Commit 8dc51fe5 authored Jan 23, 2014 by Ian Kent Committed by Linus Torvalds Jan 23, 2014

autofs: fix symlinks aren't checked for expiry



The autofs4 module doesn't consider symlinks for expire as it did in the
older autofs v3 module (so it's actually a long standing regression).

The user space daemon has focused on the use of bind mounts instead of
symlinks for a long time now and that's why this has not been noticed.
But with the future addition of amd map parsing to automount(8), not to
mention amd itself (of am-utils), symlink expiry will be needed.

The direct and offset mount types can't be symlinks and the tree mounts of
version 4 were always real mounts so only indirect mounts need expire
symlinks.

Since the current users of the autofs4 module haven't reported this as a
problem to date this patch probably isn't a candidate for backport to
stable.

Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c24930a9

fs/autofs4/expire.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -402,6 +402,20 @@ struct dentry autofs4_expire_indirect(struct super_block sb,
		goto next;
		}

		if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) {
		DPRINTK("checking symlink %p %.*s",
		dentry, (int)dentry->d_name.len, dentry->d_name.name);
		/*
		* A symlink can't be "busy" in the usual sense so
		* just check last used for expire timeout.
		*/
		if (autofs4_can_expire(dentry, timeout, do_now)) {
		expired = dentry;
		goto found;
		}
		goto next;
		}

		if (simple_empty(dentry))
		goto next;

fs/autofs4/symlink.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -14,6 +14,10 @@

		static void autofs4_follow_link(struct dentry dentry, struct nameidata *nd)
		{
		struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
		struct autofs_info *ino = autofs4_dentry_ino(dentry);
		if (ino && !autofs4_oz_mode(sbi))
		ino->last_used = jiffies;
		nd_set_link(nd, dentry->d_inode->i_private);
		return NULL;
		}