[PATCH v1] NFSD: Fix crash in nfsd4_read_release()

[Chuck Lever <cel@kernel.org>]

From: Chuck Lever <chuck.lever@oracle.com>

When tracing is enabled, the trace_nfsd_read_done trace point
crashes during the pynfs read.testNoFh test.

Fixes: 87c5942e8fae ("nfsd: Add I/O trace points in the NFSv4 read proc")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/nfs4proc.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index e466cf52d7d7..f9aeefc0da73 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -988,10 +988,11 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 static void
 nfsd4_read_release(union nfsd4_op_u *u)
 {
-	if (u->read.rd_nf)
+	if (u->read.rd_nf) {
+		trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
+				     u->read.rd_offset, u->read.rd_length);
 		nfsd_file_put(u->read.rd_nf);
-	trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
-			     u->read.rd_offset, u->read.rd_length);
+	}
 }
 
 static __be32
-- 
2.51.0