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