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