diff options
author | Ian Kent <raven@themaw.net> | 2012-05-02 15:19:09 +0400 |
---|---|---|
committer | Steve French <sfrench@us.ibm.com> | 2012-05-03 22:49:47 +0400 |
commit | 936ad9094462578953042d3395b973f1c9e6fa95 (patch) | |
tree | 22d52c9a2489768a9d70d95ef1a99c78185698c3 | |
parent | 58fa015f611b51e1f501b048bc5ac263c78852f0 (diff) | |
download | linux-936ad9094462578953042d3395b973f1c9e6fa95.tar.xz |
cifs - check S_AUTOMOUNT in revalidate
When revalidating a dentry, if the inode wasn't known to be a dfs
entry when the dentry was instantiated, such as when created via
->readdir(), the DCACHE_NEED_AUTOMOUNT flag needs to be set on the
dentry in ->d_revalidate().
The false return from cifs_d_revalidate(), due to the inode now
being marked with the S_AUTOMOUNT flag, might not invalidate the
dentry if there is a concurrent unlazy path walk. This is because
the dentry reference count will be at least 2 in this case causing
d_invalidate() to return EBUSY. So the asumption that the dentry
will be discarded then correctly instantiated via ->lookup() might
not hold.
Signed-off-by: Ian Kent <raven@themaw.net>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: Steve French <smfrench@gmail.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <sfrench@us.ibm.com>
-rw-r--r-- | fs/cifs/dir.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index d172c8ed9017..ec4e9a2a12f8 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -668,12 +668,19 @@ cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd) return 0; else { /* - * Forcibly invalidate automounting directory inodes - * (remote DFS directories) so to have them - * instantiated again for automount + * If the inode wasn't known to be a dfs entry when + * the dentry was instantiated, such as when created + * via ->readdir(), it needs to be set now since the + * attributes will have been updated by + * cifs_revalidate_dentry(). */ - if (IS_AUTOMOUNT(direntry->d_inode)) - return 0; + if (IS_AUTOMOUNT(direntry->d_inode) && + !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) { + spin_lock(&direntry->d_lock); + direntry->d_flags |= DCACHE_NEED_AUTOMOUNT; + spin_unlock(&direntry->d_lock); + } + return 1; } } |