xfs_bmap.c

linux 内核源代码

/*
 * Copyright (c) 2000-2006 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
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_ialloc.h"
#include "xfs_itable.h"
#include "xfs_dir2_data.h"
#include "xfs_dir2_leaf.h"
#include "xfs_dir2_block.h"
#include "xfs_inode_item.h"
#include "xfs_extfree_item.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_attr_leaf.h"
#include "xfs_rw.h"
#include "xfs_quota.h"
#include "xfs_trans_space.h"
#include "xfs_buf_item.h"
#include "xfs_filestream.h"
#include "xfs_vnodeops.h"


#ifdef DEBUG
STATIC void
xfs_bmap_check_leaf_extents(xfs_btree_cur_t *cur, xfs_inode_t *ip, int whichfork);
#endif

kmem_zone_t		*xfs_bmap_free_item_zone;

/*
 * Prototypes for internal bmap routines.
 */


/*
 * Called from xfs_bmap_add_attrfork to handle extents format files.
 */
STATIC int					/* error */
xfs_bmap_add_attrfork_extents(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_inode_t		*ip,		/* incore inode pointer */
	xfs_fsblock_t		*firstblock,	/* first block allocated */
	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
	int			*flags);	/* inode logging flags */

/*
 * Called from xfs_bmap_add_attrfork to handle local format files.
 */
STATIC int					/* error */
xfs_bmap_add_attrfork_local(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_inode_t		*ip,		/* incore inode pointer */
	xfs_fsblock_t		*firstblock,	/* first block allocated */
	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
	int			*flags);	/* inode logging flags */

/*
 * Called by xfs_bmapi to update file extent records and the btree
 * after allocating space (or doing a delayed allocation).
 */
STATIC int				/* error */
xfs_bmap_add_extent(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	xfs_fsblock_t		*first,	/* pointer to firstblock variable */
	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
	int			*logflagsp, /* inode logging flags */
	xfs_extdelta_t		*delta, /* Change made to incore extents */
	int			whichfork, /* data or attr fork */
	int			rsvd);	/* OK to allocate reserved blocks */

/*
 * Called by xfs_bmap_add_extent to handle cases converting a delayed
 * allocation to a real allocation.
 */
STATIC int				/* error */
xfs_bmap_add_extent_delay_real(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	xfs_filblks_t		*dnew,	/* new delayed-alloc indirect blocks */
	xfs_fsblock_t		*first,	/* pointer to firstblock variable */
	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
	int			*logflagsp, /* inode logging flags */
	xfs_extdelta_t		*delta, /* Change made to incore extents */
	int			rsvd);	/* OK to allocate reserved blocks */

/*
 * Called by xfs_bmap_add_extent to handle cases converting a hole
 * to a delayed allocation.
 */
STATIC int				/* error */
xfs_bmap_add_extent_hole_delay(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	int			*logflagsp,/* inode logging flags */
	xfs_extdelta_t		*delta, /* Change made to incore extents */
	int			rsvd);	/* OK to allocate reserved blocks */

/*
 * Called by xfs_bmap_add_extent to handle cases converting a hole
 * to a real allocation.
 */
STATIC int				/* error */
xfs_bmap_add_extent_hole_real(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_btree_cur_t		*cur,	/* if null, not a btree */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	int			*logflagsp, /* inode logging flags */
	xfs_extdelta_t		*delta, /* Change made to incore extents */
	int			whichfork); /* data or attr fork */

/*
 * Called by xfs_bmap_add_extent to handle cases converting an unwritten
 * allocation to a real allocation or vice versa.
 */
STATIC int				/* error */
xfs_bmap_add_extent_unwritten_real(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	int			*logflagsp, /* inode logging flags */
	xfs_extdelta_t		*delta); /* Change made to incore extents */

/*
 * xfs_bmap_alloc is called by xfs_bmapi to allocate an extent for a file.
 * It figures out where to ask the underlying allocator to put the new extent.
 */
STATIC int				/* error */
xfs_bmap_alloc(
	xfs_bmalloca_t		*ap);	/* bmap alloc argument struct */

/*
 * Transform a btree format file with only one leaf node, where the
 * extents list will fit in the inode, into an extents format file.
 * Since the file extents are already in-core, all we have to do is
 * give up the space for the btree root and pitch the leaf block.
 */
STATIC int				/* error */
xfs_bmap_btree_to_extents(
	xfs_trans_t		*tp,	/* transaction pointer */
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_btree_cur_t		*cur,	/* btree cursor */
	int			*logflagsp, /* inode logging flags */
	int			whichfork); /* data or attr fork */

/*
 * Called by xfs_bmapi to update file extent records and the btree
 * after removing space (or undoing a delayed allocation).
 */
STATIC int				/* error */
xfs_bmap_del_extent(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_trans_t		*tp,	/* current trans pointer */
	xfs_extnum_t		idx,	/* extent number to update/insert */
	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
	xfs_btree_cur_t		*cur,	/* if null, not a btree */
	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
	int			*logflagsp,/* inode logging flags */
	xfs_extdelta_t		*delta, /* Change made to incore extents */
	int			whichfork, /* data or attr fork */
	int			rsvd);	 /* OK to allocate reserved blocks */

/*
 * Remove the entry "free" from the free item list.  Prev points to the
 * previous entry, unless "free" is the head of the list.
 */
STATIC void
xfs_bmap_del_free(
	xfs_bmap_free_t		*flist,	/* free item list header */
	xfs_bmap_free_item_t	*prev,	/* previous item on list, if any */
	xfs_bmap_free_item_t	*free);	/* list item to be freed */

/*
 * Convert an extents-format file into a btree-format file.
 * The new file will have a root block (in the inode) and a single child block.
 */
STATIC int					/* error */
xfs_bmap_extents_to_btree(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_inode_t		*ip,		/* incore inode pointer */
	xfs_fsblock_t		*firstblock,	/* first-block-allocated */
	xfs_bmap_free_t		*flist,		/* blocks freed in xaction */
	xfs_btree_cur_t		**curp,		/* cursor returned to caller */
	int			wasdel,		/* converting a delayed alloc */
	int			*logflagsp,	/* inode logging flags */
	int			whichfork);	/* data or attr fork */

/*
 * Convert a local file to an extents file.
 * This code is sort of bogus, since the file data needs to get
 * logged so it won't be lost.  The bmap-level manipulations are ok, though.
 */
STATIC int				/* error */
xfs_bmap_local_to_extents(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_fsblock_t	*firstblock,	/* first block allocated in xaction */
	xfs_extlen_t	total,		/* total blocks needed by transaction */
	int		*logflagsp,	/* inode logging flags */
	int		whichfork);	/* data or attr fork */

/*
 * Search the extents list for the inode, for the extent containing bno.
 * If bno lies in a hole, point to the next entry.  If bno lies past eof,
 * *eofp will be set, and *prevp will contain the last entry (null if none).
 * Else, *lastxp will be set to the index of the found
 * entry; *gotp will contain the entry.
 */
STATIC xfs_bmbt_rec_host_t *		/* pointer to found extent entry */
xfs_bmap_search_extents(
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_fileoff_t	bno,		/* block number searched for */
	int		whichfork,	/* data or attr fork */
	int		*eofp,		/* out: end of file found */
	xfs_extnum_t	*lastxp,	/* out: last extent index */
	xfs_bmbt_irec_t	*gotp,		/* out: extent entry found */
	xfs_bmbt_irec_t	*prevp);	/* out: previous extent entry found */

/*
 * Check the last inode extent to determine whether this allocation will result
 * in blocks being allocated at the end of the file. When we allocate new data
 * blocks at the end of the file which do not start at the previous data block,
 * we will try to align the new blocks at stripe unit boundaries.
 */
STATIC int				/* error */
xfs_bmap_isaeof(
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_fileoff_t   off,		/* file offset in fsblocks */
	int             whichfork,	/* data or attribute fork */
	char		*aeof);		/* return value */

#ifdef XFS_BMAP_TRACE
/*
 * Add bmap trace entry prior to a call to xfs_iext_remove.
 */
STATIC void
xfs_bmap_trace_delete(
	const char	*fname,		/* function name */
	char		*desc,		/* operation description */
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_extnum_t	idx,		/* index of entry(entries) deleted */
	xfs_extnum_t	cnt,		/* count of entries deleted, 1 or 2 */
	int		whichfork);	/* data or attr fork */

/*
 * Add bmap trace entry prior to a call to xfs_iext_insert, or
 * reading in the extents list from the disk (in the btree).
 */
STATIC void
xfs_bmap_trace_insert(
	const char	*fname,		/* function name */
	char		*desc,		/* operation description */
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_extnum_t	idx,		/* index of entry(entries) inserted */
	xfs_extnum_t	cnt,		/* count of entries inserted, 1 or 2 */
	xfs_bmbt_irec_t	*r1,		/* inserted record 1 */
	xfs_bmbt_irec_t	*r2,		/* inserted record 2 or null */
	int		whichfork);	/* data or attr fork */

/*
 * Add bmap trace entry after updating an extent record in place.
 */
STATIC void
xfs_bmap_trace_post_update(
	const char	*fname,		/* function name */
	char		*desc,		/* operation description */
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_extnum_t	idx,		/* index of entry updated */
	int		whichfork);	/* data or attr fork */

/*
 * Add bmap trace entry prior to updating an extent record in place.
 */
STATIC void
xfs_bmap_trace_pre_update(
	const char	*fname,		/* function name */
	char		*desc,		/* operation description */
	xfs_inode_t	*ip,		/* incore inode pointer */
	xfs_extnum_t	idx,		/* index of entry to be updated */
	int		whichfork);	/* data or attr fork */

#define	XFS_BMAP_TRACE_DELETE(d,ip,i,c,w)	\
	xfs_bmap_trace_delete(__FUNCTION__,d,ip,i,c,w)
#define	XFS_BMAP_TRACE_INSERT(d,ip,i,c,r1,r2,w)	\
	xfs_bmap_trace_insert(__FUNCTION__,d,ip,i,c,r1,r2,w)
#define	XFS_BMAP_TRACE_POST_UPDATE(d,ip,i,w)	\
	xfs_bmap_trace_post_update(__FUNCTION__,d,ip,i,w)
#define	XFS_BMAP_TRACE_PRE_UPDATE(d,ip,i,w)	\
	xfs_bmap_trace_pre_update(__FUNCTION__,d,ip,i,w)
#else
#define	XFS_BMAP_TRACE_DELETE(d,ip,i,c,w)
#define	XFS_BMAP_TRACE_INSERT(d,ip,i,c,r1,r2,w)
#define	XFS_BMAP_TRACE_POST_UPDATE(d,ip,i,w)
#define	XFS_BMAP_TRACE_PRE_UPDATE(d,ip,i,w)
#endif	/* XFS_BMAP_TRACE */

/*
 * Compute the worst-case number of indirect blocks that will be used
 * for ip's delayed extent of length "len".
 */
STATIC xfs_filblks_t
xfs_bmap_worst_indlen(
	xfs_inode_t		*ip,	/* incore inode pointer */
	xfs_filblks_t		len);	/* delayed extent length */

#ifdef DEBUG
/*
 * Perform various validation checks on the values being returned
 * from xfs_bmapi().
 */
STATIC void
xfs_bmap_validate_ret(
	xfs_fileoff_t		bno,
	xfs_filblks_t		len,
	int			flags,
	xfs_bmbt_irec_t		*mval,
	int			nmap,
	int			ret_nmap);
#else
#define	xfs_bmap_validate_ret(bno,len,flags,mval,onmap,nmap)
#endif /* DEBUG */

#if defined(XFS_RW_TRACE)
STATIC void
xfs_bunmap_trace(
	xfs_inode_t		*ip,
	xfs_fileoff_t		bno,
	xfs_filblks_t		len,
	int			flags,
	inst_t			*ra);
#else
#define	xfs_bunmap_trace(ip, bno, len, flags, ra)
#endif	/* XFS_RW_TRACE */

STATIC int
xfs_bmap_count_tree(
	xfs_mount_t     *mp,
	xfs_trans_t     *tp,
	xfs_ifork_t	*ifp,
	xfs_fsblock_t   blockno,
	int             levelin,
	int		*count);

STATIC int
xfs_bmap_count_leaves(
	xfs_ifork_t		*ifp,
	xfs_extnum_t		idx,
	int			numrecs,
	int			*count);

STATIC int
xfs_bmap_disk_count_leaves(
	xfs_extnum_t		idx,
	xfs_bmbt_block_t	*block,
	int			numrecs,
	int			*count);

/*
 * Bmap internal routines.
 */

/*
 * Called from xfs_bmap_add_attrfork to handle btree format files.