be able to
1120          * distinguish regular resize and cancel
1121          */
1122         vol_args = memdup_user(arg, sizeof(*vol_args));
1123         if (IS_ERR(vol_args)) {
1124                 ret = PTR_ERR(vol_args);
1125                 goto out_drop;
1126         }
1127         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1128         sizestr = vol_args->name;
1129         cancel = (strcmp("cancel", sizestr) == 0);
1130         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_RESIZE, cancel);
1131         if (ret)
1132                 goto out_free;
1133         /* Exclusive operation is now claimed */
1134
1135         devstr = strchr(sizestr, ':');
1136         if (devstr) {
1137                 sizestr = devstr + 1;
1138                 *devstr = '\0';
1139                 devstr = vol_args->name;
1140                 ret = kstrtoull(devstr, 10, &devid);
1141                 if (ret)
1142                         goto out_finish;
1143                 if (!devid) {
1144                         ret = -EINVAL;
1145                         goto out_finish;
1146                 }
1147                 btrfs_info(fs_info, "resizing devid %llu", devid);
1148         }
1149
1150         args.devid = devid;
1151         device = btrfs_find_device(fs_info->fs_devices, &args);
1152         if (!device) {
1153                 btrfs_info(fs_info, "resizer unable to find device %llu",
1154                            devid);
1155                 ret = -ENODEV;
1156                 goto out_finish;
1157         }
1158
1159         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1160                 btrfs_info(fs_info,
1161                            "resizer unable to apply on readonly device %llu",
1162                        devid);
1163                 ret = -EPERM;
1164                 goto out_finish;
1165         }
1166
1167         if (!strcmp(sizestr, "max"))
1168                 new_size = bdev_nr_bytes(device->bdev);
1169         else {
1170                 if (sizestr[0] == '-') {
1171                         mod = -1;
1172                         sizestr++;
1173                 } else if (sizestr[0] == '+') {
1174                         mod = 1;
1175                         sizestr++;
1176                 }
1177                 new_size = memparse(sizestr, &retptr);
1178                 if (*retptr != '\0' || new_size == 0) {
1179                         ret = -EINVAL;
1180                         goto out_finish;
1181                 }
1182         }
1183
1184         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1185                 ret = -EPERM;
1186                 goto out_finish;
1187         }
1188
1189         old_size = btrfs_device_get_total_bytes(device);
1190
1191         if (mod < 0) {
1192                 if (new_size > old_size) {
1193                         ret = -EINVAL;
1194                         goto out_finish;
1195                 }
1196                 new_size = old_size - new_size;
1197         } else if (mod > 0) {
1198                 if (new_size > ULLONG_MAX - old_size) {
1199                         ret = -ERANGE;
1200                         goto out_finish;
1201                 }
1202                 new_size = old_size + new_size;
1203         }
1204
1205         if (new_size < SZ_256M) {
1206                 ret = -EINVAL;
1207                 goto out_finish;
1208         }
1209         if (new_size > bdev_nr_bytes(device->bdev)) {
1210                 ret = -EFBIG;
1211                 goto out_finish;
1212         }
1213
1214         new_size = round_down(new_size, fs_info->sectorsize);
1215
1216         if (new_size > old_size) {
1217                 trans = btrfs_start_transaction(root, 0);
1218                 if (IS_ERR(trans)) {
1219                         ret = PTR_ERR(trans);
1220                         goto out_finish;
1221                 }
1222                 ret = btrfs_grow_device(trans, device, new_size);
1223                 btrfs_commit_transaction(trans);
1224         } else if (new_size < old_size) {
1225                 ret = btrfs_shrink_device(device, new_size);
1226         } /* equal, nothing need to do */
1227
1228         if (ret == 0 && new_size != old_size)
1229                 btrfs_info_in_rcu(fs_info,
1230                         "resize device %s (devid %llu) from %llu to %llu",
1231                         btrfs_dev_name(device), device->devid,
1232                         old_size, new_size);
1233 out_finish:
1234         btrfs_exclop_finish(fs_info);
1235 out_free:
1236         kfree(vol_args);
1237 out_drop:
1238         mnt_drop_write_file(file);
1239         return ret;
1240 }
1241
1242 static noinline int __btrfs_ioctl_snap_create(struct file *file,
1243                                 struct mnt_idmap *idmap,
1244                                 const char *name, unsigned long fd, int subvol,
1245                                 bool readonly,
1246                                 struct btrfs_qgroup_inherit *inherit)
1247 {
1248         int namelen;
1249         int ret = 0;
1250
1251         if (!S_ISDIR(file_inode(file)->i_mode))
1252                 return -ENOTDIR;
1253
1254         ret = mnt_want_write_file(file);
1255         if (ret)
1256                 goto out;
1257
1258         namelen = strlen(name);
1259         if (strchr(name, '/')) {
1260                 ret = -EINVAL;
1261                 goto out_drop_write;
1262         }
1263
1264         if (name[0] == '.' &&
1265            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1266                 ret = -EEXIST;
1267                 goto out_drop_write;
1268         }
1269
1270         if (subvol) {
1271                 ret = btrfs_mksubvol(&file->f_path, idmap, name,
1272                                      namelen, NULL, readonly, inherit);
1273         } else {
1274                 struct fd src = fdget(fd);
1275                 struct inode *src_inode;
1276                 if (!src.file) {
1277                         ret = -EINVAL;
1278                         goto out_drop_write;
1279                 }
1280
1281                 src_inode = file_inode(src.file);
1282                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1283                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1284                                    "Snapshot src from another FS");
1285                         ret = -EXDEV;
1286                 } else if (!inode_owner_or_capable(idmap, src_inode)) {
1287                         /*
1288                          * Subvolume creation is not restricted, but snapshots
1289                          * are limited to own subvolumes only
1290                          */
1291                         ret = -EPERM;
1292                 } else {
1293                         ret = btrfs_mksnapshot(&file->f_path, idmap,
1294                                                name, namelen,
1295                                                BTRFS_I(src_inode)->root,
1296                                                readonly, inherit);
1297                 }
1298                 fdput(src);
1299         }
1300 out_drop_write:
1301         mnt_drop_write_file(file);
1302 out:
1303         return ret;
1304 }
1305
1306 static noinline int btrfs_ioctl_snap_create(struct file *file,
1307                                             void __user *arg, int subvol)
1308 {
1309         struct btrfs_ioctl_vol_args *vol_args;
1310         int ret;
1311
1312         if (!S_ISDIR(file_inode(file)->i_mode))
1313                 return -ENOTDIR;
1314
1315         vol_args = memdup_user(arg, sizeof(*vol_args));
1316         if (IS_ERR(vol_args))
1317                 return PTR_ERR(vol_args);
1318         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1319
1320         ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
1321                                         vol_args->name, vol_args->fd, subvol,
1322                                         false, NULL);
1323
1324         kfree(vol_args);
1325         return ret;
1326 }
1327
1328 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1329                                                void __user *arg, int subvol)
1330 {
1331         struct btrfs_ioctl_vol_args_v2 *vol_args;
1332         int ret;
1333         bool readonly = false;
1334         struct btrfs_qgroup_inherit *inherit = NULL;
1335
1336         if (!S_ISDIR(file_inode(file)->i_mode))
1337                 return -ENOTDIR;
1338
1339         vol_args = memdup_user(arg, sizeof(*vol_args));
1340         if (IS_ERR(vol_args))
1341                 return PTR_ERR(vol_args);
1342         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1343
1344         if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1345                 ret = -EOPNOTSUPP;
1346                 goto free_args;
1347         }
1348
1349         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1350                 readonly = true;
1351         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1352                 u64 nums;
1353
1354                 if (vol_args->size < sizeof(*inherit) ||
1355                     vol_args->size > PAGE_SIZE) {
1356                         ret = -EINVAL;
1357                         goto free_args;
1358                 }
1359                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1360                 if (IS_ERR(inherit)) {
1361                         ret = PTR_ERR(inherit);
1362                         goto free_args;
1363                 }
1364
1365                 if (inherit->num_qgroups > PAGE_SIZE ||
1366                     inherit->num_ref_copies > PAGE_SIZE ||
1367                     inherit->num_excl_copies > PAGE_SIZE) {
1368                         ret = -EINVAL;
1369                         goto free_inherit;
1370                 }
1371
1372                 nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
1373                        2 * inherit->num_excl_copies;
1374                 if (vol_args->size != struct_size(inherit, qgroups, nums)) {
1375                         ret = -EINVAL;
1376                         goto free_inherit;
1377                 }
1378         }
1379
1380         ret = __btrfs_ioctl_snap_create(file, file_mnt_idmap(file),
1381                                         vol_args->name, vol_args->fd, subvol,
1382                                         readonly, inherit);
1383         if (ret)
1384                 goto free_inherit;
1385 free_inherit:
1386         kfree(inherit);
1387 free_args:
1388         kfree(vol_args);
1389         return ret;
1390 }
1391
1392 static noinline int btrfs_ioctl_subvol_getflags(struct inode *inode,
1393                                                 void __user *arg)
1394 {
1395         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1396         struct btrfs_root *root = BTRFS_I(inode)->root;
1397         int ret = 0;
1398         u64 flags = 0;
1399
1400         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1401                 return -EINVAL;
1402
1403         down_read(&fs_info->subvol_sem);
1404         if (btrfs_root_readonly(root))
1405                 flags |= BTRFS_SUBVOL_RDONLY;
1406         up_read(&fs_info->subvol_sem);
1407
1408         if (copy_to_user(arg, &flags, sizeof(flags)))
1409                 ret = -EFAULT;
1410
1411         return ret;
1412 }
1413
1414 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1415                                               void __user *arg)
1416 {
1417         struct inode *inode = file_inode(file);
1418         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1419         struct btrfs_root *root = BTRFS_I(inode)->root;
1420         struct btrfs_trans_handle *trans;
1421         u64 root_flags;
1422         u64 flags;
1423         int ret = 0;
1424
1425         if (!inode_owner_or_capable(file_mnt_idmap(file), inode))
1426                 return -EPERM;
1427
1428         ret = mnt_want_write_file(file);
1429         if (ret)
1430                 goto out;
1431
1432         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1433                 ret = -EINVAL;
1434                 goto out_drop_write;
1435         }
1436
1437         if (copy_from_user(&flags, arg, sizeof(flags))) {
1438                 ret = -EFAULT;
1439                 goto out_drop_write;
1440         }
1441
1442         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1443                 ret = -EOPNOTSUPP;
1444                 goto out_drop_write;
1445         }
1446
1447         down_write(&fs_info->subvol_sem);
1448
1449         /* nothing to do */
1450         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1451                 goto out_drop_sem;
1452
1453         root_flags = btrfs_root_flags(&root->root_item);
1454         if (flags & BTRFS_SUBVOL_RDONLY) {
1455                 btrfs_set_root_flags(&root->root_item,
1456                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1457         } else {
1458                 /*
1459                  * Block RO -> RW transition if this subvolume is involved in
1460                  * send
1461                  */
1462                 spin_lock(&root->root_item_lock);
1463                 if (root->send_in_progress == 0) {
1464                         btrfs_set_root_flags(&root->root_item,
1465                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1466                         spin_unlock(&root->root_item_lock);
1467                 } else {
1468                         spin_unlock(&root->root_item_lock);
1469                         btrfs_warn(fs_info,
1470                                    "Attempt to set subvolume %llu read-write during send",
1471                                    root->root_key.objectid);
1472                         ret = -EPERM;
1473                         goto out_drop_sem;
1474                 }
1475         }
1476
1477         trans = btrfs_start_transaction(root, 1);
1478         if (IS_ERR(trans)) {
1479                 ret = PTR_ERR(trans);
1480                 goto out_reset;
1481         }
1482
1483         ret = btrfs_update_root(trans, fs_info->tree_root,
1484                                 &root->root_key, &root->root_item);
1485         if (ret < 0) {
1486                 btrfs_end_transaction(trans);
1487                 goto out_reset;
1488         }
1489
1490         ret = btrfs_commit_transaction(trans);
1491
1492 out_reset:
1493         if (ret)
1494                 btrfs_set_root_flags(&root->root_item, root_flags);
1495 out_drop_sem:
1496         up_write(&fs_info->subvol_sem);
1497 out_drop_write:
1498         mnt_drop_write_file(file);
1499 out:
1500         return ret;
1501 }
1502
1503 static noinline int key_in_sk(struct btrfs_key *key,
1504                               struct btrfs_ioctl_search_key *sk)
1505 {
1506         struct btrfs_key test;
1507         int ret;
1508
1509         test.objectid = sk->min_objectid;
1510         test.type = sk->min_type;
1511         test.offset = sk->min_offset;
1512
1513         ret = btrfs_comp_cpu_keys(key, &test);
1514         if (ret < 0)
1515                 return 0;
1516
1517         test.objectid = sk->max_objectid;
1518         test.type = sk->max_type;
1519         test.offset = sk->max_offset;
1520
1521         ret = btrfs_comp_cpu_keys(key, &test);
1522         if (ret > 0)
1523                 return 0;
1524         return 1;
1525 }
1526
1527 static noinline int copy_to_sk(struct btrfs_path *path,
1528                                struct btrfs_key *key,
1529                                struct btrfs_ioctl_search_key *sk,
1530                                size_t *buf_size,
1531                                char __user *ubuf,
1532                                unsigned long *sk_offset,
1533                                int *num_found)
1534 {
1535         u64 found_transid;
1536         struct extent_buffer *leaf;
1537         struct btrfs_ioctl_search_header sh;
1538         struct btrfs_key test;
1539         unsigned long item_off;
1540         unsigned long item_len;
1541         int nritems;
1542         int i;
1543         int slot;
1544         int ret = 0;
1545
1546         leaf = path->nodes[0];
1547         slot = path->slots[0];
1548         nritems = btrfs_header_nritems(leaf);
1549
1550         if (btrfs_header_generation(leaf) > sk->max_transid) {
1551                 i = nritems;
1552                 goto advance_key;
1553         }
1554         found_transid = btrfs_header_generation(leaf);
1555
1556         for (i = slot; i < nritems; i++) {
1557                 item_off = btrfs_item_ptr_offset(leaf, i);
1558                 item_len = btrfs_item_size(leaf, i);
1559
1560                 btrfs_item_key_to_cpu(leaf, key, i);
1561                 if (!key_in_sk(key, sk))
1562                         continue;
1563
1564                 if (sizeof(sh) + item_len > *buf_size) {
1565                         if (*num_found) {
1566                                 ret = 1;
1567                                 goto out;
1568                         }
1569
1570                         /*
1571                          * return one empty item back for v1, which does not
1572                          * handle -EOVERFLOW
1573                          */
1574
1575                         *buf_size = sizeof(sh) + item_len;
1576                         item_len = 0;
1577                         ret = -EOVERFLOW;
1578                 }
1579
1580                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
1581                         ret = 1;
1582                         goto out;
1583                 }
1584
1585                 sh.objectid = key->objectid;
1586                 sh.offset = key->offset;
1587                 sh.type = key->type;
1588                 sh.len = item_len;
1589                 sh.transid = found_transid;
1590
1591                 /*
1592                  * Copy search result header. If we fault then loop again so we
1593                  * can fault in the pages and -EFAULT there if there's a
1594                  * problem. Otherwise we'll fault and then copy the buffer in
1595                  * properly this next time through
1596                  */
1597                 if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
1598                         ret = 0;
1599                         goto out;
1600                 }
1601
1602                 *sk_offset += sizeof(sh);
1603
1604                 if (item_len) {
1605                         char __user *up = ubuf + *sk_offset;
1606                         /*
1607                          * Copy the item, same behavior as above, but reset the
1608                          * * sk_offset so we copy the full thing again.
1609                          */
1610                         if (read_extent_buffer_to_user_nofault(leaf, up,
1611                                                 item_off, item_len)) {
1612                                 ret = 0;
1613                                 *sk_offset -= sizeof(sh);
1614                                 goto out;
1615                         }
1616
1617                         *sk_offset += item_len;
1618                 }
1619                 (*num_found)++;
1620
1621                 if (ret) /* -EOVERFLOW from above */
1622                         goto out;
1623
1624                 if (*num_found >= sk->nr_items) {
1625                         ret = 1;
1626                         goto out;
1627                 }
1628         }
1629 advance_key:
1630         ret = 0;
1631         test.objectid = sk->max_objectid;
1632         test.type = sk->max_type;
1633         test.offset = sk->max_offset;
1634         if (btrfs_comp_cpu_keys(key, &test) >= 0)
1635                 ret = 1;
1636         else if (key->offset < (u64)-1)
1637                 key->offset++;
1638         else if (key->type < (u8)-1) {
1639                 key->offset = 0;
1640                 key->type++;
1641         } else if (key->objectid < (u64)-1) {
1642                 key->offset = 0;
1643                 key->type = 0;
1644                 key->objectid++;
1645         } else
1646                 ret = 1;
1647 out:
1648         /*
1649          *  0: all items from this leaf copied, continue with next
1650          *  1: * more items can be copied, but unused buffer is too small
1651          *     * all items were found
1652          *     Either way, it will stops the loop which iterates to the next
1653          *     leaf
1654          *  -EOVERFLOW: item was to large for buffer
1655          *  -EFAULT: could not copy extent buffer back to userspace
1656          */
1657         return ret;
1658 }
1659
1660 static noinline int search_ioctl(struct inode *inode,
1661                                  struct btrfs_ioctl_search_key *sk,
1662                                  size_t *buf_size,
1663                                  char __user *ubuf)
1664 {
1665         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
1666         struct btrfs_root *root;
1667         struct btrfs_key key;
1668         struct btrfs_path *path;
1669         int ret;
1670         int num_found = 0;
1671         unsigned long sk_offset = 0;
1672
1673         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
1674                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
1675                 return -EOVERFLOW;
1676         }
1677
1678         path = btrfs_alloc_path();
1679         if (!path)
1680                 return -ENOMEM;
1681
1682         if (sk->tree_id == 0) {
1683                 /* search the root of the inode that was passed */
1684                 root = btrfs_grab_root(BTRFS_I(inode)->root);
1685         } else {
1686                 root = btrfs_get_fs_root(info, sk->tree_id, true);
1687                 if (IS_ERR(root)) {
1688                         btrfs_free_path(path);
1689                         return PTR_ERR(root);
1690                 }
1691         }
1692
1693         key.objectid = sk->min_objectid;
1694         key.type = sk->min_type;
1695         key.offset = sk->min_offset;
1696
1697         while (1) {
1698                 ret = -EFAULT;
1699                 /*
1700                  * Ensure that the whole user buffer is faulted in at sub-page
1701                  * granularity, otherwise the loop may live-lock.
1702                  */
1703                 if (fault_in_subpage_writeable(ubuf + sk_offset,
1704                                                *buf_size - sk_offset))
1705                         break;
1706
1707                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
1708                 if (ret != 0) {
1709                         if (ret > 0)
1710                                 ret = 0;
1711                         goto err;
1712                 }
1713                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
1714                                  &sk_offset, &num_found);
1715                 btrfs_release_path(path);
1716                 if (ret)
1717                         break;
1718
1719         }
1720         if (ret > 0)
1721                 ret = 0;
1722 err:
1723         sk->nr_items = num_found;
1724         btrfs_put_root(root);
1725         btrfs_free_path(path);
1726         return ret;
1727 }
1728
1729 static noinline int btrfs_ioctl_tree_search(struct inode *inode,
1730                                             void __user *argp)
1731 {
1732         struct btrfs_ioctl_search_args __user *uargs = argp;
1733         struct btrfs_ioctl_search_key sk;
1734         int ret;
1735         size_t buf_size;
1736
1737         if (!capable(CAP_SYS_ADMIN))
1738                 return -EPERM;
1739
1740         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
1741                 return -EFAULT;
1742
1743         buf_size = sizeof(uargs->buf);
1744
1745         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
1746
1747         /*
1748          * In the origin implementation an overflow is handled by returning a
1749          * search header with a len of zero, so reset ret.
1750          */
1751         if (ret == -EOVERFLOW)
1752                 ret = 0;
1753
1754         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
1755                 ret = -EFAULT;
1756         return ret;
1757 }
1758
1759 static noinline int btrfs_ioctl_tree_search_v2(struct inode *inode,
1760                                                void __user *argp)
1761 {
1762         struct btrfs_ioctl_search_args_v2 __user *uarg = argp;
1763         struct btrfs_ioctl_search_args_v2 args;
1764         int ret;
1765         size_t buf_size;
1766         const size_t buf_limit = SZ_16M;
1767
1768         if (!capable(CAP_SYS_ADMIN))
1769                 return -EPERM;
1770
1771         /* copy search header and buffer size */
1772         if (copy_from_user(&args, uarg, sizeof(args)))
1773                 return -EFAULT;
1774
1775         buf_size = args.buf_size;
1776
1777         /* limit result size to 16MB */
1778         if (buf_size > buf_limit)
1779                 buf_size = buf_limit;
1780
1781         ret = search_ioctl(inode, &args.key, &buf_size,
1782                            (char __user *)(&uarg->buf[0]));
1783         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
1784                 ret = -EFAULT;
1785         else if (ret == -EOVERFLOW &&
1786                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
1787                 ret = -EFAULT;
1788
1789         return ret;
1790 }
1791
1792 /*
1793  * Search INODE_REFs to identify path name of 'dirid' directory
1794  * in a 'tree_id' tree. and sets path name to 'name'.
1795  */
1796 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1797                                 u64 tree_id, u64 dirid, char *name)
1798 {
1799         struct btrfs_root *root;
1800         struct btrfs_key key;
1801         char *ptr;
1802         int ret = -1;
1803         int slot;
1804         int len;
1805         int total_len = 0;
1806         struct btrfs_inode_ref *iref;
1807         struct extent_buffer *l;
1808         struct btrfs_path *path;
1809
1810         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1811                 name[0]='\0';
1812                 return 0;
1813         }
1814
1815         path = btrfs_alloc_path();
1816         if (!path)
1817                 return -ENOMEM;
1818
1819         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
1820
1821         root = btrfs_get_fs_root(info, tree_id, true);
1822         if (IS_ERR(root)) {
1823                 ret = PTR_ERR(root);
1824                 root = NULL;
1825                 goto out;
1826         }
1827
1828         key.objectid = dirid;
1829         key.type = BTRFS_INODE_REF_KEY;
1830         key.offset = (u64)-1;
1831
1832         while (1) {
1833                 ret = btrfs_search_backwards(root, &key, path);
1834                 if (ret < 0)
1835                         goto out;
1836                 else if (ret > 0) {
1837                         ret = -ENOENT;
1838                         goto out;
1839                 }
1840
1841                 l = path->nodes[0];
1842                 slot = path->slots[0];
1843
1844                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1845                 len = btrfs_inode_ref_name_len(l, iref);
1846                 ptr -= len + 1;
1847                 total_len += len + 1;
1848                 if (ptr < name) {
1849                         ret = -ENAMETOOLONG;
1850                         goto out;
1851                 }
1852
1853                 *(ptr + len) = '/';
1854                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
1855
1856                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1857                         break;
1858
1859                 btrfs_release_path(path);
1860                 key.objectid = key.offset;
1861                 key.offset = (u64)-1;
1862                 dirid = key.objectid;
1863         }
1864         memmove(name, ptr, total_len);
1865         name[total_len] = '\0';
1866         ret = 0;
1867 out:
1868         btrfs_put_root(root);
1869         btrfs_free_path(path);
1870         return ret;
1871 }
1872
1873 static int btrfs_search_path_in_tree_user(struct mnt_idmap *idmap,
1874                                 struct inode *inode,
1875                                 struct btrfs_ioctl_ino_lookup_user_args *args)
1876 {
1877         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1878         struct super_block *sb = inode->i_sb;
1879         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
1880         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
1881         u64 dirid = args->dirid;
1882         unsigned long item_off;
1883         unsigned long item_len;
1884         struct btrfs_inode_ref *iref;
1885         struct btrfs_root_ref *rref;
1886         struct btrfs_root *root = NULL;
1887         struct btrfs_path *path;
1888         struct btrfs_key key, key2;
1889         struct extent_buffer *leaf;
1890         struct inode *temp_inode;
1891         char *ptr;
1892         int slot;
1893         int len;
1894         int total_len = 0;
1895         int ret;
1896
1897         path = btrfs_alloc_path();
1898         if (!path)
1899                 return -ENOMEM;
1900
1901         /*
1902          * If the bottom subvolume does not exist directly under upper_limit,
1903          * construct the path in from the bottom up.
1904          */
1905         if (dirid != upper_limit.objectid) {
1906                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
1907
1908                 root = btrfs_get_fs_root(fs_info, treeid, true);
1909                 if (IS_ERR(root)) {
1910                         ret = PTR_ERR(root);
1911                         goto out;
1912                 }
1913
1914                 key.objectid = dirid;
1915                 key.type = BTRFS_INODE_REF_KEY;
1916                 key.offset = (u64)-1;
1917                 while (1) {
1918                         ret = btrfs_search_backwards(root, &key, path);
1919                         if (ret < 0)
1920                                 goto out_put;
1921                         else if (ret > 0) {
1922                                 ret = -ENOENT;
1923                                 goto out_put;
1924                         }
1925
1926                         leaf = path->nodes[0];
1927                         slot = path->slots[0];
1928
1929                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
1930                         len = btrfs_inode_ref_name_len(leaf, iref);
1931                         ptr -= len + 1;
1932                         total_len += len + 1;
1933                         if (ptr < args->path) {
1934                                 ret = -ENAMETOOLONG;
1935                                 goto out_put;
1936                         }
1937
1938                         *(ptr + len) = '/';
1939                         read_extent_buffer(leaf, ptr,
1940                                         (unsigned long)(iref + 1), len);
1941
1942                         /* Check the read+exec permission of this directory */
1943                         ret = btrfs_previous_item(root, path, dirid,
1944                                                   BTRFS_INODE_ITEM_KEY);
1945                         if (ret < 0) {
1946                                 goto out_put;
1947                         } else if (ret > 0) {
1948                                 ret = -ENOENT;
1949                                 goto out_put;
1950                         }
1951
1952                         leaf = path->nodes[0];
1953                         slot = path->slots[0];
1954                         btrfs_item_key_to_cpu(leaf, &key2, slot);
1955                         if (key2.objectid != dirid) {
1956                                 ret = -ENOENT;
1957                                 goto out_put;
1958                         }
1959
1960                         temp_inode = btrfs_iget(sb, key2.objectid, root);
1961                         if (IS_ERR(temp_inode)) {
1962                                 ret = PTR_ERR(temp_inode);
1963                                 goto out_put;
1964                         }
1965                         ret = inode_permission(idmap, temp_inode,
1966                                                MAY_READ | MAY_EXEC);
1967                         iput(temp_inode);
1968                         if (ret) {
1969                                 ret = -EACCES;
1970                                 goto out_put;
1971                         }
1972
1973                         if (key.offset == upper_limit.objectid)
1974                                 break;
1975                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
1976                                 ret = -EACCES;
1977                                 goto out_put;
1978                         }
1979
1980                         btrfs_release_path(path);
1981                         key.objectid = key.offset;
1982                         key.offset = (u64)-1;
1983                         dirid = key.objectid;
1984                 }
1985
1986                 memmove(args->path, ptr, total_len);
1987                 args->path[total_len] = '\0';
1988                 btrfs_put_root(root);
1989                 root = NULL;
1990                 btrfs_release_path(path);
1991         }
1992
1993         /* Get the bottom subvolume's name from ROOT_REF */
1994         key.objectid = treeid;
1995         key.type = BTRFS_ROOT_REF_KEY;
1996         key.offset = args->treeid;
1997         ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
1998         if (ret < 0) {
1999                 goto out;
2000         } else if (ret > 0) {
2001                 ret = -ENOENT;
2002                 goto out;
2003         }
2004
2005         leaf = path->nodes[0];
2006         slot = path->slots[0];
2007         btrfs_item_key_to_cpu(leaf, &key, slot);
2008
2009         item_off = btrfs_item_ptr_offset(leaf, slot);
2010         item_len = btrfs_item_size(leaf, slot);
2011         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2012         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2013         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2014                 ret = -EINVAL;
2015                 goto out;
2016         }
2017
2018         /* Copy subvolume's name */
2019         item_off += sizeof(struct btrfs_root_ref);
2020         item_len -= sizeof(struct btrfs_root_ref);
2021         read_extent_buffer(leaf, args->name, item_off, item_len);
2022         args->name[item_len] = 0;
2023
2024 out_put:
2025         btrfs_put_root(root);
2026 out:
2027         btrfs_free_path(path);
2028         return ret;
2029 }
2030
2031 static noinline int btrfs_ioctl_ino_lookup(struct btrfs_root *root,
2032                                            void __user *argp)
2033 {
2034         struct btrfs_ioctl_ino_lookup_args *args;
2035         int ret = 0;
2036
2037         args = memdup_user(argp, sizeof(*args));
2038         if (IS_ERR(args))
2039                 return PTR_ERR(args);
2040
2041         /*
2042          * Unprivileged query to obtain the containing subvolume root id. The
2043          * path is reset so it's consistent with btrfs_search_path_in_tree.
2044          */
2045         if (args->treeid == 0)
2046                 args->treeid = root->root_key.objectid;
2047
2048         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2049                 args->name[0] = 0;
2050                 goto out;
2051         }
2052
2053         if (!capable(CAP_SYS_ADMIN)) {
2054                 ret = -EPERM;
2055                 goto out;
2056         }
2057
2058         ret = btrfs_search_path_in_tree(root->fs_info,
2059                                         args->treeid, args->objectid,
2060                                         args->name);
2061
2062 out:
2063         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2064                 ret = -EFAULT;
2065
2066         kfree(args);
2067         return ret;
2068 }
2069
2070 /*
2071  * Version of ino_lookup ioctl (unprivileged)
2072  *
2073  * The main differences from ino_lookup ioctl are:
2074  *
2075  *   1. Read + Exec permission will be checked using inode_permission() during
2076  *      path construction. -EACCES will be returned in case of failure.
2077  *   2. Path construction will be stopped at the inode number which corresponds
2078  *      to the fd with which this ioctl is called. If constructed path does not
2079  *      exist under fd's inode, -EACCES will be returned.
2080  *   3. The name of bottom subvolume is also searched and filled.
2081  */
2082 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2083 {
2084         struct btrfs_ioctl_ino_lookup_user_args *args;
2085         struct inode *inode;
2086         int ret;
2087
2088         args = memdup_user(argp, sizeof(*args));
2089         if (IS_ERR(args))
2090                 return PTR_ERR(args);
2091
2092         inode = file_inode(file);
2093
2094         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2095             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2096                 /*
2097                  * The subvolume does not exist under fd with which this is
2098                  * called
2099                  */
2100                 kfree(args);
2101                 return -EACCES;
2102         }
2103
2104         ret = btrfs_search_path_in_tree_user(file_mnt_idmap(file), inode, args);
2105
2106         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2107                 ret = -EFAULT;
2108
2109         kfree(args);
2110         return ret;
2111 }
2112
2113 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2114 static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
2115 {
2116         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2117         struct btrfs_fs_info *fs_info;
2118         struct btrfs_root *root;
2119         struct btrfs_path *path;
2120         struct btrfs_key key;
2121         struct btrfs_root_item *root_item;
2122         struct btrfs_root_ref *rref;
2123         struct extent_buffer *leaf;
2124         unsigned long item_off;
2125         unsigned long item_len;
2126         int slot;
2127         int ret = 0;
2128
2129         path = btrfs_alloc_path();
2130         if (!path)
2131                 return -ENOMEM;
2132
2133         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2134         if (!subvol_info) {
2135                 btrfs_free_path(path);
2136                 return -ENOMEM;
2137         }
2138
2139         fs_info = BTRFS_I(inode)->root->fs_info;
2140
2141         /* Get root_item of inode's subvolume */
2142         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2143         root = btrfs_get_fs_root(fs_info, key.objectid, true);
2144         if (IS_ERR(root)) {
2145                 ret = PTR_ERR(root);
2146                 goto out_free;
2147         }
2148         root_item = &root->root_item;
2149
2150         subvol_info->treeid = key.objectid;
2151
2152         subvol_info->generation = btrfs_root_generation(root_item);
2153         subvol_info->flags = btrfs_root_flags(root_item);
2154
2155         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2156         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2157                                                     BTRFS_UUID_SIZE);
2158         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2159                                                     BTRFS_UUID_SIZE);
2160
2161         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2162         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2163         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2164
2165         subvol_info->otransid = btrfs_root_otransid(root_item);
2166         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2167         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2168
2169         subvol_info->stransid = btrfs_root_stransid(root_item);
2170         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2171         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2172
2173         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2174         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2175         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2176
2177         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2178                 /* Search root tree for ROOT_BACKREF of this subvolume */
2179                 key.type = BTRFS_ROOT_BACKREF_KEY;
2180                 key.offset = 0;
2181                 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2182                 if (ret < 0) {
2183                         goto out;
2184                 } else if (path->slots[0] >=
2185                            btrfs_header_nritems(path->nodes[0])) {
2186                         ret = btrfs_next_leaf(fs_info->tree_root, path);
2187                         if (ret < 0) {
2188                                 goto out;
2189                         } else if (ret > 0) {
2190                                 ret = -EUCLEAN;
2191                                 goto out;
2192                         }
2193                 }
2194
2195                 leaf = path->nodes[0];
2196                 slot = path->slots[0];
2197                 btrfs_item_key_to_cpu(leaf, &key, slot);
2198                 if (key.objectid == subvol_info->treeid &&
2199                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2200                         subvol_info->parent_id = key.offset;
2201
2202                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2203                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2204
2205                         item_off = btrfs_item_ptr_offset(leaf, slot)
2206                                         + sizeof(struct btrfs_root_ref);
2207                         item_len = btrfs_item_size(leaf, slot)
2208                                         - sizeof(struct btrfs_root_ref);
2209                         read_extent_buffer(leaf, subvol_info->name,
2210                                            item_off, item_len);
2211                 } else {
2212                         ret = -ENOENT;
2213                         goto out;
2214                 }
2215         }
2216
2217         btrfs_free_path(path);
2218         path = NULL;
2219         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2220                 ret = -EFAULT;
2221
2222 out:
2223         btrfs_put_root(root);
2224 out_free:
2225         btrfs_free_path(path);
2226         kfree(subvol_info);
2227         return ret;
2228 }
2229
2230 /*
2231  * Return ROOT_REF information of the subvolume containing this inode
2232  * except the subvolume name.
2233  */
2234 static int btrfs_ioctl_get_subvol_rootref(struct btrfs_root *root,
2235                                           void __user *argp)
2236 {
2237         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2238         struct btrfs_root_ref *rref;
2239         struct btrfs_path *path;
2240         struct btrfs_key key;
2241         struct extent_buffer *leaf;
2242         u64 objectid;
2243         int slot;
2244         int ret;
2245         u8 found;
2246
2247         path = btrfs_alloc_path();
2248         if (!path)
2249                 return -ENOMEM;
2250
2251         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2252         if (IS_ERR(rootrefs)) {
2253                 btrfs_free_path(path);
2254                 return PTR_ERR(rootrefs);
2255         }
2256
2257         objectid = root->root_key.objectid;
2258         key.objectid = objectid;
2259         key.type = BTRFS_ROOT_REF_KEY;
2260         key.offset = rootrefs->min_treeid;
2261         found = 0;
2262
2263         root = root->fs_info->tree_root;
2264         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2265         if (ret < 0) {
2266                 goto out;
2267         } else if (path->slots[0] >=
2268                    btrfs_header_nritems(path->nodes[0])) {
2269                 ret = btrfs_next_leaf(root, path);
2270                 if (ret < 0) {
2271                         goto out;
2272                 } else if (ret > 0) {
2273                         ret = -EUCLEAN;
2274                         goto out;
2275                 }
2276         }
2277         while (1) {
2278                 leaf = path->nodes[0];
2279                 slot = path->slots[0];
2280
2281                 btrfs_item_key_to_cpu(leaf, &key, slot);
2282                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2283                         ret = 0;
2284                         goto out;
2285                 }
2286
2287                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2288                         ret = -EOVERFLOW;
2289                         goto out;
2290                 }
2291
2292                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2293                 rootrefs->rootref[found].treeid = key.offset;
2294                 rootrefs->rootref[found].dirid =
2295                                   btrfs_root_ref_dirid(leaf, rref);
2296                 found++;
2297
2298                 ret = btrfs_next_item(root, path);
2299                 if (ret < 0) {
2300                         goto out;
2301                 } else if (ret > 0) {
2302                         ret = -EUCLEAN;
2303                         goto out;
2304                 }
2305         }
2306
2307 out:
2308         btrfs_free_path(path);
2309
2310         if (!ret || ret == -EOVERFLOW) {
2311                 rootrefs->num_items = found;
2312                 /* update min_treeid for next search */
2313                 if (found)
2314                         rootrefs->min_treeid =
2315                                 rootrefs->rootref[found - 1].treeid + 1;
2316                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2317                         ret = -EFAULT;
2318         }
2319
2320         kfree(rootrefs);
2321
2322         return ret;
2323 }
2324
2325 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2326                                              void __user *arg,
2327                                              bool destroy_v2)
2328 {
2329         struct dentry *parent = file->f_path.dentry;
2330         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2331         struct dentry *dentry;
2332         struct inode *dir = d_inode(parent);
2333         struct inode *inode;
2334         struct btrfs_root *root = BTRFS_I(dir)->root;
2335         struct btrfs_root *dest = NULL;
2336         struct btrfs_ioctl_vol_args *vol_args = NULL;
2337         struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2338         struct mnt_idmap *idmap = file_mnt_idmap(file);
2339         char *subvol_name, *subvol_name_ptr = NULL;
2340         int subvol_namelen;
2341         int err = 0;
2342         bool destroy_parent = false;
2343
2344         /* We don't support snapshots with extent tree v2 yet. */
2345         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2346                 btrfs_err(fs_info,
2347                           "extent tree v2 doesn't support snapshot deletion yet");
2348                 return -EOPNOTSUPP;
2349         }
2350
2351         if (destroy_v2) {
2352                 vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2353                 if (IS_ERR(vol_args2))
2354                         return PTR_ERR(vol_args2);
2355
2356                 if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2357                         err = -EOPNOTSUPP;
2358                         goto out;
2359                 }
2360
2361                 /*
2362                  * If SPEC_BY_ID is not set, we are looking for the subvolume by
2363                  * name, same as v1 currently does.
2364                  */
2365                 if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2366                         vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2367                         subvol_name = vol_args2->name;
2368
2369                         err = mnt_want_write_file(file);
2370                         if (err)
2371                                 goto out;
2372                 } else {
2373                         struct inode *old_dir;
2374
2375                         if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2376                                 err = -EINVAL;
2377                                 goto out;
2378                         }
2379
2380                         err = mnt_want_write_file(file);
2381                         if (err)
2382                                 goto out;
2383
2384                         dentry = btrfs_get_dentry(fs_info->sb,
2385                                         BTRFS_FIRST_FREE_OBJECTID,
2386                                         vol_args2->subvolid, 0);
2387                         if (IS_ERR(dentry)) {
2388                                 err = PTR_ERR(dentry);
2389                                 goto out_drop_write;
2390                         }
2391
2392                         /*
2393                          * Change the default parent since the subvolume being
2394                          * deleted can be outside of the current mount point.
2395                          */
2396                         parent = btrfs_get_parent(dentry);
2397
2398                         /*
2399                          * At this point dentry->d_name can point to '/' if the
2400                          * subvolume we want to destroy is outsite of the
2401                          * current mount point, so we need to release the
2402                          * current dentry and execute the lookup to return a new
2403                          * one with ->d_name pointing to the
2404                          * <mount point>/subvol_name.
2405                          */
2406                         dput(dentry);
2407                         if (IS_ERR(parent)) {
2408                                 err = PTR_ERR(parent);
2409                                 goto out_drop_write;
2410                         }
2411                         old_dir = dir;
2412                         dir = d_inode(parent);
2413
2414                         /*
2415                          * If v2 was used with SPEC_BY_ID, a new parent was
2416                          * allocated since the subvolume can be outside of the
2417                          * current mount point. Later on we need to release this
2418                          * new parent dentry.
2419                          */
2420                         destroy_parent = true;
2421
2422                         /*
2423                          * On idmapped mounts, deletion via subvolid is
2424                          * restricted to subvolumes that are immediate
2425                          * ancestors of the inode referenced by the file
2426                          * descriptor in the ioctl. Otherwise the idmapping
2427                          * could potentially be abused to delete subvolumes
2428                          * anywhere in the filesystem the user wouldn't be able
2429                          * to delete without an idmapped mount.
2430                          */
2431                         if (old_dir != dir && idmap != &nop_mnt_idmap) {
2432                                 err = -EOPNOTSUPP;
2433                                 goto free_parent;
2434                         }
2435
2436                         subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
2437                                                 fs_info, vol_args2->subvolid);
2438                         if (IS_ERR(subvol_name_ptr)) {
2439                                 err = PTR_ERR(subvol_name_ptr);
2440                                 goto free_parent;
2441                         }
2442                         /* subvol_name_ptr is already nul terminated */
2443                         subvol_name = (char *)kbasename(subvol_name_ptr);
2444                 }
2445         } else {
2446                 vol_args = memdup_user(arg, sizeof(*vol_args));
2447                 if (IS_ERR(vol_args))
2448                         return PTR_ERR(vol_args);
2449
2450                 vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
2451                 subvol_name = vol_args->name;
2452
2453                 err = mnt_want_write_file(file);
2454                 if (err)
2455                         goto out;
2456         }
2457
2458         subvol_namelen = strlen(subvol_name);
2459
2460         if (strchr(subvol_name, '/') ||
2461             strncmp(subvol_name, "..", subvol_namelen) == 0) {
2462                 err = -EINVAL;
2463                 goto free_subvol_name;
2464         }
2465
2466         if (!S_ISDIR(dir->i_mode)) {
2467                 err = -ENOTDIR;
2468                 goto free_subvol_name;
2469         }
2470
2471         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2472         if (err == -EINTR)
2473                 goto free_subvol_name;
2474         dentry = lookup_one(idmap, subvol_name, parent, subvol_namelen);
2475         if (IS_ERR(dentry)) {
2476                 err = PTR_ERR(dentry);
2477                 goto out_unlock_dir;
2478         }
2479
2480         if (d_really_is_negative(dentry)) {
2481                 err = -ENOENT;
2482                 goto out_dput;
2483         }
2484
2485         inode = d_inode(dentry);
2486         dest = BTRFS_I(inode)->root;
2487         if (!capable(CAP_SYS_ADMIN)) {
2488                 /*
2489                  * Regular user.  Only allow this with a special mount
2490                  * option, when the user has write+exec access to the
2491                  * subvol root, and when rmdir(2) would have been
2492                  * allowed.
2493                  *
2494                  * Note that this is _not_ check that the subvol is
2495                  * empty or doesn't contain data that we wouldn't
2496                  * otherwise be able to delete.
2497                  *
2498                  * Users who want to delete empty subvols should try
2499                  * rmdir(2).
2500                  */
2501                 err = -EPERM;
2502                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2503                         goto out_dput;
2504
2505                 /*
2506                  * Do not allow deletion if the parent dir is the same
2507                  * as the dir to be deleted.  That means the ioctl
2508                  * must be called on the dentry referencing the root
2509                  * of the subvol, not a random directory contained
2510                  * within it.
2511                  */
2512                 err = -EINVAL;
2513                 if (root == dest)
2514                         goto out_dput;
2515
2516                 err = inode_permission(idmap, inode, MAY_WRITE | MAY_EXEC);
2517                 if (err)
2518                         goto out_dput;
2519         }
2520
2521         /* check if subvolume may be deleted by a user */
2522         err = btrfs_may_delete(idmap, dir, dentry, 1);
2523         if (err)
2524                 goto out_dput;
2525
2526         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2527                 err = -EINVAL;
2528                 goto out_dput;
2529         }
2530
2531         btrfs_inode_lock(BTRFS_I(inode), 0);
2532         err = btrfs_delete_subvolume(BTRFS_I(dir), dentry);
2533         btrfs_inode_unlock(BTRFS_I(inode), 0);
2534         if (!err)
2535                 d_delete_notify(dir, dentry);
2536
2537 out_dput:
2538         dput(dentry);
2539 out_unlock_dir:
2540         btrfs_inode_unlock(BTRFS_I(dir), 0);
2541 free_subvol_name:
2542         kfree(subvol_name_ptr);
2543 free_parent:
2544         if (destroy_parent)
2545                 dput(parent);
2546 out_drop_write:
2547         mnt_drop_write_file(file);
2548 out:
2549         kfree(vol_args2);
2550         kfree(vol_args);
2551         return err;
2552 }
2553
2554 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2555 {
2556         struct inode *inode = file_inode(file);
2557         struct btrfs_root *root = BTRFS_I(inode)->root;
2558         struct btrfs_ioctl_defrag_range_args range = {0};
2559         int ret;
2560
2561         ret = mnt_want_write_file(file);
2562         if (ret)
2563                 return ret;
2564
2565         if (btrfs_root_readonly(root)) {
2566                 ret = -EROFS;
2567                 goto out;
2568         }
2569
2570         switch (inode->i_mode & S_IFMT) {
2571         case S_IFDIR:
2572                 if (!capable(CAP_SYS_ADMIN)) {
2573                         ret = -EPERM;
2574                         goto out;
2575                 }
2576                 ret = btrfs_defrag_root(root);
2577                 break;
2578         case S_IFREG:
2579                 /*
2580                  * Note that this does not check the file descriptor for write
2581                  * access. This prevents defragmenting executables that are
2582                  * running and allows defrag on files open in read-only mode.
2583                  */
2584                 if (!capable(CAP_SYS_ADMIN) &&
2585                     inode_permission(&nop_mnt_idmap, inode, MAY_WRITE)) {
2586                         ret = -EPERM;
2587                         goto out;
2588                 }
2589
2590                 if (argp) {
2591                         if (copy_from_user(&range, argp, sizeof(range))) {
2592                                 ret = -EFAULT;
2593                                 goto out;
2594                         }
2595                         /* compression requires us to start the IO */
2596                         if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2597                                 range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
2598                                 range.extent_thresh = (u32)-1;
2599                         }
2600                 } else {
2601                         /* the rest are all set to zero by kzalloc */
2602                         range.len = (u64)-1;
2603                 }
2604                 ret = btrfs_defrag_file(file_inode(file), &file->f_ra,
2605                                         &range, BTRFS_OLDEST_GENERATION, 0);
2606                 if (ret > 0)
2607                         ret = 0;
2608                 break;
2609         default:
2610                 ret = -EINVAL;
2611         }
2612 out:
2613         mnt_drop_write_file(file);
2614         return ret;
2615 }
2616
2617 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2618 {
2619         struct btrfs_ioctl_vol_args *vol_args;
2620         bool restore_op = false;
2621         int ret;
2622
2623         if (!capable(CAP_SYS_ADMIN))
2624                 return -EPERM;
2625
2626         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
2627                 btrfs_err(fs_info, "device add not supported on extent tree v2 yet");
2628                 return -EINVAL;
2629         }
2630
2631         if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) {
2632                 if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD))
2633                         return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2634
2635                 /*
2636                  * We can do the device add because we have a paused balanced,
2637                  * change the exclusive op type and remember we should bring
2638                  * back the paused balance
2639                  */
2640                 fs_info->exclusive_operation = BTRFS_EXCLOP_DEV_ADD;
2641                 btrfs_exclop_start_unlock(fs_info);
2642                 restore_op = true;
2643         }
2644
2645         vol_args = memdup_user(arg, sizeof(*vol_args));
2646         if (IS_ERR(vol_args)) {
2647                 ret = PTR_ERR(vol_args);
2648                 goto out;
2649         }
2650
2651         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2652         ret = btrfs_init_new_device(fs_info, vol_args->name);
2653
2654         if (!ret)
2655                 btrfs_info(fs_info, "disk added %s", vol_args->name);
2656
2657         kfree(vol_args);
2658 out:
2659         if (restore_op)
2660                 btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
2661         else
2662                 btrfs_exclop_finish(fs_info);
2663         return ret;
2664 }
2665
2666 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2667 {
2668         BTRFS_DEV_LOOKUP_ARGS(args);
2669         struct inode *inode = file_inode(file);
2670         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2671         struct btrfs_ioctl_vol_args_v2 *vol_args;
2672         struct block_device *bdev = NULL;
2673         fmode_t mode;
2674         int ret;
2675         bool cancel = false;
2676
2677         if (!capable(CAP_SYS_ADMIN))
2678                 return -EPERM;
2679
2680         vol_args = memdup_user(arg, sizeof(*vol_args));
2681         if (IS_ERR(vol_args))
2682                 return PTR_ERR(vol_args);
2683
2684         if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
2685                 ret = -EOPNOTSUPP;
2686                 goto out;
2687         }
2688
2689         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2690         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2691                 args.devid = vol_args->devid;
2692         } else if (!strcmp("cancel", vol_args->name)) {
2693                 cancel = true;
2694         } else {
2695                 ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
2696                 if (ret)
2697                         goto out;
2698         }
2699
2700         ret = mnt_want_write_file(file);
2701         if (ret)
2702                 goto out;
2703
2704         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
2705                                            cancel);
2706         if (ret)
2707                 goto err_drop;
2708
2709         /* Exclusive operation is now claimed */
2710         ret = btrfs_rm_device(fs_info, &args, &bdev, &mode);
2711
2712         btrfs_exclop_finish(fs_info);
2713
2714         if (!ret) {
2715                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2716                         btrfs_info(fs_info, "device deleted: id %llu",
2717                                         vol_args->devid);
2718                 else
2719                         btrfs_info(fs_info, "device deleted: %s",
2720                                         vol_args->name);
2721         }
2722 err_drop:
2723         mnt_drop_write_file(file);
2724         if (bdev)
2725                 blkdev_put(bdev, mode);
2726 out:
2727         btrfs_put_dev_args_from_path(&args);
2728         kfree(vol_args);
2729         return ret;
2730 }
2731
2732 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2733 {
2734         BTRFS_DEV_LOOKUP_ARGS(args);
2735         struct inode *inode = file_inode(file);
2736         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2737         struct btrfs_ioctl_vol_args *vol_args;
2738         struct block_device *bdev = NULL;
2739         fmode_t mode;
2740         int ret;
2741         bool cancel = false;
2742
2743         if (!capable(CAP_SYS_ADMIN))
2744                 return -EPERM;
2745
2746         vol_args = memdup_user(arg, sizeof(*vol_args));
2747         if (IS_ERR(vol_args))
2748                 return PTR_ERR(vol_args);
2749
2750         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2751         if (!strcmp("cancel", vol_args->name)) {
2752                 cancel = true;
2753         } else {
2754                 ret = btrfs_get_dev_args_from_path(fs_info, &args, vol_args->name);
2755                 if (ret)
2756                         goto out;
2757         }
2758
2759         ret = mnt_want_write_file(file);
2760         if (ret)
2761                 goto out;
2762
2763         ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
2764                                            cancel);
2765         if (ret == 0) {
2766                 ret = btrfs_rm_device(fs_info, &args, &bdev, &mode);
2767                 if (!ret)
2768                         btrfs_info(fs_info, "disk deleted %s", vol_args->name);
2769                 btrfs_exclop_finish(fs_info);
2770         }
2771
2772         mnt_drop_write_file(file);
2773         if (bdev)
2774                 blkdev_put(bdev, mode);
2775 out:
2776         btrfs_put_dev_args_from_path(&args);
2777         kfree(vol_args);
2778         return ret;
2779 }
2780
2781 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
2782                                 void __user *arg)
2783 {
2784         struct btrfs_ioctl_fs_info_args *fi_args;
2785         struct btrfs_device *device;
2786         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
2787         u64 flags_in;
2788         int ret = 0;
2789
2790         fi_args = memdup_user(arg, sizeof(*fi_args));
2791         if (IS_ERR(fi_args))
2792                 return PTR_ERR(fi_args);
2793
2794         flags_in = fi_args->flags;
2795         memset(fi_args, 0, sizeof(*fi_args));
2796
2797         rcu_read_lock();
2798         fi_args->num_devices = fs_devices->num_devices;
2799
2800         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
2801                 if (device->devid > fi_args->max_id)
2802                         fi_args->max_id = device->devid;
2803         }
2804         rcu_read_unlock();
2805
2806         memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
2807         fi_args->nodesize = fs_info->nodesize;
2808         fi_args->sectorsize = fs_info->sectorsize;
2809         fi_args->clone_alignment = fs_info->sectorsize;
2810
2811         if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
2812                 fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
2813                 fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
2814                 fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
2815         }
2816
2817         if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
2818                 fi_args->generation = fs_info->generation;
2819                 fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
2820         }
2821
2822         if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
2823                 memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
2824                        sizeof(fi_args->metadata_uuid));
2825                 fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
2826         }
2827
2828         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2829                 ret = -EFAULT;
2830
2831         kfree(fi_args);
2832         return ret;
2833 }
2834
2835 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
2836                                  void __user *arg)
2837 {
2838         BTRFS_DEV_LOOKUP_ARGS(args);
2839         struct btrfs_ioctl_dev_info_args *di_args;
2840         struct btrfs_device *dev;
2841         int ret = 0;
2842
2843         di_args = memdup_user(arg, sizeof(*di_args));
2844         if (IS_ERR(di_args))
2845                 return PTR_ERR(di_args);
2846
2847         args.devid = di_args->devid;
2848         if (!btrfs_is_empty_uuid(di_args->uuid))
2849                 args.uuid = di_args->uuid;
2850
2851         rcu_read_lock();
2852         dev = btrfs_find_device(fs_info->fs_devices, &args);
2853         if (!dev) {
2854                 ret = -ENODEV;
2855                 goto out;
2856         }
2857
2858         di_args->devid = dev->devid;
2859         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2860         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2861         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2862         memcpy(di_args->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2863         if (dev->name)
2864                 strscpy(di_args->path, btrfs_dev_name(dev), sizeof(di_args->path));
2865         else
2866                 di_args->path[0] = '\0';
2867
2868 out:
2869         rcu_read_unlock();
2870         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2871                 ret = -EFAULT;
2872
2873         kfree(di_args);
2874         return ret;
2875 }
2876
2877 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2878 {
2879         struct inode *inode = file_inode(file);
2880         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2881         struct btrfs_root *root = BTRFS_I(inode)->root;
2882         struct btrfs_root *new_root;
2883         struct btrfs_dir_item *di;
2884         struct btrfs_trans_handle *trans;
2885         struct btrfs_path *path = NULL;
2886         struct btrfs_disk_key disk_key;
2887         struct fscrypt_str name = FSTR_INIT("default", 7);
2888         u64 objectid = 0;
2889         u64 dir_id;
2890         int ret;
2891
2892         if (!capable(CAP_SYS_ADMIN))
2893                 return -EPERM;
2894
2895         ret = mnt_want_write_file(file);
2896         if (ret)
2897                 return ret;
2898
2899         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2900                 ret = -EFAULT;
2901                 goto out;
2902         }
2903
2904         if (!objectid)
2905                 objectid = BTRFS_FS_TREE_OBJECTID;
2906
2907         new_root = btrfs_get_fs_root(fs_info, objectid, true);
2908         if (IS_ERR(new_root)) {
2909                 ret = PTR_ERR(new_root);
2910                 goto out;
2911         }
2912         if (!is_fstree(new_root->root_key.objectid)) {
2913                 ret = -ENOENT;
2914                 goto out_free;
2915         }
2916
2917         path = btrfs_alloc_path();
2918         if (!path) {
2919                 ret = -ENOMEM;
2920                 goto out_free;
2921         }
2922
2923         trans = btrfs_start_transaction(root, 1);
2924         if (IS_ERR(trans)) {
2925                 ret = PTR_ERR(trans);
2926                 goto out_free;
2927         }
2928
2929         dir_id = btrfs_super_root_dir(fs_info->super_copy);
2930         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
2931                                    dir_id, &name, 1);
2932         if (IS_ERR_OR_NULL(di)) {
2933                 btrfs_release_path(path);
2934                 btrfs_end_transaction(trans);
2935                 btrfs_err(fs_info,
2936                           "Umm, you don't have the default diritem, this isn't going to work");
2937                 ret = -ENOENT;
2938                 goto out_free;
2939         }
2940
2941         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2942         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2943         btrfs_mark_buffer_dirty(path->nodes[0]);
2944         btrfs_release_path(path);
2945
2946         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
2947         btrfs_end_transaction(trans);
2948 out_free:
2949         btrfs_put_root(new_root);
2950         btrfs_free_path(path);
2951 out:
2952         mnt_drop_write_file(file);
2953         return ret;
2954 }
2955
2956 static void get_block_group_info(struct list_head *groups_list,
2957                                  struct btrfs_ioctl_space_info *space)
2958 {
2959         struct btrfs_block_group *block_group;
2960
2961         space->total_bytes = 0;
2962         space->used_bytes = 0;
2963         space->flags = 0;
2964         list_for_each_entry(block_group, groups_list, list) {
2965                 space->flags = block_group->flags;
2966                 space->total_bytes += block_group->length;
2967                 space->used_bytes += block_group->used;
2968         }
2969 }
2970
2971 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
2972                                    void __user *arg)
2973 {
2974         struct btrfs_ioctl_space_args space_args;
2975         struct btrfs_ioctl_space_info space;
2976         struct btrfs_ioctl_space_info *dest;
2977         struct btrfs_ioctl_space_info *dest_orig;
2978         struct btrfs_ioctl_space_info __user *user_dest;
2979         struct btrfs_space_info *info;
2980         static const u64 types[] = {
2981                 BTRFS_BLOCK_GROUP_DATA,
2982                 BTRFS_BLOCK_GROUP_SYSTEM,
2983                 BTRFS_BLOCK_GROUP_METADATA,
2984                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
2985         };
2986         int num_types = 4;
2987         int alloc_size;
2988         int ret = 0;
2989         u64 slot_count = 0;
2990         int i, c;
2991
2992         if (copy_from_user(&space_args,
2993                            (struct btrfs_ioctl_space_args __user *)arg,
2994                            sizeof(space_args)))
2995                 return -EFAULT;
2996
2997         for (i = 0; i < num_types; i++) {
2998                 struct btrfs_space_info *tmp;
2999
3000                 info = NULL;
3001                 list_for_each_entry(tmp, &fs_info->space_info, list) {
3002                         if (tmp->flags == types[i]) {
3003                                 info = tmp;
3004                                 break;
3005                         }
3006                 }
3007
3008                 if (!info)
3009                         continue;
3010
3011                 down_read(&info->groups_sem);
3012                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3013                         if (!list_empty(&info->block_groups[c]))
3014                                 slot_count++;
3015                 }
3016                 up_read(&info->groups_sem);
3017         }
3018
3019         /*
3020          * Global block reserve, exported as a space_info
3021          */
3022         slot_count++;
3023
3024         /* space_slots == 0 means they are asking for a count */
3025         if (space_args.space_slots == 0) {
3026                 space_args.total_spaces = slot_count;
3027                 goto out;
3028         }
3029
3030         slot_count = min_t(u64, space_args.space_slots, slot_count);
3031
3032         alloc_size = sizeof(*dest) * slot_count;
3033
3034         /* we generally have at most 6 or so space infos, one for each raid
3035          * level.  So, a whole page should be more than enough for everyone
3036          */
3037         if (alloc_size > PAGE_SIZE)
3038                 return -ENOMEM;
3039
3040         space_args.total_spaces = 0;
3041         dest = kmalloc(alloc_size, GFP_KERNEL);
3042         if (!dest)
3043                 return -ENOMEM;
3044         dest_orig = dest;
3045
3046         /* now we have a buffer to copy into */
3047         for (i = 0; i < num_types; i++) {
3048                 struct btrfs_space_info *tmp;
3049
3050                 if (!slot_count)
3051                         break;
3052
3053                 info = NULL;
3054                 list_for_each_entry(tmp, &fs_info->space_info, list) {
3055                         if (tmp->flags == types[i]) {
3056                                 info = tmp;
3057                                 break;
3058                         }
3059                 }
3060
3061                 if (!info)
3062                         continue;
3063                 down_read(&info->groups_sem);
3064                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3065                         if (!list_empty(&info->block_groups[c])) {
3066                                 get_block_group_info(&info->block_groups[c],
3067                                                      &space);
3068                                 memcpy(dest, &space, sizeof(space));
3069                                 dest++;
3070                                 space_args.total_spaces++;
3071                                 slot_count--;
3072                         }
3073                         if (!slot_count)
3074                                 break;
3075                 }
3076                 up_read(&info->groups_sem);
3077         }
3078
3079         /*
3080          * Add global block reserve
3081          */
3082         if (slot_count) {
3083                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3084
3085                 spin_lock(&block_rsv->lock);
3086                 space.total_bytes = block_rsv->size;
3087                 space.used_bytes = block_rsv->size - block_rsv->reserved;
3088                 spin_unlock(&block_rsv->lock);
3089                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3090                 memcpy(dest, &space, sizeof(space));
3091                 space_args.total_spaces++;
3092         }
3093
3094         user_dest = (struct btrfs_ioctl_space_info __user *)
3095                 (arg + sizeof(struct btrfs_ioctl_space_args));
3096
3097         if (copy_to_user(user_dest, dest_orig, alloc_size))
3098                 ret = -EFAULT;
3099
3100         kfree(dest_orig);
3101 out:
3102         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3103                 ret = -EFAULT;
3104
3105         return ret;
3106 }
3107
3108 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3109                                             void __user *argp)
3110 {
3111         struct btrfs_trans_handle *trans;
3112         u64 transid;
3113
3114         trans = btrfs_attach_transaction_barrier(root);
3115         if (IS_ERR(trans)) {
3116                 if (PTR_ERR(trans) != -ENOENT)
3117                         return PTR_ERR(trans);
3118
3119                 /* No running transaction, don't bother */
3120                 transid = root->fs_info->last_trans_committed;
3121                 goto out;
3122         }
3123         transid = trans->transid;
3124         btrfs_commit_transaction_async(trans);
3125 out:
3126         if (argp)
3127                 if (copy_to_user(argp, &transid, sizeof(transid)))
3128                         return -EFAULT;
3129         return 0;
3130 }
3131
3132 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3133                                            void __user *argp)
3134 {
3135         u64 transid;
3136
3137         if (argp) {
3138                 if (copy_from_user(&transid, argp, sizeof(transid)))
3139                         return -EFAULT;
3140         } else {
3141                 transid = 0;  /* current trans */
3142         }
3143         return btrfs_wait_for_commit(fs_info, transid);
3144 }
3145
3146 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3147 {
3148         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3149         struct btrfs_ioctl_scrub_args *sa;
3150         int ret;
3151
3152         if (!capable(CAP_SYS_ADMIN))
3153                 return -EPERM;
3154
3155         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
3156                 btrfs_err(fs_info, "scrub is not supported on extent tree v2 yet");
3157                 return -EINVAL;
3158         }
3159
3160         sa = memdup_user(arg, sizeof(*sa));
3161         if (IS_ERR(sa))
3162                 return PTR_ERR(sa);
3163
3164         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3165                 ret = mnt_want_write_file(file);
3166                 if (ret)
3167                         goto out;
3168         }
3169
3170         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3171                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3172                               0);
3173
3174         /*
3175          * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3176          * error. This is important as it allows user space to know how much
3177          * progress scrub has done. For example, if scrub is canceled we get
3178          * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3179          * space. Later user space can inspect the progress from the structure
3180          * btrfs_ioctl_scrub_args and resume scrub from where it left off
3181          * previously (btrfs-progs does this).
3182          * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3183          * then return -EFAULT to signal the structure was not copied or it may
3184          * be corrupt and unreliable due to a partial copy.
3185          */
3186         if (copy_to_user(arg, sa, sizeof(*sa)))
3187                 ret = -EFAULT;
3188
3189         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3190                 mnt_drop_write_file(file);
3191 out:
3192         kfree(sa);
3193         return ret;
3194 }
3195
3196 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3197 {
3198         if (!capable(CAP_SYS_ADMIN))
3199                 return -EPERM;
3200
3201         return btrfs_scrub_cancel(fs_info);
3202 }
3203
3204 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3205                                        void __user *arg)
3206 {
3207         struct btrfs_ioctl_scrub_args *sa;
3208         int ret;
3209
3210         if (!capable(CAP_SYS_ADMIN))
3211                 return -EPERM;
3212
3213         sa = memdup_user(arg, sizeof(*sa));
3214         if (IS_ERR(sa))
3215                 return PTR_ERR(sa);
3216
3217         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3218
3219         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3220                 ret = -EFAULT;
3221
3222         kfree(sa);
3223         return ret;
3224 }
3225
3226 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3227                                       void __user *arg)
3228 {
3229         struct btrfs_ioctl_get_dev_stats *sa;
3230         int ret;
3231
3232         sa = memdup_user(arg, sizeof(*sa));
3233         if (IS_ERR(sa))
3234                 return PTR_ERR(sa);
3235
3236         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3237                 kfree(sa);
3238                 return -EPERM;
3239         }
3240
3241         ret = btrfs_get_dev_stats(fs_info, sa);
3242
3243         if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3244                 ret = -EFAULT;
3245
3246         kfree(sa);
3247         return ret;
3248 }
3249
3250 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3251                                     void __user *arg)
3252 {
3253         struct btrfs_ioctl_dev_replace_args *p;
3254         int ret;
3255
3256         if (!capable(CAP_SYS_ADMIN))
3257                 return -EPERM;
3258
3259         if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
3260                 btrfs_err(fs_info, "device replace not supported on extent tree v2 yet");
3261                 return -EINVAL;
3262         }
3263
3264         p = memdup_user(arg, sizeof(*p));
3265         if (IS_ERR(p))
3266                 return PTR_ERR(p);
3267
3268         switch (p->cmd) {
3269         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3270                 if (sb_rdonly(fs_info->sb)) {
3271                         ret = -EROFS;
3272                         goto out;
3273                 }
3274                 if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
3275                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3276                 } else {
3277                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3278                         btrfs_exclop_finish(fs_info);
3279                 }
3280                 break;
3281         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3282                 btrfs_dev_replace_status(fs_info, p);
3283                 ret = 0;
3284                 break;
3285         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3286                 p->result = btrfs_dev_replace_cancel(fs_info);
3287                 ret = 0;
3288                 break;
3289         default:
3290                 ret = -EINVAL;
3291                 break;
3292         }
3293
3294         if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3295                 ret = -EFAULT;
3296 out:
3297         kfree(p);
3298         return ret;
3299 }
3300
3301 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3302 {
3303         int ret = 0;
3304         int i;
3305         u64 rel_ptr;
3306         int size;
3307         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3308         struct inode_fs_paths *ipath = NULL;
3309         struct btrfs_path *path;
3310
3311         if (!capable(CAP_DAC_READ_SEARCH))
3312                 return -EPERM;
3313
3314         path = btrfs_alloc_path();
3315         if (!path) {
3316                 ret = -ENOMEM;
3317                 goto out;
3318         }
3319
3320         ipa = memdup_user(arg, sizeof(*ipa));
3321         if (IS_ERR(ipa)) {
3322                 ret = PTR_ERR(ipa);
3323                 ipa = NULL;
3324                 goto out;
3325         }
3326
3327         size = min_t(u32, ipa->size, 4096);
3328         ipath = init_ipath(size, root, path);
3329         if (IS_ERR(ipath)) {
3330                 ret = PTR_ERR(ipath);
3331                 ipath = NULL;
3332                 goto out;
3333         }
3334
3335         ret = paths_from_inode(ipa->inum, ipath);
3336         if (ret < 0)
3337                 goto out;
3338
3339         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3340                 rel_ptr = ipath->fspath->val[i] -
3341                           (u64)(unsigned long)ipath->fspath->val;
3342                 ipath->fspath->val[i] = rel_ptr;
3343         }
3344
3345         btrfs_free_path(path);
3346         path = NULL;
3347         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3348                            ipath->fspath, size);
3349         if (ret) {
3350                 ret = -EFAULT;
3351                 goto out;
3352         }
3353
3354 out:
3355         btrfs_free_path(path);
3356         free_ipath(ipath);
3357         kfree(ipa);
3358
3359         return ret;
3360 }
3361
3362 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3363                                         void __user *arg, int version)
3364 {
3365         int ret = 0;
3366         int size;
3367         struct btrfs_ioctl_logical_ino_args *loi;
3368         struct btrfs_data_container *inodes = NULL;
3369         struct btrfs_path *path = NULL;
3370         bool ignore_offset;
3371
3372         if (!capable(CAP_SYS_ADMIN))
3373                 return -EPERM;
3374
3375         loi = memdup_user(arg, sizeof(*loi));
3376         if (IS_ERR(loi))
3377                 return PTR_ERR(loi);
3378
3379         if (version == 1) {
3380                 ignore_offset = false;
3381                 size = min_t(u32, loi->size, SZ_64K);
3382         } else {
3383                 /* All reserved bits must be 0 for now */
3384                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3385                         ret = -EINVAL;
3386                         goto out_loi;
3387                 }
3388                 /* Only accept flags we have defined so far */
3389                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3390                         ret = -EINVAL;
3391                         goto out_loi;
3392                 }
3393                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3394                 size = min_t(u32, loi->size, SZ_16M);
3395         }
3396
3397         inodes = init_data_container(size);
3398         if (IS_ERR(inodes)) {
3399                 ret = PTR_ERR(inodes);
3400                 goto out_loi;
3401         }
3402
3403         path = btrfs_alloc_path();
3404         if (!path) {
3405                 ret = -ENOMEM;
3406                 goto out;
3407         }
3408         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3409                                           inodes, ignore_offset);
3410         btrfs_free_path(path);
3411         if (ret == -EINVAL)
3412                 ret = -ENOENT;
3413         if (ret < 0)
3414                 goto out;
3415
3416         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3417                            size);
3418         if (ret)
3419                 ret = -EFAULT;
3420
3421 out:
3422         kvfree(inodes);
3423 out_loi:
3424         kfree(loi);
3425
3426         return ret;
3427 }
3428
3429 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3430                                struct btrfs_ioctl_balance_args *bargs)
3431 {
3432         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3433
3434         bargs->flags = bctl->flags;
3435
3436         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3437                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3438         if (atomic_read(&fs_info->balance_pause_req))
3439                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3440         if (atomic_read(&fs_info->balance_cancel_req))
3441                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3442
3443         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3444         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3445         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3446
3447         spin_lock(&fs_info->balance_lock);
3448         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3449         spin_unlock(&fs_info->balance_lock);
3450 }
3451
3452 /*
3453  * Try to acquire fs_info::balance_mutex as well as set BTRFS_EXLCOP_BALANCE as
3454  * required.
3455  *
3456  * @fs_info:       the filesystem
3457  * @excl_acquired: ptr to boolean value which is set to false in case balance
3458  *                 is being resumed
3459  *
3460  * Return 0 on success in which case both fs_info::balance is acquired as well
3461  * as exclusive ops are blocked. In case of failure return an error code.
3462  */
3463 static int btrfs_try_lock_balance(struct btrfs_fs_info *fs_info, bool *excl_acquired)
3464 {
3465         int ret;
3466
3467         /*
3468          * Exclusive operation is locked. Three possibilities:
3469          *   (1) some other op is running
3470          *   (2) balance is running
3471          *   (3) balance is paused -- special case (think resume)
3472          */
3473         while (1) {
3474                 if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
3475                         *excl_acquired = true;
3476                         mutex_lock(&fs_info->balance_mutex);
3477                         return 0;
3478                 }
3479
3480                 mutex_lock(&fs_info->balance_mutex);
3481                 if (fs_info->balance_ctl) {
3482                         /* This is either (2) or (3) */
3483                         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3484                                 /* This is (2) */
3485                                 ret = -EINPROGRESS;
3486                                 goto out_failure;
3487
3488                         } else {
3489                                 mutex_unlock(&fs_info->balance_mutex);
3490                                 /*
3491                                  * Lock released to allow other waiters to
3492                                  * continue, we'll reexamine the status again.
3493                                  */
3494                                 mutex_lock(&fs_info->balance_mutex);
3495
3496                                 if (fs_info->balance_ctl &&
3497                                     !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3498                                         /* This is (3) */
3499                                         *excl_acquired = false;
3500                                         return 0;
3501                                 }
3502                         }
3503                 } else {
3504                         /* This is (1) */
3505                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3506                         goto out_failure;
3507                 }
3508
3509                 mutex_unlock(&fs_info->balance_mutex);
3510         }
3511
3512 out_failure:
3513         mutex_unlock(&fs_info->balance_mutex);
3514         *excl_acquired = false;
3515         return ret;
3516 }
3517
3518 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3519 {
3520         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3521         struct btrfs_fs_info *fs_info = root->fs_info;
3522         struct btrfs_ioctl_balance_args *bargs;
3523         struct btrfs_balance_control *bctl;
3524         bool need_unlock = true;
3525         int ret;
3526
3527         if (!capable(CAP_SYS_ADMIN))
3528                 return -EPERM;
3529
3530         ret = mnt_want_write_file(file);
3531         if (ret)
3532                 return ret;
3533
3534         bargs = memdup_user(arg, sizeof(*bargs));
3535         if (IS_ERR(bargs)) {
3536                 ret = PTR_ERR(bargs);
3537                 bargs = NULL;
3538                 goto out;
3539         }
3540
3541         ret = btrfs_try_lock_balance(fs_info, &need_unlock);
3542         if (ret)
3543                 goto out;
3544
3545         lockdep_assert_held(&fs_info->balance_mutex);
3546
3547         if (bargs->flags & BTRFS_BALANCE_RESUME) {
3548                 if (!fs_info->balance_ctl) {
3549                         ret = -ENOTCONN;
3550                         goto out_unlock;
3551                 }
3552
3553                 bctl = fs_info->balance_ctl;
3554                 spin_lock(&fs_info->balance_lock);
3555                 bctl->flags |= BTRFS_BALANCE_RESUME;
3556                 spin_unlock(&fs_info->balance_lock);
3557                 btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE);
3558
3559                 goto do_balance;
3560         }
3561
3562         if (bargs->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
3563                 ret = -EINVAL;
3564                 goto out_unlock;
3565         }
3566
3567         if (fs_info->balance_ctl) {
3568                 ret = -EINPROGRESS;
3569                 goto out_unlock;
3570         }
3571
3572         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
3573         if (!bctl) {
3574                 ret = -ENOMEM;
3575                 goto out_unlock;
3576         }
3577
3578         memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3579         memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3580         memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3581
3582         bctl->flags = bargs->flags;
3583 do_balance:
3584         /*
3585          * Ownership of bctl and exclusive operation goes to btrfs_balance.
3586          * bctl is freed in reset_balance_state, or, if restriper was paused
3587          * all the way until unmount, in free_fs_info.  The flag should be
3588          * cleared after reset_balance_state.
3589          */
3590         need_unlock = false;
3591
3592         ret = btrfs_balance(fs_info, bctl, bargs);
3593         bctl = NULL;
3594
3595         if (ret == 0 || ret == -ECANCELED) {
3596                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3597                         ret = -EFAULT;
3598         }
3599
3600         kfree(bctl);
3601 out_unlock:
3602         mutex_unlock(&fs_info->balance_mutex);
3603         if (need_unlock)
3604                 btrfs_exclop_finish(fs_info);
3605 out:
3606         mnt_drop_write_file(file);
3607         kfree(bargs);
3608         return ret;
3609 }
3610
3611 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
3612 {
3613         if (!capable(CAP_SYS_ADMIN))
3614                 return -EPERM;
3615
3616         switch (cmd) {
3617         case BTRFS_BALANCE_CTL_PAUSE:
3618                 return btrfs_pause_balance(fs_info);
3619         case BTRFS_BALANCE_CTL_CANCEL:
3620                 return btrfs_cancel_balance(fs_info);
3621         }
3622
3623         return -EINVAL;
3624 }
3625
3626 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
3627                                          void __user *arg)
3628 {
3629         struct btrfs_ioctl_balance_args *bargs;
3630         int ret = 0;
3631
3632         if (!capable(CAP_SYS_ADMIN))
3633                 return -EPERM;
3634
3635         mutex_lock(&fs_info->balance_mutex);
3636         if (!fs_info->balance_ctl) {
3637                 ret = -ENOTCONN;
3638                 goto out;
3639         }
3640
3641         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
3642         if (!bargs) {
3643                 ret = -ENOMEM;
3644                 goto out;
3645         }
3646
3647         btrfs_update_ioctl_balance_args(fs_info, bargs);
3648
3649         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3650                 ret = -EFAULT;
3651
3652         kfree(bargs);
3653 out:
3654         mutex_unlock(&fs_info->balance_mutex);
3655         return ret;
3656 }
3657
3658 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3659 {
3660         struct inode *inode = file_inode(file);
3661         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3662         struct btrfs_ioctl_quota_ctl_args *sa;
3663         int ret;
3664
3665         if (!capable(CAP_SYS_ADMIN))
3666                 return -EPERM;
3667
3668         ret = mnt_want_write_file(file);
3669         if (ret)
3670                 return ret;
3671
3672         sa = memdup_user(arg, sizeof(*sa));
3673         if (IS_ERR(sa)) {
3674                 ret = PTR_ERR(sa);
3675                 goto drop_write;
3676         }
3677
3678         down_write(&fs_info->subvol_sem);
3679
3680         switch (sa->cmd) {
3681         case BTRFS_QUOTA_CTL_ENABLE:
3682                 ret = btrfs_quota_enable(fs_info);
3683                 break;
3684         case BTRFS_QUOTA_CTL_DISABLE:
3685                 ret = btrfs_quota_disable(fs_info);
3686                 break;
3687         default:
3688                 ret = -EINVAL;
3689                 break;
3690         }
3691
3692         kfree(sa);
3693         up_write(&fs_info->subvol_sem);
3694 drop_write:
3695         mnt_drop_write_file(file);
3696         return ret;
3697 }
3698
3699 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3700 {
3701         struct inode *inode = file_inode(file);
3702         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3703         struct btrfs_root *root = BTRFS_I(inode)->root;
3704         struct btrfs_ioctl_qgroup_assign_args *sa;
3705         struct btrfs_trans_handle *trans;
3706         int ret;
3707         int err;
3708
3709         if (!capable(CAP_SYS_ADMIN))
3710                 return -EPERM;
3711
3712         ret = mnt_want_write_file(file);
3713         if (ret)
3714                 return ret;
3715
3716         sa = memdup_user(arg, sizeof(*sa));
3717         if (IS_ERR(sa)) {
3718                 ret = PTR_ERR(sa);
3719                 goto drop_write;
3720         }
3721
3722         trans = btrfs_join_transaction(root);
3723         if (IS_ERR(trans)) {
3724                 ret = PTR_ERR(trans);
3725                 goto out;
3726         }
3727
3728         if (sa->assign) {
3729                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
3730         } else {
3731                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
3732         }
3733
3734         /* update qgroup status and info */
3735         err = btrfs_run_qgroups(trans);
3736         if (err < 0)
3737                 btrfs_handle_fs_error(fs_info, err,
3738                                       "failed to update qgroup status and info");
3739         err = btrfs_end_transaction(trans);
3740         if (err && !ret)
3741                 ret = err;
3742
3743 out:
3744         kfree(sa);
3745 drop_write:
3746         mnt_drop_write_file(file);
3747         return ret;
3748 }
3749
3750 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3751 {
3752         struct inode *inode = file_inode(file);
3753         struct btrfs_root *root = BTRFS_I(inode)->root;
3754         struct btrfs_ioctl_qgroup_create_args *sa;
3755         struct btrfs_trans_handle *trans;
3756         int ret;
3757         int err;
3758
3759         if (!capable(CAP_SYS_ADMIN))
3760                 return -EPERM;
3761
3762         ret = mnt_want_write_file(file);
3763         if (ret)
3764                 return ret;
3765
3766         sa = memdup_user(arg, sizeof(*sa));
3767         if (IS_ERR(sa)) {
3768                 ret = PTR_ERR(sa);
3769                 goto drop_write;
3770         }
3771
3772         if (!sa->qgroupid) {
3773                 ret = -EINVAL;
3774                 goto out;
3775         }
3776
3777         trans = btrfs_join_transaction(root);
3778         if (IS_ERR(trans)) {
3779                 ret = PTR_ERR(trans);
3780                 goto out;
3781         }
3782
3783         if (sa->create) {
3784                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
3785         } else {
3786                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
3787         }
3788
3789         err = btrfs_end_transaction(trans);
3790         if (err && !ret)
3791                 ret = err;
3792
3793 out:
3794         kfree(sa);
3795 drop_write:
3796         mnt_drop_write_file(file);
3797         return ret;
3798 }
3799
3800 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3801 {
3802         struct inode *inode = file_inode(file);
3803         struct btrfs_root *root = BTRFS_I(inode)->root;
3804         struct btrfs_ioctl_qgroup_limit_args *sa;
3805         struct btrfs_trans_handle *trans;
3806         int ret;
3807         int err;
3808         u64 qgroupid;
3809
3810         if (!capable(CAP_SYS_ADMIN))
3811                 return -EPERM;
3812
3813         ret = mnt_want_write_file(file);
3814         if (ret)
3815                 return ret;
3816
3817         sa = memdup_user(arg, sizeof(*sa));
3818         if (IS_ERR(sa)) {
3819                 ret = PTR_ERR(sa);
3820                 goto drop_write;
3821         }
3822
3823         trans = btrfs_join_transaction(root);
3824         if (IS_ERR(trans)) {
3825                 ret = PTR_ERR(trans);
3826                 goto out;
3827         }
3828
3829         qgroupid = sa->qgroupid;
3830         if (!qgroupid) {
3831                 /* take the current subvol as qgroup */
3832                 qgroupid = root->root_key.objectid;
3833         }
3834
3835         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
3836
3837         err = btrfs_end_transaction(trans);
3838         if (err && !ret)
3839                 ret = err;
3840
3841 out:
3842         kfree(sa);
3843 drop_write:
3844         mnt_drop_write_file(file);
3845         return ret;
3846 }
3847
3848 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
3849 {
3850         struct inode *inode = file_inode(file);
3851         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3852         struct btrfs_ioctl_quota_rescan_args *qsa;
3853         int ret;
3854
3855         if (!capable(CAP_SYS_ADMIN))
3856                 return -EPERM;
3857
3858         ret = mnt_want_write_file(file);
3859         if (ret)
3860                 return ret;
3861
3862         qsa = memdup_user(arg, sizeof(*qsa));
3863         if (IS_ERR(qsa)) {
3864                 ret = PTR_ERR(qsa);
3865                 goto drop_write;
3866         }
3867
3868         if (qsa->flags) {
3869                 ret = -EINVAL;
3870                 goto out;
3871         }
3872
3873         ret = btrfs_qgroup_rescan(fs_info);
3874
3875 out:
3876         kfree(qsa);
3877 drop_write:
3878         mnt_drop_write_file(file);
3879         return ret;
3880 }
3881
3882 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
3883                                                 void __user *arg)
3884 {
3885         struct btrfs_ioctl_quota_rescan_args qsa = {0};
3886
3887         if (!capable(CAP_SYS_ADMIN))
3888                 return -EPERM;
3889
3890         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
3891                 qsa.flags = 1;
3892                 qsa.progress = fs_info->qgroup_rescan_progress.objectid;
3893         }
3894
3895         if (copy_to_user(arg, &qsa, sizeof(qsa)))
3896                 return -EFAULT;
3897
3898         return 0;
3899 }
3900
3901 static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
3902                                                 void __user *arg)
3903 {
3904         if (!capable(CAP_SYS_ADMIN))
3905                 return -EPERM;
3906
3907         return btrfs_qgroup_wait_for_completion(fs_info, true);
3908 }
3909
3910 static long _btrfs_ioctl_set_received_subvol(struct file *file,
3911                                             struct mnt_idmap *idmap,
3912                                             struct btrfs_ioctl_received_subvol_args *sa)
3913 {
3914         struct inode *inode = file_inode(file);
3915         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3916         struct btrfs_root *root = BTRFS_I(inode)->root;
3917         struct btrfs_root_item *root_item = &root->root_item;
3918         struct btrfs_trans_handle *trans;
3919         struct timespec64 ct = current_time(inode);
3920         int ret = 0;
3921         int received_uuid_changed;
3922
3923         if (!inode_owner_or_capable(idmap, inode))
3924                 return -EPERM;
3925
3926         ret = mnt_want_write_file(file);
3927         if (ret < 0)
3928                 return ret;
3929
3930         down_write(&fs_info->subvol_sem);
3931
3932         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
3933                 ret = -EINVAL;
3934                 goto out;
3935         }
3936
3937         if (btrfs_root_readonly(root)) {
3938                 ret = -EROFS;
3939                 goto out;
3940         }
3941
3942         /*
3943          * 1 - root item
3944          * 2 - uuid items (received uuid + subvol uuid)
3945          */
3946         trans = btrfs_start_transaction(root, 3);
3947         if (IS_ERR(trans)) {
3948                 ret = PTR_ERR(trans);
3949                 trans = NULL;
3950                 goto out;
3951         }
3952
3953         sa->rtransid = trans->transid;
3954         sa->rtime.sec = ct.tv_sec;
3955         sa->rtime.nsec = ct.tv_nsec;
3956
3957         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
3958                                        BTRFS_UUID_SIZE);
3959         if (received_uuid_changed &&
3960             !btrfs_is_empty_uuid(root_item->received_uuid)) {
3961                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
3962                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3963                                           root->root_key.objectid);
3964                 if (ret && ret != -ENOENT) {
3965                         btrfs_abort_transaction(trans, ret);
3966                         btrfs_end_transaction(trans);
3967                         goto out;
3968                 }
3969         }
3970         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3971         btrfs_set_root_stransid(root_item, sa->stransid);
3972         btrfs_set_root_rtransid(root_item, sa->rtransid);
3973         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
3974         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
3975         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
3976         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
3977
3978         ret = btrfs_update_root(trans, fs_info->tree_root,
3979                                 &root->root_key, &root->root_item);
3980         if (ret < 0) {
3981                 btrfs_end_transaction(trans);
3982                 goto out;
3983         }
3984         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
3985                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
3986                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3987                                           root->root_key.objectid);
3988                 if (ret < 0 && ret != -EEXIST) {
3989                         btrfs_abort_transaction(trans, ret);
3990                         btrfs_end_transaction(trans);
3991                         goto out;
3992                 }
3993         }
3994         ret = btrfs_commit_transaction(trans);
3995 out:
3996         up_write(&fs_info->subvol_sem);
3997         mnt_drop_write_file(file);
3998         return ret;
3999 }
4000
4001 #ifdef CONFIG_64BIT
4002 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4003                                                 void __user *arg)
4004 {
4005         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4006         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4007         int ret = 0;
4008
4009         args32 = memdup_user(arg, sizeof(*args32));
4010         if (IS_ERR(args32))
4011                 return PTR_ERR(args32);
4012
4013         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4014         if (!args64) {
4015                 ret = -ENOMEM;
4016                 goto out;
4017         }
4018
4019         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4020         args64->stransid = args32->stransid;
4021         args64->rtransid = args32->rtransid;
4022         args64->stime.sec = args32->stime.sec;
4023         args64->stime.nsec = args32->stime.nsec;
4024         args64->rtime.sec = args32->rtime.sec;
4025         args64->rtime.nsec = args32->rtime.nsec;
4026         args64->flags = args32->flags;
4027
4028         ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), args64);
4029         if (ret)
4030                 goto out;
4031
4032         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4033         args32->stransid = args64->stransid;
4034         args32->rtransid = args64->rtransid;
4035         args32->stime.sec = args64->stime.sec;
4036         args32->stime.nsec = args64->stime.nsec;
4037         args32->rtime.sec = args64->rtime.sec;
4038         args32->rtime.nsec = args64->rtime.nsec;
4039         args32->flags = args64->flags;
4040
4041         ret = copy_to_user(arg, args32, sizeof(*args32));
4042         if (ret)
4043                 ret = -EFAULT;
4044
4045 out:
4046         kfree(args32);
4047         kfree(args64);
4048         return ret;
4049 }
4050 #endif
4051
4052 static long btrfs_ioctl_set_received_subvol(struct file *file,
4053                                             void __user *arg)
4054 {
4055         struct btrfs_ioctl_received_subvol_args *sa = NULL;
4056         int ret = 0;
4057
4058         sa = memdup_user(arg, sizeof(*sa));
4059         if (IS_ERR(sa))
4060                 return PTR_ERR(sa);
4061
4062         ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_idmap(file), sa);
4063
4064         if (ret)
4065                 goto out;
4066
4067         ret = copy_to_user(arg, sa, sizeof(*sa));
4068         if (ret)
4069                 ret = -EFAULT;
4070
4071 out:
4072         kfree(sa);
4073         return ret;
4074 }
4075
4076 static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4077                                         void __user *arg)
4078 {
4079         size_t len;
4080         int ret;
4081         char label[BTRFS_LABEL_SIZE];
4082
4083         spin_lock(&fs_info->super_lock);
4084         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4085         spin_unlock(&fs_info->super_lock);
4086
4087         len = strnlen(label, BTRFS_LABEL_SIZE);
4088
4089         if (len == BTRFS_LABEL_SIZE) {
4090                 btrfs_warn(fs_info,
4091                            "label is too long, return the first %zu bytes",
4092                            --len);
4093         }
4094
4095         ret = copy_to_user(arg, label, len);
4096
4097         return ret ? -EFAULT : 0;
4098 }
4099
4100 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4101 {
4102         struct inode *inode = file_inode(file);
4103         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4104         struct btrfs_root *root = BTRFS_I(inode)->root;
4105         struct btrfs_super_block *super_block = fs_info->super_copy;
4106         struct btrfs_trans_handle *trans;
4107         char label[BTRFS_LABEL_SIZE];
4108         int ret;
4109
4110         if (!capable(CAP_SYS_ADMIN))
4111                 return -EPERM;
4112
4113         if (copy_from_user(label, arg, sizeof(label)))
4114                 return -EFAULT;
4115
4116         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4117                 btrfs_err(fs_info,
4118                           "unable to set label with more than %d bytes",
4119                           BTRFS_LABEL_SIZE - 1);
4120                 return -EINVAL;
4121         }
4122
4123         ret = mnt_want_write_file(file);
4124         if (ret)
4125                 return ret;
4126
4127         trans = btrfs_start_transaction(root, 0);
4128         if (IS_ERR(trans)) {
4129                 ret = PTR_ERR(trans);
4130                 goto out_unlock;
4131         }
4132
4133         spin_lock(&fs_info->super_lock);
4134         strcpy(super_block->label, label);
4135         spin_unlock(&fs_info->super_lock);
4136         ret = btrfs_commit_transaction(trans);
4137
4138 out_unlock:
4139         mnt_drop_write_file(file);
4140         return ret;
4141 }
4142
4143 #define INIT_FEATURE_FLAGS(suffix) \
4144         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4145           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4146           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4147
4148 int btrfs_ioctl_get_supported_features(void __user *arg)
4149 {
4150         static const struct btrfs_ioctl_feature_flags features[3] = {
4151                 INIT_FEATURE_FLAGS(SUPP),
4152                 INIT_FEATURE_FLAGS(SAFE_SET),
4153                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
4154         };
4155
4156         if (copy_to_user(arg, &features, sizeof(features)))
4157                 return -EFAULT;
4158
4159         return 0;
4160 }
4161
4162 static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4163                                         void __user *arg)
4164 {
4165         struct btrfs_super_block *super_block = fs_info->super_copy;
4166         struct btrfs_ioctl_feature_flags features;
4167
4168         features.compat_flags = btrfs_super_compat_flags(super_block);
4169         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4170         features.incompat_flags = btrfs_super_incompat_flags(super_block);
4171
4172         if (copy_to_user(arg, &features, sizeof(features)))
4173                 return -EFAULT;
4174
4175         return 0;
4176 }
4177
4178 static int check_feature_bits(struct btrfs_fs_info *fs_info,
4179                               enum btrfs_feature_set set,
4180                               u64 change_mask, u64 flags, u64 supported_flags,
4181                               u64 safe_set, u64 safe_clear)
4182 {
4183         const char *type = btrfs_feature_set_name(set);
4184         char *names;
4185         u64 disallowed, unsupported;
4186         u64 set_mask = flags & change_mask;
4187         u64 clear_mask = ~flags & change_mask;
4188
4189         unsupported = set_mask & ~supported_flags;
4190         if (unsupported) {
4191                 names = btrfs_printable_features(set, unsupported);
4192                 if (names) {
4193                         btrfs_warn(fs_info,
4194                                    "this kernel does not support the %s feature bit%s",
4195                                    names, strchr(names, ',') ? "s" : "");
4196                         kfree(names);
4197                 } else
4198                         btrfs_warn(fs_info,
4199                                    "this kernel does not support %s bits 0x%llx",
4200                                    type, unsupported);
4201                 return -EOPNOTSUPP;
4202         }
4203
4204         disallowed = set_mask & ~safe_set;
4205         if (disallowed) {
4206                 names = btrfs_printable_features(set, disallowed);
4207                 if (names) {
4208                         btrfs_warn(fs_info,
4209                                    "can't set the %s feature bit%s while mounted",
4210                                    names, strchr(names, ',') ? "s" : "");
4211                         kfree(names);
4212                 } else
4213                         btrfs_warn(fs_info,
4214                                    "can't set %s bits 0x%llx while mounted",
4215                                    type, disallowed);
4216                 return -EPERM;
4217         }
4218
4219         disallowed = clear_mask & ~safe_clear;
4220         if (disallowed) {
4221                 names = btrfs_printable_features(set, disallowed);
4222                 if (names) {
4223                         btrfs_warn(fs_info,
4224                                    "can't clear the %s feature bit%s while mounted",
4225                                    names, strchr(names, ',') ? "s" : "");
4226                         kfree(names);
4227                 } else
4228                         btrfs_warn(fs_info,
4229                                    "can't clear %s bits 0x%llx while mounted",
4230                                    type, disallowed);
4231                 return -EPERM;
4232         }
4233
4234         return 0;
4235 }
4236
4237 #define check_feature(fs_info, change_mask, flags, mask_base)   \
4238 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
4239                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
4240                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
4241                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4242
4243 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4244 {
4245         struct inode *inode = file_inode(file);
4246         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4247         struct btrfs_root *root = BTRFS_I(inode)->root;
4248         struct btrfs_super_block *super_block = fs_info->super_copy;
4249         struct btrfs_ioctl_feature_flags flags[2];
4250         struct btrfs_trans_handle *trans;
4251         u64 newflags;
4252         int ret;
4253
4254         if (!capable(CAP_SYS_ADMIN))
4255                 return -EPERM;
4256
4257         if (copy_from_user(flags, arg, sizeof(flags)))
4258                 return -EFAULT;
4259
4260         /* Nothing to do */
4261         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4262             !flags[0].incompat_flags)
4263                 return 0;
4264
4265         ret = check_feature(fs_info, flags[0].compat_flags,
4266                             flags[1].compat_flags, COMPAT);
4267         if (ret)
4268                 return ret;
4269
4270         ret = check_feature(fs_info, flags[0].compat_ro_flags,
4271                             flags[1].compat_ro_flags, COMPAT_RO);
4272         if (ret)
4273                 return ret;
4274
4275         ret = check_feature(fs_info, flags[0].incompat_flags,
4276                             flags[1].incompat_flags, INCOMPAT);
4277         if (ret)
4278                 return ret;
4279
4280         ret = mnt_want_write_file(file);
4281         if (ret)
4282                 return ret;
4283
4284         trans = btrfs_start_transaction(root, 0);
4285         if (IS_ERR(trans)) {
4286                 ret = PTR_ERR(trans);
4287                 goto out_drop_write;
4288         }
4289
4290         spin_lock(&fs_info->super_lock);
4291         newflags = btrfs_super_compat_flags(super_block);
4292         newflags |= flags[0].compat_flags & flags[1].compat_flags;
4293         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4294         btrfs_set_super_compat_flags(super_block, newflags);
4295
4296         newflags = btrfs_super_compat_ro_flags(super_block);
4297         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4298         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4299         btrfs_set_super_compat_ro_flags(super_block, newflags);
4300
4301         newflags = btrfs_super_incompat_flags(super_block);
4302         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4303         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4304         btrfs_set_super_incompat_flags(super_block, newflags);
4305         spin_unlock(&fs_info->super_lock);
4306
4307         ret = btrfs_commit_transaction(trans);
4308 out_drop_write:
4309         mnt_drop_write_file(file);
4310
4311         return ret;
4312 }
4313
4314 static int _btrfs_ioctl_send(struct inode *inode, void __user *argp, bool compat)
4315 {
4316         struct btrfs_ioctl_send_args *arg;
4317         int ret;
4318
4319         if (compat) {
4320 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4321                 struct btrfs_ioctl_send_args_32 args32;
4322
4323                 ret = copy_from_user(&args32, argp, sizeof(args32));
4324                 if (ret)
4325                         return -EFAULT;
4326                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4327                 if (!arg)
4328                         return -ENOMEM;
4329                 arg->send_fd = args32.send_fd;
4330                 arg->clone_sources_count = args32.clone_sources_count;
4331                 arg->clone_sources = compat_ptr(args32.clone_sources);
4332                 arg->parent_root = args32.parent_root;
4333                 arg->flags = args32.flags;
4334                 memcpy(arg->reserved, args32.reserved,
4335                        sizeof(args32.reserved));
4336 #else
4337                 return -ENOTTY;
4338 #endif
4339         } else {
4340                 arg = memdup_user(argp, sizeof(*arg));
4341                 if (IS_ERR(arg))
4342                         return PTR_ERR(arg);
4343         }
4344         ret = btrfs_ioctl_send(inode, arg);
4345         kfree(arg);
4346         return ret;
4347 }
4348
4349 static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp,
4350                                     bool compat)
4351 {
4352         struct btrfs_ioctl_encoded_io_args args = { 0 };
4353         size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args,
4354                                              flags);
4355         size_t copy_end;
4356         struct iovec iovstack[UIO_FASTIOV];
4357         struct iovec *iov = iovstack;
4358         struct iov_iter iter;
4359         loff_t pos;
4360         struct kiocb kiocb;
4361         ssize_t ret;
4362
4363         if (!capable(CAP_SYS_ADMIN)) {
4364                 ret = -EPERM;
4365                 goto out_acct;
4366         }
4367
4368         if (compat) {
4369 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4370                 struct btrfs_ioctl_encoded_io_args_32 args32;
4371
4372                 copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32,
4373                                        flags);
4374                 if (copy_from_user(&args32, argp, copy_end)) {
4375                         ret = -EFAULT;
4376                         goto out_acct;
4377                 }
4378                 args.iov = compat_ptr(args32.iov);
4379                 args.iovcnt = args32.iovcnt;
4380                 args.offset = args32.offset;
4381                 args.flags = args32.flags;
4382 #else
4383                 return -ENOTTY;
4384 #endif
4385         } else {
4386                 copy_end = copy_end_kernel;
4387                 if (copy_from_user(&args, argp, copy_end)) {
4388                         ret = -EFAULT;
4389                         goto out_acct;
4390                 }
4391         }
4392         if (args.flags != 0) {
4393                 ret = -EINVAL;
4394                 goto out_acct;
4395         }
4396
4397         ret = import_iovec(ITER_DEST, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4398                            &iov, &iter);
4399         if (ret < 0)
4400                 goto out_acct;
4401
4402         if (iov_iter_count(&iter) == 0) {
4403                 ret = 0;
4404                 goto out_iov;
4405         }
4406         pos = args.offset;
4407         ret = rw_verify_area(READ, file, &pos, args.len);
4408         if (ret < 0)
4409                 goto out_iov;
4410
4411         init_sync_kiocb(&kiocb, file);
4412         kiocb.ki_pos = pos;
4413
4414         ret = btrfs_encoded_read(&kiocb, &iter, &args);
4415         if (ret >= 0) {
4416                 fsnotify_access(file);
4417                 if (copy_to_user(argp + copy_end,
4418                                  (char *)&args + copy_end_kernel,
4419                                  sizeof(args) - copy_end_kernel))
4420                         ret = -EFAULT;
4421         }
4422
4423 out_iov:
4424         kfree(iov);
4425 out_acct:
4426         if (ret > 0)
4427                 add_rchar(current, ret);
4428         inc_syscr(current);
4429         return ret;
4430 }
4431
4432 static int btrfs_ioctl_encoded_write(struct file *file, void __user *argp, bool compat)
4433 {
4434         struct btrfs_ioctl_encoded_io_args args;
4435         struct iovec iovstack[UIO_FASTIOV];
4436         struct iovec *iov = iovstack;
4437         struct iov_iter iter;
4438         loff_t pos;
4439         struct kiocb kiocb;
4440         ssize_t ret;
4441
4442         if (!capable(CAP_SYS_ADMIN)) {
4443                 ret = -EPERM;
4444                 goto out_acct;
4445         }
4446
4447         if (!(file->f_mode & FMODE_WRITE)) {
4448                 ret = -EBADF;
4449                 goto out_acct;
4450         }
4451
4452         if (compat) {
4453 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4454                 struct btrfs_ioctl_encoded_io_args_32 args32;
4455
4456                 if (copy_from_user(&args32, argp, sizeof(args32))) {
4457                         ret = -EFAULT;
4458                         goto out_acct;
4459                 }
4460                 args.iov = compat_ptr(args32.iov);
4461                 args.iovcnt = args32.iovcnt;
4462                 args.offset = args32.offset;
4463                 args.flags = args32.flags;
4464                 args.len = args32.len;
4465                 args.unencoded_len = args32.unencoded_len;
4466                 args.unencoded_offset = args32.unencoded_offset;
4467                 args.compression = args32.compression;
4468                 args.encryption = args32.encryption;
4469                 memcpy(args.reserved, args32.reserved, sizeof(args.reserved));
4470 #else
4471                 return -ENOTTY;
4472 #endif
4473         } else {
4474                 if (copy_from_user(&args, argp, sizeof(args))) {
4475                         ret = -EFAULT;
4476                         goto out_acct;
4477                 }
4478         }
4479
4480         ret = -EINVAL;
4481         if (args.flags != 0)
4482                 goto out_acct;
4483         if (memchr_inv(args.reserved, 0, sizeof(args.reserved)))
4484                 goto out_acct;
4485         if (args.compression == BTRFS_ENCODED_IO_COMPRESSION_NONE &&
4486             args.encryption == BTRFS_ENCODED_IO_ENCRYPTION_NONE)
4487                 goto out_acct;
4488         if (args.compression >= BTRFS_ENCODED_IO_COMPRESSION_TYPES ||
4489             args.encryption >= BTRFS_ENCODED_IO_ENCRYPTION_TYPES)
4490                 goto out_acct;
4491         if (args.unencoded_offset > args.unencoded_len)
4492                 goto out_acct;
4493         if (args.len > args.unencoded_len - args.unencoded_offset)
4494                 goto out_acct;
4495
4496         ret = import_iovec(ITER_SOURCE, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
4497                            &iov, &iter);
4498         if (ret < 0)
4499                 goto out_acct;
4500
4501         file_start_write(file);
4502
4503         if (iov_iter_count(&iter) == 0) {
4504                 ret = 0;
4505                 goto out_end_write;
4506         }
4507         pos = args.offset;
4508         ret = rw_verify_area(WRITE, file, &pos, args.len);
4509         if (ret < 0)
4510                 goto out_end_write;
4511
4512         init_sync_kiocb(&kiocb, file);
4513         ret = kiocb_set_rw_flags(&kiocb, 0);
4514         if (ret)
4515                 goto out_end_write;
4516         kiocb.ki_pos = pos;
4517
4518         ret = btrfs_do_write_iter(&kiocb, &iter, &args);
4519         if (ret > 0)
4520                 fsnotify_modify(file);
4521
4522 out_end_write:
4523         file_end_write(file);
4524         kfree(iov);
4525 out_acct:
4526         if (ret > 0)
4527                 add_wchar(current, ret);
4528         inc_syscw(current);
4529         return ret;
4530 }
4531
4532 long btrfs_ioctl(struct file *file, unsigned int
4533                 cmd, unsigned long arg)
4534 {
4535         struct inode *inode = file_inode(file);
4536         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4537         struct btrfs_root *root = BTRFS_I(inode)->root;
4538         void __user *argp = (void __user *)arg;
4539
4540         switch (cmd) {
4541         case FS_IOC_GETVERSION:
4542                 return btrfs_ioctl_getversion(inode, argp);
4543         case FS_IOC_GETFSLABEL:
4544                 return btrfs_ioctl_get_fslabel(fs_info, argp);
4545         case FS_IOC_SETFSLABEL:
4546                 return btrfs_ioctl_set_fslabel(file, argp);
4547         case FITRIM:
4548                 return btrfs_ioctl_fitrim(fs_info, argp);
4549         case BTRFS_IOC_SNAP_CREATE:
4550                 return btrfs_ioctl_snap_create(file, argp, 0);
4551         case BTRFS_IOC_SNAP_CREATE_V2:
4552                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
4553         case BTRFS_IOC_SUBVOL_CREATE:
4554                 return btrfs_ioctl_snap_create(file, argp, 1);
4555         case BTRFS_IOC_SUBVOL_CREATE_V2:
4556                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
4557         case BTRFS_IOC_SNAP_DESTROY:
4558                 return btrfs_ioctl_snap_destroy(file, argp, false);
4559         case BTRFS_IOC_SNAP_DESTROY_V2:
4560                 return btrfs_ioctl_snap_destroy(file, argp, true);
4561         case BTRFS_IOC_SUBVOL_GETFLAGS:
4562                 return btrfs_ioctl_subvol_getflags(inode, argp);
4563         case BTRFS_IOC_SUBVOL_SETFLAGS:
4564                 return btrfs_ioctl_subvol_setflags(file, argp);
4565         case BTRFS_IOC_DEFAULT_SUBVOL:
4566                 return btrfs_ioctl_default_subvol(file, argp);
4567         case BTRFS_IOC_DEFRAG:
4568                 return btrfs_ioctl_defrag(file, NULL);
4569         case BTRFS_IOC_DEFRAG_RANGE:
4570                 return btrfs_ioctl_defrag(file, argp);
4571         case BTRFS_IOC_RESIZE:
4572                 return btrfs_ioctl_resize(file, argp);
4573         case BTRFS_IOC_ADD_DEV:
4574                 return btrfs_ioctl_add_dev(fs_info, argp);
4575         case BTRFS_IOC_RM_DEV:
4576                 return btrfs_ioctl_rm_dev(file, argp);
4577         case BTRFS_IOC_RM_DEV_V2:
4578                 return btrfs_ioctl_rm_dev_v2(file, argp);
4579         case BTRFS_IOC_FS_INFO:
4580                 return btrfs_ioctl_fs_info(fs_info, argp);
4581         case BTRFS_IOC_DEV_INFO:
4582                 return btrfs_ioctl_dev_info(fs_info, argp);
4583         case BTRFS_IOC_TREE_SEARCH:
4584                 return btrfs_ioctl_tree_search(inode, argp);
4585         case BTRFS_IOC_TREE_SEARCH_V2:
4586                 return btrfs_ioctl_tree_search_v2(inode, argp);
4587         case BTRFS_IOC_INO_LOOKUP:
4588                 return btrfs_ioctl_ino_lookup(root, argp);
4589         case BTRFS_IOC_INO_PATHS:
4590                 return btrfs_ioctl_ino_to_path(root, argp);
4591         case BTRFS_IOC_LOGICAL_INO:
4592                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
4593         case BTRFS_IOC_LOGICAL_INO_V2:
4594                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
4595         case BTRFS_IOC_SPACE_INFO:
4596                 return btrfs_ioctl_space_info(fs_info, argp);
4597         case BTRFS_IOC_SYNC: {
4598                 int ret;
4599
4600                 ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
4601                 if (ret)
4602                         return ret;
4603                 ret = btrfs_sync_fs(inode->i_sb, 1);
4604                 /*
4605                  * The transaction thread may want to do more work,
4606                  * namely it pokes the cleaner kthread that will start
4607                  * processing uncleaned subvols.
4608                  */
4609                 wake_up_process(fs_info->transaction_kthread);
4610                 return ret;
4611         }
4612         case BTRFS_IOC_START_SYNC:
4613                 return btrfs_ioctl_start_sync(root, argp);
4614         case BTRFS_IOC_WAIT_SYNC:
4615                 return btrfs_ioctl_wait_sync(fs_info, argp);
4616         case BTRFS_IOC_SCRUB:
4617                 return btrfs_ioctl_scrub(file, argp);
4618         case BTRFS_IOC_SCRUB_CANCEL:
4619                 return btrfs_ioctl_scrub_cancel(fs_info);
4620         case BTRFS_IOC_SCRUB_PROGRESS:
4621                 return btrfs_ioctl_scrub_progress(fs_info, argp);
4622         case BTRFS_IOC_BALANCE_V2:
4623                 return btrfs_ioctl_balance(file, argp);
4624         case BTRFS_IOC_BALANCE_CTL:
4625                 return btrfs_ioctl_balance_ctl(fs_info, arg);
4626         case BTRFS_IOC_BALANCE_PROGRESS:
4627                 return btrfs_ioctl_balance_progress(fs_info, argp);
4628         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4629                 return btrfs_ioctl_set_received_subvol(file, argp);
4630 #ifdef CONFIG_64BIT
4631         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
4632                 return btrfs_ioctl_set_received_subvol_32(file, argp);
4633 #endif
4634         case BTRFS_IOC_SEND:
4635                 return _btrfs_ioctl_send(inode, argp, false);
4636 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4637         case BTRFS_IOC_SEND_32:
4638                 return _btrfs_ioctl_send(inode, argp, true);
4639 #endif
4640         case BTRFS_IOC_GET_DEV_STATS:
4641                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
4642         case BTRFS_IOC_QUOTA_CTL:
4643                 return btrfs_ioctl_quota_ctl(file, argp);
4644         case BTRFS_IOC_QGROUP_ASSIGN:
4645                 return btrfs_ioctl_qgroup_assign(file, argp);
4646         case BTRFS_IOC_QGROUP_CREATE:
4647                 return btrfs_ioctl_qgroup_create(file, argp);
4648         case BTRFS_IOC_QGROUP_LIMIT:
4649                 return btrfs_ioctl_qgroup_limit(file, argp);
4650         case BTRFS_IOC_QUOTA_RESCAN:
4651                 return btrfs_ioctl_quota_rescan(file, argp);
4652         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
4653                 return btrfs_ioctl_quota_rescan_status(fs_info, argp);
4654         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
4655                 return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
4656         case BTRFS_IOC_DEV_REPLACE:
4657                 return btrfs_ioctl_dev_replace(fs_info, argp);
4658         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
4659                 return btrfs_ioctl_get_supported_features(argp);
4660         case BTRFS_IOC_GET_FEATURES:
4661                 return btrfs_ioctl_get_features(fs_info, argp);
4662         case BTRFS_IOC_SET_FEATURES:
4663                 return btrfs_ioctl_set_features(file, argp);
4664         case BTRFS_IOC_GET_SUBVOL_INFO:
4665                 return btrfs_ioctl_get_subvol_info(inode, argp);
4666         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
4667                 return btrfs_ioctl_get_subvol_rootref(root, argp);
4668         case BTRFS_IOC_INO_LOOKUP_USER:
4669                 return btrfs_ioctl_ino_lookup_user(file, argp);
4670         case FS_IOC_ENABLE_VERITY:
4671                 return fsverity_ioctl_enable(file, (const void __user *)argp);
4672         case FS_IOC_MEASURE_VERITY:
4673                 return fsverity_ioctl_measure(file, argp);
4674         case BTRFS_IOC_ENCODED_READ:
4675                 return btrfs_ioctl_encoded_read(file, argp, false);
4676         case BTRFS_IOC_ENCODED_WRITE:
4677                 return btrfs_ioctl_encoded_write(file, argp, false);
4678 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4679         case BTRFS_IOC_ENCODED_READ_32:
4680                 return btrfs_ioctl_encoded_read(file, argp, true);
4681         case BTRFS_IOC_ENCODED_WRITE_32:
4682                 return btrfs_ioctl_encoded_write(file, argp, true);
4683 #endif
4684         }
4685
4686         return -ENOTTY;
4687 }
4688
4689 #ifdef CONFIG_COMPAT
4690 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4691 {
4692         /*
4693          * These all access 32-bit values anyway so no further
4694          * handling is necessary.
4695          */
4696         switch (cmd) {
4697         case FS_IOC32_GETVERSION:
4698                 cmd = FS_IOC_GETVERSION;
4699                 break;
4700         }
4701
4702         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
4703 }
4704 #endif