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