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 <linux/fiemap.h>
   9 #include "ulist.h"
  10
  11 /*
  12  * flags for bio submission. The high bits indicate the compression
  13  * type for this bio
  14  */
  15 #define EXTENT_BIO_COMPRESSED 1
  16 #define EXTENT_BIO_FLAG_SHIFT 16
  17
  18 enum {
  19         EXTENT_BUFFER_UPTODATE,
  20         EXTENT_BUFFER_DIRTY,
  21         EXTENT_BUFFER_CORRUPT,
  22         /* this got triggered by readahead */
  23         EXTENT_BUFFER_READAHEAD,
  24         EXTENT_BUFFER_TREE_REF,
  25         EXTENT_BUFFER_STALE,
  26         EXTENT_BUFFER_WRITEBACK,
  27         /* read IO error */
  28         EXTENT_BUFFER_READ_ERR,
  29         EXTENT_BUFFER_UNMAPPED,
  30         EXTENT_BUFFER_IN_TREE,
  31         /* write IO error */
  32         EXTENT_BUFFER_WRITE_ERR,
  33 };
  34
  35 /* these are flags for __process_pages_contig */
  36 #define PAGE_UNLOCK             (1 << 0)
  37 #define PAGE_CLEAR_DIRTY        (1 << 1)
  38 #define PAGE_SET_WRITEBACK      (1 << 2)
  39 #define PAGE_END_WRITEBACK      (1 << 3)
  40 #define PAGE_SET_PRIVATE2       (1 << 4)
  41 #define PAGE_SET_ERROR          (1 << 5)
  42 #define PAGE_LOCK               (1 << 6)
  43
  44 /*
  45  * page->private values.  Every page that is controlled by the extent
  46  * map has page->private set to one.
  47  */
  48 #define EXTENT_PAGE_PRIVATE 1
  49
  50 /*
  51  * The extent buffer bitmap operations are done with byte granularity instead of
  52  * word granularity for two reasons:
  53  * 1. The bitmaps must be little-endian on disk.
  54  * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
  55  *    single word in a bitmap may straddle two pages in the extent buffer.
  56  */
  57 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
  58 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
  59 #define BITMAP_FIRST_BYTE_MASK(start) \
  60         ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
  61 #define BITMAP_LAST_BYTE_MASK(nbits) \
  62         (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
  63
  64 struct btrfs_root;
  65 struct btrfs_inode;
  66 struct btrfs_io_bio;
  67 struct io_failure_record;
  68 struct extent_io_tree;
  69
  70 typedef blk_status_t (submit_bio_hook_t)(struct inode *inode, struct bio *bio,
  71                                          int mirror_num,
  72                                          unsigned long bio_flags);
  73
  74 typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
  75                 struct bio *bio, u64 bio_offset);
  76
  77 struct extent_io_ops {
  78         /*
  79          * The following callbacks must be always defined, the function
  80          * pointer will be called unconditionally.
  81          */
  82         submit_bio_hook_t *submit_bio_hook;
  83         int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
  84                                     struct page *page, u64 start, u64 end,
  85                                     int mirror);
  86 };
  87
  88
  89 #define INLINE_EXTENT_BUFFER_PAGES 16
  90 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
  91 struct extent_buffer {
  92         u64 start;
  93         unsigned long len;
  94         unsigned long bflags;
  95         struct btrfs_fs_info *fs_info;
  96         spinlock_t refs_lock;
  97         atomic_t refs;
  98         atomic_t io_pages;
  99         int read_mirror;
 100         struct rcu_head rcu_head;
 101         pid_t lock_owner;
 102
 103         int blocking_writers;
 104         atomic_t blocking_readers;
 105         bool lock_nested;
 106         /* >= 0 if eb belongs to a log tree, -1 otherwise */
 107         short log_index;
 108
 109         /* protects write locks */
 110         rwlock_t lock;
 111
 112         /* readers use lock_wq while they wait for the write
 113          * lock holders to unlock
 114          */
 115         wait_queue_head_t write_lock_wq;
 116
 117         /* writers use read_lock_wq while they wait for readers
 118          * to unlock
 119          */
 120         wait_queue_head_t read_lock_wq;
 121         struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 122 #ifdef CONFIG_BTRFS_DEBUG
 123         int spinning_writers;
 124         atomic_t spinning_readers;
 125         atomic_t read_locks;
 126         int write_locks;
 127         struct list_head leak_list;
 128 #endif
 129 };
 130
 131 /*
 132  * Structure to record how many bytes and which ranges are set/cleared
 133  */
 134 struct extent_changeset {
 135         /* How many bytes are set/cleared in this operation */
 136         unsigned int bytes_changed;
 137
 138         /* Changed ranges */
 139         struct ulist range_changed;
 140 };
 141
 142 static inline void extent_changeset_init(struct extent_changeset *changeset)
 143 {
 144         changeset->bytes_changed = 0;
 145         ulist_init(&changeset->range_changed);
 146 }
 147
 148 static inline struct extent_changeset *extent_changeset_alloc(void)
 149 {
 150         struct extent_changeset *ret;
 151
 152         ret = kmalloc(sizeof(*ret), GFP_KERNEL);
 153         if (!ret)
 154                 return NULL;
 155
 156         extent_changeset_init(ret);
 157         return ret;
 158 }
 159
 160 static inline void extent_changeset_release(struct extent_changeset *changeset)
 161 {
 162         if (!changeset)
 163                 return;
 164         changeset->bytes_changed = 0;
 165         ulist_release(&changeset->range_changed);
 166 }
 167
 168 static inline void extent_changeset_free(struct extent_changeset *changeset)
 169 {
 170         if (!changeset)
 171                 return;
 172         extent_changeset_release(changeset);
 173         kfree(changeset);
 174 }
 175
 176 static inline void extent_set_compress_type(unsigned long *bio_flags,
 177                                             int compress_type)
 178 {
 179         *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
 180 }
 181
 182 static inline int extent_compress_type(unsigned long bio_flags)
 183 {
 184         return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
 185 }
 186
 187 struct extent_map_tree;
 188
 189 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
 190                                           struct page *page, size_t pg_offset,
 191                                           u64 start, u64 len);
 192
 193 int try_release_extent_mapping(struct page *page, gfp_t mask);
 194 int try_release_extent_buffer(struct page *page);
 195
 196 int extent_read_full_page(struct page *page, get_extent_t *get_extent,
 197                           int mirror_num);
 198 int extent_write_full_page(struct page *page, struct writeback_control *wbc);
 199 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 200                               int mode);
 201 int extent_writepages(struct address_space *mapping,
 202                       struct writeback_control *wbc);
 203 int btree_write_cache_pages(struct address_space *mapping,
 204                             struct writeback_control *wbc);
 205 void extent_readahead(struct readahead_control *rac);
 206 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 207                   u64 start, u64 len);
 208 void set_page_extent_mapped(struct page *page);
 209
 210 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 211                                           u64 start);
 212 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 213                                                   u64 start, unsigned long len);
 214 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 215                                                 u64 start);
 216 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
 217 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 218                                          u64 start);
 219 void free_extent_buffer(struct extent_buffer *eb);
 220 void free_extent_buffer_stale(struct extent_buffer *eb);
 221 #define WAIT_NONE       0
 222 #define WAIT_COMPLETE   1
 223 #define WAIT_PAGE_LOCK  2
 224 int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
 225                              int mirror_num);
 226 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 227
 228 static inline int num_extent_pages(const struct extent_buffer *eb)
 229 {
 230         return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) -
 231                (eb->start >> PAGE_SHIFT);
 232 }
 233
 234 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
 235 {
 236         return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 237 }
 238
 239 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
 240                          unsigned long start, unsigned long len);
 241 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
 242                         unsigned long start,
 243                         unsigned long len);
 244 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
 245                                        void __user *dst, unsigned long start,
 246                                        unsigned long len);
 247 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src);
 248 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
 249                 const void *src);
 250 void write_extent_buffer(const struct extent_buffer *eb, const void *src,
 251                          unsigned long start, unsigned long len);
 252 void copy_extent_buffer_full(const struct extent_buffer *dst,
 253                              const struct extent_buffer *src);
 254 void copy_extent_buffer(const struct extent_buffer *dst,
 255                         const struct extent_buffer *src,
 256                         unsigned long dst_offset, unsigned long src_offset,
 257                         unsigned long len);
 258 void memcpy_extent_buffer(const struct extent_buffer *dst,
 259                           unsigned long dst_offset, unsigned long src_offset,
 260                           unsigned long len);
 261 void memmove_extent_buffer(const struct extent_buffer *dst,
 262                            unsigned long dst_offset, unsigned long src_offset,
 263                            unsigned long len);
 264 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
 265                            unsigned long len);
 266 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
 267                            unsigned long pos);
 268 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
 269                               unsigned long pos, unsigned long len);
 270 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
 271                                 unsigned long start, unsigned long pos,
 272                                 unsigned long len);
 273 void clear_extent_buffer_dirty(const struct extent_buffer *eb);
 274 bool set_extent_buffer_dirty(struct extent_buffer *eb);
 275 void set_extent_buffer_uptodate(struct extent_buffer *eb);
 276 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 277 int extent_buffer_under_io(const struct extent_buffer *eb);
 278 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 279 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 280 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
 281                                   struct page *locked_page,
 282                                   unsigned bits_to_clear,
 283                                   unsigned long page_ops);
 284 struct bio *btrfs_bio_alloc(u64 first_byte);
 285 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 286 struct bio *btrfs_bio_clone(struct bio *bio);
 287 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
 288
 289 struct btrfs_fs_info;
 290 struct btrfs_inode;
 291
 292 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 293                       u64 length, u64 logical, struct page *page,
 294                       unsigned int pg_offset, int mirror_num);
 295 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
 296 int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num);
 297
 298 /*
 299  * When IO fails, either with EIO or csum verification fails, we
 300  * try other mirrors that might have a good copy of the data.  This
 301  * io_failure_record is used to record state as we go through all the
 302  * mirrors.  If another mirror has good data, the page is set up to date
 303  * and things continue.  If a good mirror can't be found, the original
 304  * bio end_io callback is called to indicate things have failed.
 305  */
 306 struct io_failure_record {
 307         struct page *page;
 308         u64 start;
 309         u64 len;
 310         u64 logical;
 311         unsigned long bio_flags;
 312         int this_mirror;
 313         int failed_mirror;
 314         int in_validation;
 315 };
 316
 317
 318 blk_status_t btrfs_submit_read_repair(struct inode *inode,
 319                                       struct bio *failed_bio, u64 phy_offset,
 320                                       struct page *page, unsigned int pgoff,
 321                                       u64 start, u64 end, int failed_mirror,
 322                                       submit_bio_hook_t *submit_bio_hook);
 323
 324 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 325 bool find_lock_delalloc_range(struct inode *inode,
 326                              struct page *locked_page, u64 *start,
 327                              u64 *end);
 328 #endif
 329 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 330                                                u64 start);
 331
 332 #ifdef CONFIG_BTRFS_DEBUG
 333 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
 334 #else
 335 #define btrfs_extent_buffer_leak_debug_check(fs_info)   do {} while (0)
 336 #endif
 337
 338 #endif