Merge tag 'nfs-for-4.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - Fix the NFSv4.1 r/wsize sanity checking
   - Reset the RPC/RDMA credit grant properly after a disconnect
   - Fix a missed page unlock after pg_doio()

  Features and optimisations:
   - Overhaul of the RPC client socket code to eliminate a locking
     bottleneck and reduce the latency when transmitting lots of
     requests in parallel.
   - Allow parallelisation of the RPCSEC_GSS encoding of an RPC request.
   - Convert the RPC client socket receive code to use iovec_iter() for
     improved efficiency.
   - Convert several NFS and RPC lookup operations to use RCU instead of
     taking global locks.
   - Avoid the need for BH-safe locks in the RPC/RDMA back channel.

  Bugfixes and cleanups:
   - Fix lock recovery during NFSv4 delegation recalls
   - Fix the NFSv4 + NFSv4.1 "lookup revalidate + open file" case.
   - Fixes for the RPC connection metrics
   - Various RPC client layer cleanups to consolidate stream based
     sockets
   - RPC/RDMA connection cleanups
   - Simplify the RPC/RDMA cleanup after memory operation failures
   - Clean ups for NFS v4.2 copy completion and NFSv4 open state
     reclaim"

* tag 'nfs-for-4.20-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (97 commits)
  SUNRPC: Convert the auth cred cache to use refcount_t
  SUNRPC: Convert auth creds to use refcount_t
  SUNRPC: Simplify lookup code
  SUNRPC: Clean up the AUTH cache code
  NFS: change sign of nfs_fh length
  sunrpc: safely reallow resvport min/max inversion
  nfs: remove redundant call to nfs_context_set_write_error()
  nfs: Fix a missed page unlock after pg_doio()
  SUNRPC: Fix a compile warning for cmpxchg64()
  NFSv4.x: fix lock recovery during delegation recall
  SUNRPC: use cmpxchg64() in gss_seq_send64_fetch_and_inc()
  xprtrdma: Squelch a sparse warning
  xprtrdma: Clean up xprt_rdma_disconnect_inject
  xprtrdma: Add documenting comments
  xprtrdma: Report when there were zero posted Receives
  xprtrdma: Move rb_flags initialization
  xprtrdma: Don't disable BH's in backchannel server
  xprtrdma: Remove memory address of "ep" from an error message
  xprtrdma: Rename rpcrdma_qp_async_error_upcall
  xprtrdma: Simplify RPC wake-ups on connect
  ...

net/sunrpc/auth_gss/auth_gss.c

@@ -1058,7 +1058,7 @@ gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 	auth->au_flavor = flavor;
 	if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
 		auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
-	atomic_set(&auth->au_count, 1);
+	refcount_set(&auth->au_count, 1);
 	kref_init(&gss_auth->kref);
 
 	err = rpcauth_init_credcache(auth);
@@ -1187,7 +1187,7 @@ gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
 			if (strcmp(gss_auth->target_name, args->target_name))
 				continue;
 		}
-		if (!atomic_inc_not_zero(&gss_auth->rpc_auth.au_count))
+		if (!refcount_inc_not_zero(&gss_auth->rpc_auth.au_count))
 			continue;
 		goto out;
 	}
@@ -1984,6 +1984,46 @@ gss_unwrap_req_decode(kxdrdproc_t decode, struct rpc_rqst *rqstp,
 	return decode(rqstp, &xdr, obj);
 }
 
+static bool
+gss_seq_is_newer(u32 new, u32 old)
+{
+	return (s32)(new - old) > 0;
+}
+
+static bool
+gss_xmit_need_reencode(struct rpc_task *task)
+{
+	struct rpc_rqst *req = task->tk_rqstp;
+	struct rpc_cred *cred = req->rq_cred;
+	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
+	u32 win, seq_xmit;
+	bool ret = true;
+
+	if (!ctx)
+		return true;
+
+	if (gss_seq_is_newer(req->rq_seqno, READ_ONCE(ctx->gc_seq)))
+		goto out;
+
+	seq_xmit = READ_ONCE(ctx->gc_seq_xmit);
+	while (gss_seq_is_newer(req->rq_seqno, seq_xmit)) {
+		u32 tmp = seq_xmit;
+
+		seq_xmit = cmpxchg(&ctx->gc_seq_xmit, tmp, req->rq_seqno);
+		if (seq_xmit == tmp) {
+			ret = false;
+			goto out;
+		}
+	}
+
+	win = ctx->gc_win;
+	if (win > 0)
+		ret = !gss_seq_is_newer(req->rq_seqno, seq_xmit - win);
+out:
+	gss_put_ctx(ctx);
+	return ret;
+}
+
 static int
 gss_unwrap_resp(struct rpc_task *task,
 		kxdrdproc_t decode, void *rqstp, __be32 *p, void *obj)
@@ -2052,6 +2092,7 @@ static const struct rpc_credops gss_credops = {
 	.crunwrap_resp		= gss_unwrap_resp,
 	.crkey_timeout		= gss_key_timeout,
 	.crstringify_acceptor	= gss_stringify_acceptor,
+	.crneed_reencode	= gss_xmit_need_reencode,
 };
 
 static const struct rpc_credops gss_nullops = {

net/sunrpc/auth_gss/gss_krb5_seal.c

@@ -63,13 +63,12 @@
 #include <linux/sunrpc/gss_krb5.h>
 #include <linux/random.h>
 #include <linux/crypto.h>
+#include <linux/atomic.h>
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY        RPCDBG_AUTH
 #endif
 
-DEFINE_SPINLOCK(krb5_seq_lock);
-
 static void *
 setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token)
 {
@@ -124,6 +123,30 @@ setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
 	return krb5_hdr;
 }
 
+u32
+gss_seq_send_fetch_and_inc(struct krb5_ctx *ctx)
+{
+	u32 old, seq_send = READ_ONCE(ctx->seq_send);
+
+	do {
+		old = seq_send;
+		seq_send = cmpxchg(&ctx->seq_send, old, old + 1);
+	} while (old != seq_send);
+	return seq_send;
+}
+
+u64
+gss_seq_send64_fetch_and_inc(struct krb5_ctx *ctx)
+{
+	u64 old, seq_send = READ_ONCE(ctx->seq_send);
+
+	do {
+		old = seq_send;
+		seq_send = cmpxchg64(&ctx->seq_send64, old, old + 1);
+	} while (old != seq_send);
+	return seq_send;
+}
+
 static u32
 gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
 		struct xdr_netobj *token)
@@ -154,9 +177,7 @@ gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
 
 	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);
 
-	spin_lock(&krb5_seq_lock);
-	seq_send = ctx->seq_send++;
-	spin_unlock(&krb5_seq_lock);
+	seq_send = gss_seq_send_fetch_and_inc(ctx);
 
 	if (krb5_make_seq_num(ctx, ctx->seq, ctx->initiate ? 0 : 0xff,
 			      seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))
@@ -174,7 +195,6 @@ gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 				       .data = cksumdata};
 	void *krb5_hdr;
 	s32 now;
-	u64 seq_send;
 	u8 *cksumkey;
 	unsigned int cksum_usage;
 	__be64 seq_send_be64;
@@ -185,11 +205,7 @@ gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 
 	/* Set up the sequence number. Now 64-bits in clear
 	 * text and w/o direction indicator */
-	spin_lock(&krb5_seq_lock);
-	seq_send = ctx->seq_send64++;
-	spin_unlock(&krb5_seq_lock);
-
-	seq_send_be64 = cpu_to_be64(seq_send);
+	seq_send_be64 = cpu_to_be64(gss_seq_send64_fetch_and_inc(ctx));
 	memcpy(krb5_hdr + 8, (char *) &seq_send_be64, 8);
 
 	if (ctx->initiate) {

net/sunrpc/auth_gss/gss_krb5_wrap.c

@@ -228,9 +228,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 
 	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);
 
-	spin_lock(&krb5_seq_lock);
-	seq_send = kctx->seq_send++;
-	spin_unlock(&krb5_seq_lock);
+	seq_send = gss_seq_send_fetch_and_inc(kctx);
 
 	/* XXX would probably be more efficient to compute checksum
 	 * and encrypt at the same time: */
@@ -477,9 +475,7 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	*be16ptr++ = 0;
 
 	be64ptr = (__be64 *)be16ptr;
-	spin_lock(&krb5_seq_lock);
-	*be64ptr = cpu_to_be64(kctx->seq_send64++);
-	spin_unlock(&krb5_seq_lock);
+	*be64ptr = cpu_to_be64(gss_seq_send64_fetch_and_inc(kctx));
 
 	err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, pages);
 	if (err)

net/sunrpc/auth_gss/gss_mech_switch.c

@@ -117,7 +117,7 @@ int gss_mech_register(struct gss_api_mech *gm)
 	if (status)
 		return status;
 	spin_lock(&registered_mechs_lock);
-	list_add(&gm->gm_list, &registered_mechs);
+	list_add_rcu(&gm->gm_list, &registered_mechs);
 	spin_unlock(&registered_mechs_lock);
 	dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
 	return 0;
@@ -132,7 +132,7 @@ EXPORT_SYMBOL_GPL(gss_mech_register);
 void gss_mech_unregister(struct gss_api_mech *gm)
 {
 	spin_lock(&registered_mechs_lock);
-	list_del(&gm->gm_list);
+	list_del_rcu(&gm->gm_list);
 	spin_unlock(&registered_mechs_lock);
 	dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
 	gss_mech_free(gm);
@@ -151,15 +151,15 @@ _gss_mech_get_by_name(const char *name)
 {
 	struct gss_api_mech	*pos, *gm = NULL;
 
-	spin_lock(&registered_mechs_lock);
-	list_for_each_entry(pos, &registered_mechs, gm_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 		if (0 == strcmp(name, pos->gm_name)) {
 			if (try_module_get(pos->gm_owner))
 				gm = pos;
 			break;
 		}
 	}
-	spin_unlock(&registered_mechs_lock);
+	rcu_read_unlock();
 	return gm;
 
 }
@@ -186,8 +186,8 @@ struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 	dprintk("RPC:       %s(%s)\n", __func__, buf);
 	request_module("rpc-auth-gss-%s", buf);
 
-	spin_lock(&registered_mechs_lock);
-	list_for_each_entry(pos, &registered_mechs, gm_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 		if (obj->len == pos->gm_oid.len) {
 			if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
 				if (try_module_get(pos->gm_owner))
@@ -196,7 +196,7 @@ struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 			}
 		}
 	}
-	spin_unlock(&registered_mechs_lock);
+	rcu_read_unlock();
 	return gm;
 }
 
@@ -216,15 +216,15 @@ static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 {
 	struct gss_api_mech *gm = NULL, *pos;
 
-	spin_lock(&registered_mechs_lock);
-	list_for_each_entry(pos, &registered_mechs, gm_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 		if (!mech_supports_pseudoflavor(pos, pseudoflavor))
 			continue;
 		if (try_module_get(pos->gm_owner))
 			gm = pos;
 		break;
 	}
-	spin_unlock(&registered_mechs_lock);
+	rcu_read_unlock();
 	return gm;
 }
 
@@ -257,8 +257,8 @@ int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 	struct gss_api_mech *pos = NULL;
 	int j, i = 0;
 
-	spin_lock(&registered_mechs_lock);
-	list_for_each_entry(pos, &registered_mechs, gm_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 		for (j = 0; j < pos->gm_pf_num; j++) {
 			if (i >= size) {
 				spin_unlock(&registered_mechs_lock);
@@ -267,7 +267,7 @@ int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 			array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 		}
 	}
-	spin_unlock(&registered_mechs_lock);
+	rcu_read_unlock();
 	return i;
 }
 

net/sunrpc/auth_gss/gss_rpc_xdr.c

@@ -784,6 +784,7 @@ void gssx_enc_accept_sec_context(struct rpc_rqst *req,
 	xdr_inline_pages(&req->rq_rcv_buf,
 		PAGE_SIZE/2 /* pretty arbitrary */,
 		arg->pages, 0 /* page base */, arg->npages * PAGE_SIZE);
+	req->rq_rcv_buf.flags |= XDRBUF_SPARSE_PAGES;
 done:
 	if (err)
 		dprintk("RPC:       gssx_enc_accept_sec_context: %d\n", err);