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 /* 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 */
38 enum {
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
66 struct btrfs_root;
67 struct btrfs_inode;
68 struct btrfs_fs_info;
69 struct extent_io_tree;
70 struct btrfs_tree_parent_check;
71
72 int __init extent_buffer_init_cachep(void);
73 void __cold extent_buffer_free_cachep(void);
74
75 #define INLINE_EXTENT_BUFFER_PAGES (BTRFS_MAX_METADATA_BLOCKSIZE / PAGE_SIZE)
76 struct 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
109 struct 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 */
get_eb_offset_in_folio(const struct extent_buffer * eb,unsigned long offset)124 static 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
get_eb_folio_index(const struct extent_buffer * eb,unsigned long offset)145 static 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 */
166 struct 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
extent_changeset_init(struct extent_changeset * changeset)174 static inline void extent_changeset_init(struct extent_changeset *changeset)
175 {
176 changeset->bytes_changed = 0;
177 ulist_init(&changeset->range_changed);
178 }
179
extent_changeset_alloc(void)180 static 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
extent_changeset_release(struct extent_changeset * changeset)192 static 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
extent_changeset_free(struct extent_changeset * changeset)200 static 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
208 struct extent_map_tree;
209
210 int try_release_extent_mapping(struct page *page, gfp_t mask);
211 int try_release_extent_buffer(struct page *page);
212
213 int btrfs_read_folio(struct file *file, struct folio *folio);
214 void extent_write_locked_range(struct inode *inode, struct page *locked_page,
215 u64 start, u64 end, struct writeback_control *wbc,
216 bool pages_dirty);
217 int extent_writepages(struct address_space *mapping,
218 struct writeback_control *wbc);
219 int btree_write_cache_pages(struct address_space *mapping,
220 struct writeback_control *wbc);
221 void extent_readahead(struct readahead_control *rac);
222 int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
223 u64 start, u64 len);
224 int set_page_extent_mapped(struct page *page);
225 void clear_page_extent_mapped(struct page *page);
226
227 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
228 u64 start, u64 owner_root, int level);
229 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
230 u64 start, unsigned long len);
231 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
232 u64 start);
233 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
234 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
235 u64 start);
236 void free_extent_buffer(struct extent_buffer *eb);
237 void free_extent_buffer_stale(struct extent_buffer *eb);
238 #define WAIT_NONE 0
239 #define WAIT_COMPLETE 1
240 #define WAIT_PAGE_LOCK 2
241 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
242 struct btrfs_tree_parent_check *parent_check);
243 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
244 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
245 u64 bytenr, u64 owner_root, u64 gen, int level);
246 void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
247
num_extent_pages(const struct extent_buffer * eb)248 static 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 */
num_extent_folios(const struct extent_buffer * eb)267 static 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
extent_buffer_uptodate(const struct extent_buffer * eb)274 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
275 {
276 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
277 }
278
279 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
280 unsigned long start, unsigned long len);
281 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
282 unsigned long start,
283 unsigned long len);
284 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
285 void __user *dst, unsigned long start,
286 unsigned long len);
287 void write_extent_buffer(const struct extent_buffer *eb, const void *src,
288 unsigned long start, unsigned long len);
289
write_extent_buffer_chunk_tree_uuid(const struct extent_buffer * eb,const void * chunk_tree_uuid)290 static 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
write_extent_buffer_fsid(const struct extent_buffer * eb,const void * fsid)298 static 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
305 void copy_extent_buffer_full(const struct extent_buffer *dst,
306 const struct extent_buffer *src);
307 void 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);
311 void memcpy_extent_buffer(const struct extent_buffer *dst,
312 unsigned long dst_offset, unsigned long src_offset,
313 unsigned long len);
314 void memmove_extent_buffer(const struct extent_buffer *dst,
315 unsigned long dst_offset, unsigned long src_offset,
316 unsigned long len);
317 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
318 unsigned long len);
319 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
320 unsigned long pos);
321 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
322 unsigned long pos, unsigned long len);
323 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
324 unsigned long start, unsigned long pos,
325 unsigned long len);
326 void set_extent_buffer_dirty(struct extent_buffer *eb);
327 void set_extent_buffer_uptodate(struct extent_buffer *eb);
328 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
329 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
330 void 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);
333 int extent_invalidate_folio(struct extent_io_tree *tree,
334 struct folio *folio, size_t offset);
335 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
336 struct extent_buffer *buf);
337
338 int 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
342 bool find_lock_delalloc_range(struct inode *inode,
343 struct page *locked_page, u64 *start,
344 u64 *end);
345 #endif
346 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
347 u64 start);
348
349 #ifdef CONFIG_BTRFS_DEBUG
350 void 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
356