Line data Source code
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 : #define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */
48 : #define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */
49 : #define XBF_UNMAPPED (1u << 31)/* do not map the buffer */
50 :
51 :
52 : typedef unsigned int xfs_buf_flags_t;
53 :
54 : #define XFS_BUF_FLAGS \
55 : { XBF_READ, "READ" }, \
56 : { XBF_WRITE, "WRITE" }, \
57 : { XBF_READ_AHEAD, "READ_AHEAD" }, \
58 : { XBF_NO_IOACCT, "NO_IOACCT" }, \
59 : { XBF_ASYNC, "ASYNC" }, \
60 : { XBF_DONE, "DONE" }, \
61 : { XBF_STALE, "STALE" }, \
62 : { XBF_WRITE_FAIL, "WRITE_FAIL" }, \
63 : { _XBF_INODES, "INODES" }, \
64 : { _XBF_DQUOTS, "DQUOTS" }, \
65 : { _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \
66 : { _XBF_PAGES, "PAGES" }, \
67 : { _XBF_KMEM, "KMEM" }, \
68 : { _XBF_DELWRI_Q, "DELWRI_Q" }, \
69 : /* The following interface flags should never be set */ \
70 : { XBF_INCORE, "INCORE" }, \
71 : { XBF_TRYLOCK, "TRYLOCK" }, \
72 : { XBF_UNMAPPED, "UNMAPPED" }
73 :
74 : /*
75 : * Internal state flags.
76 : */
77 : #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
78 : #define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */
79 :
80 : /*
81 : * The xfs_buftarg contains 2 notions of "sector size" -
82 : *
83 : * 1) The metadata sector size, which is the minimum unit and
84 : * alignment of IO which will be performed by metadata operations.
85 : * 2) The device logical sector size
86 : *
87 : * The first is specified at mkfs time, and is stored on-disk in the
88 : * superblock's sb_sectsize.
89 : *
90 : * The latter is derived from the underlying device, and controls direct IO
91 : * alignment constraints.
92 : */
93 : typedef struct xfs_buftarg {
94 : dev_t bt_dev;
95 : struct block_device *bt_bdev;
96 : struct dax_device *bt_daxdev;
97 : u64 bt_dax_part_off;
98 : struct xfs_mount *bt_mount;
99 : unsigned int bt_meta_sectorsize;
100 : size_t bt_meta_sectormask;
101 : size_t bt_logical_sectorsize;
102 : size_t bt_logical_sectormask;
103 :
104 : /* LRU control structures */
105 : struct shrinker bt_shrinker;
106 : struct list_lru bt_lru;
107 :
108 : struct percpu_counter bt_io_count;
109 : struct ratelimit_state bt_ioerror_rl;
110 : } xfs_buftarg_t;
111 :
112 : #define XB_PAGES 2
113 :
114 : struct xfs_buf_map {
115 : xfs_daddr_t bm_bn; /* block number for I/O */
116 : int bm_len; /* size of I/O */
117 : };
118 :
119 : #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
120 : struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
121 :
122 : struct xfs_buf_ops {
123 : char *name;
124 : union {
125 : __be32 magic[2]; /* v4 and v5 on disk magic values */
126 : __be16 magic16[2]; /* v4 and v5 on disk magic values */
127 : };
128 : void (*verify_read)(struct xfs_buf *);
129 : void (*verify_write)(struct xfs_buf *);
130 : xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp);
131 : };
132 :
133 : struct xfs_buf {
134 : /*
135 : * first cacheline holds all the fields needed for an uncontended cache
136 : * hit to be fully processed. The semaphore straddles the cacheline
137 : * boundary, but the counter and lock sits on the first cacheline,
138 : * which is the only bit that is touched if we hit the semaphore
139 : * fast-path on locking.
140 : */
141 : struct rhash_head b_rhash_head; /* pag buffer hash node */
142 :
143 : xfs_daddr_t b_rhash_key; /* buffer cache index */
144 : int b_length; /* size of buffer in BBs */
145 : atomic_t b_hold; /* reference count */
146 : atomic_t b_lru_ref; /* lru reclaim ref count */
147 : xfs_buf_flags_t b_flags; /* status flags */
148 : struct semaphore b_sema; /* semaphore for lockables */
149 :
150 : /*
151 : * concurrent access to b_lru and b_lru_flags are protected by
152 : * bt_lru_lock and not by b_sema
153 : */
154 : struct list_head b_lru; /* lru list */
155 : spinlock_t b_lock; /* internal state lock */
156 : unsigned int b_state; /* internal state flags */
157 : int b_io_error; /* internal IO error state */
158 : wait_queue_head_t b_waiters; /* unpin waiters */
159 : struct list_head b_list;
160 : struct xfs_perag *b_pag; /* contains rbtree root */
161 : struct xfs_mount *b_mount;
162 : struct xfs_buftarg *b_target; /* buffer target (device) */
163 : void *b_addr; /* virtual address of buffer */
164 : struct work_struct b_ioend_work;
165 : struct completion b_iowait; /* queue for I/O waiters */
166 : struct xfs_buf_log_item *b_log_item;
167 : struct list_head b_li_list; /* Log items list head */
168 : struct xfs_trans *b_transp;
169 : struct page **b_pages; /* array of page pointers */
170 : struct page *b_page_array[XB_PAGES]; /* inline pages */
171 : struct xfs_buf_map *b_maps; /* compound buffer map */
172 : struct xfs_buf_map __b_map; /* inline compound buffer map */
173 : int b_map_count;
174 : atomic_t b_pin_count; /* pin count */
175 : atomic_t b_io_remaining; /* #outstanding I/O requests */
176 : unsigned int b_page_count; /* size of page array */
177 : unsigned int b_offset; /* page offset of b_addr,
178 : only for _XBF_KMEM buffers */
179 : int b_error; /* error code on I/O */
180 :
181 : /*
182 : * async write failure retry count. Initialised to zero on the first
183 : * failure, then when it exceeds the maximum configured without a
184 : * success the write is considered to be failed permanently and the
185 : * iodone handler will take appropriate action.
186 : *
187 : * For retry timeouts, we record the jiffie of the first failure. This
188 : * means that we can change the retry timeout for buffers already under
189 : * I/O and thus avoid getting stuck in a retry loop with a long timeout.
190 : *
191 : * last_error is used to ensure that we are getting repeated errors, not
192 : * different errors. e.g. a block device might change ENOSPC to EIO when
193 : * a failure timeout occurs, so we want to re-initialise the error
194 : * retry behaviour appropriately when that happens.
195 : */
196 : int b_retries;
197 : unsigned long b_first_retry_time; /* in jiffies */
198 : int b_last_error;
199 :
200 : const struct xfs_buf_ops *b_ops;
201 : struct rcu_head b_rcu;
202 : };
203 :
204 : /* Finding and Reading Buffers */
205 : int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
206 : int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
207 : int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
208 : int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
209 : const struct xfs_buf_ops *ops, xfs_failaddr_t fa);
210 : void xfs_buf_readahead_map(struct xfs_buftarg *target,
211 : struct xfs_buf_map *map, int nmaps,
212 : const struct xfs_buf_ops *ops);
213 :
214 : static inline int
215 : xfs_buf_incore(
216 : struct xfs_buftarg *target,
217 : xfs_daddr_t blkno,
218 : size_t numblks,
219 : xfs_buf_flags_t flags,
220 : struct xfs_buf **bpp)
221 : {
222 2633 : DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
223 :
224 2633 : return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp);
225 : }
226 :
227 : static inline int
228 : xfs_buf_get(
229 : struct xfs_buftarg *target,
230 : xfs_daddr_t blkno,
231 : size_t numblks,
232 : struct xfs_buf **bpp)
233 : {
234 38851 : DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
235 :
236 38851 : return xfs_buf_get_map(target, &map, 1, 0, bpp);
237 : }
238 :
239 : static inline int
240 : xfs_buf_read(
241 : struct xfs_buftarg *target,
242 : xfs_daddr_t blkno,
243 : size_t numblks,
244 : xfs_buf_flags_t flags,
245 : struct xfs_buf **bpp,
246 : const struct xfs_buf_ops *ops)
247 : {
248 215577123 : DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
249 :
250 215577123 : return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,
251 : __builtin_return_address(0));
252 : }
253 :
254 : static inline void
255 : xfs_buf_readahead(
256 : struct xfs_buftarg *target,
257 : xfs_daddr_t blkno,
258 : size_t numblks,
259 : const struct xfs_buf_ops *ops)
260 : {
261 4399414204 : DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
262 4399414204 : return xfs_buf_readahead_map(target, &map, 1, ops);
263 : }
264 :
265 : int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
266 : xfs_buf_flags_t flags, struct xfs_buf **bpp);
267 : int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
268 : size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp,
269 : const struct xfs_buf_ops *ops);
270 : int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags);
271 : void xfs_buf_hold(struct xfs_buf *bp);
272 :
273 : /* Releasing Buffers */
274 : extern void xfs_buf_rele(struct xfs_buf *);
275 :
276 : /* Locking and Unlocking Buffers */
277 : extern int xfs_buf_trylock(struct xfs_buf *);
278 : extern void xfs_buf_lock(struct xfs_buf *);
279 : extern void xfs_buf_unlock(struct xfs_buf *);
280 : #define xfs_buf_islocked(bp) \
281 : ((bp)->b_sema.count <= 0)
282 :
283 : static inline void xfs_buf_relse(struct xfs_buf *bp)
284 : {
285 24018028179 : xfs_buf_unlock(bp);
286 24002827133 : xfs_buf_rele(bp);
287 18533359288 : }
288 :
289 : /* Buffer Read and Write Routines */
290 : extern int xfs_bwrite(struct xfs_buf *bp);
291 :
292 : extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
293 : xfs_failaddr_t failaddr);
294 : #define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
295 : extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
296 : void xfs_buf_ioend_fail(struct xfs_buf *);
297 : void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);
298 : void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa);
299 : #define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address)
300 :
301 : /* Buffer Utility Routines */
302 : extern void *xfs_buf_offset(struct xfs_buf *, size_t);
303 : extern void xfs_buf_stale(struct xfs_buf *bp);
304 :
305 : /* Delayed Write Buffer Routines */
306 : extern void xfs_buf_delwri_cancel(struct list_head *);
307 : extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
308 : extern int xfs_buf_delwri_submit(struct list_head *);
309 : extern int xfs_buf_delwri_submit_nowait(struct list_head *);
310 : extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *);
311 :
312 : static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp)
313 : {
314 >39142*10^7 : return bp->b_maps[0].bm_bn;
315 : }
316 :
317 : void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);
318 :
319 : /*
320 : * If the buffer is already on the LRU, do nothing. Otherwise set the buffer
321 : * up with a reference count of 0 so it will be tossed from the cache when
322 : * released.
323 : */
324 : static inline void xfs_buf_oneshot(struct xfs_buf *bp)
325 : {
326 395720 : if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1)
327 : return;
328 395719 : atomic_set(&bp->b_lru_ref, 0);
329 : }
330 :
331 : static inline int xfs_buf_ispinned(struct xfs_buf *bp)
332 : {
333 237705161 : return atomic_read(&bp->b_pin_count);
334 : }
335 :
336 : static inline int
337 : xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
338 : {
339 11121822 : return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
340 : cksum_offset);
341 : }
342 :
343 : static inline void
344 : xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
345 : {
346 45256727 : xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
347 : cksum_offset);
348 45256727 : }
349 :
350 : /*
351 : * Handling of buftargs.
352 : */
353 : struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,
354 : struct block_device *bdev);
355 : extern void xfs_free_buftarg(struct xfs_buftarg *);
356 : extern void xfs_buftarg_wait(struct xfs_buftarg *);
357 : extern void xfs_buftarg_drain(struct xfs_buftarg *);
358 : extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int);
359 :
360 : #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
361 : #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
362 :
363 : int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops);
364 : bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);
365 : bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);
366 :
367 : #endif /* __XFS_BUF_H__ */
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