Line data Source code
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 : ENUM_BIT(PAGE_LOCK),
44 : };
45 :
46 : /*
47 : * page->private values. Every page that is controlled by the extent
48 : * map has page->private set to one.
49 : */
50 : #define EXTENT_PAGE_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 : spinlock_t refs_lock;
82 : atomic_t refs;
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 : #ifdef CONFIG_BTRFS_DEBUG
93 : struct list_head leak_list;
94 : #endif
95 : };
96 :
97 : /*
98 : * Get the correct offset inside the page of extent buffer.
99 : *
100 : * @eb: target extent buffer
101 : * @start: offset inside the extent buffer
102 : *
103 : * Will handle both sectorsize == PAGE_SIZE and sectorsize < PAGE_SIZE cases.
104 : */
105 : static inline size_t get_eb_offset_in_page(const struct extent_buffer *eb,
106 : unsigned long offset)
107 : {
108 : /*
109 : * For sectorsize == PAGE_SIZE case, eb->start will always be aligned
110 : * to PAGE_SIZE, thus adding it won't cause any difference.
111 : *
112 : * For sectorsize < PAGE_SIZE, we must only read the data that belongs
113 : * to the eb, thus we have to take the eb->start into consideration.
114 : */
115 0 : return offset_in_page(offset + eb->start);
116 : }
117 :
118 : static inline unsigned long get_eb_page_index(unsigned long offset)
119 : {
120 : /*
121 : * For sectorsize == PAGE_SIZE case, plain >> PAGE_SHIFT is enough.
122 : *
123 : * For sectorsize < PAGE_SIZE case, we only support 64K PAGE_SIZE,
124 : * and have ensured that all tree blocks are contained in one page,
125 : * thus we always get index == 0.
126 : */
127 0 : return offset >> PAGE_SHIFT;
128 : }
129 :
130 : /*
131 : * Structure to record how many bytes and which ranges are set/cleared
132 : */
133 : struct extent_changeset {
134 : /* How many bytes are set/cleared in this operation */
135 : u64 bytes_changed;
136 :
137 : /* Changed ranges */
138 : struct ulist range_changed;
139 : };
140 :
141 : static inline void extent_changeset_init(struct extent_changeset *changeset)
142 : {
143 0 : changeset->bytes_changed = 0;
144 0 : ulist_init(&changeset->range_changed);
145 : }
146 :
147 0 : static inline struct extent_changeset *extent_changeset_alloc(void)
148 : {
149 0 : struct extent_changeset *ret;
150 :
151 0 : ret = kmalloc(sizeof(*ret), GFP_KERNEL);
152 0 : if (!ret)
153 : return NULL;
154 :
155 0 : extent_changeset_init(ret);
156 0 : return ret;
157 : }
158 :
159 : static inline void extent_changeset_release(struct extent_changeset *changeset)
160 : {
161 0 : if (!changeset)
162 : return;
163 0 : changeset->bytes_changed = 0;
164 0 : ulist_release(&changeset->range_changed);
165 : }
166 :
167 0 : static inline void extent_changeset_free(struct extent_changeset *changeset)
168 : {
169 0 : if (!changeset)
170 : return;
171 0 : extent_changeset_release(changeset);
172 0 : kfree(changeset);
173 : }
174 :
175 : struct extent_map_tree;
176 :
177 : int try_release_extent_mapping(struct page *page, gfp_t mask);
178 : int try_release_extent_buffer(struct page *page);
179 :
180 : int btrfs_read_folio(struct file *file, struct folio *folio);
181 : int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
182 : struct writeback_control *wbc);
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 :
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 0 : return (eb->len >> PAGE_SHIFT) ?: 1;
224 : }
225 :
226 : static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
227 : {
228 0 : 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 : void 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 : void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
269 : void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
270 : void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
271 : struct page *locked_page,
272 : u32 bits_to_clear, unsigned long page_ops);
273 : int extent_invalidate_folio(struct extent_io_tree *tree,
274 : struct folio *folio, size_t offset);
275 : void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
276 : struct extent_buffer *buf);
277 :
278 : int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array);
279 :
280 : void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
281 :
282 : #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
283 : bool find_lock_delalloc_range(struct inode *inode,
284 : struct page *locked_page, u64 *start,
285 : u64 *end);
286 : #endif
287 : struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
288 : u64 start);
289 :
290 : #ifdef CONFIG_BTRFS_DEBUG
291 : void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info);
292 : #else
293 : #define btrfs_extent_buffer_leak_debug_check(fs_info) do {} while (0)
294 : #endif
295 :
296 : #endif
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