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 "ulist.h" 9 10 /* 11 * flags for bio submission. The high bits indicate the compression 12 * type for this bio 13 */ 14 #define EXTENT_BIO_COMPRESSED 1 15 #define EXTENT_BIO_FLAG_SHIFT 16 16 17 enum { 18 EXTENT_BUFFER_UPTODATE, 19 EXTENT_BUFFER_DIRTY, 20 EXTENT_BUFFER_CORRUPT, 21 /* this got triggered by readahead */ 22 EXTENT_BUFFER_READAHEAD, 23 EXTENT_BUFFER_TREE_REF, 24 EXTENT_BUFFER_STALE, 25 EXTENT_BUFFER_WRITEBACK, 26 /* read IO error */ 27 EXTENT_BUFFER_READ_ERR, 28 EXTENT_BUFFER_UNMAPPED, 29 EXTENT_BUFFER_IN_TREE, 30 /* write IO error */ 31 EXTENT_BUFFER_WRITE_ERR, 32 }; 33 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) 42 43 /* 44 * page->private values. Every page that is controlled by the extent 45 * map has page->private set to one. 46 */ 47 #define EXTENT_PAGE_PRIVATE 1 48 49 /* 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. 55 */ 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))) 62 63 struct btrfs_root; 64 struct btrfs_inode; 65 struct btrfs_io_bio; 66 struct io_failure_record; 67 struct extent_io_tree; 68 69 typedef blk_status_t (submit_bio_hook_t)(struct inode *inode, struct bio *bio, 70 int mirror_num, 71 unsigned long bio_flags); 72 73 typedef blk_status_t (extent_submit_bio_start_t)(void *private_data, 74 struct bio *bio, u64 bio_offset); 75 76 struct extent_io_ops { 77 /* 78 * The following callbacks must be always defined, the function 79 * pointer will be called unconditionally. 80 */ 81 submit_bio_hook_t *submit_bio_hook; 82 int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset, 83 struct page *page, u64 start, u64 end, 84 int mirror); 85 }; 86 87 88 #define INLINE_EXTENT_BUFFER_PAGES 16 89 #define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE) 90 struct extent_buffer { 91 u64 start; 92 unsigned long len; 93 unsigned long bflags; 94 struct btrfs_fs_info *fs_info; 95 spinlock_t refs_lock; 96 atomic_t refs; 97 atomic_t io_pages; 98 int read_mirror; 99 struct rcu_head rcu_head; 100 pid_t lock_owner; 101 102 int blocking_writers; 103 atomic_t blocking_readers; 104 bool lock_nested; 105 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 106 short log_index; 107 108 /* protects write locks */ 109 rwlock_t lock; 110 111 /* readers use lock_wq while they wait for the write 112 * lock holders to unlock 113 */ 114 wait_queue_head_t write_lock_wq; 115 116 /* writers use read_lock_wq while they wait for readers 117 * to unlock 118 */ 119 wait_queue_head_t read_lock_wq; 120 struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; 121 #ifdef CONFIG_BTRFS_DEBUG 122 int spinning_writers; 123 atomic_t spinning_readers; 124 atomic_t read_locks; 125 int write_locks; 126 struct list_head leak_list; 127 #endif 128 }; 129 130 /* 131 * Structure to record how many bytes and which ranges are set/cleared 132 */ 133 struct extent_changeset { 134 /* How many bytes are set/cleared in this operation */ 135 unsigned int bytes_changed; 136 137 /* Changed ranges */ 138 struct ulist range_changed; 139 }; 140 141 static inline void extent_changeset_init(struct extent_changeset *changeset) 142 { 143 changeset->bytes_changed = 0; 144 ulist_init(&changeset->range_changed); 145 } 146 147 static inline struct extent_changeset *extent_changeset_alloc(void) 148 { 149 struct extent_changeset *ret; 150 151 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 152 if (!ret) 153 return NULL; 154 155 extent_changeset_init(ret); 156 return ret; 157 } 158 159 static inline void extent_changeset_release(struct extent_changeset *changeset) 160 { 161 if (!changeset) 162 return; 163 changeset->bytes_changed = 0; 164 ulist_release(&changeset->range_changed); 165 } 166 167 static inline void extent_changeset_free(struct extent_changeset *changeset) 168 { 169 if (!changeset) 170 return; 171 extent_changeset_release(changeset); 172 kfree(changeset); 173 } 174 175 static inline void extent_set_compress_type(unsigned long *bio_flags, 176 int compress_type) 177 { 178 *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT; 179 } 180 181 static inline int extent_compress_type(unsigned long bio_flags) 182 { 183 return bio_flags >> EXTENT_BIO_FLAG_SHIFT; 184 } 185 186 struct extent_map_tree; 187 188 typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode, 189 struct page *page, size_t pg_offset, 190 u64 start, u64 len); 191 192 int try_release_extent_mapping(struct page *page, gfp_t mask); 193 int try_release_extent_buffer(struct page *page); 194 195 int extent_read_full_page(struct page *page, get_extent_t *get_extent, 196 int mirror_num); 197 int extent_write_full_page(struct page *page, struct writeback_control *wbc); 198 int extent_write_locked_range(struct inode *inode, u64 start, u64 end, 199 int mode); 200 int extent_writepages(struct address_space *mapping, 201 struct writeback_control *wbc); 202 int btree_write_cache_pages(struct address_space *mapping, 203 struct writeback_control *wbc); 204 void extent_readahead(struct readahead_control *rac); 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); 208 209 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 210 u64 start); 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, 214 u64 start); 215 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 216 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 217 u64 start); 218 void free_extent_buffer(struct extent_buffer *eb); 219 void free_extent_buffer_stale(struct extent_buffer *eb); 220 #define WAIT_NONE 0 221 #define WAIT_COMPLETE 1 222 #define WAIT_PAGE_LOCK 2 223 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, 224 int mirror_num); 225 void wait_on_extent_buffer_writeback(struct extent_buffer *eb); 226 227 static inline int num_extent_pages(const struct extent_buffer *eb) 228 { 229 return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) - 230 (eb->start >> PAGE_SHIFT); 231 } 232 233 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 234 { 235 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 236 } 237 238 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, 241 unsigned long start, 242 unsigned long len); 243 int read_extent_buffer_to_user(const struct extent_buffer *eb, 244 void __user *dst, unsigned long start, 245 unsigned long len); 246 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src); 247 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb, 248 const void *src); 249 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 250 unsigned long start, unsigned long len); 251 void copy_extent_buffer_full(const struct extent_buffer *dst, 252 const struct extent_buffer *src); 253 void copy_extent_buffer(const struct extent_buffer *dst, 254 const struct extent_buffer *src, 255 unsigned long dst_offset, unsigned long src_offset, 256 unsigned long len); 257 void memcpy_extent_buffer(const struct extent_buffer *dst, 258 unsigned long dst_offset, unsigned long src_offset, 259 unsigned long len); 260 void memmove_extent_buffer(const struct extent_buffer *dst, 261 unsigned long dst_offset, unsigned long src_offset, 262 unsigned long len); 263 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 264 unsigned long len); 265 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 266 unsigned long pos); 267 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 268 unsigned long pos, unsigned long len); 269 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 270 unsigned long start, unsigned long pos, 271 unsigned long len); 272 void clear_extent_buffer_dirty(const struct extent_buffer *eb); 273 bool set_extent_buffer_dirty(struct extent_buffer *eb); 274 void set_extent_buffer_uptodate(struct extent_buffer *eb); 275 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 276 int extent_buffer_under_io(const struct extent_buffer *eb); 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); 287 288 struct btrfs_fs_info; 289 struct btrfs_inode; 290 291 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(const struct extent_buffer *eb, int mirror_num); 296 297 /* 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. 304 */ 305 struct io_failure_record { 306 struct page *page; 307 u64 start; 308 u64 len; 309 u64 logical; 310 unsigned long bio_flags; 311 int this_mirror; 312 int failed_mirror; 313 int in_validation; 314 }; 315 316 317 blk_status_t btrfs_submit_read_repair(struct inode *inode, 318 struct bio *failed_bio, u64 phy_offset, 319 struct page *page, unsigned int pgoff, 320 u64 start, u64 end, int failed_mirror, 321 submit_bio_hook_t *submit_bio_hook); 322 323 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 324 bool find_lock_delalloc_range(struct inode *inode, 325 struct page *locked_page, u64 *start, 326 u64 *end); 327 #endif 328 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 329 u64 start); 330 331 #ifdef CONFIG_BTRFS_DEBUG 332 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 333 #else 334 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 335 #endif 336 337 #endif 338