1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
4 | * All Rights Reserved. |
5 | */ |
6 | #ifndef __XFS_BUF_H__ |
7 | #define __XFS_BUF_H__ |
8 | |
9 | #include <linux/list.h> |
10 | #include <linux/types.h> |
11 | #include <linux/spinlock.h> |
12 | #include <linux/mm.h> |
13 | #include <linux/fs.h> |
14 | #include <linux/dax.h> |
15 | #include <linux/uio.h> |
16 | #include <linux/list_lru.h> |
17 | |
18 | extern struct kmem_cache *xfs_buf_cache; |
19 | |
20 | /* |
21 | * Base types |
22 | */ |
23 | struct xfs_buf; |
24 | |
25 | #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) |
26 | |
27 | #define XBF_READ (1u << 0) /* buffer intended for reading from device */ |
28 | #define XBF_WRITE (1u << 1) /* buffer intended for writing to device */ |
29 | #define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */ |
30 | #define XBF_NO_IOACCT (1u << 3) /* bypass I/O accounting (non-LRU bufs) */ |
31 | #define XBF_ASYNC (1u << 4) /* initiator will not wait for completion */ |
32 | #define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */ |
33 | #define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */ |
34 | #define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */ |
35 | |
36 | /* buffer type flags for write callbacks */ |
37 | #define _XBF_INODES (1u << 16)/* inode buffer */ |
38 | #define _XBF_DQUOTS (1u << 17)/* dquot buffer */ |
39 | #define _XBF_LOGRECOVERY (1u << 18)/* log recovery buffer */ |
40 | |
41 | /* flags used only internally */ |
42 | #define _XBF_PAGES (1u << 20)/* backed by refcounted pages */ |
43 | #define _XBF_KMEM (1u << 21)/* backed by heap memory */ |
44 | #define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */ |
45 | |
46 | /* flags used only as arguments to access routines */ |
47 | /* |
48 | * Online fsck is scanning the buffer cache for live buffers. Do not warn |
49 | * about length mismatches during lookups and do not return stale buffers. |
50 | */ |
51 | #define XBF_LIVESCAN (1u << 28) |
52 | #define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */ |
53 | #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */ |
54 | #define XBF_UNMAPPED (1u << 31)/* do not map the buffer */ |
55 | |
56 | |
57 | typedef unsigned int xfs_buf_flags_t; |
58 | |
59 | #define XFS_BUF_FLAGS \ |
60 | { XBF_READ, "READ" }, \ |
61 | { XBF_WRITE, "WRITE" }, \ |
62 | { XBF_READ_AHEAD, "READ_AHEAD" }, \ |
63 | { XBF_NO_IOACCT, "NO_IOACCT" }, \ |
64 | { XBF_ASYNC, "ASYNC" }, \ |
65 | { XBF_DONE, "DONE" }, \ |
66 | { XBF_STALE, "STALE" }, \ |
67 | { XBF_WRITE_FAIL, "WRITE_FAIL" }, \ |
68 | { _XBF_INODES, "INODES" }, \ |
69 | { _XBF_DQUOTS, "DQUOTS" }, \ |
70 | { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \ |
71 | { _XBF_PAGES, "PAGES" }, \ |
72 | { _XBF_KMEM, "KMEM" }, \ |
73 | { _XBF_DELWRI_Q, "DELWRI_Q" }, \ |
74 | /* The following interface flags should never be set */ \ |
75 | { XBF_LIVESCAN, "LIVESCAN" }, \ |
76 | { XBF_INCORE, "INCORE" }, \ |
77 | { XBF_TRYLOCK, "TRYLOCK" }, \ |
78 | { XBF_UNMAPPED, "UNMAPPED" } |
79 | |
80 | /* |
81 | * Internal state flags. |
82 | */ |
83 | #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ |
84 | #define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */ |
85 | |
86 | /* |
87 | * The xfs_buftarg contains 2 notions of "sector size" - |
88 | * |
89 | * 1) The metadata sector size, which is the minimum unit and |
90 | * alignment of IO which will be performed by metadata operations. |
91 | * 2) The device logical sector size |
92 | * |
93 | * The first is specified at mkfs time, and is stored on-disk in the |
94 | * superblock's sb_sectsize. |
95 | * |
96 | * The latter is derived from the underlying device, and controls direct IO |
97 | * alignment constraints. |
98 | */ |
99 | typedef struct xfs_buftarg { |
100 | dev_t bt_dev; |
101 | struct bdev_handle *bt_bdev_handle; |
102 | struct block_device *bt_bdev; |
103 | struct dax_device *bt_daxdev; |
104 | u64 bt_dax_part_off; |
105 | struct xfs_mount *bt_mount; |
106 | unsigned int bt_meta_sectorsize; |
107 | size_t bt_meta_sectormask; |
108 | size_t bt_logical_sectorsize; |
109 | size_t bt_logical_sectormask; |
110 | |
111 | /* LRU control structures */ |
112 | struct shrinker *bt_shrinker; |
113 | struct list_lru bt_lru; |
114 | |
115 | struct percpu_counter bt_io_count; |
116 | struct ratelimit_state bt_ioerror_rl; |
117 | } xfs_buftarg_t; |
118 | |
119 | #define XB_PAGES 2 |
120 | |
121 | struct xfs_buf_map { |
122 | xfs_daddr_t bm_bn; /* block number for I/O */ |
123 | int bm_len; /* size of I/O */ |
124 | unsigned int bm_flags; |
125 | }; |
126 | |
127 | /* |
128 | * Online fsck is scanning the buffer cache for live buffers. Do not warn |
129 | * about length mismatches during lookups and do not return stale buffers. |
130 | */ |
131 | #define XBM_LIVESCAN (1U << 0) |
132 | |
133 | #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ |
134 | struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; |
135 | |
136 | struct xfs_buf_ops { |
137 | char *name; |
138 | union { |
139 | __be32 magic[2]; /* v4 and v5 on disk magic values */ |
140 | __be16 magic16[2]; /* v4 and v5 on disk magic values */ |
141 | }; |
142 | void (*verify_read)(struct xfs_buf *); |
143 | void (*verify_write)(struct xfs_buf *); |
144 | xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp); |
145 | }; |
146 | |
147 | struct xfs_buf { |
148 | /* |
149 | * first cacheline holds all the fields needed for an uncontended cache |
150 | * hit to be fully processed. The semaphore straddles the cacheline |
151 | * boundary, but the counter and lock sits on the first cacheline, |
152 | * which is the only bit that is touched if we hit the semaphore |
153 | * fast-path on locking. |
154 | */ |
155 | struct rhash_head b_rhash_head; /* pag buffer hash node */ |
156 | |
157 | xfs_daddr_t b_rhash_key; /* buffer cache index */ |
158 | int b_length; /* size of buffer in BBs */ |
159 | atomic_t b_hold; /* reference count */ |
160 | atomic_t b_lru_ref; /* lru reclaim ref count */ |
161 | xfs_buf_flags_t b_flags; /* status flags */ |
162 | struct semaphore b_sema; /* semaphore for lockables */ |
163 | |
164 | /* |
165 | * concurrent access to b_lru and b_lru_flags are protected by |
166 | * bt_lru_lock and not by b_sema |
167 | */ |
168 | struct list_head b_lru; /* lru list */ |
169 | spinlock_t b_lock; /* internal state lock */ |
170 | unsigned int b_state; /* internal state flags */ |
171 | int b_io_error; /* internal IO error state */ |
172 | wait_queue_head_t b_waiters; /* unpin waiters */ |
173 | struct list_head b_list; |
174 | struct xfs_perag *b_pag; /* contains rbtree root */ |
175 | struct xfs_mount *b_mount; |
176 | struct xfs_buftarg *b_target; /* buffer target (device) */ |
177 | void *b_addr; /* virtual address of buffer */ |
178 | struct work_struct b_ioend_work; |
179 | struct completion b_iowait; /* queue for I/O waiters */ |
180 | struct xfs_buf_log_item *b_log_item; |
181 | struct list_head b_li_list; /* Log items list head */ |
182 | struct xfs_trans *b_transp; |
183 | struct page **b_pages; /* array of page pointers */ |
184 | struct page *b_page_array[XB_PAGES]; /* inline pages */ |
185 | struct xfs_buf_map *b_maps; /* compound buffer map */ |
186 | struct xfs_buf_map __b_map; /* inline compound buffer map */ |
187 | int b_map_count; |
188 | atomic_t b_pin_count; /* pin count */ |
189 | atomic_t b_io_remaining; /* #outstanding I/O requests */ |
190 | unsigned int b_page_count; /* size of page array */ |
191 | unsigned int b_offset; /* page offset of b_addr, |
192 | only for _XBF_KMEM buffers */ |
193 | int b_error; /* error code on I/O */ |
194 | |
195 | /* |
196 | * async write failure retry count. Initialised to zero on the first |
197 | * failure, then when it exceeds the maximum configured without a |
198 | * success the write is considered to be failed permanently and the |
199 | * iodone handler will take appropriate action. |
200 | * |
201 | * For retry timeouts, we record the jiffie of the first failure. This |
202 | * means that we can change the retry timeout for buffers already under |
203 | * I/O and thus avoid getting stuck in a retry loop with a long timeout. |
204 | * |
205 | * last_error is used to ensure that we are getting repeated errors, not |
206 | * different errors. e.g. a block device might change ENOSPC to EIO when |
207 | * a failure timeout occurs, so we want to re-initialise the error |
208 | * retry behaviour appropriately when that happens. |
209 | */ |
210 | int b_retries; |
211 | unsigned long b_first_retry_time; /* in jiffies */ |
212 | int b_last_error; |
213 | |
214 | const struct xfs_buf_ops *b_ops; |
215 | struct rcu_head b_rcu; |
216 | }; |
217 | |
218 | /* Finding and Reading Buffers */ |
219 | int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map, |
220 | int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp); |
221 | int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map, |
222 | int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, |
223 | const struct xfs_buf_ops *ops, xfs_failaddr_t fa); |
224 | void xfs_buf_readahead_map(struct xfs_buftarg *target, |
225 | struct xfs_buf_map *map, int nmaps, |
226 | const struct xfs_buf_ops *ops); |
227 | |
228 | static inline int |
229 | xfs_buf_incore( |
230 | struct xfs_buftarg *target, |
231 | xfs_daddr_t blkno, |
232 | size_t numblks, |
233 | xfs_buf_flags_t flags, |
234 | struct xfs_buf **bpp) |
235 | { |
236 | DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
237 | |
238 | return xfs_buf_get_map(target, map: &map, nmaps: 1, XBF_INCORE | flags, bpp); |
239 | } |
240 | |
241 | static inline int |
242 | xfs_buf_get( |
243 | struct xfs_buftarg *target, |
244 | xfs_daddr_t blkno, |
245 | size_t numblks, |
246 | struct xfs_buf **bpp) |
247 | { |
248 | DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
249 | |
250 | return xfs_buf_get_map(target, map: &map, nmaps: 1, flags: 0, bpp); |
251 | } |
252 | |
253 | static inline int |
254 | xfs_buf_read( |
255 | struct xfs_buftarg *target, |
256 | xfs_daddr_t blkno, |
257 | size_t numblks, |
258 | xfs_buf_flags_t flags, |
259 | struct xfs_buf **bpp, |
260 | const struct xfs_buf_ops *ops) |
261 | { |
262 | DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
263 | |
264 | return xfs_buf_read_map(target, map: &map, nmaps: 1, flags, bpp, ops, |
265 | fa: __builtin_return_address(0)); |
266 | } |
267 | |
268 | static inline void |
269 | xfs_buf_readahead( |
270 | struct xfs_buftarg *target, |
271 | xfs_daddr_t blkno, |
272 | size_t numblks, |
273 | const struct xfs_buf_ops *ops) |
274 | { |
275 | DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
276 | return xfs_buf_readahead_map(target, map: &map, nmaps: 1, ops); |
277 | } |
278 | |
279 | int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, |
280 | xfs_buf_flags_t flags, struct xfs_buf **bpp); |
281 | int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, |
282 | size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp, |
283 | const struct xfs_buf_ops *ops); |
284 | int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); |
285 | void xfs_buf_hold(struct xfs_buf *bp); |
286 | |
287 | /* Releasing Buffers */ |
288 | extern void xfs_buf_rele(struct xfs_buf *); |
289 | |
290 | /* Locking and Unlocking Buffers */ |
291 | extern int xfs_buf_trylock(struct xfs_buf *); |
292 | extern void xfs_buf_lock(struct xfs_buf *); |
293 | extern void xfs_buf_unlock(struct xfs_buf *); |
294 | #define xfs_buf_islocked(bp) \ |
295 | ((bp)->b_sema.count <= 0) |
296 | |
297 | static inline void xfs_buf_relse(struct xfs_buf *bp) |
298 | { |
299 | xfs_buf_unlock(bp); |
300 | xfs_buf_rele(bp); |
301 | } |
302 | |
303 | /* Buffer Read and Write Routines */ |
304 | extern int xfs_bwrite(struct xfs_buf *bp); |
305 | |
306 | extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error, |
307 | xfs_failaddr_t failaddr); |
308 | #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address) |
309 | extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa); |
310 | void xfs_buf_ioend_fail(struct xfs_buf *); |
311 | void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize); |
312 | void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa); |
313 | #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address) |
314 | |
315 | /* Buffer Utility Routines */ |
316 | extern void *xfs_buf_offset(struct xfs_buf *, size_t); |
317 | extern void xfs_buf_stale(struct xfs_buf *bp); |
318 | |
319 | /* Delayed Write Buffer Routines */ |
320 | extern void xfs_buf_delwri_cancel(struct list_head *); |
321 | extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); |
322 | extern int xfs_buf_delwri_submit(struct list_head *); |
323 | extern int xfs_buf_delwri_submit_nowait(struct list_head *); |
324 | extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *); |
325 | |
326 | static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp) |
327 | { |
328 | return bp->b_maps[0].bm_bn; |
329 | } |
330 | |
331 | void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref); |
332 | |
333 | /* |
334 | * If the buffer is already on the LRU, do nothing. Otherwise set the buffer |
335 | * up with a reference count of 0 so it will be tossed from the cache when |
336 | * released. |
337 | */ |
338 | static inline void xfs_buf_oneshot(struct xfs_buf *bp) |
339 | { |
340 | if (!list_empty(head: &bp->b_lru) || atomic_read(v: &bp->b_lru_ref) > 1) |
341 | return; |
342 | atomic_set(v: &bp->b_lru_ref, i: 0); |
343 | } |
344 | |
345 | static inline int xfs_buf_ispinned(struct xfs_buf *bp) |
346 | { |
347 | return atomic_read(v: &bp->b_pin_count); |
348 | } |
349 | |
350 | static inline int |
351 | xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset) |
352 | { |
353 | return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length), |
354 | cksum_offset); |
355 | } |
356 | |
357 | static inline void |
358 | xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset) |
359 | { |
360 | xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), |
361 | cksum_offset); |
362 | } |
363 | |
364 | /* |
365 | * Handling of buftargs. |
366 | */ |
367 | struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp, |
368 | struct bdev_handle *bdev_handle); |
369 | extern void xfs_free_buftarg(struct xfs_buftarg *); |
370 | extern void xfs_buftarg_wait(struct xfs_buftarg *); |
371 | extern void xfs_buftarg_drain(struct xfs_buftarg *); |
372 | extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int); |
373 | |
374 | #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) |
375 | #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) |
376 | |
377 | int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); |
378 | bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic); |
379 | bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic); |
380 | |
381 | #endif /* __XFS_BUF_H__ */ |
382 | |