[PATCH 11/22] RDS: Make use of the new sg_map helper function

From: Logan Gunthorpe
Date: Thu Apr 13 2017 - 18:08:47 EST


Straightforward conversion except there's no error path, so we WARN if
the sg_map fails.

Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
---
net/rds/ib_recv.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index e10624a..7f8fa99 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -801,9 +801,20 @@ static void rds_ib_cong_recv(struct rds_connection *conn,
to_copy = min(RDS_FRAG_SIZE - frag_off, PAGE_SIZE - map_off);
BUG_ON(to_copy & 7); /* Must be 64bit aligned. */

- addr = kmap_atomic(sg_page(&frag->f_sg));
+ addr = sg_map(&frag->f_sg, SG_KMAP_ATOMIC);
+ if (IS_ERR(addr)) {
+ /*
+ * This should really never happen unless
+ * the code is changed to use memory that is
+ * not mappable in the sg. Seeing there doesn't
+ * seem to be any error path out of here,
+ * we can only WARN.
+ */
+ WARN(1, "Non-mappable memory used in sg!");
+ return;
+ }

- src = addr + frag->f_sg.offset + frag_off;
+ src = addr + frag_off;
dst = (void *)map->m_page_addrs[map_page] + map_off;
for (k = 0; k < to_copy; k += 8) {
/* Record ports that became uncongested, ie
@@ -811,7 +822,7 @@ static void rds_ib_cong_recv(struct rds_connection *conn,
uncongested |= ~(*src) & *dst;
*dst++ = *src++;
}
- kunmap_atomic(addr);
+ sg_unmap(&frag->f_sg, addr, SG_KMAP_ATOMIC);

copied += to_copy;

--
2.1.4