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/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/xattr.h>
  42 #include <linux/vmalloc.h>
  43 #include "compat.h"
  44 #include "ctree.h"
  45 #include "disk-io.h"
  46 #include "transaction.h"
  47 #include "btrfs_inode.h"
  48 #include "ioctl.h"
  49 #include "print-tree.h"
  50 #include "volumes.h"
  51 #include "locking.h"
  52
  53
  54
  55 static noinline int create_subvol(struct btrfs_root *root,
  56                                   struct dentry *dentry,
  57                                   char *name, int namelen)
  58 {
  59         struct btrfs_trans_handle *trans;
  60         struct btrfs_key key;
  61         struct btrfs_root_item root_item;
  62         struct btrfs_inode_item *inode_item;
  63         struct extent_buffer *leaf;
  64         struct btrfs_root *new_root = root;
  65         struct inode *dir;
  66         int ret;
  67         int err;
  68         u64 objectid;
  69         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
  70         u64 index = 0;
  71         unsigned long nr = 1;
  72
  73         ret = btrfs_check_metadata_free_space(root);
  74         if (ret)
  75                 goto fail_commit;
  76
  77         trans = btrfs_start_transaction(root, 1);
  78         BUG_ON(!trans);
  79
  80         ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
  81                                        0, &objectid);
  82         if (ret)
  83                 goto fail;
  84
  85         leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
  86                                       0, objectid, NULL, 0, 0, 0);
  87         if (IS_ERR(leaf)) {
  88                 ret = PTR_ERR(leaf);
  89                 goto fail;
  90         }
  91
  92         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
  93         btrfs_set_header_bytenr(leaf, leaf->start);
  94         btrfs_set_header_generation(leaf, trans->transid);
  95         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
  96         btrfs_set_header_owner(leaf, objectid);
  97
  98         write_extent_buffer(leaf, root->fs_info->fsid,
  99                             (unsigned long)btrfs_header_fsid(leaf),
 100                             BTRFS_FSID_SIZE);
 101         write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
 102                             (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
 103                             BTRFS_UUID_SIZE);
 104         btrfs_mark_buffer_dirty(leaf);
 105
 106         inode_item = &root_item.inode;
 107         memset(inode_item, 0, sizeof(*inode_item));
 108         inode_item->generation = cpu_to_le64(1);
 109         inode_item->size = cpu_to_le64(3);
 110         inode_item->nlink = cpu_to_le32(1);
 111         inode_item->nbytes = cpu_to_le64(root->leafsize);
 112         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
 113
 114         btrfs_set_root_bytenr(&root_item, leaf->start);
 115         btrfs_set_root_generation(&root_item, trans->transid);
 116         btrfs_set_root_level(&root_item, 0);
 117         btrfs_set_root_refs(&root_item, 1);
 118         btrfs_set_root_used(&root_item, 0);
 119         btrfs_set_root_last_snapshot(&root_item, 0);
 120
 121         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
 122         root_item.drop_level = 0;
 123
 124         btrfs_tree_unlock(leaf);
 125         free_extent_buffer(leaf);
 126         leaf = NULL;
 127
 128         btrfs_set_root_dirid(&root_item, new_dirid);
 129
 130         key.objectid = objectid;
 131         key.offset = 0;
 132         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 133         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
 134                                 &root_item);
 135         if (ret)
 136                 goto fail;
 137
 138         /*
 139          * insert the directory item
 140          */
 141         key.offset = (u64)-1;
 142         dir = dentry->d_parent->d_inode;
 143         ret = btrfs_set_inode_index(dir, &index);
 144         BUG_ON(ret);
 145
 146         ret = btrfs_insert_dir_item(trans, root,
 147                                     name, namelen, dir->i_ino, &key,
 148                                     BTRFS_FT_DIR, index);
 149         if (ret)
 150                 goto fail;
 151
 152         btrfs_i_size_write(dir, dir->i_size + namelen * 2);
 153         ret = btrfs_update_inode(trans, root, dir);
 154         BUG_ON(ret);
 155
 156         /* add the backref first */
 157         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 158                                  objectid, BTRFS_ROOT_BACKREF_KEY,
 159                                  root->root_key.objectid,
 160                                  dir->i_ino, index, name, namelen);
 161
 162         BUG_ON(ret);
 163
 164         /* now add the forward ref */
 165         ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
 166                                  root->root_key.objectid, BTRFS_ROOT_REF_KEY,
 167                                  objectid,
 168                                  dir->i_ino, index, name, namelen);
 169
 170         BUG_ON(ret);
 171
 172         ret = btrfs_commit_transaction(trans, root);
 173         if (ret)
 174                 goto fail_commit;
 175
 176         new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
 177         BUG_ON(!new_root);
 178
 179         trans = btrfs_start_transaction(new_root, 1);
 180         BUG_ON(!trans);
 181
 182         ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid,
 183                                        BTRFS_I(dir)->block_group);
 184         if (ret)
 185                 goto fail;
 186
 187 fail:
 188         nr = trans->blocks_used;
 189         err = btrfs_commit_transaction(trans, new_root);
 190         if (err && !ret)
 191                 ret = err;
 192 fail_commit:
 193         btrfs_btree_balance_dirty(root, nr);
 194         return ret;
 195 }
 196
 197 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
 198                            char *name, int namelen)
 199 {
 200         struct btrfs_pending_snapshot *pending_snapshot;
 201         struct btrfs_trans_handle *trans;
 202         int ret = 0;
 203         int err;
 204         unsigned long nr = 0;
 205
 206         if (!root->ref_cows)
 207                 return -EINVAL;
 208
 209         ret = btrfs_check_metadata_free_space(root);
 210         if (ret)
 211                 goto fail_unlock;
 212
 213         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
 214         if (!pending_snapshot) {
 215                 ret = -ENOMEM;
 216                 goto fail_unlock;
 217         }
 218         pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS);
 219         if (!pending_snapshot->name) {
 220                 ret = -ENOMEM;
 221                 kfree(pending_snapshot);
 222                 goto fail_unlock;
 223         }
 224         memcpy(pending_snapshot->name, name, namelen);
 225         pending_snapshot->name[namelen] = '\0';
 226         pending_snapshot->dentry = dentry;
 227         trans = btrfs_start_transaction(root, 1);
 228         BUG_ON(!trans);
 229         pending_snapshot->root = root;
 230         list_add(&pending_snapshot->list,
 231                  &trans->transaction->pending_snapshots);
 232         err = btrfs_commit_transaction(trans, root);
 233
 234 fail_unlock:
 235         btrfs_btree_balance_dirty(root, nr);
 236         return ret;
 237 }
 238
 239 /* copy of may_create in fs/namei.c() */
 240 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
 241 {
 242         if (child->d_inode)
 243                 return -EEXIST;
 244         if (IS_DEADDIR(dir))
 245                 return -ENOENT;
 246         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
 247 }
 248
 249 /*
 250  * Create a new subvolume below @parent.  This is largely modeled after
 251  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
 252  * inside this filesystem so it's quite a bit simpler.
 253  */
 254 static noinline int btrfs_mksubvol(struct path *parent, char *name,
 255                                    int mode, int namelen,
 256                                    struct btrfs_root *snap_src)
 257 {
 258         struct dentry *dentry;
 259         int error;
 260
 261         mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
 262
 263         dentry = lookup_one_len(name, parent->dentry, namelen);
 264         error = PTR_ERR(dentry);
 265         if (IS_ERR(dentry))
 266                 goto out_unlock;
 267
 268         error = -EEXIST;
 269         if (dentry->d_inode)
 270                 goto out_dput;
 271
 272         if (!IS_POSIXACL(parent->dentry->d_inode))
 273                 mode &= ~current_umask();
 274
 275         error = mnt_want_write(parent->mnt);
 276         if (error)
 277                 goto out_dput;
 278
 279         error = btrfs_may_create(parent->dentry->d_inode, dentry);
 280         if (error)
 281                 goto out_drop_write;
 282
 283         /*
 284          * Actually perform the low-level subvolume creation after all
 285          * this VFS fuzz.
 286          *
 287          * Eventually we want to pass in an inode under which we create this
 288          * subvolume, but for now all are under the filesystem root.
 289          *
 290          * Also we should pass on the mode eventually to allow creating new
 291          * subvolume with specific mode bits.
 292          */
 293         if (snap_src) {
 294                 struct dentry *dir = dentry->d_parent;
 295                 struct dentry *test = dir->d_parent;
 296                 struct btrfs_path *path = btrfs_alloc_path();
 297                 int ret;
 298                 u64 test_oid;
 299                 u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid;
 300
 301                 test_oid = snap_src->root_key.objectid;
 302
 303                 ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
 304                                           path, parent_oid, test_oid);
 305                 if (ret == 0)
 306                         goto create;
 307                 btrfs_release_path(snap_src->fs_info->tree_root, path);
 308
 309                 /* we need to make sure we aren't creating a directory loop
 310                  * by taking a snapshot of something that has our current
 311                  * subvol in its directory tree.  So, this loops through
 312                  * the dentries and checks the forward refs for each subvolume
 313                  * to see if is references the subvolume where we are
 314                  * placing this new snapshot.
 315                  */
 316                 while (1) {
 317                         if (!test ||
 318                             dir == snap_src->fs_info->sb->s_root ||
 319                             test == snap_src->fs_info->sb->s_root ||
 320                             test->d_inode->i_sb != snap_src->fs_info->sb) {
 321                                 break;
 322                         }
 323                         if (S_ISLNK(test->d_inode->i_mode)) {
 324                                 printk(KERN_INFO "Btrfs symlink in snapshot "
 325                                        "path, failed\n");
 326                                 error = -EMLINK;
 327                                 btrfs_free_path(path);
 328                                 goto out_drop_write;
 329                         }
 330                         test_oid =
 331                                 BTRFS_I(test->d_inode)->root->root_key.objectid;
 332                         ret = btrfs_find_root_ref(snap_src->fs_info->tree_root,
 333                                   path, test_oid, parent_oid);
 334                         if (ret == 0) {
 335                                 printk(KERN_INFO "Btrfs snapshot creation "
 336                                        "failed, looping\n");
 337                                 error = -EMLINK;
 338                                 btrfs_free_path(path);
 339                                 goto out_drop_write;
 340                         }
 341                         btrfs_release_path(snap_src->fs_info->tree_root, path);
 342                         test = test->d_parent;
 343                 }
 344 create:
 345                 btrfs_free_path(path);
 346                 error = create_snapshot(snap_src, dentry, name, namelen);
 347         } else {
 348                 error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root,
 349                                       dentry, name, namelen);
 350         }
 351         if (error)
 352                 goto out_drop_write;
 353
 354         fsnotify_mkdir(parent->dentry->d_inode, dentry);
 355 out_drop_write:
 356         mnt_drop_write(parent->mnt);
 357 out_dput:
 358         dput(dentry);
 359 out_unlock:
 360         mutex_unlock(&parent->dentry->d_inode->i_mutex);
 361         return error;
 362 }
 363
 364
 365 static int btrfs_defrag_file(struct file *file)
 366 {
 367         struct inode *inode = fdentry(file)->d_inode;
 368         struct btrfs_root *root = BTRFS_I(inode)->root;
 369         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 370         struct btrfs_ordered_extent *ordered;
 371         struct page *page;
 372         unsigned long last_index;
 373         unsigned long ra_pages = root->fs_info->bdi.ra_pages;
 374         unsigned long total_read = 0;
 375         u64 page_start;
 376         u64 page_end;
 377         unsigned long i;
 378         int ret;
 379
 380         ret = btrfs_check_data_free_space(root, inode, inode->i_size);
 381         if (ret)
 382                 return -ENOSPC;
 383
 384         mutex_lock(&inode->i_mutex);
 385         last_index = inode->i_size >> PAGE_CACHE_SHIFT;
 386         for (i = 0; i <= last_index; i++) {
 387                 if (total_read % ra_pages == 0) {
 388                         btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
 389                                        min(last_index, i + ra_pages - 1));
 390                 }
 391                 total_read++;
 392 again:
 393                 page = grab_cache_page(inode->i_mapping, i);
 394                 if (!page)
 395                         goto out_unlock;
 396                 if (!PageUptodate(page)) {
 397                         btrfs_readpage(NULL, page);
 398                         lock_page(page);
 399                         if (!PageUptodate(page)) {
 400                                 unlock_page(page);
 401                                 page_cache_release(page);
 402                                 goto out_unlock;
 403                         }
 404                 }
 405
 406                 wait_on_page_writeback(page);
 407
 408                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
 409                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 410                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 411
 412                 ordered = btrfs_lookup_ordered_extent(inode, page_start);
 413                 if (ordered) {
 414                         unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 415                         unlock_page(page);
 416                         page_cache_release(page);
 417                         btrfs_start_ordered_extent(inode, ordered, 1);
 418                         btrfs_put_ordered_extent(ordered);
 419                         goto again;
 420                 }
 421                 set_page_extent_mapped(page);
 422
 423                 /*
 424                  * this makes sure page_mkwrite is called on the
 425                  * page if it is dirtied again later
 426                  */
 427                 clear_page_dirty_for_io(page);
 428
 429                 btrfs_set_extent_delalloc(inode, page_start, page_end);
 430
 431                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
 432                 set_page_dirty(page);
 433                 unlock_page(page);
 434                 page_cache_release(page);
 435                 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
 436         }
 437
 438 out_unlock:
 439         mutex_unlock(&inode->i_mutex);
 440         return 0;
 441 }
 442
 443 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 444 {
 445         u64 new_size;
 446         u64 old_size;
 447         u64 devid = 1;
 448         struct btrfs_ioctl_vol_args *vol_args;
 449         struct btrfs_trans_handle *trans;
 450         struct btrfs_device *device = NULL;
 451         char *sizestr;
 452         char *devstr = NULL;
 453         int ret = 0;
 454         int namelen;
 455         int mod = 0;
 456
 457         if (root->fs_info->sb->s_flags & MS_RDONLY)
 458                 return -EROFS;
 459
 460         if (!capable(CAP_SYS_ADMIN))
 461                 return -EPERM;
 462
 463         vol_args = memdup_user(arg, sizeof(*vol_args));
 464         if (IS_ERR(vol_args))
 465                 return PTR_ERR(vol_args);
 466
 467         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 468         namelen = strlen(vol_args->name);
 469
 470         mutex_lock(&root->fs_info->volume_mutex);
 471         sizestr = vol_args->name;
 472         devstr = strchr(sizestr, ':');
 473         if (devstr) {
 474                 char *end;
 475                 sizestr = devstr + 1;
 476                 *devstr = '\0';
 477                 devstr = vol_args->name;
 478                 devid = simple_strtoull(devstr, &end, 10);
 479                 printk(KERN_INFO "resizing devid %llu\n",
 480                        (unsigned long long)devid);
 481         }
 482         device = btrfs_find_device(root, devid, NULL, NULL);
 483         if (!device) {
 484                 printk(KERN_INFO "resizer unable to find device %llu\n",
 485                        (unsigned long long)devid);
 486                 ret = -EINVAL;
 487                 goto out_unlock;
 488         }
 489         if (!strcmp(sizestr, "max"))
 490                 new_size = device->bdev->bd_inode->i_size;
 491         else {
 492                 if (sizestr[0] == '-') {
 493                         mod = -1;
 494                         sizestr++;
 495                 } else if (sizestr[0] == '+') {
 496                         mod = 1;
 497                         sizestr++;
 498                 }
 499                 new_size = btrfs_parse_size(sizestr);
 500                 if (new_size == 0) {
 501                         ret = -EINVAL;
 502                         goto out_unlock;
 503                 }
 504         }
 505
 506         old_size = device->total_bytes;
 507
 508         if (mod < 0) {
 509                 if (new_size > old_size) {
 510                         ret = -EINVAL;
 511                         goto out_unlock;
 512                 }
 513                 new_size = old_size - new_size;
 514         } else if (mod > 0) {
 515                 new_size = old_size + new_size;
 516         }
 517
 518         if (new_size < 256 * 1024 * 1024) {
 519                 ret = -EINVAL;
 520                 goto out_unlock;
 521         }
 522         if (new_size > device->bdev->bd_inode->i_size) {
 523                 ret = -EFBIG;
 524                 goto out_unlock;
 525         }
 526
 527         do_div(new_size, root->sectorsize);
 528         new_size *= root->sectorsize;
 529
 530         printk(KERN_INFO "new size for %s is %llu\n",
 531                 device->name, (unsigned long long)new_size);
 532
 533         if (new_size > old_size) {
 534                 trans = btrfs_start_transaction(root, 1);
 535                 ret = btrfs_grow_device(trans, device, new_size);
 536                 btrfs_commit_transaction(trans, root);
 537         } else {
 538                 ret = btrfs_shrink_device(device, new_size);
 539         }
 540
 541 out_unlock:
 542         mutex_unlock(&root->fs_info->volume_mutex);
 543         kfree(vol_args);
 544         return ret;
 545 }
 546
 547 static noinline int btrfs_ioctl_snap_create(struct file *file,
 548                                             void __user *arg, int subvol)
 549 {
 550         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
 551         struct btrfs_ioctl_vol_args *vol_args;
 552         struct btrfs_dir_item *di;
 553         struct btrfs_path *path;
 554         struct file *src_file;
 555         u64 root_dirid;
 556         int namelen;
 557         int ret = 0;
 558
 559         if (root->fs_info->sb->s_flags & MS_RDONLY)
 560                 return -EROFS;
 561
 562         vol_args = memdup_user(arg, sizeof(*vol_args));
 563         if (IS_ERR(vol_args))
 564                 return PTR_ERR(vol_args);
 565
 566         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 567         namelen = strlen(vol_args->name);
 568         if (strchr(vol_args->name, '/')) {
 569                 ret = -EINVAL;
 570                 goto out;
 571         }
 572
 573         path = btrfs_alloc_path();
 574         if (!path) {
 575                 ret = -ENOMEM;
 576                 goto out;
 577         }
 578
 579         root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
 580         di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
 581                             path, root_dirid,
 582                             vol_args->name, namelen, 0);
 583         btrfs_free_path(path);
 584
 585         if (di && !IS_ERR(di)) {
 586                 ret = -EEXIST;
 587                 goto out;
 588         }
 589
 590         if (IS_ERR(di)) {
 591                 ret = PTR_ERR(di);
 592                 goto out;
 593         }
 594
 595         if (subvol) {
 596                 ret = btrfs_mksubvol(&file->f_path, vol_args->name,
 597                                      file->f_path.dentry->d_inode->i_mode,
 598                                      namelen, NULL);
 599         } else {
 600                 struct inode *src_inode;
 601                 src_file = fget(vol_args->fd);
 602                 if (!src_file) {
 603                         ret = -EINVAL;
 604                         goto out;
 605                 }
 606
 607                 src_inode = src_file->f_path.dentry->d_inode;
 608                 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
 609                         printk(KERN_INFO "btrfs: Snapshot src from "
 610                                "another FS\n");
 611                         ret = -EINVAL;
 612                         fput(src_file);
 613                         goto out;
 614                 }
 615                 ret = btrfs_mksubvol(&file->f_path, vol_args->name,
 616                              file->f_path.dentry->d_inode->i_mode,
 617                              namelen, BTRFS_I(src_inode)->root);
 618                 fput(src_file);
 619         }
 620
 621 out:
 622         kfree(vol_args);
 623         return ret;
 624 }
 625
 626 static int btrfs_ioctl_defrag(struct file *file)
 627 {
 628         struct inode *inode = fdentry(file)->d_inode;
 629         struct btrfs_root *root = BTRFS_I(inode)->root;
 630         int ret;
 631
 632         ret = mnt_want_write(file->f_path.mnt);
 633         if (ret)
 634                 return ret;
 635
 636         switch (inode->i_mode & S_IFMT) {
 637         case S_IFDIR:
 638                 if (!capable(CAP_SYS_ADMIN)) {
 639                         ret = -EPERM;
 640                         goto out;
 641                 }
 642                 btrfs_defrag_root(root, 0);
 643                 btrfs_defrag_root(root->fs_info->extent_root, 0);
 644                 break;
 645         case S_IFREG:
 646                 if (!(file->f_mode & FMODE_WRITE)) {
 647                         ret = -EINVAL;
 648                         goto out;
 649                 }
 650                 btrfs_defrag_file(file);
 651                 break;
 652         }
 653 out:
 654         mnt_drop_write(file->f_path.mnt);
 655         return ret;
 656 }
 657
 658 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
 659 {
 660         struct btrfs_ioctl_vol_args *vol_args;
 661         int ret;
 662
 663         if (!capable(CAP_SYS_ADMIN))
 664                 return -EPERM;
 665
 666         vol_args = memdup_user(arg, sizeof(*vol_args));
 667         if (IS_ERR(vol_args))
 668                 return PTR_ERR(vol_args);
 669
 670         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 671         ret = btrfs_init_new_device(root, vol_args->name);
 672
 673         kfree(vol_args);
 674         return ret;
 675 }
 676
 677 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
 678 {
 679         struct btrfs_ioctl_vol_args *vol_args;
 680         int ret;
 681
 682         if (!capable(CAP_SYS_ADMIN))
 683                 return -EPERM;
 684
 685         if (root->fs_info->sb->s_flags & MS_RDONLY)
 686                 return -EROFS;
 687
 688         vol_args = memdup_user(arg, sizeof(*vol_args));
 689         if (IS_ERR(vol_args))
 690                 return PTR_ERR(vol_args);
 691
 692         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
 693         ret = btrfs_rm_device(root, vol_args->name);
 694
 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         /* the destination must be opened for writing */
 729         if (!(file->f_mode & FMODE_WRITE))
 730                 return -EINVAL;
 731
 732         ret = mnt_want_write(file->f_path.mnt);
 733         if (ret)
 734                 return ret;
 735
 736         src_file = fget(srcfd);
 737         if (!src_file) {
 738                 ret = -EBADF;
 739                 goto out_drop_write;
 740         }
 741         src = src_file->f_dentry->d_inode;
 742
 743         ret = -EINVAL;
 744         if (src == inode)
 745                 goto out_fput;
 746
 747         ret = -EISDIR;
 748         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
 749                 goto out_fput;
 750
 751         ret = -EXDEV;
 752         if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
 753                 goto out_fput;
 754
 755         ret = -ENOMEM;
 756         buf = vmalloc(btrfs_level_size(root, 0));
 757         if (!buf)
 758                 goto out_fput;
 759
 760         path = btrfs_alloc_path();
 761         if (!path) {
 762                 vfree(buf);
 763                 goto out_fput;
 764         }
 765         path->reada = 2;
 766
 767         if (inode < src) {
 768                 mutex_lock(&inode->i_mutex);
 769                 mutex_lock(&src->i_mutex);
 770         } else {
 771                 mutex_lock(&src->i_mutex);
 772                 mutex_lock(&inode->i_mutex);
 773         }
 774
 775         /* determine range to clone */
 776         ret = -EINVAL;
 777         if (off >= src->i_size || off + len > src->i_size)
 778                 goto out_unlock;
 779         if (len == 0)
 780                 olen = len = src->i_size - off;
 781         /* if we extend to eof, continue to block boundary */
 782         if (off + len == src->i_size)
 783                 len = ((src->i_size + bs-1) & ~(bs-1))
 784                         - off;
 785
 786         /* verify the end result is block aligned */
 787         if ((off & (bs-1)) ||
 788             ((off + len) & (bs-1)))
 789                 goto out_unlock;
 790
 791         /* do any pending delalloc/csum calc on src, one way or
 792            another, and lock file content */
 793         while (1) {
 794                 struct btrfs_ordered_extent *ordered;
 795                 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
 796                 ordered = btrfs_lookup_first_ordered_extent(inode, off+len);
 797                 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered)
 798                         break;
 799                 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
 800                 if (ordered)
 801                         btrfs_put_ordered_extent(ordered);
 802                 btrfs_wait_ordered_range(src, off, off+len);
 803         }
 804
 805         trans = btrfs_start_transaction(root, 1);
 806         BUG_ON(!trans);
 807
 808         /* punch hole in destination first */
 809         btrfs_drop_extents(trans, root, inode, off, off + len,
 810                            off + len, 0, &hint_byte);
 811
 812         /* clone data */
 813         key.objectid = src->i_ino;
 814         key.type = BTRFS_EXTENT_DATA_KEY;
 815         key.offset = 0;
 816
 817         while (1) {
 818                 /*
 819                  * note the key will change type as we walk through the
 820                  * tree.
 821                  */
 822                 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
 823                 if (ret < 0)
 824                         goto out;
 825
 826                 nritems = btrfs_header_nritems(path->nodes[0]);
 827                 if (path->slots[0] >= nritems) {
 828                         ret = btrfs_next_leaf(root, path);
 829                         if (ret < 0)
 830                                 goto out;
 831                         if (ret > 0)
 832                                 break;
 833                         nritems = btrfs_header_nritems(path->nodes[0]);
 834                 }
 835                 leaf = path->nodes[0];
 836                 slot = path->slots[0];
 837
 838                 btrfs_item_key_to_cpu(leaf, &key, slot);
 839                 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
 840                     key.objectid != src->i_ino)
 841                         break;
 842
 843                 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
 844                         struct btrfs_file_extent_item *extent;
 845                         int type;
 846                         u32 size;
 847                         struct btrfs_key new_key;
 848                         u64 disko = 0, diskl = 0;
 849                         u64 datao = 0, datal = 0;
 850                         u8 comp;
 851
 852                         size = btrfs_item_size_nr(leaf, slot);
 853                         read_extent_buffer(leaf, buf,
 854                                            btrfs_item_ptr_offset(leaf, slot),
 855                                            size);
 856
 857                         extent = btrfs_item_ptr(leaf, slot,
 858                                                 struct btrfs_file_extent_item);
 859                         comp = btrfs_file_extent_compression(leaf, extent);
 860                         type = btrfs_file_extent_type(leaf, extent);
 861                         if (type == BTRFS_FILE_EXTENT_REG) {
 862                                 disko = btrfs_file_extent_disk_bytenr(leaf,
 863                                                                       extent);
 864                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
 865                                                                  extent);
 866                                 datao = btrfs_file_extent_offset(leaf, extent);
 867                                 datal = btrfs_file_extent_num_bytes(leaf,
 868                                                                     extent);
 869                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
 870                                 /* take upper bound, may be compressed */
 871                                 datal = btrfs_file_extent_ram_bytes(leaf,
 872                                                                     extent);
 873                         }
 874                         btrfs_release_path(root, path);
 875
 876                         if (key.offset + datal < off ||
 877                             key.offset >= off+len)
 878                                 goto next;
 879
 880                         memcpy(&new_key, &key, sizeof(new_key));
 881                         new_key.objectid = inode->i_ino;
 882                         new_key.offset = key.offset + destoff - off;
 883
 884                         if (type == BTRFS_FILE_EXTENT_REG) {
 885                                 ret = btrfs_insert_empty_item(trans, root, path,
 886                                                               &new_key, size);
 887                                 if (ret)
 888                                         goto out;
 889
 890                                 leaf = path->nodes[0];
 891                                 slot = path->slots[0];
 892                                 write_extent_buffer(leaf, buf,
 893                                             btrfs_item_ptr_offset(leaf, slot),
 894                                             size);
 895
 896                                 extent = btrfs_item_ptr(leaf, slot,
 897                                                 struct btrfs_file_extent_item);
 898
 899                                 if (off > key.offset) {
 900                                         datao += off - key.offset;
 901                                         datal -= off - key.offset;
 902                                 }
 903                                 if (key.offset + datao + datal + key.offset >
 904                                     off + len)
 905                                         datal = off + len - key.offset - datao;
 906                                 /* disko == 0 means it's a hole */
 907                                 if (!disko)
 908                                         datao = 0;
 909
 910                                 btrfs_set_file_extent_offset(leaf, extent,
 911                                                              datao);
 912                                 btrfs_set_file_extent_num_bytes(leaf, extent,
 913                                                                 datal);
 914                                 if (disko) {
 915                                         inode_add_bytes(inode, datal);
 916                                         ret = btrfs_inc_extent_ref(trans, root,
 917                                                         disko, diskl, 0,
 918                                                         root->root_key.objectid,
 919                                                         inode->i_ino,
 920                                                         new_key.offset - datao);
 921                                         BUG_ON(ret);
 922                                 }
 923                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
 924                                 u64 skip = 0;
 925                                 u64 trim = 0;
 926                                 if (off > key.offset) {
 927                                         skip = off - key.offset;
 928                                         new_key.offset += skip;
 929                                 }
 930
 931                                 if (key.offset + datal > off+len)
 932                                         trim = key.offset + datal - (off+len);
 933
 934                                 if (comp && (skip || trim)) {
 935                                         ret = -EINVAL;
 936                                         goto out;
 937                                 }
 938                                 size -= skip + trim;
 939                                 datal -= skip + trim;
 940                                 ret = btrfs_insert_empty_item(trans, root, path,
 941                                                               &new_key, size);
 942                                 if (ret)
 943                                         goto out;
 944
 945                                 if (skip) {
 946                                         u32 start =
 947                                           btrfs_file_extent_calc_inline_size(0);
 948                                         memmove(buf+start, buf+start+skip,
 949                                                 datal);
 950                                 }
 951
 952                                 leaf = path->nodes[0];
 953                                 slot = path->slots[0];
 954                                 write_extent_buffer(leaf, buf,
 955                                             btrfs_item_ptr_offset(leaf, slot),
 956                                             size);
 957                                 inode_add_bytes(inode, datal);
 958                         }
 959
 960                         btrfs_mark_buffer_dirty(leaf);
 961                 }
 962
 963 next:
 964                 btrfs_release_path(root, path);
 965                 key.offset++;
 966         }
 967         ret = 0;
 968 out:
 969         btrfs_release_path(root, path);
 970         if (ret == 0) {
 971                 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 972                 if (destoff + olen > inode->i_size)
 973                         btrfs_i_size_write(inode, destoff + olen);
 974                 BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
 975                 ret = btrfs_update_inode(trans, root, inode);
 976         }
 977         btrfs_end_transaction(trans, root);
 978         unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
 979         if (ret)
 980                 vmtruncate(inode, 0);
 981 out_unlock:
 982         mutex_unlock(&src->i_mutex);
 983         mutex_unlock(&inode->i_mutex);
 984         vfree(buf);
 985         btrfs_free_path(path);
 986 out_fput:
 987         fput(src_file);
 988 out_drop_write:
 989         mnt_drop_write(file->f_path.mnt);
 990         return ret;
 991 }
 992
 993 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
 994 {
 995         struct btrfs_ioctl_clone_range_args args;
 996
 997         if (copy_from_user(&args, argp, sizeof(args)))
 998                 return -EFAULT;
 999         return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
1000                                  args.src_length, args.dest_offset);
1001 }
1002
1003 /*
1004  * there are many ways the trans_start and trans_end ioctls can lead
1005  * to deadlocks.  They should only be used by applications that
1006  * basically own the machine, and have a very in depth understanding
1007  * of all the possible deadlocks and enospc problems.
1008  */
1009 static long btrfs_ioctl_trans_start(struct file *file)
1010 {
1011         struct inode *inode = fdentry(file)->d_inode;
1012         struct btrfs_root *root = BTRFS_I(inode)->root;
1013         struct btrfs_trans_handle *trans;
1014         int ret = 0;
1015
1016         if (!capable(CAP_SYS_ADMIN))
1017                 return -EPERM;
1018
1019         if (file->private_data) {
1020                 ret = -EINPROGRESS;
1021                 goto out;
1022         }
1023
1024         ret = mnt_want_write(file->f_path.mnt);
1025         if (ret)
1026                 goto out;
1027
1028         mutex_lock(&root->fs_info->trans_mutex);
1029         root->fs_info->open_ioctl_trans++;
1030         mutex_unlock(&root->fs_info->trans_mutex);
1031
1032         trans = btrfs_start_ioctl_transaction(root, 0);
1033         if (trans)
1034                 file->private_data = trans;
1035         else
1036                 ret = -ENOMEM;
1037         /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
1038 out:
1039         return ret;
1040 }
1041
1042 /*
1043  * there are many ways the trans_start and trans_end ioctls can lead
1044  * to deadlocks.  They should only be used by applications that
1045  * basically own the machine, and have a very in depth understanding
1046  * of all the possible deadlocks and enospc problems.
1047  */
1048 long btrfs_ioctl_trans_end(struct file *file)
1049 {
1050         struct inode *inode = fdentry(file)->d_inode;
1051         struct btrfs_root *root = BTRFS_I(inode)->root;
1052         struct btrfs_trans_handle *trans;
1053         int ret = 0;
1054
1055         trans = file->private_data;
1056         if (!trans) {
1057                 ret = -EINVAL;
1058                 goto out;
1059         }
1060         btrfs_end_transaction(trans, root);
1061         file->private_data = NULL;
1062
1063         mutex_lock(&root->fs_info->trans_mutex);
1064         root->fs_info->open_ioctl_trans--;
1065         mutex_unlock(&root->fs_info->trans_mutex);
1066
1067         mnt_drop_write(file->f_path.mnt);
1068
1069 out:
1070         return ret;
1071 }
1072
1073 long btrfs_ioctl(struct file *file, unsigned int
1074                 cmd, unsigned long arg)
1075 {
1076         struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1077         void __user *argp = (void __user *)arg;
1078
1079         switch (cmd) {
1080         case BTRFS_IOC_SNAP_CREATE:
1081                 return btrfs_ioctl_snap_create(file, argp, 0);
1082         case BTRFS_IOC_SUBVOL_CREATE:
1083                 return btrfs_ioctl_snap_create(file, argp, 1);
1084         case BTRFS_IOC_DEFRAG:
1085                 return btrfs_ioctl_defrag(file);
1086         case BTRFS_IOC_RESIZE:
1087                 return btrfs_ioctl_resize(root, argp);
1088         case BTRFS_IOC_ADD_DEV:
1089                 return btrfs_ioctl_add_dev(root, argp);
1090         case BTRFS_IOC_RM_DEV:
1091                 return btrfs_ioctl_rm_dev(root, argp);
1092         case BTRFS_IOC_BALANCE:
1093                 return btrfs_balance(root->fs_info->dev_root);
1094         case BTRFS_IOC_CLONE:
1095                 return btrfs_ioctl_clone(file, arg, 0, 0, 0);
1096         case BTRFS_IOC_CLONE_RANGE:
1097                 return btrfs_ioctl_clone_range(file, argp);
1098         case BTRFS_IOC_TRANS_START:
1099                 return btrfs_ioctl_trans_start(file);
1100         case BTRFS_IOC_TRANS_END:
1101                 return btrfs_ioctl_trans_end(file);
1102         case BTRFS_IOC_SYNC:
1103                 btrfs_sync_fs(file->f_dentry->d_sb, 1);
1104                 return 0;
1105         }
1106
1107         return -ENOTTY;
1108 }