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 <linux/btrfs_tree.h>
  10#include "ulist.h"
  11
  12/*
  13 * flags for bio submission. The high bits indicate the compression
  14 * type for this bio
  15 */
  16#define EXTENT_BIO_COMPRESSED 1
  17#define EXTENT_BIO_FLAG_SHIFT 16
  18
  19enum {
  20        EXTENT_BUFFER_UPTODATE,
  21        EXTENT_BUFFER_DIRTY,
  22        EXTENT_BUFFER_CORRUPT,
  23        /* this got triggered by readahead */
  24        EXTENT_BUFFER_READAHEAD,
  25        EXTENT_BUFFER_TREE_REF,
  26        EXTENT_BUFFER_STALE,
  27        EXTENT_BUFFER_WRITEBACK,
  28        /* read IO error */
  29        EXTENT_BUFFER_READ_ERR,
  30        EXTENT_BUFFER_UNMAPPED,
  31        EXTENT_BUFFER_IN_TREE,
  32        /* write IO error */
  33        EXTENT_BUFFER_WRITE_ERR,
  34        EXTENT_BUFFER_NO_CHECK,
  35};
  36
  37/* these are flags for __process_pages_contig */
  38#define PAGE_UNLOCK             (1 << 0)
  39/* Page starts writeback, clear dirty bit and set writeback bit */
  40#define PAGE_START_WRITEBACK    (1 << 1)
  41#define PAGE_END_WRITEBACK      (1 << 2)
  42#define PAGE_SET_ORDERED        (1 << 3)
  43#define PAGE_SET_ERROR          (1 << 4)
  44#define PAGE_LOCK               (1 << 5)
  45
  46/*
  47 * page->private values.  Every page that is controlled by the extent
  48 * map has page->private set to one.
  49 */
  50#define EXTENT_PAGE_PRIVATE 1
  51
  52/*
  53 * The extent buffer bitmap operations are done with byte granularity instead of
  54 * word granularity for two reasons:
  55 * 1. The bitmaps must be little-endian on disk.
  56 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
  57 *    single word in a bitmap may straddle two pages in the extent buffer.
  58 */
  59#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
  60#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
  61#define BITMAP_FIRST_BYTE_MASK(start) \
  62        ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
  63#define BITMAP_LAST_BYTE_MASK(nbits) \
  64        (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
  65
  66struct btrfs_root;
  67struct btrfs_inode;
  68struct btrfs_io_bio;
  69struct btrfs_fs_info;
  70struct io_failure_record;
  71struct extent_io_tree;
  72
  73typedef blk_status_t (submit_bio_hook_t)(struct inode *inode, struct bio *bio,
  74                                         int mirror_num,
  75                                         unsigned long bio_flags);
  76
  77typedef blk_status_t (extent_submit_bio_start_t)(struct inode *inode,
  78                struct bio *bio, u64 dio_file_offset);
  79
  80#define INLINE_EXTENT_BUFFER_PAGES     (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
  81struct extent_buffer {
  82        u64 start;
  83        unsigned long len;
  84        unsigned long bflags;
  85        struct btrfs_fs_info *fs_info;
  86        spinlock_t refs_lock;
  87        atomic_t refs;
  88        atomic_t io_pages;
  89        int read_mirror;
  90        struct rcu_head rcu_head;
  91        pid_t lock_owner;
  92        /* >= 0 if eb belongs to a log tree, -1 otherwise */
  93        s8 log_index;
  94
  95        struct rw_semaphore lock;
  96
  97        struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
  98        struct list_head release_list;
  99#ifdef CONFIG_BTRFS_DEBUG
 100        struct list_head leak_list;
 101#endif
 102};
 103
 104/*
 105 * Structure to record info about the bio being assembled, and other info like
 106 * how many bytes are there before stripe/ordered extent boundary.
 107 */
 108struct btrfs_bio_ctrl {
 109        struct bio *bio;
 110        unsigned long bio_flags;
 111        u32 len_to_stripe_boundary;
 112        u32 len_to_oe_boundary;
 113};
 114
 115/*
 116 * Structure to record how many bytes and which ranges are set/cleared
 117 */
 118struct extent_changeset {
 119        /* How many bytes are set/cleared in this operation */
 120        unsigned int bytes_changed;
 121
 122        /* Changed ranges */
 123        struct ulist range_changed;
 124};
 125
 126static inline void extent_changeset_init(struct extent_changeset *changeset)
 127{
 128        changeset->bytes_changed = 0;
 129        ulist_init(&changeset->range_changed);
 130}
 131
 132static inline struct extent_changeset *extent_changeset_alloc(void)
 133{
 134        struct extent_changeset *ret;
 135
 136        ret = kmalloc(sizeof(*ret), GFP_KERNEL);
 137        if (!ret)
 138                return NULL;
 139
 140        extent_changeset_init(ret);
 141        return ret;
 142}
 143
 144static inline void extent_changeset_release(struct extent_changeset *changeset)
 145{
 146        if (!changeset)
 147                return;
 148        changeset->bytes_changed = 0;
 149        ulist_release(&changeset->range_changed);
 150}
 151
 152static inline void extent_changeset_free(struct extent_changeset *changeset)
 153{
 154        if (!changeset)
 155                return;
 156        extent_changeset_release(changeset);
 157        kfree(changeset);
 158}
 159
 160static inline void extent_set_compress_type(unsigned long *bio_flags,
 161                                            int compress_type)
 162{
 163        *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
 164}
 165
 166static inline int extent_compress_type(unsigned long bio_flags)
 167{
 168        return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
 169}
 170
 171struct extent_map_tree;
 172
 173typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
 174                                          struct page *page, size_t pg_offset,
 175                                          u64 start, u64 len);
 176
 177int try_release_extent_mapping(struct page *page, gfp_t mask);
 178int try_release_extent_buffer(struct page *page);
 179
 180int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 181                                unsigned long bio_flags);
 182int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 183                      struct btrfs_bio_ctrl *bio_ctrl,
 184                      unsigned int read_flags, u64 *prev_em_start);
 185int extent_write_full_page(struct page *page, struct writeback_control *wbc);
 186int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
 187                              int mode);
 188int extent_writepages(struct address_space *mapping,
 189                      struct writeback_control *wbc);
 190int btree_write_cache_pages(struct address_space *mapping,
 191                            struct writeback_control *wbc);
 192void extent_readahead(struct readahead_control *rac);
 193int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
 194                  u64 start, u64 len);
 195int set_page_extent_mapped(struct page *page);
 196void clear_page_extent_mapped(struct page *page);
 197
 198struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 199                                          u64 start, u64 owner_root, int level);
 200struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 201                                                  u64 start, unsigned long len);
 202struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
 203                                                u64 start);
 204struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
 205struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 206                                         u64 start);
 207void free_extent_buffer(struct extent_buffer *eb);
 208void free_extent_buffer_stale(struct extent_buffer *eb);
 209#define WAIT_NONE       0
 210#define WAIT_COMPLETE   1
 211#define WAIT_PAGE_LOCK  2
 212int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
 213                             int mirror_num);
 214void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 215void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
 216                                u64 bytenr, u64 owner_root, u64 gen, int level);
 217void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
 218
 219static inline int num_extent_pages(const struct extent_buffer *eb)
 220{
 221        /*
 222         * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
 223         * sectorsize, it's just eb->len >> PAGE_SHIFT.
 224         *
 225         * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
 226         * thus have to ensure we get at least one page.
 227         */
 228        return (eb->len >> PAGE_SHIFT) ?: 1;
 229}
 230
 231static inline int extent_buffer_uptodate(const 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_nofault(const struct extent_buffer *eb,
 242                                       void __user *dst, unsigned long start,
 243                                       unsigned long len);
 244void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src);
 245void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
 246                const void *src);
 247void write_extent_buffer(const struct extent_buffer *eb, const void *src,
 248                         unsigned long start, unsigned long len);
 249void copy_extent_buffer_full(const struct extent_buffer *dst,
 250                             const struct extent_buffer *src);
 251void copy_extent_buffer(const struct extent_buffer *dst,
 252                        const struct extent_buffer *src,
 253                        unsigned long dst_offset, unsigned long src_offset,
 254                        unsigned long len);
 255void memcpy_extent_buffer(const struct extent_buffer *dst,
 256                          unsigned long dst_offset, unsigned long src_offset,
 257                          unsigned long len);
 258void memmove_extent_buffer(const struct extent_buffer *dst,
 259                           unsigned long dst_offset, unsigned long src_offset,
 260                           unsigned long len);
 261void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
 262                           unsigned long len);
 263int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
 264                           unsigned long pos);
 265void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
 266                              unsigned long pos, unsigned long len);
 267void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
 268                                unsigned long start, unsigned long pos,
 269                                unsigned long len);
 270void clear_extent_buffer_dirty(const struct extent_buffer *eb);
 271bool set_extent_buffer_dirty(struct extent_buffer *eb);
 272void set_extent_buffer_uptodate(struct extent_buffer *eb);
 273void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 274int extent_buffer_under_io(const struct extent_buffer *eb);
 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 btrfs_inode *inode, u64 start, u64 end,
 278                                  struct page *locked_page,
 279                                  u32 bits_to_clear, unsigned long page_ops);
 280struct bio *btrfs_bio_alloc(u64 first_byte);
 281struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 282struct bio *btrfs_bio_clone(struct bio *bio);
 283struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size);
 284
 285int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
 286                      u64 length, u64 logical, struct page *page,
 287                      unsigned int pg_offset, int mirror_num);
 288void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
 289int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num);
 290
 291/*
 292 * When IO fails, either with EIO or csum verification fails, we
 293 * try other mirrors that might have a good copy of the data.  This
 294 * io_failure_record is used to record state as we go through all the
 295 * mirrors.  If another mirror has good data, the sector is set up to date
 296 * and things continue.  If a good mirror can't be found, the original
 297 * bio end_io callback is called to indicate things have failed.
 298 */
 299struct io_failure_record {
 300        struct page *page;
 301        u64 start;
 302        u64 len;
 303        u64 logical;
 304        unsigned long bio_flags;
 305        int this_mirror;
 306        int failed_mirror;
 307};
 308
 309int btrfs_repair_one_sector(struct inode *inode,
 310                            struct bio *failed_bio, u32 bio_offset,
 311                            struct page *page, unsigned int pgoff,
 312                            u64 start, 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