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 ENUM_BIT(PAGE_SET_ORDERED), 59 }; 60 61 /* 62 * Folio private values. Every page that is controlled by the extent map has 63 * folio private set to this value. 64 */ 65 #define EXTENT_FOLIO_PRIVATE 1 66 67 /* 68 * The extent buffer bitmap operations are done with byte granularity instead of 69 * word granularity for two reasons: 70 * 1. The bitmaps must be little-endian on disk. 71 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a 72 * single word in a bitmap may straddle two pages in the extent buffer. 73 */ 74 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) 75 #define BYTE_MASK ((1U << BITS_PER_BYTE) - 1) 76 #define BITMAP_FIRST_BYTE_MASK(start) \ 77 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK) 78 #define BITMAP_LAST_BYTE_MASK(nbits) \ 79 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1))) 80 81 82 int __init extent_buffer_init_cachep(void); 83 void __cold extent_buffer_free_cachep(void); 84 85 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE) 86 struct extent_buffer { 87 u64 start; 88 u32 len; 89 u32 folio_size; 90 unsigned long bflags; 91 struct btrfs_fs_info *fs_info; 92 93 /* 94 * The address where the eb can be accessed without any cross-page handling. 95 * This can be NULL if not possible. 96 */ 97 void *addr; 98 99 spinlock_t refs_lock; 100 refcount_t refs; 101 int read_mirror; 102 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 103 s8 log_index; 104 u8 folio_shift; 105 struct rcu_head rcu_head; 106 107 struct rw_semaphore lock; 108 109 /* 110 * Pointers to all the folios of the extent buffer. 111 * 112 * For now the folio is always order 0 (aka, a single page). 113 */ 114 struct folio *folios[INLINE_EXTENT_BUFFER_PAGES]; 115 #ifdef CONFIG_BTRFS_DEBUG 116 struct list_head leak_list; 117 pid_t lock_owner; 118 #endif 119 }; 120 121 struct btrfs_eb_write_context { 122 struct writeback_control *wbc; 123 struct extent_buffer *eb; 124 /* Block group @eb resides in. Only used for zoned mode. */ 125 struct btrfs_block_group *zoned_bg; 126 }; 127 128 static inline unsigned long offset_in_eb_folio(const struct extent_buffer *eb, 129 u64 start) 130 { 131 ASSERT(eb->folio_size); 132 return start & (eb->folio_size - 1); 133 } 134 135 /* 136 * Get the correct offset inside the page of extent buffer. 137 * 138 * @eb: target extent buffer 139 * @start: offset inside the extent buffer 140 * 141 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases. 142 */ 143 static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb, 144 unsigned long offset) 145 { 146 /* 147 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case 148 * 1.1) One large folio covering the whole eb 149 * The eb->start is aligned to folio size, thus adding it 150 * won't cause any difference. 151 * 1.2) Several page sized folios 152 * The eb->start is aligned to folio (page) size, thus 153 * adding it won't cause any difference. 154 * 155 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case 156 * In this case there would only be one page sized folio, and there 157 * may be several different extent buffers in the page/folio. 158 * We need to add eb->start to properly access the offset inside 159 * that eb. 160 */ 161 return offset_in_folio(eb->folios[0], offset + eb->start); 162 } 163 164 static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb, 165 unsigned long offset) 166 { 167 /* 168 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case 169 * 1.1) One large folio covering the whole eb. 170 * the folio_shift would be large enough to always make us 171 * return 0 as index. 172 * 1.2) Several page sized folios 173 * The folio_shift would be PAGE_SHIFT, giving us the correct 174 * index. 175 * 176 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case 177 * The folio would only be page sized, and always give us 0 as index. 178 */ 179 return offset >> eb->folio_shift; 180 } 181 182 /* 183 * Structure to record how many bytes and which ranges are set/cleared 184 */ 185 struct extent_changeset { 186 /* How many bytes are set/cleared in this operation */ 187 u64 bytes_changed; 188 189 /* Changed ranges */ 190 struct ulist range_changed; 191 }; 192 193 static inline void extent_changeset_init(struct extent_changeset *changeset) 194 { 195 changeset->bytes_changed = 0; 196 ulist_init(&changeset->range_changed); 197 } 198 199 static inline struct extent_changeset *extent_changeset_alloc(void) 200 { 201 struct extent_changeset *ret; 202 203 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 204 if (!ret) 205 return NULL; 206 207 extent_changeset_init(ret); 208 return ret; 209 } 210 211 static inline void extent_changeset_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask) 212 { 213 ulist_prealloc(&changeset->range_changed, gfp_mask); 214 } 215 216 static inline void extent_changeset_release(struct extent_changeset *changeset) 217 { 218 if (!changeset) 219 return; 220 changeset->bytes_changed = 0; 221 ulist_release(&changeset->range_changed); 222 } 223 224 static inline void extent_changeset_free(struct extent_changeset *changeset) 225 { 226 if (!changeset) 227 return; 228 extent_changeset_release(changeset); 229 kfree(changeset); 230 } 231 232 bool try_release_extent_mapping(struct folio *folio, gfp_t mask); 233 int try_release_extent_buffer(struct folio *folio); 234 235 int btrfs_read_folio(struct file *file, struct folio *folio); 236 void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio, 237 u64 start, u64 end, struct writeback_control *wbc, 238 bool pages_dirty); 239 int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc); 240 int btree_write_cache_pages(struct address_space *mapping, 241 struct writeback_control *wbc); 242 void btrfs_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, u64 end); 243 void btrfs_readahead(struct readahead_control *rac); 244 int set_folio_extent_mapped(struct folio *folio); 245 void clear_folio_extent_mapped(struct folio *folio); 246 247 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 248 u64 start, u64 owner_root, int level); 249 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 250 u64 start); 251 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 252 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 253 u64 start); 254 void free_extent_buffer(struct extent_buffer *eb); 255 void free_extent_buffer_stale(struct extent_buffer *eb); 256 int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num, 257 const struct btrfs_tree_parent_check *parent_check); 258 int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num, 259 const struct btrfs_tree_parent_check *parent_check); 260 261 static inline void wait_on_extent_buffer_writeback(struct extent_buffer *eb) 262 { 263 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, 264 TASK_UNINTERRUPTIBLE); 265 } 266 267 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, 268 u64 bytenr, u64 owner_root, u64 gen, int level); 269 void btrfs_readahead_node_child(struct extent_buffer *node, int slot); 270 271 /* Note: this can be used in for loops without caching the value in a variable. */ 272 static inline int __pure num_extent_pages(const struct extent_buffer *eb) 273 { 274 /* 275 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to 276 * sectorsize, it's just eb->len >> PAGE_SHIFT. 277 * 278 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE, 279 * thus have to ensure we get at least one page. 280 */ 281 return (eb->len >> PAGE_SHIFT) ?: 1; 282 } 283 284 /* 285 * This can only be determined at runtime by checking eb::folios[0]. 286 * 287 * As we can have either one large folio covering the whole eb 288 * (either nodesize <= PAGE_SIZE, or high order folio), or multiple 289 * single-paged folios. 290 * 291 * Note: this can be used in for loops without caching the value in a variable. 292 */ 293 static inline int __pure num_extent_folios(const struct extent_buffer *eb) 294 { 295 if (!eb->folios[0]) 296 return 0; 297 if (folio_order(eb->folios[0])) 298 return 1; 299 return num_extent_pages(eb); 300 } 301 302 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 303 { 304 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 305 } 306 307 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 308 unsigned long start, unsigned long len); 309 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 310 unsigned long start, 311 unsigned long len); 312 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb, 313 void __user *dst, unsigned long start, 314 unsigned long len); 315 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 316 unsigned long start, unsigned long len); 317 318 static inline void write_extent_buffer_chunk_tree_uuid( 319 const struct extent_buffer *eb, const void *chunk_tree_uuid) 320 { 321 write_extent_buffer(eb, chunk_tree_uuid, 322 offsetof(struct btrfs_header, chunk_tree_uuid), 323 BTRFS_FSID_SIZE); 324 } 325 326 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb, 327 const void *fsid) 328 { 329 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid), 330 BTRFS_FSID_SIZE); 331 } 332 333 void copy_extent_buffer_full(const struct extent_buffer *dst, 334 const struct extent_buffer *src); 335 void copy_extent_buffer(const struct extent_buffer *dst, 336 const struct extent_buffer *src, 337 unsigned long dst_offset, unsigned long src_offset, 338 unsigned long len); 339 void memcpy_extent_buffer(const struct extent_buffer *dst, 340 unsigned long dst_offset, unsigned long src_offset, 341 unsigned long len); 342 void memmove_extent_buffer(const struct extent_buffer *dst, 343 unsigned long dst_offset, unsigned long src_offset, 344 unsigned long len); 345 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 346 unsigned long len); 347 bool extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 348 unsigned long pos); 349 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 350 unsigned long pos, unsigned long len); 351 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 352 unsigned long start, unsigned long pos, 353 unsigned long len); 354 void set_extent_buffer_dirty(struct extent_buffer *eb); 355 void set_extent_buffer_uptodate(struct extent_buffer *eb); 356 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 357 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 358 const struct folio *locked_folio, 359 struct extent_state **cached, 360 u32 bits_to_clear, unsigned long page_ops); 361 int extent_invalidate_folio(struct extent_io_tree *tree, 362 struct folio *folio, size_t offset); 363 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 364 struct extent_buffer *buf); 365 366 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array, 367 bool nofail); 368 int btrfs_alloc_folio_array(unsigned int nr_folios, unsigned int order, 369 struct folio **folio_array); 370 371 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 372 bool find_lock_delalloc_range(struct inode *inode, 373 struct folio *locked_folio, u64 *start, 374 u64 *end); 375 #endif 376 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 377 u64 start); 378 379 #ifdef CONFIG_BTRFS_DEBUG 380 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 381 #else 382 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 383 #endif 384 385 #endif 386