[patch 31/33] dlm: initialize file_lock struct in GETLK beforecopying conflicting lock

From: Greg KH
Date: Wed Feb 04 2009 - 13:48:59 EST


2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

From: Jeff Layton <jlayton@xxxxxxxxxx>

commit 20d5a39929232a715f29e6cb7e3f0d0c790f41eb upstream.

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@xxxxxxxxxx>
Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
fs/dlm/plock.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/dlm/plock.c
+++ b/fs/dlm/plock.c
@@ -304,7 +304,9 @@ int dlm_posix_get(dlm_lockspace_t *locks
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;

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