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[MTD] generalise the handling of MTD-specific superblocks

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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
2007-05-10 22:51:50 -07:00
committed by David Woodhouse
parent 33672f72b2
commit acaebfd8a7
5 changed files with 283 additions and 177 deletions
Download Patch File Download Diff File Expand all files Collapse all files

194
fs/jffs2/super.c
View File

@@ -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);
}