1 /* SPDX-License-Identifier: GPL-2.0 */
3 #ifndef BTRFS_EXTENT_IO_H
4 #define BTRFS_EXTENT_IO_H
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"
14 struct btrfs_trans_handle;
17 EXTENT_BUFFER_UPTODATE,
19 EXTENT_BUFFER_CORRUPT,
20 /* this got triggered by readahead */
21 EXTENT_BUFFER_READAHEAD,
22 EXTENT_BUFFER_TREE_REF,
24 EXTENT_BUFFER_WRITEBACK,
26 EXTENT_BUFFER_READ_ERR,
27 EXTENT_BUFFER_UNMAPPED,
28 EXTENT_BUFFER_IN_TREE,
30 EXTENT_BUFFER_WRITE_ERR,
31 EXTENT_BUFFER_NO_CHECK,
32 /* Indicate that extent buffer pages a being read */
33 EXTENT_BUFFER_READING,
36 /* these are flags for __process_pages_contig */
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),
47 * page->private values. Every page that is controlled by the extent
48 * map has page->private set to one.
50 #define EXTENT_PAGE_PRIVATE 1
53 * The extent buffer bitmap operations are done with byte granularity instead of
54 * word granularity for two reasons:
55 * 1. The bitmaps must be little-endian on disk.
56 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
57 * single word in a bitmap may straddle two pages in the extent buffer.
59 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
60 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
61 #define BITMAP_FIRST_BYTE_MASK(start) \
62 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
63 #define BITMAP_LAST_BYTE_MASK(nbits) \
64 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
69 struct extent_io_tree;
70 struct btrfs_tree_parent_check;
72 int __init extent_buffer_init_cachep(void);
73 void __cold extent_buffer_free_cachep(void);
75 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
76 struct extent_buffer {
80 struct btrfs_fs_info *fs_info;
84 struct rcu_head rcu_head;
86 /* >= 0 if eb belongs to a log tree, -1 otherwise */
89 struct rw_semaphore lock;
91 struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
92 #ifdef CONFIG_BTRFS_DEBUG
93 struct list_head leak_list;
98 * Get the correct offset inside the page of extent buffer.
100 * @eb: target extent buffer
101 * @start: offset inside the extent buffer
103 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
105 static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb,
106 unsigned long offset)
109 * For sectorsize == PAGE_SIZE case, eb->start will always be aligned
110 * to PAGE_SIZE, thus adding it won't cause any difference.
112 * For sectorsize < PAGE_SIZE, we must only read the data that belongs
113 * to the eb, thus we have to take the eb->start into consideration.
115 return offset_in_page(offset + eb->start);
118 static inline unsigned long get_eb_page_index(unsigned long offset)
121 * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough.
123 * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE,
124 * and have ensured that all tree blocks are contained in one page,
125 * thus we always get index == 0.
127 return offset >> PAGE_SHIFT;
131 * Structure to record how many bytes and which ranges are set/cleared
133 struct extent_changeset {
134 /* How many bytes are set/cleared in this operation */
138 struct ulist range_changed;
141 static inline void extent_changeset_init(struct extent_changeset *changeset)
143 changeset->bytes_changed = 0;
144 ulist_init(&changeset->range_changed);
147 static inline struct extent_changeset *extent_changeset_alloc(void)
149 struct extent_changeset *ret;
151 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
155 extent_changeset_init(ret);
159 static inline void extent_changeset_release(struct extent_changeset *changeset)
163 changeset->bytes_changed = 0;
164 ulist_release(&changeset->range_changed);
167 static inline void extent_changeset_free(struct extent_changeset *changeset)
171 extent_changeset_release(changeset);
175 struct extent_map_tree;
177 int try_release_extent_mapping(struct page *page, gfp_t mask);
178 int try_release_extent_buffer(struct page *page);
180 int btrfs_read_folio(struct file *file, struct folio *folio);
181 int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
182 struct writeback_control *wbc);
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,
190 int set_page_extent_mapped(struct page *page);
191 void clear_page_extent_mapped(struct page *page);
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,
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,
202 void free_extent_buffer(struct extent_buffer *eb);
203 void free_extent_buffer_stale(struct extent_buffer *eb);
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);
214 static inline int num_extent_pages(const struct extent_buffer *eb)
217 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
218 * sectorsize, it's just eb->len >> PAGE_SHIFT.
220 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
221 * thus have to ensure we get at least one page.
223 return (eb->len >> PAGE_SHIFT) ?: 1;
226 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
228 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
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,
236 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
237 void __user *dst, unsigned long start,
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,
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,
250 void memcpy_extent_buffer(const struct extent_buffer *dst,
251 unsigned long dst_offset, unsigned long src_offset,
253 void memmove_extent_buffer(const struct extent_buffer *dst,
254 unsigned long dst_offset, unsigned long src_offset,
256 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
258 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
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,
265 void 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 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
269 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
270 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
271 struct page *locked_page,
272 u32 bits_to_clear, unsigned long page_ops);
273 int extent_invalidate_folio(struct extent_io_tree *tree,
274 struct folio *folio, size_t offset);
275 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
276 struct extent_buffer *buf);
278 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array);
280 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
282 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
283 bool find_lock_delalloc_range(struct inode *inode,
284 struct page *locked_page, u64 *start,
287 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
290 #ifdef CONFIG_BTRFS_DEBUG
291 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
293 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)