From: Santosh Shilimkar <santosh.shilimkar@oracle.com>
To: netdev@vger.kernel.org, davem@davemloft.net
Cc: linux-kernel@vger.kernel.org,
Santosh Shilimkar <santosh.shilimkar@oracle.com>
Subject: [net][PATCH v2 2/2] RDS: Fix the atomicity for congestion map update
Date: Thu, 14 Apr 2016 10:43:27 -0700 [thread overview]
Message-ID: <1460655807-26236-3-git-send-email-santosh.shilimkar@oracle.com> (raw)
In-Reply-To: <1460655807-26236-1-git-send-email-santosh.shilimkar@oracle.com>
Two different threads with different rds sockets may be in
rds_recv_rcvbuf_delta() via receive path. If their ports
both map to the same word in the congestion map, then
using non-atomic ops to update it could cause the map to
be incorrect. Lets use atomics to avoid such an issue.
Full credit to Wengang <wen.gang.wang@oracle.com> for
finding the issue, analysing it and also pointing out
to offending code with spin lock based fix.
Reviewed-by: Leon Romanovsky <leon@leon.nu>
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
---
net/rds/cong.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/rds/cong.c b/net/rds/cong.c
index e6144b8..6641bcf 100644
--- a/net/rds/cong.c
+++ b/net/rds/cong.c
@@ -299,7 +299,7 @@ void rds_cong_set_bit(struct rds_cong_map *map, __be16 port)
i = be16_to_cpu(port) / RDS_CONG_MAP_PAGE_BITS;
off = be16_to_cpu(port) % RDS_CONG_MAP_PAGE_BITS;
- __set_bit_le(off, (void *)map->m_page_addrs[i]);
+ set_bit_le(off, (void *)map->m_page_addrs[i]);
}
void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port)
@@ -313,7 +313,7 @@ void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port)
i = be16_to_cpu(port) / RDS_CONG_MAP_PAGE_BITS;
off = be16_to_cpu(port) % RDS_CONG_MAP_PAGE_BITS;
- __clear_bit_le(off, (void *)map->m_page_addrs[i]);
+ clear_bit_le(off, (void *)map->m_page_addrs[i]);
}
static int rds_cong_test_bit(struct rds_cong_map *map, __be16 port)
--
1.9.1
next prev parent reply other threads:[~2016-04-14 17:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-14 17:43 [net][PATCH v2 0/2] RDS: couple of fixes for 4.6 Santosh Shilimkar
2016-04-14 17:43 ` [net][PATCH v2 1/2] RDS: fix endianness for dp_ack_seq Santosh Shilimkar
2016-04-16 23:01 ` David Miller
2016-04-14 17:43 ` Santosh Shilimkar [this message]
2016-04-16 23:01 ` [net][PATCH v2 2/2] RDS: Fix the atomicity for congestion map update David Miller
2016-04-16 22:53 ` [net][PATCH v2 0/2] RDS: couple of fixes for 4.6 David Miller
2016-04-16 23:57 ` santosh shilimkar
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