1 files changed, 199 insertions, 82 deletions

diff --git a/net/rds/message.c b/net/rds/message.c
index aba232f9f308..199a899a43e9 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006 Oracle.  All rights reserved.
+ * Copyright (c) 2006, 2020 Oracle and/or its affiliates.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -33,6 +33,9 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/export.h>
+#include <linux/skbuff.h>
+#include <linux/list.h>
+#include <linux/errqueue.h>
 
 #include "rds.h"
 
@@ -41,49 +44,137 @@ static unsigned int	rds_exthdr_size[__RDS_EXTHDR_MAX] = {
 [RDS_EXTHDR_VERSION]	= sizeof(struct rds_ext_header_version),
 [RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
 [RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
+[RDS_EXTHDR_NPATHS]	= sizeof(__be16),
+[RDS_EXTHDR_GEN_NUM]	= sizeof(__be32),
 };
 
-
 void rds_message_addref(struct rds_message *rm)
 {
-	rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
-	atomic_inc(&rm->m_refcount);
+	rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
+	refcount_inc(&rm->m_refcount);
 }
 EXPORT_SYMBOL_GPL(rds_message_addref);
 
+static inline bool rds_zcookie_add(struct rds_msg_zcopy_info *info, u32 cookie)
+{
+	struct rds_zcopy_cookies *ck = &info->zcookies;
+	int ncookies = ck->num;
+
+	if (ncookies == RDS_MAX_ZCOOKIES)
+		return false;
+	ck->cookies[ncookies] = cookie;
+	ck->num =  ++ncookies;
+	return true;
+}
+
+static struct rds_msg_zcopy_info *rds_info_from_znotifier(struct rds_znotifier *znotif)
+{
+	return container_of(znotif, struct rds_msg_zcopy_info, znotif);
+}
+
+void rds_notify_msg_zcopy_purge(struct rds_msg_zcopy_queue *q)
+{
+	unsigned long flags;
+	LIST_HEAD(copy);
+	struct rds_msg_zcopy_info *info, *tmp;
+
+	spin_lock_irqsave(&q->lock, flags);
+	list_splice(&q->zcookie_head, &copy);
+	INIT_LIST_HEAD(&q->zcookie_head);
+	spin_unlock_irqrestore(&q->lock, flags);
+
+	list_for_each_entry_safe(info, tmp, &copy, rs_zcookie_next) {
+		list_del(&info->rs_zcookie_next);
+		kfree(info);
+	}
+}
+
+static void rds_rm_zerocopy_callback(struct rds_sock *rs,
+				     struct rds_znotifier *znotif)
+{
+	struct rds_msg_zcopy_info *info;
+	struct rds_msg_zcopy_queue *q;
+	u32 cookie = znotif->z_cookie;
+	struct rds_zcopy_cookies *ck;
+	struct list_head *head;
+	unsigned long flags;
+
+	mm_unaccount_pinned_pages(&znotif->z_mmp);
+	q = &rs->rs_zcookie_queue;
+	spin_lock_irqsave(&q->lock, flags);
+	head = &q->zcookie_head;
+	if (!list_empty(head)) {
+		info = list_first_entry(head, struct rds_msg_zcopy_info,
+					rs_zcookie_next);
+		if (rds_zcookie_add(info, cookie)) {
+			spin_unlock_irqrestore(&q->lock, flags);
+			kfree(rds_info_from_znotifier(znotif));
+			/* caller invokes rds_wake_sk_sleep() */
+			return;
+		}
+	}
+
+	info = rds_info_from_znotifier(znotif);
+	ck = &info->zcookies;
+	memset(ck, 0, sizeof(*ck));
+	WARN_ON(!rds_zcookie_add(info, cookie));
+	list_add_tail(&info->rs_zcookie_next, &q->zcookie_head);
+
+	spin_unlock_irqrestore(&q->lock, flags);
+	/* caller invokes rds_wake_sk_sleep() */
+}
+
 /*
  * This relies on dma_map_sg() not touching sg[].page during merging.
  */
 static void rds_message_purge(struct rds_message *rm)
 {
-	unsigned long i;
+	unsigned long i, flags;
+	bool zcopy = false;
 
 	if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
 		return;
 
+	spin_lock_irqsave(&rm->m_rs_lock, flags);
+	if (rm->m_rs) {
+		struct rds_sock *rs = rm->m_rs;
+
+		if (rm->data.op_mmp_znotifier) {
+			zcopy = true;
+			rds_rm_zerocopy_callback(rs, rm->data.op_mmp_znotifier);
+			rds_wake_sk_sleep(rs);
+			rm->data.op_mmp_znotifier = NULL;
+		}
+		sock_put(rds_rs_to_sk(rs));
+		rm->m_rs = NULL;
+	}
+	spin_unlock_irqrestore(&rm->m_rs_lock, flags);
+
 	for (i = 0; i < rm->data.op_nents; i++) {
-		rdsdebug("putting data page %p\n", (void *)sg_page(&rm->data.op_sg[i]));
 		/* XXX will have to put_page for page refs */
-		__free_page(sg_page(&rm->data.op_sg[i]));
+		if (!zcopy)
+			__free_page(sg_page(&rm->data.op_sg[i]));
+		else
+			put_page(sg_page(&rm->data.op_sg[i]));
 	}
 	rm->data.op_nents = 0;
 
 	if (rm->rdma.op_active)
 		rds_rdma_free_op(&rm->rdma);
 	if (rm->rdma.op_rdma_mr)
-		rds_mr_put(rm->rdma.op_rdma_mr);
+		kref_put(&rm->rdma.op_rdma_mr->r_kref, __rds_put_mr_final);
 
 	if (rm->atomic.op_active)
 		rds_atomic_free_op(&rm->atomic);
 	if (rm->atomic.op_rdma_mr)
-		rds_mr_put(rm->atomic.op_rdma_mr);
+		kref_put(&rm->atomic.op_rdma_mr->r_kref, __rds_put_mr_final);
 }
 
 void rds_message_put(struct rds_message *rm)
 {
-	rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
-	WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
-	if (atomic_dec_and_test(&rm->m_refcount)) {
+	rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
+	WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
+	if (refcount_dec_and_test(&rm->m_refcount)) {
 		BUG_ON(!list_empty(&rm->m_sock_item));
 		BUG_ON(!list_empty(&rm->m_conn_item));
 		rds_message_purge(rm);
@@ -204,7 +295,7 @@ struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
 	rm->m_used_sgs = 0;
 	rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
 
-	atomic_set(&rm->m_refcount, 1);
+	refcount_set(&rm->m_refcount, 1);
 	INIT_LIST_HEAD(&rm->m_sock_item);
 	INIT_LIST_HEAD(&rm->m_conn_item);
 	spin_lock_init(&rm->m_rs_lock);
@@ -222,11 +313,16 @@ struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
 	struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
 	struct scatterlist *sg_ret;
 
-	WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
-	WARN_ON(!nents);
+	if (nents <= 0) {
+		pr_warn("rds: alloc sgs failed! nents <= 0\n");
+		return ERR_PTR(-EINVAL);
+	}
 
-	if (rm->m_used_sgs + nents > rm->m_total_sgs)
-		return NULL;
+	if (rm->m_used_sgs + nents > rm->m_total_sgs) {
+		pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
+			rm->m_total_sgs, rm->m_used_sgs, nents);
+		return ERR_PTR(-ENOMEM);
+	}
 
 	sg_ret = &sg_first[rm->m_used_sgs];
 	sg_init_table(sg_ret, nents);
@@ -239,7 +335,7 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
 {
 	struct rds_message *rm;
 	unsigned int i;
-	int num_sgs = ceil(total_len, PAGE_SIZE);
+	int num_sgs = DIV_ROUND_UP(total_len, PAGE_SIZE);
 	int extra_bytes = num_sgs * sizeof(struct scatterlist);
 
 	rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
@@ -248,91 +344,128 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
 
 	set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
 	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
-	rm->data.op_nents = ceil(total_len, PAGE_SIZE);
+	rm->data.op_nents = DIV_ROUND_UP(total_len, PAGE_SIZE);
 	rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
-	if (!rm->data.op_sg) {
+	if (IS_ERR(rm->data.op_sg)) {
+		void *err = ERR_CAST(rm->data.op_sg);
 		rds_message_put(rm);
-		return ERR_PTR(-ENOMEM);
+		return err;
 	}
 
 	for (i = 0; i < rm->data.op_nents; ++i) {
 		sg_set_page(&rm->data.op_sg[i],
-				virt_to_page(page_addrs[i]),
+				virt_to_page((void *)page_addrs[i]),
 				PAGE_SIZE, 0);
 	}
 
 	return rm;
 }
 
-int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
-					       size_t total_len)
+static int rds_message_zcopy_from_user(struct rds_message *rm, struct iov_iter *from)
 {
-	unsigned long to_copy;
-	unsigned long iov_off;
-	unsigned long sg_off;
-	struct iovec *iov;
 	struct scatterlist *sg;
 	int ret = 0;
+	int length = iov_iter_count(from);
+	struct rds_msg_zcopy_info *info;
 
-	rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
+	rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
 
 	/*
 	 * now allocate and copy in the data payload.
 	 */
 	sg = rm->data.op_sg;
-	iov = first_iov;
-	iov_off = 0;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&info->rs_zcookie_next);
+	rm->data.op_mmp_znotifier = &info->znotif;
+	if (mm_account_pinned_pages(&rm->data.op_mmp_znotifier->z_mmp,
+				    length)) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	while (iov_iter_count(from)) {
+		struct page *pages;
+		size_t start;
+		ssize_t copied;
+
+		copied = iov_iter_get_pages2(from, &pages, PAGE_SIZE,
+					    1, &start);
+		if (copied < 0) {
+			struct mmpin *mmp;
+			int i;
+
+			for (i = 0; i < rm->data.op_nents; i++)
+				put_page(sg_page(&rm->data.op_sg[i]));
+			mmp = &rm->data.op_mmp_znotifier->z_mmp;
+			mm_unaccount_pinned_pages(mmp);
+			ret = -EFAULT;
+			goto err;
+		}
+		length -= copied;
+		sg_set_page(sg, pages, copied, start);
+		rm->data.op_nents++;
+		sg++;
+	}
+	WARN_ON_ONCE(length != 0);
+	return ret;
+err:
+	kfree(info);
+	rm->data.op_mmp_znotifier = NULL;
+	return ret;
+}
+
+int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from,
+			       bool zcopy)
+{
+	unsigned long to_copy, nbytes;
+	unsigned long sg_off;
+	struct scatterlist *sg;
+	int ret = 0;
+
+	rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));
+
+	/* now allocate and copy in the data payload.  */
+	sg = rm->data.op_sg;
 	sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */
 
-	while (total_len) {
+	if (zcopy)
+		return rds_message_zcopy_from_user(rm, from);
+
+	while (iov_iter_count(from)) {
 		if (!sg_page(sg)) {
-			ret = rds_page_remainder_alloc(sg, total_len,
+			ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
 						       GFP_HIGHUSER);
 			if (ret)
-				goto out;
+				return ret;
 			rm->data.op_nents++;
 			sg_off = 0;
 		}
 
-		while (iov_off == iov->iov_len) {
-			iov_off = 0;
-			iov++;
-		}
-
-		to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
-		to_copy = min_t(size_t, to_copy, total_len);
+		to_copy = min_t(unsigned long, iov_iter_count(from),
+				sg->length - sg_off);
 
-		rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
-			 "sg [%p, %u, %u] + %lu\n",
-			 to_copy, iov->iov_base, iov->iov_len, iov_off,
-			 (void *)sg_page(sg), sg->offset, sg->length, sg_off);
+		rds_stats_add(s_copy_from_user, to_copy);
+		nbytes = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
+					     to_copy, from);
+		if (nbytes != to_copy)
+			return -EFAULT;
 
-		ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
-					      iov->iov_base + iov_off,
-					      to_copy);
-		if (ret)
-			goto out;
-
-		iov_off += to_copy;
-		total_len -= to_copy;
 		sg_off += to_copy;
 
 		if (sg_off == sg->length)
 			sg++;
 	}
 
-out:
 	return ret;
 }
 
-int rds_message_inc_copy_to_user(struct rds_incoming *inc,
-				 struct iovec *first_iov, size_t size)
+int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
 {
 	struct rds_message *rm;
-	struct iovec *iov;
 	struct scatterlist *sg;
 	unsigned long to_copy;
-	unsigned long iov_off;
 	unsigned long vec_off;
 	int copied;
 	int ret;
@@ -341,36 +474,21 @@ int rds_message_inc_copy_to_user(struct rds_incoming *inc,
 	rm = container_of(inc, struct rds_message, m_inc);
 	len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
 
-	iov = first_iov;
-	iov_off = 0;
 	sg = rm->data.op_sg;
 	vec_off = 0;
 	copied = 0;
 
-	while (copied < size && copied < len) {
-		while (iov_off == iov->iov_len) {
-			iov_off = 0;
-			iov++;
-		}
-
-		to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
-		to_copy = min_t(size_t, to_copy, size - copied);
+	while (iov_iter_count(to) && copied < len) {
+		to_copy = min_t(unsigned long, iov_iter_count(to),
+				sg->length - vec_off);
 		to_copy = min_t(unsigned long, to_copy, len - copied);
 
-		rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
-			 "sg [%p, %u, %u] + %lu\n",
-			 to_copy, iov->iov_base, iov->iov_len, iov_off,
-			 sg_page(sg), sg->offset, sg->length, vec_off);
-
-		ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
-					    iov->iov_base + iov_off,
-					    to_copy);
-		if (ret) {
-			copied = ret;
-			break;
-		}
+		rds_stats_add(s_copy_to_user, to_copy);
+		ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
+					to_copy, to);
+		if (ret != to_copy)
+			return -EFAULT;
 
-		iov_off += to_copy;
 		vec_off += to_copy;
 		copied += to_copy;
 
@@ -399,4 +517,3 @@ void rds_message_unmapped(struct rds_message *rm)
 	wake_up_interruptible(&rm->m_flush_wait);
 }
 EXPORT_SYMBOL_GPL(rds_message_unmapped);
-