| 1 | #include <linux/bitops.h> |
| 2 | #include <linux/slab.h> |
| 3 | #include <linux/bio.h> |
| 4 | #include <linux/mm.h> |
| 5 | #include <linux/pagemap.h> |
| 6 | #include <linux/page-flags.h> |
| 7 | #include <linux/spinlock.h> |
| 8 | #include <linux/blkdev.h> |
| 9 | #include <linux/swap.h> |
| 10 | #include <linux/writeback.h> |
| 11 | #include <linux/pagevec.h> |
| 12 | #include <linux/prefetch.h> |
| 13 | #include <linux/cleancache.h> |
| 14 | #include "extent_io.h" |
| 15 | #include "extent_map.h" |
| 16 | #include "ctree.h" |
| 17 | #include "btrfs_inode.h" |
| 18 | #include "volumes.h" |
| 19 | #include "check-integrity.h" |
| 20 | #include "locking.h" |
| 21 | #include "rcu-string.h" |
| 22 | #include "backref.h" |
| 23 | |
| 24 | static struct kmem_cache *extent_state_cache; |
| 25 | static struct kmem_cache *extent_buffer_cache; |
| 26 | static struct bio_set *btrfs_bioset; |
| 27 | |
| 28 | static inline bool extent_state_in_tree(const struct extent_state *state) |
| 29 | { |
| 30 | return !RB_EMPTY_NODE(&state->rb_node); |
| 31 | } |
| 32 | |
| 33 | #ifdef CONFIG_BTRFS_DEBUG |
| 34 | static LIST_HEAD(buffers); |
| 35 | static LIST_HEAD(states); |
| 36 | |
| 37 | static DEFINE_SPINLOCK(leak_lock); |
| 38 | |
| 39 | static inline |
| 40 | void btrfs_leak_debug_add(struct list_head *new, struct list_head *head) |
| 41 | { |
| 42 | unsigned long flags; |
| 43 | |
| 44 | spin_lock_irqsave(&leak_lock, flags); |
| 45 | list_add(new, head); |
| 46 | spin_unlock_irqrestore(&leak_lock, flags); |
| 47 | } |
| 48 | |
| 49 | static inline |
| 50 | void btrfs_leak_debug_del(struct list_head *entry) |
| 51 | { |
| 52 | unsigned long flags; |
| 53 | |
| 54 | spin_lock_irqsave(&leak_lock, flags); |
| 55 | list_del(entry); |
| 56 | spin_unlock_irqrestore(&leak_lock, flags); |
| 57 | } |
| 58 | |
| 59 | static inline |
| 60 | void btrfs_leak_debug_check(void) |
| 61 | { |
| 62 | struct extent_state *state; |
| 63 | struct extent_buffer *eb; |
| 64 | |
| 65 | while (!list_empty(&states)) { |
| 66 | state = list_entry(states.next, struct extent_state, leak_list); |
| 67 | pr_err("BTRFS: state leak: start %llu end %llu state %u in tree %d refs %d\n", |
| 68 | state->start, state->end, state->state, |
| 69 | extent_state_in_tree(state), |
| 70 | atomic_read(&state->refs)); |
| 71 | list_del(&state->leak_list); |
| 72 | kmem_cache_free(extent_state_cache, state); |
| 73 | } |
| 74 | |
| 75 | while (!list_empty(&buffers)) { |
| 76 | eb = list_entry(buffers.next, struct extent_buffer, leak_list); |
| 77 | printk(KERN_ERR "BTRFS: buffer leak start %llu len %lu " |
| 78 | "refs %d\n", |
| 79 | eb->start, eb->len, atomic_read(&eb->refs)); |
| 80 | list_del(&eb->leak_list); |
| 81 | kmem_cache_free(extent_buffer_cache, eb); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | #define btrfs_debug_check_extent_io_range(tree, start, end) \ |
| 86 | __btrfs_debug_check_extent_io_range(__func__, (tree), (start), (end)) |
| 87 | static inline void __btrfs_debug_check_extent_io_range(const char *caller, |
| 88 | struct extent_io_tree *tree, u64 start, u64 end) |
| 89 | { |
| 90 | struct inode *inode; |
| 91 | u64 isize; |
| 92 | |
| 93 | if (!tree->mapping) |
| 94 | return; |
| 95 | |
| 96 | inode = tree->mapping->host; |
| 97 | isize = i_size_read(inode); |
| 98 | if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) { |
| 99 | btrfs_debug_rl(BTRFS_I(inode)->root->fs_info, |
| 100 | "%s: ino %llu isize %llu odd range [%llu,%llu]", |
| 101 | caller, btrfs_ino(inode), isize, start, end); |
| 102 | } |
| 103 | } |
| 104 | #else |
| 105 | #define btrfs_leak_debug_add(new, head) do {} while (0) |
| 106 | #define btrfs_leak_debug_del(entry) do {} while (0) |
| 107 | #define btrfs_leak_debug_check() do {} while (0) |
| 108 | #define btrfs_debug_check_extent_io_range(c, s, e) do {} while (0) |
| 109 | #endif |
| 110 | |
| 111 | #define BUFFER_LRU_MAX 64 |
| 112 | |
| 113 | struct tree_entry { |
| 114 | u64 start; |
| 115 | u64 end; |
| 116 | struct rb_node rb_node; |
| 117 | }; |
| 118 | |
| 119 | struct extent_page_data { |
| 120 | struct bio *bio; |
| 121 | struct extent_io_tree *tree; |
| 122 | get_extent_t *get_extent; |
| 123 | unsigned long bio_flags; |
| 124 | |
| 125 | /* tells writepage not to lock the state bits for this range |
| 126 | * it still does the unlocking |
| 127 | */ |
| 128 | unsigned int extent_locked:1; |
| 129 | |
| 130 | /* tells the submit_bio code to use a WRITE_SYNC */ |
| 131 | unsigned int sync_io:1; |
| 132 | }; |
| 133 | |
| 134 | static void add_extent_changeset(struct extent_state *state, unsigned bits, |
| 135 | struct extent_changeset *changeset, |
| 136 | int set) |
| 137 | { |
| 138 | int ret; |
| 139 | |
| 140 | if (!changeset) |
| 141 | return; |
| 142 | if (set && (state->state & bits) == bits) |
| 143 | return; |
| 144 | if (!set && (state->state & bits) == 0) |
| 145 | return; |
| 146 | changeset->bytes_changed += state->end - state->start + 1; |
| 147 | ret = ulist_add(changeset->range_changed, state->start, state->end, |
| 148 | GFP_ATOMIC); |
| 149 | /* ENOMEM */ |
| 150 | BUG_ON(ret < 0); |
| 151 | } |
| 152 | |
| 153 | static noinline void flush_write_bio(void *data); |
| 154 | static inline struct btrfs_fs_info * |
| 155 | tree_fs_info(struct extent_io_tree *tree) |
| 156 | { |
| 157 | if (!tree->mapping) |
| 158 | return NULL; |
| 159 | return btrfs_sb(tree->mapping->host->i_sb); |
| 160 | } |
| 161 | |
| 162 | int __init extent_io_init(void) |
| 163 | { |
| 164 | extent_state_cache = kmem_cache_create("btrfs_extent_state", |
| 165 | sizeof(struct extent_state), 0, |
| 166 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); |
| 167 | if (!extent_state_cache) |
| 168 | return -ENOMEM; |
| 169 | |
| 170 | extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer", |
| 171 | sizeof(struct extent_buffer), 0, |
| 172 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); |
| 173 | if (!extent_buffer_cache) |
| 174 | goto free_state_cache; |
| 175 | |
| 176 | btrfs_bioset = bioset_create(BIO_POOL_SIZE, |
| 177 | offsetof(struct btrfs_io_bio, bio)); |
| 178 | if (!btrfs_bioset) |
| 179 | goto free_buffer_cache; |
| 180 | |
| 181 | if (bioset_integrity_create(btrfs_bioset, BIO_POOL_SIZE)) |
| 182 | goto free_bioset; |
| 183 | |
| 184 | return 0; |
| 185 | |
| 186 | free_bioset: |
| 187 | bioset_free(btrfs_bioset); |
| 188 | btrfs_bioset = NULL; |
| 189 | |
| 190 | free_buffer_cache: |
| 191 | kmem_cache_destroy(extent_buffer_cache); |
| 192 | extent_buffer_cache = NULL; |
| 193 | |
| 194 | free_state_cache: |
| 195 | kmem_cache_destroy(extent_state_cache); |
| 196 | extent_state_cache = NULL; |
| 197 | return -ENOMEM; |
| 198 | } |
| 199 | |
| 200 | void extent_io_exit(void) |
| 201 | { |
| 202 | btrfs_leak_debug_check(); |
| 203 | |
| 204 | /* |
| 205 | * Make sure all delayed rcu free are flushed before we |
| 206 | * destroy caches. |
| 207 | */ |
| 208 | rcu_barrier(); |
| 209 | kmem_cache_destroy(extent_state_cache); |
| 210 | kmem_cache_destroy(extent_buffer_cache); |
| 211 | if (btrfs_bioset) |
| 212 | bioset_free(btrfs_bioset); |
| 213 | } |
| 214 | |
| 215 | void extent_io_tree_init(struct extent_io_tree *tree, |
| 216 | struct address_space *mapping) |
| 217 | { |
| 218 | tree->state = RB_ROOT; |
| 219 | tree->ops = NULL; |
| 220 | tree->dirty_bytes = 0; |
| 221 | spin_lock_init(&tree->lock); |
| 222 | tree->mapping = mapping; |
| 223 | } |
| 224 | |
| 225 | static struct extent_state *alloc_extent_state(gfp_t mask) |
| 226 | { |
| 227 | struct extent_state *state; |
| 228 | |
| 229 | state = kmem_cache_alloc(extent_state_cache, mask); |
| 230 | if (!state) |
| 231 | return state; |
| 232 | state->state = 0; |
| 233 | state->failrec = NULL; |
| 234 | RB_CLEAR_NODE(&state->rb_node); |
| 235 | btrfs_leak_debug_add(&state->leak_list, &states); |
| 236 | atomic_set(&state->refs, 1); |
| 237 | init_waitqueue_head(&state->wq); |
| 238 | trace_alloc_extent_state(state, mask, _RET_IP_); |
| 239 | return state; |
| 240 | } |
| 241 | |
| 242 | void free_extent_state(struct extent_state *state) |
| 243 | { |
| 244 | if (!state) |
| 245 | return; |
| 246 | if (atomic_dec_and_test(&state->refs)) { |
| 247 | WARN_ON(extent_state_in_tree(state)); |
| 248 | btrfs_leak_debug_del(&state->leak_list); |
| 249 | trace_free_extent_state(state, _RET_IP_); |
| 250 | kmem_cache_free(extent_state_cache, state); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | static struct rb_node *tree_insert(struct rb_root *root, |
| 255 | struct rb_node *search_start, |
| 256 | u64 offset, |
| 257 | struct rb_node *node, |
| 258 | struct rb_node ***p_in, |
| 259 | struct rb_node **parent_in) |
| 260 | { |
| 261 | struct rb_node **p; |
| 262 | struct rb_node *parent = NULL; |
| 263 | struct tree_entry *entry; |
| 264 | |
| 265 | if (p_in && parent_in) { |
| 266 | p = *p_in; |
| 267 | parent = *parent_in; |
| 268 | goto do_insert; |
| 269 | } |
| 270 | |
| 271 | p = search_start ? &search_start : &root->rb_node; |
| 272 | while (*p) { |
| 273 | parent = *p; |
| 274 | entry = rb_entry(parent, struct tree_entry, rb_node); |
| 275 | |
| 276 | if (offset < entry->start) |
| 277 | p = &(*p)->rb_left; |
| 278 | else if (offset > entry->end) |
| 279 | p = &(*p)->rb_right; |
| 280 | else |
| 281 | return parent; |
| 282 | } |
| 283 | |
| 284 | do_insert: |
| 285 | rb_link_node(node, parent, p); |
| 286 | rb_insert_color(node, root); |
| 287 | return NULL; |
| 288 | } |
| 289 | |
| 290 | static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset, |
| 291 | struct rb_node **prev_ret, |
| 292 | struct rb_node **next_ret, |
| 293 | struct rb_node ***p_ret, |
| 294 | struct rb_node **parent_ret) |
| 295 | { |
| 296 | struct rb_root *root = &tree->state; |
| 297 | struct rb_node **n = &root->rb_node; |
| 298 | struct rb_node *prev = NULL; |
| 299 | struct rb_node *orig_prev = NULL; |
| 300 | struct tree_entry *entry; |
| 301 | struct tree_entry *prev_entry = NULL; |
| 302 | |
| 303 | while (*n) { |
| 304 | prev = *n; |
| 305 | entry = rb_entry(prev, struct tree_entry, rb_node); |
| 306 | prev_entry = entry; |
| 307 | |
| 308 | if (offset < entry->start) |
| 309 | n = &(*n)->rb_left; |
| 310 | else if (offset > entry->end) |
| 311 | n = &(*n)->rb_right; |
| 312 | else |
| 313 | return *n; |
| 314 | } |
| 315 | |
| 316 | if (p_ret) |
| 317 | *p_ret = n; |
| 318 | if (parent_ret) |
| 319 | *parent_ret = prev; |
| 320 | |
| 321 | if (prev_ret) { |
| 322 | orig_prev = prev; |
| 323 | while (prev && offset > prev_entry->end) { |
| 324 | prev = rb_next(prev); |
| 325 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
| 326 | } |
| 327 | *prev_ret = prev; |
| 328 | prev = orig_prev; |
| 329 | } |
| 330 | |
| 331 | if (next_ret) { |
| 332 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
| 333 | while (prev && offset < prev_entry->start) { |
| 334 | prev = rb_prev(prev); |
| 335 | prev_entry = rb_entry(prev, struct tree_entry, rb_node); |
| 336 | } |
| 337 | *next_ret = prev; |
| 338 | } |
| 339 | return NULL; |
| 340 | } |
| 341 | |
| 342 | static inline struct rb_node * |
| 343 | tree_search_for_insert(struct extent_io_tree *tree, |
| 344 | u64 offset, |
| 345 | struct rb_node ***p_ret, |
| 346 | struct rb_node **parent_ret) |
| 347 | { |
| 348 | struct rb_node *prev = NULL; |
| 349 | struct rb_node *ret; |
| 350 | |
| 351 | ret = __etree_search(tree, offset, &prev, NULL, p_ret, parent_ret); |
| 352 | if (!ret) |
| 353 | return prev; |
| 354 | return ret; |
| 355 | } |
| 356 | |
| 357 | static inline struct rb_node *tree_search(struct extent_io_tree *tree, |
| 358 | u64 offset) |
| 359 | { |
| 360 | return tree_search_for_insert(tree, offset, NULL, NULL); |
| 361 | } |
| 362 | |
| 363 | static void merge_cb(struct extent_io_tree *tree, struct extent_state *new, |
| 364 | struct extent_state *other) |
| 365 | { |
| 366 | if (tree->ops && tree->ops->merge_extent_hook) |
| 367 | tree->ops->merge_extent_hook(tree->mapping->host, new, |
| 368 | other); |
| 369 | } |
| 370 | |
| 371 | /* |
| 372 | * utility function to look for merge candidates inside a given range. |
| 373 | * Any extents with matching state are merged together into a single |
| 374 | * extent in the tree. Extents with EXTENT_IO in their state field |
| 375 | * are not merged because the end_io handlers need to be able to do |
| 376 | * operations on them without sleeping (or doing allocations/splits). |
| 377 | * |
| 378 | * This should be called with the tree lock held. |
| 379 | */ |
| 380 | static void merge_state(struct extent_io_tree *tree, |
| 381 | struct extent_state *state) |
| 382 | { |
| 383 | struct extent_state *other; |
| 384 | struct rb_node *other_node; |
| 385 | |
| 386 | if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) |
| 387 | return; |
| 388 | |
| 389 | other_node = rb_prev(&state->rb_node); |
| 390 | if (other_node) { |
| 391 | other = rb_entry(other_node, struct extent_state, rb_node); |
| 392 | if (other->end == state->start - 1 && |
| 393 | other->state == state->state) { |
| 394 | merge_cb(tree, state, other); |
| 395 | state->start = other->start; |
| 396 | rb_erase(&other->rb_node, &tree->state); |
| 397 | RB_CLEAR_NODE(&other->rb_node); |
| 398 | free_extent_state(other); |
| 399 | } |
| 400 | } |
| 401 | other_node = rb_next(&state->rb_node); |
| 402 | if (other_node) { |
| 403 | other = rb_entry(other_node, struct extent_state, rb_node); |
| 404 | if (other->start == state->end + 1 && |
| 405 | other->state == state->state) { |
| 406 | merge_cb(tree, state, other); |
| 407 | state->end = other->end; |
| 408 | rb_erase(&other->rb_node, &tree->state); |
| 409 | RB_CLEAR_NODE(&other->rb_node); |
| 410 | free_extent_state(other); |
| 411 | } |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | static void set_state_cb(struct extent_io_tree *tree, |
| 416 | struct extent_state *state, unsigned *bits) |
| 417 | { |
| 418 | if (tree->ops && tree->ops->set_bit_hook) |
| 419 | tree->ops->set_bit_hook(tree->mapping->host, state, bits); |
| 420 | } |
| 421 | |
| 422 | static void clear_state_cb(struct extent_io_tree *tree, |
| 423 | struct extent_state *state, unsigned *bits) |
| 424 | { |
| 425 | if (tree->ops && tree->ops->clear_bit_hook) |
| 426 | tree->ops->clear_bit_hook(tree->mapping->host, state, bits); |
| 427 | } |
| 428 | |
| 429 | static void set_state_bits(struct extent_io_tree *tree, |
| 430 | struct extent_state *state, unsigned *bits, |
| 431 | struct extent_changeset *changeset); |
| 432 | |
| 433 | /* |
| 434 | * insert an extent_state struct into the tree. 'bits' are set on the |
| 435 | * struct before it is inserted. |
| 436 | * |
| 437 | * This may return -EEXIST if the extent is already there, in which case the |
| 438 | * state struct is freed. |
| 439 | * |
| 440 | * The tree lock is not taken internally. This is a utility function and |
| 441 | * probably isn't what you want to call (see set/clear_extent_bit). |
| 442 | */ |
| 443 | static int insert_state(struct extent_io_tree *tree, |
| 444 | struct extent_state *state, u64 start, u64 end, |
| 445 | struct rb_node ***p, |
| 446 | struct rb_node **parent, |
| 447 | unsigned *bits, struct extent_changeset *changeset) |
| 448 | { |
| 449 | struct rb_node *node; |
| 450 | |
| 451 | if (end < start) |
| 452 | WARN(1, KERN_ERR "BTRFS: end < start %llu %llu\n", |
| 453 | end, start); |
| 454 | state->start = start; |
| 455 | state->end = end; |
| 456 | |
| 457 | set_state_bits(tree, state, bits, changeset); |
| 458 | |
| 459 | node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent); |
| 460 | if (node) { |
| 461 | struct extent_state *found; |
| 462 | found = rb_entry(node, struct extent_state, rb_node); |
| 463 | printk(KERN_ERR "BTRFS: found node %llu %llu on insert of " |
| 464 | "%llu %llu\n", |
| 465 | found->start, found->end, start, end); |
| 466 | return -EEXIST; |
| 467 | } |
| 468 | merge_state(tree, state); |
| 469 | return 0; |
| 470 | } |
| 471 | |
| 472 | static void split_cb(struct extent_io_tree *tree, struct extent_state *orig, |
| 473 | u64 split) |
| 474 | { |
| 475 | if (tree->ops && tree->ops->split_extent_hook) |
| 476 | tree->ops->split_extent_hook(tree->mapping->host, orig, split); |
| 477 | } |
| 478 | |
| 479 | /* |
| 480 | * split a given extent state struct in two, inserting the preallocated |
| 481 | * struct 'prealloc' as the newly created second half. 'split' indicates an |
| 482 | * offset inside 'orig' where it should be split. |
| 483 | * |
| 484 | * Before calling, |
| 485 | * the tree has 'orig' at [orig->start, orig->end]. After calling, there |
| 486 | * are two extent state structs in the tree: |
| 487 | * prealloc: [orig->start, split - 1] |
| 488 | * orig: [ split, orig->end ] |
| 489 | * |
| 490 | * The tree locks are not taken by this function. They need to be held |
| 491 | * by the caller. |
| 492 | */ |
| 493 | static int split_state(struct extent_io_tree *tree, struct extent_state *orig, |
| 494 | struct extent_state *prealloc, u64 split) |
| 495 | { |
| 496 | struct rb_node *node; |
| 497 | |
| 498 | split_cb(tree, orig, split); |
| 499 | |
| 500 | prealloc->start = orig->start; |
| 501 | prealloc->end = split - 1; |
| 502 | prealloc->state = orig->state; |
| 503 | orig->start = split; |
| 504 | |
| 505 | node = tree_insert(&tree->state, &orig->rb_node, prealloc->end, |
| 506 | &prealloc->rb_node, NULL, NULL); |
| 507 | if (node) { |
| 508 | free_extent_state(prealloc); |
| 509 | return -EEXIST; |
| 510 | } |
| 511 | return 0; |
| 512 | } |
| 513 | |
| 514 | static struct extent_state *next_state(struct extent_state *state) |
| 515 | { |
| 516 | struct rb_node *next = rb_next(&state->rb_node); |
| 517 | if (next) |
| 518 | return rb_entry(next, struct extent_state, rb_node); |
| 519 | else |
| 520 | return NULL; |
| 521 | } |
| 522 | |
| 523 | /* |
| 524 | * utility function to clear some bits in an extent state struct. |
| 525 | * it will optionally wake up any one waiting on this state (wake == 1). |
| 526 | * |
| 527 | * If no bits are set on the state struct after clearing things, the |
| 528 | * struct is freed and removed from the tree |
| 529 | */ |
| 530 | static struct extent_state *clear_state_bit(struct extent_io_tree *tree, |
| 531 | struct extent_state *state, |
| 532 | unsigned *bits, int wake, |
| 533 | struct extent_changeset *changeset) |
| 534 | { |
| 535 | struct extent_state *next; |
| 536 | unsigned bits_to_clear = *bits & ~EXTENT_CTLBITS; |
| 537 | |
| 538 | if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) { |
| 539 | u64 range = state->end - state->start + 1; |
| 540 | WARN_ON(range > tree->dirty_bytes); |
| 541 | tree->dirty_bytes -= range; |
| 542 | } |
| 543 | clear_state_cb(tree, state, bits); |
| 544 | add_extent_changeset(state, bits_to_clear, changeset, 0); |
| 545 | state->state &= ~bits_to_clear; |
| 546 | if (wake) |
| 547 | wake_up(&state->wq); |
| 548 | if (state->state == 0) { |
| 549 | next = next_state(state); |
| 550 | if (extent_state_in_tree(state)) { |
| 551 | rb_erase(&state->rb_node, &tree->state); |
| 552 | RB_CLEAR_NODE(&state->rb_node); |
| 553 | free_extent_state(state); |
| 554 | } else { |
| 555 | WARN_ON(1); |
| 556 | } |
| 557 | } else { |
| 558 | merge_state(tree, state); |
| 559 | next = next_state(state); |
| 560 | } |
| 561 | return next; |
| 562 | } |
| 563 | |
| 564 | static struct extent_state * |
| 565 | alloc_extent_state_atomic(struct extent_state *prealloc) |
| 566 | { |
| 567 | if (!prealloc) |
| 568 | prealloc = alloc_extent_state(GFP_ATOMIC); |
| 569 | |
| 570 | return prealloc; |
| 571 | } |
| 572 | |
| 573 | static void extent_io_tree_panic(struct extent_io_tree *tree, int err) |
| 574 | { |
| 575 | btrfs_panic(tree_fs_info(tree), err, "Locking error: " |
| 576 | "Extent tree was modified by another " |
| 577 | "thread while locked."); |
| 578 | } |
| 579 | |
| 580 | /* |
| 581 | * clear some bits on a range in the tree. This may require splitting |
| 582 | * or inserting elements in the tree, so the gfp mask is used to |
| 583 | * indicate which allocations or sleeping are allowed. |
| 584 | * |
| 585 | * pass 'wake' == 1 to kick any sleepers, and 'delete' == 1 to remove |
| 586 | * the given range from the tree regardless of state (ie for truncate). |
| 587 | * |
| 588 | * the range [start, end] is inclusive. |
| 589 | * |
| 590 | * This takes the tree lock, and returns 0 on success and < 0 on error. |
| 591 | */ |
| 592 | static int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 593 | unsigned bits, int wake, int delete, |
| 594 | struct extent_state **cached_state, |
| 595 | gfp_t mask, struct extent_changeset *changeset) |
| 596 | { |
| 597 | struct extent_state *state; |
| 598 | struct extent_state *cached; |
| 599 | struct extent_state *prealloc = NULL; |
| 600 | struct rb_node *node; |
| 601 | u64 last_end; |
| 602 | int err; |
| 603 | int clear = 0; |
| 604 | |
| 605 | btrfs_debug_check_extent_io_range(tree, start, end); |
| 606 | |
| 607 | if (bits & EXTENT_DELALLOC) |
| 608 | bits |= EXTENT_NORESERVE; |
| 609 | |
| 610 | if (delete) |
| 611 | bits |= ~EXTENT_CTLBITS; |
| 612 | bits |= EXTENT_FIRST_DELALLOC; |
| 613 | |
| 614 | if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY)) |
| 615 | clear = 1; |
| 616 | again: |
| 617 | if (!prealloc && gfpflags_allow_blocking(mask)) { |
| 618 | /* |
| 619 | * Don't care for allocation failure here because we might end |
| 620 | * up not needing the pre-allocated extent state at all, which |
| 621 | * is the case if we only have in the tree extent states that |
| 622 | * cover our input range and don't cover too any other range. |
| 623 | * If we end up needing a new extent state we allocate it later. |
| 624 | */ |
| 625 | prealloc = alloc_extent_state(mask); |
| 626 | } |
| 627 | |
| 628 | spin_lock(&tree->lock); |
| 629 | if (cached_state) { |
| 630 | cached = *cached_state; |
| 631 | |
| 632 | if (clear) { |
| 633 | *cached_state = NULL; |
| 634 | cached_state = NULL; |
| 635 | } |
| 636 | |
| 637 | if (cached && extent_state_in_tree(cached) && |
| 638 | cached->start <= start && cached->end > start) { |
| 639 | if (clear) |
| 640 | atomic_dec(&cached->refs); |
| 641 | state = cached; |
| 642 | goto hit_next; |
| 643 | } |
| 644 | if (clear) |
| 645 | free_extent_state(cached); |
| 646 | } |
| 647 | /* |
| 648 | * this search will find the extents that end after |
| 649 | * our range starts |
| 650 | */ |
| 651 | node = tree_search(tree, start); |
| 652 | if (!node) |
| 653 | goto out; |
| 654 | state = rb_entry(node, struct extent_state, rb_node); |
| 655 | hit_next: |
| 656 | if (state->start > end) |
| 657 | goto out; |
| 658 | WARN_ON(state->end < start); |
| 659 | last_end = state->end; |
| 660 | |
| 661 | /* the state doesn't have the wanted bits, go ahead */ |
| 662 | if (!(state->state & bits)) { |
| 663 | state = next_state(state); |
| 664 | goto next; |
| 665 | } |
| 666 | |
| 667 | /* |
| 668 | * | ---- desired range ---- | |
| 669 | * | state | or |
| 670 | * | ------------- state -------------- | |
| 671 | * |
| 672 | * We need to split the extent we found, and may flip |
| 673 | * bits on second half. |
| 674 | * |
| 675 | * If the extent we found extends past our range, we |
| 676 | * just split and search again. It'll get split again |
| 677 | * the next time though. |
| 678 | * |
| 679 | * If the extent we found is inside our range, we clear |
| 680 | * the desired bit on it. |
| 681 | */ |
| 682 | |
| 683 | if (state->start < start) { |
| 684 | prealloc = alloc_extent_state_atomic(prealloc); |
| 685 | BUG_ON(!prealloc); |
| 686 | err = split_state(tree, state, prealloc, start); |
| 687 | if (err) |
| 688 | extent_io_tree_panic(tree, err); |
| 689 | |
| 690 | prealloc = NULL; |
| 691 | if (err) |
| 692 | goto out; |
| 693 | if (state->end <= end) { |
| 694 | state = clear_state_bit(tree, state, &bits, wake, |
| 695 | changeset); |
| 696 | goto next; |
| 697 | } |
| 698 | goto search_again; |
| 699 | } |
| 700 | /* |
| 701 | * | ---- desired range ---- | |
| 702 | * | state | |
| 703 | * We need to split the extent, and clear the bit |
| 704 | * on the first half |
| 705 | */ |
| 706 | if (state->start <= end && state->end > end) { |
| 707 | prealloc = alloc_extent_state_atomic(prealloc); |
| 708 | BUG_ON(!prealloc); |
| 709 | err = split_state(tree, state, prealloc, end + 1); |
| 710 | if (err) |
| 711 | extent_io_tree_panic(tree, err); |
| 712 | |
| 713 | if (wake) |
| 714 | wake_up(&state->wq); |
| 715 | |
| 716 | clear_state_bit(tree, prealloc, &bits, wake, changeset); |
| 717 | |
| 718 | prealloc = NULL; |
| 719 | goto out; |
| 720 | } |
| 721 | |
| 722 | state = clear_state_bit(tree, state, &bits, wake, changeset); |
| 723 | next: |
| 724 | if (last_end == (u64)-1) |
| 725 | goto out; |
| 726 | start = last_end + 1; |
| 727 | if (start <= end && state && !need_resched()) |
| 728 | goto hit_next; |
| 729 | goto search_again; |
| 730 | |
| 731 | out: |
| 732 | spin_unlock(&tree->lock); |
| 733 | if (prealloc) |
| 734 | free_extent_state(prealloc); |
| 735 | |
| 736 | return 0; |
| 737 | |
| 738 | search_again: |
| 739 | if (start > end) |
| 740 | goto out; |
| 741 | spin_unlock(&tree->lock); |
| 742 | if (gfpflags_allow_blocking(mask)) |
| 743 | cond_resched(); |
| 744 | goto again; |
| 745 | } |
| 746 | |
| 747 | static void wait_on_state(struct extent_io_tree *tree, |
| 748 | struct extent_state *state) |
| 749 | __releases(tree->lock) |
| 750 | __acquires(tree->lock) |
| 751 | { |
| 752 | DEFINE_WAIT(wait); |
| 753 | prepare_to_wait(&state->wq, &wait, TASK_UNINTERRUPTIBLE); |
| 754 | spin_unlock(&tree->lock); |
| 755 | schedule(); |
| 756 | spin_lock(&tree->lock); |
| 757 | finish_wait(&state->wq, &wait); |
| 758 | } |
| 759 | |
| 760 | /* |
| 761 | * waits for one or more bits to clear on a range in the state tree. |
| 762 | * The range [start, end] is inclusive. |
| 763 | * The tree lock is taken by this function |
| 764 | */ |
| 765 | static void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 766 | unsigned long bits) |
| 767 | { |
| 768 | struct extent_state *state; |
| 769 | struct rb_node *node; |
| 770 | |
| 771 | btrfs_debug_check_extent_io_range(tree, start, end); |
| 772 | |
| 773 | spin_lock(&tree->lock); |
| 774 | again: |
| 775 | while (1) { |
| 776 | /* |
| 777 | * this search will find all the extents that end after |
| 778 | * our range starts |
| 779 | */ |
| 780 | node = tree_search(tree, start); |
| 781 | process_node: |
| 782 | if (!node) |
| 783 | break; |
| 784 | |
| 785 | state = rb_entry(node, struct extent_state, rb_node); |
| 786 | |
| 787 | if (state->start > end) |
| 788 | goto out; |
| 789 | |
| 790 | if (state->state & bits) { |
| 791 | start = state->start; |
| 792 | atomic_inc(&state->refs); |
| 793 | wait_on_state(tree, state); |
| 794 | free_extent_state(state); |
| 795 | goto again; |
| 796 | } |
| 797 | start = state->end + 1; |
| 798 | |
| 799 | if (start > end) |
| 800 | break; |
| 801 | |
| 802 | if (!cond_resched_lock(&tree->lock)) { |
| 803 | node = rb_next(node); |
| 804 | goto process_node; |
| 805 | } |
| 806 | } |
| 807 | out: |
| 808 | spin_unlock(&tree->lock); |
| 809 | } |
| 810 | |
| 811 | static void set_state_bits(struct extent_io_tree *tree, |
| 812 | struct extent_state *state, |
| 813 | unsigned *bits, struct extent_changeset *changeset) |
| 814 | { |
| 815 | unsigned bits_to_set = *bits & ~EXTENT_CTLBITS; |
| 816 | |
| 817 | set_state_cb(tree, state, bits); |
| 818 | if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) { |
| 819 | u64 range = state->end - state->start + 1; |
| 820 | tree->dirty_bytes += range; |
| 821 | } |
| 822 | add_extent_changeset(state, bits_to_set, changeset, 1); |
| 823 | state->state |= bits_to_set; |
| 824 | } |
| 825 | |
| 826 | static void cache_state_if_flags(struct extent_state *state, |
| 827 | struct extent_state **cached_ptr, |
| 828 | unsigned flags) |
| 829 | { |
| 830 | if (cached_ptr && !(*cached_ptr)) { |
| 831 | if (!flags || (state->state & flags)) { |
| 832 | *cached_ptr = state; |
| 833 | atomic_inc(&state->refs); |
| 834 | } |
| 835 | } |
| 836 | } |
| 837 | |
| 838 | static void cache_state(struct extent_state *state, |
| 839 | struct extent_state **cached_ptr) |
| 840 | { |
| 841 | return cache_state_if_flags(state, cached_ptr, |
| 842 | EXTENT_IOBITS | EXTENT_BOUNDARY); |
| 843 | } |
| 844 | |
| 845 | /* |
| 846 | * set some bits on a range in the tree. This may require allocations or |
| 847 | * sleeping, so the gfp mask is used to indicate what is allowed. |
| 848 | * |
| 849 | * If any of the exclusive bits are set, this will fail with -EEXIST if some |
| 850 | * part of the range already has the desired bits set. The start of the |
| 851 | * existing range is returned in failed_start in this case. |
| 852 | * |
| 853 | * [start, end] is inclusive This takes the tree lock. |
| 854 | */ |
| 855 | |
| 856 | static int __must_check |
| 857 | __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 858 | unsigned bits, unsigned exclusive_bits, |
| 859 | u64 *failed_start, struct extent_state **cached_state, |
| 860 | gfp_t mask, struct extent_changeset *changeset) |
| 861 | { |
| 862 | struct extent_state *state; |
| 863 | struct extent_state *prealloc = NULL; |
| 864 | struct rb_node *node; |
| 865 | struct rb_node **p; |
| 866 | struct rb_node *parent; |
| 867 | int err = 0; |
| 868 | u64 last_start; |
| 869 | u64 last_end; |
| 870 | |
| 871 | btrfs_debug_check_extent_io_range(tree, start, end); |
| 872 | |
| 873 | bits |= EXTENT_FIRST_DELALLOC; |
| 874 | again: |
| 875 | if (!prealloc && gfpflags_allow_blocking(mask)) { |
| 876 | prealloc = alloc_extent_state(mask); |
| 877 | BUG_ON(!prealloc); |
| 878 | } |
| 879 | |
| 880 | spin_lock(&tree->lock); |
| 881 | if (cached_state && *cached_state) { |
| 882 | state = *cached_state; |
| 883 | if (state->start <= start && state->end > start && |
| 884 | extent_state_in_tree(state)) { |
| 885 | node = &state->rb_node; |
| 886 | goto hit_next; |
| 887 | } |
| 888 | } |
| 889 | /* |
| 890 | * this search will find all the extents that end after |
| 891 | * our range starts. |
| 892 | */ |
| 893 | node = tree_search_for_insert(tree, start, &p, &parent); |
| 894 | if (!node) { |
| 895 | prealloc = alloc_extent_state_atomic(prealloc); |
| 896 | BUG_ON(!prealloc); |
| 897 | err = insert_state(tree, prealloc, start, end, |
| 898 | &p, &parent, &bits, changeset); |
| 899 | if (err) |
| 900 | extent_io_tree_panic(tree, err); |
| 901 | |
| 902 | cache_state(prealloc, cached_state); |
| 903 | prealloc = NULL; |
| 904 | goto out; |
| 905 | } |
| 906 | state = rb_entry(node, struct extent_state, rb_node); |
| 907 | hit_next: |
| 908 | last_start = state->start; |
| 909 | last_end = state->end; |
| 910 | |
| 911 | /* |
| 912 | * | ---- desired range ---- | |
| 913 | * | state | |
| 914 | * |
| 915 | * Just lock what we found and keep going |
| 916 | */ |
| 917 | if (state->start == start && state->end <= end) { |
| 918 | if (state->state & exclusive_bits) { |
| 919 | *failed_start = state->start; |
| 920 | err = -EEXIST; |
| 921 | goto out; |
| 922 | } |
| 923 | |
| 924 | set_state_bits(tree, state, &bits, changeset); |
| 925 | cache_state(state, cached_state); |
| 926 | merge_state(tree, state); |
| 927 | if (last_end == (u64)-1) |
| 928 | goto out; |
| 929 | start = last_end + 1; |
| 930 | state = next_state(state); |
| 931 | if (start < end && state && state->start == start && |
| 932 | !need_resched()) |
| 933 | goto hit_next; |
| 934 | goto search_again; |
| 935 | } |
| 936 | |
| 937 | /* |
| 938 | * | ---- desired range ---- | |
| 939 | * | state | |
| 940 | * or |
| 941 | * | ------------- state -------------- | |
| 942 | * |
| 943 | * We need to split the extent we found, and may flip bits on |
| 944 | * second half. |
| 945 | * |
| 946 | * If the extent we found extends past our |
| 947 | * range, we just split and search again. It'll get split |
| 948 | * again the next time though. |
| 949 | * |
| 950 | * If the extent we found is inside our range, we set the |
| 951 | * desired bit on it. |
| 952 | */ |
| 953 | if (state->start < start) { |
| 954 | if (state->state & exclusive_bits) { |
| 955 | *failed_start = start; |
| 956 | err = -EEXIST; |
| 957 | goto out; |
| 958 | } |
| 959 | |
| 960 | prealloc = alloc_extent_state_atomic(prealloc); |
| 961 | BUG_ON(!prealloc); |
| 962 | err = split_state(tree, state, prealloc, start); |
| 963 | if (err) |
| 964 | extent_io_tree_panic(tree, err); |
| 965 | |
| 966 | prealloc = NULL; |
| 967 | if (err) |
| 968 | goto out; |
| 969 | if (state->end <= end) { |
| 970 | set_state_bits(tree, state, &bits, changeset); |
| 971 | cache_state(state, cached_state); |
| 972 | merge_state(tree, state); |
| 973 | if (last_end == (u64)-1) |
| 974 | goto out; |
| 975 | start = last_end + 1; |
| 976 | state = next_state(state); |
| 977 | if (start < end && state && state->start == start && |
| 978 | !need_resched()) |
| 979 | goto hit_next; |
| 980 | } |
| 981 | goto search_again; |
| 982 | } |
| 983 | /* |
| 984 | * | ---- desired range ---- | |
| 985 | * | state | or | state | |
| 986 | * |
| 987 | * There's a hole, we need to insert something in it and |
| 988 | * ignore the extent we found. |
| 989 | */ |
| 990 | if (state->start > start) { |
| 991 | u64 this_end; |
| 992 | if (end < last_start) |
| 993 | this_end = end; |
| 994 | else |
| 995 | this_end = last_start - 1; |
| 996 | |
| 997 | prealloc = alloc_extent_state_atomic(prealloc); |
| 998 | BUG_ON(!prealloc); |
| 999 | |
| 1000 | /* |
| 1001 | * Avoid to free 'prealloc' if it can be merged with |
| 1002 | * the later extent. |
| 1003 | */ |
| 1004 | err = insert_state(tree, prealloc, start, this_end, |
| 1005 | NULL, NULL, &bits, changeset); |
| 1006 | if (err) |
| 1007 | extent_io_tree_panic(tree, err); |
| 1008 | |
| 1009 | cache_state(prealloc, cached_state); |
| 1010 | prealloc = NULL; |
| 1011 | start = this_end + 1; |
| 1012 | goto search_again; |
| 1013 | } |
| 1014 | /* |
| 1015 | * | ---- desired range ---- | |
| 1016 | * | state | |
| 1017 | * We need to split the extent, and set the bit |
| 1018 | * on the first half |
| 1019 | */ |
| 1020 | if (state->start <= end && state->end > end) { |
| 1021 | if (state->state & exclusive_bits) { |
| 1022 | *failed_start = start; |
| 1023 | err = -EEXIST; |
| 1024 | goto out; |
| 1025 | } |
| 1026 | |
| 1027 | prealloc = alloc_extent_state_atomic(prealloc); |
| 1028 | BUG_ON(!prealloc); |
| 1029 | err = split_state(tree, state, prealloc, end + 1); |
| 1030 | if (err) |
| 1031 | extent_io_tree_panic(tree, err); |
| 1032 | |
| 1033 | set_state_bits(tree, prealloc, &bits, changeset); |
| 1034 | cache_state(prealloc, cached_state); |
| 1035 | merge_state(tree, prealloc); |
| 1036 | prealloc = NULL; |
| 1037 | goto out; |
| 1038 | } |
| 1039 | |
| 1040 | goto search_again; |
| 1041 | |
| 1042 | out: |
| 1043 | spin_unlock(&tree->lock); |
| 1044 | if (prealloc) |
| 1045 | free_extent_state(prealloc); |
| 1046 | |
| 1047 | return err; |
| 1048 | |
| 1049 | search_again: |
| 1050 | if (start > end) |
| 1051 | goto out; |
| 1052 | spin_unlock(&tree->lock); |
| 1053 | if (gfpflags_allow_blocking(mask)) |
| 1054 | cond_resched(); |
| 1055 | goto again; |
| 1056 | } |
| 1057 | |
| 1058 | int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 1059 | unsigned bits, u64 * failed_start, |
| 1060 | struct extent_state **cached_state, gfp_t mask) |
| 1061 | { |
| 1062 | return __set_extent_bit(tree, start, end, bits, 0, failed_start, |
| 1063 | cached_state, mask, NULL); |
| 1064 | } |
| 1065 | |
| 1066 | |
| 1067 | /** |
| 1068 | * convert_extent_bit - convert all bits in a given range from one bit to |
| 1069 | * another |
| 1070 | * @tree: the io tree to search |
| 1071 | * @start: the start offset in bytes |
| 1072 | * @end: the end offset in bytes (inclusive) |
| 1073 | * @bits: the bits to set in this range |
| 1074 | * @clear_bits: the bits to clear in this range |
| 1075 | * @cached_state: state that we're going to cache |
| 1076 | * @mask: the allocation mask |
| 1077 | * |
| 1078 | * This will go through and set bits for the given range. If any states exist |
| 1079 | * already in this range they are set with the given bit and cleared of the |
| 1080 | * clear_bits. This is only meant to be used by things that are mergeable, ie |
| 1081 | * converting from say DELALLOC to DIRTY. This is not meant to be used with |
| 1082 | * boundary bits like LOCK. |
| 1083 | */ |
| 1084 | int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 1085 | unsigned bits, unsigned clear_bits, |
| 1086 | struct extent_state **cached_state, gfp_t mask) |
| 1087 | { |
| 1088 | struct extent_state *state; |
| 1089 | struct extent_state *prealloc = NULL; |
| 1090 | struct rb_node *node; |
| 1091 | struct rb_node **p; |
| 1092 | struct rb_node *parent; |
| 1093 | int err = 0; |
| 1094 | u64 last_start; |
| 1095 | u64 last_end; |
| 1096 | bool first_iteration = true; |
| 1097 | |
| 1098 | btrfs_debug_check_extent_io_range(tree, start, end); |
| 1099 | |
| 1100 | again: |
| 1101 | if (!prealloc && gfpflags_allow_blocking(mask)) { |
| 1102 | /* |
| 1103 | * Best effort, don't worry if extent state allocation fails |
| 1104 | * here for the first iteration. We might have a cached state |
| 1105 | * that matches exactly the target range, in which case no |
| 1106 | * extent state allocations are needed. We'll only know this |
| 1107 | * after locking the tree. |
| 1108 | */ |
| 1109 | prealloc = alloc_extent_state(mask); |
| 1110 | if (!prealloc && !first_iteration) |
| 1111 | return -ENOMEM; |
| 1112 | } |
| 1113 | |
| 1114 | spin_lock(&tree->lock); |
| 1115 | if (cached_state && *cached_state) { |
| 1116 | state = *cached_state; |
| 1117 | if (state->start <= start && state->end > start && |
| 1118 | extent_state_in_tree(state)) { |
| 1119 | node = &state->rb_node; |
| 1120 | goto hit_next; |
| 1121 | } |
| 1122 | } |
| 1123 | |
| 1124 | /* |
| 1125 | * this search will find all the extents that end after |
| 1126 | * our range starts. |
| 1127 | */ |
| 1128 | node = tree_search_for_insert(tree, start, &p, &parent); |
| 1129 | if (!node) { |
| 1130 | prealloc = alloc_extent_state_atomic(prealloc); |
| 1131 | if (!prealloc) { |
| 1132 | err = -ENOMEM; |
| 1133 | goto out; |
| 1134 | } |
| 1135 | err = insert_state(tree, prealloc, start, end, |
| 1136 | &p, &parent, &bits, NULL); |
| 1137 | if (err) |
| 1138 | extent_io_tree_panic(tree, err); |
| 1139 | cache_state(prealloc, cached_state); |
| 1140 | prealloc = NULL; |
| 1141 | goto out; |
| 1142 | } |
| 1143 | state = rb_entry(node, struct extent_state, rb_node); |
| 1144 | hit_next: |
| 1145 | last_start = state->start; |
| 1146 | last_end = state->end; |
| 1147 | |
| 1148 | /* |
| 1149 | * | ---- desired range ---- | |
| 1150 | * | state | |
| 1151 | * |
| 1152 | * Just lock what we found and keep going |
| 1153 | */ |
| 1154 | if (state->start == start && state->end <= end) { |
| 1155 | set_state_bits(tree, state, &bits, NULL); |
| 1156 | cache_state(state, cached_state); |
| 1157 | state = clear_state_bit(tree, state, &clear_bits, 0, NULL); |
| 1158 | if (last_end == (u64)-1) |
| 1159 | goto out; |
| 1160 | start = last_end + 1; |
| 1161 | if (start < end && state && state->start == start && |
| 1162 | !need_resched()) |
| 1163 | goto hit_next; |
| 1164 | goto search_again; |
| 1165 | } |
| 1166 | |
| 1167 | /* |
| 1168 | * | ---- desired range ---- | |
| 1169 | * | state | |
| 1170 | * or |
| 1171 | * | ------------- state -------------- | |
| 1172 | * |
| 1173 | * We need to split the extent we found, and may flip bits on |
| 1174 | * second half. |
| 1175 | * |
| 1176 | * If the extent we found extends past our |
| 1177 | * range, we just split and search again. It'll get split |
| 1178 | * again the next time though. |
| 1179 | * |
| 1180 | * If the extent we found is inside our range, we set the |
| 1181 | * desired bit on it. |
| 1182 | */ |
| 1183 | if (state->start < start) { |
| 1184 | prealloc = alloc_extent_state_atomic(prealloc); |
| 1185 | if (!prealloc) { |
| 1186 | err = -ENOMEM; |
| 1187 | goto out; |
| 1188 | } |
| 1189 | err = split_state(tree, state, prealloc, start); |
| 1190 | if (err) |
| 1191 | extent_io_tree_panic(tree, err); |
| 1192 | prealloc = NULL; |
| 1193 | if (err) |
| 1194 | goto out; |
| 1195 | if (state->end <= end) { |
| 1196 | set_state_bits(tree, state, &bits, NULL); |
| 1197 | cache_state(state, cached_state); |
| 1198 | state = clear_state_bit(tree, state, &clear_bits, 0, |
| 1199 | NULL); |
| 1200 | if (last_end == (u64)-1) |
| 1201 | goto out; |
| 1202 | start = last_end + 1; |
| 1203 | if (start < end && state && state->start == start && |
| 1204 | !need_resched()) |
| 1205 | goto hit_next; |
| 1206 | } |
| 1207 | goto search_again; |
| 1208 | } |
| 1209 | /* |
| 1210 | * | ---- desired range ---- | |
| 1211 | * | state | or | state | |
| 1212 | * |
| 1213 | * There's a hole, we need to insert something in it and |
| 1214 | * ignore the extent we found. |
| 1215 | */ |
| 1216 | if (state->start > start) { |
| 1217 | u64 this_end; |
| 1218 | if (end < last_start) |
| 1219 | this_end = end; |
| 1220 | else |
| 1221 | this_end = last_start - 1; |
| 1222 | |
| 1223 | prealloc = alloc_extent_state_atomic(prealloc); |
| 1224 | if (!prealloc) { |
| 1225 | err = -ENOMEM; |
| 1226 | goto out; |
| 1227 | } |
| 1228 | |
| 1229 | /* |
| 1230 | * Avoid to free 'prealloc' if it can be merged with |
| 1231 | * the later extent. |
| 1232 | */ |
| 1233 | err = insert_state(tree, prealloc, start, this_end, |
| 1234 | NULL, NULL, &bits, NULL); |
| 1235 | if (err) |
| 1236 | extent_io_tree_panic(tree, err); |
| 1237 | cache_state(prealloc, cached_state); |
| 1238 | prealloc = NULL; |
| 1239 | start = this_end + 1; |
| 1240 | goto search_again; |
| 1241 | } |
| 1242 | /* |
| 1243 | * | ---- desired range ---- | |
| 1244 | * | state | |
| 1245 | * We need to split the extent, and set the bit |
| 1246 | * on the first half |
| 1247 | */ |
| 1248 | if (state->start <= end && state->end > end) { |
| 1249 | prealloc = alloc_extent_state_atomic(prealloc); |
| 1250 | if (!prealloc) { |
| 1251 | err = -ENOMEM; |
| 1252 | goto out; |
| 1253 | } |
| 1254 | |
| 1255 | err = split_state(tree, state, prealloc, end + 1); |
| 1256 | if (err) |
| 1257 | extent_io_tree_panic(tree, err); |
| 1258 | |
| 1259 | set_state_bits(tree, prealloc, &bits, NULL); |
| 1260 | cache_state(prealloc, cached_state); |
| 1261 | clear_state_bit(tree, prealloc, &clear_bits, 0, NULL); |
| 1262 | prealloc = NULL; |
| 1263 | goto out; |
| 1264 | } |
| 1265 | |
| 1266 | goto search_again; |
| 1267 | |
| 1268 | out: |
| 1269 | spin_unlock(&tree->lock); |
| 1270 | if (prealloc) |
| 1271 | free_extent_state(prealloc); |
| 1272 | |
| 1273 | return err; |
| 1274 | |
| 1275 | search_again: |
| 1276 | if (start > end) |
| 1277 | goto out; |
| 1278 | spin_unlock(&tree->lock); |
| 1279 | if (gfpflags_allow_blocking(mask)) |
| 1280 | cond_resched(); |
| 1281 | first_iteration = false; |
| 1282 | goto again; |
| 1283 | } |
| 1284 | |
| 1285 | /* wrappers around set/clear extent bit */ |
| 1286 | int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, |
| 1287 | unsigned bits, gfp_t mask, |
| 1288 | struct extent_changeset *changeset) |
| 1289 | { |
| 1290 | /* |
| 1291 | * We don't support EXTENT_LOCKED yet, as current changeset will |
| 1292 | * record any bits changed, so for EXTENT_LOCKED case, it will |
| 1293 | * either fail with -EEXIST or changeset will record the whole |
| 1294 | * range. |
| 1295 | */ |
| 1296 | BUG_ON(bits & EXTENT_LOCKED); |
| 1297 | |
| 1298 | return __set_extent_bit(tree, start, end, bits, 0, NULL, NULL, mask, |
| 1299 | changeset); |
| 1300 | } |
| 1301 | |
| 1302 | int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 1303 | unsigned bits, int wake, int delete, |
| 1304 | struct extent_state **cached, gfp_t mask) |
| 1305 | { |
| 1306 | return __clear_extent_bit(tree, start, end, bits, wake, delete, |
| 1307 | cached, mask, NULL); |
| 1308 | } |
| 1309 | |
| 1310 | int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, |
| 1311 | unsigned bits, gfp_t mask, |
| 1312 | struct extent_changeset *changeset) |
| 1313 | { |
| 1314 | /* |
| 1315 | * Don't support EXTENT_LOCKED case, same reason as |
| 1316 | * set_record_extent_bits(). |
| 1317 | */ |
| 1318 | BUG_ON(bits & EXTENT_LOCKED); |
| 1319 | |
| 1320 | return __clear_extent_bit(tree, start, end, bits, 0, 0, NULL, mask, |
| 1321 | changeset); |
| 1322 | } |
| 1323 | |
| 1324 | /* |
| 1325 | * either insert or lock state struct between start and end use mask to tell |
| 1326 | * us if waiting is desired. |
| 1327 | */ |
| 1328 | int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, |
| 1329 | struct extent_state **cached_state) |
| 1330 | { |
| 1331 | int err; |
| 1332 | u64 failed_start; |
| 1333 | |
| 1334 | while (1) { |
| 1335 | err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, |
| 1336 | EXTENT_LOCKED, &failed_start, |
| 1337 | cached_state, GFP_NOFS, NULL); |
| 1338 | if (err == -EEXIST) { |
| 1339 | wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); |
| 1340 | start = failed_start; |
| 1341 | } else |
| 1342 | break; |
| 1343 | WARN_ON(start > end); |
| 1344 | } |
| 1345 | return err; |
| 1346 | } |
| 1347 | |
| 1348 | int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end) |
| 1349 | { |
| 1350 | int err; |
| 1351 | u64 failed_start; |
| 1352 | |
| 1353 | err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED, |
| 1354 | &failed_start, NULL, GFP_NOFS, NULL); |
| 1355 | if (err == -EEXIST) { |
| 1356 | if (failed_start > start) |
| 1357 | clear_extent_bit(tree, start, failed_start - 1, |
| 1358 | EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS); |
| 1359 | return 0; |
| 1360 | } |
| 1361 | return 1; |
| 1362 | } |
| 1363 | |
| 1364 | void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end) |
| 1365 | { |
| 1366 | unsigned long index = start >> PAGE_SHIFT; |
| 1367 | unsigned long end_index = end >> PAGE_SHIFT; |
| 1368 | struct page *page; |
| 1369 | |
| 1370 | while (index <= end_index) { |
| 1371 | page = find_get_page(inode->i_mapping, index); |
| 1372 | BUG_ON(!page); /* Pages should be in the extent_io_tree */ |
| 1373 | clear_page_dirty_for_io(page); |
| 1374 | put_page(page); |
| 1375 | index++; |
| 1376 | } |
| 1377 | } |
| 1378 | |
| 1379 | void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end) |
| 1380 | { |
| 1381 | unsigned long index = start >> PAGE_SHIFT; |
| 1382 | unsigned long end_index = end >> PAGE_SHIFT; |
| 1383 | struct page *page; |
| 1384 | |
| 1385 | while (index <= end_index) { |
| 1386 | page = find_get_page(inode->i_mapping, index); |
| 1387 | BUG_ON(!page); /* Pages should be in the extent_io_tree */ |
| 1388 | __set_page_dirty_nobuffers(page); |
| 1389 | account_page_redirty(page); |
| 1390 | put_page(page); |
| 1391 | index++; |
| 1392 | } |
| 1393 | } |
| 1394 | |
| 1395 | /* |
| 1396 | * helper function to set both pages and extents in the tree writeback |
| 1397 | */ |
| 1398 | static void set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end) |
| 1399 | { |
| 1400 | unsigned long index = start >> PAGE_SHIFT; |
| 1401 | unsigned long end_index = end >> PAGE_SHIFT; |
| 1402 | struct page *page; |
| 1403 | |
| 1404 | while (index <= end_index) { |
| 1405 | page = find_get_page(tree->mapping, index); |
| 1406 | BUG_ON(!page); /* Pages should be in the extent_io_tree */ |
| 1407 | set_page_writeback(page); |
| 1408 | put_page(page); |
| 1409 | index++; |
| 1410 | } |
| 1411 | } |
| 1412 | |
| 1413 | /* find the first state struct with 'bits' set after 'start', and |
| 1414 | * return it. tree->lock must be held. NULL will returned if |
| 1415 | * nothing was found after 'start' |
| 1416 | */ |
| 1417 | static struct extent_state * |
| 1418 | find_first_extent_bit_state(struct extent_io_tree *tree, |
| 1419 | u64 start, unsigned bits) |
| 1420 | { |
| 1421 | struct rb_node *node; |
| 1422 | struct extent_state *state; |
| 1423 | |
| 1424 | /* |
| 1425 | * this search will find all the extents that end after |
| 1426 | * our range starts. |
| 1427 | */ |
| 1428 | node = tree_search(tree, start); |
| 1429 | if (!node) |
| 1430 | goto out; |
| 1431 | |
| 1432 | while (1) { |
| 1433 | state = rb_entry(node, struct extent_state, rb_node); |
| 1434 | if (state->end >= start && (state->state & bits)) |
| 1435 | return state; |
| 1436 | |
| 1437 | node = rb_next(node); |
| 1438 | if (!node) |
| 1439 | break; |
| 1440 | } |
| 1441 | out: |
| 1442 | return NULL; |
| 1443 | } |
| 1444 | |
| 1445 | /* |
| 1446 | * find the first offset in the io tree with 'bits' set. zero is |
| 1447 | * returned if we find something, and *start_ret and *end_ret are |
| 1448 | * set to reflect the state struct that was found. |
| 1449 | * |
| 1450 | * If nothing was found, 1 is returned. If found something, return 0. |
| 1451 | */ |
| 1452 | int find_first_extent_bit(struct extent_io_tree *tree, u64 start, |
| 1453 | u64 *start_ret, u64 *end_ret, unsigned bits, |
| 1454 | struct extent_state **cached_state) |
| 1455 | { |
| 1456 | struct extent_state *state; |
| 1457 | struct rb_node *n; |
| 1458 | int ret = 1; |
| 1459 | |
| 1460 | spin_lock(&tree->lock); |
| 1461 | if (cached_state && *cached_state) { |
| 1462 | state = *cached_state; |
| 1463 | if (state->end == start - 1 && extent_state_in_tree(state)) { |
| 1464 | n = rb_next(&state->rb_node); |
| 1465 | while (n) { |
| 1466 | state = rb_entry(n, struct extent_state, |
| 1467 | rb_node); |
| 1468 | if (state->state & bits) |
| 1469 | goto got_it; |
| 1470 | n = rb_next(n); |
| 1471 | } |
| 1472 | free_extent_state(*cached_state); |
| 1473 | *cached_state = NULL; |
| 1474 | goto out; |
| 1475 | } |
| 1476 | free_extent_state(*cached_state); |
| 1477 | *cached_state = NULL; |
| 1478 | } |
| 1479 | |
| 1480 | state = find_first_extent_bit_state(tree, start, bits); |
| 1481 | got_it: |
| 1482 | if (state) { |
| 1483 | cache_state_if_flags(state, cached_state, 0); |
| 1484 | *start_ret = state->start; |
| 1485 | *end_ret = state->end; |
| 1486 | ret = 0; |
| 1487 | } |
| 1488 | out: |
| 1489 | spin_unlock(&tree->lock); |
| 1490 | return ret; |
| 1491 | } |
| 1492 | |
| 1493 | /* |
| 1494 | * find a contiguous range of bytes in the file marked as delalloc, not |
| 1495 | * more than 'max_bytes'. start and end are used to return the range, |
| 1496 | * |
| 1497 | * 1 is returned if we find something, 0 if nothing was in the tree |
| 1498 | */ |
| 1499 | static noinline u64 find_delalloc_range(struct extent_io_tree *tree, |
| 1500 | u64 *start, u64 *end, u64 max_bytes, |
| 1501 | struct extent_state **cached_state) |
| 1502 | { |
| 1503 | struct rb_node *node; |
| 1504 | struct extent_state *state; |
| 1505 | u64 cur_start = *start; |
| 1506 | u64 found = 0; |
| 1507 | u64 total_bytes = 0; |
| 1508 | |
| 1509 | spin_lock(&tree->lock); |
| 1510 | |
| 1511 | /* |
| 1512 | * this search will find all the extents that end after |
| 1513 | * our range starts. |
| 1514 | */ |
| 1515 | node = tree_search(tree, cur_start); |
| 1516 | if (!node) { |
| 1517 | if (!found) |
| 1518 | *end = (u64)-1; |
| 1519 | goto out; |
| 1520 | } |
| 1521 | |
| 1522 | while (1) { |
| 1523 | state = rb_entry(node, struct extent_state, rb_node); |
| 1524 | if (found && (state->start != cur_start || |
| 1525 | (state->state & EXTENT_BOUNDARY))) { |
| 1526 | goto out; |
| 1527 | } |
| 1528 | if (!(state->state & EXTENT_DELALLOC)) { |
| 1529 | if (!found) |
| 1530 | *end = state->end; |
| 1531 | goto out; |
| 1532 | } |
| 1533 | if (!found) { |
| 1534 | *start = state->start; |
| 1535 | *cached_state = state; |
| 1536 | atomic_inc(&state->refs); |
| 1537 | } |
| 1538 | found++; |
| 1539 | *end = state->end; |
| 1540 | cur_start = state->end + 1; |
| 1541 | node = rb_next(node); |
| 1542 | total_bytes += state->end - state->start + 1; |
| 1543 | if (total_bytes >= max_bytes) |
| 1544 | break; |
| 1545 | if (!node) |
| 1546 | break; |
| 1547 | } |
| 1548 | out: |
| 1549 | spin_unlock(&tree->lock); |
| 1550 | return found; |
| 1551 | } |
| 1552 | |
| 1553 | static noinline void __unlock_for_delalloc(struct inode *inode, |
| 1554 | struct page *locked_page, |
| 1555 | u64 start, u64 end) |
| 1556 | { |
| 1557 | int ret; |
| 1558 | struct page *pages[16]; |
| 1559 | unsigned long index = start >> PAGE_SHIFT; |
| 1560 | unsigned long end_index = end >> PAGE_SHIFT; |
| 1561 | unsigned long nr_pages = end_index - index + 1; |
| 1562 | int i; |
| 1563 | |
| 1564 | if (index == locked_page->index && end_index == index) |
| 1565 | return; |
| 1566 | |
| 1567 | while (nr_pages > 0) { |
| 1568 | ret = find_get_pages_contig(inode->i_mapping, index, |
| 1569 | min_t(unsigned long, nr_pages, |
| 1570 | ARRAY_SIZE(pages)), pages); |
| 1571 | for (i = 0; i < ret; i++) { |
| 1572 | if (pages[i] != locked_page) |
| 1573 | unlock_page(pages[i]); |
| 1574 | put_page(pages[i]); |
| 1575 | } |
| 1576 | nr_pages -= ret; |
| 1577 | index += ret; |
| 1578 | cond_resched(); |
| 1579 | } |
| 1580 | } |
| 1581 | |
| 1582 | static noinline int lock_delalloc_pages(struct inode *inode, |
| 1583 | struct page *locked_page, |
| 1584 | u64 delalloc_start, |
| 1585 | u64 delalloc_end) |
| 1586 | { |
| 1587 | unsigned long index = delalloc_start >> PAGE_SHIFT; |
| 1588 | unsigned long start_index = index; |
| 1589 | unsigned long end_index = delalloc_end >> PAGE_SHIFT; |
| 1590 | unsigned long pages_locked = 0; |
| 1591 | struct page *pages[16]; |
| 1592 | unsigned long nrpages; |
| 1593 | int ret; |
| 1594 | int i; |
| 1595 | |
| 1596 | /* the caller is responsible for locking the start index */ |
| 1597 | if (index == locked_page->index && index == end_index) |
| 1598 | return 0; |
| 1599 | |
| 1600 | /* skip the page at the start index */ |
| 1601 | nrpages = end_index - index + 1; |
| 1602 | while (nrpages > 0) { |
| 1603 | ret = find_get_pages_contig(inode->i_mapping, index, |
| 1604 | min_t(unsigned long, |
| 1605 | nrpages, ARRAY_SIZE(pages)), pages); |
| 1606 | if (ret == 0) { |
| 1607 | ret = -EAGAIN; |
| 1608 | goto done; |
| 1609 | } |
| 1610 | /* now we have an array of pages, lock them all */ |
| 1611 | for (i = 0; i < ret; i++) { |
| 1612 | /* |
| 1613 | * the caller is taking responsibility for |
| 1614 | * locked_page |
| 1615 | */ |
| 1616 | if (pages[i] != locked_page) { |
| 1617 | lock_page(pages[i]); |
| 1618 | if (!PageDirty(pages[i]) || |
| 1619 | pages[i]->mapping != inode->i_mapping) { |
| 1620 | ret = -EAGAIN; |
| 1621 | unlock_page(pages[i]); |
| 1622 | put_page(pages[i]); |
| 1623 | goto done; |
| 1624 | } |
| 1625 | } |
| 1626 | put_page(pages[i]); |
| 1627 | pages_locked++; |
| 1628 | } |
| 1629 | nrpages -= ret; |
| 1630 | index += ret; |
| 1631 | cond_resched(); |
| 1632 | } |
| 1633 | ret = 0; |
| 1634 | done: |
| 1635 | if (ret && pages_locked) { |
| 1636 | __unlock_for_delalloc(inode, locked_page, |
| 1637 | delalloc_start, |
| 1638 | ((u64)(start_index + pages_locked - 1)) << |
| 1639 | PAGE_SHIFT); |
| 1640 | } |
| 1641 | return ret; |
| 1642 | } |
| 1643 | |
| 1644 | /* |
| 1645 | * find a contiguous range of bytes in the file marked as delalloc, not |
| 1646 | * more than 'max_bytes'. start and end are used to return the range, |
| 1647 | * |
| 1648 | * 1 is returned if we find something, 0 if nothing was in the tree |
| 1649 | */ |
| 1650 | STATIC u64 find_lock_delalloc_range(struct inode *inode, |
| 1651 | struct extent_io_tree *tree, |
| 1652 | struct page *locked_page, u64 *start, |
| 1653 | u64 *end, u64 max_bytes) |
| 1654 | { |
| 1655 | u64 delalloc_start; |
| 1656 | u64 delalloc_end; |
| 1657 | u64 found; |
| 1658 | struct extent_state *cached_state = NULL; |
| 1659 | int ret; |
| 1660 | int loops = 0; |
| 1661 | |
| 1662 | again: |
| 1663 | /* step one, find a bunch of delalloc bytes starting at start */ |
| 1664 | delalloc_start = *start; |
| 1665 | delalloc_end = 0; |
| 1666 | found = find_delalloc_range(tree, &delalloc_start, &delalloc_end, |
| 1667 | max_bytes, &cached_state); |
| 1668 | if (!found || delalloc_end <= *start) { |
| 1669 | *start = delalloc_start; |
| 1670 | *end = delalloc_end; |
| 1671 | free_extent_state(cached_state); |
| 1672 | return 0; |
| 1673 | } |
| 1674 | |
| 1675 | /* |
| 1676 | * start comes from the offset of locked_page. We have to lock |
| 1677 | * pages in order, so we can't process delalloc bytes before |
| 1678 | * locked_page |
| 1679 | */ |
| 1680 | if (delalloc_start < *start) |
| 1681 | delalloc_start = *start; |
| 1682 | |
| 1683 | /* |
| 1684 | * make sure to limit the number of pages we try to lock down |
| 1685 | */ |
| 1686 | if (delalloc_end + 1 - delalloc_start > max_bytes) |
| 1687 | delalloc_end = delalloc_start + max_bytes - 1; |
| 1688 | |
| 1689 | /* step two, lock all the pages after the page that has start */ |
| 1690 | ret = lock_delalloc_pages(inode, locked_page, |
| 1691 | delalloc_start, delalloc_end); |
| 1692 | if (ret == -EAGAIN) { |
| 1693 | /* some of the pages are gone, lets avoid looping by |
| 1694 | * shortening the size of the delalloc range we're searching |
| 1695 | */ |
| 1696 | free_extent_state(cached_state); |
| 1697 | cached_state = NULL; |
| 1698 | if (!loops) { |
| 1699 | max_bytes = PAGE_SIZE; |
| 1700 | loops = 1; |
| 1701 | goto again; |
| 1702 | } else { |
| 1703 | found = 0; |
| 1704 | goto out_failed; |
| 1705 | } |
| 1706 | } |
| 1707 | BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */ |
| 1708 | |
| 1709 | /* step three, lock the state bits for the whole range */ |
| 1710 | lock_extent_bits(tree, delalloc_start, delalloc_end, &cached_state); |
| 1711 | |
| 1712 | /* then test to make sure it is all still delalloc */ |
| 1713 | ret = test_range_bit(tree, delalloc_start, delalloc_end, |
| 1714 | EXTENT_DELALLOC, 1, cached_state); |
| 1715 | if (!ret) { |
| 1716 | unlock_extent_cached(tree, delalloc_start, delalloc_end, |
| 1717 | &cached_state, GFP_NOFS); |
| 1718 | __unlock_for_delalloc(inode, locked_page, |
| 1719 | delalloc_start, delalloc_end); |
| 1720 | cond_resched(); |
| 1721 | goto again; |
| 1722 | } |
| 1723 | free_extent_state(cached_state); |
| 1724 | *start = delalloc_start; |
| 1725 | *end = delalloc_end; |
| 1726 | out_failed: |
| 1727 | return found; |
| 1728 | } |
| 1729 | |
| 1730 | void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end, |
| 1731 | struct page *locked_page, |
| 1732 | unsigned clear_bits, |
| 1733 | unsigned long page_ops) |
| 1734 | { |
| 1735 | struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| 1736 | int ret; |
| 1737 | struct page *pages[16]; |
| 1738 | unsigned long index = start >> PAGE_SHIFT; |
| 1739 | unsigned long end_index = end >> PAGE_SHIFT; |
| 1740 | unsigned long nr_pages = end_index - index + 1; |
| 1741 | int i; |
| 1742 | |
| 1743 | clear_extent_bit(tree, start, end, clear_bits, 1, 0, NULL, GFP_NOFS); |
| 1744 | if (page_ops == 0) |
| 1745 | return; |
| 1746 | |
| 1747 | if ((page_ops & PAGE_SET_ERROR) && nr_pages > 0) |
| 1748 | mapping_set_error(inode->i_mapping, -EIO); |
| 1749 | |
| 1750 | while (nr_pages > 0) { |
| 1751 | ret = find_get_pages_contig(inode->i_mapping, index, |
| 1752 | min_t(unsigned long, |
| 1753 | nr_pages, ARRAY_SIZE(pages)), pages); |
| 1754 | for (i = 0; i < ret; i++) { |
| 1755 | |
| 1756 | if (page_ops & PAGE_SET_PRIVATE2) |
| 1757 | SetPagePrivate2(pages[i]); |
| 1758 | |
| 1759 | if (pages[i] == locked_page) { |
| 1760 | put_page(pages[i]); |
| 1761 | continue; |
| 1762 | } |
| 1763 | if (page_ops & PAGE_CLEAR_DIRTY) |
| 1764 | clear_page_dirty_for_io(pages[i]); |
| 1765 | if (page_ops & PAGE_SET_WRITEBACK) |
| 1766 | set_page_writeback(pages[i]); |
| 1767 | if (page_ops & PAGE_SET_ERROR) |
| 1768 | SetPageError(pages[i]); |
| 1769 | if (page_ops & PAGE_END_WRITEBACK) |
| 1770 | end_page_writeback(pages[i]); |
| 1771 | if (page_ops & PAGE_UNLOCK) |
| 1772 | unlock_page(pages[i]); |
| 1773 | put_page(pages[i]); |
| 1774 | } |
| 1775 | nr_pages -= ret; |
| 1776 | index += ret; |
| 1777 | cond_resched(); |
| 1778 | } |
| 1779 | } |
| 1780 | |
| 1781 | /* |
| 1782 | * count the number of bytes in the tree that have a given bit(s) |
| 1783 | * set. This can be fairly slow, except for EXTENT_DIRTY which is |
| 1784 | * cached. The total number found is returned. |
| 1785 | */ |
| 1786 | u64 count_range_bits(struct extent_io_tree *tree, |
| 1787 | u64 *start, u64 search_end, u64 max_bytes, |
| 1788 | unsigned bits, int contig) |
| 1789 | { |
| 1790 | struct rb_node *node; |
| 1791 | struct extent_state *state; |
| 1792 | u64 cur_start = *start; |
| 1793 | u64 total_bytes = 0; |
| 1794 | u64 last = 0; |
| 1795 | int found = 0; |
| 1796 | |
| 1797 | if (WARN_ON(search_end <= cur_start)) |
| 1798 | return 0; |
| 1799 | |
| 1800 | spin_lock(&tree->lock); |
| 1801 | if (cur_start == 0 && bits == EXTENT_DIRTY) { |
| 1802 | total_bytes = tree->dirty_bytes; |
| 1803 | goto out; |
| 1804 | } |
| 1805 | /* |
| 1806 | * this search will find all the extents that end after |
| 1807 | * our range starts. |
| 1808 | */ |
| 1809 | node = tree_search(tree, cur_start); |
| 1810 | if (!node) |
| 1811 | goto out; |
| 1812 | |
| 1813 | while (1) { |
| 1814 | state = rb_entry(node, struct extent_state, rb_node); |
| 1815 | if (state->start > search_end) |
| 1816 | break; |
| 1817 | if (contig && found && state->start > last + 1) |
| 1818 | break; |
| 1819 | if (state->end >= cur_start && (state->state & bits) == bits) { |
| 1820 | total_bytes += min(search_end, state->end) + 1 - |
| 1821 | max(cur_start, state->start); |
| 1822 | if (total_bytes >= max_bytes) |
| 1823 | break; |
| 1824 | if (!found) { |
| 1825 | *start = max(cur_start, state->start); |
| 1826 | found = 1; |
| 1827 | } |
| 1828 | last = state->end; |
| 1829 | } else if (contig && found) { |
| 1830 | break; |
| 1831 | } |
| 1832 | node = rb_next(node); |
| 1833 | if (!node) |
| 1834 | break; |
| 1835 | } |
| 1836 | out: |
| 1837 | spin_unlock(&tree->lock); |
| 1838 | return total_bytes; |
| 1839 | } |
| 1840 | |
| 1841 | /* |
| 1842 | * set the private field for a given byte offset in the tree. If there isn't |
| 1843 | * an extent_state there already, this does nothing. |
| 1844 | */ |
| 1845 | static noinline int set_state_failrec(struct extent_io_tree *tree, u64 start, |
| 1846 | struct io_failure_record *failrec) |
| 1847 | { |
| 1848 | struct rb_node *node; |
| 1849 | struct extent_state *state; |
| 1850 | int ret = 0; |
| 1851 | |
| 1852 | spin_lock(&tree->lock); |
| 1853 | /* |
| 1854 | * this search will find all the extents that end after |
| 1855 | * our range starts. |
| 1856 | */ |
| 1857 | node = tree_search(tree, start); |
| 1858 | if (!node) { |
| 1859 | ret = -ENOENT; |
| 1860 | goto out; |
| 1861 | } |
| 1862 | state = rb_entry(node, struct extent_state, rb_node); |
| 1863 | if (state->start != start) { |
| 1864 | ret = -ENOENT; |
| 1865 | goto out; |
| 1866 | } |
| 1867 | state->failrec = failrec; |
| 1868 | out: |
| 1869 | spin_unlock(&tree->lock); |
| 1870 | return ret; |
| 1871 | } |
| 1872 | |
| 1873 | static noinline int get_state_failrec(struct extent_io_tree *tree, u64 start, |
| 1874 | struct io_failure_record **failrec) |
| 1875 | { |
| 1876 | struct rb_node *node; |
| 1877 | struct extent_state *state; |
| 1878 | int ret = 0; |
| 1879 | |
| 1880 | spin_lock(&tree->lock); |
| 1881 | /* |
| 1882 | * this search will find all the extents that end after |
| 1883 | * our range starts. |
| 1884 | */ |
| 1885 | node = tree_search(tree, start); |
| 1886 | if (!node) { |
| 1887 | ret = -ENOENT; |
| 1888 | goto out; |
| 1889 | } |
| 1890 | state = rb_entry(node, struct extent_state, rb_node); |
| 1891 | if (state->start != start) { |
| 1892 | ret = -ENOENT; |
| 1893 | goto out; |
| 1894 | } |
| 1895 | *failrec = state->failrec; |
| 1896 | out: |
| 1897 | spin_unlock(&tree->lock); |
| 1898 | return ret; |
| 1899 | } |
| 1900 | |
| 1901 | /* |
| 1902 | * searches a range in the state tree for a given mask. |
| 1903 | * If 'filled' == 1, this returns 1 only if every extent in the tree |
| 1904 | * has the bits set. Otherwise, 1 is returned if any bit in the |
| 1905 | * range is found set. |
| 1906 | */ |
| 1907 | int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, |
| 1908 | unsigned bits, int filled, struct extent_state *cached) |
| 1909 | { |
| 1910 | struct extent_state *state = NULL; |
| 1911 | struct rb_node *node; |
| 1912 | int bitset = 0; |
| 1913 | |
| 1914 | spin_lock(&tree->lock); |
| 1915 | if (cached && extent_state_in_tree(cached) && cached->start <= start && |
| 1916 | cached->end > start) |
| 1917 | node = &cached->rb_node; |
| 1918 | else |
| 1919 | node = tree_search(tree, start); |
| 1920 | while (node && start <= end) { |
| 1921 | state = rb_entry(node, struct extent_state, rb_node); |
| 1922 | |
| 1923 | if (filled && state->start > start) { |
| 1924 | bitset = 0; |
| 1925 | break; |
| 1926 | } |
| 1927 | |
| 1928 | if (state->start > end) |
| 1929 | break; |
| 1930 | |
| 1931 | if (state->state & bits) { |
| 1932 | bitset = 1; |
| 1933 | if (!filled) |
| 1934 | break; |
| 1935 | } else if (filled) { |
| 1936 | bitset = 0; |
| 1937 | break; |
| 1938 | } |
| 1939 | |
| 1940 | if (state->end == (u64)-1) |
| 1941 | break; |
| 1942 | |
| 1943 | start = state->end + 1; |
| 1944 | if (start > end) |
| 1945 | break; |
| 1946 | node = rb_next(node); |
| 1947 | if (!node) { |
| 1948 | if (filled) |
| 1949 | bitset = 0; |
| 1950 | break; |
| 1951 | } |
| 1952 | } |
| 1953 | spin_unlock(&tree->lock); |
| 1954 | return bitset; |
| 1955 | } |
| 1956 | |
| 1957 | /* |
| 1958 | * helper function to set a given page up to date if all the |
| 1959 | * extents in the tree for that page are up to date |
| 1960 | */ |
| 1961 | static void check_page_uptodate(struct extent_io_tree *tree, struct page *page) |
| 1962 | { |
| 1963 | u64 start = page_offset(page); |
| 1964 | u64 end = start + PAGE_SIZE - 1; |
| 1965 | if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL)) |
| 1966 | SetPageUptodate(page); |
| 1967 | } |
| 1968 | |
| 1969 | int free_io_failure(struct inode *inode, struct io_failure_record *rec) |
| 1970 | { |
| 1971 | int ret; |
| 1972 | int err = 0; |
| 1973 | struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; |
| 1974 | |
| 1975 | set_state_failrec(failure_tree, rec->start, NULL); |
| 1976 | ret = clear_extent_bits(failure_tree, rec->start, |
| 1977 | rec->start + rec->len - 1, |
| 1978 | EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS); |
| 1979 | if (ret) |
| 1980 | err = ret; |
| 1981 | |
| 1982 | ret = clear_extent_bits(&BTRFS_I(inode)->io_tree, rec->start, |
| 1983 | rec->start + rec->len - 1, |
| 1984 | EXTENT_DAMAGED, GFP_NOFS); |
| 1985 | if (ret && !err) |
| 1986 | err = ret; |
| 1987 | |
| 1988 | kfree(rec); |
| 1989 | return err; |
| 1990 | } |
| 1991 | |
| 1992 | /* |
| 1993 | * this bypasses the standard btrfs submit functions deliberately, as |
| 1994 | * the standard behavior is to write all copies in a raid setup. here we only |
| 1995 | * want to write the one bad copy. so we do the mapping for ourselves and issue |
| 1996 | * submit_bio directly. |
| 1997 | * to avoid any synchronization issues, wait for the data after writing, which |
| 1998 | * actually prevents the read that triggered the error from finishing. |
| 1999 | * currently, there can be no more than two copies of every data bit. thus, |
| 2000 | * exactly one rewrite is required. |
| 2001 | */ |
| 2002 | int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical, |
| 2003 | struct page *page, unsigned int pg_offset, int mirror_num) |
| 2004 | { |
| 2005 | struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; |
| 2006 | struct bio *bio; |
| 2007 | struct btrfs_device *dev; |
| 2008 | u64 map_length = 0; |
| 2009 | u64 sector; |
| 2010 | struct btrfs_bio *bbio = NULL; |
| 2011 | struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree; |
| 2012 | int ret; |
| 2013 | |
| 2014 | ASSERT(!(fs_info->sb->s_flags & MS_RDONLY)); |
| 2015 | BUG_ON(!mirror_num); |
| 2016 | |
| 2017 | /* we can't repair anything in raid56 yet */ |
| 2018 | if (btrfs_is_parity_mirror(map_tree, logical, length, mirror_num)) |
| 2019 | return 0; |
| 2020 | |
| 2021 | bio = btrfs_io_bio_alloc(GFP_NOFS, 1); |
| 2022 | if (!bio) |
| 2023 | return -EIO; |
| 2024 | bio->bi_iter.bi_size = 0; |
| 2025 | map_length = length; |
| 2026 | |
| 2027 | ret = btrfs_map_block(fs_info, WRITE, logical, |
| 2028 | &map_length, &bbio, mirror_num); |
| 2029 | if (ret) { |
| 2030 | bio_put(bio); |
| 2031 | return -EIO; |
| 2032 | } |
| 2033 | BUG_ON(mirror_num != bbio->mirror_num); |
| 2034 | sector = bbio->stripes[mirror_num-1].physical >> 9; |
| 2035 | bio->bi_iter.bi_sector = sector; |
| 2036 | dev = bbio->stripes[mirror_num-1].dev; |
| 2037 | btrfs_put_bbio(bbio); |
| 2038 | if (!dev || !dev->bdev || !dev->writeable) { |
| 2039 | bio_put(bio); |
| 2040 | return -EIO; |
| 2041 | } |
| 2042 | bio->bi_bdev = dev->bdev; |
| 2043 | bio_add_page(bio, page, length, pg_offset); |
| 2044 | |
| 2045 | if (btrfsic_submit_bio_wait(WRITE_SYNC, bio)) { |
| 2046 | /* try to remap that extent elsewhere? */ |
| 2047 | bio_put(bio); |
| 2048 | btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS); |
| 2049 | return -EIO; |
| 2050 | } |
| 2051 | |
| 2052 | btrfs_info_rl_in_rcu(fs_info, |
| 2053 | "read error corrected: ino %llu off %llu (dev %s sector %llu)", |
| 2054 | btrfs_ino(inode), start, |
| 2055 | rcu_str_deref(dev->name), sector); |
| 2056 | bio_put(bio); |
| 2057 | return 0; |
| 2058 | } |
| 2059 | |
| 2060 | int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb, |
| 2061 | int mirror_num) |
| 2062 | { |
| 2063 | u64 start = eb->start; |
| 2064 | unsigned long i, num_pages = num_extent_pages(eb->start, eb->len); |
| 2065 | int ret = 0; |
| 2066 | |
| 2067 | if (root->fs_info->sb->s_flags & MS_RDONLY) |
| 2068 | return -EROFS; |
| 2069 | |
| 2070 | for (i = 0; i < num_pages; i++) { |
| 2071 | struct page *p = eb->pages[i]; |
| 2072 | |
| 2073 | ret = repair_io_failure(root->fs_info->btree_inode, start, |
| 2074 | PAGE_SIZE, start, p, |
| 2075 | start - page_offset(p), mirror_num); |
| 2076 | if (ret) |
| 2077 | break; |
| 2078 | start += PAGE_SIZE; |
| 2079 | } |
| 2080 | |
| 2081 | return ret; |
| 2082 | } |
| 2083 | |
| 2084 | /* |
| 2085 | * each time an IO finishes, we do a fast check in the IO failure tree |
| 2086 | * to see if we need to process or clean up an io_failure_record |
| 2087 | */ |
| 2088 | int clean_io_failure(struct inode *inode, u64 start, struct page *page, |
| 2089 | unsigned int pg_offset) |
| 2090 | { |
| 2091 | u64 private; |
| 2092 | struct io_failure_record *failrec; |
| 2093 | struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; |
| 2094 | struct extent_state *state; |
| 2095 | int num_copies; |
| 2096 | int ret; |
| 2097 | |
| 2098 | private = 0; |
| 2099 | ret = count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private, |
| 2100 | (u64)-1, 1, EXTENT_DIRTY, 0); |
| 2101 | if (!ret) |
| 2102 | return 0; |
| 2103 | |
| 2104 | ret = get_state_failrec(&BTRFS_I(inode)->io_failure_tree, start, |
| 2105 | &failrec); |
| 2106 | if (ret) |
| 2107 | return 0; |
| 2108 | |
| 2109 | BUG_ON(!failrec->this_mirror); |
| 2110 | |
| 2111 | if (failrec->in_validation) { |
| 2112 | /* there was no real error, just free the record */ |
| 2113 | pr_debug("clean_io_failure: freeing dummy error at %llu\n", |
| 2114 | failrec->start); |
| 2115 | goto out; |
| 2116 | } |
| 2117 | if (fs_info->sb->s_flags & MS_RDONLY) |
| 2118 | goto out; |
| 2119 | |
| 2120 | spin_lock(&BTRFS_I(inode)->io_tree.lock); |
| 2121 | state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree, |
| 2122 | failrec->start, |
| 2123 | EXTENT_LOCKED); |
| 2124 | spin_unlock(&BTRFS_I(inode)->io_tree.lock); |
| 2125 | |
| 2126 | if (state && state->start <= failrec->start && |
| 2127 | state->end >= failrec->start + failrec->len - 1) { |
| 2128 | num_copies = btrfs_num_copies(fs_info, failrec->logical, |
| 2129 | failrec->len); |
| 2130 | if (num_copies > 1) { |
| 2131 | repair_io_failure(inode, start, failrec->len, |
| 2132 | failrec->logical, page, |
| 2133 | pg_offset, failrec->failed_mirror); |
| 2134 | } |
| 2135 | } |
| 2136 | |
| 2137 | out: |
| 2138 | free_io_failure(inode, failrec); |
| 2139 | |
| 2140 | return 0; |
| 2141 | } |
| 2142 | |
| 2143 | /* |
| 2144 | * Can be called when |
| 2145 | * - hold extent lock |
| 2146 | * - under ordered extent |
| 2147 | * - the inode is freeing |
| 2148 | */ |
| 2149 | void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end) |
| 2150 | { |
| 2151 | struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; |
| 2152 | struct io_failure_record *failrec; |
| 2153 | struct extent_state *state, *next; |
| 2154 | |
| 2155 | if (RB_EMPTY_ROOT(&failure_tree->state)) |
| 2156 | return; |
| 2157 | |
| 2158 | spin_lock(&failure_tree->lock); |
| 2159 | state = find_first_extent_bit_state(failure_tree, start, EXTENT_DIRTY); |
| 2160 | while (state) { |
| 2161 | if (state->start > end) |
| 2162 | break; |
| 2163 | |
| 2164 | ASSERT(state->end <= end); |
| 2165 | |
| 2166 | next = next_state(state); |
| 2167 | |
| 2168 | failrec = state->failrec; |
| 2169 | free_extent_state(state); |
| 2170 | kfree(failrec); |
| 2171 | |
| 2172 | state = next; |
| 2173 | } |
| 2174 | spin_unlock(&failure_tree->lock); |
| 2175 | } |
| 2176 | |
| 2177 | int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end, |
| 2178 | struct io_failure_record **failrec_ret) |
| 2179 | { |
| 2180 | struct io_failure_record *failrec; |
| 2181 | struct extent_map *em; |
| 2182 | struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; |
| 2183 | struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| 2184 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| 2185 | int ret; |
| 2186 | u64 logical; |
| 2187 | |
| 2188 | ret = get_state_failrec(failure_tree, start, &failrec); |
| 2189 | if (ret) { |
| 2190 | failrec = kzalloc(sizeof(*failrec), GFP_NOFS); |
| 2191 | if (!failrec) |
| 2192 | return -ENOMEM; |
| 2193 | |
| 2194 | failrec->start = start; |
| 2195 | failrec->len = end - start + 1; |
| 2196 | failrec->this_mirror = 0; |
| 2197 | failrec->bio_flags = 0; |
| 2198 | failrec->in_validation = 0; |
| 2199 | |
| 2200 | read_lock(&em_tree->lock); |
| 2201 | em = lookup_extent_mapping(em_tree, start, failrec->len); |
| 2202 | if (!em) { |
| 2203 | read_unlock(&em_tree->lock); |
| 2204 | kfree(failrec); |
| 2205 | return -EIO; |
| 2206 | } |
| 2207 | |
| 2208 | if (em->start > start || em->start + em->len <= start) { |
| 2209 | free_extent_map(em); |
| 2210 | em = NULL; |
| 2211 | } |
| 2212 | read_unlock(&em_tree->lock); |
| 2213 | if (!em) { |
| 2214 | kfree(failrec); |
| 2215 | return -EIO; |
| 2216 | } |
| 2217 | |
| 2218 | logical = start - em->start; |
| 2219 | logical = em->block_start + logical; |
| 2220 | if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { |
| 2221 | logical = em->block_start; |
| 2222 | failrec->bio_flags = EXTENT_BIO_COMPRESSED; |
| 2223 | extent_set_compress_type(&failrec->bio_flags, |
| 2224 | em->compress_type); |
| 2225 | } |
| 2226 | |
| 2227 | pr_debug("Get IO Failure Record: (new) logical=%llu, start=%llu, len=%llu\n", |
| 2228 | logical, start, failrec->len); |
| 2229 | |
| 2230 | failrec->logical = logical; |
| 2231 | free_extent_map(em); |
| 2232 | |
| 2233 | /* set the bits in the private failure tree */ |
| 2234 | ret = set_extent_bits(failure_tree, start, end, |
| 2235 | EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS); |
| 2236 | if (ret >= 0) |
| 2237 | ret = set_state_failrec(failure_tree, start, failrec); |
| 2238 | /* set the bits in the inode's tree */ |
| 2239 | if (ret >= 0) |
| 2240 | ret = set_extent_bits(tree, start, end, EXTENT_DAMAGED, |
| 2241 | GFP_NOFS); |
| 2242 | if (ret < 0) { |
| 2243 | kfree(failrec); |
| 2244 | return ret; |
| 2245 | } |
| 2246 | } else { |
| 2247 | pr_debug("Get IO Failure Record: (found) logical=%llu, start=%llu, len=%llu, validation=%d\n", |
| 2248 | failrec->logical, failrec->start, failrec->len, |
| 2249 | failrec->in_validation); |
| 2250 | /* |
| 2251 | * when data can be on disk more than twice, add to failrec here |
| 2252 | * (e.g. with a list for failed_mirror) to make |
| 2253 | * clean_io_failure() clean all those errors at once. |
| 2254 | */ |
| 2255 | } |
| 2256 | |
| 2257 | *failrec_ret = failrec; |
| 2258 | |
| 2259 | return 0; |
| 2260 | } |
| 2261 | |
| 2262 | int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio, |
| 2263 | struct io_failure_record *failrec, int failed_mirror) |
| 2264 | { |
| 2265 | int num_copies; |
| 2266 | |
| 2267 | num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info, |
| 2268 | failrec->logical, failrec->len); |
| 2269 | if (num_copies == 1) { |
| 2270 | /* |
| 2271 | * we only have a single copy of the data, so don't bother with |
| 2272 | * all the retry and error correction code that follows. no |
| 2273 | * matter what the error is, it is very likely to persist. |
| 2274 | */ |
| 2275 | pr_debug("Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", |
| 2276 | num_copies, failrec->this_mirror, failed_mirror); |
| 2277 | return 0; |
| 2278 | } |
| 2279 | |
| 2280 | /* |
| 2281 | * there are two premises: |
| 2282 | * a) deliver good data to the caller |
| 2283 | * b) correct the bad sectors on disk |
| 2284 | */ |
| 2285 | if (failed_bio->bi_vcnt > 1) { |
| 2286 | /* |
| 2287 | * to fulfill b), we need to know the exact failing sectors, as |
| 2288 | * we don't want to rewrite any more than the failed ones. thus, |
| 2289 | * we need separate read requests for the failed bio |
| 2290 | * |
| 2291 | * if the following BUG_ON triggers, our validation request got |
| 2292 | * merged. we need separate requests for our algorithm to work. |
| 2293 | */ |
| 2294 | BUG_ON(failrec->in_validation); |
| 2295 | failrec->in_validation = 1; |
| 2296 | failrec->this_mirror = failed_mirror; |
| 2297 | } else { |
| 2298 | /* |
| 2299 | * we're ready to fulfill a) and b) alongside. get a good copy |
| 2300 | * of the failed sector and if we succeed, we have setup |
| 2301 | * everything for repair_io_failure to do the rest for us. |
| 2302 | */ |
| 2303 | if (failrec->in_validation) { |
| 2304 | BUG_ON(failrec->this_mirror != failed_mirror); |
| 2305 | failrec->in_validation = 0; |
| 2306 | failrec->this_mirror = 0; |
| 2307 | } |
| 2308 | failrec->failed_mirror = failed_mirror; |
| 2309 | failrec->this_mirror++; |
| 2310 | if (failrec->this_mirror == failed_mirror) |
| 2311 | failrec->this_mirror++; |
| 2312 | } |
| 2313 | |
| 2314 | if (failrec->this_mirror > num_copies) { |
| 2315 | pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", |
| 2316 | num_copies, failrec->this_mirror, failed_mirror); |
| 2317 | return 0; |
| 2318 | } |
| 2319 | |
| 2320 | return 1; |
| 2321 | } |
| 2322 | |
| 2323 | |
| 2324 | struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio, |
| 2325 | struct io_failure_record *failrec, |
| 2326 | struct page *page, int pg_offset, int icsum, |
| 2327 | bio_end_io_t *endio_func, void *data) |
| 2328 | { |
| 2329 | struct bio *bio; |
| 2330 | struct btrfs_io_bio *btrfs_failed_bio; |
| 2331 | struct btrfs_io_bio *btrfs_bio; |
| 2332 | |
| 2333 | bio = btrfs_io_bio_alloc(GFP_NOFS, 1); |
| 2334 | if (!bio) |
| 2335 | return NULL; |
| 2336 | |
| 2337 | bio->bi_end_io = endio_func; |
| 2338 | bio->bi_iter.bi_sector = failrec->logical >> 9; |
| 2339 | bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev; |
| 2340 | bio->bi_iter.bi_size = 0; |
| 2341 | bio->bi_private = data; |
| 2342 | |
| 2343 | btrfs_failed_bio = btrfs_io_bio(failed_bio); |
| 2344 | if (btrfs_failed_bio->csum) { |
| 2345 | struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; |
| 2346 | u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); |
| 2347 | |
| 2348 | btrfs_bio = btrfs_io_bio(bio); |
| 2349 | btrfs_bio->csum = btrfs_bio->csum_inline; |
| 2350 | icsum *= csum_size; |
| 2351 | memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum, |
| 2352 | csum_size); |
| 2353 | } |
| 2354 | |
| 2355 | bio_add_page(bio, page, failrec->len, pg_offset); |
| 2356 | |
| 2357 | return bio; |
| 2358 | } |
| 2359 | |
| 2360 | /* |
| 2361 | * this is a generic handler for readpage errors (default |
| 2362 | * readpage_io_failed_hook). if other copies exist, read those and write back |
| 2363 | * good data to the failed position. does not investigate in remapping the |
| 2364 | * failed extent elsewhere, hoping the device will be smart enough to do this as |
| 2365 | * needed |
| 2366 | */ |
| 2367 | |
| 2368 | static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, |
| 2369 | struct page *page, u64 start, u64 end, |
| 2370 | int failed_mirror) |
| 2371 | { |
| 2372 | struct io_failure_record *failrec; |
| 2373 | struct inode *inode = page->mapping->host; |
| 2374 | struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; |
| 2375 | struct bio *bio; |
| 2376 | int read_mode; |
| 2377 | int ret; |
| 2378 | |
| 2379 | BUG_ON(failed_bio->bi_rw & REQ_WRITE); |
| 2380 | |
| 2381 | ret = btrfs_get_io_failure_record(inode, start, end, &failrec); |
| 2382 | if (ret) |
| 2383 | return ret; |
| 2384 | |
| 2385 | ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror); |
| 2386 | if (!ret) { |
| 2387 | free_io_failure(inode, failrec); |
| 2388 | return -EIO; |
| 2389 | } |
| 2390 | |
| 2391 | if (failed_bio->bi_vcnt > 1) |
| 2392 | read_mode = READ_SYNC | REQ_FAILFAST_DEV; |
| 2393 | else |
| 2394 | read_mode = READ_SYNC; |
| 2395 | |
| 2396 | phy_offset >>= inode->i_sb->s_blocksize_bits; |
| 2397 | bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, |
| 2398 | start - page_offset(page), |
| 2399 | (int)phy_offset, failed_bio->bi_end_io, |
| 2400 | NULL); |
| 2401 | if (!bio) { |
| 2402 | free_io_failure(inode, failrec); |
| 2403 | return -EIO; |
| 2404 | } |
| 2405 | |
| 2406 | pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n", |
| 2407 | read_mode, failrec->this_mirror, failrec->in_validation); |
| 2408 | |
| 2409 | ret = tree->ops->submit_bio_hook(inode, read_mode, bio, |
| 2410 | failrec->this_mirror, |
| 2411 | failrec->bio_flags, 0); |
| 2412 | if (ret) { |
| 2413 | free_io_failure(inode, failrec); |
| 2414 | bio_put(bio); |
| 2415 | } |
| 2416 | |
| 2417 | return ret; |
| 2418 | } |
| 2419 | |
| 2420 | /* lots and lots of room for performance fixes in the end_bio funcs */ |
| 2421 | |
| 2422 | void end_extent_writepage(struct page *page, int err, u64 start, u64 end) |
| 2423 | { |
| 2424 | int uptodate = (err == 0); |
| 2425 | struct extent_io_tree *tree; |
| 2426 | int ret = 0; |
| 2427 | |
| 2428 | tree = &BTRFS_I(page->mapping->host)->io_tree; |
| 2429 | |
| 2430 | if (tree->ops && tree->ops->writepage_end_io_hook) { |
| 2431 | ret = tree->ops->writepage_end_io_hook(page, start, |
| 2432 | end, NULL, uptodate); |
| 2433 | if (ret) |
| 2434 | uptodate = 0; |
| 2435 | } |
| 2436 | |
| 2437 | if (!uptodate) { |
| 2438 | ClearPageUptodate(page); |
| 2439 | SetPageError(page); |
| 2440 | ret = ret < 0 ? ret : -EIO; |
| 2441 | mapping_set_error(page->mapping, ret); |
| 2442 | } |
| 2443 | } |
| 2444 | |
| 2445 | /* |
| 2446 | * after a writepage IO is done, we need to: |
| 2447 | * clear the uptodate bits on error |
| 2448 | * clear the writeback bits in the extent tree for this IO |
| 2449 | * end_page_writeback if the page has no more pending IO |
| 2450 | * |
| 2451 | * Scheduling is not allowed, so the extent state tree is expected |
| 2452 | * to have one and only one object corresponding to this IO. |
| 2453 | */ |
| 2454 | static void end_bio_extent_writepage(struct bio *bio) |
| 2455 | { |
| 2456 | struct bio_vec *bvec; |
| 2457 | u64 start; |
| 2458 | u64 end; |
| 2459 | int i; |
| 2460 | |
| 2461 | bio_for_each_segment_all(bvec, bio, i) { |
| 2462 | struct page *page = bvec->bv_page; |
| 2463 | |
| 2464 | /* We always issue full-page reads, but if some block |
| 2465 | * in a page fails to read, blk_update_request() will |
| 2466 | * advance bv_offset and adjust bv_len to compensate. |
| 2467 | * Print a warning for nonzero offsets, and an error |
| 2468 | * if they don't add up to a full page. */ |
| 2469 | if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) { |
| 2470 | if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE) |
| 2471 | btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info, |
| 2472 | "partial page write in btrfs with offset %u and length %u", |
| 2473 | bvec->bv_offset, bvec->bv_len); |
| 2474 | else |
| 2475 | btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info, |
| 2476 | "incomplete page write in btrfs with offset %u and " |
| 2477 | "length %u", |
| 2478 | bvec->bv_offset, bvec->bv_len); |
| 2479 | } |
| 2480 | |
| 2481 | start = page_offset(page); |
| 2482 | end = start + bvec->bv_offset + bvec->bv_len - 1; |
| 2483 | |
| 2484 | end_extent_writepage(page, bio->bi_error, start, end); |
| 2485 | end_page_writeback(page); |
| 2486 | } |
| 2487 | |
| 2488 | bio_put(bio); |
| 2489 | } |
| 2490 | |
| 2491 | static void |
| 2492 | endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len, |
| 2493 | int uptodate) |
| 2494 | { |
| 2495 | struct extent_state *cached = NULL; |
| 2496 | u64 end = start + len - 1; |
| 2497 | |
| 2498 | if (uptodate && tree->track_uptodate) |
| 2499 | set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC); |
| 2500 | unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC); |
| 2501 | } |
| 2502 | |
| 2503 | /* |
| 2504 | * after a readpage IO is done, we need to: |
| 2505 | * clear the uptodate bits on error |
| 2506 | * set the uptodate bits if things worked |
| 2507 | * set the page up to date if all extents in the tree are uptodate |
| 2508 | * clear the lock bit in the extent tree |
| 2509 | * unlock the page if there are no other extents locked for it |
| 2510 | * |
| 2511 | * Scheduling is not allowed, so the extent state tree is expected |
| 2512 | * to have one and only one object corresponding to this IO. |
| 2513 | */ |
| 2514 | static void end_bio_extent_readpage(struct bio *bio) |
| 2515 | { |
| 2516 | struct bio_vec *bvec; |
| 2517 | int uptodate = !bio->bi_error; |
| 2518 | struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); |
| 2519 | struct extent_io_tree *tree; |
| 2520 | u64 offset = 0; |
| 2521 | u64 start; |
| 2522 | u64 end; |
| 2523 | u64 len; |
| 2524 | u64 extent_start = 0; |
| 2525 | u64 extent_len = 0; |
| 2526 | int mirror; |
| 2527 | int ret; |
| 2528 | int i; |
| 2529 | |
| 2530 | bio_for_each_segment_all(bvec, bio, i) { |
| 2531 | struct page *page = bvec->bv_page; |
| 2532 | struct inode *inode = page->mapping->host; |
| 2533 | |
| 2534 | pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, " |
| 2535 | "mirror=%u\n", (u64)bio->bi_iter.bi_sector, |
| 2536 | bio->bi_error, io_bio->mirror_num); |
| 2537 | tree = &BTRFS_I(inode)->io_tree; |
| 2538 | |
| 2539 | /* We always issue full-page reads, but if some block |
| 2540 | * in a page fails to read, blk_update_request() will |
| 2541 | * advance bv_offset and adjust bv_len to compensate. |
| 2542 | * Print a warning for nonzero offsets, and an error |
| 2543 | * if they don't add up to a full page. */ |
| 2544 | if (bvec->bv_offset || bvec->bv_len != PAGE_SIZE) { |
| 2545 | if (bvec->bv_offset + bvec->bv_len != PAGE_SIZE) |
| 2546 | btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info, |
| 2547 | "partial page read in btrfs with offset %u and length %u", |
| 2548 | bvec->bv_offset, bvec->bv_len); |
| 2549 | else |
| 2550 | btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info, |
| 2551 | "incomplete page read in btrfs with offset %u and " |
| 2552 | "length %u", |
| 2553 | bvec->bv_offset, bvec->bv_len); |
| 2554 | } |
| 2555 | |
| 2556 | start = page_offset(page); |
| 2557 | end = start + bvec->bv_offset + bvec->bv_len - 1; |
| 2558 | len = bvec->bv_len; |
| 2559 | |
| 2560 | mirror = io_bio->mirror_num; |
| 2561 | if (likely(uptodate && tree->ops && |
| 2562 | tree->ops->readpage_end_io_hook)) { |
| 2563 | ret = tree->ops->readpage_end_io_hook(io_bio, offset, |
| 2564 | page, start, end, |
| 2565 | mirror); |
| 2566 | if (ret) |
| 2567 | uptodate = 0; |
| 2568 | else |
| 2569 | clean_io_failure(inode, start, page, 0); |
| 2570 | } |
| 2571 | |
| 2572 | if (likely(uptodate)) |
| 2573 | goto readpage_ok; |
| 2574 | |
| 2575 | if (tree->ops && tree->ops->readpage_io_failed_hook) { |
| 2576 | ret = tree->ops->readpage_io_failed_hook(page, mirror); |
| 2577 | if (!ret && !bio->bi_error) |
| 2578 | uptodate = 1; |
| 2579 | } else { |
| 2580 | /* |
| 2581 | * The generic bio_readpage_error handles errors the |
| 2582 | * following way: If possible, new read requests are |
| 2583 | * created and submitted and will end up in |
| 2584 | * end_bio_extent_readpage as well (if we're lucky, not |
| 2585 | * in the !uptodate case). In that case it returns 0 and |
| 2586 | * we just go on with the next page in our bio. If it |
| 2587 | * can't handle the error it will return -EIO and we |
| 2588 | * remain responsible for that page. |
| 2589 | */ |
| 2590 | ret = bio_readpage_error(bio, offset, page, start, end, |
| 2591 | mirror); |
| 2592 | if (ret == 0) { |
| 2593 | uptodate = !bio->bi_error; |
| 2594 | offset += len; |
| 2595 | continue; |
| 2596 | } |
| 2597 | } |
| 2598 | readpage_ok: |
| 2599 | if (likely(uptodate)) { |
| 2600 | loff_t i_size = i_size_read(inode); |
| 2601 | pgoff_t end_index = i_size >> PAGE_SHIFT; |
| 2602 | unsigned off; |
| 2603 | |
| 2604 | /* Zero out the end if this page straddles i_size */ |
| 2605 | off = i_size & (PAGE_SIZE-1); |
| 2606 | if (page->index == end_index && off) |
| 2607 | zero_user_segment(page, off, PAGE_SIZE); |
| 2608 | SetPageUptodate(page); |
| 2609 | } else { |
| 2610 | ClearPageUptodate(page); |
| 2611 | SetPageError(page); |
| 2612 | } |
| 2613 | unlock_page(page); |
| 2614 | offset += len; |
| 2615 | |
| 2616 | if (unlikely(!uptodate)) { |
| 2617 | if (extent_len) { |
| 2618 | endio_readpage_release_extent(tree, |
| 2619 | extent_start, |
| 2620 | extent_len, 1); |
| 2621 | extent_start = 0; |
| 2622 | extent_len = 0; |
| 2623 | } |
| 2624 | endio_readpage_release_extent(tree, start, |
| 2625 | end - start + 1, 0); |
| 2626 | } else if (!extent_len) { |
| 2627 | extent_start = start; |
| 2628 | extent_len = end + 1 - start; |
| 2629 | } else if (extent_start + extent_len == start) { |
| 2630 | extent_len += end + 1 - start; |
| 2631 | } else { |
| 2632 | endio_readpage_release_extent(tree, extent_start, |
| 2633 | extent_len, uptodate); |
| 2634 | extent_start = start; |
| 2635 | extent_len = end + 1 - start; |
| 2636 | } |
| 2637 | } |
| 2638 | |
| 2639 | if (extent_len) |
| 2640 | endio_readpage_release_extent(tree, extent_start, extent_len, |
| 2641 | uptodate); |
| 2642 | if (io_bio->end_io) |
| 2643 | io_bio->end_io(io_bio, bio->bi_error); |
| 2644 | bio_put(bio); |
| 2645 | } |
| 2646 | |
| 2647 | /* |
| 2648 | * this allocates from the btrfs_bioset. We're returning a bio right now |
| 2649 | * but you can call btrfs_io_bio for the appropriate container_of magic |
| 2650 | */ |
| 2651 | struct bio * |
| 2652 | btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, |
| 2653 | gfp_t gfp_flags) |
| 2654 | { |
| 2655 | struct btrfs_io_bio *btrfs_bio; |
| 2656 | struct bio *bio; |
| 2657 | |
| 2658 | bio = bio_alloc_bioset(gfp_flags, nr_vecs, btrfs_bioset); |
| 2659 | |
| 2660 | if (bio == NULL && (current->flags & PF_MEMALLOC)) { |
| 2661 | while (!bio && (nr_vecs /= 2)) { |
| 2662 | bio = bio_alloc_bioset(gfp_flags, |
| 2663 | nr_vecs, btrfs_bioset); |
| 2664 | } |
| 2665 | } |
| 2666 | |
| 2667 | if (bio) { |
| 2668 | bio->bi_bdev = bdev; |
| 2669 | bio->bi_iter.bi_sector = first_sector; |
| 2670 | btrfs_bio = btrfs_io_bio(bio); |
| 2671 | btrfs_bio->csum = NULL; |
| 2672 | btrfs_bio->csum_allocated = NULL; |
| 2673 | btrfs_bio->end_io = NULL; |
| 2674 | } |
| 2675 | return bio; |
| 2676 | } |
| 2677 | |
| 2678 | struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask) |
| 2679 | { |
| 2680 | struct btrfs_io_bio *btrfs_bio; |
| 2681 | struct bio *new; |
| 2682 | |
| 2683 | new = bio_clone_bioset(bio, gfp_mask, btrfs_bioset); |
| 2684 | if (new) { |
| 2685 | btrfs_bio = btrfs_io_bio(new); |
| 2686 | btrfs_bio->csum = NULL; |
| 2687 | btrfs_bio->csum_allocated = NULL; |
| 2688 | btrfs_bio->end_io = NULL; |
| 2689 | |
| 2690 | #ifdef CONFIG_BLK_CGROUP |
| 2691 | /* FIXME, put this into bio_clone_bioset */ |
| 2692 | if (bio->bi_css) |
| 2693 | bio_associate_blkcg(new, bio->bi_css); |
| 2694 | #endif |
| 2695 | } |
| 2696 | return new; |
| 2697 | } |
| 2698 | |
| 2699 | /* this also allocates from the btrfs_bioset */ |
| 2700 | struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) |
| 2701 | { |
| 2702 | struct btrfs_io_bio *btrfs_bio; |
| 2703 | struct bio *bio; |
| 2704 | |
| 2705 | bio = bio_alloc_bioset(gfp_mask, nr_iovecs, btrfs_bioset); |
| 2706 | if (bio) { |
| 2707 | btrfs_bio = btrfs_io_bio(bio); |
| 2708 | btrfs_bio->csum = NULL; |
| 2709 | btrfs_bio->csum_allocated = NULL; |
| 2710 | btrfs_bio->end_io = NULL; |
| 2711 | } |
| 2712 | return bio; |
| 2713 | } |
| 2714 | |
| 2715 | |
| 2716 | static int __must_check submit_one_bio(int rw, struct bio *bio, |
| 2717 | int mirror_num, unsigned long bio_flags) |
| 2718 | { |
| 2719 | int ret = 0; |
| 2720 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; |
| 2721 | struct page *page = bvec->bv_page; |
| 2722 | struct extent_io_tree *tree = bio->bi_private; |
| 2723 | u64 start; |
| 2724 | |
| 2725 | start = page_offset(page) + bvec->bv_offset; |
| 2726 | |
| 2727 | bio->bi_private = NULL; |
| 2728 | |
| 2729 | bio_get(bio); |
| 2730 | |
| 2731 | if (tree->ops && tree->ops->submit_bio_hook) |
| 2732 | ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio, |
| 2733 | mirror_num, bio_flags, start); |
| 2734 | else |
| 2735 | btrfsic_submit_bio(rw, bio); |
| 2736 | |
| 2737 | bio_put(bio); |
| 2738 | return ret; |
| 2739 | } |
| 2740 | |
| 2741 | static int merge_bio(int rw, struct extent_io_tree *tree, struct page *page, |
| 2742 | unsigned long offset, size_t size, struct bio *bio, |
| 2743 | unsigned long bio_flags) |
| 2744 | { |
| 2745 | int ret = 0; |
| 2746 | if (tree->ops && tree->ops->merge_bio_hook) |
| 2747 | ret = tree->ops->merge_bio_hook(rw, page, offset, size, bio, |
| 2748 | bio_flags); |
| 2749 | BUG_ON(ret < 0); |
| 2750 | return ret; |
| 2751 | |
| 2752 | } |
| 2753 | |
| 2754 | static int submit_extent_page(int rw, struct extent_io_tree *tree, |
| 2755 | struct writeback_control *wbc, |
| 2756 | struct page *page, sector_t sector, |
| 2757 | size_t size, unsigned long offset, |
| 2758 | struct block_device *bdev, |
| 2759 | struct bio **bio_ret, |
| 2760 | unsigned long max_pages, |
| 2761 | bio_end_io_t end_io_func, |
| 2762 | int mirror_num, |
| 2763 | unsigned long prev_bio_flags, |
| 2764 | unsigned long bio_flags, |
| 2765 | bool force_bio_submit) |
| 2766 | { |
| 2767 | int ret = 0; |
| 2768 | struct bio *bio; |
| 2769 | int contig = 0; |
| 2770 | int old_compressed = prev_bio_flags & EXTENT_BIO_COMPRESSED; |
| 2771 | size_t page_size = min_t(size_t, size, PAGE_SIZE); |
| 2772 | |
| 2773 | if (bio_ret && *bio_ret) { |
| 2774 | bio = *bio_ret; |
| 2775 | if (old_compressed) |
| 2776 | contig = bio->bi_iter.bi_sector == sector; |
| 2777 | else |
| 2778 | contig = bio_end_sector(bio) == sector; |
| 2779 | |
| 2780 | if (prev_bio_flags != bio_flags || !contig || |
| 2781 | force_bio_submit || |
| 2782 | merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) || |
| 2783 | bio_add_page(bio, page, page_size, offset) < page_size) { |
| 2784 | ret = submit_one_bio(rw, bio, mirror_num, |
| 2785 | prev_bio_flags); |
| 2786 | if (ret < 0) { |
| 2787 | *bio_ret = NULL; |
| 2788 | return ret; |
| 2789 | } |
| 2790 | bio = NULL; |
| 2791 | } else { |
| 2792 | if (wbc) |
| 2793 | wbc_account_io(wbc, page, page_size); |
| 2794 | return 0; |
| 2795 | } |
| 2796 | } |
| 2797 | |
| 2798 | bio = btrfs_bio_alloc(bdev, sector, BIO_MAX_PAGES, |
| 2799 | GFP_NOFS | __GFP_HIGH); |
| 2800 | if (!bio) |
| 2801 | return -ENOMEM; |
| 2802 | |
| 2803 | bio_add_page(bio, page, page_size, offset); |
| 2804 | bio->bi_end_io = end_io_func; |
| 2805 | bio->bi_private = tree; |
| 2806 | if (wbc) { |
| 2807 | wbc_init_bio(wbc, bio); |
| 2808 | wbc_account_io(wbc, page, page_size); |
| 2809 | } |
| 2810 | |
| 2811 | if (bio_ret) |
| 2812 | *bio_ret = bio; |
| 2813 | else |
| 2814 | ret = submit_one_bio(rw, bio, mirror_num, bio_flags); |
| 2815 | |
| 2816 | return ret; |
| 2817 | } |
| 2818 | |
| 2819 | static void attach_extent_buffer_page(struct extent_buffer *eb, |
| 2820 | struct page *page) |
| 2821 | { |
| 2822 | if (!PagePrivate(page)) { |
| 2823 | SetPagePrivate(page); |
| 2824 | get_page(page); |
| 2825 | set_page_private(page, (unsigned long)eb); |
| 2826 | } else { |
| 2827 | WARN_ON(page->private != (unsigned long)eb); |
| 2828 | } |
| 2829 | } |
| 2830 | |
| 2831 | void set_page_extent_mapped(struct page *page) |
| 2832 | { |
| 2833 | if (!PagePrivate(page)) { |
| 2834 | SetPagePrivate(page); |
| 2835 | get_page(page); |
| 2836 | set_page_private(page, EXTENT_PAGE_PRIVATE); |
| 2837 | } |
| 2838 | } |
| 2839 | |
| 2840 | static struct extent_map * |
| 2841 | __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset, |
| 2842 | u64 start, u64 len, get_extent_t *get_extent, |
| 2843 | struct extent_map **em_cached) |
| 2844 | { |
| 2845 | struct extent_map *em; |
| 2846 | |
| 2847 | if (em_cached && *em_cached) { |
| 2848 | em = *em_cached; |
| 2849 | if (extent_map_in_tree(em) && start >= em->start && |
| 2850 | start < extent_map_end(em)) { |
| 2851 | atomic_inc(&em->refs); |
| 2852 | return em; |
| 2853 | } |
| 2854 | |
| 2855 | free_extent_map(em); |
| 2856 | *em_cached = NULL; |
| 2857 | } |
| 2858 | |
| 2859 | em = get_extent(inode, page, pg_offset, start, len, 0); |
| 2860 | if (em_cached && !IS_ERR_OR_NULL(em)) { |
| 2861 | BUG_ON(*em_cached); |
| 2862 | atomic_inc(&em->refs); |
| 2863 | *em_cached = em; |
| 2864 | } |
| 2865 | return em; |
| 2866 | } |
| 2867 | /* |
| 2868 | * basic readpage implementation. Locked extent state structs are inserted |
| 2869 | * into the tree that are removed when the IO is done (by the end_io |
| 2870 | * handlers) |
| 2871 | * XXX JDM: This needs looking at to ensure proper page locking |
| 2872 | */ |
| 2873 | static int __do_readpage(struct extent_io_tree *tree, |
| 2874 | struct page *page, |
| 2875 | get_extent_t *get_extent, |
| 2876 | struct extent_map **em_cached, |
| 2877 | struct bio **bio, int mirror_num, |
| 2878 | unsigned long *bio_flags, int rw, |
| 2879 | u64 *prev_em_start) |
| 2880 | { |
| 2881 | struct inode *inode = page->mapping->host; |
| 2882 | u64 start = page_offset(page); |
| 2883 | u64 page_end = start + PAGE_SIZE - 1; |
| 2884 | u64 end; |
| 2885 | u64 cur = start; |
| 2886 | u64 extent_offset; |
| 2887 | u64 last_byte = i_size_read(inode); |
| 2888 | u64 block_start; |
| 2889 | u64 cur_end; |
| 2890 | sector_t sector; |
| 2891 | struct extent_map *em; |
| 2892 | struct block_device *bdev; |
| 2893 | int ret; |
| 2894 | int nr = 0; |
| 2895 | size_t pg_offset = 0; |
| 2896 | size_t iosize; |
| 2897 | size_t disk_io_size; |
| 2898 | size_t blocksize = inode->i_sb->s_blocksize; |
| 2899 | unsigned long this_bio_flag = 0; |
| 2900 | |
| 2901 | set_page_extent_mapped(page); |
| 2902 | |
| 2903 | end = page_end; |
| 2904 | if (!PageUptodate(page)) { |
| 2905 | if (cleancache_get_page(page) == 0) { |
| 2906 | BUG_ON(blocksize != PAGE_SIZE); |
| 2907 | unlock_extent(tree, start, end); |
| 2908 | goto out; |
| 2909 | } |
| 2910 | } |
| 2911 | |
| 2912 | if (page->index == last_byte >> PAGE_SHIFT) { |
| 2913 | char *userpage; |
| 2914 | size_t zero_offset = last_byte & (PAGE_SIZE - 1); |
| 2915 | |
| 2916 | if (zero_offset) { |
| 2917 | iosize = PAGE_SIZE - zero_offset; |
| 2918 | userpage = kmap_atomic(page); |
| 2919 | memset(userpage + zero_offset, 0, iosize); |
| 2920 | flush_dcache_page(page); |
| 2921 | kunmap_atomic(userpage); |
| 2922 | } |
| 2923 | } |
| 2924 | while (cur <= end) { |
| 2925 | unsigned long pnr = (last_byte >> PAGE_SHIFT) + 1; |
| 2926 | bool force_bio_submit = false; |
| 2927 | |
| 2928 | if (cur >= last_byte) { |
| 2929 | char *userpage; |
| 2930 | struct extent_state *cached = NULL; |
| 2931 | |
| 2932 | iosize = PAGE_SIZE - pg_offset; |
| 2933 | userpage = kmap_atomic(page); |
| 2934 | memset(userpage + pg_offset, 0, iosize); |
| 2935 | flush_dcache_page(page); |
| 2936 | kunmap_atomic(userpage); |
| 2937 | set_extent_uptodate(tree, cur, cur + iosize - 1, |
| 2938 | &cached, GFP_NOFS); |
| 2939 | unlock_extent_cached(tree, cur, |
| 2940 | cur + iosize - 1, |
| 2941 | &cached, GFP_NOFS); |
| 2942 | break; |
| 2943 | } |
| 2944 | em = __get_extent_map(inode, page, pg_offset, cur, |
| 2945 | end - cur + 1, get_extent, em_cached); |
| 2946 | if (IS_ERR_OR_NULL(em)) { |
| 2947 | SetPageError(page); |
| 2948 | unlock_extent(tree, cur, end); |
| 2949 | break; |
| 2950 | } |
| 2951 | extent_offset = cur - em->start; |
| 2952 | BUG_ON(extent_map_end(em) <= cur); |
| 2953 | BUG_ON(end < cur); |
| 2954 | |
| 2955 | if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { |
| 2956 | this_bio_flag |= EXTENT_BIO_COMPRESSED; |
| 2957 | extent_set_compress_type(&this_bio_flag, |
| 2958 | em->compress_type); |
| 2959 | } |
| 2960 | |
| 2961 | iosize = min(extent_map_end(em) - cur, end - cur + 1); |
| 2962 | cur_end = min(extent_map_end(em) - 1, end); |
| 2963 | iosize = ALIGN(iosize, blocksize); |
| 2964 | if (this_bio_flag & EXTENT_BIO_COMPRESSED) { |
| 2965 | disk_io_size = em->block_len; |
| 2966 | sector = em->block_start >> 9; |
| 2967 | } else { |
| 2968 | sector = (em->block_start + extent_offset) >> 9; |
| 2969 | disk_io_size = iosize; |
| 2970 | } |
| 2971 | bdev = em->bdev; |
| 2972 | block_start = em->block_start; |
| 2973 | if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) |
| 2974 | block_start = EXTENT_MAP_HOLE; |
| 2975 | |
| 2976 | /* |
| 2977 | * If we have a file range that points to a compressed extent |
| 2978 | * and it's followed by a consecutive file range that points to |
| 2979 | * to the same compressed extent (possibly with a different |
| 2980 | * offset and/or length, so it either points to the whole extent |
| 2981 | * or only part of it), we must make sure we do not submit a |
| 2982 | * single bio to populate the pages for the 2 ranges because |
| 2983 | * this makes the compressed extent read zero out the pages |
| 2984 | * belonging to the 2nd range. Imagine the following scenario: |
| 2985 | * |
| 2986 | * File layout |
| 2987 | * [0 - 8K] [8K - 24K] |
| 2988 | * | | |
| 2989 | * | | |
| 2990 | * points to extent X, points to extent X, |
| 2991 | * offset 4K, length of 8K offset 0, length 16K |
| 2992 | * |
| 2993 | * [extent X, compressed length = 4K uncompressed length = 16K] |
| 2994 | * |
| 2995 | * If the bio to read the compressed extent covers both ranges, |
| 2996 | * it will decompress extent X into the pages belonging to the |
| 2997 | * first range and then it will stop, zeroing out the remaining |
| 2998 | * pages that belong to the other range that points to extent X. |
| 2999 | * So here we make sure we submit 2 bios, one for the first |
| 3000 | * range and another one for the third range. Both will target |
| 3001 | * the same physical extent from disk, but we can't currently |
| 3002 | * make the compressed bio endio callback populate the pages |
| 3003 | * for both ranges because each compressed bio is tightly |
| 3004 | * coupled with a single extent map, and each range can have |
| 3005 | * an extent map with a different offset value relative to the |
| 3006 | * uncompressed data of our extent and different lengths. This |
| 3007 | * is a corner case so we prioritize correctness over |
| 3008 | * non-optimal behavior (submitting 2 bios for the same extent). |
| 3009 | */ |
| 3010 | if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) && |
| 3011 | prev_em_start && *prev_em_start != (u64)-1 && |
| 3012 | *prev_em_start != em->orig_start) |
| 3013 | force_bio_submit = true; |
| 3014 | |
| 3015 | if (prev_em_start) |
| 3016 | *prev_em_start = em->orig_start; |
| 3017 | |
| 3018 | free_extent_map(em); |
| 3019 | em = NULL; |
| 3020 | |
| 3021 | /* we've found a hole, just zero and go on */ |
| 3022 | if (block_start == EXTENT_MAP_HOLE) { |
| 3023 | char *userpage; |
| 3024 | struct extent_state *cached = NULL; |
| 3025 | |
| 3026 | userpage = kmap_atomic(page); |
| 3027 | memset(userpage + pg_offset, 0, iosize); |
| 3028 | flush_dcache_page(page); |
| 3029 | kunmap_atomic(userpage); |
| 3030 | |
| 3031 | set_extent_uptodate(tree, cur, cur + iosize - 1, |
| 3032 | &cached, GFP_NOFS); |
| 3033 | unlock_extent_cached(tree, cur, |
| 3034 | cur + iosize - 1, |
| 3035 | &cached, GFP_NOFS); |
| 3036 | cur = cur + iosize; |
| 3037 | pg_offset += iosize; |
| 3038 | continue; |
| 3039 | } |
| 3040 | /* the get_extent function already copied into the page */ |
| 3041 | if (test_range_bit(tree, cur, cur_end, |
| 3042 | EXTENT_UPTODATE, 1, NULL)) { |
| 3043 | check_page_uptodate(tree, page); |
| 3044 | unlock_extent(tree, cur, cur + iosize - 1); |
| 3045 | cur = cur + iosize; |
| 3046 | pg_offset += iosize; |
| 3047 | continue; |
| 3048 | } |
| 3049 | /* we have an inline extent but it didn't get marked up |
| 3050 | * to date. Error out |
| 3051 | */ |
| 3052 | if (block_start == EXTENT_MAP_INLINE) { |
| 3053 | SetPageError(page); |
| 3054 | unlock_extent(tree, cur, cur + iosize - 1); |
| 3055 | cur = cur + iosize; |
| 3056 | pg_offset += iosize; |
| 3057 | continue; |
| 3058 | } |
| 3059 | |
| 3060 | pnr -= page->index; |
| 3061 | ret = submit_extent_page(rw, tree, NULL, page, |
| 3062 | sector, disk_io_size, pg_offset, |
| 3063 | bdev, bio, pnr, |
| 3064 | end_bio_extent_readpage, mirror_num, |
| 3065 | *bio_flags, |
| 3066 | this_bio_flag, |
| 3067 | force_bio_submit); |
| 3068 | if (!ret) { |
| 3069 | nr++; |
| 3070 | *bio_flags = this_bio_flag; |
| 3071 | } else { |
| 3072 | SetPageError(page); |
| 3073 | unlock_extent(tree, cur, cur + iosize - 1); |
| 3074 | } |
| 3075 | cur = cur + iosize; |
| 3076 | pg_offset += iosize; |
| 3077 | } |
| 3078 | out: |
| 3079 | if (!nr) { |
| 3080 | if (!PageError(page)) |
| 3081 | SetPageUptodate(page); |
| 3082 | unlock_page(page); |
| 3083 | } |
| 3084 | return 0; |
| 3085 | } |
| 3086 | |
| 3087 | static inline void __do_contiguous_readpages(struct extent_io_tree *tree, |
| 3088 | struct page *pages[], int nr_pages, |
| 3089 | u64 start, u64 end, |
| 3090 | get_extent_t *get_extent, |
| 3091 | struct extent_map **em_cached, |
| 3092 | struct bio **bio, int mirror_num, |
| 3093 | unsigned long *bio_flags, int rw, |
| 3094 | u64 *prev_em_start) |
| 3095 | { |
| 3096 | struct inode *inode; |
| 3097 | struct btrfs_ordered_extent *ordered; |
| 3098 | int index; |
| 3099 | |
| 3100 | inode = pages[0]->mapping->host; |
| 3101 | while (1) { |
| 3102 | lock_extent(tree, start, end); |
| 3103 | ordered = btrfs_lookup_ordered_range(inode, start, |
| 3104 | end - start + 1); |
| 3105 | if (!ordered) |
| 3106 | break; |
| 3107 | unlock_extent(tree, start, end); |
| 3108 | btrfs_start_ordered_extent(inode, ordered, 1); |
| 3109 | btrfs_put_ordered_extent(ordered); |
| 3110 | } |
| 3111 | |
| 3112 | for (index = 0; index < nr_pages; index++) { |
| 3113 | __do_readpage(tree, pages[index], get_extent, em_cached, bio, |
| 3114 | mirror_num, bio_flags, rw, prev_em_start); |
| 3115 | put_page(pages[index]); |
| 3116 | } |
| 3117 | } |
| 3118 | |
| 3119 | static void __extent_readpages(struct extent_io_tree *tree, |
| 3120 | struct page *pages[], |
| 3121 | int nr_pages, get_extent_t *get_extent, |
| 3122 | struct extent_map **em_cached, |
| 3123 | struct bio **bio, int mirror_num, |
| 3124 | unsigned long *bio_flags, int rw, |
| 3125 | u64 *prev_em_start) |
| 3126 | { |
| 3127 | u64 start = 0; |
| 3128 | u64 end = 0; |
| 3129 | u64 page_start; |
| 3130 | int index; |
| 3131 | int first_index = 0; |
| 3132 | |
| 3133 | for (index = 0; index < nr_pages; index++) { |
| 3134 | page_start = page_offset(pages[index]); |
| 3135 | if (!end) { |
| 3136 | start = page_start; |
| 3137 | end = start + PAGE_SIZE - 1; |
| 3138 | first_index = index; |
| 3139 | } else if (end + 1 == page_start) { |
| 3140 | end += PAGE_SIZE; |
| 3141 | } else { |
| 3142 | __do_contiguous_readpages(tree, &pages[first_index], |
| 3143 | index - first_index, start, |
| 3144 | end, get_extent, em_cached, |
| 3145 | bio, mirror_num, bio_flags, |
| 3146 | rw, prev_em_start); |
| 3147 | start = page_start; |
| 3148 | end = start + PAGE_SIZE - 1; |
| 3149 | first_index = index; |
| 3150 | } |
| 3151 | } |
| 3152 | |
| 3153 | if (end) |
| 3154 | __do_contiguous_readpages(tree, &pages[first_index], |
| 3155 | index - first_index, start, |
| 3156 | end, get_extent, em_cached, bio, |
| 3157 | mirror_num, bio_flags, rw, |
| 3158 | prev_em_start); |
| 3159 | } |
| 3160 | |
| 3161 | static int __extent_read_full_page(struct extent_io_tree *tree, |
| 3162 | struct page *page, |
| 3163 | get_extent_t *get_extent, |
| 3164 | struct bio **bio, int mirror_num, |
| 3165 | unsigned long *bio_flags, int rw) |
| 3166 | { |
| 3167 | struct inode *inode = page->mapping->host; |
| 3168 | struct btrfs_ordered_extent *ordered; |
| 3169 | u64 start = page_offset(page); |
| 3170 | u64 end = start + PAGE_SIZE - 1; |
| 3171 | int ret; |
| 3172 | |
| 3173 | while (1) { |
| 3174 | lock_extent(tree, start, end); |
| 3175 | ordered = btrfs_lookup_ordered_range(inode, start, |
| 3176 | PAGE_SIZE); |
| 3177 | if (!ordered) |
| 3178 | break; |
| 3179 | unlock_extent(tree, start, end); |
| 3180 | btrfs_start_ordered_extent(inode, ordered, 1); |
| 3181 | btrfs_put_ordered_extent(ordered); |
| 3182 | } |
| 3183 | |
| 3184 | ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num, |
| 3185 | bio_flags, rw, NULL); |
| 3186 | return ret; |
| 3187 | } |
| 3188 | |
| 3189 | int extent_read_full_page(struct extent_io_tree *tree, struct page *page, |
| 3190 | get_extent_t *get_extent, int mirror_num) |
| 3191 | { |
| 3192 | struct bio *bio = NULL; |
| 3193 | unsigned long bio_flags = 0; |
| 3194 | int ret; |
| 3195 | |
| 3196 | ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num, |
| 3197 | &bio_flags, READ); |
| 3198 | if (bio) |
| 3199 | ret = submit_one_bio(READ, bio, mirror_num, bio_flags); |
| 3200 | return ret; |
| 3201 | } |
| 3202 | |
| 3203 | static void update_nr_written(struct page *page, struct writeback_control *wbc, |
| 3204 | unsigned long nr_written) |
| 3205 | { |
| 3206 | wbc->nr_to_write -= nr_written; |
| 3207 | } |
| 3208 | |
| 3209 | /* |
| 3210 | * helper for __extent_writepage, doing all of the delayed allocation setup. |
| 3211 | * |
| 3212 | * This returns 1 if our fill_delalloc function did all the work required |
| 3213 | * to write the page (copy into inline extent). In this case the IO has |
| 3214 | * been started and the page is already unlocked. |
| 3215 | * |
| 3216 | * This returns 0 if all went well (page still locked) |
| 3217 | * This returns < 0 if there were errors (page still locked) |
| 3218 | */ |
| 3219 | static noinline_for_stack int writepage_delalloc(struct inode *inode, |
| 3220 | struct page *page, struct writeback_control *wbc, |
| 3221 | struct extent_page_data *epd, |
| 3222 | u64 delalloc_start, |
| 3223 | unsigned long *nr_written) |
| 3224 | { |
| 3225 | struct extent_io_tree *tree = epd->tree; |
| 3226 | u64 page_end = delalloc_start + PAGE_SIZE - 1; |
| 3227 | u64 nr_delalloc; |
| 3228 | u64 delalloc_to_write = 0; |
| 3229 | u64 delalloc_end = 0; |
| 3230 | int ret; |
| 3231 | int page_started = 0; |
| 3232 | |
| 3233 | if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc) |
| 3234 | return 0; |
| 3235 | |
| 3236 | while (delalloc_end < page_end) { |
| 3237 | nr_delalloc = find_lock_delalloc_range(inode, tree, |
| 3238 | page, |
| 3239 | &delalloc_start, |
| 3240 | &delalloc_end, |
| 3241 | BTRFS_MAX_EXTENT_SIZE); |
| 3242 | if (nr_delalloc == 0) { |
| 3243 | delalloc_start = delalloc_end + 1; |
| 3244 | continue; |
| 3245 | } |
| 3246 | ret = tree->ops->fill_delalloc(inode, page, |
| 3247 | delalloc_start, |
| 3248 | delalloc_end, |
| 3249 | &page_started, |
| 3250 | nr_written); |
| 3251 | /* File system has been set read-only */ |
| 3252 | if (ret) { |
| 3253 | SetPageError(page); |
| 3254 | /* fill_delalloc should be return < 0 for error |
| 3255 | * but just in case, we use > 0 here meaning the |
| 3256 | * IO is started, so we don't want to return > 0 |
| 3257 | * unless things are going well. |
| 3258 | */ |
| 3259 | ret = ret < 0 ? ret : -EIO; |
| 3260 | goto done; |
| 3261 | } |
| 3262 | /* |
| 3263 | * delalloc_end is already one less than the total length, so |
| 3264 | * we don't subtract one from PAGE_SIZE |
| 3265 | */ |
| 3266 | delalloc_to_write += (delalloc_end - delalloc_start + |
| 3267 | PAGE_SIZE) >> PAGE_SHIFT; |
| 3268 | delalloc_start = delalloc_end + 1; |
| 3269 | } |
| 3270 | if (wbc->nr_to_write < delalloc_to_write) { |
| 3271 | int thresh = 8192; |
| 3272 | |
| 3273 | if (delalloc_to_write < thresh * 2) |
| 3274 | thresh = delalloc_to_write; |
| 3275 | wbc->nr_to_write = min_t(u64, delalloc_to_write, |
| 3276 | thresh); |
| 3277 | } |
| 3278 | |
| 3279 | /* did the fill delalloc function already unlock and start |
| 3280 | * the IO? |
| 3281 | */ |
| 3282 | if (page_started) { |
| 3283 | /* |
| 3284 | * we've unlocked the page, so we can't update |
| 3285 | * the mapping's writeback index, just update |
| 3286 | * nr_to_write. |
| 3287 | */ |
| 3288 | wbc->nr_to_write -= *nr_written; |
| 3289 | return 1; |
| 3290 | } |
| 3291 | |
| 3292 | ret = 0; |
| 3293 | |
| 3294 | done: |
| 3295 | return ret; |
| 3296 | } |
| 3297 | |
| 3298 | /* |
| 3299 | * helper for __extent_writepage. This calls the writepage start hooks, |
| 3300 | * and does the loop to map the page into extents and bios. |
| 3301 | * |
| 3302 | * We return 1 if the IO is started and the page is unlocked, |
| 3303 | * 0 if all went well (page still locked) |
| 3304 | * < 0 if there were errors (page still locked) |
| 3305 | */ |
| 3306 | static noinline_for_stack int __extent_writepage_io(struct inode *inode, |
| 3307 | struct page *page, |
| 3308 | struct writeback_control *wbc, |
| 3309 | struct extent_page_data *epd, |
| 3310 | loff_t i_size, |
| 3311 | unsigned long nr_written, |
| 3312 | int write_flags, int *nr_ret) |
| 3313 | { |
| 3314 | struct extent_io_tree *tree = epd->tree; |
| 3315 | u64 start = page_offset(page); |
| 3316 | u64 page_end = start + PAGE_SIZE - 1; |
| 3317 | u64 end; |
| 3318 | u64 cur = start; |
| 3319 | u64 extent_offset; |
| 3320 | u64 block_start; |
| 3321 | u64 iosize; |
| 3322 | sector_t sector; |
| 3323 | struct extent_state *cached_state = NULL; |
| 3324 | struct extent_map *em; |
| 3325 | struct block_device *bdev; |
| 3326 | size_t pg_offset = 0; |
| 3327 | size_t blocksize; |
| 3328 | int ret = 0; |
| 3329 | int nr = 0; |
| 3330 | bool compressed; |
| 3331 | |
| 3332 | if (tree->ops && tree->ops->writepage_start_hook) { |
| 3333 | ret = tree->ops->writepage_start_hook(page, start, |
| 3334 | page_end); |
| 3335 | if (ret) { |
| 3336 | /* Fixup worker will requeue */ |
| 3337 | if (ret == -EBUSY) |
| 3338 | wbc->pages_skipped++; |
| 3339 | else |
| 3340 | redirty_page_for_writepage(wbc, page); |
| 3341 | |
| 3342 | update_nr_written(page, wbc, nr_written); |
| 3343 | unlock_page(page); |
| 3344 | ret = 1; |
| 3345 | goto done_unlocked; |
| 3346 | } |
| 3347 | } |
| 3348 | |
| 3349 | /* |
| 3350 | * we don't want to touch the inode after unlocking the page, |
| 3351 | * so we update the mapping writeback index now |
| 3352 | */ |
| 3353 | update_nr_written(page, wbc, nr_written + 1); |
| 3354 | |
| 3355 | end = page_end; |
| 3356 | if (i_size <= start) { |
| 3357 | if (tree->ops && tree->ops->writepage_end_io_hook) |
| 3358 | tree->ops->writepage_end_io_hook(page, start, |
| 3359 | page_end, NULL, 1); |
| 3360 | goto done; |
| 3361 | } |
| 3362 | |
| 3363 | blocksize = inode->i_sb->s_blocksize; |
| 3364 | |
| 3365 | while (cur <= end) { |
| 3366 | u64 em_end; |
| 3367 | unsigned long max_nr; |
| 3368 | |
| 3369 | if (cur >= i_size) { |
| 3370 | if (tree->ops && tree->ops->writepage_end_io_hook) |
| 3371 | tree->ops->writepage_end_io_hook(page, cur, |
| 3372 | page_end, NULL, 1); |
| 3373 | break; |
| 3374 | } |
| 3375 | em = epd->get_extent(inode, page, pg_offset, cur, |
| 3376 | end - cur + 1, 1); |
| 3377 | if (IS_ERR_OR_NULL(em)) { |
| 3378 | SetPageError(page); |
| 3379 | ret = PTR_ERR_OR_ZERO(em); |
| 3380 | break; |
| 3381 | } |
| 3382 | |
| 3383 | extent_offset = cur - em->start; |
| 3384 | em_end = extent_map_end(em); |
| 3385 | BUG_ON(em_end <= cur); |
| 3386 | BUG_ON(end < cur); |
| 3387 | iosize = min(em_end - cur, end - cur + 1); |
| 3388 | iosize = ALIGN(iosize, blocksize); |
| 3389 | sector = (em->block_start + extent_offset) >> 9; |
| 3390 | bdev = em->bdev; |
| 3391 | block_start = em->block_start; |
| 3392 | compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
| 3393 | free_extent_map(em); |
| 3394 | em = NULL; |
| 3395 | |
| 3396 | /* |
| 3397 | * compressed and inline extents are written through other |
| 3398 | * paths in the FS |
| 3399 | */ |
| 3400 | if (compressed || block_start == EXTENT_MAP_HOLE || |
| 3401 | block_start == EXTENT_MAP_INLINE) { |
| 3402 | /* |
| 3403 | * end_io notification does not happen here for |
| 3404 | * compressed extents |
| 3405 | */ |
| 3406 | if (!compressed && tree->ops && |
| 3407 | tree->ops->writepage_end_io_hook) |
| 3408 | tree->ops->writepage_end_io_hook(page, cur, |
| 3409 | cur + iosize - 1, |
| 3410 | NULL, 1); |
| 3411 | else if (compressed) { |
| 3412 | /* we don't want to end_page_writeback on |
| 3413 | * a compressed extent. this happens |
| 3414 | * elsewhere |
| 3415 | */ |
| 3416 | nr++; |
| 3417 | } |
| 3418 | |
| 3419 | cur += iosize; |
| 3420 | pg_offset += iosize; |
| 3421 | continue; |
| 3422 | } |
| 3423 | |
| 3424 | max_nr = (i_size >> PAGE_SHIFT) + 1; |
| 3425 | |
| 3426 | set_range_writeback(tree, cur, cur + iosize - 1); |
| 3427 | if (!PageWriteback(page)) { |
| 3428 | btrfs_err(BTRFS_I(inode)->root->fs_info, |
| 3429 | "page %lu not writeback, cur %llu end %llu", |
| 3430 | page->index, cur, end); |
| 3431 | } |
| 3432 | |
| 3433 | ret = submit_extent_page(write_flags, tree, wbc, page, |
| 3434 | sector, iosize, pg_offset, |
| 3435 | bdev, &epd->bio, max_nr, |
| 3436 | end_bio_extent_writepage, |
| 3437 | 0, 0, 0, false); |
| 3438 | if (ret) |
| 3439 | SetPageError(page); |
| 3440 | |
| 3441 | cur = cur + iosize; |
| 3442 | pg_offset += iosize; |
| 3443 | nr++; |
| 3444 | } |
| 3445 | done: |
| 3446 | *nr_ret = nr; |
| 3447 | |
| 3448 | done_unlocked: |
| 3449 | |
| 3450 | /* drop our reference on any cached states */ |
| 3451 | free_extent_state(cached_state); |
| 3452 | return ret; |
| 3453 | } |
| 3454 | |
| 3455 | /* |
| 3456 | * the writepage semantics are similar to regular writepage. extent |
| 3457 | * records are inserted to lock ranges in the tree, and as dirty areas |
| 3458 | * are found, they are marked writeback. Then the lock bits are removed |
| 3459 | * and the end_io handler clears the writeback ranges |
| 3460 | */ |
| 3461 | static int __extent_writepage(struct page *page, struct writeback_control *wbc, |
| 3462 | void *data) |
| 3463 | { |
| 3464 | struct inode *inode = page->mapping->host; |
| 3465 | struct extent_page_data *epd = data; |
| 3466 | u64 start = page_offset(page); |
| 3467 | u64 page_end = start + PAGE_SIZE - 1; |
| 3468 | int ret; |
| 3469 | int nr = 0; |
| 3470 | size_t pg_offset = 0; |
| 3471 | loff_t i_size = i_size_read(inode); |
| 3472 | unsigned long end_index = i_size >> PAGE_SHIFT; |
| 3473 | int write_flags; |
| 3474 | unsigned long nr_written = 0; |
| 3475 | |
| 3476 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 3477 | write_flags = WRITE_SYNC; |
| 3478 | else |
| 3479 | write_flags = WRITE; |
| 3480 | |
| 3481 | trace___extent_writepage(page, inode, wbc); |
| 3482 | |
| 3483 | WARN_ON(!PageLocked(page)); |
| 3484 | |
| 3485 | ClearPageError(page); |
| 3486 | |
| 3487 | pg_offset = i_size & (PAGE_SIZE - 1); |
| 3488 | if (page->index > end_index || |
| 3489 | (page->index == end_index && !pg_offset)) { |
| 3490 | page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE); |
| 3491 | unlock_page(page); |
| 3492 | return 0; |
| 3493 | } |
| 3494 | |
| 3495 | if (page->index == end_index) { |
| 3496 | char *userpage; |
| 3497 | |
| 3498 | userpage = kmap_atomic(page); |
| 3499 | memset(userpage + pg_offset, 0, |
| 3500 | PAGE_SIZE - pg_offset); |
| 3501 | kunmap_atomic(userpage); |
| 3502 | flush_dcache_page(page); |
| 3503 | } |
| 3504 | |
| 3505 | pg_offset = 0; |
| 3506 | |
| 3507 | set_page_extent_mapped(page); |
| 3508 | |
| 3509 | ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written); |
| 3510 | if (ret == 1) |
| 3511 | goto done_unlocked; |
| 3512 | if (ret) |
| 3513 | goto done; |
| 3514 | |
| 3515 | ret = __extent_writepage_io(inode, page, wbc, epd, |
| 3516 | i_size, nr_written, write_flags, &nr); |
| 3517 | if (ret == 1) |
| 3518 | goto done_unlocked; |
| 3519 | |
| 3520 | done: |
| 3521 | if (nr == 0) { |
| 3522 | /* make sure the mapping tag for page dirty gets cleared */ |
| 3523 | set_page_writeback(page); |
| 3524 | end_page_writeback(page); |
| 3525 | } |
| 3526 | if (PageError(page)) { |
| 3527 | ret = ret < 0 ? ret : -EIO; |
| 3528 | end_extent_writepage(page, ret, start, page_end); |
| 3529 | } |
| 3530 | unlock_page(page); |
| 3531 | return ret; |
| 3532 | |
| 3533 | done_unlocked: |
| 3534 | return 0; |
| 3535 | } |
| 3536 | |
| 3537 | void wait_on_extent_buffer_writeback(struct extent_buffer *eb) |
| 3538 | { |
| 3539 | wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, |
| 3540 | TASK_UNINTERRUPTIBLE); |
| 3541 | } |
| 3542 | |
| 3543 | static noinline_for_stack int |
| 3544 | lock_extent_buffer_for_io(struct extent_buffer *eb, |
| 3545 | struct btrfs_fs_info *fs_info, |
| 3546 | struct extent_page_data *epd) |
| 3547 | { |
| 3548 | unsigned long i, num_pages; |
| 3549 | int flush = 0; |
| 3550 | int ret = 0; |
| 3551 | |
| 3552 | if (!btrfs_try_tree_write_lock(eb)) { |
| 3553 | flush = 1; |
| 3554 | flush_write_bio(epd); |
| 3555 | btrfs_tree_lock(eb); |
| 3556 | } |
| 3557 | |
| 3558 | if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { |
| 3559 | btrfs_tree_unlock(eb); |
| 3560 | if (!epd->sync_io) |
| 3561 | return 0; |
| 3562 | if (!flush) { |
| 3563 | flush_write_bio(epd); |
| 3564 | flush = 1; |
| 3565 | } |
| 3566 | while (1) { |
| 3567 | wait_on_extent_buffer_writeback(eb); |
| 3568 | btrfs_tree_lock(eb); |
| 3569 | if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) |
| 3570 | break; |
| 3571 | btrfs_tree_unlock(eb); |
| 3572 | } |
| 3573 | } |
| 3574 | |
| 3575 | /* |
| 3576 | * We need to do this to prevent races in people who check if the eb is |
| 3577 | * under IO since we can end up having no IO bits set for a short period |
| 3578 | * of time. |
| 3579 | */ |
| 3580 | spin_lock(&eb->refs_lock); |
| 3581 | if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { |
| 3582 | set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); |
| 3583 | spin_unlock(&eb->refs_lock); |
| 3584 | btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); |
| 3585 | __percpu_counter_add(&fs_info->dirty_metadata_bytes, |
| 3586 | -eb->len, |
| 3587 | fs_info->dirty_metadata_batch); |
| 3588 | ret = 1; |
| 3589 | } else { |
| 3590 | spin_unlock(&eb->refs_lock); |
| 3591 | } |
| 3592 | |
| 3593 | btrfs_tree_unlock(eb); |
| 3594 | |
| 3595 | if (!ret) |
| 3596 | return ret; |
| 3597 | |
| 3598 | num_pages = num_extent_pages(eb->start, eb->len); |
| 3599 | for (i = 0; i < num_pages; i++) { |
| 3600 | struct page *p = eb->pages[i]; |
| 3601 | |
| 3602 | if (!trylock_page(p)) { |
| 3603 | if (!flush) { |
| 3604 | flush_write_bio(epd); |
| 3605 | flush = 1; |
| 3606 | } |
| 3607 | lock_page(p); |
| 3608 | } |
| 3609 | } |
| 3610 | |
| 3611 | return ret; |
| 3612 | } |
| 3613 | |
| 3614 | static void end_extent_buffer_writeback(struct extent_buffer *eb) |
| 3615 | { |
| 3616 | clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); |
| 3617 | smp_mb__after_atomic(); |
| 3618 | wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK); |
| 3619 | } |
| 3620 | |
| 3621 | static void set_btree_ioerr(struct page *page) |
| 3622 | { |
| 3623 | struct extent_buffer *eb = (struct extent_buffer *)page->private; |
| 3624 | struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode); |
| 3625 | |
| 3626 | SetPageError(page); |
| 3627 | if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) |
| 3628 | return; |
| 3629 | |
| 3630 | /* |
| 3631 | * If writeback for a btree extent that doesn't belong to a log tree |
| 3632 | * failed, increment the counter transaction->eb_write_errors. |
| 3633 | * We do this because while the transaction is running and before it's |
| 3634 | * committing (when we call filemap_fdata[write|wait]_range against |
| 3635 | * the btree inode), we might have |
| 3636 | * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it |
| 3637 | * returns an error or an error happens during writeback, when we're |
| 3638 | * committing the transaction we wouldn't know about it, since the pages |
| 3639 | * can be no longer dirty nor marked anymore for writeback (if a |
| 3640 | * subsequent modification to the extent buffer didn't happen before the |
| 3641 | * transaction commit), which makes filemap_fdata[write|wait]_range not |
| 3642 | * able to find the pages tagged with SetPageError at transaction |
| 3643 | * commit time. So if this happens we must abort the transaction, |
| 3644 | * otherwise we commit a super block with btree roots that point to |
| 3645 | * btree nodes/leafs whose content on disk is invalid - either garbage |
| 3646 | * or the content of some node/leaf from a past generation that got |
| 3647 | * cowed or deleted and is no longer valid. |
| 3648 | * |
| 3649 | * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would |
| 3650 | * not be enough - we need to distinguish between log tree extents vs |
| 3651 | * non-log tree extents, and the next filemap_fdatawait_range() call |
| 3652 | * will catch and clear such errors in the mapping - and that call might |
| 3653 | * be from a log sync and not from a transaction commit. Also, checking |
| 3654 | * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is |
| 3655 | * not done and would not be reliable - the eb might have been released |
| 3656 | * from memory and reading it back again means that flag would not be |
| 3657 | * set (since it's a runtime flag, not persisted on disk). |
| 3658 | * |
| 3659 | * Using the flags below in the btree inode also makes us achieve the |
| 3660 | * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started |
| 3661 | * writeback for all dirty pages and before filemap_fdatawait_range() |
| 3662 | * is called, the writeback for all dirty pages had already finished |
| 3663 | * with errors - because we were not using AS_EIO/AS_ENOSPC, |
| 3664 | * filemap_fdatawait_range() would return success, as it could not know |
| 3665 | * that writeback errors happened (the pages were no longer tagged for |
| 3666 | * writeback). |
| 3667 | */ |
| 3668 | switch (eb->log_index) { |
| 3669 | case -1: |
| 3670 | set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags); |
| 3671 | break; |
| 3672 | case 0: |
| 3673 | set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags); |
| 3674 | break; |
| 3675 | case 1: |
| 3676 | set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags); |
| 3677 | break; |
| 3678 | default: |
| 3679 | BUG(); /* unexpected, logic error */ |
| 3680 | } |
| 3681 | } |
| 3682 | |
| 3683 | static void end_bio_extent_buffer_writepage(struct bio *bio) |
| 3684 | { |
| 3685 | struct bio_vec *bvec; |
| 3686 | struct extent_buffer *eb; |
| 3687 | int i, done; |
| 3688 | |
| 3689 | bio_for_each_segment_all(bvec, bio, i) { |
| 3690 | struct page *page = bvec->bv_page; |
| 3691 | |
| 3692 | eb = (struct extent_buffer *)page->private; |
| 3693 | BUG_ON(!eb); |
| 3694 | done = atomic_dec_and_test(&eb->io_pages); |
| 3695 | |
| 3696 | if (bio->bi_error || |
| 3697 | test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) { |
| 3698 | ClearPageUptodate(page); |
| 3699 | set_btree_ioerr(page); |
| 3700 | } |
| 3701 | |
| 3702 | end_page_writeback(page); |
| 3703 | |
| 3704 | if (!done) |
| 3705 | continue; |
| 3706 | |
| 3707 | end_extent_buffer_writeback(eb); |
| 3708 | } |
| 3709 | |
| 3710 | bio_put(bio); |
| 3711 | } |
| 3712 | |
| 3713 | static noinline_for_stack int write_one_eb(struct extent_buffer *eb, |
| 3714 | struct btrfs_fs_info *fs_info, |
| 3715 | struct writeback_control *wbc, |
| 3716 | struct extent_page_data *epd) |
| 3717 | { |
| 3718 | struct block_device *bdev = fs_info->fs_devices->latest_bdev; |
| 3719 | struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree; |
| 3720 | u64 offset = eb->start; |
| 3721 | unsigned long i, num_pages; |
| 3722 | unsigned long bio_flags = 0; |
| 3723 | int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META; |
| 3724 | int ret = 0; |
| 3725 | |
| 3726 | clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags); |
| 3727 | num_pages = num_extent_pages(eb->start, eb->len); |
| 3728 | atomic_set(&eb->io_pages, num_pages); |
| 3729 | if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) |
| 3730 | bio_flags = EXTENT_BIO_TREE_LOG; |
| 3731 | |
| 3732 | for (i = 0; i < num_pages; i++) { |
| 3733 | struct page *p = eb->pages[i]; |
| 3734 | |
| 3735 | clear_page_dirty_for_io(p); |
| 3736 | set_page_writeback(p); |
| 3737 | ret = submit_extent_page(rw, tree, wbc, p, offset >> 9, |
| 3738 | PAGE_SIZE, 0, bdev, &epd->bio, |
| 3739 | -1, end_bio_extent_buffer_writepage, |
| 3740 | 0, epd->bio_flags, bio_flags, false); |
| 3741 | epd->bio_flags = bio_flags; |
| 3742 | if (ret) { |
| 3743 | set_btree_ioerr(p); |
| 3744 | end_page_writeback(p); |
| 3745 | if (atomic_sub_and_test(num_pages - i, &eb->io_pages)) |
| 3746 | end_extent_buffer_writeback(eb); |
| 3747 | ret = -EIO; |
| 3748 | break; |
| 3749 | } |
| 3750 | offset += PAGE_SIZE; |
| 3751 | update_nr_written(p, wbc, 1); |
| 3752 | unlock_page(p); |
| 3753 | } |
| 3754 | |
| 3755 | if (unlikely(ret)) { |
| 3756 | for (; i < num_pages; i++) { |
| 3757 | struct page *p = eb->pages[i]; |
| 3758 | clear_page_dirty_for_io(p); |
| 3759 | unlock_page(p); |
| 3760 | } |
| 3761 | } |
| 3762 | |
| 3763 | return ret; |
| 3764 | } |
| 3765 | |
| 3766 | int btree_write_cache_pages(struct address_space *mapping, |
| 3767 | struct writeback_control *wbc) |
| 3768 | { |
| 3769 | struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree; |
| 3770 | struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info; |
| 3771 | struct extent_buffer *eb, *prev_eb = NULL; |
| 3772 | struct extent_page_data epd = { |
| 3773 | .bio = NULL, |
| 3774 | .tree = tree, |
| 3775 | .extent_locked = 0, |
| 3776 | .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| 3777 | .bio_flags = 0, |
| 3778 | }; |
| 3779 | int ret = 0; |
| 3780 | int done = 0; |
| 3781 | int nr_to_write_done = 0; |
| 3782 | struct pagevec pvec; |
| 3783 | int nr_pages; |
| 3784 | pgoff_t index; |
| 3785 | pgoff_t end; /* Inclusive */ |
| 3786 | int scanned = 0; |
| 3787 | int tag; |
| 3788 | |
| 3789 | pagevec_init(&pvec, 0); |
| 3790 | if (wbc->range_cyclic) { |
| 3791 | index = mapping->writeback_index; /* Start from prev offset */ |
| 3792 | end = -1; |
| 3793 | } else { |
| 3794 | index = wbc->range_start >> PAGE_SHIFT; |
| 3795 | end = wbc->range_end >> PAGE_SHIFT; |
| 3796 | scanned = 1; |
| 3797 | } |
| 3798 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 3799 | tag = PAGECACHE_TAG_TOWRITE; |
| 3800 | else |
| 3801 | tag = PAGECACHE_TAG_DIRTY; |
| 3802 | retry: |
| 3803 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 3804 | tag_pages_for_writeback(mapping, index, end); |
| 3805 | while (!done && !nr_to_write_done && (index <= end) && |
| 3806 | (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, |
| 3807 | min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { |
| 3808 | unsigned i; |
| 3809 | |
| 3810 | scanned = 1; |
| 3811 | for (i = 0; i < nr_pages; i++) { |
| 3812 | struct page *page = pvec.pages[i]; |
| 3813 | |
| 3814 | if (!PagePrivate(page)) |
| 3815 | continue; |
| 3816 | |
| 3817 | if (!wbc->range_cyclic && page->index > end) { |
| 3818 | done = 1; |
| 3819 | break; |
| 3820 | } |
| 3821 | |
| 3822 | spin_lock(&mapping->private_lock); |
| 3823 | if (!PagePrivate(page)) { |
| 3824 | spin_unlock(&mapping->private_lock); |
| 3825 | continue; |
| 3826 | } |
| 3827 | |
| 3828 | eb = (struct extent_buffer *)page->private; |
| 3829 | |
| 3830 | /* |
| 3831 | * Shouldn't happen and normally this would be a BUG_ON |
| 3832 | * but no sense in crashing the users box for something |
| 3833 | * we can survive anyway. |
| 3834 | */ |
| 3835 | if (WARN_ON(!eb)) { |
| 3836 | spin_unlock(&mapping->private_lock); |
| 3837 | continue; |
| 3838 | } |
| 3839 | |
| 3840 | if (eb == prev_eb) { |
| 3841 | spin_unlock(&mapping->private_lock); |
| 3842 | continue; |
| 3843 | } |
| 3844 | |
| 3845 | ret = atomic_inc_not_zero(&eb->refs); |
| 3846 | spin_unlock(&mapping->private_lock); |
| 3847 | if (!ret) |
| 3848 | continue; |
| 3849 | |
| 3850 | prev_eb = eb; |
| 3851 | ret = lock_extent_buffer_for_io(eb, fs_info, &epd); |
| 3852 | if (!ret) { |
| 3853 | free_extent_buffer(eb); |
| 3854 | continue; |
| 3855 | } |
| 3856 | |
| 3857 | ret = write_one_eb(eb, fs_info, wbc, &epd); |
| 3858 | if (ret) { |
| 3859 | done = 1; |
| 3860 | free_extent_buffer(eb); |
| 3861 | break; |
| 3862 | } |
| 3863 | free_extent_buffer(eb); |
| 3864 | |
| 3865 | /* |
| 3866 | * the filesystem may choose to bump up nr_to_write. |
| 3867 | * We have to make sure to honor the new nr_to_write |
| 3868 | * at any time |
| 3869 | */ |
| 3870 | nr_to_write_done = wbc->nr_to_write <= 0; |
| 3871 | } |
| 3872 | pagevec_release(&pvec); |
| 3873 | cond_resched(); |
| 3874 | } |
| 3875 | if (!scanned && !done) { |
| 3876 | /* |
| 3877 | * We hit the last page and there is more work to be done: wrap |
| 3878 | * back to the start of the file |
| 3879 | */ |
| 3880 | scanned = 1; |
| 3881 | index = 0; |
| 3882 | goto retry; |
| 3883 | } |
| 3884 | flush_write_bio(&epd); |
| 3885 | return ret; |
| 3886 | } |
| 3887 | |
| 3888 | /** |
| 3889 | * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. |
| 3890 | * @mapping: address space structure to write |
| 3891 | * @wbc: subtract the number of written pages from *@wbc->nr_to_write |
| 3892 | * @writepage: function called for each page |
| 3893 | * @data: data passed to writepage function |
| 3894 | * |
| 3895 | * If a page is already under I/O, write_cache_pages() skips it, even |
| 3896 | * if it's dirty. This is desirable behaviour for memory-cleaning writeback, |
| 3897 | * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() |
| 3898 | * and msync() need to guarantee that all the data which was dirty at the time |
| 3899 | * the call was made get new I/O started against them. If wbc->sync_mode is |
| 3900 | * WB_SYNC_ALL then we were called for data integrity and we must wait for |
| 3901 | * existing IO to complete. |
| 3902 | */ |
| 3903 | static int extent_write_cache_pages(struct extent_io_tree *tree, |
| 3904 | struct address_space *mapping, |
| 3905 | struct writeback_control *wbc, |
| 3906 | writepage_t writepage, void *data, |
| 3907 | void (*flush_fn)(void *)) |
| 3908 | { |
| 3909 | struct inode *inode = mapping->host; |
| 3910 | int ret = 0; |
| 3911 | int done = 0; |
| 3912 | int nr_to_write_done = 0; |
| 3913 | struct pagevec pvec; |
| 3914 | int nr_pages; |
| 3915 | pgoff_t index; |
| 3916 | pgoff_t end; /* Inclusive */ |
| 3917 | pgoff_t done_index; |
| 3918 | int range_whole = 0; |
| 3919 | int scanned = 0; |
| 3920 | int tag; |
| 3921 | |
| 3922 | /* |
| 3923 | * We have to hold onto the inode so that ordered extents can do their |
| 3924 | * work when the IO finishes. The alternative to this is failing to add |
| 3925 | * an ordered extent if the igrab() fails there and that is a huge pain |
| 3926 | * to deal with, so instead just hold onto the inode throughout the |
| 3927 | * writepages operation. If it fails here we are freeing up the inode |
| 3928 | * anyway and we'd rather not waste our time writing out stuff that is |
| 3929 | * going to be truncated anyway. |
| 3930 | */ |
| 3931 | if (!igrab(inode)) |
| 3932 | return 0; |
| 3933 | |
| 3934 | pagevec_init(&pvec, 0); |
| 3935 | if (wbc->range_cyclic) { |
| 3936 | index = mapping->writeback_index; /* Start from prev offset */ |
| 3937 | end = -1; |
| 3938 | } else { |
| 3939 | index = wbc->range_start >> PAGE_SHIFT; |
| 3940 | end = wbc->range_end >> PAGE_SHIFT; |
| 3941 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) |
| 3942 | range_whole = 1; |
| 3943 | scanned = 1; |
| 3944 | } |
| 3945 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 3946 | tag = PAGECACHE_TAG_TOWRITE; |
| 3947 | else |
| 3948 | tag = PAGECACHE_TAG_DIRTY; |
| 3949 | retry: |
| 3950 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 3951 | tag_pages_for_writeback(mapping, index, end); |
| 3952 | done_index = index; |
| 3953 | while (!done && !nr_to_write_done && (index <= end) && |
| 3954 | (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, |
| 3955 | min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { |
| 3956 | unsigned i; |
| 3957 | |
| 3958 | scanned = 1; |
| 3959 | for (i = 0; i < nr_pages; i++) { |
| 3960 | struct page *page = pvec.pages[i]; |
| 3961 | |
| 3962 | done_index = page->index; |
| 3963 | /* |
| 3964 | * At this point we hold neither mapping->tree_lock nor |
| 3965 | * lock on the page itself: the page may be truncated or |
| 3966 | * invalidated (changing page->mapping to NULL), or even |
| 3967 | * swizzled back from swapper_space to tmpfs file |
| 3968 | * mapping |
| 3969 | */ |
| 3970 | if (!trylock_page(page)) { |
| 3971 | flush_fn(data); |
| 3972 | lock_page(page); |
| 3973 | } |
| 3974 | |
| 3975 | if (unlikely(page->mapping != mapping)) { |
| 3976 | unlock_page(page); |
| 3977 | continue; |
| 3978 | } |
| 3979 | |
| 3980 | if (!wbc->range_cyclic && page->index > end) { |
| 3981 | done = 1; |
| 3982 | unlock_page(page); |
| 3983 | continue; |
| 3984 | } |
| 3985 | |
| 3986 | if (wbc->sync_mode != WB_SYNC_NONE) { |
| 3987 | if (PageWriteback(page)) |
| 3988 | flush_fn(data); |
| 3989 | wait_on_page_writeback(page); |
| 3990 | } |
| 3991 | |
| 3992 | if (PageWriteback(page) || |
| 3993 | !clear_page_dirty_for_io(page)) { |
| 3994 | unlock_page(page); |
| 3995 | continue; |
| 3996 | } |
| 3997 | |
| 3998 | ret = (*writepage)(page, wbc, data); |
| 3999 | |
| 4000 | if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) { |
| 4001 | unlock_page(page); |
| 4002 | ret = 0; |
| 4003 | } |
| 4004 | if (ret < 0) { |
| 4005 | /* |
| 4006 | * done_index is set past this page, |
| 4007 | * so media errors will not choke |
| 4008 | * background writeout for the entire |
| 4009 | * file. This has consequences for |
| 4010 | * range_cyclic semantics (ie. it may |
| 4011 | * not be suitable for data integrity |
| 4012 | * writeout). |
| 4013 | */ |
| 4014 | done_index = page->index + 1; |
| 4015 | done = 1; |
| 4016 | break; |
| 4017 | } |
| 4018 | |
| 4019 | /* |
| 4020 | * the filesystem may choose to bump up nr_to_write. |
| 4021 | * We have to make sure to honor the new nr_to_write |
| 4022 | * at any time |
| 4023 | */ |
| 4024 | nr_to_write_done = wbc->nr_to_write <= 0; |
| 4025 | } |
| 4026 | pagevec_release(&pvec); |
| 4027 | cond_resched(); |
| 4028 | } |
| 4029 | if (!scanned && !done) { |
| 4030 | /* |
| 4031 | * We hit the last page and there is more work to be done: wrap |
| 4032 | * back to the start of the file |
| 4033 | */ |
| 4034 | scanned = 1; |
| 4035 | index = 0; |
| 4036 | goto retry; |
| 4037 | } |
| 4038 | |
| 4039 | if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole)) |
| 4040 | mapping->writeback_index = done_index; |
| 4041 | |
| 4042 | btrfs_add_delayed_iput(inode); |
| 4043 | return ret; |
| 4044 | } |
| 4045 | |
| 4046 | static void flush_epd_write_bio(struct extent_page_data *epd) |
| 4047 | { |
| 4048 | if (epd->bio) { |
| 4049 | int rw = WRITE; |
| 4050 | int ret; |
| 4051 | |
| 4052 | if (epd->sync_io) |
| 4053 | rw = WRITE_SYNC; |
| 4054 | |
| 4055 | ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags); |
| 4056 | BUG_ON(ret < 0); /* -ENOMEM */ |
| 4057 | epd->bio = NULL; |
| 4058 | } |
| 4059 | } |
| 4060 | |
| 4061 | static noinline void flush_write_bio(void *data) |
| 4062 | { |
| 4063 | struct extent_page_data *epd = data; |
| 4064 | flush_epd_write_bio(epd); |
| 4065 | } |
| 4066 | |
| 4067 | int extent_write_full_page(struct extent_io_tree *tree, struct page *page, |
| 4068 | get_extent_t *get_extent, |
| 4069 | struct writeback_control *wbc) |
| 4070 | { |
| 4071 | int ret; |
| 4072 | struct extent_page_data epd = { |
| 4073 | .bio = NULL, |
| 4074 | .tree = tree, |
| 4075 | .get_extent = get_extent, |
| 4076 | .extent_locked = 0, |
| 4077 | .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| 4078 | .bio_flags = 0, |
| 4079 | }; |
| 4080 | |
| 4081 | ret = __extent_writepage(page, wbc, &epd); |
| 4082 | |
| 4083 | flush_epd_write_bio(&epd); |
| 4084 | return ret; |
| 4085 | } |
| 4086 | |
| 4087 | int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode, |
| 4088 | u64 start, u64 end, get_extent_t *get_extent, |
| 4089 | int mode) |
| 4090 | { |
| 4091 | int ret = 0; |
| 4092 | struct address_space *mapping = inode->i_mapping; |
| 4093 | struct page *page; |
| 4094 | unsigned long nr_pages = (end - start + PAGE_SIZE) >> |
| 4095 | PAGE_SHIFT; |
| 4096 | |
| 4097 | struct extent_page_data epd = { |
| 4098 | .bio = NULL, |
| 4099 | .tree = tree, |
| 4100 | .get_extent = get_extent, |
| 4101 | .extent_locked = 1, |
| 4102 | .sync_io = mode == WB_SYNC_ALL, |
| 4103 | .bio_flags = 0, |
| 4104 | }; |
| 4105 | struct writeback_control wbc_writepages = { |
| 4106 | .sync_mode = mode, |
| 4107 | .nr_to_write = nr_pages * 2, |
| 4108 | .range_start = start, |
| 4109 | .range_end = end + 1, |
| 4110 | }; |
| 4111 | |
| 4112 | while (start <= end) { |
| 4113 | page = find_get_page(mapping, start >> PAGE_SHIFT); |
| 4114 | if (clear_page_dirty_for_io(page)) |
| 4115 | ret = __extent_writepage(page, &wbc_writepages, &epd); |
| 4116 | else { |
| 4117 | if (tree->ops && tree->ops->writepage_end_io_hook) |
| 4118 | tree->ops->writepage_end_io_hook(page, start, |
| 4119 | start + PAGE_SIZE - 1, |
| 4120 | NULL, 1); |
| 4121 | unlock_page(page); |
| 4122 | } |
| 4123 | put_page(page); |
| 4124 | start += PAGE_SIZE; |
| 4125 | } |
| 4126 | |
| 4127 | flush_epd_write_bio(&epd); |
| 4128 | return ret; |
| 4129 | } |
| 4130 | |
| 4131 | int extent_writepages(struct extent_io_tree *tree, |
| 4132 | struct address_space *mapping, |
| 4133 | get_extent_t *get_extent, |
| 4134 | struct writeback_control *wbc) |
| 4135 | { |
| 4136 | int ret = 0; |
| 4137 | struct extent_page_data epd = { |
| 4138 | .bio = NULL, |
| 4139 | .tree = tree, |
| 4140 | .get_extent = get_extent, |
| 4141 | .extent_locked = 0, |
| 4142 | .sync_io = wbc->sync_mode == WB_SYNC_ALL, |
| 4143 | .bio_flags = 0, |
| 4144 | }; |
| 4145 | |
| 4146 | ret = extent_write_cache_pages(tree, mapping, wbc, |
| 4147 | __extent_writepage, &epd, |
| 4148 | flush_write_bio); |
| 4149 | flush_epd_write_bio(&epd); |
| 4150 | return ret; |
| 4151 | } |
| 4152 | |
| 4153 | int extent_readpages(struct extent_io_tree *tree, |
| 4154 | struct address_space *mapping, |
| 4155 | struct list_head *pages, unsigned nr_pages, |
| 4156 | get_extent_t get_extent) |
| 4157 | { |
| 4158 | struct bio *bio = NULL; |
| 4159 | unsigned page_idx; |
| 4160 | unsigned long bio_flags = 0; |
| 4161 | struct page *pagepool[16]; |
| 4162 | struct page *page; |
| 4163 | struct extent_map *em_cached = NULL; |
| 4164 | int nr = 0; |
| 4165 | u64 prev_em_start = (u64)-1; |
| 4166 | |
| 4167 | for (page_idx = 0; page_idx < nr_pages; page_idx++) { |
| 4168 | page = list_entry(pages->prev, struct page, lru); |
| 4169 | |
| 4170 | prefetchw(&page->flags); |
| 4171 | list_del(&page->lru); |
| 4172 | if (add_to_page_cache_lru(page, mapping, |
| 4173 | page->index, GFP_NOFS)) { |
| 4174 | put_page(page); |
| 4175 | continue; |
| 4176 | } |
| 4177 | |
| 4178 | pagepool[nr++] = page; |
| 4179 | if (nr < ARRAY_SIZE(pagepool)) |
| 4180 | continue; |
| 4181 | __extent_readpages(tree, pagepool, nr, get_extent, &em_cached, |
| 4182 | &bio, 0, &bio_flags, READ, &prev_em_start); |
| 4183 | nr = 0; |
| 4184 | } |
| 4185 | if (nr) |
| 4186 | __extent_readpages(tree, pagepool, nr, get_extent, &em_cached, |
| 4187 | &bio, 0, &bio_flags, READ, &prev_em_start); |
| 4188 | |
| 4189 | if (em_cached) |
| 4190 | free_extent_map(em_cached); |
| 4191 | |
| 4192 | BUG_ON(!list_empty(pages)); |
| 4193 | if (bio) |
| 4194 | return submit_one_bio(READ, bio, 0, bio_flags); |
| 4195 | return 0; |
| 4196 | } |
| 4197 | |
| 4198 | /* |
| 4199 | * basic invalidatepage code, this waits on any locked or writeback |
| 4200 | * ranges corresponding to the page, and then deletes any extent state |
| 4201 | * records from the tree |
| 4202 | */ |
| 4203 | int extent_invalidatepage(struct extent_io_tree *tree, |
| 4204 | struct page *page, unsigned long offset) |
| 4205 | { |
| 4206 | struct extent_state *cached_state = NULL; |
| 4207 | u64 start = page_offset(page); |
| 4208 | u64 end = start + PAGE_SIZE - 1; |
| 4209 | size_t blocksize = page->mapping->host->i_sb->s_blocksize; |
| 4210 | |
| 4211 | start += ALIGN(offset, blocksize); |
| 4212 | if (start > end) |
| 4213 | return 0; |
| 4214 | |
| 4215 | lock_extent_bits(tree, start, end, &cached_state); |
| 4216 | wait_on_page_writeback(page); |
| 4217 | clear_extent_bit(tree, start, end, |
| 4218 | EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | |
| 4219 | EXTENT_DO_ACCOUNTING, |
| 4220 | 1, 1, &cached_state, GFP_NOFS); |
| 4221 | return 0; |
| 4222 | } |
| 4223 | |
| 4224 | /* |
| 4225 | * a helper for releasepage, this tests for areas of the page that |
| 4226 | * are locked or under IO and drops the related state bits if it is safe |
| 4227 | * to drop the page. |
| 4228 | */ |
| 4229 | static int try_release_extent_state(struct extent_map_tree *map, |
| 4230 | struct extent_io_tree *tree, |
| 4231 | struct page *page, gfp_t mask) |
| 4232 | { |
| 4233 | u64 start = page_offset(page); |
| 4234 | u64 end = start + PAGE_SIZE - 1; |
| 4235 | int ret = 1; |
| 4236 | |
| 4237 | if (test_range_bit(tree, start, end, |
| 4238 | EXTENT_IOBITS, 0, NULL)) |
| 4239 | ret = 0; |
| 4240 | else { |
| 4241 | if ((mask & GFP_NOFS) == GFP_NOFS) |
| 4242 | mask = GFP_NOFS; |
| 4243 | /* |
| 4244 | * at this point we can safely clear everything except the |
| 4245 | * locked bit and the nodatasum bit |
| 4246 | */ |
| 4247 | ret = clear_extent_bit(tree, start, end, |
| 4248 | ~(EXTENT_LOCKED | EXTENT_NODATASUM), |
| 4249 | 0, 0, NULL, mask); |
| 4250 | |
| 4251 | /* if clear_extent_bit failed for enomem reasons, |
| 4252 | * we can't allow the release to continue. |
| 4253 | */ |
| 4254 | if (ret < 0) |
| 4255 | ret = 0; |
| 4256 | else |
| 4257 | ret = 1; |
| 4258 | } |
| 4259 | return ret; |
| 4260 | } |
| 4261 | |
| 4262 | /* |
| 4263 | * a helper for releasepage. As long as there are no locked extents |
| 4264 | * in the range corresponding to the page, both state records and extent |
| 4265 | * map records are removed |
| 4266 | */ |
| 4267 | int try_release_extent_mapping(struct extent_map_tree *map, |
| 4268 | struct extent_io_tree *tree, struct page *page, |
| 4269 | gfp_t mask) |
| 4270 | { |
| 4271 | struct extent_map *em; |
| 4272 | u64 start = page_offset(page); |
| 4273 | u64 end = start + PAGE_SIZE - 1; |
| 4274 | |
| 4275 | if (gfpflags_allow_blocking(mask) && |
| 4276 | page->mapping->host->i_size > SZ_16M) { |
| 4277 | u64 len; |
| 4278 | while (start <= end) { |
| 4279 | len = end - start + 1; |
| 4280 | write_lock(&map->lock); |
| 4281 | em = lookup_extent_mapping(map, start, len); |
| 4282 | if (!em) { |
| 4283 | write_unlock(&map->lock); |
| 4284 | break; |
| 4285 | } |
| 4286 | if (test_bit(EXTENT_FLAG_PINNED, &em->flags) || |
| 4287 | em->start != start) { |
| 4288 | write_unlock(&map->lock); |
| 4289 | free_extent_map(em); |
| 4290 | break; |
| 4291 | } |
| 4292 | if (!test_range_bit(tree, em->start, |
| 4293 | extent_map_end(em) - 1, |
| 4294 | EXTENT_LOCKED | EXTENT_WRITEBACK, |
| 4295 | 0, NULL)) { |
| 4296 | remove_extent_mapping(map, em); |
| 4297 | /* once for the rb tree */ |
| 4298 | free_extent_map(em); |
| 4299 | } |
| 4300 | start = extent_map_end(em); |
| 4301 | write_unlock(&map->lock); |
| 4302 | |
| 4303 | /* once for us */ |
| 4304 | free_extent_map(em); |
| 4305 | } |
| 4306 | } |
| 4307 | return try_release_extent_state(map, tree, page, mask); |
| 4308 | } |
| 4309 | |
| 4310 | /* |
| 4311 | * helper function for fiemap, which doesn't want to see any holes. |
| 4312 | * This maps until we find something past 'last' |
| 4313 | */ |
| 4314 | static struct extent_map *get_extent_skip_holes(struct inode *inode, |
| 4315 | u64 offset, |
| 4316 | u64 last, |
| 4317 | get_extent_t *get_extent) |
| 4318 | { |
| 4319 | u64 sectorsize = BTRFS_I(inode)->root->sectorsize; |
| 4320 | struct extent_map *em; |
| 4321 | u64 len; |
| 4322 | |
| 4323 | if (offset >= last) |
| 4324 | return NULL; |
| 4325 | |
| 4326 | while (1) { |
| 4327 | len = last - offset; |
| 4328 | if (len == 0) |
| 4329 | break; |
| 4330 | len = ALIGN(len, sectorsize); |
| 4331 | em = get_extent(inode, NULL, 0, offset, len, 0); |
| 4332 | if (IS_ERR_OR_NULL(em)) |
| 4333 | return em; |
| 4334 | |
| 4335 | /* if this isn't a hole return it */ |
| 4336 | if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) && |
| 4337 | em->block_start != EXTENT_MAP_HOLE) { |
| 4338 | return em; |
| 4339 | } |
| 4340 | |
| 4341 | /* this is a hole, advance to the next extent */ |
| 4342 | offset = extent_map_end(em); |
| 4343 | free_extent_map(em); |
| 4344 | if (offset >= last) |
| 4345 | break; |
| 4346 | } |
| 4347 | return NULL; |
| 4348 | } |
| 4349 | |
| 4350 | int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
| 4351 | __u64 start, __u64 len, get_extent_t *get_extent) |
| 4352 | { |
| 4353 | int ret = 0; |
| 4354 | u64 off = start; |
| 4355 | u64 max = start + len; |
| 4356 | u32 flags = 0; |
| 4357 | u32 found_type; |
| 4358 | u64 last; |
| 4359 | u64 last_for_get_extent = 0; |
| 4360 | u64 disko = 0; |
| 4361 | u64 isize = i_size_read(inode); |
| 4362 | struct btrfs_key found_key; |
| 4363 | struct extent_map *em = NULL; |
| 4364 | struct extent_state *cached_state = NULL; |
| 4365 | struct btrfs_path *path; |
| 4366 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 4367 | int end = 0; |
| 4368 | u64 em_start = 0; |
| 4369 | u64 em_len = 0; |
| 4370 | u64 em_end = 0; |
| 4371 | |
| 4372 | if (len == 0) |
| 4373 | return -EINVAL; |
| 4374 | |
| 4375 | path = btrfs_alloc_path(); |
| 4376 | if (!path) |
| 4377 | return -ENOMEM; |
| 4378 | path->leave_spinning = 1; |
| 4379 | |
| 4380 | start = round_down(start, BTRFS_I(inode)->root->sectorsize); |
| 4381 | len = round_up(max, BTRFS_I(inode)->root->sectorsize) - start; |
| 4382 | |
| 4383 | /* |
| 4384 | * lookup the last file extent. We're not using i_size here |
| 4385 | * because there might be preallocation past i_size |
| 4386 | */ |
| 4387 | ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), -1, |
| 4388 | 0); |
| 4389 | if (ret < 0) { |
| 4390 | btrfs_free_path(path); |
| 4391 | return ret; |
| 4392 | } |
| 4393 | WARN_ON(!ret); |
| 4394 | path->slots[0]--; |
| 4395 | btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); |
| 4396 | found_type = found_key.type; |
| 4397 | |
| 4398 | /* No extents, but there might be delalloc bits */ |
| 4399 | if (found_key.objectid != btrfs_ino(inode) || |
| 4400 | found_type != BTRFS_EXTENT_DATA_KEY) { |
| 4401 | /* have to trust i_size as the end */ |
| 4402 | last = (u64)-1; |
| 4403 | last_for_get_extent = isize; |
| 4404 | } else { |
| 4405 | /* |
| 4406 | * remember the start of the last extent. There are a |
| 4407 | * bunch of different factors that go into the length of the |
| 4408 | * extent, so its much less complex to remember where it started |
| 4409 | */ |
| 4410 | last = found_key.offset; |
| 4411 | last_for_get_extent = last + 1; |
| 4412 | } |
| 4413 | btrfs_release_path(path); |
| 4414 | |
| 4415 | /* |
| 4416 | * we might have some extents allocated but more delalloc past those |
| 4417 | * extents. so, we trust isize unless the start of the last extent is |
| 4418 | * beyond isize |
| 4419 | */ |
| 4420 | if (last < isize) { |
| 4421 | last = (u64)-1; |
| 4422 | last_for_get_extent = isize; |
| 4423 | } |
| 4424 | |
| 4425 | lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1, |
| 4426 | &cached_state); |
| 4427 | |
| 4428 | em = get_extent_skip_holes(inode, start, last_for_get_extent, |
| 4429 | get_extent); |
| 4430 | if (!em) |
| 4431 | goto out; |
| 4432 | if (IS_ERR(em)) { |
| 4433 | ret = PTR_ERR(em); |
| 4434 | goto out; |
| 4435 | } |
| 4436 | |
| 4437 | while (!end) { |
| 4438 | u64 offset_in_extent = 0; |
| 4439 | |
| 4440 | /* break if the extent we found is outside the range */ |
| 4441 | if (em->start >= max || extent_map_end(em) < off) |
| 4442 | break; |
| 4443 | |
| 4444 | /* |
| 4445 | * get_extent may return an extent that starts before our |
| 4446 | * requested range. We have to make sure the ranges |
| 4447 | * we return to fiemap always move forward and don't |
| 4448 | * overlap, so adjust the offsets here |
| 4449 | */ |
| 4450 | em_start = max(em->start, off); |
| 4451 | |
| 4452 | /* |
| 4453 | * record the offset from the start of the extent |
| 4454 | * for adjusting the disk offset below. Only do this if the |
| 4455 | * extent isn't compressed since our in ram offset may be past |
| 4456 | * what we have actually allocated on disk. |
| 4457 | */ |
| 4458 | if (!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) |
| 4459 | offset_in_extent = em_start - em->start; |
| 4460 | em_end = extent_map_end(em); |
| 4461 | em_len = em_end - em_start; |
| 4462 | disko = 0; |
| 4463 | flags = 0; |
| 4464 | |
| 4465 | /* |
| 4466 | * bump off for our next call to get_extent |
| 4467 | */ |
| 4468 | off = extent_map_end(em); |
| 4469 | if (off >= max) |
| 4470 | end = 1; |
| 4471 | |
| 4472 | if (em->block_start == EXTENT_MAP_LAST_BYTE) { |
| 4473 | end = 1; |
| 4474 | flags |= FIEMAP_EXTENT_LAST; |
| 4475 | } else if (em->block_start == EXTENT_MAP_INLINE) { |
| 4476 | flags |= (FIEMAP_EXTENT_DATA_INLINE | |
| 4477 | FIEMAP_EXTENT_NOT_ALIGNED); |
| 4478 | } else if (em->block_start == EXTENT_MAP_DELALLOC) { |
| 4479 | flags |= (FIEMAP_EXTENT_DELALLOC | |
| 4480 | FIEMAP_EXTENT_UNKNOWN); |
| 4481 | } else if (fieinfo->fi_extents_max) { |
| 4482 | u64 bytenr = em->block_start - |
| 4483 | (em->start - em->orig_start); |
| 4484 | |
| 4485 | disko = em->block_start + offset_in_extent; |
| 4486 | |
| 4487 | /* |
| 4488 | * As btrfs supports shared space, this information |
| 4489 | * can be exported to userspace tools via |
| 4490 | * flag FIEMAP_EXTENT_SHARED. If fi_extents_max == 0 |
| 4491 | * then we're just getting a count and we can skip the |
| 4492 | * lookup stuff. |
| 4493 | */ |
| 4494 | ret = btrfs_check_shared(NULL, root->fs_info, |
| 4495 | root->objectid, |
| 4496 | btrfs_ino(inode), bytenr); |
| 4497 | if (ret < 0) |
| 4498 | goto out_free; |
| 4499 | if (ret) |
| 4500 | flags |= FIEMAP_EXTENT_SHARED; |
| 4501 | ret = 0; |
| 4502 | } |
| 4503 | if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) |
| 4504 | flags |= FIEMAP_EXTENT_ENCODED; |
| 4505 | if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) |
| 4506 | flags |= FIEMAP_EXTENT_UNWRITTEN; |
| 4507 | |
| 4508 | free_extent_map(em); |
| 4509 | em = NULL; |
| 4510 | if ((em_start >= last) || em_len == (u64)-1 || |
| 4511 | (last == (u64)-1 && isize <= em_end)) { |
| 4512 | flags |= FIEMAP_EXTENT_LAST; |
| 4513 | end = 1; |
| 4514 | } |
| 4515 | |
| 4516 | /* now scan forward to see if this is really the last extent. */ |
| 4517 | em = get_extent_skip_holes(inode, off, last_for_get_extent, |
| 4518 | get_extent); |
| 4519 | if (IS_ERR(em)) { |
| 4520 | ret = PTR_ERR(em); |
| 4521 | goto out; |
| 4522 | } |
| 4523 | if (!em) { |
| 4524 | flags |= FIEMAP_EXTENT_LAST; |
| 4525 | end = 1; |
| 4526 | } |
| 4527 | ret = fiemap_fill_next_extent(fieinfo, em_start, disko, |
| 4528 | em_len, flags); |
| 4529 | if (ret) { |
| 4530 | if (ret == 1) |
| 4531 | ret = 0; |
| 4532 | goto out_free; |
| 4533 | } |
| 4534 | } |
| 4535 | out_free: |
| 4536 | free_extent_map(em); |
| 4537 | out: |
| 4538 | btrfs_free_path(path); |
| 4539 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1, |
| 4540 | &cached_state, GFP_NOFS); |
| 4541 | return ret; |
| 4542 | } |
| 4543 | |
| 4544 | static void __free_extent_buffer(struct extent_buffer *eb) |
| 4545 | { |
| 4546 | btrfs_leak_debug_del(&eb->leak_list); |
| 4547 | kmem_cache_free(extent_buffer_cache, eb); |
| 4548 | } |
| 4549 | |
| 4550 | int extent_buffer_under_io(struct extent_buffer *eb) |
| 4551 | { |
| 4552 | return (atomic_read(&eb->io_pages) || |
| 4553 | test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) || |
| 4554 | test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); |
| 4555 | } |
| 4556 | |
| 4557 | /* |
| 4558 | * Helper for releasing extent buffer page. |
| 4559 | */ |
| 4560 | static void btrfs_release_extent_buffer_page(struct extent_buffer *eb) |
| 4561 | { |
| 4562 | unsigned long index; |
| 4563 | struct page *page; |
| 4564 | int mapped = !test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags); |
| 4565 | |
| 4566 | BUG_ON(extent_buffer_under_io(eb)); |
| 4567 | |
| 4568 | index = num_extent_pages(eb->start, eb->len); |
| 4569 | if (index == 0) |
| 4570 | return; |
| 4571 | |
| 4572 | do { |
| 4573 | index--; |
| 4574 | page = eb->pages[index]; |
| 4575 | if (!page) |
| 4576 | continue; |
| 4577 | if (mapped) |
| 4578 | spin_lock(&page->mapping->private_lock); |
| 4579 | /* |
| 4580 | * We do this since we'll remove the pages after we've |
| 4581 | * removed the eb from the radix tree, so we could race |
| 4582 | * and have this page now attached to the new eb. So |
| 4583 | * only clear page_private if it's still connected to |
| 4584 | * this eb. |
| 4585 | */ |
| 4586 | if (PagePrivate(page) && |
| 4587 | page->private == (unsigned long)eb) { |
| 4588 | BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); |
| 4589 | BUG_ON(PageDirty(page)); |
| 4590 | BUG_ON(PageWriteback(page)); |
| 4591 | /* |
| 4592 | * We need to make sure we haven't be attached |
| 4593 | * to a new eb. |
| 4594 | */ |
| 4595 | ClearPagePrivate(page); |
| 4596 | set_page_private(page, 0); |
| 4597 | /* One for the page private */ |
| 4598 | put_page(page); |
| 4599 | } |
| 4600 | |
| 4601 | if (mapped) |
| 4602 | spin_unlock(&page->mapping->private_lock); |
| 4603 | |
| 4604 | /* One for when we alloced the page */ |
| 4605 | put_page(page); |
| 4606 | } while (index != 0); |
| 4607 | } |
| 4608 | |
| 4609 | /* |
| 4610 | * Helper for releasing the extent buffer. |
| 4611 | */ |
| 4612 | static inline void btrfs_release_extent_buffer(struct extent_buffer *eb) |
| 4613 | { |
| 4614 | btrfs_release_extent_buffer_page(eb); |
| 4615 | __free_extent_buffer(eb); |
| 4616 | } |
| 4617 | |
| 4618 | static struct extent_buffer * |
| 4619 | __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, |
| 4620 | unsigned long len) |
| 4621 | { |
| 4622 | struct extent_buffer *eb = NULL; |
| 4623 | |
| 4624 | eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL); |
| 4625 | eb->start = start; |
| 4626 | eb->len = len; |
| 4627 | eb->fs_info = fs_info; |
| 4628 | eb->bflags = 0; |
| 4629 | rwlock_init(&eb->lock); |
| 4630 | atomic_set(&eb->write_locks, 0); |
| 4631 | atomic_set(&eb->read_locks, 0); |
| 4632 | atomic_set(&eb->blocking_readers, 0); |
| 4633 | atomic_set(&eb->blocking_writers, 0); |
| 4634 | atomic_set(&eb->spinning_readers, 0); |
| 4635 | atomic_set(&eb->spinning_writers, 0); |
| 4636 | eb->lock_nested = 0; |
| 4637 | init_waitqueue_head(&eb->write_lock_wq); |
| 4638 | init_waitqueue_head(&eb->read_lock_wq); |
| 4639 | |
| 4640 | btrfs_leak_debug_add(&eb->leak_list, &buffers); |
| 4641 | |
| 4642 | spin_lock_init(&eb->refs_lock); |
| 4643 | atomic_set(&eb->refs, 1); |
| 4644 | atomic_set(&eb->io_pages, 0); |
| 4645 | |
| 4646 | /* |
| 4647 | * Sanity checks, currently the maximum is 64k covered by 16x 4k pages |
| 4648 | */ |
| 4649 | BUILD_BUG_ON(BTRFS_MAX_METADATA_BLOCKSIZE |
| 4650 | > MAX_INLINE_EXTENT_BUFFER_SIZE); |
| 4651 | BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE); |
| 4652 | |
| 4653 | return eb; |
| 4654 | } |
| 4655 | |
| 4656 | struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src) |
| 4657 | { |
| 4658 | unsigned long i; |
| 4659 | struct page *p; |
| 4660 | struct extent_buffer *new; |
| 4661 | unsigned long num_pages = num_extent_pages(src->start, src->len); |
| 4662 | |
| 4663 | new = __alloc_extent_buffer(src->fs_info, src->start, src->len); |
| 4664 | if (new == NULL) |
| 4665 | return NULL; |
| 4666 | |
| 4667 | for (i = 0; i < num_pages; i++) { |
| 4668 | p = alloc_page(GFP_NOFS); |
| 4669 | if (!p) { |
| 4670 | btrfs_release_extent_buffer(new); |
| 4671 | return NULL; |
| 4672 | } |
| 4673 | attach_extent_buffer_page(new, p); |
| 4674 | WARN_ON(PageDirty(p)); |
| 4675 | SetPageUptodate(p); |
| 4676 | new->pages[i] = p; |
| 4677 | } |
| 4678 | |
| 4679 | copy_extent_buffer(new, src, 0, 0, src->len); |
| 4680 | set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags); |
| 4681 | set_bit(EXTENT_BUFFER_DUMMY, &new->bflags); |
| 4682 | |
| 4683 | return new; |
| 4684 | } |
| 4685 | |
| 4686 | struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, |
| 4687 | u64 start, unsigned long len) |
| 4688 | { |
| 4689 | struct extent_buffer *eb; |
| 4690 | unsigned long num_pages; |
| 4691 | unsigned long i; |
| 4692 | |
| 4693 | num_pages = num_extent_pages(start, len); |
| 4694 | |
| 4695 | eb = __alloc_extent_buffer(fs_info, start, len); |
| 4696 | if (!eb) |
| 4697 | return NULL; |
| 4698 | |
| 4699 | for (i = 0; i < num_pages; i++) { |
| 4700 | eb->pages[i] = alloc_page(GFP_NOFS); |
| 4701 | if (!eb->pages[i]) |
| 4702 | goto err; |
| 4703 | } |
| 4704 | set_extent_buffer_uptodate(eb); |
| 4705 | btrfs_set_header_nritems(eb, 0); |
| 4706 | set_bit(EXTENT_BUFFER_DUMMY, &eb->bflags); |
| 4707 | |
| 4708 | return eb; |
| 4709 | err: |
| 4710 | for (; i > 0; i--) |
| 4711 | __free_page(eb->pages[i - 1]); |
| 4712 | __free_extent_buffer(eb); |
| 4713 | return NULL; |
| 4714 | } |
| 4715 | |
| 4716 | struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, |
| 4717 | u64 start) |
| 4718 | { |
| 4719 | unsigned long len; |
| 4720 | |
| 4721 | if (!fs_info) { |
| 4722 | /* |
| 4723 | * Called only from tests that don't always have a fs_info |
| 4724 | * available, but we know that nodesize is 4096 |
| 4725 | */ |
| 4726 | len = 4096; |
| 4727 | } else { |
| 4728 | len = fs_info->tree_root->nodesize; |
| 4729 | } |
| 4730 | |
| 4731 | return __alloc_dummy_extent_buffer(fs_info, start, len); |
| 4732 | } |
| 4733 | |
| 4734 | static void check_buffer_tree_ref(struct extent_buffer *eb) |
| 4735 | { |
| 4736 | int refs; |
| 4737 | /* the ref bit is tricky. We have to make sure it is set |
| 4738 | * if we have the buffer dirty. Otherwise the |
| 4739 | * code to free a buffer can end up dropping a dirty |
| 4740 | * page |
| 4741 | * |
| 4742 | * Once the ref bit is set, it won't go away while the |
| 4743 | * buffer is dirty or in writeback, and it also won't |
| 4744 | * go away while we have the reference count on the |
| 4745 | * eb bumped. |
| 4746 | * |
| 4747 | * We can't just set the ref bit without bumping the |
| 4748 | * ref on the eb because free_extent_buffer might |
| 4749 | * see the ref bit and try to clear it. If this happens |
| 4750 | * free_extent_buffer might end up dropping our original |
| 4751 | * ref by mistake and freeing the page before we are able |
| 4752 | * to add one more ref. |
| 4753 | * |
| 4754 | * So bump the ref count first, then set the bit. If someone |
| 4755 | * beat us to it, drop the ref we added. |
| 4756 | */ |
| 4757 | refs = atomic_read(&eb->refs); |
| 4758 | if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) |
| 4759 | return; |
| 4760 | |
| 4761 | spin_lock(&eb->refs_lock); |
| 4762 | if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) |
| 4763 | atomic_inc(&eb->refs); |
| 4764 | spin_unlock(&eb->refs_lock); |
| 4765 | } |
| 4766 | |
| 4767 | static void mark_extent_buffer_accessed(struct extent_buffer *eb, |
| 4768 | struct page *accessed) |
| 4769 | { |
| 4770 | unsigned long num_pages, i; |
| 4771 | |
| 4772 | check_buffer_tree_ref(eb); |
| 4773 | |
| 4774 | num_pages = num_extent_pages(eb->start, eb->len); |
| 4775 | for (i = 0; i < num_pages; i++) { |
| 4776 | struct page *p = eb->pages[i]; |
| 4777 | |
| 4778 | if (p != accessed) |
| 4779 | mark_page_accessed(p); |
| 4780 | } |
| 4781 | } |
| 4782 | |
| 4783 | struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, |
| 4784 | u64 start) |
| 4785 | { |
| 4786 | struct extent_buffer *eb; |
| 4787 | |
| 4788 | rcu_read_lock(); |
| 4789 | eb = radix_tree_lookup(&fs_info->buffer_radix, |
| 4790 | start >> PAGE_SHIFT); |
| 4791 | if (eb && atomic_inc_not_zero(&eb->refs)) { |
| 4792 | rcu_read_unlock(); |
| 4793 | /* |
| 4794 | * Lock our eb's refs_lock to avoid races with |
| 4795 | * free_extent_buffer. When we get our eb it might be flagged |
| 4796 | * with EXTENT_BUFFER_STALE and another task running |
| 4797 | * free_extent_buffer might have seen that flag set, |
| 4798 | * eb->refs == 2, that the buffer isn't under IO (dirty and |
| 4799 | * writeback flags not set) and it's still in the tree (flag |
| 4800 | * EXTENT_BUFFER_TREE_REF set), therefore being in the process |
| 4801 | * of decrementing the extent buffer's reference count twice. |
| 4802 | * So here we could race and increment the eb's reference count, |
| 4803 | * clear its stale flag, mark it as dirty and drop our reference |
| 4804 | * before the other task finishes executing free_extent_buffer, |
| 4805 | * which would later result in an attempt to free an extent |
| 4806 | * buffer that is dirty. |
| 4807 | */ |
| 4808 | if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) { |
| 4809 | spin_lock(&eb->refs_lock); |
| 4810 | spin_unlock(&eb->refs_lock); |
| 4811 | } |
| 4812 | mark_extent_buffer_accessed(eb, NULL); |
| 4813 | return eb; |
| 4814 | } |
| 4815 | rcu_read_unlock(); |
| 4816 | |
| 4817 | return NULL; |
| 4818 | } |
| 4819 | |
| 4820 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
| 4821 | struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, |
| 4822 | u64 start) |
| 4823 | { |
| 4824 | struct extent_buffer *eb, *exists = NULL; |
| 4825 | int ret; |
| 4826 | |
| 4827 | eb = find_extent_buffer(fs_info, start); |
| 4828 | if (eb) |
| 4829 | return eb; |
| 4830 | eb = alloc_dummy_extent_buffer(fs_info, start); |
| 4831 | if (!eb) |
| 4832 | return NULL; |
| 4833 | eb->fs_info = fs_info; |
| 4834 | again: |
| 4835 | ret = radix_tree_preload(GFP_NOFS); |
| 4836 | if (ret) |
| 4837 | goto free_eb; |
| 4838 | spin_lock(&fs_info->buffer_lock); |
| 4839 | ret = radix_tree_insert(&fs_info->buffer_radix, |
| 4840 | start >> PAGE_SHIFT, eb); |
| 4841 | spin_unlock(&fs_info->buffer_lock); |
| 4842 | radix_tree_preload_end(); |
| 4843 | if (ret == -EEXIST) { |
| 4844 | exists = find_extent_buffer(fs_info, start); |
| 4845 | if (exists) |
| 4846 | goto free_eb; |
| 4847 | else |
| 4848 | goto again; |
| 4849 | } |
| 4850 | check_buffer_tree_ref(eb); |
| 4851 | set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); |
| 4852 | |
| 4853 | /* |
| 4854 | * We will free dummy extent buffer's if they come into |
| 4855 | * free_extent_buffer with a ref count of 2, but if we are using this we |
| 4856 | * want the buffers to stay in memory until we're done with them, so |
| 4857 | * bump the ref count again. |
| 4858 | */ |
| 4859 | atomic_inc(&eb->refs); |
| 4860 | return eb; |
| 4861 | free_eb: |
| 4862 | btrfs_release_extent_buffer(eb); |
| 4863 | return exists; |
| 4864 | } |
| 4865 | #endif |
| 4866 | |
| 4867 | struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, |
| 4868 | u64 start) |
| 4869 | { |
| 4870 | unsigned long len = fs_info->tree_root->nodesize; |
| 4871 | unsigned long num_pages = num_extent_pages(start, len); |
| 4872 | unsigned long i; |
| 4873 | unsigned long index = start >> PAGE_SHIFT; |
| 4874 | struct extent_buffer *eb; |
| 4875 | struct extent_buffer *exists = NULL; |
| 4876 | struct page *p; |
| 4877 | struct address_space *mapping = fs_info->btree_inode->i_mapping; |
| 4878 | int uptodate = 1; |
| 4879 | int ret; |
| 4880 | |
| 4881 | eb = find_extent_buffer(fs_info, start); |
| 4882 | if (eb) |
| 4883 | return eb; |
| 4884 | |
| 4885 | eb = __alloc_extent_buffer(fs_info, start, len); |
| 4886 | if (!eb) |
| 4887 | return NULL; |
| 4888 | |
| 4889 | for (i = 0; i < num_pages; i++, index++) { |
| 4890 | p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL); |
| 4891 | if (!p) |
| 4892 | goto free_eb; |
| 4893 | |
| 4894 | spin_lock(&mapping->private_lock); |
| 4895 | if (PagePrivate(p)) { |
| 4896 | /* |
| 4897 | * We could have already allocated an eb for this page |
| 4898 | * and attached one so lets see if we can get a ref on |
| 4899 | * the existing eb, and if we can we know it's good and |
| 4900 | * we can just return that one, else we know we can just |
| 4901 | * overwrite page->private. |
| 4902 | */ |
| 4903 | exists = (struct extent_buffer *)p->private; |
| 4904 | if (atomic_inc_not_zero(&exists->refs)) { |
| 4905 | spin_unlock(&mapping->private_lock); |
| 4906 | unlock_page(p); |
| 4907 | put_page(p); |
| 4908 | mark_extent_buffer_accessed(exists, p); |
| 4909 | goto free_eb; |
| 4910 | } |
| 4911 | exists = NULL; |
| 4912 | |
| 4913 | /* |
| 4914 | * Do this so attach doesn't complain and we need to |
| 4915 | * drop the ref the old guy had. |
| 4916 | */ |
| 4917 | ClearPagePrivate(p); |
| 4918 | WARN_ON(PageDirty(p)); |
| 4919 | put_page(p); |
| 4920 | } |
| 4921 | attach_extent_buffer_page(eb, p); |
| 4922 | spin_unlock(&mapping->private_lock); |
| 4923 | WARN_ON(PageDirty(p)); |
| 4924 | eb->pages[i] = p; |
| 4925 | if (!PageUptodate(p)) |
| 4926 | uptodate = 0; |
| 4927 | |
| 4928 | /* |
| 4929 | * see below about how we avoid a nasty race with release page |
| 4930 | * and why we unlock later |
| 4931 | */ |
| 4932 | } |
| 4933 | if (uptodate) |
| 4934 | set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| 4935 | again: |
| 4936 | ret = radix_tree_preload(GFP_NOFS); |
| 4937 | if (ret) |
| 4938 | goto free_eb; |
| 4939 | |
| 4940 | spin_lock(&fs_info->buffer_lock); |
| 4941 | ret = radix_tree_insert(&fs_info->buffer_radix, |
| 4942 | start >> PAGE_SHIFT, eb); |
| 4943 | spin_unlock(&fs_info->buffer_lock); |
| 4944 | radix_tree_preload_end(); |
| 4945 | if (ret == -EEXIST) { |
| 4946 | exists = find_extent_buffer(fs_info, start); |
| 4947 | if (exists) |
| 4948 | goto free_eb; |
| 4949 | else |
| 4950 | goto again; |
| 4951 | } |
| 4952 | /* add one reference for the tree */ |
| 4953 | check_buffer_tree_ref(eb); |
| 4954 | set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags); |
| 4955 | |
| 4956 | /* |
| 4957 | * there is a race where release page may have |
| 4958 | * tried to find this extent buffer in the radix |
| 4959 | * but failed. It will tell the VM it is safe to |
| 4960 | * reclaim the, and it will clear the page private bit. |
| 4961 | * We must make sure to set the page private bit properly |
| 4962 | * after the extent buffer is in the radix tree so |
| 4963 | * it doesn't get lost |
| 4964 | */ |
| 4965 | SetPageChecked(eb->pages[0]); |
| 4966 | for (i = 1; i < num_pages; i++) { |
| 4967 | p = eb->pages[i]; |
| 4968 | ClearPageChecked(p); |
| 4969 | unlock_page(p); |
| 4970 | } |
| 4971 | unlock_page(eb->pages[0]); |
| 4972 | return eb; |
| 4973 | |
| 4974 | free_eb: |
| 4975 | WARN_ON(!atomic_dec_and_test(&eb->refs)); |
| 4976 | for (i = 0; i < num_pages; i++) { |
| 4977 | if (eb->pages[i]) |
| 4978 | unlock_page(eb->pages[i]); |
| 4979 | } |
| 4980 | |
| 4981 | btrfs_release_extent_buffer(eb); |
| 4982 | return exists; |
| 4983 | } |
| 4984 | |
| 4985 | static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) |
| 4986 | { |
| 4987 | struct extent_buffer *eb = |
| 4988 | container_of(head, struct extent_buffer, rcu_head); |
| 4989 | |
| 4990 | __free_extent_buffer(eb); |
| 4991 | } |
| 4992 | |
| 4993 | /* Expects to have eb->eb_lock already held */ |
| 4994 | static int release_extent_buffer(struct extent_buffer *eb) |
| 4995 | { |
| 4996 | WARN_ON(atomic_read(&eb->refs) == 0); |
| 4997 | if (atomic_dec_and_test(&eb->refs)) { |
| 4998 | if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) { |
| 4999 | struct btrfs_fs_info *fs_info = eb->fs_info; |
| 5000 | |
| 5001 | spin_unlock(&eb->refs_lock); |
| 5002 | |
| 5003 | spin_lock(&fs_info->buffer_lock); |
| 5004 | radix_tree_delete(&fs_info->buffer_radix, |
| 5005 | eb->start >> PAGE_SHIFT); |
| 5006 | spin_unlock(&fs_info->buffer_lock); |
| 5007 | } else { |
| 5008 | spin_unlock(&eb->refs_lock); |
| 5009 | } |
| 5010 | |
| 5011 | /* Should be safe to release our pages at this point */ |
| 5012 | btrfs_release_extent_buffer_page(eb); |
| 5013 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS |
| 5014 | if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) { |
| 5015 | __free_extent_buffer(eb); |
| 5016 | return 1; |
| 5017 | } |
| 5018 | #endif |
| 5019 | call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); |
| 5020 | return 1; |
| 5021 | } |
| 5022 | spin_unlock(&eb->refs_lock); |
| 5023 | |
| 5024 | return 0; |
| 5025 | } |
| 5026 | |
| 5027 | void free_extent_buffer(struct extent_buffer *eb) |
| 5028 | { |
| 5029 | int refs; |
| 5030 | int old; |
| 5031 | if (!eb) |
| 5032 | return; |
| 5033 | |
| 5034 | while (1) { |
| 5035 | refs = atomic_read(&eb->refs); |
| 5036 | if (refs <= 3) |
| 5037 | break; |
| 5038 | old = atomic_cmpxchg(&eb->refs, refs, refs - 1); |
| 5039 | if (old == refs) |
| 5040 | return; |
| 5041 | } |
| 5042 | |
| 5043 | spin_lock(&eb->refs_lock); |
| 5044 | if (atomic_read(&eb->refs) == 2 && |
| 5045 | test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags)) |
| 5046 | atomic_dec(&eb->refs); |
| 5047 | |
| 5048 | if (atomic_read(&eb->refs) == 2 && |
| 5049 | test_bit(EXTENT_BUFFER_STALE, &eb->bflags) && |
| 5050 | !extent_buffer_under_io(eb) && |
| 5051 | test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) |
| 5052 | atomic_dec(&eb->refs); |
| 5053 | |
| 5054 | /* |
| 5055 | * I know this is terrible, but it's temporary until we stop tracking |
| 5056 | * the uptodate bits and such for the extent buffers. |
| 5057 | */ |
| 5058 | release_extent_buffer(eb); |
| 5059 | } |
| 5060 | |
| 5061 | void free_extent_buffer_stale(struct extent_buffer *eb) |
| 5062 | { |
| 5063 | if (!eb) |
| 5064 | return; |
| 5065 | |
| 5066 | spin_lock(&eb->refs_lock); |
| 5067 | set_bit(EXTENT_BUFFER_STALE, &eb->bflags); |
| 5068 | |
| 5069 | if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) && |
| 5070 | test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) |
| 5071 | atomic_dec(&eb->refs); |
| 5072 | release_extent_buffer(eb); |
| 5073 | } |
| 5074 | |
| 5075 | void clear_extent_buffer_dirty(struct extent_buffer *eb) |
| 5076 | { |
| 5077 | unsigned long i; |
| 5078 | unsigned long num_pages; |
| 5079 | struct page *page; |
| 5080 | |
| 5081 | num_pages = num_extent_pages(eb->start, eb->len); |
| 5082 | |
| 5083 | for (i = 0; i < num_pages; i++) { |
| 5084 | page = eb->pages[i]; |
| 5085 | if (!PageDirty(page)) |
| 5086 | continue; |
| 5087 | |
| 5088 | lock_page(page); |
| 5089 | WARN_ON(!PagePrivate(page)); |
| 5090 | |
| 5091 | clear_page_dirty_for_io(page); |
| 5092 | spin_lock_irq(&page->mapping->tree_lock); |
| 5093 | if (!PageDirty(page)) { |
| 5094 | radix_tree_tag_clear(&page->mapping->page_tree, |
| 5095 | page_index(page), |
| 5096 | PAGECACHE_TAG_DIRTY); |
| 5097 | } |
| 5098 | spin_unlock_irq(&page->mapping->tree_lock); |
| 5099 | ClearPageError(page); |
| 5100 | unlock_page(page); |
| 5101 | } |
| 5102 | WARN_ON(atomic_read(&eb->refs) == 0); |
| 5103 | } |
| 5104 | |
| 5105 | int set_extent_buffer_dirty(struct extent_buffer *eb) |
| 5106 | { |
| 5107 | unsigned long i; |
| 5108 | unsigned long num_pages; |
| 5109 | int was_dirty = 0; |
| 5110 | |
| 5111 | check_buffer_tree_ref(eb); |
| 5112 | |
| 5113 | was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); |
| 5114 | |
| 5115 | num_pages = num_extent_pages(eb->start, eb->len); |
| 5116 | WARN_ON(atomic_read(&eb->refs) == 0); |
| 5117 | WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)); |
| 5118 | |
| 5119 | for (i = 0; i < num_pages; i++) |
| 5120 | set_page_dirty(eb->pages[i]); |
| 5121 | return was_dirty; |
| 5122 | } |
| 5123 | |
| 5124 | void clear_extent_buffer_uptodate(struct extent_buffer *eb) |
| 5125 | { |
| 5126 | unsigned long i; |
| 5127 | struct page *page; |
| 5128 | unsigned long num_pages; |
| 5129 | |
| 5130 | clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| 5131 | num_pages = num_extent_pages(eb->start, eb->len); |
| 5132 | for (i = 0; i < num_pages; i++) { |
| 5133 | page = eb->pages[i]; |
| 5134 | if (page) |
| 5135 | ClearPageUptodate(page); |
| 5136 | } |
| 5137 | } |
| 5138 | |
| 5139 | void set_extent_buffer_uptodate(struct extent_buffer *eb) |
| 5140 | { |
| 5141 | unsigned long i; |
| 5142 | struct page *page; |
| 5143 | unsigned long num_pages; |
| 5144 | |
| 5145 | set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| 5146 | num_pages = num_extent_pages(eb->start, eb->len); |
| 5147 | for (i = 0; i < num_pages; i++) { |
| 5148 | page = eb->pages[i]; |
| 5149 | SetPageUptodate(page); |
| 5150 | } |
| 5151 | } |
| 5152 | |
| 5153 | int extent_buffer_uptodate(struct extent_buffer *eb) |
| 5154 | { |
| 5155 | return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| 5156 | } |
| 5157 | |
| 5158 | int read_extent_buffer_pages(struct extent_io_tree *tree, |
| 5159 | struct extent_buffer *eb, u64 start, int wait, |
| 5160 | get_extent_t *get_extent, int mirror_num) |
| 5161 | { |
| 5162 | unsigned long i; |
| 5163 | unsigned long start_i; |
| 5164 | struct page *page; |
| 5165 | int err; |
| 5166 | int ret = 0; |
| 5167 | int locked_pages = 0; |
| 5168 | int all_uptodate = 1; |
| 5169 | unsigned long num_pages; |
| 5170 | unsigned long num_reads = 0; |
| 5171 | struct bio *bio = NULL; |
| 5172 | unsigned long bio_flags = 0; |
| 5173 | |
| 5174 | if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) |
| 5175 | return 0; |
| 5176 | |
| 5177 | if (start) { |
| 5178 | WARN_ON(start < eb->start); |
| 5179 | start_i = (start >> PAGE_SHIFT) - |
| 5180 | (eb->start >> PAGE_SHIFT); |
| 5181 | } else { |
| 5182 | start_i = 0; |
| 5183 | } |
| 5184 | |
| 5185 | num_pages = num_extent_pages(eb->start, eb->len); |
| 5186 | for (i = start_i; i < num_pages; i++) { |
| 5187 | page = eb->pages[i]; |
| 5188 | if (wait == WAIT_NONE) { |
| 5189 | if (!trylock_page(page)) |
| 5190 | goto unlock_exit; |
| 5191 | } else { |
| 5192 | lock_page(page); |
| 5193 | } |
| 5194 | locked_pages++; |
| 5195 | if (!PageUptodate(page)) { |
| 5196 | num_reads++; |
| 5197 | all_uptodate = 0; |
| 5198 | } |
| 5199 | } |
| 5200 | if (all_uptodate) { |
| 5201 | if (start_i == 0) |
| 5202 | set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); |
| 5203 | goto unlock_exit; |
| 5204 | } |
| 5205 | |
| 5206 | clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); |
| 5207 | eb->read_mirror = 0; |
| 5208 | atomic_set(&eb->io_pages, num_reads); |
| 5209 | for (i = start_i; i < num_pages; i++) { |
| 5210 | page = eb->pages[i]; |
| 5211 | if (!PageUptodate(page)) { |
| 5212 | ClearPageError(page); |
| 5213 | err = __extent_read_full_page(tree, page, |
| 5214 | get_extent, &bio, |
| 5215 | mirror_num, &bio_flags, |
| 5216 | READ | REQ_META); |
| 5217 | if (err) |
| 5218 | ret = err; |
| 5219 | } else { |
| 5220 | unlock_page(page); |
| 5221 | } |
| 5222 | } |
| 5223 | |
| 5224 | if (bio) { |
| 5225 | err = submit_one_bio(READ | REQ_META, bio, mirror_num, |
| 5226 | bio_flags); |
| 5227 | if (err) |
| 5228 | return err; |
| 5229 | } |
| 5230 | |
| 5231 | if (ret || wait != WAIT_COMPLETE) |
| 5232 | return ret; |
| 5233 | |
| 5234 | for (i = start_i; i < num_pages; i++) { |
| 5235 | page = eb->pages[i]; |
| 5236 | wait_on_page_locked(page); |
| 5237 | if (!PageUptodate(page)) |
| 5238 | ret = -EIO; |
| 5239 | } |
| 5240 | |
| 5241 | return ret; |
| 5242 | |
| 5243 | unlock_exit: |
| 5244 | i = start_i; |
| 5245 | while (locked_pages > 0) { |
| 5246 | page = eb->pages[i]; |
| 5247 | i++; |
| 5248 | unlock_page(page); |
| 5249 | locked_pages--; |
| 5250 | } |
| 5251 | return ret; |
| 5252 | } |
| 5253 | |
| 5254 | void read_extent_buffer(struct extent_buffer *eb, void *dstv, |
| 5255 | unsigned long start, |
| 5256 | unsigned long len) |
| 5257 | { |
| 5258 | size_t cur; |
| 5259 | size_t offset; |
| 5260 | struct page *page; |
| 5261 | char *kaddr; |
| 5262 | char *dst = (char *)dstv; |
| 5263 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5264 | unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| 5265 | |
| 5266 | WARN_ON(start > eb->len); |
| 5267 | WARN_ON(start + len > eb->start + eb->len); |
| 5268 | |
| 5269 | offset = (start_offset + start) & (PAGE_SIZE - 1); |
| 5270 | |
| 5271 | while (len > 0) { |
| 5272 | page = eb->pages[i]; |
| 5273 | |
| 5274 | cur = min(len, (PAGE_SIZE - offset)); |
| 5275 | kaddr = page_address(page); |
| 5276 | memcpy(dst, kaddr + offset, cur); |
| 5277 | |
| 5278 | dst += cur; |
| 5279 | len -= cur; |
| 5280 | offset = 0; |
| 5281 | i++; |
| 5282 | } |
| 5283 | } |
| 5284 | |
| 5285 | int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv, |
| 5286 | unsigned long start, |
| 5287 | unsigned long len) |
| 5288 | { |
| 5289 | size_t cur; |
| 5290 | size_t offset; |
| 5291 | struct page *page; |
| 5292 | char *kaddr; |
| 5293 | char __user *dst = (char __user *)dstv; |
| 5294 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5295 | unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| 5296 | int ret = 0; |
| 5297 | |
| 5298 | WARN_ON(start > eb->len); |
| 5299 | WARN_ON(start + len > eb->start + eb->len); |
| 5300 | |
| 5301 | offset = (start_offset + start) & (PAGE_SIZE - 1); |
| 5302 | |
| 5303 | while (len > 0) { |
| 5304 | page = eb->pages[i]; |
| 5305 | |
| 5306 | cur = min(len, (PAGE_SIZE - offset)); |
| 5307 | kaddr = page_address(page); |
| 5308 | if (copy_to_user(dst, kaddr + offset, cur)) { |
| 5309 | ret = -EFAULT; |
| 5310 | break; |
| 5311 | } |
| 5312 | |
| 5313 | dst += cur; |
| 5314 | len -= cur; |
| 5315 | offset = 0; |
| 5316 | i++; |
| 5317 | } |
| 5318 | |
| 5319 | return ret; |
| 5320 | } |
| 5321 | |
| 5322 | int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, |
| 5323 | unsigned long min_len, char **map, |
| 5324 | unsigned long *map_start, |
| 5325 | unsigned long *map_len) |
| 5326 | { |
| 5327 | size_t offset = start & (PAGE_SIZE - 1); |
| 5328 | char *kaddr; |
| 5329 | struct page *p; |
| 5330 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5331 | unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| 5332 | unsigned long end_i = (start_offset + start + min_len - 1) >> |
| 5333 | PAGE_SHIFT; |
| 5334 | |
| 5335 | if (i != end_i) |
| 5336 | return -EINVAL; |
| 5337 | |
| 5338 | if (i == 0) { |
| 5339 | offset = start_offset; |
| 5340 | *map_start = 0; |
| 5341 | } else { |
| 5342 | offset = 0; |
| 5343 | *map_start = ((u64)i << PAGE_SHIFT) - start_offset; |
| 5344 | } |
| 5345 | |
| 5346 | if (start + min_len > eb->len) { |
| 5347 | WARN(1, KERN_ERR "btrfs bad mapping eb start %llu len %lu, " |
| 5348 | "wanted %lu %lu\n", |
| 5349 | eb->start, eb->len, start, min_len); |
| 5350 | return -EINVAL; |
| 5351 | } |
| 5352 | |
| 5353 | p = eb->pages[i]; |
| 5354 | kaddr = page_address(p); |
| 5355 | *map = kaddr + offset; |
| 5356 | *map_len = PAGE_SIZE - offset; |
| 5357 | return 0; |
| 5358 | } |
| 5359 | |
| 5360 | int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, |
| 5361 | unsigned long start, |
| 5362 | unsigned long len) |
| 5363 | { |
| 5364 | size_t cur; |
| 5365 | size_t offset; |
| 5366 | struct page *page; |
| 5367 | char *kaddr; |
| 5368 | char *ptr = (char *)ptrv; |
| 5369 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5370 | unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| 5371 | int ret = 0; |
| 5372 | |
| 5373 | WARN_ON(start > eb->len); |
| 5374 | WARN_ON(start + len > eb->start + eb->len); |
| 5375 | |
| 5376 | offset = (start_offset + start) & (PAGE_SIZE - 1); |
| 5377 | |
| 5378 | while (len > 0) { |
| 5379 | page = eb->pages[i]; |
| 5380 | |
| 5381 | cur = min(len, (PAGE_SIZE - offset)); |
| 5382 | |
| 5383 | kaddr = page_address(page); |
| 5384 | ret = memcmp(ptr, kaddr + offset, cur); |
| 5385 | if (ret) |
| 5386 | break; |
| 5387 | |
| 5388 | ptr += cur; |
| 5389 | len -= cur; |
| 5390 | offset = 0; |
| 5391 | i++; |
| 5392 | } |
| 5393 | return ret; |
| 5394 | } |
| 5395 | |
| 5396 | void write_extent_buffer(struct extent_buffer *eb, const void *srcv, |
| 5397 | unsigned long start, unsigned long len) |
| 5398 | { |
| 5399 | size_t cur; |
| 5400 | size_t offset; |
| 5401 | struct page *page; |
| 5402 | char *kaddr; |
| 5403 | char *src = (char *)srcv; |
| 5404 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5405 | unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| 5406 | |
| 5407 | WARN_ON(start > eb->len); |
| 5408 | WARN_ON(start + len > eb->start + eb->len); |
| 5409 | |
| 5410 | offset = (start_offset + start) & (PAGE_SIZE - 1); |
| 5411 | |
| 5412 | while (len > 0) { |
| 5413 | page = eb->pages[i]; |
| 5414 | WARN_ON(!PageUptodate(page)); |
| 5415 | |
| 5416 | cur = min(len, PAGE_SIZE - offset); |
| 5417 | kaddr = page_address(page); |
| 5418 | memcpy(kaddr + offset, src, cur); |
| 5419 | |
| 5420 | src += cur; |
| 5421 | len -= cur; |
| 5422 | offset = 0; |
| 5423 | i++; |
| 5424 | } |
| 5425 | } |
| 5426 | |
| 5427 | void memset_extent_buffer(struct extent_buffer *eb, char c, |
| 5428 | unsigned long start, unsigned long len) |
| 5429 | { |
| 5430 | size_t cur; |
| 5431 | size_t offset; |
| 5432 | struct page *page; |
| 5433 | char *kaddr; |
| 5434 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5435 | unsigned long i = (start_offset + start) >> PAGE_SHIFT; |
| 5436 | |
| 5437 | WARN_ON(start > eb->len); |
| 5438 | WARN_ON(start + len > eb->start + eb->len); |
| 5439 | |
| 5440 | offset = (start_offset + start) & (PAGE_SIZE - 1); |
| 5441 | |
| 5442 | while (len > 0) { |
| 5443 | page = eb->pages[i]; |
| 5444 | WARN_ON(!PageUptodate(page)); |
| 5445 | |
| 5446 | cur = min(len, PAGE_SIZE - offset); |
| 5447 | kaddr = page_address(page); |
| 5448 | memset(kaddr + offset, c, cur); |
| 5449 | |
| 5450 | len -= cur; |
| 5451 | offset = 0; |
| 5452 | i++; |
| 5453 | } |
| 5454 | } |
| 5455 | |
| 5456 | void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, |
| 5457 | unsigned long dst_offset, unsigned long src_offset, |
| 5458 | unsigned long len) |
| 5459 | { |
| 5460 | u64 dst_len = dst->len; |
| 5461 | size_t cur; |
| 5462 | size_t offset; |
| 5463 | struct page *page; |
| 5464 | char *kaddr; |
| 5465 | size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1); |
| 5466 | unsigned long i = (start_offset + dst_offset) >> PAGE_SHIFT; |
| 5467 | |
| 5468 | WARN_ON(src->len != dst_len); |
| 5469 | |
| 5470 | offset = (start_offset + dst_offset) & |
| 5471 | (PAGE_SIZE - 1); |
| 5472 | |
| 5473 | while (len > 0) { |
| 5474 | page = dst->pages[i]; |
| 5475 | WARN_ON(!PageUptodate(page)); |
| 5476 | |
| 5477 | cur = min(len, (unsigned long)(PAGE_SIZE - offset)); |
| 5478 | |
| 5479 | kaddr = page_address(page); |
| 5480 | read_extent_buffer(src, kaddr + offset, src_offset, cur); |
| 5481 | |
| 5482 | src_offset += cur; |
| 5483 | len -= cur; |
| 5484 | offset = 0; |
| 5485 | i++; |
| 5486 | } |
| 5487 | } |
| 5488 | |
| 5489 | /* |
| 5490 | * The extent buffer bitmap operations are done with byte granularity because |
| 5491 | * bitmap items are not guaranteed to be aligned to a word and therefore a |
| 5492 | * single word in a bitmap may straddle two pages in the extent buffer. |
| 5493 | */ |
| 5494 | #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) |
| 5495 | #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1) |
| 5496 | #define BITMAP_FIRST_BYTE_MASK(start) \ |
| 5497 | ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK) |
| 5498 | #define BITMAP_LAST_BYTE_MASK(nbits) \ |
| 5499 | (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1))) |
| 5500 | |
| 5501 | /* |
| 5502 | * eb_bitmap_offset() - calculate the page and offset of the byte containing the |
| 5503 | * given bit number |
| 5504 | * @eb: the extent buffer |
| 5505 | * @start: offset of the bitmap item in the extent buffer |
| 5506 | * @nr: bit number |
| 5507 | * @page_index: return index of the page in the extent buffer that contains the |
| 5508 | * given bit number |
| 5509 | * @page_offset: return offset into the page given by page_index |
| 5510 | * |
| 5511 | * This helper hides the ugliness of finding the byte in an extent buffer which |
| 5512 | * contains a given bit. |
| 5513 | */ |
| 5514 | static inline void eb_bitmap_offset(struct extent_buffer *eb, |
| 5515 | unsigned long start, unsigned long nr, |
| 5516 | unsigned long *page_index, |
| 5517 | size_t *page_offset) |
| 5518 | { |
| 5519 | size_t start_offset = eb->start & ((u64)PAGE_SIZE - 1); |
| 5520 | size_t byte_offset = BIT_BYTE(nr); |
| 5521 | size_t offset; |
| 5522 | |
| 5523 | /* |
| 5524 | * The byte we want is the offset of the extent buffer + the offset of |
| 5525 | * the bitmap item in the extent buffer + the offset of the byte in the |
| 5526 | * bitmap item. |
| 5527 | */ |
| 5528 | offset = start_offset + start + byte_offset; |
| 5529 | |
| 5530 | *page_index = offset >> PAGE_SHIFT; |
| 5531 | *page_offset = offset & (PAGE_SIZE - 1); |
| 5532 | } |
| 5533 | |
| 5534 | /** |
| 5535 | * extent_buffer_test_bit - determine whether a bit in a bitmap item is set |
| 5536 | * @eb: the extent buffer |
| 5537 | * @start: offset of the bitmap item in the extent buffer |
| 5538 | * @nr: bit number to test |
| 5539 | */ |
| 5540 | int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start, |
| 5541 | unsigned long nr) |
| 5542 | { |
| 5543 | char *kaddr; |
| 5544 | struct page *page; |
| 5545 | unsigned long i; |
| 5546 | size_t offset; |
| 5547 | |
| 5548 | eb_bitmap_offset(eb, start, nr, &i, &offset); |
| 5549 | page = eb->pages[i]; |
| 5550 | WARN_ON(!PageUptodate(page)); |
| 5551 | kaddr = page_address(page); |
| 5552 | return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1))); |
| 5553 | } |
| 5554 | |
| 5555 | /** |
| 5556 | * extent_buffer_bitmap_set - set an area of a bitmap |
| 5557 | * @eb: the extent buffer |
| 5558 | * @start: offset of the bitmap item in the extent buffer |
| 5559 | * @pos: bit number of the first bit |
| 5560 | * @len: number of bits to set |
| 5561 | */ |
| 5562 | void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start, |
| 5563 | unsigned long pos, unsigned long len) |
| 5564 | { |
| 5565 | char *kaddr; |
| 5566 | struct page *page; |
| 5567 | unsigned long i; |
| 5568 | size_t offset; |
| 5569 | const unsigned int size = pos + len; |
| 5570 | int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE); |
| 5571 | unsigned int mask_to_set = BITMAP_FIRST_BYTE_MASK(pos); |
| 5572 | |
| 5573 | eb_bitmap_offset(eb, start, pos, &i, &offset); |
| 5574 | page = eb->pages[i]; |
| 5575 | WARN_ON(!PageUptodate(page)); |
| 5576 | kaddr = page_address(page); |
| 5577 | |
| 5578 | while (len >= bits_to_set) { |
| 5579 | kaddr[offset] |= mask_to_set; |
| 5580 | len -= bits_to_set; |
| 5581 | bits_to_set = BITS_PER_BYTE; |
| 5582 | mask_to_set = ~0U; |
| 5583 | if (++offset >= PAGE_SIZE && len > 0) { |
| 5584 | offset = 0; |
| 5585 | page = eb->pages[++i]; |
| 5586 | WARN_ON(!PageUptodate(page)); |
| 5587 | kaddr = page_address(page); |
| 5588 | } |
| 5589 | } |
| 5590 | if (len) { |
| 5591 | mask_to_set &= BITMAP_LAST_BYTE_MASK(size); |
| 5592 | kaddr[offset] |= mask_to_set; |
| 5593 | } |
| 5594 | } |
| 5595 | |
| 5596 | |
| 5597 | /** |
| 5598 | * extent_buffer_bitmap_clear - clear an area of a bitmap |
| 5599 | * @eb: the extent buffer |
| 5600 | * @start: offset of the bitmap item in the extent buffer |
| 5601 | * @pos: bit number of the first bit |
| 5602 | * @len: number of bits to clear |
| 5603 | */ |
| 5604 | void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start, |
| 5605 | unsigned long pos, unsigned long len) |
| 5606 | { |
| 5607 | char *kaddr; |
| 5608 | struct page *page; |
| 5609 | unsigned long i; |
| 5610 | size_t offset; |
| 5611 | const unsigned int size = pos + len; |
| 5612 | int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE); |
| 5613 | unsigned int mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos); |
| 5614 | |
| 5615 | eb_bitmap_offset(eb, start, pos, &i, &offset); |
| 5616 | page = eb->pages[i]; |
| 5617 | WARN_ON(!PageUptodate(page)); |
| 5618 | kaddr = page_address(page); |
| 5619 | |
| 5620 | while (len >= bits_to_clear) { |
| 5621 | kaddr[offset] &= ~mask_to_clear; |
| 5622 | len -= bits_to_clear; |
| 5623 | bits_to_clear = BITS_PER_BYTE; |
| 5624 | mask_to_clear = ~0U; |
| 5625 | if (++offset >= PAGE_SIZE && len > 0) { |
| 5626 | offset = 0; |
| 5627 | page = eb->pages[++i]; |
| 5628 | WARN_ON(!PageUptodate(page)); |
| 5629 | kaddr = page_address(page); |
| 5630 | } |
| 5631 | } |
| 5632 | if (len) { |
| 5633 | mask_to_clear &= BITMAP_LAST_BYTE_MASK(size); |
| 5634 | kaddr[offset] &= ~mask_to_clear; |
| 5635 | } |
| 5636 | } |
| 5637 | |
| 5638 | static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len) |
| 5639 | { |
| 5640 | unsigned long distance = (src > dst) ? src - dst : dst - src; |
| 5641 | return distance < len; |
| 5642 | } |
| 5643 | |
| 5644 | static void copy_pages(struct page *dst_page, struct page *src_page, |
| 5645 | unsigned long dst_off, unsigned long src_off, |
| 5646 | unsigned long len) |
| 5647 | { |
| 5648 | char *dst_kaddr = page_address(dst_page); |
| 5649 | char *src_kaddr; |
| 5650 | int must_memmove = 0; |
| 5651 | |
| 5652 | if (dst_page != src_page) { |
| 5653 | src_kaddr = page_address(src_page); |
| 5654 | } else { |
| 5655 | src_kaddr = dst_kaddr; |
| 5656 | if (areas_overlap(src_off, dst_off, len)) |
| 5657 | must_memmove = 1; |
| 5658 | } |
| 5659 | |
| 5660 | if (must_memmove) |
| 5661 | memmove(dst_kaddr + dst_off, src_kaddr + src_off, len); |
| 5662 | else |
| 5663 | memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); |
| 5664 | } |
| 5665 | |
| 5666 | void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, |
| 5667 | unsigned long src_offset, unsigned long len) |
| 5668 | { |
| 5669 | size_t cur; |
| 5670 | size_t dst_off_in_page; |
| 5671 | size_t src_off_in_page; |
| 5672 | size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1); |
| 5673 | unsigned long dst_i; |
| 5674 | unsigned long src_i; |
| 5675 | |
| 5676 | if (src_offset + len > dst->len) { |
| 5677 | btrfs_err(dst->fs_info, |
| 5678 | "memmove bogus src_offset %lu move " |
| 5679 | "len %lu dst len %lu", src_offset, len, dst->len); |
| 5680 | BUG_ON(1); |
| 5681 | } |
| 5682 | if (dst_offset + len > dst->len) { |
| 5683 | btrfs_err(dst->fs_info, |
| 5684 | "memmove bogus dst_offset %lu move " |
| 5685 | "len %lu dst len %lu", dst_offset, len, dst->len); |
| 5686 | BUG_ON(1); |
| 5687 | } |
| 5688 | |
| 5689 | while (len > 0) { |
| 5690 | dst_off_in_page = (start_offset + dst_offset) & |
| 5691 | (PAGE_SIZE - 1); |
| 5692 | src_off_in_page = (start_offset + src_offset) & |
| 5693 | (PAGE_SIZE - 1); |
| 5694 | |
| 5695 | dst_i = (start_offset + dst_offset) >> PAGE_SHIFT; |
| 5696 | src_i = (start_offset + src_offset) >> PAGE_SHIFT; |
| 5697 | |
| 5698 | cur = min(len, (unsigned long)(PAGE_SIZE - |
| 5699 | src_off_in_page)); |
| 5700 | cur = min_t(unsigned long, cur, |
| 5701 | (unsigned long)(PAGE_SIZE - dst_off_in_page)); |
| 5702 | |
| 5703 | copy_pages(dst->pages[dst_i], dst->pages[src_i], |
| 5704 | dst_off_in_page, src_off_in_page, cur); |
| 5705 | |
| 5706 | src_offset += cur; |
| 5707 | dst_offset += cur; |
| 5708 | len -= cur; |
| 5709 | } |
| 5710 | } |
| 5711 | |
| 5712 | void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, |
| 5713 | unsigned long src_offset, unsigned long len) |
| 5714 | { |
| 5715 | size_t cur; |
| 5716 | size_t dst_off_in_page; |
| 5717 | size_t src_off_in_page; |
| 5718 | unsigned long dst_end = dst_offset + len - 1; |
| 5719 | unsigned long src_end = src_offset + len - 1; |
| 5720 | size_t start_offset = dst->start & ((u64)PAGE_SIZE - 1); |
| 5721 | unsigned long dst_i; |
| 5722 | unsigned long src_i; |
| 5723 | |
| 5724 | if (src_offset + len > dst->len) { |
| 5725 | btrfs_err(dst->fs_info, "memmove bogus src_offset %lu move " |
| 5726 | "len %lu len %lu", src_offset, len, dst->len); |
| 5727 | BUG_ON(1); |
| 5728 | } |
| 5729 | if (dst_offset + len > dst->len) { |
| 5730 | btrfs_err(dst->fs_info, "memmove bogus dst_offset %lu move " |
| 5731 | "len %lu len %lu", dst_offset, len, dst->len); |
| 5732 | BUG_ON(1); |
| 5733 | } |
| 5734 | if (dst_offset < src_offset) { |
| 5735 | memcpy_extent_buffer(dst, dst_offset, src_offset, len); |
| 5736 | return; |
| 5737 | } |
| 5738 | while (len > 0) { |
| 5739 | dst_i = (start_offset + dst_end) >> PAGE_SHIFT; |
| 5740 | src_i = (start_offset + src_end) >> PAGE_SHIFT; |
| 5741 | |
| 5742 | dst_off_in_page = (start_offset + dst_end) & |
| 5743 | (PAGE_SIZE - 1); |
| 5744 | src_off_in_page = (start_offset + src_end) & |
| 5745 | (PAGE_SIZE - 1); |
| 5746 | |
| 5747 | cur = min_t(unsigned long, len, src_off_in_page + 1); |
| 5748 | cur = min(cur, dst_off_in_page + 1); |
| 5749 | copy_pages(dst->pages[dst_i], dst->pages[src_i], |
| 5750 | dst_off_in_page - cur + 1, |
| 5751 | src_off_in_page - cur + 1, cur); |
| 5752 | |
| 5753 | dst_end -= cur; |
| 5754 | src_end -= cur; |
| 5755 | len -= cur; |
| 5756 | } |
| 5757 | } |
| 5758 | |
| 5759 | int try_release_extent_buffer(struct page *page) |
| 5760 | { |
| 5761 | struct extent_buffer *eb; |
| 5762 | |
| 5763 | /* |
| 5764 | * We need to make sure noboody is attaching this page to an eb right |
| 5765 | * now. |
| 5766 | */ |
| 5767 | spin_lock(&page->mapping->private_lock); |
| 5768 | if (!PagePrivate(page)) { |
| 5769 | spin_unlock(&page->mapping->private_lock); |
| 5770 | return 1; |
| 5771 | } |
| 5772 | |
| 5773 | eb = (struct extent_buffer *)page->private; |
| 5774 | BUG_ON(!eb); |
| 5775 | |
| 5776 | /* |
| 5777 | * This is a little awful but should be ok, we need to make sure that |
| 5778 | * the eb doesn't disappear out from under us while we're looking at |
| 5779 | * this page. |
| 5780 | */ |
| 5781 | spin_lock(&eb->refs_lock); |
| 5782 | if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) { |
| 5783 | spin_unlock(&eb->refs_lock); |
| 5784 | spin_unlock(&page->mapping->private_lock); |
| 5785 | return 0; |
| 5786 | } |
| 5787 | spin_unlock(&page->mapping->private_lock); |
| 5788 | |
| 5789 | /* |
| 5790 | * If tree ref isn't set then we know the ref on this eb is a real ref, |
| 5791 | * so just return, this page will likely be freed soon anyway. |
| 5792 | */ |
| 5793 | if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) { |
| 5794 | spin_unlock(&eb->refs_lock); |
| 5795 | return 0; |
| 5796 | } |
| 5797 | |
| 5798 | return release_extent_buffer(eb); |
| 5799 | } |