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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
14struct btrfs_trans_handle;
15
16enum {
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 /* Indicate the extent buffer is written zeroed out (for zoned) */
32 EXTENT_BUFFER_ZONED_ZEROOUT,
33 /* Indicate that extent buffer pages a being read */
34 EXTENT_BUFFER_READING,
35};
36
37/* these are flags for __process_pages_contig */
38enum {
39 ENUM_BIT(PAGE_UNLOCK),
40 /* Page starts writeback, clear dirty bit and set writeback bit */
41 ENUM_BIT(PAGE_START_WRITEBACK),
42 ENUM_BIT(PAGE_END_WRITEBACK),
43 ENUM_BIT(PAGE_SET_ORDERED),
44};
45
46/*
47 * Folio private values. Every page that is controlled by the extent map has
48 * folio private set to this value.
49 */
50#define EXTENT_FOLIO_PRIVATE 1
51
52/*
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.
58 */
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)))
65
66struct btrfs_root;
67struct btrfs_inode;
68struct btrfs_fs_info;
69struct extent_io_tree;
70struct btrfs_tree_parent_check;
71
72int __init extent_buffer_init_cachep(void);
73void __cold extent_buffer_free_cachep(void);
74
75#define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
76struct extent_buffer {
77 u64 start;
78 unsigned long len;
79 unsigned long bflags;
80 struct btrfs_fs_info *fs_info;
81
82 /*
83 * The address where the eb can be accessed without any cross-page handling.
84 * This can be NULL if not possible.
85 */
86 void *addr;
87
88 spinlock_t refs_lock;
89 atomic_t refs;
90 int read_mirror;
91 /* >= 0 if eb belongs to a log tree, -1 otherwise */
92 s8 log_index;
93 struct rcu_head rcu_head;
94
95 struct rw_semaphore lock;
96
97 /*
98 * Pointers to all the folios of the extent buffer.
99 *
100 * For now the folio is always order 0 (aka, a single page).
101 */
102 struct folio *folios[INLINE_EXTENT_BUFFER_PAGES];
103#ifdef CONFIG_BTRFS_DEBUG
104 struct list_head leak_list;
105 pid_t lock_owner;
106#endif
107};
108
109struct btrfs_eb_write_context {
110 struct writeback_control *wbc;
111 struct extent_buffer *eb;
112 /* Block group @eb resides in. Only used for zoned mode. */
113 struct btrfs_block_group *zoned_bg;
114};
115
116/*
117 * Get the correct offset inside the page of extent buffer.
118 *
119 * @eb: target extent buffer
120 * @start: offset inside the extent buffer
121 *
122 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
123 */
124static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb,
125 unsigned long offset)
126{
127 /*
128 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
129 * 1.1) One large folio covering the whole eb
130 * The eb->start is aligned to folio size, thus adding it
131 * won't cause any difference.
132 * 1.2) Several page sized folios
133 * The eb->start is aligned to folio (page) size, thus
134 * adding it won't cause any difference.
135 *
136 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
137 * In this case there would only be one page sized folio, and there
138 * may be several different extent buffers in the page/folio.
139 * We need to add eb->start to properly access the offset inside
140 * that eb.
141 */
142 return offset_in_folio(eb->folios[0], offset + eb->start);
143}
144
145static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb,
146 unsigned long offset)
147{
148 /*
149 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
150 * 1.1) One large folio covering the whole eb.
151 * the folio_shift would be large enough to always make us
152 * return 0 as index.
153 * 1.2) Several page sized folios
154 * The folio_shift() would be PAGE_SHIFT, giving us the correct
155 * index.
156 *
157 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
158 * The folio would only be page sized, and always give us 0 as index.
159 */
160 return offset >> folio_shift(eb->folios[0]);
161}
162
163/*
164 * Structure to record how many bytes and which ranges are set/cleared
165 */
166struct extent_changeset {
167 /* How many bytes are set/cleared in this operation */
168 u64 bytes_changed;
169
170 /* Changed ranges */
171 struct ulist range_changed;
172};
173
174static inline void extent_changeset_init(struct extent_changeset *changeset)
175{
176 changeset->bytes_changed = 0;
177 ulist_init(&changeset->range_changed);
178}
179
180static inline struct extent_changeset *extent_changeset_alloc(void)
181{
182 struct extent_changeset *ret;
183
184 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
185 if (!ret)
186 return NULL;
187
188 extent_changeset_init(ret);
189 return ret;
190}
191
192static inline void extent_changeset_release(struct extent_changeset *changeset)
193{
194 if (!changeset)
195 return;
196 changeset->bytes_changed = 0;
197 ulist_release(&changeset->range_changed);
198}
199
200static inline void extent_changeset_free(struct extent_changeset *changeset)
201{
202 if (!changeset)
203 return;
204 extent_changeset_release(changeset);
205 kfree(changeset);
206}
207
208struct extent_map_tree;
209
210int try_release_extent_mapping(struct page *page, gfp_t mask);
211int try_release_extent_buffer(struct page *page);
212
213int btrfs_read_folio(struct file *file, struct folio *folio);
214void extent_write_locked_range(struct inode *inode, struct page *locked_page,
215 u64 start, u64 end, struct writeback_control *wbc,
216 bool pages_dirty);
217int extent_writepages(struct address_space *mapping,
218 struct writeback_control *wbc);
219int btree_write_cache_pages(struct address_space *mapping,
220 struct writeback_control *wbc);
221void extent_readahead(struct readahead_control *rac);
222int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
223 u64 start, u64 len);
224int set_page_extent_mapped(struct page *page);
225void clear_page_extent_mapped(struct page *page);
226
227struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
228 u64 start, u64 owner_root, int level);
229struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
230 u64 start, unsigned long len);
231struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
232 u64 start);
233struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
234struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
235 u64 start);
236void free_extent_buffer(struct extent_buffer *eb);
237void free_extent_buffer_stale(struct extent_buffer *eb);
238#define WAIT_NONE 0
239#define WAIT_COMPLETE 1
240#define WAIT_PAGE_LOCK 2
241int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
242 struct btrfs_tree_parent_check *parent_check);
243void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
244void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
245 u64 bytenr, u64 owner_root, u64 gen, int level);
246void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
247
248static inline int num_extent_pages(const struct extent_buffer *eb)
249{
250 /*
251 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
252 * sectorsize, it's just eb->len >> PAGE_SHIFT.
253 *
254 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
255 * thus have to ensure we get at least one page.
256 */
257 return (eb->len >> PAGE_SHIFT) ?: 1;
258}
259
260/*
261 * This can only be determined at runtime by checking eb::folios[0].
262 *
263 * As we can have either one large folio covering the whole eb
264 * (either nodesize <= PAGE_SIZE, or high order folio), or multiple
265 * single-paged folios.
266 */
267static inline int num_extent_folios(const struct extent_buffer *eb)
268{
269 if (folio_order(eb->folios[0]))
270 return 1;
271 return num_extent_pages(eb);
272}
273
274static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
275{
276 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
277}
278
279int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
280 unsigned long start, unsigned long len);
281void read_extent_buffer(const struct extent_buffer *eb, void *dst,
282 unsigned long start,
283 unsigned long len);
284int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
285 void __user *dst, unsigned long start,
286 unsigned long len);
287void write_extent_buffer(const struct extent_buffer *eb, const void *src,
288 unsigned long start, unsigned long len);
289
290static inline void write_extent_buffer_chunk_tree_uuid(
291 const struct extent_buffer *eb, const void *chunk_tree_uuid)
292{
293 write_extent_buffer(eb, chunk_tree_uuid,
294 offsetof(struct btrfs_header, chunk_tree_uuid),
295 BTRFS_FSID_SIZE);
296}
297
298static inline void write_extent_buffer_fsid(const struct extent_buffer *eb,
299 const void *fsid)
300{
301 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
302 BTRFS_FSID_SIZE);
303}
304
305void copy_extent_buffer_full(const struct extent_buffer *dst,
306 const struct extent_buffer *src);
307void copy_extent_buffer(const struct extent_buffer *dst,
308 const struct extent_buffer *src,
309 unsigned long dst_offset, unsigned long src_offset,
310 unsigned long len);
311void memcpy_extent_buffer(const struct extent_buffer *dst,
312 unsigned long dst_offset, unsigned long src_offset,
313 unsigned long len);
314void memmove_extent_buffer(const struct extent_buffer *dst,
315 unsigned long dst_offset, unsigned long src_offset,
316 unsigned long len);
317void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
318 unsigned long len);
319int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
320 unsigned long pos);
321void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
322 unsigned long pos, unsigned long len);
323void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
324 unsigned long start, unsigned long pos,
325 unsigned long len);
326void set_extent_buffer_dirty(struct extent_buffer *eb);
327void set_extent_buffer_uptodate(struct extent_buffer *eb);
328void clear_extent_buffer_uptodate(struct extent_buffer *eb);
329void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
330void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
331 struct page *locked_page,
332 u32 bits_to_clear, unsigned long page_ops);
333int extent_invalidate_folio(struct extent_io_tree *tree,
334 struct folio *folio, size_t offset);
335void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
336 struct extent_buffer *buf);
337
338int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array,
339 gfp_t extra_gfp);
340
341#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
342bool find_lock_delalloc_range(struct inode *inode,
343 struct page *locked_page, u64 *start,
344 u64 *end);
345#endif
346struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
347 u64 start);
348
349#ifdef CONFIG_BTRFS_DEBUG
350void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
351#else
352#define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
353#endif
354
355#endif
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
20struct page;
21struct file;
22struct folio;
23struct inode;
24struct fiemap_extent_info;
25struct readahead_control;
26struct address_space;
27struct writeback_control;
28struct extent_io_tree;
29struct extent_map_tree;
30struct extent_state;
31struct btrfs_block_group;
32struct btrfs_fs_info;
33struct btrfs_inode;
34struct btrfs_root;
35struct btrfs_trans_handle;
36struct btrfs_tree_parent_check;
37
38enum {
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 */
60enum {
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
89int __init extent_buffer_init_cachep(void);
90void __cold extent_buffer_free_cachep(void);
91
92#define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
93struct 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
128struct 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
135static 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 */
150static 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
171static 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 */
192struct 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
200static inline void extent_changeset_init(struct extent_changeset *changeset)
201{
202 changeset->bytes_changed = 0;
203 ulist_init(&changeset->range_changed);
204}
205
206static 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
218static inline void extent_changeset_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask)
219{
220 ulist_prealloc(&changeset->range_changed, gfp_mask);
221}
222
223static 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
231static 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
239bool try_release_extent_mapping(struct folio *folio, gfp_t mask);
240int try_release_extent_buffer(struct folio *folio);
241
242int btrfs_read_folio(struct file *file, struct folio *folio);
243void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio,
244 u64 start, u64 end, struct writeback_control *wbc,
245 bool pages_dirty);
246int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc);
247int btree_write_cache_pages(struct address_space *mapping,
248 struct writeback_control *wbc);
249void btrfs_readahead(struct readahead_control *rac);
250int set_folio_extent_mapped(struct folio *folio);
251int set_page_extent_mapped(struct page *page);
252void clear_folio_extent_mapped(struct folio *folio);
253
254struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
255 u64 start, u64 owner_root, int level);
256struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
257 u64 start, unsigned long len);
258struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
259 u64 start);
260struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
261struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
262 u64 start);
263void free_extent_buffer(struct extent_buffer *eb);
264void free_extent_buffer_stale(struct extent_buffer *eb);
265#define WAIT_NONE 0
266#define WAIT_COMPLETE 1
267#define WAIT_PAGE_LOCK 2
268int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
269 const struct btrfs_tree_parent_check *parent_check);
270void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
271void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
272 u64 bytenr, u64 owner_root, u64 gen, int level);
273void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
274
275static 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 */
294static 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
301static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
302{
303 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
304}
305
306int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
307 unsigned long start, unsigned long len);
308void read_extent_buffer(const struct extent_buffer *eb, void *dst,
309 unsigned long start,
310 unsigned long len);
311int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
312 void __user *dst, unsigned long start,
313 unsigned long len);
314void write_extent_buffer(const struct extent_buffer *eb, const void *src,
315 unsigned long start, unsigned long len);
316
317static 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
325static 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
332void copy_extent_buffer_full(const struct extent_buffer *dst,
333 const struct extent_buffer *src);
334void 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);
338void memcpy_extent_buffer(const struct extent_buffer *dst,
339 unsigned long dst_offset, unsigned long src_offset,
340 unsigned long len);
341void memmove_extent_buffer(const struct extent_buffer *dst,
342 unsigned long dst_offset, unsigned long src_offset,
343 unsigned long len);
344void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
345 unsigned long len);
346int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
347 unsigned long pos);
348void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
349 unsigned long pos, unsigned long len);
350void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
351 unsigned long start, unsigned long pos,
352 unsigned long len);
353void set_extent_buffer_dirty(struct extent_buffer *eb);
354void set_extent_buffer_uptodate(struct extent_buffer *eb);
355void clear_extent_buffer_uptodate(struct extent_buffer *eb);
356void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
357 const struct folio *locked_folio,
358 struct extent_state **cached,
359 u32 bits_to_clear, unsigned long page_ops);
360int extent_invalidate_folio(struct extent_io_tree *tree,
361 struct folio *folio, size_t offset);
362void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
363 struct extent_buffer *buf);
364
365int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array,
366 bool nofail);
367int btrfs_alloc_folio_array(unsigned int nr_folios, struct folio **folio_array);
368
369#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
370bool find_lock_delalloc_range(struct inode *inode,
371 struct folio *locked_folio, u64 *start,
372 u64 *end);
373#endif
374struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
375 u64 start);
376
377#ifdef CONFIG_BTRFS_DEBUG
378void 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