nfs4xdr.c

}

static int decode_attr_time_access(struct xdr_stream *xdr, uint32_t *bitmap, struct timespec *time)
{
	int status = 0;

	time->tv_sec = 0;
	time->tv_nsec = 0;
	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_ACCESS - 1U)))
		return -EIO;
	if (likely(bitmap[1] & FATTR4_WORD1_TIME_ACCESS)) {
		status = decode_attr_time(xdr, time);
		if (status == 0)
			status = NFS_ATTR_FATTR_ATIME;
		bitmap[1] &= ~FATTR4_WORD1_TIME_ACCESS;
	}
	dprintk("%s: atime=%ld\n", __func__, (long)time->tv_sec);
	return status;
}

static int decode_attr_time_metadata(struct xdr_stream *xdr, uint32_t *bitmap, struct timespec *time)
{
	int status = 0;

	time->tv_sec = 0;
	time->tv_nsec = 0;
	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_METADATA - 1U)))
		return -EIO;
	if (likely(bitmap[1] & FATTR4_WORD1_TIME_METADATA)) {
		status = decode_attr_time(xdr, time);
		if (status == 0)
			status = NFS_ATTR_FATTR_CTIME;
		bitmap[1] &= ~FATTR4_WORD1_TIME_METADATA;
	}
	dprintk("%s: ctime=%ld\n", __func__, (long)time->tv_sec);
	return status;
}

static int decode_attr_time_delta(struct xdr_stream *xdr, uint32_t *bitmap,
				  struct timespec *time)
{
	int status = 0;

	time->tv_sec = 0;
	time->tv_nsec = 0;
	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_DELTA - 1U)))
		return -EIO;
	if (likely(bitmap[1] & FATTR4_WORD1_TIME_DELTA)) {
		status = decode_attr_time(xdr, time);
		bitmap[1] &= ~FATTR4_WORD1_TIME_DELTA;
	}
	dprintk("%s: time_delta=%ld %ld\n", __func__, (long)time->tv_sec,
		(long)time->tv_nsec);
	return status;
}

static int decode_attr_time_modify(struct xdr_stream *xdr, uint32_t *bitmap, struct timespec *time)
{
	int status = 0;

	time->tv_sec = 0;
	time->tv_nsec = 0;
	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_MODIFY - 1U)))
		return -EIO;
	if (likely(bitmap[1] & FATTR4_WORD1_TIME_MODIFY)) {
		status = decode_attr_time(xdr, time);
		if (status == 0)
			status = NFS_ATTR_FATTR_MTIME;
		bitmap[1] &= ~FATTR4_WORD1_TIME_MODIFY;
	}
	dprintk("%s: mtime=%ld\n", __func__, (long)time->tv_sec);
	return status;
}

static int verify_attr_len(struct xdr_stream *xdr, unsigned int savep, uint32_t attrlen)
{
	unsigned int attrwords = XDR_QUADLEN(attrlen);
	unsigned int nwords = (xdr_stream_pos(xdr) - savep) >> 2;

	if (unlikely(attrwords != nwords)) {
		dprintk("%s: server returned incorrect attribute length: "
			"%u %c %u\n",
				__func__,
				attrwords << 2,
				(attrwords < nwords) ? '<' : '>',
				nwords << 2);
		return -EIO;
	}
	return 0;
}

static int decode_change_info(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 20);
	if (unlikely(!p))
		goto out_overflow;
	cinfo->atomic = be32_to_cpup(p++);
	p = xdr_decode_hyper(p, &cinfo->before);
	xdr_decode_hyper(p, &cinfo->after);
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_access(struct xdr_stream *xdr, u32 *supported, u32 *access)
{
	__be32 *p;
	uint32_t supp, acc;
	int status;

	status = decode_op_hdr(xdr, OP_ACCESS);
	if (status)
		return status;
	p = xdr_inline_decode(xdr, 8);
	if (unlikely(!p))
		goto out_overflow;
	supp = be32_to_cpup(p++);
	acc = be32_to_cpup(p);
	*supported = supp;
	*access = acc;
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_opaque_fixed(struct xdr_stream *xdr, void *buf, size_t len)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, len);
	if (likely(p)) {
		memcpy(buf, p, len);
		return 0;
	}
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
{
	return decode_opaque_fixed(xdr, stateid, NFS4_STATEID_SIZE);
}

static int decode_close(struct xdr_stream *xdr, struct nfs_closeres *res)
{
	int status;

	status = decode_op_hdr(xdr, OP_CLOSE);
	if (status != -EIO)
		nfs_increment_open_seqid(status, res->seqid);
	if (!status)
		status = decode_stateid(xdr, &res->stateid);
	return status;
}

static int decode_verifier(struct xdr_stream *xdr, void *verifier)
{
	return decode_opaque_fixed(xdr, verifier, NFS4_VERIFIER_SIZE);
}

static int decode_write_verifier(struct xdr_stream *xdr, struct nfs_write_verifier *verifier)
{
	return decode_opaque_fixed(xdr, verifier->data, NFS4_VERIFIER_SIZE);
}

static int decode_commit(struct xdr_stream *xdr, struct nfs_commitres *res)
{
	int status;

	status = decode_op_hdr(xdr, OP_COMMIT);
	if (!status)
		status = decode_write_verifier(xdr, &res->verf->verifier);
	return status;
}

static int decode_create(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
{
	__be32 *p;
	uint32_t bmlen;
	int status;

	status = decode_op_hdr(xdr, OP_CREATE);
	if (status)
		return status;
	if ((status = decode_change_info(xdr, cinfo)))
		return status;
	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		goto out_overflow;
	bmlen = be32_to_cpup(p);
	p = xdr_inline_decode(xdr, bmlen << 2);
	if (likely(p))
		return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_server_caps(struct xdr_stream *xdr, struct nfs4_server_caps_res *res)
{
	unsigned int savep;
	uint32_t attrlen, bitmap[3] = {0};
	int status;

	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
		goto xdr_error;
	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
		goto xdr_error;
	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
		goto xdr_error;
	if ((status = decode_attr_supported(xdr, bitmap, res->attr_bitmask)) != 0)
		goto xdr_error;
	if ((status = decode_attr_fh_expire_type(xdr, bitmap,
						 &res->fh_expire_type)) != 0)
		goto xdr_error;
	if ((status = decode_attr_link_support(xdr, bitmap, &res->has_links)) != 0)
		goto xdr_error;
	if ((status = decode_attr_symlink_support(xdr, bitmap, &res->has_symlinks)) != 0)
		goto xdr_error;
	if ((status = decode_attr_aclsupport(xdr, bitmap, &res->acl_bitmask)) != 0)
		goto xdr_error;
	status = verify_attr_len(xdr, savep, attrlen);
xdr_error:
	dprintk("%s: xdr returned %d!\n", __func__, -status);
	return status;
}

static int decode_statfs(struct xdr_stream *xdr, struct nfs_fsstat *fsstat)
{
	unsigned int savep;
	uint32_t attrlen, bitmap[3] = {0};
	int status;

	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
		goto xdr_error;
	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
		goto xdr_error;
	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
		goto xdr_error;

	if ((status = decode_attr_files_avail(xdr, bitmap, &fsstat->afiles)) != 0)
		goto xdr_error;
	if ((status = decode_attr_files_free(xdr, bitmap, &fsstat->ffiles)) != 0)
		goto xdr_error;
	if ((status = decode_attr_files_total(xdr, bitmap, &fsstat->tfiles)) != 0)
		goto xdr_error;
	if ((status = decode_attr_space_avail(xdr, bitmap, &fsstat->abytes)) != 0)
		goto xdr_error;
	if ((status = decode_attr_space_free(xdr, bitmap, &fsstat->fbytes)) != 0)
		goto xdr_error;
	if ((status = decode_attr_space_total(xdr, bitmap, &fsstat->tbytes)) != 0)
		goto xdr_error;

	status = verify_attr_len(xdr, savep, attrlen);
xdr_error:
	dprintk("%s: xdr returned %d!\n", __func__, -status);
	return status;
}

static int decode_pathconf(struct xdr_stream *xdr, struct nfs_pathconf *pathconf)
{
	unsigned int savep;
	uint32_t attrlen, bitmap[3] = {0};
	int status;

	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
		goto xdr_error;
	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
		goto xdr_error;
	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
		goto xdr_error;

	if ((status = decode_attr_maxlink(xdr, bitmap, &pathconf->max_link)) != 0)
		goto xdr_error;
	if ((status = decode_attr_maxname(xdr, bitmap, &pathconf->max_namelen)) != 0)
		goto xdr_error;

	status = verify_attr_len(xdr, savep, attrlen);
xdr_error:
	dprintk("%s: xdr returned %d!\n", __func__, -status);
	return status;
}

static int decode_threshold_hint(struct xdr_stream *xdr,
				  uint32_t *bitmap,
				  uint64_t *res,
				  uint32_t hint_bit)
{
	__be32 *p;

	*res = 0;
	if (likely(bitmap[0] & hint_bit)) {
		p = xdr_inline_decode(xdr, 8);
		if (unlikely(!p))
			goto out_overflow;
		xdr_decode_hyper(p, res);
	}
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_first_threshold_item4(struct xdr_stream *xdr,
					struct nfs4_threshold *res)
{
	__be32 *p;
	unsigned int savep;
	uint32_t bitmap[3] = {0,}, attrlen;
	int status;

	/* layout type */
	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p)) {
		print_overflow_msg(__func__, xdr);
		return -EIO;
	}
	res->l_type = be32_to_cpup(p);

	/* thi_hintset bitmap */
	status = decode_attr_bitmap(xdr, bitmap);
	if (status < 0)
		goto xdr_error;

	/* thi_hintlist length */
	status = decode_attr_length(xdr, &attrlen, &savep);
	if (status < 0)
		goto xdr_error;
	/* thi_hintlist */
	status = decode_threshold_hint(xdr, bitmap, &res->rd_sz, THRESHOLD_RD);
	if (status < 0)
		goto xdr_error;
	status = decode_threshold_hint(xdr, bitmap, &res->wr_sz, THRESHOLD_WR);
	if (status < 0)
		goto xdr_error;
	status = decode_threshold_hint(xdr, bitmap, &res->rd_io_sz,
				       THRESHOLD_RD_IO);
	if (status < 0)
		goto xdr_error;
	status = decode_threshold_hint(xdr, bitmap, &res->wr_io_sz,
				       THRESHOLD_WR_IO);
	if (status < 0)
		goto xdr_error;

	status = verify_attr_len(xdr, savep, attrlen);
	res->bm = bitmap[0];

	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
		 __func__, res->bm, res->rd_sz, res->wr_sz, res->rd_io_sz,
		res->wr_io_sz);
xdr_error:
	dprintk("%s ret=%d!\n", __func__, status);
	return status;
}

/*
 * Thresholds on pNFS direct I/O vrs MDS I/O
 */
static int decode_attr_mdsthreshold(struct xdr_stream *xdr,
				    uint32_t *bitmap,
				    struct nfs4_threshold *res)
{
	__be32 *p;
	int status = 0;
	uint32_t num;

	if (unlikely(bitmap[2] & (FATTR4_WORD2_MDSTHRESHOLD - 1U)))
		return -EIO;
	if (bitmap[2] & FATTR4_WORD2_MDSTHRESHOLD) {
		/* Did the server return an unrequested attribute? */
		if (unlikely(res == NULL))
			return -EREMOTEIO;
		p = xdr_inline_decode(xdr, 4);
		if (unlikely(!p))
			goto out_overflow;
		num = be32_to_cpup(p);
		if (num == 0)
			return 0;
		if (num > 1)
			printk(KERN_INFO "%s: Warning: Multiple pNFS layout "
				"drivers per filesystem not supported\n",
				__func__);

		status = decode_first_threshold_item4(xdr, res);
		bitmap[2] &= ~FATTR4_WORD2_MDSTHRESHOLD;
	}
	return status;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap,
		struct nfs_fattr *fattr, struct nfs_fh *fh,
		struct nfs4_fs_locations *fs_loc,
		const struct nfs_server *server)
{
	int status;
	umode_t fmode = 0;
	uint32_t type;
	int32_t err;

	status = decode_attr_type(xdr, bitmap, &type);
	if (status < 0)
		goto xdr_error;
	fattr->mode = 0;
	if (status != 0) {
		fattr->mode |= nfs_type2fmt[type];
		fattr->valid |= status;
	}

	status = decode_attr_change(xdr, bitmap, &fattr->change_attr);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_size(xdr, bitmap, &fattr->size);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_fsid(xdr, bitmap, &fattr->fsid);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	err = 0;
	status = decode_attr_error(xdr, bitmap, &err);
	if (status < 0)
		goto xdr_error;

	status = decode_attr_filehandle(xdr, bitmap, fh);
	if (status < 0)
		goto xdr_error;

	status = decode_attr_fileid(xdr, bitmap, &fattr->fileid);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_fs_locations(xdr, bitmap, fs_loc);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_mode(xdr, bitmap, &fmode);
	if (status < 0)
		goto xdr_error;
	if (status != 0) {
		fattr->mode |= fmode;
		fattr->valid |= status;
	}

	status = decode_attr_nlink(xdr, bitmap, &fattr->nlink);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_owner(xdr, bitmap, server, &fattr->uid, fattr->owner_name);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_group(xdr, bitmap, server, &fattr->gid, fattr->group_name);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_rdev(xdr, bitmap, &fattr->rdev);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_space_used(xdr, bitmap, &fattr->du.nfs3.used);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_time_access(xdr, bitmap, &fattr->atime);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_time_metadata(xdr, bitmap, &fattr->ctime);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_time_modify(xdr, bitmap, &fattr->mtime);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_mounted_on_fileid(xdr, bitmap, &fattr->mounted_on_fileid);
	if (status < 0)
		goto xdr_error;
	fattr->valid |= status;

	status = decode_attr_mdsthreshold(xdr, bitmap, fattr->mdsthreshold);
	if (status < 0)
		goto xdr_error;

xdr_error:
	dprintk("%s: xdr returned %d\n", __func__, -status);
	return status;
}

static int decode_getfattr_generic(struct xdr_stream *xdr, struct nfs_fattr *fattr,
		struct nfs_fh *fh, struct nfs4_fs_locations *fs_loc,
		const struct nfs_server *server)
{
	unsigned int savep;
	uint32_t attrlen,
		 bitmap[3] = {0};
	int status;

	status = decode_op_hdr(xdr, OP_GETATTR);
	if (status < 0)
		goto xdr_error;

	status = decode_attr_bitmap(xdr, bitmap);
	if (status < 0)
		goto xdr_error;

	status = decode_attr_length(xdr, &attrlen, &savep);
	if (status < 0)
		goto xdr_error;

	status = decode_getfattr_attrs(xdr, bitmap, fattr, fh, fs_loc, server);
	if (status < 0)
		goto xdr_error;

	status = verify_attr_len(xdr, savep, attrlen);
xdr_error:
	dprintk("%s: xdr returned %d\n", __func__, -status);
	return status;
}

static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
		const struct nfs_server *server)
{
	return decode_getfattr_generic(xdr, fattr, NULL, NULL, server);
}

/*
 * Decode potentially multiple layout types. Currently we only support
 * one layout driver per file system.
 */
static int decode_first_pnfs_layout_type(struct xdr_stream *xdr,
					 uint32_t *layouttype)
{
	uint32_t *p;
	int num;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		goto out_overflow;
	num = be32_to_cpup(p);

	/* pNFS is not supported by the underlying file system */
	if (num == 0) {
		*layouttype = 0;
		return 0;
	}
	if (num > 1)
		printk(KERN_INFO "NFS: %s: Warning: Multiple pNFS layout "
			"drivers per filesystem not supported\n", __func__);

	/* Decode and set first layout type, move xdr->p past unused types */
	p = xdr_inline_decode(xdr, num * 4);
	if (unlikely(!p))
		goto out_overflow;
	*layouttype = be32_to_cpup(p);
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 * The type of file system exported.
 * Note we must ensure that layouttype is set in any non-error case.
 */
static int decode_attr_pnfstype(struct xdr_stream *xdr, uint32_t *bitmap,
				uint32_t *layouttype)
{
	int status = 0;

	dprintk("%s: bitmap is %x\n", __func__, bitmap[1]);
	if (unlikely(bitmap[1] & (FATTR4_WORD1_FS_LAYOUT_TYPES - 1U)))
		return -EIO;
	if (bitmap[1] & FATTR4_WORD1_FS_LAYOUT_TYPES) {
		status = decode_first_pnfs_layout_type(xdr, layouttype);
		bitmap[1] &= ~FATTR4_WORD1_FS_LAYOUT_TYPES;
	} else
		*layouttype = 0;
	return status;
}

/*
 * The prefered block size for layout directed io
 */
static int decode_attr_layout_blksize(struct xdr_stream *xdr, uint32_t *bitmap,
				      uint32_t *res)
{
	__be32 *p;

	dprintk("%s: bitmap is %x\n", __func__, bitmap[2]);
	*res = 0;
	if (bitmap[2] & FATTR4_WORD2_LAYOUT_BLKSIZE) {
		p = xdr_inline_decode(xdr, 4);
		if (unlikely(!p)) {
			print_overflow_msg(__func__, xdr);
			return -EIO;
		}
		*res = be32_to_cpup(p);
		bitmap[2] &= ~FATTR4_WORD2_LAYOUT_BLKSIZE;
	}
	return 0;
}

static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
{
	unsigned int savep;
	uint32_t attrlen, bitmap[3];
	int status;

	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
		goto xdr_error;
	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
		goto xdr_error;
	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
		goto xdr_error;

	fsinfo->rtmult = fsinfo->wtmult = 512;	/* ??? */

	if ((status = decode_attr_lease_time(xdr, bitmap, &fsinfo->lease_time)) != 0)
		goto xdr_error;
	if ((status = decode_attr_maxfilesize(xdr, bitmap, &fsinfo->maxfilesize)) != 0)
		goto xdr_error;
	if ((status = decode_attr_maxread(xdr, bitmap, &fsinfo->rtmax)) != 0)
		goto xdr_error;
	fsinfo->rtpref = fsinfo->dtpref = fsinfo->rtmax;
	if ((status = decode_attr_maxwrite(xdr, bitmap, &fsinfo->wtmax)) != 0)
		goto xdr_error;
	fsinfo->wtpref = fsinfo->wtmax;
	status = decode_attr_time_delta(xdr, bitmap, &fsinfo->time_delta);
	if (status != 0)
		goto xdr_error;
	status = decode_attr_pnfstype(xdr, bitmap, &fsinfo->layouttype);
	if (status != 0)
		goto xdr_error;
	status = decode_attr_layout_blksize(xdr, bitmap, &fsinfo->blksize);
	if (status)
		goto xdr_error;

	status = verify_attr_len(xdr, savep, attrlen);
xdr_error:
	dprintk("%s: xdr returned %d!\n", __func__, -status);
	return status;
}

static int decode_getfh(struct xdr_stream *xdr, struct nfs_fh *fh)
{
	__be32 *p;
	uint32_t len;
	int status;

	/* Zero handle first to allow comparisons */
	memset(fh, 0, sizeof(*fh));

	status = decode_op_hdr(xdr, OP_GETFH);
	if (status)
		return status;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		goto out_overflow;
	len = be32_to_cpup(p);
	if (len > NFS4_FHSIZE)
		return -EIO;
	fh->size = len;
	p = xdr_inline_decode(xdr, len);
	if (unlikely(!p))
		goto out_overflow;
	memcpy(fh->data, p, len);
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_link(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
{
	int status;

	status = decode_op_hdr(xdr, OP_LINK);
	if (status)
		return status;
	return decode_change_info(xdr, cinfo);
}

/*
 * We create the owner, so we know a proper owner.id length is 4.
 */
static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
{
	uint64_t offset, length, clientid;
	__be32 *p;
	uint32_t namelen, type;

	p = xdr_inline_decode(xdr, 32); /* read 32 bytes */
	if (unlikely(!p))
		goto out_overflow;
	p = xdr_decode_hyper(p, &offset); /* read 2 8-byte long words */
	p = xdr_decode_hyper(p, &length);
	type = be32_to_cpup(p++); /* 4 byte read */
	if (fl != NULL) { /* manipulate file lock */
		fl->fl_start = (loff_t)offset;
		fl->fl_end = fl->fl_start + (loff_t)length - 1;
		if (length == ~(uint64_t)0)
			fl->fl_end = OFFSET_MAX;
		fl->fl_type = F_WRLCK;
		if (type & 1)
			fl->fl_type = F_RDLCK;
		fl->fl_pid = 0;
	}
	p = xdr_decode_hyper(p, &clientid); /* read 8 bytes */
	namelen = be32_to_cpup(p); /* read 4 bytes */  /* have read all 32 bytes now */
	p = xdr_inline_decode(xdr, namelen); /* variable size field */
	if (likely(p))
		return -NFS4ERR_DENIED;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_lock(struct xdr_stream *xdr, struct nfs_lock_res *res)
{
	int status;

	status = decode_op_hdr(xdr, OP_LOCK);
	if (status == -EIO)
		goto out;
	if (status == 0) {
		status = decode_stateid(xdr, &res->stateid);
		if (unlikely(status))
			goto out;
	} else if (status == -NFS4ERR_DENIED)
		status = decode_lock_denied(xdr, NULL);
	if (res->open_seqid != NULL)
		nfs_increment_open_seqid(status, res->open_seqid);
	nfs_increment_lock_seqid(status, res->lock_seqid);
out:
	return status;
}

static int decode_lockt(struct xdr_stream *xdr, struct nfs_lockt_res *res)
{
	int status;
	status = decode_op_hdr(xdr, OP_LOCKT);
	if (status == -NFS4ERR_DENIED)
		return decode_lock_denied(xdr, res->denied);
	return status;
}

static int decode_locku(struct xdr_stream *xdr, struct nfs_locku_res *res)
{
	int status;

	status = decode_op_hdr(xdr, OP_LOCKU);
	if (status != -EIO)
		nfs_increment_lock_seqid(status, res->seqid);
	if (status == 0)
		status = decode_stateid(xdr, &res->stateid);
	return status;
}

static int decode_release_lockowner(struct xdr_stream *xdr)
{
	return decode_op_hdr(xdr, OP_RELEASE_LOCKOWNER);
}

static int decode_lookup(struct xdr_stream *xdr)
{
	return decode_op_hdr(xdr, OP_LOOKUP);
}

/* This is too sick! */
static int decode_space_limit(struct xdr_stream *xdr, u64 *maxsize)
{
	__be32 *p;
	uint32_t limit_type, nblocks, blocksize;

	p = xdr_inline_decode(xdr, 12);
	if (unlikely(!p))
		goto out_overflow;
	limit_type = be32_to_cpup(p++);
	switch (limit_type) {
	case 1:
		xdr_decode_hyper(p, maxsize);
		break;
	case 2:
		nblocks = be32_to_cpup(p++);
		blocksize = be32_to_cpup(p);
		*maxsize = (uint64_t)nblocks * (uint64_t)blocksize;
	}
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
{
	__be32 *p;
	uint32_t delegation_type;
	int status;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		goto out_overflow;
	delegation_type = be32_to_cpup(p);
	if (delegation_type == NFS4_OPEN_DELEGATE_NONE) {
		res->delegation_type = 0;
		return 0;
	}
	status = decode_stateid(xdr, &res->delegation);
	if (unlikely(status))
		return status;
	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		goto out_overflow;
	res->do_recall = be32_to_cpup(p);

	switch (delegation_type) {
	case NFS4_OPEN_DELEGATE_READ:
		res->delegation_type = FMODE_READ;
		break;
	case NFS4_OPEN_DELEGATE_WRITE:
		res->delegation_type = FMODE_WRITE|FMODE_READ;
		if (decode_space_limit(xdr, &res->maxsize) < 0)
				return -EIO;
	}
	return decode_ace(xdr, NULL, res->server->nfs_client);
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
{
	__be32 *p;
	uint32_t savewords, bmlen, i;
	int status;

	status = decode_op_hdr(xdr, OP_OPEN);
	if (status != -EIO)
		nfs_increment_open_seqid(status, res->seqid);
	if (!status)
		status = decode_stateid(xdr, &res->stateid);
	if (unlikely(status))
		return status;

	decode_change_info(xdr, &res->cinfo);

	p = xdr_inline_decode(xdr, 8);
	if (unlikely(!p))
		goto out_overflow;
	res->rflags = be32_to_cpup(p++);
	bmlen = be32_to_cpup(p);
	if (bmlen > 10)
		goto xdr_error;

	p = xdr_inline_decode(xdr, bmlen << 2);
	if (unlikely(!p))
		goto out_overflow;
	savewords = min_t(uint32_t, bmlen, NFS4_BITMAP_SIZE);
	for (i = 0; i < savewords; ++i)
		res->attrset[i] = be32_to_cpup(p++);
	for (; i < NFS4_BITMAP_SIZE; i++)
		res->attrset[i] = 0;

	return decode_delegation(xdr, res);
xdr_error:
	dprintk("%s: Bitmap too large! Length = %u\n", __func__, bmlen);
	return -EIO;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_open_confirm(struct xdr_stream *xdr, struct nfs_open_confirmres *res)
{
	int status;

	status = decode_op_hdr(xdr, OP_OPEN_CONFIRM);
	if (status != -EIO)
		nfs_increment_open_seqid(status, res->seqid);
	if (!status)
		status = decode_stateid(xdr, &res->stateid);
	return status;
}

static int decode_open_downgrade(struct xdr_stream *xdr, struct nfs_closeres *res)
{
	int status;

	status = decode_op_hdr(xdr, OP_OPEN_DOWNGRADE);
	if (status != -EIO)
		nfs_increment_open_seqid(status, res->seqid);
	if (!status)
		status = decode_stateid(xdr, &res->stateid);
	return status;
}

static int decode_putfh(struct xdr_stream *xdr)
{
	return decode_op_hdr(xdr, OP_PUTFH);
}

static int decode_putrootfh(struct xdr_stream *xdr)
{
	return decode_op_hdr(xdr, OP_PUTROOTFH);
}

static int decode_read(struct xdr_stream *xdr, struct rpc_rqst *req, struct nfs_readres *res)
{
	__be32 *p;
	uint32_t count, eof, recvd;
	int status;

	status = decode_op_hdr(xdr, OP_READ);
	if (status)
		return status;
	p = xdr_inline_decode(xdr, 8);
	if (unlikely(!p))
		goto out_overflow;
	eof = be32_to_cpup(p++);
	count = be32_to_cpup(p);
	recvd = xdr_read_pages(xdr, count);
	if (count > recvd) {
		dprintk("NFS: server cheating in read reply: "
				"count %u > recvd %u\n", count, recvd);
		count = recvd;
		eof = 0;
	}
	res->eof = eof;
	res->count = count;
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct nfs4_readdir_res *readdir)
{
	int		status;
	__be32		verf[2];

	status = decode_op_hdr(xdr, OP_READDIR);
	if (!status)
		status = decode_verifier(xdr, readdir->verifier.data);
	if (unlikely(status))
		return status;
	memcpy(verf, readdir->verifier.data, sizeof(verf));
	dprintk("%s: verifier = %08x:%08x\n",
			__func__, verf[0], verf[1]);
	return xdr_read_pages(xdr, xdr->buf->page_len);
}

static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req)
{
	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
	u32 len, recvd;
	__be32 *p;
	int status;

	status = decode_op_hdr(xdr, OP_READLINK);
	if (status)
		return status;

	/* Convert length of symlink */
	p = xdr_inline_decode(xdr, 4);
	if (unlikely(!p))
		goto out_overflow;
	len = be32_to_cpup(p);
	if (len >= rcvbuf->page_len || len <= 0) {
		dprintk("nfs: server returned giant symlink!\n");
		return -ENAMETOOLONG;
	}
	recvd = xdr_read_pages(xdr, len);
	if (recvd < len) {
		dprintk("NFS: server cheating in readlink reply: "
				"count %u > recvd %u\n", len, recvd);
		return -EIO;