libxfs/libxfs_io.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 __LIBXFS_IO_H_
#define __LIBXFS_IO_H_

/*
 * Kernel equivalent buffer based I/O interface
 */

struct xfs_buf;
struct xfs_mount;
struct xfs_perag;

/*
 * IO verifier callbacks need the xfs_mount pointer, so we have to behave
 * somewhat like the kernel now for userspace IO in terms of having buftarg
 * based devices...
 */
struct xfs_buftarg {
	struct xfs_mount	*bt_mount;
	dev_t			dev;
};

extern void	libxfs_buftarg_init(struct xfs_mount *mp, dev_t ddev,
				    dev_t logdev, dev_t rtdev);

#define LIBXFS_BBTOOFF64(bbs)	(((xfs_off_t)(bbs)) << BBSHIFT)

#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;
	void (*verify_read)(struct xfs_buf *);
	void (*verify_write)(struct xfs_buf *);
};

typedef struct xfs_buf {
	struct cache_node	b_node;
	unsigned int		b_flags;
	xfs_daddr_t		b_bn;
	unsigned		b_bcount;
	unsigned int		b_length;
	struct xfs_buftarg	*b_target;
#define b_dev		b_target->dev
	pthread_mutex_t		b_lock;
	pthread_t		b_holder;
	unsigned int		b_recur;
	void			*b_fspriv;
	void			*b_fsprivate2;
	void			*b_fsprivate3;
	void			*b_addr;
	int			b_error;
	const struct xfs_buf_ops *b_ops;
	struct xfs_perag	*b_pag;
	struct xfs_buf_map	*b_maps;
	int			b_nmaps;
#ifdef XFS_BUF_TRACING
	struct list_head	b_lock_list;
	const char		*b_func;
	const char		*b_file;
	int			b_line;
#endif
} xfs_buf_t;

enum xfs_buf_flags_t {	/* b_flags bits */
	LIBXFS_B_EXIT		= 0x0001,	/* ==LIBXFS_EXIT_ON_FAILURE */
	LIBXFS_B_DIRTY		= 0x0002,	/* buffer has been modified */
	LIBXFS_B_STALE		= 0x0004,	/* buffer marked as invalid */
	LIBXFS_B_UPTODATE	= 0x0008,	/* buffer is sync'd to disk */
	LIBXFS_B_DISCONTIG	= 0x0010,	/* discontiguous buffer */
	LIBXFS_B_UNCHECKED	= 0x0020,	/* needs verification */
};

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

#define XFS_BUF_PTR(bp)			((char *)(bp)->b_addr)
#define xfs_buf_offset(bp, offset)	((bp)->b_addr + (offset))
#define XFS_BUF_ADDR(bp)		((bp)->b_bn)
#define XFS_BUF_SIZE(bp)		((bp)->b_bcount)
#define XFS_BUF_COUNT(bp)		((bp)->b_bcount)
#define XFS_BUF_TARGET(bp)		((bp)->b_dev)
#define XFS_BUF_SET_PTR(bp,p,cnt)	({	\
	(bp)->b_addr = (char *)(p);		\
	XFS_BUF_SET_COUNT(bp,cnt);		\
})

#define XFS_BUF_SET_ADDR(bp,blk)	((bp)->b_bn = (blk))
#define XFS_BUF_SET_COUNT(bp,cnt)	((bp)->b_bcount = (cnt))

#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_fsprivate2)
#define XFS_BUF_SET_FSPRIVATE2(bp,val)	(bp)->b_fsprivate2 = (void *)(val)
#define XFS_BUF_FSPRIVATE3(bp,type)	((type)(bp)->b_fsprivate3)
#define XFS_BUF_SET_FSPRIVATE3(bp,val)	(bp)->b_fsprivate3 = (void *)(val)

#define XFS_BUF_SET_PRIORITY(bp,pri)	cache_node_set_priority( \
						libxfs_bcache, \
						(struct cache_node *)(bp), \
						(pri))
#define XFS_BUF_PRIORITY(bp)		(cache_node_get_priority( \
						(struct cache_node *)(bp)))
#define xfs_buf_set_ref(bp,ref)		((void) 0)
#define xfs_buf_ioerror(bp,err)		((bp)->b_error = (err))

#define xfs_daddr_to_agno(mp,d) \
	((xfs_agnumber_t)(XFS_BB_TO_FSBT(mp, d) / (mp)->m_sb.sb_agblocks))
#define xfs_daddr_to_agbno(mp,d) \
	((xfs_agblock_t)(XFS_BB_TO_FSBT(mp, d) % (mp)->m_sb.sb_agblocks))

/* Buffer Cache Interfaces */

extern struct cache	*libxfs_bcache;
extern struct cache_operations	libxfs_bcache_operations;

#define LIBXFS_GETBUF_TRYLOCK	(1 << 0)

#ifdef XFS_BUF_TRACING

#define libxfs_readbuf(dev, daddr, len, flags, ops) \
	libxfs_trace_readbuf(__FUNCTION__, __FILE__, __LINE__, \
			    (dev), (daddr), (len), (flags), (ops))
#define libxfs_readbuf_map(dev, map, nmaps, flags, ops) \
	libxfs_trace_readbuf_map(__FUNCTION__, __FILE__, __LINE__, \
			    (dev), (map), (nmaps), (flags), (ops))
#define libxfs_writebuf(buf, flags) \
	libxfs_trace_writebuf(__FUNCTION__, __FILE__, __LINE__, \
			      (buf), (flags))
#define libxfs_getbuf(dev, daddr, len) \
	libxfs_trace_getbuf(__FUNCTION__, __FILE__, __LINE__, \
			    (dev), (daddr), (len))
#define libxfs_getbuf_map(dev, map, nmaps, flags) \
	libxfs_trace_getbuf_map(__FUNCTION__, __FILE__, __LINE__, \
			    (dev), (map), (nmaps), (flags))
#define libxfs_getbuf_flags(dev, daddr, len, flags) \
	libxfs_trace_getbuf_flags(__FUNCTION__, __FILE__, __LINE__, \
			    (dev), (daddr), (len), (flags))
#define libxfs_putbuf(buf) \
	libxfs_trace_putbuf(__FUNCTION__, __FILE__, __LINE__, (buf))

extern xfs_buf_t *libxfs_trace_readbuf(const char *, const char *, int,
			struct xfs_buftarg *, xfs_daddr_t, int, int,
			const struct xfs_buf_ops *);
extern xfs_buf_t *libxfs_trace_readbuf_map(const char *, const char *, int,
			struct xfs_buftarg *, struct xfs_buf_map *, int, int,
			const struct xfs_buf_ops *);
extern int	libxfs_trace_writebuf(const char *, const char *, int,
			xfs_buf_t *, int);
extern xfs_buf_t *libxfs_trace_getbuf(const char *, const char *, int,
			struct xfs_buftarg *, xfs_daddr_t, int);
extern xfs_buf_t *libxfs_trace_getbuf_map(const char *, const char *, int,
			struct xfs_buftarg *, struct xfs_buf_map *, int, int);
extern xfs_buf_t *libxfs_trace_getbuf_flags(const char *, const char *, int,
			struct xfs_buftarg *, xfs_daddr_t, int, unsigned int);
extern void	libxfs_trace_putbuf (const char *, const char *, int,
			xfs_buf_t *);

#else

extern xfs_buf_t *libxfs_readbuf(struct xfs_buftarg *, xfs_daddr_t, int, int,
			const struct xfs_buf_ops *);
extern xfs_buf_t *libxfs_readbuf_map(struct xfs_buftarg *, struct xfs_buf_map *,
			int, int, const struct xfs_buf_ops *);
extern int	libxfs_writebuf(xfs_buf_t *, int);
extern xfs_buf_t *libxfs_getbuf(struct xfs_buftarg *, xfs_daddr_t, int);
extern xfs_buf_t *libxfs_getbuf_map(struct xfs_buftarg *,
			struct xfs_buf_map *, int, int);
extern xfs_buf_t *libxfs_getbuf_flags(struct xfs_buftarg *, xfs_daddr_t,
			int, unsigned int);
extern void	libxfs_putbuf (xfs_buf_t *);

#endif

extern void	libxfs_readbuf_verify(struct xfs_buf *bp,
			const struct xfs_buf_ops *ops);
extern xfs_buf_t *libxfs_getsb(struct xfs_mount *, int);
extern void	libxfs_bcache_purge(void);
extern void	libxfs_bcache_flush(void);
extern void	libxfs_purgebuf(xfs_buf_t *);
extern int	libxfs_bcache_overflowed(void);
extern int	libxfs_bcache_usage(void);

/* Buffer (Raw) Interfaces */
extern xfs_buf_t *libxfs_getbufr(struct xfs_buftarg *, xfs_daddr_t, int);
extern void	libxfs_putbufr(xfs_buf_t *);

extern int	libxfs_writebuf_int(xfs_buf_t *, int);
extern int	libxfs_writebufr(struct xfs_buf *);
extern int	libxfs_readbufr(struct xfs_buftarg *, xfs_daddr_t, xfs_buf_t *, int, int);
extern int	libxfs_readbufr_map(struct xfs_buftarg *, struct xfs_buf *, int);

extern int	libxfs_device_zero(struct xfs_buftarg *, xfs_daddr_t, uint);

extern int libxfs_bhash_size;

#define LIBXFS_BREAD	0x1
#define LIBXFS_BWRITE	0x2
#define LIBXFS_BZERO	0x4

extern void	libxfs_iomove (xfs_buf_t *, uint, int, void *, int);

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);
}

#endif	/* __LIBXFS_IO_H__ */