fs/btrfs/extent_io.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef BTRFS_EXTENT_IO_H
   4 #define BTRFS_EXTENT_IO_H
   5
   6 #include <linux/rbtree.h>
   7 #include <linux/refcount.h>
   8 #include "ulist.h"
   9
  10 /*
  11  * flags for bio submission. The high bits indicate the compression
  12  * type for this bio
  13  */
  14 #define EXTENT_BIO_COMPRESSED 1
  15 #define EXTENT_BIO_FLAG_SHIFT 16
  16
  17 enum {
  18         EXTENT_BUFFER_UPTODATE,
  19         EXTENT_BUFFER_DIRTY,
  20         EXTENT_BUFFER_CORRUPT,
  21         /* this got triggered by readahead */
  22         EXTENT_BUFFER_READAHEAD,
  23         EXTENT_BUFFER_TREE_REF,
  24         EXTENT_BUFFER_STALE,
  25         EXTENT_BUFFER_WRITEBACK,
  26         /* read IO error */
  27         EXTENT_BUFFER_READ_ERR,
  28         EXTENT_BUFFER_UNMAPPED,
  29         EXTENT_BUFFER_IN_TREE,
  30         /* write IO error */
  31         EXTENT_BUFFER_WRITE_ERR,
  32 };
  33
  34 /* these are flags for __process_pages_contig */
  35 #define PAGE_UNLOCK             (1 << 0)
  36 #define PAGE_CLEAR_DIRTY        (1 << 1)
  37 #define PAGE_SET_WRITEBACK      (1 << 2)
  38 #define PAGE_END_WRITEBACK      (1 << 3)
  39 #define PAGE_SET_PRIVATE2       (1 << 4)
  40 #define PAGE_SET_ERROR          (1 << 5)
  41 #define PAGE_LOCK               (1 << 6)
  42
  43 /*
  44  * page->private values.  Every page that is controlled by the extent
  45  * map has page->private set to one.
  46  */
  47 #define EXTENT_PAGE_PRIVATE 1
  48
  49 /*
  50  * The extent buffer bitmap operations are done with byte granularity instead of
  51  * word granularity for two reasons:
  52  * 1. The bitmaps must be little-endian on disk.
  53  * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
  54  *    single word in a bitmap may straddle two pages in the extent buffer.
  55  */
  56 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
  57 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
  58 #define BITMAP_FIRST_BYTE_MASK(start) \
  59         ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
  60 #define BITMAP_LAST_BYTE_MASK(nbits) \
  61         (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
  62
  63 struct btrfs_root;
  64 struct btrfs_inode;
  65 struct btrfs_io_bio;
  66 struct io_failure_record;
  67 struct extent_io_tree;
  68
  69 typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
  70                 struct bio *bio, u64 bio_offset);
  71
  72 struct extent_io_ops {
  73         /*
  74          * The following callbacks must be always defined, the function
  75          * pointer will be called unconditionally.
  76          */
  77         blk_status_t (*submit_bio_hook)(struct inode *inode, struct bio *bio,
  78                                         int mirror_num, unsigned long bio_flags);
  79         int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
  80                                     struct page *page, u64 start, u64 end,
  81                                     int mirror);
  82 };
  83
  84
  85 #define INLINE_EXTENT_BUFFER_PAGES 16
  86 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
  87 struct extent_buffer {
  88         u64 start;
  89         unsigned long len;
  90         unsigned long bflags;
  91         struct btrfs_fs_info *fs_info;
  92         spinlock_t refs_lock;
  93         atomic_t refs;
  94         atomic_t io_pages;
  95         int read_mirror;
  96         struct rcu_head rcu_head;
  97         pid_t lock_owner;
  98
  99         int blocking_writers;
 100         atomic_t blocking_readers;
 101         bool lock_nested;
 102         /* >= 0 if eb belongs to a log tree, -1 otherwise */
 103         short log_index;
 104
 105         /* protects write locks */
 106         rwlock_t lock;
 107
 108         /* readers use lock_wq while they wait for the write
 109          * lock holders to unlock
 110          */
 111         wait_queue_head_t write_lock_wq;
 112
 113         /* writers use read_lock_wq while they wait for readers
 114          * to unlock
 115          */
 116         wait_queue_head_t read_lock_wq;
 117         struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 118 #ifdef CONFIG_BTRFS_DEBUG
 119         int spinning_writers;
 120         atomic_t spinning_readers;
 121         atomic_t read_locks;
 122         int write_locks;
 123         struct list_head leak_list;
 124 #endif
 125 };
 126
 127 /*
 128  * Structure to record how many bytes and which ranges are set/cleared
 129  */
 130 struct extent_changeset {
 131         /* How many bytes are set/cleared in this operation */
 132         unsigned int bytes_changed;
 133
 134         /* Changed ranges */
 135         struct ulist range_changed;
 136 };
 137
 138 static inline void extent_changeset_init(struct extent_changeset *changeset)
 139 {
 140         changeset->bytes_changed = 0;
 141         ulist_init(&changeset->range_changed);
 142 }
 143
 144 static inline struct extent_changeset *extent_changeset_alloc(void)
 145 {
 146         struct extent_changeset *ret;
 147
 148         ret = kmalloc(sizeof(*ret), GFP_KERNEL);
 149         if (!ret)
 150                 return NULL;
 151
 152         extent_changeset_init(ret);
 153         return ret;
 154 }
 155
 156 static inline void extent_changeset_release(struct extent_changeset *changeset)
 157 {
 158         if (!changeset)
 159                 return;
 160         changeset->bytes_changed = 0;
 161         ulist_release(&changeset->range_changed);
 162 }
 163
 164 static inline void extent_changeset_free(struct extent_changeset *changeset)
 165 {
 166         if (!changeset)
 167                 return;
 168         extent_changeset_release(changeset);
 169         kfree(changeset);
 170 }
 171
 172 static inline void extent_set_compress_type(unsigned long *bio_flags,
 173                                             int compress_type)
 174 {
 175         *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
 176 }
 177
 178 static inline int extent_compress_type(unsigned long bio_flags)
 179 {
 180         return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
 181 }
 182
 183 struct extent_map_tree;
 184
 185 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
 186                                           struct page *page, size_t pg_offset,
 187                                           u64 start, u64 len);
 188
 189 int try_release_extent_mapping(struct page *page, gfp_t mask);
 190 int try_release_extent_buffer(struct page *page);
 191
 192 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
 193                           get_extent_t *get_extent, int mirror_num);
 194 int extent_write_full_page(struct page *page, struct writeback_control *wbc);
 195 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 196                               int mode);
 197 int extent_writepages(struct address_space *mapping,
 198                       struct writeback_control *wbc);
 199 int btree_write_cache_pages(struct address_space *mapping,
 200                             struct writeback_control *wbc);
 201 int extent_readpages(struct address_space *mapping, struct list_head *pages,
 202                      unsigned nr_pages);
 203 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 204                 __u64 start, __u64 len);
 205 void set_page_extent_mapped(struct page *page);
 206
 207 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 208                                           u64 start);
 209 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 210                                                   u64 start, unsigned long len);
 211 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 212                                                 u64 start);
 213 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
 214 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 215                                          u64 start);
 216 void free_extent_buffer(struct extent_buffer *eb);
 217 void free_extent_buffer_stale(struct extent_buffer *eb);
 218 #define WAIT_NONE       0
 219 #define WAIT_COMPLETE   1
 220 #define WAIT_PAGE_LOCK  2
 221 int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
 222                              int mirror_num);
 223 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 224
 225 static inline int num_extent_pages(const struct extent_buffer *eb)
 226 {
 227         return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) -
 228                (eb->start >> PAGE_SHIFT);
 229 }
 230
 231 static inline int extent_buffer_uptodate(struct extent_buffer *eb)
 232 {
 233         return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 234 }
 235
 236 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
 237                          unsigned long start, unsigned long len);
 238 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
 239                         unsigned long start,
 240                         unsigned long len);
 241 int read_extent_buffer_to_user(const struct extent_buffer *eb,
 242                                void __user *dst, unsigned long start,
 243                                unsigned long len);
 244 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);
 245 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
 246                 const void *src);
 247 void write_extent_buffer(struct extent_buffer *eb, const void *src,
 248                          unsigned long start, unsigned long len);
 249 void copy_extent_buffer_full(struct extent_buffer *dst,
 250                              struct extent_buffer *src);
 251 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
 252                         unsigned long dst_offset, unsigned long src_offset,
 253                         unsigned long len);
 254 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 255                            unsigned long src_offset, unsigned long len);
 256 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 257                            unsigned long src_offset, unsigned long len);
 258 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
 259                            unsigned long len);
 260 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
 261                            unsigned long pos);
 262 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
 263                               unsigned long pos, unsigned long len);
 264 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
 265                                 unsigned long pos, unsigned long len);
 266 void clear_extent_buffer_dirty(struct extent_buffer *eb);
 267 bool set_extent_buffer_dirty(struct extent_buffer *eb);
 268 void set_extent_buffer_uptodate(struct extent_buffer *eb);
 269 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 270 int extent_buffer_under_io(struct extent_buffer *eb);
 271 int map_private_extent_buffer(const struct extent_buffer *eb,
 272                               unsigned long offset, unsigned long min_len,
 273                               char **map, unsigned long *map_start,
 274                               unsigned long *map_len);
 275 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 276 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 277 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
 278                                   struct page *locked_page,
 279                                   unsigned bits_to_clear,
 280                                   unsigned long page_ops);
 281 struct bio *btrfs_bio_alloc(u64 first_byte);
 282 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 283 struct bio *btrfs_bio_clone(struct bio *bio);
 284 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
 285
 286 struct btrfs_fs_info;
 287 struct btrfs_inode;
 288
 289 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 290                       u64 length, u64 logical, struct page *page,
 291                       unsigned int pg_offset, int mirror_num);
 292 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
 293 int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num);
 294
 295 /*
 296  * When IO fails, either with EIO or csum verification fails, we
 297  * try other mirrors that might have a good copy of the data.  This
 298  * io_failure_record is used to record state as we go through all the
 299  * mirrors.  If another mirror has good data, the page is set up to date
 300  * and things continue.  If a good mirror can't be found, the original
 301  * bio end_io callback is called to indicate things have failed.
 302  */
 303 struct io_failure_record {
 304         struct page *page;
 305         u64 start;
 306         u64 len;
 307         u64 logical;
 308         unsigned long bio_flags;
 309         int this_mirror;
 310         int failed_mirror;
 311         int in_validation;
 312 };
 313
 314
 315 bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
 316                             struct io_failure_record *failrec, int fail_mirror);
 317 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
 318                                     struct io_failure_record *failrec,
 319                                     struct page *page, int pg_offset, int icsum,
 320                                     bio_end_io_t *endio_func, void *data);
 321 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 322 bool find_lock_delalloc_range(struct inode *inode,
 323                              struct page *locked_page, u64 *start,
 324                              u64 *end);
 325 #endif
 326 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 327                                                u64 start);
 328 #endif