From f537ffabb3ed687da15ec46d72c839971b142d0a Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 25 Oct 2011 13:59:45 +0200 Subject: VFS: Fix automount for negative autofs dentries commit 5a30d8a2b8ddd5102c440c7e5a7c8e1fd729c818 upstream. [ backport for 3.0.x: LOOKUP_PARENT => LOOKUP_CONTINUE by Chuck Ebbert ] Autofs may set the DCACHE_NEED_AUTOMOUNT flag on negative dentries. These need attention from the automounter daemon regardless of the LOOKUP_FOLLOW flag. Signed-off-by: David Howells Acked-by: Ian Kent Signed-off-by: Al Viro Cc: Chuck Ebbert Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/namei.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 7bab4ad..80e239d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -781,19 +781,25 @@ static int follow_automount(struct path *path, unsigned flags, if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_CONTINUE)) return -EISDIR; /* we actually want to stop here */ - /* We want to mount if someone is trying to open/create a file of any - * type under the mountpoint, wants to traverse through the mountpoint - * or wants to open the mounted directory. - * + /* * We don't want to mount if someone's just doing a stat and they've * set AT_SYMLINK_NOFOLLOW - unless they're stat'ing a directory and * appended a '/' to the name. */ - if (!(flags & LOOKUP_FOLLOW) && - !(flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY | - LOOKUP_OPEN | LOOKUP_CREATE))) - return -EISDIR; - + if (!(flags & LOOKUP_FOLLOW)) { + /* We do, however, want to mount if someone wants to open or + * create a file of any type under the mountpoint, wants to + * traverse through the mountpoint or wants to open the mounted + * directory. + * Also, autofs may mark negative dentries as being automount + * points. These will need the attentions of the daemon to + * instantiate them before they can be used. + */ + if (!(flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY | + LOOKUP_OPEN | LOOKUP_CREATE)) && + path->dentry->d_inode) + return -EISDIR; + } current->total_link_count++; if (current->total_link_count >= 40) return -ELOOP; -- cgit v1.1