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authorWengang Wang <wen.gang.wang@oracle.com>2015-07-06 14:35:11 +0800
committerSasha Levin <sasha.levin@oracle.com>2015-08-27 13:25:50 -0400
commitd52f73d1c36d9429f895306403b852980e2632ef (patch)
treeb81b1c56acf61acbbab8b6d495cd6a380a573605
parent3c239f5a90855526c93c38687c1437a153d737eb (diff)
downloadlinux-linaro-stable-d52f73d1c36d9429f895306403b852980e2632ef.tar.gz
rds: rds_ib_device.refcount overflow
[ Upstream commit 4fabb59449aa44a585b3603ffdadd4c5f4d0c033 ] Fixes: 3e0249f9c05c ("RDS/IB: add refcount tracking to struct rds_ib_device") There lacks a dropping on rds_ib_device.refcount in case rds_ib_alloc_fmr failed(mr pool running out). this lead to the refcount overflow. A complain in line 117(see following) is seen. From vmcore: s_ib_rdma_mr_pool_depleted is 2147485544 and rds_ibdev->refcount is -2147475448. That is the evidence the mr pool is used up. so rds_ib_alloc_fmr is very likely to return ERR_PTR(-EAGAIN). 115 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev) 116 { 117 BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0); 118 if (atomic_dec_and_test(&rds_ibdev->refcount)) 119 queue_work(rds_wq, &rds_ibdev->free_work); 120 } fix is to drop refcount when rds_ib_alloc_fmr failed. Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com> Reviewed-by: Haggai Eran <haggaie@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--net/rds/ib_rdma.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 273b8bff6ba4..657ba9f5d308 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -759,8 +759,10 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
}
ibmr = rds_ib_alloc_fmr(rds_ibdev);
- if (IS_ERR(ibmr))
+ if (IS_ERR(ibmr)) {
+ rds_ib_dev_put(rds_ibdev);
return ibmr;
+ }
ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
if (ret == 0)