Merge tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Olga added support for the NFSv4.2 asynchronous copy protocol. We
  already supported COPY, by copying a limited amount of data and then
  returning a short result, letting the client resend. The asynchronous
  protocol should offer better performance at the expense of some
  complexity.

  The other highlight is Trond's work to convert the duplicate reply
  cache to a red-black tree, and to move it and some other server caches
  to RCU. (Previously these have meant taking global spinlocks on every
  RPC)

  Otherwise, some RDMA work and miscellaneous bugfixes"

* tag 'nfsd-4.20' of git://linux-nfs.org/~bfields/linux: (30 commits)
  lockd: fix access beyond unterminated strings in prints
  nfsd: Fix an Oops in free_session()
  nfsd: correctly decrement odstate refcount in error path
  svcrdma: Increase the default connection credit limit
  svcrdma: Remove try_module_get from backchannel
  svcrdma: Remove ->release_rqst call in bc reply handler
  svcrdma: Reduce max_send_sges
  nfsd: fix fall-through annotations
  knfsd: Improve lookup performance in the duplicate reply cache using an rbtree
  knfsd: Further simplify the cache lookup
  knfsd: Simplify NFS duplicate replay cache
  knfsd: Remove dead code from nfsd_cache_lookup
  SUNRPC: Simplify TCP receive code
  SUNRPC: Replace the cache_detail->hash_lock with a regular spinlock
  SUNRPC: Remove non-RCU protected lookup
  NFS: Fix up a typo in nfs_dns_ent_put
  NFS: Lockless DNS lookups
  knfsd: Lockless lookup of NFSv4 identities.
  SUNRPC: Lockless server RPCSEC_GSS context lookup
  knfsd: Allow lockless lookups of the exports
  ...

Documentation/filesystems/nfs/rpc-cache.txt

@@ -84,7 +84,7 @@ Creating a Cache
 		A message from user space has arrived to fill out a
 		cache entry.  It is in 'buf' of length 'len'.
 		cache_parse should parse this, find the item in the
-		cache with sunrpc_cache_lookup, and update the item
+		cache with sunrpc_cache_lookup_rcu, and update the item
 		with sunrpc_cache_update.
 
 
@@ -95,7 +95,7 @@ Creating a Cache
 Using a cache
 -------------
 
-To find a value in a cache, call sunrpc_cache_lookup passing a pointer
+To find a value in a cache, call sunrpc_cache_lookup_rcu passing a pointer
 to the cache_head in a sample item with the 'key' fields filled in.
 This will be passed to ->match to identify the target entry.  If no
 entry is found, a new entry will be create, added to the cache, and
@@ -116,7 +116,7 @@ item does become valid, the deferred copy of the request will be
 revisited (->revisit).  It is expected that this method will
 reschedule the request for processing.
 
-The value returned by sunrpc_cache_lookup can also be passed to
+The value returned by sunrpc_cache_lookup_rcu can also be passed to
 sunrpc_cache_update to set the content for the item.  A second item is
 passed which should hold the content.  If the item found by _lookup
 has valid data, then it is discarded and a new item is created.  This

fs/lockd/host.c

@@ -341,7 +341,7 @@ struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 	};
 	struct lockd_net *ln = net_generic(net, lockd_net_id);
 
-	dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,
+	dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__,
 			(int)hostname_len, hostname, rqstp->rq_vers,
 			(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp"));
 

fs/nfs/dns_resolve.c

@@ -65,6 +65,7 @@ struct nfs_dns_ent {
 
 	struct sockaddr_storage addr;
 	size_t addrlen;
+	struct rcu_head rcu_head;
 };
 
 
@@ -101,15 +102,23 @@ static void nfs_dns_ent_init(struct cache_head *cnew,
 	}
 }
 
-static void nfs_dns_ent_put(struct kref *ref)
+static void nfs_dns_ent_free_rcu(struct rcu_head *head)
 {
 	struct nfs_dns_ent *item;
 
-	item = container_of(ref, struct nfs_dns_ent, h.ref);
+	item = container_of(head, struct nfs_dns_ent, rcu_head);
 	kfree(item->hostname);
 	kfree(item);
 }
 
+static void nfs_dns_ent_put(struct kref *ref)
+{
+	struct nfs_dns_ent *item;
+
+	item = container_of(ref, struct nfs_dns_ent, h.ref);
+	call_rcu(&item->rcu_head, nfs_dns_ent_free_rcu);
+}
+
 static struct cache_head *nfs_dns_ent_alloc(void)
 {
 	struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL);
@@ -195,7 +204,7 @@ static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd,
 {
 	struct cache_head *ch;
 
-	ch = sunrpc_cache_lookup(cd,
+	ch = sunrpc_cache_lookup_rcu(cd,
 			&key->h,
 			nfs_dns_hash(key));
 	if (!ch)

fs/nfsd/cache.h

@@ -19,18 +19,22 @@
  * is much larger than a sockaddr_in6.
  */
 struct svc_cacherep {
-	struct list_head	c_lru;
+	struct {
+		/* Keep often-read xid, csum in the same cache line: */
+		__be32			k_xid;
+		__wsum			k_csum;
+		u32			k_proc;
+		u32			k_prot;
+		u32			k_vers;
+		unsigned int		k_len;
+		struct sockaddr_in6	k_addr;
+	} c_key;
 
+	struct rb_node		c_node;
+	struct list_head	c_lru;
 	unsigned char		c_state,	/* unused, inprog, done */
 				c_type,		/* status, buffer */
 				c_secure : 1;	/* req came from port < 1024 */
-	struct sockaddr_in6	c_addr;
-	__be32			c_xid;
-	u32			c_prot;
-	u32			c_proc;
-	u32			c_vers;
-	unsigned int		c_len;
-	__wsum			c_csum;
 	unsigned long		c_timestamp;
 	union {
 		struct kvec	u_vec;

fs/nfsd/export.c

@@ -46,7 +46,7 @@ static void expkey_put(struct kref *ref)
 	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
 		path_put(&key->ek_path);
 	auth_domain_put(key->ek_client);
-	kfree(key);
+	kfree_rcu(key, ek_rcu);
 }
 
 static void expkey_request(struct cache_detail *cd,
@@ -265,7 +265,7 @@ svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
 	struct cache_head *ch;
 	int hash = svc_expkey_hash(item);
 
-	ch = sunrpc_cache_lookup(cd, &item->h, hash);
+	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
 	if (ch)
 		return container_of(ch, struct svc_expkey, h);
 	else
@@ -314,7 +314,7 @@ static void svc_export_put(struct kref *ref)
 	auth_domain_put(exp->ex_client);
 	nfsd4_fslocs_free(&exp->ex_fslocs);
 	kfree(exp->ex_uuid);
-	kfree(exp);
+	kfree_rcu(exp, ex_rcu);
 }
 
 static void svc_export_request(struct cache_detail *cd,
@@ -780,7 +780,7 @@ svc_export_lookup(struct svc_export *exp)
 	struct cache_head *ch;
 	int hash = svc_export_hash(exp);
 
-	ch = sunrpc_cache_lookup(exp->cd, &exp->h, hash);
+	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
 	if (ch)
 		return container_of(ch, struct svc_export, h);
 	else
@@ -1216,9 +1216,9 @@ static int e_show(struct seq_file *m, void *p)
 }
 
 const struct seq_operations nfs_exports_op = {
-	.start	= cache_seq_start,
-	.next	= cache_seq_next,
-	.stop	= cache_seq_stop,
+	.start	= cache_seq_start_rcu,
+	.next	= cache_seq_next_rcu,
+	.stop	= cache_seq_stop_rcu,
 	.show	= e_show,
 };
 

fs/nfsd/export.h

@@ -61,6 +61,7 @@ struct svc_export {
 	u32			ex_layout_types;
 	struct nfsd4_deviceid_map *ex_devid_map;
 	struct cache_detail	*cd;
+	struct rcu_head		ex_rcu;
 };
 
 /* an "export key" (expkey) maps a filehandlefragement to an
@@ -75,6 +76,7 @@ struct svc_expkey {
 	u32			ek_fsid[6];
 
 	struct path		ek_path;
+	struct rcu_head		ek_rcu;
 };
 
 #define EX_ISSYNC(exp)		(!((exp)->ex_flags & NFSEXP_ASYNC))

fs/nfsd/netns.h

@@ -123,6 +123,14 @@ struct nfsd_net {
 
 	wait_queue_head_t ntf_wq;
 	atomic_t ntf_refcnt;
+
+	/*
+	 * clientid and stateid data for construction of net unique COPY
+	 * stateids.
+	 */
+	u32		s2s_cp_cl_id;
+	struct idr	s2s_cp_stateids;
+	spinlock_t	s2s_cp_lock;
 };
 
 /* Simple check to find out if a given net was properly initialized */

fs/nfsd/nfs4callback.c

@@ -39,6 +39,7 @@
 #include "state.h"
 #include "netns.h"
 #include "xdr4cb.h"
+#include "xdr4.h"
 
 #define NFSDDBG_FACILITY                NFSDDBG_PROC
 
@@ -105,6 +106,7 @@ enum nfs_cb_opnum4 {
 	OP_CB_WANTS_CANCELLED		= 12,
 	OP_CB_NOTIFY_LOCK		= 13,
 	OP_CB_NOTIFY_DEVICEID		= 14,
+	OP_CB_OFFLOAD			= 15,
 	OP_CB_ILLEGAL			= 10044
 };
 
@@ -682,6 +684,101 @@ static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
 	return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
 }
 
+/*
+ * struct write_response4 {
+ *	stateid4	wr_callback_id<1>;
+ *	length4		wr_count;
+ *	stable_how4	wr_committed;
+ *	verifier4	wr_writeverf;
+ * };
+ * union offload_info4 switch (nfsstat4 coa_status) {
+ *	case NFS4_OK:
+ *		write_response4	coa_resok4;
+ *	default:
+ *	length4		coa_bytes_copied;
+ * };
+ * struct CB_OFFLOAD4args {
+ *	nfs_fh4		coa_fh;
+ *	stateid4	coa_stateid;
+ *	offload_info4	coa_offload_info;
+ * };
+ */
+static void encode_offload_info4(struct xdr_stream *xdr,
+				 __be32 nfserr,
+				 const struct nfsd4_copy *cp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = nfserr;
+	if (!nfserr) {
+		p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
+		p = xdr_encode_empty_array(p);
+		p = xdr_encode_hyper(p, cp->cp_res.wr_bytes_written);
+		*p++ = cpu_to_be32(cp->cp_res.wr_stable_how);
+		p = xdr_encode_opaque_fixed(p, cp->cp_res.wr_verifier.data,
+					    NFS4_VERIFIER_SIZE);
+	} else {
+		p = xdr_reserve_space(xdr, 8);
+		/* We always return success if bytes were written */
+		p = xdr_encode_hyper(p, 0);
+	}
+}
+
+static void encode_cb_offload4args(struct xdr_stream *xdr,
+				   __be32 nfserr,
+				   const struct knfsd_fh *fh,
+				   const struct nfsd4_copy *cp,
+				   struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = cpu_to_be32(OP_CB_OFFLOAD);
+	encode_nfs_fh4(xdr, fh);
+	encode_stateid4(xdr, &cp->cp_res.cb_stateid);
+	encode_offload_info4(xdr, nfserr, cp);
+
+	hdr->nops++;
+}
+
+static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfsd4_copy *cp =
+		container_of(cb, struct nfsd4_copy, cp_cb);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_offload4args(xdr, cp->nfserr, &cp->fh, cp, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	if (cb) {
+		status = decode_cb_sequence4res(xdr, cb);
+		if (unlikely(status || cb->cb_seq_status))
+			return status;
+	}
+	return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
+}
 /*
  * RPC procedure tables
  */
@@ -703,6 +800,7 @@ static const struct rpc_procinfo nfs4_cb_procedures[] = {
 	PROC(CB_LAYOUT,	COMPOUND,	cb_layout,	cb_layout),
 #endif
 	PROC(CB_NOTIFY_LOCK,	COMPOUND,	cb_notify_lock,	cb_notify_lock),
+	PROC(CB_OFFLOAD,	COMPOUND,	cb_offload,	cb_offload),
 };
 
 static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];

fs/nfsd/nfs4idmap.c

@@ -65,6 +65,7 @@ struct ent {
 	u32               id;
 	char              name[IDMAP_NAMESZ];
 	char              authname[IDMAP_NAMESZ];
+	struct rcu_head	  rcu_head;
 };
 
 /* Common entry handling */
@@ -89,7 +90,7 @@ static void
 ent_put(struct kref *ref)
 {
 	struct ent *map = container_of(ref, struct ent, h.ref);
-	kfree(map);
+	kfree_rcu(map, rcu_head);
 }
 
 static struct cache_head *
@@ -264,8 +265,8 @@ idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
 static struct ent *
 idtoname_lookup(struct cache_detail *cd, struct ent *item)
 {
-	struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
-						    idtoname_hash(item));
+	struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+							idtoname_hash(item));
 	if (ch)
 		return container_of(ch, struct ent, h);
 	else
@@ -422,8 +423,8 @@ nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
 static struct ent *
 nametoid_lookup(struct cache_detail *cd, struct ent *item)
 {
-	struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
-						    nametoid_hash(item));
+	struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+							nametoid_hash(item));
 	if (ch)
 		return container_of(ch, struct ent, h);
 	else

fs/nfsd/nfs4proc.c

@@ -36,6 +36,7 @@
 #include <linux/file.h>
 #include <linux/falloc.h>
 #include <linux/slab.h>
+#include <linux/kthread.h>
 
 #include "idmap.h"
 #include "cache.h"
@@ -1089,36 +1090,254 @@ nfsd4_clone(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	return status;
 }
 
+void nfs4_put_copy(struct nfsd4_copy *copy)
+{
+	if (!refcount_dec_and_test(&copy->refcount))
+		return;
+	kfree(copy);
+}
+
+static bool
+check_and_set_stop_copy(struct nfsd4_copy *copy)
+{
+	bool value;
+
+	spin_lock(&copy->cp_clp->async_lock);
+	value = copy->stopped;
+	if (!copy->stopped)
+		copy->stopped = true;
+	spin_unlock(&copy->cp_clp->async_lock);
+	return value;
+}
+
+static void nfsd4_stop_copy(struct nfsd4_copy *copy)
+{
+	/* only 1 thread should stop the copy */
+	if (!check_and_set_stop_copy(copy))
+		kthread_stop(copy->copy_task);
+	nfs4_put_copy(copy);
+}
+
+static struct nfsd4_copy *nfsd4_get_copy(struct nfs4_client *clp)
+{
+	struct nfsd4_copy *copy = NULL;
+
+	spin_lock(&clp->async_lock);
+	if (!list_empty(&clp->async_copies)) {
+		copy = list_first_entry(&clp->async_copies, struct nfsd4_copy,
+					copies);
+		refcount_inc(&copy->refcount);
+	}
+	spin_unlock(&clp->async_lock);
+	return copy;
+}
+
+void nfsd4_shutdown_copy(struct nfs4_client *clp)
+{
+	struct nfsd4_copy *copy;
+
+	while ((copy = nfsd4_get_copy(clp)) != NULL)
+		nfsd4_stop_copy(copy);
+}
+
+static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
+{
+	struct nfsd4_copy *copy = container_of(cb, struct nfsd4_copy, cp_cb);
+
+	nfs4_put_copy(copy);
+}
+
+static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
+				 struct rpc_task *task)
+{
+	return 1;
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_offload_ops = {
+	.release = nfsd4_cb_offload_release,
+	.done = nfsd4_cb_offload_done
+};
+
+static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync)
+{
+	copy->cp_res.wr_stable_how = NFS_UNSTABLE;
+	copy->cp_synchronous = sync;
+	gen_boot_verifier(&copy->cp_res.wr_verifier, copy->cp_clp->net);
+}
+
+static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy)
+{
+	ssize_t bytes_copied = 0;
+	size_t bytes_total = copy->cp_count;
+	u64 src_pos = copy->cp_src_pos;
+	u64 dst_pos = copy->cp_dst_pos;
+
+	do {
+		if (kthread_should_stop())
+			break;
+		bytes_copied = nfsd_copy_file_range(copy->file_src, src_pos,
+				copy->file_dst, dst_pos, bytes_total);
+		if (bytes_copied <= 0)
+			break;
+		bytes_total -= bytes_copied;
+		copy->cp_res.wr_bytes_written += bytes_copied;
+		src_pos += bytes_copied;
+		dst_pos += bytes_copied;
+	} while (bytes_total > 0 && !copy->cp_synchronous);
+	return bytes_copied;
+}
+
+static __be32 nfsd4_do_copy(struct nfsd4_copy *copy, bool sync)
+{
+	__be32 status;
+	ssize_t bytes;
+
+	bytes = _nfsd_copy_file_range(copy);
+	/* for async copy, we ignore the error, client can always retry
+	 * to get the error
+	 */
+	if (bytes < 0 && !copy->cp_res.wr_bytes_written)
+		status = nfserrno(bytes);
+	else {
+		nfsd4_init_copy_res(copy, sync);
+		status = nfs_ok;
+	}
+
+	fput(copy->file_src);
+	fput(copy->file_dst);
+	return status;
+}
+
+static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
+{
+	dst->cp_src_pos = src->cp_src_pos;
+	dst->cp_dst_pos = src->cp_dst_pos;
+	dst->cp_count = src->cp_count;
+	dst->cp_synchronous = src->cp_synchronous;
+	memcpy(&dst->cp_res, &src->cp_res, sizeof(src->cp_res));
+	memcpy(&dst->fh, &src->fh, sizeof(src->fh));
+	dst->cp_clp = src->cp_clp;
+	dst->file_dst = get_file(src->file_dst);
+	dst->file_src = get_file(src->file_src);
+	memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src->cp_stateid));
+}
+
+static void cleanup_async_copy(struct nfsd4_copy *copy)
+{
+	nfs4_free_cp_state(copy);
+	fput(copy->file_dst);
+	fput(copy->file_src);
+	spin_lock(&copy->cp_clp->async_lock);
+	list_del(&copy->copies);
+	spin_unlock(&copy->cp_clp->async_lock);
+	nfs4_put_copy(copy);
+}
+
+static int nfsd4_do_async_copy(void *data)
+{
+	struct nfsd4_copy *copy = (struct nfsd4_copy *)data;
+	struct nfsd4_copy *cb_copy;
+
+	copy->nfserr = nfsd4_do_copy(copy, 0);
+	cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
+	if (!cb_copy)
+		goto out;
+	memcpy(&cb_copy->cp_res, &copy->cp_res, sizeof(copy->cp_res));
+	cb_copy->cp_clp = copy->cp_clp;
+	cb_copy->nfserr = copy->nfserr;
+	memcpy(&cb_copy->fh, &copy->fh, sizeof(copy->fh));
+	nfsd4_init_cb(&cb_copy->cp_cb, cb_copy->cp_clp,
+			&nfsd4_cb_offload_ops, NFSPROC4_CLNT_CB_OFFLOAD);
+	nfsd4_run_cb(&cb_copy->cp_cb);
+out:
+	cleanup_async_copy(copy);
+	return 0;
+}
+
 static __be32
 nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		union nfsd4_op_u *u)
 {
 	struct nfsd4_copy *copy = &u->copy;
-	struct file *src, *dst;
 	__be32 status;
-	ssize_t bytes;
+	struct nfsd4_copy *async_copy = NULL;
 
-	status = nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid, &src,
-				   &copy->cp_dst_stateid, &dst);
+	status = nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid,
+				   &copy->file_src, &copy->cp_dst_stateid,
+				   &copy->file_dst);
 	if (status)
 		goto out;
 
-	bytes = nfsd_copy_file_range(src, copy->cp_src_pos,
-			dst, copy->cp_dst_pos, copy->cp_count);
+	copy->cp_clp = cstate->clp;
+	memcpy(&copy->fh, &cstate->current_fh.fh_handle,
+		sizeof(struct knfsd_fh));
+	if (!copy->cp_synchronous) {
+		struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 
-	if (bytes < 0)
-		status = nfserrno(bytes);
-	else {
-		copy->cp_res.wr_bytes_written = bytes;
-		copy->cp_res.wr_stable_how = NFS_UNSTABLE;
-		copy->cp_synchronous = 1;
-		gen_boot_verifier(&copy->cp_res.wr_verifier, SVC_NET(rqstp));
+		status = nfserrno(-ENOMEM);
+		async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
+		if (!async_copy)
+			goto out;
+		if (!nfs4_init_cp_state(nn, copy)) {
+			kfree(async_copy);
+			goto out;
+		}
+		refcount_set(&async_copy->refcount, 1);
+		memcpy(&copy->cp_res.cb_stateid, &copy->cp_stateid,
+			sizeof(copy->cp_stateid));
+		dup_copy_fields(copy, async_copy);
+		async_copy->copy_task = kthread_create(nfsd4_do_async_copy,
+				async_copy, "%s", "copy thread");
+		if (IS_ERR(async_copy->copy_task))
+			goto out_err;
+		spin_lock(&async_copy->cp_clp->async_lock);
+		list_add(&async_copy->copies,
+				&async_copy->cp_clp->async_copies);
+		spin_unlock(&async_copy->cp_clp->async_lock);
+		wake_up_process(async_copy->copy_task);
 		status = nfs_ok;
+	} else
+		status = nfsd4_do_copy(copy, 1);
+out:
+	return status;
+out_err:
+	cleanup_async_copy(async_copy);
+	goto out;
+}
+
+struct nfsd4_copy *
+find_async_copy(struct nfs4_client *clp, stateid_t *stateid)
+{
+	struct nfsd4_copy *copy;
+
+	spin_lock(&clp->async_lock);
+	list_for_each_entry(copy, &clp->async_copies, copies) {
+		if (memcmp(&copy->cp_stateid, stateid, NFS4_STATEID_SIZE))
+			continue;
+		refcount_inc(&copy->refcount);
+		spin_unlock(&clp->async_lock);
+		return copy;
 	}
+	spin_unlock(&clp->async_lock);
+	return NULL;
+}
+
+static __be32
+nfsd4_offload_cancel(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	__be32 status = 0;
+	struct nfsd4_copy *copy;
+	struct nfs4_client *clp = cstate->clp;
+
+	copy = find_async_copy(clp, &os->stateid);
+	if (copy)
+		nfsd4_stop_copy(copy);
+	else
+		status = nfserr_bad_stateid;
 
-	fput(src);
-	fput(dst);
-out:
 	return status;
 }
 
@@ -1144,6 +1363,25 @@ nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	fput(file);
 	return status;
 }
+static __be32
+nfsd4_offload_status(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	__be32 status = 0;
+	struct nfsd4_copy *copy;
+	struct nfs4_client *clp = cstate->clp;
+
+	copy = find_async_copy(clp, &os->stateid);
+	if (copy) {
+		os->count = copy->cp_res.wr_bytes_written;
+		nfs4_put_copy(copy);
+	} else
+		status = nfserr_bad_stateid;
+
+	return status;
+}
 
 static __be32
 nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
@@ -2047,6 +2285,14 @@ static inline u32 nfsd4_copy_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 		1 /* cr_synchronous */) * sizeof(__be32);
 }
 
+static inline u32 nfsd4_offload_status_rsize(struct svc_rqst *rqstp,
+					     struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		2 /* osr_count */ +
+		1 /* osr_complete<1> optional 0 for now */) * sizeof(__be32);
+}
+
 #ifdef CONFIG_NFSD_PNFS
 static inline u32 nfsd4_getdeviceinfo_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
@@ -2460,6 +2706,17 @@ static const struct nfsd4_operation nfsd4_ops[] = {
 		.op_name = "OP_SEEK",
 		.op_rsize_bop = nfsd4_seek_rsize,
 	},
+	[OP_OFFLOAD_STATUS] = {
+		.op_func = nfsd4_offload_status,
+		.op_name = "OP_OFFLOAD_STATUS",
+		.op_rsize_bop = nfsd4_offload_status_rsize,
+	},
+	[OP_OFFLOAD_CANCEL] = {
+		.op_func = nfsd4_offload_cancel,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OFFLOAD_CANCEL",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
 };
 
 /**

fs/nfsd/nfs4state.c

@@ -713,6 +713,36 @@ struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *sla
 	return NULL;
 }
 
+/*
+ * Create a unique stateid_t to represent each COPY.
+ */
+int nfs4_init_cp_state(struct nfsd_net *nn, struct nfsd4_copy *copy)
+{
+	int new_id;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&nn->s2s_cp_lock);
+	new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, copy, 0, 0, GFP_NOWAIT);
+	spin_unlock(&nn->s2s_cp_lock);
+	idr_preload_end();
+	if (new_id < 0)
+		return 0;
+	copy->cp_stateid.si_opaque.so_id = new_id;
+	copy->cp_stateid.si_opaque.so_clid.cl_boot = nn->boot_time;
+	copy->cp_stateid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
+	return 1;
+}
+
+void nfs4_free_cp_state(struct nfsd4_copy *copy)
+{
+	struct nfsd_net *nn;
+
+	nn = net_generic(copy->cp_clp->net, nfsd_net_id);
+	spin_lock(&nn->s2s_cp_lock);
+	idr_remove(&nn->s2s_cp_stateids, copy->cp_stateid.si_opaque.so_id);
+	spin_unlock(&nn->s2s_cp_lock);
+}
+
 static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp)
 {
 	struct nfs4_stid *stid;
@@ -1827,6 +1857,8 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 #ifdef CONFIG_NFSD_PNFS
 	INIT_LIST_HEAD(&clp->cl_lo_states);
 #endif
+	INIT_LIST_HEAD(&clp->async_copies);
+	spin_lock_init(&clp->async_lock);
 	spin_lock_init(&clp->cl_lock);
 	rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
 	return clp;
@@ -1942,6 +1974,7 @@ __destroy_client(struct nfs4_client *clp)
 		}
 	}
 	nfsd4_return_all_client_layouts(clp);
+	nfsd4_shutdown_copy(clp);
 	nfsd4_shutdown_callback(clp);
 	if (clp->cl_cb_conn.cb_xprt)
 		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
@@ -2475,7 +2508,8 @@ static bool client_has_state(struct nfs4_client *clp)
 		|| !list_empty(&clp->cl_lo_states)
 #endif
 		|| !list_empty(&clp->cl_delegations)
-		|| !list_empty(&clp->cl_sessions);
+		|| !list_empty(&clp->cl_sessions)
+		|| !list_empty(&clp->async_copies);
 }
 
 __be32
@@ -4364,7 +4398,7 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
 
 	fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
 	if (!fl)
-		goto out_stid;
+		goto out_clnt_odstate;
 
 	status = vfs_setlease(fp->fi_deleg_file, fl->fl_type, &fl, NULL);
 	if (fl)
@@ -4389,7 +4423,6 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
 	vfs_setlease(fp->fi_deleg_file, F_UNLCK, NULL, (void **)&dp);
 out_clnt_odstate:
 	put_clnt_odstate(dp->dl_clnt_odstate);
-out_stid:
 	nfs4_put_stid(&dp->dl_stid);
 out_delegees:
 	put_deleg_file(fp);
@@ -7161,6 +7194,8 @@ static int nfs4_state_create_net(struct net *net)
 	INIT_LIST_HEAD(&nn->close_lru);
 	INIT_LIST_HEAD(&nn->del_recall_lru);
 	spin_lock_init(&nn->client_lock);
+	spin_lock_init(&nn->s2s_cp_lock);
+	idr_init(&nn->s2s_cp_stateids);
 
 	spin_lock_init(&nn->blocked_locks_lock);
 	INIT_LIST_HEAD(&nn->blocked_locks_lru);

fs/nfsd/nfs4xdr.c

@@ -1767,6 +1767,13 @@ nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
 	DECODE_TAIL;
 }
 
+static __be32
+nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
+			    struct nfsd4_offload_status *os)
+{
+	return nfsd4_decode_stateid(argp, &os->stateid);
+}
+
 static __be32
 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
 {
@@ -1873,8 +1880,8 @@ static const nfsd4_dec nfsd4_dec_ops[] = {
 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_notsupp,
-	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_offload_status,
+	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_offload_status,
 	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_notsupp,
 	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
 	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
@@ -4224,15 +4231,27 @@ nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
 #endif /* CONFIG_NFSD_PNFS */
 
 static __be32
-nfsd42_encode_write_res(struct nfsd4_compoundres *resp, struct nfsd42_write_res *write)
+nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
+		struct nfsd42_write_res *write, bool sync)
 {
 	__be32 *p;
+	p = xdr_reserve_space(&resp->xdr, 4);
+	if (!p)
+		return nfserr_resource;
 
-	p = xdr_reserve_space(&resp->xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
+	if (sync)
+		*p++ = cpu_to_be32(0);
+	else {
+		__be32 nfserr;
+		*p++ = cpu_to_be32(1);
+		nfserr = nfsd4_encode_stateid(&resp->xdr, &write->cb_stateid);
+		if (nfserr)
+			return nfserr;
+	}
+	p = xdr_reserve_space(&resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
 	if (!p)
 		return nfserr_resource;
 
-	*p++ = cpu_to_be32(0);
 	p = xdr_encode_hyper(p, write->wr_bytes_written);
 	*p++ = cpu_to_be32(write->wr_stable_how);
 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
@@ -4246,7 +4265,8 @@ nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
 {
 	__be32 *p;
 
-	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res);
+	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
+			copy->cp_synchronous);
 	if (nfserr)
 		return nfserr;
 
@@ -4256,6 +4276,22 @@ nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
 	return 0;
 }
 
+static __be32
+nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    struct nfsd4_offload_status *os)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8 + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_hyper(p, os->count);
+	*p++ = cpu_to_be32(0);
+
+	return nfserr;
+}
+
 static __be32
 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
 		  struct nfsd4_seek *seek)
@@ -4359,7 +4395,7 @@ static const nfsd4_enc nfsd4_enc_ops[] = {
 	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
 	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
 	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
-	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_offload_status,
 	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_noop,
 	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
 	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,

fs/nfsd/nfscache.c

@@ -30,6 +30,7 @@
 #define TARGET_BUCKET_SIZE	64
 
 struct nfsd_drc_bucket {
+	struct rb_root rb_head;
 	struct list_head lru_head;
 	spinlock_t cache_lock;
 };
@@ -121,7 +122,7 @@ nfsd_cache_hash(__be32 xid)
 }
 
 static struct svc_cacherep *
-nfsd_reply_cache_alloc(void)
+nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum)
 {
 	struct svc_cacherep	*rp;
 
@@ -129,21 +130,35 @@ nfsd_reply_cache_alloc(void)
 	if (rp) {
 		rp->c_state = RC_UNUSED;
 		rp->c_type = RC_NOCACHE;
+		RB_CLEAR_NODE(&rp->c_node);
 		INIT_LIST_HEAD(&rp->c_lru);
+
+		memset(&rp->c_key, 0, sizeof(rp->c_key));
+		rp->c_key.k_xid = rqstp->rq_xid;
+		rp->c_key.k_proc = rqstp->rq_proc;
+		rpc_copy_addr((struct sockaddr *)&rp->c_key.k_addr, svc_addr(rqstp));
+		rpc_set_port((struct sockaddr *)&rp->c_key.k_addr, rpc_get_port(svc_addr(rqstp)));
+		rp->c_key.k_prot = rqstp->rq_prot;
+		rp->c_key.k_vers = rqstp->rq_vers;
+		rp->c_key.k_len = rqstp->rq_arg.len;
+		rp->c_key.k_csum = csum;
 	}
 	return rp;
 }
 
 static void
-nfsd_reply_cache_free_locked(struct svc_cacherep *rp)
+nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp)
 {
 	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
 		drc_mem_usage -= rp->c_replvec.iov_len;
 		kfree(rp->c_replvec.iov_base);
 	}
-	list_del(&rp->c_lru);
-	atomic_dec(&num_drc_entries);
-	drc_mem_usage -= sizeof(*rp);
+	if (rp->c_state != RC_UNUSED) {
+		rb_erase(&rp->c_node, &b->rb_head);
+		list_del(&rp->c_lru);
+		atomic_dec(&num_drc_entries);
+		drc_mem_usage -= sizeof(*rp);
+	}
 	kmem_cache_free(drc_slab, rp);
 }
 
@@ -151,7 +166,7 @@ static void
 nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct svc_cacherep *rp)
 {
 	spin_lock(&b->cache_lock);
-	nfsd_reply_cache_free_locked(rp);
+	nfsd_reply_cache_free_locked(b, rp);
 	spin_unlock(&b->cache_lock);
 }
 
@@ -207,7 +222,7 @@ void nfsd_reply_cache_shutdown(void)
 		struct list_head *head = &drc_hashtbl[i].lru_head;
 		while (!list_empty(head)) {
 			rp = list_first_entry(head, struct svc_cacherep, c_lru);
-			nfsd_reply_cache_free_locked(rp);
+			nfsd_reply_cache_free_locked(&drc_hashtbl[i], rp);
 		}
 	}
 
@@ -246,7 +261,7 @@ prune_bucket(struct nfsd_drc_bucket *b)
 		if (atomic_read(&num_drc_entries) <= max_drc_entries &&
 		    time_before(jiffies, rp->c_timestamp + RC_EXPIRE))
 			break;
-		nfsd_reply_cache_free_locked(rp);
+		nfsd_reply_cache_free_locked(b, rp);
 		freed++;
 	}
 	return freed;
@@ -318,51 +333,48 @@ nfsd_cache_csum(struct svc_rqst *rqstp)
 	return csum;
 }
 
-static bool
-nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp)
+static int
+nfsd_cache_key_cmp(const struct svc_cacherep *key, const struct svc_cacherep *rp)
 {
-	/* Check RPC XID first */
-	if (rqstp->rq_xid != rp->c_xid)
-		return false;
-	/* compare checksum of NFS data */
-	if (csum != rp->c_csum) {
+	if (key->c_key.k_xid == rp->c_key.k_xid &&
+	    key->c_key.k_csum != rp->c_key.k_csum)
 		++payload_misses;
-		return false;
-	}
 
-	/* Other discriminators */
-	if (rqstp->rq_proc != rp->c_proc ||
-	    rqstp->rq_prot != rp->c_prot ||
-	    rqstp->rq_vers != rp->c_vers ||
-	    rqstp->rq_arg.len != rp->c_len ||
-	    !rpc_cmp_addr(svc_addr(rqstp), (struct sockaddr *)&rp->c_addr) ||
-	    rpc_get_port(svc_addr(rqstp)) != rpc_get_port((struct sockaddr *)&rp->c_addr))
-		return false;
-
-	return true;
+	return memcmp(&key->c_key, &rp->c_key, sizeof(key->c_key));
 }
 
 /*
  * Search the request hash for an entry that matches the given rqstp.
  * Must be called with cache_lock held. Returns the found entry or
- * NULL on failure.
+ * inserts an empty key on failure.
  */
 static struct svc_cacherep *
-nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp,
-		__wsum csum)
+nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key)
 {
-	struct svc_cacherep	*rp, *ret = NULL;
-	struct list_head 	*rh = &b->lru_head;
+	struct svc_cacherep	*rp, *ret = key;
+	struct rb_node		**p = &b->rb_head.rb_node,
+				*parent = NULL;
 	unsigned int		entries = 0;
+	int cmp;
 
-	list_for_each_entry(rp, rh, c_lru) {
+	while (*p != NULL) {
 		++entries;
-		if (nfsd_cache_match(rqstp, csum, rp)) {
+		parent = *p;
+		rp = rb_entry(parent, struct svc_cacherep, c_node);
+
+		cmp = nfsd_cache_key_cmp(key, rp);
+		if (cmp < 0)
+			p = &parent->rb_left;
+		else if (cmp > 0)
+			p = &parent->rb_right;
+		else {
 			ret = rp;
-			break;
+			goto out;
 		}
 	}
-
+	rb_link_node(&key->c_node, parent, p);
+	rb_insert_color(&key->c_node, &b->rb_head);
+out:
 	/* tally hash chain length stats */
 	if (entries > longest_chain) {
 		longest_chain = entries;
@@ -374,6 +386,7 @@ nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp,
 				atomic_read(&num_drc_entries));
 	}
 
+	lru_put_end(b, ret);
 	return ret;
 }
 
@@ -389,9 +402,6 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 {
 	struct svc_cacherep	*rp, *found;
 	__be32			xid = rqstp->rq_xid;
-	u32			proto =  rqstp->rq_prot,
-				vers = rqstp->rq_vers,
-				proc = rqstp->rq_proc;
 	__wsum			csum;
 	u32 hash = nfsd_cache_hash(xid);
 	struct nfsd_drc_bucket *b = &drc_hashtbl[hash];
@@ -410,60 +420,38 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 	 * Since the common case is a cache miss followed by an insert,
 	 * preallocate an entry.
 	 */
-	rp = nfsd_reply_cache_alloc();
-	spin_lock(&b->cache_lock);
-	if (likely(rp)) {
-		atomic_inc(&num_drc_entries);
-		drc_mem_usage += sizeof(*rp);
+	rp = nfsd_reply_cache_alloc(rqstp, csum);
+	if (!rp) {
+		dprintk("nfsd: unable to allocate DRC entry!\n");
+		return rtn;
 	}
 
-	/* go ahead and prune the cache */
-	prune_bucket(b);
-
-	found = nfsd_cache_search(b, rqstp, csum);
-	if (found) {
-		if (likely(rp))
-			nfsd_reply_cache_free_locked(rp);
+	spin_lock(&b->cache_lock);
+	found = nfsd_cache_insert(b, rp);
+	if (found != rp) {
+		nfsd_reply_cache_free_locked(NULL, rp);
 		rp = found;
 		goto found_entry;
 	}
 
-	if (!rp) {
-		dprintk("nfsd: unable to allocate DRC entry!\n");
-		goto out;
-	}
-
 	nfsdstats.rcmisses++;
 	rqstp->rq_cacherep = rp;
 	rp->c_state = RC_INPROG;
-	rp->c_xid = xid;
-	rp->c_proc = proc;
-	rpc_copy_addr((struct sockaddr *)&rp->c_addr, svc_addr(rqstp));
-	rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp)));
-	rp->c_prot = proto;
-	rp->c_vers = vers;
-	rp->c_len = rqstp->rq_arg.len;
-	rp->c_csum = csum;
 
-	lru_put_end(b, rp);
+	atomic_inc(&num_drc_entries);
+	drc_mem_usage += sizeof(*rp);
 
-	/* release any buffer */
-	if (rp->c_type == RC_REPLBUFF) {
-		drc_mem_usage -= rp->c_replvec.iov_len;
-		kfree(rp->c_replvec.iov_base);
-		rp->c_replvec.iov_base = NULL;
-	}
-	rp->c_type = RC_NOCACHE;
+	/* go ahead and prune the cache */
+	prune_bucket(b);
  out:
 	spin_unlock(&b->cache_lock);
 	return rtn;
 
 found_entry:
-	nfsdstats.rchits++;
 	/* We found a matching entry which is either in progress or done. */
-	lru_put_end(b, rp);
-
+	nfsdstats.rchits++;
 	rtn = RC_DROPIT;
+
 	/* Request being processed */
 	if (rp->c_state == RC_INPROG)
 		goto out;
@@ -489,7 +477,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 		break;
 	default:
 		printk(KERN_WARNING "nfsd: bad repcache type %d\n", rp->c_type);
-		nfsd_reply_cache_free_locked(rp);
+		nfsd_reply_cache_free_locked(b, rp);
 	}
 
 	goto out;
@@ -524,7 +512,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
 	if (!rp)
 		return;
 
-	hash = nfsd_cache_hash(rp->c_xid);
+	hash = nfsd_cache_hash(rp->c_key.k_xid);
 	b = &drc_hashtbl[hash];
 
 	len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);

fs/nfsd/nfsctl.c

@@ -1242,6 +1242,7 @@ static __net_init int nfsd_init_net(struct net *net)
 	nn->somebody_reclaimed = false;
 	nn->clverifier_counter = prandom_u32();
 	nn->clientid_counter = prandom_u32();
+	nn->s2s_cp_cl_id = nn->clientid_counter++;
 
 	atomic_set(&nn->ntf_refcnt, 0);
 	init_waitqueue_head(&nn->ntf_wq);

fs/nfsd/state.h

@@ -355,6 +355,8 @@ struct nfs4_client {
 	struct rpc_wait_queue	cl_cb_waitq;	/* backchannel callers may */
 						/* wait here for slots */
 	struct net		*net;
+	struct list_head	async_copies;	/* list of async copies */
+	spinlock_t		async_lock;	/* lock for async copies */
 };
 
 /* struct nfs4_client_reset
@@ -573,6 +575,7 @@ enum nfsd4_cb_op {
 	NFSPROC4_CLNT_CB_NULL = 0,
 	NFSPROC4_CLNT_CB_RECALL,
 	NFSPROC4_CLNT_CB_LAYOUT,
+	NFSPROC4_CLNT_CB_OFFLOAD,
 	NFSPROC4_CLNT_CB_SEQUENCE,
 	NFSPROC4_CLNT_CB_NOTIFY_LOCK,
 };
@@ -599,6 +602,7 @@ struct nfsd4_blocked_lock {
 
 struct nfsd4_compound_state;
 struct nfsd_net;
+struct nfsd4_copy;
 
 extern __be32 nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
 		struct nfsd4_compound_state *cstate, struct svc_fh *fhp,
@@ -608,6 +612,8 @@ __be32 nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
 		     struct nfs4_stid **s, struct nfsd_net *nn);
 struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab,
 				  void (*sc_free)(struct nfs4_stid *));
+int nfs4_init_cp_state(struct nfsd_net *nn, struct nfsd4_copy *copy);
+void nfs4_free_cp_state(struct nfsd4_copy *copy);
 void nfs4_unhash_stid(struct nfs4_stid *s);
 void nfs4_put_stid(struct nfs4_stid *s);
 void nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid);
@@ -626,6 +632,7 @@ extern void nfsd4_run_cb(struct nfsd4_callback *cb);
 extern int nfsd4_create_callback_queue(void);
 extern void nfsd4_destroy_callback_queue(void);
 extern void nfsd4_shutdown_callback(struct nfs4_client *);
+extern void nfsd4_shutdown_copy(struct nfs4_client *clp);
 extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp);
 extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name,
 							struct nfsd_net *nn);
@@ -633,6 +640,9 @@ extern bool nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn);
 
 struct nfs4_file *find_file(struct knfsd_fh *fh);
 void put_nfs4_file(struct nfs4_file *fi);
+extern void nfs4_put_copy(struct nfsd4_copy *copy);
+extern struct nfsd4_copy *
+find_async_copy(struct nfs4_client *clp, stateid_t *staetid);
 static inline void get_nfs4_file(struct nfs4_file *fi)
 {
 	refcount_inc(&fi->fi_ref);

fs/nfsd/vfs.c

@@ -1276,7 +1276,6 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		int type, dev_t rdev, struct svc_fh *resfhp)
 {
 	struct dentry	*dentry, *dchild = NULL;
-	struct inode	*dirp;
 	__be32		err;
 	int		host_err;
 
@@ -1288,7 +1287,6 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		return err;
 
 	dentry = fhp->fh_dentry;
-	dirp = d_inode(dentry);
 
 	host_err = fh_want_write(fhp);
 	if (host_err)
@@ -1409,6 +1407,7 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 					*created = 1;
 				break;
 			}
+			/* fall through */
 		case NFS4_CREATE_EXCLUSIVE4_1:
 			if (   d_inode(dchild)->i_mtime.tv_sec == v_mtime
 			    && d_inode(dchild)->i_atime.tv_sec == v_atime
@@ -1417,7 +1416,7 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 					*created = 1;
 				goto set_attr;
 			}
-			 /* fallthru */
+			/* fall through */
 		case NFS3_CREATE_GUARDED:
 			err = nfserr_exist;
 		}

fs/nfsd/xdr4.h

@@ -511,6 +511,7 @@ struct nfsd42_write_res {
 	u64			wr_bytes_written;
 	u32			wr_stable_how;
 	nfs4_verifier		wr_verifier;
+	stateid_t		cb_stateid;
 };
 
 struct nfsd4_copy {
@@ -526,6 +527,23 @@ struct nfsd4_copy {
 
 	/* response */
 	struct nfsd42_write_res	cp_res;
+
+	/* for cb_offload */
+	struct nfsd4_callback	cp_cb;
+	__be32			nfserr;
+	struct knfsd_fh		fh;
+
+	struct nfs4_client      *cp_clp;
+
+	struct file             *file_src;
+	struct file             *file_dst;
+
+	stateid_t		cp_stateid;
+
+	struct list_head	copies;
+	struct task_struct	*copy_task;
+	refcount_t		refcount;
+	bool			stopped;
 };
 
 struct nfsd4_seek {
@@ -539,6 +557,15 @@ struct nfsd4_seek {
 	loff_t		seek_pos;
 };
 
+struct nfsd4_offload_status {
+	/* request */
+	stateid_t	stateid;
+
+	/* response */
+	u64		count;
+	u32		status;
+};
+
 struct nfsd4_op {
 	int					opnum;
 	const struct nfsd4_operation *		opdesc;
@@ -597,6 +624,7 @@ struct nfsd4_op {
 		struct nfsd4_fallocate		deallocate;
 		struct nfsd4_clone		clone;
 		struct nfsd4_copy		copy;
+		struct nfsd4_offload_status	offload_status;
 		struct nfsd4_seek		seek;
 	} u;
 	struct nfs4_replay *			replay;

fs/nfsd/xdr4cb.h

@@ -38,3 +38,13 @@
 #define NFS4_dec_cb_notify_lock_sz	(cb_compound_dec_hdr_sz  +      \
 					cb_sequence_dec_sz +            \
 					op_dec_sz)
+#define enc_cb_offload_info_sz		(1 + 1 + 2 + 1 +		\
+					XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define NFS4_enc_cb_offload_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					enc_nfs4_fh_sz +		\
+					enc_stateid_sz +		\
+					enc_cb_offload_info_sz)
+#define NFS4_dec_cb_offload_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)

include/linux/sunrpc/cache.h

@@ -67,7 +67,7 @@ struct cache_detail {
 	struct module *		owner;
 	int			hash_size;
 	struct hlist_head *	hash_table;
-	rwlock_t		hash_lock;
+	spinlock_t		hash_lock;
 
 	char			*name;
 	void			(*cache_put)(struct kref *);
@@ -168,8 +168,8 @@ extern const struct file_operations content_file_operations_pipefs;
 extern const struct file_operations cache_flush_operations_pipefs;
 
 extern struct cache_head *
-sunrpc_cache_lookup(struct cache_detail *detail,
-		    struct cache_head *key, int hash);
+sunrpc_cache_lookup_rcu(struct cache_detail *detail,
+			struct cache_head *key, int hash);
 extern struct cache_head *
 sunrpc_cache_update(struct cache_detail *detail,
 		    struct cache_head *new, struct cache_head *old, int hash);
@@ -186,6 +186,12 @@ static inline struct cache_head  *cache_get(struct cache_head *h)
 	return h;
 }
 
+static inline struct cache_head  *cache_get_rcu(struct cache_head *h)
+{
+	if (kref_get_unless_zero(&h->ref))
+		return h;
+	return NULL;
+}
 
 static inline void cache_put(struct cache_head *h, struct cache_detail *cd)
 {
@@ -224,9 +230,9 @@ extern void sunrpc_cache_unregister_pipefs(struct cache_detail *);
 extern void sunrpc_cache_unhash(struct cache_detail *, struct cache_head *);
 
 /* Must store cache_detail in seq_file->private if using next three functions */
-extern void *cache_seq_start(struct seq_file *file, loff_t *pos);
-extern void *cache_seq_next(struct seq_file *file, void *p, loff_t *pos);
-extern void cache_seq_stop(struct seq_file *file, void *p);
+extern void *cache_seq_start_rcu(struct seq_file *file, loff_t *pos);
+extern void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos);
+extern void cache_seq_stop_rcu(struct seq_file *file, void *p);
 
 extern void qword_add(char **bpp, int *lp, char *str);
 extern void qword_addhex(char **bpp, int *lp, char *buf, int blen);

include/linux/sunrpc/svc_rdma.h

@@ -113,13 +113,14 @@ struct svcxprt_rdma {
 /* sc_flags */
 #define RDMAXPRT_CONN_PENDING	3
 
-#define RPCRDMA_LISTEN_BACKLOG  10
-#define RPCRDMA_MAX_REQUESTS    32
-
-/* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
- * current NFSv4.1 implementation supports one backchannel slot.
+/*
+ * Default connection parameters
  */
-#define RPCRDMA_MAX_BC_REQUESTS	2
+enum {
+	RPCRDMA_LISTEN_BACKLOG	= 10,
+	RPCRDMA_MAX_REQUESTS	= 64,
+	RPCRDMA_MAX_BC_REQUESTS	= 2,
+};
 
 #define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
 

include/linux/sunrpc/svcauth.h

@@ -82,6 +82,7 @@ struct auth_domain {
 	struct hlist_node	hash;
 	char			*name;
 	struct auth_ops		*flavour;
+	struct rcu_head		rcu_head;
 };
 
 /*

net/sunrpc/auth_gss/svcauth_gss.c

@@ -76,6 +76,7 @@ struct rsi {
 	struct xdr_netobj	in_handle, in_token;
 	struct xdr_netobj	out_handle, out_token;
 	int			major_status, minor_status;
+	struct rcu_head		rcu_head;
 };
 
 static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old);
@@ -89,13 +90,21 @@ static void rsi_free(struct rsi *rsii)
 	kfree(rsii->out_token.data);
 }
 
-static void rsi_put(struct kref *ref)
+static void rsi_free_rcu(struct rcu_head *head)
 {
-	struct rsi *rsii = container_of(ref, struct rsi, h.ref);
+	struct rsi *rsii = container_of(head, struct rsi, rcu_head);
+
 	rsi_free(rsii);
 	kfree(rsii);
 }
 
+static void rsi_put(struct kref *ref)
+{
+	struct rsi *rsii = container_of(ref, struct rsi, h.ref);
+
+	call_rcu(&rsii->rcu_head, rsi_free_rcu);
+}
+
 static inline int rsi_hash(struct rsi *item)
 {
 	return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
@@ -282,7 +291,7 @@ static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item)
 	struct cache_head *ch;
 	int hash = rsi_hash(item);
 
-	ch = sunrpc_cache_lookup(cd, &item->h, hash);
+	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
 	if (ch)
 		return container_of(ch, struct rsi, h);
 	else
@@ -330,6 +339,7 @@ struct rsc {
 	struct svc_cred		cred;
 	struct gss_svc_seq_data	seqdata;
 	struct gss_ctx		*mechctx;
+	struct rcu_head		rcu_head;
 };
 
 static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old);
@@ -343,12 +353,22 @@ static void rsc_free(struct rsc *rsci)
 	free_svc_cred(&rsci->cred);
 }
 
+static void rsc_free_rcu(struct rcu_head *head)
+{
+	struct rsc *rsci = container_of(head, struct rsc, rcu_head);
+
+	kfree(rsci->handle.data);
+	kfree(rsci);
+}
+
 static void rsc_put(struct kref *ref)
 {
 	struct rsc *rsci = container_of(ref, struct rsc, h.ref);
 
-	rsc_free(rsci);
-	kfree(rsci);
+	if (rsci->mechctx)
+		gss_delete_sec_context(&rsci->mechctx);
+	free_svc_cred(&rsci->cred);
+	call_rcu(&rsci->rcu_head, rsc_free_rcu);
 }
 
 static inline int
@@ -542,7 +562,7 @@ static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
 	struct cache_head *ch;
 	int hash = rsc_hash(item);
 
-	ch = sunrpc_cache_lookup(cd, &item->h, hash);
+	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
 	if (ch)
 		return container_of(ch, struct rsc, h);
 	else
@@ -1764,14 +1784,21 @@ svcauth_gss_release(struct svc_rqst *rqstp)
 }
 
 static void
-svcauth_gss_domain_release(struct auth_domain *dom)
+svcauth_gss_domain_release_rcu(struct rcu_head *head)
 {
+	struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);
 	struct gss_domain *gd = container_of(dom, struct gss_domain, h);
 
 	kfree(dom->name);
 	kfree(gd);
 }
 
+static void
+svcauth_gss_domain_release(struct auth_domain *dom)
+{
+	call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu);
+}
+
 static struct auth_ops svcauthops_gss = {
 	.name		= "rpcsec_gss",
 	.owner		= THIS_MODULE,

net/sunrpc/svc_xprt.c

@@ -987,7 +987,7 @@ static void call_xpt_users(struct svc_xprt *xprt)
 	spin_lock(&xprt->xpt_lock);
 	while (!list_empty(&xprt->xpt_users)) {
 		u = list_first_entry(&xprt->xpt_users, struct svc_xpt_user, list);
-		list_del(&u->list);
+		list_del_init(&u->list);
 		u->callback(u);
 	}
 	spin_unlock(&xprt->xpt_lock);

net/sunrpc/svcauth.c

@@ -27,12 +27,32 @@
 extern struct auth_ops svcauth_null;
 extern struct auth_ops svcauth_unix;
 
-static DEFINE_SPINLOCK(authtab_lock);
-static struct auth_ops	*authtab[RPC_AUTH_MAXFLAVOR] = {
-	[0] = &svcauth_null,
-	[1] = &svcauth_unix,
+static struct auth_ops __rcu *authtab[RPC_AUTH_MAXFLAVOR] = {
+	[RPC_AUTH_NULL] = (struct auth_ops __force __rcu *)&svcauth_null,
+	[RPC_AUTH_UNIX] = (struct auth_ops __force __rcu *)&svcauth_unix,
 };
 
+static struct auth_ops *
+svc_get_auth_ops(rpc_authflavor_t flavor)
+{
+	struct auth_ops		*aops;
+
+	if (flavor >= RPC_AUTH_MAXFLAVOR)
+		return NULL;
+	rcu_read_lock();
+	aops = rcu_dereference(authtab[flavor]);
+	if (aops != NULL && !try_module_get(aops->owner))
+		aops = NULL;
+	rcu_read_unlock();
+	return aops;
+}
+
+static void
+svc_put_auth_ops(struct auth_ops *aops)
+{
+	module_put(aops->owner);
+}
+
 int
 svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
 {
@@ -45,14 +65,11 @@ svc_authenticate(struct svc_rqst *rqstp, __be32 *authp)
 
 	dprintk("svc: svc_authenticate (%d)\n", flavor);
 
-	spin_lock(&authtab_lock);
-	if (flavor >= RPC_AUTH_MAXFLAVOR || !(aops = authtab[flavor]) ||
-	    !try_module_get(aops->owner)) {
-		spin_unlock(&authtab_lock);
+	aops = svc_get_auth_ops(flavor);
+	if (aops == NULL) {
 		*authp = rpc_autherr_badcred;
 		return SVC_DENIED;
 	}
-	spin_unlock(&authtab_lock);
 
 	rqstp->rq_auth_slack = 0;
 	init_svc_cred(&rqstp->rq_cred);
@@ -82,7 +99,7 @@ int svc_authorise(struct svc_rqst *rqstp)
 
 	if (aops) {
 		rv = aops->release(rqstp);
-		module_put(aops->owner);
+		svc_put_auth_ops(aops);
 	}
 	return rv;
 }
@@ -90,13 +107,14 @@ int svc_authorise(struct svc_rqst *rqstp)
 int
 svc_auth_register(rpc_authflavor_t flavor, struct auth_ops *aops)
 {
+	struct auth_ops *old;
 	int rv = -EINVAL;
-	spin_lock(&authtab_lock);
-	if (flavor < RPC_AUTH_MAXFLAVOR && authtab[flavor] == NULL) {
-		authtab[flavor] = aops;
-		rv = 0;
+
+	if (flavor < RPC_AUTH_MAXFLAVOR) {
+		old = cmpxchg((struct auth_ops ** __force)&authtab[flavor], NULL, aops);
+		if (old == NULL || old == aops)
+			rv = 0;
 	}
-	spin_unlock(&authtab_lock);
 	return rv;
 }
 EXPORT_SYMBOL_GPL(svc_auth_register);
@@ -104,10 +122,8 @@ EXPORT_SYMBOL_GPL(svc_auth_register);
 void
 svc_auth_unregister(rpc_authflavor_t flavor)
 {
-	spin_lock(&authtab_lock);
 	if (flavor < RPC_AUTH_MAXFLAVOR)
-		authtab[flavor] = NULL;
-	spin_unlock(&authtab_lock);
+		rcu_assign_pointer(authtab[flavor], NULL);
 }
 EXPORT_SYMBOL_GPL(svc_auth_unregister);
 
@@ -127,10 +143,11 @@ static struct hlist_head	auth_domain_table[DN_HASHMAX];
 static DEFINE_SPINLOCK(auth_domain_lock);
 
 static void auth_domain_release(struct kref *kref)
+	__releases(&auth_domain_lock)
 {
 	struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
 
-	hlist_del(&dom->hash);
+	hlist_del_rcu(&dom->hash);
 	dom->flavour->domain_release(dom);
 	spin_unlock(&auth_domain_lock);
 }
@@ -159,7 +176,7 @@ auth_domain_lookup(char *name, struct auth_domain *new)
 		}
 	}
 	if (new)
-		hlist_add_head(&new->hash, head);
+		hlist_add_head_rcu(&new->hash, head);
 	spin_unlock(&auth_domain_lock);
 	return new;
 }
@@ -167,6 +184,21 @@ EXPORT_SYMBOL_GPL(auth_domain_lookup);
 
 struct auth_domain *auth_domain_find(char *name)
 {
-	return auth_domain_lookup(name, NULL);
+	struct auth_domain *hp;
+	struct hlist_head *head;
+
+	head = &auth_domain_table[hash_str(name, DN_HASHBITS)];
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(hp, head, hash) {
+		if (strcmp(hp->name, name)==0) {
+			if (!kref_get_unless_zero(&hp->ref))
+				hp = NULL;
+			rcu_read_unlock();
+			return hp;
+		}
+	}
+	rcu_read_unlock();
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(auth_domain_find);

net/sunrpc/svcauth_unix.c

@@ -37,20 +37,26 @@ struct unix_domain {
 extern struct auth_ops svcauth_null;
 extern struct auth_ops svcauth_unix;
 
-static void svcauth_unix_domain_release(struct auth_domain *dom)
+static void svcauth_unix_domain_release_rcu(struct rcu_head *head)
 {
+	struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);
 	struct unix_domain *ud = container_of(dom, struct unix_domain, h);
 
 	kfree(dom->name);
 	kfree(ud);
 }
 
+static void svcauth_unix_domain_release(struct auth_domain *dom)
+{
+	call_rcu(&dom->rcu_head, svcauth_unix_domain_release_rcu);
+}
+
 struct auth_domain *unix_domain_find(char *name)
 {
 	struct auth_domain *rv;
 	struct unix_domain *new = NULL;
 
-	rv = auth_domain_lookup(name, NULL);
+	rv = auth_domain_find(name);
 	while(1) {
 		if (rv) {
 			if (new && rv != &new->h)
@@ -91,6 +97,7 @@ struct ip_map {
 	char			m_class[8]; /* e.g. "nfsd" */
 	struct in6_addr		m_addr;
 	struct unix_domain	*m_client;
+	struct rcu_head		m_rcu;
 };
 
 static void ip_map_put(struct kref *kref)
@@ -101,7 +108,7 @@ static void ip_map_put(struct kref *kref)
 	if (test_bit(CACHE_VALID, &item->flags) &&
 	    !test_bit(CACHE_NEGATIVE, &item->flags))
 		auth_domain_put(&im->m_client->h);
-	kfree(im);
+	kfree_rcu(im, m_rcu);
 }
 
 static inline int hash_ip6(const struct in6_addr *ip)
@@ -280,9 +287,9 @@ static struct ip_map *__ip_map_lookup(struct cache_detail *cd, char *class,
 
 	strcpy(ip.m_class, class);
 	ip.m_addr = *addr;
-	ch = sunrpc_cache_lookup(cd, &ip.h,
-				 hash_str(class, IP_HASHBITS) ^
-				 hash_ip6(addr));
+	ch = sunrpc_cache_lookup_rcu(cd, &ip.h,
+				     hash_str(class, IP_HASHBITS) ^
+				     hash_ip6(addr));
 
 	if (ch)
 		return container_of(ch, struct ip_map, h);
@@ -412,6 +419,7 @@ struct unix_gid {
 	struct cache_head	h;
 	kuid_t			uid;
 	struct group_info	*gi;
+	struct rcu_head		rcu;
 };
 
 static int unix_gid_hash(kuid_t uid)
@@ -426,7 +434,7 @@ static void unix_gid_put(struct kref *kref)
 	if (test_bit(CACHE_VALID, &item->flags) &&
 	    !test_bit(CACHE_NEGATIVE, &item->flags))
 		put_group_info(ug->gi);
-	kfree(ug);
+	kfree_rcu(ug, rcu);
 }
 
 static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
@@ -619,7 +627,7 @@ static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid)
 	struct cache_head *ch;
 
 	ug.uid = uid;
-	ch = sunrpc_cache_lookup(cd, &ug.h, unix_gid_hash(uid));
+	ch = sunrpc_cache_lookup_rcu(cd, &ug.h, unix_gid_hash(uid));
 	if (ch)
 		return container_of(ch, struct unix_gid, h);
 	else

net/sunrpc/svcsock.c

@@ -325,59 +325,34 @@ static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
 /*
  * Generic recvfrom routine.
  */
-static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
-			int buflen)
+static ssize_t svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov,
+			    unsigned int nr, size_t buflen, unsigned int base)
 {
 	struct svc_sock *svsk =
 		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
-	struct msghdr msg = {
-		.msg_flags	= MSG_DONTWAIT,
-	};
-	int len;
+	struct msghdr msg = { NULL };
+	ssize_t len;
 
 	rqstp->rq_xprt_hlen = 0;
 
 	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, iov, nr, buflen);
-	len = sock_recvmsg(svsk->sk_sock, &msg, msg.msg_flags);
+	if (base != 0) {
+		iov_iter_advance(&msg.msg_iter, base);
+		buflen -= base;
+	}
+	len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
 	/* If we read a full record, then assume there may be more
 	 * data to read (stream based sockets only!)
 	 */
 	if (len == buflen)
 		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 
-	dprintk("svc: socket %p recvfrom(%p, %zu) = %d\n",
+	dprintk("svc: socket %p recvfrom(%p, %zu) = %zd\n",
 		svsk, iov[0].iov_base, iov[0].iov_len, len);
 	return len;
 }
 
-static int svc_partial_recvfrom(struct svc_rqst *rqstp,
-				struct kvec *iov, int nr,
-				int buflen, unsigned int base)
-{
-	size_t save_iovlen;
-	void *save_iovbase;
-	unsigned int i;
-	int ret;
-
-	if (base == 0)
-		return svc_recvfrom(rqstp, iov, nr, buflen);
-
-	for (i = 0; i < nr; i++) {
-		if (iov[i].iov_len > base)
-			break;
-		base -= iov[i].iov_len;
-	}
-	save_iovlen = iov[i].iov_len;
-	save_iovbase = iov[i].iov_base;
-	iov[i].iov_len -= base;
-	iov[i].iov_base += base;
-	ret = svc_recvfrom(rqstp, &iov[i], nr - i, buflen);
-	iov[i].iov_len = save_iovlen;
-	iov[i].iov_base = save_iovbase;
-	return ret;
-}
-
 /*
  * Set socket snd and rcv buffer lengths
  */
@@ -962,7 +937,8 @@ static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
 		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
 		iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
 		iov.iov_len  = want;
-		if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
+		len = svc_recvfrom(rqstp, &iov, 1, want, 0);
+		if (len < 0)
 			goto error;
 		svsk->sk_tcplen += len;
 
@@ -1088,14 +1064,13 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 
 	vec = rqstp->rq_vec;
 
-	pnum = copy_pages_to_kvecs(&vec[0], &rqstp->rq_pages[0],
-						svsk->sk_datalen + want);
+	pnum = copy_pages_to_kvecs(&vec[0], &rqstp->rq_pages[0], base + want);
 
 	rqstp->rq_respages = &rqstp->rq_pages[pnum];
 	rqstp->rq_next_page = rqstp->rq_respages + 1;
 
 	/* Now receive data */
-	len = svc_partial_recvfrom(rqstp, vec, pnum, want, base);
+	len = svc_recvfrom(rqstp, vec, pnum, base + want, base);
 	if (len >= 0) {
 		svsk->sk_tcplen += len;
 		svsk->sk_datalen += len;

net/sunrpc/xprtrdma/svc_rdma_backchannel.c

@@ -5,8 +5,6 @@
  * Support for backward direction RPCs on RPC/RDMA (server-side).
  */
 
-#include <linux/module.h>
-
 #include <linux/sunrpc/svc_rdma.h>
 
 #include "xprt_rdma.h"
@@ -32,7 +30,6 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp,
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 	struct kvec *dst, *src = &rcvbuf->head[0];
 	struct rpc_rqst *req;
-	unsigned long cwnd;
 	u32 credits;
 	size_t len;
 	__be32 xid;
@@ -66,6 +63,8 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp,
 	if (dst->iov_len < len)
 		goto out_unlock;
 	memcpy(dst->iov_base, p, len);
+	xprt_pin_rqst(req);
+	spin_unlock(&xprt->queue_lock);
 
 	credits = be32_to_cpup(rdma_resp + 2);
 	if (credits == 0)
@@ -74,15 +73,13 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, __be32 *rdma_resp,
 		credits = r_xprt->rx_buf.rb_bc_max_requests;
 
 	spin_lock_bh(&xprt->transport_lock);
-	cwnd = xprt->cwnd;
 	xprt->cwnd = credits << RPC_CWNDSHIFT;
-	if (xprt->cwnd > cwnd)
-		xprt_release_rqst_cong(req->rq_task);
 	spin_unlock_bh(&xprt->transport_lock);
 
-
+	spin_lock(&xprt->queue_lock);
 	ret = 0;
 	xprt_complete_rqst(req->rq_task, rcvbuf->len);
+	xprt_unpin_rqst(req);
 	rcvbuf->len = 0;
 
 out_unlock:
@@ -251,7 +248,6 @@ xprt_rdma_bc_put(struct rpc_xprt *xprt)
 	dprintk("svcrdma: %s: xprt %p\n", __func__, xprt);
 
 	xprt_free(xprt);
-	module_put(THIS_MODULE);
 }
 
 static const struct rpc_xprt_ops xprt_rdma_bc_procs = {
@@ -323,20 +319,9 @@ xprt_setup_rdma_bc(struct xprt_create *args)
 	args->bc_xprt->xpt_bc_xprt = xprt;
 	xprt->bc_xprt = args->bc_xprt;
 
-	if (!try_module_get(THIS_MODULE))
-		goto out_fail;
-
 	/* Final put for backchannel xprt is in __svc_rdma_free */
 	xprt_get(xprt);
 	return xprt;
-
-out_fail:
-	xprt_rdma_free_addresses(xprt);
-	args->bc_xprt->xpt_bc_xprt = NULL;
-	args->bc_xprt->xpt_bc_xps = NULL;
-	xprt_put(xprt);
-	xprt_free(xprt);
-	return ERR_PTR(-EINVAL);
 }
 
 struct xprt_class xprt_rdma_bc = {

net/sunrpc/xprtrdma/svc_rdma_transport.c

@@ -475,10 +475,12 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 
 	/* Qualify the transport resource defaults with the
 	 * capabilities of this particular device */
-	newxprt->sc_max_send_sges = dev->attrs.max_send_sge;
-	/* transport hdr, head iovec, one page list entry, tail iovec */
-	if (newxprt->sc_max_send_sges < 4) {
-		pr_err("svcrdma: too few Send SGEs available (%d)\n",
+	/* Transport header, head iovec, tail iovec */
+	newxprt->sc_max_send_sges = 3;
+	/* Add one SGE per page list entry */
+	newxprt->sc_max_send_sges += svcrdma_max_req_size / PAGE_SIZE;
+	if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge) {
+		pr_err("svcrdma: too few Send SGEs available (%d needed)\n",
 		       newxprt->sc_max_send_sges);
 		goto errout;
 	}