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v3.1
  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__ */
v4.6
  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__ */