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 "compat.h"
  43 #include "ctree.h"
  44 #include "disk-io.h"
  45 #include "transaction.h"
  46 #include "btrfs_inode.h"
  47 #include "ioctl.h"
  48 #include "print-tree.h"
  49 #include "volumes.h"
  50 #include "locking.h"
  51
  52 /* Mask out flags that are inappropriate for the given type of inode. */
  53 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
  54 {
  55         if (S_ISDIR(mode))
  56                 return flags;
  57         else if (S_ISREG(mode))
  58                 return flags & ~FS_DIRSYNC_FL;
  59         else
  60                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
  61 }
  62
  63 /*
  64  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
  65  */
  66 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
  67 {
  68         unsigned int iflags = 0;
  69
  70         if (flags & BTRFS_INODE_SYNC)
  71                 iflags |= FS_SYNC_FL;
  72         if (flags & BTRFS_INODE_IMMUTABLE)
  73                 iflags |= FS_IMMUTABLE_FL;
  74         if (flags & BTRFS_INODE_APPEND)
  75                 iflags |= FS_APPEND_FL;
  76         if (flags & BTRFS_INODE_NODUMP)
  77                 iflags |= FS_NODUMP_FL;
  78         if (flags & BTRFS_INODE_NOATIME)
  79                 iflags |= FS_NOATIME_FL;
  80         if (flags & BTRFS_INODE_DIRSYNC)
  81                 iflags |= FS_DIRSYNC_FL;
  82
  83         return iflags;
  84 }
  85
  86 /*
  87  * Update inode->i_flags based on the btrfs internal flags.
  88  */
  89 void btrfs_update_iflags(struct inode *inode)
  90 {
  91         struct btrfs_inode *ip = BTRFS_I(inode);
  92
  93         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
  94
  95         if (ip->flags & BTRFS_INODE_SYNC)
  96                 inode->i_flags |= S_SYNC;
  97         if (ip->flags & BTRFS_INODE_IMMUTABLE)
  98                 inode->i_flags |= S_IMMUTABLE;
  99         if (ip->flags & BTRFS_INODE_APPEND)
 100                 inode->i_flags |= S_APPEND;
 101         if (ip->flags & BTRFS_INODE_NOATIME)
 102                 inode->i_flags |= S_NOATIME;
 103         if (ip->flags & BTRFS_INODE_DIRSYNC)
 104                 inode->i_flags |= S_DIRSYNC;
 105 }
 106
 107 /*
 108  * Inherit flags from the parent inode.
 109  *
 110  * Unlike extN we don't have any flags we don't want to inherit currently.
 111  */
 112 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
 113 {
 114         unsigned int flags;
 115
 116         if (!dir)
 117                 return;
 118
 119         flags = BTRFS_I(dir)->flags;
 120
 121         if (S_ISREG(inode->i_mode))
 122                 flags &= ~BTRFS_INODE_DIRSYNC;
 123         else if (!S_ISDIR(inode->i_mode))
 124                 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
 125
 126         BTRFS_I(inode)->flags = flags;
 127         btrfs_update_iflags(inode);
 128 }
 129
 130 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
 131 {
 132         struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
 133         unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
 134
 135         if (copy_to_user(arg, &flags, sizeof(flags)))
 136                 return -EFAULT;
 137         return 0;
 138 }
 139
 140 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 141 {
 142         struct inode *inode = file->f_path.dentry->d_inode;
 143         struct btrfs_inode *ip = BTRFS_I(inode);
 144         struct btrfs_root *root = ip->root;
 145         struct btrfs_trans_handle *trans;
 146         unsigned int flags, oldflags;
 147         int ret;
 148
 149         if (copy_from_user(&flags, arg, sizeof(flags)))
 150                 return -EFAULT;
 151
 152         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
 153                       FS_NOATIME_FL | FS_NODUMP_FL | \
 154                       FS_SYNC_FL | FS_DIRSYNC_FL))
 155                 return -EOPNOTSUPP;
 156
 157         if (!is_owner_or_cap(inode))
 158                 return -EACCES;
 159
 160         mutex_lock(&inode->i_mutex);
 161
 162         flags = btrfs_mask_flags(inode->i_mode, flags);
 163         oldflags = btrfs_flags_to_ioctl(ip->flags);
 164         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 165                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 166                         ret = -EPERM;
 167                         goto out_unlock;
 168                 }
 169         }
 170
 171         ret = mnt_want_write(file->f_path.mnt);
 172         if (ret)
 173                 goto out_unlock;
 174
 175         if (flags & FS_SYNC_FL)
 176                 ip->flags |= BTRFS_INODE_SYNC;
 177         else
 178                 ip->flags &= ~BTRFS_INODE_SYNC;
 179         if (flags & FS_IMMUTABLE_FL)
 180                 ip->flags |= BTRFS_INODE_IMMUTABLE;
 181         else
 182                 ip->flags &= ~BTRFS_INODE_IMMUTABLE;
 183         if (flags & FS_APPEND_FL)
 184                 ip->flags |= BTRFS_INODE_APPEND;
 185         else
 186                 ip->flags &= ~BTRFS_INODE_APPEND;
 187         if (flags & FS_NODUMP_FL)
 188                 ip->flags |= BTRFS_INODE_NODUMP;
 189         else
 190                 ip->flags &= ~BTRFS_INODE_NODUMP;
 191         if (flags & FS_NOATIME_FL)
 192                 ip->flags |= BTRFS_INODE_NOATIME;
 193         else
 194                 ip->flags &= ~BTRFS_INODE_NOATIME;
 195         if (flags & FS_DIRSYNC_FL)
 196                 ip->flags |= BTRFS_INODE_DIRSYNC;
 197         else
 198                 ip->flags &= ~BTRFS_INODE_DIRSYNC;
 199
 200
 201         trans = btrfs_join_transaction(root, 1);
 202         BUG_ON(!trans);
 203
 204         ret = btrfs_update_inode(trans, root, inode);
 205         BUG_ON(ret);
 206
 207         btrfs_update_iflags(inode);
 208         inode->i_ctime = CURRENT_TIME;
 209         btrfs_end_transaction(trans, root);
 210
 211         mnt_drop_write(file->f_path.mnt);
 212  out_unlock:
 213         mutex_unlock(&inode->i_mutex);
 214         return 0;
 215 }
 216
 217 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
 218 {
 219         struct inode *inode = file->f_path.dentry->d_inode;
 220
 221         return put_user(inode->i_generation, arg);
 222 }
 223
 224 static noinline int create_subvol(struct btrfs_root *root,
 225                                   struct dentry *dentry,
 226                                   char *name, int namelen)
 227 {
 228         struct btrfs_trans_handle *trans;
 229         struct btrfs_key key;
 230         struct btrfs_root_item root_item;
 231         struct btrfs_inode_item *inode_item;
 232         struct extent_buffer *leaf;
 233         struct btrfs_root *new_root;
 234         struct inode *dir = dentry->d_parent->d_inode;
 235         int ret;
 236         int err;
 237         u64 objectid;
 238         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 239         u64 index = 0;
 240
 241         /*
 242          * 1 - inode item
 243          * 2 - refs
 244          * 1 - root item
 245          * 2 - dir items
 246          */
 247         ret = btrfs_reserve_metadata_space(root, 6);
 248         if (ret)
 249                 return ret;
 250
 251         trans = btrfs_start_transaction(root, 1);
 252         BUG_ON(!trans);
 253
 254         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
 255                                        0, &objectid);
 256         if (ret)
 257                 goto fail;
 258
 259         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
 260                                       0, objectid, NULL, 0, 0, 0);
 261         if (IS_ERR(leaf)) {
 262                 ret = PTR_ERR(leaf);
 263                 goto fail;
 264         }
 265
 266         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
 267         btrfs_set_header_bytenr(leaf, leaf->start);
 268         btrfs_set_header_generation(leaf, trans->transid);
 269         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
 270         btrfs_set_header_owner(leaf, objectid);
 271
 272         write_extent_buffer(leaf, root->fs_info->fsid,
 273                             (unsigned long)btrfs_header_fsid(leaf),
 274                             BTRFS_FSID_SIZE);
 275         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 276                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 277                             BTRFS_UUID_SIZE);
 278         btrfs_mark_buffer_dirty(leaf);
 279
 280         inode_item = &root_item.inode;
 281         memset(inode_item, 0, sizeof(*inode_item));
 282         inode_item->generation = cpu_to_le64(1);
 283         inode_item->size = cpu_to_le64(3);
 284         inode_item->nlink = cpu_to_le32(1);
 285         inode_item->nbytes = cpu_to_le64(root->leafsize);
 286         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 287
 288         root_item.flags = 0;
 289         root_item.byte_limit = 0;
 290         inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
 291
 292         btrfs_set_root_bytenr(&root_item, leaf->start);
 293         btrfs_set_root_generation(&root_item, trans->transid);
 294         btrfs_set_root_level(&root_item, 0);
 295         btrfs_set_root_refs(&root_item, 1);
 296         btrfs_set_root_used(&root_item, leaf->len);
 297         btrfs_set_root_last_snapshot(&root_item, 0);
 298
 299         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 300         root_item.drop_level = 0;
 301
 302         btrfs_tree_unlock(leaf);
 303         free_extent_buffer(leaf);
 304         leaf = NULL;
 305
 306         btrfs_set_root_dirid(&root_item, new_dirid);
 307
 308         key.objectid = objectid;
 309         key.offset = 0;
 310         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 311         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 312                                 &root_item);
 313         if (ret)
 314                 goto fail;
 315
 316         key.offset = (u64)-1;
 317         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 318         BUG_ON(IS_ERR(new_root));
 319
 320         btrfs_record_root_in_trans(trans, new_root);
 321
 322         ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
 323                                        BTRFS_I(dir)->block_group);
 324         /*
 325          * insert the directory item
 326          */
 327         ret = btrfs_set_inode_index(dir, &index);
 328         BUG_ON(ret);
 329
 330         ret = btrfs_insert_dir_item(trans, root,
 331                                     name, namelen, dir->i_ino, &key,
 332                                     BTRFS_FT_DIR, index);
 333         if (ret)
 334                 goto fail;
 335
 336         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 337         ret = btrfs_update_inode(trans, root, dir);
 338         BUG_ON(ret);
 339
 340         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 341                                  objectid, root->root_key.objectid,
 342                                  dir->i_ino, index, name, namelen);
 343
 344         BUG_ON(ret);
 345
 346         d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
 347 fail:
 348         err = btrfs_commit_transaction(trans, root);
 349         if (err && !ret)
 350                 ret = err;
 351
 352         btrfs_unreserve_metadata_space(root, 6);
 353         return ret;
 354 }
 355
 356 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 357                            char *name, int namelen)
 358 {
 359         struct inode *inode;
 360         struct btrfs_pending_snapshot *pending_snapshot;
 361         struct btrfs_trans_handle *trans;
 362         int ret;
 363
 364         if (!root->ref_cows)
 365                 return -EINVAL;
 366
 367         /*
 368          * 1 - inode item
 369          * 2 - refs
 370          * 1 - root item
 371          * 2 - dir items
 372          */
 373         ret = btrfs_reserve_metadata_space(root, 6);
 374         if (ret)
 375                 goto fail;
 376
 377         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 378         if (!pending_snapshot) {
 379                 ret = -ENOMEM;
 380                 btrfs_unreserve_metadata_space(root, 6);
 381                 goto fail;
 382         }
 383         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
 384         if (!pending_snapshot->name) {
 385                 ret = -ENOMEM;
 386                 kfree(pending_snapshot);
 387                 btrfs_unreserve_metadata_space(root, 6);
 388                 goto fail;
 389         }
 390         memcpy(pending_snapshot->name, name, namelen);
 391         pending_snapshot->name[namelen] = '\0';
 392         pending_snapshot->dentry = dentry;
 393         trans = btrfs_start_transaction(root, 1);
 394         BUG_ON(!trans);
 395         pending_snapshot->root = root;
 396         list_add(&pending_snapshot->list,
 397                  &trans->transaction->pending_snapshots);
 398         ret = btrfs_commit_transaction(trans, root);
 399         BUG_ON(ret);
 400         btrfs_unreserve_metadata_space(root, 6);
 401
 402         inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
 403         if (IS_ERR(inode)) {
 404                 ret = PTR_ERR(inode);
 405                 goto fail;
 406         }
 407         BUG_ON(!inode);
 408         d_instantiate(dentry, inode);
 409         ret = 0;
 410 fail:
 411         return ret;
 412 }
 413
 414 /* copy of may_create in fs/namei.c() */
 415 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 416 {
 417         if (child->d_inode)
 418                 return -EEXIST;
 419         if (IS_DEADDIR(dir))
 420                 return -ENOENT;
 421         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 422 }
 423
 424 /*
 425  * Create a new subvolume below @parent.  This is largely modeled after
 426  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 427  * inside this filesystem so it's quite a bit simpler.
 428  */
 429 static noinline int btrfs_mksubvol(struct path *parent,
 430                                    char *name, int namelen,
 431                                    struct btrfs_root *snap_src)
 432 {
 433         struct inode *dir  = parent->dentry->d_inode;
 434         struct dentry *dentry;
 435         int error;
 436
 437         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 438
 439         dentry = lookup_one_len(name, parent->dentry, namelen);
 440         error = PTR_ERR(dentry);
 441         if (IS_ERR(dentry))
 442                 goto out_unlock;
 443
 444         error = -EEXIST;
 445         if (dentry->d_inode)
 446                 goto out_dput;
 447
 448         error = mnt_want_write(parent->mnt);
 449         if (error)
 450                 goto out_dput;
 451
 452         error = btrfs_may_create(dir, dentry);
 453         if (error)
 454                 goto out_drop_write;
 455
 456         down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 457
 458         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
 459                 goto out_up_read;
 460
 461         if (snap_src) {
 462                 error = create_snapshot(snap_src, dentry,
 463                                         name, namelen);
 464         } else {
 465                 error = create_subvol(BTRFS_I(dir)->root, dentry,
 466                                       name, namelen);
 467         }
 468         if (!error)
 469                 fsnotify_mkdir(dir, dentry);
 470 out_up_read:
 471         up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
 472 out_drop_write:
 473         mnt_drop_write(parent->mnt);
 474 out_dput:
 475         dput(dentry);
 476 out_unlock:
 477         mutex_unlock(&dir->i_mutex);
 478         return error;
 479 }
 480
 481 static int btrfs_defrag_file(struct file *file)
 482 {
 483         struct inode *inode = fdentry(file)->d_inode;
 484         struct btrfs_root *root = BTRFS_I(inode)->root;
 485         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 486         struct btrfs_ordered_extent *ordered;
 487         struct page *page;
 488         unsigned long last_index;
 489         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 490         unsigned long total_read = 0;
 491         u64 page_start;
 492         u64 page_end;
 493         unsigned long i;
 494         int ret;
 495
 496         ret = btrfs_check_data_free_space(root, inode, inode->i_size);
 497         if (ret)
 498                 return -ENOSPC;
 499
 500         mutex_lock(&inode->i_mutex);
 501         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
 502         for (i = 0; i <= last_index; i++) {
 503                 if (total_read % ra_pages == 0) {
 504                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 505                                        min(last_index, i + ra_pages - 1));
 506                 }
 507                 total_read++;
 508 again:
 509                 page = grab_cache_page(inode->i_mapping, i);
 510                 if (!page)
 511                         goto out_unlock;
 512                 if (!PageUptodate(page)) {
 513                         btrfs_readpage(NULL, page);
 514                         lock_page(page);
 515                         if (!PageUptodate(page)) {
 516                                 unlock_page(page);
 517                                 page_cache_release(page);
 518                                 goto out_unlock;
 519                         }
 520                 }
 521
 522                 wait_on_page_writeback(page);
 523
 524                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 525                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 526                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 527
 528                 ordered = btrfs_lookup_ordered_extent(inode, page_start);
 529                 if (ordered) {
 530                         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 531                         unlock_page(page);
 532                         page_cache_release(page);
 533                         btrfs_start_ordered_extent(inode, ordered, 1);
 534                         btrfs_put_ordered_extent(ordered);
 535                         goto again;
 536                 }
 537                 set_page_extent_mapped(page);
 538
 539                 /*
 540                  * this makes sure page_mkwrite is called on the
 541                  * page if it is dirtied again later
 542                  */
 543                 clear_page_dirty_for_io(page);
 544
 545                 btrfs_set_extent_delalloc(inode, page_start, page_end);
 546                 set_page_dirty(page);
 547                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 548                 unlock_page(page);
 549                 page_cache_release(page);
 550                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 551         }
 552
 553 out_unlock:
 554         mutex_unlock(&inode->i_mutex);
 555         return 0;
 556 }
 557
 558 static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 559                                         void __user *arg)
 560 {
 561         u64 new_size;
 562         u64 old_size;
 563         u64 devid = 1;
 564         struct btrfs_ioctl_vol_args *vol_args;
 565         struct btrfs_trans_handle *trans;
 566         struct btrfs_device *device = NULL;
 567         char *sizestr;
 568         char *devstr = NULL;
 569         int ret = 0;
 570         int namelen;
 571         int mod = 0;
 572
 573         if (root->fs_info->sb->s_flags & MS_RDONLY)
 574                 return -EROFS;
 575
 576         if (!capable(CAP_SYS_ADMIN))
 577                 return -EPERM;
 578
 579         vol_args = memdup_user(arg, sizeof(*vol_args));
 580         if (IS_ERR(vol_args))
 581                 return PTR_ERR(vol_args);
 582
 583         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 584         namelen = strlen(vol_args->name);
 585
 586         mutex_lock(&root->fs_info->volume_mutex);
 587         sizestr = vol_args->name;
 588         devstr = strchr(sizestr, ':');
 589         if (devstr) {
 590                 char *end;
 591                 sizestr = devstr + 1;
 592                 *devstr = '\0';
 593                 devstr = vol_args->name;
 594                 devid = simple_strtoull(devstr, &end, 10);
 595                 printk(KERN_INFO "resizing devid %llu\n",
 596                        (unsigned long long)devid);
 597         }
 598         device = btrfs_find_device(root, devid, NULL, NULL);
 599         if (!device) {
 600                 printk(KERN_INFO "resizer unable to find device %llu\n",
 601                        (unsigned long long)devid);
 602                 ret = -EINVAL;
 603                 goto out_unlock;
 604         }
 605         if (!strcmp(sizestr, "max"))
 606                 new_size = device->bdev->bd_inode->i_size;
 607         else {
 608                 if (sizestr[0] == '-') {
 609                         mod = -1;
 610                         sizestr++;
 611                 } else if (sizestr[0] == '+') {
 612                         mod = 1;
 613                         sizestr++;
 614                 }
 615                 new_size = btrfs_parse_size(sizestr);
 616                 if (new_size == 0) {
 617                         ret = -EINVAL;
 618                         goto out_unlock;
 619                 }
 620         }
 621
 622         old_size = device->total_bytes;
 623
 624         if (mod < 0) {
 625                 if (new_size > old_size) {
 626                         ret = -EINVAL;
 627                         goto out_unlock;
 628                 }
 629                 new_size = old_size - new_size;
 630         } else if (mod > 0) {
 631                 new_size = old_size + new_size;
 632         }
 633
 634         if (new_size < 256 * 1024 * 1024) {
 635                 ret = -EINVAL;
 636                 goto out_unlock;
 637         }
 638         if (new_size > device->bdev->bd_inode->i_size) {
 639                 ret = -EFBIG;
 640                 goto out_unlock;
 641         }
 642
 643         do_div(new_size, root->sectorsize);
 644         new_size *= root->sectorsize;
 645
 646         printk(KERN_INFO "new size for %s is %llu\n",
 647                 device->name, (unsigned long long)new_size);
 648
 649         if (new_size > old_size) {
 650                 trans = btrfs_start_transaction(root, 1);
 651                 ret = btrfs_grow_device(trans, device, new_size);
 652                 btrfs_commit_transaction(trans, root);
 653         } else {
 654                 ret = btrfs_shrink_device(device, new_size);
 655         }
 656
 657 out_unlock:
 658         mutex_unlock(&root->fs_info->volume_mutex);
 659         kfree(vol_args);
 660         return ret;
 661 }
 662
 663 static noinline int btrfs_ioctl_snap_create(struct file *file,
 664                                             void __user *arg, int subvol)
 665 {
 666         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 667         struct btrfs_ioctl_vol_args *vol_args;
 668         struct file *src_file;
 669         int namelen;
 670         int ret = 0;
 671
 672         if (root->fs_info->sb->s_flags & MS_RDONLY)
 673                 return -EROFS;
 674
 675         vol_args = memdup_user(arg, sizeof(*vol_args));
 676         if (IS_ERR(vol_args))
 677                 return PTR_ERR(vol_args);
 678
 679         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 680         namelen = strlen(vol_args->name);
 681         if (strchr(vol_args->name, '/')) {
 682                 ret = -EINVAL;
 683                 goto out;
 684         }
 685
 686         if (subvol) {
 687                 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
 688                                      NULL);
 689         } else {
 690                 struct inode *src_inode;
 691                 src_file = fget(vol_args->fd);
 692                 if (!src_file) {
 693                         ret = -EINVAL;
 694                         goto out;
 695                 }
 696
 697                 src_inode = src_file->f_path.dentry->d_inode;
 698                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
 699                         printk(KERN_INFO "btrfs: Snapshot src from "
 700                                "another FS\n");
 701                         ret = -EINVAL;
 702                         fput(src_file);
 703                         goto out;
 704                 }
 705                 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen,
 706                                      BTRFS_I(src_inode)->root);
 707                 fput(src_file);
 708         }
 709 out:
 710         kfree(vol_args);
 711         return ret;
 712 }
 713
 714 /*
 715  * helper to check if the subvolume references other subvolumes
 716  */
 717 static noinline int may_destroy_subvol(struct btrfs_root *root)
 718 {
 719         struct btrfs_path *path;
 720         struct btrfs_key key;
 721         int ret;
 722
 723         path = btrfs_alloc_path();
 724         if (!path)
 725                 return -ENOMEM;
 726
 727         key.objectid = root->root_key.objectid;
 728         key.type = BTRFS_ROOT_REF_KEY;
 729         key.offset = (u64)-1;
 730
 731         ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
 732                                 &key, path, 0, 0);
 733         if (ret < 0)
 734                 goto out;
 735         BUG_ON(ret == 0);
 736
 737         ret = 0;
 738         if (path->slots[0] > 0) {
 739                 path->slots[0]--;
 740                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
 741                 if (key.objectid == root->root_key.objectid &&
 742                     key.type == BTRFS_ROOT_REF_KEY)
 743                         ret = -ENOTEMPTY;
 744         }
 745 out:
 746         btrfs_free_path(path);
 747         return ret;
 748 }
 749
 750 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 751                                              void __user *arg)
 752 {
 753         struct dentry *parent = fdentry(file);
 754         struct dentry *dentry;
 755         struct inode *dir = parent->d_inode;
 756         struct inode *inode;
 757         struct btrfs_root *root = BTRFS_I(dir)->root;
 758         struct btrfs_root *dest = NULL;
 759         struct btrfs_ioctl_vol_args *vol_args;
 760         struct btrfs_trans_handle *trans;
 761         int namelen;
 762         int ret;
 763         int err = 0;
 764
 765         if (!capable(CAP_SYS_ADMIN))
 766                 return -EPERM;
 767
 768         vol_args = memdup_user(arg, sizeof(*vol_args));
 769         if (IS_ERR(vol_args))
 770                 return PTR_ERR(vol_args);
 771
 772         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 773         namelen = strlen(vol_args->name);
 774         if (strchr(vol_args->name, '/') ||
 775             strncmp(vol_args->name, "..", namelen) == 0) {
 776                 err = -EINVAL;
 777                 goto out;
 778         }
 779
 780         err = mnt_want_write(file->f_path.mnt);
 781         if (err)
 782                 goto out;
 783
 784         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
 785         dentry = lookup_one_len(vol_args->name, parent, namelen);
 786         if (IS_ERR(dentry)) {
 787                 err = PTR_ERR(dentry);
 788                 goto out_unlock_dir;
 789         }
 790
 791         if (!dentry->d_inode) {
 792                 err = -ENOENT;
 793                 goto out_dput;
 794         }
 795
 796         inode = dentry->d_inode;
 797         if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
 798                 err = -EINVAL;
 799                 goto out_dput;
 800         }
 801
 802         dest = BTRFS_I(inode)->root;
 803
 804         mutex_lock(&inode->i_mutex);
 805         err = d_invalidate(dentry);
 806         if (err)
 807                 goto out_unlock;
 808
 809         down_write(&root->fs_info->subvol_sem);
 810
 811         err = may_destroy_subvol(dest);
 812         if (err)
 813                 goto out_up_write;
 814
 815         trans = btrfs_start_transaction(root, 1);
 816         ret = btrfs_unlink_subvol(trans, root, dir,
 817                                 dest->root_key.objectid,
 818                                 dentry->d_name.name,
 819                                 dentry->d_name.len);
 820         BUG_ON(ret);
 821
 822         btrfs_record_root_in_trans(trans, dest);
 823
 824         memset(&dest->root_item.drop_progress, 0,
 825                 sizeof(dest->root_item.drop_progress));
 826         dest->root_item.drop_level = 0;
 827         btrfs_set_root_refs(&dest->root_item, 0);
 828
 829         ret = btrfs_insert_orphan_item(trans,
 830                                 root->fs_info->tree_root,
 831                                 dest->root_key.objectid);
 832         BUG_ON(ret);
 833
 834         ret = btrfs_commit_transaction(trans, root);
 835         BUG_ON(ret);
 836         inode->i_flags |= S_DEAD;
 837 out_up_write:
 838         up_write(&root->fs_info->subvol_sem);
 839 out_unlock:
 840         mutex_unlock(&inode->i_mutex);
 841         if (!err) {
 842                 shrink_dcache_sb(root->fs_info->sb);
 843                 btrfs_invalidate_inodes(dest);
 844                 d_delete(dentry);
 845         }
 846 out_dput:
 847         dput(dentry);
 848 out_unlock_dir:
 849         mutex_unlock(&dir->i_mutex);
 850         mnt_drop_write(file->f_path.mnt);
 851 out:
 852         kfree(vol_args);
 853         return err;
 854 }
 855
 856 static int btrfs_ioctl_defrag(struct file *file)
 857 {
 858         struct inode *inode = fdentry(file)->d_inode;
 859         struct btrfs_root *root = BTRFS_I(inode)->root;
 860         int ret;
 861
 862         ret = mnt_want_write(file->f_path.mnt);
 863         if (ret)
 864                 return ret;
 865
 866         switch (inode->i_mode & S_IFMT) {
 867         case S_IFDIR:
 868                 if (!capable(CAP_SYS_ADMIN)) {
 869                         ret = -EPERM;
 870                         goto out;
 871                 }
 872                 btrfs_defrag_root(root, 0);
 873                 btrfs_defrag_root(root->fs_info->extent_root, 0);
 874                 break;
 875         case S_IFREG:
 876                 if (!(file->f_mode & FMODE_WRITE)) {
 877                         ret = -EINVAL;
 878                         goto out;
 879                 }
 880                 btrfs_defrag_file(file);
 881                 break;
 882         }
 883 out:
 884         mnt_drop_write(file->f_path.mnt);
 885         return ret;
 886 }
 887
 888 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 889 {
 890         struct btrfs_ioctl_vol_args *vol_args;
 891         int ret;
 892
 893         if (!capable(CAP_SYS_ADMIN))
 894                 return -EPERM;
 895
 896         vol_args = memdup_user(arg, sizeof(*vol_args));
 897         if (IS_ERR(vol_args))
 898                 return PTR_ERR(vol_args);
 899
 900         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 901         ret = btrfs_init_new_device(root, vol_args->name);
 902
 903         kfree(vol_args);
 904         return ret;
 905 }
 906
 907 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 908 {
 909         struct btrfs_ioctl_vol_args *vol_args;
 910         int ret;
 911
 912         if (!capable(CAP_SYS_ADMIN))
 913                 return -EPERM;
 914
 915         if (root->fs_info->sb->s_flags & MS_RDONLY)
 916                 return -EROFS;
 917
 918         vol_args = memdup_user(arg, sizeof(*vol_args));
 919         if (IS_ERR(vol_args))
 920                 return PTR_ERR(vol_args);
 921
 922         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 923         ret = btrfs_rm_device(root, vol_args->name);
 924
 925         kfree(vol_args);
 926         return ret;
 927 }
 928
 929 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 930                                        u64 off, u64 olen, u64 destoff)
 931 {
 932         struct inode *inode = fdentry(file)->d_inode;
 933         struct btrfs_root *root = BTRFS_I(inode)->root;
 934         struct file *src_file;
 935         struct inode *src;
 936         struct btrfs_trans_handle *trans;
 937         struct btrfs_path *path;
 938         struct extent_buffer *leaf;
 939         char *buf;
 940         struct btrfs_key key;
 941         u32 nritems;
 942         int slot;
 943         int ret;
 944         u64 len = olen;
 945         u64 bs = root->fs_info->sb->s_blocksize;
 946         u64 hint_byte;
 947
 948         /*
 949          * TODO:
 950          * - split compressed inline extents.  annoying: we need to
 951          *   decompress into destination's address_space (the file offset
 952          *   may change, so source mapping won't do), then recompress (or
 953          *   otherwise reinsert) a subrange.
 954          * - allow ranges within the same file to be cloned (provided
 955          *   they don't overlap)?
 956          */
 957
 958         /* the destination must be opened for writing */
 959         if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
 960                 return -EINVAL;
 961
 962         ret = mnt_want_write(file->f_path.mnt);
 963         if (ret)
 964                 return ret;
 965
 966         src_file = fget(srcfd);
 967         if (!src_file) {
 968                 ret = -EBADF;
 969                 goto out_drop_write;
 970         }
 971
 972         src = src_file->f_dentry->d_inode;
 973
 974         ret = -EINVAL;
 975         if (src == inode)
 976                 goto out_fput;
 977
 978         /* the src must be open for reading */
 979         if (!(src_file->f_mode & FMODE_READ))
 980                 goto out_fput;
 981
 982         ret = -EISDIR;
 983         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
 984                 goto out_fput;
 985
 986         ret = -EXDEV;
 987         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
 988                 goto out_fput;
 989
 990         ret = -ENOMEM;
 991         buf = vmalloc(btrfs_level_size(root, 0));
 992         if (!buf)
 993                 goto out_fput;
 994
 995         path = btrfs_alloc_path();
 996         if (!path) {
 997                 vfree(buf);
 998                 goto out_fput;
 999         }
1000         path->reada = 2;
1001
1002         if (inode < src) {
1003                 mutex_lock(&inode->i_mutex);
1004                 mutex_lock(&src->i_mutex);
1005         } else {
1006                 mutex_lock(&src->i_mutex);
1007                 mutex_lock(&inode->i_mutex);
1008         }
1009
1010         /* determine range to clone */
1011         ret = -EINVAL;
1012         if (off + len > src->i_size || off + len < off)
1013                 goto out_unlock;
1014         if (len == 0)
1015                 olen = len = src->i_size - off;
1016         /* if we extend to eof, continue to block boundary */
1017         if (off + len == src->i_size)
1018                 len = ((src->i_size + bs-1) & ~(bs-1))
1019                         - off;
1020
1021         /* verify the end result is block aligned */
1022         if ((off & (bs-1)) ||
1023             ((off + len) & (bs-1)))
1024                 goto out_unlock;
1025
1026         /* do any pending delalloc/csum calc on src, one way or
1027            another, and lock file content */
1028         while (1) {
1029                 struct btrfs_ordered_extent *ordered;
1030                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1031                 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
1032                 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
1033                         break;
1034                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1035                 if (ordered)
1036                         btrfs_put_ordered_extent(ordered);
1037                 btrfs_wait_ordered_range(src, off, off+len);
1038         }
1039
1040         trans = btrfs_start_transaction(root, 1);
1041         BUG_ON(!trans);
1042
1043         /* punch hole in destination first */
1044         btrfs_drop_extents(trans, inode, off, off + len, &hint_byte, 1);
1045
1046         /* clone data */
1047         key.objectid = src->i_ino;
1048         key.type = BTRFS_EXTENT_DATA_KEY;
1049         key.offset = 0;
1050
1051         while (1) {
1052                 /*
1053                  * note the key will change type as we walk through the
1054                  * tree.
1055                  */
1056                 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
1057                 if (ret < 0)
1058                         goto out;
1059
1060                 nritems = btrfs_header_nritems(path->nodes[0]);
1061                 if (path->slots[0] >= nritems) {
1062                         ret = btrfs_next_leaf(root, path);
1063                         if (ret < 0)
1064                                 goto out;
1065                         if (ret > 0)
1066                                 break;
1067                         nritems = btrfs_header_nritems(path->nodes[0]);
1068                 }
1069                 leaf = path->nodes[0];
1070                 slot = path->slots[0];
1071
1072                 btrfs_item_key_to_cpu(leaf, &key, slot);
1073                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
1074                     key.objectid != src->i_ino)
1075                         break;
1076
1077                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
1078                         struct btrfs_file_extent_item *extent;
1079                         int type;
1080                         u32 size;
1081                         struct btrfs_key new_key;
1082                         u64 disko = 0, diskl = 0;
1083                         u64 datao = 0, datal = 0;
1084                         u8 comp;
1085
1086                         size = btrfs_item_size_nr(leaf, slot);
1087                         read_extent_buffer(leaf, buf,
1088                                            btrfs_item_ptr_offset(leaf, slot),
1089                                            size);
1090
1091                         extent = btrfs_item_ptr(leaf, slot,
1092                                                 struct btrfs_file_extent_item);
1093                         comp = btrfs_file_extent_compression(leaf, extent);
1094                         type = btrfs_file_extent_type(leaf, extent);
1095                         if (type == BTRFS_FILE_EXTENT_REG ||
1096                             type == BTRFS_FILE_EXTENT_PREALLOC) {
1097                                 disko = btrfs_file_extent_disk_bytenr(leaf,
1098                                                                       extent);
1099                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
1100                                                                  extent);
1101                                 datao = btrfs_file_extent_offset(leaf, extent);
1102                                 datal = btrfs_file_extent_num_bytes(leaf,
1103                                                                     extent);
1104                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1105                                 /* take upper bound, may be compressed */
1106                                 datal = btrfs_file_extent_ram_bytes(leaf,
1107                                                                     extent);
1108                         }
1109                         btrfs_release_path(root, path);
1110
1111                         if (key.offset + datal < off ||
1112                             key.offset >= off+len)
1113                                 goto next;
1114
1115                         memcpy(&new_key, &key, sizeof(new_key));
1116                         new_key.objectid = inode->i_ino;
1117                         new_key.offset = key.offset + destoff - off;
1118
1119                         if (type == BTRFS_FILE_EXTENT_REG ||
1120                             type == BTRFS_FILE_EXTENT_PREALLOC) {
1121                                 ret = btrfs_insert_empty_item(trans, root, path,
1122                                                               &new_key, size);
1123                                 if (ret)
1124                                         goto out;
1125
1126                                 leaf = path->nodes[0];
1127                                 slot = path->slots[0];
1128                                 write_extent_buffer(leaf, buf,
1129                                             btrfs_item_ptr_offset(leaf, slot),
1130                                             size);
1131
1132                                 extent = btrfs_item_ptr(leaf, slot,
1133                                                 struct btrfs_file_extent_item);
1134
1135                                 if (off > key.offset) {
1136                                         datao += off - key.offset;
1137                                         datal -= off - key.offset;
1138                                 }
1139
1140                                 if (key.offset + datal > off + len)
1141                                         datal = off + len - key.offset;
1142
1143                                 /* disko == 0 means it's a hole */
1144                                 if (!disko)
1145                                         datao = 0;
1146
1147                                 btrfs_set_file_extent_offset(leaf, extent,
1148                                                              datao);
1149                                 btrfs_set_file_extent_num_bytes(leaf, extent,
1150                                                                 datal);
1151                                 if (disko) {
1152                                         inode_add_bytes(inode, datal);
1153                                         ret = btrfs_inc_extent_ref(trans, root,
1154                                                         disko, diskl, 0,
1155                                                         root->root_key.objectid,
1156                                                         inode->i_ino,
1157                                                         new_key.offset - datao);
1158                                         BUG_ON(ret);
1159                                 }
1160                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
1161                                 u64 skip = 0;
1162                                 u64 trim = 0;
1163                                 if (off > key.offset) {
1164                                         skip = off - key.offset;
1165                                         new_key.offset += skip;
1166                                 }
1167
1168                                 if (key.offset + datal > off+len)
1169                                         trim = key.offset + datal - (off+len);
1170
1171                                 if (comp && (skip || trim)) {
1172                                         ret = -EINVAL;
1173                                         goto out;
1174                                 }
1175                                 size -= skip + trim;
1176                                 datal -= skip + trim;
1177                                 ret = btrfs_insert_empty_item(trans, root, path,
1178                                                               &new_key, size);
1179                                 if (ret)
1180                                         goto out;
1181
1182                                 if (skip) {
1183                                         u32 start =
1184                                           btrfs_file_extent_calc_inline_size(0);
1185                                         memmove(buf+start, buf+start+skip,
1186                                                 datal);
1187                                 }
1188
1189                                 leaf = path->nodes[0];
1190                                 slot = path->slots[0];
1191                                 write_extent_buffer(leaf, buf,
1192                                             btrfs_item_ptr_offset(leaf, slot),
1193                                             size);
1194                                 inode_add_bytes(inode, datal);
1195                         }
1196
1197                         btrfs_mark_buffer_dirty(leaf);
1198                 }
1199
1200 next:
1201                 btrfs_release_path(root, path);
1202                 key.offset++;
1203         }
1204         ret = 0;
1205 out:
1206         btrfs_release_path(root, path);
1207         if (ret == 0) {
1208                 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1209                 if (destoff + olen > inode->i_size)
1210                         btrfs_i_size_write(inode, destoff + olen);
1211                 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
1212                 ret = btrfs_update_inode(trans, root, inode);
1213         }
1214         btrfs_end_transaction(trans, root);
1215         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
1216         if (ret)
1217                 vmtruncate(inode, 0);
1218 out_unlock:
1219         mutex_unlock(&src->i_mutex);
1220         mutex_unlock(&inode->i_mutex);
1221         vfree(buf);
1222         btrfs_free_path(path);
1223 out_fput:
1224         fput(src_file);
1225 out_drop_write:
1226         mnt_drop_write(file->f_path.mnt);
1227         return ret;
1228 }
1229
1230 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
1231 {
1232         struct btrfs_ioctl_clone_range_args args;
1233
1234         if (copy_from_user(&args, argp, sizeof(args)))
1235                 return -EFAULT;
1236         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
1237                                  args.src_length, args.dest_offset);
1238 }
1239
1240 /*
1241  * there are many ways the trans_start and trans_end ioctls can lead
1242  * to deadlocks.  They should only be used by applications that
1243  * basically own the machine, and have a very in depth understanding
1244  * of all the possible deadlocks and enospc problems.
1245  */
1246 static long btrfs_ioctl_trans_start(struct file *file)
1247 {
1248         struct inode *inode = fdentry(file)->d_inode;
1249         struct btrfs_root *root = BTRFS_I(inode)->root;
1250         struct btrfs_trans_handle *trans;
1251         int ret;
1252
1253         ret = -EPERM;
1254         if (!capable(CAP_SYS_ADMIN))
1255                 goto out;
1256
1257         ret = -EINPROGRESS;
1258         if (file->private_data)
1259                 goto out;
1260
1261         ret = mnt_want_write(file->f_path.mnt);
1262         if (ret)
1263                 goto out;
1264
1265         mutex_lock(&root->fs_info->trans_mutex);
1266         root->fs_info->open_ioctl_trans++;
1267         mutex_unlock(&root->fs_info->trans_mutex);
1268
1269         ret = -ENOMEM;
1270         trans = btrfs_start_ioctl_transaction(root, 0);
1271         if (!trans)
1272                 goto out_drop;
1273
1274         file->private_data = trans;
1275         return 0;
1276
1277 out_drop:
1278         mutex_lock(&root->fs_info->trans_mutex);
1279         root->fs_info->open_ioctl_trans--;
1280         mutex_unlock(&root->fs_info->trans_mutex);
1281         mnt_drop_write(file->f_path.mnt);
1282 out:
1283         return ret;
1284 }
1285
1286 /*
1287  * there are many ways the trans_start and trans_end ioctls can lead
1288  * to deadlocks.  They should only be used by applications that
1289  * basically own the machine, and have a very in depth understanding
1290  * of all the possible deadlocks and enospc problems.
1291  */
1292 long btrfs_ioctl_trans_end(struct file *file)
1293 {
1294         struct inode *inode = fdentry(file)->d_inode;
1295         struct btrfs_root *root = BTRFS_I(inode)->root;
1296         struct btrfs_trans_handle *trans;
1297
1298         trans = file->private_data;
1299         if (!trans)
1300                 return -EINVAL;
1301         file->private_data = NULL;
1302
1303         btrfs_end_transaction(trans, root);
1304
1305         mutex_lock(&root->fs_info->trans_mutex);
1306         root->fs_info->open_ioctl_trans--;
1307         mutex_unlock(&root->fs_info->trans_mutex);
1308
1309         mnt_drop_write(file->f_path.mnt);
1310         return 0;
1311 }
1312
1313 long btrfs_ioctl(struct file *file, unsigned int
1314                 cmd, unsigned long arg)
1315 {
1316         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1317         void __user *argp = (void __user *)arg;
1318
1319         switch (cmd) {
1320         case FS_IOC_GETFLAGS:
1321                 return btrfs_ioctl_getflags(file, argp);
1322         case FS_IOC_SETFLAGS:
1323                 return btrfs_ioctl_setflags(file, argp);
1324         case FS_IOC_GETVERSION:
1325                 return btrfs_ioctl_getversion(file, argp);
1326         case BTRFS_IOC_SNAP_CREATE:
1327                 return btrfs_ioctl_snap_create(file, argp, 0);
1328         case BTRFS_IOC_SUBVOL_CREATE:
1329                 return btrfs_ioctl_snap_create(file, argp, 1);
1330         case BTRFS_IOC_SNAP_DESTROY:
1331                 return btrfs_ioctl_snap_destroy(file, argp);
1332         case BTRFS_IOC_DEFRAG:
1333                 return btrfs_ioctl_defrag(file);
1334         case BTRFS_IOC_RESIZE:
1335                 return btrfs_ioctl_resize(root, argp);
1336         case BTRFS_IOC_ADD_DEV:
1337                 return btrfs_ioctl_add_dev(root, argp);
1338         case BTRFS_IOC_RM_DEV:
1339                 return btrfs_ioctl_rm_dev(root, argp);
1340         case BTRFS_IOC_BALANCE:
1341                 return btrfs_balance(root->fs_info->dev_root);
1342         case BTRFS_IOC_CLONE:
1343                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
1344         case BTRFS_IOC_CLONE_RANGE:
1345                 return btrfs_ioctl_clone_range(file, argp);
1346         case BTRFS_IOC_TRANS_START:
1347                 return btrfs_ioctl_trans_start(file);
1348         case BTRFS_IOC_TRANS_END:
1349                 return btrfs_ioctl_trans_end(file);
1350         case BTRFS_IOC_SYNC:
1351                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
1352                 return 0;
1353         }
1354
1355         return -ENOTTY;
1356 }