fs/btrfs/ioctl.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/fsnotify.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/highmem.h>
  27 #include <linux/time.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mount.h>
  32 #include <linux/mpage.h>
  33 #include <linux/namei.h>
  34 #include <linux/swap.h>
  35 #include <linux/writeback.h>
  36 #include <linux/statfs.h>
  37 #include <linux/compat.h>
  38 #include <linux/bit_spinlock.h>
  39 #include <linux/security.h>
  40 #include <linux/xattr.h>
  41 #include <linux/vmalloc.h>
  42 #include <linux/slab.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/uuid.h>
  45 #include <linux/btrfs.h>
  46 #include <linux/uaccess.h>
  47 #include "ctree.h"
  48 #include "disk-io.h"
  49 #include "transaction.h"
  50 #include "btrfs_inode.h"
  51 #include "print-tree.h"
  52 #include "volumes.h"
  53 #include "locking.h"
  54 #include "inode-map.h"
  55 #include "backref.h"
  56 #include "rcu-string.h"
  57 #include "send.h"
  58 #include "dev-replace.h"
  59 #include "props.h"
  60 #include "sysfs.h"
  61 #include "qgroup.h"
  62 #include "tree-log.h"
  63 #include "compression.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
  91 static int btrfs_clone(struct inode *src, struct inode *inode,
  92                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
  93                        int no_time_update);
  94
  95 /* Mask out flags that are inappropriate for the given type of inode. */
  96 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  97 {
  98         if (S_ISDIR(mode))
  99                 return flags;
 100         else if (S_ISREG(mode))
 101                 return flags & ~FS_DIRSYNC_FL;
 102         else
 103                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
 104 }
 105
 106 /*
 107  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
 108  */
 109 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
 110 {
 111         unsigned int iflags = 0;
 112
 113         if (flags & BTRFS_INODE_SYNC)
 114                 iflags |= FS_SYNC_FL;
 115         if (flags & BTRFS_INODE_IMMUTABLE)
 116                 iflags |= FS_IMMUTABLE_FL;
 117         if (flags & BTRFS_INODE_APPEND)
 118                 iflags |= FS_APPEND_FL;
 119         if (flags & BTRFS_INODE_NODUMP)
 120                 iflags |= FS_NODUMP_FL;
 121         if (flags & BTRFS_INODE_NOATIME)
 122                 iflags |= FS_NOATIME_FL;
 123         if (flags & BTRFS_INODE_DIRSYNC)
 124                 iflags |= FS_DIRSYNC_FL;
 125         if (flags & BTRFS_INODE_NODATACOW)
 126                 iflags |= FS_NOCOW_FL;
 127
 128         if (flags & BTRFS_INODE_NOCOMPRESS)
 129                 iflags |= FS_NOCOMP_FL;
 130         else if (flags & BTRFS_INODE_COMPRESS)
 131                 iflags |= FS_COMPR_FL;
 132
 133         return iflags;
 134 }
 135
 136 /*
 137  * Update inode->i_flags based on the btrfs internal flags.
 138  */
 139 void btrfs_update_iflags(struct inode *inode)
 140 {
 141         struct btrfs_inode *ip = BTRFS_I(inode);
 142         unsigned int new_fl = 0;
 143
 144         if (ip->flags & BTRFS_INODE_SYNC)
 145                 new_fl |= S_SYNC;
 146         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 147                 new_fl |= S_IMMUTABLE;
 148         if (ip->flags & BTRFS_INODE_APPEND)
 149                 new_fl |= S_APPEND;
 150         if (ip->flags & BTRFS_INODE_NOATIME)
 151                 new_fl |= S_NOATIME;
 152         if (ip->flags & BTRFS_INODE_DIRSYNC)
 153                 new_fl |= S_DIRSYNC;
 154
 155         set_mask_bits(&inode->i_flags,
 156                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
 157                       new_fl);
 158 }
 159
 160 /*
 161  * Inherit flags from the parent inode.
 162  *
 163  * Currently only the compression flags and the cow flags are inherited.
 164  */
 165 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 166 {
 167         unsigned int flags;
 168
 169         if (!dir)
 170                 return;
 171
 172         flags = BTRFS_I(dir)->flags;
 173
 174         if (flags & BTRFS_INODE_NOCOMPRESS) {
 175                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 176                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 177         } else if (flags & BTRFS_INODE_COMPRESS) {
 178                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 179                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 180         }
 181
 182         if (flags & BTRFS_INODE_NODATACOW) {
 183                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 184                 if (S_ISREG(inode->i_mode))
 185                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 186         }
 187
 188         btrfs_update_iflags(inode);
 189 }
 190
 191 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 192 {
 193         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 194         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 195
 196         if (copy_to_user(arg, &flags, sizeof(flags)))
 197                 return -EFAULT;
 198         return 0;
 199 }
 200
 201 static int check_flags(unsigned int flags)
 202 {
 203         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 204                       FS_NOATIME_FL | FS_NODUMP_FL | \
 205                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 206                       FS_NOCOMP_FL | FS_COMPR_FL |
 207                       FS_NOCOW_FL))
 208                 return -EOPNOTSUPP;
 209
 210         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 211                 return -EINVAL;
 212
 213         return 0;
 214 }
 215
 216 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 217 {
 218         struct inode *inode = file_inode(file);
 219         struct btrfs_inode *ip = BTRFS_I(inode);
 220         struct btrfs_root *root = ip->root;
 221         struct btrfs_trans_handle *trans;
 222         unsigned int flags, oldflags;
 223         int ret;
 224         u64 ip_oldflags;
 225         unsigned int i_oldflags;
 226         umode_t mode;
 227
 228         if (!inode_owner_or_capable(inode))
 229                 return -EPERM;
 230
 231         if (btrfs_root_readonly(root))
 232                 return -EROFS;
 233
 234         if (copy_from_user(&flags, arg, sizeof(flags)))
 235                 return -EFAULT;
 236
 237         ret = check_flags(flags);
 238         if (ret)
 239                 return ret;
 240
 241         ret = mnt_want_write_file(file);
 242         if (ret)
 243                 return ret;
 244
 245         inode_lock(inode);
 246
 247         ip_oldflags = ip->flags;
 248         i_oldflags = inode->i_flags;
 249         mode = inode->i_mode;
 250
 251         flags = btrfs_mask_flags(inode->i_mode, flags);
 252         oldflags = btrfs_flags_to_ioctl(ip->flags);
 253         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 254                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 255                         ret = -EPERM;
 256                         goto out_unlock;
 257                 }
 258         }
 259
 260         if (flags & FS_SYNC_FL)
 261                 ip->flags |= BTRFS_INODE_SYNC;
 262         else
 263                 ip->flags &= ~BTRFS_INODE_SYNC;
 264         if (flags & FS_IMMUTABLE_FL)
 265                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 266         else
 267                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 268         if (flags & FS_APPEND_FL)
 269                 ip->flags |= BTRFS_INODE_APPEND;
 270         else
 271                 ip->flags &= ~BTRFS_INODE_APPEND;
 272         if (flags & FS_NODUMP_FL)
 273                 ip->flags |= BTRFS_INODE_NODUMP;
 274         else
 275                 ip->flags &= ~BTRFS_INODE_NODUMP;
 276         if (flags & FS_NOATIME_FL)
 277                 ip->flags |= BTRFS_INODE_NOATIME;
 278         else
 279                 ip->flags &= ~BTRFS_INODE_NOATIME;
 280         if (flags & FS_DIRSYNC_FL)
 281                 ip->flags |= BTRFS_INODE_DIRSYNC;
 282         else
 283                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 284         if (flags & FS_NOCOW_FL) {
 285                 if (S_ISREG(mode)) {
 286                         /*
 287                          * It's safe to turn csums off here, no extents exist.
 288                          * Otherwise we want the flag to reflect the real COW
 289                          * status of the file and will not set it.
 290                          */
 291                         if (inode->i_size == 0)
 292                                 ip->flags |= BTRFS_INODE_NODATACOW
 293                                            | BTRFS_INODE_NODATASUM;
 294                 } else {
 295                         ip->flags |= BTRFS_INODE_NODATACOW;
 296                 }
 297         } else {
 298                 /*
 299                  * Revert back under same assumptions as above
 300                  */
 301                 if (S_ISREG(mode)) {
 302                         if (inode->i_size == 0)
 303                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 304                                              | BTRFS_INODE_NODATASUM);
 305                 } else {
 306                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 307                 }
 308         }
 309
 310         /*
 311          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 312          * flag may be changed automatically if compression code won't make
 313          * things smaller.
 314          */
 315         if (flags & FS_NOCOMP_FL) {
 316                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 317                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 318
 319                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 320                 if (ret && ret != -ENODATA)
 321                         goto out_drop;
 322         } else if (flags & FS_COMPR_FL) {
 323                 const char *comp;
 324
 325                 ip->flags |= BTRFS_INODE_COMPRESS;
 326                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 327
 328                 if (root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
 329                         comp = "lzo";
 330                 else
 331                         comp = "zlib";
 332                 ret = btrfs_set_prop(inode, "btrfs.compression",
 333                                      comp, strlen(comp), 0);
 334                 if (ret)
 335                         goto out_drop;
 336
 337         } else {
 338                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
 339                 if (ret && ret != -ENODATA)
 340                         goto out_drop;
 341                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 342         }
 343
 344         trans = btrfs_start_transaction(root, 1);
 345         if (IS_ERR(trans)) {
 346                 ret = PTR_ERR(trans);
 347                 goto out_drop;
 348         }
 349
 350         btrfs_update_iflags(inode);
 351         inode_inc_iversion(inode);
 352         inode->i_ctime = current_fs_time(inode->i_sb);
 353         ret = btrfs_update_inode(trans, root, inode);
 354
 355         btrfs_end_transaction(trans, root);
 356  out_drop:
 357         if (ret) {
 358                 ip->flags = ip_oldflags;
 359                 inode->i_flags = i_oldflags;
 360         }
 361
 362  out_unlock:
 363         inode_unlock(inode);
 364         mnt_drop_write_file(file);
 365         return ret;
 366 }
 367
 368 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 369 {
 370         struct inode *inode = file_inode(file);
 371
 372         return put_user(inode->i_generation, arg);
 373 }
 374
 375 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 376 {
 377         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
 378         struct btrfs_device *device;
 379         struct request_queue *q;
 380         struct fstrim_range range;
 381         u64 minlen = ULLONG_MAX;
 382         u64 num_devices = 0;
 383         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 384         int ret;
 385
 386         if (!capable(CAP_SYS_ADMIN))
 387                 return -EPERM;
 388
 389         rcu_read_lock();
 390         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 391                                 dev_list) {
 392                 if (!device->bdev)
 393                         continue;
 394                 q = bdev_get_queue(device->bdev);
 395                 if (blk_queue_discard(q)) {
 396                         num_devices++;
 397                         minlen = min((u64)q->limits.discard_granularity,
 398                                      minlen);
 399                 }
 400         }
 401         rcu_read_unlock();
 402
 403         if (!num_devices)
 404                 return -EOPNOTSUPP;
 405         if (copy_from_user(&range, arg, sizeof(range)))
 406                 return -EFAULT;
 407         if (range.start > total_bytes ||
 408             range.len < fs_info->sb->s_blocksize)
 409                 return -EINVAL;
 410
 411         range.len = min(range.len, total_bytes - range.start);
 412         range.minlen = max(range.minlen, minlen);
 413         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 414         if (ret < 0)
 415                 return ret;
 416
 417         if (copy_to_user(arg, &range, sizeof(range)))
 418                 return -EFAULT;
 419
 420         return 0;
 421 }
 422
 423 int btrfs_is_empty_uuid(u8 *uuid)
 424 {
 425         int i;
 426
 427         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
 428                 if (uuid[i])
 429                         return 0;
 430         }
 431         return 1;
 432 }
 433
 434 static noinline int create_subvol(struct inode *dir,
 435                                   struct dentry *dentry,
 436                                   char *name, int namelen,
 437                                   u64 *async_transid,
 438                                   struct btrfs_qgroup_inherit *inherit)
 439 {
 440         struct btrfs_trans_handle *trans;
 441         struct btrfs_key key;
 442         struct btrfs_root_item *root_item;
 443         struct btrfs_inode_item *inode_item;
 444         struct extent_buffer *leaf;
 445         struct btrfs_root *root = BTRFS_I(dir)->root;
 446         struct btrfs_root *new_root;
 447         struct btrfs_block_rsv block_rsv;
 448         struct timespec cur_time = current_fs_time(dir->i_sb);
 449         struct inode *inode;
 450         int ret;
 451         int err;
 452         u64 objectid;
 453         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 454         u64 index = 0;
 455         u64 qgroup_reserved;
 456         uuid_le new_uuid;
 457
 458         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 459         if (!root_item)
 460                 return -ENOMEM;
 461
 462         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 463         if (ret)
 464                 goto fail_free;
 465
 466         /*
 467          * Don't create subvolume whose level is not zero. Or qgroup will be
 468          * screwed up since it assumes subvolume qgroup's level to be 0.
 469          */
 470         if (btrfs_qgroup_level(objectid)) {
 471                 ret = -ENOSPC;
 472                 goto fail_free;
 473         }
 474
 475         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
 476         /*
 477          * The same as the snapshot creation, please see the comment
 478          * of create_snapshot().
 479          */
 480         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
 481                                                8, &qgroup_reserved, false);
 482         if (ret)
 483                 goto fail_free;
 484
 485         trans = btrfs_start_transaction(root, 0);
 486         if (IS_ERR(trans)) {
 487                 ret = PTR_ERR(trans);
 488                 btrfs_subvolume_release_metadata(root, &block_rsv,
 489                                                  qgroup_reserved);
 490                 goto fail_free;
 491         }
 492         trans->block_rsv = &block_rsv;
 493         trans->bytes_reserved = block_rsv.size;
 494
 495         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
 496         if (ret)
 497                 goto fail;
 498
 499         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
 500         if (IS_ERR(leaf)) {
 501                 ret = PTR_ERR(leaf);
 502                 goto fail;
 503         }
 504
 505         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 506         btrfs_set_header_bytenr(leaf, leaf->start);
 507         btrfs_set_header_generation(leaf, trans->transid);
 508         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 509         btrfs_set_header_owner(leaf, objectid);
 510
 511         write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(),
 512                             BTRFS_FSID_SIZE);
 513         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 514                             btrfs_header_chunk_tree_uuid(leaf),
 515                             BTRFS_UUID_SIZE);
 516         btrfs_mark_buffer_dirty(leaf);
 517
 518         inode_item = &root_item->inode;
 519         btrfs_set_stack_inode_generation(inode_item, 1);
 520         btrfs_set_stack_inode_size(inode_item, 3);
 521         btrfs_set_stack_inode_nlink(inode_item, 1);
 522         btrfs_set_stack_inode_nbytes(inode_item, root->nodesize);
 523         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
 524
 525         btrfs_set_root_flags(root_item, 0);
 526         btrfs_set_root_limit(root_item, 0);
 527         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
 528
 529         btrfs_set_root_bytenr(root_item, leaf->start);
 530         btrfs_set_root_generation(root_item, trans->transid);
 531         btrfs_set_root_level(root_item, 0);
 532         btrfs_set_root_refs(root_item, 1);
 533         btrfs_set_root_used(root_item, leaf->len);
 534         btrfs_set_root_last_snapshot(root_item, 0);
 535
 536         btrfs_set_root_generation_v2(root_item,
 537                         btrfs_root_generation(root_item));
 538         uuid_le_gen(&new_uuid);
 539         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
 540         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 541         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 542         root_item->ctime = root_item->otime;
 543         btrfs_set_root_ctransid(root_item, trans->transid);
 544         btrfs_set_root_otransid(root_item, trans->transid);
 545
 546         btrfs_tree_unlock(leaf);
 547         free_extent_buffer(leaf);
 548         leaf = NULL;
 549
 550         btrfs_set_root_dirid(root_item, new_dirid);
 551
 552         key.objectid = objectid;
 553         key.offset = 0;
 554         key.type = BTRFS_ROOT_ITEM_KEY;
 555         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 556                                 root_item);
 557         if (ret)
 558                 goto fail;
 559
 560         key.offset = (u64)-1;
 561         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 562         if (IS_ERR(new_root)) {
 563                 ret = PTR_ERR(new_root);
 564                 btrfs_abort_transaction(trans, root, ret);
 565                 goto fail;
 566         }
 567
 568         btrfs_record_root_in_trans(trans, new_root);
 569
 570         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
 571         if (ret) {
 572                 /* We potentially lose an unused inode item here */
 573                 btrfs_abort_transaction(trans, root, ret);
 574                 goto fail;
 575         }
 576
 577         mutex_lock(&new_root->objectid_mutex);
 578         new_root->highest_objectid = new_dirid;
 579         mutex_unlock(&new_root->objectid_mutex);
 580
 581         /*
 582          * insert the directory item
 583          */
 584         ret = btrfs_set_inode_index(dir, &index);
 585         if (ret) {
 586                 btrfs_abort_transaction(trans, root, ret);
 587                 goto fail;
 588         }
 589
 590         ret = btrfs_insert_dir_item(trans, root,
 591                                     name, namelen, dir, &key,
 592                                     BTRFS_FT_DIR, index);
 593         if (ret) {
 594                 btrfs_abort_transaction(trans, root, ret);
 595                 goto fail;
 596         }
 597
 598         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 599         ret = btrfs_update_inode(trans, root, dir);
 600         BUG_ON(ret);
 601
 602         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 603                                  objectid, root->root_key.objectid,
 604                                  btrfs_ino(dir), index, name, namelen);
 605         BUG_ON(ret);
 606
 607         ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
 608                                   root_item->uuid, BTRFS_UUID_KEY_SUBVOL,
 609                                   objectid);
 610         if (ret)
 611                 btrfs_abort_transaction(trans, root, ret);
 612
 613 fail:
 614         kfree(root_item);
 615         trans->block_rsv = NULL;
 616         trans->bytes_reserved = 0;
 617         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
 618
 619         if (async_transid) {
 620                 *async_transid = trans->transid;
 621                 err = btrfs_commit_transaction_async(trans, root, 1);
 622                 if (err)
 623                         err = btrfs_commit_transaction(trans, root);
 624         } else {
 625                 err = btrfs_commit_transaction(trans, root);
 626         }
 627         if (err && !ret)
 628                 ret = err;
 629
 630         if (!ret) {
 631                 inode = btrfs_lookup_dentry(dir, dentry);
 632                 if (IS_ERR(inode))
 633                         return PTR_ERR(inode);
 634                 d_instantiate(dentry, inode);
 635         }
 636         return ret;
 637
 638 fail_free:
 639         kfree(root_item);
 640         return ret;
 641 }
 642
 643 static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)
 644 {
 645         s64 writers;
 646         DEFINE_WAIT(wait);
 647
 648         do {
 649                 prepare_to_wait(&root->subv_writers->wait, &wait,
 650                                 TASK_UNINTERRUPTIBLE);
 651
 652                 writers = percpu_counter_sum(&root->subv_writers->counter);
 653                 if (writers)
 654                         schedule();
 655
 656                 finish_wait(&root->subv_writers->wait, &wait);
 657         } while (writers);
 658 }
 659
 660 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 661                            struct dentry *dentry, char *name, int namelen,
 662                            u64 *async_transid, bool readonly,
 663                            struct btrfs_qgroup_inherit *inherit)
 664 {
 665         struct inode *inode;
 666         struct btrfs_pending_snapshot *pending_snapshot;
 667         struct btrfs_trans_handle *trans;
 668         int ret;
 669
 670         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
 671                 return -EINVAL;
 672
 673         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 674         if (!pending_snapshot)
 675                 return -ENOMEM;
 676
 677         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
 678                         GFP_NOFS);
 679         pending_snapshot->path = btrfs_alloc_path();
 680         if (!pending_snapshot->root_item || !pending_snapshot->path) {
 681                 ret = -ENOMEM;
 682                 goto free_pending;
 683         }
 684
 685         atomic_inc(&root->will_be_snapshoted);
 686         smp_mb__after_atomic();
 687         btrfs_wait_for_no_snapshoting_writes(root);
 688
 689         ret = btrfs_start_delalloc_inodes(root, 0);
 690         if (ret)
 691                 goto dec_and_free;
 692
 693         btrfs_wait_ordered_extents(root, -1, 0, (u64)-1);
 694
 695         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 696                              BTRFS_BLOCK_RSV_TEMP);
 697         /*
 698          * 1 - parent dir inode
 699          * 2 - dir entries
 700          * 1 - root item
 701          * 2 - root ref/backref
 702          * 1 - root of snapshot
 703          * 1 - UUID item
 704          */
 705         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
 706                                         &pending_snapshot->block_rsv, 8,
 707                                         &pending_snapshot->qgroup_reserved,
 708                                         false);
 709         if (ret)
 710                 goto dec_and_free;
 711
 712         pending_snapshot->dentry = dentry;
 713         pending_snapshot->root = root;
 714         pending_snapshot->readonly = readonly;
 715         pending_snapshot->dir = dir;
 716         pending_snapshot->inherit = inherit;
 717
 718         trans = btrfs_start_transaction(root, 0);
 719         if (IS_ERR(trans)) {
 720                 ret = PTR_ERR(trans);
 721                 goto fail;
 722         }
 723
 724         spin_lock(&root->fs_info->trans_lock);
 725         list_add(&pending_snapshot->list,
 726                  &trans->transaction->pending_snapshots);
 727         spin_unlock(&root->fs_info->trans_lock);
 728         if (async_transid) {
 729                 *async_transid = trans->transid;
 730                 ret = btrfs_commit_transaction_async(trans,
 731                                      root->fs_info->extent_root, 1);
 732                 if (ret)
 733                         ret = btrfs_commit_transaction(trans, root);
 734         } else {
 735                 ret = btrfs_commit_transaction(trans,
 736                                                root->fs_info->extent_root);
 737         }
 738         if (ret)
 739                 goto fail;
 740
 741         ret = pending_snapshot->error;
 742         if (ret)
 743                 goto fail;
 744
 745         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 746         if (ret)
 747                 goto fail;
 748
 749         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
 750         if (IS_ERR(inode)) {
 751                 ret = PTR_ERR(inode);
 752                 goto fail;
 753         }
 754
 755         d_instantiate(dentry, inode);
 756         ret = 0;
 757 fail:
 758         btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
 759                                          &pending_snapshot->block_rsv,
 760                                          pending_snapshot->qgroup_reserved);
 761 dec_and_free:
 762         if (atomic_dec_and_test(&root->will_be_snapshoted))
 763                 wake_up_atomic_t(&root->will_be_snapshoted);
 764 free_pending:
 765         kfree(pending_snapshot->root_item);
 766         btrfs_free_path(pending_snapshot->path);
 767         kfree(pending_snapshot);
 768
 769         return ret;
 770 }
 771
 772 /*  copy of may_delete in fs/namei.c()
 773  *      Check whether we can remove a link victim from directory dir, check
 774  *  whether the type of victim is right.
 775  *  1. We can't do it if dir is read-only (done in permission())
 776  *  2. We should have write and exec permissions on dir
 777  *  3. We can't remove anything from append-only dir
 778  *  4. We can't do anything with immutable dir (done in permission())
 779  *  5. If the sticky bit on dir is set we should either
 780  *      a. be owner of dir, or
 781  *      b. be owner of victim, or
 782  *      c. have CAP_FOWNER capability
 783  *  6. If the victim is append-only or immutable we can't do anything with
 784  *     links pointing to it.
 785  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 786  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 787  *  9. We can't remove a root or mountpoint.
 788  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 789  *     nfs_async_unlink().
 790  */
 791
 792 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
 793 {
 794         int error;
 795
 796         if (d_really_is_negative(victim))
 797                 return -ENOENT;
 798
 799         BUG_ON(d_inode(victim->d_parent) != dir);
 800         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 801
 802         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 803         if (error)
 804                 return error;
 805         if (IS_APPEND(dir))
 806                 return -EPERM;
 807         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
 808             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
 809                 return -EPERM;
 810         if (isdir) {
 811                 if (!d_is_dir(victim))
 812                         return -ENOTDIR;
 813                 if (IS_ROOT(victim))
 814                         return -EBUSY;
 815         } else if (d_is_dir(victim))
 816                 return -EISDIR;
 817         if (IS_DEADDIR(dir))
 818                 return -ENOENT;
 819         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 820                 return -EBUSY;
 821         return 0;
 822 }
 823
 824 /* copy of may_create in fs/namei.c() */
 825 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 826 {
 827         if (d_really_is_positive(child))
 828                 return -EEXIST;
 829         if (IS_DEADDIR(dir))
 830                 return -ENOENT;
 831         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 832 }
 833
 834 /*
 835  * Create a new subvolume below @parent.  This is largely modeled after
 836  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 837  * inside this filesystem so it's quite a bit simpler.
 838  */
 839 static noinline int btrfs_mksubvol(struct path *parent,
 840                                    char *name, int namelen,
 841                                    struct btrfs_root *snap_src,
 842                                    u64 *async_transid, bool readonly,
 843                                    struct btrfs_qgroup_inherit *inherit)
 844 {
 845         struct inode *dir  = d_inode(parent->dentry);
 846         struct dentry *dentry;
 847         int error;
 848
 849         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
 850         if (error == -EINTR)
 851                 return error;
 852
 853         dentry = lookup_one_len(name, parent->dentry, namelen);
 854         error = PTR_ERR(dentry);
 855         if (IS_ERR(dentry))
 856                 goto out_unlock;
 857
 858         error = btrfs_may_create(dir, dentry);
 859         if (error)
 860                 goto out_dput;
 861
 862         /*
 863          * even if this name doesn't exist, we may get hash collisions.
 864          * check for them now when we can safely fail
 865          */
 866         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 867                                                dir->i_ino, name,
 868                                                namelen);
 869         if (error)
 870                 goto out_dput;
 871
 872         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 873
 874         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 875                 goto out_up_read;
 876
 877         if (snap_src) {
 878                 error = create_snapshot(snap_src, dir, dentry, name, namelen,
 879                                         async_transid, readonly, inherit);
 880         } else {
 881                 error = create_subvol(dir, dentry, name, namelen,
 882                                       async_transid, inherit);
 883         }
 884         if (!error)
 885                 fsnotify_mkdir(dir, dentry);
 886 out_up_read:
 887         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 888 out_dput:
 889         dput(dentry);
 890 out_unlock:
 891         inode_unlock(dir);
 892         return error;
 893 }
 894
 895 /*
 896  * When we're defragging a range, we don't want to kick it off again
 897  * if it is really just waiting for delalloc to send it down.
 898  * If we find a nice big extent or delalloc range for the bytes in the
 899  * file you want to defrag, we return 0 to let you know to skip this
 900  * part of the file
 901  */
 902 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
 903 {
 904         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 905         struct extent_map *em = NULL;
 906         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 907         u64 end;
 908
 909         read_lock(&em_tree->lock);
 910         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
 911         read_unlock(&em_tree->lock);
 912
 913         if (em) {
 914                 end = extent_map_end(em);
 915                 free_extent_map(em);
 916                 if (end - offset > thresh)
 917                         return 0;
 918         }
 919         /* if we already have a nice delalloc here, just stop */
 920         thresh /= 2;
 921         end = count_range_bits(io_tree, &offset, offset + thresh,
 922                                thresh, EXTENT_DELALLOC, 1);
 923         if (end >= thresh)
 924                 return 0;
 925         return 1;
 926 }
 927
 928 /*
 929  * helper function to walk through a file and find extents
 930  * newer than a specific transid, and smaller than thresh.
 931  *
 932  * This is used by the defragging code to find new and small
 933  * extents
 934  */
 935 static int find_new_extents(struct btrfs_root *root,
 936                             struct inode *inode, u64 newer_than,
 937                             u64 *off, u32 thresh)
 938 {
 939         struct btrfs_path *path;
 940         struct btrfs_key min_key;
 941         struct extent_buffer *leaf;
 942         struct btrfs_file_extent_item *extent;
 943         int type;
 944         int ret;
 945         u64 ino = btrfs_ino(inode);
 946
 947         path = btrfs_alloc_path();
 948         if (!path)
 949                 return -ENOMEM;
 950
 951         min_key.objectid = ino;
 952         min_key.type = BTRFS_EXTENT_DATA_KEY;
 953         min_key.offset = *off;
 954
 955         while (1) {
 956                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
 957                 if (ret != 0)
 958                         goto none;
 959 process_slot:
 960                 if (min_key.objectid != ino)
 961                         goto none;
 962                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 963                         goto none;
 964
 965                 leaf = path->nodes[0];
 966                 extent = btrfs_item_ptr(leaf, path->slots[0],
 967                                         struct btrfs_file_extent_item);
 968
 969                 type = btrfs_file_extent_type(leaf, extent);
 970                 if (type == BTRFS_FILE_EXTENT_REG &&
 971                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 972                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 973                         *off = min_key.offset;
 974                         btrfs_free_path(path);
 975                         return 0;
 976                 }
 977
 978                 path->slots[0]++;
 979                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
 980                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
 981                         goto process_slot;
 982                 }
 983
 984                 if (min_key.offset == (u64)-1)
 985                         goto none;
 986
 987                 min_key.offset++;
 988                 btrfs_release_path(path);
 989         }
 990 none:
 991         btrfs_free_path(path);
 992         return -ENOENT;
 993 }
 994
 995 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 996 {
 997         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 998         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 999         struct extent_map *em;
1000         u64 len = PAGE_SIZE;
1001
1002         /*
1003          * hopefully we have this extent in the tree already, try without
1004          * the full extent lock
1005          */
1006         read_lock(&em_tree->lock);
1007         em = lookup_extent_mapping(em_tree, start, len);
1008         read_unlock(&em_tree->lock);
1009
1010         if (!em) {
1011                 struct extent_state *cached = NULL;
1012                 u64 end = start + len - 1;
1013
1014                 /* get the big lock and read metadata off disk */
1015                 lock_extent_bits(io_tree, start, end, &cached);
1016                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
1017                 unlock_extent_cached(io_tree, start, end, &cached, GFP_NOFS);
1018
1019                 if (IS_ERR(em))
1020                         return NULL;
1021         }
1022
1023         return em;
1024 }
1025
1026 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1027 {
1028         struct extent_map *next;
1029         bool ret = true;
1030
1031         /* this is the last extent */
1032         if (em->start + em->len >= i_size_read(inode))
1033                 return false;
1034
1035         next = defrag_lookup_extent(inode, em->start + em->len);
1036         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1037                 ret = false;
1038         else if ((em->block_start + em->block_len == next->block_start) &&
1039                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1040                 ret = false;
1041
1042         free_extent_map(next);
1043         return ret;
1044 }
1045
1046 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1047                                u64 *last_len, u64 *skip, u64 *defrag_end,
1048                                int compress)
1049 {
1050         struct extent_map *em;
1051         int ret = 1;
1052         bool next_mergeable = true;
1053         bool prev_mergeable = true;
1054
1055         /*
1056          * make sure that once we start defragging an extent, we keep on
1057          * defragging it
1058          */
1059         if (start < *defrag_end)
1060                 return 1;
1061
1062         *skip = 0;
1063
1064         em = defrag_lookup_extent(inode, start);
1065         if (!em)
1066                 return 0;
1067
1068         /* this will cover holes, and inline extents */
1069         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1070                 ret = 0;
1071                 goto out;
1072         }
1073
1074         if (!*defrag_end)
1075                 prev_mergeable = false;
1076
1077         next_mergeable = defrag_check_next_extent(inode, em);
1078         /*
1079          * we hit a real extent, if it is big or the next extent is not a
1080          * real extent, don't bother defragging it
1081          */
1082         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1083             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1084                 ret = 0;
1085 out:
1086         /*
1087          * last_len ends up being a counter of how many bytes we've defragged.
1088          * every time we choose not to defrag an extent, we reset *last_len
1089          * so that the next tiny extent will force a defrag.
1090          *
1091          * The end result of this is that tiny extents before a single big
1092          * extent will force at least part of that big extent to be defragged.
1093          */
1094         if (ret) {
1095                 *defrag_end = extent_map_end(em);
1096         } else {
1097                 *last_len = 0;
1098                 *skip = extent_map_end(em);
1099                 *defrag_end = 0;
1100         }
1101
1102         free_extent_map(em);
1103         return ret;
1104 }
1105
1106 /*
1107  * it doesn't do much good to defrag one or two pages
1108  * at a time.  This pulls in a nice chunk of pages
1109  * to COW and defrag.
1110  *
1111  * It also makes sure the delalloc code has enough
1112  * dirty data to avoid making new small extents as part
1113  * of the defrag
1114  *
1115  * It's a good idea to start RA on this range
1116  * before calling this.
1117  */
1118 static int cluster_pages_for_defrag(struct inode *inode,
1119                                     struct page **pages,
1120                                     unsigned long start_index,
1121                                     unsigned long num_pages)
1122 {
1123         unsigned long file_end;
1124         u64 isize = i_size_read(inode);
1125         u64 page_start;
1126         u64 page_end;
1127         u64 page_cnt;
1128         int ret;
1129         int i;
1130         int i_done;
1131         struct btrfs_ordered_extent *ordered;
1132         struct extent_state *cached_state = NULL;
1133         struct extent_io_tree *tree;
1134         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1135
1136         file_end = (isize - 1) >> PAGE_SHIFT;
1137         if (!isize || start_index > file_end)
1138                 return 0;
1139
1140         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1141
1142         ret = btrfs_delalloc_reserve_space(inode,
1143                         start_index << PAGE_SHIFT,
1144                         page_cnt << PAGE_SHIFT);
1145         if (ret)
1146                 return ret;
1147         i_done = 0;
1148         tree = &BTRFS_I(inode)->io_tree;
1149
1150         /* step one, lock all the pages */
1151         for (i = 0; i < page_cnt; i++) {
1152                 struct page *page;
1153 again:
1154                 page = find_or_create_page(inode->i_mapping,
1155                                            start_index + i, mask);
1156                 if (!page)
1157                         break;
1158
1159                 page_start = page_offset(page);
1160                 page_end = page_start + PAGE_SIZE - 1;
1161                 while (1) {
1162                         lock_extent_bits(tree, page_start, page_end,
1163                                          &cached_state);
1164                         ordered = btrfs_lookup_ordered_extent(inode,
1165                                                               page_start);
1166                         unlock_extent_cached(tree, page_start, page_end,
1167                                              &cached_state, GFP_NOFS);
1168                         if (!ordered)
1169                                 break;
1170
1171                         unlock_page(page);
1172                         btrfs_start_ordered_extent(inode, ordered, 1);
1173                         btrfs_put_ordered_extent(ordered);
1174                         lock_page(page);
1175                         /*
1176                          * we unlocked the page above, so we need check if
1177                          * it was released or not.
1178                          */
1179                         if (page->mapping != inode->i_mapping) {
1180                                 unlock_page(page);
1181                                 put_page(page);
1182                                 goto again;
1183                         }
1184                 }
1185
1186                 if (!PageUptodate(page)) {
1187                         btrfs_readpage(NULL, page);
1188                         lock_page(page);
1189                         if (!PageUptodate(page)) {
1190                                 unlock_page(page);
1191                                 put_page(page);
1192                                 ret = -EIO;
1193                                 break;
1194                         }
1195                 }
1196
1197                 if (page->mapping != inode->i_mapping) {
1198                         unlock_page(page);
1199                         put_page(page);
1200                         goto again;
1201                 }
1202
1203                 pages[i] = page;
1204                 i_done++;
1205         }
1206         if (!i_done || ret)
1207                 goto out;
1208
1209         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1210                 goto out;
1211
1212         /*
1213          * so now we have a nice long stream of locked
1214          * and up to date pages, lets wait on them
1215          */
1216         for (i = 0; i < i_done; i++)
1217                 wait_on_page_writeback(pages[i]);
1218
1219         page_start = page_offset(pages[0]);
1220         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1221
1222         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1223                          page_start, page_end - 1, &cached_state);
1224         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1225                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1226                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1227                           &cached_state, GFP_NOFS);
1228
1229         if (i_done != page_cnt) {
1230                 spin_lock(&BTRFS_I(inode)->lock);
1231                 BTRFS_I(inode)->outstanding_extents++;
1232                 spin_unlock(&BTRFS_I(inode)->lock);
1233                 btrfs_delalloc_release_space(inode,
1234                                 start_index << PAGE_SHIFT,
1235                                 (page_cnt - i_done) << PAGE_SHIFT);
1236         }
1237
1238
1239         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1240                           &cached_state);
1241
1242         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1243                              page_start, page_end - 1, &cached_state,
1244                              GFP_NOFS);
1245
1246         for (i = 0; i < i_done; i++) {
1247                 clear_page_dirty_for_io(pages[i]);
1248                 ClearPageChecked(pages[i]);
1249                 set_page_extent_mapped(pages[i]);
1250                 set_page_dirty(pages[i]);
1251                 unlock_page(pages[i]);
1252                 put_page(pages[i]);
1253         }
1254         return i_done;
1255 out:
1256         for (i = 0; i < i_done; i++) {
1257                 unlock_page(pages[i]);
1258                 put_page(pages[i]);
1259         }
1260         btrfs_delalloc_release_space(inode,
1261                         start_index << PAGE_SHIFT,
1262                         page_cnt << PAGE_SHIFT);
1263         return ret;
1264
1265 }
1266
1267 int btrfs_defrag_file(struct inode *inode, struct file *file,
1268                       struct btrfs_ioctl_defrag_range_args *range,
1269                       u64 newer_than, unsigned long max_to_defrag)
1270 {
1271         struct btrfs_root *root = BTRFS_I(inode)->root;
1272         struct file_ra_state *ra = NULL;
1273         unsigned long last_index;
1274         u64 isize = i_size_read(inode);
1275         u64 last_len = 0;
1276         u64 skip = 0;
1277         u64 defrag_end = 0;
1278         u64 newer_off = range->start;
1279         unsigned long i;
1280         unsigned long ra_index = 0;
1281         int ret;
1282         int defrag_count = 0;
1283         int compress_type = BTRFS_COMPRESS_ZLIB;
1284         u32 extent_thresh = range->extent_thresh;
1285         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1286         unsigned long cluster = max_cluster;
1287         u64 new_align = ~((u64)SZ_128K - 1);
1288         struct page **pages = NULL;
1289
1290         if (isize == 0)
1291                 return 0;
1292
1293         if (range->start >= isize)
1294                 return -EINVAL;
1295
1296         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1297                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1298                         return -EINVAL;
1299                 if (range->compress_type)
1300                         compress_type = range->compress_type;
1301         }
1302
1303         if (extent_thresh == 0)
1304                 extent_thresh = SZ_256K;
1305
1306         /*
1307          * if we were not given a file, allocate a readahead
1308          * context
1309          */
1310         if (!file) {
1311                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1312                 if (!ra)
1313                         return -ENOMEM;
1314                 file_ra_state_init(ra, inode->i_mapping);
1315         } else {
1316                 ra = &file->f_ra;
1317         }
1318
1319         pages = kmalloc_array(max_cluster, sizeof(struct page *),
1320                         GFP_NOFS);
1321         if (!pages) {
1322                 ret = -ENOMEM;
1323                 goto out_ra;
1324         }
1325
1326         /* find the last page to defrag */
1327         if (range->start + range->len > range->start) {
1328                 last_index = min_t(u64, isize - 1,
1329                          range->start + range->len - 1) >> PAGE_SHIFT;
1330         } else {
1331                 last_index = (isize - 1) >> PAGE_SHIFT;
1332         }
1333
1334         if (newer_than) {
1335                 ret = find_new_extents(root, inode, newer_than,
1336                                        &newer_off, SZ_64K);
1337                 if (!ret) {
1338                         range->start = newer_off;
1339                         /*
1340                          * we always align our defrag to help keep
1341                          * the extents in the file evenly spaced
1342                          */
1343                         i = (newer_off & new_align) >> PAGE_SHIFT;
1344                 } else
1345                         goto out_ra;
1346         } else {
1347                 i = range->start >> PAGE_SHIFT;
1348         }
1349         if (!max_to_defrag)
1350                 max_to_defrag = last_index - i + 1;
1351
1352         /*
1353          * make writeback starts from i, so the defrag range can be
1354          * written sequentially.
1355          */
1356         if (i < inode->i_mapping->writeback_index)
1357                 inode->i_mapping->writeback_index = i;
1358
1359         while (i <= last_index && defrag_count < max_to_defrag &&
1360                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1361                 /*
1362                  * make sure we stop running if someone unmounts
1363                  * the FS
1364                  */
1365                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1366                         break;
1367
1368                 if (btrfs_defrag_cancelled(root->fs_info)) {
1369                         btrfs_debug(root->fs_info, "defrag_file cancelled");
1370                         ret = -EAGAIN;
1371                         break;
1372                 }
1373
1374                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1375                                          extent_thresh, &last_len, &skip,
1376                                          &defrag_end, range->flags &
1377                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1378                         unsigned long next;
1379                         /*
1380                          * the should_defrag function tells us how much to skip
1381                          * bump our counter by the suggested amount
1382                          */
1383                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1384                         i = max(i + 1, next);
1385                         continue;
1386                 }
1387
1388                 if (!newer_than) {
1389                         cluster = (PAGE_ALIGN(defrag_end) >>
1390                                    PAGE_SHIFT) - i;
1391                         cluster = min(cluster, max_cluster);
1392                 } else {
1393                         cluster = max_cluster;
1394                 }
1395
1396                 if (i + cluster > ra_index) {
1397                         ra_index = max(i, ra_index);
1398                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1399                                        cluster);
1400                         ra_index += cluster;
1401                 }
1402
1403                 inode_lock(inode);
1404                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1405                         BTRFS_I(inode)->force_compress = compress_type;
1406                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1407                 if (ret < 0) {
1408                         inode_unlock(inode);
1409                         goto out_ra;
1410                 }
1411
1412                 defrag_count += ret;
1413                 balance_dirty_pages_ratelimited(inode->i_mapping);
1414                 inode_unlock(inode);
1415
1416                 if (newer_than) {
1417                         if (newer_off == (u64)-1)
1418                                 break;
1419
1420                         if (ret > 0)
1421                                 i += ret;
1422
1423                         newer_off = max(newer_off + 1,
1424                                         (u64)i << PAGE_SHIFT);
1425
1426                         ret = find_new_extents(root, inode, newer_than,
1427                                                &newer_off, SZ_64K);
1428                         if (!ret) {
1429                                 range->start = newer_off;
1430                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1431                         } else {
1432                                 break;
1433                         }
1434                 } else {
1435                         if (ret > 0) {
1436                                 i += ret;
1437                                 last_len += ret << PAGE_SHIFT;
1438                         } else {
1439                                 i++;
1440                                 last_len = 0;
1441                         }
1442                 }
1443         }
1444
1445         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1446                 filemap_flush(inode->i_mapping);
1447                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1448                              &BTRFS_I(inode)->runtime_flags))
1449                         filemap_flush(inode->i_mapping);
1450         }
1451
1452         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1453                 /* the filemap_flush will queue IO into the worker threads, but
1454                  * we have to make sure the IO is actually started and that
1455                  * ordered extents get created before we return
1456                  */
1457                 atomic_inc(&root->fs_info->async_submit_draining);
1458                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1459                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1460                         wait_event(root->fs_info->async_submit_wait,
1461                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1462                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1463                 }
1464                 atomic_dec(&root->fs_info->async_submit_draining);
1465         }
1466
1467         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1468                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1469         }
1470
1471         ret = defrag_count;
1472
1473 out_ra:
1474         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1475                 inode_lock(inode);
1476                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1477                 inode_unlock(inode);
1478         }
1479         if (!file)
1480                 kfree(ra);
1481         kfree(pages);
1482         return ret;
1483 }
1484
1485 static noinline int btrfs_ioctl_resize(struct file *file,
1486                                         void __user *arg)
1487 {
1488         u64 new_size;
1489         u64 old_size;
1490         u64 devid = 1;
1491         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1492         struct btrfs_ioctl_vol_args *vol_args;
1493         struct btrfs_trans_handle *trans;
1494         struct btrfs_device *device = NULL;
1495         char *sizestr;
1496         char *retptr;
1497         char *devstr = NULL;
1498         int ret = 0;
1499         int mod = 0;
1500
1501         if (!capable(CAP_SYS_ADMIN))
1502                 return -EPERM;
1503
1504         ret = mnt_want_write_file(file);
1505         if (ret)
1506                 return ret;
1507
1508         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1509                         1)) {
1510                 mnt_drop_write_file(file);
1511                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1512         }
1513
1514         mutex_lock(&root->fs_info->volume_mutex);
1515         vol_args = memdup_user(arg, sizeof(*vol_args));
1516         if (IS_ERR(vol_args)) {
1517                 ret = PTR_ERR(vol_args);
1518                 goto out;
1519         }
1520
1521         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1522
1523         sizestr = vol_args->name;
1524         devstr = strchr(sizestr, ':');
1525         if (devstr) {
1526                 sizestr = devstr + 1;
1527                 *devstr = '\0';
1528                 devstr = vol_args->name;
1529                 ret = kstrtoull(devstr, 10, &devid);
1530                 if (ret)
1531                         goto out_free;
1532                 if (!devid) {
1533                         ret = -EINVAL;
1534                         goto out_free;
1535                 }
1536                 btrfs_info(root->fs_info, "resizing devid %llu", devid);
1537         }
1538
1539         device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1540         if (!device) {
1541                 btrfs_info(root->fs_info, "resizer unable to find device %llu",
1542                        devid);
1543                 ret = -ENODEV;
1544                 goto out_free;
1545         }
1546
1547         if (!device->writeable) {
1548                 btrfs_info(root->fs_info,
1549                            "resizer unable to apply on readonly device %llu",
1550                        devid);
1551                 ret = -EPERM;
1552                 goto out_free;
1553         }
1554
1555         if (!strcmp(sizestr, "max"))
1556                 new_size = device->bdev->bd_inode->i_size;
1557         else {
1558                 if (sizestr[0] == '-') {
1559                         mod = -1;
1560                         sizestr++;
1561                 } else if (sizestr[0] == '+') {
1562                         mod = 1;
1563                         sizestr++;
1564                 }
1565                 new_size = memparse(sizestr, &retptr);
1566                 if (*retptr != '\0' || new_size == 0) {
1567                         ret = -EINVAL;
1568                         goto out_free;
1569                 }
1570         }
1571
1572         if (device->is_tgtdev_for_dev_replace) {
1573                 ret = -EPERM;
1574                 goto out_free;
1575         }
1576
1577         old_size = btrfs_device_get_total_bytes(device);
1578
1579         if (mod < 0) {
1580                 if (new_size > old_size) {
1581                         ret = -EINVAL;
1582                         goto out_free;
1583                 }
1584                 new_size = old_size - new_size;
1585         } else if (mod > 0) {
1586                 if (new_size > ULLONG_MAX - old_size) {
1587                         ret = -ERANGE;
1588                         goto out_free;
1589                 }
1590                 new_size = old_size + new_size;
1591         }
1592
1593         if (new_size < SZ_256M) {
1594                 ret = -EINVAL;
1595                 goto out_free;
1596         }
1597         if (new_size > device->bdev->bd_inode->i_size) {
1598                 ret = -EFBIG;
1599                 goto out_free;
1600         }
1601
1602         new_size = div_u64(new_size, root->sectorsize);
1603         new_size *= root->sectorsize;
1604
1605         btrfs_info_in_rcu(root->fs_info, "new size for %s is %llu",
1606                       rcu_str_deref(device->name), new_size);
1607
1608         if (new_size > old_size) {
1609                 trans = btrfs_start_transaction(root, 0);
1610                 if (IS_ERR(trans)) {
1611                         ret = PTR_ERR(trans);
1612                         goto out_free;
1613                 }
1614                 ret = btrfs_grow_device(trans, device, new_size);
1615                 btrfs_commit_transaction(trans, root);
1616         } else if (new_size < old_size) {
1617                 ret = btrfs_shrink_device(device, new_size);
1618         } /* equal, nothing need to do */
1619
1620 out_free:
1621         kfree(vol_args);
1622 out:
1623         mutex_unlock(&root->fs_info->volume_mutex);
1624         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1625         mnt_drop_write_file(file);
1626         return ret;
1627 }
1628
1629 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1630                                 char *name, unsigned long fd, int subvol,
1631                                 u64 *transid, bool readonly,
1632                                 struct btrfs_qgroup_inherit *inherit)
1633 {
1634         int namelen;
1635         int ret = 0;
1636
1637         ret = mnt_want_write_file(file);
1638         if (ret)
1639                 goto out;
1640
1641         namelen = strlen(name);
1642         if (strchr(name, '/')) {
1643                 ret = -EINVAL;
1644                 goto out_drop_write;
1645         }
1646
1647         if (name[0] == '.' &&
1648            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1649                 ret = -EEXIST;
1650                 goto out_drop_write;
1651         }
1652
1653         if (subvol) {
1654                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1655                                      NULL, transid, readonly, inherit);
1656         } else {
1657                 struct fd src = fdget(fd);
1658                 struct inode *src_inode;
1659                 if (!src.file) {
1660                         ret = -EINVAL;
1661                         goto out_drop_write;
1662                 }
1663
1664                 src_inode = file_inode(src.file);
1665                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1666                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1667                                    "Snapshot src from another FS");
1668                         ret = -EXDEV;
1669                 } else if (!inode_owner_or_capable(src_inode)) {
1670                         /*
1671                          * Subvolume creation is not restricted, but snapshots
1672                          * are limited to own subvolumes only
1673                          */
1674                         ret = -EPERM;
1675                 } else {
1676                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1677                                              BTRFS_I(src_inode)->root,
1678                                              transid, readonly, inherit);
1679                 }
1680                 fdput(src);
1681         }
1682 out_drop_write:
1683         mnt_drop_write_file(file);
1684 out:
1685         return ret;
1686 }
1687
1688 static noinline int btrfs_ioctl_snap_create(struct file *file,
1689                                             void __user *arg, int subvol)
1690 {
1691         struct btrfs_ioctl_vol_args *vol_args;
1692         int ret;
1693
1694         vol_args = memdup_user(arg, sizeof(*vol_args));
1695         if (IS_ERR(vol_args))
1696                 return PTR_ERR(vol_args);
1697         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1698
1699         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1700                                               vol_args->fd, subvol,
1701                                               NULL, false, NULL);
1702
1703         kfree(vol_args);
1704         return ret;
1705 }
1706
1707 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1708                                                void __user *arg, int subvol)
1709 {
1710         struct btrfs_ioctl_vol_args_v2 *vol_args;
1711         int ret;
1712         u64 transid = 0;
1713         u64 *ptr = NULL;
1714         bool readonly = false;
1715         struct btrfs_qgroup_inherit *inherit = NULL;
1716
1717         vol_args = memdup_user(arg, sizeof(*vol_args));
1718         if (IS_ERR(vol_args))
1719                 return PTR_ERR(vol_args);
1720         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1721
1722         if (vol_args->flags &
1723             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1724               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1725                 ret = -EOPNOTSUPP;
1726                 goto free_args;
1727         }
1728
1729         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1730                 ptr = &transid;
1731         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1732                 readonly = true;
1733         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1734                 if (vol_args->size > PAGE_SIZE) {
1735                         ret = -EINVAL;
1736                         goto free_args;
1737                 }
1738                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1739                 if (IS_ERR(inherit)) {
1740                         ret = PTR_ERR(inherit);
1741                         goto free_args;
1742                 }
1743         }
1744
1745         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1746                                               vol_args->fd, subvol, ptr,
1747                                               readonly, inherit);
1748         if (ret)
1749                 goto free_inherit;
1750
1751         if (ptr && copy_to_user(arg +
1752                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1753                                         transid),
1754                                 ptr, sizeof(*ptr)))
1755                 ret = -EFAULT;
1756
1757 free_inherit:
1758         kfree(inherit);
1759 free_args:
1760         kfree(vol_args);
1761         return ret;
1762 }
1763
1764 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1765                                                 void __user *arg)
1766 {
1767         struct inode *inode = file_inode(file);
1768         struct btrfs_root *root = BTRFS_I(inode)->root;
1769         int ret = 0;
1770         u64 flags = 0;
1771
1772         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1773                 return -EINVAL;
1774
1775         down_read(&root->fs_info->subvol_sem);
1776         if (btrfs_root_readonly(root))
1777                 flags |= BTRFS_SUBVOL_RDONLY;
1778         up_read(&root->fs_info->subvol_sem);
1779
1780         if (copy_to_user(arg, &flags, sizeof(flags)))
1781                 ret = -EFAULT;
1782
1783         return ret;
1784 }
1785
1786 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1787                                               void __user *arg)
1788 {
1789         struct inode *inode = file_inode(file);
1790         struct btrfs_root *root = BTRFS_I(inode)->root;
1791         struct btrfs_trans_handle *trans;
1792         u64 root_flags;
1793         u64 flags;
1794         int ret = 0;
1795
1796         if (!inode_owner_or_capable(inode))
1797                 return -EPERM;
1798
1799         ret = mnt_want_write_file(file);
1800         if (ret)
1801                 goto out;
1802
1803         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1804                 ret = -EINVAL;
1805                 goto out_drop_write;
1806         }
1807
1808         if (copy_from_user(&flags, arg, sizeof(flags))) {
1809                 ret = -EFAULT;
1810                 goto out_drop_write;
1811         }
1812
1813         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1814                 ret = -EINVAL;
1815                 goto out_drop_write;
1816         }
1817
1818         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1819                 ret = -EOPNOTSUPP;
1820                 goto out_drop_write;
1821         }
1822
1823         down_write(&root->fs_info->subvol_sem);
1824
1825         /* nothing to do */
1826         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1827                 goto out_drop_sem;
1828
1829         root_flags = btrfs_root_flags(&root->root_item);
1830         if (flags & BTRFS_SUBVOL_RDONLY) {
1831                 btrfs_set_root_flags(&root->root_item,
1832                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1833         } else {
1834                 /*
1835                  * Block RO -> RW transition if this subvolume is involved in
1836                  * send
1837                  */
1838                 spin_lock(&root->root_item_lock);
1839                 if (root->send_in_progress == 0) {
1840                         btrfs_set_root_flags(&root->root_item,
1841                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1842                         spin_unlock(&root->root_item_lock);
1843                 } else {
1844                         spin_unlock(&root->root_item_lock);
1845                         btrfs_warn(root->fs_info,
1846                         "Attempt to set subvolume %llu read-write during send",
1847                                         root->root_key.objectid);
1848                         ret = -EPERM;
1849                         goto out_drop_sem;
1850                 }
1851         }
1852
1853         trans = btrfs_start_transaction(root, 1);
1854         if (IS_ERR(trans)) {
1855                 ret = PTR_ERR(trans);
1856                 goto out_reset;
1857         }
1858
1859         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1860                                 &root->root_key, &root->root_item);
1861
1862         btrfs_commit_transaction(trans, root);
1863 out_reset:
1864         if (ret)
1865                 btrfs_set_root_flags(&root->root_item, root_flags);
1866 out_drop_sem:
1867         up_write(&root->fs_info->subvol_sem);
1868 out_drop_write:
1869         mnt_drop_write_file(file);
1870 out:
1871         return ret;
1872 }
1873
1874 /*
1875  * helper to check if the subvolume references other subvolumes
1876  */
1877 static noinline int may_destroy_subvol(struct btrfs_root *root)
1878 {
1879         struct btrfs_path *path;
1880         struct btrfs_dir_item *di;
1881         struct btrfs_key key;
1882         u64 dir_id;
1883         int ret;
1884
1885         path = btrfs_alloc_path();
1886         if (!path)
1887                 return -ENOMEM;
1888
1889         /* Make sure this root isn't set as the default subvol */
1890         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
1891         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
1892                                    dir_id, "default", 7, 0);
1893         if (di && !IS_ERR(di)) {
1894                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1895                 if (key.objectid == root->root_key.objectid) {
1896                         ret = -EPERM;
1897                         btrfs_err(root->fs_info, "deleting default subvolume "
1898                                   "%llu is not allowed", key.objectid);
1899                         goto out;
1900                 }
1901                 btrfs_release_path(path);
1902         }
1903
1904         key.objectid = root->root_key.objectid;
1905         key.type = BTRFS_ROOT_REF_KEY;
1906         key.offset = (u64)-1;
1907
1908         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1909                                 &key, path, 0, 0);
1910         if (ret < 0)
1911                 goto out;
1912         BUG_ON(ret == 0);
1913
1914         ret = 0;
1915         if (path->slots[0] > 0) {
1916                 path->slots[0]--;
1917                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1918                 if (key.objectid == root->root_key.objectid &&
1919                     key.type == BTRFS_ROOT_REF_KEY)
1920                         ret = -ENOTEMPTY;
1921         }
1922 out:
1923         btrfs_free_path(path);
1924         return ret;
1925 }
1926
1927 static noinline int key_in_sk(struct btrfs_key *key,
1928                               struct btrfs_ioctl_search_key *sk)
1929 {
1930         struct btrfs_key test;
1931         int ret;
1932
1933         test.objectid = sk->min_objectid;
1934         test.type = sk->min_type;
1935         test.offset = sk->min_offset;
1936
1937         ret = btrfs_comp_cpu_keys(key, &test);
1938         if (ret < 0)
1939                 return 0;
1940
1941         test.objectid = sk->max_objectid;
1942         test.type = sk->max_type;
1943         test.offset = sk->max_offset;
1944
1945         ret = btrfs_comp_cpu_keys(key, &test);
1946         if (ret > 0)
1947                 return 0;
1948         return 1;
1949 }
1950
1951 static noinline int copy_to_sk(struct btrfs_root *root,
1952                                struct btrfs_path *path,
1953                                struct btrfs_key *key,
1954                                struct btrfs_ioctl_search_key *sk,
1955                                size_t *buf_size,
1956                                char __user *ubuf,
1957                                unsigned long *sk_offset,
1958                                int *num_found)
1959 {
1960         u64 found_transid;
1961         struct extent_buffer *leaf;
1962         struct btrfs_ioctl_search_header sh;
1963         struct btrfs_key test;
1964         unsigned long item_off;
1965         unsigned long item_len;
1966         int nritems;
1967         int i;
1968         int slot;
1969         int ret = 0;
1970
1971         leaf = path->nodes[0];
1972         slot = path->slots[0];
1973         nritems = btrfs_header_nritems(leaf);
1974
1975         if (btrfs_header_generation(leaf) > sk->max_transid) {
1976                 i = nritems;
1977                 goto advance_key;
1978         }
1979         found_transid = btrfs_header_generation(leaf);
1980
1981         for (i = slot; i < nritems; i++) {
1982                 item_off = btrfs_item_ptr_offset(leaf, i);
1983                 item_len = btrfs_item_size_nr(leaf, i);
1984
1985                 btrfs_item_key_to_cpu(leaf, key, i);
1986                 if (!key_in_sk(key, sk))
1987                         continue;
1988
1989                 if (sizeof(sh) + item_len > *buf_size) {
1990                         if (*num_found) {
1991                                 ret = 1;
1992                                 goto out;
1993                         }
1994
1995                         /*
1996                          * return one empty item back for v1, which does not
1997                          * handle -EOVERFLOW
1998                          */
1999
2000                         *buf_size = sizeof(sh) + item_len;
2001                         item_len = 0;
2002                         ret = -EOVERFLOW;
2003                 }
2004
2005                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2006                         ret = 1;
2007                         goto out;
2008                 }
2009
2010                 sh.objectid = key->objectid;
2011                 sh.offset = key->offset;
2012                 sh.type = key->type;
2013                 sh.len = item_len;
2014                 sh.transid = found_transid;
2015
2016                 /* copy search result header */
2017                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2018                         ret = -EFAULT;
2019                         goto out;
2020                 }
2021
2022                 *sk_offset += sizeof(sh);
2023
2024                 if (item_len) {
2025                         char __user *up = ubuf + *sk_offset;
2026                         /* copy the item */
2027                         if (read_extent_buffer_to_user(leaf, up,
2028                                                        item_off, item_len)) {
2029                                 ret = -EFAULT;
2030                                 goto out;
2031                         }
2032
2033                         *sk_offset += item_len;
2034                 }
2035                 (*num_found)++;
2036
2037                 if (ret) /* -EOVERFLOW from above */
2038                         goto out;
2039
2040                 if (*num_found >= sk->nr_items) {
2041                         ret = 1;
2042                         goto out;
2043                 }
2044         }
2045 advance_key:
2046         ret = 0;
2047         test.objectid = sk->max_objectid;
2048         test.type = sk->max_type;
2049         test.offset = sk->max_offset;
2050         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2051                 ret = 1;
2052         else if (key->offset < (u64)-1)
2053                 key->offset++;
2054         else if (key->type < (u8)-1) {
2055                 key->offset = 0;
2056                 key->type++;
2057         } else if (key->objectid < (u64)-1) {
2058                 key->offset = 0;
2059                 key->type = 0;
2060                 key->objectid++;
2061         } else
2062                 ret = 1;
2063 out:
2064         /*
2065          *  0: all items from this leaf copied, continue with next
2066          *  1: * more items can be copied, but unused buffer is too small
2067          *     * all items were found
2068          *     Either way, it will stops the loop which iterates to the next
2069          *     leaf
2070          *  -EOVERFLOW: item was to large for buffer
2071          *  -EFAULT: could not copy extent buffer back to userspace
2072          */
2073         return ret;
2074 }
2075
2076 static noinline int search_ioctl(struct inode *inode,
2077                                  struct btrfs_ioctl_search_key *sk,
2078                                  size_t *buf_size,
2079                                  char __user *ubuf)
2080 {
2081         struct btrfs_root *root;
2082         struct btrfs_key key;
2083         struct btrfs_path *path;
2084         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
2085         int ret;
2086         int num_found = 0;
2087         unsigned long sk_offset = 0;
2088
2089         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2090                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2091                 return -EOVERFLOW;
2092         }
2093
2094         path = btrfs_alloc_path();
2095         if (!path)
2096                 return -ENOMEM;
2097
2098         if (sk->tree_id == 0) {
2099                 /* search the root of the inode that was passed */
2100                 root = BTRFS_I(inode)->root;
2101         } else {
2102                 key.objectid = sk->tree_id;
2103                 key.type = BTRFS_ROOT_ITEM_KEY;
2104                 key.offset = (u64)-1;
2105                 root = btrfs_read_fs_root_no_name(info, &key);
2106                 if (IS_ERR(root)) {
2107                         btrfs_free_path(path);
2108                         return -ENOENT;
2109                 }
2110         }
2111
2112         key.objectid = sk->min_objectid;
2113         key.type = sk->min_type;
2114         key.offset = sk->min_offset;
2115
2116         while (1) {
2117                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2118                 if (ret != 0) {
2119                         if (ret > 0)
2120                                 ret = 0;
2121                         goto err;
2122                 }
2123                 ret = copy_to_sk(root, path, &key, sk, buf_size, ubuf,
2124                                  &sk_offset, &num_found);
2125                 btrfs_release_path(path);
2126                 if (ret)
2127                         break;
2128
2129         }
2130         if (ret > 0)
2131                 ret = 0;
2132 err:
2133         sk->nr_items = num_found;
2134         btrfs_free_path(path);
2135         return ret;
2136 }
2137
2138 static noinline int btrfs_ioctl_tree_search(struct file *file,
2139                                            void __user *argp)
2140 {
2141         struct btrfs_ioctl_search_args __user *uargs;
2142         struct btrfs_ioctl_search_key sk;
2143         struct inode *inode;
2144         int ret;
2145         size_t buf_size;
2146
2147         if (!capable(CAP_SYS_ADMIN))
2148                 return -EPERM;
2149
2150         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2151
2152         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2153                 return -EFAULT;
2154
2155         buf_size = sizeof(uargs->buf);
2156
2157         inode = file_inode(file);
2158         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2159
2160         /*
2161          * In the origin implementation an overflow is handled by returning a
2162          * search header with a len of zero, so reset ret.
2163          */
2164         if (ret == -EOVERFLOW)
2165                 ret = 0;
2166
2167         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2168                 ret = -EFAULT;
2169         return ret;
2170 }
2171
2172 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2173                                                void __user *argp)
2174 {
2175         struct btrfs_ioctl_search_args_v2 __user *uarg;
2176         struct btrfs_ioctl_search_args_v2 args;
2177         struct inode *inode;
2178         int ret;
2179         size_t buf_size;
2180         const size_t buf_limit = SZ_16M;
2181
2182         if (!capable(CAP_SYS_ADMIN))
2183                 return -EPERM;
2184
2185         /* copy search header and buffer size */
2186         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2187         if (copy_from_user(&args, uarg, sizeof(args)))
2188                 return -EFAULT;
2189
2190         buf_size = args.buf_size;
2191
2192         if (buf_size < sizeof(struct btrfs_ioctl_search_header))
2193                 return -EOVERFLOW;
2194
2195         /* limit result size to 16MB */
2196         if (buf_size > buf_limit)
2197                 buf_size = buf_limit;
2198
2199         inode = file_inode(file);
2200         ret = search_ioctl(inode, &args.key, &buf_size,
2201                            (char *)(&uarg->buf[0]));
2202         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2203                 ret = -EFAULT;
2204         else if (ret == -EOVERFLOW &&
2205                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2206                 ret = -EFAULT;
2207
2208         return ret;
2209 }
2210
2211 /*
2212  * Search INODE_REFs to identify path name of 'dirid' directory
2213  * in a 'tree_id' tree. and sets path name to 'name'.
2214  */
2215 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2216                                 u64 tree_id, u64 dirid, char *name)
2217 {
2218         struct btrfs_root *root;
2219         struct btrfs_key key;
2220         char *ptr;
2221         int ret = -1;
2222         int slot;
2223         int len;
2224         int total_len = 0;
2225         struct btrfs_inode_ref *iref;
2226         struct extent_buffer *l;
2227         struct btrfs_path *path;
2228
2229         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2230                 name[0]='\0';
2231                 return 0;
2232         }
2233
2234         path = btrfs_alloc_path();
2235         if (!path)
2236                 return -ENOMEM;
2237
2238         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
2239
2240         key.objectid = tree_id;
2241         key.type = BTRFS_ROOT_ITEM_KEY;
2242         key.offset = (u64)-1;
2243         root = btrfs_read_fs_root_no_name(info, &key);
2244         if (IS_ERR(root)) {
2245                 btrfs_err(info, "could not find root %llu", tree_id);
2246                 ret = -ENOENT;
2247                 goto out;
2248         }
2249
2250         key.objectid = dirid;
2251         key.type = BTRFS_INODE_REF_KEY;
2252         key.offset = (u64)-1;
2253
2254         while (1) {
2255                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2256                 if (ret < 0)
2257                         goto out;
2258                 else if (ret > 0) {
2259                         ret = btrfs_previous_item(root, path, dirid,
2260                                                   BTRFS_INODE_REF_KEY);
2261                         if (ret < 0)
2262                                 goto out;
2263                         else if (ret > 0) {
2264                                 ret = -ENOENT;
2265                                 goto out;
2266                         }
2267                 }
2268
2269                 l = path->nodes[0];
2270                 slot = path->slots[0];
2271                 btrfs_item_key_to_cpu(l, &key, slot);
2272
2273                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2274                 len = btrfs_inode_ref_name_len(l, iref);
2275                 ptr -= len + 1;
2276                 total_len += len + 1;
2277                 if (ptr < name) {
2278                         ret = -ENAMETOOLONG;
2279                         goto out;
2280                 }
2281
2282                 *(ptr + len) = '/';
2283                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2284
2285                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2286                         break;
2287
2288                 btrfs_release_path(path);
2289                 key.objectid = key.offset;
2290                 key.offset = (u64)-1;
2291                 dirid = key.objectid;
2292         }
2293         memmove(name, ptr, total_len);
2294         name[total_len] = '\0';
2295         ret = 0;
2296 out:
2297         btrfs_free_path(path);
2298         return ret;
2299 }
2300
2301 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2302                                            void __user *argp)
2303 {
2304          struct btrfs_ioctl_ino_lookup_args *args;
2305          struct inode *inode;
2306         int ret = 0;
2307
2308         args = memdup_user(argp, sizeof(*args));
2309         if (IS_ERR(args))
2310                 return PTR_ERR(args);
2311
2312         inode = file_inode(file);
2313
2314         /*
2315          * Unprivileged query to obtain the containing subvolume root id. The
2316          * path is reset so it's consistent with btrfs_search_path_in_tree.
2317          */
2318         if (args->treeid == 0)
2319                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2320
2321         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2322                 args->name[0] = 0;
2323                 goto out;
2324         }
2325
2326         if (!capable(CAP_SYS_ADMIN)) {
2327                 ret = -EPERM;
2328                 goto out;
2329         }
2330
2331         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2332                                         args->treeid, args->objectid,
2333                                         args->name);
2334
2335 out:
2336         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2337                 ret = -EFAULT;
2338
2339         kfree(args);
2340         return ret;
2341 }
2342
2343 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2344                                              void __user *arg)
2345 {
2346         struct dentry *parent = file->f_path.dentry;
2347         struct dentry *dentry;
2348         struct inode *dir = d_inode(parent);
2349         struct inode *inode;
2350         struct btrfs_root *root = BTRFS_I(dir)->root;
2351         struct btrfs_root *dest = NULL;
2352         struct btrfs_ioctl_vol_args *vol_args;
2353         struct btrfs_trans_handle *trans;
2354         struct btrfs_block_rsv block_rsv;
2355         u64 root_flags;
2356         u64 qgroup_reserved;
2357         int namelen;
2358         int ret;
2359         int err = 0;
2360
2361         vol_args = memdup_user(arg, sizeof(*vol_args));
2362         if (IS_ERR(vol_args))
2363                 return PTR_ERR(vol_args);
2364
2365         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2366         namelen = strlen(vol_args->name);
2367         if (strchr(vol_args->name, '/') ||
2368             strncmp(vol_args->name, "..", namelen) == 0) {
2369                 err = -EINVAL;
2370                 goto out;
2371         }
2372
2373         err = mnt_want_write_file(file);
2374         if (err)
2375                 goto out;
2376
2377
2378         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2379         if (err == -EINTR)
2380                 goto out_drop_write;
2381         dentry = lookup_one_len(vol_args->name, parent, namelen);
2382         if (IS_ERR(dentry)) {
2383                 err = PTR_ERR(dentry);
2384                 goto out_unlock_dir;
2385         }
2386
2387         if (d_really_is_negative(dentry)) {
2388                 err = -ENOENT;
2389                 goto out_dput;
2390         }
2391
2392         inode = d_inode(dentry);
2393         dest = BTRFS_I(inode)->root;
2394         if (!capable(CAP_SYS_ADMIN)) {
2395                 /*
2396                  * Regular user.  Only allow this with a special mount
2397                  * option, when the user has write+exec access to the
2398                  * subvol root, and when rmdir(2) would have been
2399                  * allowed.
2400                  *
2401                  * Note that this is _not_ check that the subvol is
2402                  * empty or doesn't contain data that we wouldn't
2403                  * otherwise be able to delete.
2404                  *
2405                  * Users who want to delete empty subvols should try
2406                  * rmdir(2).
2407                  */
2408                 err = -EPERM;
2409                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2410                         goto out_dput;
2411
2412                 /*
2413                  * Do not allow deletion if the parent dir is the same
2414                  * as the dir to be deleted.  That means the ioctl
2415                  * must be called on the dentry referencing the root
2416                  * of the subvol, not a random directory contained
2417                  * within it.
2418                  */
2419                 err = -EINVAL;
2420                 if (root == dest)
2421                         goto out_dput;
2422
2423                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2424                 if (err)
2425                         goto out_dput;
2426         }
2427
2428         /* check if subvolume may be deleted by a user */
2429         err = btrfs_may_delete(dir, dentry, 1);
2430         if (err)
2431                 goto out_dput;
2432
2433         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2434                 err = -EINVAL;
2435                 goto out_dput;
2436         }
2437
2438         inode_lock(inode);
2439
2440         /*
2441          * Don't allow to delete a subvolume with send in progress. This is
2442          * inside the i_mutex so the error handling that has to drop the bit
2443          * again is not run concurrently.
2444          */
2445         spin_lock(&dest->root_item_lock);
2446         root_flags = btrfs_root_flags(&dest->root_item);
2447         if (dest->send_in_progress == 0) {
2448                 btrfs_set_root_flags(&dest->root_item,
2449                                 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
2450                 spin_unlock(&dest->root_item_lock);
2451         } else {
2452                 spin_unlock(&dest->root_item_lock);
2453                 btrfs_warn(root->fs_info,
2454                         "Attempt to delete subvolume %llu during send",
2455                         dest->root_key.objectid);
2456                 err = -EPERM;
2457                 goto out_unlock_inode;
2458         }
2459
2460         down_write(&root->fs_info->subvol_sem);
2461
2462         err = may_destroy_subvol(dest);
2463         if (err)
2464                 goto out_up_write;
2465
2466         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
2467         /*
2468          * One for dir inode, two for dir entries, two for root
2469          * ref/backref.
2470          */
2471         err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
2472                                                5, &qgroup_reserved, true);
2473         if (err)
2474                 goto out_up_write;
2475
2476         trans = btrfs_start_transaction(root, 0);
2477         if (IS_ERR(trans)) {
2478                 err = PTR_ERR(trans);
2479                 goto out_release;
2480         }
2481         trans->block_rsv = &block_rsv;
2482         trans->bytes_reserved = block_rsv.size;
2483
2484         btrfs_record_snapshot_destroy(trans, dir);
2485
2486         ret = btrfs_unlink_subvol(trans, root, dir,
2487                                 dest->root_key.objectid,
2488                                 dentry->d_name.name,
2489                                 dentry->d_name.len);
2490         if (ret) {
2491                 err = ret;
2492                 btrfs_abort_transaction(trans, root, ret);
2493                 goto out_end_trans;
2494         }
2495
2496         btrfs_record_root_in_trans(trans, dest);
2497
2498         memset(&dest->root_item.drop_progress, 0,
2499                 sizeof(dest->root_item.drop_progress));
2500         dest->root_item.drop_level = 0;
2501         btrfs_set_root_refs(&dest->root_item, 0);
2502
2503         if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
2504                 ret = btrfs_insert_orphan_item(trans,
2505                                         root->fs_info->tree_root,
2506                                         dest->root_key.objectid);
2507                 if (ret) {
2508                         btrfs_abort_transaction(trans, root, ret);
2509                         err = ret;
2510                         goto out_end_trans;
2511                 }
2512         }
2513
2514         ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2515                                   dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL,
2516                                   dest->root_key.objectid);
2517         if (ret && ret != -ENOENT) {
2518                 btrfs_abort_transaction(trans, root, ret);
2519                 err = ret;
2520                 goto out_end_trans;
2521         }
2522         if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
2523                 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
2524                                           dest->root_item.received_uuid,
2525                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
2526                                           dest->root_key.objectid);
2527                 if (ret && ret != -ENOENT) {
2528                         btrfs_abort_transaction(trans, root, ret);
2529                         err = ret;
2530                         goto out_end_trans;
2531                 }
2532         }
2533
2534 out_end_trans:
2535         trans->block_rsv = NULL;
2536         trans->bytes_reserved = 0;
2537         ret = btrfs_end_transaction(trans, root);
2538         if (ret && !err)
2539                 err = ret;
2540         inode->i_flags |= S_DEAD;
2541 out_release:
2542         btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
2543 out_up_write:
2544         up_write(&root->fs_info->subvol_sem);
2545         if (err) {
2546                 spin_lock(&dest->root_item_lock);
2547                 root_flags = btrfs_root_flags(&dest->root_item);
2548                 btrfs_set_root_flags(&dest->root_item,
2549                                 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
2550                 spin_unlock(&dest->root_item_lock);
2551         }
2552 out_unlock_inode:
2553         inode_unlock(inode);
2554         if (!err) {
2555                 d_invalidate(dentry);
2556                 btrfs_invalidate_inodes(dest);
2557                 d_delete(dentry);
2558                 ASSERT(dest->send_in_progress == 0);
2559
2560                 /* the last ref */
2561                 if (dest->ino_cache_inode) {
2562                         iput(dest->ino_cache_inode);
2563                         dest->ino_cache_inode = NULL;
2564                 }
2565         }
2566 out_dput:
2567         dput(dentry);
2568 out_unlock_dir:
2569         inode_unlock(dir);
2570 out_drop_write:
2571         mnt_drop_write_file(file);
2572 out:
2573         kfree(vol_args);
2574         return err;
2575 }
2576
2577 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2578 {
2579         struct inode *inode = file_inode(file);
2580         struct btrfs_root *root = BTRFS_I(inode)->root;
2581         struct btrfs_ioctl_defrag_range_args *range;
2582         int ret;
2583
2584         ret = mnt_want_write_file(file);
2585         if (ret)
2586                 return ret;
2587
2588         if (btrfs_root_readonly(root)) {
2589                 ret = -EROFS;
2590                 goto out;
2591         }
2592
2593         switch (inode->i_mode & S_IFMT) {
2594         case S_IFDIR:
2595                 if (!capable(CAP_SYS_ADMIN)) {
2596                         ret = -EPERM;
2597                         goto out;
2598                 }
2599                 ret = btrfs_defrag_root(root);
2600                 if (ret)
2601                         goto out;
2602                 ret = btrfs_defrag_root(root->fs_info->extent_root);
2603                 break;
2604         case S_IFREG:
2605                 if (!(file->f_mode & FMODE_WRITE)) {
2606                         ret = -EINVAL;
2607                         goto out;
2608                 }
2609
2610                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2611                 if (!range) {
2612                         ret = -ENOMEM;
2613                         goto out;
2614                 }
2615
2616                 if (argp) {
2617                         if (copy_from_user(range, argp,
2618                                            sizeof(*range))) {
2619                                 ret = -EFAULT;
2620                                 kfree(range);
2621                                 goto out;
2622                         }
2623                         /* compression requires us to start the IO */
2624                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2625                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2626                                 range->extent_thresh = (u32)-1;
2627                         }
2628                 } else {
2629                         /* the rest are all set to zero by kzalloc */
2630                         range->len = (u64)-1;
2631                 }
2632                 ret = btrfs_defrag_file(file_inode(file), file,
2633                                         range, 0, 0);
2634                 if (ret > 0)
2635                         ret = 0;
2636                 kfree(range);
2637                 break;
2638         default:
2639                 ret = -EINVAL;
2640         }
2641 out:
2642         mnt_drop_write_file(file);
2643         return ret;
2644 }
2645
2646 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2647 {
2648         struct btrfs_ioctl_vol_args *vol_args;
2649         int ret;
2650
2651         if (!capable(CAP_SYS_ADMIN))
2652                 return -EPERM;
2653
2654         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2655                         1)) {
2656                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2657         }
2658
2659         mutex_lock(&root->fs_info->volume_mutex);
2660         vol_args = memdup_user(arg, sizeof(*vol_args));
2661         if (IS_ERR(vol_args)) {
2662                 ret = PTR_ERR(vol_args);
2663                 goto out;
2664         }
2665
2666         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2667         ret = btrfs_init_new_device(root, vol_args->name);
2668
2669         if (!ret)
2670                 btrfs_info(root->fs_info, "disk added %s",vol_args->name);
2671
2672         kfree(vol_args);
2673 out:
2674         mutex_unlock(&root->fs_info->volume_mutex);
2675         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2676         return ret;
2677 }
2678
2679 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
2680 {
2681         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2682         struct btrfs_ioctl_vol_args_v2 *vol_args;
2683         int ret;
2684
2685         if (!capable(CAP_SYS_ADMIN))
2686                 return -EPERM;
2687
2688         ret = mnt_want_write_file(file);
2689         if (ret)
2690                 return ret;
2691
2692         vol_args = memdup_user(arg, sizeof(*vol_args));
2693         if (IS_ERR(vol_args)) {
2694                 ret = PTR_ERR(vol_args);
2695                 goto err_drop;
2696         }
2697
2698         /* Check for compatibility reject unknown flags */
2699         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED)
2700                 return -EOPNOTSUPP;
2701
2702         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2703                         1)) {
2704                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2705                 goto out;
2706         }
2707
2708         mutex_lock(&root->fs_info->volume_mutex);
2709         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
2710                 ret = btrfs_rm_device(root, NULL, vol_args->devid);
2711         } else {
2712                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
2713                 ret = btrfs_rm_device(root, vol_args->name, 0);
2714         }
2715         mutex_unlock(&root->fs_info->volume_mutex);
2716         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2717
2718         if (!ret) {
2719                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
2720                         btrfs_info(root->fs_info, "device deleted: id %llu",
2721                                         vol_args->devid);
2722                 else
2723                         btrfs_info(root->fs_info, "device deleted: %s",
2724                                         vol_args->name);
2725         }
2726 out:
2727         kfree(vol_args);
2728 err_drop:
2729         mnt_drop_write_file(file);
2730         return ret;
2731 }
2732
2733 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2734 {
2735         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2736         struct btrfs_ioctl_vol_args *vol_args;
2737         int ret;
2738
2739         if (!capable(CAP_SYS_ADMIN))
2740                 return -EPERM;
2741
2742         ret = mnt_want_write_file(file);
2743         if (ret)
2744                 return ret;
2745
2746         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2747                         1)) {
2748                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
2749                 goto out_drop_write;
2750         }
2751
2752         vol_args = memdup_user(arg, sizeof(*vol_args));
2753         if (IS_ERR(vol_args)) {
2754                 ret = PTR_ERR(vol_args);
2755                 goto out;
2756         }
2757
2758         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2759         mutex_lock(&root->fs_info->volume_mutex);
2760         ret = btrfs_rm_device(root, vol_args->name, 0);
2761         mutex_unlock(&root->fs_info->volume_mutex);
2762
2763         if (!ret)
2764                 btrfs_info(root->fs_info, "disk deleted %s",vol_args->name);
2765         kfree(vol_args);
2766 out:
2767         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2768 out_drop_write:
2769         mnt_drop_write_file(file);
2770
2771         return ret;
2772 }
2773
2774 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2775 {
2776         struct btrfs_ioctl_fs_info_args *fi_args;
2777         struct btrfs_device *device;
2778         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2779         int ret = 0;
2780
2781         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2782         if (!fi_args)
2783                 return -ENOMEM;
2784
2785         mutex_lock(&fs_devices->device_list_mutex);
2786         fi_args->num_devices = fs_devices->num_devices;
2787         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2788
2789         list_for_each_entry(device, &fs_devices->devices, dev_list) {
2790                 if (device->devid > fi_args->max_id)
2791                         fi_args->max_id = device->devid;
2792         }
2793         mutex_unlock(&fs_devices->device_list_mutex);
2794
2795         fi_args->nodesize = root->fs_info->super_copy->nodesize;
2796         fi_args->sectorsize = root->fs_info->super_copy->sectorsize;
2797         fi_args->clone_alignment = root->fs_info->super_copy->sectorsize;
2798
2799         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2800                 ret = -EFAULT;
2801
2802         kfree(fi_args);
2803         return ret;
2804 }
2805
2806 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2807 {
2808         struct btrfs_ioctl_dev_info_args *di_args;
2809         struct btrfs_device *dev;
2810         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2811         int ret = 0;
2812         char *s_uuid = NULL;
2813
2814         di_args = memdup_user(arg, sizeof(*di_args));
2815         if (IS_ERR(di_args))
2816                 return PTR_ERR(di_args);
2817
2818         if (!btrfs_is_empty_uuid(di_args->uuid))
2819                 s_uuid = di_args->uuid;
2820
2821         mutex_lock(&fs_devices->device_list_mutex);
2822         dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2823
2824         if (!dev) {
2825                 ret = -ENODEV;
2826                 goto out;
2827         }
2828
2829         di_args->devid = dev->devid;
2830         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
2831         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
2832         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2833         if (dev->name) {
2834                 struct rcu_string *name;
2835
2836                 rcu_read_lock();
2837                 name = rcu_dereference(dev->name);
2838                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2839                 rcu_read_unlock();
2840                 di_args->path[sizeof(di_args->path) - 1] = 0;
2841         } else {
2842                 di_args->path[0] = '\0';
2843         }
2844
2845 out:
2846         mutex_unlock(&fs_devices->device_list_mutex);
2847         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2848                 ret = -EFAULT;
2849
2850         kfree(di_args);
2851         return ret;
2852 }
2853
2854 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
2855 {
2856         struct page *page;
2857
2858         page = grab_cache_page(inode->i_mapping, index);
2859         if (!page)
2860                 return ERR_PTR(-ENOMEM);
2861
2862         if (!PageUptodate(page)) {
2863                 int ret;
2864
2865                 ret = btrfs_readpage(NULL, page);
2866                 if (ret)
2867                         return ERR_PTR(ret);
2868                 lock_page(page);
2869                 if (!PageUptodate(page)) {
2870                         unlock_page(page);
2871                         put_page(page);
2872                         return ERR_PTR(-EIO);
2873                 }
2874                 if (page->mapping != inode->i_mapping) {
2875                         unlock_page(page);
2876                         put_page(page);
2877                         return ERR_PTR(-EAGAIN);
2878                 }
2879         }
2880
2881         return page;
2882 }
2883
2884 static int gather_extent_pages(struct inode *inode, struct page **pages,
2885                                int num_pages, u64 off)
2886 {
2887         int i;
2888         pgoff_t index = off >> PAGE_SHIFT;
2889
2890         for (i = 0; i < num_pages; i++) {
2891 again:
2892                 pages[i] = extent_same_get_page(inode, index + i);
2893                 if (IS_ERR(pages[i])) {
2894                         int err = PTR_ERR(pages[i]);
2895
2896                         if (err == -EAGAIN)
2897                                 goto again;
2898                         pages[i] = NULL;
2899                         return err;
2900                 }
2901         }
2902         return 0;
2903 }
2904
2905 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
2906                              bool retry_range_locking)
2907 {
2908         /*
2909          * Do any pending delalloc/csum calculations on inode, one way or
2910          * another, and lock file content.
2911          * The locking order is:
2912          *
2913          *   1) pages
2914          *   2) range in the inode's io tree
2915          */
2916         while (1) {
2917                 struct btrfs_ordered_extent *ordered;
2918                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2919                 ordered = btrfs_lookup_first_ordered_extent(inode,
2920                                                             off + len - 1);
2921                 if ((!ordered ||
2922                      ordered->file_offset + ordered->len <= off ||
2923                      ordered->file_offset >= off + len) &&
2924                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
2925                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
2926                         if (ordered)
2927                                 btrfs_put_ordered_extent(ordered);
2928                         break;
2929                 }
2930                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
2931                 if (ordered)
2932                         btrfs_put_ordered_extent(ordered);
2933                 if (!retry_range_locking)
2934                         return -EAGAIN;
2935                 btrfs_wait_ordered_range(inode, off, len);
2936         }
2937         return 0;
2938 }
2939
2940 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
2941 {
2942         inode_unlock(inode1);
2943         inode_unlock(inode2);
2944 }
2945
2946 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
2947 {
2948         if (inode1 < inode2)
2949                 swap(inode1, inode2);
2950
2951         inode_lock_nested(inode1, I_MUTEX_PARENT);
2952         inode_lock_nested(inode2, I_MUTEX_CHILD);
2953 }
2954
2955 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
2956                                       struct inode *inode2, u64 loff2, u64 len)
2957 {
2958         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
2959         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
2960 }
2961
2962 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
2963                                     struct inode *inode2, u64 loff2, u64 len,
2964                                     bool retry_range_locking)
2965 {
2966         int ret;
2967
2968         if (inode1 < inode2) {
2969                 swap(inode1, inode2);
2970                 swap(loff1, loff2);
2971         }
2972         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
2973         if (ret)
2974                 return ret;
2975         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
2976         if (ret)
2977                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
2978                               loff1 + len - 1);
2979         return ret;
2980 }
2981
2982 struct cmp_pages {
2983         int             num_pages;
2984         struct page     **src_pages;
2985         struct page     **dst_pages;
2986 };
2987
2988 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
2989 {
2990         int i;
2991         struct page *pg;
2992
2993         for (i = 0; i < cmp->num_pages; i++) {
2994                 pg = cmp->src_pages[i];
2995                 if (pg) {
2996                         unlock_page(pg);
2997                         put_page(pg);
2998                 }
2999                 pg = cmp->dst_pages[i];
3000                 if (pg) {
3001                         unlock_page(pg);
3002                         put_page(pg);
3003                 }
3004         }
3005         kfree(cmp->src_pages);
3006         kfree(cmp->dst_pages);
3007 }
3008
3009 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3010                                   struct inode *dst, u64 dst_loff,
3011                                   u64 len, struct cmp_pages *cmp)
3012 {
3013         int ret;
3014         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3015         struct page **src_pgarr, **dst_pgarr;
3016
3017         /*
3018          * We must gather up all the pages before we initiate our
3019          * extent locking. We use an array for the page pointers. Size
3020          * of the array is bounded by len, which is in turn bounded by
3021          * BTRFS_MAX_DEDUPE_LEN.
3022          */
3023         src_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3024         dst_pgarr = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL);
3025         if (!src_pgarr || !dst_pgarr) {
3026                 kfree(src_pgarr);
3027                 kfree(dst_pgarr);
3028                 return -ENOMEM;
3029         }
3030         cmp->num_pages = num_pages;
3031         cmp->src_pages = src_pgarr;
3032         cmp->dst_pages = dst_pgarr;
3033
3034         ret = gather_extent_pages(src, cmp->src_pages, cmp->num_pages, loff);
3035         if (ret)
3036                 goto out;
3037
3038         ret = gather_extent_pages(dst, cmp->dst_pages, cmp->num_pages, dst_loff);
3039
3040 out:
3041         if (ret)
3042                 btrfs_cmp_data_free(cmp);
3043         return 0;
3044 }
3045
3046 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
3047                           u64 dst_loff, u64 len, struct cmp_pages *cmp)
3048 {
3049         int ret = 0;
3050         int i;
3051         struct page *src_page, *dst_page;
3052         unsigned int cmp_len = PAGE_SIZE;
3053         void *addr, *dst_addr;
3054
3055         i = 0;
3056         while (len) {
3057                 if (len < PAGE_SIZE)
3058                         cmp_len = len;
3059
3060                 BUG_ON(i >= cmp->num_pages);
3061
3062                 src_page = cmp->src_pages[i];
3063                 dst_page = cmp->dst_pages[i];
3064                 ASSERT(PageLocked(src_page));
3065                 ASSERT(PageLocked(dst_page));
3066
3067                 addr = kmap_atomic(src_page);
3068                 dst_addr = kmap_atomic(dst_page);
3069
3070                 flush_dcache_page(src_page);
3071                 flush_dcache_page(dst_page);
3072
3073                 if (memcmp(addr, dst_addr, cmp_len))
3074                         ret = -EBADE;
3075
3076                 kunmap_atomic(addr);
3077                 kunmap_atomic(dst_addr);
3078
3079                 if (ret)
3080                         break;
3081
3082                 len -= cmp_len;
3083                 i++;
3084         }
3085
3086         return ret;
3087 }
3088
3089 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3090                                      u64 olen)
3091 {
3092         u64 len = *plen;
3093         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3094
3095         if (off + olen > inode->i_size || off + olen < off)
3096                 return -EINVAL;
3097
3098         /* if we extend to eof, continue to block boundary */
3099         if (off + len == inode->i_size)
3100                 *plen = len = ALIGN(inode->i_size, bs) - off;
3101
3102         /* Check that we are block aligned - btrfs_clone() requires this */
3103         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3104                 return -EINVAL;
3105
3106         return 0;
3107 }
3108
3109 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3110                              struct inode *dst, u64 dst_loff)
3111 {
3112         int ret;
3113         u64 len = olen;
3114         struct cmp_pages cmp;
3115         int same_inode = 0;
3116         u64 same_lock_start = 0;
3117         u64 same_lock_len = 0;
3118
3119         if (src == dst)
3120                 same_inode = 1;
3121
3122         if (len == 0)
3123                 return 0;
3124
3125         if (same_inode) {
3126                 inode_lock(src);
3127
3128                 ret = extent_same_check_offsets(src, loff, &len, olen);
3129                 if (ret)
3130                         goto out_unlock;
3131                 ret = extent_same_check_offsets(src, dst_loff, &len, olen);
3132                 if (ret)
3133                         goto out_unlock;
3134
3135                 /*
3136                  * Single inode case wants the same checks, except we
3137                  * don't want our length pushed out past i_size as
3138                  * comparing that data range makes no sense.
3139                  *
3140                  * extent_same_check_offsets() will do this for an
3141                  * unaligned length at i_size, so catch it here and
3142                  * reject the request.
3143                  *
3144                  * This effectively means we require aligned extents
3145                  * for the single-inode case, whereas the other cases
3146                  * allow an unaligned length so long as it ends at
3147                  * i_size.
3148                  */
3149                 if (len != olen) {
3150                         ret = -EINVAL;
3151                         goto out_unlock;
3152                 }
3153
3154                 /* Check for overlapping ranges */
3155                 if (dst_loff + len > loff && dst_loff < loff + len) {
3156                         ret = -EINVAL;
3157                         goto out_unlock;
3158                 }
3159
3160                 same_lock_start = min_t(u64, loff, dst_loff);
3161                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3162         } else {
3163                 btrfs_double_inode_lock(src, dst);
3164
3165                 ret = extent_same_check_offsets(src, loff, &len, olen);
3166                 if (ret)
3167                         goto out_unlock;
3168
3169                 ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3170                 if (ret)
3171                         goto out_unlock;
3172         }
3173
3174         /* don't make the dst file partly checksummed */
3175         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3176             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3177                 ret = -EINVAL;
3178                 goto out_unlock;
3179         }
3180
3181 again:
3182         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
3183         if (ret)
3184                 goto out_unlock;
3185
3186         if (same_inode)
3187                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3188                                         false);
3189         else
3190                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3191                                                false);
3192         /*
3193          * If one of the inodes has dirty pages in the respective range or
3194          * ordered extents, we need to flush dellaloc and wait for all ordered
3195          * extents in the range. We must unlock the pages and the ranges in the
3196          * io trees to avoid deadlocks when flushing delalloc (requires locking
3197          * pages) and when waiting for ordered extents to complete (they require
3198          * range locking).
3199          */
3200         if (ret == -EAGAIN) {
3201                 /*
3202                  * Ranges in the io trees already unlocked. Now unlock all
3203                  * pages before waiting for all IO to complete.
3204                  */
3205                 btrfs_cmp_data_free(&cmp);
3206                 if (same_inode) {
3207                         btrfs_wait_ordered_range(src, same_lock_start,
3208                                                  same_lock_len);
3209                 } else {
3210                         btrfs_wait_ordered_range(src, loff, len);
3211                         btrfs_wait_ordered_range(dst, dst_loff, len);
3212                 }
3213                 goto again;
3214         }
3215         ASSERT(ret == 0);
3216         if (WARN_ON(ret)) {
3217                 /* ranges in the io trees already unlocked */
3218                 btrfs_cmp_data_free(&cmp);
3219                 return ret;
3220         }
3221
3222         /* pass original length for comparison so we stay within i_size */
3223         ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp);
3224         if (ret == 0)
3225                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3226
3227         if (same_inode)
3228                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3229                               same_lock_start + same_lock_len - 1);
3230         else
3231                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3232
3233         btrfs_cmp_data_free(&cmp);
3234 out_unlock:
3235         if (same_inode)
3236                 inode_unlock(src);
3237         else
3238                 btrfs_double_inode_unlock(src, dst);
3239
3240         return ret;
3241 }
3242
3243 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3244
3245 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,
3246                                 struct file *dst_file, u64 dst_loff)
3247 {
3248         struct inode *src = file_inode(src_file);
3249         struct inode *dst = file_inode(dst_file);
3250         u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3251         ssize_t res;
3252
3253         if (olen > BTRFS_MAX_DEDUPE_LEN)
3254                 olen = BTRFS_MAX_DEDUPE_LEN;
3255
3256         if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
3257                 /*
3258                  * Btrfs does not support blocksize < page_size. As a
3259                  * result, btrfs_cmp_data() won't correctly handle
3260                  * this situation without an update.
3261                  */
3262                 return -EINVAL;
3263         }
3264
3265         res = btrfs_extent_same(src, loff, olen, dst, dst_loff);
3266         if (res)
3267                 return res;
3268         return olen;
3269 }
3270
3271 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3272                                      struct inode *inode,
3273                                      u64 endoff,
3274                                      const u64 destoff,
3275                                      const u64 olen,
3276                                      int no_time_update)
3277 {
3278         struct btrfs_root *root = BTRFS_I(inode)->root;
3279         int ret;
3280
3281         inode_inc_iversion(inode);
3282         if (!no_time_update)
3283                 inode->i_mtime = inode->i_ctime = current_fs_time(inode->i_sb);
3284         /*
3285          * We round up to the block size at eof when determining which
3286          * extents to clone above, but shouldn't round up the file size.
3287          */
3288         if (endoff > destoff + olen)
3289                 endoff = destoff + olen;
3290         if (endoff > inode->i_size)
3291                 btrfs_i_size_write(inode, endoff);
3292
3293         ret = btrfs_update_inode(trans, root, inode);
3294         if (ret) {
3295                 btrfs_abort_transaction(trans, root, ret);
3296                 btrfs_end_transaction(trans, root);
3297                 goto out;
3298         }
3299         ret = btrfs_end_transaction(trans, root);
3300 out:
3301         return ret;
3302 }
3303
3304 static void clone_update_extent_map(struct inode *inode,
3305                                     const struct btrfs_trans_handle *trans,
3306                                     const struct btrfs_path *path,
3307                                     const u64 hole_offset,
3308                                     const u64 hole_len)
3309 {
3310         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3311         struct extent_map *em;
3312         int ret;
3313
3314         em = alloc_extent_map();
3315         if (!em) {
3316                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3317                         &BTRFS_I(inode)->runtime_flags);
3318                 return;
3319         }
3320
3321         if (path) {
3322                 struct btrfs_file_extent_item *fi;
3323
3324                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3325                                     struct btrfs_file_extent_item);
3326                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3327                 em->generation = -1;
3328                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3329                     BTRFS_FILE_EXTENT_INLINE)
3330                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3331                                 &BTRFS_I(inode)->runtime_flags);
3332         } else {
3333                 em->start = hole_offset;
3334                 em->len = hole_len;
3335                 em->ram_bytes = em->len;
3336                 em->orig_start = hole_offset;
3337                 em->block_start = EXTENT_MAP_HOLE;
3338                 em->block_len = 0;
3339                 em->orig_block_len = 0;
3340                 em->compress_type = BTRFS_COMPRESS_NONE;
3341                 em->generation = trans->transid;
3342         }
3343
3344         while (1) {
3345                 write_lock(&em_tree->lock);
3346                 ret = add_extent_mapping(em_tree, em, 1);
3347                 write_unlock(&em_tree->lock);
3348                 if (ret != -EEXIST) {
3349                         free_extent_map(em);
3350                         break;
3351                 }
3352                 btrfs_drop_extent_cache(inode, em->start,
3353                                         em->start + em->len - 1, 0);
3354         }
3355
3356         if (ret)
3357                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3358                         &BTRFS_I(inode)->runtime_flags);
3359 }
3360
3361 /*
3362  * Make sure we do not end up inserting an inline extent into a file that has
3363  * already other (non-inline) extents. If a file has an inline extent it can
3364  * not have any other extents and the (single) inline extent must start at the
3365  * file offset 0. Failing to respect these rules will lead to file corruption,
3366  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3367  *
3368  * We can have extents that have been already written to disk or we can have
3369  * dirty ranges still in delalloc, in which case the extent maps and items are
3370  * created only when we run delalloc, and the delalloc ranges might fall outside
3371  * the range we are currently locking in the inode's io tree. So we check the
3372  * inode's i_size because of that (i_size updates are done while holding the
3373  * i_mutex, which we are holding here).
3374  * We also check to see if the inode has a size not greater than "datal" but has
3375  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3376  * protected against such concurrent fallocate calls by the i_mutex).
3377  *
3378  * If the file has no extents but a size greater than datal, do not allow the
3379  * copy because we would need turn the inline extent into a non-inline one (even
3380  * with NO_HOLES enabled). If we find our destination inode only has one inline
3381  * extent, just overwrite it with the source inline extent if its size is less
3382  * than the source extent's size, or we could copy the source inline extent's
3383  * data into the destination inode's inline extent if the later is greater then
3384  * the former.
3385  */
3386 static int clone_copy_inline_extent(struct inode *src,
3387                                     struct inode *dst,
3388                                     struct btrfs_trans_handle *trans,
3389                                     struct btrfs_path *path,
3390                                     struct btrfs_key *new_key,
3391                                     const u64 drop_start,
3392                                     const u64 datal,
3393                                     const u64 skip,
3394                                     const u64 size,
3395                                     char *inline_data)
3396 {
3397         struct btrfs_root *root = BTRFS_I(dst)->root;
3398         const u64 aligned_end = ALIGN(new_key->offset + datal,
3399                                       root->sectorsize);
3400         int ret;
3401         struct btrfs_key key;
3402
3403         if (new_key->offset > 0)
3404                 return -EOPNOTSUPP;
3405
3406         key.objectid = btrfs_ino(dst);
3407         key.type = BTRFS_EXTENT_DATA_KEY;
3408         key.offset = 0;
3409         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3410         if (ret < 0) {
3411                 return ret;
3412         } else if (ret > 0) {
3413                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3414                         ret = btrfs_next_leaf(root, path);
3415                         if (ret < 0)
3416                                 return ret;
3417                         else if (ret > 0)
3418                                 goto copy_inline_extent;
3419                 }
3420                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3421                 if (key.objectid == btrfs_ino(dst) &&
3422                     key.type == BTRFS_EXTENT_DATA_KEY) {
3423                         ASSERT(key.offset > 0);
3424                         return -EOPNOTSUPP;
3425                 }
3426         } else if (i_size_read(dst) <= datal) {
3427                 struct btrfs_file_extent_item *ei;
3428                 u64 ext_len;
3429
3430                 /*
3431                  * If the file size is <= datal, make sure there are no other
3432                  * extents following (can happen do to an fallocate call with
3433                  * the flag FALLOC_FL_KEEP_SIZE).
3434                  */
3435                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3436                                     struct btrfs_file_extent_item);
3437                 /*
3438                  * If it's an inline extent, it can not have other extents
3439                  * following it.
3440                  */
3441                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3442                     BTRFS_FILE_EXTENT_INLINE)
3443                         goto copy_inline_extent;
3444
3445                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3446                 if (ext_len > aligned_end)
3447                         return -EOPNOTSUPP;
3448
3449                 ret = btrfs_next_item(root, path);
3450                 if (ret < 0) {
3451                         return ret;
3452                 } else if (ret == 0) {
3453                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3454                                               path->slots[0]);
3455                         if (key.objectid == btrfs_ino(dst) &&
3456                             key.type == BTRFS_EXTENT_DATA_KEY)
3457                                 return -EOPNOTSUPP;
3458                 }
3459         }
3460
3461 copy_inline_extent:
3462         /*
3463          * We have no extent items, or we have an extent at offset 0 which may
3464          * or may not be inlined. All these cases are dealt the same way.
3465          */
3466         if (i_size_read(dst) > datal) {
3467                 /*
3468                  * If the destination inode has an inline extent...
3469                  * This would require copying the data from the source inline
3470                  * extent into the beginning of the destination's inline extent.
3471                  * But this is really complex, both extents can be compressed
3472                  * or just one of them, which would require decompressing and
3473                  * re-compressing data (which could increase the new compressed
3474                  * size, not allowing the compressed data to fit anymore in an
3475                  * inline extent).
3476                  * So just don't support this case for now (it should be rare,
3477                  * we are not really saving space when cloning inline extents).
3478                  */
3479                 return -EOPNOTSUPP;
3480         }
3481
3482         btrfs_release_path(path);
3483         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3484         if (ret)
3485                 return ret;
3486         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3487         if (ret)
3488                 return ret;
3489
3490         if (skip) {
3491                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3492
3493                 memmove(inline_data + start, inline_data + start + skip, datal);
3494         }
3495
3496         write_extent_buffer(path->nodes[0], inline_data,
3497                             btrfs_item_ptr_offset(path->nodes[0],
3498                                                   path->slots[0]),
3499                             size);
3500         inode_add_bytes(dst, datal);
3501
3502         return 0;
3503 }
3504
3505 /**
3506  * btrfs_clone() - clone a range from inode file to another
3507  *
3508  * @src: Inode to clone from
3509  * @inode: Inode to clone to
3510  * @off: Offset within source to start clone from
3511  * @olen: Original length, passed by user, of range to clone
3512  * @olen_aligned: Block-aligned value of olen
3513  * @destoff: Offset within @inode to start clone
3514  * @no_time_update: Whether to update mtime/ctime on the target inode
3515  */
3516 static int btrfs_clone(struct inode *src, struct inode *inode,
3517                        const u64 off, const u64 olen, const u64 olen_aligned,
3518                        const u64 destoff, int no_time_update)
3519 {
3520         struct btrfs_root *root = BTRFS_I(inode)->root;
3521         struct btrfs_path *path = NULL;
3522         struct extent_buffer *leaf;
3523         struct btrfs_trans_handle *trans;
3524         char *buf = NULL;
3525         struct btrfs_key key;
3526         u32 nritems;
3527         int slot;
3528         int ret;
3529         const u64 len = olen_aligned;
3530         u64 last_dest_end = destoff;
3531
3532         ret = -ENOMEM;
3533         buf = kmalloc(root->nodesize, GFP_KERNEL | __GFP_NOWARN);
3534         if (!buf) {
3535                 buf = vmalloc(root->nodesize);
3536                 if (!buf)
3537                         return ret;
3538         }
3539
3540         path = btrfs_alloc_path();
3541         if (!path) {
3542                 kvfree(buf);
3543                 return ret;
3544         }
3545
3546         path->reada = READA_FORWARD;
3547         /* clone data */
3548         key.objectid = btrfs_ino(src);
3549         key.type = BTRFS_EXTENT_DATA_KEY;
3550         key.offset = off;
3551
3552         while (1) {
3553                 u64 next_key_min_offset = key.offset + 1;
3554
3555                 /*
3556                  * note the key will change type as we walk through the
3557                  * tree.
3558                  */
3559                 path->leave_spinning = 1;
3560                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3561                                 0, 0);
3562                 if (ret < 0)
3563                         goto out;
3564                 /*
3565                  * First search, if no extent item that starts at offset off was
3566                  * found but the previous item is an extent item, it's possible
3567                  * it might overlap our target range, therefore process it.
3568                  */
3569                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3570                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3571                                               path->slots[0] - 1);
3572                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3573                                 path->slots[0]--;
3574                 }
3575
3576                 nritems = btrfs_header_nritems(path->nodes[0]);
3577 process_slot:
3578                 if (path->slots[0] >= nritems) {
3579                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3580                         if (ret < 0)
3581                                 goto out;
3582                         if (ret > 0)
3583                                 break;
3584                         nritems = btrfs_header_nritems(path->nodes[0]);
3585                 }
3586                 leaf = path->nodes[0];
3587                 slot = path->slots[0];
3588
3589                 btrfs_item_key_to_cpu(leaf, &key, slot);
3590                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3591                     key.objectid != btrfs_ino(src))
3592                         break;
3593
3594                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3595                         struct btrfs_file_extent_item *extent;
3596                         int type;
3597                         u32 size;
3598                         struct btrfs_key new_key;
3599                         u64 disko = 0, diskl = 0;
3600                         u64 datao = 0, datal = 0;
3601                         u8 comp;
3602                         u64 drop_start;
3603
3604                         extent = btrfs_item_ptr(leaf, slot,
3605                                                 struct btrfs_file_extent_item);
3606                         comp = btrfs_file_extent_compression(leaf, extent);
3607                         type = btrfs_file_extent_type(leaf, extent);
3608                         if (type == BTRFS_FILE_EXTENT_REG ||
3609                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3610                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3611                                                                       extent);
3612                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3613                                                                  extent);
3614                                 datao = btrfs_file_extent_offset(leaf, extent);
3615                                 datal = btrfs_file_extent_num_bytes(leaf,
3616                                                                     extent);
3617                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3618                                 /* take upper bound, may be compressed */
3619                                 datal = btrfs_file_extent_ram_bytes(leaf,
3620                                                                     extent);
3621                         }
3622
3623                         /*
3624                          * The first search might have left us at an extent
3625                          * item that ends before our target range's start, can
3626                          * happen if we have holes and NO_HOLES feature enabled.
3627                          */
3628                         if (key.offset + datal <= off) {
3629                                 path->slots[0]++;
3630                                 goto process_slot;
3631                         } else if (key.offset >= off + len) {
3632                                 break;
3633                         }
3634                         next_key_min_offset = key.offset + datal;
3635                         size = btrfs_item_size_nr(leaf, slot);
3636                         read_extent_buffer(leaf, buf,
3637                                            btrfs_item_ptr_offset(leaf, slot),
3638                                            size);
3639
3640                         btrfs_release_path(path);
3641                         path->leave_spinning = 0;
3642
3643                         memcpy(&new_key, &key, sizeof(new_key));
3644                         new_key.objectid = btrfs_ino(inode);
3645                         if (off <= key.offset)
3646                                 new_key.offset = key.offset + destoff - off;
3647                         else
3648                                 new_key.offset = destoff;
3649
3650                         /*
3651                          * Deal with a hole that doesn't have an extent item
3652                          * that represents it (NO_HOLES feature enabled).
3653                          * This hole is either in the middle of the cloning
3654                          * range or at the beginning (fully overlaps it or
3655                          * partially overlaps it).
3656                          */
3657                         if (new_key.offset != last_dest_end)
3658                                 drop_start = last_dest_end;
3659                         else
3660                                 drop_start = new_key.offset;
3661
3662                         /*
3663                          * 1 - adjusting old extent (we may have to split it)
3664                          * 1 - add new extent
3665                          * 1 - inode update
3666                          */
3667                         trans = btrfs_start_transaction(root, 3);
3668                         if (IS_ERR(trans)) {
3669                                 ret = PTR_ERR(trans);
3670                                 goto out;
3671                         }
3672
3673                         if (type == BTRFS_FILE_EXTENT_REG ||
3674                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3675                                 /*
3676                                  *    a  | --- range to clone ---|  b
3677                                  * | ------------- extent ------------- |
3678                                  */
3679
3680                                 /* subtract range b */
3681                                 if (key.offset + datal > off + len)
3682                                         datal = off + len - key.offset;
3683
3684                                 /* subtract range a */
3685                                 if (off > key.offset) {
3686                                         datao += off - key.offset;
3687                                         datal -= off - key.offset;
3688                                 }
3689
3690                                 ret = btrfs_drop_extents(trans, root, inode,
3691                                                          drop_start,
3692                                                          new_key.offset + datal,
3693                                                          1);
3694                                 if (ret) {
3695                                         if (ret != -EOPNOTSUPP)
3696                                                 btrfs_abort_transaction(trans,
3697                                                                 root, ret);
3698                                         btrfs_end_transaction(trans, root);
3699                                         goto out;
3700                                 }
3701
3702                                 ret = btrfs_insert_empty_item(trans, root, path,
3703                                                               &new_key, size);
3704                                 if (ret) {
3705                                         btrfs_abort_transaction(trans, root,
3706                                                                 ret);
3707                                         btrfs_end_transaction(trans, root);
3708                                         goto out;
3709                                 }
3710
3711                                 leaf = path->nodes[0];
3712                                 slot = path->slots[0];
3713                                 write_extent_buffer(leaf, buf,
3714                                             btrfs_item_ptr_offset(leaf, slot),
3715                                             size);
3716
3717                                 extent = btrfs_item_ptr(leaf, slot,
3718                                                 struct btrfs_file_extent_item);
3719
3720                                 /* disko == 0 means it's a hole */
3721                                 if (!disko)
3722                                         datao = 0;
3723
3724                                 btrfs_set_file_extent_offset(leaf, extent,
3725                                                              datao);
3726                                 btrfs_set_file_extent_num_bytes(leaf, extent,
3727                                                                 datal);
3728
3729                                 if (disko) {
3730                                         inode_add_bytes(inode, datal);
3731                                         ret = btrfs_inc_extent_ref(trans, root,
3732                                                         disko, diskl, 0,
3733                                                         root->root_key.objectid,
3734                                                         btrfs_ino(inode),
3735                                                         new_key.offset - datao);
3736                                         if (ret) {
3737                                                 btrfs_abort_transaction(trans,
3738                                                                         root,
3739                                                                         ret);
3740                                                 btrfs_end_transaction(trans,
3741                                                                       root);
3742                                                 goto out;
3743
3744                                         }
3745                                 }
3746                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3747                                 u64 skip = 0;
3748                                 u64 trim = 0;
3749
3750                                 if (off > key.offset) {
3751                                         skip = off - key.offset;
3752                                         new_key.offset += skip;
3753                                 }
3754
3755                                 if (key.offset + datal > off + len)
3756                                         trim = key.offset + datal - (off + len);
3757
3758                                 if (comp && (skip || trim)) {
3759                                         ret = -EINVAL;
3760                                         btrfs_end_transaction(trans, root);
3761                                         goto out;
3762                                 }
3763                                 size -= skip + trim;
3764                                 datal -= skip + trim;
3765
3766                                 ret = clone_copy_inline_extent(src, inode,
3767                                                                trans, path,
3768                                                                &new_key,
3769                                                                drop_start,
3770                                                                datal,
3771                                                                skip, size, buf);
3772                                 if (ret) {
3773                                         if (ret != -EOPNOTSUPP)
3774                                                 btrfs_abort_transaction(trans,
3775                                                                         root,
3776                                                                         ret);
3777                                         btrfs_end_transaction(trans, root);
3778                                         goto out;
3779                                 }
3780                                 leaf = path->nodes[0];
3781                                 slot = path->slots[0];
3782                         }
3783
3784                         /* If we have an implicit hole (NO_HOLES feature). */
3785                         if (drop_start < new_key.offset)
3786                                 clone_update_extent_map(inode, trans,
3787                                                 NULL, drop_start,
3788                                                 new_key.offset - drop_start);
3789
3790                         clone_update_extent_map(inode, trans, path, 0, 0);
3791
3792                         btrfs_mark_buffer_dirty(leaf);
3793                         btrfs_release_path(path);
3794
3795                         last_dest_end = ALIGN(new_key.offset + datal,
3796                                               root->sectorsize);
3797                         ret = clone_finish_inode_update(trans, inode,
3798                                                         last_dest_end,
3799                                                         destoff, olen,
3800                                                         no_time_update);
3801                         if (ret)
3802                                 goto out;
3803                         if (new_key.offset + datal >= destoff + len)
3804                                 break;
3805                 }
3806                 btrfs_release_path(path);
3807                 key.offset = next_key_min_offset;
3808         }
3809         ret = 0;
3810
3811         if (last_dest_end < destoff + len) {
3812                 /*
3813                  * We have an implicit hole (NO_HOLES feature is enabled) that
3814                  * fully or partially overlaps our cloning range at its end.
3815                  */
3816                 btrfs_release_path(path);
3817
3818                 /*
3819                  * 1 - remove extent(s)
3820                  * 1 - inode update
3821                  */
3822                 trans = btrfs_start_transaction(root, 2);
3823                 if (IS_ERR(trans)) {
3824                         ret = PTR_ERR(trans);
3825                         goto out;
3826                 }
3827                 ret = btrfs_drop_extents(trans, root, inode,
3828                                          last_dest_end, destoff + len, 1);
3829                 if (ret) {
3830                         if (ret != -EOPNOTSUPP)
3831                                 btrfs_abort_transaction(trans, root, ret);
3832                         btrfs_end_transaction(trans, root);
3833                         goto out;
3834                 }
3835                 clone_update_extent_map(inode, trans, NULL, last_dest_end,
3836                                         destoff + len - last_dest_end);
3837                 ret = clone_finish_inode_update(trans, inode, destoff + len,
3838                                                 destoff, olen, no_time_update);
3839         }
3840
3841 out:
3842         btrfs_free_path(path);
3843         kvfree(buf);
3844         return ret;
3845 }
3846
3847 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3848                                         u64 off, u64 olen, u64 destoff)
3849 {
3850         struct inode *inode = file_inode(file);
3851         struct inode *src = file_inode(file_src);
3852         struct btrfs_root *root = BTRFS_I(inode)->root;
3853         int ret;
3854         u64 len = olen;
3855         u64 bs = root->fs_info->sb->s_blocksize;
3856         int same_inode = src == inode;
3857
3858         /*
3859          * TODO:
3860          * - split compressed inline extents.  annoying: we need to
3861          *   decompress into destination's address_space (the file offset
3862          *   may change, so source mapping won't do), then recompress (or
3863          *   otherwise reinsert) a subrange.
3864          *
3865          * - split destination inode's inline extents.  The inline extents can
3866          *   be either compressed or non-compressed.
3867          */
3868
3869         if (btrfs_root_readonly(root))
3870                 return -EROFS;
3871
3872         if (file_src->f_path.mnt != file->f_path.mnt ||
3873             src->i_sb != inode->i_sb)
3874                 return -EXDEV;
3875
3876         /* don't make the dst file partly checksummed */
3877         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3878             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3879                 return -EINVAL;
3880
3881         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
3882                 return -EISDIR;
3883
3884         if (!same_inode) {
3885                 btrfs_double_inode_lock(src, inode);
3886         } else {
3887                 inode_lock(src);
3888         }
3889
3890         /* determine range to clone */
3891         ret = -EINVAL;
3892         if (off + len > src->i_size || off + len < off)
3893                 goto out_unlock;
3894         if (len == 0)
3895                 olen = len = src->i_size - off;
3896         /* if we extend to eof, continue to block boundary */
3897         if (off + len == src->i_size)
3898                 len = ALIGN(src->i_size, bs) - off;
3899
3900         if (len == 0) {
3901                 ret = 0;
3902                 goto out_unlock;
3903         }
3904
3905         /* verify the end result is block aligned */
3906         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
3907             !IS_ALIGNED(destoff, bs))
3908                 goto out_unlock;
3909
3910         /* verify if ranges are overlapped within the same file */
3911         if (same_inode) {
3912                 if (destoff + len > off && destoff < off + len)
3913                         goto out_unlock;
3914         }
3915
3916         if (destoff > inode->i_size) {
3917                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3918                 if (ret)
3919                         goto out_unlock;
3920         }
3921
3922         /*
3923          * Lock the target range too. Right after we replace the file extent
3924          * items in the fs tree (which now point to the cloned data), we might
3925          * have a worker replace them with extent items relative to a write
3926          * operation that was issued before this clone operation (i.e. confront
3927          * with inode.c:btrfs_finish_ordered_io).
3928          */
3929         if (same_inode) {
3930                 u64 lock_start = min_t(u64, off, destoff);
3931                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
3932
3933                 ret = lock_extent_range(src, lock_start, lock_len, true);
3934         } else {
3935                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
3936                                                true);
3937         }
3938         ASSERT(ret == 0);
3939         if (WARN_ON(ret)) {
3940                 /* ranges in the io trees already unlocked */
3941                 goto out_unlock;
3942         }
3943
3944         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3945
3946         if (same_inode) {
3947                 u64 lock_start = min_t(u64, off, destoff);
3948                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
3949
3950                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
3951         } else {
3952                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
3953         }
3954         /*
3955          * Truncate page cache pages so that future reads will see the cloned
3956          * data immediately and not the previous data.
3957          */
3958         truncate_inode_pages_range(&inode->i_data,
3959                                 round_down(destoff, PAGE_SIZE),
3960                                 round_up(destoff + len, PAGE_SIZE) - 1);
3961 out_unlock:
3962         if (!same_inode)
3963                 btrfs_double_inode_unlock(src, inode);
3964         else
3965                 inode_unlock(src);
3966         return ret;
3967 }
3968
3969 ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
3970                               struct file *file_out, loff_t pos_out,
3971                               size_t len, unsigned int flags)
3972 {
3973         ssize_t ret;
3974
3975         ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
3976         if (ret == 0)
3977                 ret = len;
3978         return ret;
3979 }
3980
3981 int btrfs_clone_file_range(struct file *src_file, loff_t off,
3982                 struct file *dst_file, loff_t destoff, u64 len)
3983 {
3984         return btrfs_clone_files(dst_file, src_file, off, len, destoff);
3985 }
3986
3987 /*
3988  * there are many ways the trans_start and trans_end ioctls can lead
3989  * to deadlocks.  They should only be used by applications that
3990  * basically own the machine, and have a very in depth understanding
3991  * of all the possible deadlocks and enospc problems.
3992  */
3993 static long btrfs_ioctl_trans_start(struct file *file)
3994 {
3995         struct inode *inode = file_inode(file);
3996         struct btrfs_root *root = BTRFS_I(inode)->root;
3997         struct btrfs_trans_handle *trans;
3998         int ret;
3999
4000         ret = -EPERM;
4001         if (!capable(CAP_SYS_ADMIN))
4002                 goto out;
4003
4004         ret = -EINPROGRESS;
4005         if (file->private_data)
4006                 goto out;
4007
4008         ret = -EROFS;
4009         if (btrfs_root_readonly(root))
4010                 goto out;
4011
4012         ret = mnt_want_write_file(file);
4013         if (ret)
4014                 goto out;
4015
4016         atomic_inc(&root->fs_info->open_ioctl_trans);
4017
4018         ret = -ENOMEM;
4019         trans = btrfs_start_ioctl_transaction(root);
4020         if (IS_ERR(trans))
4021                 goto out_drop;
4022
4023         file->private_data = trans;
4024         return 0;
4025
4026 out_drop:
4027         atomic_dec(&root->fs_info->open_ioctl_trans);
4028         mnt_drop_write_file(file);
4029 out:
4030         return ret;
4031 }
4032
4033 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4034 {
4035         struct inode *inode = file_inode(file);
4036         struct btrfs_root *root = BTRFS_I(inode)->root;
4037         struct btrfs_root *new_root;
4038         struct btrfs_dir_item *di;
4039         struct btrfs_trans_handle *trans;
4040         struct btrfs_path *path;
4041         struct btrfs_key location;
4042         struct btrfs_disk_key disk_key;
4043         u64 objectid = 0;
4044         u64 dir_id;
4045         int ret;
4046
4047         if (!capable(CAP_SYS_ADMIN))
4048                 return -EPERM;
4049
4050         ret = mnt_want_write_file(file);
4051         if (ret)
4052                 return ret;
4053
4054         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4055                 ret = -EFAULT;
4056                 goto out;
4057         }
4058
4059         if (!objectid)
4060                 objectid = BTRFS_FS_TREE_OBJECTID;
4061
4062         location.objectid = objectid;
4063         location.type = BTRFS_ROOT_ITEM_KEY;
4064         location.offset = (u64)-1;
4065
4066         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
4067         if (IS_ERR(new_root)) {
4068                 ret = PTR_ERR(new_root);
4069                 goto out;
4070         }
4071
4072         path = btrfs_alloc_path();
4073         if (!path) {
4074                 ret = -ENOMEM;
4075                 goto out;
4076         }
4077         path->leave_spinning = 1;
4078
4079         trans = btrfs_start_transaction(root, 1);
4080         if (IS_ERR(trans)) {
4081                 btrfs_free_path(path);
4082                 ret = PTR_ERR(trans);
4083                 goto out;
4084         }
4085
4086         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
4087         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
4088                                    dir_id, "default", 7, 1);
4089         if (IS_ERR_OR_NULL(di)) {
4090                 btrfs_free_path(path);
4091                 btrfs_end_transaction(trans, root);
4092                 btrfs_err(new_root->fs_info, "Umm, you don't have the default dir"
4093                            "item, this isn't going to work");
4094                 ret = -ENOENT;
4095                 goto out;
4096         }
4097
4098         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4099         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4100         btrfs_mark_buffer_dirty(path->nodes[0]);
4101         btrfs_free_path(path);
4102
4103         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
4104         btrfs_end_transaction(trans, root);
4105 out:
4106         mnt_drop_write_file(file);
4107         return ret;
4108 }
4109
4110 void btrfs_get_block_group_info(struct list_head *groups_list,
4111                                 struct btrfs_ioctl_space_info *space)
4112 {
4113         struct btrfs_block_group_cache *block_group;
4114
4115         space->total_bytes = 0;
4116         space->used_bytes = 0;
4117         space->flags = 0;
4118         list_for_each_entry(block_group, groups_list, list) {
4119                 space->flags = block_group->flags;
4120                 space->total_bytes += block_group->key.offset;
4121                 space->used_bytes +=
4122                         btrfs_block_group_used(&block_group->item);
4123         }
4124 }
4125
4126 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
4127 {
4128         struct btrfs_ioctl_space_args space_args;
4129         struct btrfs_ioctl_space_info space;
4130         struct btrfs_ioctl_space_info *dest;
4131         struct btrfs_ioctl_space_info *dest_orig;
4132         struct btrfs_ioctl_space_info __user *user_dest;
4133         struct btrfs_space_info *info;
4134         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
4135                        BTRFS_BLOCK_GROUP_SYSTEM,
4136                        BTRFS_BLOCK_GROUP_METADATA,
4137                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
4138         int num_types = 4;
4139         int alloc_size;
4140         int ret = 0;
4141         u64 slot_count = 0;
4142         int i, c;
4143
4144         if (copy_from_user(&space_args,
4145                            (struct btrfs_ioctl_space_args __user *)arg,
4146                            sizeof(space_args)))
4147                 return -EFAULT;
4148
4149         for (i = 0; i < num_types; i++) {
4150                 struct btrfs_space_info *tmp;
4151
4152                 info = NULL;
4153                 rcu_read_lock();
4154                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4155                                         list) {
4156                         if (tmp->flags == types[i]) {
4157                                 info = tmp;
4158                                 break;
4159                         }
4160                 }
4161                 rcu_read_unlock();
4162
4163                 if (!info)
4164                         continue;
4165
4166                 down_read(&info->groups_sem);
4167                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4168                         if (!list_empty(&info->block_groups[c]))
4169                                 slot_count++;
4170                 }
4171                 up_read(&info->groups_sem);
4172         }
4173
4174         /*
4175          * Global block reserve, exported as a space_info
4176          */
4177         slot_count++;
4178
4179         /* space_slots == 0 means they are asking for a count */
4180         if (space_args.space_slots == 0) {
4181                 space_args.total_spaces = slot_count;
4182                 goto out;
4183         }
4184
4185         slot_count = min_t(u64, space_args.space_slots, slot_count);
4186
4187         alloc_size = sizeof(*dest) * slot_count;
4188
4189         /* we generally have at most 6 or so space infos, one for each raid
4190          * level.  So, a whole page should be more than enough for everyone
4191          */
4192         if (alloc_size > PAGE_SIZE)
4193                 return -ENOMEM;
4194
4195         space_args.total_spaces = 0;
4196         dest = kmalloc(alloc_size, GFP_KERNEL);
4197         if (!dest)
4198                 return -ENOMEM;
4199         dest_orig = dest;
4200
4201         /* now we have a buffer to copy into */
4202         for (i = 0; i < num_types; i++) {
4203                 struct btrfs_space_info *tmp;
4204
4205                 if (!slot_count)
4206                         break;
4207
4208                 info = NULL;
4209                 rcu_read_lock();
4210                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
4211                                         list) {
4212                         if (tmp->flags == types[i]) {
4213                                 info = tmp;
4214                                 break;
4215                         }
4216                 }
4217                 rcu_read_unlock();
4218
4219                 if (!info)
4220                         continue;
4221                 down_read(&info->groups_sem);
4222                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4223                         if (!list_empty(&info->block_groups[c])) {
4224                                 btrfs_get_block_group_info(
4225                                         &info->block_groups[c], &space);
4226                                 memcpy(dest, &space, sizeof(space));
4227                                 dest++;
4228                                 space_args.total_spaces++;
4229                                 slot_count--;
4230                         }
4231                         if (!slot_count)
4232                                 break;
4233                 }
4234                 up_read(&info->groups_sem);
4235         }
4236
4237         /*
4238          * Add global block reserve
4239          */
4240         if (slot_count) {
4241                 struct btrfs_block_rsv *block_rsv = &root->fs_info->global_block_rsv;
4242
4243                 spin_lock(&block_rsv->lock);
4244                 space.total_bytes = block_rsv->size;
4245                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4246                 spin_unlock(&block_rsv->lock);
4247                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4248                 memcpy(dest, &space, sizeof(space));
4249                 space_args.total_spaces++;
4250         }
4251
4252         user_dest = (struct btrfs_ioctl_space_info __user *)
4253                 (arg + sizeof(struct btrfs_ioctl_space_args));
4254
4255         if (copy_to_user(user_dest, dest_orig, alloc_size))
4256                 ret = -EFAULT;
4257
4258         kfree(dest_orig);
4259 out:
4260         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4261                 ret = -EFAULT;
4262
4263         return ret;
4264 }
4265
4266 /*
4267  * there are many ways the trans_start and trans_end ioctls can lead
4268  * to deadlocks.  They should only be used by applications that
4269  * basically own the machine, and have a very in depth understanding
4270  * of all the possible deadlocks and enospc problems.
4271  */
4272 long btrfs_ioctl_trans_end(struct file *file)
4273 {
4274         struct inode *inode = file_inode(file);
4275         struct btrfs_root *root = BTRFS_I(inode)->root;
4276         struct btrfs_trans_handle *trans;
4277
4278         trans = file->private_data;
4279         if (!trans)
4280                 return -EINVAL;
4281         file->private_data = NULL;
4282
4283         btrfs_end_transaction(trans, root);
4284
4285         atomic_dec(&root->fs_info->open_ioctl_trans);
4286
4287         mnt_drop_write_file(file);
4288         return 0;
4289 }
4290
4291 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4292                                             void __user *argp)
4293 {
4294         struct btrfs_trans_handle *trans;
4295         u64 transid;
4296         int ret;
4297
4298         trans = btrfs_attach_transaction_barrier(root);
4299         if (IS_ERR(trans)) {
4300                 if (PTR_ERR(trans) != -ENOENT)
4301                         return PTR_ERR(trans);
4302
4303                 /* No running transaction, don't bother */
4304                 transid = root->fs_info->last_trans_committed;
4305                 goto out;
4306         }
4307         transid = trans->transid;
4308         ret = btrfs_commit_transaction_async(trans, root, 0);
4309         if (ret) {
4310                 btrfs_end_transaction(trans, root);
4311                 return ret;
4312         }
4313 out:
4314         if (argp)
4315                 if (copy_to_user(argp, &transid, sizeof(transid)))
4316                         return -EFAULT;
4317         return 0;
4318 }
4319
4320 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
4321                                            void __user *argp)
4322 {
4323         u64 transid;
4324
4325         if (argp) {
4326                 if (copy_from_user(&transid, argp, sizeof(transid)))
4327                         return -EFAULT;
4328         } else {
4329                 transid = 0;  /* current trans */
4330         }
4331         return btrfs_wait_for_commit(root, transid);
4332 }
4333
4334 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4335 {
4336         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4337         struct btrfs_ioctl_scrub_args *sa;
4338         int ret;
4339
4340         if (!capable(CAP_SYS_ADMIN))
4341                 return -EPERM;
4342
4343         sa = memdup_user(arg, sizeof(*sa));
4344         if (IS_ERR(sa))
4345                 return PTR_ERR(sa);
4346
4347         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4348                 ret = mnt_want_write_file(file);
4349                 if (ret)
4350                         goto out;
4351         }
4352
4353         ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
4354                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4355                               0);
4356
4357         if (copy_to_user(arg, sa, sizeof(*sa)))
4358                 ret = -EFAULT;
4359
4360         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4361                 mnt_drop_write_file(file);
4362 out:
4363         kfree(sa);
4364         return ret;
4365 }
4366
4367 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
4368 {
4369         if (!capable(CAP_SYS_ADMIN))
4370                 return -EPERM;
4371
4372         return btrfs_scrub_cancel(root->fs_info);
4373 }
4374
4375 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
4376                                        void __user *arg)
4377 {
4378         struct btrfs_ioctl_scrub_args *sa;
4379         int ret;
4380
4381         if (!capable(CAP_SYS_ADMIN))
4382                 return -EPERM;
4383
4384         sa = memdup_user(arg, sizeof(*sa));
4385         if (IS_ERR(sa))
4386                 return PTR_ERR(sa);
4387
4388         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
4389
4390         if (copy_to_user(arg, sa, sizeof(*sa)))
4391                 ret = -EFAULT;
4392
4393         kfree(sa);
4394         return ret;
4395 }
4396
4397 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
4398                                       void __user *arg)
4399 {
4400         struct btrfs_ioctl_get_dev_stats *sa;
4401         int ret;
4402
4403         sa = memdup_user(arg, sizeof(*sa));
4404         if (IS_ERR(sa))
4405                 return PTR_ERR(sa);
4406
4407         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4408                 kfree(sa);
4409                 return -EPERM;
4410         }
4411
4412         ret = btrfs_get_dev_stats(root, sa);
4413
4414         if (copy_to_user(arg, sa, sizeof(*sa)))
4415                 ret = -EFAULT;
4416
4417         kfree(sa);
4418         return ret;
4419 }
4420
4421 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
4422 {
4423         struct btrfs_ioctl_dev_replace_args *p;
4424         int ret;
4425
4426         if (!capable(CAP_SYS_ADMIN))
4427                 return -EPERM;
4428
4429         p = memdup_user(arg, sizeof(*p));
4430         if (IS_ERR(p))
4431                 return PTR_ERR(p);
4432
4433         switch (p->cmd) {
4434         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4435                 if (root->fs_info->sb->s_flags & MS_RDONLY) {
4436                         ret = -EROFS;
4437                         goto out;
4438                 }
4439                 if (atomic_xchg(
4440                         &root->fs_info->mutually_exclusive_operation_running,
4441                         1)) {
4442                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4443                 } else {
4444                         ret = btrfs_dev_replace_by_ioctl(root, p);
4445                         atomic_set(
4446                          &root->fs_info->mutually_exclusive_operation_running,
4447                          0);
4448                 }
4449                 break;
4450         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4451                 btrfs_dev_replace_status(root->fs_info, p);
4452                 ret = 0;
4453                 break;
4454         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4455                 ret = btrfs_dev_replace_cancel(root->fs_info, p);
4456                 break;
4457         default:
4458                 ret = -EINVAL;
4459                 break;
4460         }
4461
4462         if (copy_to_user(arg, p, sizeof(*p)))
4463                 ret = -EFAULT;
4464 out:
4465         kfree(p);
4466         return ret;
4467 }
4468
4469 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4470 {
4471         int ret = 0;
4472         int i;
4473         u64 rel_ptr;
4474         int size;
4475         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4476         struct inode_fs_paths *ipath = NULL;
4477         struct btrfs_path *path;
4478
4479         if (!capable(CAP_DAC_READ_SEARCH))
4480                 return -EPERM;
4481
4482         path = btrfs_alloc_path();
4483         if (!path) {
4484                 ret = -ENOMEM;
4485                 goto out;
4486         }
4487
4488         ipa = memdup_user(arg, sizeof(*ipa));
4489         if (IS_ERR(ipa)) {
4490                 ret = PTR_ERR(ipa);
4491                 ipa = NULL;
4492                 goto out;
4493         }
4494
4495         size = min_t(u32, ipa->size, 4096);
4496         ipath = init_ipath(size, root, path);
4497         if (IS_ERR(ipath)) {
4498                 ret = PTR_ERR(ipath);
4499                 ipath = NULL;
4500                 goto out;
4501         }
4502
4503         ret = paths_from_inode(ipa->inum, ipath);
4504         if (ret < 0)
4505                 goto out;
4506
4507         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4508                 rel_ptr = ipath->fspath->val[i] -
4509                           (u64)(unsigned long)ipath->fspath->val;
4510                 ipath->fspath->val[i] = rel_ptr;
4511         }
4512
4513         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
4514                            (void *)(unsigned long)ipath->fspath, size);
4515         if (ret) {
4516                 ret = -EFAULT;
4517                 goto out;
4518         }
4519
4520 out:
4521         btrfs_free_path(path);
4522         free_ipath(ipath);
4523         kfree(ipa);
4524
4525         return ret;
4526 }
4527
4528 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4529 {
4530         struct btrfs_data_container *inodes = ctx;
4531         const size_t c = 3 * sizeof(u64);
4532
4533         if (inodes->bytes_left >= c) {
4534                 inodes->bytes_left -= c;
4535                 inodes->val[inodes->elem_cnt] = inum;
4536                 inodes->val[inodes->elem_cnt + 1] = offset;
4537                 inodes->val[inodes->elem_cnt + 2] = root;
4538                 inodes->elem_cnt += 3;
4539         } else {
4540                 inodes->bytes_missing += c - inodes->bytes_left;
4541                 inodes->bytes_left = 0;
4542                 inodes->elem_missed += 3;
4543         }
4544
4545         return 0;
4546 }
4547
4548 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
4549                                         void __user *arg)
4550 {
4551         int ret = 0;
4552         int size;
4553         struct btrfs_ioctl_logical_ino_args *loi;
4554         struct btrfs_data_container *inodes = NULL;
4555         struct btrfs_path *path = NULL;
4556
4557         if (!capable(CAP_SYS_ADMIN))
4558                 return -EPERM;
4559
4560         loi = memdup_user(arg, sizeof(*loi));
4561         if (IS_ERR(loi)) {
4562                 ret = PTR_ERR(loi);
4563                 loi = NULL;
4564                 goto out;
4565         }
4566
4567         path = btrfs_alloc_path();
4568         if (!path) {
4569                 ret = -ENOMEM;
4570                 goto out;
4571         }
4572
4573         size = min_t(u32, loi->size, SZ_64K);
4574         inodes = init_data_container(size);
4575         if (IS_ERR(inodes)) {
4576                 ret = PTR_ERR(inodes);
4577                 inodes = NULL;
4578                 goto out;
4579         }
4580
4581         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
4582                                           build_ino_list, inodes);
4583         if (ret == -EINVAL)
4584                 ret = -ENOENT;
4585         if (ret < 0)
4586                 goto out;
4587
4588         ret = copy_to_user((void *)(unsigned long)loi->inodes,
4589                            (void *)(unsigned long)inodes, size);
4590         if (ret)
4591                 ret = -EFAULT;
4592
4593 out:
4594         btrfs_free_path(path);
4595         vfree(inodes);
4596         kfree(loi);
4597
4598         return ret;
4599 }
4600
4601 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
4602                                struct btrfs_ioctl_balance_args *bargs)
4603 {
4604         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4605
4606         bargs->flags = bctl->flags;
4607
4608         if (atomic_read(&fs_info->balance_running))
4609                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4610         if (atomic_read(&fs_info->balance_pause_req))
4611                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4612         if (atomic_read(&fs_info->balance_cancel_req))
4613                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4614
4615         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4616         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4617         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4618
4619         if (lock) {
4620                 spin_lock(&fs_info->balance_lock);
4621                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4622                 spin_unlock(&fs_info->balance_lock);
4623         } else {
4624                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4625         }
4626 }
4627
4628 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4629 {
4630         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4631         struct btrfs_fs_info *fs_info = root->fs_info;
4632         struct btrfs_ioctl_balance_args *bargs;
4633         struct btrfs_balance_control *bctl;
4634         bool need_unlock; /* for mut. excl. ops lock */
4635         int ret;
4636
4637         if (!capable(CAP_SYS_ADMIN))
4638                 return -EPERM;
4639
4640         ret = mnt_want_write_file(file);
4641         if (ret)
4642                 return ret;
4643
4644 again:
4645         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
4646                 mutex_lock(&fs_info->volume_mutex);
4647                 mutex_lock(&fs_info->balance_mutex);
4648                 need_unlock = true;
4649                 goto locked;
4650         }
4651
4652         /*
4653          * mut. excl. ops lock is locked.  Three possibilities:
4654          *   (1) some other op is running
4655          *   (2) balance is running
4656          *   (3) balance is paused -- special case (think resume)
4657          */
4658         mutex_lock(&fs_info->balance_mutex);
4659         if (fs_info->balance_ctl) {
4660                 /* this is either (2) or (3) */
4661                 if (!atomic_read(&fs_info->balance_running)) {
4662                         mutex_unlock(&fs_info->balance_mutex);
4663                         if (!mutex_trylock(&fs_info->volume_mutex))
4664                                 goto again;
4665                         mutex_lock(&fs_info->balance_mutex);
4666
4667                         if (fs_info->balance_ctl &&
4668                             !atomic_read(&fs_info->balance_running)) {
4669                                 /* this is (3) */
4670                                 need_unlock = false;
4671                                 goto locked;
4672                         }
4673
4674                         mutex_unlock(&fs_info->balance_mutex);
4675                         mutex_unlock(&fs_info->volume_mutex);
4676                         goto again;
4677                 } else {
4678                         /* this is (2) */
4679                         mutex_unlock(&fs_info->balance_mutex);
4680                         ret = -EINPROGRESS;
4681                         goto out;
4682                 }
4683         } else {
4684                 /* this is (1) */
4685                 mutex_unlock(&fs_info->balance_mutex);
4686                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4687                 goto out;
4688         }
4689
4690 locked:
4691         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
4692
4693         if (arg) {
4694                 bargs = memdup_user(arg, sizeof(*bargs));
4695                 if (IS_ERR(bargs)) {
4696                         ret = PTR_ERR(bargs);
4697                         goto out_unlock;
4698                 }
4699
4700                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
4701                         if (!fs_info->balance_ctl) {
4702                                 ret = -ENOTCONN;
4703                                 goto out_bargs;
4704                         }
4705
4706                         bctl = fs_info->balance_ctl;
4707                         spin_lock(&fs_info->balance_lock);
4708                         bctl->flags |= BTRFS_BALANCE_RESUME;
4709                         spin_unlock(&fs_info->balance_lock);
4710
4711                         goto do_balance;
4712                 }
4713         } else {
4714                 bargs = NULL;
4715         }
4716
4717         if (fs_info->balance_ctl) {
4718                 ret = -EINPROGRESS;
4719                 goto out_bargs;
4720         }
4721
4722         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4723         if (!bctl) {
4724                 ret = -ENOMEM;
4725                 goto out_bargs;
4726         }
4727
4728         bctl->fs_info = fs_info;
4729         if (arg) {
4730                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4731                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4732                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4733
4734                 bctl->flags = bargs->flags;
4735         } else {
4736                 /* balance everything - no filters */
4737                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4738         }
4739
4740         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4741                 ret = -EINVAL;
4742                 goto out_bctl;
4743         }
4744
4745 do_balance:
4746         /*
4747          * Ownership of bctl and mutually_exclusive_operation_running
4748          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
4749          * or, if restriper was paused all the way until unmount, in
4750          * free_fs_info.  mutually_exclusive_operation_running is
4751          * cleared in __cancel_balance.
4752          */
4753         need_unlock = false;
4754
4755         ret = btrfs_balance(bctl, bargs);
4756         bctl = NULL;
4757
4758         if (arg) {
4759                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
4760                         ret = -EFAULT;
4761         }
4762
4763 out_bctl:
4764         kfree(bctl);
4765 out_bargs:
4766         kfree(bargs);
4767 out_unlock:
4768         mutex_unlock(&fs_info->balance_mutex);
4769         mutex_unlock(&fs_info->volume_mutex);
4770         if (need_unlock)
4771                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
4772 out:
4773         mnt_drop_write_file(file);
4774         return ret;
4775 }
4776
4777 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
4778 {
4779         if (!capable(CAP_SYS_ADMIN))
4780                 return -EPERM;
4781
4782         switch (cmd) {
4783         case BTRFS_BALANCE_CTL_PAUSE:
4784                 return btrfs_pause_balance(root->fs_info);
4785         case BTRFS_BALANCE_CTL_CANCEL:
4786                 return btrfs_cancel_balance(root->fs_info);
4787         }
4788
4789         return -EINVAL;
4790 }
4791
4792 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
4793                                          void __user *arg)
4794 {
4795         struct btrfs_fs_info *fs_info = root->fs_info;
4796         struct btrfs_ioctl_balance_args *bargs;
4797         int ret = 0;
4798
4799         if (!capable(CAP_SYS_ADMIN))
4800                 return -EPERM;
4801
4802         mutex_lock(&fs_info->balance_mutex);
4803         if (!fs_info->balance_ctl) {
4804                 ret = -ENOTCONN;
4805                 goto out;
4806         }
4807
4808         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4809         if (!bargs) {
4810                 ret = -ENOMEM;
4811                 goto out;
4812         }
4813
4814         update_ioctl_balance_args(fs_info, 1, bargs);
4815
4816         if (copy_to_user(arg, bargs, sizeof(*bargs)))
4817                 ret = -EFAULT;
4818
4819         kfree(bargs);
4820 out:
4821         mutex_unlock(&fs_info->balance_mutex);
4822         return ret;
4823 }
4824
4825 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4826 {
4827         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4828         struct btrfs_ioctl_quota_ctl_args *sa;
4829         struct btrfs_trans_handle *trans = NULL;
4830         int ret;
4831         int err;
4832
4833         if (!capable(CAP_SYS_ADMIN))
4834                 return -EPERM;
4835
4836         ret = mnt_want_write_file(file);
4837         if (ret)
4838                 return ret;
4839
4840         sa = memdup_user(arg, sizeof(*sa));
4841         if (IS_ERR(sa)) {
4842                 ret = PTR_ERR(sa);
4843                 goto drop_write;
4844         }
4845
4846         down_write(&root->fs_info->subvol_sem);
4847         trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
4848         if (IS_ERR(trans)) {
4849                 ret = PTR_ERR(trans);
4850                 goto out;
4851         }
4852
4853         switch (sa->cmd) {
4854         case BTRFS_QUOTA_CTL_ENABLE:
4855                 ret = btrfs_quota_enable(trans, root->fs_info);
4856                 break;
4857         case BTRFS_QUOTA_CTL_DISABLE:
4858                 ret = btrfs_quota_disable(trans, root->fs_info);
4859                 break;
4860         default:
4861                 ret = -EINVAL;
4862                 break;
4863         }
4864
4865         err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
4866         if (err && !ret)
4867                 ret = err;
4868 out:
4869         kfree(sa);
4870         up_write(&root->fs_info->subvol_sem);
4871 drop_write:
4872         mnt_drop_write_file(file);
4873         return ret;
4874 }
4875
4876 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4877 {
4878         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4879         struct btrfs_ioctl_qgroup_assign_args *sa;
4880         struct btrfs_trans_handle *trans;
4881         int ret;
4882         int err;
4883
4884         if (!capable(CAP_SYS_ADMIN))
4885                 return -EPERM;
4886
4887         ret = mnt_want_write_file(file);
4888         if (ret)
4889                 return ret;
4890
4891         sa = memdup_user(arg, sizeof(*sa));
4892         if (IS_ERR(sa)) {
4893                 ret = PTR_ERR(sa);
4894                 goto drop_write;
4895         }
4896
4897         trans = btrfs_join_transaction(root);
4898         if (IS_ERR(trans)) {
4899                 ret = PTR_ERR(trans);
4900                 goto out;
4901         }
4902
4903         /* FIXME: check if the IDs really exist */
4904         if (sa->assign) {
4905                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
4906                                                 sa->src, sa->dst);
4907         } else {
4908                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
4909                                                 sa->src, sa->dst);
4910         }
4911
4912         /* update qgroup status and info */
4913         err = btrfs_run_qgroups(trans, root->fs_info);
4914         if (err < 0)
4915                 btrfs_handle_fs_error(root->fs_info, err,
4916                             "failed to update qgroup status and info");
4917         err = btrfs_end_transaction(trans, root);
4918         if (err && !ret)
4919                 ret = err;
4920
4921 out:
4922         kfree(sa);
4923 drop_write:
4924         mnt_drop_write_file(file);
4925         return ret;
4926 }
4927
4928 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4929 {
4930         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4931         struct btrfs_ioctl_qgroup_create_args *sa;
4932         struct btrfs_trans_handle *trans;
4933         int ret;
4934         int err;
4935
4936         if (!capable(CAP_SYS_ADMIN))
4937                 return -EPERM;
4938
4939         ret = mnt_want_write_file(file);
4940         if (ret)
4941                 return ret;
4942
4943         sa = memdup_user(arg, sizeof(*sa));
4944         if (IS_ERR(sa)) {
4945                 ret = PTR_ERR(sa);
4946                 goto drop_write;
4947         }
4948
4949         if (!sa->qgroupid) {
4950                 ret = -EINVAL;
4951                 goto out;
4952         }
4953
4954         trans = btrfs_join_transaction(root);
4955         if (IS_ERR(trans)) {
4956                 ret = PTR_ERR(trans);
4957                 goto out;
4958         }
4959
4960         /* FIXME: check if the IDs really exist */
4961         if (sa->create) {
4962                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid);
4963         } else {
4964                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
4965         }
4966
4967         err = btrfs_end_transaction(trans, root);
4968         if (err && !ret)
4969                 ret = err;
4970
4971 out:
4972         kfree(sa);
4973 drop_write:
4974         mnt_drop_write_file(file);
4975         return ret;
4976 }
4977
4978 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4979 {
4980         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4981         struct btrfs_ioctl_qgroup_limit_args *sa;
4982         struct btrfs_trans_handle *trans;
4983         int ret;
4984         int err;
4985         u64 qgroupid;
4986
4987         if (!capable(CAP_SYS_ADMIN))
4988                 return -EPERM;
4989
4990         ret = mnt_want_write_file(file);
4991         if (ret)
4992                 return ret;
4993
4994         sa = memdup_user(arg, sizeof(*sa));
4995         if (IS_ERR(sa)) {
4996                 ret = PTR_ERR(sa);
4997                 goto drop_write;
4998         }
4999
5000         trans = btrfs_join_transaction(root);
5001         if (IS_ERR(trans)) {
5002                 ret = PTR_ERR(trans);
5003                 goto out;
5004         }
5005
5006         qgroupid = sa->qgroupid;
5007         if (!qgroupid) {
5008                 /* take the current subvol as qgroup */
5009                 qgroupid = root->root_key.objectid;
5010         }
5011
5012         /* FIXME: check if the IDs really exist */
5013         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
5014
5015         err = btrfs_end_transaction(trans, root);
5016         if (err && !ret)
5017                 ret = err;
5018
5019 out:
5020         kfree(sa);
5021 drop_write:
5022         mnt_drop_write_file(file);
5023         return ret;
5024 }
5025
5026 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5027 {
5028         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5029         struct btrfs_ioctl_quota_rescan_args *qsa;
5030         int ret;
5031
5032         if (!capable(CAP_SYS_ADMIN))
5033                 return -EPERM;
5034
5035         ret = mnt_want_write_file(file);
5036         if (ret)
5037                 return ret;
5038
5039         qsa = memdup_user(arg, sizeof(*qsa));
5040         if (IS_ERR(qsa)) {
5041                 ret = PTR_ERR(qsa);
5042                 goto drop_write;
5043         }
5044
5045         if (qsa->flags) {
5046                 ret = -EINVAL;
5047                 goto out;
5048         }
5049
5050         ret = btrfs_qgroup_rescan(root->fs_info);
5051
5052 out:
5053         kfree(qsa);
5054 drop_write:
5055         mnt_drop_write_file(file);
5056         return ret;
5057 }
5058
5059 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5060 {
5061         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5062         struct btrfs_ioctl_quota_rescan_args *qsa;
5063         int ret = 0;
5064
5065         if (!capable(CAP_SYS_ADMIN))
5066                 return -EPERM;
5067
5068         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5069         if (!qsa)
5070                 return -ENOMEM;
5071
5072         if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5073                 qsa->flags = 1;
5074                 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
5075         }
5076
5077         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5078                 ret = -EFAULT;
5079
5080         kfree(qsa);
5081         return ret;
5082 }
5083
5084 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5085 {
5086         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5087
5088         if (!capable(CAP_SYS_ADMIN))
5089                 return -EPERM;
5090
5091         return btrfs_qgroup_wait_for_completion(root->fs_info);
5092 }
5093
5094 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5095                                             struct btrfs_ioctl_received_subvol_args *sa)
5096 {
5097         struct inode *inode = file_inode(file);
5098         struct btrfs_root *root = BTRFS_I(inode)->root;
5099         struct btrfs_root_item *root_item = &root->root_item;
5100         struct btrfs_trans_handle *trans;
5101         struct timespec ct = current_fs_time(inode->i_sb);
5102         int ret = 0;
5103         int received_uuid_changed;
5104
5105         if (!inode_owner_or_capable(inode))
5106                 return -EPERM;
5107
5108         ret = mnt_want_write_file(file);
5109         if (ret < 0)
5110                 return ret;
5111
5112         down_write(&root->fs_info->subvol_sem);
5113
5114         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
5115                 ret = -EINVAL;
5116                 goto out;
5117         }
5118
5119         if (btrfs_root_readonly(root)) {
5120                 ret = -EROFS;
5121                 goto out;
5122         }
5123
5124         /*
5125          * 1 - root item
5126          * 2 - uuid items (received uuid + subvol uuid)
5127          */
5128         trans = btrfs_start_transaction(root, 3);
5129         if (IS_ERR(trans)) {
5130                 ret = PTR_ERR(trans);
5131                 trans = NULL;
5132                 goto out;
5133         }
5134
5135         sa->rtransid = trans->transid;
5136         sa->rtime.sec = ct.tv_sec;
5137         sa->rtime.nsec = ct.tv_nsec;
5138
5139         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5140                                        BTRFS_UUID_SIZE);
5141         if (received_uuid_changed &&
5142             !btrfs_is_empty_uuid(root_item->received_uuid))
5143                 btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root,
5144                                     root_item->received_uuid,
5145                                     BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5146                                     root->root_key.objectid);
5147         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5148         btrfs_set_root_stransid(root_item, sa->stransid);
5149         btrfs_set_root_rtransid(root_item, sa->rtransid);
5150         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5151         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5152         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5153         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5154
5155         ret = btrfs_update_root(trans, root->fs_info->tree_root,
5156                                 &root->root_key, &root->root_item);
5157         if (ret < 0) {
5158                 btrfs_end_transaction(trans, root);
5159                 goto out;
5160         }
5161         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5162                 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root,
5163                                           sa->uuid,
5164                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5165                                           root->root_key.objectid);
5166                 if (ret < 0 && ret != -EEXIST) {
5167                         btrfs_abort_transaction(trans, root, ret);
5168                         goto out;
5169                 }
5170         }
5171         ret = btrfs_commit_transaction(trans, root);
5172         if (ret < 0) {
5173                 btrfs_abort_transaction(trans, root, ret);
5174                 goto out;
5175         }
5176
5177 out:
5178         up_write(&root->fs_info->subvol_sem);
5179         mnt_drop_write_file(file);
5180         return ret;
5181 }
5182
5183 #ifdef CONFIG_64BIT
5184 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5185                                                 void __user *arg)
5186 {
5187         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5188         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5189         int ret = 0;
5190
5191         args32 = memdup_user(arg, sizeof(*args32));
5192         if (IS_ERR(args32)) {
5193                 ret = PTR_ERR(args32);
5194                 args32 = NULL;
5195                 goto out;
5196         }
5197
5198         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5199         if (!args64) {
5200                 ret = -ENOMEM;
5201                 goto out;
5202         }
5203
5204         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5205         args64->stransid = args32->stransid;
5206         args64->rtransid = args32->rtransid;
5207         args64->stime.sec = args32->stime.sec;
5208         args64->stime.nsec = args32->stime.nsec;
5209         args64->rtime.sec = args32->rtime.sec;
5210         args64->rtime.nsec = args32->rtime.nsec;
5211         args64->flags = args32->flags;
5212
5213         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5214         if (ret)
5215                 goto out;
5216
5217         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5218         args32->stransid = args64->stransid;
5219         args32->rtransid = args64->rtransid;
5220         args32->stime.sec = args64->stime.sec;
5221         args32->stime.nsec = args64->stime.nsec;
5222         args32->rtime.sec = args64->rtime.sec;
5223         args32->rtime.nsec = args64->rtime.nsec;
5224         args32->flags = args64->flags;
5225
5226         ret = copy_to_user(arg, args32, sizeof(*args32));
5227         if (ret)
5228                 ret = -EFAULT;
5229
5230 out:
5231         kfree(args32);
5232         kfree(args64);
5233         return ret;
5234 }
5235 #endif
5236
5237 static long btrfs_ioctl_set_received_subvol(struct file *file,
5238                                             void __user *arg)
5239 {
5240         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5241         int ret = 0;
5242
5243         sa = memdup_user(arg, sizeof(*sa));
5244         if (IS_ERR(sa)) {
5245                 ret = PTR_ERR(sa);
5246                 sa = NULL;
5247                 goto out;
5248         }
5249
5250         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5251
5252         if (ret)
5253                 goto out;
5254
5255         ret = copy_to_user(arg, sa, sizeof(*sa));
5256         if (ret)
5257                 ret = -EFAULT;
5258
5259 out:
5260         kfree(sa);
5261         return ret;
5262 }
5263
5264 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5265 {
5266         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5267         size_t len;
5268         int ret;
5269         char label[BTRFS_LABEL_SIZE];
5270
5271         spin_lock(&root->fs_info->super_lock);
5272         memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5273         spin_unlock(&root->fs_info->super_lock);
5274
5275         len = strnlen(label, BTRFS_LABEL_SIZE);
5276
5277         if (len == BTRFS_LABEL_SIZE) {
5278                 btrfs_warn(root->fs_info,
5279                         "label is too long, return the first %zu bytes", --len);
5280         }
5281
5282         ret = copy_to_user(arg, label, len);
5283
5284         return ret ? -EFAULT : 0;
5285 }
5286
5287 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5288 {
5289         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5290         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5291         struct btrfs_trans_handle *trans;
5292         char label[BTRFS_LABEL_SIZE];
5293         int ret;
5294
5295         if (!capable(CAP_SYS_ADMIN))
5296                 return -EPERM;
5297
5298         if (copy_from_user(label, arg, sizeof(label)))
5299                 return -EFAULT;
5300
5301         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5302                 btrfs_err(root->fs_info, "unable to set label with more than %d bytes",
5303                        BTRFS_LABEL_SIZE - 1);
5304                 return -EINVAL;
5305         }
5306
5307         ret = mnt_want_write_file(file);
5308         if (ret)
5309                 return ret;
5310
5311         trans = btrfs_start_transaction(root, 0);
5312         if (IS_ERR(trans)) {
5313                 ret = PTR_ERR(trans);
5314                 goto out_unlock;
5315         }
5316
5317         spin_lock(&root->fs_info->super_lock);
5318         strcpy(super_block->label, label);
5319         spin_unlock(&root->fs_info->super_lock);
5320         ret = btrfs_commit_transaction(trans, root);
5321
5322 out_unlock:
5323         mnt_drop_write_file(file);
5324         return ret;
5325 }
5326
5327 #define INIT_FEATURE_FLAGS(suffix) \
5328         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5329           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5330           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5331
5332 int btrfs_ioctl_get_supported_features(void __user *arg)
5333 {
5334         static const struct btrfs_ioctl_feature_flags features[3] = {
5335                 INIT_FEATURE_FLAGS(SUPP),
5336                 INIT_FEATURE_FLAGS(SAFE_SET),
5337                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5338         };
5339
5340         if (copy_to_user(arg, &features, sizeof(features)))
5341                 return -EFAULT;
5342
5343         return 0;
5344 }
5345
5346 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5347 {
5348         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5349         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5350         struct btrfs_ioctl_feature_flags features;
5351
5352         features.compat_flags = btrfs_super_compat_flags(super_block);
5353         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5354         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5355
5356         if (copy_to_user(arg, &features, sizeof(features)))
5357                 return -EFAULT;
5358
5359         return 0;
5360 }
5361
5362 static int check_feature_bits(struct btrfs_root *root,
5363                               enum btrfs_feature_set set,
5364                               u64 change_mask, u64 flags, u64 supported_flags,
5365                               u64 safe_set, u64 safe_clear)
5366 {
5367         const char *type = btrfs_feature_set_names[set];
5368         char *names;
5369         u64 disallowed, unsupported;
5370         u64 set_mask = flags & change_mask;
5371         u64 clear_mask = ~flags & change_mask;
5372
5373         unsupported = set_mask & ~supported_flags;
5374         if (unsupported) {
5375                 names = btrfs_printable_features(set, unsupported);
5376                 if (names) {
5377                         btrfs_warn(root->fs_info,
5378                            "this kernel does not support the %s feature bit%s",
5379                            names, strchr(names, ',') ? "s" : "");
5380                         kfree(names);
5381                 } else
5382                         btrfs_warn(root->fs_info,
5383                            "this kernel does not support %s bits 0x%llx",
5384                            type, unsupported);
5385                 return -EOPNOTSUPP;
5386         }
5387
5388         disallowed = set_mask & ~safe_set;
5389         if (disallowed) {
5390                 names = btrfs_printable_features(set, disallowed);
5391                 if (names) {
5392                         btrfs_warn(root->fs_info,
5393                            "can't set the %s feature bit%s while mounted",
5394                            names, strchr(names, ',') ? "s" : "");
5395                         kfree(names);
5396                 } else
5397                         btrfs_warn(root->fs_info,
5398                            "can't set %s bits 0x%llx while mounted",
5399                            type, disallowed);
5400                 return -EPERM;
5401         }
5402
5403         disallowed = clear_mask & ~safe_clear;
5404         if (disallowed) {
5405                 names = btrfs_printable_features(set, disallowed);
5406                 if (names) {
5407                         btrfs_warn(root->fs_info,
5408                            "can't clear the %s feature bit%s while mounted",
5409                            names, strchr(names, ',') ? "s" : "");
5410                         kfree(names);
5411                 } else
5412                         btrfs_warn(root->fs_info,
5413                            "can't clear %s bits 0x%llx while mounted",
5414                            type, disallowed);
5415                 return -EPERM;
5416         }
5417
5418         return 0;
5419 }
5420
5421 #define check_feature(root, change_mask, flags, mask_base)      \
5422 check_feature_bits(root, FEAT_##mask_base, change_mask, flags,  \
5423                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5424                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5425                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5426
5427 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5428 {
5429         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5430         struct btrfs_super_block *super_block = root->fs_info->super_copy;
5431         struct btrfs_ioctl_feature_flags flags[2];
5432         struct btrfs_trans_handle *trans;
5433         u64 newflags;
5434         int ret;
5435
5436         if (!capable(CAP_SYS_ADMIN))
5437                 return -EPERM;
5438
5439         if (copy_from_user(flags, arg, sizeof(flags)))
5440                 return -EFAULT;
5441
5442         /* Nothing to do */
5443         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5444             !flags[0].incompat_flags)
5445                 return 0;
5446
5447         ret = check_feature(root, flags[0].compat_flags,
5448                             flags[1].compat_flags, COMPAT);
5449         if (ret)
5450                 return ret;
5451
5452         ret = check_feature(root, flags[0].compat_ro_flags,
5453                             flags[1].compat_ro_flags, COMPAT_RO);
5454         if (ret)
5455                 return ret;
5456
5457         ret = check_feature(root, flags[0].incompat_flags,
5458                             flags[1].incompat_flags, INCOMPAT);
5459         if (ret)
5460                 return ret;
5461
5462         ret = mnt_want_write_file(file);
5463         if (ret)
5464                 return ret;
5465
5466         trans = btrfs_start_transaction(root, 0);
5467         if (IS_ERR(trans)) {
5468                 ret = PTR_ERR(trans);
5469                 goto out_drop_write;
5470         }
5471
5472         spin_lock(&root->fs_info->super_lock);
5473         newflags = btrfs_super_compat_flags(super_block);
5474         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5475         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5476         btrfs_set_super_compat_flags(super_block, newflags);
5477
5478         newflags = btrfs_super_compat_ro_flags(super_block);
5479         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5480         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5481         btrfs_set_super_compat_ro_flags(super_block, newflags);
5482
5483         newflags = btrfs_super_incompat_flags(super_block);
5484         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5485         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5486         btrfs_set_super_incompat_flags(super_block, newflags);
5487         spin_unlock(&root->fs_info->super_lock);
5488
5489         ret = btrfs_commit_transaction(trans, root);
5490 out_drop_write:
5491         mnt_drop_write_file(file);
5492
5493         return ret;
5494 }
5495
5496 long btrfs_ioctl(struct file *file, unsigned int
5497                 cmd, unsigned long arg)
5498 {
5499         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
5500         void __user *argp = (void __user *)arg;
5501
5502         switch (cmd) {
5503         case FS_IOC_GETFLAGS:
5504                 return btrfs_ioctl_getflags(file, argp);
5505         case FS_IOC_SETFLAGS:
5506                 return btrfs_ioctl_setflags(file, argp);
5507         case FS_IOC_GETVERSION:
5508                 return btrfs_ioctl_getversion(file, argp);
5509         case FITRIM:
5510                 return btrfs_ioctl_fitrim(file, argp);
5511         case BTRFS_IOC_SNAP_CREATE:
5512                 return btrfs_ioctl_snap_create(file, argp, 0);
5513         case BTRFS_IOC_SNAP_CREATE_V2:
5514                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5515         case BTRFS_IOC_SUBVOL_CREATE:
5516                 return btrfs_ioctl_snap_create(file, argp, 1);
5517         case BTRFS_IOC_SUBVOL_CREATE_V2:
5518                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5519         case BTRFS_IOC_SNAP_DESTROY:
5520                 return btrfs_ioctl_snap_destroy(file, argp);
5521         case BTRFS_IOC_SUBVOL_GETFLAGS:
5522                 return btrfs_ioctl_subvol_getflags(file, argp);
5523         case BTRFS_IOC_SUBVOL_SETFLAGS:
5524                 return btrfs_ioctl_subvol_setflags(file, argp);
5525         case BTRFS_IOC_DEFAULT_SUBVOL:
5526                 return btrfs_ioctl_default_subvol(file, argp);
5527         case BTRFS_IOC_DEFRAG:
5528                 return btrfs_ioctl_defrag(file, NULL);
5529         case BTRFS_IOC_DEFRAG_RANGE:
5530                 return btrfs_ioctl_defrag(file, argp);
5531         case BTRFS_IOC_RESIZE:
5532                 return btrfs_ioctl_resize(file, argp);
5533         case BTRFS_IOC_ADD_DEV:
5534                 return btrfs_ioctl_add_dev(root, argp);
5535         case BTRFS_IOC_RM_DEV:
5536                 return btrfs_ioctl_rm_dev(file, argp);
5537         case BTRFS_IOC_RM_DEV_V2:
5538                 return btrfs_ioctl_rm_dev_v2(file, argp);
5539         case BTRFS_IOC_FS_INFO:
5540                 return btrfs_ioctl_fs_info(root, argp);
5541         case BTRFS_IOC_DEV_INFO:
5542                 return btrfs_ioctl_dev_info(root, argp);
5543         case BTRFS_IOC_BALANCE:
5544                 return btrfs_ioctl_balance(file, NULL);
5545         case BTRFS_IOC_TRANS_START:
5546                 return btrfs_ioctl_trans_start(file);
5547         case BTRFS_IOC_TRANS_END:
5548                 return btrfs_ioctl_trans_end(file);
5549         case BTRFS_IOC_TREE_SEARCH:
5550                 return btrfs_ioctl_tree_search(file, argp);
5551         case BTRFS_IOC_TREE_SEARCH_V2:
5552                 return btrfs_ioctl_tree_search_v2(file, argp);
5553         case BTRFS_IOC_INO_LOOKUP:
5554                 return btrfs_ioctl_ino_lookup(file, argp);
5555         case BTRFS_IOC_INO_PATHS:
5556                 return btrfs_ioctl_ino_to_path(root, argp);
5557         case BTRFS_IOC_LOGICAL_INO:
5558                 return btrfs_ioctl_logical_to_ino(root, argp);
5559         case BTRFS_IOC_SPACE_INFO:
5560                 return btrfs_ioctl_space_info(root, argp);
5561         case BTRFS_IOC_SYNC: {
5562                 int ret;
5563
5564                 ret = btrfs_start_delalloc_roots(root->fs_info, 0, -1);
5565                 if (ret)
5566                         return ret;
5567                 ret = btrfs_sync_fs(file_inode(file)->i_sb, 1);
5568                 /*
5569                  * The transaction thread may want to do more work,
5570                  * namely it pokes the cleaner kthread that will start
5571                  * processing uncleaned subvols.
5572                  */
5573                 wake_up_process(root->fs_info->transaction_kthread);
5574                 return ret;
5575         }
5576         case BTRFS_IOC_START_SYNC:
5577                 return btrfs_ioctl_start_sync(root, argp);
5578         case BTRFS_IOC_WAIT_SYNC:
5579                 return btrfs_ioctl_wait_sync(root, argp);
5580         case BTRFS_IOC_SCRUB:
5581                 return btrfs_ioctl_scrub(file, argp);
5582         case BTRFS_IOC_SCRUB_CANCEL:
5583                 return btrfs_ioctl_scrub_cancel(root, argp);
5584         case BTRFS_IOC_SCRUB_PROGRESS:
5585                 return btrfs_ioctl_scrub_progress(root, argp);
5586         case BTRFS_IOC_BALANCE_V2:
5587                 return btrfs_ioctl_balance(file, argp);
5588         case BTRFS_IOC_BALANCE_CTL:
5589                 return btrfs_ioctl_balance_ctl(root, arg);
5590         case BTRFS_IOC_BALANCE_PROGRESS:
5591                 return btrfs_ioctl_balance_progress(root, argp);
5592         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5593                 return btrfs_ioctl_set_received_subvol(file, argp);
5594 #ifdef CONFIG_64BIT
5595         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5596                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5597 #endif
5598         case BTRFS_IOC_SEND:
5599                 return btrfs_ioctl_send(file, argp);
5600         case BTRFS_IOC_GET_DEV_STATS:
5601                 return btrfs_ioctl_get_dev_stats(root, argp);
5602         case BTRFS_IOC_QUOTA_CTL:
5603                 return btrfs_ioctl_quota_ctl(file, argp);
5604         case BTRFS_IOC_QGROUP_ASSIGN:
5605                 return btrfs_ioctl_qgroup_assign(file, argp);
5606         case BTRFS_IOC_QGROUP_CREATE:
5607                 return btrfs_ioctl_qgroup_create(file, argp);
5608         case BTRFS_IOC_QGROUP_LIMIT:
5609                 return btrfs_ioctl_qgroup_limit(file, argp);
5610         case BTRFS_IOC_QUOTA_RESCAN:
5611                 return btrfs_ioctl_quota_rescan(file, argp);
5612         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5613                 return btrfs_ioctl_quota_rescan_status(file, argp);
5614         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5615                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5616         case BTRFS_IOC_DEV_REPLACE:
5617                 return btrfs_ioctl_dev_replace(root, argp);
5618         case BTRFS_IOC_GET_FSLABEL:
5619                 return btrfs_ioctl_get_fslabel(file, argp);
5620         case BTRFS_IOC_SET_FSLABEL:
5621                 return btrfs_ioctl_set_fslabel(file, argp);
5622         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5623                 return btrfs_ioctl_get_supported_features(argp);
5624         case BTRFS_IOC_GET_FEATURES:
5625                 return btrfs_ioctl_get_features(file, argp);
5626         case BTRFS_IOC_SET_FEATURES:
5627                 return btrfs_ioctl_set_features(file, argp);
5628         }
5629
5630         return -ENOTTY;
5631 }
5632
5633 #ifdef CONFIG_COMPAT
5634 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5635 {
5636         switch (cmd) {
5637         case FS_IOC32_GETFLAGS:
5638                 cmd = FS_IOC_GETFLAGS;
5639                 break;
5640         case FS_IOC32_SETFLAGS:
5641                 cmd = FS_IOC_SETFLAGS;
5642                 break;
5643         case FS_IOC32_GETVERSION:
5644                 cmd = FS_IOC_GETVERSION;
5645                 break;
5646         default:
5647                 return -ENOIOCTLCMD;
5648         }
5649
5650         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5651 }
5652 #endif