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 "compat.h"
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "ioctl.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
  60 /* Mask out flags that are inappropriate for the given type of inode. */
  61 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  62 {
  63         if (S_ISDIR(mode))
  64                 return flags;
  65         else if (S_ISREG(mode))
  66                 return flags & ~FS_DIRSYNC_FL;
  67         else
  68                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  69 }
  70
  71 /*
  72  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  73  */
  74 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  75 {
  76         unsigned int iflags = 0;
  77
  78         if (flags & BTRFS_INODE_SYNC)
  79                 iflags |= FS_SYNC_FL;
  80         if (flags & BTRFS_INODE_IMMUTABLE)
  81                 iflags |= FS_IMMUTABLE_FL;
  82         if (flags & BTRFS_INODE_APPEND)
  83                 iflags |= FS_APPEND_FL;
  84         if (flags & BTRFS_INODE_NODUMP)
  85                 iflags |= FS_NODUMP_FL;
  86         if (flags & BTRFS_INODE_NOATIME)
  87                 iflags |= FS_NOATIME_FL;
  88         if (flags & BTRFS_INODE_DIRSYNC)
  89                 iflags |= FS_DIRSYNC_FL;
  90         if (flags & BTRFS_INODE_NODATACOW)
  91                 iflags |= FS_NOCOW_FL;
  92
  93         if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
  94                 iflags |= FS_COMPR_FL;
  95         else if (flags & BTRFS_INODE_NOCOMPRESS)
  96                 iflags |= FS_NOCOMP_FL;
  97
  98         return iflags;
  99 }
 100
 101 /*
 102  * Update inode->i_flags based on the btrfs internal flags.
 103  */
 104 void btrfs_update_iflags(struct inode *inode)
 105 {
 106         struct btrfs_inode *ip = BTRFS_I(inode);
 107
 108         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
 109
 110         if (ip->flags & BTRFS_INODE_SYNC)
 111                 inode->i_flags |= S_SYNC;
 112         if (ip->flags & BTRFS_INODE_IMMUTABLE)
 113                 inode->i_flags |= S_IMMUTABLE;
 114         if (ip->flags & BTRFS_INODE_APPEND)
 115                 inode->i_flags |= S_APPEND;
 116         if (ip->flags & BTRFS_INODE_NOATIME)
 117                 inode->i_flags |= S_NOATIME;
 118         if (ip->flags & BTRFS_INODE_DIRSYNC)
 119                 inode->i_flags |= S_DIRSYNC;
 120 }
 121
 122 /*
 123  * Inherit flags from the parent inode.
 124  *
 125  * Currently only the compression flags and the cow flags are inherited.
 126  */
 127 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 128 {
 129         unsigned int flags;
 130
 131         if (!dir)
 132                 return;
 133
 134         flags = BTRFS_I(dir)->flags;
 135
 136         if (flags & BTRFS_INODE_NOCOMPRESS) {
 137                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
 138                 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 139         } else if (flags & BTRFS_INODE_COMPRESS) {
 140                 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
 141                 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
 142         }
 143
 144         if (flags & BTRFS_INODE_NODATACOW) {
 145                 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
 146                 if (S_ISREG(inode->i_mode))
 147                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
 148         }
 149
 150         btrfs_update_iflags(inode);
 151 }
 152
 153 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 154 {
 155         struct btrfs_inode *ip = BTRFS_I(file_inode(file));
 156         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 157
 158         if (copy_to_user(arg, &flags, sizeof(flags)))
 159                 return -EFAULT;
 160         return 0;
 161 }
 162
 163 static int check_flags(unsigned int flags)
 164 {
 165         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 166                       FS_NOATIME_FL | FS_NODUMP_FL | \
 167                       FS_SYNC_FL | FS_DIRSYNC_FL | \
 168                       FS_NOCOMP_FL | FS_COMPR_FL |
 169                       FS_NOCOW_FL))
 170                 return -EOPNOTSUPP;
 171
 172         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
 173                 return -EINVAL;
 174
 175         return 0;
 176 }
 177
 178 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 179 {
 180         struct inode *inode = file_inode(file);
 181         struct btrfs_inode *ip = BTRFS_I(inode);
 182         struct btrfs_root *root = ip->root;
 183         struct btrfs_trans_handle *trans;
 184         unsigned int flags, oldflags;
 185         int ret;
 186         u64 ip_oldflags;
 187         unsigned int i_oldflags;
 188         umode_t mode;
 189
 190         if (btrfs_root_readonly(root))
 191                 return -EROFS;
 192
 193         if (copy_from_user(&flags, arg, sizeof(flags)))
 194                 return -EFAULT;
 195
 196         ret = check_flags(flags);
 197         if (ret)
 198                 return ret;
 199
 200         if (!inode_owner_or_capable(inode))
 201                 return -EACCES;
 202
 203         ret = mnt_want_write_file(file);
 204         if (ret)
 205                 return ret;
 206
 207         mutex_lock(&inode->i_mutex);
 208
 209         ip_oldflags = ip->flags;
 210         i_oldflags = inode->i_flags;
 211         mode = inode->i_mode;
 212
 213         flags = btrfs_mask_flags(inode->i_mode, flags);
 214         oldflags = btrfs_flags_to_ioctl(ip->flags);
 215         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 216                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 217                         ret = -EPERM;
 218                         goto out_unlock;
 219                 }
 220         }
 221
 222         if (flags & FS_SYNC_FL)
 223                 ip->flags |= BTRFS_INODE_SYNC;
 224         else
 225                 ip->flags &= ~BTRFS_INODE_SYNC;
 226         if (flags & FS_IMMUTABLE_FL)
 227                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 228         else
 229                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 230         if (flags & FS_APPEND_FL)
 231                 ip->flags |= BTRFS_INODE_APPEND;
 232         else
 233                 ip->flags &= ~BTRFS_INODE_APPEND;
 234         if (flags & FS_NODUMP_FL)
 235                 ip->flags |= BTRFS_INODE_NODUMP;
 236         else
 237                 ip->flags &= ~BTRFS_INODE_NODUMP;
 238         if (flags & FS_NOATIME_FL)
 239                 ip->flags |= BTRFS_INODE_NOATIME;
 240         else
 241                 ip->flags &= ~BTRFS_INODE_NOATIME;
 242         if (flags & FS_DIRSYNC_FL)
 243                 ip->flags |= BTRFS_INODE_DIRSYNC;
 244         else
 245                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 246         if (flags & FS_NOCOW_FL) {
 247                 if (S_ISREG(mode)) {
 248                         /*
 249                          * It's safe to turn csums off here, no extents exist.
 250                          * Otherwise we want the flag to reflect the real COW
 251                          * status of the file and will not set it.
 252                          */
 253                         if (inode->i_size == 0)
 254                                 ip->flags |= BTRFS_INODE_NODATACOW
 255                                            | BTRFS_INODE_NODATASUM;
 256                 } else {
 257                         ip->flags |= BTRFS_INODE_NODATACOW;
 258                 }
 259         } else {
 260                 /*
 261                  * Revert back under same assuptions as above
 262                  */
 263                 if (S_ISREG(mode)) {
 264                         if (inode->i_size == 0)
 265                                 ip->flags &= ~(BTRFS_INODE_NODATACOW
 266                                              | BTRFS_INODE_NODATASUM);
 267                 } else {
 268                         ip->flags &= ~BTRFS_INODE_NODATACOW;
 269                 }
 270         }
 271
 272         /*
 273          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
 274          * flag may be changed automatically if compression code won't make
 275          * things smaller.
 276          */
 277         if (flags & FS_NOCOMP_FL) {
 278                 ip->flags &= ~BTRFS_INODE_COMPRESS;
 279                 ip->flags |= BTRFS_INODE_NOCOMPRESS;
 280         } else if (flags & FS_COMPR_FL) {
 281                 ip->flags |= BTRFS_INODE_COMPRESS;
 282                 ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 283         } else {
 284                 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
 285         }
 286
 287         trans = btrfs_start_transaction(root, 1);
 288         if (IS_ERR(trans)) {
 289                 ret = PTR_ERR(trans);
 290                 goto out_drop;
 291         }
 292
 293         btrfs_update_iflags(inode);
 294         inode_inc_iversion(inode);
 295         inode->i_ctime = CURRENT_TIME;
 296         ret = btrfs_update_inode(trans, root, inode);
 297
 298         btrfs_end_transaction(trans, root);
 299  out_drop:
 300         if (ret) {
 301                 ip->flags = ip_oldflags;
 302                 inode->i_flags = i_oldflags;
 303         }
 304
 305  out_unlock:
 306         mutex_unlock(&inode->i_mutex);
 307         mnt_drop_write_file(file);
 308         return ret;
 309 }
 310
 311 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 312 {
 313         struct inode *inode = file_inode(file);
 314
 315         return put_user(inode->i_generation, arg);
 316 }
 317
 318 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 319 {
 320         struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
 321         struct btrfs_device *device;
 322         struct request_queue *q;
 323         struct fstrim_range range;
 324         u64 minlen = ULLONG_MAX;
 325         u64 num_devices = 0;
 326         u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
 327         int ret;
 328
 329         if (!capable(CAP_SYS_ADMIN))
 330                 return -EPERM;
 331
 332         rcu_read_lock();
 333         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
 334                                 dev_list) {
 335                 if (!device->bdev)
 336                         continue;
 337                 q = bdev_get_queue(device->bdev);
 338                 if (blk_queue_discard(q)) {
 339                         num_devices++;
 340                         minlen = min((u64)q->limits.discard_granularity,
 341                                      minlen);
 342                 }
 343         }
 344         rcu_read_unlock();
 345
 346         if (!num_devices)
 347                 return -EOPNOTSUPP;
 348         if (copy_from_user(&range, arg, sizeof(range)))
 349                 return -EFAULT;
 350         if (range.start > total_bytes ||
 351             range.len < fs_info->sb->s_blocksize)
 352                 return -EINVAL;
 353
 354         range.len = min(range.len, total_bytes - range.start);
 355         range.minlen = max(range.minlen, minlen);
 356         ret = btrfs_trim_fs(fs_info->tree_root, &range);
 357         if (ret < 0)
 358                 return ret;
 359
 360         if (copy_to_user(arg, &range, sizeof(range)))
 361                 return -EFAULT;
 362
 363         return 0;
 364 }
 365
 366 static noinline int create_subvol(struct btrfs_root *root,
 367                                   struct dentry *dentry,
 368                                   char *name, int namelen,
 369                                   u64 *async_transid,
 370                                   struct btrfs_qgroup_inherit **inherit)
 371 {
 372         struct btrfs_trans_handle *trans;
 373         struct btrfs_key key;
 374         struct btrfs_root_item root_item;
 375         struct btrfs_inode_item *inode_item;
 376         struct extent_buffer *leaf;
 377         struct btrfs_root *new_root;
 378         struct dentry *parent = dentry->d_parent;
 379         struct inode *dir;
 380         struct timespec cur_time = CURRENT_TIME;
 381         int ret;
 382         int err;
 383         u64 objectid;
 384         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 385         u64 index = 0;
 386         uuid_le new_uuid;
 387
 388         ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
 389         if (ret)
 390                 return ret;
 391
 392         dir = parent->d_inode;
 393
 394         /*
 395          * 1 - inode item
 396          * 2 - refs
 397          * 1 - root item
 398          * 2 - dir items
 399          */
 400         trans = btrfs_start_transaction(root, 6);
 401         if (IS_ERR(trans))
 402                 return PTR_ERR(trans);
 403
 404         ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid,
 405                                    inherit ? *inherit : NULL);
 406         if (ret)
 407                 goto fail;
 408
 409         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 410                                       0, objectid, NULL, 0, 0, 0);
 411         if (IS_ERR(leaf)) {
 412                 ret = PTR_ERR(leaf);
 413                 goto fail;
 414         }
 415
 416         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 417         btrfs_set_header_bytenr(leaf, leaf->start);
 418         btrfs_set_header_generation(leaf, trans->transid);
 419         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 420         btrfs_set_header_owner(leaf, objectid);
 421
 422         write_extent_buffer(leaf, root->fs_info->fsid,
 423                             (unsigned long)btrfs_header_fsid(leaf),
 424                             BTRFS_FSID_SIZE);
 425         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 426                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 427                             BTRFS_UUID_SIZE);
 428         btrfs_mark_buffer_dirty(leaf);
 429
 430         memset(&root_item, 0, sizeof(root_item));
 431
 432         inode_item = &root_item.inode;
 433         inode_item->generation = cpu_to_le64(1);
 434         inode_item->size = cpu_to_le64(3);
 435         inode_item->nlink = cpu_to_le32(1);
 436         inode_item->nbytes = cpu_to_le64(root->leafsize);
 437         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 438
 439         root_item.flags = 0;
 440         root_item.byte_limit = 0;
 441         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 442
 443         btrfs_set_root_bytenr(&root_item, leaf->start);
 444         btrfs_set_root_generation(&root_item, trans->transid);
 445         btrfs_set_root_level(&root_item, 0);
 446         btrfs_set_root_refs(&root_item, 1);
 447         btrfs_set_root_used(&root_item, leaf->len);
 448         btrfs_set_root_last_snapshot(&root_item, 0);
 449
 450         btrfs_set_root_generation_v2(&root_item,
 451                         btrfs_root_generation(&root_item));
 452         uuid_le_gen(&new_uuid);
 453         memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 454         root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
 455         root_item.otime.nsec = cpu_to_le32(cur_time.tv_nsec);
 456         root_item.ctime = root_item.otime;
 457         btrfs_set_root_ctransid(&root_item, trans->transid);
 458         btrfs_set_root_otransid(&root_item, trans->transid);
 459
 460         btrfs_tree_unlock(leaf);
 461         free_extent_buffer(leaf);
 462         leaf = NULL;
 463
 464         btrfs_set_root_dirid(&root_item, new_dirid);
 465
 466         key.objectid = objectid;
 467         key.offset = 0;
 468         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 469         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 470                                 &root_item);
 471         if (ret)
 472                 goto fail;
 473
 474         key.offset = (u64)-1;
 475         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 476         if (IS_ERR(new_root)) {
 477                 btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
 478                 ret = PTR_ERR(new_root);
 479                 goto fail;
 480         }
 481
 482         btrfs_record_root_in_trans(trans, new_root);
 483
 484         ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
 485         if (ret) {
 486                 /* We potentially lose an unused inode item here */
 487                 btrfs_abort_transaction(trans, root, ret);
 488                 goto fail;
 489         }
 490
 491         /*
 492          * insert the directory item
 493          */
 494         ret = btrfs_set_inode_index(dir, &index);
 495         if (ret) {
 496                 btrfs_abort_transaction(trans, root, ret);
 497                 goto fail;
 498         }
 499
 500         ret = btrfs_insert_dir_item(trans, root,
 501                                     name, namelen, dir, &key,
 502                                     BTRFS_FT_DIR, index);
 503         if (ret) {
 504                 btrfs_abort_transaction(trans, root, ret);
 505                 goto fail;
 506         }
 507
 508         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 509         ret = btrfs_update_inode(trans, root, dir);
 510         BUG_ON(ret);
 511
 512         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 513                                  objectid, root->root_key.objectid,
 514                                  btrfs_ino(dir), index, name, namelen);
 515
 516         BUG_ON(ret);
 517
 518 fail:
 519         if (async_transid) {
 520                 *async_transid = trans->transid;
 521                 err = btrfs_commit_transaction_async(trans, root, 1);
 522         } else {
 523                 err = btrfs_commit_transaction(trans, root);
 524         }
 525         if (err && !ret)
 526                 ret = err;
 527
 528         if (!ret)
 529                 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 530
 531         return ret;
 532 }
 533
 534 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 535                            char *name, int namelen, u64 *async_transid,
 536                            bool readonly, struct btrfs_qgroup_inherit **inherit)
 537 {
 538         struct inode *inode;
 539         struct btrfs_pending_snapshot *pending_snapshot;
 540         struct btrfs_trans_handle *trans;
 541         int ret;
 542
 543         if (!root->ref_cows)
 544                 return -EINVAL;
 545
 546         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 547         if (!pending_snapshot)
 548                 return -ENOMEM;
 549
 550         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
 551                              BTRFS_BLOCK_RSV_TEMP);
 552         pending_snapshot->dentry = dentry;
 553         pending_snapshot->root = root;
 554         pending_snapshot->readonly = readonly;
 555         if (inherit) {
 556                 pending_snapshot->inherit = *inherit;
 557                 *inherit = NULL;        /* take responsibility to free it */
 558         }
 559
 560         trans = btrfs_start_transaction(root->fs_info->extent_root, 6);
 561         if (IS_ERR(trans)) {
 562                 ret = PTR_ERR(trans);
 563                 goto fail;
 564         }
 565
 566         ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
 567         BUG_ON(ret);
 568
 569         spin_lock(&root->fs_info->trans_lock);
 570         list_add(&pending_snapshot->list,
 571                  &trans->transaction->pending_snapshots);
 572         spin_unlock(&root->fs_info->trans_lock);
 573         if (async_transid) {
 574                 *async_transid = trans->transid;
 575                 ret = btrfs_commit_transaction_async(trans,
 576                                      root->fs_info->extent_root, 1);
 577         } else {
 578                 ret = btrfs_commit_transaction(trans,
 579                                                root->fs_info->extent_root);
 580         }
 581         if (ret) {
 582                 /* cleanup_transaction has freed this for us */
 583                 if (trans->aborted)
 584                         pending_snapshot = NULL;
 585                 goto fail;
 586         }
 587
 588         ret = pending_snapshot->error;
 589         if (ret)
 590                 goto fail;
 591
 592         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
 593         if (ret)
 594                 goto fail;
 595
 596         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 597         if (IS_ERR(inode)) {
 598                 ret = PTR_ERR(inode);
 599                 goto fail;
 600         }
 601         BUG_ON(!inode);
 602         d_instantiate(dentry, inode);
 603         ret = 0;
 604 fail:
 605         kfree(pending_snapshot);
 606         return ret;
 607 }
 608
 609 /*  copy of check_sticky in fs/namei.c()
 610 * It's inline, so penalty for filesystems that don't use sticky bit is
 611 * minimal.
 612 */
 613 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
 614 {
 615         kuid_t fsuid = current_fsuid();
 616
 617         if (!(dir->i_mode & S_ISVTX))
 618                 return 0;
 619         if (uid_eq(inode->i_uid, fsuid))
 620                 return 0;
 621         if (uid_eq(dir->i_uid, fsuid))
 622                 return 0;
 623         return !capable(CAP_FOWNER);
 624 }
 625
 626 /*  copy of may_delete in fs/namei.c()
 627  *      Check whether we can remove a link victim from directory dir, check
 628  *  whether the type of victim is right.
 629  *  1. We can't do it if dir is read-only (done in permission())
 630  *  2. We should have write and exec permissions on dir
 631  *  3. We can't remove anything from append-only dir
 632  *  4. We can't do anything with immutable dir (done in permission())
 633  *  5. If the sticky bit on dir is set we should either
 634  *      a. be owner of dir, or
 635  *      b. be owner of victim, or
 636  *      c. have CAP_FOWNER capability
 637  *  6. If the victim is append-only or immutable we can't do antyhing with
 638  *     links pointing to it.
 639  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
 640  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
 641  *  9. We can't remove a root or mountpoint.
 642  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
 643  *     nfs_async_unlink().
 644  */
 645
 646 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
 647 {
 648         int error;
 649
 650         if (!victim->d_inode)
 651                 return -ENOENT;
 652
 653         BUG_ON(victim->d_parent->d_inode != dir);
 654         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
 655
 656         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
 657         if (error)
 658                 return error;
 659         if (IS_APPEND(dir))
 660                 return -EPERM;
 661         if (btrfs_check_sticky(dir, victim->d_inode)||
 662                 IS_APPEND(victim->d_inode)||
 663             IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
 664                 return -EPERM;
 665         if (isdir) {
 666                 if (!S_ISDIR(victim->d_inode->i_mode))
 667                         return -ENOTDIR;
 668                 if (IS_ROOT(victim))
 669                         return -EBUSY;
 670         } else if (S_ISDIR(victim->d_inode->i_mode))
 671                 return -EISDIR;
 672         if (IS_DEADDIR(dir))
 673                 return -ENOENT;
 674         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
 675                 return -EBUSY;
 676         return 0;
 677 }
 678
 679 /* copy of may_create in fs/namei.c() */
 680 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 681 {
 682         if (child->d_inode)
 683                 return -EEXIST;
 684         if (IS_DEADDIR(dir))
 685                 return -ENOENT;
 686         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 687 }
 688
 689 /*
 690  * Create a new subvolume below @parent.  This is largely modeled after
 691  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 692  * inside this filesystem so it's quite a bit simpler.
 693  */
 694 static noinline int btrfs_mksubvol(struct path *parent,
 695                                    char *name, int namelen,
 696                                    struct btrfs_root *snap_src,
 697                                    u64 *async_transid, bool readonly,
 698                                    struct btrfs_qgroup_inherit **inherit)
 699 {
 700         struct inode *dir  = parent->dentry->d_inode;
 701         struct dentry *dentry;
 702         int error;
 703
 704         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 705
 706         dentry = lookup_one_len(name, parent->dentry, namelen);
 707         error = PTR_ERR(dentry);
 708         if (IS_ERR(dentry))
 709                 goto out_unlock;
 710
 711         error = -EEXIST;
 712         if (dentry->d_inode)
 713                 goto out_dput;
 714
 715         error = btrfs_may_create(dir, dentry);
 716         if (error)
 717                 goto out_dput;
 718
 719         /*
 720          * even if this name doesn't exist, we may get hash collisions.
 721          * check for them now when we can safely fail
 722          */
 723         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
 724                                                dir->i_ino, name,
 725                                                namelen);
 726         if (error)
 727                 goto out_dput;
 728
 729         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 730
 731         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 732                 goto out_up_read;
 733
 734         if (snap_src) {
 735                 error = create_snapshot(snap_src, dentry, name, namelen,
 736                                         async_transid, readonly, inherit);
 737         } else {
 738                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 739                                       name, namelen, async_transid, inherit);
 740         }
 741         if (!error)
 742                 fsnotify_mkdir(dir, dentry);
 743 out_up_read:
 744         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 745 out_dput:
 746         dput(dentry);
 747 out_unlock:
 748         mutex_unlock(&dir->i_mutex);
 749         return error;
 750 }
 751
 752 /*
 753  * When we're defragging a range, we don't want to kick it off again
 754  * if it is really just waiting for delalloc to send it down.
 755  * If we find a nice big extent or delalloc range for the bytes in the
 756  * file you want to defrag, we return 0 to let you know to skip this
 757  * part of the file
 758  */
 759 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
 760 {
 761         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 762         struct extent_map *em = NULL;
 763         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 764         u64 end;
 765
 766         read_lock(&em_tree->lock);
 767         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 768         read_unlock(&em_tree->lock);
 769
 770         if (em) {
 771                 end = extent_map_end(em);
 772                 free_extent_map(em);
 773                 if (end - offset > thresh)
 774                         return 0;
 775         }
 776         /* if we already have a nice delalloc here, just stop */
 777         thresh /= 2;
 778         end = count_range_bits(io_tree, &offset, offset + thresh,
 779                                thresh, EXTENT_DELALLOC, 1);
 780         if (end >= thresh)
 781                 return 0;
 782         return 1;
 783 }
 784
 785 /*
 786  * helper function to walk through a file and find extents
 787  * newer than a specific transid, and smaller than thresh.
 788  *
 789  * This is used by the defragging code to find new and small
 790  * extents
 791  */
 792 static int find_new_extents(struct btrfs_root *root,
 793                             struct inode *inode, u64 newer_than,
 794                             u64 *off, int thresh)
 795 {
 796         struct btrfs_path *path;
 797         struct btrfs_key min_key;
 798         struct btrfs_key max_key;
 799         struct extent_buffer *leaf;
 800         struct btrfs_file_extent_item *extent;
 801         int type;
 802         int ret;
 803         u64 ino = btrfs_ino(inode);
 804
 805         path = btrfs_alloc_path();
 806         if (!path)
 807                 return -ENOMEM;
 808
 809         min_key.objectid = ino;
 810         min_key.type = BTRFS_EXTENT_DATA_KEY;
 811         min_key.offset = *off;
 812
 813         max_key.objectid = ino;
 814         max_key.type = (u8)-1;
 815         max_key.offset = (u64)-1;
 816
 817         path->keep_locks = 1;
 818
 819         while(1) {
 820                 ret = btrfs_search_forward(root, &min_key, &max_key,
 821                                            path, 0, newer_than);
 822                 if (ret != 0)
 823                         goto none;
 824                 if (min_key.objectid != ino)
 825                         goto none;
 826                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
 827                         goto none;
 828
 829                 leaf = path->nodes[0];
 830                 extent = btrfs_item_ptr(leaf, path->slots[0],
 831                                         struct btrfs_file_extent_item);
 832
 833                 type = btrfs_file_extent_type(leaf, extent);
 834                 if (type == BTRFS_FILE_EXTENT_REG &&
 835                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
 836                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
 837                         *off = min_key.offset;
 838                         btrfs_free_path(path);
 839                         return 0;
 840                 }
 841
 842                 if (min_key.offset == (u64)-1)
 843                         goto none;
 844
 845                 min_key.offset++;
 846                 btrfs_release_path(path);
 847         }
 848 none:
 849         btrfs_free_path(path);
 850         return -ENOENT;
 851 }
 852
 853 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 854 {
 855         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 856         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 857         struct extent_map *em;
 858         u64 len = PAGE_CACHE_SIZE;
 859
 860         /*
 861          * hopefully we have this extent in the tree already, try without
 862          * the full extent lock
 863          */
 864         read_lock(&em_tree->lock);
 865         em = lookup_extent_mapping(em_tree, start, len);
 866         read_unlock(&em_tree->lock);
 867
 868         if (!em) {
 869                 /* get the big lock and read metadata off disk */
 870                 lock_extent(io_tree, start, start + len - 1);
 871                 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
 872                 unlock_extent(io_tree, start, start + len - 1);
 873
 874                 if (IS_ERR(em))
 875                         return NULL;
 876         }
 877
 878         return em;
 879 }
 880
 881 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
 882 {
 883         struct extent_map *next;
 884         bool ret = true;
 885
 886         /* this is the last extent */
 887         if (em->start + em->len >= i_size_read(inode))
 888                 return false;
 889
 890         next = defrag_lookup_extent(inode, em->start + em->len);
 891         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
 892                 ret = false;
 893
 894         free_extent_map(next);
 895         return ret;
 896 }
 897
 898 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
 899                                u64 *last_len, u64 *skip, u64 *defrag_end,
 900                                int compress)
 901 {
 902         struct extent_map *em;
 903         int ret = 1;
 904         bool next_mergeable = true;
 905
 906         /*
 907          * make sure that once we start defragging an extent, we keep on
 908          * defragging it
 909          */
 910         if (start < *defrag_end)
 911                 return 1;
 912
 913         *skip = 0;
 914
 915         em = defrag_lookup_extent(inode, start);
 916         if (!em)
 917                 return 0;
 918
 919         /* this will cover holes, and inline extents */
 920         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 921                 ret = 0;
 922                 goto out;
 923         }
 924
 925         next_mergeable = defrag_check_next_extent(inode, em);
 926
 927         /*
 928          * we hit a real extent, if it is big or the next extent is not a
 929          * real extent, don't bother defragging it
 930          */
 931         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
 932             (em->len >= thresh || !next_mergeable))
 933                 ret = 0;
 934 out:
 935         /*
 936          * last_len ends up being a counter of how many bytes we've defragged.
 937          * every time we choose not to defrag an extent, we reset *last_len
 938          * so that the next tiny extent will force a defrag.
 939          *
 940          * The end result of this is that tiny extents before a single big
 941          * extent will force at least part of that big extent to be defragged.
 942          */
 943         if (ret) {
 944                 *defrag_end = extent_map_end(em);
 945         } else {
 946                 *last_len = 0;
 947                 *skip = extent_map_end(em);
 948                 *defrag_end = 0;
 949         }
 950
 951         free_extent_map(em);
 952         return ret;
 953 }
 954
 955 /*
 956  * it doesn't do much good to defrag one or two pages
 957  * at a time.  This pulls in a nice chunk of pages
 958  * to COW and defrag.
 959  *
 960  * It also makes sure the delalloc code has enough
 961  * dirty data to avoid making new small extents as part
 962  * of the defrag
 963  *
 964  * It's a good idea to start RA on this range
 965  * before calling this.
 966  */
 967 static int cluster_pages_for_defrag(struct inode *inode,
 968                                     struct page **pages,
 969                                     unsigned long start_index,
 970                                     int num_pages)
 971 {
 972         unsigned long file_end;
 973         u64 isize = i_size_read(inode);
 974         u64 page_start;
 975         u64 page_end;
 976         u64 page_cnt;
 977         int ret;
 978         int i;
 979         int i_done;
 980         struct btrfs_ordered_extent *ordered;
 981         struct extent_state *cached_state = NULL;
 982         struct extent_io_tree *tree;
 983         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
 984
 985         file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
 986         if (!isize || start_index > file_end)
 987                 return 0;
 988
 989         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
 990
 991         ret = btrfs_delalloc_reserve_space(inode,
 992                                            page_cnt << PAGE_CACHE_SHIFT);
 993         if (ret)
 994                 return ret;
 995         i_done = 0;
 996         tree = &BTRFS_I(inode)->io_tree;
 997
 998         /* step one, lock all the pages */
 999         for (i = 0; i < page_cnt; i++) {
1000                 struct page *page;
1001 again:
1002                 page = find_or_create_page(inode->i_mapping,
1003                                            start_index + i, mask);
1004                 if (!page)
1005                         break;
1006
1007                 page_start = page_offset(page);
1008                 page_end = page_start + PAGE_CACHE_SIZE - 1;
1009                 while (1) {
1010                         lock_extent(tree, page_start, page_end);
1011                         ordered = btrfs_lookup_ordered_extent(inode,
1012                                                               page_start);
1013                         unlock_extent(tree, page_start, page_end);
1014                         if (!ordered)
1015                                 break;
1016
1017                         unlock_page(page);
1018                         btrfs_start_ordered_extent(inode, ordered, 1);
1019                         btrfs_put_ordered_extent(ordered);
1020                         lock_page(page);
1021                         /*
1022                          * we unlocked the page above, so we need check if
1023                          * it was released or not.
1024                          */
1025                         if (page->mapping != inode->i_mapping) {
1026                                 unlock_page(page);
1027                                 page_cache_release(page);
1028                                 goto again;
1029                         }
1030                 }
1031
1032                 if (!PageUptodate(page)) {
1033                         btrfs_readpage(NULL, page);
1034                         lock_page(page);
1035                         if (!PageUptodate(page)) {
1036                                 unlock_page(page);
1037                                 page_cache_release(page);
1038                                 ret = -EIO;
1039                                 break;
1040                         }
1041                 }
1042
1043                 if (page->mapping != inode->i_mapping) {
1044                         unlock_page(page);
1045                         page_cache_release(page);
1046                         goto again;
1047                 }
1048
1049                 pages[i] = page;
1050                 i_done++;
1051         }
1052         if (!i_done || ret)
1053                 goto out;
1054
1055         if (!(inode->i_sb->s_flags & MS_ACTIVE))
1056                 goto out;
1057
1058         /*
1059          * so now we have a nice long stream of locked
1060          * and up to date pages, lets wait on them
1061          */
1062         for (i = 0; i < i_done; i++)
1063                 wait_on_page_writeback(pages[i]);
1064
1065         page_start = page_offset(pages[0]);
1066         page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1067
1068         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1069                          page_start, page_end - 1, 0, &cached_state);
1070         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1071                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1072                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1073                           &cached_state, GFP_NOFS);
1074
1075         if (i_done != page_cnt) {
1076                 spin_lock(&BTRFS_I(inode)->lock);
1077                 BTRFS_I(inode)->outstanding_extents++;
1078                 spin_unlock(&BTRFS_I(inode)->lock);
1079                 btrfs_delalloc_release_space(inode,
1080                                      (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1081         }
1082
1083
1084         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1085                           &cached_state, GFP_NOFS);
1086
1087         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1088                              page_start, page_end - 1, &cached_state,
1089                              GFP_NOFS);
1090
1091         for (i = 0; i < i_done; i++) {
1092                 clear_page_dirty_for_io(pages[i]);
1093                 ClearPageChecked(pages[i]);
1094                 set_page_extent_mapped(pages[i]);
1095                 set_page_dirty(pages[i]);
1096                 unlock_page(pages[i]);
1097                 page_cache_release(pages[i]);
1098         }
1099         return i_done;
1100 out:
1101         for (i = 0; i < i_done; i++) {
1102                 unlock_page(pages[i]);
1103                 page_cache_release(pages[i]);
1104         }
1105         btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1106         return ret;
1107
1108 }
1109
1110 int btrfs_defrag_file(struct inode *inode, struct file *file,
1111                       struct btrfs_ioctl_defrag_range_args *range,
1112                       u64 newer_than, unsigned long max_to_defrag)
1113 {
1114         struct btrfs_root *root = BTRFS_I(inode)->root;
1115         struct file_ra_state *ra = NULL;
1116         unsigned long last_index;
1117         u64 isize = i_size_read(inode);
1118         u64 last_len = 0;
1119         u64 skip = 0;
1120         u64 defrag_end = 0;
1121         u64 newer_off = range->start;
1122         unsigned long i;
1123         unsigned long ra_index = 0;
1124         int ret;
1125         int defrag_count = 0;
1126         int compress_type = BTRFS_COMPRESS_ZLIB;
1127         int extent_thresh = range->extent_thresh;
1128         int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1129         int cluster = max_cluster;
1130         u64 new_align = ~((u64)128 * 1024 - 1);
1131         struct page **pages = NULL;
1132
1133         if (extent_thresh == 0)
1134                 extent_thresh = 256 * 1024;
1135
1136         if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1137                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1138                         return -EINVAL;
1139                 if (range->compress_type)
1140                         compress_type = range->compress_type;
1141         }
1142
1143         if (isize == 0)
1144                 return 0;
1145
1146         /*
1147          * if we were not given a file, allocate a readahead
1148          * context
1149          */
1150         if (!file) {
1151                 ra = kzalloc(sizeof(*ra), GFP_NOFS);
1152                 if (!ra)
1153                         return -ENOMEM;
1154                 file_ra_state_init(ra, inode->i_mapping);
1155         } else {
1156                 ra = &file->f_ra;
1157         }
1158
1159         pages = kmalloc(sizeof(struct page *) * max_cluster,
1160                         GFP_NOFS);
1161         if (!pages) {
1162                 ret = -ENOMEM;
1163                 goto out_ra;
1164         }
1165
1166         /* find the last page to defrag */
1167         if (range->start + range->len > range->start) {
1168                 last_index = min_t(u64, isize - 1,
1169                          range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1170         } else {
1171                 last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1172         }
1173
1174         if (newer_than) {
1175                 ret = find_new_extents(root, inode, newer_than,
1176                                        &newer_off, 64 * 1024);
1177                 if (!ret) {
1178                         range->start = newer_off;
1179                         /*
1180                          * we always align our defrag to help keep
1181                          * the extents in the file evenly spaced
1182                          */
1183                         i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1184                 } else
1185                         goto out_ra;
1186         } else {
1187                 i = range->start >> PAGE_CACHE_SHIFT;
1188         }
1189         if (!max_to_defrag)
1190                 max_to_defrag = last_index + 1;
1191
1192         /*
1193          * make writeback starts from i, so the defrag range can be
1194          * written sequentially.
1195          */
1196         if (i < inode->i_mapping->writeback_index)
1197                 inode->i_mapping->writeback_index = i;
1198
1199         while (i <= last_index && defrag_count < max_to_defrag &&
1200                (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1201                 PAGE_CACHE_SHIFT)) {
1202                 /*
1203                  * make sure we stop running if someone unmounts
1204                  * the FS
1205                  */
1206                 if (!(inode->i_sb->s_flags & MS_ACTIVE))
1207                         break;
1208
1209                 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1210                                          extent_thresh, &last_len, &skip,
1211                                          &defrag_end, range->flags &
1212                                          BTRFS_DEFRAG_RANGE_COMPRESS)) {
1213                         unsigned long next;
1214                         /*
1215                          * the should_defrag function tells us how much to skip
1216                          * bump our counter by the suggested amount
1217                          */
1218                         next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1219                         i = max(i + 1, next);
1220                         continue;
1221                 }
1222
1223                 if (!newer_than) {
1224                         cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1225                                    PAGE_CACHE_SHIFT) - i;
1226                         cluster = min(cluster, max_cluster);
1227                 } else {
1228                         cluster = max_cluster;
1229                 }
1230
1231                 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1232                         BTRFS_I(inode)->force_compress = compress_type;
1233
1234                 if (i + cluster > ra_index) {
1235                         ra_index = max(i, ra_index);
1236                         btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1237                                        cluster);
1238                         ra_index += max_cluster;
1239                 }
1240
1241                 mutex_lock(&inode->i_mutex);
1242                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1243                 if (ret < 0) {
1244                         mutex_unlock(&inode->i_mutex);
1245                         goto out_ra;
1246                 }
1247
1248                 defrag_count += ret;
1249                 balance_dirty_pages_ratelimited(inode->i_mapping);
1250                 mutex_unlock(&inode->i_mutex);
1251
1252                 if (newer_than) {
1253                         if (newer_off == (u64)-1)
1254                                 break;
1255
1256                         if (ret > 0)
1257                                 i += ret;
1258
1259                         newer_off = max(newer_off + 1,
1260                                         (u64)i << PAGE_CACHE_SHIFT);
1261
1262                         ret = find_new_extents(root, inode,
1263                                                newer_than, &newer_off,
1264                                                64 * 1024);
1265                         if (!ret) {
1266                                 range->start = newer_off;
1267                                 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1268                         } else {
1269                                 break;
1270                         }
1271                 } else {
1272                         if (ret > 0) {
1273                                 i += ret;
1274                                 last_len += ret << PAGE_CACHE_SHIFT;
1275                         } else {
1276                                 i++;
1277                                 last_len = 0;
1278                         }
1279                 }
1280         }
1281
1282         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1283                 filemap_flush(inode->i_mapping);
1284
1285         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1286                 /* the filemap_flush will queue IO into the worker threads, but
1287                  * we have to make sure the IO is actually started and that
1288                  * ordered extents get created before we return
1289                  */
1290                 atomic_inc(&root->fs_info->async_submit_draining);
1291                 while (atomic_read(&root->fs_info->nr_async_submits) ||
1292                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1293                         wait_event(root->fs_info->async_submit_wait,
1294                            (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1295                             atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1296                 }
1297                 atomic_dec(&root->fs_info->async_submit_draining);
1298
1299                 mutex_lock(&inode->i_mutex);
1300                 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1301                 mutex_unlock(&inode->i_mutex);
1302         }
1303
1304         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1305                 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1306         }
1307
1308         ret = defrag_count;
1309
1310 out_ra:
1311         if (!file)
1312                 kfree(ra);
1313         kfree(pages);
1314         return ret;
1315 }
1316
1317 static noinline int btrfs_ioctl_resize(struct file *file,
1318                                         void __user *arg)
1319 {
1320         u64 new_size;
1321         u64 old_size;
1322         u64 devid = 1;
1323         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
1324         struct btrfs_ioctl_vol_args *vol_args;
1325         struct btrfs_trans_handle *trans;
1326         struct btrfs_device *device = NULL;
1327         char *sizestr;
1328         char *devstr = NULL;
1329         int ret = 0;
1330         int mod = 0;
1331
1332         if (root->fs_info->sb->s_flags & MS_RDONLY)
1333                 return -EROFS;
1334
1335         if (!capable(CAP_SYS_ADMIN))
1336                 return -EPERM;
1337
1338         ret = mnt_want_write_file(file);
1339         if (ret)
1340                 return ret;
1341
1342         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1343                         1)) {
1344                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
1345                 mnt_drop_write_file(file);
1346                 return -EINVAL;
1347         }
1348
1349         mutex_lock(&root->fs_info->volume_mutex);
1350         vol_args = memdup_user(arg, sizeof(*vol_args));
1351         if (IS_ERR(vol_args)) {
1352                 ret = PTR_ERR(vol_args);
1353                 goto out;
1354         }
1355
1356         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1357
1358         sizestr = vol_args->name;
1359         devstr = strchr(sizestr, ':');
1360         if (devstr) {
1361                 char *end;
1362                 sizestr = devstr + 1;
1363                 *devstr = '\0';
1364                 devstr = vol_args->name;
1365                 devid = simple_strtoull(devstr, &end, 10);
1366                 printk(KERN_INFO "btrfs: resizing devid %llu\n",
1367                        (unsigned long long)devid);
1368         }
1369
1370         device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1371         if (!device) {
1372                 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1373                        (unsigned long long)devid);
1374                 ret = -EINVAL;
1375                 goto out_free;
1376         }
1377
1378         if (!device->writeable) {
1379                 printk(KERN_INFO "btrfs: resizer unable to apply on "
1380                        "readonly device %llu\n",
1381                        (unsigned long long)devid);
1382                 ret = -EINVAL;
1383                 goto out_free;
1384         }
1385
1386         if (!strcmp(sizestr, "max"))
1387                 new_size = device->bdev->bd_inode->i_size;
1388         else {
1389                 if (sizestr[0] == '-') {
1390                         mod = -1;
1391                         sizestr++;
1392                 } else if (sizestr[0] == '+') {
1393                         mod = 1;
1394                         sizestr++;
1395                 }
1396                 new_size = memparse(sizestr, NULL);
1397                 if (new_size == 0) {
1398                         ret = -EINVAL;
1399                         goto out_free;
1400                 }
1401         }
1402
1403         if (device->is_tgtdev_for_dev_replace) {
1404                 ret = -EINVAL;
1405                 goto out_free;
1406         }
1407
1408         old_size = device->total_bytes;
1409
1410         if (mod < 0) {
1411                 if (new_size > old_size) {
1412                         ret = -EINVAL;
1413                         goto out_free;
1414                 }
1415                 new_size = old_size - new_size;
1416         } else if (mod > 0) {
1417                 new_size = old_size + new_size;
1418         }
1419
1420         if (new_size < 256 * 1024 * 1024) {
1421                 ret = -EINVAL;
1422                 goto out_free;
1423         }
1424         if (new_size > device->bdev->bd_inode->i_size) {
1425                 ret = -EFBIG;
1426                 goto out_free;
1427         }
1428
1429         do_div(new_size, root->sectorsize);
1430         new_size *= root->sectorsize;
1431
1432         printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1433                       rcu_str_deref(device->name),
1434                       (unsigned long long)new_size);
1435
1436         if (new_size > old_size) {
1437                 trans = btrfs_start_transaction(root, 0);
1438                 if (IS_ERR(trans)) {
1439                         ret = PTR_ERR(trans);
1440                         goto out_free;
1441                 }
1442                 ret = btrfs_grow_device(trans, device, new_size);
1443                 btrfs_commit_transaction(trans, root);
1444         } else if (new_size < old_size) {
1445                 ret = btrfs_shrink_device(device, new_size);
1446         } /* equal, nothing need to do */
1447
1448 out_free:
1449         kfree(vol_args);
1450 out:
1451         mutex_unlock(&root->fs_info->volume_mutex);
1452         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1453         mnt_drop_write_file(file);
1454         return ret;
1455 }
1456
1457 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1458                                 char *name, unsigned long fd, int subvol,
1459                                 u64 *transid, bool readonly,
1460                                 struct btrfs_qgroup_inherit **inherit)
1461 {
1462         int namelen;
1463         int ret = 0;
1464
1465         ret = mnt_want_write_file(file);
1466         if (ret)
1467                 goto out;
1468
1469         namelen = strlen(name);
1470         if (strchr(name, '/')) {
1471                 ret = -EINVAL;
1472                 goto out_drop_write;
1473         }
1474
1475         if (name[0] == '.' &&
1476            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1477                 ret = -EEXIST;
1478                 goto out_drop_write;
1479         }
1480
1481         if (subvol) {
1482                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1483                                      NULL, transid, readonly, inherit);
1484         } else {
1485                 struct fd src = fdget(fd);
1486                 struct inode *src_inode;
1487                 if (!src.file) {
1488                         ret = -EINVAL;
1489                         goto out_drop_write;
1490                 }
1491
1492                 src_inode = file_inode(src.file);
1493                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1494                         printk(KERN_INFO "btrfs: Snapshot src from "
1495                                "another FS\n");
1496                         ret = -EINVAL;
1497                 } else {
1498                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1499                                              BTRFS_I(src_inode)->root,
1500                                              transid, readonly, inherit);
1501                 }
1502                 fdput(src);
1503         }
1504 out_drop_write:
1505         mnt_drop_write_file(file);
1506 out:
1507         return ret;
1508 }
1509
1510 static noinline int btrfs_ioctl_snap_create(struct file *file,
1511                                             void __user *arg, int subvol)
1512 {
1513         struct btrfs_ioctl_vol_args *vol_args;
1514         int ret;
1515
1516         vol_args = memdup_user(arg, sizeof(*vol_args));
1517         if (IS_ERR(vol_args))
1518                 return PTR_ERR(vol_args);
1519         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1520
1521         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1522                                               vol_args->fd, subvol,
1523                                               NULL, false, NULL);
1524
1525         kfree(vol_args);
1526         return ret;
1527 }
1528
1529 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1530                                                void __user *arg, int subvol)
1531 {
1532         struct btrfs_ioctl_vol_args_v2 *vol_args;
1533         int ret;
1534         u64 transid = 0;
1535         u64 *ptr = NULL;
1536         bool readonly = false;
1537         struct btrfs_qgroup_inherit *inherit = NULL;
1538
1539         vol_args = memdup_user(arg, sizeof(*vol_args));
1540         if (IS_ERR(vol_args))
1541                 return PTR_ERR(vol_args);
1542         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1543
1544         if (vol_args->flags &
1545             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1546               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1547                 ret = -EOPNOTSUPP;
1548                 goto out;
1549         }
1550
1551         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1552                 ptr = &transid;
1553         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1554                 readonly = true;
1555         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1556                 if (vol_args->size > PAGE_CACHE_SIZE) {
1557                         ret = -EINVAL;
1558                         goto out;
1559                 }
1560                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1561                 if (IS_ERR(inherit)) {
1562                         ret = PTR_ERR(inherit);
1563                         goto out;
1564                 }
1565         }
1566
1567         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1568                                               vol_args->fd, subvol, ptr,
1569                                               readonly, &inherit);
1570
1571         if (ret == 0 && ptr &&
1572             copy_to_user(arg +
1573                          offsetof(struct btrfs_ioctl_vol_args_v2,
1574                                   transid), ptr, sizeof(*ptr)))
1575                 ret = -EFAULT;
1576 out:
1577         kfree(vol_args);
1578         kfree(inherit);
1579         return ret;
1580 }
1581
1582 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1583                                                 void __user *arg)
1584 {
1585         struct inode *inode = file_inode(file);
1586         struct btrfs_root *root = BTRFS_I(inode)->root;
1587         int ret = 0;
1588         u64 flags = 0;
1589
1590         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1591                 return -EINVAL;
1592
1593         down_read(&root->fs_info->subvol_sem);
1594         if (btrfs_root_readonly(root))
1595                 flags |= BTRFS_SUBVOL_RDONLY;
1596         up_read(&root->fs_info->subvol_sem);
1597
1598         if (copy_to_user(arg, &flags, sizeof(flags)))
1599                 ret = -EFAULT;
1600
1601         return ret;
1602 }
1603
1604 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1605                                               void __user *arg)
1606 {
1607         struct inode *inode = file_inode(file);
1608         struct btrfs_root *root = BTRFS_I(inode)->root;
1609         struct btrfs_trans_handle *trans;
1610         u64 root_flags;
1611         u64 flags;
1612         int ret = 0;
1613
1614         ret = mnt_want_write_file(file);
1615         if (ret)
1616                 goto out;
1617
1618         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1619                 ret = -EINVAL;
1620                 goto out_drop_write;
1621         }
1622
1623         if (copy_from_user(&flags, arg, sizeof(flags))) {
1624                 ret = -EFAULT;
1625                 goto out_drop_write;
1626         }
1627
1628         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1629                 ret = -EINVAL;
1630                 goto out_drop_write;
1631         }
1632
1633         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1634                 ret = -EOPNOTSUPP;
1635                 goto out_drop_write;
1636         }
1637
1638         if (!inode_owner_or_capable(inode)) {
1639                 ret = -EACCES;
1640                 goto out_drop_write;
1641         }
1642
1643         down_write(&root->fs_info->subvol_sem);
1644
1645         /* nothing to do */
1646         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1647                 goto out_drop_sem;
1648
1649         root_flags = btrfs_root_flags(&root->root_item);
1650         if (flags & BTRFS_SUBVOL_RDONLY)
1651                 btrfs_set_root_flags(&root->root_item,
1652                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1653         else
1654                 btrfs_set_root_flags(&root->root_item,
1655                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1656
1657         trans = btrfs_start_transaction(root, 1);
1658         if (IS_ERR(trans)) {
1659                 ret = PTR_ERR(trans);
1660                 goto out_reset;
1661         }
1662
1663         ret = btrfs_update_root(trans, root->fs_info->tree_root,
1664                                 &root->root_key, &root->root_item);
1665
1666         btrfs_commit_transaction(trans, root);
1667 out_reset:
1668         if (ret)
1669                 btrfs_set_root_flags(&root->root_item, root_flags);
1670 out_drop_sem:
1671         up_write(&root->fs_info->subvol_sem);
1672 out_drop_write:
1673         mnt_drop_write_file(file);
1674 out:
1675         return ret;
1676 }
1677
1678 /*
1679  * helper to check if the subvolume references other subvolumes
1680  */
1681 static noinline int may_destroy_subvol(struct btrfs_root *root)
1682 {
1683         struct btrfs_path *path;
1684         struct btrfs_key key;
1685         int ret;
1686
1687         path = btrfs_alloc_path();
1688         if (!path)
1689                 return -ENOMEM;
1690
1691         key.objectid = root->root_key.objectid;
1692         key.type = BTRFS_ROOT_REF_KEY;
1693         key.offset = (u64)-1;
1694
1695         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1696                                 &key, path, 0, 0);
1697         if (ret < 0)
1698                 goto out;
1699         BUG_ON(ret == 0);
1700
1701         ret = 0;
1702         if (path->slots[0] > 0) {
1703                 path->slots[0]--;
1704                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1705                 if (key.objectid == root->root_key.objectid &&
1706                     key.type == BTRFS_ROOT_REF_KEY)
1707                         ret = -ENOTEMPTY;
1708         }
1709 out:
1710         btrfs_free_path(path);
1711         return ret;
1712 }
1713
1714 static noinline int key_in_sk(struct btrfs_key *key,
1715                               struct btrfs_ioctl_search_key *sk)
1716 {
1717         struct btrfs_key test;
1718         int ret;
1719
1720         test.objectid = sk->min_objectid;
1721         test.type = sk->min_type;
1722         test.offset = sk->min_offset;
1723
1724         ret = btrfs_comp_cpu_keys(key, &test);
1725         if (ret < 0)
1726                 return 0;
1727
1728         test.objectid = sk->max_objectid;
1729         test.type = sk->max_type;
1730         test.offset = sk->max_offset;
1731
1732         ret = btrfs_comp_cpu_keys(key, &test);
1733         if (ret > 0)
1734                 return 0;
1735         return 1;
1736 }
1737
1738 static noinline int copy_to_sk(struct btrfs_root *root,
1739                                struct btrfs_path *path,
1740                                struct btrfs_key *key,
1741                                struct btrfs_ioctl_search_key *sk,
1742                                char *buf,
1743                                unsigned long *sk_offset,
1744                                int *num_found)
1745 {
1746         u64 found_transid;
1747         struct extent_buffer *leaf;
1748         struct btrfs_ioctl_search_header sh;
1749         unsigned long item_off;
1750         unsigned long item_len;
1751         int nritems;
1752         int i;
1753         int slot;
1754         int ret = 0;
1755
1756         leaf = path->nodes[0];
1757         slot = path->slots[0];
1758         nritems = btrfs_header_nritems(leaf);
1759
1760         if (btrfs_header_generation(leaf) > sk->max_transid) {
1761                 i = nritems;
1762                 goto advance_key;
1763         }
1764         found_transid = btrfs_header_generation(leaf);
1765
1766         for (i = slot; i < nritems; i++) {
1767                 item_off = btrfs_item_ptr_offset(leaf, i);
1768                 item_len = btrfs_item_size_nr(leaf, i);
1769
1770                 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1771                         item_len = 0;
1772
1773                 if (sizeof(sh) + item_len + *sk_offset >
1774                     BTRFS_SEARCH_ARGS_BUFSIZE) {
1775                         ret = 1;
1776                         goto overflow;
1777                 }
1778
1779                 btrfs_item_key_to_cpu(leaf, key, i);
1780                 if (!key_in_sk(key, sk))
1781                         continue;
1782
1783                 sh.objectid = key->objectid;
1784                 sh.offset = key->offset;
1785                 sh.type = key->type;
1786                 sh.len = item_len;
1787                 sh.transid = found_transid;
1788
1789                 /* copy search result header */
1790                 memcpy(buf + *sk_offset, &sh, sizeof(sh));
1791                 *sk_offset += sizeof(sh);
1792
1793                 if (item_len) {
1794                         char *p = buf + *sk_offset;
1795                         /* copy the item */
1796                         read_extent_buffer(leaf, p,
1797                                            item_off, item_len);
1798                         *sk_offset += item_len;
1799                 }
1800                 (*num_found)++;
1801
1802                 if (*num_found >= sk->nr_items)
1803                         break;
1804         }
1805 advance_key:
1806         ret = 0;
1807         if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1808                 key->offset++;
1809         else if (key->type < (u8)-1 && key->type < sk->max_type) {
1810                 key->offset = 0;
1811                 key->type++;
1812         } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1813                 key->offset = 0;
1814                 key->type = 0;
1815                 key->objectid++;
1816         } else
1817                 ret = 1;
1818 overflow:
1819         return ret;
1820 }
1821
1822 static noinline int search_ioctl(struct inode *inode,
1823                                  struct btrfs_ioctl_search_args *args)
1824 {
1825         struct btrfs_root *root;
1826         struct btrfs_key key;
1827         struct btrfs_key max_key;
1828         struct btrfs_path *path;
1829         struct btrfs_ioctl_search_key *sk = &args->key;
1830         struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1831         int ret;
1832         int num_found = 0;
1833         unsigned long sk_offset = 0;
1834
1835         path = btrfs_alloc_path();
1836         if (!path)
1837                 return -ENOMEM;
1838
1839         if (sk->tree_id == 0) {
1840                 /* search the root of the inode that was passed */
1841                 root = BTRFS_I(inode)->root;
1842         } else {
1843                 key.objectid = sk->tree_id;
1844                 key.type = BTRFS_ROOT_ITEM_KEY;
1845                 key.offset = (u64)-1;
1846                 root = btrfs_read_fs_root_no_name(info, &key);
1847                 if (IS_ERR(root)) {
1848                         printk(KERN_ERR "could not find root %llu\n",
1849                                sk->tree_id);
1850                         btrfs_free_path(path);
1851                         return -ENOENT;
1852                 }
1853         }
1854
1855         key.objectid = sk->min_objectid;
1856         key.type = sk->min_type;
1857         key.offset = sk->min_offset;
1858
1859         max_key.objectid = sk->max_objectid;
1860         max_key.type = sk->max_type;
1861         max_key.offset = sk->max_offset;
1862
1863         path->keep_locks = 1;
1864
1865         while(1) {
1866                 ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1867                                            sk->min_transid);
1868                 if (ret != 0) {
1869                         if (ret > 0)
1870                                 ret = 0;
1871                         goto err;
1872                 }
1873                 ret = copy_to_sk(root, path, &key, sk, args->buf,
1874                                  &sk_offset, &num_found);
1875                 btrfs_release_path(path);
1876                 if (ret || num_found >= sk->nr_items)
1877                         break;
1878
1879         }
1880         ret = 0;
1881 err:
1882         sk->nr_items = num_found;
1883         btrfs_free_path(path);
1884         return ret;
1885 }
1886
1887 static noinline int btrfs_ioctl_tree_search(struct file *file,
1888                                            void __user *argp)
1889 {
1890          struct btrfs_ioctl_search_args *args;
1891          struct inode *inode;
1892          int ret;
1893
1894         if (!capable(CAP_SYS_ADMIN))
1895                 return -EPERM;
1896
1897         args = memdup_user(argp, sizeof(*args));
1898         if (IS_ERR(args))
1899                 return PTR_ERR(args);
1900
1901         inode = file_inode(file);
1902         ret = search_ioctl(inode, args);
1903         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1904                 ret = -EFAULT;
1905         kfree(args);
1906         return ret;
1907 }
1908
1909 /*
1910  * Search INODE_REFs to identify path name of 'dirid' directory
1911  * in a 'tree_id' tree. and sets path name to 'name'.
1912  */
1913 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1914                                 u64 tree_id, u64 dirid, char *name)
1915 {
1916         struct btrfs_root *root;
1917         struct btrfs_key key;
1918         char *ptr;
1919         int ret = -1;
1920         int slot;
1921         int len;
1922         int total_len = 0;
1923         struct btrfs_inode_ref *iref;
1924         struct extent_buffer *l;
1925         struct btrfs_path *path;
1926
1927         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1928                 name[0]='\0';
1929                 return 0;
1930         }
1931
1932         path = btrfs_alloc_path();
1933         if (!path)
1934                 return -ENOMEM;
1935
1936         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1937
1938         key.objectid = tree_id;
1939         key.type = BTRFS_ROOT_ITEM_KEY;
1940         key.offset = (u64)-1;
1941         root = btrfs_read_fs_root_no_name(info, &key);
1942         if (IS_ERR(root)) {
1943                 printk(KERN_ERR "could not find root %llu\n", tree_id);
1944                 ret = -ENOENT;
1945                 goto out;
1946         }
1947
1948         key.objectid = dirid;
1949         key.type = BTRFS_INODE_REF_KEY;
1950         key.offset = (u64)-1;
1951
1952         while(1) {
1953                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1954                 if (ret < 0)
1955                         goto out;
1956
1957                 l = path->nodes[0];
1958                 slot = path->slots[0];
1959                 if (ret > 0 && slot > 0)
1960                         slot--;
1961                 btrfs_item_key_to_cpu(l, &key, slot);
1962
1963                 if (ret > 0 && (key.objectid != dirid ||
1964                                 key.type != BTRFS_INODE_REF_KEY)) {
1965                         ret = -ENOENT;
1966                         goto out;
1967                 }
1968
1969                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1970                 len = btrfs_inode_ref_name_len(l, iref);
1971                 ptr -= len + 1;
1972                 total_len += len + 1;
1973                 if (ptr < name)
1974                         goto out;
1975
1976                 *(ptr + len) = '/';
1977                 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1978
1979                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1980                         break;
1981
1982                 btrfs_release_path(path);
1983                 key.objectid = key.offset;
1984                 key.offset = (u64)-1;
1985                 dirid = key.objectid;
1986         }
1987         if (ptr < name)
1988                 goto out;
1989         memmove(name, ptr, total_len);
1990         name[total_len]='\0';
1991         ret = 0;
1992 out:
1993         btrfs_free_path(path);
1994         return ret;
1995 }
1996
1997 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1998                                            void __user *argp)
1999 {
2000          struct btrfs_ioctl_ino_lookup_args *args;
2001          struct inode *inode;
2002          int ret;
2003
2004         if (!capable(CAP_SYS_ADMIN))
2005                 return -EPERM;
2006
2007         args = memdup_user(argp, sizeof(*args));
2008         if (IS_ERR(args))
2009                 return PTR_ERR(args);
2010
2011         inode = file_inode(file);
2012
2013         if (args->treeid == 0)
2014                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2015
2016         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2017                                         args->treeid, args->objectid,
2018                                         args->name);
2019
2020         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2021                 ret = -EFAULT;
2022
2023         kfree(args);
2024         return ret;
2025 }
2026
2027 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2028                                              void __user *arg)
2029 {
2030         struct dentry *parent = fdentry(file);
2031         struct dentry *dentry;
2032         struct inode *dir = parent->d_inode;
2033         struct inode *inode;
2034         struct btrfs_root *root = BTRFS_I(dir)->root;
2035         struct btrfs_root *dest = NULL;
2036         struct btrfs_ioctl_vol_args *vol_args;
2037         struct btrfs_trans_handle *trans;
2038         int namelen;
2039         int ret;
2040         int err = 0;
2041
2042         vol_args = memdup_user(arg, sizeof(*vol_args));
2043         if (IS_ERR(vol_args))
2044                 return PTR_ERR(vol_args);
2045
2046         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2047         namelen = strlen(vol_args->name);
2048         if (strchr(vol_args->name, '/') ||
2049             strncmp(vol_args->name, "..", namelen) == 0) {
2050                 err = -EINVAL;
2051                 goto out;
2052         }
2053
2054         err = mnt_want_write_file(file);
2055         if (err)
2056                 goto out;
2057
2058         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
2059         dentry = lookup_one_len(vol_args->name, parent, namelen);
2060         if (IS_ERR(dentry)) {
2061                 err = PTR_ERR(dentry);
2062                 goto out_unlock_dir;
2063         }
2064
2065         if (!dentry->d_inode) {
2066                 err = -ENOENT;
2067                 goto out_dput;
2068         }
2069
2070         inode = dentry->d_inode;
2071         dest = BTRFS_I(inode)->root;
2072         if (!capable(CAP_SYS_ADMIN)){
2073                 /*
2074                  * Regular user.  Only allow this with a special mount
2075                  * option, when the user has write+exec access to the
2076                  * subvol root, and when rmdir(2) would have been
2077                  * allowed.
2078                  *
2079                  * Note that this is _not_ check that the subvol is
2080                  * empty or doesn't contain data that we wouldn't
2081                  * otherwise be able to delete.
2082                  *
2083                  * Users who want to delete empty subvols should try
2084                  * rmdir(2).
2085                  */
2086                 err = -EPERM;
2087                 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2088                         goto out_dput;
2089
2090                 /*
2091                  * Do not allow deletion if the parent dir is the same
2092                  * as the dir to be deleted.  That means the ioctl
2093                  * must be called on the dentry referencing the root
2094                  * of the subvol, not a random directory contained
2095                  * within it.
2096                  */
2097                 err = -EINVAL;
2098                 if (root == dest)
2099                         goto out_dput;
2100
2101                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2102                 if (err)
2103                         goto out_dput;
2104         }
2105
2106         /* check if subvolume may be deleted by a user */
2107         err = btrfs_may_delete(dir, dentry, 1);
2108         if (err)
2109                 goto out_dput;
2110
2111         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2112                 err = -EINVAL;
2113                 goto out_dput;
2114         }
2115
2116         mutex_lock(&inode->i_mutex);
2117         err = d_invalidate(dentry);
2118         if (err)
2119                 goto out_unlock;
2120
2121         down_write(&root->fs_info->subvol_sem);
2122
2123         err = may_destroy_subvol(dest);
2124         if (err)
2125                 goto out_up_write;
2126
2127         trans = btrfs_start_transaction(root, 0);
2128         if (IS_ERR(trans)) {
2129                 err = PTR_ERR(trans);
2130                 goto out_up_write;
2131         }
2132         trans->block_rsv = &root->fs_info->global_block_rsv;
2133
2134         ret = btrfs_unlink_subvol(trans, root, dir,
2135                                 dest->root_key.objectid,
2136                                 dentry->d_name.name,
2137                                 dentry->d_name.len);
2138         if (ret) {
2139                 err = ret;
2140                 btrfs_abort_transaction(trans, root, ret);
2141                 goto out_end_trans;
2142         }
2143
2144         btrfs_record_root_in_trans(trans, dest);
2145
2146         memset(&dest->root_item.drop_progress, 0,
2147                 sizeof(dest->root_item.drop_progress));
2148         dest->root_item.drop_level = 0;
2149         btrfs_set_root_refs(&dest->root_item, 0);
2150
2151         if (!xchg(&dest->orphan_item_inserted, 1)) {
2152                 ret = btrfs_insert_orphan_item(trans,
2153                                         root->fs_info->tree_root,
2154                                         dest->root_key.objectid);
2155                 if (ret) {
2156                         btrfs_abort_transaction(trans, root, ret);
2157                         err = ret;
2158                         goto out_end_trans;
2159                 }
2160         }
2161 out_end_trans:
2162         ret = btrfs_end_transaction(trans, root);
2163         if (ret && !err)
2164                 err = ret;
2165         inode->i_flags |= S_DEAD;
2166 out_up_write:
2167         up_write(&root->fs_info->subvol_sem);
2168 out_unlock:
2169         mutex_unlock(&inode->i_mutex);
2170         if (!err) {
2171                 shrink_dcache_sb(root->fs_info->sb);
2172                 btrfs_invalidate_inodes(dest);
2173                 d_delete(dentry);
2174         }
2175 out_dput:
2176         dput(dentry);
2177 out_unlock_dir:
2178         mutex_unlock(&dir->i_mutex);
2179         mnt_drop_write_file(file);
2180 out:
2181         kfree(vol_args);
2182         return err;
2183 }
2184
2185 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2186 {
2187         struct inode *inode = file_inode(file);
2188         struct btrfs_root *root = BTRFS_I(inode)->root;
2189         struct btrfs_ioctl_defrag_range_args *range;
2190         int ret;
2191
2192         ret = mnt_want_write_file(file);
2193         if (ret)
2194                 return ret;
2195
2196         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2197                         1)) {
2198                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2199                 mnt_drop_write_file(file);
2200                 return -EINVAL;
2201         }
2202
2203         if (btrfs_root_readonly(root)) {
2204                 ret = -EROFS;
2205                 goto out;
2206         }
2207
2208         switch (inode->i_mode & S_IFMT) {
2209         case S_IFDIR:
2210                 if (!capable(CAP_SYS_ADMIN)) {
2211                         ret = -EPERM;
2212                         goto out;
2213                 }
2214                 ret = btrfs_defrag_root(root, 0);
2215                 if (ret)
2216                         goto out;
2217                 ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2218                 break;
2219         case S_IFREG:
2220                 if (!(file->f_mode & FMODE_WRITE)) {
2221                         ret = -EINVAL;
2222                         goto out;
2223                 }
2224
2225                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2226                 if (!range) {
2227                         ret = -ENOMEM;
2228                         goto out;
2229                 }
2230
2231                 if (argp) {
2232                         if (copy_from_user(range, argp,
2233                                            sizeof(*range))) {
2234                                 ret = -EFAULT;
2235                                 kfree(range);
2236                                 goto out;
2237                         }
2238                         /* compression requires us to start the IO */
2239                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2240                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2241                                 range->extent_thresh = (u32)-1;
2242                         }
2243                 } else {
2244                         /* the rest are all set to zero by kzalloc */
2245                         range->len = (u64)-1;
2246                 }
2247                 ret = btrfs_defrag_file(file_inode(file), file,
2248                                         range, 0, 0);
2249                 if (ret > 0)
2250                         ret = 0;
2251                 kfree(range);
2252                 break;
2253         default:
2254                 ret = -EINVAL;
2255         }
2256 out:
2257         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2258         mnt_drop_write_file(file);
2259         return ret;
2260 }
2261
2262 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2263 {
2264         struct btrfs_ioctl_vol_args *vol_args;
2265         int ret;
2266
2267         if (!capable(CAP_SYS_ADMIN))
2268                 return -EPERM;
2269
2270         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2271                         1)) {
2272                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2273                 return -EINVAL;
2274         }
2275
2276         mutex_lock(&root->fs_info->volume_mutex);
2277         vol_args = memdup_user(arg, sizeof(*vol_args));
2278         if (IS_ERR(vol_args)) {
2279                 ret = PTR_ERR(vol_args);
2280                 goto out;
2281         }
2282
2283         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2284         ret = btrfs_init_new_device(root, vol_args->name);
2285
2286         kfree(vol_args);
2287 out:
2288         mutex_unlock(&root->fs_info->volume_mutex);
2289         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2290         return ret;
2291 }
2292
2293 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2294 {
2295         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
2296         struct btrfs_ioctl_vol_args *vol_args;
2297         int ret;
2298
2299         if (!capable(CAP_SYS_ADMIN))
2300                 return -EPERM;
2301
2302         ret = mnt_want_write_file(file);
2303         if (ret)
2304                 return ret;
2305
2306         if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2307                         1)) {
2308                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2309                 mnt_drop_write_file(file);
2310                 return -EINVAL;
2311         }
2312
2313         mutex_lock(&root->fs_info->volume_mutex);
2314         vol_args = memdup_user(arg, sizeof(*vol_args));
2315         if (IS_ERR(vol_args)) {
2316                 ret = PTR_ERR(vol_args);
2317                 goto out;
2318         }
2319
2320         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2321         ret = btrfs_rm_device(root, vol_args->name);
2322
2323         kfree(vol_args);
2324 out:
2325         mutex_unlock(&root->fs_info->volume_mutex);
2326         atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2327         mnt_drop_write_file(file);
2328         return ret;
2329 }
2330
2331 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2332 {
2333         struct btrfs_ioctl_fs_info_args *fi_args;
2334         struct btrfs_device *device;
2335         struct btrfs_device *next;
2336         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2337         int ret = 0;
2338
2339         if (!capable(CAP_SYS_ADMIN))
2340                 return -EPERM;
2341
2342         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2343         if (!fi_args)
2344                 return -ENOMEM;
2345
2346         fi_args->num_devices = fs_devices->num_devices;
2347         memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2348
2349         mutex_lock(&fs_devices->device_list_mutex);
2350         list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2351                 if (device->devid > fi_args->max_id)
2352                         fi_args->max_id = device->devid;
2353         }
2354         mutex_unlock(&fs_devices->device_list_mutex);
2355
2356         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2357                 ret = -EFAULT;
2358
2359         kfree(fi_args);
2360         return ret;
2361 }
2362
2363 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2364 {
2365         struct btrfs_ioctl_dev_info_args *di_args;
2366         struct btrfs_device *dev;
2367         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2368         int ret = 0;
2369         char *s_uuid = NULL;
2370         char empty_uuid[BTRFS_UUID_SIZE] = {0};
2371
2372         if (!capable(CAP_SYS_ADMIN))
2373                 return -EPERM;
2374
2375         di_args = memdup_user(arg, sizeof(*di_args));
2376         if (IS_ERR(di_args))
2377                 return PTR_ERR(di_args);
2378
2379         if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2380                 s_uuid = di_args->uuid;
2381
2382         mutex_lock(&fs_devices->device_list_mutex);
2383         dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2384         mutex_unlock(&fs_devices->device_list_mutex);
2385
2386         if (!dev) {
2387                 ret = -ENODEV;
2388                 goto out;
2389         }
2390
2391         di_args->devid = dev->devid;
2392         di_args->bytes_used = dev->bytes_used;
2393         di_args->total_bytes = dev->total_bytes;
2394         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2395         if (dev->name) {
2396                 struct rcu_string *name;
2397
2398                 rcu_read_lock();
2399                 name = rcu_dereference(dev->name);
2400                 strncpy(di_args->path, name->str, sizeof(di_args->path));
2401                 rcu_read_unlock();
2402                 di_args->path[sizeof(di_args->path) - 1] = 0;
2403         } else {
2404                 di_args->path[0] = '\0';
2405         }
2406
2407 out:
2408         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2409                 ret = -EFAULT;
2410
2411         kfree(di_args);
2412         return ret;
2413 }
2414
2415 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2416                                        u64 off, u64 olen, u64 destoff)
2417 {
2418         struct inode *inode = file_inode(file);
2419         struct btrfs_root *root = BTRFS_I(inode)->root;
2420         struct fd src_file;
2421         struct inode *src;
2422         struct btrfs_trans_handle *trans;
2423         struct btrfs_path *path;
2424         struct extent_buffer *leaf;
2425         char *buf;
2426         struct btrfs_key key;
2427         u32 nritems;
2428         int slot;
2429         int ret;
2430         u64 len = olen;
2431         u64 bs = root->fs_info->sb->s_blocksize;
2432
2433         /*
2434          * TODO:
2435          * - split compressed inline extents.  annoying: we need to
2436          *   decompress into destination's address_space (the file offset
2437          *   may change, so source mapping won't do), then recompress (or
2438          *   otherwise reinsert) a subrange.
2439          * - allow ranges within the same file to be cloned (provided
2440          *   they don't overlap)?
2441          */
2442
2443         /* the destination must be opened for writing */
2444         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2445                 return -EINVAL;
2446
2447         if (btrfs_root_readonly(root))
2448                 return -EROFS;
2449
2450         ret = mnt_want_write_file(file);
2451         if (ret)
2452                 return ret;
2453
2454         src_file = fdget(srcfd);
2455         if (!src_file.file) {
2456                 ret = -EBADF;
2457                 goto out_drop_write;
2458         }
2459
2460         ret = -EXDEV;
2461         if (src_file.file->f_path.mnt != file->f_path.mnt)
2462                 goto out_fput;
2463
2464         src = file_inode(src_file.file);
2465
2466         ret = -EINVAL;
2467         if (src == inode)
2468                 goto out_fput;
2469
2470         /* the src must be open for reading */
2471         if (!(src_file.file->f_mode & FMODE_READ))
2472                 goto out_fput;
2473
2474         /* don't make the dst file partly checksummed */
2475         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2476             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2477                 goto out_fput;
2478
2479         ret = -EISDIR;
2480         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2481                 goto out_fput;
2482
2483         ret = -EXDEV;
2484         if (src->i_sb != inode->i_sb)
2485                 goto out_fput;
2486
2487         ret = -ENOMEM;
2488         buf = vmalloc(btrfs_level_size(root, 0));
2489         if (!buf)
2490                 goto out_fput;
2491
2492         path = btrfs_alloc_path();
2493         if (!path) {
2494                 vfree(buf);
2495                 goto out_fput;
2496         }
2497         path->reada = 2;
2498
2499         if (inode < src) {
2500                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2501                 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2502         } else {
2503                 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2504                 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2505         }
2506
2507         /* determine range to clone */
2508         ret = -EINVAL;
2509         if (off + len > src->i_size || off + len < off)
2510                 goto out_unlock;
2511         if (len == 0)
2512                 olen = len = src->i_size - off;
2513         /* if we extend to eof, continue to block boundary */
2514         if (off + len == src->i_size)
2515                 len = ALIGN(src->i_size, bs) - off;
2516
2517         /* verify the end result is block aligned */
2518         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2519             !IS_ALIGNED(destoff, bs))
2520                 goto out_unlock;
2521
2522         if (destoff > inode->i_size) {
2523                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2524                 if (ret)
2525                         goto out_unlock;
2526         }
2527
2528         /* truncate page cache pages from target inode range */
2529         truncate_inode_pages_range(&inode->i_data, destoff,
2530                                    PAGE_CACHE_ALIGN(destoff + len) - 1);
2531
2532         /* do any pending delalloc/csum calc on src, one way or
2533            another, and lock file content */
2534         while (1) {
2535                 struct btrfs_ordered_extent *ordered;
2536                 lock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2537                 ordered = btrfs_lookup_first_ordered_extent(src, off + len - 1);
2538                 if (!ordered &&
2539                     !test_range_bit(&BTRFS_I(src)->io_tree, off, off + len - 1,
2540                                     EXTENT_DELALLOC, 0, NULL))
2541                         break;
2542                 unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2543                 if (ordered)
2544                         btrfs_put_ordered_extent(ordered);
2545                 btrfs_wait_ordered_range(src, off, len);
2546         }
2547
2548         /* clone data */
2549         key.objectid = btrfs_ino(src);
2550         key.type = BTRFS_EXTENT_DATA_KEY;
2551         key.offset = 0;
2552
2553         while (1) {
2554                 /*
2555                  * note the key will change type as we walk through the
2556                  * tree.
2557                  */
2558                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2559                                 0, 0);
2560                 if (ret < 0)
2561                         goto out;
2562
2563                 nritems = btrfs_header_nritems(path->nodes[0]);
2564                 if (path->slots[0] >= nritems) {
2565                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2566                         if (ret < 0)
2567                                 goto out;
2568                         if (ret > 0)
2569                                 break;
2570                         nritems = btrfs_header_nritems(path->nodes[0]);
2571                 }
2572                 leaf = path->nodes[0];
2573                 slot = path->slots[0];
2574
2575                 btrfs_item_key_to_cpu(leaf, &key, slot);
2576                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2577                     key.objectid != btrfs_ino(src))
2578                         break;
2579
2580                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2581                         struct btrfs_file_extent_item *extent;
2582                         int type;
2583                         u32 size;
2584                         struct btrfs_key new_key;
2585                         u64 disko = 0, diskl = 0;
2586                         u64 datao = 0, datal = 0;
2587                         u8 comp;
2588                         u64 endoff;
2589
2590                         size = btrfs_item_size_nr(leaf, slot);
2591                         read_extent_buffer(leaf, buf,
2592                                            btrfs_item_ptr_offset(leaf, slot),
2593                                            size);
2594
2595                         extent = btrfs_item_ptr(leaf, slot,
2596                                                 struct btrfs_file_extent_item);
2597                         comp = btrfs_file_extent_compression(leaf, extent);
2598                         type = btrfs_file_extent_type(leaf, extent);
2599                         if (type == BTRFS_FILE_EXTENT_REG ||
2600                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2601                                 disko = btrfs_file_extent_disk_bytenr(leaf,
2602                                                                       extent);
2603                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
2604                                                                  extent);
2605                                 datao = btrfs_file_extent_offset(leaf, extent);
2606                                 datal = btrfs_file_extent_num_bytes(leaf,
2607                                                                     extent);
2608                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2609                                 /* take upper bound, may be compressed */
2610                                 datal = btrfs_file_extent_ram_bytes(leaf,
2611                                                                     extent);
2612                         }
2613                         btrfs_release_path(path);
2614
2615                         if (key.offset + datal <= off ||
2616                             key.offset >= off + len - 1)
2617                                 goto next;
2618
2619                         memcpy(&new_key, &key, sizeof(new_key));
2620                         new_key.objectid = btrfs_ino(inode);
2621                         if (off <= key.offset)
2622                                 new_key.offset = key.offset + destoff - off;
2623                         else
2624                                 new_key.offset = destoff;
2625
2626                         /*
2627                          * 1 - adjusting old extent (we may have to split it)
2628                          * 1 - add new extent
2629                          * 1 - inode update
2630                          */
2631                         trans = btrfs_start_transaction(root, 3);
2632                         if (IS_ERR(trans)) {
2633                                 ret = PTR_ERR(trans);
2634                                 goto out;
2635                         }
2636
2637                         if (type == BTRFS_FILE_EXTENT_REG ||
2638                             type == BTRFS_FILE_EXTENT_PREALLOC) {
2639                                 /*
2640                                  *    a  | --- range to clone ---|  b
2641                                  * | ------------- extent ------------- |
2642                                  */
2643
2644                                 /* substract range b */
2645                                 if (key.offset + datal > off + len)
2646                                         datal = off + len - key.offset;
2647
2648                                 /* substract range a */
2649                                 if (off > key.offset) {
2650                                         datao += off - key.offset;
2651                                         datal -= off - key.offset;
2652                                 }
2653
2654                                 ret = btrfs_drop_extents(trans, root, inode,
2655                                                          new_key.offset,
2656                                                          new_key.offset + datal,
2657                                                          1);
2658                                 if (ret) {
2659                                         btrfs_abort_transaction(trans, root,
2660                                                                 ret);
2661                                         btrfs_end_transaction(trans, root);
2662                                         goto out;
2663                                 }
2664
2665                                 ret = btrfs_insert_empty_item(trans, root, path,
2666                                                               &new_key, size);
2667                                 if (ret) {
2668                                         btrfs_abort_transaction(trans, root,
2669                                                                 ret);
2670                                         btrfs_end_transaction(trans, root);
2671                                         goto out;
2672                                 }
2673
2674                                 leaf = path->nodes[0];
2675                                 slot = path->slots[0];
2676                                 write_extent_buffer(leaf, buf,
2677                                             btrfs_item_ptr_offset(leaf, slot),
2678                                             size);
2679
2680                                 extent = btrfs_item_ptr(leaf, slot,
2681                                                 struct btrfs_file_extent_item);
2682
2683                                 /* disko == 0 means it's a hole */
2684                                 if (!disko)
2685                                         datao = 0;
2686
2687                                 btrfs_set_file_extent_offset(leaf, extent,
2688                                                              datao);
2689                                 btrfs_set_file_extent_num_bytes(leaf, extent,
2690                                                                 datal);
2691                                 if (disko) {
2692                                         inode_add_bytes(inode, datal);
2693                                         ret = btrfs_inc_extent_ref(trans, root,
2694                                                         disko, diskl, 0,
2695                                                         root->root_key.objectid,
2696                                                         btrfs_ino(inode),
2697                                                         new_key.offset - datao,
2698                                                         0);
2699                                         if (ret) {
2700                                                 btrfs_abort_transaction(trans,
2701                                                                         root,
2702                                                                         ret);
2703                                                 btrfs_end_transaction(trans,
2704                                                                       root);
2705                                                 goto out;
2706
2707                                         }
2708                                 }
2709                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
2710                                 u64 skip = 0;
2711                                 u64 trim = 0;
2712                                 if (off > key.offset) {
2713                                         skip = off - key.offset;
2714                                         new_key.offset += skip;
2715                                 }
2716
2717                                 if (key.offset + datal > off + len)
2718                                         trim = key.offset + datal - (off + len);
2719
2720                                 if (comp && (skip || trim)) {
2721                                         ret = -EINVAL;
2722                                         btrfs_end_transaction(trans, root);
2723                                         goto out;
2724                                 }
2725                                 size -= skip + trim;
2726                                 datal -= skip + trim;
2727
2728                                 ret = btrfs_drop_extents(trans, root, inode,
2729                                                          new_key.offset,
2730                                                          new_key.offset + datal,
2731                                                          1);
2732                                 if (ret) {
2733                                         btrfs_abort_transaction(trans, root,
2734                                                                 ret);
2735                                         btrfs_end_transaction(trans, root);
2736                                         goto out;
2737                                 }
2738
2739                                 ret = btrfs_insert_empty_item(trans, root, path,
2740                                                               &new_key, size);
2741                                 if (ret) {
2742                                         btrfs_abort_transaction(trans, root,
2743                                                                 ret);
2744                                         btrfs_end_transaction(trans, root);
2745                                         goto out;
2746                                 }
2747
2748                                 if (skip) {
2749                                         u32 start =
2750                                           btrfs_file_extent_calc_inline_size(0);
2751                                         memmove(buf+start, buf+start+skip,
2752                                                 datal);
2753                                 }
2754
2755                                 leaf = path->nodes[0];
2756                                 slot = path->slots[0];
2757                                 write_extent_buffer(leaf, buf,
2758                                             btrfs_item_ptr_offset(leaf, slot),
2759                                             size);
2760                                 inode_add_bytes(inode, datal);
2761                         }
2762
2763                         btrfs_mark_buffer_dirty(leaf);
2764                         btrfs_release_path(path);
2765
2766                         inode_inc_iversion(inode);
2767                         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2768
2769                         /*
2770                          * we round up to the block size at eof when
2771                          * determining which extents to clone above,
2772                          * but shouldn't round up the file size
2773                          */
2774                         endoff = new_key.offset + datal;
2775                         if (endoff > destoff+olen)
2776                                 endoff = destoff+olen;
2777                         if (endoff > inode->i_size)
2778                                 btrfs_i_size_write(inode, endoff);
2779
2780                         ret = btrfs_update_inode(trans, root, inode);
2781                         if (ret) {
2782                                 btrfs_abort_transaction(trans, root, ret);
2783                                 btrfs_end_transaction(trans, root);
2784                                 goto out;
2785                         }
2786                         ret = btrfs_end_transaction(trans, root);
2787                 }
2788 next:
2789                 btrfs_release_path(path);
2790                 key.offset++;
2791         }
2792         ret = 0;
2793 out:
2794         btrfs_release_path(path);
2795         unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2796 out_unlock:
2797         mutex_unlock(&src->i_mutex);
2798         mutex_unlock(&inode->i_mutex);
2799         vfree(buf);
2800         btrfs_free_path(path);
2801 out_fput:
2802         fdput(src_file);
2803 out_drop_write:
2804         mnt_drop_write_file(file);
2805         return ret;
2806 }
2807
2808 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2809 {
2810         struct btrfs_ioctl_clone_range_args args;
2811
2812         if (copy_from_user(&args, argp, sizeof(args)))
2813                 return -EFAULT;
2814         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2815                                  args.src_length, args.dest_offset);
2816 }
2817
2818 /*
2819  * there are many ways the trans_start and trans_end ioctls can lead
2820  * to deadlocks.  They should only be used by applications that
2821  * basically own the machine, and have a very in depth understanding
2822  * of all the possible deadlocks and enospc problems.
2823  */
2824 static long btrfs_ioctl_trans_start(struct file *file)
2825 {
2826         struct inode *inode = file_inode(file);
2827         struct btrfs_root *root = BTRFS_I(inode)->root;
2828         struct btrfs_trans_handle *trans;
2829         int ret;
2830
2831         ret = -EPERM;
2832         if (!capable(CAP_SYS_ADMIN))
2833                 goto out;
2834
2835         ret = -EINPROGRESS;
2836         if (file->private_data)
2837                 goto out;
2838
2839         ret = -EROFS;
2840         if (btrfs_root_readonly(root))
2841                 goto out;
2842
2843         ret = mnt_want_write_file(file);
2844         if (ret)
2845                 goto out;
2846
2847         atomic_inc(&root->fs_info->open_ioctl_trans);
2848
2849         ret = -ENOMEM;
2850         trans = btrfs_start_ioctl_transaction(root);
2851         if (IS_ERR(trans))
2852                 goto out_drop;
2853
2854         file->private_data = trans;
2855         return 0;
2856
2857 out_drop:
2858         atomic_dec(&root->fs_info->open_ioctl_trans);
2859         mnt_drop_write_file(file);
2860 out:
2861         return ret;
2862 }
2863
2864 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2865 {
2866         struct inode *inode = file_inode(file);
2867         struct btrfs_root *root = BTRFS_I(inode)->root;
2868         struct btrfs_root *new_root;
2869         struct btrfs_dir_item *di;
2870         struct btrfs_trans_handle *trans;
2871         struct btrfs_path *path;
2872         struct btrfs_key location;
2873         struct btrfs_disk_key disk_key;
2874         u64 objectid = 0;
2875         u64 dir_id;
2876         int ret;
2877
2878         if (!capable(CAP_SYS_ADMIN))
2879                 return -EPERM;
2880
2881         ret = mnt_want_write_file(file);
2882         if (ret)
2883                 return ret;
2884
2885         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2886                 ret = -EFAULT;
2887                 goto out;
2888         }
2889
2890         if (!objectid)
2891                 objectid = root->root_key.objectid;
2892
2893         location.objectid = objectid;
2894         location.type = BTRFS_ROOT_ITEM_KEY;
2895         location.offset = (u64)-1;
2896
2897         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2898         if (IS_ERR(new_root)) {
2899                 ret = PTR_ERR(new_root);
2900                 goto out;
2901         }
2902
2903         if (btrfs_root_refs(&new_root->root_item) == 0) {
2904                 ret = -ENOENT;
2905                 goto out;
2906         }
2907
2908         path = btrfs_alloc_path();
2909         if (!path) {
2910                 ret = -ENOMEM;
2911                 goto out;
2912         }
2913         path->leave_spinning = 1;
2914
2915         trans = btrfs_start_transaction(root, 1);
2916         if (IS_ERR(trans)) {
2917                 btrfs_free_path(path);
2918                 ret = PTR_ERR(trans);
2919                 goto out;
2920         }
2921
2922         dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2923         di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2924                                    dir_id, "default", 7, 1);
2925         if (IS_ERR_OR_NULL(di)) {
2926                 btrfs_free_path(path);
2927                 btrfs_end_transaction(trans, root);
2928                 printk(KERN_ERR "Umm, you don't have the default dir item, "
2929                        "this isn't going to work\n");
2930                 ret = -ENOENT;
2931                 goto out;
2932         }
2933
2934         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2935         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2936         btrfs_mark_buffer_dirty(path->nodes[0]);
2937         btrfs_free_path(path);
2938
2939         btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2940         btrfs_end_transaction(trans, root);
2941 out:
2942         mnt_drop_write_file(file);
2943         return ret;
2944 }
2945
2946 void btrfs_get_block_group_info(struct list_head *groups_list,
2947                                 struct btrfs_ioctl_space_info *space)
2948 {
2949         struct btrfs_block_group_cache *block_group;
2950
2951         space->total_bytes = 0;
2952         space->used_bytes = 0;
2953         space->flags = 0;
2954         list_for_each_entry(block_group, groups_list, list) {
2955                 space->flags = block_group->flags;
2956                 space->total_bytes += block_group->key.offset;
2957                 space->used_bytes +=
2958                         btrfs_block_group_used(&block_group->item);
2959         }
2960 }
2961
2962 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2963 {
2964         struct btrfs_ioctl_space_args space_args;
2965         struct btrfs_ioctl_space_info space;
2966         struct btrfs_ioctl_space_info *dest;
2967         struct btrfs_ioctl_space_info *dest_orig;
2968         struct btrfs_ioctl_space_info __user *user_dest;
2969         struct btrfs_space_info *info;
2970         u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2971                        BTRFS_BLOCK_GROUP_SYSTEM,
2972                        BTRFS_BLOCK_GROUP_METADATA,
2973                        BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2974         int num_types = 4;
2975         int alloc_size;
2976         int ret = 0;
2977         u64 slot_count = 0;
2978         int i, c;
2979
2980         if (copy_from_user(&space_args,
2981                            (struct btrfs_ioctl_space_args __user *)arg,
2982                            sizeof(space_args)))
2983                 return -EFAULT;
2984
2985         for (i = 0; i < num_types; i++) {
2986                 struct btrfs_space_info *tmp;
2987
2988                 info = NULL;
2989                 rcu_read_lock();
2990                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2991                                         list) {
2992                         if (tmp->flags == types[i]) {
2993                                 info = tmp;
2994                                 break;
2995                         }
2996                 }
2997                 rcu_read_unlock();
2998
2999                 if (!info)
3000                         continue;
3001
3002                 down_read(&info->groups_sem);
3003                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3004                         if (!list_empty(&info->block_groups[c]))
3005                                 slot_count++;
3006                 }
3007                 up_read(&info->groups_sem);
3008         }
3009
3010         /* space_slots == 0 means they are asking for a count */
3011         if (space_args.space_slots == 0) {
3012                 space_args.total_spaces = slot_count;
3013                 goto out;
3014         }
3015
3016         slot_count = min_t(u64, space_args.space_slots, slot_count);
3017
3018         alloc_size = sizeof(*dest) * slot_count;
3019
3020         /* we generally have at most 6 or so space infos, one for each raid
3021          * level.  So, a whole page should be more than enough for everyone
3022          */
3023         if (alloc_size > PAGE_CACHE_SIZE)
3024                 return -ENOMEM;
3025
3026         space_args.total_spaces = 0;
3027         dest = kmalloc(alloc_size, GFP_NOFS);
3028         if (!dest)
3029                 return -ENOMEM;
3030         dest_orig = dest;
3031
3032         /* now we have a buffer to copy into */
3033         for (i = 0; i < num_types; i++) {
3034                 struct btrfs_space_info *tmp;
3035
3036                 if (!slot_count)
3037                         break;
3038
3039                 info = NULL;
3040                 rcu_read_lock();
3041                 list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3042                                         list) {
3043                         if (tmp->flags == types[i]) {
3044                                 info = tmp;
3045                                 break;
3046                         }
3047                 }
3048                 rcu_read_unlock();
3049
3050                 if (!info)
3051                         continue;
3052                 down_read(&info->groups_sem);
3053                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3054                         if (!list_empty(&info->block_groups[c])) {
3055                                 btrfs_get_block_group_info(
3056                                         &info->block_groups[c], &space);
3057                                 memcpy(dest, &space, sizeof(space));
3058                                 dest++;
3059                                 space_args.total_spaces++;
3060                                 slot_count--;
3061                         }
3062                         if (!slot_count)
3063                                 break;
3064                 }
3065                 up_read(&info->groups_sem);
3066         }
3067
3068         user_dest = (struct btrfs_ioctl_space_info __user *)
3069                 (arg + sizeof(struct btrfs_ioctl_space_args));
3070
3071         if (copy_to_user(user_dest, dest_orig, alloc_size))
3072                 ret = -EFAULT;
3073
3074         kfree(dest_orig);
3075 out:
3076         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3077                 ret = -EFAULT;
3078
3079         return ret;
3080 }
3081
3082 /*
3083  * there are many ways the trans_start and trans_end ioctls can lead
3084  * to deadlocks.  They should only be used by applications that
3085  * basically own the machine, and have a very in depth understanding
3086  * of all the possible deadlocks and enospc problems.
3087  */
3088 long btrfs_ioctl_trans_end(struct file *file)
3089 {
3090         struct inode *inode = file_inode(file);
3091         struct btrfs_root *root = BTRFS_I(inode)->root;
3092         struct btrfs_trans_handle *trans;
3093
3094         trans = file->private_data;
3095         if (!trans)
3096                 return -EINVAL;
3097         file->private_data = NULL;
3098
3099         btrfs_end_transaction(trans, root);
3100
3101         atomic_dec(&root->fs_info->open_ioctl_trans);
3102
3103         mnt_drop_write_file(file);
3104         return 0;
3105 }
3106
3107 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3108                                             void __user *argp)
3109 {
3110         struct btrfs_trans_handle *trans;
3111         u64 transid;
3112         int ret;
3113
3114         trans = btrfs_attach_transaction(root);
3115         if (IS_ERR(trans)) {
3116                 if (PTR_ERR(trans) != -ENOENT)
3117                         return PTR_ERR(trans);
3118
3119                 /* No running transaction, don't bother */
3120                 transid = root->fs_info->last_trans_committed;
3121                 goto out;
3122         }
3123         transid = trans->transid;
3124         ret = btrfs_commit_transaction_async(trans, root, 0);
3125         if (ret) {
3126                 btrfs_end_transaction(trans, root);
3127                 return ret;
3128         }
3129 out:
3130         if (argp)
3131                 if (copy_to_user(argp, &transid, sizeof(transid)))
3132                         return -EFAULT;
3133         return 0;
3134 }
3135
3136 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
3137                                            void __user *argp)
3138 {
3139         u64 transid;
3140
3141         if (argp) {
3142                 if (copy_from_user(&transid, argp, sizeof(transid)))
3143                         return -EFAULT;
3144         } else {
3145                 transid = 0;  /* current trans */
3146         }
3147         return btrfs_wait_for_commit(root, transid);
3148 }
3149
3150 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3151 {
3152         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3153         struct btrfs_ioctl_scrub_args *sa;
3154         int ret;
3155
3156         if (!capable(CAP_SYS_ADMIN))
3157                 return -EPERM;
3158
3159         sa = memdup_user(arg, sizeof(*sa));
3160         if (IS_ERR(sa))
3161                 return PTR_ERR(sa);
3162
3163         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3164                 ret = mnt_want_write_file(file);
3165                 if (ret)
3166                         goto out;
3167         }
3168
3169         ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
3170                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3171                               0);
3172
3173         if (copy_to_user(arg, sa, sizeof(*sa)))
3174                 ret = -EFAULT;
3175
3176         if (!(sa->flags & BTRFS_SCRUB_READONLY))
3177                 mnt_drop_write_file(file);
3178 out:
3179         kfree(sa);
3180         return ret;
3181 }
3182
3183 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3184 {
3185         if (!capable(CAP_SYS_ADMIN))
3186                 return -EPERM;
3187
3188         return btrfs_scrub_cancel(root->fs_info);
3189 }
3190
3191 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3192                                        void __user *arg)
3193 {
3194         struct btrfs_ioctl_scrub_args *sa;
3195         int ret;
3196
3197         if (!capable(CAP_SYS_ADMIN))
3198                 return -EPERM;
3199
3200         sa = memdup_user(arg, sizeof(*sa));
3201         if (IS_ERR(sa))
3202                 return PTR_ERR(sa);
3203
3204         ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3205
3206         if (copy_to_user(arg, sa, sizeof(*sa)))
3207                 ret = -EFAULT;
3208
3209         kfree(sa);
3210         return ret;
3211 }
3212
3213 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3214                                       void __user *arg)
3215 {
3216         struct btrfs_ioctl_get_dev_stats *sa;
3217         int ret;
3218
3219         sa = memdup_user(arg, sizeof(*sa));
3220         if (IS_ERR(sa))
3221                 return PTR_ERR(sa);
3222
3223         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3224                 kfree(sa);
3225                 return -EPERM;
3226         }
3227
3228         ret = btrfs_get_dev_stats(root, sa);
3229
3230         if (copy_to_user(arg, sa, sizeof(*sa)))
3231                 ret = -EFAULT;
3232
3233         kfree(sa);
3234         return ret;
3235 }
3236
3237 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
3238 {
3239         struct btrfs_ioctl_dev_replace_args *p;
3240         int ret;
3241
3242         if (!capable(CAP_SYS_ADMIN))
3243                 return -EPERM;
3244
3245         p = memdup_user(arg, sizeof(*p));
3246         if (IS_ERR(p))
3247                 return PTR_ERR(p);
3248
3249         switch (p->cmd) {
3250         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3251                 if (atomic_xchg(
3252                         &root->fs_info->mutually_exclusive_operation_running,
3253                         1)) {
3254                         pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3255                         ret = -EINPROGRESS;
3256                 } else {
3257                         ret = btrfs_dev_replace_start(root, p);
3258                         atomic_set(
3259                          &root->fs_info->mutually_exclusive_operation_running,
3260                          0);
3261                 }
3262                 break;
3263         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3264                 btrfs_dev_replace_status(root->fs_info, p);
3265                 ret = 0;
3266                 break;
3267         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3268                 ret = btrfs_dev_replace_cancel(root->fs_info, p);
3269                 break;
3270         default:
3271                 ret = -EINVAL;
3272                 break;
3273         }
3274
3275         if (copy_to_user(arg, p, sizeof(*p)))
3276                 ret = -EFAULT;
3277
3278         kfree(p);
3279         return ret;
3280 }
3281
3282 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3283 {
3284         int ret = 0;
3285         int i;
3286         u64 rel_ptr;
3287         int size;
3288         struct btrfs_ioctl_ino_path_args *ipa = NULL;
3289         struct inode_fs_paths *ipath = NULL;
3290         struct btrfs_path *path;
3291
3292         if (!capable(CAP_SYS_ADMIN))
3293                 return -EPERM;
3294
3295         path = btrfs_alloc_path();
3296         if (!path) {
3297                 ret = -ENOMEM;
3298                 goto out;
3299         }
3300
3301         ipa = memdup_user(arg, sizeof(*ipa));
3302         if (IS_ERR(ipa)) {
3303                 ret = PTR_ERR(ipa);
3304                 ipa = NULL;
3305                 goto out;
3306         }
3307
3308         size = min_t(u32, ipa->size, 4096);
3309         ipath = init_ipath(size, root, path);
3310         if (IS_ERR(ipath)) {
3311                 ret = PTR_ERR(ipath);
3312                 ipath = NULL;
3313                 goto out;
3314         }
3315
3316         ret = paths_from_inode(ipa->inum, ipath);
3317         if (ret < 0)
3318                 goto out;
3319
3320         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3321                 rel_ptr = ipath->fspath->val[i] -
3322                           (u64)(unsigned long)ipath->fspath->val;
3323                 ipath->fspath->val[i] = rel_ptr;
3324         }
3325
3326         ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3327                            (void *)(unsigned long)ipath->fspath, size);
3328         if (ret) {
3329                 ret = -EFAULT;
3330                 goto out;
3331         }
3332
3333 out:
3334         btrfs_free_path(path);
3335         free_ipath(ipath);
3336         kfree(ipa);
3337
3338         return ret;
3339 }
3340
3341 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3342 {
3343         struct btrfs_data_container *inodes = ctx;
3344         const size_t c = 3 * sizeof(u64);
3345
3346         if (inodes->bytes_left >= c) {
3347                 inodes->bytes_left -= c;
3348                 inodes->val[inodes->elem_cnt] = inum;
3349                 inodes->val[inodes->elem_cnt + 1] = offset;
3350                 inodes->val[inodes->elem_cnt + 2] = root;
3351                 inodes->elem_cnt += 3;
3352         } else {
3353                 inodes->bytes_missing += c - inodes->bytes_left;
3354                 inodes->bytes_left = 0;
3355                 inodes->elem_missed += 3;
3356         }
3357
3358         return 0;
3359 }
3360
3361 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3362                                         void __user *arg)
3363 {
3364         int ret = 0;
3365         int size;
3366         struct btrfs_ioctl_logical_ino_args *loi;
3367         struct btrfs_data_container *inodes = NULL;
3368         struct btrfs_path *path = NULL;
3369
3370         if (!capable(CAP_SYS_ADMIN))
3371                 return -EPERM;
3372
3373         loi = memdup_user(arg, sizeof(*loi));
3374         if (IS_ERR(loi)) {
3375                 ret = PTR_ERR(loi);
3376                 loi = NULL;
3377                 goto out;
3378         }
3379
3380         path = btrfs_alloc_path();
3381         if (!path) {
3382                 ret = -ENOMEM;
3383                 goto out;
3384         }
3385
3386         size = min_t(u32, loi->size, 64 * 1024);
3387         inodes = init_data_container(size);
3388         if (IS_ERR(inodes)) {
3389                 ret = PTR_ERR(inodes);
3390                 inodes = NULL;
3391                 goto out;
3392         }
3393
3394         ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
3395                                           build_ino_list, inodes);
3396         if (ret == -EINVAL)
3397                 ret = -ENOENT;
3398         if (ret < 0)
3399                 goto out;
3400
3401         ret = copy_to_user((void *)(unsigned long)loi->inodes,
3402                            (void *)(unsigned long)inodes, size);
3403         if (ret)
3404                 ret = -EFAULT;
3405
3406 out:
3407         btrfs_free_path(path);
3408         vfree(inodes);
3409         kfree(loi);
3410
3411         return ret;
3412 }
3413
3414 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3415                                struct btrfs_ioctl_balance_args *bargs)
3416 {
3417         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3418
3419         bargs->flags = bctl->flags;
3420
3421         if (atomic_read(&fs_info->balance_running))
3422                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3423         if (atomic_read(&fs_info->balance_pause_req))
3424                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3425         if (atomic_read(&fs_info->balance_cancel_req))
3426                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3427
3428         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3429         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3430         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3431
3432         if (lock) {
3433                 spin_lock(&fs_info->balance_lock);
3434                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3435                 spin_unlock(&fs_info->balance_lock);
3436         } else {
3437                 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3438         }
3439 }
3440
3441 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3442 {
3443         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3444         struct btrfs_fs_info *fs_info = root->fs_info;
3445         struct btrfs_ioctl_balance_args *bargs;
3446         struct btrfs_balance_control *bctl;
3447         bool need_unlock; /* for mut. excl. ops lock */
3448         int ret;
3449
3450         if (!capable(CAP_SYS_ADMIN))
3451                 return -EPERM;
3452
3453         ret = mnt_want_write_file(file);
3454         if (ret)
3455                 return ret;
3456
3457 again:
3458         if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
3459                 mutex_lock(&fs_info->volume_mutex);
3460                 mutex_lock(&fs_info->balance_mutex);
3461                 need_unlock = true;
3462                 goto locked;
3463         }
3464
3465         /*
3466          * mut. excl. ops lock is locked.  Three possibilites:
3467          *   (1) some other op is running
3468          *   (2) balance is running
3469          *   (3) balance is paused -- special case (think resume)
3470          */
3471         mutex_lock(&fs_info->balance_mutex);
3472         if (fs_info->balance_ctl) {
3473                 /* this is either (2) or (3) */
3474                 if (!atomic_read(&fs_info->balance_running)) {
3475                         mutex_unlock(&fs_info->balance_mutex);
3476                         if (!mutex_trylock(&fs_info->volume_mutex))
3477                                 goto again;
3478                         mutex_lock(&fs_info->balance_mutex);
3479
3480                         if (fs_info->balance_ctl &&
3481                             !atomic_read(&fs_info->balance_running)) {
3482                                 /* this is (3) */
3483                                 need_unlock = false;
3484                                 goto locked;
3485                         }
3486
3487                         mutex_unlock(&fs_info->balance_mutex);
3488                         mutex_unlock(&fs_info->volume_mutex);
3489                         goto again;
3490                 } else {
3491                         /* this is (2) */
3492                         mutex_unlock(&fs_info->balance_mutex);
3493                         ret = -EINPROGRESS;
3494                         goto out;
3495                 }
3496         } else {
3497                 /* this is (1) */
3498                 mutex_unlock(&fs_info->balance_mutex);
3499                 pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3500                 ret = -EINVAL;
3501                 goto out;
3502         }
3503
3504 locked:
3505         BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
3506
3507         if (arg) {
3508                 bargs = memdup_user(arg, sizeof(*bargs));
3509                 if (IS_ERR(bargs)) {
3510                         ret = PTR_ERR(bargs);
3511                         goto out_unlock;
3512                 }
3513
3514                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
3515                         if (!fs_info->balance_ctl) {
3516                                 ret = -ENOTCONN;
3517                                 goto out_bargs;
3518                         }
3519
3520                         bctl = fs_info->balance_ctl;
3521                         spin_lock(&fs_info->balance_lock);
3522                         bctl->flags |= BTRFS_BALANCE_RESUME;
3523                         spin_unlock(&fs_info->balance_lock);
3524
3525                         goto do_balance;
3526                 }
3527         } else {
3528                 bargs = NULL;
3529         }
3530
3531         if (fs_info->balance_ctl) {
3532                 ret = -EINPROGRESS;
3533                 goto out_bargs;
3534         }
3535
3536         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3537         if (!bctl) {
3538                 ret = -ENOMEM;
3539                 goto out_bargs;
3540         }
3541
3542         bctl->fs_info = fs_info;
3543         if (arg) {
3544                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3545                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3546                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3547
3548                 bctl->flags = bargs->flags;
3549         } else {
3550                 /* balance everything - no filters */
3551                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3552         }
3553
3554 do_balance:
3555         /*
3556          * Ownership of bctl and mutually_exclusive_operation_running
3557          * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
3558          * or, if restriper was paused all the way until unmount, in
3559          * free_fs_info.  mutually_exclusive_operation_running is
3560          * cleared in __cancel_balance.
3561          */
3562         need_unlock = false;
3563
3564         ret = btrfs_balance(bctl, bargs);
3565
3566         if (arg) {
3567                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
3568                         ret = -EFAULT;
3569         }
3570
3571 out_bargs:
3572         kfree(bargs);
3573 out_unlock:
3574         mutex_unlock(&fs_info->balance_mutex);
3575         mutex_unlock(&fs_info->volume_mutex);
3576         if (need_unlock)
3577                 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3578 out:
3579         mnt_drop_write_file(file);
3580         return ret;
3581 }
3582
3583 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3584 {
3585         if (!capable(CAP_SYS_ADMIN))
3586                 return -EPERM;
3587
3588         switch (cmd) {
3589         case BTRFS_BALANCE_CTL_PAUSE:
3590                 return btrfs_pause_balance(root->fs_info);
3591         case BTRFS_BALANCE_CTL_CANCEL:
3592                 return btrfs_cancel_balance(root->fs_info);
3593         }
3594
3595         return -EINVAL;
3596 }
3597
3598 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3599                                          void __user *arg)
3600 {
3601         struct btrfs_fs_info *fs_info = root->fs_info;
3602         struct btrfs_ioctl_balance_args *bargs;
3603         int ret = 0;
3604
3605         if (!capable(CAP_SYS_ADMIN))
3606                 return -EPERM;
3607
3608         mutex_lock(&fs_info->balance_mutex);
3609         if (!fs_info->balance_ctl) {
3610                 ret = -ENOTCONN;
3611                 goto out;
3612         }
3613
3614         bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3615         if (!bargs) {
3616                 ret = -ENOMEM;
3617                 goto out;
3618         }
3619
3620         update_ioctl_balance_args(fs_info, 1, bargs);
3621
3622         if (copy_to_user(arg, bargs, sizeof(*bargs)))
3623                 ret = -EFAULT;
3624
3625         kfree(bargs);
3626 out:
3627         mutex_unlock(&fs_info->balance_mutex);
3628         return ret;
3629 }
3630
3631 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3632 {
3633         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3634         struct btrfs_ioctl_quota_ctl_args *sa;
3635         struct btrfs_trans_handle *trans = NULL;
3636         int ret;
3637         int err;
3638
3639         if (!capable(CAP_SYS_ADMIN))
3640                 return -EPERM;
3641
3642         ret = mnt_want_write_file(file);
3643         if (ret)
3644                 return ret;
3645
3646         sa = memdup_user(arg, sizeof(*sa));
3647         if (IS_ERR(sa)) {
3648                 ret = PTR_ERR(sa);
3649                 goto drop_write;
3650         }
3651
3652         if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
3653                 trans = btrfs_start_transaction(root, 2);
3654                 if (IS_ERR(trans)) {
3655                         ret = PTR_ERR(trans);
3656                         goto out;
3657                 }
3658         }
3659
3660         switch (sa->cmd) {
3661         case BTRFS_QUOTA_CTL_ENABLE:
3662                 ret = btrfs_quota_enable(trans, root->fs_info);
3663                 break;
3664         case BTRFS_QUOTA_CTL_DISABLE:
3665                 ret = btrfs_quota_disable(trans, root->fs_info);
3666                 break;
3667         case BTRFS_QUOTA_CTL_RESCAN:
3668                 ret = btrfs_quota_rescan(root->fs_info);
3669                 break;
3670         default:
3671                 ret = -EINVAL;
3672                 break;
3673         }
3674
3675         if (copy_to_user(arg, sa, sizeof(*sa)))
3676                 ret = -EFAULT;
3677
3678         if (trans) {
3679                 err = btrfs_commit_transaction(trans, root);
3680                 if (err && !ret)
3681                         ret = err;
3682         }
3683 out:
3684         kfree(sa);
3685 drop_write:
3686         mnt_drop_write_file(file);
3687         return ret;
3688 }
3689
3690 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3691 {
3692         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3693         struct btrfs_ioctl_qgroup_assign_args *sa;
3694         struct btrfs_trans_handle *trans;
3695         int ret;
3696         int err;
3697
3698         if (!capable(CAP_SYS_ADMIN))
3699                 return -EPERM;
3700
3701         ret = mnt_want_write_file(file);
3702         if (ret)
3703                 return ret;
3704
3705         sa = memdup_user(arg, sizeof(*sa));
3706         if (IS_ERR(sa)) {
3707                 ret = PTR_ERR(sa);
3708                 goto drop_write;
3709         }
3710
3711         trans = btrfs_join_transaction(root);
3712         if (IS_ERR(trans)) {
3713                 ret = PTR_ERR(trans);
3714                 goto out;
3715         }
3716
3717         /* FIXME: check if the IDs really exist */
3718         if (sa->assign) {
3719                 ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3720                                                 sa->src, sa->dst);
3721         } else {
3722                 ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3723                                                 sa->src, sa->dst);
3724         }
3725
3726         err = btrfs_end_transaction(trans, root);
3727         if (err && !ret)
3728                 ret = err;
3729
3730 out:
3731         kfree(sa);
3732 drop_write:
3733         mnt_drop_write_file(file);
3734         return ret;
3735 }
3736
3737 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3738 {
3739         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3740         struct btrfs_ioctl_qgroup_create_args *sa;
3741         struct btrfs_trans_handle *trans;
3742         int ret;
3743         int err;
3744
3745         if (!capable(CAP_SYS_ADMIN))
3746                 return -EPERM;
3747
3748         ret = mnt_want_write_file(file);
3749         if (ret)
3750                 return ret;
3751
3752         sa = memdup_user(arg, sizeof(*sa));
3753         if (IS_ERR(sa)) {
3754                 ret = PTR_ERR(sa);
3755                 goto drop_write;
3756         }
3757
3758         if (!sa->qgroupid) {
3759                 ret = -EINVAL;
3760                 goto out;
3761         }
3762
3763         trans = btrfs_join_transaction(root);
3764         if (IS_ERR(trans)) {
3765                 ret = PTR_ERR(trans);
3766                 goto out;
3767         }
3768
3769         /* FIXME: check if the IDs really exist */
3770         if (sa->create) {
3771                 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3772                                           NULL);
3773         } else {
3774                 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3775         }
3776
3777         err = btrfs_end_transaction(trans, root);
3778         if (err && !ret)
3779                 ret = err;
3780
3781 out:
3782         kfree(sa);
3783 drop_write:
3784         mnt_drop_write_file(file);
3785         return ret;
3786 }
3787
3788 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3789 {
3790         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3791         struct btrfs_ioctl_qgroup_limit_args *sa;
3792         struct btrfs_trans_handle *trans;
3793         int ret;
3794         int err;
3795         u64 qgroupid;
3796
3797         if (!capable(CAP_SYS_ADMIN))
3798                 return -EPERM;
3799
3800         ret = mnt_want_write_file(file);
3801         if (ret)
3802                 return ret;
3803
3804         sa = memdup_user(arg, sizeof(*sa));
3805         if (IS_ERR(sa)) {
3806                 ret = PTR_ERR(sa);
3807                 goto drop_write;
3808         }
3809
3810         trans = btrfs_join_transaction(root);
3811         if (IS_ERR(trans)) {
3812                 ret = PTR_ERR(trans);
3813                 goto out;
3814         }
3815
3816         qgroupid = sa->qgroupid;
3817         if (!qgroupid) {
3818                 /* take the current subvol as qgroup */
3819                 qgroupid = root->root_key.objectid;
3820         }
3821
3822         /* FIXME: check if the IDs really exist */
3823         ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3824
3825         err = btrfs_end_transaction(trans, root);
3826         if (err && !ret)
3827                 ret = err;
3828
3829 out:
3830         kfree(sa);
3831 drop_write:
3832         mnt_drop_write_file(file);
3833         return ret;
3834 }
3835
3836 static long btrfs_ioctl_set_received_subvol(struct file *file,
3837                                             void __user *arg)
3838 {
3839         struct btrfs_ioctl_received_subvol_args *sa = NULL;
3840         struct inode *inode = file_inode(file);
3841         struct btrfs_root *root = BTRFS_I(inode)->root;
3842         struct btrfs_root_item *root_item = &root->root_item;
3843         struct btrfs_trans_handle *trans;
3844         struct timespec ct = CURRENT_TIME;
3845         int ret = 0;
3846
3847         ret = mnt_want_write_file(file);
3848         if (ret < 0)
3849                 return ret;
3850
3851         down_write(&root->fs_info->subvol_sem);
3852
3853         if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3854                 ret = -EINVAL;
3855                 goto out;
3856         }
3857
3858         if (btrfs_root_readonly(root)) {
3859                 ret = -EROFS;
3860                 goto out;
3861         }
3862
3863         if (!inode_owner_or_capable(inode)) {
3864                 ret = -EACCES;
3865                 goto out;
3866         }
3867
3868         sa = memdup_user(arg, sizeof(*sa));
3869         if (IS_ERR(sa)) {
3870                 ret = PTR_ERR(sa);
3871                 sa = NULL;
3872                 goto out;
3873         }
3874
3875         trans = btrfs_start_transaction(root, 1);
3876         if (IS_ERR(trans)) {
3877                 ret = PTR_ERR(trans);
3878                 trans = NULL;
3879                 goto out;
3880         }
3881
3882         sa->rtransid = trans->transid;
3883         sa->rtime.sec = ct.tv_sec;
3884         sa->rtime.nsec = ct.tv_nsec;
3885
3886         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3887         btrfs_set_root_stransid(root_item, sa->stransid);
3888         btrfs_set_root_rtransid(root_item, sa->rtransid);
3889         root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3890         root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3891         root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3892         root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
3893
3894         ret = btrfs_update_root(trans, root->fs_info->tree_root,
3895                                 &root->root_key, &root->root_item);
3896         if (ret < 0) {
3897                 btrfs_end_transaction(trans, root);
3898                 trans = NULL;
3899                 goto out;
3900         } else {
3901                 ret = btrfs_commit_transaction(trans, root);
3902                 if (ret < 0)
3903                         goto out;
3904         }
3905
3906         ret = copy_to_user(arg, sa, sizeof(*sa));
3907         if (ret)
3908                 ret = -EFAULT;
3909
3910 out:
3911         kfree(sa);
3912         up_write(&root->fs_info->subvol_sem);
3913         mnt_drop_write_file(file);
3914         return ret;
3915 }
3916
3917 long btrfs_ioctl(struct file *file, unsigned int
3918                 cmd, unsigned long arg)
3919 {
3920         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3921         void __user *argp = (void __user *)arg;
3922
3923         switch (cmd) {
3924         case FS_IOC_GETFLAGS:
3925                 return btrfs_ioctl_getflags(file, argp);
3926         case FS_IOC_SETFLAGS:
3927                 return btrfs_ioctl_setflags(file, argp);
3928         case FS_IOC_GETVERSION:
3929                 return btrfs_ioctl_getversion(file, argp);
3930         case FITRIM:
3931                 return btrfs_ioctl_fitrim(file, argp);
3932         case BTRFS_IOC_SNAP_CREATE:
3933                 return btrfs_ioctl_snap_create(file, argp, 0);
3934         case BTRFS_IOC_SNAP_CREATE_V2:
3935                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
3936         case BTRFS_IOC_SUBVOL_CREATE:
3937                 return btrfs_ioctl_snap_create(file, argp, 1);
3938         case BTRFS_IOC_SUBVOL_CREATE_V2:
3939                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
3940         case BTRFS_IOC_SNAP_DESTROY:
3941                 return btrfs_ioctl_snap_destroy(file, argp);
3942         case BTRFS_IOC_SUBVOL_GETFLAGS:
3943                 return btrfs_ioctl_subvol_getflags(file, argp);
3944         case BTRFS_IOC_SUBVOL_SETFLAGS:
3945                 return btrfs_ioctl_subvol_setflags(file, argp);
3946         case BTRFS_IOC_DEFAULT_SUBVOL:
3947                 return btrfs_ioctl_default_subvol(file, argp);
3948         case BTRFS_IOC_DEFRAG:
3949                 return btrfs_ioctl_defrag(file, NULL);
3950         case BTRFS_IOC_DEFRAG_RANGE:
3951                 return btrfs_ioctl_defrag(file, argp);
3952         case BTRFS_IOC_RESIZE:
3953                 return btrfs_ioctl_resize(file, argp);
3954         case BTRFS_IOC_ADD_DEV:
3955                 return btrfs_ioctl_add_dev(root, argp);
3956         case BTRFS_IOC_RM_DEV:
3957                 return btrfs_ioctl_rm_dev(file, argp);
3958         case BTRFS_IOC_FS_INFO:
3959                 return btrfs_ioctl_fs_info(root, argp);
3960         case BTRFS_IOC_DEV_INFO:
3961                 return btrfs_ioctl_dev_info(root, argp);
3962         case BTRFS_IOC_BALANCE:
3963                 return btrfs_ioctl_balance(file, NULL);
3964         case BTRFS_IOC_CLONE:
3965                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3966         case BTRFS_IOC_CLONE_RANGE:
3967                 return btrfs_ioctl_clone_range(file, argp);
3968         case BTRFS_IOC_TRANS_START:
3969                 return btrfs_ioctl_trans_start(file);
3970         case BTRFS_IOC_TRANS_END:
3971                 return btrfs_ioctl_trans_end(file);
3972         case BTRFS_IOC_TREE_SEARCH:
3973                 return btrfs_ioctl_tree_search(file, argp);
3974         case BTRFS_IOC_INO_LOOKUP:
3975                 return btrfs_ioctl_ino_lookup(file, argp);
3976         case BTRFS_IOC_INO_PATHS:
3977                 return btrfs_ioctl_ino_to_path(root, argp);
3978         case BTRFS_IOC_LOGICAL_INO:
3979                 return btrfs_ioctl_logical_to_ino(root, argp);
3980         case BTRFS_IOC_SPACE_INFO:
3981                 return btrfs_ioctl_space_info(root, argp);
3982         case BTRFS_IOC_SYNC:
3983                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
3984                 return 0;
3985         case BTRFS_IOC_START_SYNC:
3986                 return btrfs_ioctl_start_sync(root, argp);
3987         case BTRFS_IOC_WAIT_SYNC:
3988                 return btrfs_ioctl_wait_sync(root, argp);
3989         case BTRFS_IOC_SCRUB:
3990                 return btrfs_ioctl_scrub(file, argp);
3991         case BTRFS_IOC_SCRUB_CANCEL:
3992                 return btrfs_ioctl_scrub_cancel(root, argp);
3993         case BTRFS_IOC_SCRUB_PROGRESS:
3994                 return btrfs_ioctl_scrub_progress(root, argp);
3995         case BTRFS_IOC_BALANCE_V2:
3996                 return btrfs_ioctl_balance(file, argp);
3997         case BTRFS_IOC_BALANCE_CTL:
3998                 return btrfs_ioctl_balance_ctl(root, arg);
3999         case BTRFS_IOC_BALANCE_PROGRESS:
4000                 return btrfs_ioctl_balance_progress(root, argp);
4001         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4002                 return btrfs_ioctl_set_received_subvol(file, argp);
4003         case BTRFS_IOC_SEND:
4004                 return btrfs_ioctl_send(file, argp);
4005         case BTRFS_IOC_GET_DEV_STATS:
4006                 return btrfs_ioctl_get_dev_stats(root, argp);
4007         case BTRFS_IOC_QUOTA_CTL:
4008                 return btrfs_ioctl_quota_ctl(file, argp);
4009         case BTRFS_IOC_QGROUP_ASSIGN:
4010                 return btrfs_ioctl_qgroup_assign(file, argp);
4011         case BTRFS_IOC_QGROUP_CREATE:
4012                 return btrfs_ioctl_qgroup_create(file, argp);
4013         case BTRFS_IOC_QGROUP_LIMIT:
4014                 return btrfs_ioctl_qgroup_limit(file, argp);
4015         case BTRFS_IOC_DEV_REPLACE:
4016                 return btrfs_ioctl_dev_replace(root, argp);
4017         }
4018
4019         return -ENOTTY;
4020 }