1 /* SPDX-License-Identifier: GPL-2.0 */
3 #ifndef BTRFS_EXTENT_IO_H
4 #define BTRFS_EXTENT_IO_H
6 #include <linux/rbtree.h>
7 #include <linux/refcount.h>
11 * flags for bio submission. The high bits indicate the compression
14 #define EXTENT_BIO_COMPRESSED 1
15 #define EXTENT_BIO_FLAG_SHIFT 16
18 EXTENT_BUFFER_UPTODATE,
20 EXTENT_BUFFER_CORRUPT,
21 /* this got triggered by readahead */
22 EXTENT_BUFFER_READAHEAD,
23 EXTENT_BUFFER_TREE_REF,
25 EXTENT_BUFFER_WRITEBACK,
27 EXTENT_BUFFER_READ_ERR,
28 EXTENT_BUFFER_UNMAPPED,
29 EXTENT_BUFFER_IN_TREE,
31 EXTENT_BUFFER_WRITE_ERR,
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)
44 * page->private values. Every page that is controlled by the extent
45 * map has page->private set to one.
47 #define EXTENT_PAGE_PRIVATE 1
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.
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)))
66 struct io_failure_record;
67 struct extent_io_tree;
69 typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
70 struct bio *bio, u64 bio_offset);
72 struct extent_io_ops {
74 * The following callbacks must be always defined, the function
75 * pointer will be called unconditionally.
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,
85 #define INLINE_EXTENT_BUFFER_PAGES 16
86 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
87 struct extent_buffer {
91 struct btrfs_fs_info *fs_info;
96 struct rcu_head rcu_head;
100 atomic_t blocking_readers;
102 /* >= 0 if eb belongs to a log tree, -1 otherwise */
105 /* protects write locks */
108 /* readers use lock_wq while they wait for the write
109 * lock holders to unlock
111 wait_queue_head_t write_lock_wq;
113 /* writers use read_lock_wq while they wait for readers
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;
123 struct list_head leak_list;
128 * Structure to record how many bytes and which ranges are set/cleared
130 struct extent_changeset {
131 /* How many bytes are set/cleared in this operation */
132 unsigned int bytes_changed;
135 struct ulist range_changed;
138 static inline void extent_changeset_init(struct extent_changeset *changeset)
140 changeset->bytes_changed = 0;
141 ulist_init(&changeset->range_changed);
144 static inline struct extent_changeset *extent_changeset_alloc(void)
146 struct extent_changeset *ret;
148 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
152 extent_changeset_init(ret);
156 static inline void extent_changeset_release(struct extent_changeset *changeset)
160 changeset->bytes_changed = 0;
161 ulist_release(&changeset->range_changed);
164 static inline void extent_changeset_free(struct extent_changeset *changeset)
168 extent_changeset_release(changeset);
172 static inline void extent_set_compress_type(unsigned long *bio_flags,
175 *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
178 static inline int extent_compress_type(unsigned long bio_flags)
180 return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
183 struct extent_map_tree;
185 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
191 int try_release_extent_mapping(struct page *page, gfp_t mask);
192 int try_release_extent_buffer(struct page *page);
194 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
195 get_extent_t *get_extent, int mirror_num);
196 int extent_write_full_page(struct page *page, struct writeback_control *wbc);
197 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
199 int extent_writepages(struct address_space *mapping,
200 struct writeback_control *wbc);
201 int btree_write_cache_pages(struct address_space *mapping,
202 struct writeback_control *wbc);
203 int extent_readpages(struct address_space *mapping, struct list_head *pages,
205 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
206 __u64 start, __u64 len);
207 void set_page_extent_mapped(struct page *page);
209 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
211 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
212 u64 start, unsigned long len);
213 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
215 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
216 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
218 void free_extent_buffer(struct extent_buffer *eb);
219 void free_extent_buffer_stale(struct extent_buffer *eb);
221 #define WAIT_COMPLETE 1
222 #define WAIT_PAGE_LOCK 2
223 int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
225 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
227 static inline int num_extent_pages(const struct extent_buffer *eb)
229 return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) -
230 (eb->start >> PAGE_SHIFT);
233 static inline int extent_buffer_uptodate(struct extent_buffer *eb)
235 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
238 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
239 unsigned long start, unsigned long len);
240 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
243 int read_extent_buffer_to_user(const struct extent_buffer *eb,
244 void __user *dst, unsigned long start,
246 void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);
247 void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
249 void write_extent_buffer(struct extent_buffer *eb, const void *src,
250 unsigned long start, unsigned long len);
251 void copy_extent_buffer_full(struct extent_buffer *dst,
252 struct extent_buffer *src);
253 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
254 unsigned long dst_offset, unsigned long src_offset,
256 void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
257 unsigned long src_offset, unsigned long len);
258 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
259 unsigned long src_offset, unsigned long len);
260 void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
262 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
264 void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
265 unsigned long pos, unsigned long len);
266 void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
267 unsigned long pos, unsigned long len);
268 void clear_extent_buffer_dirty(struct extent_buffer *eb);
269 bool set_extent_buffer_dirty(struct extent_buffer *eb);
270 void set_extent_buffer_uptodate(struct extent_buffer *eb);
271 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
272 int extent_buffer_under_io(struct extent_buffer *eb);
273 int map_private_extent_buffer(const struct extent_buffer *eb,
274 unsigned long offset, unsigned long min_len,
275 char **map, unsigned long *map_start,
276 unsigned long *map_len);
277 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
278 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
279 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
280 struct page *locked_page,
281 unsigned bits_to_clear,
282 unsigned long page_ops);
283 struct bio *btrfs_bio_alloc(u64 first_byte);
284 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
285 struct bio *btrfs_bio_clone(struct bio *bio);
286 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
288 struct btrfs_fs_info;
291 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
292 u64 length, u64 logical, struct page *page,
293 unsigned int pg_offset, int mirror_num);
294 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
295 int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num);
298 * When IO fails, either with EIO or csum verification fails, we
299 * try other mirrors that might have a good copy of the data. This
300 * io_failure_record is used to record state as we go through all the
301 * mirrors. If another mirror has good data, the page is set up to date
302 * and things continue. If a good mirror can't be found, the original
303 * bio end_io callback is called to indicate things have failed.
305 struct io_failure_record {
310 unsigned long bio_flags;
317 bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
318 struct io_failure_record *failrec, int fail_mirror);
319 struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
320 struct io_failure_record *failrec,
321 struct page *page, int pg_offset, int icsum,
322 bio_end_io_t *endio_func, void *data);
323 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
324 bool find_lock_delalloc_range(struct inode *inode,
325 struct page *locked_page, u64 *start,
328 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,