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xfs: use blocks for counting length of buffers
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1da177e4 1/*
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2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
1da177e4 4 *
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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
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LT
7 * published by the Free Software Foundation.
8 *
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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 *
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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 */
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18#ifndef __XFS_BUF_H__
19#define __XFS_BUF_H__
20
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21#include <linux/list.h>
22#include <linux/types.h>
23#include <linux/spinlock.h>
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24#include <linux/mm.h>
25#include <linux/fs.h>
26#include <linux/buffer_head.h>
27#include <linux/uio.h>
28
29/*
30 * Base types
31 */
32
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33#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
34
35#define xfs_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE)
36#define xfs_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
37#define xfs_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT)
38#define xfs_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK)
39
40typedef enum {
41 XBRW_READ = 1, /* transfer into target memory */
42 XBRW_WRITE = 2, /* transfer from target memory */
43 XBRW_ZERO = 3, /* Zero target memory */
44} xfs_buf_rw_t;
45
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46#define XBF_READ (1 << 0) /* buffer intended for reading from device */
47#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */
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48#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
49#define XBF_MAPPED (1 << 3) /* buffer mapped (b_addr valid) */
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CH
50#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */
51#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */
43ff2122 52#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
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CH
53
54/* I/O hints for the BIO layer */
55#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */
56#define XBF_FUA (1 << 11)/* force cache write through mode */
57#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */
1da177e4 58
807cbbdb 59/* flags used only as arguments to access routines */
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60#define XBF_LOCK (1 << 15)/* lock requested */
61#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
62#define XBF_DONT_BLOCK (1 << 17)/* do not block in current thread */
1da177e4 63
807cbbdb 64/* flags used only internally */
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65#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
66#define _XBF_KMEM (1 << 21)/* backed by heap memory */
43ff2122 67#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */
6ab455ee 68
807cbbdb 69typedef unsigned int xfs_buf_flags_t;
1da177e4 70
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71#define XFS_BUF_FLAGS \
72 { XBF_READ, "READ" }, \
73 { XBF_WRITE, "WRITE" }, \
1d5ae5df 74 { XBF_READ_AHEAD, "READ_AHEAD" }, \
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75 { XBF_MAPPED, "MAPPED" }, \
76 { XBF_ASYNC, "ASYNC" }, \
77 { XBF_DONE, "DONE" }, \
0b1b213f 78 { XBF_STALE, "STALE" }, \
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79 { XBF_SYNCIO, "SYNCIO" }, \
80 { XBF_FUA, "FUA" }, \
81 { XBF_FLUSH, "FLUSH" }, \
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82 { XBF_LOCK, "LOCK" }, /* should never be set */\
83 { XBF_TRYLOCK, "TRYLOCK" }, /* ditto */\
84 { XBF_DONT_BLOCK, "DONT_BLOCK" }, /* ditto */\
0b1b213f 85 { _XBF_PAGES, "PAGES" }, \
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DC
86 { _XBF_KMEM, "KMEM" }, \
87 { _XBF_DELWRI_Q, "DELWRI_Q" }
0b1b213f 88
1da177e4 89typedef struct xfs_buftarg {
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90 dev_t bt_dev;
91 struct block_device *bt_bdev;
0e6e847f 92 struct backing_dev_info *bt_bdi;
ebad861b 93 struct xfs_mount *bt_mount;
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94 unsigned int bt_bsize;
95 unsigned int bt_sshift;
96 size_t bt_smask;
97
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98 /* LRU control structures */
99 struct shrinker bt_shrinker;
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100 struct list_head bt_lru;
101 spinlock_t bt_lru_lock;
102 unsigned int bt_lru_nr;
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103} xfs_buftarg_t;
104
1da177e4 105struct xfs_buf;
ce8e922c 106typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
1da177e4 107
ce8e922c 108#define XB_PAGES 2
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109
110typedef struct xfs_buf {
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111 /*
112 * first cacheline holds all the fields needed for an uncontended cache
113 * hit to be fully processed. The semaphore straddles the cacheline
114 * boundary, but the counter and lock sits on the first cacheline,
115 * which is the only bit that is touched if we hit the semaphore
116 * fast-path on locking.
117 */
118 struct rb_node b_rbnode; /* rbtree node */
de1cbee4 119 xfs_daddr_t b_bn; /* block number for I/O */
4e94b71b 120 int b_length; /* size of buffer in BBs */
50f59e8e 121 atomic_t b_hold; /* reference count */
430cbeb8 122 atomic_t b_lru_ref; /* lru reclaim ref count */
50f59e8e 123 xfs_buf_flags_t b_flags; /* status flags */
ce8e922c 124 struct semaphore b_sema; /* semaphore for lockables */
50f59e8e 125
430cbeb8 126 struct list_head b_lru; /* lru list */
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127 wait_queue_head_t b_waiters; /* unpin waiters */
128 struct list_head b_list;
74f75a0c 129 struct xfs_perag *b_pag; /* contains rbtree root */
ce8e922c 130 xfs_buftarg_t *b_target; /* buffer target (device) */
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131 size_t b_count_desired;/* desired transfer size */
132 void *b_addr; /* virtual address of buffer */
133 struct work_struct b_iodone_work;
ce8e922c 134 xfs_buf_iodone_t b_iodone; /* I/O completion function */
b4dd330b 135 struct completion b_iowait; /* queue for I/O waiters */
ce8e922c 136 void *b_fspriv;
bf9d9013 137 struct xfs_trans *b_transp;
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138 struct page **b_pages; /* array of page pointers */
139 struct page *b_page_array[XB_PAGES]; /* inline pages */
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140 atomic_t b_pin_count; /* pin count */
141 atomic_t b_io_remaining; /* #outstanding I/O requests */
142 unsigned int b_page_count; /* size of page array */
143 unsigned int b_offset; /* page offset in first page */
144 unsigned short b_error; /* error code on I/O */
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145#ifdef XFS_BUF_LOCK_TRACKING
146 int b_last_holder;
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147#endif
148} xfs_buf_t;
149
150
151/* Finding and Reading Buffers */
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152struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target, xfs_daddr_t blkno,
153 size_t numblks, xfs_buf_flags_t flags,
154 struct xfs_buf *new_bp);
1da177e4 155#define xfs_incore(buftarg,blkno,len,lockit) \
ce8e922c 156 _xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
1da177e4 157
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158struct xfs_buf *xfs_buf_get(struct xfs_buftarg *target, xfs_daddr_t blkno,
159 size_t numblks, xfs_buf_flags_t flags);
160struct xfs_buf *xfs_buf_read(struct xfs_buftarg *target, xfs_daddr_t blkno,
161 size_t numblks, xfs_buf_flags_t flags);
162void xfs_buf_readahead(struct xfs_buftarg *target, xfs_daddr_t blkno,
163 size_t numblks);
164
165struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks);
166struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *target, xfs_daddr_t blkno,
167 size_t numblks, xfs_buf_flags_t flags);
168void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks);
169int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length);
170
171struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
172 int flags);
173struct xfs_buf *xfs_buf_read_uncached(struct xfs_buftarg *target,
174 xfs_daddr_t daddr, size_t numblks, int flags);
175void xfs_buf_hold(struct xfs_buf *bp);
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176
177/* Releasing Buffers */
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178extern void xfs_buf_free(xfs_buf_t *);
179extern void xfs_buf_rele(xfs_buf_t *);
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180
181/* Locking and Unlocking Buffers */
0c842ad4 182extern int xfs_buf_trylock(xfs_buf_t *);
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183extern void xfs_buf_lock(xfs_buf_t *);
184extern void xfs_buf_unlock(xfs_buf_t *);
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185#define xfs_buf_islocked(bp) \
186 ((bp)->b_sema.count <= 0)
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187
188/* Buffer Read and Write Routines */
c2b006c1 189extern int xfs_bwrite(struct xfs_buf *bp);
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190
191extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
192extern int xfs_bdstrat_cb(struct xfs_buf *);
193
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194extern void xfs_buf_ioend(xfs_buf_t *, int);
195extern void xfs_buf_ioerror(xfs_buf_t *, int);
901796af 196extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
0e95f19a 197extern void xfs_buf_iorequest(xfs_buf_t *);
ce8e922c 198extern int xfs_buf_iowait(xfs_buf_t *);
b9c48649 199extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
ce8e922c 200 xfs_buf_rw_t);
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201#define xfs_buf_zero(bp, off, len) \
202 xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
ce8e922c 203
ce8e922c 204static inline int xfs_buf_geterror(xfs_buf_t *bp)
1da177e4 205{
ce8e922c 206 return bp ? bp->b_error : ENOMEM;
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207}
208
209/* Buffer Utility Routines */
ce8e922c 210extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
1da177e4 211
1da177e4 212/* Delayed Write Buffer Routines */
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CH
213extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
214extern int xfs_buf_delwri_submit(struct list_head *);
215extern int xfs_buf_delwri_submit_nowait(struct list_head *);
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216
217/* Buffer Daemon Setup Routines */
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218extern int xfs_buf_init(void);
219extern void xfs_buf_terminate(void);
1da177e4 220
1d5ae5df 221#define XFS_BUF_ZEROFLAGS(bp) \
43ff2122 222 ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC| \
1d5ae5df 223 XBF_SYNCIO|XBF_FUA|XBF_FLUSH))
ce8e922c 224
430cbeb8 225void xfs_buf_stale(struct xfs_buf *bp);
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CH
226#define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE)
227#define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE)
1da177e4 228
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229#define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE)
230#define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
231#define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
232
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233#define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC)
234#define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
235#define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
236
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237#define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ)
238#define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
239#define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
240
241#define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE)
242#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
243#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
244
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245#define XFS_BUF_ADDR(bp) ((bp)->b_bn)
246#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
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247#define XFS_BUF_COUNT(bp) ((bp)->b_count_desired)
248#define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt))
ce8e922c 249
38f23232 250static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
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DC
251{
252 atomic_set(&bp->b_lru_ref, lru_ref);
253}
ce8e922c 254
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255static inline int xfs_buf_ispinned(struct xfs_buf *bp)
256{
257 return atomic_read(&bp->b_pin_count);
258}
ce8e922c 259
ce8e922c 260static inline void xfs_buf_relse(xfs_buf_t *bp)
1da177e4 261{
bfc60177 262 xfs_buf_unlock(bp);
ce8e922c 263 xfs_buf_rele(bp);
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264}
265
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LT
266/*
267 * Handling of buftargs.
268 */
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DC
269extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
270 struct block_device *, int, const char *);
c141b292 271extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
1da177e4
LT
272extern void xfs_wait_buftarg(xfs_buftarg_t *);
273extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
d808f617 274
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NS
275#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
276#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
277
1da177e4 278#endif /* __XFS_BUF_H__ */