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// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
  4 * All Rights Reserved.
 
 
 
 
 
 
 
 
 
 
 
 
 
  5 */
  6#ifndef __XFS_BUF_H__
  7#define __XFS_BUF_H__
  8
  9#include <linux/list.h>
 10#include <linux/types.h>
 11#include <linux/spinlock.h>
 
 12#include <linux/mm.h>
 13#include <linux/fs.h>
 14#include <linux/dax.h>
 15#include <linux/uio.h>
 16#include <linux/list_lru.h>
 17
 18/*
 19 *	Base types
 20 */
 21struct xfs_buf;
 22
 23#define XFS_BUF_DADDR_NULL	((xfs_daddr_t) (-1LL))
 24
 25#define XBF_READ	 (1 << 0) /* buffer intended for reading from device */
 26#define XBF_WRITE	 (1 << 1) /* buffer intended for writing to device */
 27#define XBF_READ_AHEAD	 (1 << 2) /* asynchronous read-ahead */
 28#define XBF_NO_IOACCT	 (1 << 3) /* bypass I/O accounting (non-LRU bufs) */
 29#define XBF_ASYNC	 (1 << 4) /* initiator will not wait for completion */
 30#define XBF_DONE	 (1 << 5) /* all pages in the buffer uptodate */
 31#define XBF_STALE	 (1 << 6) /* buffer has been staled, do not find it */
 32#define XBF_WRITE_FAIL	 (1 << 7) /* async writes have failed on this buffer */
 33
 34/* buffer type flags for write callbacks */
 35#define _XBF_INODES	 (1 << 16)/* inode buffer */
 36#define _XBF_DQUOTS	 (1 << 17)/* dquot buffer */
 37#define _XBF_LOGRECOVERY	 (1 << 18)/* log recovery buffer */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 38
 39/* flags used only internally */
 40#define _XBF_PAGES	 (1 << 20)/* backed by refcounted pages */
 41#define _XBF_KMEM	 (1 << 21)/* backed by heap memory */
 42#define _XBF_DELWRI_Q	 (1 << 22)/* buffer on a delwri queue */
 43
 44/* flags used only as arguments to access routines */
 45#define XBF_TRYLOCK	 (1 << 30)/* lock requested, but do not wait */
 46#define XBF_UNMAPPED	 (1 << 31)/* do not map the buffer */
 47
 48typedef unsigned int xfs_buf_flags_t;
 49
 50#define XFS_BUF_FLAGS \
 51	{ XBF_READ,		"READ" }, \
 52	{ XBF_WRITE,		"WRITE" }, \
 53	{ XBF_READ_AHEAD,	"READ_AHEAD" }, \
 54	{ XBF_NO_IOACCT,	"NO_IOACCT" }, \
 55	{ XBF_ASYNC,		"ASYNC" }, \
 56	{ XBF_DONE,		"DONE" }, \
 
 57	{ XBF_STALE,		"STALE" }, \
 58	{ XBF_WRITE_FAIL,	"WRITE_FAIL" }, \
 59	{ _XBF_INODES,		"INODES" }, \
 60	{ _XBF_DQUOTS,		"DQUOTS" }, \
 61	{ _XBF_LOGRECOVERY,		"LOG_RECOVERY" }, \
 
 
 62	{ _XBF_PAGES,		"PAGES" }, \
 63	{ _XBF_KMEM,		"KMEM" }, \
 64	{ _XBF_DELWRI_Q,	"DELWRI_Q" }, \
 65	/* The following interface flags should never be set */ \
 66	{ XBF_TRYLOCK,		"TRYLOCK" }, \
 67	{ XBF_UNMAPPED,		"UNMAPPED" }
 68
 69/*
 70 * Internal state flags.
 71 */
 72#define XFS_BSTATE_DISPOSE	 (1 << 0)	/* buffer being discarded */
 73#define XFS_BSTATE_IN_FLIGHT	 (1 << 1)	/* I/O in flight */
 74
 75/*
 76 * The xfs_buftarg contains 2 notions of "sector size" -
 77 *
 78 * 1) The metadata sector size, which is the minimum unit and
 79 *    alignment of IO which will be performed by metadata operations.
 80 * 2) The device logical sector size
 81 *
 82 * The first is specified at mkfs time, and is stored on-disk in the
 83 * superblock's sb_sectsize.
 84 *
 85 * The latter is derived from the underlying device, and controls direct IO
 86 * alignment constraints.
 87 */
 88typedef struct xfs_buftarg {
 89	dev_t			bt_dev;
 90	struct block_device	*bt_bdev;
 91	struct dax_device	*bt_daxdev;
 92	struct xfs_mount	*bt_mount;
 93	unsigned int		bt_meta_sectorsize;
 94	size_t			bt_meta_sectormask;
 95	size_t			bt_logical_sectorsize;
 96	size_t			bt_logical_sectormask;
 
 
 
 
 
 97
 98	/* LRU control structures */
 99	struct shrinker		bt_shrinker;
100	struct list_lru		bt_lru;
 
 
 
101
102	struct percpu_counter	bt_io_count;
103	struct ratelimit_state	bt_ioerror_rl;
104} xfs_buftarg_t;
105
106#define XB_PAGES	2
107
108struct xfs_buf_map {
109	xfs_daddr_t		bm_bn;	/* block number for I/O */
110	int			bm_len;	/* size of I/O */
111};
112
113#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
114	struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
115
116struct xfs_buf_ops {
117	char *name;
118	union {
119		__be32 magic[2];	/* v4 and v5 on disk magic values */
120		__be16 magic16[2];	/* v4 and v5 on disk magic values */
121	};
122	void (*verify_read)(struct xfs_buf *);
123	void (*verify_write)(struct xfs_buf *);
124	xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp);
125};
126
127typedef struct xfs_buf {
128	/*
129	 * first cacheline holds all the fields needed for an uncontended cache
130	 * hit to be fully processed. The semaphore straddles the cacheline
131	 * boundary, but the counter and lock sits on the first cacheline,
132	 * which is the only bit that is touched if we hit the semaphore
133	 * fast-path on locking.
134	 */
135	struct rhash_head	b_rhash_head;	/* pag buffer hash node */
136	xfs_daddr_t		b_bn;		/* block number of buffer */
137	int			b_length;	/* size of buffer in BBs */
138	atomic_t		b_hold;		/* reference count */
139	atomic_t		b_lru_ref;	/* lru reclaim ref count */
140	xfs_buf_flags_t		b_flags;	/* status flags */
141	struct semaphore	b_sema;		/* semaphore for lockables */
142
143	/*
144	 * concurrent access to b_lru and b_lru_flags are protected by
145	 * bt_lru_lock and not by b_sema
146	 */
147	struct list_head	b_lru;		/* lru list */
148	spinlock_t		b_lock;		/* internal state lock */
149	unsigned int		b_state;	/* internal state flags */
150	int			b_io_error;	/* internal IO error state */
151	wait_queue_head_t	b_waiters;	/* unpin waiters */
152	struct list_head	b_list;
153	struct xfs_perag	*b_pag;		/* contains rbtree root */
154	struct xfs_mount	*b_mount;
155	xfs_buftarg_t		*b_target;	/* buffer target (device) */
 
 
156	void			*b_addr;	/* virtual address of buffer */
157	struct work_struct	b_ioend_work;
 
158	struct completion	b_iowait;	/* queue for I/O waiters */
159	struct xfs_buf_log_item	*b_log_item;
160	struct list_head	b_li_list;	/* Log items list head */
161	struct xfs_trans	*b_transp;
162	struct page		**b_pages;	/* array of page pointers */
163	struct page		*b_page_array[XB_PAGES]; /* inline pages */
164	struct xfs_buf_map	*b_maps;	/* compound buffer map */
165	struct xfs_buf_map	__b_map;	/* inline compound buffer map */
166	int			b_map_count;
167	atomic_t		b_pin_count;	/* pin count */
168	atomic_t		b_io_remaining;	/* #outstanding I/O requests */
169	unsigned int		b_page_count;	/* size of page array */
170	unsigned int		b_offset;	/* page offset in first page */
171	int			b_error;	/* error code on I/O */
 
 
 
 
172
173	/*
174	 * async write failure retry count. Initialised to zero on the first
175	 * failure, then when it exceeds the maximum configured without a
176	 * success the write is considered to be failed permanently and the
177	 * iodone handler will take appropriate action.
178	 *
179	 * For retry timeouts, we record the jiffie of the first failure. This
180	 * means that we can change the retry timeout for buffers already under
181	 * I/O and thus avoid getting stuck in a retry loop with a long timeout.
182	 *
183	 * last_error is used to ensure that we are getting repeated errors, not
184	 * different errors. e.g. a block device might change ENOSPC to EIO when
185	 * a failure timeout occurs, so we want to re-initialise the error
186	 * retry behaviour appropriately when that happens.
187	 */
188	int			b_retries;
189	unsigned long		b_first_retry_time; /* in jiffies */
190	int			b_last_error;
191
192	const struct xfs_buf_ops	*b_ops;
193} xfs_buf_t;
194
195/* Finding and Reading Buffers */
196struct xfs_buf *xfs_buf_incore(struct xfs_buftarg *target,
197			   xfs_daddr_t blkno, size_t numblks,
198			   xfs_buf_flags_t flags);
199
200int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
201		int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
202int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
203		int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
204		const struct xfs_buf_ops *ops, xfs_failaddr_t fa);
205void xfs_buf_readahead_map(struct xfs_buftarg *target,
206			       struct xfs_buf_map *map, int nmaps,
207			       const struct xfs_buf_ops *ops);
208
209static inline int
210xfs_buf_get(
211	struct xfs_buftarg	*target,
212	xfs_daddr_t		blkno,
213	size_t			numblks,
214	struct xfs_buf		**bpp)
215{
216	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
217
218	return xfs_buf_get_map(target, &map, 1, 0, bpp);
219}
220
221static inline int
222xfs_buf_read(
223	struct xfs_buftarg	*target,
224	xfs_daddr_t		blkno,
225	size_t			numblks,
226	xfs_buf_flags_t		flags,
227	struct xfs_buf		**bpp,
228	const struct xfs_buf_ops *ops)
229{
230	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
231
232	return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,
233			__builtin_return_address(0));
234}
235
236static inline void
237xfs_buf_readahead(
238	struct xfs_buftarg	*target,
239	xfs_daddr_t		blkno,
240	size_t			numblks,
241	const struct xfs_buf_ops *ops)
242{
243	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
244	return xfs_buf_readahead_map(target, &map, 1, ops);
245}
246
247int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, int flags,
248		struct xfs_buf **bpp);
249int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
250			  size_t numblks, int flags, struct xfs_buf **bpp,
251			  const struct xfs_buf_ops *ops);
252void xfs_buf_hold(struct xfs_buf *bp);
253
254/* Releasing Buffers */
 
255extern void xfs_buf_rele(xfs_buf_t *);
256
257/* Locking and Unlocking Buffers */
258extern int xfs_buf_trylock(xfs_buf_t *);
259extern void xfs_buf_lock(xfs_buf_t *);
260extern void xfs_buf_unlock(xfs_buf_t *);
261#define xfs_buf_islocked(bp) \
262	((bp)->b_sema.count <= 0)
263
264static inline void xfs_buf_relse(xfs_buf_t *bp)
265{
266	xfs_buf_unlock(bp);
267	xfs_buf_rele(bp);
268}
269
270/* Buffer Read and Write Routines */
271extern int xfs_bwrite(struct xfs_buf *bp);
272extern void xfs_buf_ioend(struct xfs_buf *bp);
273static inline void xfs_buf_ioend_finish(struct xfs_buf *bp)
274{
275	if (bp->b_flags & XBF_ASYNC)
276		xfs_buf_relse(bp);
277	else
278		complete(&bp->b_iowait);
279}
280
281extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
282		xfs_failaddr_t failaddr);
283#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
284extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
285void xfs_buf_ioend_fail(struct xfs_buf *);
 
 
 
286
287extern int __xfs_buf_submit(struct xfs_buf *bp, bool);
288static inline int xfs_buf_submit(struct xfs_buf *bp)
289{
290	bool wait = bp->b_flags & XBF_ASYNC ? false : true;
291	return __xfs_buf_submit(bp, wait);
292}
293
294void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);
295void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa);
296#define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address)
297
298/* Buffer Utility Routines */
299extern void *xfs_buf_offset(struct xfs_buf *, size_t);
300extern void xfs_buf_stale(struct xfs_buf *bp);
301
302/* Delayed Write Buffer Routines */
303extern void xfs_buf_delwri_cancel(struct list_head *);
304extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
305extern int xfs_buf_delwri_submit(struct list_head *);
306extern int xfs_buf_delwri_submit_nowait(struct list_head *);
307extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *);
308
309/* Buffer Daemon Setup Routines */
310extern int xfs_buf_init(void);
311extern void xfs_buf_terminate(void);
312
313/*
314 * These macros use the IO block map rather than b_bn. b_bn is now really
315 * just for the buffer cache index for cached buffers. As IO does not use b_bn
316 * anymore, uncached buffers do not use b_bn at all and hence must modify the IO
317 * map directly. Uncached buffers are not allowed to be discontiguous, so this
318 * is safe to do.
319 *
320 * In future, uncached buffers will pass the block number directly to the io
321 * request function and hence these macros will go away at that point.
322 */
323#define XFS_BUF_ADDR(bp)		((bp)->b_maps[0].bm_bn)
324#define XFS_BUF_SET_ADDR(bp, bno)	((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
325
326void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
327
328/*
329 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer
330 * up with a reference count of 0 so it will be tossed from the cache when
331 * released.
332 */
333static inline void xfs_buf_oneshot(struct xfs_buf *bp)
334{
335	if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1)
336		return;
337	atomic_set(&bp->b_lru_ref, 0);
338}
 
 
339
340static inline int xfs_buf_ispinned(struct xfs_buf *bp)
341{
342	return atomic_read(&bp->b_pin_count);
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 *, struct dax_device *);
364extern void xfs_free_buftarg(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
371static inline int
372xfs_buftarg_dma_alignment(struct xfs_buftarg *bt)
373{
374	return queue_dma_alignment(bt->bt_bdev->bd_disk->queue);
375}
376
377int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops);
378bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);
379bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);
380
381#endif	/* __XFS_BUF_H__ */