git.oblomov.eu Git - 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/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/smp_lock.h>
  31 #include <linux/backing-dev.h>
  32 #include <linux/mount.h>
  33 #include <linux/mpage.h>
  34 #include <linux/namei.h>
  35 #include <linux/swap.h>
  36 #include <linux/writeback.h>
  37 #include <linux/statfs.h>
  38 #include <linux/compat.h>
  39 #include <linux/bit_spinlock.h>
  40 #include <linux/security.h>
  41 #include <linux/version.h>
  42 #include <linux/xattr.h>
  43 #include <linux/vmalloc.h>
  44 #include "compat.h"
  45 #include "ctree.h"
  46 #include "disk-io.h"
  47 #include "transaction.h"
  48 #include "btrfs_inode.h"
  49 #include "ioctl.h"
  50 #include "print-tree.h"
  51 #include "volumes.h"
  52 #include "locking.h"
  53
  54
  55
  56 static noinline int create_subvol(struct btrfs_root *root,
  57                                   struct dentry *dentry,
  58                                   char *name, int namelen)
  59 {
  60         struct btrfs_trans_handle *trans;
  61         struct btrfs_key key;
  62         struct btrfs_root_item root_item;
  63         struct btrfs_inode_item *inode_item;
  64         struct extent_buffer *leaf;
  65         struct btrfs_root *new_root = root;
  66         struct inode *dir;
  67         int ret;
  68         int err;
  69         u64 objectid;
  70         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
  71         u64 index = 0;
  72         unsigned long nr = 1;
  73
  74         ret = btrfs_check_free_space(root, 1, 0);
  75         if (ret)
  76                 goto fail_commit;
  77
  78         trans = btrfs_start_transaction(root, 1);
  79         BUG_ON(!trans);
  80
  81         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
  82                                        0, &objectid);
  83         if (ret)
  84                 goto fail;
  85
  86         leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
  87                                       objectid, trans->transid, 0, 0, 0);
  88         if (IS_ERR(leaf)) {
  89                 ret = PTR_ERR(leaf);
  90                 goto fail;
  91         }
  92
  93         btrfs_set_header_nritems(leaf, 0);
  94         btrfs_set_header_level(leaf, 0);
  95         btrfs_set_header_bytenr(leaf, leaf->start);
  96         btrfs_set_header_generation(leaf, trans->transid);
  97         btrfs_set_header_owner(leaf, objectid);
  98
  99         write_extent_buffer(leaf, root->fs_info->fsid,
 100                             (unsigned long)btrfs_header_fsid(leaf),
 101                             BTRFS_FSID_SIZE);
 102         btrfs_mark_buffer_dirty(leaf);
 103
 104         inode_item = &root_item.inode;
 105         memset(inode_item, 0, sizeof(*inode_item));
 106         inode_item->generation = cpu_to_le64(1);
 107         inode_item->size = cpu_to_le64(3);
 108         inode_item->nlink = cpu_to_le32(1);
 109         inode_item->nbytes = cpu_to_le64(root->leafsize);
 110         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 111
 112         btrfs_set_root_bytenr(&root_item, leaf->start);
 113         btrfs_set_root_generation(&root_item, trans->transid);
 114         btrfs_set_root_level(&root_item, 0);
 115         btrfs_set_root_refs(&root_item, 1);
 116         btrfs_set_root_used(&root_item, 0);
 117         btrfs_set_root_last_snapshot(&root_item, 0);
 118
 119         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 120         root_item.drop_level = 0;
 121
 122         btrfs_tree_unlock(leaf);
 123         free_extent_buffer(leaf);
 124         leaf = NULL;
 125
 126         btrfs_set_root_dirid(&root_item, new_dirid);
 127
 128         key.objectid = objectid;
 129         key.offset = 1;
 130         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 131         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 132                                 &root_item);
 133         if (ret)
 134                 goto fail;
 135
 136         /*
 137          * insert the directory item
 138          */
 139         key.offset = (u64)-1;
 140         dir = dentry->d_parent->d_inode;
 141         ret = btrfs_set_inode_index(dir, &index);
 142         BUG_ON(ret);
 143
 144         ret = btrfs_insert_dir_item(trans, root,
 145                                     name, namelen, dir->i_ino, &key,
 146                                     BTRFS_FT_DIR, index);
 147         if (ret)
 148                 goto fail;
 149
 150         /* add the backref first */
 151         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 152                                  objectid, BTRFS_ROOT_BACKREF_KEY,
 153                                  root->root_key.objectid,
 154                                  dir->i_ino, index, name, namelen);
 155
 156         BUG_ON(ret);
 157
 158         /* now add the forward ref */
 159         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 160                                  root->root_key.objectid, BTRFS_ROOT_REF_KEY,
 161                                  objectid,
 162                                  dir->i_ino, index, name, namelen);
 163
 164         BUG_ON(ret);
 165
 166         ret = btrfs_commit_transaction(trans, root);
 167         if (ret)
 168                 goto fail_commit;
 169
 170         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 171         BUG_ON(!new_root);
 172
 173         trans = btrfs_start_transaction(new_root, 1);
 174         BUG_ON(!trans);
 175
 176         ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid,
 177                                        BTRFS_I(dir)->block_group);
 178         if (ret)
 179                 goto fail;
 180
 181 fail:
 182         nr = trans->blocks_used;
 183         err = btrfs_commit_transaction(trans, new_root);
 184         if (err && !ret)
 185                 ret = err;
 186 fail_commit:
 187         btrfs_btree_balance_dirty(root, nr);
 188         return ret;
 189 }
 190
 191 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 192                            char *name, int namelen)
 193 {
 194         struct btrfs_pending_snapshot *pending_snapshot;
 195         struct btrfs_trans_handle *trans;
 196         int ret = 0;
 197         int err;
 198         unsigned long nr = 0;
 199
 200         if (!root->ref_cows)
 201                 return -EINVAL;
 202
 203         ret = btrfs_check_free_space(root, 1, 0);
 204         if (ret)
 205                 goto fail_unlock;
 206
 207         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 208         if (!pending_snapshot) {
 209                 ret = -ENOMEM;
 210                 goto fail_unlock;
 211         }
 212         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
 213         if (!pending_snapshot->name) {
 214                 ret = -ENOMEM;
 215                 kfree(pending_snapshot);
 216                 goto fail_unlock;
 217         }
 218         memcpy(pending_snapshot->name, name, namelen);
 219         pending_snapshot->name[namelen] = '\0';
 220         pending_snapshot->dentry = dentry;
 221         trans = btrfs_start_transaction(root, 1);
 222         BUG_ON(!trans);
 223         pending_snapshot->root = root;
 224         list_add(&pending_snapshot->list,
 225                  &trans->transaction->pending_snapshots);
 226         err = btrfs_commit_transaction(trans, root);
 227
 228 fail_unlock:
 229         btrfs_btree_balance_dirty(root, nr);
 230         return ret;
 231 }
 232
 233 /* copy of may_create in fs/namei.c() */
 234 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 235 {
 236         if (child->d_inode)
 237                 return -EEXIST;
 238         if (IS_DEADDIR(dir))
 239                 return -ENOENT;
 240         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 241 }
 242
 243 /*
 244  * Create a new subvolume below @parent.  This is largely modeled after
 245  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 246  * inside this filesystem so it's quite a bit simpler.
 247  */
 248 static noinline int btrfs_mksubvol(struct path *parent, char *name,
 249                                    int mode, int namelen,
 250                                    struct btrfs_root *snap_src)
 251 {
 252         struct dentry *dentry;
 253         int error;
 254
 255         mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
 256
 257         dentry = lookup_one_len(name, parent->dentry, namelen);
 258         error = PTR_ERR(dentry);
 259         if (IS_ERR(dentry))
 260                 goto out_unlock;
 261
 262         error = -EEXIST;
 263         if (dentry->d_inode)
 264                 goto out_dput;
 265
 266         if (!IS_POSIXACL(parent->dentry->d_inode))
 267                 mode &= ~current->fs->umask;
 268
 269         error = mnt_want_write(parent->mnt);
 270         if (error)
 271                 goto out_dput;
 272
 273         error = btrfs_may_create(parent->dentry->d_inode, dentry);
 274         if (error)
 275                 goto out_drop_write;
 276
 277         /*
 278          * Actually perform the low-level subvolume creation after all
 279          * this VFS fuzz.
 280          *
 281          * Eventually we want to pass in an inode under which we create this
 282          * subvolume, but for now all are under the filesystem root.
 283          *
 284          * Also we should pass on the mode eventually to allow creating new
 285          * subvolume with specific mode bits.
 286          */
 287         if (snap_src) {
 288                 struct dentry *dir = dentry->d_parent;
 289                 struct dentry *test = dir->d_parent;
 290                 struct btrfs_path *path = btrfs_alloc_path();
 291                 int ret;
 292                 u64 test_oid;
 293                 u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid;
 294
 295                 test_oid = snap_src->root_key.objectid;
 296
 297                 ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
 298                                           path, parent_oid, test_oid);
 299                 if (ret == 0)
 300                         goto create;
 301                 btrfs_release_path(snap_src->fs_info->tree_root, path);
 302
 303                 /* we need to make sure we aren't creating a directory loop
 304                  * by taking a snapshot of something that has our current
 305                  * subvol in its directory tree.  So, this loops through
 306                  * the dentries and checks the forward refs for each subvolume
 307                  * to see if is references the subvolume where we are
 308                  * placing this new snapshot.
 309                  */
 310                 while(1) {
 311                         if (!test ||
 312                             dir == snap_src->fs_info->sb->s_root ||
 313                             test == snap_src->fs_info->sb->s_root ||
 314                             test->d_inode->i_sb != snap_src->fs_info->sb) {
 315                                 break;
 316                         }
 317                         if (S_ISLNK(test->d_inode->i_mode)) {
 318                                 printk("Symlink in snapshot path, failed\n");
 319                                 error = -EMLINK;
 320                                 btrfs_free_path(path);
 321                                 goto out_drop_write;
 322                         }
 323                         test_oid =
 324                                 BTRFS_I(test->d_inode)->root->root_key.objectid;
 325                         ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
 326                                   path, test_oid, parent_oid);
 327                         if (ret == 0) {
 328                                 printk("Snapshot creation failed, looping\n");
 329                                 error = -EMLINK;
 330                                 btrfs_free_path(path);
 331                                 goto out_drop_write;
 332                         }
 333                         btrfs_release_path(snap_src->fs_info->tree_root, path);
 334                         test = test->d_parent;
 335                 }
 336 create:
 337                 btrfs_free_path(path);
 338                 error = create_snapshot(snap_src, dentry, name, namelen);
 339         } else {
 340                 error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root,
 341                                       dentry, name, namelen);
 342         }
 343         if (error)
 344                 goto out_drop_write;
 345
 346         fsnotify_mkdir(parent->dentry->d_inode, dentry);
 347 out_drop_write:
 348         mnt_drop_write(parent->mnt);
 349 out_dput:
 350         dput(dentry);
 351 out_unlock:
 352         mutex_unlock(&parent->dentry->d_inode->i_mutex);
 353         return error;
 354 }
 355
 356
 357 static int btrfs_defrag_file(struct file *file)
 358 {
 359         struct inode *inode = fdentry(file)->d_inode;
 360         struct btrfs_root *root = BTRFS_I(inode)->root;
 361         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 362         struct btrfs_ordered_extent *ordered;
 363         struct page *page;
 364         unsigned long last_index;
 365         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 366         unsigned long total_read = 0;
 367         u64 page_start;
 368         u64 page_end;
 369         unsigned long i;
 370         int ret;
 371
 372         ret = btrfs_check_free_space(root, inode->i_size, 0);
 373         if (ret)
 374                 return -ENOSPC;
 375
 376         mutex_lock(&inode->i_mutex);
 377         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
 378         for (i = 0; i <= last_index; i++) {
 379                 if (total_read % ra_pages == 0) {
 380                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 381                                        min(last_index, i + ra_pages - 1));
 382                 }
 383                 total_read++;
 384 again:
 385                 page = grab_cache_page(inode->i_mapping, i);
 386                 if (!page)
 387                         goto out_unlock;
 388                 if (!PageUptodate(page)) {
 389                         btrfs_readpage(NULL, page);
 390                         lock_page(page);
 391                         if (!PageUptodate(page)) {
 392                                 unlock_page(page);
 393                                 page_cache_release(page);
 394                                 goto out_unlock;
 395                         }
 396                 }
 397
 398                 wait_on_page_writeback(page);
 399
 400                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 401                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 402                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 403
 404                 ordered = btrfs_lookup_ordered_extent(inode, page_start);
 405                 if (ordered) {
 406                         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 407                         unlock_page(page);
 408                         page_cache_release(page);
 409                         btrfs_start_ordered_extent(inode, ordered, 1);
 410                         btrfs_put_ordered_extent(ordered);
 411                         goto again;
 412                 }
 413                 set_page_extent_mapped(page);
 414
 415                 /*
 416                  * this makes sure page_mkwrite is called on the
 417                  * page if it is dirtied again later
 418                  */
 419                 clear_page_dirty_for_io(page);
 420
 421                 btrfs_set_extent_delalloc(inode, page_start, page_end);
 422
 423                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 424                 set_page_dirty(page);
 425                 unlock_page(page);
 426                 page_cache_release(page);
 427                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 428         }
 429
 430 out_unlock:
 431         mutex_unlock(&inode->i_mutex);
 432         return 0;
 433 }
 434
 435 /*
 436  * Called inside transaction, so use GFP_NOFS
 437  */
 438
 439 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 440 {
 441         u64 new_size;
 442         u64 old_size;
 443         u64 devid = 1;
 444         struct btrfs_ioctl_vol_args *vol_args;
 445         struct btrfs_trans_handle *trans;
 446         struct btrfs_device *device = NULL;
 447         char *sizestr;
 448         char *devstr = NULL;
 449         int ret = 0;
 450         int namelen;
 451         int mod = 0;
 452
 453         if (root->fs_info->sb->s_flags & MS_RDONLY)
 454                 return -EROFS;
 455
 456         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 457
 458         if (!vol_args)
 459                 return -ENOMEM;
 460
 461         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 462                 ret = -EFAULT;
 463                 goto out;
 464         }
 465
 466         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 467         namelen = strlen(vol_args->name);
 468
 469         mutex_lock(&root->fs_info->volume_mutex);
 470         sizestr = vol_args->name;
 471         devstr = strchr(sizestr, ':');
 472         if (devstr) {
 473                 char *end;
 474                 sizestr = devstr + 1;
 475                 *devstr = '\0';
 476                 devstr = vol_args->name;
 477                 devid = simple_strtoull(devstr, &end, 10);
 478                 printk(KERN_INFO "resizing devid %llu\n", devid);
 479         }
 480         device = btrfs_find_device(root, devid, NULL, NULL);
 481         if (!device) {
 482                 printk(KERN_INFO "resizer unable to find device %llu\n", devid);
 483                 ret = -EINVAL;
 484                 goto out_unlock;
 485         }
 486         if (!strcmp(sizestr, "max"))
 487                 new_size = device->bdev->bd_inode->i_size;
 488         else {
 489                 if (sizestr[0] == '-') {
 490                         mod = -1;
 491                         sizestr++;
 492                 } else if (sizestr[0] == '+') {
 493                         mod = 1;
 494                         sizestr++;
 495                 }
 496                 new_size = btrfs_parse_size(sizestr);
 497                 if (new_size == 0) {
 498                         ret = -EINVAL;
 499                         goto out_unlock;
 500                 }
 501         }
 502
 503         old_size = device->total_bytes;
 504
 505         if (mod < 0) {
 506                 if (new_size > old_size) {
 507                         ret = -EINVAL;
 508                         goto out_unlock;
 509                 }
 510                 new_size = old_size - new_size;
 511         } else if (mod > 0) {
 512                 new_size = old_size + new_size;
 513         }
 514
 515         if (new_size < 256 * 1024 * 1024) {
 516                 ret = -EINVAL;
 517                 goto out_unlock;
 518         }
 519         if (new_size > device->bdev->bd_inode->i_size) {
 520                 ret = -EFBIG;
 521                 goto out_unlock;
 522         }
 523
 524         do_div(new_size, root->sectorsize);
 525         new_size *= root->sectorsize;
 526
 527         printk(KERN_INFO "new size for %s is %llu\n",
 528                 device->name, (unsigned long long)new_size);
 529
 530         if (new_size > old_size) {
 531                 trans = btrfs_start_transaction(root, 1);
 532                 ret = btrfs_grow_device(trans, device, new_size);
 533                 btrfs_commit_transaction(trans, root);
 534         } else {
 535                 ret = btrfs_shrink_device(device, new_size);
 536         }
 537
 538 out_unlock:
 539         mutex_unlock(&root->fs_info->volume_mutex);
 540 out:
 541         kfree(vol_args);
 542         return ret;
 543 }
 544
 545 static noinline int btrfs_ioctl_snap_create(struct file *file,
 546                                             void __user *arg, int subvol)
 547 {
 548         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 549         struct btrfs_ioctl_vol_args *vol_args;
 550         struct btrfs_dir_item *di;
 551         struct btrfs_path *path;
 552         struct file *src_file;
 553         u64 root_dirid;
 554         int namelen;
 555         int ret = 0;
 556
 557         if (root->fs_info->sb->s_flags & MS_RDONLY)
 558                 return -EROFS;
 559
 560         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 561
 562         if (!vol_args)
 563                 return -ENOMEM;
 564
 565         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 566                 ret = -EFAULT;
 567                 goto out;
 568         }
 569
 570         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 571         namelen = strlen(vol_args->name);
 572         if (strchr(vol_args->name, '/')) {
 573                 ret = -EINVAL;
 574                 goto out;
 575         }
 576
 577         path = btrfs_alloc_path();
 578         if (!path) {
 579                 ret = -ENOMEM;
 580                 goto out;
 581         }
 582
 583         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
 584         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
 585                             path, root_dirid,
 586                             vol_args->name, namelen, 0);
 587         btrfs_free_path(path);
 588
 589         if (di && !IS_ERR(di)) {
 590                 ret = -EEXIST;
 591                 goto out;
 592         }
 593
 594         if (IS_ERR(di)) {
 595                 ret = PTR_ERR(di);
 596                 goto out;
 597         }
 598
 599         if (subvol) {
 600                 ret = btrfs_mksubvol(&file->f_path, vol_args->name,
 601                                      file->f_path.dentry->d_inode->i_mode,
 602                                      namelen, NULL);
 603         } else {
 604                 struct inode *src_inode;
 605                 src_file = fget(vol_args->fd);
 606                 if (!src_file) {
 607                         ret = -EINVAL;
 608                         goto out;
 609                 }
 610
 611                 src_inode = src_file->f_path.dentry->d_inode;
 612                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
 613                         printk("btrfs: Snapshot src from another FS\n");
 614                         ret = -EINVAL;
 615                         fput(src_file);
 616                         goto out;
 617                 }
 618                 ret = btrfs_mksubvol(&file->f_path, vol_args->name,
 619                              file->f_path.dentry->d_inode->i_mode,
 620                              namelen, BTRFS_I(src_inode)->root);
 621                 fput(src_file);
 622         }
 623
 624 out:
 625         kfree(vol_args);
 626         return ret;
 627 }
 628
 629 static int btrfs_ioctl_defrag(struct file *file)
 630 {
 631         struct inode *inode = fdentry(file)->d_inode;
 632         struct btrfs_root *root = BTRFS_I(inode)->root;
 633         int ret;
 634
 635         ret = mnt_want_write(file->f_path.mnt);
 636         if (ret)
 637                 return ret;
 638
 639         switch (inode->i_mode & S_IFMT) {
 640         case S_IFDIR:
 641                 btrfs_defrag_root(root, 0);
 642                 btrfs_defrag_root(root->fs_info->extent_root, 0);
 643                 break;
 644         case S_IFREG:
 645                 btrfs_defrag_file(file);
 646                 break;
 647         }
 648
 649         return 0;
 650 }
 651
 652 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 653 {
 654         struct btrfs_ioctl_vol_args *vol_args;
 655         int ret;
 656
 657         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 658
 659         if (!vol_args)
 660                 return -ENOMEM;
 661
 662         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 663                 ret = -EFAULT;
 664                 goto out;
 665         }
 666         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 667         ret = btrfs_init_new_device(root, vol_args->name);
 668
 669 out:
 670         kfree(vol_args);
 671         return ret;
 672 }
 673
 674 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 675 {
 676         struct btrfs_ioctl_vol_args *vol_args;
 677         int ret;
 678
 679         if (root->fs_info->sb->s_flags & MS_RDONLY)
 680                 return -EROFS;
 681
 682         vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 683
 684         if (!vol_args)
 685                 return -ENOMEM;
 686
 687         if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
 688                 ret = -EFAULT;
 689                 goto out;
 690         }
 691         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 692         ret = btrfs_rm_device(root, vol_args->name);
 693
 694 out:
 695         kfree(vol_args);
 696         return ret;
 697 }
 698
 699 static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 700                 u64 off, u64 olen, u64 destoff)
 701 {
 702         struct inode *inode = fdentry(file)->d_inode;
 703         struct btrfs_root *root = BTRFS_I(inode)->root;
 704         struct file *src_file;
 705         struct inode *src;
 706         struct btrfs_trans_handle *trans;
 707         struct btrfs_path *path;
 708         struct extent_buffer *leaf;
 709         char *buf;
 710         struct btrfs_key key;
 711         u32 nritems;
 712         int slot;
 713         int ret;
 714         u64 len = olen;
 715         u64 bs = root->fs_info->sb->s_blocksize;
 716         u64 hint_byte;
 717
 718         /*
 719          * TODO:
 720          * - split compressed inline extents.  annoying: we need to
 721          *   decompress into destination's address_space (the file offset
 722          *   may change, so source mapping won't do), then recompress (or
 723          *   otherwise reinsert) a subrange.
 724          * - allow ranges within the same file to be cloned (provided
 725          *   they don't overlap)?
 726          */
 727
 728         ret = mnt_want_write(file->f_path.mnt);
 729         if (ret)
 730                 return ret;
 731
 732         src_file = fget(srcfd);
 733         if (!src_file)
 734                 return -EBADF;
 735         src = src_file->f_dentry->d_inode;
 736
 737         ret = -EINVAL;
 738         if (src == inode)
 739                 goto out_fput;
 740
 741         ret = -EISDIR;
 742         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
 743                 goto out_fput;
 744
 745         ret = -EXDEV;
 746         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
 747                 goto out_fput;
 748
 749         ret = -ENOMEM;
 750         buf = vmalloc(btrfs_level_size(root, 0));
 751         if (!buf)
 752                 goto out_fput;
 753
 754         path = btrfs_alloc_path();
 755         if (!path) {
 756                 vfree(buf);
 757                 goto out_fput;
 758         }
 759         path->reada = 2;
 760
 761         if (inode < src) {
 762                 mutex_lock(&inode->i_mutex);
 763                 mutex_lock(&src->i_mutex);
 764         } else {
 765                 mutex_lock(&src->i_mutex);
 766                 mutex_lock(&inode->i_mutex);
 767         }
 768
 769         /* determine range to clone */
 770         ret = -EINVAL;
 771         if (off >= src->i_size || off + len > src->i_size)
 772                 goto out_unlock;
 773         if (len == 0)
 774                 olen = len = src->i_size - off;
 775         /* if we extend to eof, continue to block boundary */
 776         if (off + len == src->i_size)
 777                 len = ((src->i_size + bs-1) & ~(bs-1))
 778                         - off;
 779
 780         /* verify the end result is block aligned */
 781         if ((off & (bs-1)) ||
 782             ((off + len) & (bs-1)))
 783                 goto out_unlock;
 784
 785         printk("final src extent is %llu~%llu\n", off, len);
 786         printk("final dst extent is %llu~%llu\n", destoff, len);
 787
 788         /* do any pending delalloc/csum calc on src, one way or
 789            another, and lock file content */
 790         while (1) {
 791                 struct btrfs_ordered_extent *ordered;
 792                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
 793                 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
 794                 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
 795                         break;
 796                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
 797                 if (ordered)
 798                         btrfs_put_ordered_extent(ordered);
 799                 btrfs_wait_ordered_range(src, off, off+len);
 800         }
 801
 802         trans = btrfs_start_transaction(root, 1);
 803         BUG_ON(!trans);
 804
 805         /* punch hole in destination first */
 806         btrfs_drop_extents(trans, root, inode, off, off+len, 0, &hint_byte);
 807
 808         /* clone data */
 809         key.objectid = src->i_ino;
 810         key.type = BTRFS_EXTENT_DATA_KEY;
 811         key.offset = 0;
 812
 813         while (1) {
 814                 /*
 815                  * note the key will change type as we walk through the
 816                  * tree.
 817                  */
 818                 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
 819                 if (ret < 0)
 820                         goto out;
 821
 822                 nritems = btrfs_header_nritems(path->nodes[0]);
 823                 if (path->slots[0] >= nritems) {
 824                         ret = btrfs_next_leaf(root, path);
 825                         if (ret < 0)
 826                                 goto out;
 827                         if (ret > 0)
 828                                 break;
 829                         nritems = btrfs_header_nritems(path->nodes[0]);
 830                 }
 831                 leaf = path->nodes[0];
 832                 slot = path->slots[0];
 833
 834                 btrfs_item_key_to_cpu(leaf, &key, slot);
 835                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
 836                     key.objectid != src->i_ino)
 837                         break;
 838
 839                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
 840                         struct btrfs_file_extent_item *extent;
 841                         int type;
 842                         u32 size;
 843                         struct btrfs_key new_key;
 844                         u64 disko = 0, diskl = 0;
 845                         u64 datao = 0, datal = 0;
 846                         u8 comp;
 847
 848                         size = btrfs_item_size_nr(leaf, slot);
 849                         read_extent_buffer(leaf, buf,
 850                                            btrfs_item_ptr_offset(leaf, slot),
 851                                            size);
 852
 853                         extent = btrfs_item_ptr(leaf, slot,
 854                                                 struct btrfs_file_extent_item);
 855                         comp = btrfs_file_extent_compression(leaf, extent);
 856                         type = btrfs_file_extent_type(leaf, extent);
 857                         if (type == BTRFS_FILE_EXTENT_REG) {
 858                                 disko = btrfs_file_extent_disk_bytenr(leaf, extent);
 859                                 diskl = btrfs_file_extent_disk_num_bytes(leaf, extent);
 860                                 datao = btrfs_file_extent_offset(leaf, extent);
 861                                 datal = btrfs_file_extent_num_bytes(leaf, extent);
 862                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
 863                                 /* take upper bound, may be compressed */
 864                                 datal = btrfs_file_extent_ram_bytes(leaf,
 865                                                                     extent);
 866                         }
 867                         btrfs_release_path(root, path);
 868
 869                         if (key.offset + datal < off ||
 870                             key.offset >= off+len)
 871                                 goto next;
 872
 873                         memcpy(&new_key, &key, sizeof(new_key));
 874                         new_key.objectid = inode->i_ino;
 875                         new_key.offset = key.offset + destoff - off;
 876
 877                         if (type == BTRFS_FILE_EXTENT_REG) {
 878                                 ret = btrfs_insert_empty_item(trans, root, path,
 879                                                               &new_key, size);
 880                                 if (ret)
 881                                         goto out;
 882
 883                                 leaf = path->nodes[0];
 884                                 slot = path->slots[0];
 885                                 write_extent_buffer(leaf, buf,
 886                                             btrfs_item_ptr_offset(leaf, slot),
 887                                             size);
 888
 889                                 extent = btrfs_item_ptr(leaf, slot,
 890                                                 struct btrfs_file_extent_item);
 891                                 printk("  orig disk %llu~%llu data %llu~%llu\n",
 892                                        disko, diskl, datao, datal);
 893
 894                                 if (off > key.offset) {
 895                                         datao += off - key.offset;
 896                                         datal -= off - key.offset;
 897                                 }
 898                                 if (key.offset + datao + datal + key.offset >
 899                                     off + len)
 900                                         datal = off + len - key.offset - datao;
 901                                 /* disko == 0 means it's a hole */
 902                                 if (!disko)
 903                                         datao = 0;
 904                                 printk(" final disk %llu~%llu data %llu~%llu\n",
 905                                        disko, diskl, datao, datal);
 906
 907                                 btrfs_set_file_extent_offset(leaf, extent,
 908                                                              datao);
 909                                 btrfs_set_file_extent_num_bytes(leaf, extent,
 910                                                                 datal);
 911                                 if (disko) {
 912                                         inode_add_bytes(inode, datal);
 913                                         ret = btrfs_inc_extent_ref(trans, root,
 914                                                    disko, diskl, leaf->start,
 915                                                    root->root_key.objectid,
 916                                                    trans->transid,
 917                                                    inode->i_ino);
 918                                         BUG_ON(ret);
 919                                 }
 920                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
 921                                 u64 skip = 0;
 922                                 u64 trim = 0;
 923                                 if (off > key.offset) {
 924                                         skip = off - key.offset;
 925                                         new_key.offset += skip;
 926                                 }
 927                                 if (key.offset + datal > off+len)
 928                                         trim = key.offset + datal - (off+len);
 929                                 printk("len %lld skip %lld trim %lld\n",
 930                                        datal, skip, trim);
 931                                 if (comp && (skip || trim)) {
 932                                         printk("btrfs clone_range can't split compressed inline extents yet\n");
 933                                         ret = -EINVAL;
 934                                         goto out;
 935                                 }
 936                                 size -= skip + trim;
 937                                 datal -= skip + trim;
 938                                 ret = btrfs_insert_empty_item(trans, root, path,
 939                                                               &new_key, size);
 940                                 if (ret)
 941                                         goto out;
 942
 943                                 if (skip) {
 944                                         u32 start = btrfs_file_extent_calc_inline_size(0);
 945                                         memmove(buf+start, buf+start+skip,
 946                                                 datal);
 947                                 }
 948
 949                                 leaf = path->nodes[0];
 950                                 slot = path->slots[0];
 951                                 write_extent_buffer(leaf, buf,
 952                                             btrfs_item_ptr_offset(leaf, slot),
 953                                             size);
 954                                 inode_add_bytes(inode, datal);
 955                         }
 956
 957                         btrfs_mark_buffer_dirty(leaf);
 958                 }
 959
 960         next:
 961                 btrfs_release_path(root, path);
 962                 key.offset++;
 963         }
 964         ret = 0;
 965 out:
 966         btrfs_release_path(root, path);
 967         if (ret == 0) {
 968                 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 969                 if (destoff + olen > inode->i_size)
 970                         btrfs_i_size_write(inode, destoff + olen);
 971                 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
 972                 ret = btrfs_update_inode(trans, root, inode);
 973         }
 974         btrfs_end_transaction(trans, root);
 975         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
 976         if (ret)
 977                 vmtruncate(inode, 0);
 978 out_unlock:
 979         mutex_unlock(&src->i_mutex);
 980         mutex_unlock(&inode->i_mutex);
 981         vfree(buf);
 982         btrfs_free_path(path);
 983 out_fput:
 984         fput(src_file);
 985         return ret;
 986 }
 987
 988 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
 989 {
 990         struct btrfs_ioctl_clone_range_args args;
 991
 992         if (copy_from_user(&args, argp, sizeof(args)))
 993                 return -EFAULT;
 994         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
 995                                  args.src_length, args.dest_offset);
 996 }
 997
 998 /*
 999  * there are many ways the trans_start and trans_end ioctls can lead
1000  * to deadlocks.  They should only be used by applications that
1001  * basically own the machine, and have a very in depth understanding
1002  * of all the possible deadlocks and enospc problems.
1003  */
1004 static long btrfs_ioctl_trans_start(struct file *file)
1005 {
1006         struct inode *inode = fdentry(file)->d_inode;
1007         struct btrfs_root *root = BTRFS_I(inode)->root;
1008         struct btrfs_trans_handle *trans;
1009         int ret = 0;
1010
1011         if (!capable(CAP_SYS_ADMIN))
1012                 return -EPERM;
1013
1014         if (file->private_data) {
1015                 ret = -EINPROGRESS;
1016                 goto out;
1017         }
1018
1019         ret = mnt_want_write(file->f_path.mnt);
1020         if (ret)
1021                 goto out;
1022
1023         mutex_lock(&root->fs_info->trans_mutex);
1024         root->fs_info->open_ioctl_trans++;
1025         mutex_unlock(&root->fs_info->trans_mutex);
1026
1027         trans = btrfs_start_ioctl_transaction(root, 0);
1028         if (trans)
1029                 file->private_data = trans;
1030         else
1031                 ret = -ENOMEM;
1032         /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
1033 out:
1034         return ret;
1035 }
1036
1037 /*
1038  * there are many ways the trans_start and trans_end ioctls can lead
1039  * to deadlocks.  They should only be used by applications that
1040  * basically own the machine, and have a very in depth understanding
1041  * of all the possible deadlocks and enospc problems.
1042  */
1043 long btrfs_ioctl_trans_end(struct file *file)
1044 {
1045         struct inode *inode = fdentry(file)->d_inode;
1046         struct btrfs_root *root = BTRFS_I(inode)->root;
1047         struct btrfs_trans_handle *trans;
1048         int ret = 0;
1049
1050         trans = file->private_data;
1051         if (!trans) {
1052                 ret = -EINVAL;
1053                 goto out;
1054         }
1055         btrfs_end_transaction(trans, root);
1056         file->private_data = NULL;
1057
1058         mutex_lock(&root->fs_info->trans_mutex);
1059         root->fs_info->open_ioctl_trans--;
1060         mutex_unlock(&root->fs_info->trans_mutex);
1061
1062         mnt_drop_write(file->f_path.mnt);
1063
1064 out:
1065         return ret;
1066 }
1067
1068 long btrfs_ioctl(struct file *file, unsigned int
1069                 cmd, unsigned long arg)
1070 {
1071         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1072         void __user *argp = (void __user *)arg;
1073
1074         switch (cmd) {
1075         case BTRFS_IOC_SNAP_CREATE:
1076                 return btrfs_ioctl_snap_create(file, argp, 0);
1077         case BTRFS_IOC_SUBVOL_CREATE:
1078                 return btrfs_ioctl_snap_create(file, argp, 1);
1079         case BTRFS_IOC_DEFRAG:
1080                 return btrfs_ioctl_defrag(file);
1081         case BTRFS_IOC_RESIZE:
1082                 return btrfs_ioctl_resize(root, argp);
1083         case BTRFS_IOC_ADD_DEV:
1084                 return btrfs_ioctl_add_dev(root, argp);
1085         case BTRFS_IOC_RM_DEV:
1086                 return btrfs_ioctl_rm_dev(root, argp);
1087         case BTRFS_IOC_BALANCE:
1088                 return btrfs_balance(root->fs_info->dev_root);
1089         case BTRFS_IOC_CLONE:
1090                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
1091         case BTRFS_IOC_CLONE_RANGE:
1092                 return btrfs_ioctl_clone_range(file, argp);
1093         case BTRFS_IOC_TRANS_START:
1094                 return btrfs_ioctl_trans_start(file);
1095         case BTRFS_IOC_TRANS_END:
1096                 return btrfs_ioctl_trans_end(file);
1097         case BTRFS_IOC_SYNC:
1098                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
1099                 return 0;
1100         }
1101
1102         return -ENOTTY;
1103 }