NFS: nfs4_bitmask_adjust() must not change the server global bitmasks

As currently set, the calls to nfs4_bitmask_adjust() will end up
overwriting the contents of the nfs_server cache_consistency_bitmask
field.
The intention here should be to modify a private copy of that mask in
the close/delegreturn/write arguments.

Fixes: 76bd5c016ef4 ("NFSv4: make cache consistency bitmask dynamic")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 3327239fa2f9..cc29dee508f7 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -15,6 +15,8 @@
 #define NFS_DEF_FILE_IO_SIZE	(4096U)
 #define NFS_MIN_FILE_IO_SIZE	(1024U)
 
+#define NFS_BITMASK_SZ		3
+
 struct nfs4_string {
 	unsigned int len;
 	char *data;
@@ -525,7 +527,8 @@ struct nfs_closeargs {
 	struct nfs_seqid *	seqid;
 	fmode_t			fmode;
 	u32			share_access;
-	u32 *			bitmask;
+	const u32 *		bitmask;
+	u32			bitmask_store[NFS_BITMASK_SZ];
 	struct nfs4_layoutreturn_args *lr_args;
 };
 
@@ -608,7 +611,8 @@ struct nfs4_delegreturnargs {
 	struct nfs4_sequence_args	seq_args;
 	const struct nfs_fh *fhandle;
 	const nfs4_stateid *stateid;
-	u32 * bitmask;
+	const u32 *bitmask;
+	u32 bitmask_store[NFS_BITMASK_SZ];
 	struct nfs4_layoutreturn_args *lr_args;
 };
 
@@ -648,7 +652,8 @@ struct nfs_pgio_args {
 	union {
 		unsigned int		replen;			/* used by read */
 		struct {
-			u32 *			bitmask;	/* used by write */
+			const u32 *		bitmask;	/* used by write */
+			u32 bitmask_store[NFS_BITMASK_SZ];	/* used by write */
 			enum nfs3_stable_how	stable;		/* used by write */
 		};
 	};