fs/btrfs/extent_io.h

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