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 /* Indicate that extent buffer pages a being read */
33 EXTENT_BUFFER_READING,
34 };
35
36 /* these are flags for __process_pages_contig */
37 enum {
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),
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 int read_mirror;
83 struct rcu_head rcu_head;
84 pid_t lock_owner;
85 /* >= 0 if eb belongs to a log tree, -1 otherwise */
86 s8 log_index;
87
88 struct rw_semaphore lock;
89
90 struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
91 #ifdef CONFIG_BTRFS_DEBUG
92 struct list_head leak_list;
93 #endif
94 };
95
96 struct btrfs_eb_write_context {
97 struct writeback_control *wbc;
98 struct extent_buffer *eb;
99 /* Block group @eb resides in. Only used for zoned mode. */
100 struct btrfs_block_group *zoned_bg;
101 };
102
103 /*
104 * Get the correct offset inside the page of extent buffer.
105 *
106 * @eb: target extent buffer
107 * @start: offset inside the extent buffer
108 *
109 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
110 */
get_eb_offset_in_page(const struct extent_buffer * eb,unsigned long offset)111 static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb,
112 unsigned long offset)
113 {
114 /*
115 * For sectorsize == PAGE_SIZE case, eb->start will always be aligned
116 * to PAGE_SIZE, thus adding it won't cause any difference.
117 *
118 * For sectorsize < PAGE_SIZE, we must only read the data that belongs
119 * to the eb, thus we have to take the eb->start into consideration.
120 */
121 return offset_in_page(offset + eb->start);
122 }
123
get_eb_page_index(unsigned long offset)124 static inline unsigned long get_eb_page_index(unsigned long offset)
125 {
126 /*
127 * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough.
128 *
129 * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE,
130 * and have ensured that all tree blocks are contained in one page,
131 * thus we always get index == 0.
132 */
133 return offset >> PAGE_SHIFT;
134 }
135
136 /*
137 * Structure to record how many bytes and which ranges are set/cleared
138 */
139 struct extent_changeset {
140 /* How many bytes are set/cleared in this operation */
141 u64 bytes_changed;
142
143 /* Changed ranges */
144 struct ulist range_changed;
145 };
146
extent_changeset_init(struct extent_changeset * changeset)147 static inline void extent_changeset_init(struct extent_changeset *changeset)
148 {
149 changeset->bytes_changed = 0;
150 ulist_init(&changeset->range_changed);
151 }
152
extent_changeset_alloc(void)153 static inline struct extent_changeset *extent_changeset_alloc(void)
154 {
155 struct extent_changeset *ret;
156
157 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
158 if (!ret)
159 return NULL;
160
161 extent_changeset_init(ret);
162 return ret;
163 }
164
extent_changeset_release(struct extent_changeset * changeset)165 static inline void extent_changeset_release(struct extent_changeset *changeset)
166 {
167 if (!changeset)
168 return;
169 changeset->bytes_changed = 0;
170 ulist_release(&changeset->range_changed);
171 }
172
extent_changeset_free(struct extent_changeset * changeset)173 static inline void extent_changeset_free(struct extent_changeset *changeset)
174 {
175 if (!changeset)
176 return;
177 extent_changeset_release(changeset);
178 kfree(changeset);
179 }
180
181 struct extent_map_tree;
182
183 int try_release_extent_mapping(struct page *page, gfp_t mask);
184 int try_release_extent_buffer(struct page *page);
185
186 int btrfs_read_folio(struct file *file, struct folio *folio);
187 void extent_write_locked_range(struct inode *inode, struct page *locked_page,
188 u64 start, u64 end, struct writeback_control *wbc,
189 bool pages_dirty);
190 int extent_writepages(struct address_space *mapping,
191 struct writeback_control *wbc);
192 int btree_write_cache_pages(struct address_space *mapping,
193 struct writeback_control *wbc);
194 void extent_readahead(struct readahead_control *rac);
195 int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
196 u64 start, u64 len);
197 int set_page_extent_mapped(struct page *page);
198 void clear_page_extent_mapped(struct page *page);
199
200 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
201 u64 start, u64 owner_root, int level);
202 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
203 u64 start, unsigned long len);
204 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
205 u64 start);
206 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
207 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
208 u64 start);
209 void free_extent_buffer(struct extent_buffer *eb);
210 void free_extent_buffer_stale(struct extent_buffer *eb);
211 #define WAIT_NONE 0
212 #define WAIT_COMPLETE 1
213 #define WAIT_PAGE_LOCK 2
214 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
215 struct btrfs_tree_parent_check *parent_check);
216 void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
217 void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
218 u64 bytenr, u64 owner_root, u64 gen, int level);
219 void btrfs_readahead_node_child(struct extent_buffer *node, int slot);
220
num_extent_pages(const struct extent_buffer * eb)221 static inline int num_extent_pages(const struct extent_buffer *eb)
222 {
223 /*
224 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
225 * sectorsize, it's just eb->len >> PAGE_SHIFT.
226 *
227 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
228 * thus have to ensure we get at least one page.
229 */
230 return (eb->len >> PAGE_SHIFT) ?: 1;
231 }
232
extent_buffer_uptodate(const struct extent_buffer * eb)233 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
234 {
235 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
236 }
237
238 int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
239 unsigned long start, unsigned long len);
240 void read_extent_buffer(const struct extent_buffer *eb, void *dst,
241 unsigned long start,
242 unsigned long len);
243 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
244 void __user *dst, unsigned long start,
245 unsigned long len);
246 void write_extent_buffer(const struct extent_buffer *eb, const void *src,
247 unsigned long start, unsigned long len);
248
write_extent_buffer_chunk_tree_uuid(const struct extent_buffer * eb,const void * chunk_tree_uuid)249 static inline void write_extent_buffer_chunk_tree_uuid(
250 const struct extent_buffer *eb, const void *chunk_tree_uuid)
251 {
252 write_extent_buffer(eb, chunk_tree_uuid,
253 offsetof(struct btrfs_header, chunk_tree_uuid),
254 BTRFS_FSID_SIZE);
255 }
256
write_extent_buffer_fsid(const struct extent_buffer * eb,const void * fsid)257 static inline void write_extent_buffer_fsid(const struct extent_buffer *eb,
258 const void *fsid)
259 {
260 write_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid),
261 BTRFS_FSID_SIZE);
262 }
263
264 void copy_extent_buffer_full(const struct extent_buffer *dst,
265 const struct extent_buffer *src);
266 void copy_extent_buffer(const struct extent_buffer *dst,
267 const struct extent_buffer *src,
268 unsigned long dst_offset, unsigned long src_offset,
269 unsigned long len);
270 void memcpy_extent_buffer(const struct extent_buffer *dst,
271 unsigned long dst_offset, unsigned long src_offset,
272 unsigned long len);
273 void memmove_extent_buffer(const struct extent_buffer *dst,
274 unsigned long dst_offset, unsigned long src_offset,
275 unsigned long len);
276 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
277 unsigned long len);
278 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
279 unsigned long pos);
280 void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
281 unsigned long pos, unsigned long len);
282 void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
283 unsigned long start, unsigned long pos,
284 unsigned long len);
285 void set_extent_buffer_dirty(struct extent_buffer *eb);
286 void set_extent_buffer_uptodate(struct extent_buffer *eb);
287 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
288 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
289 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
290 struct page *locked_page,
291 u32 bits_to_clear, unsigned long page_ops);
292 int extent_invalidate_folio(struct extent_io_tree *tree,
293 struct folio *folio, size_t offset);
294 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
295 struct extent_buffer *buf);
296
297 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array);
298
299 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
300 bool find_lock_delalloc_range(struct inode *inode,
301 struct page *locked_page, u64 *start,
302 u64 *end);
303 #endif
304 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
305 u64 start);
306
307 #ifdef CONFIG_BTRFS_DEBUG
308 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
309 #else
310 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
311 #endif
312
313 #endif
314