[PATCH v1] NFSD: Define a proc_layoutcommit for the FlexFiles layout type

[Chuck Lever <cel@kernel.org>]

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

Avoid a crash if a pNFS client should happen to send a LAYOUTCOMMIT
operation on a FlexFiles layout.

Reported-by: Robert Morris <rtm@csail.mit.edu>
Closes: https://lore.kernel.org/linux-nfs/152f99b2-ba35-4dec-93a9-4690e625dccd@oracle.com/T/#t
Cc: Thomas Haynes <loghyr@hammerspace.com>
Fixes: 9b9960a0ca47 ("nfsd: Add a super simple flex file server")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/flexfilelayout.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/nfsd/flexfilelayout.c b/fs/nfsd/flexfilelayout.c
index c318cf74e388..0f1a35400cd5 100644
--- a/fs/nfsd/flexfilelayout.c
+++ b/fs/nfsd/flexfilelayout.c
@@ -125,6 +125,13 @@ nfsd4_ff_proc_getdeviceinfo(struct super_block *sb, struct svc_rqst *rqstp,
 	return 0;
 }
 
+static __be32
+nfsd4_ff_proc_layoutcommit(struct inode *inode, struct svc_rqst *rqstp,
+		struct nfsd4_layoutcommit *lcp)
+{
+	return nfs_ok;
+}
+
 const struct nfsd4_layout_ops ff_layout_ops = {
 	.notify_types		=
 			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
@@ -133,4 +140,5 @@ const struct nfsd4_layout_ops ff_layout_ops = {
 	.encode_getdeviceinfo	= nfsd4_ff_encode_getdeviceinfo,
 	.proc_layoutget		= nfsd4_ff_proc_layoutget,
 	.encode_layoutget	= nfsd4_ff_encode_layoutget,
+	.proc_layoutcommit	= nfsd4_ff_proc_layoutcommit,
 };
-- 
2.50.0