Chris Mason | 0b86a83 | 2008-03-24 15:01:56 -0400 | [diff] [blame^] | 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 | #include <linux/sched.h> |
| 19 | #include <linux/bio.h> |
| 20 | #include "ctree.h" |
| 21 | #include "extent_map.h" |
| 22 | #include "disk-io.h" |
| 23 | #include "transaction.h" |
| 24 | #include "print-tree.h" |
| 25 | #include "volumes.h" |
| 26 | |
| 27 | struct map_lookup { |
| 28 | struct btrfs_device *dev; |
| 29 | u64 physical; |
| 30 | }; |
| 31 | |
| 32 | /* |
| 33 | * this uses a pretty simple search, the expectation is that it is |
| 34 | * called very infrequently and that a given device has a small number |
| 35 | * of extents |
| 36 | */ |
| 37 | static int find_free_dev_extent(struct btrfs_trans_handle *trans, |
| 38 | struct btrfs_device *device, |
| 39 | struct btrfs_path *path, |
| 40 | u64 num_bytes, u64 *start) |
| 41 | { |
| 42 | struct btrfs_key key; |
| 43 | struct btrfs_root *root = device->dev_root; |
| 44 | struct btrfs_dev_extent *dev_extent = NULL; |
| 45 | u64 hole_size = 0; |
| 46 | u64 last_byte = 0; |
| 47 | u64 search_start = 0; |
| 48 | u64 search_end = device->total_bytes; |
| 49 | int ret; |
| 50 | int slot = 0; |
| 51 | int start_found; |
| 52 | struct extent_buffer *l; |
| 53 | |
| 54 | start_found = 0; |
| 55 | path->reada = 2; |
| 56 | |
| 57 | /* FIXME use last free of some kind */ |
| 58 | |
| 59 | key.objectid = device->devid; |
| 60 | key.offset = search_start; |
| 61 | key.type = BTRFS_DEV_EXTENT_KEY; |
| 62 | ret = btrfs_search_slot(trans, root, &key, path, 0, 0); |
| 63 | if (ret < 0) |
| 64 | goto error; |
| 65 | ret = btrfs_previous_item(root, path, 0, key.type); |
| 66 | if (ret < 0) |
| 67 | goto error; |
| 68 | l = path->nodes[0]; |
| 69 | btrfs_item_key_to_cpu(l, &key, path->slots[0]); |
| 70 | while (1) { |
| 71 | l = path->nodes[0]; |
| 72 | slot = path->slots[0]; |
| 73 | if (slot >= btrfs_header_nritems(l)) { |
| 74 | ret = btrfs_next_leaf(root, path); |
| 75 | if (ret == 0) |
| 76 | continue; |
| 77 | if (ret < 0) |
| 78 | goto error; |
| 79 | no_more_items: |
| 80 | if (!start_found) { |
| 81 | if (search_start >= search_end) { |
| 82 | ret = -ENOSPC; |
| 83 | goto error; |
| 84 | } |
| 85 | *start = search_start; |
| 86 | start_found = 1; |
| 87 | goto check_pending; |
| 88 | } |
| 89 | *start = last_byte > search_start ? |
| 90 | last_byte : search_start; |
| 91 | if (search_end <= *start) { |
| 92 | ret = -ENOSPC; |
| 93 | goto error; |
| 94 | } |
| 95 | goto check_pending; |
| 96 | } |
| 97 | btrfs_item_key_to_cpu(l, &key, slot); |
| 98 | |
| 99 | if (key.objectid < device->devid) |
| 100 | goto next; |
| 101 | |
| 102 | if (key.objectid > device->devid) |
| 103 | goto no_more_items; |
| 104 | |
| 105 | if (key.offset >= search_start && key.offset > last_byte && |
| 106 | start_found) { |
| 107 | if (last_byte < search_start) |
| 108 | last_byte = search_start; |
| 109 | hole_size = key.offset - last_byte; |
| 110 | if (key.offset > last_byte && |
| 111 | hole_size >= num_bytes) { |
| 112 | *start = last_byte; |
| 113 | goto check_pending; |
| 114 | } |
| 115 | } |
| 116 | if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) { |
| 117 | goto next; |
| 118 | } |
| 119 | |
| 120 | start_found = 1; |
| 121 | dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); |
| 122 | last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent); |
| 123 | next: |
| 124 | path->slots[0]++; |
| 125 | cond_resched(); |
| 126 | } |
| 127 | check_pending: |
| 128 | /* we have to make sure we didn't find an extent that has already |
| 129 | * been allocated by the map tree or the original allocation |
| 130 | */ |
| 131 | btrfs_release_path(root, path); |
| 132 | BUG_ON(*start < search_start); |
| 133 | |
| 134 | if (*start + num_bytes >= search_end) { |
| 135 | ret = -ENOSPC; |
| 136 | goto error; |
| 137 | } |
| 138 | /* check for pending inserts here */ |
| 139 | return 0; |
| 140 | |
| 141 | error: |
| 142 | btrfs_release_path(root, path); |
| 143 | return ret; |
| 144 | } |
| 145 | |
| 146 | int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans, |
| 147 | struct btrfs_device *device, |
| 148 | u64 owner, u64 num_bytes, u64 *start) |
| 149 | { |
| 150 | int ret; |
| 151 | struct btrfs_path *path; |
| 152 | struct btrfs_root *root = device->dev_root; |
| 153 | struct btrfs_dev_extent *extent; |
| 154 | struct extent_buffer *leaf; |
| 155 | struct btrfs_key key; |
| 156 | |
| 157 | path = btrfs_alloc_path(); |
| 158 | if (!path) |
| 159 | return -ENOMEM; |
| 160 | |
| 161 | ret = find_free_dev_extent(trans, device, path, num_bytes, start); |
| 162 | if (ret) |
| 163 | goto err; |
| 164 | |
| 165 | key.objectid = device->devid; |
| 166 | key.offset = *start; |
| 167 | key.type = BTRFS_DEV_EXTENT_KEY; |
| 168 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
| 169 | sizeof(*extent)); |
| 170 | BUG_ON(ret); |
| 171 | |
| 172 | leaf = path->nodes[0]; |
| 173 | extent = btrfs_item_ptr(leaf, path->slots[0], |
| 174 | struct btrfs_dev_extent); |
| 175 | btrfs_set_dev_extent_owner(leaf, extent, owner); |
| 176 | btrfs_set_dev_extent_length(leaf, extent, num_bytes); |
| 177 | btrfs_mark_buffer_dirty(leaf); |
| 178 | err: |
| 179 | btrfs_free_path(path); |
| 180 | return ret; |
| 181 | } |
| 182 | |
| 183 | static int find_next_chunk(struct btrfs_root *root, u64 *objectid) |
| 184 | { |
| 185 | struct btrfs_path *path; |
| 186 | int ret; |
| 187 | struct btrfs_key key; |
| 188 | struct btrfs_key found_key; |
| 189 | |
| 190 | path = btrfs_alloc_path(); |
| 191 | BUG_ON(!path); |
| 192 | |
| 193 | key.objectid = (u64)-1; |
| 194 | key.offset = (u64)-1; |
| 195 | key.type = BTRFS_CHUNK_ITEM_KEY; |
| 196 | |
| 197 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 198 | if (ret < 0) |
| 199 | goto error; |
| 200 | |
| 201 | BUG_ON(ret == 0); |
| 202 | |
| 203 | ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY); |
| 204 | if (ret) { |
| 205 | *objectid = 0; |
| 206 | } else { |
| 207 | btrfs_item_key_to_cpu(path->nodes[0], &found_key, |
| 208 | path->slots[0]); |
| 209 | *objectid = found_key.objectid + found_key.offset; |
| 210 | } |
| 211 | ret = 0; |
| 212 | error: |
| 213 | btrfs_free_path(path); |
| 214 | return ret; |
| 215 | } |
| 216 | |
| 217 | static struct btrfs_device *next_device(struct list_head *head, |
| 218 | struct list_head *last) |
| 219 | { |
| 220 | struct list_head *next = last->next; |
| 221 | struct btrfs_device *dev; |
| 222 | |
| 223 | if (list_empty(head)) |
| 224 | return NULL; |
| 225 | |
| 226 | if (next == head) |
| 227 | next = next->next; |
| 228 | |
| 229 | dev = list_entry(next, struct btrfs_device, dev_list); |
| 230 | return dev; |
| 231 | } |
| 232 | |
| 233 | static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path, |
| 234 | u64 *objectid) |
| 235 | { |
| 236 | int ret; |
| 237 | struct btrfs_key key; |
| 238 | struct btrfs_key found_key; |
| 239 | |
| 240 | key.objectid = BTRFS_DEV_ITEMS_OBJECTID; |
| 241 | key.type = BTRFS_DEV_ITEM_KEY; |
| 242 | key.offset = (u64)-1; |
| 243 | |
| 244 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 245 | if (ret < 0) |
| 246 | goto error; |
| 247 | |
| 248 | BUG_ON(ret == 0); |
| 249 | |
| 250 | ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID, |
| 251 | BTRFS_DEV_ITEM_KEY); |
| 252 | if (ret) { |
| 253 | *objectid = 1; |
| 254 | } else { |
| 255 | btrfs_item_key_to_cpu(path->nodes[0], &found_key, |
| 256 | path->slots[0]); |
| 257 | *objectid = found_key.offset + 1; |
| 258 | } |
| 259 | ret = 0; |
| 260 | error: |
| 261 | btrfs_release_path(root, path); |
| 262 | return ret; |
| 263 | } |
| 264 | |
| 265 | /* |
| 266 | * the device information is stored in the chunk root |
| 267 | * the btrfs_device struct should be fully filled in |
| 268 | */ |
| 269 | int btrfs_add_device(struct btrfs_trans_handle *trans, |
| 270 | struct btrfs_root *root, |
| 271 | struct btrfs_device *device) |
| 272 | { |
| 273 | int ret; |
| 274 | struct btrfs_path *path; |
| 275 | struct btrfs_dev_item *dev_item; |
| 276 | struct extent_buffer *leaf; |
| 277 | struct btrfs_key key; |
| 278 | unsigned long ptr; |
| 279 | u64 free_devid; |
| 280 | |
| 281 | root = root->fs_info->chunk_root; |
| 282 | |
| 283 | path = btrfs_alloc_path(); |
| 284 | if (!path) |
| 285 | return -ENOMEM; |
| 286 | |
| 287 | ret = find_next_devid(root, path, &free_devid); |
| 288 | if (ret) |
| 289 | goto out; |
| 290 | |
| 291 | key.objectid = BTRFS_DEV_ITEMS_OBJECTID; |
| 292 | key.type = BTRFS_DEV_ITEM_KEY; |
| 293 | key.offset = free_devid; |
| 294 | |
| 295 | ret = btrfs_insert_empty_item(trans, root, path, &key, |
| 296 | sizeof(*dev_item) + device->name_len); |
| 297 | if (ret) |
| 298 | goto out; |
| 299 | |
| 300 | leaf = path->nodes[0]; |
| 301 | dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); |
| 302 | |
| 303 | btrfs_set_device_id(leaf, dev_item, device->devid); |
| 304 | btrfs_set_device_type(leaf, dev_item, device->type); |
| 305 | btrfs_set_device_io_align(leaf, dev_item, device->io_align); |
| 306 | btrfs_set_device_io_width(leaf, dev_item, device->io_width); |
| 307 | btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); |
| 308 | btrfs_set_device_rdev(leaf, dev_item, device->rdev); |
| 309 | btrfs_set_device_partition(leaf, dev_item, device->partition); |
| 310 | btrfs_set_device_name_len(leaf, dev_item, device->name_len); |
| 311 | btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); |
| 312 | btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); |
| 313 | |
| 314 | ptr = (unsigned long)btrfs_device_name(dev_item); |
| 315 | write_extent_buffer(leaf, device->name, ptr, device->name_len); |
| 316 | |
| 317 | ptr = (unsigned long)btrfs_device_uuid(dev_item); |
| 318 | write_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE); |
| 319 | btrfs_mark_buffer_dirty(leaf); |
| 320 | ret = 0; |
| 321 | |
| 322 | out: |
| 323 | btrfs_free_path(path); |
| 324 | return ret; |
| 325 | } |
| 326 | int btrfs_update_device(struct btrfs_trans_handle *trans, |
| 327 | struct btrfs_device *device) |
| 328 | { |
| 329 | int ret; |
| 330 | struct btrfs_path *path; |
| 331 | struct btrfs_root *root; |
| 332 | struct btrfs_dev_item *dev_item; |
| 333 | struct extent_buffer *leaf; |
| 334 | struct btrfs_key key; |
| 335 | |
| 336 | root = device->dev_root->fs_info->chunk_root; |
| 337 | |
| 338 | path = btrfs_alloc_path(); |
| 339 | if (!path) |
| 340 | return -ENOMEM; |
| 341 | |
| 342 | key.objectid = BTRFS_DEV_ITEMS_OBJECTID; |
| 343 | key.type = BTRFS_DEV_ITEM_KEY; |
| 344 | key.offset = device->devid; |
| 345 | |
| 346 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| 347 | if (ret < 0) |
| 348 | goto out; |
| 349 | |
| 350 | if (ret > 0) { |
| 351 | ret = -ENOENT; |
| 352 | goto out; |
| 353 | } |
| 354 | |
| 355 | leaf = path->nodes[0]; |
| 356 | dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); |
| 357 | |
| 358 | btrfs_set_device_id(leaf, dev_item, device->devid); |
| 359 | btrfs_set_device_type(leaf, dev_item, device->type); |
| 360 | btrfs_set_device_io_align(leaf, dev_item, device->io_align); |
| 361 | btrfs_set_device_io_width(leaf, dev_item, device->io_width); |
| 362 | btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); |
| 363 | btrfs_set_device_rdev(leaf, dev_item, device->rdev); |
| 364 | btrfs_set_device_partition(leaf, dev_item, device->partition); |
| 365 | btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes); |
| 366 | btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used); |
| 367 | btrfs_mark_buffer_dirty(leaf); |
| 368 | |
| 369 | out: |
| 370 | btrfs_free_path(path); |
| 371 | return ret; |
| 372 | } |
| 373 | |
| 374 | int btrfs_add_system_chunk(struct btrfs_trans_handle *trans, |
| 375 | struct btrfs_root *root, |
| 376 | struct btrfs_key *key, |
| 377 | struct btrfs_chunk *chunk, int item_size) |
| 378 | { |
| 379 | struct btrfs_super_block *super_copy = &root->fs_info->super_copy; |
| 380 | struct btrfs_disk_key disk_key; |
| 381 | u32 array_size; |
| 382 | u8 *ptr; |
| 383 | |
| 384 | array_size = btrfs_super_sys_array_size(super_copy); |
| 385 | if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) |
| 386 | return -EFBIG; |
| 387 | |
| 388 | ptr = super_copy->sys_chunk_array + array_size; |
| 389 | btrfs_cpu_key_to_disk(&disk_key, key); |
| 390 | memcpy(ptr, &disk_key, sizeof(disk_key)); |
| 391 | ptr += sizeof(disk_key); |
| 392 | memcpy(ptr, chunk, item_size); |
| 393 | item_size += sizeof(disk_key); |
| 394 | btrfs_set_super_sys_array_size(super_copy, array_size + item_size); |
| 395 | return 0; |
| 396 | } |
| 397 | |
| 398 | int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, |
| 399 | struct btrfs_root *extent_root, u64 *start, |
| 400 | u64 *num_bytes, u32 type) |
| 401 | { |
| 402 | u64 dev_offset; |
| 403 | struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root; |
| 404 | struct btrfs_stripe *stripes; |
| 405 | struct btrfs_device *device = NULL; |
| 406 | struct btrfs_chunk *chunk; |
| 407 | struct list_head *dev_list = &extent_root->fs_info->devices; |
| 408 | struct list_head *last_dev = extent_root->fs_info->last_device; |
| 409 | struct extent_map_tree *em_tree; |
| 410 | struct map_lookup *map; |
| 411 | struct extent_map *em; |
| 412 | u64 physical; |
| 413 | u64 calc_size = 1024 * 1024 * 1024; |
| 414 | int num_stripes; |
| 415 | int ret; |
| 416 | int index = 0; |
| 417 | struct btrfs_key key; |
| 418 | |
| 419 | |
| 420 | ret = find_next_chunk(chunk_root, &key.objectid); |
| 421 | if (ret) |
| 422 | return ret; |
| 423 | |
| 424 | num_stripes = 1; |
| 425 | chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS); |
| 426 | if (!chunk) |
| 427 | return -ENOMEM; |
| 428 | |
| 429 | stripes = &chunk->stripe; |
| 430 | |
| 431 | *num_bytes = calc_size; |
| 432 | while(index < num_stripes) { |
| 433 | device = next_device(dev_list, last_dev); |
| 434 | BUG_ON(!device); |
| 435 | last_dev = &device->dev_list; |
| 436 | extent_root->fs_info->last_device = last_dev; |
| 437 | |
| 438 | ret = btrfs_alloc_dev_extent(trans, device, |
| 439 | key.objectid, |
| 440 | calc_size, &dev_offset); |
| 441 | BUG_ON(ret); |
| 442 | |
| 443 | device->bytes_used += calc_size; |
| 444 | ret = btrfs_update_device(trans, device); |
| 445 | BUG_ON(ret); |
| 446 | |
| 447 | btrfs_set_stack_stripe_devid(stripes + index, device->devid); |
| 448 | btrfs_set_stack_stripe_offset(stripes + index, dev_offset); |
| 449 | physical = dev_offset; |
| 450 | index++; |
| 451 | } |
| 452 | |
| 453 | /* key.objectid was set above */ |
| 454 | key.offset = *num_bytes; |
| 455 | key.type = BTRFS_CHUNK_ITEM_KEY; |
| 456 | btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid); |
| 457 | btrfs_set_stack_chunk_stripe_len(chunk, 64 * 1024); |
| 458 | btrfs_set_stack_chunk_type(chunk, type); |
| 459 | btrfs_set_stack_chunk_num_stripes(chunk, num_stripes); |
| 460 | btrfs_set_stack_chunk_io_align(chunk, extent_root->sectorsize); |
| 461 | btrfs_set_stack_chunk_io_width(chunk, extent_root->sectorsize); |
| 462 | btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize); |
| 463 | |
| 464 | ret = btrfs_insert_item(trans, chunk_root, &key, chunk, |
| 465 | btrfs_chunk_item_size(num_stripes)); |
| 466 | BUG_ON(ret); |
| 467 | *start = key.objectid; |
| 468 | |
| 469 | em = alloc_extent_map(GFP_NOFS); |
| 470 | if (!em) |
| 471 | return -ENOMEM; |
| 472 | map = kmalloc(sizeof(*map), GFP_NOFS); |
| 473 | if (!map) { |
| 474 | free_extent_map(em); |
| 475 | return -ENOMEM; |
| 476 | } |
| 477 | |
| 478 | em->bdev = (struct block_device *)map; |
| 479 | em->start = key.objectid; |
| 480 | em->len = key.offset; |
| 481 | em->block_start = 0; |
| 482 | |
| 483 | map->physical = physical; |
| 484 | map->dev = device; |
| 485 | |
| 486 | if (!map->dev) { |
| 487 | kfree(map); |
| 488 | free_extent_map(em); |
| 489 | return -EIO; |
| 490 | } |
| 491 | kfree(chunk); |
| 492 | |
| 493 | em_tree = &extent_root->fs_info->mapping_tree.map_tree; |
| 494 | spin_lock(&em_tree->lock); |
| 495 | ret = add_extent_mapping(em_tree, em); |
| 496 | BUG_ON(ret); |
| 497 | spin_unlock(&em_tree->lock); |
| 498 | free_extent_map(em); |
| 499 | return ret; |
| 500 | } |
| 501 | |
| 502 | void btrfs_mapping_init(struct btrfs_mapping_tree *tree) |
| 503 | { |
| 504 | extent_map_tree_init(&tree->map_tree, GFP_NOFS); |
| 505 | } |
| 506 | |
| 507 | void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree) |
| 508 | { |
| 509 | struct extent_map *em; |
| 510 | |
| 511 | while(1) { |
| 512 | spin_lock(&tree->map_tree.lock); |
| 513 | em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1); |
| 514 | if (em) |
| 515 | remove_extent_mapping(&tree->map_tree, em); |
| 516 | spin_unlock(&tree->map_tree.lock); |
| 517 | if (!em) |
| 518 | break; |
| 519 | kfree(em->bdev); |
| 520 | /* once for us */ |
| 521 | free_extent_map(em); |
| 522 | /* once for the tree */ |
| 523 | free_extent_map(em); |
| 524 | } |
| 525 | } |
| 526 | |
| 527 | int btrfs_map_block(struct btrfs_mapping_tree *map_tree, |
| 528 | u64 logical, u64 *phys, u64 *length, |
| 529 | struct btrfs_device **dev) |
| 530 | { |
| 531 | struct extent_map *em; |
| 532 | struct map_lookup *map; |
| 533 | struct extent_map_tree *em_tree = &map_tree->map_tree; |
| 534 | u64 offset; |
| 535 | |
| 536 | |
| 537 | spin_lock(&em_tree->lock); |
| 538 | em = lookup_extent_mapping(em_tree, logical, *length); |
| 539 | BUG_ON(!em); |
| 540 | |
| 541 | BUG_ON(em->start > logical || em->start + em->len < logical); |
| 542 | map = (struct map_lookup *)em->bdev; |
| 543 | offset = logical - em->start; |
| 544 | *phys = map->physical + offset; |
| 545 | *length = em->len - offset; |
| 546 | *dev = map->dev; |
| 547 | free_extent_map(em); |
| 548 | spin_unlock(&em_tree->lock); |
| 549 | return 0; |
| 550 | } |
| 551 | |
| 552 | int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio) |
| 553 | { |
| 554 | struct btrfs_mapping_tree *map_tree; |
| 555 | struct btrfs_device *dev; |
| 556 | u64 logical = bio->bi_sector << 9; |
| 557 | u64 physical; |
| 558 | u64 length = 0; |
| 559 | u64 map_length; |
| 560 | struct bio_vec *bvec; |
| 561 | int i; |
| 562 | int ret; |
| 563 | |
| 564 | bio_for_each_segment(bvec, bio, i) { |
| 565 | length += bvec->bv_len; |
| 566 | } |
| 567 | map_tree = &root->fs_info->mapping_tree; |
| 568 | map_length = length; |
| 569 | ret = btrfs_map_block(map_tree, logical, &physical, &map_length, &dev); |
| 570 | BUG_ON(map_length < length); |
| 571 | bio->bi_sector = physical >> 9; |
| 572 | bio->bi_bdev = dev->bdev; |
| 573 | submit_bio(rw, bio); |
| 574 | return 0; |
| 575 | } |
| 576 | |
| 577 | struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid) |
| 578 | { |
| 579 | struct btrfs_device *dev; |
| 580 | struct list_head *cur = root->fs_info->devices.next; |
| 581 | struct list_head *head = &root->fs_info->devices; |
| 582 | |
| 583 | while(cur != head) { |
| 584 | dev = list_entry(cur, struct btrfs_device, dev_list); |
| 585 | if (dev->devid == devid) |
| 586 | return dev; |
| 587 | cur = cur->next; |
| 588 | } |
| 589 | return NULL; |
| 590 | } |
| 591 | |
| 592 | static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key, |
| 593 | struct extent_buffer *leaf, |
| 594 | struct btrfs_chunk *chunk) |
| 595 | { |
| 596 | struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; |
| 597 | struct map_lookup *map; |
| 598 | struct extent_map *em; |
| 599 | u64 logical; |
| 600 | u64 length; |
| 601 | u64 devid; |
| 602 | int ret; |
| 603 | |
| 604 | logical = key->objectid; |
| 605 | length = key->offset; |
| 606 | spin_lock(&map_tree->map_tree.lock); |
| 607 | em = lookup_extent_mapping(&map_tree->map_tree, logical, 1); |
| 608 | |
| 609 | /* already mapped? */ |
| 610 | if (em && em->start <= logical && em->start + em->len > logical) { |
| 611 | free_extent_map(em); |
| 612 | spin_unlock(&map_tree->map_tree.lock); |
| 613 | return 0; |
| 614 | } else if (em) { |
| 615 | free_extent_map(em); |
| 616 | } |
| 617 | spin_unlock(&map_tree->map_tree.lock); |
| 618 | |
| 619 | map = kzalloc(sizeof(*map), GFP_NOFS); |
| 620 | if (!map) |
| 621 | return -ENOMEM; |
| 622 | |
| 623 | em = alloc_extent_map(GFP_NOFS); |
| 624 | if (!em) |
| 625 | return -ENOMEM; |
| 626 | map = kmalloc(sizeof(*map), GFP_NOFS); |
| 627 | if (!map) { |
| 628 | free_extent_map(em); |
| 629 | return -ENOMEM; |
| 630 | } |
| 631 | |
| 632 | em->bdev = (struct block_device *)map; |
| 633 | em->start = logical; |
| 634 | em->len = length; |
| 635 | em->block_start = 0; |
| 636 | |
| 637 | map->physical = btrfs_stripe_offset_nr(leaf, chunk, 0); |
| 638 | devid = btrfs_stripe_devid_nr(leaf, chunk, 0); |
| 639 | map->dev = btrfs_find_device(root, devid); |
| 640 | if (!map->dev) { |
| 641 | kfree(map); |
| 642 | free_extent_map(em); |
| 643 | return -EIO; |
| 644 | } |
| 645 | |
| 646 | spin_lock(&map_tree->map_tree.lock); |
| 647 | ret = add_extent_mapping(&map_tree->map_tree, em); |
| 648 | BUG_ON(ret); |
| 649 | spin_unlock(&map_tree->map_tree.lock); |
| 650 | free_extent_map(em); |
| 651 | |
| 652 | return 0; |
| 653 | } |
| 654 | |
| 655 | static int fill_device_from_item(struct extent_buffer *leaf, |
| 656 | struct btrfs_dev_item *dev_item, |
| 657 | struct btrfs_device *device) |
| 658 | { |
| 659 | unsigned long ptr; |
| 660 | char *name; |
| 661 | |
| 662 | device->devid = btrfs_device_id(leaf, dev_item); |
| 663 | device->total_bytes = btrfs_device_total_bytes(leaf, dev_item); |
| 664 | device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); |
| 665 | device->type = btrfs_device_type(leaf, dev_item); |
| 666 | device->io_align = btrfs_device_io_align(leaf, dev_item); |
| 667 | device->io_width = btrfs_device_io_width(leaf, dev_item); |
| 668 | device->sector_size = btrfs_device_sector_size(leaf, dev_item); |
| 669 | device->rdev = btrfs_device_rdev(leaf, dev_item); |
| 670 | device->partition = btrfs_device_partition(leaf, dev_item); |
| 671 | device->name_len = btrfs_device_name_len(leaf, dev_item); |
| 672 | |
| 673 | ptr = (unsigned long)btrfs_device_uuid(dev_item); |
| 674 | read_extent_buffer(leaf, device->uuid, ptr, BTRFS_DEV_UUID_SIZE); |
| 675 | |
| 676 | name = kmalloc(device->name_len + 1, GFP_NOFS); |
| 677 | if (!name) |
| 678 | return -ENOMEM; |
| 679 | device->name = name; |
| 680 | ptr = (unsigned long)btrfs_device_name(dev_item); |
| 681 | read_extent_buffer(leaf, name, ptr, device->name_len); |
| 682 | name[device->name_len] = '\0'; |
| 683 | return 0; |
| 684 | } |
| 685 | |
| 686 | static int read_one_dev(struct btrfs_root *root, struct btrfs_key *key, |
| 687 | struct extent_buffer *leaf, |
| 688 | struct btrfs_dev_item *dev_item) |
| 689 | { |
| 690 | struct btrfs_device *device; |
| 691 | u64 devid; |
| 692 | int ret; |
| 693 | |
| 694 | devid = btrfs_device_id(leaf, dev_item); |
| 695 | if (btrfs_find_device(root, devid)) |
| 696 | return 0; |
| 697 | |
| 698 | device = kmalloc(sizeof(*device), GFP_NOFS); |
| 699 | if (!device) |
| 700 | return -ENOMEM; |
| 701 | |
| 702 | fill_device_from_item(leaf, dev_item, device); |
| 703 | device->dev_root = root->fs_info->dev_root; |
| 704 | device->bdev = root->fs_info->sb->s_bdev; |
| 705 | list_add(&device->dev_list, &root->fs_info->devices); |
| 706 | memcpy(&device->dev_key, key, sizeof(*key)); |
| 707 | ret = 0; |
| 708 | #if 0 |
| 709 | ret = btrfs_open_device(device); |
| 710 | if (ret) { |
| 711 | kfree(device); |
| 712 | } |
| 713 | #endif |
| 714 | return ret; |
| 715 | } |
| 716 | |
| 717 | int btrfs_read_sys_array(struct btrfs_root *root) |
| 718 | { |
| 719 | struct btrfs_super_block *super_copy = &root->fs_info->super_copy; |
| 720 | struct extent_buffer *sb = root->fs_info->sb_buffer; |
| 721 | struct btrfs_disk_key *disk_key; |
| 722 | struct btrfs_dev_item *dev_item; |
| 723 | struct btrfs_chunk *chunk; |
| 724 | struct btrfs_key key; |
| 725 | u32 num_stripes; |
| 726 | u32 array_size; |
| 727 | u32 len = 0; |
| 728 | u8 *ptr; |
| 729 | unsigned long sb_ptr; |
| 730 | u32 cur; |
| 731 | int ret; |
| 732 | int dev_only = 1; |
| 733 | |
| 734 | array_size = btrfs_super_sys_array_size(super_copy); |
| 735 | |
| 736 | /* |
| 737 | * we do this loop twice, once for the device items and |
| 738 | * once for all of the chunks. This way there are device |
| 739 | * structs filled in for every chunk |
| 740 | */ |
| 741 | again: |
| 742 | ptr = super_copy->sys_chunk_array; |
| 743 | sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array); |
| 744 | cur = 0; |
| 745 | |
| 746 | while (cur < array_size) { |
| 747 | disk_key = (struct btrfs_disk_key *)ptr; |
| 748 | btrfs_disk_key_to_cpu(&key, disk_key); |
| 749 | |
| 750 | len = sizeof(*disk_key); |
| 751 | ptr += len; |
| 752 | sb_ptr += len; |
| 753 | cur += len; |
| 754 | |
| 755 | if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID && |
| 756 | key.type == BTRFS_DEV_ITEM_KEY) { |
| 757 | dev_item = (struct btrfs_dev_item *)sb_ptr; |
| 758 | if (dev_only) { |
| 759 | ret = read_one_dev(root, &key, sb, dev_item); |
| 760 | BUG_ON(ret); |
| 761 | } |
| 762 | len = sizeof(*dev_item); |
| 763 | len += btrfs_device_name_len(sb, dev_item); |
| 764 | } else if (key.type == BTRFS_CHUNK_ITEM_KEY) { |
| 765 | |
| 766 | chunk = (struct btrfs_chunk *)sb_ptr; |
| 767 | if (!dev_only) { |
| 768 | ret = read_one_chunk(root, &key, sb, chunk); |
| 769 | BUG_ON(ret); |
| 770 | } |
| 771 | num_stripes = btrfs_chunk_num_stripes(sb, chunk); |
| 772 | len = btrfs_chunk_item_size(num_stripes); |
| 773 | } else { |
| 774 | BUG(); |
| 775 | } |
| 776 | ptr += len; |
| 777 | sb_ptr += len; |
| 778 | cur += len; |
| 779 | } |
| 780 | if (dev_only == 1) { |
| 781 | dev_only = 0; |
| 782 | goto again; |
| 783 | } |
| 784 | return 0; |
| 785 | } |
| 786 | |
| 787 | int btrfs_read_chunk_tree(struct btrfs_root *root) |
| 788 | { |
| 789 | struct btrfs_path *path; |
| 790 | struct extent_buffer *leaf; |
| 791 | struct btrfs_key key; |
| 792 | struct btrfs_key found_key; |
| 793 | int ret; |
| 794 | int slot; |
| 795 | |
| 796 | root = root->fs_info->chunk_root; |
| 797 | |
| 798 | path = btrfs_alloc_path(); |
| 799 | if (!path) |
| 800 | return -ENOMEM; |
| 801 | |
| 802 | /* first we search for all of the device items, and then we |
| 803 | * read in all of the chunk items. This way we can create chunk |
| 804 | * mappings that reference all of the devices that are afound |
| 805 | */ |
| 806 | key.objectid = BTRFS_DEV_ITEMS_OBJECTID; |
| 807 | key.offset = 0; |
| 808 | key.type = 0; |
| 809 | again: |
| 810 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 811 | while(1) { |
| 812 | leaf = path->nodes[0]; |
| 813 | slot = path->slots[0]; |
| 814 | if (slot >= btrfs_header_nritems(leaf)) { |
| 815 | ret = btrfs_next_leaf(root, path); |
| 816 | if (ret == 0) |
| 817 | continue; |
| 818 | if (ret < 0) |
| 819 | goto error; |
| 820 | break; |
| 821 | } |
| 822 | btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| 823 | if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { |
| 824 | if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID) |
| 825 | break; |
| 826 | if (found_key.type == BTRFS_DEV_ITEM_KEY) { |
| 827 | struct btrfs_dev_item *dev_item; |
| 828 | dev_item = btrfs_item_ptr(leaf, slot, |
| 829 | struct btrfs_dev_item); |
| 830 | ret = read_one_dev(root, &found_key, leaf, |
| 831 | dev_item); |
| 832 | BUG_ON(ret); |
| 833 | } |
| 834 | } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { |
| 835 | struct btrfs_chunk *chunk; |
| 836 | chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); |
| 837 | ret = read_one_chunk(root, &found_key, leaf, chunk); |
| 838 | } |
| 839 | path->slots[0]++; |
| 840 | } |
| 841 | if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) { |
| 842 | key.objectid = 0; |
| 843 | btrfs_release_path(root, path); |
| 844 | goto again; |
| 845 | } |
| 846 | |
| 847 | btrfs_free_path(path); |
| 848 | ret = 0; |
| 849 | error: |
| 850 | return ret; |
| 851 | } |
| 852 | |