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linux-next/fs/xfs/xfs_dir2.h
Barry Naujok 384f3ced07 [XFS] Return case-insensitive match for dentry cache
This implements the code to store the actual filename found during a
lookup in the dentry cache and to avoid multiple entries in the dcache
pointing to the same inode.

To avoid polluting the dcache, we implement a new directory inode
operations for lookup. xfs_vn_ci_lookup() stores the correct case name in
the dcache.

The "actual name" is only allocated and returned for a case- insensitive
match and not an actual match.

Another unusual interaction with the dcache is not storing negative
dentries like other filesystems doing a d_add(dentry, NULL) when an ENOENT
is returned. During the VFS lookup, if a dentry returned has no inode,
dput is called and ENOENT is returned. By not doing a d_add, this actually
removes it completely from the dcache to be reused. create/rename have to
be modified to support unhashed dentries being passed in.

SGI-PV: 981521
SGI-Modid: xfs-linux-melb:xfs-kern:31208a

Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-07-28 16:58:40 +10:00

107 lines
3.5 KiB
C

/*
* 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
*/
#ifndef __XFS_DIR2_H__
#define __XFS_DIR2_H__
struct uio;
struct xfs_dabuf;
struct xfs_da_args;
struct xfs_dir2_put_args;
struct xfs_bmap_free;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
/*
* Directory version 2.
* There are 4 possible formats:
* shortform
* single block - data with embedded leaf at the end
* multiple data blocks, single leaf+freeindex block
* data blocks, node&leaf blocks (btree), freeindex blocks
*
* The shortform format is in xfs_dir2_sf.h.
* The single block format is in xfs_dir2_block.h.
* The data block format is in xfs_dir2_data.h.
* The leaf and freeindex block formats are in xfs_dir2_leaf.h.
* Node blocks are the same as the other version, in xfs_da_btree.h.
*/
/*
* Byte offset in data block and shortform entry.
*/
typedef __uint16_t xfs_dir2_data_off_t;
#define NULLDATAOFF 0xffffU
typedef uint xfs_dir2_data_aoff_t; /* argument form */
/*
* Directory block number (logical dirblk in file)
*/
typedef __uint32_t xfs_dir2_db_t;
/*
* Byte offset in a directory.
*/
typedef xfs_off_t xfs_dir2_off_t;
extern struct xfs_name xfs_name_dotdot;
/*
* Generic directory interface routines
*/
extern void xfs_dir_startup(void);
extern void xfs_dir_mount(struct xfs_mount *mp);
extern int xfs_dir_isempty(struct xfs_inode *dp);
extern int xfs_dir_init(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_inode *pdp);
extern int xfs_dir_createname(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t inum,
xfs_fsblock_t *first,
struct xfs_bmap_free *flist, xfs_extlen_t tot);
extern int xfs_dir_lookup(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t *inum,
struct xfs_name *ci_name);
extern int xfs_dir_removename(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t ino,
xfs_fsblock_t *first,
struct xfs_bmap_free *flist, xfs_extlen_t tot);
extern int xfs_dir_replace(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, xfs_ino_t inum,
xfs_fsblock_t *first,
struct xfs_bmap_free *flist, xfs_extlen_t tot);
extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
struct xfs_name *name, uint resblks);
extern int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
/*
* Utility routines for v2 directories.
*/
extern int xfs_dir2_grow_inode(struct xfs_da_args *args, int space,
xfs_dir2_db_t *dbp);
extern int xfs_dir2_isblock(struct xfs_trans *tp, struct xfs_inode *dp,
int *vp);
extern int xfs_dir2_isleaf(struct xfs_trans *tp, struct xfs_inode *dp,
int *vp);
extern int xfs_dir2_shrink_inode(struct xfs_da_args *args, xfs_dir2_db_t db,
struct xfs_dabuf *bp);
extern int xfs_dir_cilookup_result(struct xfs_da_args *args, const char *name,
int len);
#endif /* __XFS_DIR2_H__ */