Initial import

1 files changed, 1033 insertions, 0 deletions

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
new file mode 100644
index 000000000..19ca95cdf
--- /dev/null
+++ b/fs/nfs/callback_xdr.c
@@ -0,0 +1,1033 @@
+/*
+ * linux/fs/nfs/callback_xdr.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback encode/decode procedures
+ */
+#include <linux/kernel.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/ratelimit.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/bc_xprt.h>
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "internal.h"
+#include "nfs4session.h"
+
+#define CB_OP_TAGLEN_MAXSZ	(512)
+#define CB_OP_HDR_RES_MAXSZ	(2 + CB_OP_TAGLEN_MAXSZ)
+#define CB_OP_GETATTR_BITMAP_MAXSZ	(4)
+#define CB_OP_GETATTR_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
+				CB_OP_GETATTR_BITMAP_MAXSZ + \
+				2 + 2 + 3 + 3)
+#define CB_OP_RECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+
+#if defined(CONFIG_NFS_V4_1)
+#define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
+					4 + 1 + 3)
+#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#endif /* CONFIG_NFS_V4_1 */
+
+#define NFSDBG_FACILITY NFSDBG_CALLBACK
+
+/* Internal error code */
+#define NFS4ERR_RESOURCE_HDR	11050
+
+typedef __be32 (*callback_process_op_t)(void *, void *,
+					struct cb_process_state *);
+typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
+typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
+
+
+struct callback_op {
+	callback_process_op_t process_op;
+	callback_decode_arg_t decode_args;
+	callback_encode_res_t encode_res;
+	long res_maxsize;
+};
+
+static struct callback_op callback_ops[];
+
+static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
+{
+	return htonl(NFS4_OK);
+}
+
+static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
+{
+	return xdr_argsize_check(rqstp, p);
+}
+
+static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
+{
+	return xdr_ressize_check(rqstp, p);
+}
+
+static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, nbytes);
+	if (unlikely(p == NULL))
+		printk(KERN_WARNING "NFS: NFSv4 callback reply buffer overflowed!\n");
+	return p;
+}
+
+static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
+{
+	__be32 *p;
+
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	*len = ntohl(*p);
+
+	if (*len != 0) {
+		p = read_buf(xdr, *len);
+		if (unlikely(p == NULL))
+			return htonl(NFS4ERR_RESOURCE);
+		*str = (const char *)p;
+	} else
+		*str = NULL;
+
+	return 0;
+}
+
+static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	fh->size = ntohl(*p);
+	if (fh->size > NFS4_FHSIZE)
+		return htonl(NFS4ERR_BADHANDLE);
+	p = read_buf(xdr, fh->size);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	memcpy(&fh->data[0], p, fh->size);
+	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
+	return 0;
+}
+
+static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
+{
+	__be32 *p;
+	unsigned int attrlen;
+
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	attrlen = ntohl(*p);
+	p = read_buf(xdr, attrlen << 2);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	if (likely(attrlen > 0))
+		bitmap[0] = ntohl(*p++);
+	if (attrlen > 1)
+		bitmap[1] = ntohl(*p);
+	return 0;
+}
+
+static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	__be32 *p;
+
+	p = read_buf(xdr, NFS4_STATEID_SIZE);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	memcpy(stateid, p, NFS4_STATEID_SIZE);
+	return 0;
+}
+
+static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
+{
+	__be32 *p;
+	__be32 status;
+
+	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
+	if (unlikely(status != 0))
+		return status;
+	/* We do not like overly long tags! */
+	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
+		printk("NFS: NFSv4 CALLBACK %s: client sent tag of length %u\n",
+				__func__, hdr->taglen);
+		return htonl(NFS4ERR_RESOURCE);
+	}
+	p = read_buf(xdr, 12);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	hdr->minorversion = ntohl(*p++);
+	/* Check for minor version support */
+	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
+		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
+	} else {
+		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
+			"illegal minor version %u!\n",
+			__func__, hdr->minorversion);
+		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+	}
+	hdr->nops = ntohl(*p);
+	dprintk("%s: minorversion %d nops %d\n", __func__,
+		hdr->minorversion, hdr->nops);
+	return 0;
+}
+
+static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
+{
+	__be32 *p;
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE_HDR);
+	*op = ntohl(*p);
+	return 0;
+}
+
+static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
+{
+	__be32 status;
+
+	status = decode_fh(xdr, &args->fh);
+	if (unlikely(status != 0))
+		goto out;
+	args->addr = svc_addr(rqstp);
+	status = decode_bitmap(xdr, args->bitmap);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
+{
+	__be32 *p;
+	__be32 status;
+
+	args->addr = svc_addr(rqstp);
+	status = decode_stateid(xdr, &args->stateid);
+	if (unlikely(status != 0))
+		goto out;
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL)) {
+		status = htonl(NFS4ERR_RESOURCE);
+		goto out;
+	}
+	args->truncate = ntohl(*p);
+	status = decode_fh(xdr, &args->fh);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       struct cb_layoutrecallargs *args)
+{
+	__be32 *p;
+	__be32 status = 0;
+	uint32_t iomode;
+
+	args->cbl_addr = svc_addr(rqstp);
+	p = read_buf(xdr, 4 * sizeof(uint32_t));
+	if (unlikely(p == NULL)) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
+	}
+
+	args->cbl_layout_type = ntohl(*p++);
+	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
+	 * as it is unusable and ignored with the other types.
+	 */
+	iomode = ntohl(*p++);
+	args->cbl_layoutchanged = ntohl(*p++);
+	args->cbl_recall_type = ntohl(*p++);
+
+	if (args->cbl_recall_type == RETURN_FILE) {
+		args->cbl_range.iomode = iomode;
+		status = decode_fh(xdr, &args->cbl_fh);
+		if (unlikely(status != 0))
+			goto out;
+
+		p = read_buf(xdr, 2 * sizeof(uint64_t));
+		if (unlikely(p == NULL)) {
+			status = htonl(NFS4ERR_BADXDR);
+			goto out;
+		}
+		p = xdr_decode_hyper(p, &args->cbl_range.offset);
+		p = xdr_decode_hyper(p, &args->cbl_range.length);
+		status = decode_stateid(xdr, &args->cbl_stateid);
+		if (unlikely(status != 0))
+			goto out;
+	} else if (args->cbl_recall_type == RETURN_FSID) {
+		p = read_buf(xdr, 2 * sizeof(uint64_t));
+		if (unlikely(p == NULL)) {
+			status = htonl(NFS4ERR_BADXDR);
+			goto out;
+		}
+		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
+		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
+	} else if (args->cbl_recall_type != RETURN_ALL) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
+	}
+	dprintk("%s: ltype 0x%x iomode %d changed %d recall_type %d\n",
+		__func__,
+		args->cbl_layout_type, iomode,
+		args->cbl_layoutchanged, args->cbl_recall_type);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+static
+__be32 decode_devicenotify_args(struct svc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				struct cb_devicenotifyargs *args)
+{
+	__be32 *p;
+	__be32 status = 0;
+	u32 tmp;
+	int n, i;
+	args->ndevs = 0;
+
+	/* Num of device notifications */
+	p = read_buf(xdr, sizeof(uint32_t));
+	if (unlikely(p == NULL)) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
+	}
+	n = ntohl(*p++);
+	if (n <= 0)
+		goto out;
+	if (n > ULONG_MAX / sizeof(*args->devs)) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
+	}
+
+	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
+	if (!args->devs) {
+		status = htonl(NFS4ERR_DELAY);
+		goto out;
+	}
+
+	/* Decode each dev notification */
+	for (i = 0; i < n; i++) {
+		struct cb_devicenotifyitem *dev = &args->devs[i];
+
+		p = read_buf(xdr, (4 * sizeof(uint32_t)) + NFS4_DEVICEID4_SIZE);
+		if (unlikely(p == NULL)) {
+			status = htonl(NFS4ERR_BADXDR);
+			goto err;
+		}
+
+		tmp = ntohl(*p++);	/* bitmap size */
+		if (tmp != 1) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+		dev->cbd_notify_type = ntohl(*p++);
+		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
+		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+
+		tmp = ntohl(*p++);	/* opaque size */
+		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
+		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
+		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
+		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+		dev->cbd_layout_type = ntohl(*p++);
+		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
+		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+
+		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
+			p = read_buf(xdr, sizeof(uint32_t));
+			if (unlikely(p == NULL)) {
+				status = htonl(NFS4ERR_BADXDR);
+				goto err;
+			}
+			dev->cbd_immediate = ntohl(*p++);
+		} else {
+			dev->cbd_immediate = 0;
+		}
+
+		args->ndevs++;
+
+		dprintk("%s: type %d layout 0x%x immediate %d\n",
+			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
+			dev->cbd_immediate);
+	}
+out:
+	dprintk("%s: status %d ndevs %d\n",
+		__func__, ntohl(status), args->ndevs);
+	return status;
+err:
+	kfree(args->devs);
+	goto out;
+}
+
+static __be32 decode_sessionid(struct xdr_stream *xdr,
+				 struct nfs4_sessionid *sid)
+{
+	__be32 *p;
+	int len = NFS4_MAX_SESSIONID_LEN;
+
+	p = read_buf(xdr, len);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	memcpy(sid->data, p, len);
+	return 0;
+}
+
+static __be32 decode_rc_list(struct xdr_stream *xdr,
+			       struct referring_call_list *rc_list)
+{
+	__be32 *p;
+	int i;
+	__be32 status;
+
+	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
+	if (status)
+		goto out;
+
+	status = htonl(NFS4ERR_RESOURCE);
+	p = read_buf(xdr, sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		goto out;
+
+	rc_list->rcl_nrefcalls = ntohl(*p++);
+	if (rc_list->rcl_nrefcalls) {
+		p = read_buf(xdr,
+			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
+		if (unlikely(p == NULL))
+			goto out;
+		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
+						sizeof(*rc_list->rcl_refcalls),
+						GFP_KERNEL);
+		if (unlikely(rc_list->rcl_refcalls == NULL))
+			goto out;
+		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
+			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
+			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
+		}
+	}
+	status = 0;
+
+out:
+	return status;
+}
+
+static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					struct cb_sequenceargs *args)
+{
+	__be32 *p;
+	int i;
+	__be32 status;
+
+	status = decode_sessionid(xdr, &args->csa_sessionid);
+	if (status)
+		goto out;
+
+	status = htonl(NFS4ERR_RESOURCE);
+	p = read_buf(xdr, 5 * sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		goto out;
+
+	args->csa_addr = svc_addr(rqstp);
+	args->csa_sequenceid = ntohl(*p++);
+	args->csa_slotid = ntohl(*p++);
+	args->csa_highestslotid = ntohl(*p++);
+	args->csa_cachethis = ntohl(*p++);
+	args->csa_nrclists = ntohl(*p++);
+	args->csa_rclists = NULL;
+	if (args->csa_nrclists) {
+		args->csa_rclists = kmalloc_array(args->csa_nrclists,
+						  sizeof(*args->csa_rclists),
+						  GFP_KERNEL);
+		if (unlikely(args->csa_rclists == NULL))
+			goto out;
+
+		for (i = 0; i < args->csa_nrclists; i++) {
+			status = decode_rc_list(xdr, &args->csa_rclists[i]);
+			if (status) {
+				args->csa_nrclists = i;
+				goto out_free;
+			}
+		}
+	}
+	status = 0;
+
+	dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
+		"highestslotid %u cachethis %d nrclists %u\n",
+		__func__,
+		((u32 *)&args->csa_sessionid)[0],
+		((u32 *)&args->csa_sessionid)[1],
+		((u32 *)&args->csa_sessionid)[2],
+		((u32 *)&args->csa_sessionid)[3],
+		args->csa_sequenceid, args->csa_slotid,
+		args->csa_highestslotid, args->csa_cachethis,
+		args->csa_nrclists);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+
+out_free:
+	for (i = 0; i < args->csa_nrclists; i++)
+		kfree(args->csa_rclists[i].rcl_refcalls);
+	kfree(args->csa_rclists);
+	goto out;
+}
+
+static __be32 decode_recallany_args(struct svc_rqst *rqstp,
+				      struct xdr_stream *xdr,
+				      struct cb_recallanyargs *args)
+{
+	uint32_t bitmap[2];
+	__be32 *p, status;
+
+	args->craa_addr = svc_addr(rqstp);
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+	args->craa_objs_to_keep = ntohl(*p++);
+	status = decode_bitmap(xdr, bitmap);
+	if (unlikely(status))
+		return status;
+	args->craa_type_mask = bitmap[0];
+
+	return 0;
+}
+
+static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					struct cb_recallslotargs *args)
+{
+	__be32 *p;
+
+	args->crsa_addr = svc_addr(rqstp);
+	p = read_buf(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+	args->crsa_target_highest_slotid = ntohl(*p++);
+	return 0;
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + len);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	xdr_encode_opaque(p, str, len);
+	return 0;
+}
+
+#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
+#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
+static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
+{
+	__be32 bm[2];
+	__be32 *p;
+
+	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
+	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
+	if (bm[1] != 0) {
+		p = xdr_reserve_space(xdr, 16);
+		if (unlikely(p == NULL))
+			return htonl(NFS4ERR_RESOURCE);
+		*p++ = htonl(2);
+		*p++ = bm[0];
+		*p++ = bm[1];
+	} else if (bm[0] != 0) {
+		p = xdr_reserve_space(xdr, 12);
+		if (unlikely(p == NULL))
+			return htonl(NFS4ERR_RESOURCE);
+		*p++ = htonl(1);
+		*p++ = bm[0];
+	} else {
+		p = xdr_reserve_space(xdr, 8);
+		if (unlikely(p == NULL))
+			return htonl(NFS4ERR_RESOURCE);
+		*p++ = htonl(0);
+	}
+	*savep = p;
+	return 0;
+}
+
+static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
+{
+	__be32 *p;
+
+	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
+		return 0;
+	p = xdr_reserve_space(xdr, 8);
+	if (unlikely(!p))
+		return htonl(NFS4ERR_RESOURCE);
+	p = xdr_encode_hyper(p, change);
+	return 0;
+}
+
+static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
+{
+	__be32 *p;
+
+	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
+		return 0;
+	p = xdr_reserve_space(xdr, 8);
+	if (unlikely(!p))
+		return htonl(NFS4ERR_RESOURCE);
+	p = xdr_encode_hyper(p, size);
+	return 0;
+}
+
+static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 12);
+	if (unlikely(!p))
+		return htonl(NFS4ERR_RESOURCE);
+	p = xdr_encode_hyper(p, time->tv_sec);
+	*p = htonl(time->tv_nsec);
+	return 0;
+}
+
+static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
+{
+	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
+		return 0;
+	return encode_attr_time(xdr,time);
+}
+
+static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
+{
+	if (!(bitmap[1] & FATTR4_WORD1_TIME_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;
+
+	hdr->status = xdr_reserve_space(xdr, 4);
+	if (unlikely(hdr->status == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	status = encode_string(xdr, hdr->taglen, hdr->tag);
+	if (unlikely(status != 0))
+		return status;
+	hdr->nops = xdr_reserve_space(xdr, 4);
+	if (unlikely(hdr->nops == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	return 0;
+}
+
+static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
+{
+	__be32 *p;
+	
+	p = xdr_reserve_space(xdr, 8);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE_HDR);
+	*p++ = htonl(op);
+	*p = res;
+	return 0;
+}
+
+static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
+{
+	__be32 *savep = NULL;
+	__be32 status = res->status;
+	
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_size(xdr, res->bitmap, res->size);
+	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);
+	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+static __be32 encode_sessionid(struct xdr_stream *xdr,
+				 const struct nfs4_sessionid *sid)
+{
+	__be32 *p;
+	int len = NFS4_MAX_SESSIONID_LEN;
+
+	p = xdr_reserve_space(xdr, len);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	memcpy(p, sid, len);
+	return 0;
+}
+
+static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       const struct cb_sequenceres *res)
+{
+	__be32 *p;
+	__be32 status = res->csr_status;
+
+	if (unlikely(status != 0))
+		goto out;
+
+	encode_sessionid(xdr, &res->csr_sessionid);
+
+	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	*p++ = htonl(res->csr_sequenceid);
+	*p++ = htonl(res->csr_slotid);
+	*p++ = htonl(res->csr_highestslotid);
+	*p++ = htonl(res->csr_target_highestslotid);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+static __be32
+preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	if (op_nr == OP_CB_SEQUENCE) {
+		if (nop != 0)
+			return htonl(NFS4ERR_SEQUENCE_POS);
+	} else {
+		if (nop == 0)
+			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
+	}
+
+	switch (op_nr) {
+	case OP_CB_GETATTR:
+	case OP_CB_RECALL:
+	case OP_CB_SEQUENCE:
+	case OP_CB_RECALL_ANY:
+	case OP_CB_RECALL_SLOT:
+	case OP_CB_LAYOUTRECALL:
+	case OP_CB_NOTIFY_DEVICEID:
+		*op = &callback_ops[op_nr];
+		break;
+
+	case OP_CB_NOTIFY:
+	case OP_CB_PUSH_DELEG:
+	case OP_CB_RECALLABLE_OBJ_AVAIL:
+	case OP_CB_WANTS_CANCELLED:
+	case OP_CB_NOTIFY_LOCK:
+		return htonl(NFS4ERR_NOTSUPP);
+
+	default:
+		return htonl(NFS4ERR_OP_ILLEGAL);
+	}
+
+	return htonl(NFS_OK);
+}
+
+static void nfs4_callback_free_slot(struct nfs4_session *session)
+{
+	struct nfs4_slot_table *tbl = &session->bc_slot_table;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	/*
+	 * Let the state manager know callback processing done.
+	 * A single slot, so highest used slotid is either 0 or -1
+	 */
+	tbl->highest_used_slotid = NFS4_NO_SLOT;
+	nfs4_slot_tbl_drain_complete(tbl);
+	spin_unlock(&tbl->slot_tbl_lock);
+}
+
+static void nfs4_cb_free_slot(struct cb_process_state *cps)
+{
+	if (cps->slotid != NFS4_NO_SLOT)
+		nfs4_callback_free_slot(cps->clp->cl_session);
+}
+
+#else /* CONFIG_NFS_V4_1 */
+
+static __be32
+preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+}
+
+static void nfs4_cb_free_slot(struct cb_process_state *cps)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+#ifdef CONFIG_NFS_V4_2
+static __be32
+preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
+	if (status != htonl(NFS4ERR_OP_ILLEGAL))
+		return status;
+
+	if (op_nr == OP_CB_OFFLOAD)
+		return htonl(NFS4ERR_NOTSUPP);
+	return htonl(NFS4ERR_OP_ILLEGAL);
+}
+#else /* CONFIG_NFS_V4_2 */
+static __be32
+preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+static __be32
+preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
+{
+	switch (op_nr) {
+	case OP_CB_GETATTR:
+	case OP_CB_RECALL:
+		*op = &callback_ops[op_nr];
+		break;
+	default:
+		return htonl(NFS4ERR_OP_ILLEGAL);
+	}
+
+	return htonl(NFS_OK);
+}
+
+static __be32 process_op(int nop, struct svc_rqst *rqstp,
+		struct xdr_stream *xdr_in, void *argp,
+		struct xdr_stream *xdr_out, void *resp,
+		struct cb_process_state *cps)
+{
+	struct callback_op *op = &callback_ops[0];
+	unsigned int op_nr;
+	__be32 status;
+	long maxlen;
+	__be32 res;
+
+	dprintk("%s: start\n", __func__);
+	status = decode_op_hdr(xdr_in, &op_nr);
+	if (unlikely(status))
+		return status;
+
+	dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
+		__func__, cps->minorversion, nop, op_nr);
+
+	switch (cps->minorversion) {
+	case 0:
+		status = preprocess_nfs4_op(op_nr, &op);
+		break;
+	case 1:
+		status = preprocess_nfs41_op(nop, op_nr, &op);
+		break;
+	case 2:
+		status = preprocess_nfs42_op(nop, op_nr, &op);
+		break;
+	default:
+		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+	}
+
+	if (status == htonl(NFS4ERR_OP_ILLEGAL))
+		op_nr = OP_CB_ILLEGAL;
+	if (status)
+		goto encode_hdr;
+
+	if (cps->drc_status) {
+		status = cps->drc_status;
+		goto encode_hdr;
+	}
+
+	maxlen = xdr_out->end - xdr_out->p;
+	if (maxlen > 0 && maxlen < PAGE_SIZE) {
+		status = op->decode_args(rqstp, xdr_in, argp);
+		if (likely(status == 0))
+			status = op->process_op(argp, resp, cps);
+	} else
+		status = htonl(NFS4ERR_RESOURCE);
+
+encode_hdr:
+	res = encode_op_hdr(xdr_out, op_nr, status);
+	if (unlikely(res))
+		return res;
+	if (op->encode_res != NULL && status == 0)
+		status = op->encode_res(rqstp, xdr_out, resp);
+	dprintk("%s: done, status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+/*
+ * Decode, process and encode a COMPOUND
+ */
+static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
+{
+	struct cb_compound_hdr_arg hdr_arg = { 0 };
+	struct cb_compound_hdr_res hdr_res = { NULL };
+	struct xdr_stream xdr_in, xdr_out;
+	__be32 *p, status;
+	struct cb_process_state cps = {
+		.drc_status = 0,
+		.clp = NULL,
+		.slotid = NFS4_NO_SLOT,
+		.net = SVC_NET(rqstp),
+	};
+	unsigned int nops = 0;
+
+	dprintk("%s: start\n", __func__);
+
+	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
+
+	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
+	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
+
+	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
+	if (status == __constant_htonl(NFS4ERR_RESOURCE))
+		return rpc_garbage_args;
+
+	if (hdr_arg.minorversion == 0) {
+		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
+		if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
+			return rpc_drop_reply;
+	}
+
+	cps.minorversion = hdr_arg.minorversion;
+	hdr_res.taglen = hdr_arg.taglen;
+	hdr_res.tag = hdr_arg.tag;
+	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
+		return rpc_system_err;
+
+	while (status == 0 && nops != hdr_arg.nops) {
+		status = process_op(nops, rqstp, &xdr_in,
+				    argp, &xdr_out, resp, &cps);
+		nops++;
+	}
+
+	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
+	* resource error in cb_compound status without returning op */
+	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
+		status = htonl(NFS4ERR_RESOURCE);
+		nops--;
+	}
+
+	*hdr_res.status = status;
+	*hdr_res.nops = htonl(nops);
+	nfs4_cb_free_slot(&cps);
+	nfs_put_client(cps.clp);
+	dprintk("%s: done, status = %u\n", __func__, ntohl(status));
+	return rpc_success;
+}
+
+/*
+ * Define NFS4 callback COMPOUND ops.
+ */
+static struct callback_op callback_ops[] = {
+	[0] = {
+		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
+	},
+	[OP_CB_GETATTR] = {
+		.process_op = (callback_process_op_t)nfs4_callback_getattr,
+		.decode_args = (callback_decode_arg_t)decode_getattr_args,
+		.encode_res = (callback_encode_res_t)encode_getattr_res,
+		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
+	},
+	[OP_CB_RECALL] = {
+		.process_op = (callback_process_op_t)nfs4_callback_recall,
+		.decode_args = (callback_decode_arg_t)decode_recall_args,
+		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
+	},
+#if defined(CONFIG_NFS_V4_1)
+	[OP_CB_LAYOUTRECALL] = {
+		.process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
+		.decode_args =
+			(callback_decode_arg_t)decode_layoutrecall_args,
+		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
+	},
+	[OP_CB_NOTIFY_DEVICEID] = {
+		.process_op = (callback_process_op_t)nfs4_callback_devicenotify,
+		.decode_args =
+			(callback_decode_arg_t)decode_devicenotify_args,
+		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
+	},
+	[OP_CB_SEQUENCE] = {
+		.process_op = (callback_process_op_t)nfs4_callback_sequence,
+		.decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
+		.encode_res = (callback_encode_res_t)encode_cb_sequence_res,
+		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
+	},
+	[OP_CB_RECALL_ANY] = {
+		.process_op = (callback_process_op_t)nfs4_callback_recallany,
+		.decode_args = (callback_decode_arg_t)decode_recallany_args,
+		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
+	},
+	[OP_CB_RECALL_SLOT] = {
+		.process_op = (callback_process_op_t)nfs4_callback_recallslot,
+		.decode_args = (callback_decode_arg_t)decode_recallslot_args,
+		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
+	},
+#endif /* CONFIG_NFS_V4_1 */
+};
+
+/*
+ * Define NFS4 callback procedures
+ */
+static struct svc_procedure nfs4_callback_procedures1[] = {
+	[CB_NULL] = {
+		.pc_func = nfs4_callback_null,
+		.pc_decode = (kxdrproc_t)nfs4_decode_void,
+		.pc_encode = (kxdrproc_t)nfs4_encode_void,
+		.pc_xdrressize = 1,
+	},
+	[CB_COMPOUND] = {
+		.pc_func = nfs4_callback_compound,
+		.pc_encode = (kxdrproc_t)nfs4_encode_void,
+		.pc_argsize = 256,
+		.pc_ressize = 256,
+		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
+	}
+};
+
+struct svc_version nfs4_callback_version1 = {
+	.vs_vers = 1,
+	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
+	.vs_proc = nfs4_callback_procedures1,
+	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
+	.vs_dispatch = NULL,
+	.vs_hidden = 1,
+};
+
+struct svc_version nfs4_callback_version4 = {
+	.vs_vers = 4,
+	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
+	.vs_proc = nfs4_callback_procedures1,
+	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
+	.vs_dispatch = NULL,
+	.vs_hidden = 1,
+};