discontigous buffer in separate buffer format structures. This means log recovery will recover all the changes on a per segment basis without requiring any knowledge of the fact that it was logged from a compound buffer. To do this, we need to be able to determine what buffer segment any given offset into the compound buffer sits over. This enables us to translate the dirty bitmap in the number of separate buffer format structures required. We also need to be able to determine the number of bitmap elements that a given buffer segment has, as this determines the size of the buffer format structure. Hence we need to be able to determine the both the start offset into the buffer and the length of a given segment to be able to calculate this. With this information, we can preallocate, build and format the correct log vector array for each segment in a compound buffer to appear exactly the same as individually logged buffers in the log. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
		
			
				
	
	
		
			132 lines
		
	
	
	
		
			4.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			132 lines
		
	
	
	
		
			4.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
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 * All Rights Reserved.
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation.
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 *
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 * This program is distributed in the hope that it would be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write the Free Software Foundation,
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 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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#ifndef	__XFS_BUF_ITEM_H__
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#define	__XFS_BUF_ITEM_H__
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extern kmem_zone_t	*xfs_buf_item_zone;
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/*
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 * This flag indicates that the buffer contains on disk inodes
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 * and requires special recovery handling.
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 */
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#define	XFS_BLF_INODE_BUF	0x1
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/*
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 * This flag indicates that the buffer should not be replayed
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 * during recovery because its blocks are being freed.
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 */
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#define	XFS_BLF_CANCEL		0x2
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/*
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 * This flag indicates that the buffer contains on disk
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 * user or group dquots and may require special recovery handling.
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 */
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#define	XFS_BLF_UDQUOT_BUF	0x4
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#define XFS_BLF_PDQUOT_BUF	0x8
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#define	XFS_BLF_GDQUOT_BUF	0x10
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#define	XFS_BLF_CHUNK		128
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#define	XFS_BLF_SHIFT		7
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#define	BIT_TO_WORD_SHIFT	5
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#define	NBWORD			(NBBY * sizeof(unsigned int))
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/*
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 * This is the structure used to lay out a buf log item in the
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 * log.  The data map describes which 128 byte chunks of the buffer
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 * have been logged.
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 */
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#define XFS_BLF_DATAMAP_SIZE	((XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK) / NBWORD)
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typedef struct xfs_buf_log_format {
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	unsigned short	blf_type;	/* buf log item type indicator */
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	unsigned short	blf_size;	/* size of this item */
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	ushort		blf_flags;	/* misc state */
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	ushort		blf_len;	/* number of blocks in this buf */
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	__int64_t	blf_blkno;	/* starting blkno of this buf */
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	unsigned int	blf_map_size;	/* used size of data bitmap in words */
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	unsigned int	blf_data_map[XFS_BLF_DATAMAP_SIZE]; /* dirty bitmap */
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} xfs_buf_log_format_t;
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/*
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 * buf log item flags
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 */
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#define	XFS_BLI_HOLD		0x01
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#define	XFS_BLI_DIRTY		0x02
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#define	XFS_BLI_STALE		0x04
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#define	XFS_BLI_LOGGED		0x08
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#define	XFS_BLI_INODE_ALLOC_BUF	0x10
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#define XFS_BLI_STALE_INODE	0x20
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#define	XFS_BLI_INODE_BUF	0x40
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#define XFS_BLI_FLAGS \
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	{ XFS_BLI_HOLD,		"HOLD" }, \
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	{ XFS_BLI_DIRTY,	"DIRTY" }, \
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	{ XFS_BLI_STALE,	"STALE" }, \
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	{ XFS_BLI_LOGGED,	"LOGGED" }, \
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	{ XFS_BLI_INODE_ALLOC_BUF, "INODE_ALLOC" }, \
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	{ XFS_BLI_STALE_INODE,	"STALE_INODE" }, \
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	{ XFS_BLI_INODE_BUF,	"INODE_BUF" }
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#ifdef __KERNEL__
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struct xfs_buf;
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struct xfs_mount;
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struct xfs_buf_log_item;
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/*
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 * This is the in core log item structure used to track information
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 * needed to log buffers.  It tracks how many times the lock has been
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 * locked, and which 128 byte chunks of the buffer are dirty.
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 */
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typedef struct xfs_buf_log_item {
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	xfs_log_item_t		bli_item;	/* common item structure */
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	struct xfs_buf		*bli_buf;	/* real buffer pointer */
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	unsigned int		bli_flags;	/* misc flags */
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	unsigned int		bli_recur;	/* lock recursion count */
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	atomic_t		bli_refcount;	/* cnt of tp refs */
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#ifdef XFS_TRANS_DEBUG
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	char			*bli_orig;	/* original buffer copy */
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	char			*bli_logged;	/* bytes logged (bitmap) */
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#endif
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	int			bli_format_count;	/* count of headers */
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	struct xfs_buf_log_format *bli_formats;	/* array of in-log header ptrs */
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	struct xfs_buf_log_format bli_format;	/* embedded in-log header */
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} xfs_buf_log_item_t;
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void	xfs_buf_item_init(struct xfs_buf *, struct xfs_mount *);
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void	xfs_buf_item_relse(struct xfs_buf *);
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void	xfs_buf_item_log(xfs_buf_log_item_t *, uint, uint);
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uint	xfs_buf_item_dirty(xfs_buf_log_item_t *);
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void	xfs_buf_attach_iodone(struct xfs_buf *,
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			      void(*)(struct xfs_buf *, xfs_log_item_t *),
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			      xfs_log_item_t *);
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void	xfs_buf_iodone_callbacks(struct xfs_buf *);
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void	xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
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#ifdef XFS_TRANS_DEBUG
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void
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xfs_buf_item_flush_log_debug(
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	struct xfs_buf *bp,
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	uint	first,
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	uint	last);
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#else
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#define	xfs_buf_item_flush_log_debug(bp, first, last)
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#endif
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#endif	/* __KERNEL__ */
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#endif	/* __XFS_BUF_ITEM_H__ */
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