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