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 <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
  18enum {
  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
  64struct btrfs_root;
  65struct btrfs_inode;
  66struct btrfs_io_bio;
  67struct io_failure_record;
  68struct extent_io_tree;
  69
  70typedef blk_status_t (submit_bio_hook_t)(struct inode *inode, struct bio *bio,
  71                                         int mirror_num,
  72                                         unsigned long bio_flags);
  73
  74typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
  75                struct bio *bio, u64 bio_offset);
  76
  77#define INLINE_EXTENT_BUFFER_PAGES 16
  78#define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
  79struct extent_buffer {
  80        u64 start;
  81        unsigned long len;
  82        unsigned long bflags;
  83        struct btrfs_fs_info *fs_info;
  84        spinlock_t refs_lock;
  85        atomic_t refs;
  86        atomic_t io_pages;
  87        int read_mirror;
  88        struct rcu_head rcu_head;
  89        pid_t lock_owner;
  90
  91        int blocking_writers;
  92        atomic_t blocking_readers;
  93        bool lock_recursed;
  94        /* >= 0 if eb belongs to a log tree, -1 otherwise */
  95        short log_index;
  96
  97        /* protects write locks */
  98        rwlock_t lock;
  99
 100        /* readers use lock_wq while they wait for the write
 101         * lock holders to unlock
 102         */
 103        wait_queue_head_t write_lock_wq;
 104
 105        /* writers use read_lock_wq while they wait for readers
 106         * to unlock
 107         */
 108        wait_queue_head_t read_lock_wq;
 109        struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
 110#ifdef CONFIG_BTRFS_DEBUG
 111        int spinning_writers;
 112        atomic_t spinning_readers;
 113        atomic_t read_locks;
 114        int write_locks;
 115        struct list_head leak_list;
 116#endif
 117};
 118
 119/*
 120 * Structure to record how many bytes and which ranges are set/cleared
 121 */
 122struct extent_changeset {
 123        /* How many bytes are set/cleared in this operation */
 124        unsigned int bytes_changed;
 125
 126        /* Changed ranges */
 127        struct ulist range_changed;
 128};
 129
 130static inline void extent_changeset_init(struct extent_changeset *changeset)
 131{
 132        changeset->bytes_changed = 0;
 133        ulist_init(&changeset->range_changed);
 134}
 135
 136static inline struct extent_changeset *extent_changeset_alloc(void)
 137{
 138        struct extent_changeset *ret;
 139
 140        ret = kmalloc(sizeof(*ret), GFP_KERNEL);
 141        if (!ret)
 142                return NULL;
 143
 144        extent_changeset_init(ret);
 145        return ret;
 146}
 147
 148static inline void extent_changeset_release(struct extent_changeset *changeset)
 149{
 150        if (!changeset)
 151                return;
 152        changeset->bytes_changed = 0;
 153        ulist_release(&changeset->range_changed);
 154}
 155
 156static inline void extent_changeset_free(struct extent_changeset *changeset)
 157{
 158        if (!changeset)
 159                return;
 160        extent_changeset_release(changeset);
 161        kfree(changeset);
 162}
 163
 164static inline void extent_set_compress_type(unsigned long *bio_flags,
 165                                            int compress_type)
 166{
 167        *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
 168}
 169
 170static inline int extent_compress_type(unsigned long bio_flags)
 171{
 172        return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
 173}
 174
 175struct extent_map_tree;
 176
 177typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
 178                                          struct page *page, size_t pg_offset,
 179                                          u64 start, u64 len);
 180
 181int try_release_extent_mapping(struct page *page, gfp_t mask);
 182int try_release_extent_buffer(struct page *page);
 183
 184int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 185                                unsigned long bio_flags);
 186int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 187                      struct bio **bio, unsigned long *bio_flags,
 188                      unsigned int read_flags, u64 *prev_em_start);
 189int extent_write_full_page(struct page *page, struct writeback_control *wbc);
 190int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 191                              int mode);
 192int extent_writepages(struct address_space *mapping,
 193                      struct writeback_control *wbc);
 194int btree_write_cache_pages(struct address_space *mapping,
 195                            struct writeback_control *wbc);
 196void extent_readahead(struct readahead_control *rac);
 197int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
 198                  u64 start, u64 len);
 199void set_page_extent_mapped(struct page *page);
 200
 201struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 202                                          u64 start);
 203struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 204                                                  u64 start, unsigned long len);
 205struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 206                                                u64 start);
 207struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
 208struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 209                                         u64 start);
 210void free_extent_buffer(struct extent_buffer *eb);
 211void free_extent_buffer_stale(struct extent_buffer *eb);
 212#define WAIT_NONE       0
 213#define WAIT_COMPLETE   1
 214#define WAIT_PAGE_LOCK  2
 215int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
 216                             int mirror_num);
 217void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 218
 219static inline int num_extent_pages(const struct extent_buffer *eb)
 220{
 221        return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) -
 222               (eb->start >> PAGE_SHIFT);
 223}
 224
 225static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
 226{
 227        return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 228}
 229
 230int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
 231                         unsigned long start, unsigned long len);
 232void read_extent_buffer(const struct extent_buffer *eb, void *dst,
 233                        unsigned long start,
 234                        unsigned long len);
 235int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
 236                                       void __user *dst, unsigned long start,
 237                                       unsigned long len);
 238void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src);
 239void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
 240                const void *src);
 241void write_extent_buffer(const struct extent_buffer *eb, const void *src,
 242                         unsigned long start, unsigned long len);
 243void copy_extent_buffer_full(const struct extent_buffer *dst,
 244                             const struct extent_buffer *src);
 245void copy_extent_buffer(const struct extent_buffer *dst,
 246                        const struct extent_buffer *src,
 247                        unsigned long dst_offset, unsigned long src_offset,
 248                        unsigned long len);
 249void memcpy_extent_buffer(const struct extent_buffer *dst,
 250                          unsigned long dst_offset, unsigned long src_offset,
 251                          unsigned long len);
 252void memmove_extent_buffer(const struct extent_buffer *dst,
 253                           unsigned long dst_offset, unsigned long src_offset,
 254                           unsigned long len);
 255void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
 256                           unsigned long len);
 257int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
 258                           unsigned long pos);
 259void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
 260                              unsigned long pos, unsigned long len);
 261void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
 262                                unsigned long start, unsigned long pos,
 263                                unsigned long len);
 264void clear_extent_buffer_dirty(const struct extent_buffer *eb);
 265bool set_extent_buffer_dirty(struct extent_buffer *eb);
 266void set_extent_buffer_uptodate(struct extent_buffer *eb);
 267void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 268int extent_buffer_under_io(const struct extent_buffer *eb);
 269void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
 270void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
 271void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
 272                                  struct page *locked_page,
 273                                  unsigned bits_to_clear,
 274                                  unsigned long page_ops);
 275struct bio *btrfs_bio_alloc(u64 first_byte);
 276struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 277struct bio *btrfs_bio_clone(struct bio *bio);
 278struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
 279
 280struct btrfs_fs_info;
 281struct btrfs_inode;
 282
 283int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 284                      u64 length, u64 logical, struct page *page,
 285                      unsigned int pg_offset, int mirror_num);
 286void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
 287int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num);
 288
 289/*
 290 * When IO fails, either with EIO or csum verification fails, we
 291 * try other mirrors that might have a good copy of the data.  This
 292 * io_failure_record is used to record state as we go through all the
 293 * mirrors.  If another mirror has good data, the page is set up to date
 294 * and things continue.  If a good mirror can't be found, the original
 295 * bio end_io callback is called to indicate things have failed.
 296 */
 297struct io_failure_record {
 298        struct page *page;
 299        u64 start;
 300        u64 len;
 301        u64 logical;
 302        unsigned long bio_flags;
 303        int this_mirror;
 304        int failed_mirror;
 305        int in_validation;
 306};
 307
 308
 309blk_status_t btrfs_submit_read_repair(struct inode *inode,
 310                                      struct bio *failed_bio, u64 phy_offset,
 311                                      struct page *page, unsigned int pgoff,
 312                                      u64 start, u64 end, int failed_mirror,
 313                                      submit_bio_hook_t *submit_bio_hook);
 314
 315#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 316bool find_lock_delalloc_range(struct inode *inode,
 317                             struct page *locked_page, u64 *start,
 318                             u64 *end);
 319#endif
 320struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 321                                               u64 start);
 322
 323#ifdef CONFIG_BTRFS_DEBUG
 324void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
 325#else
 326#define btrfs_extent_buffer_leak_debug_check(fs_info)   do {} while (0)
 327#endif
 328
 329#endif
 330