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 #define INLINE_EXTENT_BUFFER_PAGES 16
78 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
79 struct 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 */
122 struct 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
extent_changeset_init(struct extent_changeset * changeset)130 static inline void extent_changeset_init(struct extent_changeset *changeset)
131 {
132 changeset->bytes_changed = 0;
133 ulist_init(&changeset->range_changed);
134 }
135
extent_changeset_alloc(void)136 static 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
extent_changeset_release(struct extent_changeset * changeset)148 static 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
extent_changeset_free(struct extent_changeset * changeset)156 static 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
extent_set_compress_type(unsigned long * bio_flags,int compress_type)164 static 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
extent_compress_type(unsigned long bio_flags)170 static inline int extent_compress_type(unsigned long bio_flags)
171 {
172 return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
173 }
174
175 struct extent_map_tree;
176
177 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
178 struct page *page, size_t pg_offset,
179 u64 start, u64 len);
180
181 int try_release_extent_mapping(struct page *page, gfp_t mask);
182 int try_release_extent_buffer(struct page *page);
183
184 int __must_check submit_one_bio(struct bio *bio, int mirror_num,
185 unsigned long bio_flags);
186 int 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);
189 int extent_write_full_page(struct page *page, struct writeback_control *wbc);
190 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
191 int mode);
192 int extent_writepages(struct address_space *mapping,
193 struct writeback_control *wbc);
194 int btree_write_cache_pages(struct address_space *mapping,
195 struct writeback_control *wbc);
196 void extent_readahead(struct readahead_control *rac);
197 int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
198 u64 start, u64 len);
199 void set_page_extent_mapped(struct page *page);
200
201 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
202 u64 start);
203 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
204 u64 start, unsigned long len);
205 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
206 u64 start);
207 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
208 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
209 u64 start);
210 void free_extent_buffer(struct extent_buffer *eb);
211 void free_extent_buffer_stale(struct extent_buffer *eb);
212 #define WAIT_NONE 0
213 #define WAIT_COMPLETE 1
214 #define WAIT_PAGE_LOCK 2
215 int read_extent_buffer_pages(struct extent_buffer *eb, int wait,
216 int mirror_num);
217 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
218
num_extent_pages(const struct extent_buffer * eb)219 static 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
extent_buffer_uptodate(const struct extent_buffer * eb)225 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
226 {
227 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
228 }
229
230 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
231 unsigned long start, unsigned long len);
232 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
233 unsigned long start,
234 unsigned long len);
235 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
236 void __user *dst, unsigned long start,
237 unsigned long len);
238 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src);
239 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
240 const void *src);
241 void write_extent_buffer(const struct extent_buffer *eb, const void *src,
242 unsigned long start, unsigned long len);
243 void copy_extent_buffer_full(const struct extent_buffer *dst,
244 const struct extent_buffer *src);
245 void 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);
249 void memcpy_extent_buffer(const struct extent_buffer *dst,
250 unsigned long dst_offset, unsigned long src_offset,
251 unsigned long len);
252 void memmove_extent_buffer(const struct extent_buffer *dst,
253 unsigned long dst_offset, unsigned long src_offset,
254 unsigned long len);
255 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
256 unsigned long len);
257 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
258 unsigned long pos);
259 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
260 unsigned long pos, unsigned long len);
261 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
262 unsigned long start, unsigned long pos,
263 unsigned long len);
264 void clear_extent_buffer_dirty(const struct extent_buffer *eb);
265 bool set_extent_buffer_dirty(struct extent_buffer *eb);
266 void set_extent_buffer_uptodate(struct extent_buffer *eb);
267 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
268 int extent_buffer_under_io(const struct extent_buffer *eb);
269 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
270 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
271 void 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);
275 struct bio *btrfs_bio_alloc(u64 first_byte);
276 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
277 struct bio *btrfs_bio_clone(struct bio *bio);
278 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);
279
280 struct btrfs_fs_info;
281 struct btrfs_inode;
282
283 int 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);
286 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
287 int 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 */
297 struct 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
309 blk_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
316 bool find_lock_delalloc_range(struct inode *inode,
317 struct page *locked_page, u64 *start,
318 u64 *end);
319 #endif
320 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
321 u64 start);
322
323 #ifdef CONFIG_BTRFS_DEBUG
324 void 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
