NFSv4: Support NFSv4 optional attributes in the struct nfs_fattr

Currently, filling struct nfs_fattr is more or less an all or nothing
operation, since NFSv2 and NFSv3 have only mandatory attributes.
In NFSv4, some attributes are optional, and so we may simply not be able to
fill in those fields. Furthermore, NFSv4 allows you to specify which
attributes you are interested in retrieving, thus permitting you to
optimise away retrieval of attributes that you know will no change...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs2xdr.c

@@ -136,7 +136,7 @@ xdr_decode_fattr(__be32 *p, struct nfs_fattr *fattr)
 	p = xdr_decode_time(p, &fattr->atime);
 	p = xdr_decode_time(p, &fattr->mtime);
 	p = xdr_decode_time(p, &fattr->ctime);
-	fattr->valid |= NFS_ATTR_FATTR;
+	fattr->valid |= NFS_ATTR_FATTR_V2;
 	fattr->rdev = new_decode_dev(rdev);
 	if (fattr->type == NFCHR && rdev == NFS2_FIFO_DEV) {
 		fattr->type = NFFIFO;

fs/nfs/nfs3xdr.c

@@ -177,7 +177,7 @@ xdr_decode_fattr(__be32 *p, struct nfs_fattr *fattr)
 	p = xdr_decode_time3(p, &fattr->ctime);
 
 	/* Update the mode bits */
-	fattr->valid |= (NFS_ATTR_FATTR | NFS_ATTR_FATTR_V3);
+	fattr->valid |= NFS_ATTR_FATTR_V3;
 	return p;
 }
 
@@ -233,7 +233,9 @@ xdr_decode_wcc_attr(__be32 *p, struct nfs_fattr *fattr)
 	p = xdr_decode_hyper(p, &fattr->pre_size);
 	p = xdr_decode_time3(p, &fattr->pre_mtime);
 	p = xdr_decode_time3(p, &fattr->pre_ctime);
-	fattr->valid |= NFS_ATTR_WCC;
+	fattr->valid |= NFS_ATTR_FATTR_PRESIZE
+		| NFS_ATTR_FATTR_PREMTIME
+		| NFS_ATTR_FATTR_PRECTIME;
 	return p;
 }
 

fs/nfs/nfs4xdr.c

@@ -3012,7 +3012,7 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, cons
 	if ((status = decode_attr_type(xdr, bitmap, &type)) != 0)
 		goto xdr_error;
 	fattr->type = nfs_type2fmt[type].nfs2type;
-	fmode = nfs_type2fmt[type].mode;
+	fattr->mode = nfs_type2fmt[type].mode;
 
 	if ((status = decode_attr_change(xdr, bitmap, &fattr->change_attr)) != 0)
 		goto xdr_error;
@@ -3026,7 +3026,7 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, cons
 						struct nfs4_fs_locations,
 						fattr))) != 0)
 		goto xdr_error;
-	if ((status = decode_attr_mode(xdr, bitmap, &fattr->mode)) != 0)
+	if ((status = decode_attr_mode(xdr, bitmap, &fmode)) != 0)
 		goto xdr_error;
 	fattr->mode |= fmode;
 	if ((status = decode_attr_nlink(xdr, bitmap, &fattr->nlink)) != 0)
@@ -3050,7 +3050,7 @@ static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr, cons
 	if (fattr->fileid == 0 && fileid != 0)
 		fattr->fileid = fileid;
 	if ((status = verify_attr_len(xdr, savep, attrlen)) == 0)
-		fattr->valid = NFS_ATTR_FATTR | NFS_ATTR_FATTR_V3 | NFS_ATTR_FATTR_V4;
+		fattr->valid = NFS_ATTR_FATTR_V4;
 xdr_error:
 	dprintk("%s: xdr returned %d\n", __func__, -status);
 	return status;

include/linux/nfs_xdr.h

@@ -27,7 +27,7 @@ static inline int nfs_fsid_equal(const struct nfs_fsid *a, const struct nfs_fsid
 }
 
 struct nfs_fattr {
-	unsigned short		valid;		/* which fields are valid */
+	unsigned int		valid;		/* which fields are valid */
 	__u64			pre_size;	/* pre_op_attr.size	  */
 	struct timespec		pre_mtime;	/* pre_op_attr.mtime	  */
 	struct timespec		pre_ctime;	/* pre_op_attr.ctime	  */
@@ -59,12 +59,46 @@ struct nfs_fattr {
 	unsigned long		gencount;
 };
 
-#define NFS_ATTR_WCC		0x0001		/* pre-op WCC data    */
-#define NFS_ATTR_FATTR		0x0002		/* post-op attributes */
-#define NFS_ATTR_FATTR_V3	0x0004		/* NFSv3 attributes */
-#define NFS_ATTR_FATTR_V4	0x0008		/* NFSv4 change attribute */
-#define NFS_ATTR_WCC_V4		0x0010		/* pre-op change attribute */
-#define NFS_ATTR_FATTR_V4_REFERRAL	0x0020		/* NFSv4 referral */
+#define NFS_ATTR_FATTR_TYPE		(1U << 0)
+#define NFS_ATTR_FATTR_MODE		(1U << 1)
+#define NFS_ATTR_FATTR_NLINK		(1U << 2)
+#define NFS_ATTR_FATTR_OWNER		(1U << 3)
+#define NFS_ATTR_FATTR_GROUP		(1U << 4)
+#define NFS_ATTR_FATTR_RDEV		(1U << 5)
+#define NFS_ATTR_FATTR_SIZE		(1U << 6)
+#define NFS_ATTR_FATTR_PRESIZE		(1U << 7)
+#define NFS_ATTR_FATTR_BLOCKS_USED	(1U << 8)
+#define NFS_ATTR_FATTR_SPACE_USED	(1U << 9)
+#define NFS_ATTR_FATTR_FSID		(1U << 10)
+#define NFS_ATTR_FATTR_FILEID		(1U << 11)
+#define NFS_ATTR_FATTR_ATIME		(1U << 12)
+#define NFS_ATTR_FATTR_MTIME		(1U << 13)
+#define NFS_ATTR_FATTR_CTIME		(1U << 14)
+#define NFS_ATTR_FATTR_PREMTIME		(1U << 15)
+#define NFS_ATTR_FATTR_PRECTIME		(1U << 16)
+#define NFS_ATTR_FATTR_CHANGE		(1U << 17)
+#define NFS_ATTR_FATTR_PRECHANGE	(1U << 18)
+#define NFS_ATTR_FATTR_V4_REFERRAL	(1U << 19)	/* NFSv4 referral */
+
+#define NFS_ATTR_FATTR (NFS_ATTR_FATTR_TYPE \
+		| NFS_ATTR_FATTR_MODE \
+		| NFS_ATTR_FATTR_NLINK \
+		| NFS_ATTR_FATTR_OWNER \
+		| NFS_ATTR_FATTR_GROUP \
+		| NFS_ATTR_FATTR_RDEV \
+		| NFS_ATTR_FATTR_SIZE \
+		| NFS_ATTR_FATTR_FSID \
+		| NFS_ATTR_FATTR_FILEID \
+		| NFS_ATTR_FATTR_ATIME \
+		| NFS_ATTR_FATTR_MTIME \
+		| NFS_ATTR_FATTR_CTIME)
+#define NFS_ATTR_FATTR_V2 (NFS_ATTR_FATTR \
+		| NFS_ATTR_FATTR_BLOCKS_USED)
+#define NFS_ATTR_FATTR_V3 (NFS_ATTR_FATTR \
+		| NFS_ATTR_FATTR_SPACE_USED)
+#define NFS_ATTR_FATTR_V4 (NFS_ATTR_FATTR \
+		| NFS_ATTR_FATTR_SPACE_USED \
+		| NFS_ATTR_FATTR_CHANGE)
 
 /*
  * Info on the file system