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xfs: clean up buffer allocation
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1da177e4 1/*
7b718769
NS
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
1da177e4 4 *
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NS
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
1da177e4
LT
7 * published by the Free Software Foundation.
8 *
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NS
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.
1da177e4 13 *
7b718769
NS
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
1da177e4 17 */
1da177e4
LT
18#ifndef __XFS_BUF_H__
19#define __XFS_BUF_H__
20
1da177e4
LT
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
ce8e922c
NS
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
807cbbdb
CH
47#define XBF_READ (1 << 0) /* buffer intended for reading from device */
48#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
1d5ae5df
CH
49#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
50#define XBF_MAPPED (1 << 3) /* buffer mapped (b_addr valid) */
807cbbdb
CH
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 */
1d5ae5df
CH
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 */
1da177e4 60
807cbbdb 61/* flags used only as arguments to access routines */
1d5ae5df
CH
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 */
1da177e4 65
807cbbdb 66/* flags used only internally */
1d5ae5df
CH
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 */
6ab455ee 70
807cbbdb 71typedef unsigned int xfs_buf_flags_t;
1da177e4 72
0b1b213f
CH
73#define XFS_BUF_FLAGS \
74 { XBF_READ, "READ" }, \
75 { XBF_WRITE, "WRITE" }, \
1d5ae5df 76 { XBF_READ_AHEAD, "READ_AHEAD" }, \
0b1b213f
CH
77 { XBF_MAPPED, "MAPPED" }, \
78 { XBF_ASYNC, "ASYNC" }, \
79 { XBF_DONE, "DONE" }, \
80 { XBF_DELWRI, "DELWRI" }, \
81 { XBF_STALE, "STALE" }, \
1d5ae5df
CH
82 { XBF_SYNCIO, "SYNCIO" }, \
83 { XBF_FUA, "FUA" }, \
84 { XBF_FLUSH, "FLUSH" }, \
0b1b213f
CH
85 { XBF_LOCK, "LOCK" }, /* should never be set */\
86 { XBF_TRYLOCK, "TRYLOCK" }, /* ditto */\
87 { XBF_DONT_BLOCK, "DONT_BLOCK" }, /* ditto */\
0b1b213f 88 { _XBF_PAGES, "PAGES" }, \
0e6e847f
DC
89 { _XBF_KMEM, "KMEM" }, \
90 { _XBF_DELWRI_Q, "DELWRI_Q" }
0b1b213f 91
ce8e922c 92typedef enum {
5e6a07df
DC
93 XBT_FORCE_SLEEP = 0,
94 XBT_FORCE_FLUSH = 1,
ce8e922c 95} xfs_buftarg_flags_t;
1da177e4 96
1da177e4 97typedef struct xfs_buftarg {
ce8e922c
NS
98 dev_t bt_dev;
99 struct block_device *bt_bdev;
0e6e847f 100 struct backing_dev_info *bt_bdi;
ebad861b 101 struct xfs_mount *bt_mount;
ce8e922c
NS
102 unsigned int bt_bsize;
103 unsigned int bt_sshift;
104 size_t bt_smask;
105
a6867a68
DC
106 /* per device delwri queue */
107 struct task_struct *bt_task;
c4e1c098
CH
108 struct list_head bt_delwri_queue;
109 spinlock_t bt_delwri_lock;
ce8e922c 110 unsigned long bt_flags;
ff57ab21
DC
111
112 /* LRU control structures */
113 struct shrinker bt_shrinker;
430cbeb8
DC
114 struct list_head bt_lru;
115 spinlock_t bt_lru_lock;
116 unsigned int bt_lru_nr;
1da177e4
LT
117} xfs_buftarg_t;
118
1da177e4 119struct xfs_buf;
ce8e922c 120typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
1da177e4 121
ce8e922c 122#define XB_PAGES 2
1da177e4
LT
123
124typedef struct xfs_buf {
50f59e8e
DC
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 */
430cbeb8 136 atomic_t b_lru_ref; /* lru reclaim ref count */
50f59e8e 137 xfs_buf_flags_t b_flags; /* status flags */
ce8e922c 138 struct semaphore b_sema; /* semaphore for lockables */
50f59e8e 139
430cbeb8 140 struct list_head b_lru; /* lru list */
ce8e922c
NS
141 wait_queue_head_t b_waiters; /* unpin waiters */
142 struct list_head b_list;
74f75a0c 143 struct xfs_perag *b_pag; /* contains rbtree root */
ce8e922c 144 xfs_buftarg_t *b_target; /* buffer target (device) */
ce8e922c 145 xfs_daddr_t b_bn; /* block number for I/O */
ce8e922c
NS
146 size_t b_count_desired;/* desired transfer size */
147 void *b_addr; /* virtual address of buffer */
148 struct work_struct b_iodone_work;
ce8e922c 149 xfs_buf_iodone_t b_iodone; /* I/O completion function */
b4dd330b 150 struct completion b_iowait; /* queue for I/O waiters */
ce8e922c 151 void *b_fspriv;
bf9d9013 152 struct xfs_trans *b_transp;
ce8e922c
NS
153 struct page **b_pages; /* array of page pointers */
154 struct page *b_page_array[XB_PAGES]; /* inline pages */
50f59e8e
DC
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 */
ce8e922c
NS
161#ifdef XFS_BUF_LOCK_TRACKING
162 int b_last_holder;
1da177e4
LT
163#endif
164} xfs_buf_t;
165
166
167/* Finding and Reading Buffers */
ce8e922c
NS
168extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
169 xfs_buf_flags_t, xfs_buf_t *);
1da177e4 170#define xfs_incore(buftarg,blkno,len,lockit) \
ce8e922c 171 _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
1da177e4 172
6ad112bf 173extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t,
ce8e922c 174 xfs_buf_flags_t);
6ad112bf 175extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t,
ce8e922c 176 xfs_buf_flags_t);
1da177e4 177
4347b9d7
CH
178struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *, xfs_off_t, size_t,
179 xfs_buf_flags_t);
44396476 180extern void xfs_buf_set_empty(struct xfs_buf *bp, size_t len);
686865f7 181extern xfs_buf_t *xfs_buf_get_uncached(struct xfs_buftarg *, size_t, int);
ce8e922c
NS
182extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
183extern void xfs_buf_hold(xfs_buf_t *);
1a1a3e97 184extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t);
5adc94c2
DC
185struct xfs_buf *xfs_buf_read_uncached(struct xfs_mount *mp,
186 struct xfs_buftarg *target,
187 xfs_daddr_t daddr, size_t length, int flags);
1da177e4
LT
188
189/* Releasing Buffers */
ce8e922c
NS
190extern void xfs_buf_free(xfs_buf_t *);
191extern void xfs_buf_rele(xfs_buf_t *);
1da177e4
LT
192
193/* Locking and Unlocking Buffers */
0c842ad4 194extern int xfs_buf_trylock(xfs_buf_t *);
ce8e922c
NS
195extern void xfs_buf_lock(xfs_buf_t *);
196extern void xfs_buf_unlock(xfs_buf_t *);
0c842ad4
CH
197#define xfs_buf_islocked(bp) \
198 ((bp)->b_sema.count <= 0)
1da177e4
LT
199
200/* Buffer Read and Write Routines */
c2b006c1 201extern int xfs_bwrite(struct xfs_buf *bp);
4e23471a
CH
202
203extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
204extern int xfs_bdstrat_cb(struct xfs_buf *);
205
ce8e922c
NS
206extern void xfs_buf_ioend(xfs_buf_t *, int);
207extern void xfs_buf_ioerror(xfs_buf_t *, int);
ce8e922c
NS
208extern int xfs_buf_iorequest(xfs_buf_t *);
209extern int xfs_buf_iowait(xfs_buf_t *);
b9c48649 210extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
ce8e922c 211 xfs_buf_rw_t);
1a1a3e97
CH
212#define xfs_buf_zero(bp, off, len) \
213 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
ce8e922c 214
ce8e922c 215static inline int xfs_buf_geterror(xfs_buf_t *bp)
1da177e4 216{
ce8e922c 217 return bp ? bp->b_error : ENOMEM;
1da177e4
LT
218}
219
220/* Buffer Utility Routines */
ce8e922c 221extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
1da177e4 222
1da177e4 223/* Delayed Write Buffer Routines */
61551f1e
CH
224extern void xfs_buf_delwri_queue(struct xfs_buf *);
225extern void xfs_buf_delwri_dequeue(struct xfs_buf *);
226extern void xfs_buf_delwri_promote(struct xfs_buf *);
1da177e4
LT
227
228/* Buffer Daemon Setup Routines */
ce8e922c
NS
229extern int xfs_buf_init(void);
230extern void xfs_buf_terminate(void);
1da177e4 231
c35a549c
CS
232static inline const char *
233xfs_buf_target_name(struct xfs_buftarg *target)
234{
235 static char __b[BDEVNAME_SIZE];
236
237 return bdevname(target->bt_bdev, __b);
238}
1da177e4
LT
239
240
1d5ae5df
CH
241#define XFS_BUF_ZEROFLAGS(bp) \
242 ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI| \
243 XBF_SYNCIO|XBF_FUA|XBF_FLUSH))
ce8e922c 244
430cbeb8 245void xfs_buf_stale(struct xfs_buf *bp);
0cadda1c
CH
246#define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE)
247#define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE)
1da177e4 248
ce8e922c
NS
249#define XFS_BUF_ISDELAYWRITE(bp) ((bp)->b_flags & XBF_DELWRI)
250
ce8e922c
NS
251#define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE)
252#define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
253#define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
254
ce8e922c
NS
255#define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC)
256#define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
257#define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
258
ce8e922c
NS
259#define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ)
260#define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
261#define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
262
263#define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE)
264#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
265#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
266
ce8e922c
NS
267#define XFS_BUF_ADDR(bp) ((bp)->b_bn)
268#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
269#define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset)
270#define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off))
271#define XFS_BUF_COUNT(bp) ((bp)->b_count_desired)
272#define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt))
273#define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length)
274#define XFS_BUF_SET_SIZE(bp, cnt) ((bp)->b_buffer_length = (cnt))
275
38f23232 276static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
821eb21d
DC
277{
278 atomic_set(&bp->b_lru_ref, lru_ref);
279}
ce8e922c 280
811e64c7
CS
281static inline int xfs_buf_ispinned(struct xfs_buf *bp)
282{
283 return atomic_read(&bp->b_pin_count);
284}
ce8e922c 285
ce8e922c 286static inline void xfs_buf_relse(xfs_buf_t *bp)
1da177e4 287{
bfc60177 288 xfs_buf_unlock(bp);
ce8e922c 289 xfs_buf_rele(bp);
1da177e4
LT
290}
291
1da177e4
LT
292/*
293 * Handling of buftargs.
294 */
ebad861b
DC
295extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
296 struct block_device *, int, const char *);
c141b292 297extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
1da177e4
LT
298extern void xfs_wait_buftarg(xfs_buftarg_t *);
299extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
1da177e4 300extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
d808f617 301
ce8e922c
NS
302#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
303#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
304
ce8e922c 305#define XFS_bflush(buftarg) xfs_flush_buftarg(buftarg, 1)
1da177e4
LT
306
307#endif /* __XFS_BUF_H__ */