nfsd4: initialize delegation pointer to lease

The NFSv4 server was initializing the dp->dl_flock pointer by the
somewhat ridiculous method of a locks_copy_lock callback.

Now that setlease uses the passed-in lock instead of doing a copy,
dl_flock no longer gets set, resulting in the lock leaking on delegation
release, and later possible hangs (among other problems).

So, initialize dl_flock and get rid of the callback.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 56347e0..b7f818b 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2309,22 +2309,6 @@ void nfsd_release_deleg_cb(struct file_lock *fl)
        dp->dl_flock = NULL;
 }
 
-/*
- * Set the delegation file_lock back pointer.
- *
- * Called from setlease() with lock_kernel() held.
- */
-static
-void nfsd_copy_lock_deleg_cb(struct file_lock *new, struct file_lock *fl)
-{
-       struct nfs4_delegation *dp = (struct nfs4_delegation *)new->fl_owner;
-
-       dprintk("NFSD: nfsd_copy_lock_deleg_cb: new fl %p dp %p\n", new, dp);
-       if (!dp)
-               return;
-       dp->dl_flock = new;
-}
-
 /*
  * Called from setlease() with lock_kernel() held
  */
@@ -2355,7 +2339,6 @@ int nfsd_change_deleg_cb(struct file_lock **onlist, int arg)
 static const struct lock_manager_operations nfsd_lease_mng_ops = {
        .fl_break = nfsd_break_deleg_cb,
        .fl_release_private = nfsd_release_deleg_cb,
-       .fl_copy_lock = nfsd_copy_lock_deleg_cb,
        .fl_mylease = nfsd_same_client_deleg_cb,
        .fl_change = nfsd_change_deleg_cb,
 };
@@ -2661,12 +2644,14 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta
        fl->fl_file = find_readable_file(stp->st_file);
        BUG_ON(!fl->fl_file);
        fl->fl_pid = current->tgid;
+       dp->dl_flock = fl;
 
        /* vfs_setlease checks to see if delegation should be handed out.
         * the lock_manager callbacks fl_mylease and fl_change are used
         */
        if ((status = vfs_setlease(fl->fl_file, fl->fl_type, &fl))) {
                dprintk("NFSD: setlease failed [%d], no delegation\n", status);
+               dp->dl_flock = NULL;
                unhash_delegation(dp);
                flag = NFS4_OPEN_DELEGATE_NONE;
                goto out;