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 };
33
34 /* these are flags for __process_pages_contig */
35 enum {
36 ENUM_BIT(PAGE_UNLOCK),
37 /* Page starts writeback, clear dirty bit and set writeback bit */
38 ENUM_BIT(PAGE_START_WRITEBACK),
39 ENUM_BIT(PAGE_END_WRITEBACK),
40 ENUM_BIT(PAGE_SET_ORDERED),
41 ENUM_BIT(PAGE_SET_ERROR),
42 ENUM_BIT(PAGE_LOCK),
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 atomic_t io_pages;
83 int read_mirror;
84 struct rcu_head rcu_head;
85 pid_t lock_owner;
86 /* >= 0 if eb belongs to a log tree, -1 otherwise */
87 s8 log_index;
88
89 struct rw_semaphore lock;
90
91 struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
92 struct list_head release_list;
93 #ifdef CONFIG_BTRFS_DEBUG
94 struct list_head leak_list;
95 #endif
96 };
97
98 /*
99 * Get the correct offset inside the page of extent buffer.
100 *
101 * @eb: target extent buffer
102 * @start: offset inside the extent buffer
103 *
104 * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
105 */
get_eb_offset_in_page(const struct extent_buffer * eb,unsigned long offset)106 static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb,
107 unsigned long offset)
108 {
109 /*
110 * For sectorsize == PAGE_SIZE case, eb->start will always be aligned
111 * to PAGE_SIZE, thus adding it won't cause any difference.
112 *
113 * For sectorsize < PAGE_SIZE, we must only read the data that belongs
114 * to the eb, thus we have to take the eb->start into consideration.
115 */
116 return offset_in_page(offset + eb->start);
117 }
118
get_eb_page_index(unsigned long offset)119 static inline unsigned long get_eb_page_index(unsigned long offset)
120 {
121 /*
122 * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough.
123 *
124 * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE,
125 * and have ensured that all tree blocks are contained in one page,
126 * thus we always get index == 0.
127 */
128 return offset >> PAGE_SHIFT;
129 }
130
131 /*
132 * Structure to record how many bytes and which ranges are set/cleared
133 */
134 struct extent_changeset {
135 /* How many bytes are set/cleared in this operation */
136 u64 bytes_changed;
137
138 /* Changed ranges */
139 struct ulist range_changed;
140 };
141
extent_changeset_init(struct extent_changeset * changeset)142 static inline void extent_changeset_init(struct extent_changeset *changeset)
143 {
144 changeset->bytes_changed = 0;
145 ulist_init(&changeset->range_changed);
146 }
147
extent_changeset_alloc(void)148 static inline struct extent_changeset *extent_changeset_alloc(void)
149 {
150 struct extent_changeset *ret;
151
152 ret = kmalloc(sizeof(*ret), GFP_KERNEL);
153 if (!ret)
154 return NULL;
155
156 extent_changeset_init(ret);
157 return ret;
158 }
159
extent_changeset_release(struct extent_changeset * changeset)160 static inline void extent_changeset_release(struct extent_changeset *changeset)
161 {
162 if (!changeset)
163 return;
164 changeset->bytes_changed = 0;
165 ulist_release(&changeset->range_changed);
166 }
167
extent_changeset_free(struct extent_changeset * changeset)168 static inline void extent_changeset_free(struct extent_changeset *changeset)
169 {
170 if (!changeset)
171 return;
172 extent_changeset_release(changeset);
173 kfree(changeset);
174 }
175
176 struct extent_map_tree;
177
178 int try_release_extent_mapping(struct page *page, gfp_t mask);
179 int try_release_extent_buffer(struct page *page);
180
181 int btrfs_read_folio(struct file *file, struct folio *folio);
182 int extent_write_locked_range(struct inode *inode, u64 start, u64 end);
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,
189 u64 start, u64 len);
190 int set_page_extent_mapped(struct page *page);
191 void clear_page_extent_mapped(struct page *page);
192
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,
198 u64 start);
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,
201 u64 start);
202 void free_extent_buffer(struct extent_buffer *eb);
203 void free_extent_buffer_stale(struct extent_buffer *eb);
204 #define WAIT_NONE 0
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);
213
num_extent_pages(const struct extent_buffer * eb)214 static inline int num_extent_pages(const struct extent_buffer *eb)
215 {
216 /*
217 * For sectorsize == PAGE_SIZE case, since nodesize is always aligned to
218 * sectorsize, it's just eb->len >> PAGE_SHIFT.
219 *
220 * For sectorsize < PAGE_SIZE case, we could have nodesize < PAGE_SIZE,
221 * thus have to ensure we get at least one page.
222 */
223 return (eb->len >> PAGE_SHIFT) ?: 1;
224 }
225
extent_buffer_uptodate(const struct extent_buffer * eb)226 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
227 {
228 return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
229 }
230
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,
234 unsigned long start,
235 unsigned long len);
236 int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
237 void __user *dst, unsigned long start,
238 unsigned long len);
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,
241 const void *src);
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,
249 unsigned long len);
250 void memcpy_extent_buffer(const struct extent_buffer *dst,
251 unsigned long dst_offset, unsigned long src_offset,
252 unsigned long len);
253 void memmove_extent_buffer(const struct extent_buffer *dst,
254 unsigned long dst_offset, unsigned long src_offset,
255 unsigned long len);
256 void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
257 unsigned long len);
258 int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
259 unsigned long pos);
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,
264 unsigned long len);
265 bool 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 int extent_buffer_under_io(const struct extent_buffer *eb);
269 void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
270 void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
271 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
272 struct page *locked_page,
273 u32 bits_to_clear, unsigned long page_ops);
274 int extent_invalidate_folio(struct extent_io_tree *tree,
275 struct folio *folio, size_t offset);
276 void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
277 struct extent_buffer *buf);
278
279 int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array);
280
281 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
282
283 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
284 bool find_lock_delalloc_range(struct inode *inode,
285 struct page *locked_page, u64 *start,
286 u64 *end);
287 #endif
288 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
289 u64 start);
290
291 #ifdef CONFIG_BTRFS_DEBUG
292 void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
293 #else
294 #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
295 #endif
296
297 #endif
298