xfs_dir2.c

linux 内核源代码

/*
 * Copyright (c) 2000-2001,2005 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
 */
#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_dmapi.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.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"


void
xfs_dir_mount(
	xfs_mount_t	*mp)
{
	ASSERT(XFS_SB_VERSION_HASDIRV2(&mp->m_sb));
	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 "..".
 */
int
xfs_dir_isempty(
	xfs_inode_t	*dp)
{
	xfs_dir2_sf_t	*sfp;

	ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
	if (dp->i_d.di_size == 0)	/* might happen during shutdown. */
		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 !sfp->hdr.count;
}

/*
 * Validate a given inode number.
 */
int
xfs_dir_ino_validate(
	xfs_mount_t	*mp,
	xfs_ino_t	ino)
{
	xfs_agblock_t	agblkno;
	xfs_agino_t	agino;
	xfs_agnumber_t	agno;
	int		ino_ok;
	int		ioff;

	agno = XFS_INO_TO_AGNO(mp, ino);
	agblkno = XFS_INO_TO_AGBNO(mp, ino);
	ioff = XFS_INO_TO_OFFSET(mp, ino);
	agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
	ino_ok =
		agno < mp->m_sb.sb_agcount &&
		agblkno < mp->m_sb.sb_agblocks &&
		agblkno != 0 &&
		ioff < (1 << mp->m_sb.sb_inopblog) &&
		XFS_AGINO_TO_INO(mp, agno, agino) == ino;
	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
			XFS_RANDOM_DIR_INO_VALIDATE))) {
		xfs_fs_cmn_err(CE_WARN, mp, "Invalid inode number 0x%Lx",
				(unsigned long long) ino);
		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
		return XFS_ERROR(EFSCORRUPTED);
	}
	return 0;
}

/*
 * Initialize a directory with its "." and ".." entries.
 */
int
xfs_dir_init(
	xfs_trans_t	*tp,
	xfs_inode_t	*dp,
	xfs_inode_t	*pdp)
{
	xfs_da_args_t	args;
	int		error;

	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.
 */
int
xfs_dir_createname(
	xfs_trans_t		*tp,
	xfs_inode_t		*dp,
	char			*name,
	int			namelen,
	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;
	int			rval;
	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);

	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;

	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.
 */
int
xfs_dir_lookup(
	xfs_trans_t	*tp,
	xfs_inode_t	*dp,
	char		*name,
	int		namelen,
	xfs_ino_t	*inum)		/* out: inode number */
{
	xfs_da_args_t	args;
	int		rval;
	int		v;		/* type-checking value */

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

	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;

	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.
 */
int
xfs_dir_removename(
	xfs_trans_t	*tp,
	xfs_inode_t	*dp,
	char		*name,
	int		namelen,
	xfs_ino_t	ino,
	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;
	int		rval;
	int		v;		/* type-checking value */

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

	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;

	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.
 */
int
xfs_readdir(
	xfs_inode_t	*dp,
	void		*dirent,
	size_t		bufsize,
	xfs_off_t	*offset,
	filldir_t	filldir)
{
	int		rval;		/* return value */
	int		v;		/* type-checking value */

	vn_trace_entry(dp, __FUNCTION__, (inst_t *)__return_address);

	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
		return XFS_ERROR(EIO);

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

	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
		rval = xfs_dir2_sf_getdents(dp, dirent, offset, filldir);
	else if ((rval = xfs_dir2_isblock(NULL, dp, &v)))
		;
	else if (v)
		rval = xfs_dir2_block_getdents(dp, dirent, offset, filldir);
	else
		rval = xfs_dir2_leaf_getdents(dp, dirent, bufsize, offset,
					      filldir);
	return rval;
}

/*
 * Replace the inode number of a directory entry.
 */
int
xfs_dir_replace(
	xfs_trans_t	*tp,
	xfs_inode_t	*dp,
	char		*name,		/* name of entry to replace */
	int		namelen,
	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;
	int		rval;