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 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_CORRUPT, 41 /* this got triggered by readahead */ 42 EXTENT_BUFFER_READAHEAD, 43 EXTENT_BUFFER_TREE_REF, 44 EXTENT_BUFFER_STALE, 45 EXTENT_BUFFER_WRITEBACK, 46 /* read IO error */ 47 EXTENT_BUFFER_READ_ERR, 48 EXTENT_BUFFER_UNMAPPED, 49 EXTENT_BUFFER_IN_TREE, 50 /* write IO error */ 51 EXTENT_BUFFER_WRITE_ERR, 52 /* Indicate the extent buffer is written zeroed out (for zoned) */ 53 EXTENT_BUFFER_ZONED_ZEROOUT, 54 /* Indicate that extent buffer pages a being read */ 55 EXTENT_BUFFER_READING, 56 }; 57 58 /* these are flags for __process_pages_contig */ 59 enum { 60 ENUM_BIT(PAGE_UNLOCK), 61 /* Page starts writeback, clear dirty bit and set writeback bit */ 62 ENUM_BIT(PAGE_START_WRITEBACK), 63 ENUM_BIT(PAGE_END_WRITEBACK), 64 ENUM_BIT(PAGE_SET_ORDERED), 65 }; 66 67 /* 68 * Folio private values. Every page that is controlled by the extent map has 69 * folio private set to this value. 70 */ 71 #define EXTENT_FOLIO_PRIVATE 1 72 73 /* 74 * The extent buffer bitmap operations are done with byte granularity instead of 75 * word granularity for two reasons: 76 * 1. The bitmaps must be little-endian on disk. 77 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a 78 * single word in a bitmap may straddle two pages in the extent buffer. 79 */ 80 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) 81 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1) 82 #define BITMAP_FIRST_BYTE_MASK(start) \ 83 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK) 84 #define BITMAP_LAST_BYTE_MASK(nbits) \ 85 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1))) 86 87 88 int __init extent_buffer_init_cachep(void); 89 void __cold extent_buffer_free_cachep(void); 90 91 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE) 92 struct extent_buffer { 93 u64 start; 94 u32 len; 95 u32 folio_size; 96 unsigned long bflags; 97 struct btrfs_fs_info *fs_info; 98 99 /* 100 * The address where the eb can be accessed without any cross-page handling. 101 * This can be NULL if not possible. 102 */ 103 void *addr; 104 105 spinlock_t refs_lock; 106 atomic_t refs; 107 int read_mirror; 108 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 109 s8 log_index; 110 u8 folio_shift; 111 struct rcu_head rcu_head; 112 113 struct rw_semaphore lock; 114 115 /* 116 * Pointers to all the folios of the extent buffer. 117 * 118 * For now the folio is always order 0 (aka, a single page). 119 */ 120 struct folio *folios[INLINE_EXTENT_BUFFER_PAGES]; 121 #ifdef CONFIG_BTRFS_DEBUG 122 struct list_head leak_list; 123 pid_t lock_owner; 124 #endif 125 }; 126 127 struct btrfs_eb_write_context { 128 struct writeback_control *wbc; 129 struct extent_buffer *eb; 130 /* Block group @eb resides in. Only used for zoned mode. */ 131 struct btrfs_block_group *zoned_bg; 132 }; 133 134 static inline unsigned long offset_in_eb_folio(const struct extent_buffer *eb, 135 u64 start) 136 { 137 ASSERT(eb->folio_size); 138 return start & (eb->folio_size - 1); 139 } 140 141 /* 142 * Get the correct offset inside the page of extent buffer. 143 * 144 * @eb: target extent buffer 145 * @start: offset inside the extent buffer 146 * 147 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases. 148 */ 149 static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb, 150 unsigned long offset) 151 { 152 /* 153 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case 154 * 1.1) One large folio covering the whole eb 155 * The eb->start is aligned to folio size, thus adding it 156 * won't cause any difference. 157 * 1.2) Several page sized folios 158 * The eb->start is aligned to folio (page) size, thus 159 * adding it won't cause any difference. 160 * 161 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case 162 * In this case there would only be one page sized folio, and there 163 * may be several different extent buffers in the page/folio. 164 * We need to add eb->start to properly access the offset inside 165 * that eb. 166 */ 167 return offset_in_folio(eb->folios[0], offset + eb->start); 168 } 169 170 static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb, 171 unsigned long offset) 172 { 173 /* 174 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case 175 * 1.1) One large folio covering the whole eb. 176 * the folio_shift would be large enough to always make us 177 * return 0 as index. 178 * 1.2) Several page sized folios 179 * The folio_shift would be PAGE_SHIFT, giving us the correct 180 * index. 181 * 182 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case 183 * The folio would only be page sized, and always give us 0 as index. 184 */ 185 return offset >> eb->folio_shift; 186 } 187 188 /* 189 * Structure to record how many bytes and which ranges are set/cleared 190 */ 191 struct extent_changeset { 192 /* How many bytes are set/cleared in this operation */ 193 u64 bytes_changed; 194 195 /* Changed ranges */ 196 struct ulist range_changed; 197 }; 198 199 static inline void extent_changeset_init(struct extent_changeset *changeset) 200 { 201 changeset->bytes_changed = 0; 202 ulist_init(&changeset->range_changed); 203 } 204 205 static inline struct extent_changeset *extent_changeset_alloc(void) 206 { 207 struct extent_changeset *ret; 208 209 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 210 if (!ret) 211 return NULL; 212 213 extent_changeset_init(ret); 214 return ret; 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 int try_release_extent_mapping(struct page *page, gfp_t mask); 234 int try_release_extent_buffer(struct page *page); 235 236 int btrfs_read_folio(struct file *file, struct folio *folio); 237 void extent_write_locked_range(struct inode *inode, struct page *locked_page, 238 u64 start, u64 end, struct writeback_control *wbc, 239 bool pages_dirty); 240 int extent_writepages(struct address_space *mapping, 241 struct writeback_control *wbc); 242 int btree_write_cache_pages(struct address_space *mapping, 243 struct writeback_control *wbc); 244 void extent_readahead(struct readahead_control *rac); 245 int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo, 246 u64 start, u64 len); 247 int set_folio_extent_mapped(struct folio *folio); 248 int set_page_extent_mapped(struct page *page); 249 void clear_page_extent_mapped(struct page *page); 250 251 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 252 u64 start, u64 owner_root, int level); 253 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 254 u64 start, unsigned long len); 255 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 256 u64 start); 257 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 258 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 259 u64 start); 260 void free_extent_buffer(struct extent_buffer *eb); 261 void free_extent_buffer_stale(struct extent_buffer *eb); 262 #define WAIT_NONE 0 263 #define WAIT_COMPLETE 1 264 #define WAIT_PAGE_LOCK 2 265 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, 266 struct btrfs_tree_parent_check *parent_check); 267 void wait_on_extent_buffer_writeback(struct extent_buffer *eb); 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 static inline int 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 static inline int num_extent_folios(const struct extent_buffer *eb) 292 { 293 if (folio_order(eb->folios[0])) 294 return 1; 295 return num_extent_pages(eb); 296 } 297 298 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 299 { 300 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 301 } 302 303 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 304 unsigned long start, unsigned long len); 305 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 306 unsigned long start, 307 unsigned long len); 308 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb, 309 void __user *dst, unsigned long start, 310 unsigned long len); 311 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 312 unsigned long start, unsigned long len); 313 314 static inline void write_extent_buffer_chunk_tree_uuid( 315 const struct extent_buffer *eb, const void *chunk_tree_uuid) 316 { 317 write_extent_buffer(eb, chunk_tree_uuid, 318 offsetof(struct btrfs_header, chunk_tree_uuid), 319 BTRFS_FSID_SIZE); 320 } 321 322 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb, 323 const void *fsid) 324 { 325 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid), 326 BTRFS_FSID_SIZE); 327 } 328 329 void copy_extent_buffer_full(const struct extent_buffer *dst, 330 const struct extent_buffer *src); 331 void copy_extent_buffer(const struct extent_buffer *dst, 332 const struct extent_buffer *src, 333 unsigned long dst_offset, unsigned long src_offset, 334 unsigned long len); 335 void memcpy_extent_buffer(const struct extent_buffer *dst, 336 unsigned long dst_offset, unsigned long src_offset, 337 unsigned long len); 338 void memmove_extent_buffer(const struct extent_buffer *dst, 339 unsigned long dst_offset, unsigned long src_offset, 340 unsigned long len); 341 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 342 unsigned long len); 343 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 344 unsigned long pos); 345 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 346 unsigned long pos, unsigned long len); 347 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 348 unsigned long start, unsigned long pos, 349 unsigned long len); 350 void set_extent_buffer_dirty(struct extent_buffer *eb); 351 void set_extent_buffer_uptodate(struct extent_buffer *eb); 352 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 353 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end); 354 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 355 struct page *locked_page, 356 u32 bits_to_clear, unsigned long page_ops); 357 int extent_invalidate_folio(struct extent_io_tree *tree, 358 struct folio *folio, size_t offset); 359 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 360 struct extent_buffer *buf); 361 362 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array, 363 gfp_t extra_gfp); 364 365 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 366 bool find_lock_delalloc_range(struct inode *inode, 367 struct page *locked_page, u64 *start, 368 u64 *end); 369 #endif 370 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 371 u64 start); 372 373 #ifdef CONFIG_BTRFS_DEBUG 374 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 375 #else 376 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 377 #endif 378 379 #endif 380