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