mtdchar: kill persistently held vfsmount (00292bbf) · Commits · 戴 / test

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");
		}

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