Loading...
1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#ifndef __XFS_BUF_H__
19#define __XFS_BUF_H__
20
21#include <linux/list.h>
22#include <linux/types.h>
23#include <linux/spinlock.h>
24#include <linux/mm.h>
25#include <linux/fs.h>
26#include <linux/dax.h>
27#include <linux/buffer_head.h>
28#include <linux/uio.h>
29#include <linux/list_lru.h>
30
31/*
32 * Base types
33 */
34
35#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
36
37typedef enum {
38 XBRW_READ = 1, /* transfer into target memory */
39 XBRW_WRITE = 2, /* transfer from target memory */
40 XBRW_ZERO = 3, /* Zero target memory */
41} xfs_buf_rw_t;
42
43#define XBF_READ (1 << 0) /* buffer intended for reading from device */
44#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
45#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
46#define XBF_NO_IOACCT (1 << 3) /* bypass I/O accounting (non-LRU bufs) */
47#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
48#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
49#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
50#define XBF_WRITE_FAIL (1 << 24)/* async writes have failed on this buffer */
51
52/* I/O hints for the BIO layer */
53#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
54#define XBF_FUA (1 << 11)/* force cache write through mode */
55#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
56
57/* flags used only as arguments to access routines */
58#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
59#define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
60
61/* flags used only internally */
62#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
63#define _XBF_KMEM (1 << 21)/* backed by heap memory */
64#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
65#define _XBF_COMPOUND (1 << 23)/* compound buffer */
66#define _XBF_IN_FLIGHT (1 << 25) /* I/O in flight, for accounting purposes */
67
68typedef unsigned int xfs_buf_flags_t;
69
70#define XFS_BUF_FLAGS \
71 { XBF_READ, "READ" }, \
72 { XBF_WRITE, "WRITE" }, \
73 { XBF_READ_AHEAD, "READ_AHEAD" }, \
74 { XBF_NO_IOACCT, "NO_IOACCT" }, \
75 { XBF_ASYNC, "ASYNC" }, \
76 { XBF_DONE, "DONE" }, \
77 { XBF_STALE, "STALE" }, \
78 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \
79 { XBF_SYNCIO, "SYNCIO" }, \
80 { XBF_FUA, "FUA" }, \
81 { XBF_FLUSH, "FLUSH" }, \
82 { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
83 { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\
84 { _XBF_PAGES, "PAGES" }, \
85 { _XBF_KMEM, "KMEM" }, \
86 { _XBF_DELWRI_Q, "DELWRI_Q" }, \
87 { _XBF_COMPOUND, "COMPOUND" }, \
88 { _XBF_IN_FLIGHT, "IN_FLIGHT" }
89
90
91/*
92 * Internal state flags.
93 */
94#define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
95
96/*
97 * The xfs_buftarg contains 2 notions of "sector size" -
98 *
99 * 1) The metadata sector size, which is the minimum unit and
100 * alignment of IO which will be performed by metadata operations.
101 * 2) The device logical sector size
102 *
103 * The first is specified at mkfs time, and is stored on-disk in the
104 * superblock's sb_sectsize.
105 *
106 * The latter is derived from the underlying device, and controls direct IO
107 * alignment constraints.
108 */
109typedef struct xfs_buftarg {
110 dev_t bt_dev;
111 struct block_device *bt_bdev;
112 struct backing_dev_info *bt_bdi;
113 struct xfs_mount *bt_mount;
114 unsigned int bt_meta_sectorsize;
115 size_t bt_meta_sectormask;
116 size_t bt_logical_sectorsize;
117 size_t bt_logical_sectormask;
118
119 /* LRU control structures */
120 struct shrinker bt_shrinker;
121 struct list_lru bt_lru;
122
123 struct percpu_counter bt_io_count;
124} xfs_buftarg_t;
125
126struct xfs_buf;
127typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
128
129
130#define XB_PAGES 2
131
132struct xfs_buf_map {
133 xfs_daddr_t bm_bn; /* block number for I/O */
134 int bm_len; /* size of I/O */
135};
136
137#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
138 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
139
140struct xfs_buf_ops {
141 char *name;
142 void (*verify_read)(struct xfs_buf *);
143 void (*verify_write)(struct xfs_buf *);
144};
145
146typedef struct xfs_buf {
147 /*
148 * first cacheline holds all the fields needed for an uncontended cache
149 * hit to be fully processed. The semaphore straddles the cacheline
150 * boundary, but the counter and lock sits on the first cacheline,
151 * which is the only bit that is touched if we hit the semaphore
152 * fast-path on locking.
153 */
154 struct rhash_head b_rhash_head; /* pag buffer hash node */
155 xfs_daddr_t b_bn; /* block number of buffer */
156 int b_length; /* size of buffer in BBs */
157 atomic_t b_hold; /* reference count */
158 atomic_t b_lru_ref; /* lru reclaim ref count */
159 xfs_buf_flags_t b_flags; /* status flags */
160 struct semaphore b_sema; /* semaphore for lockables */
161
162 /*
163 * concurrent access to b_lru and b_lru_flags are protected by
164 * bt_lru_lock and not by b_sema
165 */
166 struct list_head b_lru; /* lru list */
167 spinlock_t b_lock; /* internal state lock */
168 unsigned int b_state; /* internal state flags */
169 int b_io_error; /* internal IO error state */
170 wait_queue_head_t b_waiters; /* unpin waiters */
171 struct list_head b_list;
172 struct xfs_perag *b_pag; /* contains rbtree root */
173 xfs_buftarg_t *b_target; /* buffer target (device) */
174 void *b_addr; /* virtual address of buffer */
175 struct work_struct b_ioend_work;
176 struct workqueue_struct *b_ioend_wq; /* I/O completion wq */
177 xfs_buf_iodone_t b_iodone; /* I/O completion function */
178 struct completion b_iowait; /* queue for I/O waiters */
179 void *b_fspriv;
180 struct xfs_trans *b_transp;
181 struct page **b_pages; /* array of page pointers */
182 struct page *b_page_array[XB_PAGES]; /* inline pages */
183 struct xfs_buf_map *b_maps; /* compound buffer map */
184 struct xfs_buf_map __b_map; /* inline compound buffer map */
185 int b_map_count;
186 int b_io_length; /* IO size in BBs */
187 atomic_t b_pin_count; /* pin count */
188 atomic_t b_io_remaining; /* #outstanding I/O requests */
189 unsigned int b_page_count; /* size of page array */
190 unsigned int b_offset; /* page offset in first page */
191 int b_error; /* error code on I/O */
192
193 /*
194 * async write failure retry count. Initialised to zero on the first
195 * failure, then when it exceeds the maximum configured without a
196 * success the write is considered to be failed permanently and the
197 * iodone handler will take appropriate action.
198 *
199 * For retry timeouts, we record the jiffie of the first failure. This
200 * means that we can change the retry timeout for buffers already under
201 * I/O and thus avoid getting stuck in a retry loop with a long timeout.
202 *
203 * last_error is used to ensure that we are getting repeated errors, not
204 * different errors. e.g. a block device might change ENOSPC to EIO when
205 * a failure timeout occurs, so we want to re-initialise the error
206 * retry behaviour appropriately when that happens.
207 */
208 int b_retries;
209 unsigned long b_first_retry_time; /* in jiffies */
210 int b_last_error;
211
212 const struct xfs_buf_ops *b_ops;
213
214#ifdef XFS_BUF_LOCK_TRACKING
215 int b_last_holder;
216#endif
217} xfs_buf_t;
218
219/* Finding and Reading Buffers */
220struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target,
221 struct xfs_buf_map *map, int nmaps,
222 xfs_buf_flags_t flags, struct xfs_buf *new_bp);
223
224static inline struct xfs_buf *
225xfs_incore(
226 struct xfs_buftarg *target,
227 xfs_daddr_t blkno,
228 size_t numblks,
229 xfs_buf_flags_t flags)
230{
231 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
232 return _xfs_buf_find(target, &map, 1, flags, NULL);
233}
234
235struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target,
236 struct xfs_buf_map *map, int nmaps,
237 xfs_buf_flags_t flags);
238
239static inline struct xfs_buf *
240xfs_buf_alloc(
241 struct xfs_buftarg *target,
242 xfs_daddr_t blkno,
243 size_t numblks,
244 xfs_buf_flags_t flags)
245{
246 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
247 return _xfs_buf_alloc(target, &map, 1, flags);
248}
249
250struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target,
251 struct xfs_buf_map *map, int nmaps,
252 xfs_buf_flags_t flags);
253struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target,
254 struct xfs_buf_map *map, int nmaps,
255 xfs_buf_flags_t flags,
256 const struct xfs_buf_ops *ops);
257void xfs_buf_readahead_map(struct xfs_buftarg *target,
258 struct xfs_buf_map *map, int nmaps,
259 const struct xfs_buf_ops *ops);
260
261static inline struct xfs_buf *
262xfs_buf_get(
263 struct xfs_buftarg *target,
264 xfs_daddr_t blkno,
265 size_t numblks,
266 xfs_buf_flags_t flags)
267{
268 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
269 return xfs_buf_get_map(target, &map, 1, flags);
270}
271
272static inline struct xfs_buf *
273xfs_buf_read(
274 struct xfs_buftarg *target,
275 xfs_daddr_t blkno,
276 size_t numblks,
277 xfs_buf_flags_t flags,
278 const struct xfs_buf_ops *ops)
279{
280 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
281 return xfs_buf_read_map(target, &map, 1, flags, ops);
282}
283
284static inline void
285xfs_buf_readahead(
286 struct xfs_buftarg *target,
287 xfs_daddr_t blkno,
288 size_t numblks,
289 const struct xfs_buf_ops *ops)
290{
291 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
292 return xfs_buf_readahead_map(target, &map, 1, ops);
293}
294
295struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks);
296void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks);
297int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length);
298
299struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
300 int flags);
301int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
302 size_t numblks, int flags, struct xfs_buf **bpp,
303 const struct xfs_buf_ops *ops);
304void xfs_buf_hold(struct xfs_buf *bp);
305
306/* Releasing Buffers */
307extern void xfs_buf_free(xfs_buf_t *);
308extern void xfs_buf_rele(xfs_buf_t *);
309
310/* Locking and Unlocking Buffers */
311extern int xfs_buf_trylock(xfs_buf_t *);
312extern void xfs_buf_lock(xfs_buf_t *);
313extern void xfs_buf_unlock(xfs_buf_t *);
314#define xfs_buf_islocked(bp) \
315 ((bp)->b_sema.count <= 0)
316
317/* Buffer Read and Write Routines */
318extern int xfs_bwrite(struct xfs_buf *bp);
319extern void xfs_buf_ioend(struct xfs_buf *bp);
320extern void xfs_buf_ioerror(xfs_buf_t *, int);
321extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
322extern void xfs_buf_submit(struct xfs_buf *bp);
323extern int xfs_buf_submit_wait(struct xfs_buf *bp);
324extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
325 xfs_buf_rw_t);
326#define xfs_buf_zero(bp, off, len) \
327 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
328
329/* Buffer Utility Routines */
330extern void *xfs_buf_offset(struct xfs_buf *, size_t);
331extern void xfs_buf_stale(struct xfs_buf *bp);
332
333/* Delayed Write Buffer Routines */
334extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
335extern int xfs_buf_delwri_submit(struct list_head *);
336extern int xfs_buf_delwri_submit_nowait(struct list_head *);
337
338/* Buffer Daemon Setup Routines */
339extern int xfs_buf_init(void);
340extern void xfs_buf_terminate(void);
341
342/*
343 * These macros use the IO block map rather than b_bn. b_bn is now really
344 * just for the buffer cache index for cached buffers. As IO does not use b_bn
345 * anymore, uncached buffers do not use b_bn at all and hence must modify the IO
346 * map directly. Uncached buffers are not allowed to be discontiguous, so this
347 * is safe to do.
348 *
349 * In future, uncached buffers will pass the block number directly to the io
350 * request function and hence these macros will go away at that point.
351 */
352#define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn)
353#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
354
355static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
356{
357 atomic_set(&bp->b_lru_ref, lru_ref);
358}
359
360static inline int xfs_buf_ispinned(struct xfs_buf *bp)
361{
362 return atomic_read(&bp->b_pin_count);
363}
364
365static inline void xfs_buf_relse(xfs_buf_t *bp)
366{
367 xfs_buf_unlock(bp);
368 xfs_buf_rele(bp);
369}
370
371static inline int
372xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
373{
374 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
375 cksum_offset);
376}
377
378static inline void
379xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
380{
381 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
382 cksum_offset);
383}
384
385/*
386 * Handling of buftargs.
387 */
388extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
389 struct block_device *);
390extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
391extern void xfs_wait_buftarg(xfs_buftarg_t *);
392extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int);
393
394#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
395#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
396
397#endif /* __XFS_BUF_H__ */
1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#ifndef __XFS_BUF_H__
19#define __XFS_BUF_H__
20
21#include <linux/list.h>
22#include <linux/types.h>
23#include <linux/spinlock.h>
24#include <linux/mm.h>
25#include <linux/fs.h>
26#include <linux/dax.h>
27#include <linux/buffer_head.h>
28#include <linux/uio.h>
29#include <linux/list_lru.h>
30
31/*
32 * Base types
33 */
34
35#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
36
37typedef enum {
38 XBRW_READ = 1, /* transfer into target memory */
39 XBRW_WRITE = 2, /* transfer from target memory */
40 XBRW_ZERO = 3, /* Zero target memory */
41} xfs_buf_rw_t;
42
43#define XBF_READ (1 << 0) /* buffer intended for reading from device */
44#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
45#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
46#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
47#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
48#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
49#define XBF_WRITE_FAIL (1 << 24)/* async writes have failed on this buffer */
50
51/* I/O hints for the BIO layer */
52#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
53#define XBF_FUA (1 << 11)/* force cache write through mode */
54#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
55
56/* flags used only as arguments to access routines */
57#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
58#define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
59
60/* flags used only internally */
61#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
62#define _XBF_KMEM (1 << 21)/* backed by heap memory */
63#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
64#define _XBF_COMPOUND (1 << 23)/* compound buffer */
65
66typedef unsigned int xfs_buf_flags_t;
67
68#define XFS_BUF_FLAGS \
69 { XBF_READ, "READ" }, \
70 { XBF_WRITE, "WRITE" }, \
71 { XBF_READ_AHEAD, "READ_AHEAD" }, \
72 { XBF_ASYNC, "ASYNC" }, \
73 { XBF_DONE, "DONE" }, \
74 { XBF_STALE, "STALE" }, \
75 { XBF_WRITE_FAIL, "WRITE_FAIL" }, \
76 { XBF_SYNCIO, "SYNCIO" }, \
77 { XBF_FUA, "FUA" }, \
78 { XBF_FLUSH, "FLUSH" }, \
79 { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
80 { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\
81 { _XBF_PAGES, "PAGES" }, \
82 { _XBF_KMEM, "KMEM" }, \
83 { _XBF_DELWRI_Q, "DELWRI_Q" }, \
84 { _XBF_COMPOUND, "COMPOUND" }
85
86
87/*
88 * Internal state flags.
89 */
90#define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
91
92/*
93 * The xfs_buftarg contains 2 notions of "sector size" -
94 *
95 * 1) The metadata sector size, which is the minimum unit and
96 * alignment of IO which will be performed by metadata operations.
97 * 2) The device logical sector size
98 *
99 * The first is specified at mkfs time, and is stored on-disk in the
100 * superblock's sb_sectsize.
101 *
102 * The latter is derived from the underlying device, and controls direct IO
103 * alignment constraints.
104 */
105typedef struct xfs_buftarg {
106 dev_t bt_dev;
107 struct block_device *bt_bdev;
108 struct backing_dev_info *bt_bdi;
109 struct xfs_mount *bt_mount;
110 unsigned int bt_meta_sectorsize;
111 size_t bt_meta_sectormask;
112 size_t bt_logical_sectorsize;
113 size_t bt_logical_sectormask;
114
115 /* LRU control structures */
116 struct shrinker bt_shrinker;
117 struct list_lru bt_lru;
118} xfs_buftarg_t;
119
120struct xfs_buf;
121typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
122
123
124#define XB_PAGES 2
125
126struct xfs_buf_map {
127 xfs_daddr_t bm_bn; /* block number for I/O */
128 int bm_len; /* size of I/O */
129};
130
131#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
132 struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
133
134struct xfs_buf_ops {
135 char *name;
136 void (*verify_read)(struct xfs_buf *);
137 void (*verify_write)(struct xfs_buf *);
138};
139
140typedef struct xfs_buf {
141 /*
142 * first cacheline holds all the fields needed for an uncontended cache
143 * hit to be fully processed. The semaphore straddles the cacheline
144 * boundary, but the counter and lock sits on the first cacheline,
145 * which is the only bit that is touched if we hit the semaphore
146 * fast-path on locking.
147 */
148 struct rb_node b_rbnode; /* rbtree node */
149 xfs_daddr_t b_bn; /* block number of buffer */
150 int b_length; /* size of buffer in BBs */
151 atomic_t b_hold; /* reference count */
152 atomic_t b_lru_ref; /* lru reclaim ref count */
153 xfs_buf_flags_t b_flags; /* status flags */
154 struct semaphore b_sema; /* semaphore for lockables */
155
156 /*
157 * concurrent access to b_lru and b_lru_flags are protected by
158 * bt_lru_lock and not by b_sema
159 */
160 struct list_head b_lru; /* lru list */
161 spinlock_t b_lock; /* internal state lock */
162 unsigned int b_state; /* internal state flags */
163 int b_io_error; /* internal IO error state */
164 wait_queue_head_t b_waiters; /* unpin waiters */
165 struct list_head b_list;
166 struct xfs_perag *b_pag; /* contains rbtree root */
167 xfs_buftarg_t *b_target; /* buffer target (device) */
168 void *b_addr; /* virtual address of buffer */
169 struct work_struct b_ioend_work;
170 struct workqueue_struct *b_ioend_wq; /* I/O completion wq */
171 xfs_buf_iodone_t b_iodone; /* I/O completion function */
172 struct completion b_iowait; /* queue for I/O waiters */
173 void *b_fspriv;
174 struct xfs_trans *b_transp;
175 struct page **b_pages; /* array of page pointers */
176 struct page *b_page_array[XB_PAGES]; /* inline pages */
177 struct xfs_buf_map *b_maps; /* compound buffer map */
178 struct xfs_buf_map __b_map; /* inline compound buffer map */
179 int b_map_count;
180 int b_io_length; /* IO size in BBs */
181 atomic_t b_pin_count; /* pin count */
182 atomic_t b_io_remaining; /* #outstanding I/O requests */
183 unsigned int b_page_count; /* size of page array */
184 unsigned int b_offset; /* page offset in first page */
185 int b_error; /* error code on I/O */
186 const struct xfs_buf_ops *b_ops;
187
188#ifdef XFS_BUF_LOCK_TRACKING
189 int b_last_holder;
190#endif
191} xfs_buf_t;
192
193/* Finding and Reading Buffers */
194struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target,
195 struct xfs_buf_map *map, int nmaps,
196 xfs_buf_flags_t flags, struct xfs_buf *new_bp);
197
198static inline struct xfs_buf *
199xfs_incore(
200 struct xfs_buftarg *target,
201 xfs_daddr_t blkno,
202 size_t numblks,
203 xfs_buf_flags_t flags)
204{
205 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
206 return _xfs_buf_find(target, &map, 1, flags, NULL);
207}
208
209struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target,
210 struct xfs_buf_map *map, int nmaps,
211 xfs_buf_flags_t flags);
212
213static inline struct xfs_buf *
214xfs_buf_alloc(
215 struct xfs_buftarg *target,
216 xfs_daddr_t blkno,
217 size_t numblks,
218 xfs_buf_flags_t flags)
219{
220 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
221 return _xfs_buf_alloc(target, &map, 1, flags);
222}
223
224struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target,
225 struct xfs_buf_map *map, int nmaps,
226 xfs_buf_flags_t flags);
227struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target,
228 struct xfs_buf_map *map, int nmaps,
229 xfs_buf_flags_t flags,
230 const struct xfs_buf_ops *ops);
231void xfs_buf_readahead_map(struct xfs_buftarg *target,
232 struct xfs_buf_map *map, int nmaps,
233 const struct xfs_buf_ops *ops);
234
235static inline struct xfs_buf *
236xfs_buf_get(
237 struct xfs_buftarg *target,
238 xfs_daddr_t blkno,
239 size_t numblks,
240 xfs_buf_flags_t flags)
241{
242 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
243 return xfs_buf_get_map(target, &map, 1, flags);
244}
245
246static inline struct xfs_buf *
247xfs_buf_read(
248 struct xfs_buftarg *target,
249 xfs_daddr_t blkno,
250 size_t numblks,
251 xfs_buf_flags_t flags,
252 const struct xfs_buf_ops *ops)
253{
254 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
255 return xfs_buf_read_map(target, &map, 1, flags, ops);
256}
257
258static inline void
259xfs_buf_readahead(
260 struct xfs_buftarg *target,
261 xfs_daddr_t blkno,
262 size_t numblks,
263 const struct xfs_buf_ops *ops)
264{
265 DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
266 return xfs_buf_readahead_map(target, &map, 1, ops);
267}
268
269struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks);
270void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks);
271int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length);
272
273struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
274 int flags);
275int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
276 size_t numblks, int flags, struct xfs_buf **bpp,
277 const struct xfs_buf_ops *ops);
278void xfs_buf_hold(struct xfs_buf *bp);
279
280/* Releasing Buffers */
281extern void xfs_buf_free(xfs_buf_t *);
282extern void xfs_buf_rele(xfs_buf_t *);
283
284/* Locking and Unlocking Buffers */
285extern int xfs_buf_trylock(xfs_buf_t *);
286extern void xfs_buf_lock(xfs_buf_t *);
287extern void xfs_buf_unlock(xfs_buf_t *);
288#define xfs_buf_islocked(bp) \
289 ((bp)->b_sema.count <= 0)
290
291/* Buffer Read and Write Routines */
292extern int xfs_bwrite(struct xfs_buf *bp);
293extern void xfs_buf_ioend(struct xfs_buf *bp);
294extern void xfs_buf_ioerror(xfs_buf_t *, int);
295extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
296extern void xfs_buf_submit(struct xfs_buf *bp);
297extern int xfs_buf_submit_wait(struct xfs_buf *bp);
298extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
299 xfs_buf_rw_t);
300#define xfs_buf_zero(bp, off, len) \
301 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
302
303/* Buffer Utility Routines */
304extern void *xfs_buf_offset(struct xfs_buf *, size_t);
305extern void xfs_buf_stale(struct xfs_buf *bp);
306
307/* Delayed Write Buffer Routines */
308extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
309extern int xfs_buf_delwri_submit(struct list_head *);
310extern int xfs_buf_delwri_submit_nowait(struct list_head *);
311
312/* Buffer Daemon Setup Routines */
313extern int xfs_buf_init(void);
314extern void xfs_buf_terminate(void);
315
316/*
317 * These macros use the IO block map rather than b_bn. b_bn is now really
318 * just for the buffer cache index for cached buffers. As IO does not use b_bn
319 * anymore, uncached buffers do not use b_bn at all and hence must modify the IO
320 * map directly. Uncached buffers are not allowed to be discontiguous, so this
321 * is safe to do.
322 *
323 * In future, uncached buffers will pass the block number directly to the io
324 * request function and hence these macros will go away at that point.
325 */
326#define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn)
327#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
328
329static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
330{
331 atomic_set(&bp->b_lru_ref, lru_ref);
332}
333
334static inline int xfs_buf_ispinned(struct xfs_buf *bp)
335{
336 return atomic_read(&bp->b_pin_count);
337}
338
339static inline void xfs_buf_relse(xfs_buf_t *bp)
340{
341 xfs_buf_unlock(bp);
342 xfs_buf_rele(bp);
343}
344
345static inline int
346xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
347{
348 return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
349 cksum_offset);
350}
351
352static inline void
353xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
354{
355 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
356 cksum_offset);
357}
358
359/*
360 * Handling of buftargs.
361 */
362extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
363 struct block_device *);
364extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
365extern void xfs_wait_buftarg(xfs_buftarg_t *);
366extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int);
367
368#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
369#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
370
371#endif /* __XFS_BUF_H__ */