SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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
  47
  48
  49 static noinline int create_subvol(struct btrfs_root *root, char *name,
  50                                   int namelen)
  51 {
  52         struct btrfs_trans_handle *trans;
  53         struct btrfs_key key;
  54         struct btrfs_root_item root_item;
  55         struct btrfs_inode_item *inode_item;
  56         struct extent_buffer *leaf;
  57         struct btrfs_root *new_root = root;
  58         struct inode *dir;
  59         int ret;
  60         int err;
  61         u64 objectid;
  62         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
  63         unsigned long nr = 1;
  64
  65         mutex_lock(&root->fs_info->fs_mutex);
  66         ret = btrfs_check_free_space(root, 1, 0);
  67         if (ret)
  68                 goto fail_commit;
  69
  70         trans = btrfs_start_transaction(root, 1);
  71         BUG_ON(!trans);
  72
  73         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
  74                                        0, &objectid);
  75         if (ret)
  76                 goto fail;
  77
  78         leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
  79                                         objectid, trans->transid, 0, 0,
  80                                         0, 0);
  81         if (IS_ERR(leaf))
  82                 return PTR_ERR(leaf);
  83
  84         btrfs_set_header_nritems(leaf, 0);
  85         btrfs_set_header_level(leaf, 0);
  86         btrfs_set_header_bytenr(leaf, leaf->start);
  87         btrfs_set_header_generation(leaf, trans->transid);
  88         btrfs_set_header_owner(leaf, objectid);
  89
  90         write_extent_buffer(leaf, root->fs_info->fsid,
  91                             (unsigned long)btrfs_header_fsid(leaf),
  92                             BTRFS_FSID_SIZE);
  93         btrfs_mark_buffer_dirty(leaf);
  94
  95         inode_item = &root_item.inode;
  96         memset(inode_item, 0, sizeof(*inode_item));
  97         inode_item->generation = cpu_to_le64(1);
  98         inode_item->size = cpu_to_le64(3);
  99         inode_item->nlink = cpu_to_le32(1);
 100         inode_item->nblocks = cpu_to_le64(1);
 101         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 102
 103         btrfs_set_root_bytenr(&root_item, leaf->start);
 104         btrfs_set_root_level(&root_item, 0);
 105         btrfs_set_root_refs(&root_item, 1);
 106         btrfs_set_root_used(&root_item, 0);
 107
 108         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 109         root_item.drop_level = 0;
 110
 111         free_extent_buffer(leaf);
 112         leaf = NULL;
 113
 114         btrfs_set_root_dirid(&root_item, new_dirid);
 115
 116         key.objectid = objectid;
 117         key.offset = 1;
 118         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 119         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 120                                 &root_item);
 121         if (ret)
 122                 goto fail;
 123
 124         /*
 125          * insert the directory item
 126          */
 127         key.offset = (u64)-1;
 128         dir = root->fs_info->sb->s_root->d_inode;
 129         ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
 130                                     name, namelen, dir->i_ino, &key,
 131                                     BTRFS_FT_DIR);
 132         if (ret)
 133                 goto fail;
 134
 135         ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root,
 136                              name, namelen, objectid,
 137                              root->fs_info->sb->s_root->d_inode->i_ino);
 138         if (ret)
 139                 goto fail;
 140
 141         ret = btrfs_commit_transaction(trans, root);
 142         if (ret)
 143                 goto fail_commit;
 144
 145         new_root = btrfs_read_fs_root(root->fs_info, &key, name, namelen);
 146         BUG_ON(!new_root);
 147
 148         trans = btrfs_start_transaction(new_root, 1);
 149         BUG_ON(!trans);
 150
 151         ret = btrfs_create_subvol_root(new_root, trans, new_dirid,
 152                                        BTRFS_I(dir)->block_group);
 153         if (ret)
 154                 goto fail;
 155
 156         /* Invalidate existing dcache entry for new subvolume. */
 157         btrfs_invalidate_dcache_root(root, name, namelen);
 158
 159 fail:
 160         nr = trans->blocks_used;
 161         err = btrfs_commit_transaction(trans, new_root);
 162         if (err && !ret)
 163                 ret = err;
 164 fail_commit:
 165         mutex_unlock(&root->fs_info->fs_mutex);
 166         btrfs_btree_balance_dirty(root, nr);
 167         btrfs_throttle(root);
 168         return ret;
 169 }
 170
 171 static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
 172 {
 173         struct btrfs_pending_snapshot *pending_snapshot;
 174         struct btrfs_trans_handle *trans;
 175         int ret;
 176         int err;
 177         unsigned long nr = 0;
 178
 179         if (!root->ref_cows)
 180                 return -EINVAL;
 181
 182         mutex_lock(&root->fs_info->fs_mutex);
 183         ret = btrfs_check_free_space(root, 1, 0);
 184         if (ret)
 185                 goto fail_unlock;
 186
 187         pending_snapshot = kmalloc(sizeof(*pending_snapshot), GFP_NOFS);
 188         if (!pending_snapshot) {
 189                 ret = -ENOMEM;
 190                 goto fail_unlock;
 191         }
 192         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
 193         if (!pending_snapshot->name) {
 194                 ret = -ENOMEM;
 195                 kfree(pending_snapshot);
 196                 goto fail_unlock;
 197         }
 198         memcpy(pending_snapshot->name, name, namelen);
 199         pending_snapshot->name[namelen] = '\0';
 200         trans = btrfs_start_transaction(root, 1);
 201         BUG_ON(!trans);
 202         pending_snapshot->root = root;
 203         list_add(&pending_snapshot->list,
 204                  &trans->transaction->pending_snapshots);
 205         ret = btrfs_update_inode(trans, root, root->inode);
 206         err = btrfs_commit_transaction(trans, root);
 207
 208 fail_unlock:
 209         mutex_unlock(&root->fs_info->fs_mutex);
 210         btrfs_btree_balance_dirty(root, nr);
 211         btrfs_throttle(root);
 212         return ret;
 213 }
 214
 215 int btrfs_defrag_file(struct file *file)
 216 {
 217         struct inode *inode = fdentry(file)->d_inode;
 218         struct btrfs_root *root = BTRFS_I(inode)->root;
 219         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 220         struct page *page;
 221         unsigned long last_index;
 222         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 223         unsigned long total_read = 0;
 224         u64 page_start;
 225         u64 page_end;
 226         unsigned long i;
 227         int ret;
 228
 229         mutex_lock(&root->fs_info->fs_mutex);
 230         ret = btrfs_check_free_space(root, inode->i_size, 0);
 231         mutex_unlock(&root->fs_info->fs_mutex);
 232         if (ret)
 233                 return -ENOSPC;
 234
 235         mutex_lock(&inode->i_mutex);
 236         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
 237         for (i = 0; i <= last_index; i++) {
 238                 if (total_read % ra_pages == 0) {
 239                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 240                                        min(last_index, i + ra_pages - 1));
 241                 }
 242                 total_read++;
 243                 page = grab_cache_page(inode->i_mapping, i);
 244                 if (!page)
 245                         goto out_unlock;
 246                 if (!PageUptodate(page)) {
 247                         btrfs_readpage(NULL, page);
 248                         lock_page(page);
 249                         if (!PageUptodate(page)) {
 250                                 unlock_page(page);
 251                                 page_cache_release(page);
 252                                 goto out_unlock;
 253                         }
 254                 }
 255
 256 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
 257                 ClearPageDirty(page);
 258 #else
 259                 cancel_dirty_page(page, PAGE_CACHE_SIZE);
 260 #endif
 261                 wait_on_page_writeback(page);
 262                 set_page_extent_mapped(page);
 263
 264                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 265                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 266
 267                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 268                 set_extent_delalloc(io_tree, page_start,
 269                                     page_end, GFP_NOFS);
 270
 271                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 272                 set_page_dirty(page);
 273                 unlock_page(page);
 274                 page_cache_release(page);
 275                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 276         }
 277
 278 out_unlock:
 279         mutex_unlock(&inode->i_mutex);
 280         return 0;
 281 }
 282
 283 /*
 284  * Called inside transaction, so use GFP_NOFS
 285  */
 286
 287 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 288 {
 289         u64 new_size;
 290         u64 old_size;
 291         u64 devid = 1;
 292         struct btrfs_ioctl_vol_args *vol_args;
 293         struct btrfs_trans_handle *trans;
 294         struct btrfs_device *device = NULL;
 295         char *sizestr;
 296         char *devstr = NULL;
 297         int ret = 0;
 298         int namelen;
 299         int mod = 0;
 300
 301         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 302
 303         if (!vol_args)
 304                 return -ENOMEM;
 305
 306         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 307                 ret = -EFAULT;
 308                 goto out;
 309         }
 310         namelen = strlen(vol_args->name);
 311         if (namelen > BTRFS_VOL_NAME_MAX) {
 312                 ret = -EINVAL;
 313                 goto out;
 314         }
 315
 316         mutex_lock(&root->fs_info->fs_mutex);
 317         sizestr = vol_args->name;
 318         devstr = strchr(sizestr, ':');
 319         if (devstr) {
 320                 char *end;
 321                 sizestr = devstr + 1;
 322                 *devstr = '\0';
 323                 devstr = vol_args->name;
 324                 devid = simple_strtoull(devstr, &end, 10);
 325                 printk(KERN_INFO "resizing devid %llu\n", devid);
 326         }
 327         device = btrfs_find_device(root, devid, NULL);
 328         if (!device) {
 329                 printk(KERN_INFO "resizer unable to find device %llu\n", devid);
 330                 ret = -EINVAL;
 331                 goto out_unlock;
 332         }
 333         if (!strcmp(sizestr, "max"))
 334                 new_size = device->bdev->bd_inode->i_size;
 335         else {
 336                 if (sizestr[0] == '-') {
 337                         mod = -1;
 338                         sizestr++;
 339                 } else if (sizestr[0] == '+') {
 340                         mod = 1;
 341                         sizestr++;
 342                 }
 343                 new_size = btrfs_parse_size(sizestr);
 344                 if (new_size == 0) {
 345                         ret = -EINVAL;
 346                         goto out_unlock;
 347                 }
 348         }
 349
 350         old_size = device->total_bytes;
 351
 352         if (mod < 0) {
 353                 if (new_size > old_size) {
 354                         ret = -EINVAL;
 355                         goto out_unlock;
 356                 }
 357                 new_size = old_size - new_size;
 358         } else if (mod > 0) {
 359                 new_size = old_size + new_size;
 360         }
 361
 362         if (new_size < 256 * 1024 * 1024) {
 363                 ret = -EINVAL;
 364                 goto out_unlock;
 365         }
 366         if (new_size > device->bdev->bd_inode->i_size) {
 367                 ret = -EFBIG;
 368                 goto out_unlock;
 369         }
 370
 371         do_div(new_size, root->sectorsize);
 372         new_size *= root->sectorsize;
 373
 374         printk(KERN_INFO "new size for %s is %llu\n",
 375                 device->name, (unsigned long long)new_size);
 376
 377         if (new_size > old_size) {
 378                 trans = btrfs_start_transaction(root, 1);
 379                 ret = btrfs_grow_device(trans, device, new_size);
 380                 btrfs_commit_transaction(trans, root);
 381         } else {
 382                 ret = btrfs_shrink_device(device, new_size);
 383         }
 384
 385 out_unlock:
 386         mutex_unlock(&root->fs_info->fs_mutex);
 387 out:
 388         kfree(vol_args);
 389         return ret;
 390 }
 391
 392 static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
 393                                             void __user *arg)
 394 {
 395         struct btrfs_ioctl_vol_args *vol_args;
 396         struct btrfs_dir_item *di;
 397         struct btrfs_path *path;
 398         u64 root_dirid;
 399         int namelen;
 400         int ret;
 401
 402         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 403
 404         if (!vol_args)
 405                 return -ENOMEM;
 406
 407         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 408                 ret = -EFAULT;
 409                 goto out;
 410         }
 411
 412         namelen = strlen(vol_args->name);
 413         if (namelen > BTRFS_VOL_NAME_MAX) {
 414                 ret = -EINVAL;
 415                 goto out;
 416         }
 417         if (strchr(vol_args->name, '/')) {
 418                 ret = -EINVAL;
 419                 goto out;
 420         }
 421
 422         path = btrfs_alloc_path();
 423         if (!path) {
 424                 ret = -ENOMEM;
 425                 goto out;
 426         }
 427
 428         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
 429         mutex_lock(&root->fs_info->fs_mutex);
 430         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
 431                             path, root_dirid,
 432                             vol_args->name, namelen, 0);
 433         mutex_unlock(&root->fs_info->fs_mutex);
 434         btrfs_free_path(path);
 435
 436         if (di && !IS_ERR(di)) {
 437                 ret = -EEXIST;
 438                 goto out;
 439         }
 440
 441         if (IS_ERR(di)) {
 442                 ret = PTR_ERR(di);
 443                 goto out;
 444         }
 445
 446         if (root == root->fs_info->tree_root)
 447                 ret = create_subvol(root, vol_args->name, namelen);
 448         else
 449                 ret = create_snapshot(root, vol_args->name, namelen);
 450 out:
 451         kfree(vol_args);
 452         return ret;
 453 }
 454
 455 static int btrfs_ioctl_defrag(struct file *file)
 456 {
 457         struct inode *inode = fdentry(file)->d_inode;
 458         struct btrfs_root *root = BTRFS_I(inode)->root;
 459
 460         switch (inode->i_mode & S_IFMT) {
 461         case S_IFDIR:
 462                 mutex_lock(&root->fs_info->fs_mutex);
 463                 btrfs_defrag_root(root, 0);
 464                 btrfs_defrag_root(root->fs_info->extent_root, 0);
 465                 mutex_unlock(&root->fs_info->fs_mutex);
 466                 break;
 467         case S_IFREG:
 468                 btrfs_defrag_file(file);
 469                 break;
 470         }
 471
 472         return 0;
 473 }
 474
 475 long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 476 {
 477         struct btrfs_ioctl_vol_args *vol_args;
 478         int ret;
 479
 480         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 481
 482         if (!vol_args)
 483                 return -ENOMEM;
 484
 485         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 486                 ret = -EFAULT;
 487                 goto out;
 488         }
 489         ret = btrfs_init_new_device(root, vol_args->name);
 490
 491 out:
 492         kfree(vol_args);
 493         return ret;
 494 }
 495
 496 long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 497 {
 498         struct btrfs_ioctl_vol_args *vol_args;
 499         int ret;
 500
 501         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 502
 503         if (!vol_args)
 504                 return -ENOMEM;
 505
 506         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 507                 ret = -EFAULT;
 508                 goto out;
 509         }
 510         ret = btrfs_rm_device(root, vol_args->name);
 511
 512 out:
 513         kfree(vol_args);
 514         return ret;
 515 }
 516
 517 int dup_item_to_inode(struct btrfs_trans_handle *trans,
 518                        struct btrfs_root *root,
 519                        struct btrfs_path *path,
 520                        struct extent_buffer *leaf,
 521                        int slot,
 522                        struct btrfs_key *key,
 523                        u64 destino)
 524 {
 525         char *dup;
 526         int len = btrfs_item_size_nr(leaf, slot);
 527         struct btrfs_key ckey = *key;
 528         int ret = 0;
 529
 530         dup = kmalloc(len, GFP_NOFS);
 531         if (!dup)
 532                 return -ENOMEM;
 533
 534         read_extent_buffer(leaf, dup, btrfs_item_ptr_offset(leaf, slot), len);
 535         btrfs_release_path(root, path);
 536
 537         ckey.objectid = destino;
 538         ret = btrfs_insert_item(trans, root, &ckey, dup, len);
 539         kfree(dup);
 540         return ret;
 541 }
 542
 543 long btrfs_ioctl_clone(struct file *file, unsigned long src_fd)
 544 {
 545         struct inode *inode = fdentry(file)->d_inode;
 546         struct btrfs_root *root = BTRFS_I(inode)->root;
 547         struct file *src_file;
 548         struct inode *src;
 549         struct btrfs_trans_handle *trans;
 550         int ret;
 551         u64 pos;
 552         struct btrfs_path *path;
 553         struct btrfs_key key;
 554         struct extent_buffer *leaf;
 555         u32 nritems;
 556         int slot;
 557
 558         src_file = fget(src_fd);
 559         if (!src_file)
 560                 return -EBADF;
 561         src = src_file->f_dentry->d_inode;
 562
 563         ret = -EXDEV;
 564         if (src->i_sb != inode->i_sb)
 565                 goto out_fput;
 566
 567         if (inode < src) {
 568                 mutex_lock(&inode->i_mutex);
 569                 mutex_lock(&src->i_mutex);
 570         } else {
 571                 mutex_lock(&src->i_mutex);
 572                 mutex_lock(&inode->i_mutex);
 573         }
 574
 575         ret = -ENOTEMPTY;
 576         if (inode->i_size)
 577                 goto out_unlock;
 578
 579         /* do any pending delalloc/csum calc on src, one way or
 580            another, and lock file content */
 581         while (1) {
 582                 filemap_write_and_wait(src->i_mapping);
 583                 lock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 584                 if (BTRFS_I(src)->delalloc_bytes == 0)
 585                         break;
 586                 unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 587         }
 588
 589         mutex_lock(&root->fs_info->fs_mutex);
 590         trans = btrfs_start_transaction(root, 0);
 591         path = btrfs_alloc_path();
 592         if (!path) {
 593                 ret = -ENOMEM;
 594                 goto out;
 595         }
 596         key.offset = 0;
 597         key.type = BTRFS_EXTENT_DATA_KEY;
 598         key.objectid = src->i_ino;
 599         pos = 0;
 600         path->reada = 2;
 601
 602         while (1) {
 603                 /*
 604                  * note the key will change type as we walk through the
 605                  * tree.
 606                  */
 607                 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
 608                 if (ret < 0)
 609                         goto out;
 610
 611                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
 612                         ret = btrfs_next_leaf(root, path);
 613                         if (ret < 0)
 614                                 goto out;
 615                         if (ret > 0)
 616                                 break;
 617                 }
 618                 leaf = path->nodes[0];
 619                 slot = path->slots[0];
 620                 btrfs_item_key_to_cpu(leaf, &key, slot);
 621                 nritems = btrfs_header_nritems(leaf);
 622
 623                 if (btrfs_key_type(&key) > BTRFS_CSUM_ITEM_KEY ||
 624                     key.objectid != src->i_ino)
 625                         break;
 626
 627                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
 628                         struct btrfs_file_extent_item *extent;
 629                         int found_type;
 630                         pos = key.offset;
 631                         extent = btrfs_item_ptr(leaf, slot,
 632                                                 struct btrfs_file_extent_item);
 633                         found_type = btrfs_file_extent_type(leaf, extent);
 634                         if (found_type == BTRFS_FILE_EXTENT_REG) {
 635                                 u64 len = btrfs_file_extent_num_bytes(leaf,
 636                                                                       extent);
 637                                 u64 ds = btrfs_file_extent_disk_bytenr(leaf,
 638                                                                        extent);
 639                                 u64 dl = btrfs_file_extent_disk_num_bytes(leaf,
 640                                                                  extent);
 641                                 u64 off = btrfs_file_extent_offset(leaf,
 642                                                                    extent);
 643                                 btrfs_insert_file_extent(trans, root,
 644                                                          inode->i_ino, pos,
 645                                                          ds, dl, len, off);
 646                                 /* ds == 0 means there's a hole */
 647                                 if (ds != 0) {
 648                                         btrfs_inc_extent_ref(trans, root,
 649                                                      ds, dl,
 650                                                      root->root_key.objectid,
 651                                                      trans->transid,
 652                                                      inode->i_ino, pos);
 653                                 }
 654                                 pos = key.offset + len;
 655                         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 656                                 ret = dup_item_to_inode(trans, root, path,
 657                                                         leaf, slot, &key,
 658                                                         inode->i_ino);
 659                                 if (ret)
 660                                         goto out;
 661                                 pos = key.offset + btrfs_item_size_nr(leaf,
 662                                                                       slot);
 663                         }
 664                 } else if (btrfs_key_type(&key) == BTRFS_CSUM_ITEM_KEY) {
 665                         ret = dup_item_to_inode(trans, root, path, leaf,
 666                                                 slot, &key, inode->i_ino);
 667
 668                         if (ret)
 669                                 goto out;
 670                 }
 671                 key.offset++;
 672                 btrfs_release_path(root, path);
 673         }
 674
 675         ret = 0;
 676 out:
 677         btrfs_free_path(path);
 678
 679         inode->i_blocks = src->i_blocks;
 680         i_size_write(inode, src->i_size);
 681         btrfs_update_inode(trans, root, inode);
 682
 683         unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 684
 685         btrfs_end_transaction(trans, root);
 686         mutex_unlock(&root->fs_info->fs_mutex);
 687
 688 out_unlock:
 689         mutex_unlock(&src->i_mutex);
 690         mutex_unlock(&inode->i_mutex);
 691 out_fput:
 692         fput(src_file);
 693         return ret;
 694 }
 695
 696 /*
 697  * there are many ways the trans_start and trans_end ioctls can lead
 698  * to deadlocks.  They should only be used by applications that
 699  * basically own the machine, and have a very in depth understanding
 700  * of all the possible deadlocks and enospc problems.
 701  */
 702 long btrfs_ioctl_trans_start(struct file *file)
 703 {
 704         struct inode *inode = fdentry(file)->d_inode;
 705         struct btrfs_root *root = BTRFS_I(inode)->root;
 706         struct btrfs_trans_handle *trans;
 707         int ret = 0;
 708
 709         if (!capable(CAP_SYS_ADMIN))
 710                 return -EPERM;
 711
 712         mutex_lock(&root->fs_info->fs_mutex);
 713         if (file->private_data) {
 714                 ret = -EINPROGRESS;
 715                 goto out;
 716         }
 717         trans = btrfs_start_transaction(root, 0);
 718         if (trans)
 719                 file->private_data = trans;
 720         else
 721                 ret = -ENOMEM;
 722         /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
 723 out:
 724         mutex_unlock(&root->fs_info->fs_mutex);
 725         return ret;
 726 }
 727
 728 /*
 729  * there are many ways the trans_start and trans_end ioctls can lead
 730  * to deadlocks.  They should only be used by applications that
 731  * basically own the machine, and have a very in depth understanding
 732  * of all the possible deadlocks and enospc problems.
 733  */
 734 long btrfs_ioctl_trans_end(struct file *file)
 735 {
 736         struct inode *inode = fdentry(file)->d_inode;
 737         struct btrfs_root *root = BTRFS_I(inode)->root;
 738         struct btrfs_trans_handle *trans;
 739         int ret = 0;
 740
 741         mutex_lock(&root->fs_info->fs_mutex);
 742         trans = file->private_data;
 743         if (!trans) {
 744                 ret = -EINVAL;
 745                 goto out;
 746         }
 747         btrfs_end_transaction(trans, root);
 748         file->private_data = 0;
 749 out:
 750         mutex_unlock(&root->fs_info->fs_mutex);
 751         return ret;
 752 }
 753
 754 long btrfs_ioctl(struct file *file, unsigned int
 755                 cmd, unsigned long arg)
 756 {
 757         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 758
 759         switch (cmd) {
 760         case BTRFS_IOC_SNAP_CREATE:
 761                 return btrfs_ioctl_snap_create(root, (void __user *)arg);
 762         case BTRFS_IOC_DEFRAG:
 763                 return btrfs_ioctl_defrag(file);
 764         case BTRFS_IOC_RESIZE:
 765                 return btrfs_ioctl_resize(root, (void __user *)arg);
 766         case BTRFS_IOC_ADD_DEV:
 767                 return btrfs_ioctl_add_dev(root, (void __user *)arg);
 768         case BTRFS_IOC_RM_DEV:
 769                 return btrfs_ioctl_rm_dev(root, (void __user *)arg);
 770         case BTRFS_IOC_BALANCE:
 771                 return btrfs_balance(root->fs_info->dev_root);
 772         case BTRFS_IOC_CLONE:
 773                 return btrfs_ioctl_clone(file, arg);
 774         case BTRFS_IOC_TRANS_START:
 775                 return btrfs_ioctl_trans_start(file);
 776         case BTRFS_IOC_TRANS_END:
 777                 return btrfs_ioctl_trans_end(file);
 778         case BTRFS_IOC_SYNC:
 779                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
 780                 return 0;
 781         }
 782
 783         return -ENOTTY;
 784 }