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 extent_state;
31 struct btrfs_block_group;
32 struct btrfs_fs_info;
33 struct btrfs_inode;
34 struct btrfs_root;
35 struct btrfs_trans_handle;
36 struct btrfs_tree_parent_check;
37
38 enum {
39 EXTENT_BUFFER_UPTODATE,
40 EXTENT_BUFFER_DIRTY,
41 EXTENT_BUFFER_TREE_REF,
42 EXTENT_BUFFER_STALE,
43 EXTENT_BUFFER_WRITEBACK,
44 EXTENT_BUFFER_UNMAPPED,
45 /* write IO error */
46 EXTENT_BUFFER_WRITE_ERR,
47 /* Indicate the extent buffer is written zeroed out (for zoned) */
48 EXTENT_BUFFER_ZONED_ZEROOUT,
49 /* Indicate that extent buffer pages a being read */
50 EXTENT_BUFFER_READING,
51 };
52
53 /* these are flags for __process_pages_contig */
54 enum {
55 ENUM_BIT(PAGE_UNLOCK),
56 /* Page starts writeback, clear dirty bit and set writeback bit */
57 ENUM_BIT(PAGE_START_WRITEBACK),
58 ENUM_BIT(PAGE_END_WRITEBACK),
59 ENUM_BIT(PAGE_SET_ORDERED),
60 };
61
62 /*
63 * Folio private values. Every page that is controlled by the extent map has
64 * folio private set to this value.
65 */
66 #define EXTENT_FOLIO_PRIVATE 1
67
68 /*
69 * The extent buffer bitmap operations are done with byte granularity instead of
70 * word granularity for two reasons:
71 * 1. The bitmaps must be little-endian on disk.
72 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
73 * single word in a bitmap may straddle two pages in the extent buffer.
74 */
75 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
76 #define BYTE_MASK ((1U << BITS_PER_BYTE) - 1)
77 #define BITMAP_FIRST_BYTE_MASK(start) \
78 ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
79 #define BITMAP_LAST_BYTE_MASK(nbits) \
80 (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
81
82
83 int __init extent_buffer_init_cachep(void);
84 void __cold extent_buffer_free_cachep(void);
85
86 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
87 struct extent_buffer {
88 u64 start;
89 u32 len;
90 u32 folio_size;
91 unsigned long bflags;
92 struct btrfs_fs_info *fs_info;
93
94 /*
95 * The address where the eb can be accessed without any cross-page handling.
96 * This can be NULL if not possible.
97 */
98 void *addr;
99
100 spinlock_t refs_lock;
101 atomic_t refs;
102 int read_mirror;
103 /* >= 0 if eb belongs to a log tree, -1 otherwise */
104 s8 log_index;
105 u8 folio_shift;
106 struct rcu_head rcu_head;
107
108 struct rw_semaphore lock;
109
110 /*
111 * Pointers to all the folios of the extent buffer.
112 *
113 * For now the folio is always order 0 (aka, a single page).
114 */
115 struct folio *folios[INLINE_EXTENT_BUFFER_PAGES];
116 #ifdef CONFIG_BTRFS_DEBUG
117 struct list_head leak_list;
118 pid_t lock_owner;
119 #endif
120 };
121
122 struct btrfs_eb_write_context {
123 struct writeback_control *wbc;
124 struct extent_buffer *eb;
125 /* Block group @eb resides in. Only used for zoned mode. */
126 struct btrfs_block_group *zoned_bg;
127 };
128
offset_in_eb_folio(const struct extent_buffer * eb,u64 start)129 static inline unsigned long offset_in_eb_folio(const struct extent_buffer *eb,
130 u64 start)
131 {
132 ASSERT(eb->folio_size);
133 return start & (eb->folio_size - 1);
134 }
135
136 /*
137 * Get the correct offset inside the page of extent buffer.
138 *
139 * @eb: target extent buffer
140 * @start: offset inside the extent buffer
141 *
142 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
143 */
get_eb_offset_in_folio(const struct extent_buffer * eb,unsigned long offset)144 static inline size_t get_eb_offset_in_folio(const struct extent_buffer *eb,
145 unsigned long offset)
146 {
147 /*
148 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
149 * 1.1) One large folio covering the whole eb
150 * The eb->start is aligned to folio size, thus adding it
151 * won't cause any difference.
152 * 1.2) Several page sized folios
153 * The eb->start is aligned to folio (page) size, thus
154 * adding it won't cause any difference.
155 *
156 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
157 * In this case there would only be one page sized folio, and there
158 * may be several different extent buffers in the page/folio.
159 * We need to add eb->start to properly access the offset inside
160 * that eb.
161 */
162 return offset_in_folio(eb->folios[0], offset + eb->start);
163 }
164
get_eb_folio_index(const struct extent_buffer * eb,unsigned long offset)165 static inline unsigned long get_eb_folio_index(const struct extent_buffer *eb,
166 unsigned long offset)
167 {
168 /*
169 * 1) sectorsize == PAGE_SIZE and nodesize >= PAGE_SIZE case
170 * 1.1) One large folio covering the whole eb.
171 * the folio_shift would be large enough to always make us
172 * return 0 as index.
173 * 1.2) Several page sized folios
174 * The folio_shift would be PAGE_SHIFT, giving us the correct
175 * index.
176 *
177 * 2) sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE case
178 * The folio would only be page sized, and always give us 0 as index.
179 */
180 return offset >> eb->folio_shift;
181 }
182
183 /*
184 * Structure to record how many bytes and which ranges are set/cleared
185 */
186 struct extent_changeset {
187 /* How many bytes are set/cleared in this operation */
188 u64 bytes_changed;
189
190 /* Changed ranges */
191 struct ulist range_changed;
192 };
193
extent_changeset_init(struct extent_changeset * changeset)194 static inline void extent_changeset_init(struct extent_changeset *changeset)
195 {
196 changeset->bytes_changed = 0;
197 ulist_init(&changeset->range_changed);
198 }
199
extent_changeset_alloc(void)200 static inline struct extent_changeset *extent_changeset_alloc(void)
201 {
202 struct extent_changeset *ret;
203
204 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
205 if (!ret)
206 return NULL;
207
208 extent_changeset_init(ret);
209 return ret;
210 }
211
extent_changeset_prealloc(struct extent_changeset * changeset,gfp_t gfp_mask)212 static inline void extent_changeset_prealloc(struct extent_changeset *changeset, gfp_t gfp_mask)
213 {
214 ulist_prealloc(&changeset->range_changed, gfp_mask);
215 }
216
extent_changeset_release(struct extent_changeset * changeset)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
extent_changeset_free(struct extent_changeset * changeset)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 bool try_release_extent_mapping(struct folio *folio, gfp_t mask);
234 int try_release_extent_buffer(struct folio *folio);
235
236 int btrfs_read_folio(struct file *file, struct folio *folio);
237 void extent_write_locked_range(struct inode *inode, const struct folio *locked_folio,
238 u64 start, u64 end, struct writeback_control *wbc,
239 bool pages_dirty);
240 int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc);
241 int btree_write_cache_pages(struct address_space *mapping,
242 struct writeback_control *wbc);
243 void btrfs_btree_wait_writeback_range(struct btrfs_fs_info *fs_info, u64 start, u64 end);
244 void btrfs_readahead(struct readahead_control *rac);
245 int set_folio_extent_mapped(struct folio *folio);
246 void clear_folio_extent_mapped(struct folio *folio);
247
248 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
249 u64 start, u64 owner_root, int level);
250 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
251 u64 start);
252 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
253 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
254 u64 start);
255 void free_extent_buffer(struct extent_buffer *eb);
256 void free_extent_buffer_stale(struct extent_buffer *eb);
257 int read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num,
258 const struct btrfs_tree_parent_check *parent_check);
259 int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num,
260 const struct btrfs_tree_parent_check *parent_check);
261
wait_on_extent_buffer_writeback(struct extent_buffer * eb)262 static inline void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
263 {
264 wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
265 TASK_UNINTERRUPTIBLE);
266 }
267
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 /* Note: this can be used in for loops without caching the value in a variable. */
num_extent_pages(const struct extent_buffer * eb)273 static inline int __pure num_extent_pages(const struct extent_buffer *eb)
274 {
275 /*
276 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
277 * sectorsize, it's just eb->len >> PAGE_SHIFT.
278 *
279 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
280 * thus have to ensure we get at least one page.
281 */
282 return (eb->len >> PAGE_SHIFT) ?: 1;
283 }
284
285 /*
286 * This can only be determined at runtime by checking eb::folios[0].
287 *
288 * As we can have either one large folio covering the whole eb
289 * (either nodesize <= PAGE_SIZE, or high order folio), or multiple
290 * single-paged folios.
291 *
292 * Note: this can be used in for loops without caching the value in a variable.
293 */
num_extent_folios(const struct extent_buffer * eb)294 static inline int __pure num_extent_folios(const struct extent_buffer *eb)
295 {
296 if (!eb->folios[0])
297 return 0;
298 if (folio_order(eb->folios[0]))
299 return 1;
300 return num_extent_pages(eb);
301 }
302
extent_buffer_uptodate(const struct extent_buffer * eb)303 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
304 {
305 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
306 }
307
308 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
309 unsigned long start, unsigned long len);
310 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
311 unsigned long start,
312 unsigned long len);
313 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
314 void __user *dst, unsigned long start,
315 unsigned long len);
316 void write_extent_buffer(const struct extent_buffer *eb, const void *src,
317 unsigned long start, unsigned long len);
318
write_extent_buffer_chunk_tree_uuid(const struct extent_buffer * eb,const void * chunk_tree_uuid)319 static inline void write_extent_buffer_chunk_tree_uuid(
320 const struct extent_buffer *eb, const void *chunk_tree_uuid)
321 {
322 write_extent_buffer(eb, chunk_tree_uuid,
323 offsetof(struct btrfs_header, chunk_tree_uuid),
324 BTRFS_FSID_SIZE);
325 }
326
write_extent_buffer_fsid(const struct extent_buffer * eb,const void * fsid)327 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb,
328 const void *fsid)
329 {
330 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
331 BTRFS_FSID_SIZE);
332 }
333
334 void copy_extent_buffer_full(const struct extent_buffer *dst,
335 const struct extent_buffer *src);
336 void copy_extent_buffer(const struct extent_buffer *dst,
337 const struct extent_buffer *src,
338 unsigned long dst_offset, unsigned long src_offset,
339 unsigned long len);
340 void memcpy_extent_buffer(const struct extent_buffer *dst,
341 unsigned long dst_offset, unsigned long src_offset,
342 unsigned long len);
343 void memmove_extent_buffer(const struct extent_buffer *dst,
344 unsigned long dst_offset, unsigned long src_offset,
345 unsigned long len);
346 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
347 unsigned long len);
348 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
349 unsigned long pos);
350 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
351 unsigned long pos, unsigned long len);
352 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
353 unsigned long start, unsigned long pos,
354 unsigned long len);
355 void set_extent_buffer_dirty(struct extent_buffer *eb);
356 void set_extent_buffer_uptodate(struct extent_buffer *eb);
357 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
358 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
359 const struct folio *locked_folio,
360 struct extent_state **cached,
361 u32 bits_to_clear, unsigned long page_ops);
362 int extent_invalidate_folio(struct extent_io_tree *tree,
363 struct folio *folio, size_t offset);
364 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
365 struct extent_buffer *buf);
366
367 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array,
368 bool nofail);
369 int btrfs_alloc_folio_array(unsigned int nr_folios, struct folio **folio_array);
370
371 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
372 bool find_lock_delalloc_range(struct inode *inode,
373 struct folio *locked_folio, u64 *start,
374 u64 *end);
375 #endif
376 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
377 u64 start);
378
379 #ifdef CONFIG_BTRFS_DEBUG
380 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
381 #else
382 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
383 #endif
384
385 #endif
386