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 }; 33 34 /* these are flags for __process_pages_contig */ 35 enum { 36 ENUM_BIT(PAGE_UNLOCK), 37 /* Page starts writeback, clear dirty bit and set writeback bit */ 38 ENUM_BIT(PAGE_START_WRITEBACK), 39 ENUM_BIT(PAGE_END_WRITEBACK), 40 ENUM_BIT(PAGE_SET_ORDERED), 41 ENUM_BIT(PAGE_SET_ERROR), 42 ENUM_BIT(PAGE_LOCK), 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 atomic_t io_pages; 83 int read_mirror; 84 struct rcu_head rcu_head; 85 pid_t lock_owner; 86 /* >= 0 if eb belongs to a log tree, -1 otherwise */ 87 s8 log_index; 88 89 struct rw_semaphore lock; 90 91 struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; 92 struct list_head release_list; 93 #ifdef CONFIG_BTRFS_DEBUG 94 struct list_head leak_list; 95 #endif 96 }; 97 98 /* 99 * Get the correct offset inside the page of extent buffer. 100 * 101 * @eb: target extent buffer 102 * @start: offset inside the extent buffer 103 * 104 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases. 105 */ 106 static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb, 107 unsigned long offset) 108 { 109 /* 110 * For sectorsize == PAGE_SIZE case, eb->start will always be aligned 111 * to PAGE_SIZE, thus adding it won't cause any difference. 112 * 113 * For sectorsize < PAGE_SIZE, we must only read the data that belongs 114 * to the eb, thus we have to take the eb->start into consideration. 115 */ 116 return offset_in_page(offset + eb->start); 117 } 118 119 static inline unsigned long get_eb_page_index(unsigned long offset) 120 { 121 /* 122 * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough. 123 * 124 * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE, 125 * and have ensured that all tree blocks are contained in one page, 126 * thus we always get index == 0. 127 */ 128 return offset >> PAGE_SHIFT; 129 } 130 131 /* 132 * Structure to record how many bytes and which ranges are set/cleared 133 */ 134 struct extent_changeset { 135 /* How many bytes are set/cleared in this operation */ 136 u64 bytes_changed; 137 138 /* Changed ranges */ 139 struct ulist range_changed; 140 }; 141 142 static inline void extent_changeset_init(struct extent_changeset *changeset) 143 { 144 changeset->bytes_changed = 0; 145 ulist_init(&changeset->range_changed); 146 } 147 148 static inline struct extent_changeset *extent_changeset_alloc(void) 149 { 150 struct extent_changeset *ret; 151 152 ret = kmalloc(sizeof(*ret), GFP_KERNEL); 153 if (!ret) 154 return NULL; 155 156 extent_changeset_init(ret); 157 return ret; 158 } 159 160 static inline void extent_changeset_release(struct extent_changeset *changeset) 161 { 162 if (!changeset) 163 return; 164 changeset->bytes_changed = 0; 165 ulist_release(&changeset->range_changed); 166 } 167 168 static inline void extent_changeset_free(struct extent_changeset *changeset) 169 { 170 if (!changeset) 171 return; 172 extent_changeset_release(changeset); 173 kfree(changeset); 174 } 175 176 struct extent_map_tree; 177 178 int try_release_extent_mapping(struct page *page, gfp_t mask); 179 int try_release_extent_buffer(struct page *page); 180 181 int btrfs_read_folio(struct file *file, struct folio *folio); 182 int extent_write_locked_range(struct inode *inode, u64 start, u64 end); 183 int extent_writepages(struct address_space *mapping, 184 struct writeback_control *wbc); 185 int btree_write_cache_pages(struct address_space *mapping, 186 struct writeback_control *wbc); 187 void extent_readahead(struct readahead_control *rac); 188 int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo, 189 u64 start, u64 len); 190 int set_page_extent_mapped(struct page *page); 191 void clear_page_extent_mapped(struct page *page); 192 193 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 194 u64 start, u64 owner_root, int level); 195 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 196 u64 start, unsigned long len); 197 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 198 u64 start); 199 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src); 200 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info, 201 u64 start); 202 void free_extent_buffer(struct extent_buffer *eb); 203 void free_extent_buffer_stale(struct extent_buffer *eb); 204 #define WAIT_NONE 0 205 #define WAIT_COMPLETE 1 206 #define WAIT_PAGE_LOCK 2 207 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num, 208 struct btrfs_tree_parent_check *parent_check); 209 void wait_on_extent_buffer_writeback(struct extent_buffer *eb); 210 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info, 211 u64 bytenr, u64 owner_root, u64 gen, int level); 212 void btrfs_readahead_node_child(struct extent_buffer *node, int slot); 213 214 static inline int num_extent_pages(const struct extent_buffer *eb) 215 { 216 /* 217 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to 218 * sectorsize, it's just eb->len >> PAGE_SHIFT. 219 * 220 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE, 221 * thus have to ensure we get at least one page. 222 */ 223 return (eb->len >> PAGE_SHIFT) ?: 1; 224 } 225 226 static inline int extent_buffer_uptodate(const struct extent_buffer *eb) 227 { 228 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); 229 } 230 231 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv, 232 unsigned long start, unsigned long len); 233 void read_extent_buffer(const struct extent_buffer *eb, void *dst, 234 unsigned long start, 235 unsigned long len); 236 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb, 237 void __user *dst, unsigned long start, 238 unsigned long len); 239 void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src); 240 void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb, 241 const void *src); 242 void write_extent_buffer(const struct extent_buffer *eb, const void *src, 243 unsigned long start, unsigned long len); 244 void copy_extent_buffer_full(const struct extent_buffer *dst, 245 const struct extent_buffer *src); 246 void copy_extent_buffer(const struct extent_buffer *dst, 247 const struct extent_buffer *src, 248 unsigned long dst_offset, unsigned long src_offset, 249 unsigned long len); 250 void memcpy_extent_buffer(const struct extent_buffer *dst, 251 unsigned long dst_offset, unsigned long src_offset, 252 unsigned long len); 253 void memmove_extent_buffer(const struct extent_buffer *dst, 254 unsigned long dst_offset, unsigned long src_offset, 255 unsigned long len); 256 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start, 257 unsigned long len); 258 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start, 259 unsigned long pos); 260 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start, 261 unsigned long pos, unsigned long len); 262 void extent_buffer_bitmap_clear(const struct extent_buffer *eb, 263 unsigned long start, unsigned long pos, 264 unsigned long len); 265 bool set_extent_buffer_dirty(struct extent_buffer *eb); 266 void set_extent_buffer_uptodate(struct extent_buffer *eb); 267 void clear_extent_buffer_uptodate(struct extent_buffer *eb); 268 int extent_buffer_under_io(const struct extent_buffer *eb); 269 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end); 270 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end); 271 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end, 272 struct page *locked_page, 273 u32 bits_to_clear, unsigned long page_ops); 274 int extent_invalidate_folio(struct extent_io_tree *tree, 275 struct folio *folio, size_t offset); 276 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 277 struct extent_buffer *buf); 278 279 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array); 280 281 void end_extent_writepage(struct page *page, int err, u64 start, u64 end); 282 283 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 284 bool find_lock_delalloc_range(struct inode *inode, 285 struct page *locked_page, u64 *start, 286 u64 *end); 287 #endif 288 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, 289 u64 start); 290 291 #ifdef CONFIG_BTRFS_DEBUG 292 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info); 293 #else 294 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0) 295 #endif 296 297 #endif 298