nfsd4: don't try to encode conflicting owner if low on space
I ran into this corner case in testing: in theory clients can provide
state owners up to 1024 bytes long. In the sessions case there might be
a risk of this pushing us over the DRC slot size.
The conflicting owner isn't really that important, so let's humor a
client that provides a small maxresponsize_cached by allowing ourselves
to return without the conflicting owner instead of outright failing the
operation.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 5d8f915..20aad5a 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1432,7 +1432,8 @@
#define op_encode_change_info_maxsz (5)
#define nfs4_fattr_bitmap_maxsz (4)
-#define op_encode_lockowner_maxsz (1 + XDR_QUADLEN(IDMAP_NAMESZ))
+/* We'll fall back on returning no lockowner if run out of space: */
+#define op_encode_lockowner_maxsz (0)
#define op_encode_lock_denied_maxsz (8 + op_encode_lockowner_maxsz)
#define nfs4_owner_maxsz (1 + XDR_QUADLEN(IDMAP_NAMESZ))