[PATCH 4.20 38/65] lockd: Show pid of lockd for remote locks

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

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

From: Benjamin Coddington <bcodding@xxxxxxxxxx>

commit b8eee0e90f9797b747113638bc75e739b192ad38 upstream.

Commit 9d5b86ac13c5 ("fs/locks: Remove fl_nspid and use fs-specific l_pid
for remote locks") specified that the l_pid returned for F_GETLK on a local
file that has a remote lock should be the pid of the lock manager process.
That commit, while updating other filesystems, failed to update lockd, such
that locks created by lockd had their fl_pid set to that of the remote
process holding the lock.  Fix that here to be the pid of lockd.

Also, fix the client case so that the returned lock pid is negative, which
indicates a remote lock on a remote file.

Fixes: 9d5b86ac13c5 ("fs/locks: Remove fl_nspid and use fs-specific...")
Cc: stable@xxxxxxxxxxxxxxx

Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/lockd/clntproc.c |    2 +-
 fs/lockd/xdr.c      |    4 ++--
 fs/lockd/xdr4.c     |    4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -442,7 +442,7 @@ nlmclnt_test(struct nlm_rqst *req, struc
 			fl->fl_start = req->a_res.lock.fl.fl_start;
 			fl->fl_end = req->a_res.lock.fl.fl_end;
 			fl->fl_type = req->a_res.lock.fl.fl_type;
-			fl->fl_pid = 0;
+			fl->fl_pid = -req->a_res.lock.fl.fl_pid;
 			break;
 		default:
 			status = nlm_stat_to_errno(req->a_res.status);
--- a/fs/lockd/xdr.c
+++ b/fs/lockd/xdr.c
@@ -127,7 +127,7 @@ nlm_decode_lock(__be32 *p, struct nlm_lo
 
 	locks_init_lock(fl);
 	fl->fl_owner = current->files;
-	fl->fl_pid   = (pid_t)lock->svid;
+	fl->fl_pid   = current->tgid;
 	fl->fl_flags = FL_POSIX;
 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
 	start = ntohl(*p++);
@@ -269,7 +269,7 @@ nlmsvc_decode_shareargs(struct svc_rqst
 	memset(lock, 0, sizeof(*lock));
 	locks_init_lock(&lock->fl);
 	lock->svid = ~(u32) 0;
-	lock->fl.fl_pid = (pid_t)lock->svid;
+	lock->fl.fl_pid = current->tgid;
 
 	if (!(p = nlm_decode_cookie(p, &argp->cookie))
 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
--- a/fs/lockd/xdr4.c
+++ b/fs/lockd/xdr4.c
@@ -119,7 +119,7 @@ nlm4_decode_lock(__be32 *p, struct nlm_l
 
 	locks_init_lock(fl);
 	fl->fl_owner = current->files;
-	fl->fl_pid   = (pid_t)lock->svid;
+	fl->fl_pid   = current->tgid;
 	fl->fl_flags = FL_POSIX;
 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
 	p = xdr_decode_hyper(p, &start);
@@ -266,7 +266,7 @@ nlm4svc_decode_shareargs(struct svc_rqst
 	memset(lock, 0, sizeof(*lock));
 	locks_init_lock(&lock->fl);
 	lock->svid = ~(u32) 0;
-	lock->fl.fl_pid = (pid_t)lock->svid;
+	lock->fl.fl_pid = current->tgid;
 
 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,