alistair23-linux/fs/gfs2/dir.h
Steven Whitehouse 18ec7d5c3f [GFS2] Make journaled data files identical to normal files on disk
This is a very large patch, with a few still to be resolved issues
so you might want to check out the previous head of the tree since
this is known to be unstable. Fixes for the various bugs will be
forthcoming shortly.

This patch removes the special data format which has been used
up till now for journaled data files. Directories still retain the
old format so that they will remain on disk compatible with earlier
releases. As a result you can now do the following with journaled
data files:

 1) mmap them
 2) export them over NFS
 3) convert to/from normal files whenever you want to (the zero length
    restriction is gone)

In addition the level at which GFS' locking is done has changed for all
files (since they all now use the page cache) such that the locking is
done at the page cache level rather than the level of the fs operations.
This should mean that things like loopback mounts and other things which
touch the page cache directly should now work.

Current known issues:

 1. There is a lock mode inversion problem related to the resource
    group hold function which needs to be resolved.
 2. Any significant amount of I/O causes an oops with an offset of hex 320
    (NULL pointer dereference) which appears to be related to a journaled data
    buffer appearing on a list where it shouldn't be.
 3. Direct I/O writes are disabled for the time being (will reappear later)
 4. There is probably a deadlock between the page lock and GFS' locks under
    certain combinations of mmap and fs operation I/O.
 5. Issue relating to ref counting on internally used inodes causes a hang
    on umount (discovered before this patch, and not fixed by it)
 6. One part of the directory metadata is different from GFS1 and will need
    to be resolved before next release.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-02-08 11:50:51 +00:00

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1.9 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*/
#ifndef __DIR_DOT_H__
#define __DIR_DOT_H__
/**
* gfs2_filldir_t - Report a directory entry to the caller of gfs2_dir_read()
* @opaque: opaque data used by the function
* @name: the name of the directory entry
* @length: the length of the name
* @offset: the entry's offset in the directory
* @inum: the inode number the entry points to
* @type: the type of inode the entry points to
*
* Returns: 0 on success, 1 if buffer full
*/
typedef int (*gfs2_filldir_t) (void *opaque,
const char *name, unsigned int length,
uint64_t offset,
struct gfs2_inum *inum, unsigned int type);
int gfs2_filecmp(struct qstr *file1, char *file2, int len_of_file2);
int gfs2_dirent_alloc(struct gfs2_inode *dip, struct buffer_head *bh,
int name_len, struct gfs2_dirent **dent_out);
int gfs2_dir_search(struct gfs2_inode *dip, struct qstr *filename,
struct gfs2_inum *inum, unsigned int *type);
int gfs2_dir_add(struct gfs2_inode *dip, struct qstr *filename,
struct gfs2_inum *inum, unsigned int type);
int gfs2_dir_del(struct gfs2_inode *dip, struct qstr *filename);
int gfs2_dir_read(struct gfs2_inode *dip, uint64_t * offset, void *opaque,
gfs2_filldir_t filldir);
int gfs2_dir_mvino(struct gfs2_inode *dip, struct qstr *filename,
struct gfs2_inum *new_inum, unsigned int new_type);
int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
int gfs2_diradd_alloc_required(struct gfs2_inode *dip, struct qstr *filename,
int *alloc_required);
int gfs2_dir_get_buffer(struct gfs2_inode *ip, uint64_t block, int new,
struct buffer_head **bhp);
#endif /* __DIR_DOT_H__ */