[MTD] generalise the handling of MTD-specific superblocks (acaebfd8) · Commits · e / devices / android_kernel_xiaomi_nabu

drivers/mtd/Makefile

+1 −2

Original line number	Original line	Diff line number	Diff line
	#		#
	# Makefile for the memory technology device drivers.		# Makefile for the memory technology device drivers.
	#		#
	# $Id: Makefile.common,v 1.7 2005/07/11 10:39:27 gleixner Exp $

	# Core functionality.		# Core functionality.
	mtd-y := mtdcore.o		mtd-y := mtdcore.o mtdsuper.o
	mtd-$(CONFIG_MTD_PARTITIONS) += mtdpart.o		mtd-$(CONFIG_MTD_PARTITIONS) += mtdpart.o
	obj-$(CONFIG_MTD) += $(mtd-y)		obj-$(CONFIG_MTD) += $(mtd-y)

drivers/mtd/mtdsuper.c

0 → 100644

+232 −0

Original line number	Original line	Diff line number	Diff line
			/* 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);

fs/jffs2/super.c

+19 −175

Original line number	Original line	Diff line number	Diff line
	@@ -19,7 +19,7 @@
	#include <linux/mount.h>		#include <linux/mount.h>
	#include <linux/jffs2.h>		#include <linux/jffs2.h>
	#include <linux/pagemap.h>		#include <linux/pagemap.h>
	#include <linux/mtd/mtd.h>		#include <linux/mtd/super.h>
	#include <linux/ctype.h>		#include <linux/ctype.h>
	#include <linux/namei.h>		#include <linux/namei.h>
	#include "compr.h"		#include "compr.h"
	@@ -78,69 +78,27 @@ static const struct super_operations jffs2_super_operations =
	.sync_fs = jffs2_sync_fs,		.sync_fs = jffs2_sync_fs,
	};		};

	static int jffs2_sb_compare(struct super_block sb, void data)		/*
	{		* fill in the superblock
	struct jffs2_sb_info *p = data;		*/
	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);		static int jffs2_fill_super(struct super_block sb, void data, int silent)

	/* 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;		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);		c = kzalloc(sizeof(*c), GFP_KERNEL);
	if (!c)		if (!c)
	return -ENOMEM;		return -ENOMEM;
	c->mtd = mtd;

	sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c);

	if (IS_ERR(sb))		c->mtd = sb->s_mtd;
	goto out_error;		c->os_priv = sb;
			sb->s_fs_info = c;

	if (sb->s_root) {		/* Initialize JFFS2 superblock locks, the further initialization will
	/* New mountpoint for JFFS2 which is already mounted */		* be done later */
	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 */
	init_MUTEX(&c->alloc_sem);		init_MUTEX(&c->alloc_sem);
	init_MUTEX(&c->erase_free_sem);		init_MUTEX(&c->erase_free_sem);
	init_waitqueue_head(&c->erase_wait);		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);		spin_lock_init(&c->inocache_lock);

	sb->s_op = &jffs2_super_operations;		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;		sb->s_xattr = jffs2_xattr_handlers;
	#ifdef CONFIG_JFFS2_FS_POSIX_ACL		#ifdef CONFIG_JFFS2_FS_POSIX_ACL
	sb->s_flags \|= MS_POSIXACL;		sb->s_flags \|= MS_POSIXACL;
	#endif		#endif
	ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);		return jffs2_do_fill_super(sb, data, silent);

	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);
	}		}

	static int jffs2_get_sb(struct file_system_type *fs_type,		static int jffs2_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name,		int flags, const char *dev_name,
	void data, struct vfsmount mnt)		void data, struct vfsmount mnt)
	{		{
	int err;		return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
	struct nameidata nd;		mnt);
	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;
	}		}

	static void jffs2_put_super (struct super_block *sb)		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);		struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
	if (!(sb->s_flags & MS_RDONLY))		if (!(sb->s_flags & MS_RDONLY))
	jffs2_stop_garbage_collect_thread(c);		jffs2_stop_garbage_collect_thread(c);
	generic_shutdown_super(sb);		kill_mtd_super(sb);
	put_mtd_device(c->mtd);
	kfree(c);		kfree(c);
	}		}

include/linux/fs.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -937,6 +937,7 @@ struct super_block {
	struct list_head s_files;		struct list_head s_files;

	struct block_device *s_bdev;		struct block_device *s_bdev;
			struct mtd_info *s_mtd;
	struct list_head s_instances;		struct list_head s_instances;
	struct quota_info s_dquot; /* Diskquota specific options */		struct quota_info s_dquot; /* Diskquota specific options */

include/linux/mtd/super.h

0 → 100644

+30 −0

Original line number	Original line	Diff line number	Diff line
			/* 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__ */