[people/ms/linux.git] / fs / xfs / xfs_buf.h

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_BUF_H__
#define __XFS_BUF_H__

#include <linux/list.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/dax.h>
#include <linux/uio.h>
#include <linux/list_lru.h>

extern struct kmem_cache *xfs_buf_cache;

/*
 *	Base types
 */
struct xfs_buf;

#define XFS_BUF_DADDR_NULL	((xfs_daddr_t) (-1LL))

#define XBF_READ	 (1u << 0) /* buffer intended for reading from device */
#define XBF_WRITE	 (1u << 1) /* buffer intended for writing to device */
#define XBF_READ_AHEAD	 (1u << 2) /* asynchronous read-ahead */
#define XBF_NO_IOACCT	 (1u << 3) /* bypass I/O accounting (non-LRU bufs) */
#define XBF_ASYNC	 (1u << 4) /* initiator will not wait for completion */
#define XBF_DONE	 (1u << 5) /* all pages in the buffer uptodate */
#define XBF_STALE	 (1u << 6) /* buffer has been staled, do not find it */
#define XBF_WRITE_FAIL	 (1u << 7) /* async writes have failed on this buffer */

/* buffer type flags for write callbacks */
#define _XBF_INODES	 (1u << 16)/* inode buffer */
#define _XBF_DQUOTS	 (1u << 17)/* dquot buffer */
#define _XBF_LOGRECOVERY (1u << 18)/* log recovery buffer */

/* flags used only internally */
#define _XBF_PAGES	 (1u << 20)/* backed by refcounted pages */
#define _XBF_KMEM	 (1u << 21)/* backed by heap memory */
#define _XBF_DELWRI_Q	 (1u << 22)/* buffer on a delwri queue */

/* flags used only as arguments to access routines */
#define XBF_INCORE	 (1u << 29)/* lookup only, return if found in cache */
#define XBF_TRYLOCK	 (1u << 30)/* lock requested, but do not wait */
#define XBF_UNMAPPED	 (1u << 31)/* do not map the buffer */


typedef unsigned int xfs_buf_flags_t;

#define XFS_BUF_FLAGS \
	{ XBF_READ,		"READ" }, \
	{ XBF_WRITE,		"WRITE" }, \
	{ XBF_READ_AHEAD,	"READ_AHEAD" }, \
	{ XBF_NO_IOACCT,	"NO_IOACCT" }, \
	{ XBF_ASYNC,		"ASYNC" }, \
	{ XBF_DONE,		"DONE" }, \
	{ XBF_STALE,		"STALE" }, \
	{ XBF_WRITE_FAIL,	"WRITE_FAIL" }, \
	{ _XBF_INODES,		"INODES" }, \
	{ _XBF_DQUOTS,		"DQUOTS" }, \
	{ _XBF_LOGRECOVERY,	"LOG_RECOVERY" }, \
	{ _XBF_PAGES,		"PAGES" }, \
	{ _XBF_KMEM,		"KMEM" }, \
	{ _XBF_DELWRI_Q,	"DELWRI_Q" }, \
	/* The following interface flags should never be set */ \
	{ XBF_INCORE,		"INCORE" }, \
	{ XBF_TRYLOCK,		"TRYLOCK" }, \
	{ XBF_UNMAPPED,		"UNMAPPED" }

/*
 * Internal state flags.
 */
#define XFS_BSTATE_DISPOSE	 (1 << 0)	/* buffer being discarded */
#define XFS_BSTATE_IN_FLIGHT	 (1 << 1)	/* I/O in flight */

/*
 * The xfs_buftarg contains 2 notions of "sector size" -
 *
 * 1) The metadata sector size, which is the minimum unit and
 *    alignment of IO which will be performed by metadata operations.
 * 2) The device logical sector size
 *
 * The first is specified at mkfs time, and is stored on-disk in the
 * superblock's sb_sectsize.
 *
 * The latter is derived from the underlying device, and controls direct IO
 * alignment constraints.
 */
typedef struct xfs_buftarg {
	dev_t			bt_dev;
	struct block_device	*bt_bdev;
	struct dax_device	*bt_daxdev;
	u64			bt_dax_part_off;
	struct xfs_mount	*bt_mount;
	unsigned int		bt_meta_sectorsize;
	size_t			bt_meta_sectormask;
	size_t			bt_logical_sectorsize;
	size_t			bt_logical_sectormask;

	/* LRU control structures */
	struct shrinker		bt_shrinker;
	struct list_lru		bt_lru;

	struct percpu_counter	bt_io_count;
	struct ratelimit_state	bt_ioerror_rl;
} xfs_buftarg_t;

#define XB_PAGES	2

struct xfs_buf_map {
	xfs_daddr_t		bm_bn;	/* block number for I/O */
	int			bm_len;	/* size of I/O */
};

#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
	struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };

struct xfs_buf_ops {
	char *name;
	union {
		__be32 magic[2];	/* v4 and v5 on disk magic values */
		__be16 magic16[2];	/* v4 and v5 on disk magic values */
	};
	void (*verify_read)(struct xfs_buf *);
	void (*verify_write)(struct xfs_buf *);
	xfs_failaddr_t (*verify_struct)(struct xfs_buf *bp);
};

struct xfs_buf {
	/*
	 * first cacheline holds all the fields needed for an uncontended cache
	 * hit to be fully processed. The semaphore straddles the cacheline
	 * boundary, but the counter and lock sits on the first cacheline,
	 * which is the only bit that is touched if we hit the semaphore
	 * fast-path on locking.
	 */
	struct rhash_head	b_rhash_head;	/* pag buffer hash node */

	xfs_daddr_t		b_rhash_key;	/* buffer cache index */
	int			b_length;	/* size of buffer in BBs */
	atomic_t		b_hold;		/* reference count */
	atomic_t		b_lru_ref;	/* lru reclaim ref count */
	xfs_buf_flags_t		b_flags;	/* status flags */
	struct semaphore	b_sema;		/* semaphore for lockables */

	/*
	 * concurrent access to b_lru and b_lru_flags are protected by
	 * bt_lru_lock and not by b_sema
	 */
	struct list_head	b_lru;		/* lru list */
	spinlock_t		b_lock;		/* internal state lock */
	unsigned int		b_state;	/* internal state flags */
	int			b_io_error;	/* internal IO error state */
	wait_queue_head_t	b_waiters;	/* unpin waiters */
	struct list_head	b_list;
	struct xfs_perag	*b_pag;		/* contains rbtree root */
	struct xfs_mount	*b_mount;
	struct xfs_buftarg	*b_target;	/* buffer target (device) */
	void			*b_addr;	/* virtual address of buffer */
	struct work_struct	b_ioend_work;
	struct completion	b_iowait;	/* queue for I/O waiters */
	struct xfs_buf_log_item	*b_log_item;
	struct list_head	b_li_list;	/* Log items list head */
	struct xfs_trans	*b_transp;
	struct page		**b_pages;	/* array of page pointers */
	struct page		*b_page_array[XB_PAGES]; /* inline pages */
	struct xfs_buf_map	*b_maps;	/* compound buffer map */
	struct xfs_buf_map	__b_map;	/* inline compound buffer map */
	int			b_map_count;
	atomic_t		b_pin_count;	/* pin count */
	atomic_t		b_io_remaining;	/* #outstanding I/O requests */
	unsigned int		b_page_count;	/* size of page array */
	unsigned int		b_offset;	/* page offset of b_addr,
						   only for _XBF_KMEM buffers */
	int			b_error;	/* error code on I/O */

	/*
	 * async write failure retry count. Initialised to zero on the first
	 * failure, then when it exceeds the maximum configured without a
	 * success the write is considered to be failed permanently and the
	 * iodone handler will take appropriate action.
	 *
	 * For retry timeouts, we record the jiffie of the first failure. This
	 * means that we can change the retry timeout for buffers already under
	 * I/O and thus avoid getting stuck in a retry loop with a long timeout.
	 *
	 * last_error is used to ensure that we are getting repeated errors, not
	 * different errors. e.g. a block device might change ENOSPC to EIO when
	 * a failure timeout occurs, so we want to re-initialise the error
	 * retry behaviour appropriately when that happens.
	 */
	int			b_retries;
	unsigned long		b_first_retry_time; /* in jiffies */
	int			b_last_error;

	const struct xfs_buf_ops	*b_ops;
	struct rcu_head		b_rcu;
};

/* Finding and Reading Buffers */
int xfs_buf_get_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
		int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
int xfs_buf_read_map(struct xfs_buftarg *target, struct xfs_buf_map *map,
		int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
		const struct xfs_buf_ops *ops, xfs_failaddr_t fa);
void xfs_buf_readahead_map(struct xfs_buftarg *target,
			       struct xfs_buf_map *map, int nmaps,
			       const struct xfs_buf_ops *ops);

static inline int
xfs_buf_incore(
	struct xfs_buftarg	*target,
	xfs_daddr_t		blkno,
	size_t			numblks,
	xfs_buf_flags_t		flags,
	struct xfs_buf		**bpp)
{
	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);

	return xfs_buf_get_map(target, &map, 1, XBF_INCORE | flags, bpp);
}

static inline int
xfs_buf_get(
	struct xfs_buftarg	*target,
	xfs_daddr_t		blkno,
	size_t			numblks,
	struct xfs_buf		**bpp)
{
	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);

	return xfs_buf_get_map(target, &map, 1, 0, bpp);
}

static inline int
xfs_buf_read(
	struct xfs_buftarg	*target,
	xfs_daddr_t		blkno,
	size_t			numblks,
	xfs_buf_flags_t		flags,
	struct xfs_buf		**bpp,
	const struct xfs_buf_ops *ops)
{
	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);

	return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,
			__builtin_return_address(0));
}

static inline void
xfs_buf_readahead(
	struct xfs_buftarg	*target,
	xfs_daddr_t		blkno,
	size_t			numblks,
	const struct xfs_buf_ops *ops)
{
	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
	return xfs_buf_readahead_map(target, &map, 1, ops);
}

int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
		xfs_buf_flags_t flags, struct xfs_buf **bpp);
int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
		size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp,
		const struct xfs_buf_ops *ops);
int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags);
void xfs_buf_hold(struct xfs_buf *bp);

/* Releasing Buffers */
extern void xfs_buf_rele(struct xfs_buf *);

/* Locking and Unlocking Buffers */
extern int xfs_buf_trylock(struct xfs_buf *);
extern void xfs_buf_lock(struct xfs_buf *);
extern void xfs_buf_unlock(struct xfs_buf *);
#define xfs_buf_islocked(bp) \
	((bp)->b_sema.count <= 0)

static inline void xfs_buf_relse(struct xfs_buf *bp)
{
	xfs_buf_unlock(bp);
	xfs_buf_rele(bp);
}

/* Buffer Read and Write Routines */
extern int xfs_bwrite(struct xfs_buf *bp);

extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
		xfs_failaddr_t failaddr);
#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
void xfs_buf_ioend_fail(struct xfs_buf *);
void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);
void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa);
#define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address)

/* Buffer Utility Routines */
extern void *xfs_buf_offset(struct xfs_buf *, size_t);
extern void xfs_buf_stale(struct xfs_buf *bp);

/* Delayed Write Buffer Routines */
extern void xfs_buf_delwri_cancel(struct list_head *);
extern bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *);
extern int xfs_buf_delwri_submit(struct list_head *);
extern int xfs_buf_delwri_submit_nowait(struct list_head *);
extern int xfs_buf_delwri_pushbuf(struct xfs_buf *, struct list_head *);

static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp)
{
	return bp->b_maps[0].bm_bn;
}

void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);

/*
 * If the buffer is already on the LRU, do nothing. Otherwise set the buffer
 * up with a reference count of 0 so it will be tossed from the cache when
 * released.
 */
static inline void xfs_buf_oneshot(struct xfs_buf *bp)
{
	if (!list_empty(&bp->b_lru) || atomic_read(&bp->b_lru_ref) > 1)
		return;
	atomic_set(&bp->b_lru_ref, 0);
}

static inline int xfs_buf_ispinned(struct xfs_buf *bp)
{
	return atomic_read(&bp->b_pin_count);
}

static inline int
xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
{
	return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
				cksum_offset);
}

static inline void
xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
{
	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
			 cksum_offset);
}

/*
 *	Handling of buftargs.
 */
struct xfs_buftarg *xfs_alloc_buftarg(struct xfs_mount *mp,
		struct block_device *bdev);
extern void xfs_free_buftarg(struct xfs_buftarg *);
extern void xfs_buftarg_wait(struct xfs_buftarg *);
extern void xfs_buftarg_drain(struct xfs_buftarg *);
extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int);

#define xfs_getsize_buftarg(buftarg)	block_size((buftarg)->bt_bdev)
#define xfs_readonly_buftarg(buftarg)	bdev_read_only((buftarg)->bt_bdev)

int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops);
bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);
bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);

#endif	/* __XFS_BUF_H__ */
Commit	Line	Data
0b61f8a4	1	// SPDX-License-Identifier: GPL-2.0
1da177e4	2	/*
7b718769 NS	3	* Copyright (c) 2000-2005 Silicon Graphics, Inc.
7b718769 NS	4	* All Rights Reserved.
1da177e4	5	*/
1da177e4 LT	6	#ifndef __XFS_BUF_H__
	7	#define __XFS_BUF_H__
	8
1da177e4 LT	9	#include <linux/list.h>
	10	#include <linux/types.h>
	11	#include <linux/spinlock.h>
1da177e4 LT	12	#include <linux/mm.h>
1da177e4 LT	13	#include <linux/fs.h>
c94c2acf	14	#include <linux/dax.h>
1da177e4	15	#include <linux/uio.h>
e80dfa19	16	#include <linux/list_lru.h>
1da177e4	17
231f91ab DC	18	extern struct kmem_cache *xfs_buf_cache;
231f91ab DC	19
1da177e4 LT	20	/*
	21	* Base types
	22	*/
b01d1461	23	struct xfs_buf;
1da177e4	24
ce8e922c NS	25	#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
ce8e922c NS	26
b9b3fe15 DC	27	#define XBF_READ (1u << 0) /* buffer intended for reading from device */
	28	#define XBF_WRITE (1u << 1) /* buffer intended for writing to device */
	29	#define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */
	30	#define XBF_NO_IOACCT (1u << 3) /* bypass I/O accounting (non-LRU bufs) */
	31	#define XBF_ASYNC (1u << 4) /* initiator will not wait for completion */
	32	#define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */
	33	#define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */
	34	#define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */
1d5ae5df	35
f593bf14	36	/* buffer type flags for write callbacks */
b9b3fe15 DC	37	#define _XBF_INODES (1u << 16)/* inode buffer */
	38	#define _XBF_DQUOTS (1u << 17)/* dquot buffer */
	39	#define _XBF_LOGRECOVERY (1u << 18)/* log recovery buffer */
1da177e4	40
807cbbdb	41	/* flags used only internally */
b9b3fe15 DC	42	#define _XBF_PAGES (1u << 20)/* backed by refcounted pages */
	43	#define _XBF_KMEM (1u << 21)/* backed by heap memory */
	44	#define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */
6ab455ee	45
f593bf14	46	/* flags used only as arguments to access routines */
85c73bf7	47	#define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */
b9b3fe15 DC	48	#define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */
b9b3fe15 DC	49	#define XBF_UNMAPPED (1u << 31)/* do not map the buffer */
f593bf14	50
85c73bf7	51
807cbbdb	52	typedef unsigned int xfs_buf_flags_t;
1da177e4	53
0b1b213f CH	54	#define XFS_BUF_FLAGS \
	55	{ XBF_READ, "READ" }, \
	56	{ XBF_WRITE, "WRITE" }, \
1d5ae5df	57	{ XBF_READ_AHEAD, "READ_AHEAD" }, \
1247ec4c	58	{ XBF_NO_IOACCT, "NO_IOACCT" }, \
0b1b213f CH	59	{ XBF_ASYNC, "ASYNC" }, \
0b1b213f CH	60	{ XBF_DONE, "DONE" }, \
0b1b213f	61	{ XBF_STALE, "STALE" }, \
ac8809f9	62	{ XBF_WRITE_FAIL, "WRITE_FAIL" }, \
f593bf14	63	{ _XBF_INODES, "INODES" }, \
0c7e5afb	64	{ _XBF_DQUOTS, "DQUOTS" }, \
b9b3fe15	65	{ _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \
0b1b213f	66	{ _XBF_PAGES, "PAGES" }, \
0e6e847f	67	{ _XBF_KMEM, "KMEM" }, \
f593bf14 DC	68	{ _XBF_DELWRI_Q, "DELWRI_Q" }, \
f593bf14 DC	69	/* The following interface flags should never be set */ \
85c73bf7	70	{ XBF_INCORE, "INCORE" }, \
f593bf14 DC	71	{ XBF_TRYLOCK, "TRYLOCK" }, \
f593bf14 DC	72	{ XBF_UNMAPPED, "UNMAPPED" }
ac8809f9	73
a4082357 DC	74	/*
	75	* Internal state flags.
	76	*/
	77	#define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
63db7c81	78	#define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */
0b1b213f	79
7c71ee78 ES	80	/*
	81	* The xfs_buftarg contains 2 notions of "sector size" -
	82	*
	83	* 1) The metadata sector size, which is the minimum unit and
	84	* alignment of IO which will be performed by metadata operations.
	85	* 2) The device logical sector size
	86	*
	87	* The first is specified at mkfs time, and is stored on-disk in the
	88	* superblock's sb_sectsize.
	89	*
	90	* The latter is derived from the underlying device, and controls direct IO
	91	* alignment constraints.
	92	*/
1da177e4	93	typedef struct xfs_buftarg {
ce8e922c NS	94	dev_t bt_dev;
ce8e922c NS	95	struct block_device *bt_bdev;
486aff5e	96	struct dax_device *bt_daxdev;
cd913c76	97	u64 bt_dax_part_off;
ebad861b	98	struct xfs_mount *bt_mount;
6da54179 ES	99	unsigned int bt_meta_sectorsize;
6da54179 ES	100	size_t bt_meta_sectormask;
7c71ee78 ES	101	size_t bt_logical_sectorsize;
7c71ee78 ES	102	size_t bt_logical_sectormask;
ce8e922c	103
ff57ab21 DC	104	/* LRU control structures */
ff57ab21 DC	105	struct shrinker bt_shrinker;
e80dfa19	106	struct list_lru bt_lru;
9c7504aa BF	107
9c7504aa BF	108	struct percpu_counter bt_io_count;
f9bccfcc	109	struct ratelimit_state bt_ioerror_rl;
1da177e4 LT	110	} xfs_buftarg_t;
1da177e4 LT	111
ce8e922c	112	#define XB_PAGES 2
1da177e4	113
cbb7baab DC	114	struct xfs_buf_map {
	115	xfs_daddr_t bm_bn; /* block number for I/O */
	116	int bm_len; /* size of I/O */
	117	};
	118
3e85c868 DC	119	#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
	120	struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
	121
1813dd64	122	struct xfs_buf_ops {
233135b7	123	char *name;
15baadf7 DW	124	union {
	125	__be32 magic[2]; /* v4 and v5 on disk magic values */
	126	__be16 magic16[2]; /* v4 and v5 on disk magic values */
	127	};
1813dd64 DC	128	void (verify_read)(struct xfs_buf );
1813dd64 DC	129	void (verify_write)(struct xfs_buf );
b5572597	130	xfs_failaddr_t (verify_struct)(struct xfs_buf bp);
1813dd64 DC	131	};
1813dd64 DC	132
e8222613	133	struct xfs_buf {
50f59e8e DC	134	/*
	135	* first cacheline holds all the fields needed for an uncontended cache
	136	* hit to be fully processed. The semaphore straddles the cacheline
	137	* boundary, but the counter and lock sits on the first cacheline,
	138	* which is the only bit that is touched if we hit the semaphore
	139	* fast-path on locking.
	140	*/
6031e73a	141	struct rhash_head b_rhash_head; /* pag buffer hash node */
8cf07f3d	142
4c7f65ae	143	xfs_daddr_t b_rhash_key; /* buffer cache index */
4e94b71b	144	int b_length; /* size of buffer in BBs */
50f59e8e	145	atomic_t b_hold; /* reference count */
430cbeb8	146	atomic_t b_lru_ref; /* lru reclaim ref count */
50f59e8e	147	xfs_buf_flags_t b_flags; /* status flags */
ce8e922c	148	struct semaphore b_sema; /* semaphore for lockables */
50f59e8e	149
6fb8a90a CM	150	/*
	151	* concurrent access to b_lru and b_lru_flags are protected by
	152	* bt_lru_lock and not by b_sema
	153	*/
430cbeb8	154	struct list_head b_lru; /* lru list */
a4082357 DC	155	spinlock_t b_lock; /* internal state lock */
a4082357 DC	156	unsigned int b_state; /* internal state flags */
61be9c52	157	int b_io_error; /* internal IO error state */
ce8e922c NS	158	wait_queue_head_t b_waiters; /* unpin waiters */
ce8e922c NS	159	struct list_head b_list;
74f75a0c	160	struct xfs_perag b_pag; / contains rbtree root */
dbd329f1	161	struct xfs_mount *b_mount;
10fb9ac1	162	struct xfs_buftarg b_target; / buffer target (device) */
ce8e922c	163	void b_addr; / virtual address of buffer */
b29c70f5	164	struct work_struct b_ioend_work;
b4dd330b	165	struct completion b_iowait; /* queue for I/O waiters */
e99b4bd0	166	struct xfs_buf_log_item *b_log_item;
643c8c05	167	struct list_head b_li_list; /* Log items list head */
bf9d9013	168	struct xfs_trans *b_transp;
ce8e922c NS	169	struct page *b_pages; / array of page pointers */
ce8e922c NS	170	struct page b_page_array[XB_PAGES]; / inline pages */
3e85c868	171	struct xfs_buf_map b_maps; / compound buffer map */
d44d9bc6	172	struct xfs_buf_map __b_map; /* inline compound buffer map */
3e85c868	173	int b_map_count;
50f59e8e DC	174	atomic_t b_pin_count; /* pin count */
	175	atomic_t b_io_remaining; /* #outstanding I/O requests */
	176	unsigned int b_page_count; /* size of page array */
54cd3aa6 CH	177	unsigned int b_offset; /* page offset of b_addr,
54cd3aa6 CH	178	only for _XBF_KMEM buffers */
2451337d	179	int b_error; /* error code on I/O */
a5ea70d2 CM	180
	181	/*
	182	* async write failure retry count. Initialised to zero on the first
	183	* failure, then when it exceeds the maximum configured without a
	184	* success the write is considered to be failed permanently and the
	185	* iodone handler will take appropriate action.
	186	*
	187	* For retry timeouts, we record the jiffie of the first failure. This
	188	* means that we can change the retry timeout for buffers already under
	189	* I/O and thus avoid getting stuck in a retry loop with a long timeout.
	190	*
	191	* last_error is used to ensure that we are getting repeated errors, not
	192	* different errors. e.g. a block device might change ENOSPC to EIO when
	193	* a failure timeout occurs, so we want to re-initialise the error
	194	* retry behaviour appropriately when that happens.
	195	*/
	196	int b_retries;
	197	unsigned long b_first_retry_time; /* in jiffies */
	198	int b_last_error;
	199
1813dd64	200	const struct xfs_buf_ops *b_ops;
298f3422	201	struct rcu_head b_rcu;
e8222613	202	};
1da177e4	203
1da177e4	204	/* Finding and Reading Buffers */
3848b5f6 DW	205	int xfs_buf_get_map(struct xfs_buftarg target, struct xfs_buf_map map,
3848b5f6 DW	206	int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
4ed8e27b DW	207	int xfs_buf_read_map(struct xfs_buftarg target, struct xfs_buf_map map,
4ed8e27b DW	208	int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
cdbcf82b	209	const struct xfs_buf_ops *ops, xfs_failaddr_t fa);
6dde2707	210	void xfs_buf_readahead_map(struct xfs_buftarg *target,
c3f8fc73	211	struct xfs_buf_map *map, int nmaps,
1813dd64	212	const struct xfs_buf_ops *ops);
6dde2707	213
85c73bf7 DC	214	static inline int
	215	xfs_buf_incore(
	216	struct xfs_buftarg *target,
	217	xfs_daddr_t blkno,
	218	size_t numblks,
	219	xfs_buf_flags_t flags,
	220	struct xfs_buf **bpp)
	221	{
	222	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
	223
	224	return xfs_buf_get_map(target, &map, 1, XBF_INCORE \| flags, bpp);
	225	}
	226
841263e9	227	static inline int
6dde2707 DC	228	xfs_buf_get(
	229	struct xfs_buftarg *target,
	230	xfs_daddr_t blkno,
841263e9 DW	231	size_t numblks,
841263e9 DW	232	struct xfs_buf **bpp)
6dde2707 DC	233	{
6dde2707 DC	234	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
3848b5f6	235
841263e9	236	return xfs_buf_get_map(target, &map, 1, 0, bpp);
6dde2707 DC	237	}
6dde2707 DC	238
0e3eccce	239	static inline int
6dde2707 DC	240	xfs_buf_read(
	241	struct xfs_buftarg *target,
	242	xfs_daddr_t blkno,
	243	size_t numblks,
c3f8fc73	244	xfs_buf_flags_t flags,
0e3eccce	245	struct xfs_buf **bpp,
1813dd64	246	const struct xfs_buf_ops *ops)
6dde2707 DC	247	{
6dde2707 DC	248	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
4ed8e27b	249
cdbcf82b DW	250	return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,
cdbcf82b DW	251	__builtin_return_address(0));
6dde2707 DC	252	}
	253
	254	static inline void
	255	xfs_buf_readahead(
	256	struct xfs_buftarg *target,
	257	xfs_daddr_t blkno,
c3f8fc73	258	size_t numblks,
1813dd64	259	const struct xfs_buf_ops *ops)
6dde2707 DC	260	{
6dde2707 DC	261	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
1813dd64	262	return xfs_buf_readahead_map(target, &map, 1, ops);
6dde2707	263	}
e70b73f8	264
b9b3fe15 DC	265	int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
b9b3fe15 DC	266	xfs_buf_flags_t flags, struct xfs_buf **bpp);
ba372674	267	int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
b9b3fe15 DC	268	size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp,
b9b3fe15 DC	269	const struct xfs_buf_ops *ops);
26e32875	270	int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags);
e70b73f8	271	void xfs_buf_hold(struct xfs_buf *bp);
1da177e4 LT	272
1da177e4 LT	273	/* Releasing Buffers */
e8222613	274	extern void xfs_buf_rele(struct xfs_buf *);
1da177e4 LT	275
1da177e4 LT	276	/* Locking and Unlocking Buffers */
e8222613 DC	277	extern int xfs_buf_trylock(struct xfs_buf *);
	278	extern void xfs_buf_lock(struct xfs_buf *);
	279	extern void xfs_buf_unlock(struct xfs_buf *);
0c842ad4 CH	280	#define xfs_buf_islocked(bp) \
0c842ad4 CH	281	((bp)->b_sema.count <= 0)
1da177e4	282
e8222613	283	static inline void xfs_buf_relse(struct xfs_buf *bp)
f593bf14 DC	284	{
	285	xfs_buf_unlock(bp);
	286	xfs_buf_rele(bp);
	287	}
	288
1da177e4	289	/* Buffer Read and Write Routines */
c2b006c1	290	extern int xfs_bwrite(struct xfs_buf *bp);
f593bf14	291
31ca03c9 DW	292	extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
	293	xfs_failaddr_t failaddr);
	294	#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
cdbcf82b	295	extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
54b3b1f6	296	void xfs_buf_ioend_fail(struct xfs_buf *);
f9a196ee	297	void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);
8d57c216 DW	298	void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa);
8d57c216 DW	299	#define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address)
ce8e922c	300
1da177e4	301	/* Buffer Utility Routines */
88ee2df7	302	extern void xfs_buf_offset(struct xfs_buf , size_t);
5cfd28b6	303	extern void xfs_buf_stale(struct xfs_buf *bp);
1da177e4	304
1da177e4	305	/* Delayed Write Buffer Routines */
20e8a063	306	extern void xfs_buf_delwri_cancel(struct list_head *);
43ff2122 CH	307	extern bool xfs_buf_delwri_queue(struct xfs_buf , struct list_head );
	308	extern int xfs_buf_delwri_submit(struct list_head *);
	309	extern int xfs_buf_delwri_submit_nowait(struct list_head *);
7912e7fe	310	extern int xfs_buf_delwri_pushbuf(struct xfs_buf , struct list_head );
1da177e4	311
04fcad80 DC	312	static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp)
	313	{
	314	return bp->b_maps[0].bm_bn;
	315	}
	316
7561d27e	317	void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);
ce8e922c	318
879de98e DC	319	/*
	320	* If the buffer is already on the LRU, do nothing. Otherwise set the buffer
	321	* up with a reference count of 0 so it will be tossed from the cache when
	322	* released.
	323	*/
	324	static inline void xfs_buf_oneshot(struct xfs_buf *bp)
	325	{
	326	if (!list_empty(&bp->b_lru) \|\| atomic_read(&bp->b_lru_ref) > 1)
	327	return;
	328	atomic_set(&bp->b_lru_ref, 0);
	329	}
	330
811e64c7 CS	331	static inline int xfs_buf_ispinned(struct xfs_buf *bp)
	332	{
	333	return atomic_read(&bp->b_pin_count);
	334	}
ce8e922c	335
51582170 ES	336	static inline int
	337	xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
	338	{
	339	return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
	340	cksum_offset);
	341	}
	342
f1dbcd7e ES	343	static inline void
	344	xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
	345	{
	346	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
	347	cksum_offset);
	348	}
	349
1da177e4 LT	350	/*
	351	* Handling of buftargs.
	352	*/
5b5abbef CH	353	struct xfs_buftarg xfs_alloc_buftarg(struct xfs_mount mp,
5b5abbef CH	354	struct block_device *bdev);
a1f69417	355	extern void xfs_free_buftarg(struct xfs_buftarg *);
8321ddb2	356	extern void xfs_buftarg_wait(struct xfs_buftarg *);
10fb9ac1 BF	357	extern void xfs_buftarg_drain(struct xfs_buftarg *);
10fb9ac1 BF	358	extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int);
d808f617	359
ce8e922c NS	360	#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
	361	#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
	362
75d02303	363	int xfs_buf_reverify(struct xfs_buf bp, const struct xfs_buf_ops ops);
15baadf7 DW	364	bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);
15baadf7 DW	365	bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);
1aff5696	366
1da177e4	367	#endif /* __XFS_BUF_H__ */