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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 <asm/system.h>
25#include <linux/mm.h>
26#include <linux/fs.h>
27#include <linux/buffer_head.h>
28#include <linux/uio.h>
29
30/*
31 * Base types
32 */
33
34#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
35
36#define xfs_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE)
37#define xfs_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
38#define xfs_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT)
39#define xfs_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK)
40
41typedef enum {
42 XBRW_READ = 1, /* transfer into target memory */
43 XBRW_WRITE = 2, /* transfer from target memory */
44 XBRW_ZERO = 3, /* Zero target memory */
45} xfs_buf_rw_t;
46
47#define XBF_READ (1 << 0) /* buffer intended for reading from device */
48#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
49#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
50#define XBF_MAPPED (1 << 3) /* buffer mapped (b_addr valid) */
51#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
52#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
53#define XBF_DELWRI (1 << 6) /* buffer has dirty pages */
54#define XBF_STALE (1 << 7) /* buffer has been staled, do not find it */
55
56/* I/O hints for the BIO layer */
57#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
58#define XBF_FUA (1 << 11)/* force cache write through mode */
59#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
60
61/* flags used only as arguments to access routines */
62#define XBF_LOCK (1 << 15)/* lock requested */
63#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
64#define XBF_DONT_BLOCK (1 << 17)/* do not block in current thread */
65
66/* flags used only internally */
67#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
68#define _XBF_KMEM (1 << 21)/* backed by heap memory */
69#define _XBF_DELWRI_Q (1 << 22)/* buffer on delwri queue */
70
71typedef unsigned int xfs_buf_flags_t;
72
73#define XFS_BUF_FLAGS \
74 { XBF_READ, "READ" }, \
75 { XBF_WRITE, "WRITE" }, \
76 { XBF_READ_AHEAD, "READ_AHEAD" }, \
77 { XBF_MAPPED, "MAPPED" }, \
78 { XBF_ASYNC, "ASYNC" }, \
79 { XBF_DONE, "DONE" }, \
80 { XBF_DELWRI, "DELWRI" }, \
81 { XBF_STALE, "STALE" }, \
82 { XBF_SYNCIO, "SYNCIO" }, \
83 { XBF_FUA, "FUA" }, \
84 { XBF_FLUSH, "FLUSH" }, \
85 { XBF_LOCK, "LOCK" }, /* should never be set */\
86 { XBF_TRYLOCK, "TRYLOCK" }, /* ditto */\
87 { XBF_DONT_BLOCK, "DONT_BLOCK" }, /* ditto */\
88 { _XBF_PAGES, "PAGES" }, \
89 { _XBF_KMEM, "KMEM" }, \
90 { _XBF_DELWRI_Q, "DELWRI_Q" }
91
92typedef enum {
93 XBT_FORCE_SLEEP = 0,
94 XBT_FORCE_FLUSH = 1,
95} xfs_buftarg_flags_t;
96
97typedef struct xfs_buftarg {
98 dev_t bt_dev;
99 struct block_device *bt_bdev;
100 struct backing_dev_info *bt_bdi;
101 struct xfs_mount *bt_mount;
102 unsigned int bt_bsize;
103 unsigned int bt_sshift;
104 size_t bt_smask;
105
106 /* per device delwri queue */
107 struct task_struct *bt_task;
108 struct list_head bt_delwrite_queue;
109 spinlock_t bt_delwrite_lock;
110 unsigned long bt_flags;
111
112 /* LRU control structures */
113 struct shrinker bt_shrinker;
114 struct list_head bt_lru;
115 spinlock_t bt_lru_lock;
116 unsigned int bt_lru_nr;
117} xfs_buftarg_t;
118
119struct xfs_buf;
120typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
121
122#define XB_PAGES 2
123
124typedef struct xfs_buf {
125 /*
126 * first cacheline holds all the fields needed for an uncontended cache
127 * hit to be fully processed. The semaphore straddles the cacheline
128 * boundary, but the counter and lock sits on the first cacheline,
129 * which is the only bit that is touched if we hit the semaphore
130 * fast-path on locking.
131 */
132 struct rb_node b_rbnode; /* rbtree node */
133 xfs_off_t b_file_offset; /* offset in file */
134 size_t b_buffer_length;/* size of buffer in bytes */
135 atomic_t b_hold; /* reference count */
136 atomic_t b_lru_ref; /* lru reclaim ref count */
137 xfs_buf_flags_t b_flags; /* status flags */
138 struct semaphore b_sema; /* semaphore for lockables */
139
140 struct list_head b_lru; /* lru list */
141 wait_queue_head_t b_waiters; /* unpin waiters */
142 struct list_head b_list;
143 struct xfs_perag *b_pag; /* contains rbtree root */
144 xfs_buftarg_t *b_target; /* buffer target (device) */
145 xfs_daddr_t b_bn; /* block number for I/O */
146 size_t b_count_desired;/* desired transfer size */
147 void *b_addr; /* virtual address of buffer */
148 struct work_struct b_iodone_work;
149 xfs_buf_iodone_t b_iodone; /* I/O completion function */
150 struct completion b_iowait; /* queue for I/O waiters */
151 void *b_fspriv;
152 struct xfs_trans *b_transp;
153 struct page **b_pages; /* array of page pointers */
154 struct page *b_page_array[XB_PAGES]; /* inline pages */
155 unsigned long b_queuetime; /* time buffer was queued */
156 atomic_t b_pin_count; /* pin count */
157 atomic_t b_io_remaining; /* #outstanding I/O requests */
158 unsigned int b_page_count; /* size of page array */
159 unsigned int b_offset; /* page offset in first page */
160 unsigned short b_error; /* error code on I/O */
161#ifdef XFS_BUF_LOCK_TRACKING
162 int b_last_holder;
163#endif
164} xfs_buf_t;
165
166
167/* Finding and Reading Buffers */
168extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
169 xfs_buf_flags_t, xfs_buf_t *);
170#define xfs_incore(buftarg,blkno,len,lockit) \
171 _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
172
173extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t,
174 xfs_buf_flags_t);
175extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t,
176 xfs_buf_flags_t);
177
178extern xfs_buf_t *xfs_buf_get_empty(size_t, xfs_buftarg_t *);
179extern void xfs_buf_set_empty(struct xfs_buf *bp, size_t len);
180extern xfs_buf_t *xfs_buf_get_uncached(struct xfs_buftarg *, size_t, int);
181extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
182extern void xfs_buf_hold(xfs_buf_t *);
183extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t);
184struct xfs_buf *xfs_buf_read_uncached(struct xfs_mount *mp,
185 struct xfs_buftarg *target,
186 xfs_daddr_t daddr, size_t length, int flags);
187
188/* Releasing Buffers */
189extern void xfs_buf_free(xfs_buf_t *);
190extern void xfs_buf_rele(xfs_buf_t *);
191
192/* Locking and Unlocking Buffers */
193extern int xfs_buf_trylock(xfs_buf_t *);
194extern void xfs_buf_lock(xfs_buf_t *);
195extern void xfs_buf_unlock(xfs_buf_t *);
196#define xfs_buf_islocked(bp) \
197 ((bp)->b_sema.count <= 0)
198
199/* Buffer Read and Write Routines */
200extern int xfs_bwrite(struct xfs_mount *mp, struct xfs_buf *bp);
201extern void xfs_bdwrite(void *mp, xfs_buf_t *bp);
202
203extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
204extern int xfs_bdstrat_cb(struct xfs_buf *);
205
206extern void xfs_buf_ioend(xfs_buf_t *, int);
207extern void xfs_buf_ioerror(xfs_buf_t *, int);
208extern int xfs_buf_iorequest(xfs_buf_t *);
209extern int xfs_buf_iowait(xfs_buf_t *);
210extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
211 xfs_buf_rw_t);
212#define xfs_buf_zero(bp, off, len) \
213 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
214
215static inline int xfs_buf_geterror(xfs_buf_t *bp)
216{
217 return bp ? bp->b_error : ENOMEM;
218}
219
220/* Buffer Utility Routines */
221extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
222
223/* Delayed Write Buffer Routines */
224extern void xfs_buf_delwri_dequeue(xfs_buf_t *);
225extern void xfs_buf_delwri_promote(xfs_buf_t *);
226
227/* Buffer Daemon Setup Routines */
228extern int xfs_buf_init(void);
229extern void xfs_buf_terminate(void);
230
231static inline const char *
232xfs_buf_target_name(struct xfs_buftarg *target)
233{
234 static char __b[BDEVNAME_SIZE];
235
236 return bdevname(target->bt_bdev, __b);
237}
238
239
240#define XFS_BUF_ZEROFLAGS(bp) \
241 ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI| \
242 XBF_SYNCIO|XBF_FUA|XBF_FLUSH))
243
244void xfs_buf_stale(struct xfs_buf *bp);
245#define XFS_BUF_STALE(bp) xfs_buf_stale(bp);
246#define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE)
247#define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE)
248#define XFS_BUF_SUPER_STALE(bp) do { \
249 XFS_BUF_STALE(bp); \
250 xfs_buf_delwri_dequeue(bp); \
251 XFS_BUF_DONE(bp); \
252 } while (0)
253
254#define XFS_BUF_DELAYWRITE(bp) ((bp)->b_flags |= XBF_DELWRI)
255#define XFS_BUF_UNDELAYWRITE(bp) xfs_buf_delwri_dequeue(bp)
256#define XFS_BUF_ISDELAYWRITE(bp) ((bp)->b_flags & XBF_DELWRI)
257
258#define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE)
259#define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
260#define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
261
262#define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC)
263#define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
264#define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
265
266#define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ)
267#define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
268#define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
269
270#define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE)
271#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
272#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
273
274#define XFS_BUF_ADDR(bp) ((bp)->b_bn)
275#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
276#define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset)
277#define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off))
278#define XFS_BUF_COUNT(bp) ((bp)->b_count_desired)
279#define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt))
280#define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length)
281#define XFS_BUF_SET_SIZE(bp, cnt) ((bp)->b_buffer_length = (cnt))
282
283static inline void
284xfs_buf_set_ref(
285 struct xfs_buf *bp,
286 int lru_ref)
287{
288 atomic_set(&bp->b_lru_ref, lru_ref);
289}
290#define XFS_BUF_SET_VTYPE_REF(bp, type, ref) xfs_buf_set_ref(bp, ref)
291#define XFS_BUF_SET_VTYPE(bp, type) do { } while (0)
292
293static inline int xfs_buf_ispinned(struct xfs_buf *bp)
294{
295 return atomic_read(&bp->b_pin_count);
296}
297
298#define XFS_BUF_FINISH_IOWAIT(bp) complete(&bp->b_iowait);
299
300static inline void xfs_buf_relse(xfs_buf_t *bp)
301{
302 xfs_buf_unlock(bp);
303 xfs_buf_rele(bp);
304}
305
306/*
307 * Handling of buftargs.
308 */
309extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
310 struct block_device *, int, const char *);
311extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
312extern void xfs_wait_buftarg(xfs_buftarg_t *);
313extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
314extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
315
316#ifdef CONFIG_KDB_MODULES
317extern struct list_head *xfs_get_buftarg_list(void);
318#endif
319
320#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
321#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
322
323#define xfs_binval(buftarg) xfs_flush_buftarg(buftarg, 1)
324#define XFS_bflush(buftarg) xfs_flush_buftarg(buftarg, 1)
325
326#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_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__ */