sysfs: use check_submounts_and_drop() (6497d160) · Commits · 戴 / test

Do have_submounts(), shrink_dcache_parent() and d_drop() atomically. check_submounts_and_drop() can deal with negative dentries and non-directories as well. Non-directories can also be mounted on. And just like directories we don't want these to disappear with invalidation. Signed-off-by:

Miklos Szeredi <mszeredi@suse.cz> Acked-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:

Al Viro <viro@zeniv.linux.org.uk>

fs/sysfs/dir.c

+8 −12

Original line number	Diff line number	Diff line
		@@ -297,7 +297,6 @@ static int sysfs_dentry_delete(const struct dentry *dentry)
		static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
		{
		struct sysfs_dirent *sd;
		int is_dir;
		int type;

		if (flags & LOOKUP_RCU)
		@@ -341,18 +340,15 @@ out_bad:
		* is performed at its new name the dentry will be readded
		* to the dcache hashes.
		*/
		is_dir = (sysfs_type(sd) == SYSFS_DIR);
		mutex_unlock(&sysfs_mutex);
		if (is_dir) {

		/* If we have submounts we must allow the vfs caches
		* to lie about the state of the filesystem to prevent
		* leaks and other nasty things.
		*/
		if (have_submounts(dentry))
		if (check_submounts_and_drop(dentry) != 0)
		goto out_valid;
		shrink_dcache_parent(dentry);
		}
		d_drop(dentry);

		return 0;
		}

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