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 <linux/spinlock.h> 11 #include <linux/atomic.h> 12 #include <linux/rwsem.h> 13 #include <linux/list.h> 14 #include <linux/slab.h> 15 #include "messages.h" 16 #include "ulist.h" 17 #include "misc.h" 18 19 struct page; 20 struct file; 21 struct folio; 22 struct inode; 23 struct fiemap_extent_info; 24 struct readahead_control; 25 struct address_space; 26 struct writeback_control; 27 struct extent_io_tree; 28 struct extent_map_tree; 29 struct extent_state; 30 struct btrfs_block_group; 31 struct btrfs_fs_info; 32 struct btrfs_inode; 33 struct btrfs_root; 34 struct btrfs_trans_handle; 35 struct btrfs_tree_parent_check; 36 37 enum { 38 EXTENT_BUFFER_UPTODATE, 39 EXTENT_BUFFER_DIRTY, 40 EXTENT_BUFFER_TREE_REF, 41 EXTENT_BUFFER_STALE, 42 EXTENT_BUFFER_WRITEBACK, 43 EXTENT_BUFFER_UNMAPPED, 44 /* write IO error */ 45 EXTENT_BUFFER_WRITE_ERR, 46 /* Indicate the extent buffer is written zeroed out (for zoned) */ 47 EXTENT_BUFFER_ZONED_ZEROOUT, 48 /* Indicate that extent buffer pages a being read */ 49 EXTENT_BUFFER_READING, 50 }; 51 52 /* these are flags for __process_pages_contig */ 53 enum { 54 ENUM_BIT(PAGE_UNLOCK), 55 /* Page starts writeback, clear dirty bit and set writeback bit */ 56 ENUM_BIT(PAGE_START_WRITEBACK), 57 ENUM_BIT(PAGE_END_WRITEBACK), 58 }; 59 60 /* 61 * Folio private values. Every page that is controlled by the extent map has 62 * folio private set to this value. 63 */ 64 #define EXTENT_FOLIO_PRIVATE 1 65 66 /* 67 * The extent buffer bitmap operations are done with byte granularity instead of 68 * word granularity for two reasons: 69 * 1. The bitmaps must be little-endian on disk. 70 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a 71 * single word in a bitmap may straddle two pages in the extent buffer. 72 */ 73 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) 74 #define BYTE_MASK ((1U << BITS_PER_BYTE) - 1) 75 #define BITMAP_FIRST_BYTE_MASK(start) \ 76 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK) 77 #define BITMAP_LAST_BYTE_MASK(nbits) \ 78 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1))) 79 80 81 int __init extent_buffer_init_cachep(void); 82 void __cold extent_buffer_free_cachep(void); 83 84 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE) 85 struct extent_buffer { 86 u64 start; 87 u32 len; 88 u32 folio_size; 89 unsigned long bflags; 90 struct btrfs_fs_info *fs_info; 91 92 /* 93 * The address where the eb can be accessed without any cross-page handling. 94 * This can be NULL if not possible. 95 */ 96 void *addr; 97 98 spinlock_t refs_lock; 99 refcount_t refs; 100 int read_mirror; 101 /* Inhibit WB_SYNC_NONE writeback when > 0. */ 102 atomic_t writeback_inhibitors; 103 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 104 s8 log_index; 105 u8 folio_shift; 106 struct rcu_head rcu_head; 107 108 struct rw_semaphore lock; 109 110 /* 111 * Pointers to all the folios of the extent buffer. 112 * 113 * For now the folio is always order 0 (aka, a single page). 114 */ 115 struct folio *folios[INLINE_EXTENT_BUFFER_PAGES]; 116 #ifdef CONFIG_BTRFS_DEBUG 117 struct list_head leak_list; 118 pid_t lock_owner; 119 #endif 120 }; 121 122 struct btrfs_eb_write_context { 123 struct writeback_control *wbc; 124 struct extent_buffer *eb; 125 /* Block group @eb resides in. Only used for zoned mode. */ 126 struct btrfs_block_group *zoned_bg; 127 }; 128 129 static inline unsigned long offset_in_eb_folio(const struct extent_buffer *eb, 130 u64 start) 131 { 132 ASSERT(eb->folio_size); 133 return start & (eb->folio_size - 1); 134 } 135 136 /* 137 * Get the correct offset inside the page of extent buffer. 138 * 139 * @eb: target extent buffer 140 * @start: offset inside the extent buffer 141 * 142 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases. 143 */ 144 static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb, 145 unsigned long offset) 146 { 147 /* 148 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case 149 * 1.1) One large folio covering the whole eb 150 * The eb->start is aligned to folio size, thus adding it 151 * won't cause any difference. 152 * 1.2) Several page sized folios 153 * The eb->start is aligned to folio (page) size, thus 154 * adding it won't cause any difference. 155 * 156 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case 157 * In this case there would only be one page sized folio, and there 158 * may be several different extent buffers in the page/folio. 159 * We need to add eb->start to properly access the offset inside 160 * that eb. 161 */ 162 return offset_in_folio(eb->folios[0], offset + eb->start); 163 } 164 165 static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb, 166 unsigned long offset) 167 { 168 /* 169 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case 170 * 1.1) One large folio covering the whole eb. 171 * the folio_shift would be large enough to always make us 172 * return 0 as index. 173 * 1.2) Several page sized folios 174 * The folio_shift would be PAGE_SHIFT, giving us the correct 175 * index. 176 * 177 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case 178 * The folio would only be page sized, and always give us 0 as index. 179 */ 180 return offset >> eb->folio_shift; 181 } 182 183 /* 184 * Structure to record how many bytes and which ranges are set/cleared 185 */ 186 struct extent_changeset { 187 /* How many bytes are set/cleared in this operation */ 188 u64 bytes_changed; 189 190 /* Changed ranges */ 191 struct ulist range_changed; 192 }; 193 194 static inline void extent_changeset_init(struct extent_changeset *changeset) 195 { 196 changeset->bytes_changed = 0; 197 ulist_init(&changeset->range_changed); 198 } 199 200 /* 201 * Sentinel value for range_changed.prealloc indicating that the changeset 202 * only tracks bytes_changed and does not record individual ranges. This 203 * avoids GFP_ATOMIC allocations inside add_extent_changeset() when the 204 * caller doesn't need to iterate the changed ranges afterwards. 205 */ 206 #define EXTENT_CHANGESET_BYTES_ONLY ((struct ulist_node *)1) 207 208 static inline void extent_changeset_init_bytes_only(struct extent_changeset *changeset) 209 { 210 changeset->bytes_changed = 0; 211 changeset->range_changed.prealloc = EXTENT_CHANGESET_BYTES_ONLY; 212 } 213 214 static inline bool extent_changeset_tracks_ranges(const struct extent_changeset *changeset) 215 { 216 return changeset->range_changed.prealloc != EXTENT_CHANGESET_BYTES_ONLY; 217 } 218 219 static inline struct extent_changeset *extent_changeset_alloc(void) 220 { 221 struct extent_changeset *ret; 222 223 ret = kmalloc_obj(*ret); 224 if (!ret) 225 return NULL; 226 227 extent_changeset_init(ret); 228 return ret; 229 } 230 231 static inline void extent_changeset_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask) 232 { 233 ASSERT(extent_changeset_tracks_ranges(changeset)); 234 ulist_prealloc(&changeset->range_changed, gfp_mask); 235 } 236 237 static inline void extent_changeset_release(struct extent_changeset *changeset) 238 { 239 if (!changeset) 240 return; 241 changeset->bytes_changed = 0; 242 if (extent_changeset_tracks_ranges(changeset)) 243 ulist_release(&changeset->range_changed); 244 } 245 246 static inline void extent_changeset_free(struct extent_changeset *changeset) 247 { 248 if (!changeset) 249 return; 250 extent_changeset_release(changeset); 251 kfree(changeset); 252 } 253 254 bool try_release_extent_mapping(struct folio *folio, gfp_t mask); 255 int try_release_extent_buffer(struct folio *folio); 256 257 int btrfs_read_folio(struct file *file, struct folio *folio); 258 void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio, 259 u64 start, u64 end, struct writeback_control *wbc, 260 bool pages_dirty); 261 int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc); 262 int btree_writepages(struct address_space *mapping, struct writeback_control *wbc); 263 void btrfs_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, u64 end); 264 void btrfs_readahead(struct readahead_control *rac); 265 int set_folio_extent_mapped(struct folio *folio); 266 void clear_folio_extent_mapped(struct folio *folio); 267 268 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 269 u64 start, u64 owner_root, int level); 270 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 271 u64 start); 272 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 273 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 274 u64 start); 275 void free_extent_buffer(struct extent_buffer *eb); 276 void free_extent_buffer_stale(struct extent_buffer *eb); 277 int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num, 278 const struct btrfs_tree_parent_check *parent_check); 279 int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num, 280 const struct btrfs_tree_parent_check *parent_check); 281 282 static inline void wait_on_extent_buffer_writeback(struct extent_buffer *eb) 283 { 284 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, 285 TASK_UNINTERRUPTIBLE); 286 } 287 288 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, 289 u64 bytenr, u64 owner_root, u64 gen, int level, 290 const struct btrfs_key *first_key); 291 void btrfs_readahead_node_child(struct extent_buffer *node, int slot); 292 293 /* Note: this can be used in for loops without caching the value in a variable. */ 294 static inline int __pure num_extent_pages(const struct extent_buffer *eb) 295 { 296 /* 297 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to 298 * sectorsize, it's just eb->len >> PAGE_SHIFT. 299 * 300 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE, 301 * thus have to ensure we get at least one page. 302 */ 303 return (eb->len >> PAGE_SHIFT) ?: 1; 304 } 305 306 /* 307 * This can only be determined at runtime by checking eb::folios[0]. 308 * 309 * As we can have either one large folio covering the whole eb 310 * (either nodesize <= PAGE_SIZE, or high order folio), or multiple 311 * single-paged folios. 312 * 313 * Note: this can be used in for loops without caching the value in a variable. 314 */ 315 static inline int __pure num_extent_folios(const struct extent_buffer *eb) 316 { 317 if (!eb->folios[0]) 318 return 0; 319 if (folio_order(eb->folios[0])) 320 return 1; 321 return num_extent_pages(eb); 322 } 323 324 static inline bool extent_buffer_uptodate(const struct extent_buffer *eb) 325 { 326 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 327 } 328 329 static inline bool extent_buffer_under_io(const struct extent_buffer *eb) 330 { 331 return (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) || 332 test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); 333 } 334 335 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 336 unsigned long start, unsigned long len); 337 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 338 unsigned long start, 339 unsigned long len); 340 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb, 341 void __user *dst, unsigned long start, 342 unsigned long len); 343 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 344 unsigned long start, unsigned long len); 345 346 static inline void write_extent_buffer_chunk_tree_uuid( 347 const struct extent_buffer *eb, const void *chunk_tree_uuid) 348 { 349 write_extent_buffer(eb, chunk_tree_uuid, 350 offsetof(struct btrfs_header, chunk_tree_uuid), 351 BTRFS_FSID_SIZE); 352 } 353 354 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb, 355 const void *fsid) 356 { 357 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid), 358 BTRFS_FSID_SIZE); 359 } 360 361 void copy_extent_buffer_full(const struct extent_buffer *dst, 362 const struct extent_buffer *src); 363 void copy_extent_buffer(const struct extent_buffer *dst, 364 const struct extent_buffer *src, 365 unsigned long dst_offset, unsigned long src_offset, 366 unsigned long len); 367 void memcpy_extent_buffer(const struct extent_buffer *dst, 368 unsigned long dst_offset, unsigned long src_offset, 369 unsigned long len); 370 void memmove_extent_buffer(const struct extent_buffer *dst, 371 unsigned long dst_offset, unsigned long src_offset, 372 unsigned long len); 373 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 374 unsigned long len); 375 bool extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 376 unsigned long pos); 377 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 378 unsigned long pos, unsigned long len); 379 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 380 unsigned long start, unsigned long pos, 381 unsigned long len); 382 void set_extent_buffer_dirty(struct extent_buffer *eb); 383 void set_extent_buffer_uptodate(struct extent_buffer *eb); 384 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 385 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 386 const struct folio *locked_folio, 387 struct extent_state **cached, 388 u32 bits_to_clear, unsigned long page_ops); 389 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 390 struct extent_buffer *buf); 391 392 static inline void btrfs_clear_folio_dirty_tag(struct folio *folio) 393 { 394 ASSERT(!folio_test_dirty(folio)); 395 ASSERT(folio_test_locked(folio)); 396 ASSERT(folio->mapping); 397 xa_lock_irq(&folio->mapping->i_pages); 398 __xa_clear_mark(&folio->mapping->i_pages, folio->index, 399 PAGECACHE_TAG_DIRTY); 400 xa_unlock_irq(&folio->mapping->i_pages); 401 } 402 403 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array, gfp_t gfp); 404 int btrfs_alloc_folio_array(unsigned int nr_folios, unsigned int order, 405 struct folio **folio_array, gfp_t gfp); 406 407 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 408 bool find_lock_delalloc_range(struct inode *inode, 409 struct folio *locked_folio, u64 *start, 410 u64 *end); 411 #endif 412 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 413 u64 start); 414 415 #ifdef CONFIG_BTRFS_DEBUG 416 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 417 #else 418 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 419 #endif 420 421 void btrfs_inhibit_eb_writeback(struct btrfs_trans_handle *trans, 422 struct extent_buffer *eb); 423 void btrfs_uninhibit_all_eb_writeback(struct btrfs_trans_handle *trans); 424 425 #endif 426