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/pagemap.h>
  25 #include <linux/highmem.h>
  26 #include <linux/time.h>
  27 #include <linux/init.h>
  28 #include <linux/string.h>
  29 #include <linux/smp_lock.h>
  30 #include <linux/backing-dev.h>
  31 #include <linux/mpage.h>
  32 #include <linux/swap.h>
  33 #include <linux/writeback.h>
  34 #include <linux/statfs.h>
  35 #include <linux/compat.h>
  36 #include <linux/bit_spinlock.h>
  37 #include <linux/version.h>
  38 #include <linux/xattr.h>
  39 #include "ctree.h"
  40 #include "disk-io.h"
  41 #include "transaction.h"
  42 #include "btrfs_inode.h"
  43 #include "ioctl.h"
  44 #include "print-tree.h"
  45 #include "volumes.h"
  46 #include "locking.h"
  47
  48
  49
  50 static noinline int create_subvol(struct btrfs_root *root, char *name,
  51                                   int namelen)
  52 {
  53         struct btrfs_trans_handle *trans;
  54         struct btrfs_key key;
  55         struct btrfs_root_item root_item;
  56         struct btrfs_inode_item *inode_item;
  57         struct extent_buffer *leaf;
  58         struct btrfs_root *new_root = root;
  59         struct inode *dir;
  60         int ret;
  61         int err;
  62         u64 objectid;
  63         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
  64         unsigned long nr = 1;
  65
  66         mutex_lock(&root->fs_info->fs_mutex);
  67         ret = btrfs_check_free_space(root, 1, 0);
  68         if (ret)
  69                 goto fail_commit;
  70
  71         trans = btrfs_start_transaction(root, 1);
  72         BUG_ON(!trans);
  73
  74         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
  75                                        0, &objectid);
  76         if (ret)
  77                 goto fail;
  78
  79         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
  80                                       objectid, trans->transid, 0, 0,
  81                                       0, 0);
  82         if (IS_ERR(leaf))
  83                 return PTR_ERR(leaf);
  84
  85         btrfs_set_header_nritems(leaf, 0);
  86         btrfs_set_header_level(leaf, 0);
  87         btrfs_set_header_bytenr(leaf, leaf->start);
  88         btrfs_set_header_generation(leaf, trans->transid);
  89         btrfs_set_header_owner(leaf, objectid);
  90
  91         write_extent_buffer(leaf, root->fs_info->fsid,
  92                             (unsigned long)btrfs_header_fsid(leaf),
  93                             BTRFS_FSID_SIZE);
  94         btrfs_mark_buffer_dirty(leaf);
  95
  96         inode_item = &root_item.inode;
  97         memset(inode_item, 0, sizeof(*inode_item));
  98         inode_item->generation = cpu_to_le64(1);
  99         inode_item->size = cpu_to_le64(3);
 100         inode_item->nlink = cpu_to_le32(1);
 101         inode_item->nblocks = cpu_to_le64(1);
 102         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 103
 104         btrfs_set_root_bytenr(&root_item, leaf->start);
 105         btrfs_set_root_level(&root_item, 0);
 106         btrfs_set_root_refs(&root_item, 1);
 107         btrfs_set_root_used(&root_item, 0);
 108
 109         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 110         root_item.drop_level = 0;
 111
 112         btrfs_tree_unlock(leaf);
 113         free_extent_buffer(leaf);
 114         leaf = NULL;
 115
 116         btrfs_set_root_dirid(&root_item, new_dirid);
 117
 118         key.objectid = objectid;
 119         key.offset = 1;
 120         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 121         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 122                                 &root_item);
 123         if (ret)
 124                 goto fail;
 125
 126         /*
 127          * insert the directory item
 128          */
 129         key.offset = (u64)-1;
 130         dir = root->fs_info->sb->s_root->d_inode;
 131         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
 132                                     name, namelen, dir->i_ino, &key,
 133                                     BTRFS_FT_DIR);
 134         if (ret)
 135                 goto fail;
 136
 137         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
 138                              name, namelen, objectid,
 139                              root->fs_info->sb->s_root->d_inode->i_ino);
 140         if (ret)
 141                 goto fail;
 142
 143         ret = btrfs_commit_transaction(trans, root);
 144         if (ret)
 145                 goto fail_commit;
 146
 147         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
 148         BUG_ON(!new_root);
 149
 150         trans = btrfs_start_transaction(new_root, 1);
 151         BUG_ON(!trans);
 152
 153         ret = btrfs_create_subvol_root(new_root, trans, new_dirid,
 154                                        BTRFS_I(dir)->block_group);
 155         if (ret)
 156                 goto fail;
 157
 158         /* Invalidate existing dcache entry for new subvolume. */
 159         btrfs_invalidate_dcache_root(root, name, namelen);
 160
 161 fail:
 162         nr = trans->blocks_used;
 163         err = btrfs_commit_transaction(trans, new_root);
 164         if (err && !ret)
 165                 ret = err;
 166 fail_commit:
 167         mutex_unlock(&root->fs_info->fs_mutex);
 168         btrfs_btree_balance_dirty(root, nr);
 169         btrfs_throttle(root);
 170         return ret;
 171 }
 172
 173 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
 174 {
 175         struct btrfs_pending_snapshot *pending_snapshot;
 176         struct btrfs_trans_handle *trans;
 177         int ret;
 178         int err;
 179         unsigned long nr = 0;
 180
 181         if (!root->ref_cows)
 182                 return -EINVAL;
 183
 184         mutex_lock(&root->fs_info->fs_mutex);
 185         ret = btrfs_check_free_space(root, 1, 0);
 186         if (ret)
 187                 goto fail_unlock;
 188
 189         pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
 190         if (!pending_snapshot) {
 191                 ret = -ENOMEM;
 192                 goto fail_unlock;
 193         }
 194         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
 195         if (!pending_snapshot->name) {
 196                 ret = -ENOMEM;
 197                 kfree(pending_snapshot);
 198                 goto fail_unlock;
 199         }
 200         memcpy(pending_snapshot->name, name, namelen);
 201         pending_snapshot->name[namelen] = '\0';
 202         trans = btrfs_start_transaction(root, 1);
 203         BUG_ON(!trans);
 204         pending_snapshot->root = root;
 205         list_add(&pending_snapshot->list,
 206                  &trans->transaction->pending_snapshots);
 207         ret = btrfs_update_inode(trans, root, root->inode);
 208         err = btrfs_commit_transaction(trans, root);
 209
 210 fail_unlock:
 211         mutex_unlock(&root->fs_info->fs_mutex);
 212         btrfs_btree_balance_dirty(root, nr);
 213         btrfs_throttle(root);
 214         return ret;
 215 }
 216
 217 int btrfs_defrag_file(struct file *file)
 218 {
 219         struct inode *inode = fdentry(file)->d_inode;
 220         struct btrfs_root *root = BTRFS_I(inode)->root;
 221         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 222         struct page *page;
 223         unsigned long last_index;
 224         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 225         unsigned long total_read = 0;
 226         u64 page_start;
 227         u64 page_end;
 228         unsigned long i;
 229         int ret;
 230
 231         mutex_lock(&root->fs_info->fs_mutex);
 232         ret = btrfs_check_free_space(root, inode->i_size, 0);
 233         mutex_unlock(&root->fs_info->fs_mutex);
 234         if (ret)
 235                 return -ENOSPC;
 236
 237         mutex_lock(&inode->i_mutex);
 238         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
 239         for (i = 0; i <= last_index; i++) {
 240                 if (total_read % ra_pages == 0) {
 241                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 242                                        min(last_index, i + ra_pages - 1));
 243                 }
 244                 total_read++;
 245                 page = grab_cache_page(inode->i_mapping, i);
 246                 if (!page)
 247                         goto out_unlock;
 248                 if (!PageUptodate(page)) {
 249                         btrfs_readpage(NULL, page);
 250                         lock_page(page);
 251                         if (!PageUptodate(page)) {
 252                                 unlock_page(page);
 253                                 page_cache_release(page);
 254                                 goto out_unlock;
 255                         }
 256                 }
 257
 258 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 259                 ClearPageDirty(page);
 260 #else
 261                 cancel_dirty_page(page, PAGE_CACHE_SIZE);
 262 #endif
 263                 wait_on_page_writeback(page);
 264                 set_page_extent_mapped(page);
 265
 266                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 267                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 268
 269                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 270                 set_extent_delalloc(io_tree, page_start,
 271                                     page_end, GFP_NOFS);
 272
 273                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 274                 set_page_dirty(page);
 275                 unlock_page(page);
 276                 page_cache_release(page);
 277                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 278         }
 279
 280 out_unlock:
 281         mutex_unlock(&inode->i_mutex);
 282         return 0;
 283 }
 284
 285 /*
 286  * Called inside transaction, so use GFP_NOFS
 287  */
 288
 289 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 290 {
 291         u64 new_size;
 292         u64 old_size;
 293         u64 devid = 1;
 294         struct btrfs_ioctl_vol_args *vol_args;
 295         struct btrfs_trans_handle *trans;
 296         struct btrfs_device *device = NULL;
 297         char *sizestr;
 298         char *devstr = NULL;
 299         int ret = 0;
 300         int namelen;
 301         int mod = 0;
 302
 303         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 304
 305         if (!vol_args)
 306                 return -ENOMEM;
 307
 308         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 309                 ret = -EFAULT;
 310                 goto out;
 311         }
 312         namelen = strlen(vol_args->name);
 313         if (namelen > BTRFS_VOL_NAME_MAX) {
 314                 ret = -EINVAL;
 315                 goto out;
 316         }
 317
 318         mutex_lock(&root->fs_info->fs_mutex);
 319         sizestr = vol_args->name;
 320         devstr = strchr(sizestr, ':');
 321         if (devstr) {
 322                 char *end;
 323                 sizestr = devstr + 1;
 324                 *devstr = '\0';
 325                 devstr = vol_args->name;
 326                 devid = simple_strtoull(devstr, &end, 10);
 327                 printk(KERN_INFO "resizing devid %llu\n", devid);
 328         }
 329         device = btrfs_find_device(root, devid, NULL);
 330         if (!device) {
 331                 printk(KERN_INFO "resizer unable to find device %llu\n", devid);
 332                 ret = -EINVAL;
 333                 goto out_unlock;
 334         }
 335         if (!strcmp(sizestr, "max"))
 336                 new_size = device->bdev->bd_inode->i_size;
 337         else {
 338                 if (sizestr[0] == '-') {
 339                         mod = -1;
 340                         sizestr++;
 341                 } else if (sizestr[0] == '+') {
 342                         mod = 1;
 343                         sizestr++;
 344                 }
 345                 new_size = btrfs_parse_size(sizestr);
 346                 if (new_size == 0) {
 347                         ret = -EINVAL;
 348                         goto out_unlock;
 349                 }
 350         }
 351
 352         old_size = device->total_bytes;
 353
 354         if (mod < 0) {
 355                 if (new_size > old_size) {
 356                         ret = -EINVAL;
 357                         goto out_unlock;
 358                 }
 359                 new_size = old_size - new_size;
 360         } else if (mod > 0) {
 361                 new_size = old_size + new_size;
 362         }
 363
 364         if (new_size < 256 * 1024 * 1024) {
 365                 ret = -EINVAL;
 366                 goto out_unlock;
 367         }
 368         if (new_size > device->bdev->bd_inode->i_size) {
 369                 ret = -EFBIG;
 370                 goto out_unlock;
 371         }
 372
 373         do_div(new_size, root->sectorsize);
 374         new_size *= root->sectorsize;
 375
 376         printk(KERN_INFO "new size for %s is %llu\n",
 377                 device->name, (unsigned long long)new_size);
 378
 379         if (new_size > old_size) {
 380                 trans = btrfs_start_transaction(root, 1);
 381                 ret = btrfs_grow_device(trans, device, new_size);
 382                 btrfs_commit_transaction(trans, root);
 383         } else {
 384                 ret = btrfs_shrink_device(device, new_size);
 385         }
 386
 387 out_unlock:
 388         mutex_unlock(&root->fs_info->fs_mutex);
 389 out:
 390         kfree(vol_args);
 391         return ret;
 392 }
 393
 394 static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
 395                                             void __user *arg)
 396 {
 397         struct btrfs_ioctl_vol_args *vol_args;
 398         struct btrfs_dir_item *di;
 399         struct btrfs_path *path;
 400         u64 root_dirid;
 401         int namelen;
 402         int ret;
 403
 404         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 405
 406         if (!vol_args)
 407                 return -ENOMEM;
 408
 409         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 410                 ret = -EFAULT;
 411                 goto out;
 412         }
 413
 414         namelen = strlen(vol_args->name);
 415         if (namelen > BTRFS_VOL_NAME_MAX) {
 416                 ret = -EINVAL;
 417                 goto out;
 418         }
 419         if (strchr(vol_args->name, '/')) {
 420                 ret = -EINVAL;
 421                 goto out;
 422         }
 423
 424         path = btrfs_alloc_path();
 425         if (!path) {
 426                 ret = -ENOMEM;
 427                 goto out;
 428         }
 429
 430         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
 431         mutex_lock(&root->fs_info->fs_mutex);
 432         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
 433                             path, root_dirid,
 434                             vol_args->name, namelen, 0);
 435         mutex_unlock(&root->fs_info->fs_mutex);
 436         btrfs_free_path(path);
 437
 438         if (di && !IS_ERR(di)) {
 439                 ret = -EEXIST;
 440                 goto out;
 441         }
 442
 443         if (IS_ERR(di)) {
 444                 ret = PTR_ERR(di);
 445                 goto out;
 446         }
 447
 448         if (root == root->fs_info->tree_root)
 449                 ret = create_subvol(root, vol_args->name, namelen);
 450         else
 451                 ret = create_snapshot(root, vol_args->name, namelen);
 452 out:
 453         kfree(vol_args);
 454         return ret;
 455 }
 456
 457 static int btrfs_ioctl_defrag(struct file *file)
 458 {
 459         struct inode *inode = fdentry(file)->d_inode;
 460         struct btrfs_root *root = BTRFS_I(inode)->root;
 461
 462         switch (inode->i_mode & S_IFMT) {
 463         case S_IFDIR:
 464                 mutex_lock(&root->fs_info->fs_mutex);
 465                 btrfs_defrag_root(root, 0);
 466                 btrfs_defrag_root(root->fs_info->extent_root, 0);
 467                 mutex_unlock(&root->fs_info->fs_mutex);
 468                 break;
 469         case S_IFREG:
 470                 btrfs_defrag_file(file);
 471                 break;
 472         }
 473
 474         return 0;
 475 }
 476
 477 long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 478 {
 479         struct btrfs_ioctl_vol_args *vol_args;
 480         int ret;
 481
 482         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 483
 484         if (!vol_args)
 485                 return -ENOMEM;
 486
 487         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 488                 ret = -EFAULT;
 489                 goto out;
 490         }
 491         ret = btrfs_init_new_device(root, vol_args->name);
 492
 493 out:
 494         kfree(vol_args);
 495         return ret;
 496 }
 497
 498 long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 499 {
 500         struct btrfs_ioctl_vol_args *vol_args;
 501         int ret;
 502
 503         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 504
 505         if (!vol_args)
 506                 return -ENOMEM;
 507
 508         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 509                 ret = -EFAULT;
 510                 goto out;
 511         }
 512         ret = btrfs_rm_device(root, vol_args->name);
 513
 514 out:
 515         kfree(vol_args);
 516         return ret;
 517 }
 518
 519 int dup_item_to_inode(struct btrfs_trans_handle *trans,
 520                        struct btrfs_root *root,
 521                        struct btrfs_path *path,
 522                        struct extent_buffer *leaf,
 523                        int slot,
 524                        struct btrfs_key *key,
 525                        u64 destino)
 526 {
 527         char *dup;
 528         int len = btrfs_item_size_nr(leaf, slot);
 529         struct btrfs_key ckey = *key;
 530         int ret = 0;
 531
 532         dup = kmalloc(len, GFP_NOFS);
 533         if (!dup)
 534                 return -ENOMEM;
 535
 536         read_extent_buffer(leaf, dup, btrfs_item_ptr_offset(leaf, slot), len);
 537         btrfs_release_path(root, path);
 538
 539         ckey.objectid = destino;
 540         ret = btrfs_insert_item(trans, root, &ckey, dup, len);
 541         kfree(dup);
 542         return ret;
 543 }
 544
 545 long btrfs_ioctl_clone(struct file *file, unsigned long src_fd)
 546 {
 547         struct inode *inode = fdentry(file)->d_inode;
 548         struct btrfs_root *root = BTRFS_I(inode)->root;
 549         struct file *src_file;
 550         struct inode *src;
 551         struct btrfs_trans_handle *trans;
 552         int ret;
 553         u64 pos;
 554         struct btrfs_path *path;
 555         struct btrfs_key key;
 556         struct extent_buffer *leaf;
 557         u32 nritems;
 558         int slot;
 559
 560         src_file = fget(src_fd);
 561         if (!src_file)
 562                 return -EBADF;
 563         src = src_file->f_dentry->d_inode;
 564
 565         ret = -EXDEV;
 566         if (src->i_sb != inode->i_sb)
 567                 goto out_fput;
 568
 569         if (inode < src) {
 570                 mutex_lock(&inode->i_mutex);
 571                 mutex_lock(&src->i_mutex);
 572         } else {
 573                 mutex_lock(&src->i_mutex);
 574                 mutex_lock(&inode->i_mutex);
 575         }
 576
 577         ret = -ENOTEMPTY;
 578         if (inode->i_size)
 579                 goto out_unlock;
 580
 581         /* do any pending delalloc/csum calc on src, one way or
 582            another, and lock file content */
 583         while (1) {
 584                 filemap_write_and_wait(src->i_mapping);
 585                 lock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 586                 if (BTRFS_I(src)->delalloc_bytes == 0)
 587                         break;
 588                 unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 589         }
 590
 591         mutex_lock(&root->fs_info->fs_mutex);
 592         trans = btrfs_start_transaction(root, 0);
 593         path = btrfs_alloc_path();
 594         if (!path) {
 595                 ret = -ENOMEM;
 596                 goto out;
 597         }
 598         key.offset = 0;
 599         key.type = BTRFS_EXTENT_DATA_KEY;
 600         key.objectid = src->i_ino;
 601         pos = 0;
 602         path->reada = 2;
 603
 604         while (1) {
 605                 /*
 606                  * note the key will change type as we walk through the
 607                  * tree.
 608                  */
 609                 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
 610                 if (ret < 0)
 611                         goto out;
 612
 613                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
 614                         ret = btrfs_next_leaf(root, path);
 615                         if (ret < 0)
 616                                 goto out;
 617                         if (ret > 0)
 618                                 break;
 619                 }
 620                 leaf = path->nodes[0];
 621                 slot = path->slots[0];
 622                 btrfs_item_key_to_cpu(leaf, &key, slot);
 623                 nritems = btrfs_header_nritems(leaf);
 624
 625                 if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
 626                     key.objectid != src->i_ino)
 627                         break;
 628
 629                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
 630                         struct btrfs_file_extent_item *extent;
 631                         int found_type;
 632                         pos = key.offset;
 633                         extent = btrfs_item_ptr(leaf, slot,
 634                                                 struct btrfs_file_extent_item);
 635                         found_type = btrfs_file_extent_type(leaf, extent);
 636                         if (found_type == BTRFS_FILE_EXTENT_REG) {
 637                                 u64 len = btrfs_file_extent_num_bytes(leaf,
 638                                                                       extent);
 639                                 u64 ds = btrfs_file_extent_disk_bytenr(leaf,
 640                                                                        extent);
 641                                 u64 dl = btrfs_file_extent_disk_num_bytes(leaf,
 642                                                                  extent);
 643                                 u64 off = btrfs_file_extent_offset(leaf,
 644                                                                    extent);
 645                                 btrfs_insert_file_extent(trans, root,
 646                                                          inode->i_ino, pos,
 647                                                          ds, dl, len, off);
 648                                 /* ds == 0 means there's a hole */
 649                                 if (ds != 0) {
 650                                         btrfs_inc_extent_ref(trans, root,
 651                                                      ds, dl,
 652                                                      root->root_key.objectid,
 653                                                      trans->transid,
 654                                                      inode->i_ino, pos);
 655                                 }
 656                                 pos = key.offset + len;
 657                         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 658                                 ret = dup_item_to_inode(trans, root, path,
 659                                                         leaf, slot, &key,
 660                                                         inode->i_ino);
 661                                 if (ret)
 662                                         goto out;
 663                                 pos = key.offset + btrfs_item_size_nr(leaf,
 664                                                                       slot);
 665                         }
 666                 } else if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) {
 667                         ret = dup_item_to_inode(trans, root, path, leaf,
 668                                                 slot, &key, inode->i_ino);
 669
 670                         if (ret)
 671                                 goto out;
 672                 }
 673                 key.offset++;
 674                 btrfs_release_path(root, path);
 675         }
 676
 677         ret = 0;
 678 out:
 679         btrfs_free_path(path);
 680
 681         inode->i_blocks = src->i_blocks;
 682         i_size_write(inode, src->i_size);
 683         btrfs_update_inode(trans, root, inode);
 684
 685         unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 686
 687         btrfs_end_transaction(trans, root);
 688         mutex_unlock(&root->fs_info->fs_mutex);
 689
 690 out_unlock:
 691         mutex_unlock(&src->i_mutex);
 692         mutex_unlock(&inode->i_mutex);
 693 out_fput:
 694         fput(src_file);
 695         return ret;
 696 }
 697
 698 /*
 699  * there are many ways the trans_start and trans_end ioctls can lead
 700  * to deadlocks.  They should only be used by applications that
 701  * basically own the machine, and have a very in depth understanding
 702  * of all the possible deadlocks and enospc problems.
 703  */
 704 long btrfs_ioctl_trans_start(struct file *file)
 705 {
 706         struct inode *inode = fdentry(file)->d_inode;
 707         struct btrfs_root *root = BTRFS_I(inode)->root;
 708         struct btrfs_trans_handle *trans;
 709         int ret = 0;
 710
 711         if (!capable(CAP_SYS_ADMIN))
 712                 return -EPERM;
 713
 714         mutex_lock(&root->fs_info->fs_mutex);
 715         if (file->private_data) {
 716                 ret = -EINPROGRESS;
 717                 goto out;
 718         }
 719         trans = btrfs_start_transaction(root, 0);
 720         if (trans)
 721                 file->private_data = trans;
 722         else
 723                 ret = -ENOMEM;
 724         /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
 725 out:
 726         mutex_unlock(&root->fs_info->fs_mutex);
 727         return ret;
 728 }
 729
 730 /*
 731  * there are many ways the trans_start and trans_end ioctls can lead
 732  * to deadlocks.  They should only be used by applications that
 733  * basically own the machine, and have a very in depth understanding
 734  * of all the possible deadlocks and enospc problems.
 735  */
 736 long btrfs_ioctl_trans_end(struct file *file)
 737 {
 738         struct inode *inode = fdentry(file)->d_inode;
 739         struct btrfs_root *root = BTRFS_I(inode)->root;
 740         struct btrfs_trans_handle *trans;
 741         int ret = 0;
 742
 743         mutex_lock(&root->fs_info->fs_mutex);
 744         trans = file->private_data;
 745         if (!trans) {
 746                 ret = -EINVAL;
 747                 goto out;
 748         }
 749         btrfs_end_transaction(trans, root);
 750         file->private_data = 0;
 751 out:
 752         mutex_unlock(&root->fs_info->fs_mutex);
 753         return ret;
 754 }
 755
 756 long btrfs_ioctl(struct file *file, unsigned int
 757                 cmd, unsigned long arg)
 758 {
 759         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 760
 761         switch (cmd) {
 762         case BTRFS_IOC_SNAP_CREATE:
 763                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
 764         case BTRFS_IOC_DEFRAG:
 765                 return btrfs_ioctl_defrag(file);
 766         case BTRFS_IOC_RESIZE:
 767                 return btrfs_ioctl_resize(root, (void __user *)arg);
 768         case BTRFS_IOC_ADD_DEV:
 769                 return btrfs_ioctl_add_dev(root, (void __user *)arg);
 770         case BTRFS_IOC_RM_DEV:
 771                 return btrfs_ioctl_rm_dev(root, (void __user *)arg);
 772         case BTRFS_IOC_BALANCE:
 773                 return btrfs_balance(root->fs_info->dev_root);
 774         case BTRFS_IOC_CLONE:
 775                 return btrfs_ioctl_clone(file, arg);
 776         case BTRFS_IOC_TRANS_START:
 777                 return btrfs_ioctl_trans_start(file);
 778         case BTRFS_IOC_TRANS_END:
 779                 return btrfs_ioctl_trans_end(file);
 780         case BTRFS_IOC_SYNC:
 781                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
 782                 return 0;
 783         }
 784
 785         return -ENOTTY;
 786 }