LXR linux/fs/btrfs/extent

   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
  17enum {
  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
  63struct btrfs_root;
  64struct btrfs_inode;
  65struct btrfs_io_bio;
  66struct io_failure_record;
  67struct extent_io_tree;
  68
  69typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
  70                struct bio *bio, u64 bio_offset);
  71
  72struct 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)
  87struct 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 */
 130struct 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
 138static inline void extent_changeset_init(struct extent_changeset *changeset)
 139{
 140        changeset->bytes_changed = 0;
 141        ulist_init(&changeset->range_changed);
 142}
 143
 144static 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
 156static 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
 164static 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
 172static 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
 178static inline int extent_compress_type(unsigned long bio_flags)
 179{
 180        return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
 181}
 182
 183struct extent_map_tree;
 184
 185typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
 186                                          struct page *page, size_t pg_offset,
 187                                          u64 start, u64 len);
 188
 189int try_release_extent_mapping(struct page *page, gfp_t mask);
 190int try_release_extent_buffer(struct page *page);
 191
 192int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
 193                          get_extent_t *get_extent, int mirror_num);
 194int extent_write_full_page(struct page *page, struct writeback_control *wbc);
 195int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 196                              int mode);
 197int extent_writepages(struct address_space *mapping,
 198                      struct writeback_control *wbc);
 199int btree_write_cache_pages(struct address_space *mapping,
 200                            struct writeback_control *wbc);
 201int extent_readpages(struct address_space *mapping, struct list_head *pages,
 202                     unsigned nr_pages);
 203int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 204                __u64 start, __u64 len);
 205void set_page_extent_mapped(struct page *page);
 206
 207struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 208                                          u64 start);
 209struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 210                                                  u64 start, unsigned long len);
 211struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 212                                                u64 start);
 213struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
 214struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 215                                         u64 start);
 216void free_extent_buffer(struct extent_buffer *eb);
 217void free_extent_buffer_stale(struct extent_buffer *eb);
 218#define WAIT_NONE       0
 219#define WAIT_COMPLETE   1
 220#define WAIT_PAGE_LOCK  2
 221int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
 222                             int mirror_num);
 223void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 224
 225static 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
 231static inline int extent_buffer_uptodate(struct extent_buffer *eb)
 232{
 233        return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 234}
 235
 236int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
 237                         unsigned long start, unsigned long len);
 238void read_extent_buffer(const struct extent_buffer *eb, void *dst,
 239                        unsigned long start,
 240                        unsigned long len);
 241int read_extent_buffer_to_user(const struct extent_buffer *eb,
 242                               void __user *dst, unsigned long start,
 243                               unsigned long len);
 244void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);
 245void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
 246                const void *src);
 247void write_extent_buffer(struct extent_buffer *eb, const void *src,
 248                         unsigned long start, unsigned long len);
 249void copy_extent_buffer_full(struct extent_buffer *dst,
 250                             struct extent_buffer *src);
 251void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
 252                        unsigned long dst_offset, unsigned long src_offset,
 253                        unsigned long len);
 254void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 255                           unsigned long src_offset, unsigned long len);
 256void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 257                           unsigned long src_offset, unsigned long len);
 258void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
 259                           unsigned long len);
 260int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
 261                           unsigned long pos);
 262void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
 263                              unsigned long pos, unsigned long len);
 264void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
 265                                unsigned long pos, unsigned long len);
 266void clear_extent_buffer_dirty(struct extent_buffer *eb);
 267bool set_extent_buffer_dirty(struct extent_buffer *eb);
 268void set_extent_buffer_uptodate(struct extent_buffer *eb);
 269void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 270int extent_buffer_under_io(struct extent_buffer *eb);
 271int 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);
 275void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 276void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 277void 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);
 281struct bio *btrfs_bio_alloc(u64 first_byte);
 282struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 283struct bio *btrfs_bio_clone(struct bio *bio);
 284struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
 285
 286struct btrfs_fs_info;
 287struct btrfs_inode;
 288
 289int 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);
 292void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
 293int 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 */
 303struct 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
 315bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
 316                            struct io_failure_record *failrec, int fail_mirror);
 317struct 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
 322bool find_lock_delalloc_range(struct inode *inode,
 323                             struct page *locked_page, u64 *start,
 324                             u64 *end);
 325#endif
 326struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 327                                               u64 start);
 328#endif
 329