fs/btrfs/extent_io.h

   1 #ifndef __EXTENTIO__
   2 #define __EXTENTIO__
   3
   4 #include <linux/rbtree.h>
   5 #include <linux/refcount.h>
   6 #include "ulist.h"
   7
   8 /* bits for the extent state */
   9 #define EXTENT_DIRTY            (1U << 0)
  10 #define EXTENT_WRITEBACK        (1U << 1)
  11 #define EXTENT_UPTODATE         (1U << 2)
  12 #define EXTENT_LOCKED           (1U << 3)
  13 #define EXTENT_NEW              (1U << 4)
  14 #define EXTENT_DELALLOC         (1U << 5)
  15 #define EXTENT_DEFRAG           (1U << 6)
  16 #define EXTENT_BOUNDARY         (1U << 9)
  17 #define EXTENT_NODATASUM        (1U << 10)
  18 #define EXTENT_CLEAR_META_RESV  (1U << 11)
  19 #define EXTENT_FIRST_DELALLOC   (1U << 12)
  20 #define EXTENT_NEED_WAIT        (1U << 13)
  21 #define EXTENT_DAMAGED          (1U << 14)
  22 #define EXTENT_NORESERVE        (1U << 15)
  23 #define EXTENT_QGROUP_RESERVED  (1U << 16)
  24 #define EXTENT_CLEAR_DATA_RESV  (1U << 17)
  25 #define EXTENT_DELALLOC_NEW     (1U << 18)
  26 #define EXTENT_IOBITS           (EXTENT_LOCKED | EXTENT_WRITEBACK)
  27 #define EXTENT_DO_ACCOUNTING    (EXTENT_CLEAR_META_RESV | \
  28                                  EXTENT_CLEAR_DATA_RESV)
  29 #define EXTENT_CTLBITS          (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
  30
  31 /*
  32  * flags for bio submission. The high bits indicate the compression
  33  * type for this bio
  34  */
  35 #define EXTENT_BIO_COMPRESSED 1
  36 #define EXTENT_BIO_TREE_LOG 2
  37 #define EXTENT_BIO_FLAG_SHIFT 16
  38
  39 /* these are bit numbers for test/set bit */
  40 #define EXTENT_BUFFER_UPTODATE 0
  41 #define EXTENT_BUFFER_DIRTY 2
  42 #define EXTENT_BUFFER_CORRUPT 3
  43 #define EXTENT_BUFFER_READAHEAD 4       /* this got triggered by readahead */
  44 #define EXTENT_BUFFER_TREE_REF 5
  45 #define EXTENT_BUFFER_STALE 6
  46 #define EXTENT_BUFFER_WRITEBACK 7
  47 #define EXTENT_BUFFER_READ_ERR 8        /* read IO error */
  48 #define EXTENT_BUFFER_DUMMY 9
  49 #define EXTENT_BUFFER_IN_TREE 10
  50 #define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */
  51
  52 /* these are flags for __process_pages_contig */
  53 #define PAGE_UNLOCK             (1 << 0)
  54 #define PAGE_CLEAR_DIRTY        (1 << 1)
  55 #define PAGE_SET_WRITEBACK      (1 << 2)
  56 #define PAGE_END_WRITEBACK      (1 << 3)
  57 #define PAGE_SET_PRIVATE2       (1 << 4)
  58 #define PAGE_SET_ERROR          (1 << 5)
  59 #define PAGE_LOCK               (1 << 6)
  60
  61 /*
  62  * page->private values.  Every page that is controlled by the extent
  63  * map has page->private set to one.
  64  */
  65 #define EXTENT_PAGE_PRIVATE 1
  66
  67 /*
  68  * The extent buffer bitmap operations are done with byte granularity instead of
  69  * word granularity for two reasons:
  70  * 1. The bitmaps must be little-endian on disk.
  71  * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
  72  *    single word in a bitmap may straddle two pages in the extent buffer.
  73  */
  74 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
  75 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
  76 #define BITMAP_FIRST_BYTE_MASK(start) \
  77         ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
  78 #define BITMAP_LAST_BYTE_MASK(nbits) \
  79         (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
  80
  81 static inline int le_test_bit(int nr, const u8 *addr)
  82 {
  83         return 1U & (addr[BIT_BYTE(nr)] >> (nr & (BITS_PER_BYTE-1)));
  84 }
  85
  86 extern void le_bitmap_set(u8 *map, unsigned int start, int len);
  87 extern void le_bitmap_clear(u8 *map, unsigned int start, int len);
  88
  89 struct extent_state;
  90 struct btrfs_root;
  91 struct btrfs_inode;
  92 struct btrfs_io_bio;
  93 struct io_failure_record;
  94
  95 typedef blk_status_t (extent_submit_bio_hook_t)(struct inode *inode,
  96                 struct bio *bio, int mirror_num, unsigned long bio_flags,
  97                 u64 bio_offset);
  98 struct extent_io_ops {
  99         /*
 100          * The following callbacks must be allways defined, the function
 101          * pointer will be called unconditionally.
 102          */
 103         extent_submit_bio_hook_t *submit_bio_hook;
 104         int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
 105                                     struct page *page, u64 start, u64 end,
 106                                     int mirror);
 107         int (*merge_bio_hook)(struct page *page, unsigned long offset,
 108                               size_t size, struct bio *bio,
 109                               unsigned long bio_flags);
 110         int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
 111
 112         /*
 113          * Optional hooks, called if the pointer is not NULL
 114          */
 115         int (*fill_delalloc)(struct inode *inode, struct page *locked_page,
 116                              u64 start, u64 end, int *page_started,
 117                              unsigned long *nr_written);
 118
 119         int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
 120         void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
 121                                       struct extent_state *state, int uptodate);
 122         void (*set_bit_hook)(struct inode *inode, struct extent_state *state,
 123                              unsigned *bits);
 124         void (*clear_bit_hook)(struct btrfs_inode *inode,
 125                         struct extent_state *state,
 126                         unsigned *bits);
 127         void (*merge_extent_hook)(struct inode *inode,
 128                                   struct extent_state *new,
 129                                   struct extent_state *other);
 130         void (*split_extent_hook)(struct inode *inode,
 131                                   struct extent_state *orig, u64 split);
 132 };
 133
 134 struct extent_io_tree {
 135         struct rb_root state;
 136         struct address_space *mapping;
 137         u64 dirty_bytes;
 138         int track_uptodate;
 139         spinlock_t lock;
 140         const struct extent_io_ops *ops;
 141 };
 142
 143 struct extent_state {
 144         u64 start;
 145         u64 end; /* inclusive */
 146         struct rb_node rb_node;
 147
 148         /* ADD NEW ELEMENTS AFTER THIS */
 149         wait_queue_head_t wq;
 150         refcount_t refs;
 151         unsigned state;
 152
 153         struct io_failure_record *failrec;
 154
 155 #ifdef CONFIG_BTRFS_DEBUG
 156         struct list_head leak_list;
 157 #endif
 158 };
 159
 160 #define INLINE_EXTENT_BUFFER_PAGES 16
 161 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
 162 struct extent_buffer {
 163         u64 start;
 164         unsigned long len;
 165         unsigned long bflags;
 166         struct btrfs_fs_info *fs_info;
 167         spinlock_t refs_lock;
 168         atomic_t refs;
 169         atomic_t io_pages;
 170         int read_mirror;
 171         struct rcu_head rcu_head;
 172         pid_t lock_owner;
 173
 174         /* count of read lock holders on the extent buffer */
 175         atomic_t write_locks;
 176         atomic_t read_locks;
 177         atomic_t blocking_writers;
 178         atomic_t blocking_readers;
 179         atomic_t spinning_readers;
 180         atomic_t spinning_writers;
 181         short lock_nested;
 182         /* >= 0 if eb belongs to a log tree, -1 otherwise */
 183         short log_index;
 184
 185         /* protects write locks */
 186         rwlock_t lock;
 187
 188         /* readers use lock_wq while they wait for the write
 189          * lock holders to unlock
 190          */
 191         wait_queue_head_t write_lock_wq;
 192
 193         /* writers use read_lock_wq while they wait for readers
 194          * to unlock
 195          */
 196         wait_queue_head_t read_lock_wq;
 197         struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 198 #ifdef CONFIG_BTRFS_DEBUG
 199         struct list_head leak_list;
 200 #endif
 201 };
 202
 203 /*
 204  * Structure to record how many bytes and which ranges are set/cleared
 205  */
 206 struct extent_changeset {
 207         /* How many bytes are set/cleared in this operation */
 208         u64 bytes_changed;
 209
 210         /* Changed ranges */
 211         struct ulist range_changed;
 212 };
 213
 214 static inline void extent_set_compress_type(unsigned long *bio_flags,
 215                                             int compress_type)
 216 {
 217         *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
 218 }
 219
 220 static inline int extent_compress_type(unsigned long bio_flags)
 221 {
 222         return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
 223 }
 224
 225 struct extent_map_tree;
 226
 227 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
 228                                           struct page *page,
 229                                           size_t pg_offset,
 230                                           u64 start, u64 len,
 231                                           int create);
 232
 233 void extent_io_tree_init(struct extent_io_tree *tree,
 234                          struct address_space *mapping);
 235 int try_release_extent_mapping(struct extent_map_tree *map,
 236                                struct extent_io_tree *tree, struct page *page,
 237                                gfp_t mask);
 238 int try_release_extent_buffer(struct page *page);
 239 int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
 240                      struct extent_state **cached);
 241
 242 static inline int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
 243 {
 244         return lock_extent_bits(tree, start, end, NULL);
 245 }
 246
 247 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
 248 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
 249                           get_extent_t *get_extent, int mirror_num);
 250 int __init extent_io_init(void);
 251 void extent_io_exit(void);
 252
 253 u64 count_range_bits(struct extent_io_tree *tree,
 254                      u64 *start, u64 search_end,
 255                      u64 max_bytes, unsigned bits, int contig);
 256
 257 void free_extent_state(struct extent_state *state);
 258 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
 259                    unsigned bits, int filled,
 260                    struct extent_state *cached_state);
 261 int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
 262                 unsigned bits, struct extent_changeset *changeset);
 263 int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 264                      unsigned bits, int wake, int delete,
 265                      struct extent_state **cached, gfp_t mask);
 266
 267 static inline int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
 268 {
 269         return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
 270                                 GFP_NOFS);
 271 }
 272
 273 static inline int unlock_extent_cached(struct extent_io_tree *tree, u64 start,
 274                 u64 end, struct extent_state **cached, gfp_t mask)
 275 {
 276         return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
 277                                 mask);
 278 }
 279
 280 static inline int clear_extent_bits(struct extent_io_tree *tree, u64 start,
 281                 u64 end, unsigned bits)
 282 {
 283         int wake = 0;
 284
 285         if (bits & EXTENT_LOCKED)
 286                 wake = 1;
 287
 288         return clear_extent_bit(tree, start, end, bits, wake, 0, NULL,
 289                         GFP_NOFS);
 290 }
 291
 292 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
 293                            unsigned bits, struct extent_changeset *changeset);
 294 int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 295                    unsigned bits, u64 *failed_start,
 296                    struct extent_state **cached_state, gfp_t mask);
 297
 298 static inline int set_extent_bits(struct extent_io_tree *tree, u64 start,
 299                 u64 end, unsigned bits)
 300 {
 301         return set_extent_bit(tree, start, end, bits, NULL, NULL, GFP_NOFS);
 302 }
 303
 304 static inline int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
 305                 u64 end, struct extent_state **cached_state, gfp_t mask)
 306 {
 307         return clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
 308                                 cached_state, mask);
 309 }
 310
 311 static inline int set_extent_dirty(struct extent_io_tree *tree, u64 start,
 312                 u64 end, gfp_t mask)
 313 {
 314         return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
 315                               NULL, mask);
 316 }
 317
 318 static inline int clear_extent_dirty(struct extent_io_tree *tree, u64 start,
 319                 u64 end)
 320 {
 321         return clear_extent_bit(tree, start, end,
 322                                 EXTENT_DIRTY | EXTENT_DELALLOC |
 323                                 EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS);
 324 }
 325
 326 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 327                        unsigned bits, unsigned clear_bits,
 328                        struct extent_state **cached_state);
 329
 330 static inline int set_extent_delalloc(struct extent_io_tree *tree, u64 start,
 331                 u64 end, struct extent_state **cached_state)
 332 {
 333         return set_extent_bit(tree, start, end,
 334                               EXTENT_DELALLOC | EXTENT_UPTODATE,
 335                               NULL, cached_state, GFP_NOFS);
 336 }
 337
 338 static inline int set_extent_defrag(struct extent_io_tree *tree, u64 start,
 339                 u64 end, struct extent_state **cached_state)
 340 {
 341         return set_extent_bit(tree, start, end,
 342                               EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
 343                               NULL, cached_state, GFP_NOFS);
 344 }
 345
 346 static inline int set_extent_new(struct extent_io_tree *tree, u64 start,
 347                 u64 end)
 348 {
 349         return set_extent_bit(tree, start, end, EXTENT_NEW, NULL, NULL,
 350                         GFP_NOFS);
 351 }
 352
 353 static inline int set_extent_uptodate(struct extent_io_tree *tree, u64 start,
 354                 u64 end, struct extent_state **cached_state, gfp_t mask)
 355 {
 356         return set_extent_bit(tree, start, end, EXTENT_UPTODATE, NULL,
 357                               cached_state, mask);
 358 }
 359
 360 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 361                           u64 *start_ret, u64 *end_ret, unsigned bits,
 362                           struct extent_state **cached_state);
 363 int extent_invalidatepage(struct extent_io_tree *tree,
 364                           struct page *page, unsigned long offset);
 365 int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
 366                           get_extent_t *get_extent,
 367                           struct writeback_control *wbc);
 368 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
 369                               u64 start, u64 end, get_extent_t *get_extent,
 370                               int mode);
 371 int extent_writepages(struct extent_io_tree *tree,
 372                       struct address_space *mapping,
 373                       get_extent_t *get_extent,
 374                       struct writeback_control *wbc);
 375 int btree_write_cache_pages(struct address_space *mapping,
 376                             struct writeback_control *wbc);
 377 int extent_readpages(struct extent_io_tree *tree,
 378                      struct address_space *mapping,
 379                      struct list_head *pages, unsigned nr_pages,
 380                      get_extent_t get_extent);
 381 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 382                 __u64 start, __u64 len, get_extent_t *get_extent);
 383 void set_page_extent_mapped(struct page *page);
 384
 385 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 386                                           u64 start);
 387 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 388                                                   u64 start, unsigned long len);
 389 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 390                                                 u64 start);
 391 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
 392 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 393                                          u64 start);
 394 void free_extent_buffer(struct extent_buffer *eb);
 395 void free_extent_buffer_stale(struct extent_buffer *eb);
 396 #define WAIT_NONE       0
 397 #define WAIT_COMPLETE   1
 398 #define WAIT_PAGE_LOCK  2
 399 int read_extent_buffer_pages(struct extent_io_tree *tree,
 400                              struct extent_buffer *eb, int wait,
 401                              get_extent_t *get_extent, int mirror_num);
 402 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 403
 404 static inline unsigned long num_extent_pages(u64 start, u64 len)
 405 {
 406         return ((start + len + PAGE_SIZE - 1) >> PAGE_SHIFT) -
 407                 (start >> PAGE_SHIFT);
 408 }
 409
 410 static inline void extent_buffer_get(struct extent_buffer *eb)
 411 {
 412         atomic_inc(&eb->refs);
 413 }
 414
 415 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
 416                           unsigned long start,
 417                           unsigned long len);
 418 void read_extent_buffer(struct extent_buffer *eb, void *dst,
 419                         unsigned long start,
 420                         unsigned long len);
 421 int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dst,
 422                                unsigned long start,
 423                                unsigned long len);
 424 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);
 425 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
 426                 const void *src);
 427 void write_extent_buffer(struct extent_buffer *eb, const void *src,
 428                          unsigned long start, unsigned long len);
 429 void copy_extent_buffer_full(struct extent_buffer *dst,
 430                              struct extent_buffer *src);
 431 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
 432                         unsigned long dst_offset, unsigned long src_offset,
 433                         unsigned long len);
 434 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 435                            unsigned long src_offset, unsigned long len);
 436 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 437                            unsigned long src_offset, unsigned long len);
 438 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
 439                            unsigned long len);
 440 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
 441                            unsigned long pos);
 442 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
 443                               unsigned long pos, unsigned long len);
 444 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
 445                                 unsigned long pos, unsigned long len);
 446 void clear_extent_buffer_dirty(struct extent_buffer *eb);
 447 int set_extent_buffer_dirty(struct extent_buffer *eb);
 448 void set_extent_buffer_uptodate(struct extent_buffer *eb);
 449 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 450 int extent_buffer_uptodate(struct extent_buffer *eb);
 451 int extent_buffer_under_io(struct extent_buffer *eb);
 452 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,
 453                       unsigned long min_len, char **map,
 454                       unsigned long *map_start,
 455                       unsigned long *map_len);
 456 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 457 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 458 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
 459                                  u64 delalloc_end, struct page *locked_page,
 460                                  unsigned bits_to_clear,
 461                                  unsigned long page_ops);
 462 struct bio *
 463 btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
 464                 gfp_t gfp_flags);
 465 struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs);
 466 struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask);
 467
 468 struct btrfs_fs_info;
 469 struct btrfs_inode;
 470
 471 int repair_io_failure(struct btrfs_inode *inode, u64 start, u64 length,
 472                 u64 logical, struct page *page,
 473                 unsigned int pg_offset, int mirror_num);
 474 int clean_io_failure(struct btrfs_inode *inode, u64 start,
 475                 struct page *page, unsigned int pg_offset);
 476 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
 477 int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
 478                          struct extent_buffer *eb, int mirror_num);
 479
 480 /*
 481  * When IO fails, either with EIO or csum verification fails, we
 482  * try other mirrors that might have a good copy of the data.  This
 483  * io_failure_record is used to record state as we go through all the
 484  * mirrors.  If another mirror has good data, the page is set up to date
 485  * and things continue.  If a good mirror can't be found, the original
 486  * bio end_io callback is called to indicate things have failed.
 487  */
 488 struct io_failure_record {
 489         struct page *page;
 490         u64 start;
 491         u64 len;
 492         u64 logical;
 493         unsigned long bio_flags;
 494         int this_mirror;
 495         int failed_mirror;
 496         int in_validation;
 497 };
 498
 499
 500 void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start,
 501                 u64 end);
 502 int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
 503                                 struct io_failure_record **failrec_ret);
 504 int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
 505                            struct io_failure_record *failrec, int fail_mirror);
 506 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
 507                                     struct io_failure_record *failrec,
 508                                     struct page *page, int pg_offset, int icsum,
 509                                     bio_end_io_t *endio_func, void *data);
 510 int free_io_failure(struct btrfs_inode *inode, struct io_failure_record *rec);
 511 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 512 noinline u64 find_lock_delalloc_range(struct inode *inode,
 513                                       struct extent_io_tree *tree,
 514                                       struct page *locked_page, u64 *start,
 515                                       u64 *end, u64 max_bytes);
 516 #endif
 517 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 518                                                u64 start);
 519 #endif