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 "compression.h" 11 #include "ulist.h" 12 #include "misc.h" 13 14 struct btrfs_trans_handle; 15 16 enum { 17 EXTENT_BUFFER_UPTODATE, 18 EXTENT_BUFFER_DIRTY, 19 EXTENT_BUFFER_CORRUPT, 20 /* this got triggered by readahead */ 21 EXTENT_BUFFER_READAHEAD, 22 EXTENT_BUFFER_TREE_REF, 23 EXTENT_BUFFER_STALE, 24 EXTENT_BUFFER_WRITEBACK, 25 /* read IO error */ 26 EXTENT_BUFFER_READ_ERR, 27 EXTENT_BUFFER_UNMAPPED, 28 EXTENT_BUFFER_IN_TREE, 29 /* write IO error */ 30 EXTENT_BUFFER_WRITE_ERR, 31 EXTENT_BUFFER_NO_CHECK, 32 /* Indicate that extent buffer pages a being read */ 33 EXTENT_BUFFER_READING, 34 }; 35 36 /* these are flags for __process_pages_contig */ 37 enum { 38 ENUM_BIT(PAGE_UNLOCK), 39 /* Page starts writeback, clear dirty bit and set writeback bit */ 40 ENUM_BIT(PAGE_START_WRITEBACK), 41 ENUM_BIT(PAGE_END_WRITEBACK), 42 ENUM_BIT(PAGE_SET_ORDERED), 43 }; 44 45 /* 46 * page->private values. Every page that is controlled by the extent 47 * map has page->private set to one. 48 */ 49 #define EXTENT_PAGE_PRIVATE 1 50 51 /* 52 * The extent buffer bitmap operations are done with byte granularity instead of 53 * word granularity for two reasons: 54 * 1. The bitmaps must be little-endian on disk. 55 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a 56 * single word in a bitmap may straddle two pages in the extent buffer. 57 */ 58 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE) 59 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1) 60 #define BITMAP_FIRST_BYTE_MASK(start) \ 61 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK) 62 #define BITMAP_LAST_BYTE_MASK(nbits) \ 63 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1))) 64 65 struct btrfs_root; 66 struct btrfs_inode; 67 struct btrfs_fs_info; 68 struct extent_io_tree; 69 struct btrfs_tree_parent_check; 70 71 int __init extent_buffer_init_cachep(void); 72 void __cold extent_buffer_free_cachep(void); 73 74 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE) 75 struct extent_buffer { 76 u64 start; 77 unsigned long len; 78 unsigned long bflags; 79 struct btrfs_fs_info *fs_info; 80 spinlock_t refs_lock; 81 atomic_t refs; 82 int read_mirror; 83 struct rcu_head rcu_head; 84 pid_t lock_owner; 85 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 86 s8 log_index; 87 88 struct rw_semaphore lock; 89 90 struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; 91 #ifdef CONFIG_BTRFS_DEBUG 92 struct list_head leak_list; 93 #endif 94 }; 95 96 struct btrfs_eb_write_context { 97 struct writeback_control *wbc; 98 struct extent_buffer *eb; 99 /* Block group @eb resides in. Only used for zoned mode. */ 100 struct btrfs_block_group *zoned_bg; 101 }; 102 103 /* 104 * Get the correct offset inside the page of extent buffer. 105 * 106 * @eb: target extent buffer 107 * @start: offset inside the extent buffer 108 * 109 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases. 110 */ 111 static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb, 112 unsigned long offset) 113 { 114 /* 115 * For sectorsize == PAGE_SIZE case, eb->start will always be aligned 116 * to PAGE_SIZE, thus adding it won't cause any difference. 117 * 118 * For sectorsize < PAGE_SIZE, we must only read the data that belongs 119 * to the eb, thus we have to take the eb->start into consideration. 120 */ 121 return offset_in_page(offset + eb->start); 122 } 123 124 static inline unsigned long get_eb_page_index(unsigned long offset) 125 { 126 /* 127 * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough. 128 * 129 * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE, 130 * and have ensured that all tree blocks are contained in one page, 131 * thus we always get index == 0. 132 */ 133 return offset >> PAGE_SHIFT; 134 } 135 136 /* 137 * Structure to record how many bytes and which ranges are set/cleared 138 */ 139 struct extent_changeset { 140 /* How many bytes are set/cleared in this operation */ 141 u64 bytes_changed; 142 143 /* Changed ranges */ 144 struct ulist range_changed; 145 }; 146 147 static inline void extent_changeset_init(struct extent_changeset *changeset) 148 { 149 changeset->bytes_changed = 0; 150 ulist_init(&changeset->range_changed); 151 } 152 153 static inline struct extent_changeset *extent_changeset_alloc(void) 154 { 155 struct extent_changeset *ret; 156 157 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 158 if (!ret) 159 return NULL; 160 161 extent_changeset_init(ret); 162 return ret; 163 } 164 165 static inline void extent_changeset_release(struct extent_changeset *changeset) 166 { 167 if (!changeset) 168 return; 169 changeset->bytes_changed = 0; 170 ulist_release(&changeset->range_changed); 171 } 172 173 static inline void extent_changeset_free(struct extent_changeset *changeset) 174 { 175 if (!changeset) 176 return; 177 extent_changeset_release(changeset); 178 kfree(changeset); 179 } 180 181 struct extent_map_tree; 182 183 int try_release_extent_mapping(struct page *page, gfp_t mask); 184 int try_release_extent_buffer(struct page *page); 185 186 int btrfs_read_folio(struct file *file, struct folio *folio); 187 void extent_write_locked_range(struct inode *inode, struct page *locked_page, 188 u64 start, u64 end, struct writeback_control *wbc, 189 bool pages_dirty); 190 int extent_writepages(struct address_space *mapping, 191 struct writeback_control *wbc); 192 int btree_write_cache_pages(struct address_space *mapping, 193 struct writeback_control *wbc); 194 void extent_readahead(struct readahead_control *rac); 195 int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo, 196 u64 start, u64 len); 197 int set_page_extent_mapped(struct page *page); 198 void clear_page_extent_mapped(struct page *page); 199 200 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 201 u64 start, u64 owner_root, int level); 202 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 203 u64 start, unsigned long len); 204 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 205 u64 start); 206 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 207 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 208 u64 start); 209 void free_extent_buffer(struct extent_buffer *eb); 210 void free_extent_buffer_stale(struct extent_buffer *eb); 211 #define WAIT_NONE 0 212 #define WAIT_COMPLETE 1 213 #define WAIT_PAGE_LOCK 2 214 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, 215 struct btrfs_tree_parent_check *parent_check); 216 void wait_on_extent_buffer_writeback(struct extent_buffer *eb); 217 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, 218 u64 bytenr, u64 owner_root, u64 gen, int level); 219 void btrfs_readahead_node_child(struct extent_buffer *node, int slot); 220 221 static inline int num_extent_pages(const struct extent_buffer *eb) 222 { 223 /* 224 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to 225 * sectorsize, it's just eb->len >> PAGE_SHIFT. 226 * 227 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE, 228 * thus have to ensure we get at least one page. 229 */ 230 return (eb->len >> PAGE_SHIFT) ?: 1; 231 } 232 233 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 234 { 235 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 236 } 237 238 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 239 unsigned long start, unsigned long len); 240 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 241 unsigned long start, 242 unsigned long len); 243 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb, 244 void __user *dst, unsigned long start, 245 unsigned long len); 246 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 247 unsigned long start, unsigned long len); 248 249 static inline void write_extent_buffer_chunk_tree_uuid( 250 const struct extent_buffer *eb, const void *chunk_tree_uuid) 251 { 252 write_extent_buffer(eb, chunk_tree_uuid, 253 offsetof(struct btrfs_header, chunk_tree_uuid), 254 BTRFS_FSID_SIZE); 255 } 256 257 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb, 258 const void *fsid) 259 { 260 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid), 261 BTRFS_FSID_SIZE); 262 } 263 264 void copy_extent_buffer_full(const struct extent_buffer *dst, 265 const struct extent_buffer *src); 266 void copy_extent_buffer(const struct extent_buffer *dst, 267 const struct extent_buffer *src, 268 unsigned long dst_offset, unsigned long src_offset, 269 unsigned long len); 270 void memcpy_extent_buffer(const struct extent_buffer *dst, 271 unsigned long dst_offset, unsigned long src_offset, 272 unsigned long len); 273 void memmove_extent_buffer(const struct extent_buffer *dst, 274 unsigned long dst_offset, unsigned long src_offset, 275 unsigned long len); 276 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 277 unsigned long len); 278 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 279 unsigned long pos); 280 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 281 unsigned long pos, unsigned long len); 282 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 283 unsigned long start, unsigned long pos, 284 unsigned long len); 285 void set_extent_buffer_dirty(struct extent_buffer *eb); 286 void set_extent_buffer_uptodate(struct extent_buffer *eb); 287 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 288 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end); 289 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 290 struct page *locked_page, 291 u32 bits_to_clear, unsigned long page_ops); 292 int extent_invalidate_folio(struct extent_io_tree *tree, 293 struct folio *folio, size_t offset); 294 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 295 struct extent_buffer *buf); 296 297 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array); 298 299 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 300 bool find_lock_delalloc_range(struct inode *inode, 301 struct page *locked_page, u64 *start, 302 u64 *end); 303 #endif 304 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 305 u64 start); 306 307 #ifdef CONFIG_BTRFS_DEBUG 308 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 309 #else 310 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 311 #endif 312 313 #endif 314