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 "compression.h" 16 #include "messages.h" 17 #include "ulist.h" 18 #include "misc.h" 19 20 struct page; 21 struct file; 22 struct folio; 23 struct inode; 24 struct fiemap_extent_info; 25 struct readahead_control; 26 struct address_space; 27 struct writeback_control; 28 struct extent_io_tree; 29 struct extent_map_tree; 30 struct extent_state; 31 struct btrfs_block_group; 32 struct btrfs_fs_info; 33 struct btrfs_inode; 34 struct btrfs_root; 35 struct btrfs_trans_handle; 36 struct btrfs_tree_parent_check; 37 38 enum { 39 EXTENT_BUFFER_UPTODATE, 40 EXTENT_BUFFER_DIRTY, 41 EXTENT_BUFFER_TREE_REF, 42 EXTENT_BUFFER_STALE, 43 EXTENT_BUFFER_WRITEBACK, 44 EXTENT_BUFFER_UNMAPPED, 45 /* write IO error */ 46 EXTENT_BUFFER_WRITE_ERR, 47 /* Indicate the extent buffer is written zeroed out (for zoned) */ 48 EXTENT_BUFFER_ZONED_ZEROOUT, 49 /* Indicate that extent buffer pages a being read */ 50 EXTENT_BUFFER_READING, 51 }; 52 53 /* these are flags for __process_pages_contig */ 54 enum { 55 ENUM_BIT(PAGE_UNLOCK), 56 /* Page starts writeback, clear dirty bit and set writeback bit */ 57 ENUM_BIT(PAGE_START_WRITEBACK), 58 ENUM_BIT(PAGE_END_WRITEBACK), 59 ENUM_BIT(PAGE_SET_ORDERED), 60 }; 61 62 /* 63 * Folio private values. Every page that is controlled by the extent map has 64 * folio private set to this value. 65 */ 66 #define EXTENT_FOLIO_PRIVATE 1 67 68 /* 69 * The extent buffer bitmap operations are done with byte granularity instead of 70 * word granularity for two reasons: 71 * 1. The bitmaps must be little-endian on disk. 72 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a 73 * single word in a bitmap may straddle two pages in the extent buffer. 74 */ 75 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) 76 #define BYTE_MASK ((1U << BITS_PER_BYTE) - 1) 77 #define BITMAP_FIRST_BYTE_MASK(start) \ 78 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK) 79 #define BITMAP_LAST_BYTE_MASK(nbits) \ 80 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1))) 81 82 83 int __init extent_buffer_init_cachep(void); 84 void __cold extent_buffer_free_cachep(void); 85 86 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE) 87 struct extent_buffer { 88 u64 start; 89 u32 len; 90 u32 folio_size; 91 unsigned long bflags; 92 struct btrfs_fs_info *fs_info; 93 94 /* 95 * The address where the eb can be accessed without any cross-page handling. 96 * This can be NULL if not possible. 97 */ 98 void *addr; 99 100 spinlock_t refs_lock; 101 atomic_t refs; 102 int read_mirror; 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 static inline struct extent_changeset *extent_changeset_alloc(void) 201 { 202 struct extent_changeset *ret; 203 204 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 205 if (!ret) 206 return NULL; 207 208 extent_changeset_init(ret); 209 return ret; 210 } 211 212 static inline void extent_changeset_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask) 213 { 214 ulist_prealloc(&changeset->range_changed, gfp_mask); 215 } 216 217 static inline void extent_changeset_release(struct extent_changeset *changeset) 218 { 219 if (!changeset) 220 return; 221 changeset->bytes_changed = 0; 222 ulist_release(&changeset->range_changed); 223 } 224 225 static inline void extent_changeset_free(struct extent_changeset *changeset) 226 { 227 if (!changeset) 228 return; 229 extent_changeset_release(changeset); 230 kfree(changeset); 231 } 232 233 bool try_release_extent_mapping(struct folio *folio, gfp_t mask); 234 int try_release_extent_buffer(struct folio *folio); 235 236 int btrfs_read_folio(struct file *file, struct folio *folio); 237 void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio, 238 u64 start, u64 end, struct writeback_control *wbc, 239 bool pages_dirty); 240 int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc); 241 int btree_write_cache_pages(struct address_space *mapping, 242 struct writeback_control *wbc); 243 void btrfs_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, u64 end); 244 void btrfs_readahead(struct readahead_control *rac); 245 int set_folio_extent_mapped(struct folio *folio); 246 void clear_folio_extent_mapped(struct folio *folio); 247 248 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 249 u64 start, u64 owner_root, int level); 250 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 251 u64 start); 252 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 253 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 254 u64 start); 255 void free_extent_buffer(struct extent_buffer *eb); 256 void free_extent_buffer_stale(struct extent_buffer *eb); 257 int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num, 258 const struct btrfs_tree_parent_check *parent_check); 259 int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num, 260 const struct btrfs_tree_parent_check *parent_check); 261 262 static inline void wait_on_extent_buffer_writeback(struct extent_buffer *eb) 263 { 264 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK, 265 TASK_UNINTERRUPTIBLE); 266 } 267 268 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, 269 u64 bytenr, u64 owner_root, u64 gen, int level); 270 void btrfs_readahead_node_child(struct extent_buffer *node, int slot); 271 272 /* Note: this can be used in for loops without caching the value in a variable. */ 273 static inline int __pure num_extent_pages(const struct extent_buffer *eb) 274 { 275 /* 276 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to 277 * sectorsize, it's just eb->len >> PAGE_SHIFT. 278 * 279 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE, 280 * thus have to ensure we get at least one page. 281 */ 282 return (eb->len >> PAGE_SHIFT) ?: 1; 283 } 284 285 /* 286 * This can only be determined at runtime by checking eb::folios[0]. 287 * 288 * As we can have either one large folio covering the whole eb 289 * (either nodesize <= PAGE_SIZE, or high order folio), or multiple 290 * single-paged folios. 291 * 292 * Note: this can be used in for loops without caching the value in a variable. 293 */ 294 static inline int __pure num_extent_folios(const struct extent_buffer *eb) 295 { 296 if (!eb->folios[0]) 297 return 0; 298 if (folio_order(eb->folios[0])) 299 return 1; 300 return num_extent_pages(eb); 301 } 302 303 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 304 { 305 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 306 } 307 308 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 309 unsigned long start, unsigned long len); 310 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 311 unsigned long start, 312 unsigned long len); 313 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb, 314 void __user *dst, unsigned long start, 315 unsigned long len); 316 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 317 unsigned long start, unsigned long len); 318 319 static inline void write_extent_buffer_chunk_tree_uuid( 320 const struct extent_buffer *eb, const void *chunk_tree_uuid) 321 { 322 write_extent_buffer(eb, chunk_tree_uuid, 323 offsetof(struct btrfs_header, chunk_tree_uuid), 324 BTRFS_FSID_SIZE); 325 } 326 327 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb, 328 const void *fsid) 329 { 330 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid), 331 BTRFS_FSID_SIZE); 332 } 333 334 void copy_extent_buffer_full(const struct extent_buffer *dst, 335 const struct extent_buffer *src); 336 void copy_extent_buffer(const struct extent_buffer *dst, 337 const struct extent_buffer *src, 338 unsigned long dst_offset, unsigned long src_offset, 339 unsigned long len); 340 void memcpy_extent_buffer(const struct extent_buffer *dst, 341 unsigned long dst_offset, unsigned long src_offset, 342 unsigned long len); 343 void memmove_extent_buffer(const struct extent_buffer *dst, 344 unsigned long dst_offset, unsigned long src_offset, 345 unsigned long len); 346 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 347 unsigned long len); 348 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 349 unsigned long pos); 350 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 351 unsigned long pos, unsigned long len); 352 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 353 unsigned long start, unsigned long pos, 354 unsigned long len); 355 void set_extent_buffer_dirty(struct extent_buffer *eb); 356 void set_extent_buffer_uptodate(struct extent_buffer *eb); 357 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 358 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 359 const struct folio *locked_folio, 360 struct extent_state **cached, 361 u32 bits_to_clear, unsigned long page_ops); 362 int extent_invalidate_folio(struct extent_io_tree *tree, 363 struct folio *folio, size_t offset); 364 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 365 struct extent_buffer *buf); 366 367 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array, 368 bool nofail); 369 int btrfs_alloc_folio_array(unsigned int nr_folios, 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