| Message ID | 1439297760-30645-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c index e8fdb172adbb..a985158d95d5 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)
This is a note to let you know that I have just added a patch titled rds: rds_ib_device.refcount overflow to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt16. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 373f2d629bcc15ac81901dd13d3d87a2376b8c60 Mon Sep 17 00:00:00 2001 From: Wengang Wang <wen.gang.wang@oracle.com> Date: Mon, 6 Jul 2015 14:35:11 +0800 Subject: rds: rds_ib_device.refcount overflow commit 4fabb59449aa44a585b3603ffdadd4c5f4d0c033 upstream. 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: Luis Henriques <luis.henriques@canonical.com> --- net/rds/ib_rdma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)