[mirror_ubuntu-zesty-kernel.git] / fs / xfs / linux-2.6 / xfs_buf.h

/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_BUF_H__
#define __XFS_BUF_H__

#include <linux/list.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/uio.h>

/*
 *	Base types
 */

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

#define xfs_buf_ctob(pp)	((pp) * PAGE_CACHE_SIZE)
#define xfs_buf_btoc(dd)	(((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
#define xfs_buf_btoct(dd)	((dd) >> PAGE_CACHE_SHIFT)
#define xfs_buf_poff(aa)	((aa) & ~PAGE_CACHE_MASK)

typedef enum {
	XBRW_READ = 1,			/* transfer into target memory */
	XBRW_WRITE = 2,			/* transfer from target memory */
	XBRW_ZERO = 3,			/* Zero target memory */
} xfs_buf_rw_t;

typedef enum {
	XBF_READ = (1 << 0),	/* buffer intended for reading from device */
	XBF_WRITE = (1 << 1),	/* buffer intended for writing to device   */
	XBF_MAPPED = (1 << 2),  /* buffer mapped (b_addr valid)            */
	XBF_ASYNC = (1 << 4),   /* initiator will not wait for completion  */
	XBF_DONE = (1 << 5),    /* all pages in the buffer uptodate	   */
	XBF_DELWRI = (1 << 6),  /* buffer has dirty pages                  */
	XBF_STALE = (1 << 7),	/* buffer has been staled, do not find it  */
	XBF_FS_MANAGED = (1 << 8),  /* filesystem controls freeing memory  */
 	XBF_ORDERED = (1 << 11),    /* use ordered writes		   */
	XBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead		   */

	/* flags used only as arguments to access routines */
	XBF_LOCK = (1 << 14),       /* lock requested			   */
	XBF_TRYLOCK = (1 << 15),    /* lock requested, but do not wait	   */
	XBF_DONT_BLOCK = (1 << 16), /* do not block in current thread	   */

	/* flags used only internally */
	_XBF_PAGE_CACHE = (1 << 17),/* backed by pagecache		   */
	_XBF_PAGES = (1 << 18),	    /* backed by refcounted pages	   */
	_XBF_RUN_QUEUES = (1 << 19),/* run block device task queue	   */
	_XBF_DELWRI_Q = (1 << 21),   /* buffer on delwri queue		   */
} xfs_buf_flags_t;

typedef enum {
	XBT_FORCE_SLEEP = 0,
	XBT_FORCE_FLUSH = 1,
} xfs_buftarg_flags_t;

typedef struct xfs_bufhash {
	struct list_head	bh_list;
	spinlock_t		bh_lock;
} xfs_bufhash_t;

typedef struct xfs_buftarg {
	dev_t			bt_dev;
	struct block_device	*bt_bdev;
	struct address_space	*bt_mapping;
	unsigned int		bt_bsize;
	unsigned int		bt_sshift;
	size_t			bt_smask;

	/* per device buffer hash table */
	uint			bt_hashmask;
	uint			bt_hashshift;
	xfs_bufhash_t		*bt_hash;

	/* per device delwri queue */
	struct task_struct	*bt_task;
	struct list_head	bt_list;
	struct list_head	bt_delwrite_queue;
	spinlock_t		bt_delwrite_lock;
	unsigned long		bt_flags;
} xfs_buftarg_t;

/*
 *	xfs_buf_t:  Buffer structure for pagecache-based buffers
 *
 * This buffer structure is used by the pagecache buffer management routines
 * to refer to an assembly of pages forming a logical buffer.
 *
 * The buffer structure is used on a temporary basis only, and discarded when
 * released.  The real data storage is recorded in the pagecache. Buffers are
 * hashed to the block device on which the file system resides.
 */

struct xfs_buf;
typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
typedef void (*xfs_buf_relse_t)(struct xfs_buf *);
typedef int (*xfs_buf_bdstrat_t)(struct xfs_buf *);

#define XB_PAGES	2

typedef struct xfs_buf {
	struct semaphore	b_sema;		/* semaphore for lockables */
	unsigned long		b_queuetime;	/* time buffer was queued */
	atomic_t		b_pin_count;	/* pin count */
	wait_queue_head_t	b_waiters;	/* unpin waiters */
	struct list_head	b_list;
	xfs_buf_flags_t		b_flags;	/* status flags */
	struct list_head	b_hash_list;	/* hash table list */
	xfs_bufhash_t		*b_hash;	/* hash table list start */
	xfs_buftarg_t		*b_target;	/* buffer target (device) */
	atomic_t		b_hold;		/* reference count */
	xfs_daddr_t		b_bn;		/* block number for I/O */
	xfs_off_t		b_file_offset;	/* offset in file */
	size_t			b_buffer_length;/* size of buffer in bytes */
	size_t			b_count_desired;/* desired transfer size */
	void			*b_addr;	/* virtual address of buffer */
	struct work_struct	b_iodone_work;
	atomic_t		b_io_remaining;	/* #outstanding I/O requests */
	xfs_buf_iodone_t	b_iodone;	/* I/O completion function */
	xfs_buf_relse_t		b_relse;	/* releasing function */
	xfs_buf_bdstrat_t	b_strat;	/* pre-write function */
	struct semaphore	b_iodonesema;	/* Semaphore for I/O waiters */
	void			*b_fspriv;
	void			*b_fspriv2;
	void			*b_fspriv3;
	unsigned short		b_error;	/* error code on I/O */
	unsigned int		b_page_count;	/* size of page array */
	unsigned int		b_offset;	/* page offset in first page */
	struct page		**b_pages;	/* array of page pointers */
	struct page		*b_page_array[XB_PAGES]; /* inline pages */
#ifdef XFS_BUF_LOCK_TRACKING
	int			b_last_holder;
#endif
} xfs_buf_t;


/* Finding and Reading Buffers */
extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
				xfs_buf_flags_t, xfs_buf_t *);
#define xfs_incore(buftarg,blkno,len,lockit) \
	_xfs_buf_find(buftarg, blkno ,len, lockit, NULL)

extern xfs_buf_t *xfs_buf_get_flags(xfs_buftarg_t *, xfs_off_t, size_t,
				xfs_buf_flags_t);
#define xfs_buf_get(target, blkno, len, flags) \
	xfs_buf_get_flags((target), (blkno), (len), XBF_LOCK | XBF_MAPPED)

extern xfs_buf_t *xfs_buf_read_flags(xfs_buftarg_t *, xfs_off_t, size_t,
				xfs_buf_flags_t);
#define xfs_buf_read(target, blkno, len, flags) \
	xfs_buf_read_flags((target), (blkno), (len), XBF_LOCK | XBF_MAPPED)

extern xfs_buf_t *xfs_buf_get_empty(size_t, xfs_buftarg_t *);
extern xfs_buf_t *xfs_buf_get_noaddr(size_t, xfs_buftarg_t *);
extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
extern void xfs_buf_hold(xfs_buf_t *);
extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t,
				xfs_buf_flags_t);

/* Releasing Buffers */
extern void xfs_buf_free(xfs_buf_t *);
extern void xfs_buf_rele(xfs_buf_t *);

/* Locking and Unlocking Buffers */
extern int xfs_buf_cond_lock(xfs_buf_t *);
extern int xfs_buf_lock_value(xfs_buf_t *);
extern void xfs_buf_lock(xfs_buf_t *);
extern void xfs_buf_unlock(xfs_buf_t *);

/* Buffer Read and Write Routines */
extern void xfs_buf_ioend(xfs_buf_t *,	int);
extern void xfs_buf_ioerror(xfs_buf_t *, int);
extern int xfs_buf_iostart(xfs_buf_t *, xfs_buf_flags_t);
extern int xfs_buf_iorequest(xfs_buf_t *);
extern int xfs_buf_iowait(xfs_buf_t *);
extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, xfs_caddr_t,
				xfs_buf_rw_t);

static inline int xfs_buf_iostrategy(xfs_buf_t *bp)
{
	return bp->b_strat ? bp->b_strat(bp) : xfs_buf_iorequest(bp);
}

static inline int xfs_buf_geterror(xfs_buf_t *bp)
{
	return bp ? bp->b_error : ENOMEM;
}

/* Buffer Utility Routines */
extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);

/* Pinning Buffer Storage in Memory */
extern void xfs_buf_pin(xfs_buf_t *);
extern void xfs_buf_unpin(xfs_buf_t *);
extern int xfs_buf_ispin(xfs_buf_t *);

/* Delayed Write Buffer Routines */
extern void xfs_buf_delwri_dequeue(xfs_buf_t *);

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

#ifdef XFS_BUF_TRACE
extern ktrace_t *xfs_buf_trace_buf;
extern void xfs_buf_trace(xfs_buf_t *, char *, void *, void *);
#else
#define xfs_buf_trace(bp,id,ptr,ra)	do { } while (0)
#endif

#define xfs_buf_target_name(target)	\
	({ char __b[BDEVNAME_SIZE]; bdevname((target)->bt_bdev, __b); __b; })


#define XFS_B_ASYNC		XBF_ASYNC
#define XFS_B_DELWRI		XBF_DELWRI
#define XFS_B_READ		XBF_READ
#define XFS_B_WRITE		XBF_WRITE
#define XFS_B_STALE		XBF_STALE

#define XFS_BUF_TRYLOCK		XBF_TRYLOCK
#define XFS_INCORE_TRYLOCK	XBF_TRYLOCK
#define XFS_BUF_LOCK		XBF_LOCK
#define XFS_BUF_MAPPED		XBF_MAPPED

#define BUF_BUSY		XBF_DONT_BLOCK

#define XFS_BUF_BFLAGS(bp)	((bp)->b_flags)
#define XFS_BUF_ZEROFLAGS(bp)	((bp)->b_flags &= \
		~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI|XBF_ORDERED))

#define XFS_BUF_STALE(bp)	((bp)->b_flags |= XFS_B_STALE)
#define XFS_BUF_UNSTALE(bp)	((bp)->b_flags &= ~XFS_B_STALE)
#define XFS_BUF_ISSTALE(bp)	((bp)->b_flags & XFS_B_STALE)
#define XFS_BUF_SUPER_STALE(bp)	do {				\
					XFS_BUF_STALE(bp);	\
					xfs_buf_delwri_dequeue(bp);	\
					XFS_BUF_DONE(bp);	\
				} while (0)

#define XFS_BUF_MANAGE		XBF_FS_MANAGED
#define XFS_BUF_UNMANAGE(bp)	((bp)->b_flags &= ~XBF_FS_MANAGED)

#define XFS_BUF_DELAYWRITE(bp)		((bp)->b_flags |= XBF_DELWRI)
#define XFS_BUF_UNDELAYWRITE(bp)	xfs_buf_delwri_dequeue(bp)
#define XFS_BUF_ISDELAYWRITE(bp)	((bp)->b_flags & XBF_DELWRI)

#define XFS_BUF_ERROR(bp,no)	xfs_buf_ioerror(bp,no)
#define XFS_BUF_GETERROR(bp)	xfs_buf_geterror(bp)
#define XFS_BUF_ISERROR(bp)	(xfs_buf_geterror(bp) ? 1 : 0)

#define XFS_BUF_DONE(bp)	((bp)->b_flags |= XBF_DONE)
#define XFS_BUF_UNDONE(bp)	((bp)->b_flags &= ~XBF_DONE)
#define XFS_BUF_ISDONE(bp)	((bp)->b_flags & XBF_DONE)

#define XFS_BUF_BUSY(bp)	do { } while (0)
#define XFS_BUF_UNBUSY(bp)	do { } while (0)
#define XFS_BUF_ISBUSY(bp)	(1)

#define XFS_BUF_ASYNC(bp)	((bp)->b_flags |= XBF_ASYNC)
#define XFS_BUF_UNASYNC(bp)	((bp)->b_flags &= ~XBF_ASYNC)
#define XFS_BUF_ISASYNC(bp)	((bp)->b_flags & XBF_ASYNC)

#define XFS_BUF_ORDERED(bp)	((bp)->b_flags |= XBF_ORDERED)
#define XFS_BUF_UNORDERED(bp)	((bp)->b_flags &= ~XBF_ORDERED)
#define XFS_BUF_ISORDERED(bp)	((bp)->b_flags & XBF_ORDERED)

#define XFS_BUF_SHUT(bp)	do { } while (0)
#define XFS_BUF_UNSHUT(bp)	do { } while (0)
#define XFS_BUF_ISSHUT(bp)	(0)

#define XFS_BUF_HOLD(bp)	xfs_buf_hold(bp)
#define XFS_BUF_READ(bp)	((bp)->b_flags |= XBF_READ)
#define XFS_BUF_UNREAD(bp)	((bp)->b_flags &= ~XBF_READ)
#define XFS_BUF_ISREAD(bp)	((bp)->b_flags & XBF_READ)

#define XFS_BUF_WRITE(bp)	((bp)->b_flags |= XBF_WRITE)
#define XFS_BUF_UNWRITE(bp)	((bp)->b_flags &= ~XBF_WRITE)
#define XFS_BUF_ISWRITE(bp)	((bp)->b_flags & XBF_WRITE)

#define XFS_BUF_IODONE_FUNC(bp)			((bp)->b_iodone)
#define XFS_BUF_SET_IODONE_FUNC(bp, func)	((bp)->b_iodone = (func))
#define XFS_BUF_CLR_IODONE_FUNC(bp)		((bp)->b_iodone = NULL)
#define XFS_BUF_SET_BDSTRAT_FUNC(bp, func)	((bp)->b_strat = (func))
#define XFS_BUF_CLR_BDSTRAT_FUNC(bp)		((bp)->b_strat = NULL)

#define XFS_BUF_FSPRIVATE(bp, type)		((type)(bp)->b_fspriv)
#define XFS_BUF_SET_FSPRIVATE(bp, val)		((bp)->b_fspriv = (void*)(val))
#define XFS_BUF_FSPRIVATE2(bp, type)		((type)(bp)->b_fspriv2)
#define XFS_BUF_SET_FSPRIVATE2(bp, val)		((bp)->b_fspriv2 = (void*)(val))
#define XFS_BUF_FSPRIVATE3(bp, type)		((type)(bp)->b_fspriv3)
#define XFS_BUF_SET_FSPRIVATE3(bp, val)		((bp)->b_fspriv3 = (void*)(val))
#define XFS_BUF_SET_START(bp)			do { } while (0)
#define XFS_BUF_SET_BRELSE_FUNC(bp, func)	((bp)->b_relse = (func))

#define XFS_BUF_PTR(bp)			(xfs_caddr_t)((bp)->b_addr)
#define XFS_BUF_SET_PTR(bp, val, cnt)	xfs_buf_associate_memory(bp, val, cnt)
#define XFS_BUF_ADDR(bp)		((bp)->b_bn)
#define XFS_BUF_SET_ADDR(bp, bno)	((bp)->b_bn = (xfs_daddr_t)(bno))
#define XFS_BUF_OFFSET(bp)		((bp)->b_file_offset)
#define XFS_BUF_SET_OFFSET(bp, off)	((bp)->b_file_offset = (off))
#define XFS_BUF_COUNT(bp)		((bp)->b_count_desired)
#define XFS_BUF_SET_COUNT(bp, cnt)	((bp)->b_count_desired = (cnt))
#define XFS_BUF_SIZE(bp)		((bp)->b_buffer_length)
#define XFS_BUF_SET_SIZE(bp, cnt)	((bp)->b_buffer_length = (cnt))

#define XFS_BUF_SET_VTYPE_REF(bp, type, ref)	do { } while (0)
#define XFS_BUF_SET_VTYPE(bp, type)		do { } while (0)
#define XFS_BUF_SET_REF(bp, ref)		do { } while (0)

#define XFS_BUF_ISPINNED(bp)	xfs_buf_ispin(bp)

#define XFS_BUF_VALUSEMA(bp)	xfs_buf_lock_value(bp)
#define XFS_BUF_CPSEMA(bp)	(xfs_buf_cond_lock(bp) == 0)
#define XFS_BUF_VSEMA(bp)	xfs_buf_unlock(bp)
#define XFS_BUF_PSEMA(bp,x)	xfs_buf_lock(bp)
#define XFS_BUF_V_IODONESEMA(bp) up(&bp->b_iodonesema);

#define XFS_BUF_SET_TARGET(bp, target)	((bp)->b_target = (target))
#define XFS_BUF_TARGET(bp)		((bp)->b_target)
#define XFS_BUFTARG_NAME(target)	xfs_buf_target_name(target)

static inline int xfs_bawrite(void *mp, xfs_buf_t *bp)
{
	bp->b_fspriv3 = mp;
	bp->b_strat = xfs_bdstrat_cb;
	xfs_buf_delwri_dequeue(bp);
	return xfs_buf_iostart(bp, XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES);
}

static inline void xfs_buf_relse(xfs_buf_t *bp)
{
	if (!bp->b_relse)
		xfs_buf_unlock(bp);
	xfs_buf_rele(bp);
}

#define xfs_bpin(bp)		xfs_buf_pin(bp)
#define xfs_bunpin(bp)		xfs_buf_unpin(bp)

#define xfs_buftrace(id, bp)	\
	    xfs_buf_trace(bp, id, NULL, (void *)__builtin_return_address(0))

#define xfs_biodone(bp)		xfs_buf_ioend(bp, 0)

#define xfs_biomove(bp, off, len, data, rw) \
	    xfs_buf_iomove((bp), (off), (len), (data), \
		((rw) == XFS_B_WRITE) ? XBRW_WRITE : XBRW_READ)

#define xfs_biozero(bp, off, len) \
	    xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)


static inline int XFS_bwrite(xfs_buf_t *bp)
{
	int	iowait = (bp->b_flags & XBF_ASYNC) == 0;
	int	error = 0;

	if (!iowait)
		bp->b_flags |= _XBF_RUN_QUEUES;

	xfs_buf_delwri_dequeue(bp);
	xfs_buf_iostrategy(bp);
	if (iowait) {
		error = xfs_buf_iowait(bp);
		xfs_buf_relse(bp);
	}
	return error;
}

/*
 * No error can be returned from xfs_buf_iostart for delwri
 * buffers as they are queued and no I/O is issued.
 */
static inline void xfs_bdwrite(void *mp, xfs_buf_t *bp)
{
	bp->b_strat = xfs_bdstrat_cb;
	bp->b_fspriv3 = mp;
	(void)xfs_buf_iostart(bp, XBF_DELWRI | XBF_ASYNC);
}

#define XFS_bdstrat(bp) xfs_buf_iorequest(bp)

#define xfs_iowait(bp)	xfs_buf_iowait(bp)

#define xfs_baread(target, rablkno, ralen)  \
	xfs_buf_readahead((target), (rablkno), (ralen), XBF_DONT_BLOCK)


/*
 *	Handling of buftargs.
 */
extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *, int);
extern void xfs_free_buftarg(xfs_buftarg_t *, int);
extern void xfs_wait_buftarg(xfs_buftarg_t *);
extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
#ifdef CONFIG_KDB_MODULES
extern struct list_head *xfs_get_buftarg_list(void);
#endif

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

#define xfs_binval(buftarg)		xfs_flush_buftarg(buftarg, 1)
#define XFS_bflush(buftarg)		xfs_flush_buftarg(buftarg, 1)

#endif	/* __XFS_BUF_H__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000-2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4	17	*/
1da177e4 LT	18	#ifndef __XFS_BUF_H__
	19	#define __XFS_BUF_H__
	20
1da177e4 LT	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
ce8e922c NS	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
	41	typedef 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	typedef enum {
	48	XBF_READ = (1 << 0), /* buffer intended for reading from device */
	49	XBF_WRITE = (1 << 1), /* buffer intended for writing to device */
	50	XBF_MAPPED = (1 << 2), /* buffer mapped (b_addr valid) */
	51	XBF_ASYNC = (1 << 4), /* initiator will not wait for completion */
	52	XBF_DONE = (1 << 5), /* all pages in the buffer uptodate */
	53	XBF_DELWRI = (1 << 6), /* buffer has dirty pages */
	54	XBF_STALE = (1 << 7), /* buffer has been staled, do not find it */
	55	XBF_FS_MANAGED = (1 << 8), /* filesystem controls freeing memory */
	56	XBF_ORDERED = (1 << 11), /* use ordered writes */
	57	XBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead */
1da177e4 LT	58
1da177e4 LT	59	/* flags used only as arguments to access routines */
ce8e922c NS	60	XBF_LOCK = (1 << 14), /* lock requested */
	61	XBF_TRYLOCK = (1 << 15), /* lock requested, but do not wait */
	62	XBF_DONT_BLOCK = (1 << 16), /* do not block in current thread */
1da177e4 LT	63
1da177e4 LT	64	/* flags used only internally */
ce8e922c	65	_XBF_PAGE_CACHE = (1 << 17),/* backed by pagecache */
1fa40b01	66	_XBF_PAGES = (1 << 18), /* backed by refcounted pages */
ce8e922c NS	67	_XBF_RUN_QUEUES = (1 << 19),/* run block device task queue */
	68	_XBF_DELWRI_Q = (1 << 21), /* buffer on delwri queue */
	69	} xfs_buf_flags_t;
1da177e4	70
ce8e922c	71	typedef enum {
5e6a07df DC	72	XBT_FORCE_SLEEP = 0,
5e6a07df DC	73	XBT_FORCE_FLUSH = 1,
ce8e922c	74	} xfs_buftarg_flags_t;
1da177e4 LT	75
	76	typedef struct xfs_bufhash {
	77	struct list_head bh_list;
	78	spinlock_t bh_lock;
	79	} xfs_bufhash_t;
	80
	81	typedef struct xfs_buftarg {
ce8e922c NS	82	dev_t bt_dev;
	83	struct block_device *bt_bdev;
	84	struct address_space *bt_mapping;
	85	unsigned int bt_bsize;
	86	unsigned int bt_sshift;
	87	size_t bt_smask;
	88
	89	/* per device buffer hash table */
1da177e4 LT	90	uint bt_hashmask;
	91	uint bt_hashshift;
	92	xfs_bufhash_t *bt_hash;
a6867a68 DC	93
	94	/* per device delwri queue */
	95	struct task_struct *bt_task;
	96	struct list_head bt_list;
	97	struct list_head bt_delwrite_queue;
	98	spinlock_t bt_delwrite_lock;
ce8e922c	99	unsigned long bt_flags;
1da177e4 LT	100	} xfs_buftarg_t;
	101
	102	/*
ce8e922c	103	* xfs_buf_t: Buffer structure for pagecache-based buffers
1da177e4	104	*
ce8e922c NS	105	* This buffer structure is used by the pagecache buffer management routines
	106	* to refer to an assembly of pages forming a logical buffer.
	107	*
	108	* The buffer structure is used on a temporary basis only, and discarded when
	109	* released. The real data storage is recorded in the pagecache. Buffers are
1da177e4 LT	110	* hashed to the block device on which the file system resides.
	111	*/
	112
	113	struct xfs_buf;
ce8e922c NS	114	typedef void (xfs_buf_iodone_t)(struct xfs_buf );
	115	typedef void (xfs_buf_relse_t)(struct xfs_buf );
	116	typedef int (xfs_buf_bdstrat_t)(struct xfs_buf );
1da177e4	117
ce8e922c	118	#define XB_PAGES 2
1da177e4 LT	119
1da177e4 LT	120	typedef struct xfs_buf {
ce8e922c NS	121	struct semaphore b_sema; /* semaphore for lockables */
	122	unsigned long b_queuetime; /* time buffer was queued */
	123	atomic_t b_pin_count; /* pin count */
	124	wait_queue_head_t b_waiters; /* unpin waiters */
	125	struct list_head b_list;
	126	xfs_buf_flags_t b_flags; /* status flags */
	127	struct list_head b_hash_list; /* hash table list */
	128	xfs_bufhash_t b_hash; / hash table list start */
	129	xfs_buftarg_t b_target; / buffer target (device) */
	130	atomic_t b_hold; /* reference count */
	131	xfs_daddr_t b_bn; /* block number for I/O */
	132	xfs_off_t b_file_offset; /* offset in file */
	133	size_t b_buffer_length;/* size of buffer in bytes */
	134	size_t b_count_desired;/* desired transfer size */
	135	void b_addr; / virtual address of buffer */
	136	struct work_struct b_iodone_work;
	137	atomic_t b_io_remaining; /* #outstanding I/O requests */
	138	xfs_buf_iodone_t b_iodone; /* I/O completion function */
	139	xfs_buf_relse_t b_relse; /* releasing function */
	140	xfs_buf_bdstrat_t b_strat; /* pre-write function */
	141	struct semaphore b_iodonesema; /* Semaphore for I/O waiters */
	142	void *b_fspriv;
	143	void *b_fspriv2;
	144	void *b_fspriv3;
	145	unsigned short b_error; /* error code on I/O */
ce8e922c NS	146	unsigned int b_page_count; /* size of page array */
	147	unsigned int b_offset; /* page offset in first page */
	148	struct page *b_pages; / array of page pointers */
	149	struct page b_page_array[XB_PAGES]; / inline pages */
	150	#ifdef XFS_BUF_LOCK_TRACKING
	151	int b_last_holder;
1da177e4 LT	152	#endif
	153	} xfs_buf_t;
	154
	155
	156	/* Finding and Reading Buffers */
ce8e922c NS	157	extern xfs_buf_t _xfs_buf_find(xfs_buftarg_t , xfs_off_t, size_t,
ce8e922c NS	158	xfs_buf_flags_t, xfs_buf_t *);
1da177e4	159	#define xfs_incore(buftarg,blkno,len,lockit) \
ce8e922c	160	_xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
1da177e4	161
ce8e922c NS	162	extern xfs_buf_t xfs_buf_get_flags(xfs_buftarg_t , xfs_off_t, size_t,
ce8e922c NS	163	xfs_buf_flags_t);
1da177e4	164	#define xfs_buf_get(target, blkno, len, flags) \
ce8e922c	165	xfs_buf_get_flags((target), (blkno), (len), XBF_LOCK \| XBF_MAPPED)
1da177e4	166
ce8e922c NS	167	extern xfs_buf_t xfs_buf_read_flags(xfs_buftarg_t , xfs_off_t, size_t,
ce8e922c NS	168	xfs_buf_flags_t);
1da177e4	169	#define xfs_buf_read(target, blkno, len, flags) \
ce8e922c	170	xfs_buf_read_flags((target), (blkno), (len), XBF_LOCK \| XBF_MAPPED)
1da177e4	171
ce8e922c NS	172	extern xfs_buf_t xfs_buf_get_empty(size_t, xfs_buftarg_t );
	173	extern xfs_buf_t xfs_buf_get_noaddr(size_t, xfs_buftarg_t );
	174	extern int xfs_buf_associate_memory(xfs_buf_t , void , size_t);
	175	extern void xfs_buf_hold(xfs_buf_t *);
	176	extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t,
	177	xfs_buf_flags_t);
1da177e4 LT	178
1da177e4 LT	179	/* Releasing Buffers */
ce8e922c NS	180	extern void xfs_buf_free(xfs_buf_t *);
ce8e922c NS	181	extern void xfs_buf_rele(xfs_buf_t *);
1da177e4 LT	182
1da177e4 LT	183	/* Locking and Unlocking Buffers */
ce8e922c NS	184	extern int xfs_buf_cond_lock(xfs_buf_t *);
	185	extern int xfs_buf_lock_value(xfs_buf_t *);
	186	extern void xfs_buf_lock(xfs_buf_t *);
	187	extern void xfs_buf_unlock(xfs_buf_t *);
1da177e4 LT	188
1da177e4 LT	189	/* Buffer Read and Write Routines */
ce8e922c NS	190	extern void xfs_buf_ioend(xfs_buf_t *, int);
	191	extern void xfs_buf_ioerror(xfs_buf_t *, int);
	192	extern int xfs_buf_iostart(xfs_buf_t *, xfs_buf_flags_t);
	193	extern int xfs_buf_iorequest(xfs_buf_t *);
	194	extern int xfs_buf_iowait(xfs_buf_t *);
	195	extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, xfs_caddr_t,
	196	xfs_buf_rw_t);
	197
	198	static inline int xfs_buf_iostrategy(xfs_buf_t *bp)
1da177e4	199	{
ce8e922c	200	return bp->b_strat ? bp->b_strat(bp) : xfs_buf_iorequest(bp);
1da177e4 LT	201	}
1da177e4 LT	202
ce8e922c	203	static inline int xfs_buf_geterror(xfs_buf_t *bp)
1da177e4	204	{
ce8e922c	205	return bp ? bp->b_error : ENOMEM;
1da177e4 LT	206	}
	207
	208	/* Buffer Utility Routines */
ce8e922c	209	extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
1da177e4 LT	210
1da177e4 LT	211	/* Pinning Buffer Storage in Memory */
ce8e922c NS	212	extern void xfs_buf_pin(xfs_buf_t *);
	213	extern void xfs_buf_unpin(xfs_buf_t *);
	214	extern int xfs_buf_ispin(xfs_buf_t *);
1da177e4 LT	215
1da177e4 LT	216	/* Delayed Write Buffer Routines */
ce8e922c	217	extern void xfs_buf_delwri_dequeue(xfs_buf_t *);
1da177e4 LT	218
1da177e4 LT	219	/* Buffer Daemon Setup Routines */
ce8e922c NS	220	extern int xfs_buf_init(void);
ce8e922c NS	221	extern void xfs_buf_terminate(void);
1da177e4	222
ce8e922c NS	223	#ifdef XFS_BUF_TRACE
	224	extern ktrace_t *xfs_buf_trace_buf;
	225	extern void xfs_buf_trace(xfs_buf_t , char , void , void );
1da177e4	226	#else
ce8e922c	227	#define xfs_buf_trace(bp,id,ptr,ra) do { } while (0)
1da177e4 LT	228	#endif
1da177e4 LT	229
ce8e922c NS	230	#define xfs_buf_target_name(target) \
ce8e922c NS	231	({ char __b[BDEVNAME_SIZE]; bdevname((target)->bt_bdev, __b); __b; })
1da177e4 LT	232
1da177e4 LT	233
ce8e922c NS	234	#define XFS_B_ASYNC XBF_ASYNC
	235	#define XFS_B_DELWRI XBF_DELWRI
	236	#define XFS_B_READ XBF_READ
	237	#define XFS_B_WRITE XBF_WRITE
	238	#define XFS_B_STALE XBF_STALE
1da177e4	239
ce8e922c NS	240	#define XFS_BUF_TRYLOCK XBF_TRYLOCK
	241	#define XFS_INCORE_TRYLOCK XBF_TRYLOCK
	242	#define XFS_BUF_LOCK XBF_LOCK
	243	#define XFS_BUF_MAPPED XBF_MAPPED
1da177e4	244
ce8e922c NS	245	#define BUF_BUSY XBF_DONT_BLOCK
	246
	247	#define XFS_BUF_BFLAGS(bp) ((bp)->b_flags)
f5faad79 NS	248	#define XFS_BUF_ZEROFLAGS(bp) ((bp)->b_flags &= \
f5faad79 NS	249	~(XBF_READ\|XBF_WRITE\|XBF_ASYNC\|XBF_DELWRI\|XBF_ORDERED))
ce8e922c NS	250
	251	#define XFS_BUF_STALE(bp) ((bp)->b_flags \|= XFS_B_STALE)
	252	#define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XFS_B_STALE)
	253	#define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XFS_B_STALE)
	254	#define XFS_BUF_SUPER_STALE(bp) do { \
	255	XFS_BUF_STALE(bp); \
	256	xfs_buf_delwri_dequeue(bp); \
	257	XFS_BUF_DONE(bp); \
	258	} while (0)
1da177e4	259
ce8e922c NS	260	#define XFS_BUF_MANAGE XBF_FS_MANAGED
	261	#define XFS_BUF_UNMANAGE(bp) ((bp)->b_flags &= ~XBF_FS_MANAGED)
	262
	263	#define XFS_BUF_DELAYWRITE(bp) ((bp)->b_flags \|= XBF_DELWRI)
	264	#define XFS_BUF_UNDELAYWRITE(bp) xfs_buf_delwri_dequeue(bp)
	265	#define XFS_BUF_ISDELAYWRITE(bp) ((bp)->b_flags & XBF_DELWRI)
	266
	267	#define XFS_BUF_ERROR(bp,no) xfs_buf_ioerror(bp,no)
	268	#define XFS_BUF_GETERROR(bp) xfs_buf_geterror(bp)
	269	#define XFS_BUF_ISERROR(bp) (xfs_buf_geterror(bp) ? 1 : 0)
	270
	271	#define XFS_BUF_DONE(bp) ((bp)->b_flags \|= XBF_DONE)
	272	#define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE)
	273	#define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE)
	274
	275	#define XFS_BUF_BUSY(bp) do { } while (0)
	276	#define XFS_BUF_UNBUSY(bp) do { } while (0)
	277	#define XFS_BUF_ISBUSY(bp) (1)
	278
	279	#define XFS_BUF_ASYNC(bp) ((bp)->b_flags \|= XBF_ASYNC)
	280	#define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC)
	281	#define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC)
	282
	283	#define XFS_BUF_ORDERED(bp) ((bp)->b_flags \|= XBF_ORDERED)
	284	#define XFS_BUF_UNORDERED(bp) ((bp)->b_flags &= ~XBF_ORDERED)
	285	#define XFS_BUF_ISORDERED(bp) ((bp)->b_flags & XBF_ORDERED)
	286
	287	#define XFS_BUF_SHUT(bp) do { } while (0)
	288	#define XFS_BUF_UNSHUT(bp) do { } while (0)
	289	#define XFS_BUF_ISSHUT(bp) (0)
	290
	291	#define XFS_BUF_HOLD(bp) xfs_buf_hold(bp)
	292	#define XFS_BUF_READ(bp) ((bp)->b_flags \|= XBF_READ)
	293	#define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ)
	294	#define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ)
	295
	296	#define XFS_BUF_WRITE(bp) ((bp)->b_flags \|= XBF_WRITE)
	297	#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE)
	298	#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE)
	299
ce8e922c NS	300	#define XFS_BUF_IODONE_FUNC(bp) ((bp)->b_iodone)
	301	#define XFS_BUF_SET_IODONE_FUNC(bp, func) ((bp)->b_iodone = (func))
	302	#define XFS_BUF_CLR_IODONE_FUNC(bp) ((bp)->b_iodone = NULL)
	303	#define XFS_BUF_SET_BDSTRAT_FUNC(bp, func) ((bp)->b_strat = (func))
	304	#define XFS_BUF_CLR_BDSTRAT_FUNC(bp) ((bp)->b_strat = NULL)
	305
	306	#define XFS_BUF_FSPRIVATE(bp, type) ((type)(bp)->b_fspriv)
	307	#define XFS_BUF_SET_FSPRIVATE(bp, val) ((bp)->b_fspriv = (void*)(val))
	308	#define XFS_BUF_FSPRIVATE2(bp, type) ((type)(bp)->b_fspriv2)
	309	#define XFS_BUF_SET_FSPRIVATE2(bp, val) ((bp)->b_fspriv2 = (void*)(val))
	310	#define XFS_BUF_FSPRIVATE3(bp, type) ((type)(bp)->b_fspriv3)
	311	#define XFS_BUF_SET_FSPRIVATE3(bp, val) ((bp)->b_fspriv3 = (void*)(val))
	312	#define XFS_BUF_SET_START(bp) do { } while (0)
	313	#define XFS_BUF_SET_BRELSE_FUNC(bp, func) ((bp)->b_relse = (func))
	314
	315	#define XFS_BUF_PTR(bp) (xfs_caddr_t)((bp)->b_addr)
	316	#define XFS_BUF_SET_PTR(bp, val, cnt) xfs_buf_associate_memory(bp, val, cnt)
	317	#define XFS_BUF_ADDR(bp) ((bp)->b_bn)
	318	#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno))
	319	#define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset)
	320	#define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off))
	321	#define XFS_BUF_COUNT(bp) ((bp)->b_count_desired)
	322	#define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt))
	323	#define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length)
	324	#define XFS_BUF_SET_SIZE(bp, cnt) ((bp)->b_buffer_length = (cnt))
	325
	326	#define XFS_BUF_SET_VTYPE_REF(bp, type, ref) do { } while (0)
	327	#define XFS_BUF_SET_VTYPE(bp, type) do { } while (0)
	328	#define XFS_BUF_SET_REF(bp, ref) do { } while (0)
	329
	330	#define XFS_BUF_ISPINNED(bp) xfs_buf_ispin(bp)
	331
	332	#define XFS_BUF_VALUSEMA(bp) xfs_buf_lock_value(bp)
	333	#define XFS_BUF_CPSEMA(bp) (xfs_buf_cond_lock(bp) == 0)
	334	#define XFS_BUF_VSEMA(bp) xfs_buf_unlock(bp)
	335	#define XFS_BUF_PSEMA(bp,x) xfs_buf_lock(bp)
	336	#define XFS_BUF_V_IODONESEMA(bp) up(&bp->b_iodonesema);
	337
	338	#define XFS_BUF_SET_TARGET(bp, target) ((bp)->b_target = (target))
	339	#define XFS_BUF_TARGET(bp) ((bp)->b_target)
	340	#define XFS_BUFTARG_NAME(target) xfs_buf_target_name(target)
	341
	342	static inline int xfs_bawrite(void mp, xfs_buf_t bp)
1da177e4	343	{
ce8e922c NS	344	bp->b_fspriv3 = mp;
	345	bp->b_strat = xfs_bdstrat_cb;
	346	xfs_buf_delwri_dequeue(bp);
	347	return xfs_buf_iostart(bp, XBF_WRITE \| XBF_ASYNC \| _XBF_RUN_QUEUES);
1da177e4 LT	348	}
1da177e4 LT	349
ce8e922c	350	static inline void xfs_buf_relse(xfs_buf_t *bp)
1da177e4	351	{
ce8e922c NS	352	if (!bp->b_relse)
	353	xfs_buf_unlock(bp);
	354	xfs_buf_rele(bp);
1da177e4 LT	355	}
1da177e4 LT	356
ce8e922c NS	357	#define xfs_bpin(bp) xfs_buf_pin(bp)
ce8e922c NS	358	#define xfs_bunpin(bp) xfs_buf_unpin(bp)
1da177e4 LT	359
1da177e4 LT	360	#define xfs_buftrace(id, bp) \
ce8e922c	361	xfs_buf_trace(bp, id, NULL, (void *)__builtin_return_address(0))
1da177e4	362
ce8e922c	363	#define xfs_biodone(bp) xfs_buf_ioend(bp, 0)
1da177e4	364
ce8e922c NS	365	#define xfs_biomove(bp, off, len, data, rw) \
	366	xfs_buf_iomove((bp), (off), (len), (data), \
	367	((rw) == XFS_B_WRITE) ? XBRW_WRITE : XBRW_READ)
1da177e4	368
ce8e922c NS	369	#define xfs_biozero(bp, off, len) \
ce8e922c NS	370	xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
1da177e4 LT	371
1da177e4 LT	372
ce8e922c	373	static inline int XFS_bwrite(xfs_buf_t *bp)
1da177e4	374	{
ce8e922c	375	int iowait = (bp->b_flags & XBF_ASYNC) == 0;
1da177e4 LT	376	int error = 0;
	377
	378	if (!iowait)
ce8e922c	379	bp->b_flags \|= _XBF_RUN_QUEUES;
1da177e4	380
ce8e922c NS	381	xfs_buf_delwri_dequeue(bp);
ce8e922c NS	382	xfs_buf_iostrategy(bp);
1da177e4	383	if (iowait) {
ce8e922c NS	384	error = xfs_buf_iowait(bp);
ce8e922c NS	385	xfs_buf_relse(bp);
1da177e4 LT	386	}
	387	return error;
	388	}
	389
958d4ec6 DC	390	/*
	391	* No error can be returned from xfs_buf_iostart for delwri
	392	* buffers as they are queued and no I/O is issued.
	393	*/
	394	static inline void xfs_bdwrite(void mp, xfs_buf_t bp)
1da177e4	395	{
ce8e922c NS	396	bp->b_strat = xfs_bdstrat_cb;
ce8e922c NS	397	bp->b_fspriv3 = mp;
958d4ec6	398	(void)xfs_buf_iostart(bp, XBF_DELWRI \| XBF_ASYNC);
1da177e4 LT	399	}
1da177e4 LT	400
ce8e922c	401	#define XFS_bdstrat(bp) xfs_buf_iorequest(bp)
1da177e4	402
ce8e922c	403	#define xfs_iowait(bp) xfs_buf_iowait(bp)
1da177e4 LT	404
1da177e4 LT	405	#define xfs_baread(target, rablkno, ralen) \
ce8e922c	406	xfs_buf_readahead((target), (rablkno), (ralen), XBF_DONT_BLOCK)
1da177e4 LT	407
	408
	409	/*
	410	* Handling of buftargs.
	411	*/
1da177e4 LT	412	extern xfs_buftarg_t xfs_alloc_buftarg(struct block_device , int);
	413	extern void xfs_free_buftarg(xfs_buftarg_t *, int);
	414	extern void xfs_wait_buftarg(xfs_buftarg_t *);
	415	extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
1da177e4	416	extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
e6a0e9cd TS	417	#ifdef CONFIG_KDB_MODULES
	418	extern struct list_head *xfs_get_buftarg_list(void);
	419	#endif
1da177e4	420
ce8e922c NS	421	#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev)
	422	#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev)
	423
	424	#define xfs_binval(buftarg) xfs_flush_buftarg(buftarg, 1)
	425	#define XFS_bflush(buftarg) xfs_flush_buftarg(buftarg, 1)
1da177e4 LT	426
1da177e4 LT	427	#endif /* __XFS_BUF_H__ */