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 struct extent_io_ops { 78 /* 79 * The following callbacks must be always defined, the function 80 * pointer will be called unconditionally. 81 */ 82 submit_bio_hook_t *submit_bio_hook; 83 int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset, 84 struct page *page, u64 start, u64 end, 85 int mirror); 86 }; 87 88 89 #define INLINE_EXTENT_BUFFER_PAGES 16 90 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE) 91 struct extent_buffer { 92 u64 start; 93 unsigned long len; 94 unsigned long bflags; 95 struct btrfs_fs_info *fs_info; 96 spinlock_t refs_lock; 97 atomic_t refs; 98 atomic_t io_pages; 99 int read_mirror; 100 struct rcu_head rcu_head; 101 pid_t lock_owner; 102 103 int blocking_writers; 104 atomic_t blocking_readers; 105 bool lock_nested; 106 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 107 short log_index; 108 109 /* protects write locks */ 110 rwlock_t lock; 111 112 /* readers use lock_wq while they wait for the write 113 * lock holders to unlock 114 */ 115 wait_queue_head_t write_lock_wq; 116 117 /* writers use read_lock_wq while they wait for readers 118 * to unlock 119 */ 120 wait_queue_head_t read_lock_wq; 121 struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; 122 #ifdef CONFIG_BTRFS_DEBUG 123 int spinning_writers; 124 atomic_t spinning_readers; 125 atomic_t read_locks; 126 int write_locks; 127 struct list_head leak_list; 128 #endif 129 }; 130 131 /* 132 * Structure to record how many bytes and which ranges are set/cleared 133 */ 134 struct extent_changeset { 135 /* How many bytes are set/cleared in this operation */ 136 unsigned int bytes_changed; 137 138 /* Changed ranges */ 139 struct ulist range_changed; 140 }; 141 142 static inline void extent_changeset_init(struct extent_changeset *changeset) 143 { 144 changeset->bytes_changed = 0; 145 ulist_init(&changeset->range_changed); 146 } 147 148 static inline struct extent_changeset *extent_changeset_alloc(void) 149 { 150 struct extent_changeset *ret; 151 152 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 153 if (!ret) 154 return NULL; 155 156 extent_changeset_init(ret); 157 return ret; 158 } 159 160 static inline void extent_changeset_release(struct extent_changeset *changeset) 161 { 162 if (!changeset) 163 return; 164 changeset->bytes_changed = 0; 165 ulist_release(&changeset->range_changed); 166 } 167 168 static inline void extent_changeset_free(struct extent_changeset *changeset) 169 { 170 if (!changeset) 171 return; 172 extent_changeset_release(changeset); 173 kfree(changeset); 174 } 175 176 static inline void extent_set_compress_type(unsigned long *bio_flags, 177 int compress_type) 178 { 179 *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT; 180 } 181 182 static inline int extent_compress_type(unsigned long bio_flags) 183 { 184 return bio_flags >> EXTENT_BIO_FLAG_SHIFT; 185 } 186 187 struct extent_map_tree; 188 189 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode, 190 struct page *page, size_t pg_offset, 191 u64 start, u64 len); 192 193 int try_release_extent_mapping(struct page *page, gfp_t mask); 194 int try_release_extent_buffer(struct page *page); 195 196 int extent_read_full_page(struct page *page, get_extent_t *get_extent, 197 int mirror_num); 198 int extent_write_full_page(struct page *page, struct writeback_control *wbc); 199 int extent_write_locked_range(struct inode *inode, u64 start, u64 end, 200 int mode); 201 int extent_writepages(struct address_space *mapping, 202 struct writeback_control *wbc); 203 int btree_write_cache_pages(struct address_space *mapping, 204 struct writeback_control *wbc); 205 void extent_readahead(struct readahead_control *rac); 206 int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 207 u64 start, u64 len); 208 void set_page_extent_mapped(struct page *page); 209 210 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 211 u64 start); 212 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 213 u64 start, unsigned long len); 214 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 215 u64 start); 216 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 217 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 218 u64 start); 219 void free_extent_buffer(struct extent_buffer *eb); 220 void free_extent_buffer_stale(struct extent_buffer *eb); 221 #define WAIT_NONE 0 222 #define WAIT_COMPLETE 1 223 #define WAIT_PAGE_LOCK 2 224 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, 225 int mirror_num); 226 void wait_on_extent_buffer_writeback(struct extent_buffer *eb); 227 228 static inline int num_extent_pages(const struct extent_buffer *eb) 229 { 230 return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) - 231 (eb->start >> PAGE_SHIFT); 232 } 233 234 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 235 { 236 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 237 } 238 239 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 240 unsigned long start, unsigned long len); 241 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 242 unsigned long start, 243 unsigned long len); 244 int read_extent_buffer_to_user(const struct extent_buffer *eb, 245 void __user *dst, unsigned long start, 246 unsigned long len); 247 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src); 248 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb, 249 const void *src); 250 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 251 unsigned long start, unsigned long len); 252 void copy_extent_buffer_full(const struct extent_buffer *dst, 253 const struct extent_buffer *src); 254 void copy_extent_buffer(const struct extent_buffer *dst, 255 const struct extent_buffer *src, 256 unsigned long dst_offset, unsigned long src_offset, 257 unsigned long len); 258 void memcpy_extent_buffer(const struct extent_buffer *dst, 259 unsigned long dst_offset, unsigned long src_offset, 260 unsigned long len); 261 void memmove_extent_buffer(const struct extent_buffer *dst, 262 unsigned long dst_offset, unsigned long src_offset, 263 unsigned long len); 264 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 265 unsigned long len); 266 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 267 unsigned long pos); 268 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 269 unsigned long pos, unsigned long len); 270 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 271 unsigned long start, unsigned long pos, 272 unsigned long len); 273 void clear_extent_buffer_dirty(const struct extent_buffer *eb); 274 bool set_extent_buffer_dirty(struct extent_buffer *eb); 275 void set_extent_buffer_uptodate(struct extent_buffer *eb); 276 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 277 int extent_buffer_under_io(const struct extent_buffer *eb); 278 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end); 279 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end); 280 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 281 struct page *locked_page, 282 unsigned bits_to_clear, 283 unsigned long page_ops); 284 struct bio *btrfs_bio_alloc(u64 first_byte); 285 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs); 286 struct bio *btrfs_bio_clone(struct bio *bio); 287 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size); 288 289 struct btrfs_fs_info; 290 struct btrfs_inode; 291 292 int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start, 293 u64 length, u64 logical, struct page *page, 294 unsigned int pg_offset, int mirror_num); 295 void end_extent_writepage(struct page *page, int err, u64 start, u64 end); 296 int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num); 297 298 /* 299 * When IO fails, either with EIO or csum verification fails, we 300 * try other mirrors that might have a good copy of the data. This 301 * io_failure_record is used to record state as we go through all the 302 * mirrors. If another mirror has good data, the page is set up to date 303 * and things continue. If a good mirror can't be found, the original 304 * bio end_io callback is called to indicate things have failed. 305 */ 306 struct io_failure_record { 307 struct page *page; 308 u64 start; 309 u64 len; 310 u64 logical; 311 unsigned long bio_flags; 312 int this_mirror; 313 int failed_mirror; 314 int in_validation; 315 }; 316 317 318 blk_status_t btrfs_submit_read_repair(struct inode *inode, 319 struct bio *failed_bio, u64 phy_offset, 320 struct page *page, unsigned int pgoff, 321 u64 start, u64 end, int failed_mirror, 322 submit_bio_hook_t *submit_bio_hook); 323 324 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 325 bool find_lock_delalloc_range(struct inode *inode, 326 struct page *locked_page, u64 *start, 327 u64 *end); 328 #endif 329 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 330 u64 start); 331 332 #ifdef CONFIG_BTRFS_DEBUG 333 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 334 #else 335 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 336 #endif 337 338 #endif 339