alistair23-linux/fs/gfs2/dir.h
Steven Whitehouse 3c1c0ae1db GFS2: Add directory addition info structure
The intent is that this structure will hold the information
required when adding entries to a directory (linking). To
start with, it will contain only the number of blocks which
are required to link the new entry into the directory. The
current calculation returns either 0 or the maximim number of
blocks that can ever be requested by such a transaction.

The intent is that in a later patch, we can update the dir
code to calculate this value more accurately. In addition
further patches will also add further fields to the new
structure to increase its utility.

In addition this patch fixes a bug where the link used during
inode creation was adding requesting too many blocks in
some cases. This is harmless unless the fs is close to being
full.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-01-06 11:28:41 +00:00

76 lines
2.4 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 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 version 2.
*/
#ifndef __DIR_DOT_H__
#define __DIR_DOT_H__
#include <linux/dcache.h>
#include <linux/crc32.h>
struct inode;
struct gfs2_inode;
struct gfs2_inum;
struct gfs2_diradd {
unsigned nr_blocks;
};
extern struct inode *gfs2_dir_search(struct inode *dir,
const struct qstr *filename,
bool fail_on_exist);
extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,
const struct gfs2_inode *ip);
extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,
const struct gfs2_inode *ip);
extern int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry);
extern int gfs2_dir_read(struct inode *inode, struct dir_context *ctx,
struct file_ra_state *f_ra);
extern int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
const struct gfs2_inode *nip, unsigned int new_type);
extern int gfs2_dir_exhash_dealloc(struct gfs2_inode *dip);
extern int gfs2_diradd_alloc_required(struct inode *dir,
const struct qstr *filename,
struct gfs2_diradd *da);
extern int gfs2_dir_get_new_buffer(struct gfs2_inode *ip, u64 block,
struct buffer_head **bhp);
extern void gfs2_dir_hash_inval(struct gfs2_inode *ip);
static inline u32 gfs2_disk_hash(const char *data, int len)
{
return crc32_le((u32)~0, data, len) ^ (u32)~0;
}
static inline void gfs2_str2qstr(struct qstr *name, const char *fname)
{
name->name = fname;
name->len = strlen(fname);
name->hash = gfs2_disk_hash(name->name, name->len);
}
/* N.B. This probably ought to take inum & type as args as well */
static inline void gfs2_qstr2dirent(const struct qstr *name, u16 reclen, struct gfs2_dirent *dent)
{
dent->de_inum.no_addr = cpu_to_be64(0);
dent->de_inum.no_formal_ino = cpu_to_be64(0);
dent->de_hash = cpu_to_be32(name->hash);
dent->de_rec_len = cpu_to_be16(reclen);
dent->de_name_len = cpu_to_be16(name->len);
dent->de_type = cpu_to_be16(0);
memset(dent->__pad, 0, sizeof(dent->__pad));
memcpy(dent + 1, name->name, name->len);
}
extern struct qstr gfs2_qdot;
extern struct qstr gfs2_qdotdot;
#endif /* __DIR_DOT_H__ */