| 1 | #include <linux/module.h> |
| 2 | #include <linux/buffer_head.h> |
| 3 | #include <linux/fs.h> |
| 4 | #include <linux/pagemap.h> |
| 5 | #include <linux/highmem.h> |
| 6 | #include <linux/time.h> |
| 7 | #include <linux/init.h> |
| 8 | #include <linux/string.h> |
| 9 | #include <linux/smp_lock.h> |
| 10 | #include <linux/backing-dev.h> |
| 11 | #include <linux/mpage.h> |
| 12 | #include <linux/swap.h> |
| 13 | #include <linux/writeback.h> |
| 14 | #include <linux/statfs.h> |
| 15 | #include "ctree.h" |
| 16 | #include "disk-io.h" |
| 17 | #include "transaction.h" |
| 18 | #include "btrfs_inode.h" |
| 19 | #include "ioctl.h" |
| 20 | |
| 21 | void btrfs_fsinfo_release(struct kobject *obj) |
| 22 | { |
| 23 | struct btrfs_fs_info *fsinfo = container_of(obj, |
| 24 | struct btrfs_fs_info, kobj); |
| 25 | kfree(fsinfo); |
| 26 | } |
| 27 | |
| 28 | struct kobj_type btrfs_fsinfo_ktype = { |
| 29 | .release = btrfs_fsinfo_release, |
| 30 | }; |
| 31 | |
| 32 | struct btrfs_iget_args { |
| 33 | u64 ino; |
| 34 | struct btrfs_root *root; |
| 35 | }; |
| 36 | |
| 37 | decl_subsys(btrfs, &btrfs_fsinfo_ktype, NULL); |
| 38 | |
| 39 | #define BTRFS_SUPER_MAGIC 0x9123682E |
| 40 | |
| 41 | static struct inode_operations btrfs_dir_inode_operations; |
| 42 | static struct inode_operations btrfs_dir_ro_inode_operations; |
| 43 | static struct super_operations btrfs_super_ops; |
| 44 | static struct file_operations btrfs_dir_file_operations; |
| 45 | static struct inode_operations btrfs_file_inode_operations; |
| 46 | static struct address_space_operations btrfs_aops; |
| 47 | static struct file_operations btrfs_file_operations; |
| 48 | |
| 49 | static void btrfs_read_locked_inode(struct inode *inode) |
| 50 | { |
| 51 | struct btrfs_path *path; |
| 52 | struct btrfs_inode_item *inode_item; |
| 53 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 54 | struct btrfs_key location; |
| 55 | int ret; |
| 56 | |
| 57 | path = btrfs_alloc_path(); |
| 58 | BUG_ON(!path); |
| 59 | btrfs_init_path(path); |
| 60 | mutex_lock(&root->fs_info->fs_mutex); |
| 61 | |
| 62 | memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); |
| 63 | ret = btrfs_lookup_inode(NULL, root, path, &location, 0); |
| 64 | if (ret) { |
| 65 | btrfs_free_path(path); |
| 66 | goto make_bad; |
| 67 | } |
| 68 | inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
| 69 | path->slots[0], |
| 70 | struct btrfs_inode_item); |
| 71 | |
| 72 | inode->i_mode = btrfs_inode_mode(inode_item); |
| 73 | inode->i_nlink = btrfs_inode_nlink(inode_item); |
| 74 | inode->i_uid = btrfs_inode_uid(inode_item); |
| 75 | inode->i_gid = btrfs_inode_gid(inode_item); |
| 76 | inode->i_size = btrfs_inode_size(inode_item); |
| 77 | inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime); |
| 78 | inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime); |
| 79 | inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime); |
| 80 | inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime); |
| 81 | inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime); |
| 82 | inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime); |
| 83 | inode->i_blocks = btrfs_inode_nblocks(inode_item); |
| 84 | inode->i_generation = btrfs_inode_generation(inode_item); |
| 85 | |
| 86 | btrfs_free_path(path); |
| 87 | inode_item = NULL; |
| 88 | |
| 89 | mutex_unlock(&root->fs_info->fs_mutex); |
| 90 | |
| 91 | switch (inode->i_mode & S_IFMT) { |
| 92 | #if 0 |
| 93 | default: |
| 94 | init_special_inode(inode, inode->i_mode, |
| 95 | btrfs_inode_rdev(inode_item)); |
| 96 | break; |
| 97 | #endif |
| 98 | case S_IFREG: |
| 99 | inode->i_mapping->a_ops = &btrfs_aops; |
| 100 | inode->i_fop = &btrfs_file_operations; |
| 101 | inode->i_op = &btrfs_file_inode_operations; |
| 102 | break; |
| 103 | case S_IFDIR: |
| 104 | inode->i_fop = &btrfs_dir_file_operations; |
| 105 | if (root == root->fs_info->tree_root) |
| 106 | inode->i_op = &btrfs_dir_ro_inode_operations; |
| 107 | else |
| 108 | inode->i_op = &btrfs_dir_inode_operations; |
| 109 | break; |
| 110 | case S_IFLNK: |
| 111 | // inode->i_op = &page_symlink_inode_operations; |
| 112 | break; |
| 113 | } |
| 114 | return; |
| 115 | |
| 116 | make_bad: |
| 117 | btrfs_release_path(root, path); |
| 118 | btrfs_free_path(path); |
| 119 | mutex_unlock(&root->fs_info->fs_mutex); |
| 120 | make_bad_inode(inode); |
| 121 | } |
| 122 | |
| 123 | static int btrfs_unlink_trans(struct btrfs_trans_handle *trans, |
| 124 | struct btrfs_root *root, |
| 125 | struct inode *dir, |
| 126 | struct dentry *dentry) |
| 127 | { |
| 128 | struct btrfs_path *path; |
| 129 | const char *name = dentry->d_name.name; |
| 130 | int name_len = dentry->d_name.len; |
| 131 | int ret = 0; |
| 132 | u64 objectid; |
| 133 | struct btrfs_dir_item *di; |
| 134 | |
| 135 | path = btrfs_alloc_path(); |
| 136 | BUG_ON(!path); |
| 137 | btrfs_init_path(path); |
| 138 | di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino, |
| 139 | name, name_len, -1); |
| 140 | if (IS_ERR(di)) { |
| 141 | ret = PTR_ERR(di); |
| 142 | goto err; |
| 143 | } |
| 144 | if (!di) { |
| 145 | ret = -ENOENT; |
| 146 | goto err; |
| 147 | } |
| 148 | objectid = btrfs_disk_key_objectid(&di->location); |
| 149 | ret = btrfs_delete_one_dir_name(trans, root, path, di); |
| 150 | BUG_ON(ret); |
| 151 | btrfs_release_path(root, path); |
| 152 | |
| 153 | di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, |
| 154 | objectid, name, name_len, -1); |
| 155 | if (IS_ERR(di)) { |
| 156 | ret = PTR_ERR(di); |
| 157 | goto err; |
| 158 | } |
| 159 | if (!di) { |
| 160 | ret = -ENOENT; |
| 161 | goto err; |
| 162 | } |
| 163 | ret = btrfs_delete_one_dir_name(trans, root, path, di); |
| 164 | BUG_ON(ret); |
| 165 | |
| 166 | dentry->d_inode->i_ctime = dir->i_ctime; |
| 167 | err: |
| 168 | btrfs_free_path(path); |
| 169 | if (ret == 0) { |
| 170 | inode_dec_link_count(dentry->d_inode); |
| 171 | dir->i_size -= name_len * 2; |
| 172 | mark_inode_dirty(dir); |
| 173 | } |
| 174 | return ret; |
| 175 | } |
| 176 | |
| 177 | static int btrfs_unlink(struct inode *dir, struct dentry *dentry) |
| 178 | { |
| 179 | struct btrfs_root *root; |
| 180 | struct btrfs_trans_handle *trans; |
| 181 | int ret; |
| 182 | |
| 183 | root = BTRFS_I(dir)->root; |
| 184 | mutex_lock(&root->fs_info->fs_mutex); |
| 185 | trans = btrfs_start_transaction(root, 1); |
| 186 | ret = btrfs_unlink_trans(trans, root, dir, dentry); |
| 187 | btrfs_end_transaction(trans, root); |
| 188 | mutex_unlock(&root->fs_info->fs_mutex); |
| 189 | return ret; |
| 190 | } |
| 191 | |
| 192 | static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) |
| 193 | { |
| 194 | struct inode *inode = dentry->d_inode; |
| 195 | int err; |
| 196 | int ret; |
| 197 | struct btrfs_root *root = BTRFS_I(dir)->root; |
| 198 | struct btrfs_path *path; |
| 199 | struct btrfs_key key; |
| 200 | struct btrfs_trans_handle *trans; |
| 201 | struct btrfs_key found_key; |
| 202 | int found_type; |
| 203 | struct btrfs_leaf *leaf; |
| 204 | char *goodnames = ".."; |
| 205 | |
| 206 | path = btrfs_alloc_path(); |
| 207 | BUG_ON(!path); |
| 208 | btrfs_init_path(path); |
| 209 | mutex_lock(&root->fs_info->fs_mutex); |
| 210 | trans = btrfs_start_transaction(root, 1); |
| 211 | key.objectid = inode->i_ino; |
| 212 | key.offset = (u64)-1; |
| 213 | key.flags = (u32)-1; |
| 214 | while(1) { |
| 215 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| 216 | if (ret < 0) { |
| 217 | err = ret; |
| 218 | goto out; |
| 219 | } |
| 220 | BUG_ON(ret == 0); |
| 221 | if (path->slots[0] == 0) { |
| 222 | err = -ENOENT; |
| 223 | goto out; |
| 224 | } |
| 225 | path->slots[0]--; |
| 226 | leaf = btrfs_buffer_leaf(path->nodes[0]); |
| 227 | btrfs_disk_key_to_cpu(&found_key, |
| 228 | &leaf->items[path->slots[0]].key); |
| 229 | found_type = btrfs_key_type(&found_key); |
| 230 | if (found_key.objectid != inode->i_ino) { |
| 231 | err = -ENOENT; |
| 232 | goto out; |
| 233 | } |
| 234 | if ((found_type != BTRFS_DIR_ITEM_KEY && |
| 235 | found_type != BTRFS_DIR_INDEX_KEY) || |
| 236 | (!btrfs_match_dir_item_name(root, path, goodnames, 2) && |
| 237 | !btrfs_match_dir_item_name(root, path, goodnames, 1))) { |
| 238 | err = -ENOTEMPTY; |
| 239 | goto out; |
| 240 | } |
| 241 | ret = btrfs_del_item(trans, root, path); |
| 242 | BUG_ON(ret); |
| 243 | |
| 244 | if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1) |
| 245 | break; |
| 246 | btrfs_release_path(root, path); |
| 247 | } |
| 248 | ret = 0; |
| 249 | btrfs_release_path(root, path); |
| 250 | |
| 251 | /* now the directory is empty */ |
| 252 | err = btrfs_unlink_trans(trans, root, dir, dentry); |
| 253 | if (!err) { |
| 254 | inode->i_size = 0; |
| 255 | } |
| 256 | out: |
| 257 | btrfs_release_path(root, path); |
| 258 | btrfs_free_path(path); |
| 259 | mutex_unlock(&root->fs_info->fs_mutex); |
| 260 | ret = btrfs_end_transaction(trans, root); |
| 261 | if (ret && !err) |
| 262 | err = ret; |
| 263 | return err; |
| 264 | } |
| 265 | |
| 266 | static int btrfs_free_inode(struct btrfs_trans_handle *trans, |
| 267 | struct btrfs_root *root, |
| 268 | struct inode *inode) |
| 269 | { |
| 270 | struct btrfs_path *path; |
| 271 | int ret; |
| 272 | |
| 273 | clear_inode(inode); |
| 274 | |
| 275 | path = btrfs_alloc_path(); |
| 276 | BUG_ON(!path); |
| 277 | btrfs_init_path(path); |
| 278 | ret = btrfs_lookup_inode(trans, root, path, |
| 279 | &BTRFS_I(inode)->location, -1); |
| 280 | BUG_ON(ret); |
| 281 | ret = btrfs_del_item(trans, root, path); |
| 282 | BUG_ON(ret); |
| 283 | btrfs_free_path(path); |
| 284 | return ret; |
| 285 | } |
| 286 | |
| 287 | static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans, |
| 288 | struct btrfs_root *root, |
| 289 | struct inode *inode) |
| 290 | { |
| 291 | int ret; |
| 292 | struct btrfs_path *path; |
| 293 | struct btrfs_key key; |
| 294 | struct btrfs_disk_key *found_key; |
| 295 | struct btrfs_leaf *leaf; |
| 296 | struct btrfs_file_extent_item *fi = NULL; |
| 297 | u64 extent_start = 0; |
| 298 | u64 extent_num_blocks = 0; |
| 299 | int found_extent; |
| 300 | |
| 301 | path = btrfs_alloc_path(); |
| 302 | BUG_ON(!path); |
| 303 | /* FIXME, add redo link to tree so we don't leak on crash */ |
| 304 | key.objectid = inode->i_ino; |
| 305 | key.offset = (u64)-1; |
| 306 | key.flags = 0; |
| 307 | /* |
| 308 | * use BTRFS_CSUM_ITEM_KEY because it is larger than inline keys |
| 309 | * or extent data |
| 310 | */ |
| 311 | btrfs_set_key_type(&key, BTRFS_CSUM_ITEM_KEY); |
| 312 | while(1) { |
| 313 | btrfs_init_path(path); |
| 314 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| 315 | if (ret < 0) { |
| 316 | goto error; |
| 317 | } |
| 318 | if (ret > 0) { |
| 319 | BUG_ON(path->slots[0] == 0); |
| 320 | path->slots[0]--; |
| 321 | } |
| 322 | leaf = btrfs_buffer_leaf(path->nodes[0]); |
| 323 | found_key = &leaf->items[path->slots[0]].key; |
| 324 | if (btrfs_disk_key_objectid(found_key) != inode->i_ino) |
| 325 | break; |
| 326 | if (btrfs_disk_key_type(found_key) != BTRFS_CSUM_ITEM_KEY && |
| 327 | btrfs_disk_key_type(found_key) != BTRFS_INLINE_DATA_KEY && |
| 328 | btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) |
| 329 | break; |
| 330 | if (btrfs_disk_key_offset(found_key) < inode->i_size) |
| 331 | break; |
| 332 | found_extent = 0; |
| 333 | if (btrfs_disk_key_type(found_key) == BTRFS_EXTENT_DATA_KEY) { |
| 334 | fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
| 335 | path->slots[0], |
| 336 | struct btrfs_file_extent_item); |
| 337 | if (btrfs_file_extent_type(fi) != |
| 338 | BTRFS_FILE_EXTENT_INLINE) { |
| 339 | extent_start = |
| 340 | btrfs_file_extent_disk_blocknr(fi); |
| 341 | extent_num_blocks = |
| 342 | btrfs_file_extent_disk_num_blocks(fi); |
| 343 | /* FIXME blocksize != 4096 */ |
| 344 | inode->i_blocks -= |
| 345 | btrfs_file_extent_num_blocks(fi) << 3; |
| 346 | found_extent = 1; |
| 347 | } |
| 348 | } |
| 349 | ret = btrfs_del_item(trans, root, path); |
| 350 | BUG_ON(ret); |
| 351 | btrfs_release_path(root, path); |
| 352 | if (found_extent) { |
| 353 | ret = btrfs_free_extent(trans, root, extent_start, |
| 354 | extent_num_blocks, 0); |
| 355 | BUG_ON(ret); |
| 356 | } |
| 357 | } |
| 358 | ret = 0; |
| 359 | error: |
| 360 | btrfs_release_path(root, path); |
| 361 | btrfs_free_path(path); |
| 362 | return ret; |
| 363 | } |
| 364 | |
| 365 | static void btrfs_delete_inode(struct inode *inode) |
| 366 | { |
| 367 | struct btrfs_trans_handle *trans; |
| 368 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 369 | int ret; |
| 370 | |
| 371 | truncate_inode_pages(&inode->i_data, 0); |
| 372 | if (is_bad_inode(inode)) { |
| 373 | goto no_delete; |
| 374 | } |
| 375 | inode->i_size = 0; |
| 376 | mutex_lock(&root->fs_info->fs_mutex); |
| 377 | trans = btrfs_start_transaction(root, 1); |
| 378 | if (S_ISREG(inode->i_mode)) { |
| 379 | ret = btrfs_truncate_in_trans(trans, root, inode); |
| 380 | BUG_ON(ret); |
| 381 | } |
| 382 | btrfs_free_inode(trans, root, inode); |
| 383 | btrfs_end_transaction(trans, root); |
| 384 | mutex_unlock(&root->fs_info->fs_mutex); |
| 385 | return; |
| 386 | no_delete: |
| 387 | clear_inode(inode); |
| 388 | } |
| 389 | |
| 390 | static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, |
| 391 | struct btrfs_key *location) |
| 392 | { |
| 393 | const char *name = dentry->d_name.name; |
| 394 | int namelen = dentry->d_name.len; |
| 395 | struct btrfs_dir_item *di; |
| 396 | struct btrfs_path *path; |
| 397 | struct btrfs_root *root = BTRFS_I(dir)->root; |
| 398 | int ret; |
| 399 | |
| 400 | path = btrfs_alloc_path(); |
| 401 | BUG_ON(!path); |
| 402 | btrfs_init_path(path); |
| 403 | di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name, |
| 404 | namelen, 0); |
| 405 | if (!di || IS_ERR(di)) { |
| 406 | location->objectid = 0; |
| 407 | ret = 0; |
| 408 | goto out; |
| 409 | } |
| 410 | btrfs_disk_key_to_cpu(location, &di->location); |
| 411 | out: |
| 412 | btrfs_release_path(root, path); |
| 413 | btrfs_free_path(path); |
| 414 | return ret; |
| 415 | } |
| 416 | |
| 417 | int fixup_tree_root_location(struct btrfs_root *root, |
| 418 | struct btrfs_key *location, |
| 419 | struct btrfs_root **sub_root) |
| 420 | { |
| 421 | struct btrfs_path *path; |
| 422 | struct btrfs_root_item *ri; |
| 423 | |
| 424 | if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY) |
| 425 | return 0; |
| 426 | if (location->objectid == BTRFS_ROOT_TREE_OBJECTID) |
| 427 | return 0; |
| 428 | |
| 429 | path = btrfs_alloc_path(); |
| 430 | BUG_ON(!path); |
| 431 | mutex_lock(&root->fs_info->fs_mutex); |
| 432 | |
| 433 | *sub_root = btrfs_read_fs_root(root->fs_info, location); |
| 434 | if (IS_ERR(*sub_root)) |
| 435 | return PTR_ERR(*sub_root); |
| 436 | |
| 437 | ri = &(*sub_root)->root_item; |
| 438 | location->objectid = btrfs_root_dirid(ri); |
| 439 | location->flags = 0; |
| 440 | btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); |
| 441 | location->offset = 0; |
| 442 | |
| 443 | btrfs_free_path(path); |
| 444 | mutex_unlock(&root->fs_info->fs_mutex); |
| 445 | return 0; |
| 446 | } |
| 447 | |
| 448 | int btrfs_init_locked_inode(struct inode *inode, void *p) |
| 449 | { |
| 450 | struct btrfs_iget_args *args = p; |
| 451 | inode->i_ino = args->ino; |
| 452 | BTRFS_I(inode)->root = args->root; |
| 453 | return 0; |
| 454 | } |
| 455 | |
| 456 | int btrfs_find_actor(struct inode *inode, void *opaque) |
| 457 | { |
| 458 | struct btrfs_iget_args *args = opaque; |
| 459 | return (args->ino == inode->i_ino && |
| 460 | args->root == BTRFS_I(inode)->root); |
| 461 | } |
| 462 | |
| 463 | struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid, |
| 464 | struct btrfs_root *root) |
| 465 | { |
| 466 | struct inode *inode; |
| 467 | struct btrfs_iget_args args; |
| 468 | args.ino = objectid; |
| 469 | args.root = root; |
| 470 | |
| 471 | inode = iget5_locked(s, objectid, btrfs_find_actor, |
| 472 | btrfs_init_locked_inode, |
| 473 | (void *)&args); |
| 474 | return inode; |
| 475 | } |
| 476 | |
| 477 | static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, |
| 478 | struct nameidata *nd) |
| 479 | { |
| 480 | struct inode * inode; |
| 481 | struct btrfs_inode *bi = BTRFS_I(dir); |
| 482 | struct btrfs_root *root = bi->root; |
| 483 | struct btrfs_root *sub_root = root; |
| 484 | struct btrfs_key location; |
| 485 | int ret; |
| 486 | |
| 487 | if (dentry->d_name.len > BTRFS_NAME_LEN) |
| 488 | return ERR_PTR(-ENAMETOOLONG); |
| 489 | mutex_lock(&root->fs_info->fs_mutex); |
| 490 | ret = btrfs_inode_by_name(dir, dentry, &location); |
| 491 | mutex_unlock(&root->fs_info->fs_mutex); |
| 492 | if (ret < 0) |
| 493 | return ERR_PTR(ret); |
| 494 | inode = NULL; |
| 495 | if (location.objectid) { |
| 496 | ret = fixup_tree_root_location(root, &location, &sub_root); |
| 497 | if (ret < 0) |
| 498 | return ERR_PTR(ret); |
| 499 | if (ret > 0) |
| 500 | return ERR_PTR(-ENOENT); |
| 501 | inode = btrfs_iget_locked(dir->i_sb, location.objectid, |
| 502 | sub_root); |
| 503 | if (!inode) |
| 504 | return ERR_PTR(-EACCES); |
| 505 | if (inode->i_state & I_NEW) { |
| 506 | if (sub_root != root) { |
| 507 | printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root); |
| 508 | igrab(inode); |
| 509 | sub_root->inode = inode; |
| 510 | } |
| 511 | BTRFS_I(inode)->root = sub_root; |
| 512 | memcpy(&BTRFS_I(inode)->location, &location, |
| 513 | sizeof(location)); |
| 514 | btrfs_read_locked_inode(inode); |
| 515 | unlock_new_inode(inode); |
| 516 | } |
| 517 | } |
| 518 | return d_splice_alias(inode, dentry); |
| 519 | } |
| 520 | |
| 521 | static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) |
| 522 | { |
| 523 | struct inode *inode = filp->f_path.dentry->d_inode; |
| 524 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 525 | struct btrfs_item *item; |
| 526 | struct btrfs_dir_item *di; |
| 527 | struct btrfs_key key; |
| 528 | struct btrfs_path *path; |
| 529 | int ret; |
| 530 | u32 nritems; |
| 531 | struct btrfs_leaf *leaf; |
| 532 | int slot; |
| 533 | int advance; |
| 534 | unsigned char d_type = DT_UNKNOWN; |
| 535 | int over = 0; |
| 536 | u32 di_cur; |
| 537 | u32 di_total; |
| 538 | u32 di_len; |
| 539 | int key_type = BTRFS_DIR_INDEX_KEY; |
| 540 | |
| 541 | /* FIXME, use a real flag for deciding about the key type */ |
| 542 | if (root->fs_info->tree_root == root) |
| 543 | key_type = BTRFS_DIR_ITEM_KEY; |
| 544 | mutex_lock(&root->fs_info->fs_mutex); |
| 545 | key.objectid = inode->i_ino; |
| 546 | key.flags = 0; |
| 547 | btrfs_set_key_type(&key, key_type); |
| 548 | key.offset = filp->f_pos; |
| 549 | path = btrfs_alloc_path(); |
| 550 | btrfs_init_path(path); |
| 551 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 552 | if (ret < 0) |
| 553 | goto err; |
| 554 | advance = 0; |
| 555 | while(1) { |
| 556 | leaf = btrfs_buffer_leaf(path->nodes[0]); |
| 557 | nritems = btrfs_header_nritems(&leaf->header); |
| 558 | slot = path->slots[0]; |
| 559 | if (advance || slot >= nritems) { |
| 560 | if (slot >= nritems -1) { |
| 561 | ret = btrfs_next_leaf(root, path); |
| 562 | if (ret) |
| 563 | break; |
| 564 | leaf = btrfs_buffer_leaf(path->nodes[0]); |
| 565 | nritems = btrfs_header_nritems(&leaf->header); |
| 566 | slot = path->slots[0]; |
| 567 | } else { |
| 568 | slot++; |
| 569 | path->slots[0]++; |
| 570 | } |
| 571 | } |
| 572 | advance = 1; |
| 573 | item = leaf->items + slot; |
| 574 | if (btrfs_disk_key_objectid(&item->key) != key.objectid) |
| 575 | break; |
| 576 | if (btrfs_disk_key_type(&item->key) != key_type) |
| 577 | break; |
| 578 | if (btrfs_disk_key_offset(&item->key) < filp->f_pos) |
| 579 | continue; |
| 580 | filp->f_pos = btrfs_disk_key_offset(&item->key); |
| 581 | advance = 1; |
| 582 | di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); |
| 583 | di_cur = 0; |
| 584 | di_total = btrfs_item_size(leaf->items + slot); |
| 585 | while(di_cur < di_total) { |
| 586 | over = filldir(dirent, (const char *)(di + 1), |
| 587 | btrfs_dir_name_len(di), |
| 588 | btrfs_disk_key_offset(&item->key), |
| 589 | btrfs_disk_key_objectid(&di->location), |
| 590 | d_type); |
| 591 | if (over) |
| 592 | goto nopos; |
| 593 | di_len = btrfs_dir_name_len(di) + sizeof(*di); |
| 594 | di_cur += di_len; |
| 595 | di = (struct btrfs_dir_item *)((char *)di + di_len); |
| 596 | } |
| 597 | } |
| 598 | filp->f_pos++; |
| 599 | nopos: |
| 600 | ret = 0; |
| 601 | err: |
| 602 | btrfs_release_path(root, path); |
| 603 | btrfs_free_path(path); |
| 604 | mutex_unlock(&root->fs_info->fs_mutex); |
| 605 | return ret; |
| 606 | } |
| 607 | |
| 608 | static void btrfs_put_super (struct super_block * sb) |
| 609 | { |
| 610 | struct btrfs_root *root = btrfs_sb(sb); |
| 611 | int ret; |
| 612 | |
| 613 | ret = close_ctree(root); |
| 614 | if (ret) { |
| 615 | printk("close ctree returns %d\n", ret); |
| 616 | } |
| 617 | sb->s_fs_info = NULL; |
| 618 | } |
| 619 | |
| 620 | static int btrfs_fill_super(struct super_block * sb, void * data, int silent) |
| 621 | { |
| 622 | struct inode * inode; |
| 623 | struct dentry * root_dentry; |
| 624 | struct btrfs_super_block *disk_super; |
| 625 | struct btrfs_root *tree_root; |
| 626 | struct btrfs_inode *bi; |
| 627 | |
| 628 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
| 629 | sb->s_magic = BTRFS_SUPER_MAGIC; |
| 630 | sb->s_op = &btrfs_super_ops; |
| 631 | sb->s_time_gran = 1; |
| 632 | |
| 633 | tree_root = open_ctree(sb); |
| 634 | |
| 635 | if (!tree_root) { |
| 636 | printk("btrfs: open_ctree failed\n"); |
| 637 | return -EIO; |
| 638 | } |
| 639 | sb->s_fs_info = tree_root; |
| 640 | disk_super = tree_root->fs_info->disk_super; |
| 641 | printk("read in super total blocks %Lu root %Lu\n", |
| 642 | btrfs_super_total_blocks(disk_super), |
| 643 | btrfs_super_root_dir(disk_super)); |
| 644 | |
| 645 | inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super), |
| 646 | tree_root); |
| 647 | bi = BTRFS_I(inode); |
| 648 | bi->location.objectid = inode->i_ino; |
| 649 | bi->location.offset = 0; |
| 650 | bi->location.flags = 0; |
| 651 | bi->root = tree_root; |
| 652 | btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY); |
| 653 | |
| 654 | if (!inode) |
| 655 | return -ENOMEM; |
| 656 | if (inode->i_state & I_NEW) { |
| 657 | btrfs_read_locked_inode(inode); |
| 658 | unlock_new_inode(inode); |
| 659 | } |
| 660 | |
| 661 | root_dentry = d_alloc_root(inode); |
| 662 | if (!root_dentry) { |
| 663 | iput(inode); |
| 664 | return -ENOMEM; |
| 665 | } |
| 666 | sb->s_root = root_dentry; |
| 667 | |
| 668 | return 0; |
| 669 | } |
| 670 | |
| 671 | static void fill_inode_item(struct btrfs_inode_item *item, |
| 672 | struct inode *inode) |
| 673 | { |
| 674 | btrfs_set_inode_uid(item, inode->i_uid); |
| 675 | btrfs_set_inode_gid(item, inode->i_gid); |
| 676 | btrfs_set_inode_size(item, inode->i_size); |
| 677 | btrfs_set_inode_mode(item, inode->i_mode); |
| 678 | btrfs_set_inode_nlink(item, inode->i_nlink); |
| 679 | btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec); |
| 680 | btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec); |
| 681 | btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec); |
| 682 | btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec); |
| 683 | btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec); |
| 684 | btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec); |
| 685 | btrfs_set_inode_nblocks(item, inode->i_blocks); |
| 686 | btrfs_set_inode_generation(item, inode->i_generation); |
| 687 | } |
| 688 | |
| 689 | static int btrfs_update_inode(struct btrfs_trans_handle *trans, |
| 690 | struct btrfs_root *root, |
| 691 | struct inode *inode) |
| 692 | { |
| 693 | struct btrfs_inode_item *inode_item; |
| 694 | struct btrfs_path *path; |
| 695 | int ret; |
| 696 | |
| 697 | path = btrfs_alloc_path(); |
| 698 | BUG_ON(!path); |
| 699 | btrfs_init_path(path); |
| 700 | ret = btrfs_lookup_inode(trans, root, path, |
| 701 | &BTRFS_I(inode)->location, 1); |
| 702 | if (ret) { |
| 703 | if (ret > 0) |
| 704 | ret = -ENOENT; |
| 705 | goto failed; |
| 706 | } |
| 707 | |
| 708 | inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
| 709 | path->slots[0], |
| 710 | struct btrfs_inode_item); |
| 711 | |
| 712 | fill_inode_item(inode_item, inode); |
| 713 | btrfs_mark_buffer_dirty(path->nodes[0]); |
| 714 | ret = 0; |
| 715 | failed: |
| 716 | btrfs_release_path(root, path); |
| 717 | btrfs_free_path(path); |
| 718 | return ret; |
| 719 | } |
| 720 | |
| 721 | static int btrfs_write_inode(struct inode *inode, int wait) |
| 722 | { |
| 723 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 724 | struct btrfs_trans_handle *trans; |
| 725 | int ret = 0; |
| 726 | |
| 727 | if (wait) { |
| 728 | mutex_lock(&root->fs_info->fs_mutex); |
| 729 | trans = btrfs_start_transaction(root, 1); |
| 730 | ret = btrfs_commit_transaction(trans, root); |
| 731 | mutex_unlock(&root->fs_info->fs_mutex); |
| 732 | } |
| 733 | return ret; |
| 734 | } |
| 735 | |
| 736 | static void btrfs_dirty_inode(struct inode *inode) |
| 737 | { |
| 738 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 739 | struct btrfs_trans_handle *trans; |
| 740 | |
| 741 | mutex_lock(&root->fs_info->fs_mutex); |
| 742 | trans = btrfs_start_transaction(root, 1); |
| 743 | btrfs_update_inode(trans, root, inode); |
| 744 | btrfs_end_transaction(trans, root); |
| 745 | mutex_unlock(&root->fs_info->fs_mutex); |
| 746 | } |
| 747 | |
| 748 | static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, |
| 749 | struct btrfs_root *root, |
| 750 | u64 objectid, int mode) |
| 751 | { |
| 752 | struct inode *inode; |
| 753 | struct btrfs_inode_item inode_item; |
| 754 | struct btrfs_key *location; |
| 755 | int ret; |
| 756 | |
| 757 | inode = new_inode(root->fs_info->sb); |
| 758 | if (!inode) |
| 759 | return ERR_PTR(-ENOMEM); |
| 760 | |
| 761 | BTRFS_I(inode)->root = root; |
| 762 | |
| 763 | inode->i_uid = current->fsuid; |
| 764 | inode->i_gid = current->fsgid; |
| 765 | inode->i_mode = mode; |
| 766 | inode->i_ino = objectid; |
| 767 | inode->i_blocks = 0; |
| 768 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 769 | fill_inode_item(&inode_item, inode); |
| 770 | location = &BTRFS_I(inode)->location; |
| 771 | location->objectid = objectid; |
| 772 | location->flags = 0; |
| 773 | location->offset = 0; |
| 774 | btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); |
| 775 | |
| 776 | ret = btrfs_insert_inode(trans, root, objectid, &inode_item); |
| 777 | BUG_ON(ret); |
| 778 | |
| 779 | insert_inode_hash(inode); |
| 780 | return inode; |
| 781 | } |
| 782 | |
| 783 | static int btrfs_add_link(struct btrfs_trans_handle *trans, |
| 784 | struct dentry *dentry, struct inode *inode) |
| 785 | { |
| 786 | int ret; |
| 787 | struct btrfs_key key; |
| 788 | struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root; |
| 789 | key.objectid = inode->i_ino; |
| 790 | key.flags = 0; |
| 791 | btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); |
| 792 | key.offset = 0; |
| 793 | |
| 794 | ret = btrfs_insert_dir_item(trans, root, |
| 795 | dentry->d_name.name, dentry->d_name.len, |
| 796 | dentry->d_parent->d_inode->i_ino, |
| 797 | &key, 0); |
| 798 | if (ret == 0) { |
| 799 | dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2; |
| 800 | ret = btrfs_update_inode(trans, root, |
| 801 | dentry->d_parent->d_inode); |
| 802 | } |
| 803 | return ret; |
| 804 | } |
| 805 | |
| 806 | static int btrfs_add_nondir(struct btrfs_trans_handle *trans, |
| 807 | struct dentry *dentry, struct inode *inode) |
| 808 | { |
| 809 | int err = btrfs_add_link(trans, dentry, inode); |
| 810 | if (!err) { |
| 811 | d_instantiate(dentry, inode); |
| 812 | return 0; |
| 813 | } |
| 814 | if (err > 0) |
| 815 | err = -EEXIST; |
| 816 | return err; |
| 817 | } |
| 818 | |
| 819 | static int btrfs_create(struct inode *dir, struct dentry *dentry, |
| 820 | int mode, struct nameidata *nd) |
| 821 | { |
| 822 | struct btrfs_trans_handle *trans; |
| 823 | struct btrfs_root *root = BTRFS_I(dir)->root; |
| 824 | struct inode *inode; |
| 825 | int err; |
| 826 | int drop_inode = 0; |
| 827 | u64 objectid; |
| 828 | |
| 829 | mutex_lock(&root->fs_info->fs_mutex); |
| 830 | trans = btrfs_start_transaction(root, 1); |
| 831 | |
| 832 | err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); |
| 833 | if (err) { |
| 834 | err = -ENOSPC; |
| 835 | goto out_unlock; |
| 836 | } |
| 837 | |
| 838 | inode = btrfs_new_inode(trans, root, objectid, mode); |
| 839 | err = PTR_ERR(inode); |
| 840 | if (IS_ERR(inode)) |
| 841 | goto out_unlock; |
| 842 | // FIXME mark the inode dirty |
| 843 | err = btrfs_add_nondir(trans, dentry, inode); |
| 844 | if (err) |
| 845 | drop_inode = 1; |
| 846 | else { |
| 847 | inode->i_mapping->a_ops = &btrfs_aops; |
| 848 | inode->i_fop = &btrfs_file_operations; |
| 849 | inode->i_op = &btrfs_file_inode_operations; |
| 850 | } |
| 851 | dir->i_sb->s_dirt = 1; |
| 852 | out_unlock: |
| 853 | btrfs_end_transaction(trans, root); |
| 854 | mutex_unlock(&root->fs_info->fs_mutex); |
| 855 | |
| 856 | if (drop_inode) { |
| 857 | inode_dec_link_count(inode); |
| 858 | iput(inode); |
| 859 | } |
| 860 | return err; |
| 861 | } |
| 862 | |
| 863 | static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans, |
| 864 | struct btrfs_root *root, |
| 865 | u64 objectid, u64 dirid) |
| 866 | { |
| 867 | int ret; |
| 868 | char buf[2]; |
| 869 | struct btrfs_key key; |
| 870 | |
| 871 | buf[0] = '.'; |
| 872 | buf[1] = '.'; |
| 873 | |
| 874 | key.objectid = objectid; |
| 875 | key.offset = 0; |
| 876 | key.flags = 0; |
| 877 | btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); |
| 878 | |
| 879 | ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid, |
| 880 | &key, 1); |
| 881 | if (ret) |
| 882 | goto error; |
| 883 | key.objectid = dirid; |
| 884 | ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid, |
| 885 | &key, 1); |
| 886 | if (ret) |
| 887 | goto error; |
| 888 | error: |
| 889 | return ret; |
| 890 | } |
| 891 | |
| 892 | static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
| 893 | { |
| 894 | struct inode *inode; |
| 895 | struct btrfs_trans_handle *trans; |
| 896 | struct btrfs_root *root = BTRFS_I(dir)->root; |
| 897 | int err = 0; |
| 898 | int drop_on_err = 0; |
| 899 | u64 objectid; |
| 900 | |
| 901 | mutex_lock(&root->fs_info->fs_mutex); |
| 902 | trans = btrfs_start_transaction(root, 1); |
| 903 | if (IS_ERR(trans)) { |
| 904 | err = PTR_ERR(trans); |
| 905 | goto out_unlock; |
| 906 | } |
| 907 | |
| 908 | err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid); |
| 909 | if (err) { |
| 910 | err = -ENOSPC; |
| 911 | goto out_unlock; |
| 912 | } |
| 913 | |
| 914 | inode = btrfs_new_inode(trans, root, objectid, S_IFDIR | mode); |
| 915 | if (IS_ERR(inode)) { |
| 916 | err = PTR_ERR(inode); |
| 917 | goto out_fail; |
| 918 | } |
| 919 | drop_on_err = 1; |
| 920 | inode->i_op = &btrfs_dir_inode_operations; |
| 921 | inode->i_fop = &btrfs_dir_file_operations; |
| 922 | |
| 923 | err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino); |
| 924 | if (err) |
| 925 | goto out_fail; |
| 926 | |
| 927 | inode->i_size = 6; |
| 928 | err = btrfs_update_inode(trans, root, inode); |
| 929 | if (err) |
| 930 | goto out_fail; |
| 931 | err = btrfs_add_link(trans, dentry, inode); |
| 932 | if (err) |
| 933 | goto out_fail; |
| 934 | d_instantiate(dentry, inode); |
| 935 | drop_on_err = 0; |
| 936 | |
| 937 | out_fail: |
| 938 | btrfs_end_transaction(trans, root); |
| 939 | out_unlock: |
| 940 | mutex_unlock(&root->fs_info->fs_mutex); |
| 941 | if (drop_on_err) |
| 942 | iput(inode); |
| 943 | return err; |
| 944 | } |
| 945 | |
| 946 | static int btrfs_sync_file(struct file *file, |
| 947 | struct dentry *dentry, int datasync) |
| 948 | { |
| 949 | struct inode *inode = dentry->d_inode; |
| 950 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 951 | int ret; |
| 952 | struct btrfs_trans_handle *trans; |
| 953 | |
| 954 | mutex_lock(&root->fs_info->fs_mutex); |
| 955 | trans = btrfs_start_transaction(root, 1); |
| 956 | if (!trans) { |
| 957 | ret = -ENOMEM; |
| 958 | goto out; |
| 959 | } |
| 960 | ret = btrfs_commit_transaction(trans, root); |
| 961 | mutex_unlock(&root->fs_info->fs_mutex); |
| 962 | out: |
| 963 | return ret > 0 ? EIO : ret; |
| 964 | } |
| 965 | |
| 966 | static int btrfs_sync_fs(struct super_block *sb, int wait) |
| 967 | { |
| 968 | struct btrfs_trans_handle *trans; |
| 969 | struct btrfs_root *root; |
| 970 | int ret; |
| 971 | root = btrfs_sb(sb); |
| 972 | |
| 973 | sb->s_dirt = 0; |
| 974 | if (!wait) { |
| 975 | filemap_flush(root->fs_info->btree_inode->i_mapping); |
| 976 | return 0; |
| 977 | } |
| 978 | filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); |
| 979 | mutex_lock(&root->fs_info->fs_mutex); |
| 980 | trans = btrfs_start_transaction(root, 1); |
| 981 | ret = btrfs_commit_transaction(trans, root); |
| 982 | sb->s_dirt = 0; |
| 983 | BUG_ON(ret); |
| 984 | printk("btrfs sync_fs\n"); |
| 985 | mutex_unlock(&root->fs_info->fs_mutex); |
| 986 | return 0; |
| 987 | } |
| 988 | |
| 989 | static int btrfs_get_block_lock(struct inode *inode, sector_t iblock, |
| 990 | struct buffer_head *result, int create) |
| 991 | { |
| 992 | int ret; |
| 993 | int err = 0; |
| 994 | u64 blocknr; |
| 995 | u64 extent_start = 0; |
| 996 | u64 extent_end = 0; |
| 997 | u64 objectid = inode->i_ino; |
| 998 | u32 found_type; |
| 999 | struct btrfs_path *path; |
| 1000 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1001 | struct btrfs_file_extent_item *item; |
| 1002 | struct btrfs_leaf *leaf; |
| 1003 | struct btrfs_disk_key *found_key; |
| 1004 | |
| 1005 | path = btrfs_alloc_path(); |
| 1006 | BUG_ON(!path); |
| 1007 | btrfs_init_path(path); |
| 1008 | if (create) { |
| 1009 | WARN_ON(1); |
| 1010 | } |
| 1011 | |
| 1012 | ret = btrfs_lookup_file_extent(NULL, root, path, |
| 1013 | inode->i_ino, |
| 1014 | iblock << inode->i_blkbits, 0); |
| 1015 | if (ret < 0) { |
| 1016 | err = ret; |
| 1017 | goto out; |
| 1018 | } |
| 1019 | |
| 1020 | if (ret != 0) { |
| 1021 | if (path->slots[0] == 0) { |
| 1022 | btrfs_release_path(root, path); |
| 1023 | goto out; |
| 1024 | } |
| 1025 | path->slots[0]--; |
| 1026 | } |
| 1027 | |
| 1028 | item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0], |
| 1029 | struct btrfs_file_extent_item); |
| 1030 | leaf = btrfs_buffer_leaf(path->nodes[0]); |
| 1031 | blocknr = btrfs_file_extent_disk_blocknr(item); |
| 1032 | blocknr += btrfs_file_extent_offset(item); |
| 1033 | |
| 1034 | /* are we inside the extent that was found? */ |
| 1035 | found_key = &leaf->items[path->slots[0]].key; |
| 1036 | found_type = btrfs_disk_key_type(found_key); |
| 1037 | if (btrfs_disk_key_objectid(found_key) != objectid || |
| 1038 | found_type != BTRFS_EXTENT_DATA_KEY) { |
| 1039 | extent_end = 0; |
| 1040 | extent_start = 0; |
| 1041 | btrfs_release_path(root, path); |
| 1042 | goto out; |
| 1043 | } |
| 1044 | found_type = btrfs_file_extent_type(item); |
| 1045 | extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key); |
| 1046 | if (found_type == BTRFS_FILE_EXTENT_REG) { |
| 1047 | extent_start = extent_start >> inode->i_blkbits; |
| 1048 | extent_end = extent_start + btrfs_file_extent_num_blocks(item); |
| 1049 | if (iblock >= extent_start && iblock < extent_end) { |
| 1050 | err = 0; |
| 1051 | btrfs_map_bh_to_logical(root, result, blocknr + |
| 1052 | iblock - extent_start); |
| 1053 | goto out; |
| 1054 | } |
| 1055 | } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { |
| 1056 | char *ptr; |
| 1057 | char *map; |
| 1058 | u32 size; |
| 1059 | size = btrfs_file_extent_inline_len(leaf->items + |
| 1060 | path->slots[0]); |
| 1061 | extent_end = (extent_start + size) >> inode->i_blkbits; |
| 1062 | extent_start >>= inode->i_blkbits; |
| 1063 | if (iblock < extent_start || iblock > extent_end) { |
| 1064 | goto out; |
| 1065 | } |
| 1066 | ptr = btrfs_file_extent_inline_start(item); |
| 1067 | map = kmap(result->b_page); |
| 1068 | memcpy(map, ptr, size); |
| 1069 | memset(map + size, 0, PAGE_CACHE_SIZE - size); |
| 1070 | flush_dcache_page(result->b_page); |
| 1071 | kunmap(result->b_page); |
| 1072 | set_buffer_uptodate(result); |
| 1073 | SetPageChecked(result->b_page); |
| 1074 | btrfs_map_bh_to_logical(root, result, 0); |
| 1075 | } |
| 1076 | out: |
| 1077 | btrfs_release_path(root, path); |
| 1078 | btrfs_free_path(path); |
| 1079 | return err; |
| 1080 | } |
| 1081 | |
| 1082 | static int btrfs_get_block(struct inode *inode, sector_t iblock, |
| 1083 | struct buffer_head *result, int create) |
| 1084 | { |
| 1085 | int err; |
| 1086 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1087 | mutex_lock(&root->fs_info->fs_mutex); |
| 1088 | err = btrfs_get_block_lock(inode, iblock, result, create); |
| 1089 | mutex_unlock(&root->fs_info->fs_mutex); |
| 1090 | return err; |
| 1091 | } |
| 1092 | |
| 1093 | static int btrfs_prepare_write(struct file *file, struct page *page, |
| 1094 | unsigned from, unsigned to) |
| 1095 | { |
| 1096 | return nobh_prepare_write(page, from, to, btrfs_get_block); |
| 1097 | } |
| 1098 | |
| 1099 | static void btrfs_write_super(struct super_block *sb) |
| 1100 | { |
| 1101 | btrfs_sync_fs(sb, 1); |
| 1102 | } |
| 1103 | |
| 1104 | static int btrfs_readpage(struct file *file, struct page *page) |
| 1105 | { |
| 1106 | return mpage_readpage(page, btrfs_get_block); |
| 1107 | } |
| 1108 | |
| 1109 | /* |
| 1110 | * While block_write_full_page is writing back the dirty buffers under |
| 1111 | * the page lock, whoever dirtied the buffers may decide to clean them |
| 1112 | * again at any time. We handle that by only looking at the buffer |
| 1113 | * state inside lock_buffer(). |
| 1114 | * |
| 1115 | * If block_write_full_page() is called for regular writeback |
| 1116 | * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a |
| 1117 | * locked buffer. This only can happen if someone has written the buffer |
| 1118 | * directly, with submit_bh(). At the address_space level PageWriteback |
| 1119 | * prevents this contention from occurring. |
| 1120 | */ |
| 1121 | static int __btrfs_write_full_page(struct inode *inode, struct page *page, |
| 1122 | struct writeback_control *wbc) |
| 1123 | { |
| 1124 | int err; |
| 1125 | sector_t block; |
| 1126 | sector_t last_block; |
| 1127 | struct buffer_head *bh, *head; |
| 1128 | const unsigned blocksize = 1 << inode->i_blkbits; |
| 1129 | int nr_underway = 0; |
| 1130 | |
| 1131 | BUG_ON(!PageLocked(page)); |
| 1132 | |
| 1133 | last_block = (i_size_read(inode) - 1) >> inode->i_blkbits; |
| 1134 | |
| 1135 | if (!page_has_buffers(page)) { |
| 1136 | create_empty_buffers(page, blocksize, |
| 1137 | (1 << BH_Dirty)|(1 << BH_Uptodate)); |
| 1138 | } |
| 1139 | |
| 1140 | /* |
| 1141 | * Be very careful. We have no exclusion from __set_page_dirty_buffers |
| 1142 | * here, and the (potentially unmapped) buffers may become dirty at |
| 1143 | * any time. If a buffer becomes dirty here after we've inspected it |
| 1144 | * then we just miss that fact, and the page stays dirty. |
| 1145 | * |
| 1146 | * Buffers outside i_size may be dirtied by __set_page_dirty_buffers; |
| 1147 | * handle that here by just cleaning them. |
| 1148 | */ |
| 1149 | |
| 1150 | block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| 1151 | head = page_buffers(page); |
| 1152 | bh = head; |
| 1153 | |
| 1154 | /* |
| 1155 | * Get all the dirty buffers mapped to disk addresses and |
| 1156 | * handle any aliases from the underlying blockdev's mapping. |
| 1157 | */ |
| 1158 | do { |
| 1159 | if (block > last_block) { |
| 1160 | /* |
| 1161 | * mapped buffers outside i_size will occur, because |
| 1162 | * this page can be outside i_size when there is a |
| 1163 | * truncate in progress. |
| 1164 | */ |
| 1165 | /* |
| 1166 | * The buffer was zeroed by block_write_full_page() |
| 1167 | */ |
| 1168 | clear_buffer_dirty(bh); |
| 1169 | set_buffer_uptodate(bh); |
| 1170 | } else if (!buffer_mapped(bh) && buffer_dirty(bh)) { |
| 1171 | WARN_ON(bh->b_size != blocksize); |
| 1172 | err = btrfs_get_block(inode, block, bh, 0); |
| 1173 | if (err) |
| 1174 | goto recover; |
| 1175 | if (buffer_new(bh)) { |
| 1176 | /* blockdev mappings never come here */ |
| 1177 | clear_buffer_new(bh); |
| 1178 | unmap_underlying_metadata(bh->b_bdev, |
| 1179 | bh->b_blocknr); |
| 1180 | } |
| 1181 | } |
| 1182 | bh = bh->b_this_page; |
| 1183 | block++; |
| 1184 | } while (bh != head); |
| 1185 | |
| 1186 | do { |
| 1187 | if (!buffer_mapped(bh)) |
| 1188 | continue; |
| 1189 | /* |
| 1190 | * If it's a fully non-blocking write attempt and we cannot |
| 1191 | * lock the buffer then redirty the page. Note that this can |
| 1192 | * potentially cause a busy-wait loop from pdflush and kswapd |
| 1193 | * activity, but those code paths have their own higher-level |
| 1194 | * throttling. |
| 1195 | */ |
| 1196 | if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) { |
| 1197 | lock_buffer(bh); |
| 1198 | } else if (test_set_buffer_locked(bh)) { |
| 1199 | redirty_page_for_writepage(wbc, page); |
| 1200 | continue; |
| 1201 | } |
| 1202 | if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) { |
| 1203 | mark_buffer_async_write(bh); |
| 1204 | } else { |
| 1205 | unlock_buffer(bh); |
| 1206 | } |
| 1207 | } while ((bh = bh->b_this_page) != head); |
| 1208 | |
| 1209 | /* |
| 1210 | * The page and its buffers are protected by PageWriteback(), so we can |
| 1211 | * drop the bh refcounts early. |
| 1212 | */ |
| 1213 | BUG_ON(PageWriteback(page)); |
| 1214 | set_page_writeback(page); |
| 1215 | |
| 1216 | do { |
| 1217 | struct buffer_head *next = bh->b_this_page; |
| 1218 | if (buffer_async_write(bh)) { |
| 1219 | submit_bh(WRITE, bh); |
| 1220 | nr_underway++; |
| 1221 | } |
| 1222 | bh = next; |
| 1223 | } while (bh != head); |
| 1224 | unlock_page(page); |
| 1225 | |
| 1226 | err = 0; |
| 1227 | done: |
| 1228 | if (nr_underway == 0) { |
| 1229 | /* |
| 1230 | * The page was marked dirty, but the buffers were |
| 1231 | * clean. Someone wrote them back by hand with |
| 1232 | * ll_rw_block/submit_bh. A rare case. |
| 1233 | */ |
| 1234 | int uptodate = 1; |
| 1235 | do { |
| 1236 | if (!buffer_uptodate(bh)) { |
| 1237 | uptodate = 0; |
| 1238 | break; |
| 1239 | } |
| 1240 | bh = bh->b_this_page; |
| 1241 | } while (bh != head); |
| 1242 | if (uptodate) |
| 1243 | SetPageUptodate(page); |
| 1244 | end_page_writeback(page); |
| 1245 | /* |
| 1246 | * The page and buffer_heads can be released at any time from |
| 1247 | * here on. |
| 1248 | */ |
| 1249 | wbc->pages_skipped++; /* We didn't write this page */ |
| 1250 | } |
| 1251 | return err; |
| 1252 | |
| 1253 | recover: |
| 1254 | /* |
| 1255 | * ENOSPC, or some other error. We may already have added some |
| 1256 | * blocks to the file, so we need to write these out to avoid |
| 1257 | * exposing stale data. |
| 1258 | * The page is currently locked and not marked for writeback |
| 1259 | */ |
| 1260 | bh = head; |
| 1261 | /* Recovery: lock and submit the mapped buffers */ |
| 1262 | do { |
| 1263 | if (buffer_mapped(bh) && buffer_dirty(bh)) { |
| 1264 | lock_buffer(bh); |
| 1265 | mark_buffer_async_write(bh); |
| 1266 | } else { |
| 1267 | /* |
| 1268 | * The buffer may have been set dirty during |
| 1269 | * attachment to a dirty page. |
| 1270 | */ |
| 1271 | clear_buffer_dirty(bh); |
| 1272 | } |
| 1273 | } while ((bh = bh->b_this_page) != head); |
| 1274 | SetPageError(page); |
| 1275 | BUG_ON(PageWriteback(page)); |
| 1276 | set_page_writeback(page); |
| 1277 | do { |
| 1278 | struct buffer_head *next = bh->b_this_page; |
| 1279 | if (buffer_async_write(bh)) { |
| 1280 | clear_buffer_dirty(bh); |
| 1281 | submit_bh(WRITE, bh); |
| 1282 | nr_underway++; |
| 1283 | } |
| 1284 | bh = next; |
| 1285 | } while (bh != head); |
| 1286 | unlock_page(page); |
| 1287 | goto done; |
| 1288 | } |
| 1289 | |
| 1290 | /* |
| 1291 | * The generic ->writepage function for buffer-backed address_spaces |
| 1292 | */ |
| 1293 | static int btrfs_writepage(struct page *page, struct writeback_control *wbc) |
| 1294 | { |
| 1295 | struct inode * const inode = page->mapping->host; |
| 1296 | loff_t i_size = i_size_read(inode); |
| 1297 | const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; |
| 1298 | unsigned offset; |
| 1299 | void *kaddr; |
| 1300 | |
| 1301 | /* Is the page fully inside i_size? */ |
| 1302 | if (page->index < end_index) |
| 1303 | return __btrfs_write_full_page(inode, page, wbc); |
| 1304 | |
| 1305 | /* Is the page fully outside i_size? (truncate in progress) */ |
| 1306 | offset = i_size & (PAGE_CACHE_SIZE-1); |
| 1307 | if (page->index >= end_index+1 || !offset) { |
| 1308 | /* |
| 1309 | * The page may have dirty, unmapped buffers. For example, |
| 1310 | * they may have been added in ext3_writepage(). Make them |
| 1311 | * freeable here, so the page does not leak. |
| 1312 | */ |
| 1313 | block_invalidatepage(page, 0); |
| 1314 | unlock_page(page); |
| 1315 | return 0; /* don't care */ |
| 1316 | } |
| 1317 | |
| 1318 | /* |
| 1319 | * The page straddles i_size. It must be zeroed out on each and every |
| 1320 | * writepage invokation because it may be mmapped. "A file is mapped |
| 1321 | * in multiples of the page size. For a file that is not a multiple of |
| 1322 | * the page size, the remaining memory is zeroed when mapped, and |
| 1323 | * writes to that region are not written out to the file." |
| 1324 | */ |
| 1325 | kaddr = kmap_atomic(page, KM_USER0); |
| 1326 | memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); |
| 1327 | flush_dcache_page(page); |
| 1328 | kunmap_atomic(kaddr, KM_USER0); |
| 1329 | return __btrfs_write_full_page(inode, page, wbc); |
| 1330 | } |
| 1331 | |
| 1332 | static void btrfs_truncate(struct inode *inode) |
| 1333 | { |
| 1334 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1335 | int ret; |
| 1336 | struct btrfs_trans_handle *trans; |
| 1337 | |
| 1338 | if (!S_ISREG(inode->i_mode)) |
| 1339 | return; |
| 1340 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
| 1341 | return; |
| 1342 | |
| 1343 | nobh_truncate_page(inode->i_mapping, inode->i_size); |
| 1344 | |
| 1345 | /* FIXME, add redo link to tree so we don't leak on crash */ |
| 1346 | mutex_lock(&root->fs_info->fs_mutex); |
| 1347 | trans = btrfs_start_transaction(root, 1); |
| 1348 | ret = btrfs_truncate_in_trans(trans, root, inode); |
| 1349 | BUG_ON(ret); |
| 1350 | ret = btrfs_end_transaction(trans, root); |
| 1351 | BUG_ON(ret); |
| 1352 | mutex_unlock(&root->fs_info->fs_mutex); |
| 1353 | mark_inode_dirty(inode); |
| 1354 | } |
| 1355 | |
| 1356 | /* |
| 1357 | * Make sure any changes to nobh_commit_write() are reflected in |
| 1358 | * nobh_truncate_page(), since it doesn't call commit_write(). |
| 1359 | */ |
| 1360 | static int btrfs_commit_write(struct file *file, struct page *page, |
| 1361 | unsigned from, unsigned to) |
| 1362 | { |
| 1363 | struct inode *inode = page->mapping->host; |
| 1364 | struct buffer_head *bh; |
| 1365 | loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; |
| 1366 | |
| 1367 | SetPageUptodate(page); |
| 1368 | bh = page_buffers(page); |
| 1369 | if (buffer_mapped(bh) && bh->b_blocknr != 0) { |
| 1370 | set_page_dirty(page); |
| 1371 | } |
| 1372 | if (pos > inode->i_size) { |
| 1373 | i_size_write(inode, pos); |
| 1374 | mark_inode_dirty(inode); |
| 1375 | } |
| 1376 | return 0; |
| 1377 | } |
| 1378 | |
| 1379 | static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes, |
| 1380 | struct page **prepared_pages, |
| 1381 | const char __user * buf) |
| 1382 | { |
| 1383 | long page_fault = 0; |
| 1384 | int i; |
| 1385 | int offset = pos & (PAGE_CACHE_SIZE - 1); |
| 1386 | |
| 1387 | for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { |
| 1388 | size_t count = min_t(size_t, |
| 1389 | PAGE_CACHE_SIZE - offset, write_bytes); |
| 1390 | struct page *page = prepared_pages[i]; |
| 1391 | fault_in_pages_readable(buf, count); |
| 1392 | |
| 1393 | /* Copy data from userspace to the current page */ |
| 1394 | kmap(page); |
| 1395 | page_fault = __copy_from_user(page_address(page) + offset, |
| 1396 | buf, count); |
| 1397 | /* Flush processor's dcache for this page */ |
| 1398 | flush_dcache_page(page); |
| 1399 | kunmap(page); |
| 1400 | buf += count; |
| 1401 | write_bytes -= count; |
| 1402 | |
| 1403 | if (page_fault) |
| 1404 | break; |
| 1405 | } |
| 1406 | return page_fault ? -EFAULT : 0; |
| 1407 | } |
| 1408 | |
| 1409 | static void btrfs_drop_pages(struct page **pages, size_t num_pages) |
| 1410 | { |
| 1411 | size_t i; |
| 1412 | for (i = 0; i < num_pages; i++) { |
| 1413 | if (!pages[i]) |
| 1414 | break; |
| 1415 | unlock_page(pages[i]); |
| 1416 | mark_page_accessed(pages[i]); |
| 1417 | page_cache_release(pages[i]); |
| 1418 | } |
| 1419 | } |
| 1420 | static int dirty_and_release_pages(struct btrfs_trans_handle *trans, |
| 1421 | struct btrfs_root *root, |
| 1422 | struct file *file, |
| 1423 | struct page **pages, |
| 1424 | size_t num_pages, |
| 1425 | loff_t pos, |
| 1426 | size_t write_bytes) |
| 1427 | { |
| 1428 | int i; |
| 1429 | int offset; |
| 1430 | int err = 0; |
| 1431 | int ret; |
| 1432 | int this_write; |
| 1433 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1434 | struct buffer_head *bh; |
| 1435 | struct btrfs_file_extent_item *ei; |
| 1436 | |
| 1437 | for (i = 0; i < num_pages; i++) { |
| 1438 | offset = pos & (PAGE_CACHE_SIZE -1); |
| 1439 | this_write = min(PAGE_CACHE_SIZE - offset, write_bytes); |
| 1440 | /* FIXME, one block at a time */ |
| 1441 | |
| 1442 | mutex_lock(&root->fs_info->fs_mutex); |
| 1443 | trans = btrfs_start_transaction(root, 1); |
| 1444 | |
| 1445 | bh = page_buffers(pages[i]); |
| 1446 | if (buffer_mapped(bh) && bh->b_blocknr == 0) { |
| 1447 | struct btrfs_key key; |
| 1448 | struct btrfs_path *path; |
| 1449 | char *ptr; |
| 1450 | u32 datasize; |
| 1451 | |
| 1452 | path = btrfs_alloc_path(); |
| 1453 | BUG_ON(!path); |
| 1454 | key.objectid = inode->i_ino; |
| 1455 | key.offset = pages[i]->index << PAGE_CACHE_SHIFT; |
| 1456 | key.flags = 0; |
| 1457 | btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); |
| 1458 | BUG_ON(write_bytes >= PAGE_CACHE_SIZE); |
| 1459 | datasize = offset + |
| 1460 | btrfs_file_extent_calc_inline_size(write_bytes); |
| 1461 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
| 1462 | datasize); |
| 1463 | BUG_ON(ret); |
| 1464 | ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
| 1465 | path->slots[0], struct btrfs_file_extent_item); |
| 1466 | btrfs_set_file_extent_generation(ei, trans->transid); |
| 1467 | btrfs_set_file_extent_type(ei, |
| 1468 | BTRFS_FILE_EXTENT_INLINE); |
| 1469 | ptr = btrfs_file_extent_inline_start(ei); |
| 1470 | memcpy(ptr, bh->b_data, offset + write_bytes); |
| 1471 | mark_buffer_dirty(path->nodes[0]); |
| 1472 | btrfs_free_path(path); |
| 1473 | } else { |
| 1474 | btrfs_csum_file_block(trans, root, inode->i_ino, |
| 1475 | pages[i]->index << PAGE_CACHE_SHIFT, |
| 1476 | kmap(pages[i]), PAGE_CACHE_SIZE); |
| 1477 | kunmap(pages[i]); |
| 1478 | } |
| 1479 | SetPageChecked(pages[i]); |
| 1480 | ret = btrfs_end_transaction(trans, root); |
| 1481 | BUG_ON(ret); |
| 1482 | mutex_unlock(&root->fs_info->fs_mutex); |
| 1483 | |
| 1484 | ret = btrfs_commit_write(file, pages[i], offset, |
| 1485 | offset + this_write); |
| 1486 | pos += this_write; |
| 1487 | if (ret) { |
| 1488 | err = ret; |
| 1489 | goto failed; |
| 1490 | } |
| 1491 | WARN_ON(this_write > write_bytes); |
| 1492 | write_bytes -= this_write; |
| 1493 | } |
| 1494 | failed: |
| 1495 | return err; |
| 1496 | } |
| 1497 | |
| 1498 | static int drop_extents(struct btrfs_trans_handle *trans, |
| 1499 | struct btrfs_root *root, |
| 1500 | struct inode *inode, |
| 1501 | u64 start, u64 end) |
| 1502 | { |
| 1503 | int ret; |
| 1504 | struct btrfs_key key; |
| 1505 | struct btrfs_leaf *leaf; |
| 1506 | int slot; |
| 1507 | struct btrfs_file_extent_item *extent; |
| 1508 | u64 extent_end = 0; |
| 1509 | int keep; |
| 1510 | struct btrfs_file_extent_item old; |
| 1511 | struct btrfs_path *path; |
| 1512 | u64 search_start = start; |
| 1513 | int bookend; |
| 1514 | int found_type; |
| 1515 | int found_extent; |
| 1516 | int found_inline; |
| 1517 | |
| 1518 | path = btrfs_alloc_path(); |
| 1519 | if (!path) |
| 1520 | return -ENOMEM; |
| 1521 | while(1) { |
| 1522 | btrfs_release_path(root, path); |
| 1523 | ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, |
| 1524 | search_start, -1); |
| 1525 | if (ret < 0) |
| 1526 | goto out; |
| 1527 | if (ret > 0) { |
| 1528 | if (path->slots[0] == 0) { |
| 1529 | ret = 0; |
| 1530 | goto out; |
| 1531 | } |
| 1532 | path->slots[0]--; |
| 1533 | } |
| 1534 | keep = 0; |
| 1535 | bookend = 0; |
| 1536 | found_extent = 0; |
| 1537 | found_inline = 0; |
| 1538 | extent = NULL; |
| 1539 | leaf = btrfs_buffer_leaf(path->nodes[0]); |
| 1540 | slot = path->slots[0]; |
| 1541 | btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key); |
| 1542 | if (key.offset >= end || key.objectid != inode->i_ino) { |
| 1543 | ret = 0; |
| 1544 | goto out; |
| 1545 | } |
| 1546 | if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) { |
| 1547 | ret = 0; |
| 1548 | goto out; |
| 1549 | } |
| 1550 | extent = btrfs_item_ptr(leaf, slot, |
| 1551 | struct btrfs_file_extent_item); |
| 1552 | found_type = btrfs_file_extent_type(extent); |
| 1553 | if (found_type == BTRFS_FILE_EXTENT_REG) { |
| 1554 | extent_end = key.offset + |
| 1555 | (btrfs_file_extent_num_blocks(extent) << |
| 1556 | inode->i_blkbits); |
| 1557 | found_extent = 1; |
| 1558 | } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { |
| 1559 | found_inline = 1; |
| 1560 | extent_end = key.offset + |
| 1561 | btrfs_file_extent_inline_len(leaf->items + slot); |
| 1562 | } |
| 1563 | |
| 1564 | if (!found_extent && !found_inline) { |
| 1565 | ret = 0; |
| 1566 | goto out; |
| 1567 | } |
| 1568 | |
| 1569 | if (search_start >= extent_end) { |
| 1570 | ret = 0; |
| 1571 | goto out; |
| 1572 | } |
| 1573 | |
| 1574 | search_start = extent_end; |
| 1575 | |
| 1576 | if (end < extent_end && end >= key.offset) { |
| 1577 | if (found_extent) { |
| 1578 | memcpy(&old, extent, sizeof(old)); |
| 1579 | ret = btrfs_inc_extent_ref(trans, root, |
| 1580 | btrfs_file_extent_disk_blocknr(&old), |
| 1581 | btrfs_file_extent_disk_num_blocks(&old)); |
| 1582 | BUG_ON(ret); |
| 1583 | } |
| 1584 | WARN_ON(found_inline); |
| 1585 | bookend = 1; |
| 1586 | } |
| 1587 | |
| 1588 | if (start > key.offset) { |
| 1589 | u64 new_num; |
| 1590 | u64 old_num; |
| 1591 | /* truncate existing extent */ |
| 1592 | keep = 1; |
| 1593 | WARN_ON(start & (root->blocksize - 1)); |
| 1594 | if (found_extent) { |
| 1595 | new_num = (start - key.offset) >> |
| 1596 | inode->i_blkbits; |
| 1597 | old_num = btrfs_file_extent_num_blocks(extent); |
| 1598 | inode->i_blocks -= (old_num - new_num) << 3; |
| 1599 | btrfs_set_file_extent_num_blocks(extent, |
| 1600 | new_num); |
| 1601 | mark_buffer_dirty(path->nodes[0]); |
| 1602 | } else { |
| 1603 | WARN_ON(1); |
| 1604 | /* |
| 1605 | ret = btrfs_truncate_item(trans, root, path, |
| 1606 | start - key.offset); |
| 1607 | BUG_ON(ret); |
| 1608 | */ |
| 1609 | } |
| 1610 | } |
| 1611 | if (!keep) { |
| 1612 | u64 disk_blocknr = 0; |
| 1613 | u64 disk_num_blocks = 0; |
| 1614 | u64 extent_num_blocks = 0; |
| 1615 | if (found_extent) { |
| 1616 | disk_blocknr = |
| 1617 | btrfs_file_extent_disk_blocknr(extent); |
| 1618 | disk_num_blocks = |
| 1619 | btrfs_file_extent_disk_num_blocks(extent); |
| 1620 | extent_num_blocks = |
| 1621 | btrfs_file_extent_num_blocks(extent); |
| 1622 | } |
| 1623 | ret = btrfs_del_item(trans, root, path); |
| 1624 | BUG_ON(ret); |
| 1625 | btrfs_release_path(root, path); |
| 1626 | if (found_extent) { |
| 1627 | inode->i_blocks -= |
| 1628 | btrfs_file_extent_num_blocks(extent) << 3; |
| 1629 | ret = btrfs_free_extent(trans, root, |
| 1630 | disk_blocknr, |
| 1631 | disk_num_blocks, 0); |
| 1632 | } |
| 1633 | |
| 1634 | BUG_ON(ret); |
| 1635 | if (!bookend && search_start >= end) { |
| 1636 | ret = 0; |
| 1637 | goto out; |
| 1638 | } |
| 1639 | if (!bookend) |
| 1640 | continue; |
| 1641 | } |
| 1642 | if (bookend && found_extent) { |
| 1643 | /* create bookend */ |
| 1644 | struct btrfs_key ins; |
| 1645 | ins.objectid = inode->i_ino; |
| 1646 | ins.offset = end; |
| 1647 | ins.flags = 0; |
| 1648 | btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY); |
| 1649 | |
| 1650 | btrfs_release_path(root, path); |
| 1651 | ret = btrfs_insert_empty_item(trans, root, path, &ins, |
| 1652 | sizeof(*extent)); |
| 1653 | BUG_ON(ret); |
| 1654 | extent = btrfs_item_ptr( |
| 1655 | btrfs_buffer_leaf(path->nodes[0]), |
| 1656 | path->slots[0], |
| 1657 | struct btrfs_file_extent_item); |
| 1658 | btrfs_set_file_extent_disk_blocknr(extent, |
| 1659 | btrfs_file_extent_disk_blocknr(&old)); |
| 1660 | btrfs_set_file_extent_disk_num_blocks(extent, |
| 1661 | btrfs_file_extent_disk_num_blocks(&old)); |
| 1662 | |
| 1663 | btrfs_set_file_extent_offset(extent, |
| 1664 | btrfs_file_extent_offset(&old) + |
| 1665 | ((end - key.offset) >> inode->i_blkbits)); |
| 1666 | WARN_ON(btrfs_file_extent_num_blocks(&old) < |
| 1667 | (end - key.offset) >> inode->i_blkbits); |
| 1668 | btrfs_set_file_extent_num_blocks(extent, |
| 1669 | btrfs_file_extent_num_blocks(&old) - |
| 1670 | ((end - key.offset) >> inode->i_blkbits)); |
| 1671 | |
| 1672 | btrfs_set_file_extent_type(extent, |
| 1673 | BTRFS_FILE_EXTENT_REG); |
| 1674 | btrfs_set_file_extent_generation(extent, |
| 1675 | btrfs_file_extent_generation(&old)); |
| 1676 | btrfs_mark_buffer_dirty(path->nodes[0]); |
| 1677 | inode->i_blocks += |
| 1678 | btrfs_file_extent_num_blocks(extent) << 3; |
| 1679 | ret = 0; |
| 1680 | goto out; |
| 1681 | } |
| 1682 | } |
| 1683 | out: |
| 1684 | btrfs_free_path(path); |
| 1685 | return ret; |
| 1686 | } |
| 1687 | |
| 1688 | static int prepare_pages(struct btrfs_root *root, |
| 1689 | struct file *file, |
| 1690 | struct page **pages, |
| 1691 | size_t num_pages, |
| 1692 | loff_t pos, |
| 1693 | unsigned long first_index, |
| 1694 | unsigned long last_index, |
| 1695 | size_t write_bytes, |
| 1696 | u64 alloc_extent_start) |
| 1697 | { |
| 1698 | int i; |
| 1699 | unsigned long index = pos >> PAGE_CACHE_SHIFT; |
| 1700 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1701 | int offset; |
| 1702 | int err = 0; |
| 1703 | int this_write; |
| 1704 | struct buffer_head *bh; |
| 1705 | struct buffer_head *head; |
| 1706 | loff_t isize = i_size_read(inode); |
| 1707 | |
| 1708 | memset(pages, 0, num_pages * sizeof(struct page *)); |
| 1709 | |
| 1710 | for (i = 0; i < num_pages; i++) { |
| 1711 | pages[i] = grab_cache_page(inode->i_mapping, index + i); |
| 1712 | if (!pages[i]) { |
| 1713 | err = -ENOMEM; |
| 1714 | goto failed_release; |
| 1715 | } |
| 1716 | offset = pos & (PAGE_CACHE_SIZE -1); |
| 1717 | this_write = min(PAGE_CACHE_SIZE - offset, write_bytes); |
| 1718 | create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize, |
| 1719 | (1 << BH_Uptodate)); |
| 1720 | head = page_buffers(pages[i]); |
| 1721 | bh = head; |
| 1722 | do { |
| 1723 | err = btrfs_map_bh_to_logical(root, bh, |
| 1724 | alloc_extent_start); |
| 1725 | BUG_ON(err); |
| 1726 | if (err) |
| 1727 | goto failed_truncate; |
| 1728 | bh = bh->b_this_page; |
| 1729 | if (alloc_extent_start) |
| 1730 | alloc_extent_start++; |
| 1731 | } while (bh != head); |
| 1732 | pos += this_write; |
| 1733 | WARN_ON(this_write > write_bytes); |
| 1734 | write_bytes -= this_write; |
| 1735 | } |
| 1736 | return 0; |
| 1737 | |
| 1738 | failed_release: |
| 1739 | btrfs_drop_pages(pages, num_pages); |
| 1740 | return err; |
| 1741 | |
| 1742 | failed_truncate: |
| 1743 | btrfs_drop_pages(pages, num_pages); |
| 1744 | if (pos > isize) |
| 1745 | vmtruncate(inode, isize); |
| 1746 | return err; |
| 1747 | } |
| 1748 | |
| 1749 | static ssize_t btrfs_file_write(struct file *file, const char __user *buf, |
| 1750 | size_t count, loff_t *ppos) |
| 1751 | { |
| 1752 | loff_t pos; |
| 1753 | size_t num_written = 0; |
| 1754 | int err = 0; |
| 1755 | int ret = 0; |
| 1756 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1757 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1758 | struct page *pages[8]; |
| 1759 | struct page *pinned[2] = { NULL, NULL }; |
| 1760 | unsigned long first_index; |
| 1761 | unsigned long last_index; |
| 1762 | u64 start_pos; |
| 1763 | u64 num_blocks; |
| 1764 | u64 alloc_extent_start; |
| 1765 | struct btrfs_trans_handle *trans; |
| 1766 | struct btrfs_key ins; |
| 1767 | |
| 1768 | if (file->f_flags & O_DIRECT) |
| 1769 | return -EINVAL; |
| 1770 | pos = *ppos; |
| 1771 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); |
| 1772 | current->backing_dev_info = inode->i_mapping->backing_dev_info; |
| 1773 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
| 1774 | if (err) |
| 1775 | goto out; |
| 1776 | if (count == 0) |
| 1777 | goto out; |
| 1778 | err = remove_suid(file->f_path.dentry); |
| 1779 | if (err) |
| 1780 | goto out; |
| 1781 | file_update_time(file); |
| 1782 | |
| 1783 | start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1); |
| 1784 | num_blocks = (count + pos - start_pos + root->blocksize - 1) >> |
| 1785 | inode->i_blkbits; |
| 1786 | |
| 1787 | mutex_lock(&inode->i_mutex); |
| 1788 | first_index = pos >> PAGE_CACHE_SHIFT; |
| 1789 | last_index = (pos + count) >> PAGE_CACHE_SHIFT; |
| 1790 | |
| 1791 | if ((first_index << PAGE_CACHE_SHIFT) < inode->i_size && |
| 1792 | (pos & (PAGE_CACHE_SIZE - 1))) { |
| 1793 | pinned[0] = grab_cache_page(inode->i_mapping, first_index); |
| 1794 | if (!PageUptodate(pinned[0])) { |
| 1795 | ret = mpage_readpage(pinned[0], btrfs_get_block); |
| 1796 | BUG_ON(ret); |
| 1797 | } else { |
| 1798 | unlock_page(pinned[0]); |
| 1799 | } |
| 1800 | } |
| 1801 | if (first_index != last_index && |
| 1802 | (last_index << PAGE_CACHE_SHIFT) < inode->i_size && |
| 1803 | (count & (PAGE_CACHE_SIZE - 1))) { |
| 1804 | pinned[1] = grab_cache_page(inode->i_mapping, last_index); |
| 1805 | if (!PageUptodate(pinned[1])) { |
| 1806 | ret = mpage_readpage(pinned[1], btrfs_get_block); |
| 1807 | BUG_ON(ret); |
| 1808 | } else { |
| 1809 | unlock_page(pinned[1]); |
| 1810 | } |
| 1811 | } |
| 1812 | |
| 1813 | mutex_lock(&root->fs_info->fs_mutex); |
| 1814 | trans = btrfs_start_transaction(root, 1); |
| 1815 | if (!trans) { |
| 1816 | err = -ENOMEM; |
| 1817 | mutex_unlock(&root->fs_info->fs_mutex); |
| 1818 | goto out_unlock; |
| 1819 | } |
| 1820 | /* FIXME blocksize != 4096 */ |
| 1821 | inode->i_blocks += num_blocks << 3; |
| 1822 | if (start_pos < inode->i_size) { |
| 1823 | /* FIXME blocksize != pagesize */ |
| 1824 | ret = drop_extents(trans, root, inode, |
| 1825 | start_pos, |
| 1826 | (pos + count + root->blocksize -1) & |
| 1827 | ~((u64)root->blocksize - 1)); |
| 1828 | BUG_ON(ret); |
| 1829 | } |
| 1830 | if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size || |
| 1831 | pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) { |
| 1832 | ret = btrfs_alloc_extent(trans, root, inode->i_ino, |
| 1833 | BTRFS_EXTENT_FILE, num_blocks, 1, |
| 1834 | (u64)-1, &ins); |
| 1835 | BUG_ON(ret); |
| 1836 | ret = btrfs_insert_file_extent(trans, root, inode->i_ino, |
| 1837 | start_pos, ins.objectid, ins.offset); |
| 1838 | BUG_ON(ret); |
| 1839 | } else { |
| 1840 | ins.offset = 0; |
| 1841 | ins.objectid = 0; |
| 1842 | } |
| 1843 | BUG_ON(ret); |
| 1844 | alloc_extent_start = ins.objectid; |
| 1845 | ret = btrfs_end_transaction(trans, root); |
| 1846 | mutex_unlock(&root->fs_info->fs_mutex); |
| 1847 | |
| 1848 | while(count > 0) { |
| 1849 | size_t offset = pos & (PAGE_CACHE_SIZE - 1); |
| 1850 | size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset); |
| 1851 | size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> |
| 1852 | PAGE_CACHE_SHIFT; |
| 1853 | |
| 1854 | memset(pages, 0, sizeof(pages)); |
| 1855 | ret = prepare_pages(root, file, pages, num_pages, |
| 1856 | pos, first_index, last_index, |
| 1857 | write_bytes, alloc_extent_start); |
| 1858 | BUG_ON(ret); |
| 1859 | |
| 1860 | /* FIXME blocks != pagesize */ |
| 1861 | if (alloc_extent_start) |
| 1862 | alloc_extent_start += num_pages; |
| 1863 | ret = btrfs_copy_from_user(pos, num_pages, |
| 1864 | write_bytes, pages, buf); |
| 1865 | BUG_ON(ret); |
| 1866 | |
| 1867 | ret = dirty_and_release_pages(NULL, root, file, pages, |
| 1868 | num_pages, pos, write_bytes); |
| 1869 | BUG_ON(ret); |
| 1870 | btrfs_drop_pages(pages, num_pages); |
| 1871 | |
| 1872 | buf += write_bytes; |
| 1873 | count -= write_bytes; |
| 1874 | pos += write_bytes; |
| 1875 | num_written += write_bytes; |
| 1876 | |
| 1877 | balance_dirty_pages_ratelimited(inode->i_mapping); |
| 1878 | cond_resched(); |
| 1879 | } |
| 1880 | out_unlock: |
| 1881 | mutex_unlock(&inode->i_mutex); |
| 1882 | out: |
| 1883 | if (pinned[0]) |
| 1884 | page_cache_release(pinned[0]); |
| 1885 | if (pinned[1]) |
| 1886 | page_cache_release(pinned[1]); |
| 1887 | *ppos = pos; |
| 1888 | current->backing_dev_info = NULL; |
| 1889 | mark_inode_dirty(inode); |
| 1890 | return num_written ? num_written : err; |
| 1891 | } |
| 1892 | |
| 1893 | static int btrfs_read_actor(read_descriptor_t *desc, struct page *page, |
| 1894 | unsigned long offset, unsigned long size) |
| 1895 | { |
| 1896 | char *kaddr; |
| 1897 | unsigned long left, count = desc->count; |
| 1898 | struct inode *inode = page->mapping->host; |
| 1899 | |
| 1900 | if (size > count) |
| 1901 | size = count; |
| 1902 | |
| 1903 | if (!PageChecked(page)) { |
| 1904 | /* FIXME, do it per block */ |
| 1905 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1906 | |
| 1907 | int ret = btrfs_csum_verify_file_block(root, |
| 1908 | page->mapping->host->i_ino, |
| 1909 | page->index << PAGE_CACHE_SHIFT, |
| 1910 | kmap(page), PAGE_CACHE_SIZE); |
| 1911 | if (ret) { |
| 1912 | printk("failed to verify ino %lu page %lu\n", |
| 1913 | page->mapping->host->i_ino, |
| 1914 | page->index); |
| 1915 | memset(page_address(page), 0, PAGE_CACHE_SIZE); |
| 1916 | } |
| 1917 | SetPageChecked(page); |
| 1918 | kunmap(page); |
| 1919 | } |
| 1920 | /* |
| 1921 | * Faults on the destination of a read are common, so do it before |
| 1922 | * taking the kmap. |
| 1923 | */ |
| 1924 | if (!fault_in_pages_writeable(desc->arg.buf, size)) { |
| 1925 | kaddr = kmap_atomic(page, KM_USER0); |
| 1926 | left = __copy_to_user_inatomic(desc->arg.buf, |
| 1927 | kaddr + offset, size); |
| 1928 | kunmap_atomic(kaddr, KM_USER0); |
| 1929 | if (left == 0) |
| 1930 | goto success; |
| 1931 | } |
| 1932 | |
| 1933 | /* Do it the slow way */ |
| 1934 | kaddr = kmap(page); |
| 1935 | left = __copy_to_user(desc->arg.buf, kaddr + offset, size); |
| 1936 | kunmap(page); |
| 1937 | |
| 1938 | if (left) { |
| 1939 | size -= left; |
| 1940 | desc->error = -EFAULT; |
| 1941 | } |
| 1942 | success: |
| 1943 | desc->count = count - size; |
| 1944 | desc->written += size; |
| 1945 | desc->arg.buf += size; |
| 1946 | return size; |
| 1947 | } |
| 1948 | |
| 1949 | /** |
| 1950 | * btrfs_file_aio_read - filesystem read routine |
| 1951 | * @iocb: kernel I/O control block |
| 1952 | * @iov: io vector request |
| 1953 | * @nr_segs: number of segments in the iovec |
| 1954 | * @pos: current file position |
| 1955 | */ |
| 1956 | static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov, |
| 1957 | unsigned long nr_segs, loff_t pos) |
| 1958 | { |
| 1959 | struct file *filp = iocb->ki_filp; |
| 1960 | ssize_t retval; |
| 1961 | unsigned long seg; |
| 1962 | size_t count; |
| 1963 | loff_t *ppos = &iocb->ki_pos; |
| 1964 | |
| 1965 | count = 0; |
| 1966 | for (seg = 0; seg < nr_segs; seg++) { |
| 1967 | const struct iovec *iv = &iov[seg]; |
| 1968 | |
| 1969 | /* |
| 1970 | * If any segment has a negative length, or the cumulative |
| 1971 | * length ever wraps negative then return -EINVAL. |
| 1972 | */ |
| 1973 | count += iv->iov_len; |
| 1974 | if (unlikely((ssize_t)(count|iv->iov_len) < 0)) |
| 1975 | return -EINVAL; |
| 1976 | if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len)) |
| 1977 | continue; |
| 1978 | if (seg == 0) |
| 1979 | return -EFAULT; |
| 1980 | nr_segs = seg; |
| 1981 | count -= iv->iov_len; /* This segment is no good */ |
| 1982 | break; |
| 1983 | } |
| 1984 | retval = 0; |
| 1985 | if (count) { |
| 1986 | for (seg = 0; seg < nr_segs; seg++) { |
| 1987 | read_descriptor_t desc; |
| 1988 | |
| 1989 | desc.written = 0; |
| 1990 | desc.arg.buf = iov[seg].iov_base; |
| 1991 | desc.count = iov[seg].iov_len; |
| 1992 | if (desc.count == 0) |
| 1993 | continue; |
| 1994 | desc.error = 0; |
| 1995 | do_generic_file_read(filp, ppos, &desc, |
| 1996 | btrfs_read_actor); |
| 1997 | retval += desc.written; |
| 1998 | if (desc.error) { |
| 1999 | retval = retval ?: desc.error; |
| 2000 | break; |
| 2001 | } |
| 2002 | } |
| 2003 | } |
| 2004 | return retval; |
| 2005 | } |
| 2006 | |
| 2007 | static int create_subvol(struct btrfs_root *root, char *name, int namelen) |
| 2008 | { |
| 2009 | struct btrfs_trans_handle *trans; |
| 2010 | struct btrfs_key key; |
| 2011 | struct btrfs_root_item root_item; |
| 2012 | struct btrfs_inode_item *inode_item; |
| 2013 | struct buffer_head *subvol; |
| 2014 | struct btrfs_leaf *leaf; |
| 2015 | struct btrfs_root *new_root; |
| 2016 | struct inode *inode; |
| 2017 | int ret; |
| 2018 | u64 objectid; |
| 2019 | u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; |
| 2020 | |
| 2021 | mutex_lock(&root->fs_info->fs_mutex); |
| 2022 | trans = btrfs_start_transaction(root, 1); |
| 2023 | BUG_ON(!trans); |
| 2024 | |
| 2025 | subvol = btrfs_alloc_free_block(trans, root); |
| 2026 | if (subvol == NULL) |
| 2027 | return -ENOSPC; |
| 2028 | leaf = btrfs_buffer_leaf(subvol); |
| 2029 | btrfs_set_header_nritems(&leaf->header, 0); |
| 2030 | btrfs_set_header_level(&leaf->header, 0); |
| 2031 | btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol)); |
| 2032 | btrfs_set_header_generation(&leaf->header, trans->transid); |
| 2033 | btrfs_set_header_owner(&leaf->header, root->root_key.objectid); |
| 2034 | memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid, |
| 2035 | sizeof(leaf->header.fsid)); |
| 2036 | mark_buffer_dirty(subvol); |
| 2037 | |
| 2038 | inode_item = &root_item.inode; |
| 2039 | memset(inode_item, 0, sizeof(*inode_item)); |
| 2040 | btrfs_set_inode_generation(inode_item, 1); |
| 2041 | btrfs_set_inode_size(inode_item, 3); |
| 2042 | btrfs_set_inode_nlink(inode_item, 1); |
| 2043 | btrfs_set_inode_nblocks(inode_item, 1); |
| 2044 | btrfs_set_inode_mode(inode_item, S_IFDIR | 0755); |
| 2045 | |
| 2046 | btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol)); |
| 2047 | btrfs_set_root_refs(&root_item, 1); |
| 2048 | brelse(subvol); |
| 2049 | subvol = NULL; |
| 2050 | |
| 2051 | ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root, |
| 2052 | 0, &objectid); |
| 2053 | BUG_ON(ret); |
| 2054 | |
| 2055 | btrfs_set_root_dirid(&root_item, new_dirid); |
| 2056 | |
| 2057 | key.objectid = objectid; |
| 2058 | key.offset = 1; |
| 2059 | key.flags = 0; |
| 2060 | btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
| 2061 | ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, |
| 2062 | &root_item); |
| 2063 | BUG_ON(ret); |
| 2064 | |
| 2065 | /* |
| 2066 | * insert the directory item |
| 2067 | */ |
| 2068 | key.offset = (u64)-1; |
| 2069 | ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root, |
| 2070 | name, namelen, |
| 2071 | root->fs_info->sb->s_root->d_inode->i_ino, |
| 2072 | &key, 0); |
| 2073 | BUG_ON(ret); |
| 2074 | |
| 2075 | ret = btrfs_commit_transaction(trans, root); |
| 2076 | BUG_ON(ret); |
| 2077 | |
| 2078 | new_root = btrfs_read_fs_root(root->fs_info, &key); |
| 2079 | BUG_ON(!new_root); |
| 2080 | |
| 2081 | trans = btrfs_start_transaction(new_root, 1); |
| 2082 | BUG_ON(!trans); |
| 2083 | |
| 2084 | inode = btrfs_new_inode(trans, new_root, new_dirid, S_IFDIR | 0700); |
| 2085 | inode->i_op = &btrfs_dir_inode_operations; |
| 2086 | inode->i_fop = &btrfs_dir_file_operations; |
| 2087 | |
| 2088 | ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid); |
| 2089 | BUG_ON(ret); |
| 2090 | |
| 2091 | inode->i_nlink = 1; |
| 2092 | inode->i_size = 6; |
| 2093 | ret = btrfs_update_inode(trans, new_root, inode); |
| 2094 | BUG_ON(ret); |
| 2095 | |
| 2096 | ret = btrfs_commit_transaction(trans, new_root); |
| 2097 | BUG_ON(ret); |
| 2098 | |
| 2099 | iput(inode); |
| 2100 | |
| 2101 | mutex_unlock(&root->fs_info->fs_mutex); |
| 2102 | return 0; |
| 2103 | } |
| 2104 | |
| 2105 | static int create_snapshot(struct btrfs_root *root, char *name, int namelen) |
| 2106 | { |
| 2107 | struct btrfs_trans_handle *trans; |
| 2108 | struct btrfs_key key; |
| 2109 | struct btrfs_root_item new_root_item; |
| 2110 | int ret; |
| 2111 | u64 objectid; |
| 2112 | |
| 2113 | if (!root->ref_cows) |
| 2114 | return -EINVAL; |
| 2115 | |
| 2116 | mutex_lock(&root->fs_info->fs_mutex); |
| 2117 | trans = btrfs_start_transaction(root, 1); |
| 2118 | BUG_ON(!trans); |
| 2119 | |
| 2120 | ret = btrfs_update_inode(trans, root, root->inode); |
| 2121 | BUG_ON(ret); |
| 2122 | |
| 2123 | ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root, |
| 2124 | 0, &objectid); |
| 2125 | BUG_ON(ret); |
| 2126 | |
| 2127 | memcpy(&new_root_item, &root->root_item, |
| 2128 | sizeof(new_root_item)); |
| 2129 | |
| 2130 | key.objectid = objectid; |
| 2131 | key.offset = 1; |
| 2132 | key.flags = 0; |
| 2133 | btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
| 2134 | btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node)); |
| 2135 | |
| 2136 | ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, |
| 2137 | &new_root_item); |
| 2138 | BUG_ON(ret); |
| 2139 | |
| 2140 | /* |
| 2141 | * insert the directory item |
| 2142 | */ |
| 2143 | key.offset = (u64)-1; |
| 2144 | ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root, |
| 2145 | name, namelen, |
| 2146 | root->fs_info->sb->s_root->d_inode->i_ino, |
| 2147 | &key, 0); |
| 2148 | |
| 2149 | BUG_ON(ret); |
| 2150 | |
| 2151 | ret = btrfs_inc_root_ref(trans, root); |
| 2152 | BUG_ON(ret); |
| 2153 | |
| 2154 | ret = btrfs_commit_transaction(trans, root); |
| 2155 | BUG_ON(ret); |
| 2156 | mutex_unlock(&root->fs_info->fs_mutex); |
| 2157 | return 0; |
| 2158 | } |
| 2159 | |
| 2160 | static int add_disk(struct btrfs_root *root, char *name, int namelen) |
| 2161 | { |
| 2162 | struct block_device *bdev; |
| 2163 | struct btrfs_path *path; |
| 2164 | struct super_block *sb = root->fs_info->sb; |
| 2165 | struct btrfs_root *dev_root = root->fs_info->dev_root; |
| 2166 | struct btrfs_trans_handle *trans; |
| 2167 | struct btrfs_device_item *dev_item; |
| 2168 | struct btrfs_key key; |
| 2169 | u16 item_size; |
| 2170 | u64 num_blocks; |
| 2171 | u64 new_blocks; |
| 2172 | u64 device_id; |
| 2173 | int ret; |
| 2174 | |
| 2175 | printk("adding disk %s\n", name); |
| 2176 | path = btrfs_alloc_path(); |
| 2177 | if (!path) |
| 2178 | return -ENOMEM; |
| 2179 | num_blocks = btrfs_super_total_blocks(root->fs_info->disk_super); |
| 2180 | bdev = open_bdev_excl(name, O_RDWR, sb); |
| 2181 | if (IS_ERR(bdev)) { |
| 2182 | ret = PTR_ERR(bdev); |
| 2183 | printk("open bdev excl failed ret %d\n", ret); |
| 2184 | goto out_nolock; |
| 2185 | } |
| 2186 | set_blocksize(bdev, sb->s_blocksize); |
| 2187 | new_blocks = bdev->bd_inode->i_size >> sb->s_blocksize_bits; |
| 2188 | key.objectid = num_blocks; |
| 2189 | key.offset = new_blocks; |
| 2190 | key.flags = 0; |
| 2191 | btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY); |
| 2192 | |
| 2193 | mutex_lock(&dev_root->fs_info->fs_mutex); |
| 2194 | trans = btrfs_start_transaction(dev_root, 1); |
| 2195 | item_size = sizeof(*dev_item) + namelen; |
| 2196 | printk("insert empty on %Lu %Lu %u size %d\n", num_blocks, new_blocks, key.flags, item_size); |
| 2197 | ret = btrfs_insert_empty_item(trans, dev_root, path, &key, item_size); |
| 2198 | if (ret) { |
| 2199 | printk("insert failed %d\n", ret); |
| 2200 | close_bdev_excl(bdev); |
| 2201 | if (ret > 0) |
| 2202 | ret = -EEXIST; |
| 2203 | goto out; |
| 2204 | } |
| 2205 | dev_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), |
| 2206 | path->slots[0], struct btrfs_device_item); |
| 2207 | btrfs_set_device_pathlen(dev_item, namelen); |
| 2208 | memcpy(dev_item + 1, name, namelen); |
| 2209 | |
| 2210 | device_id = btrfs_super_last_device_id(root->fs_info->disk_super) + 1; |
| 2211 | btrfs_set_super_last_device_id(root->fs_info->disk_super, device_id); |
| 2212 | btrfs_set_device_id(dev_item, device_id); |
| 2213 | mark_buffer_dirty(path->nodes[0]); |
| 2214 | |
| 2215 | ret = btrfs_insert_dev_radix(root, bdev, device_id, num_blocks, |
| 2216 | new_blocks); |
| 2217 | |
| 2218 | if (!ret) { |
| 2219 | btrfs_set_super_total_blocks(root->fs_info->disk_super, |
| 2220 | num_blocks + new_blocks); |
| 2221 | i_size_write(root->fs_info->btree_inode, |
| 2222 | (num_blocks + new_blocks) << |
| 2223 | root->fs_info->btree_inode->i_blkbits); |
| 2224 | } |
| 2225 | |
| 2226 | out: |
| 2227 | ret = btrfs_commit_transaction(trans, dev_root); |
| 2228 | BUG_ON(ret); |
| 2229 | mutex_unlock(&root->fs_info->fs_mutex); |
| 2230 | out_nolock: |
| 2231 | btrfs_free_path(path); |
| 2232 | |
| 2233 | return ret; |
| 2234 | } |
| 2235 | |
| 2236 | static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int |
| 2237 | cmd, unsigned long arg) |
| 2238 | { |
| 2239 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 2240 | struct btrfs_ioctl_vol_args vol_args; |
| 2241 | int ret = 0; |
| 2242 | struct btrfs_dir_item *di; |
| 2243 | int namelen; |
| 2244 | struct btrfs_path *path; |
| 2245 | u64 root_dirid; |
| 2246 | |
| 2247 | switch (cmd) { |
| 2248 | case BTRFS_IOC_SNAP_CREATE: |
| 2249 | if (copy_from_user(&vol_args, |
| 2250 | (struct btrfs_ioctl_vol_args __user *)arg, |
| 2251 | sizeof(vol_args))) |
| 2252 | return -EFAULT; |
| 2253 | namelen = strlen(vol_args.name); |
| 2254 | if (namelen > BTRFS_VOL_NAME_MAX) |
| 2255 | return -EINVAL; |
| 2256 | path = btrfs_alloc_path(); |
| 2257 | if (!path) |
| 2258 | return -ENOMEM; |
| 2259 | root_dirid = root->fs_info->sb->s_root->d_inode->i_ino, |
| 2260 | mutex_lock(&root->fs_info->fs_mutex); |
| 2261 | di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, |
| 2262 | path, root_dirid, |
| 2263 | vol_args.name, namelen, 0); |
| 2264 | mutex_unlock(&root->fs_info->fs_mutex); |
| 2265 | btrfs_free_path(path); |
| 2266 | if (di && !IS_ERR(di)) |
| 2267 | return -EEXIST; |
| 2268 | |
| 2269 | if (root == root->fs_info->tree_root) |
| 2270 | ret = create_subvol(root, vol_args.name, namelen); |
| 2271 | else |
| 2272 | ret = create_snapshot(root, vol_args.name, namelen); |
| 2273 | WARN_ON(ret); |
| 2274 | break; |
| 2275 | case BTRFS_IOC_ADD_DISK: |
| 2276 | if (copy_from_user(&vol_args, |
| 2277 | (struct btrfs_ioctl_vol_args __user *)arg, |
| 2278 | sizeof(vol_args))) |
| 2279 | return -EFAULT; |
| 2280 | namelen = strlen(vol_args.name); |
| 2281 | if (namelen > BTRFS_VOL_NAME_MAX) |
| 2282 | return -EINVAL; |
| 2283 | vol_args.name[namelen] = '\0'; |
| 2284 | ret = add_disk(root, vol_args.name, namelen); |
| 2285 | break; |
| 2286 | default: |
| 2287 | return -ENOTTY; |
| 2288 | } |
| 2289 | return ret; |
| 2290 | } |
| 2291 | |
| 2292 | static struct kmem_cache *btrfs_inode_cachep; |
| 2293 | struct kmem_cache *btrfs_trans_handle_cachep; |
| 2294 | struct kmem_cache *btrfs_transaction_cachep; |
| 2295 | struct kmem_cache *btrfs_bit_radix_cachep; |
| 2296 | struct kmem_cache *btrfs_path_cachep; |
| 2297 | |
| 2298 | /* |
| 2299 | * Called inside transaction, so use GFP_NOFS |
| 2300 | */ |
| 2301 | static struct inode *btrfs_alloc_inode(struct super_block *sb) |
| 2302 | { |
| 2303 | struct btrfs_inode *ei; |
| 2304 | |
| 2305 | ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); |
| 2306 | if (!ei) |
| 2307 | return NULL; |
| 2308 | return &ei->vfs_inode; |
| 2309 | } |
| 2310 | |
| 2311 | static void btrfs_destroy_inode(struct inode *inode) |
| 2312 | { |
| 2313 | WARN_ON(!list_empty(&inode->i_dentry)); |
| 2314 | WARN_ON(inode->i_data.nrpages); |
| 2315 | |
| 2316 | kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); |
| 2317 | } |
| 2318 | |
| 2319 | static void init_once(void * foo, struct kmem_cache * cachep, |
| 2320 | unsigned long flags) |
| 2321 | { |
| 2322 | struct btrfs_inode *ei = (struct btrfs_inode *) foo; |
| 2323 | |
| 2324 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == |
| 2325 | SLAB_CTOR_CONSTRUCTOR) { |
| 2326 | inode_init_once(&ei->vfs_inode); |
| 2327 | } |
| 2328 | } |
| 2329 | |
| 2330 | static int init_inodecache(void) |
| 2331 | { |
| 2332 | btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache", |
| 2333 | sizeof(struct btrfs_inode), |
| 2334 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 2335 | SLAB_MEM_SPREAD), |
| 2336 | init_once, NULL); |
| 2337 | btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache", |
| 2338 | sizeof(struct btrfs_trans_handle), |
| 2339 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 2340 | SLAB_MEM_SPREAD), |
| 2341 | NULL, NULL); |
| 2342 | btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache", |
| 2343 | sizeof(struct btrfs_transaction), |
| 2344 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 2345 | SLAB_MEM_SPREAD), |
| 2346 | NULL, NULL); |
| 2347 | btrfs_path_cachep = kmem_cache_create("btrfs_path_cache", |
| 2348 | sizeof(struct btrfs_transaction), |
| 2349 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 2350 | SLAB_MEM_SPREAD), |
| 2351 | NULL, NULL); |
| 2352 | btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix", |
| 2353 | 256, |
| 2354 | 0, (SLAB_RECLAIM_ACCOUNT| |
| 2355 | SLAB_MEM_SPREAD | |
| 2356 | SLAB_DESTROY_BY_RCU), |
| 2357 | NULL, NULL); |
| 2358 | if (btrfs_inode_cachep == NULL || btrfs_trans_handle_cachep == NULL || |
| 2359 | btrfs_transaction_cachep == NULL || btrfs_bit_radix_cachep == NULL) |
| 2360 | return -ENOMEM; |
| 2361 | return 0; |
| 2362 | } |
| 2363 | |
| 2364 | static void destroy_inodecache(void) |
| 2365 | { |
| 2366 | kmem_cache_destroy(btrfs_inode_cachep); |
| 2367 | kmem_cache_destroy(btrfs_trans_handle_cachep); |
| 2368 | kmem_cache_destroy(btrfs_transaction_cachep); |
| 2369 | kmem_cache_destroy(btrfs_bit_radix_cachep); |
| 2370 | kmem_cache_destroy(btrfs_path_cachep); |
| 2371 | } |
| 2372 | |
| 2373 | static int btrfs_get_sb(struct file_system_type *fs_type, |
| 2374 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
| 2375 | { |
| 2376 | return get_sb_bdev(fs_type, flags, dev_name, data, |
| 2377 | btrfs_fill_super, mnt); |
| 2378 | } |
| 2379 | |
| 2380 | |
| 2381 | static int btrfs_getattr(struct vfsmount *mnt, |
| 2382 | struct dentry *dentry, struct kstat *stat) |
| 2383 | { |
| 2384 | struct inode *inode = dentry->d_inode; |
| 2385 | generic_fillattr(inode, stat); |
| 2386 | stat->blksize = 256 * 1024; |
| 2387 | return 0; |
| 2388 | } |
| 2389 | |
| 2390 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 2391 | { |
| 2392 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); |
| 2393 | struct btrfs_super_block *disk_super = root->fs_info->disk_super; |
| 2394 | |
| 2395 | buf->f_namelen = BTRFS_NAME_LEN; |
| 2396 | buf->f_blocks = btrfs_super_total_blocks(disk_super); |
| 2397 | buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super); |
| 2398 | buf->f_bavail = buf->f_bfree; |
| 2399 | buf->f_bsize = dentry->d_sb->s_blocksize; |
| 2400 | buf->f_type = BTRFS_SUPER_MAGIC; |
| 2401 | return 0; |
| 2402 | } |
| 2403 | |
| 2404 | static struct file_system_type btrfs_fs_type = { |
| 2405 | .owner = THIS_MODULE, |
| 2406 | .name = "btrfs", |
| 2407 | .get_sb = btrfs_get_sb, |
| 2408 | .kill_sb = kill_block_super, |
| 2409 | .fs_flags = FS_REQUIRES_DEV, |
| 2410 | }; |
| 2411 | |
| 2412 | static struct super_operations btrfs_super_ops = { |
| 2413 | .delete_inode = btrfs_delete_inode, |
| 2414 | .put_super = btrfs_put_super, |
| 2415 | .read_inode = btrfs_read_locked_inode, |
| 2416 | .write_super = btrfs_write_super, |
| 2417 | .sync_fs = btrfs_sync_fs, |
| 2418 | .write_inode = btrfs_write_inode, |
| 2419 | .dirty_inode = btrfs_dirty_inode, |
| 2420 | .alloc_inode = btrfs_alloc_inode, |
| 2421 | .destroy_inode = btrfs_destroy_inode, |
| 2422 | .statfs = btrfs_statfs, |
| 2423 | }; |
| 2424 | |
| 2425 | static struct inode_operations btrfs_dir_inode_operations = { |
| 2426 | .lookup = btrfs_lookup, |
| 2427 | .create = btrfs_create, |
| 2428 | .unlink = btrfs_unlink, |
| 2429 | .mkdir = btrfs_mkdir, |
| 2430 | .rmdir = btrfs_rmdir, |
| 2431 | }; |
| 2432 | |
| 2433 | static struct inode_operations btrfs_dir_ro_inode_operations = { |
| 2434 | .lookup = btrfs_lookup, |
| 2435 | }; |
| 2436 | |
| 2437 | static struct file_operations btrfs_dir_file_operations = { |
| 2438 | .llseek = generic_file_llseek, |
| 2439 | .read = generic_read_dir, |
| 2440 | .readdir = btrfs_readdir, |
| 2441 | .ioctl = btrfs_ioctl, |
| 2442 | }; |
| 2443 | |
| 2444 | static struct address_space_operations btrfs_aops = { |
| 2445 | .readpage = btrfs_readpage, |
| 2446 | .writepage = btrfs_writepage, |
| 2447 | .sync_page = block_sync_page, |
| 2448 | .prepare_write = btrfs_prepare_write, |
| 2449 | .commit_write = btrfs_commit_write, |
| 2450 | }; |
| 2451 | |
| 2452 | static struct inode_operations btrfs_file_inode_operations = { |
| 2453 | .truncate = btrfs_truncate, |
| 2454 | .getattr = btrfs_getattr, |
| 2455 | }; |
| 2456 | |
| 2457 | static struct file_operations btrfs_file_operations = { |
| 2458 | .llseek = generic_file_llseek, |
| 2459 | .read = do_sync_read, |
| 2460 | .aio_read = btrfs_file_aio_read, |
| 2461 | .write = btrfs_file_write, |
| 2462 | .mmap = generic_file_mmap, |
| 2463 | .open = generic_file_open, |
| 2464 | .ioctl = btrfs_ioctl, |
| 2465 | .fsync = btrfs_sync_file, |
| 2466 | }; |
| 2467 | |
| 2468 | static int __init init_btrfs_fs(void) |
| 2469 | { |
| 2470 | int err; |
| 2471 | printk("btrfs loaded!\n"); |
| 2472 | err = init_inodecache(); |
| 2473 | if (err) |
| 2474 | return err; |
| 2475 | kset_set_kset_s(&btrfs_subsys, fs_subsys); |
| 2476 | err = subsystem_register(&btrfs_subsys); |
| 2477 | if (err) |
| 2478 | goto out; |
| 2479 | return register_filesystem(&btrfs_fs_type); |
| 2480 | out: |
| 2481 | destroy_inodecache(); |
| 2482 | return err; |
| 2483 | } |
| 2484 | |
| 2485 | static void __exit exit_btrfs_fs(void) |
| 2486 | { |
| 2487 | destroy_inodecache(); |
| 2488 | unregister_filesystem(&btrfs_fs_type); |
| 2489 | subsystem_unregister(&btrfs_subsys); |
| 2490 | printk("btrfs unloaded\n"); |
| 2491 | } |
| 2492 | |
| 2493 | module_init(init_btrfs_fs) |
| 2494 | module_exit(exit_btrfs_fs) |
| 2495 | |
| 2496 | MODULE_LICENSE("GPL"); |