dlm: initialize file_lock struct in GETLK before copying conflicting lock

dlm_posix_get fills out the relevant fields in the file_lock before
returning when there is a lock conflict, but doesn't clean out any of
the other fields in the file_lock.

When nfsd does a NFSv4 lockt call, it sets the fl_lmops to
nfsd_posix_mng_ops before calling the lower fs. When the lock comes back
after testing a lock on GFS2, it still has that field set. This confuses
nfsd into thinking that the file_lock is a nfsd4 lock.

Fix this by making DLM reinitialize the file_lock before copying the
fields from the conflicting lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c
index 502b1ea5ef6b..894a32d438d5 100644
--- a/fs/dlm/plock.c
+++ b/fs/dlm/plock.c
@@ -304,7 +304,9 @@ int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
         if (rv == -ENOENT)
                 rv = 0;
         else if (rv > 0) {
+                locks_init_lock(fl);
                 fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;
+                fl->fl_flags = FL_POSIX;
                 fl->fl_pid = op->info.pid;
                 fl->fl_start = op->info.start;
                 fl->fl_end = op->info.end;