nfsd: add support for delegated timestamps

Add support for the delegated timestamps on write delegations. This
allows the server to proxy timestamps from the delegation holder to
other clients that are doing GETATTRs vs. the same inode.

When OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS bit is set in the OPEN
call, set the dl_type to the *_ATTRS_DELEG flavor of delegation.

Add timespec64 fields to nfs4_cb_fattr and decode the timestamps into
those. Vet those timestamps according to the delstid spec and update
the inode attrs if necessary.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

1 files changed, 38 insertions, 4 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 1457f61ae051..50e468bdb8d4 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -42,6 +42,7 @@
 #include "trace.h"
 #include "xdr4cb.h"
 #include "xdr4.h"
+#include "nfs4xdr_gen.h"
 
 #define NFSDDBG_FACILITY                NFSDDBG_PROC
 
@@ -93,12 +94,35 @@ static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
 {
 	fattr->ncf_cb_change = 0;
 	fattr->ncf_cb_fsize = 0;
+	fattr->ncf_cb_atime.tv_sec = 0;
+	fattr->ncf_cb_atime.tv_nsec = 0;
+	fattr->ncf_cb_mtime.tv_sec = 0;
+	fattr->ncf_cb_mtime.tv_nsec = 0;
+
 	if (bitmap[0] & FATTR4_WORD0_CHANGE)
 		if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0)
 			return -NFSERR_BAD_XDR;
 	if (bitmap[0] & FATTR4_WORD0_SIZE)
 		if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0)
 			return -NFSERR_BAD_XDR;
+	if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) {
+		fattr4_time_deleg_access access;
+
+		if (!xdrgen_decode_fattr4_time_deleg_access(xdr, &access))
+			return -NFSERR_BAD_XDR;
+		fattr->ncf_cb_atime.tv_sec = access.seconds;
+		fattr->ncf_cb_atime.tv_nsec = access.nseconds;
+
+	}
+	if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
+		fattr4_time_deleg_modify modify;
+
+		if (!xdrgen_decode_fattr4_time_deleg_modify(xdr, &modify))
+			return -NFSERR_BAD_XDR;
+		fattr->ncf_cb_mtime.tv_sec = modify.seconds;
+		fattr->ncf_cb_mtime.tv_nsec = modify.nseconds;
+
+	}
 	return 0;
 }
 
@@ -364,15 +388,21 @@ encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr,
 	struct nfs4_delegation *dp = container_of(fattr, struct nfs4_delegation, dl_cb_fattr);
 	struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle;
 	struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr;
-	u32 bmap[1];
+	u32 bmap_size = 1;
+	u32 bmap[3];
 
 	bmap[0] = FATTR4_WORD0_SIZE;
 	if (!ncf->ncf_file_modified)
 		bmap[0] |= FATTR4_WORD0_CHANGE;
 
+	if (deleg_attrs_deleg(dp->dl_type)) {
+		bmap[1] = 0;
+		bmap[2] = FATTR4_WORD2_TIME_DELEG_ACCESS | FATTR4_WORD2_TIME_DELEG_MODIFY;
+		bmap_size = 3;
+	}
 	encode_nfs_cb_opnum4(xdr, OP_CB_GETATTR);
 	encode_nfs_fh4(xdr, fh);
-	encode_bitmap4(xdr, bmap, ARRAY_SIZE(bmap));
+	encode_bitmap4(xdr, bmap, bmap_size);
 	hdr->nops++;
 }
 
@@ -636,7 +666,7 @@ static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
 	struct nfs4_cb_compound_hdr hdr;
 	int status;
 	u32 bitmap[3] = {0};
-	u32 attrlen;
+	u32 attrlen, maxlen;
 	struct nfs4_cb_fattr *ncf =
 		container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
 
@@ -655,7 +685,11 @@ static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
 		return -NFSERR_BAD_XDR;
 	if (xdr_stream_decode_u32(xdr, &attrlen) < 0)
 		return -NFSERR_BAD_XDR;
-	if (attrlen > (sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize)))
+	maxlen = sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize);
+	if (bitmap[2] != 0)
+		maxlen += (sizeof(ncf->ncf_cb_mtime.tv_sec) +
+			   sizeof(ncf->ncf_cb_mtime.tv_nsec)) * 2;
+	if (attrlen > maxlen)
 		return -NFSERR_BAD_XDR;
 	status = decode_cb_fattr4(xdr, bitmap, ncf);
 	return status;