xfs_dir2.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 860 行 · 第 1/2 页

/*
 * Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 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.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

/*
 * XFS v2 directory implmentation.
 * Top-level and utility routines.
 */

#include "xfs.h"

#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode_item.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_da_btree.h"
#include "xfs_dir_leaf.h"
#include "xfs_dir2_data.h"
#include "xfs_dir2_leaf.h"
#include "xfs_dir2_block.h"
#include "xfs_dir2_node.h"
#include "xfs_dir2_trace.h"
#include "xfs_error.h"
#include "xfs_bit.h"

/*
 * Declarations for interface routines.
 */
static void	xfs_dir2_mount(xfs_mount_t *mp);
static int	xfs_dir2_isempty(xfs_inode_t *dp);
static int	xfs_dir2_init(xfs_trans_t *tp, xfs_inode_t *dp,
			      xfs_inode_t *pdp);
static int	xfs_dir2_createname(xfs_trans_t *tp, xfs_inode_t *dp,
				    char *name, int namelen, xfs_ino_t inum,
				    xfs_fsblock_t *first,
				    xfs_bmap_free_t *flist, xfs_extlen_t total);
static int	xfs_dir2_lookup(xfs_trans_t *tp, xfs_inode_t *dp, char *name,
				int namelen, xfs_ino_t *inum);
static int	xfs_dir2_removename(xfs_trans_t *tp, xfs_inode_t *dp,
				    char *name, int namelen, xfs_ino_t ino,
				    xfs_fsblock_t *first,
				    xfs_bmap_free_t *flist, xfs_extlen_t total);
static int	xfs_dir2_getdents(xfs_trans_t *tp, xfs_inode_t *dp, uio_t *uio,
				  int *eofp);
static int	xfs_dir2_replace(xfs_trans_t *tp, xfs_inode_t *dp, char *name,
				 int namelen, xfs_ino_t inum,
				 xfs_fsblock_t *first, xfs_bmap_free_t *flist,
				 xfs_extlen_t total);
static int	xfs_dir2_canenter(xfs_trans_t *tp, xfs_inode_t *dp, char *name,
				  int namelen);
static int	xfs_dir2_shortform_validate_ondisk(xfs_mount_t *mp,
						   xfs_dinode_t *dip);

/*
 * Utility routine declarations.
 */
static int	xfs_dir2_put_dirent64_direct(xfs_dir2_put_args_t *pa);
static int	xfs_dir2_put_dirent64_uio(xfs_dir2_put_args_t *pa);

/*
 * Directory operations vector.
 */
xfs_dirops_t	xfsv2_dirops = {
	.xd_mount			= xfs_dir2_mount,
	.xd_isempty			= xfs_dir2_isempty,
	.xd_init			= xfs_dir2_init,
	.xd_createname			= xfs_dir2_createname,
	.xd_lookup			= xfs_dir2_lookup,
	.xd_removename			= xfs_dir2_removename,
	.xd_getdents			= xfs_dir2_getdents,
	.xd_replace			= xfs_dir2_replace,
	.xd_canenter			= xfs_dir2_canenter,
	.xd_shortform_validate_ondisk	= xfs_dir2_shortform_validate_ondisk,
	.xd_shortform_to_single		= xfs_dir2_sf_to_block,
};

/*
 * Interface routines.
 */

/*
 * Initialize directory-related fields in the mount structure.
 */
static void
xfs_dir2_mount(
	xfs_mount_t	*mp)		/* filesystem mount point */
{
	mp->m_dirversion = 2;
	ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
	       XFS_MAX_BLOCKSIZE);
	mp->m_dirblksize = 1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog);
	mp->m_dirblkfsbs = 1 << mp->m_sb.sb_dirblklog;
	mp->m_dirdatablk = XFS_DIR2_DB_TO_DA(mp, XFS_DIR2_DATA_FIRSTDB(mp));
	mp->m_dirleafblk = XFS_DIR2_DB_TO_DA(mp, XFS_DIR2_LEAF_FIRSTDB(mp));
	mp->m_dirfreeblk = XFS_DIR2_DB_TO_DA(mp, XFS_DIR2_FREE_FIRSTDB(mp));
	mp->m_attr_node_ents =
		(mp->m_sb.sb_blocksize - (uint)sizeof(xfs_da_node_hdr_t)) /
		(uint)sizeof(xfs_da_node_entry_t);
	mp->m_dir_node_ents =
		(mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
		(uint)sizeof(xfs_da_node_entry_t);
	mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
}

/*
 * Return 1 if directory contains only "." and "..".
 */
static int				/* return code */
xfs_dir2_isempty(
	xfs_inode_t	*dp)		/* incore inode structure */
{
	xfs_dir2_sf_t	*sfp;		/* shortform directory structure */

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	/*
	 * Might happen during shutdown.
	 */
	if (dp->i_d.di_size == 0) {
		return 1;
	}
	if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
		return 0;
	sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
	return INT_ISZERO(sfp->hdr.count, ARCH_CONVERT);
}

/*
 * Initialize a directory with its "." and ".." entries.
 */
static int				/* error */
xfs_dir2_init(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_inode_t	*dp,		/* incore directory inode */
	xfs_inode_t	*pdp)		/* incore parent directory inode */
{
	xfs_da_args_t	args;		/* operation arguments */
	int		error;		/* error return value */

	memset((char *)&args, 0, sizeof(args));
	args.dp = dp;
	args.trans = tp;
	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	if ((error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino))) {
		return error;
	}
	return xfs_dir2_sf_create(&args, pdp->i_ino);
}

/*
  Enter a name in a directory.
 */
static int					/* error */
xfs_dir2_createname(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_inode_t		*dp,		/* incore directory inode */
	char			*name,		/* new entry name */
	int			namelen,	/* new entry name length */
	xfs_ino_t		inum,		/* new entry inode number */
	xfs_fsblock_t		*first,		/* bmap's firstblock */
	xfs_bmap_free_t		*flist,		/* bmap's freeblock list */
	xfs_extlen_t		total)		/* bmap's total block count */
{
	xfs_da_args_t		args;		/* operation arguments */
	int			rval;		/* return value */
	int			v;		/* type-checking value */

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum))) {
		return rval;
	}
	XFS_STATS_INC(xs_dir_create);
	/*
	 * Fill in the arg structure for this request.
	 */
	args.name = name;
	args.namelen = namelen;
	args.hashval = xfs_da_hashname(name, namelen);
	args.inumber = inum;
	args.dp = dp;
	args.firstblock = first;
	args.flist = flist;
	args.total = total;
	args.whichfork = XFS_DATA_FORK;
	args.trans = tp;
	args.justcheck = 0;
	args.addname = args.oknoent = 1;
	/*
	 * Decide on what work routines to call based on the inode size.
	 */
	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
		rval = xfs_dir2_sf_addname(&args);
	else if ((rval = xfs_dir2_isblock(tp, dp, &v))) {
		return rval;
	} else if (v)
		rval = xfs_dir2_block_addname(&args);
	else if ((rval = xfs_dir2_isleaf(tp, dp, &v))) {
		return rval;
	} else if (v)
		rval = xfs_dir2_leaf_addname(&args);
	else
		rval = xfs_dir2_node_addname(&args);
	return rval;
}

/*
 * Lookup a name in a directory, give back the inode number.
 */
static int				/* error */
xfs_dir2_lookup(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_inode_t	*dp,		/* incore directory inode */
	char		*name,		/* lookup name */
	int		namelen,	/* lookup name length */
	xfs_ino_t	*inum)		/* out: inode number */
{
	xfs_da_args_t	args;		/* operation arguments */
	int		rval;		/* return value */
	int		v;		/* type-checking value */

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	XFS_STATS_INC(xs_dir_lookup);

	/*
	 * Fill in the arg structure for this request.
	 */
	args.name = name;
	args.namelen = namelen;
	args.hashval = xfs_da_hashname(name, namelen);
	args.inumber = 0;
	args.dp = dp;
	args.firstblock = NULL;
	args.flist = NULL;
	args.total = 0;
	args.whichfork = XFS_DATA_FORK;
	args.trans = tp;
	args.justcheck = args.addname = 0;
	args.oknoent = 1;
	/*
	 * Decide on what work routines to call based on the inode size.
	 */
	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
		rval = xfs_dir2_sf_lookup(&args);
	else if ((rval = xfs_dir2_isblock(tp, dp, &v))) {
		return rval;
	} else if (v)
		rval = xfs_dir2_block_lookup(&args);
	else if ((rval = xfs_dir2_isleaf(tp, dp, &v))) {
		return rval;
	} else if (v)
		rval = xfs_dir2_leaf_lookup(&args);
	else
		rval = xfs_dir2_node_lookup(&args);
	if (rval == EEXIST)
		rval = 0;
	if (rval == 0)
		*inum = args.inumber;
	return rval;
}

/*
 * Remove an entry from a directory.
 */
static int				/* error */
xfs_dir2_removename(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_inode_t	*dp,		/* incore directory inode */
	char		*name,		/* name of entry to remove */
	int		namelen,	/* name length of entry to remove */
	xfs_ino_t	ino,		/* inode number of entry to remove */
	xfs_fsblock_t	*first,		/* bmap's firstblock */
	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
	xfs_extlen_t	total)		/* bmap's total block count */
{
	xfs_da_args_t	args;		/* operation arguments */
	int		rval;		/* return value */
	int		v;		/* type-checking value */

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	XFS_STATS_INC(xs_dir_remove);
	/*
	 * Fill in the arg structure for this request.
	 */
	args.name = name;
	args.namelen = namelen;
	args.hashval = xfs_da_hashname(name, namelen);
	args.inumber = ino;
	args.dp = dp;
	args.firstblock = first;
	args.flist = flist;
	args.total = total;
	args.whichfork = XFS_DATA_FORK;
	args.trans = tp;
	args.justcheck = args.addname = args.oknoent = 0;
	/*
	 * Decide on what work routines to call based on the inode size.
	 */
	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
		rval = xfs_dir2_sf_removename(&args);
	else if ((rval = xfs_dir2_isblock(tp, dp, &v))) {
		return rval;
	} else if (v)
		rval = xfs_dir2_block_removename(&args);
	else if ((rval = xfs_dir2_isleaf(tp, dp, &v))) {
		return rval;
	} else if (v)
		rval = xfs_dir2_leaf_removename(&args);
	else
		rval = xfs_dir2_node_removename(&args);
	return rval;
}

/*
 * Read a directory.
 */
static int				/* error */
xfs_dir2_getdents(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_inode_t	*dp,		/* incore directory inode */
	uio_t		*uio,		/* caller's buffer control */
	int		*eofp)		/* out: eof reached */
{
	int		alignment;	/* alignment required for ABI */
	xfs_dirent_t	*dbp;		/* malloc'ed buffer */
	xfs_dir2_put_t	put;		/* entry formatting routine */
	int		rval;		/* return value */
	int		v;		/* type-checking value */

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	XFS_STATS_INC(xs_dir_getdents);
	/*
	 * If our caller has given us a single contiguous aligned memory buffer,
	 * just work directly within that buffer.  If it's in user memory,
	 * lock it down first.
	 */
	alignment = sizeof(xfs_off_t) - 1;
	if ((uio->uio_iovcnt == 1) &&
	    (((__psint_t)uio->uio_iov[0].iov_base & alignment) == 0) &&
	    ((uio->uio_iov[0].iov_len & alignment) == 0)) {
		dbp = NULL;
		put = xfs_dir2_put_dirent64_direct;
	} else {
		dbp = kmem_alloc(sizeof(*dbp) + MAXNAMELEN, KM_SLEEP);
		put = xfs_dir2_put_dirent64_uio;
	}

	*eofp = 0;
	/*
	 * Decide on what work routines to call based on the inode size.
	 */
	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
		rval = xfs_dir2_sf_getdents(dp, uio, eofp, dbp, put);
	else if ((rval = xfs_dir2_isblock(tp, dp, &v))) {
		;
	} else if (v)
		rval = xfs_dir2_block_getdents(tp, dp, uio, eofp, dbp, put);
	else
		rval = xfs_dir2_leaf_getdents(tp, dp, uio, eofp, dbp, put);
	if (dbp != NULL)
		kmem_free(dbp, sizeof(*dbp) + MAXNAMELEN);
	return rval;
}

/*
 * Replace the inode number of a directory entry.
 */
static int				/* error */
xfs_dir2_replace(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_inode_t	*dp,		/* incore directory inode */
	char		*name,		/* name of entry to replace */
	int		namelen,	/* name length of entry to replace */
	xfs_ino_t	inum,		/* new inode number */
	xfs_fsblock_t	*first,		/* bmap's firstblock */
	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
	xfs_extlen_t	total)		/* bmap's total block count */
{
	xfs_da_args_t	args;		/* operation arguments */
	int		rval;		/* return value */
	int		v;		/* type-checking value */

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);

	if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum))) {
		return rval;
	}
	/*