NFS client fixes for Linux 5.0

Stable bugfixes:
 - Fix TCP receive code on archs with flush_dcache_page()
 
 Other bugfixes:
 - Fix error code in rpcrdma_buffer_create()
 - Fix a double free in rpcrdma_send_ctxs_create()
 - Fix kernel BUG at kernel/cred.c:825
 - Fix unnecessary retry in nfs42_proc_copy_file_range()
 - Ensure rq_bytes_sent is reset before request transmission
 - Ensure we respect the RPCSEC_GSS sequence number limit
 - Address Kerberos performance/behavior regression
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Merge tag 'nfs-for-5.0-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client fixes from Anna Schumaker:
 "These are mostly fixes for SUNRPC bugs, with a single v4.2
  copy_file_range() fix mixed in.

  Stable bugfixes:
   - Fix TCP receive code on archs with flush_dcache_page()

  Other bugfixes:
   - Fix error code in rpcrdma_buffer_create()
   - Fix a double free in rpcrdma_send_ctxs_create()
   - Fix kernel BUG at kernel/cred.c:825
   - Fix unnecessary retry in nfs42_proc_copy_file_range()
   - Ensure rq_bytes_sent is reset before request transmission
   - Ensure we respect the RPCSEC_GSS sequence number limit
   - Address Kerberos performance/behavior regression"

* tag 'nfs-for-5.0-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  SUNRPC: Address Kerberos performance/behavior regression
  SUNRPC: Ensure we respect the RPCSEC_GSS sequence number limit
  SUNRPC: Ensure rq_bytes_sent is reset before request transmission
  NFSv4.2 fix unnecessary retry in nfs4_copy_file_range
  sunrpc: kernel BUG at kernel/cred.c:825!
  SUNRPC: Fix TCP receive code on archs with flush_dcache_page()
  xprtrdma: Double free in rpcrdma_sendctxs_create()
  xprtrdma: Fix error code in rpcrdma_buffer_create()

fs/nfs/nfs4file.c

@@ -133,15 +133,9 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 				    struct file *file_out, loff_t pos_out,
 				    size_t count, unsigned int flags)
 {
-	ssize_t ret;
-
 	if (file_inode(file_in) == file_inode(file_out))
 		return -EINVAL;
-retry:
-	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
-	if (ret == -EAGAIN)
-		goto retry;
-	return ret;
+	return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 }
 
 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)

net/sunrpc/auth.c

@@ -41,6 +41,9 @@ static unsigned long number_cred_unused;
 
 static struct cred machine_cred = {
 	.usage = ATOMIC_INIT(1),
+#ifdef CONFIG_DEBUG_CREDENTIALS
+	.magic = CRED_MAGIC,
+#endif
 };
 
 /*

net/sunrpc/auth_gss/auth_gss.c

@@ -1549,8 +1549,10 @@ gss_marshal(struct rpc_task *task, __be32 *p)
 	cred_len = p++;
 
 	spin_lock(&ctx->gc_seq_lock);
-	req->rq_seqno = ctx->gc_seq++;
+	req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ;
 	spin_unlock(&ctx->gc_seq_lock);
+	if (req->rq_seqno == MAXSEQ)
+		goto out_expired;
 
 	*p++ = htonl((u32) RPC_GSS_VERSION);
 	*p++ = htonl((u32) ctx->gc_proc);
@@ -1572,14 +1574,18 @@ gss_marshal(struct rpc_task *task, __be32 *p)
 	mic.data = (u8 *)(p + 1);
 	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
 	if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
-		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+		goto out_expired;
 	} else if (maj_stat != 0) {
-		printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
+		pr_warn("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
+		task->tk_status = -EIO;
 		goto out_put_ctx;
 	}
 	p = xdr_encode_opaque(p, NULL, mic.len);
 	gss_put_ctx(ctx);
 	return p;
+out_expired:
+	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+	task->tk_status = -EKEYEXPIRED;
 out_put_ctx:
 	gss_put_ctx(ctx);
 	return NULL;

net/sunrpc/clnt.c

@@ -1739,14 +1739,10 @@ rpc_xdr_encode(struct rpc_task *task)
 	xdr_buf_init(&req->rq_rcv_buf,
 		     req->rq_rbuffer,
 		     req->rq_rcvsize);
-	req->rq_bytes_sent = 0;
 
 	p = rpc_encode_header(task);
-	if (p == NULL) {
-		printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
-		rpc_exit(task, -EIO);
+	if (p == NULL)
 		return;
-	}
 
 	encode = task->tk_msg.rpc_proc->p_encode;
 	if (encode == NULL)
@@ -1771,10 +1767,17 @@ call_encode(struct rpc_task *task)
 	/* Did the encode result in an error condition? */
 	if (task->tk_status != 0) {
 		/* Was the error nonfatal? */
-		if (task->tk_status == -EAGAIN || task->tk_status == -ENOMEM)
+		switch (task->tk_status) {
+		case -EAGAIN:
+		case -ENOMEM:
 			rpc_delay(task, HZ >> 4);
-		else
+			break;
+		case -EKEYEXPIRED:
+			task->tk_action = call_refresh;
+			break;
+		default:
 			rpc_exit(task, task->tk_status);
+		}
 		return;
 	}
 
@@ -2336,7 +2339,8 @@ rpc_encode_header(struct rpc_task *task)
 	*p++ = htonl(clnt->cl_vers);	/* program version */
 	*p++ = htonl(task->tk_msg.rpc_proc->p_proc);	/* procedure */
 	p = rpcauth_marshcred(task, p);
-	req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
+	if (p)
+		req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
 	return p;
 }
 

net/sunrpc/xprt.c

@@ -1151,6 +1151,7 @@ xprt_request_enqueue_transmit(struct rpc_task *task)
 	struct rpc_xprt *xprt = req->rq_xprt;
 
 	if (xprt_request_need_enqueue_transmit(task, req)) {
+		req->rq_bytes_sent = 0;
 		spin_lock(&xprt->queue_lock);
 		/*
 		 * Requests that carry congestion control credits are added
@@ -1177,7 +1178,7 @@ xprt_request_enqueue_transmit(struct rpc_task *task)
 				INIT_LIST_HEAD(&req->rq_xmit2);
 				goto out;
 			}
-		} else {
+		} else if (!req->rq_seqno) {
 			list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) {
 				if (pos->rq_task->tk_owner != task->tk_owner)
 					continue;

net/sunrpc/xprtrdma/verbs.c

@@ -845,17 +845,13 @@ static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
 	for (i = 0; i <= buf->rb_sc_last; i++) {
 		sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
 		if (!sc)
-			goto out_destroy;
+			return -ENOMEM;
 
 		sc->sc_xprt = r_xprt;
 		buf->rb_sc_ctxs[i] = sc;
 	}
 
 	return 0;
-
-out_destroy:
-	rpcrdma_sendctxs_destroy(buf);
-	return -ENOMEM;
 }
 
 /* The sendctx queue is not guaranteed to have a size that is a
@@ -1113,8 +1109,10 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 						WQ_MEM_RECLAIM | WQ_HIGHPRI,
 						0,
 			r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR]);
-	if (!buf->rb_completion_wq)
+	if (!buf->rb_completion_wq) {
+		rc = -ENOMEM;
 		goto out;
+	}
 
 	return 0;
 out:

net/sunrpc/xprtsock.c

@@ -48,6 +48,7 @@
 #include <net/udp.h>
 #include <net/tcp.h>
 #include <linux/bvec.h>
+#include <linux/highmem.h>
 #include <linux/uio.h>
 
 #include <trace/events/sunrpc.h>
@@ -376,6 +377,26 @@ xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
 	return sock_recvmsg(sock, msg, flags);
 }
 
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+static void
+xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
+{
+	struct bvec_iter bi = {
+		.bi_size = count,
+	};
+	struct bio_vec bv;
+
+	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
+	for_each_bvec(bv, bvec, bi, bi)
+		flush_dcache_page(bv.bv_page);
+}
+#else
+static inline void
+xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
+{
+}
+#endif
+
 static ssize_t
 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
@@ -409,6 +430,7 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
 				seek + buf->page_base);
 		if (ret <= 0)
 			goto sock_err;
+		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
 		offset += ret - buf->page_base;
 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 			goto out;