[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>

/*
 *	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;
};

/* 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 *);

/* Buffer Daemon Setup Routines */
extern int xfs_buf_init(void);
extern void xfs_buf_terminate(void);

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 LT	17
	18	/*
	19	* Base types
	20	*/
b01d1461	21	struct xfs_buf;
1da177e4	22
ce8e922c NS	23	#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL))
ce8e922c NS	24
b9b3fe15 DC	25	#define XBF_READ (1u << 0) /* buffer intended for reading from device */
	26	#define XBF_WRITE (1u << 1) /* buffer intended for writing to device */
	27	#define XBF_READ_AHEAD (1u << 2) /* asynchronous read-ahead */
	28	#define XBF_NO_IOACCT (1u << 3) /* bypass I/O accounting (non-LRU bufs) */
	29	#define XBF_ASYNC (1u << 4) /* initiator will not wait for completion */
	30	#define XBF_DONE (1u << 5) /* all pages in the buffer uptodate */
	31	#define XBF_STALE (1u << 6) /* buffer has been staled, do not find it */
	32	#define XBF_WRITE_FAIL (1u << 7) /* async writes have failed on this buffer */
1d5ae5df	33
f593bf14	34	/* buffer type flags for write callbacks */
b9b3fe15 DC	35	#define _XBF_INODES (1u << 16)/* inode buffer */
	36	#define _XBF_DQUOTS (1u << 17)/* dquot buffer */
	37	#define _XBF_LOGRECOVERY (1u << 18)/* log recovery buffer */
1da177e4	38
807cbbdb	39	/* flags used only internally */
b9b3fe15 DC	40	#define _XBF_PAGES (1u << 20)/* backed by refcounted pages */
	41	#define _XBF_KMEM (1u << 21)/* backed by heap memory */
	42	#define _XBF_DELWRI_Q (1u << 22)/* buffer on a delwri queue */
6ab455ee	43
f593bf14	44	/* flags used only as arguments to access routines */
85c73bf7	45	#define XBF_INCORE (1u << 29)/* lookup only, return if found in cache */
b9b3fe15 DC	46	#define XBF_TRYLOCK (1u << 30)/* lock requested, but do not wait */
b9b3fe15 DC	47	#define XBF_UNMAPPED (1u << 31)/* do not map the buffer */
f593bf14	48
85c73bf7	49
807cbbdb	50	typedef unsigned int xfs_buf_flags_t;
1da177e4	51
0b1b213f CH	52	#define XFS_BUF_FLAGS \
	53	{ XBF_READ, "READ" }, \
	54	{ XBF_WRITE, "WRITE" }, \
1d5ae5df	55	{ XBF_READ_AHEAD, "READ_AHEAD" }, \
1247ec4c	56	{ XBF_NO_IOACCT, "NO_IOACCT" }, \
0b1b213f CH	57	{ XBF_ASYNC, "ASYNC" }, \
0b1b213f CH	58	{ XBF_DONE, "DONE" }, \
0b1b213f	59	{ XBF_STALE, "STALE" }, \
ac8809f9	60	{ XBF_WRITE_FAIL, "WRITE_FAIL" }, \
f593bf14	61	{ _XBF_INODES, "INODES" }, \
0c7e5afb	62	{ _XBF_DQUOTS, "DQUOTS" }, \
b9b3fe15	63	{ _XBF_LOGRECOVERY, "LOG_RECOVERY" }, \
0b1b213f	64	{ _XBF_PAGES, "PAGES" }, \
0e6e847f	65	{ _XBF_KMEM, "KMEM" }, \
f593bf14 DC	66	{ _XBF_DELWRI_Q, "DELWRI_Q" }, \
f593bf14 DC	67	/* The following interface flags should never be set */ \
85c73bf7	68	{ XBF_INCORE, "INCORE" }, \
f593bf14 DC	69	{ XBF_TRYLOCK, "TRYLOCK" }, \
f593bf14 DC	70	{ XBF_UNMAPPED, "UNMAPPED" }
ac8809f9	71
a4082357 DC	72	/*
	73	* Internal state flags.
	74	*/
	75	#define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */
63db7c81	76	#define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */
0b1b213f	77
7c71ee78 ES	78	/*
	79	* The xfs_buftarg contains 2 notions of "sector size" -
	80	*
	81	* 1) The metadata sector size, which is the minimum unit and
	82	* alignment of IO which will be performed by metadata operations.
	83	* 2) The device logical sector size
	84	*
	85	* The first is specified at mkfs time, and is stored on-disk in the
	86	* superblock's sb_sectsize.
	87	*
	88	* The latter is derived from the underlying device, and controls direct IO
	89	* alignment constraints.
	90	*/
1da177e4	91	typedef struct xfs_buftarg {
ce8e922c NS	92	dev_t bt_dev;
ce8e922c NS	93	struct block_device *bt_bdev;
486aff5e	94	struct dax_device *bt_daxdev;
cd913c76	95	u64 bt_dax_part_off;
ebad861b	96	struct xfs_mount *bt_mount;
6da54179 ES	97	unsigned int bt_meta_sectorsize;
6da54179 ES	98	size_t bt_meta_sectormask;
7c71ee78 ES	99	size_t bt_logical_sectorsize;
7c71ee78 ES	100	size_t bt_logical_sectormask;
ce8e922c	101
ff57ab21 DC	102	/* LRU control structures */
ff57ab21 DC	103	struct shrinker bt_shrinker;
e80dfa19	104	struct list_lru bt_lru;
9c7504aa BF	105
9c7504aa BF	106	struct percpu_counter bt_io_count;
f9bccfcc	107	struct ratelimit_state bt_ioerror_rl;
1da177e4 LT	108	} xfs_buftarg_t;
1da177e4 LT	109
ce8e922c	110	#define XB_PAGES 2
1da177e4	111
cbb7baab DC	112	struct xfs_buf_map {
	113	xfs_daddr_t bm_bn; /* block number for I/O */
	114	int bm_len; /* size of I/O */
	115	};
	116
3e85c868 DC	117	#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
	118	struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
	119
1813dd64	120	struct xfs_buf_ops {
233135b7	121	char *name;
15baadf7 DW	122	union {
	123	__be32 magic[2]; /* v4 and v5 on disk magic values */
	124	__be16 magic16[2]; /* v4 and v5 on disk magic values */
	125	};
1813dd64 DC	126	void (verify_read)(struct xfs_buf );
1813dd64 DC	127	void (verify_write)(struct xfs_buf );
b5572597	128	xfs_failaddr_t (verify_struct)(struct xfs_buf bp);
1813dd64 DC	129	};
1813dd64 DC	130
e8222613	131	struct xfs_buf {
50f59e8e DC	132	/*
	133	* first cacheline holds all the fields needed for an uncontended cache
	134	* hit to be fully processed. The semaphore straddles the cacheline
	135	* boundary, but the counter and lock sits on the first cacheline,
	136	* which is the only bit that is touched if we hit the semaphore
	137	* fast-path on locking.
	138	*/
6031e73a	139	struct rhash_head b_rhash_head; /* pag buffer hash node */
8cf07f3d	140
4c7f65ae	141	xfs_daddr_t b_rhash_key; /* buffer cache index */
4e94b71b	142	int b_length; /* size of buffer in BBs */
50f59e8e	143	atomic_t b_hold; /* reference count */
430cbeb8	144	atomic_t b_lru_ref; /* lru reclaim ref count */
50f59e8e	145	xfs_buf_flags_t b_flags; /* status flags */
ce8e922c	146	struct semaphore b_sema; /* semaphore for lockables */
50f59e8e	147
6fb8a90a CM	148	/*
	149	* concurrent access to b_lru and b_lru_flags are protected by
	150	* bt_lru_lock and not by b_sema
	151	*/
430cbeb8	152	struct list_head b_lru; /* lru list */
a4082357 DC	153	spinlock_t b_lock; /* internal state lock */
a4082357 DC	154	unsigned int b_state; /* internal state flags */
61be9c52	155	int b_io_error; /* internal IO error state */
ce8e922c NS	156	wait_queue_head_t b_waiters; /* unpin waiters */
ce8e922c NS	157	struct list_head b_list;
74f75a0c	158	struct xfs_perag b_pag; / contains rbtree root */
dbd329f1	159	struct xfs_mount *b_mount;
10fb9ac1	160	struct xfs_buftarg b_target; / buffer target (device) */
ce8e922c	161	void b_addr; / virtual address of buffer */
b29c70f5	162	struct work_struct b_ioend_work;
b4dd330b	163	struct completion b_iowait; /* queue for I/O waiters */
e99b4bd0	164	struct xfs_buf_log_item *b_log_item;
643c8c05	165	struct list_head b_li_list; /* Log items list head */
bf9d9013	166	struct xfs_trans *b_transp;
ce8e922c NS	167	struct page *b_pages; / array of page pointers */
ce8e922c NS	168	struct page b_page_array[XB_PAGES]; / inline pages */
3e85c868	169	struct xfs_buf_map b_maps; / compound buffer map */
d44d9bc6	170	struct xfs_buf_map __b_map; /* inline compound buffer map */
3e85c868	171	int b_map_count;
50f59e8e DC	172	atomic_t b_pin_count; /* pin count */
	173	atomic_t b_io_remaining; /* #outstanding I/O requests */
	174	unsigned int b_page_count; /* size of page array */
54cd3aa6 CH	175	unsigned int b_offset; /* page offset of b_addr,
54cd3aa6 CH	176	only for _XBF_KMEM buffers */
2451337d	177	int b_error; /* error code on I/O */
a5ea70d2 CM	178
	179	/*
	180	* async write failure retry count. Initialised to zero on the first
	181	* failure, then when it exceeds the maximum configured without a
	182	* success the write is considered to be failed permanently and the
	183	* iodone handler will take appropriate action.
	184	*
	185	* For retry timeouts, we record the jiffie of the first failure. This
	186	* means that we can change the retry timeout for buffers already under
	187	* I/O and thus avoid getting stuck in a retry loop with a long timeout.
	188	*
	189	* last_error is used to ensure that we are getting repeated errors, not
	190	* different errors. e.g. a block device might change ENOSPC to EIO when
	191	* a failure timeout occurs, so we want to re-initialise the error
	192	* retry behaviour appropriately when that happens.
	193	*/
	194	int b_retries;
	195	unsigned long b_first_retry_time; /* in jiffies */
	196	int b_last_error;
	197
1813dd64	198	const struct xfs_buf_ops *b_ops;
e8222613	199	};
1da177e4	200
1da177e4	201	/* Finding and Reading Buffers */
3848b5f6 DW	202	int xfs_buf_get_map(struct xfs_buftarg target, struct xfs_buf_map map,
3848b5f6 DW	203	int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp);
4ed8e27b DW	204	int xfs_buf_read_map(struct xfs_buftarg target, struct xfs_buf_map map,
4ed8e27b DW	205	int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp,
cdbcf82b	206	const struct xfs_buf_ops *ops, xfs_failaddr_t fa);
6dde2707	207	void xfs_buf_readahead_map(struct xfs_buftarg *target,
c3f8fc73	208	struct xfs_buf_map *map, int nmaps,
1813dd64	209	const struct xfs_buf_ops *ops);
6dde2707	210
85c73bf7 DC	211	static inline int
	212	xfs_buf_incore(
	213	struct xfs_buftarg *target,
	214	xfs_daddr_t blkno,
	215	size_t numblks,
	216	xfs_buf_flags_t flags,
	217	struct xfs_buf **bpp)
	218	{
	219	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
	220
	221	return xfs_buf_get_map(target, &map, 1, XBF_INCORE \| flags, bpp);
	222	}
	223
841263e9	224	static inline int
6dde2707 DC	225	xfs_buf_get(
	226	struct xfs_buftarg *target,
	227	xfs_daddr_t blkno,
841263e9 DW	228	size_t numblks,
841263e9 DW	229	struct xfs_buf **bpp)
6dde2707 DC	230	{
6dde2707 DC	231	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
3848b5f6	232
841263e9	233	return xfs_buf_get_map(target, &map, 1, 0, bpp);
6dde2707 DC	234	}
6dde2707 DC	235
0e3eccce	236	static inline int
6dde2707 DC	237	xfs_buf_read(
	238	struct xfs_buftarg *target,
	239	xfs_daddr_t blkno,
	240	size_t numblks,
c3f8fc73	241	xfs_buf_flags_t flags,
0e3eccce	242	struct xfs_buf **bpp,
1813dd64	243	const struct xfs_buf_ops *ops)
6dde2707 DC	244	{
6dde2707 DC	245	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
4ed8e27b	246
cdbcf82b DW	247	return xfs_buf_read_map(target, &map, 1, flags, bpp, ops,
cdbcf82b DW	248	__builtin_return_address(0));
6dde2707 DC	249	}
	250
	251	static inline void
	252	xfs_buf_readahead(
	253	struct xfs_buftarg *target,
	254	xfs_daddr_t blkno,
c3f8fc73	255	size_t numblks,
1813dd64	256	const struct xfs_buf_ops *ops)
6dde2707 DC	257	{
6dde2707 DC	258	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
1813dd64	259	return xfs_buf_readahead_map(target, &map, 1, ops);
6dde2707	260	}
e70b73f8	261
b9b3fe15 DC	262	int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks,
b9b3fe15 DC	263	xfs_buf_flags_t flags, struct xfs_buf **bpp);
ba372674	264	int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr,
b9b3fe15 DC	265	size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp,
b9b3fe15 DC	266	const struct xfs_buf_ops *ops);
26e32875	267	int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags);
e70b73f8	268	void xfs_buf_hold(struct xfs_buf *bp);
1da177e4 LT	269
1da177e4 LT	270	/* Releasing Buffers */
e8222613	271	extern void xfs_buf_rele(struct xfs_buf *);
1da177e4 LT	272
1da177e4 LT	273	/* Locking and Unlocking Buffers */
e8222613 DC	274	extern int xfs_buf_trylock(struct xfs_buf *);
	275	extern void xfs_buf_lock(struct xfs_buf *);
	276	extern void xfs_buf_unlock(struct xfs_buf *);
0c842ad4 CH	277	#define xfs_buf_islocked(bp) \
0c842ad4 CH	278	((bp)->b_sema.count <= 0)
1da177e4	279
e8222613	280	static inline void xfs_buf_relse(struct xfs_buf *bp)
f593bf14 DC	281	{
	282	xfs_buf_unlock(bp);
	283	xfs_buf_rele(bp);
	284	}
	285
1da177e4	286	/* Buffer Read and Write Routines */
c2b006c1	287	extern int xfs_bwrite(struct xfs_buf *bp);
f593bf14	288
31ca03c9 DW	289	extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
	290	xfs_failaddr_t failaddr);
	291	#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
cdbcf82b	292	extern void xfs_buf_ioerror_alert(struct xfs_buf *bp, xfs_failaddr_t fa);
54b3b1f6	293	void xfs_buf_ioend_fail(struct xfs_buf *);
f9a196ee	294	void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);
8d57c216 DW	295	void __xfs_buf_mark_corrupt(struct xfs_buf *bp, xfs_failaddr_t fa);
8d57c216 DW	296	#define xfs_buf_mark_corrupt(bp) __xfs_buf_mark_corrupt((bp), __this_address)
ce8e922c	297
1da177e4	298	/* Buffer Utility Routines */
88ee2df7	299	extern void xfs_buf_offset(struct xfs_buf , size_t);
5cfd28b6	300	extern void xfs_buf_stale(struct xfs_buf *bp);
1da177e4	301
1da177e4	302	/* Delayed Write Buffer Routines */
20e8a063	303	extern void xfs_buf_delwri_cancel(struct list_head *);
43ff2122 CH	304	extern bool xfs_buf_delwri_queue(struct xfs_buf , struct list_head );
	305	extern int xfs_buf_delwri_submit(struct list_head *);
	306	extern int xfs_buf_delwri_submit_nowait(struct list_head *);
7912e7fe	307	extern int xfs_buf_delwri_pushbuf(struct xfs_buf , struct list_head );
1da177e4 LT	308
1da177e4 LT	309	/* Buffer Daemon Setup Routines */
ce8e922c NS	310	extern int xfs_buf_init(void);
ce8e922c NS	311	extern void xfs_buf_terminate(void);
1da177e4	312
04fcad80 DC	313	static inline xfs_daddr_t xfs_buf_daddr(struct xfs_buf *bp)
	314	{
	315	return bp->b_maps[0].bm_bn;
	316	}
	317
7561d27e	318	void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);
ce8e922c	319
879de98e DC	320	/*
	321	* If the buffer is already on the LRU, do nothing. Otherwise set the buffer
	322	* up with a reference count of 0 so it will be tossed from the cache when
	323	* released.
	324	*/
	325	static inline void xfs_buf_oneshot(struct xfs_buf *bp)
	326	{
	327	if (!list_empty(&bp->b_lru) \|\| atomic_read(&bp->b_lru_ref) > 1)
	328	return;
	329	atomic_set(&bp->b_lru_ref, 0);
	330	}
	331
811e64c7 CS	332	static inline int xfs_buf_ispinned(struct xfs_buf *bp)
	333	{
	334	return atomic_read(&bp->b_pin_count);
	335	}
ce8e922c	336
51582170 ES	337	static inline int
	338	xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
	339	{
	340	return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
	341	cksum_offset);
	342	}
	343
f1dbcd7e ES	344	static inline void
	345	xfs_buf_update_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
	346	{
	347	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
	348	cksum_offset);
	349	}
	350
1da177e4 LT	351	/*
	352	* Handling of buftargs.
	353	*/
5b5abbef CH	354	struct xfs_buftarg xfs_alloc_buftarg(struct xfs_mount mp,
5b5abbef CH	355	struct block_device *bdev);
a1f69417	356	extern void xfs_free_buftarg(struct xfs_buftarg *);
8321ddb2	357	extern void xfs_buftarg_wait(struct xfs_buftarg *);
10fb9ac1 BF	358	extern void xfs_buftarg_drain(struct xfs_buftarg *);
10fb9ac1 BF	359	extern int xfs_setsize_buftarg(struct xfs_buftarg *, unsigned int);
d808f617	360
ce8e922c NS	361	#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
	362	#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
	363
75d02303	364	int xfs_buf_reverify(struct xfs_buf bp, const struct xfs_buf_ops ops);
15baadf7 DW	365	bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);
15baadf7 DW	366	bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);
1aff5696	367
1da177e4	368	#endif /* __XFS_BUF_H__ */