mirror of
https://github.com/torvalds/linux.git
synced 2024-12-29 14:21:47 +00:00
[MTD] generalise the handling of MTD-specific superblocks
Generalise the handling of MTD-specific superblocks so that JFFS2 and ROMFS can both share it. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
David Howells
David Woodhouse
parent
33672f72b2
commit
acaebfd8a7
@ -1,10 +1,9 @@
|
||||
#
|
||||
# Makefile for the memory technology device drivers.
|
||||
#
|
||||
# $Id: Makefile.common,v 1.7 2005/07/11 10:39:27 gleixner Exp $
|
||||
|
||||
# Core functionality.
|
||||
mtd-y := mtdcore.o
|
||||
mtd-y := mtdcore.o mtdsuper.o
|
||||
mtd-$(CONFIG_MTD_PARTITIONS) += mtdpart.o
|
||||
obj-$(CONFIG_MTD) += $(mtd-y)
|
||||
|
||||
|
||||
232
drivers/mtd/mtdsuper.c
Normal file
232
drivers/mtd/mtdsuper.c
Normal file
@ -0,0 +1,232 @@
|
||||
/* MTD-based superblock management
|
||||
*
|
||||
* Copyright © 2001-2007 Red Hat, Inc. All Rights Reserved.
|
||||
* Written by: David Howells <dhowells@redhat.com>
|
||||
* David Woodhouse <dwmw2@infradead.org>
|
||||
*
|
||||
* 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; either version
|
||||
* 2 of the License, or (at your option) any later version.
|
||||
*/
|
||||
|
||||
#include <linux/mtd/super.h>
|
||||
#include <linux/namei.h>
|
||||
#include <linux/ctype.h>
|
||||
|
||||
/*
|
||||
* compare superblocks to see if they're equivalent
|
||||
* - they are if the underlying MTD device is the same
|
||||
*/
|
||||
static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
|
||||
{
|
||||
struct mtd_info *mtd = _mtd;
|
||||
|
||||
if (sb->s_mtd == mtd) {
|
||||
DEBUG(2, "MTDSB: Match on device %d (\"%s\")\n",
|
||||
mtd->index, mtd->name);
|
||||
return 1;
|
||||
}
|
||||
|
||||
DEBUG(2, "MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
|
||||
sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* mark the superblock by the MTD device it is using
|
||||
* - set the device number to be the correct MTD block device for pesuperstence
|
||||
* of NFS exports
|
||||
*/
|
||||
static int get_sb_mtd_set(struct super_block *sb, void *_mtd)
|
||||
{
|
||||
struct mtd_info *mtd = _mtd;
|
||||
|
||||
sb->s_mtd = mtd;
|
||||
sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* get a superblock on an MTD-backed filesystem
|
||||
*/
|
||||
static int get_sb_mtd_aux(struct file_system_type *fs_type, int flags,
|
||||
const char *dev_name, void *data,
|
||||
struct mtd_info *mtd,
|
||||
int (*fill_super)(struct super_block *, void *, int),
|
||||
struct vfsmount *mnt)
|
||||
{
|
||||
struct super_block *sb;
|
||||
int ret;
|
||||
|
||||
sb = sget(fs_type, get_sb_mtd_compare, get_sb_mtd_set, mtd);
|
||||
if (IS_ERR(sb))
|
||||
goto out_error;
|
||||
|
||||
if (sb->s_root)
|
||||
goto already_mounted;
|
||||
|
||||
/* fresh new superblock */
|
||||
DEBUG(1, "MTDSB: New superblock for device %d (\"%s\")\n",
|
||||
mtd->index, mtd->name);
|
||||
|
||||
ret = fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
|
||||
if (ret < 0) {
|
||||
up_write(&sb->s_umount);
|
||||
deactivate_super(sb);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* go */
|
||||
sb->s_flags |= MS_ACTIVE;
|
||||
return simple_set_mnt(mnt, sb);
|
||||
|
||||
/* new mountpoint for an already mounted superblock */
|
||||
already_mounted:
|
||||
DEBUG(1, "MTDSB: Device %d (\"%s\") is already mounted\n",
|
||||
mtd->index, mtd->name);
|
||||
ret = simple_set_mnt(mnt, sb);
|
||||
goto out_put;
|
||||
|
||||
out_error:
|
||||
ret = PTR_ERR(sb);
|
||||
out_put:
|
||||
put_mtd_device(mtd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* get a superblock on an MTD-backed filesystem by MTD device number
|
||||
*/
|
||||
static int get_sb_mtd_nr(struct file_system_type *fs_type, int flags,
|
||||
const char *dev_name, void *data, int mtdnr,
|
||||
int (*fill_super)(struct super_block *, void *, int),
|
||||
struct vfsmount *mnt)
|
||||
{
|
||||
struct mtd_info *mtd;
|
||||
|
||||
mtd = get_mtd_device(NULL, mtdnr);
|
||||
if (!mtd) {
|
||||
DEBUG(0, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
return get_sb_mtd_aux(fs_type, flags, dev_name, data, mtd, fill_super,
|
||||
mnt);
|
||||
}
|
||||
|
||||
/*
|
||||
* set up an MTD-based superblock
|
||||
*/
|
||||
int get_sb_mtd(struct file_system_type *fs_type, int flags,
|
||||
const char *dev_name, void *data,
|
||||
int (*fill_super)(struct super_block *, void *, int),
|
||||
struct vfsmount *mnt)
|
||||
{
|
||||
struct nameidata nd;
|
||||
int mtdnr, ret;
|
||||
|
||||
if (!dev_name)
|
||||
return -EINVAL;
|
||||
|
||||
DEBUG(2, "MTDSB: dev_name \"%s\"\n", dev_name);
|
||||
|
||||
/* the preferred way of mounting in future; especially when
|
||||
* CONFIG_BLOCK=n - we specify the underlying MTD device by number or
|
||||
* by name, so that we don't require block device support to be present
|
||||
* in the kernel. */
|
||||
if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
|
||||
if (dev_name[3] == ':') {
|
||||
struct mtd_info *mtd;
|
||||
|
||||
/* mount by MTD device name */
|
||||
DEBUG(1, "MTDSB: mtd:%%s, name \"%s\"\n",
|
||||
dev_name + 4);
|
||||
|
||||
for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
|
||||
mtd = get_mtd_device(NULL, mtdnr);
|
||||
if (mtd) {
|
||||
if (!strcmp(mtd->name, dev_name + 4))
|
||||
return get_sb_mtd_aux(
|
||||
fs_type, flags,
|
||||
dev_name, data, mtd,
|
||||
fill_super, mnt);
|
||||
|
||||
put_mtd_device(mtd);
|
||||
}
|
||||
}
|
||||
|
||||
printk(KERN_NOTICE "MTD:"
|
||||
" MTD device with name \"%s\" not found.\n",
|
||||
dev_name + 4);
|
||||
|
||||
} else if (isdigit(dev_name[3])) {
|
||||
/* mount by MTD device number name */
|
||||
char *endptr;
|
||||
|
||||
mtdnr = simple_strtoul(dev_name + 3, &endptr, 0);
|
||||
if (!*endptr) {
|
||||
/* It was a valid number */
|
||||
DEBUG(1, "MTDSB: mtd%%d, mtdnr %d\n",
|
||||
mtdnr);
|
||||
return get_sb_mtd_nr(fs_type, flags,
|
||||
dev_name, data,
|
||||
mtdnr, fill_super, mnt);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* try the old way - the hack where we allowed users to mount
|
||||
* /dev/mtdblock$(n) but didn't actually _use_ the blockdev
|
||||
*/
|
||||
ret = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
|
||||
|
||||
DEBUG(1, "MTDSB: path_lookup() returned %d, inode %p\n",
|
||||
ret, nd.dentry ? nd.dentry->d_inode : NULL);
|
||||
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
ret = -EINVAL;
|
||||
|
||||
if (!S_ISBLK(nd.dentry->d_inode->i_mode))
|
||||
goto out;
|
||||
|
||||
if (nd.mnt->mnt_flags & MNT_NODEV) {
|
||||
ret = -EACCES;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR)
|
||||
goto not_an_MTD_device;
|
||||
|
||||
mtdnr = iminor(nd.dentry->d_inode);
|
||||
path_release(&nd);
|
||||
|
||||
return get_sb_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super,
|
||||
mnt);
|
||||
|
||||
not_an_MTD_device:
|
||||
if (!(flags & MS_SILENT))
|
||||
printk(KERN_NOTICE
|
||||
"MTD: Attempt to mount non-MTD device \"%s\"\n",
|
||||
dev_name);
|
||||
out:
|
||||
path_release(&nd);
|
||||
return ret;
|
||||
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL_GPL(get_sb_mtd);
|
||||
|
||||
/*
|
||||
* destroy an MTD-based superblock
|
||||
*/
|
||||
void kill_mtd_super(struct super_block *sb)
|
||||
{
|
||||
generic_shutdown_super(sb);
|
||||
put_mtd_device(sb->s_mtd);
|
||||
sb->s_mtd = NULL;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL_GPL(kill_mtd_super);
|
||||
194
fs/jffs2/super.c
194
fs/jffs2/super.c
@ -19,7 +19,7 @@
|
||||
#include <linux/mount.h>
|
||||
#include <linux/jffs2.h>
|
||||
#include <linux/pagemap.h>
|
||||
#include <linux/mtd/mtd.h>
|
||||
#include <linux/mtd/super.h>
|
||||
#include <linux/ctype.h>
|
||||
#include <linux/namei.h>
|
||||
#include "compr.h"
|
||||
@ -78,69 +78,27 @@ static const struct super_operations jffs2_super_operations =
|
||||
.sync_fs = jffs2_sync_fs,
|
||||
};
|
||||
|
||||
static int jffs2_sb_compare(struct super_block *sb, void *data)
|
||||
/*
|
||||
* fill in the superblock
|
||||
*/
|
||||
static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
|
||||
{
|
||||
struct jffs2_sb_info *p = data;
|
||||
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
|
||||
|
||||
/* The superblocks are considered to be equivalent if the underlying MTD
|
||||
device is the same one */
|
||||
if (c->mtd == p->mtd) {
|
||||
D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name));
|
||||
return 1;
|
||||
} else {
|
||||
D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n",
|
||||
c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name));
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
static int jffs2_sb_set(struct super_block *sb, void *data)
|
||||
{
|
||||
struct jffs2_sb_info *p = data;
|
||||
|
||||
/* For persistence of NFS exports etc. we use the same s_dev
|
||||
each time we mount the device, don't just use an anonymous
|
||||
device */
|
||||
sb->s_fs_info = p;
|
||||
p->os_priv = sb;
|
||||
sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int jffs2_get_sb_mtd(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name,
|
||||
void *data, struct mtd_info *mtd,
|
||||
struct vfsmount *mnt)
|
||||
{
|
||||
struct super_block *sb;
|
||||
struct jffs2_sb_info *c;
|
||||
int ret;
|
||||
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
|
||||
" New superblock for device %d (\"%s\")\n",
|
||||
sb->s_mtd->index, sb->s_mtd->name));
|
||||
|
||||
c = kzalloc(sizeof(*c), GFP_KERNEL);
|
||||
if (!c)
|
||||
return -ENOMEM;
|
||||
c->mtd = mtd;
|
||||
|
||||
sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c);
|
||||
c->mtd = sb->s_mtd;
|
||||
c->os_priv = sb;
|
||||
sb->s_fs_info = c;
|
||||
|
||||
if (IS_ERR(sb))
|
||||
goto out_error;
|
||||
|
||||
if (sb->s_root) {
|
||||
/* New mountpoint for JFFS2 which is already mounted */
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n",
|
||||
mtd->index, mtd->name));
|
||||
ret = simple_set_mnt(mnt, sb);
|
||||
goto out_put;
|
||||
}
|
||||
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n",
|
||||
mtd->index, mtd->name));
|
||||
|
||||
/* Initialize JFFS2 superblock locks, the further initialization will be
|
||||
* done later */
|
||||
/* Initialize JFFS2 superblock locks, the further initialization will
|
||||
* be done later */
|
||||
init_MUTEX(&c->alloc_sem);
|
||||
init_MUTEX(&c->erase_free_sem);
|
||||
init_waitqueue_head(&c->erase_wait);
|
||||
@ -149,133 +107,20 @@ static int jffs2_get_sb_mtd(struct file_system_type *fs_type,
|
||||
spin_lock_init(&c->inocache_lock);
|
||||
|
||||
sb->s_op = &jffs2_super_operations;
|
||||
sb->s_flags = flags | MS_NOATIME;
|
||||
sb->s_flags = sb->s_flags | MS_NOATIME;
|
||||
sb->s_xattr = jffs2_xattr_handlers;
|
||||
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
|
||||
sb->s_flags |= MS_POSIXACL;
|
||||
#endif
|
||||
ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
|
||||
|
||||
if (ret) {
|
||||
/* Failure case... */
|
||||
up_write(&sb->s_umount);
|
||||
deactivate_super(sb);
|
||||
return ret;
|
||||
}
|
||||
|
||||
sb->s_flags |= MS_ACTIVE;
|
||||
return simple_set_mnt(mnt, sb);
|
||||
|
||||
out_error:
|
||||
ret = PTR_ERR(sb);
|
||||
out_put:
|
||||
kfree(c);
|
||||
put_mtd_device(mtd);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name,
|
||||
void *data, int mtdnr,
|
||||
struct vfsmount *mnt)
|
||||
{
|
||||
struct mtd_info *mtd;
|
||||
|
||||
mtd = get_mtd_device(NULL, mtdnr);
|
||||
if (IS_ERR(mtd)) {
|
||||
D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr));
|
||||
return PTR_ERR(mtd);
|
||||
}
|
||||
|
||||
return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt);
|
||||
return jffs2_do_fill_super(sb, data, silent);
|
||||
}
|
||||
|
||||
static int jffs2_get_sb(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name,
|
||||
void *data, struct vfsmount *mnt)
|
||||
{
|
||||
int err;
|
||||
struct nameidata nd;
|
||||
int mtdnr;
|
||||
|
||||
if (!dev_name)
|
||||
return -EINVAL;
|
||||
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name));
|
||||
|
||||
/* The preferred way of mounting in future; especially when
|
||||
CONFIG_BLK_DEV is implemented - we specify the underlying
|
||||
MTD device by number or by name, so that we don't require
|
||||
block device support to be present in the kernel. */
|
||||
|
||||
/* FIXME: How to do the root fs this way? */
|
||||
|
||||
if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
|
||||
/* Probably mounting without the blkdev crap */
|
||||
if (dev_name[3] == ':') {
|
||||
struct mtd_info *mtd;
|
||||
|
||||
/* Mount by MTD device name */
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4));
|
||||
for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
|
||||
mtd = get_mtd_device(NULL, mtdnr);
|
||||
if (!IS_ERR(mtd)) {
|
||||
if (!strcmp(mtd->name, dev_name+4))
|
||||
return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt);
|
||||
put_mtd_device(mtd);
|
||||
}
|
||||
}
|
||||
printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4);
|
||||
} else if (isdigit(dev_name[3])) {
|
||||
/* Mount by MTD device number name */
|
||||
char *endptr;
|
||||
|
||||
mtdnr = simple_strtoul(dev_name+3, &endptr, 0);
|
||||
if (!*endptr) {
|
||||
/* It was a valid number */
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr));
|
||||
return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Try the old way - the hack where we allowed users to mount
|
||||
/dev/mtdblock$(n) but didn't actually _use_ the blkdev */
|
||||
|
||||
err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
|
||||
|
||||
D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n",
|
||||
err, nd.dentry->d_inode));
|
||||
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
err = -EINVAL;
|
||||
|
||||
if (!S_ISBLK(nd.dentry->d_inode->i_mode))
|
||||
goto out;
|
||||
|
||||
if (nd.mnt->mnt_flags & MNT_NODEV) {
|
||||
err = -EACCES;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) {
|
||||
if (!(flags & MS_SILENT))
|
||||
printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n",
|
||||
dev_name);
|
||||
goto out;
|
||||
}
|
||||
|
||||
mtdnr = iminor(nd.dentry->d_inode);
|
||||
path_release(&nd);
|
||||
|
||||
return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt);
|
||||
|
||||
out:
|
||||
path_release(&nd);
|
||||
return err;
|
||||
return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
|
||||
mnt);
|
||||
}
|
||||
|
||||
static void jffs2_put_super (struct super_block *sb)
|
||||
@ -310,8 +155,7 @@ static void jffs2_kill_sb(struct super_block *sb)
|
||||
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
|
||||
if (!(sb->s_flags & MS_RDONLY))
|
||||
jffs2_stop_garbage_collect_thread(c);
|
||||
generic_shutdown_super(sb);
|
||||
put_mtd_device(c->mtd);
|
||||
kill_mtd_super(sb);
|
||||
kfree(c);
|
||||
}
|
||||
|
||||
|
||||
@ -937,6 +937,7 @@ struct super_block {
|
||||
struct list_head s_files;
|
||||
|
||||
struct block_device *s_bdev;
|
||||
struct mtd_info *s_mtd;
|
||||
struct list_head s_instances;
|
||||
struct quota_info s_dquot; /* Diskquota specific options */
|
||||
|
||||
|
||||
30
include/linux/mtd/super.h
Normal file
30
include/linux/mtd/super.h
Normal file
@ -0,0 +1,30 @@
|
||||
/* MTD-based superblock handling
|
||||
*
|
||||
* Copyright © 2006 Red Hat, Inc. All Rights Reserved.
|
||||
* Written by David Howells (dhowells@redhat.com)
|
||||
*
|
||||
* 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; either version
|
||||
* 2 of the License, or (at your option) any later version.
|
||||
*/
|
||||
|
||||
#ifndef __MTD_SUPER_H__
|
||||
#define __MTD_SUPER_H__
|
||||
|
||||
#ifdef __KERNEL__
|
||||
|
||||
#include <linux/mtd/mtd.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/mount.h>
|
||||
|
||||
extern int get_sb_mtd(struct file_system_type *fs_type, int flags,
|
||||
const char *dev_name, void *data,
|
||||
int (*fill_super)(struct super_block *, void *, int),
|
||||
struct vfsmount *mnt);
|
||||
extern void kill_mtd_super(struct super_block *sb);
|
||||
|
||||
|
||||
#endif /* __KERNEL__ */
|
||||
|
||||
#endif /* __MTD_SUPER_H__ */
|
||||
Loading…
Reference in New Issue
Block a user