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lvm2/driver/device-mapper/dmfs-tdir.c
Steven Whitehouse 01c4ac1315 Tidy and changes to make code smaller.
o Created dmfs.h as a private header for the filesystem code
 o Using seq_file.[ch] written by Al Viro as a generic mechanism for /proc
   style files which have one record per line. We use a slight modification
   here, so if you are using a recent -ac kernel you'll need to replace the
   existing seq_file.[ch] with  the ones here and do a bit of editing to make
   it work. I'll submit the changes to Al Viro shortly as they are very
   small and I think make sense generally.
 o Using fail_writepage()
 o Init code for filesystem now all in dmfs-super.c
 o Some common code reduction amoung the dmfs-*.c files
 o Auto allocation of major device number (default). You can specify a
   particular major by using a module argument. If built in then you don't
   get this option at the moment but it could be added if required.
 o Hotplug support
 o General tidying
 o Updated projects.txt file
 o Patches updated to 2.4.14
2001-11-07 12:12:56 +00:00

139 lines
3.2 KiB
C

/*
* dmfs-tdir.c
*
* Copyright (C) 2001 Sistina Software
*
* This software 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; either version 2, or (at
* your option) any later version.
*
* This software is distributed in the hope that it will 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 GNU CC; see the file COPYING. If not, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/* Heavily based upon ramfs */
#include <linux/config.h>
#include <linux/fs.h>
#include "dm.h"
#include "dmfs.h"
extern struct inode *dmfs_create_error(struct inode *, int);
extern struct inode *dmfs_create_table(struct inode *, int);
extern struct inode *dmfs_create_status(struct inode *, int);
static int dmfs_tdir_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
inode->i_mapping = &inode->i_data;
inode->i_nlink--;
dput(dentry);
return 0;
}
static struct dentry *dmfs_tdir_lookup(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = NULL;
const char *name = dentry->d_name.name;
switch(dentry->d_name.len) {
case 5:
if (memcmp("table", name, 5) == 0) {
inode = dmfs_create_table(dir, 0600);
break;
}
if (memcmp("error", name, 5) == 0)
inode = dmfs_create_error(dir, 0600);
break;
case 6:
if (memcmp("status", name, 6) == 0)
inode = dmfs_create_status(dir, 0600);
break;
}
d_add(dentry, inode);
return NULL;
}
static int dmfs_tdir_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
int i;
struct dentry *dentry = filp->f_dentry;
i = filp->f_pos;
switch(i) {
case 0:
if (filldir(dirent, ".", 1, i, dentry->d_inode->i_ino, DT_DIR) < 0)
break;
i++;
filp->f_pos++;
/* fallthrough */
case 1:
if (filldir(dirent, "..", 2, i, dentry->d_parent->d_inode->i_ino, DT_DIR) < 0)
break;
i++;
filp->f_pos++;
/* fallthrough */
case 2:
if (filldir(dirent, "table", 5, i, 2, DT_REG) < 0)
break;
i++;
filp->f_pos++;
/* fallthrough */
case 3:
if (filldir(dirent, "error", 5, i, 3, DT_REG) < 0)
break;
i++;
filp->f_pos++;
/* fallthrough */
case 4:
if (filldir(dirent, "status", 6, i, 4, DT_REG) < 0)
break;
i++;
filp->f_pos++;
}
return 0;
}
static int dmfs_tdir_sync(struct file *file, struct dentry *dentry, int datasync)
{
return 0;
}
static struct file_operations dmfs_tdir_file_operations = {
read: generic_read_dir,
readdir: dmfs_tdir_readdir,
fsync: dmfs_tdir_sync,
};
static struct inode_operations dmfs_tdir_inode_operations = {
lookup: dmfs_tdir_lookup,
unlink: dmfs_tdir_unlink,
};
struct inode *dmfs_create_tdir(struct super_block *sb, int mode)
{
struct inode *inode = dmfs_new_private_inode(sb, mode | S_IFDIR);
if (inode) {
inode->i_fop = &dmfs_tdir_file_operations;
inode->i_op = &dmfs_tdir_inode_operations;
}
return inode;
}