NFSv4: Add CB_GETATTR support for delegated attributes

When the client holds an attribute delegation, the server may retrieve
all the timestamps through a CB_GETATTR callback.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/callback.h

@@ -46,14 +46,15 @@ struct cb_compound_hdr_res {
 
 struct cb_getattrargs {
 	struct nfs_fh fh;
-	uint32_t bitmap[2];
+	uint32_t bitmap[3];
 };
 
 struct cb_getattrres {
 	__be32 status;
-	uint32_t bitmap[2];
+	uint32_t bitmap[3];
 	uint64_t size;
 	uint64_t change_attr;
+	struct timespec64 atime;
 	struct timespec64 ctime;
 	struct timespec64 mtime;
 };

fs/nfs/callback_proc.c

@@ -37,7 +37,7 @@ __be32 nfs4_callback_getattr(void *argp, void *resp,
 	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
 		goto out;
 
-	res->bitmap[0] = res->bitmap[1] = 0;
+	memset(res->bitmap, 0, sizeof(res->bitmap));
 	res->status = htonl(NFS4ERR_BADHANDLE);
 
 	dprintk_rcu("NFS: GETATTR callback request from %s\n",
@@ -59,12 +59,16 @@ __be32 nfs4_callback_getattr(void *argp, void *resp,
 	res->change_attr = delegation->change_attr;
 	if (nfs_have_writebacks(inode))
 		res->change_attr++;
+	res->atime = inode_get_atime(inode);
 	res->ctime = inode_get_ctime(inode);
 	res->mtime = inode_get_mtime(inode);
-	res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
-		args->bitmap[0];
-	res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
-		args->bitmap[1];
+	res->bitmap[0] = (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE) &
+			 args->bitmap[0];
+	res->bitmap[1] = (FATTR4_WORD1_TIME_ACCESS |
+			  FATTR4_WORD1_TIME_METADATA |
+			  FATTR4_WORD1_TIME_MODIFY) & args->bitmap[1];
+	res->bitmap[2] = (FATTR4_WORD2_TIME_DELEG_ACCESS |
+			  FATTR4_WORD2_TIME_DELEG_MODIFY) & args->bitmap[2];
 	res->status = 0;
 out_iput:
 	rcu_read_unlock();

fs/nfs/callback_xdr.c

@@ -25,8 +25,9 @@
 #define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
 #define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
 					 CB_OP_GETATTR_BITMAP_MAXSZ + \
-					 /* change, size, ctime, mtime */\
-					 (2 + 2 + 3 + 3) * 4)
+					 /* change, size, atime, ctime,
+					  * mtime, deleg_atime, deleg_mtime */\
+					 (2 + 2 + 3 + 3 + 3 + 3 + 3) * 4)
 #define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
 
 #if defined(CONFIG_NFS_V4_1)
@@ -635,6 +636,13 @@ static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *
 	return 0;
 }
 
+static __be32 encode_attr_atime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
+{
+	if (!(bitmap[1] & FATTR4_WORD1_TIME_ACCESS))
+		return 0;
+	return encode_attr_time(xdr,time);
+}
+
 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 {
 	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
@@ -649,6 +657,24 @@ static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap,
 	return encode_attr_time(xdr,time);
 }
 
+static __be32 encode_attr_delegatime(struct xdr_stream *xdr,
+				     const uint32_t *bitmap,
+				     const struct timespec64 *time)
+{
+	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS))
+		return 0;
+	return encode_attr_time(xdr,time);
+}
+
+static __be32 encode_attr_delegmtime(struct xdr_stream *xdr,
+				     const uint32_t *bitmap,
+				     const struct timespec64 *time)
+{
+	if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY))
+		return 0;
+	return encode_attr_time(xdr,time);
+}
+
 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 {
 	__be32 status;
@@ -697,12 +723,21 @@ static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	if (unlikely(status != 0))
 		goto out;
 	status = encode_attr_size(xdr, res->bitmap, res->size);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_atime(xdr, res->bitmap, &res->atime);
 	if (unlikely(status != 0))
 		goto out;
 	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 	if (unlikely(status != 0))
 		goto out;
 	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_delegatime(xdr, res->bitmap, &res->atime);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_delegmtime(xdr, res->bitmap, &res->mtime);
 	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 out:
 	return status;