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Commit 00292bbf authored by Al Viro's avatar Al Viro
Browse files

mtdchar: kill persistently held vfsmount 



... and mtdchar_notifier along with it; just have ->drop_inode() that
will unconditionally get evict them instead of dances on mtd device
removal and use simple_pin_fs() instead of kern_mount()

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 22a71c30

drivers/mtd/mtdchar.c

+16 −37
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ 
#include <asm/uaccess.h>



static DEFINE_MUTEX(mtd_mutex);

static struct vfsmount *mtd_inode_mnt __read_mostly;



/*

 * Data structure to hold the pointer to the mtd device as well
@@ -75,7 +74,9 @@ static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig) 
	return -EINVAL;

}





static int count;

static struct vfsmount *mnt;

static struct file_system_type mtd_inodefs_type;



static int mtdchar_open(struct inode *inode, struct file *file)

{
@@ -92,6 +93,10 @@ static int mtdchar_open(struct inode *inode, struct file *file) 
	if ((file->f_mode & FMODE_WRITE) && (minor & 1))

		return -EACCES;



	ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);

	if (ret)

		return ret;



	mutex_lock(&mtd_mutex);

	mtd = get_mtd_device(NULL, devnum);
@@ -106,7 +111,7 @@ static int mtdchar_open(struct inode *inode, struct file *file) 
		goto out;

	}



	mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);

	mtd_ino = iget_locked(mnt->mnt_sb, devnum);

	if (!mtd_ino) {

		put_mtd_device(mtd);

		ret = -ENOMEM;
@@ -141,6 +146,7 @@ static int mtdchar_open(struct inode *inode, struct file *file) 


out:

	mutex_unlock(&mtd_mutex);

	simple_release_fs(&mnt, &count);

	return ret;

} /* mtdchar_open */
@@ -162,6 +168,7 @@ static int mtdchar_close(struct inode *inode, struct file *file) 
	put_mtd_device(mtd);

	file->private_data = NULL;

	kfree(mfi);

	simple_release_fs(&mnt, &count);



	return 0;

} /* mtdchar_close */
@@ -1175,10 +1182,15 @@ static const struct file_operations mtd_fops = { 
#endif

};



static const struct super_operations mtd_ops = {

	.drop_inode = generic_delete_inode,

	.statfs = simple_statfs,

};



static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,

				int flags, const char *dev_name, void *data)

{

	return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);

	return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);

}



static struct file_system_type mtd_inodefs_type = {
@@ -1187,26 +1199,6 @@ static struct file_system_type mtd_inodefs_type = { 
       .kill_sb = kill_anon_super,

};



static void mtdchar_notify_add(struct mtd_info *mtd)

{

}



static void mtdchar_notify_remove(struct mtd_info *mtd)

{

	struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);



	if (mtd_ino) {

		/* Destroy the inode if it exists */

		clear_nlink(mtd_ino);

		iput(mtd_ino);

	}

}



static struct mtd_notifier mtdchar_notifier = {

	.add = mtdchar_notify_add,

	.remove = mtdchar_notify_remove,

};



static int __init init_mtdchar(void)

{

	int ret;
@@ -1224,19 +1216,8 @@ static int __init init_mtdchar(void) 
		pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);

		goto err_unregister_chdev;

	}



	mtd_inode_mnt = kern_mount(&mtd_inodefs_type);

	if (IS_ERR(mtd_inode_mnt)) {

		ret = PTR_ERR(mtd_inode_mnt);

		pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);

		goto err_unregister_filesystem;

	}

	register_mtd_user(&mtdchar_notifier);



	return ret;



err_unregister_filesystem:

	unregister_filesystem(&mtd_inodefs_type);

err_unregister_chdev:

	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");

	return ret;
@@ -1244,8 +1225,6 @@ err_unregister_chdev: 


static void __exit cleanup_mtdchar(void)

{

	unregister_mtd_user(&mtdchar_notifier);

	kern_unmount(mtd_inode_mnt);

	unregister_filesystem(&mtd_inodefs_type);

	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");

}