Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
CC:     Bharat Potnuri <bharat@chelsio.com>,
        Jason Gunthorpe <jgg@mellanox.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.14 39/67] iser-target: avoid reinitializing rdma
 contexts for isert commands
Thread-Topic: [PATCH AUTOSEL for 4.14 39/67] iser-target: avoid reinitializing
 rdma contexts for isert commands
Thread-Index: AQHTtpoBojOIARTzaE2eLQNdl3gbjw==
Date:   Thu, 8 Mar 2018 04:57:48 +0000
Message-ID: <20180308045641.7814-39-alexander.levin@microsoft.com>
References: <20180308045641.7814-1-alexander.levin@microsoft.com>
In-Reply-To: <20180308045641.7814-1-alexander.levin@microsoft.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: microsoft.com does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: e6f47a21-2b84-49ca-81ec-08d584b14ccc
X-MS-Exchange-CrossTenant-originalarrivaltime: 08 Mar 2018 04:57:48.6287
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR2101MB1015
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Bharat Potnuri <bharat@chelsio.com>

[ Upstream commit 66f53e6f5400578bae58db0c06d85a8820831f40 ]

isert commands that failed during isert_rdma_rw_ctx_post() are queued to
Queue-Full(QF) queue and are scheduled to be reposted during queue-full
queue processing. During this reposting, the rdma contexts are initialised
again in isert_rdma_rw_ctx_post(), which is leaking significant memory.

unreferenced object 0xffff8830201d9640 (size 64):
  comm "kworker/0:2", pid 195, jiffies 4295374851 (age 4528.436s)
  hex dump (first 32 bytes):
    00 60 8b cb 2e 00 00 00 00 10 00 00 00 00 00 00  .`..............
    00 90 e3 cb 2e 00 00 00 00 10 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8170711e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811f8ba5>] __kmalloc+0x125/0x2b0
    [<ffffffffa046b24f>] rdma_rw_ctx_init+0x15f/0x6f0 [ib_core]
    [<ffffffffa07ab644>] isert_rdma_rw_ctx_post+0xc4/0x3c0 [ib_isert]
    [<ffffffffa07ad972>] isert_put_datain+0x112/0x1c0 [ib_isert]
    [<ffffffffa07dddce>] lio_queue_data_in+0x2e/0x30 [iscsi_target_mod]
    [<ffffffffa076c322>] target_qf_do_work+0x2b2/0x4b0 [target_core_mod]
    [<ffffffff81080c3b>] process_one_work+0x1db/0x5d0
    [<ffffffff8108107d>] worker_thread+0x4d/0x3e0
    [<ffffffff81088667>] kthread+0x117/0x150
    [<ffffffff81713fa7>] ret_from_fork+0x27/0x40
    [<ffffffffffffffff>] 0xffffffffffffffff

Here is patch to use the older rdma contexts while reposting
the isert commands intead of reinitialising them.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/infiniband/ulp/isert/ib_isert.c | 7 +++++++
 drivers/infiniband/ulp/isert/ib_isert.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/u=
lp/isert/ib_isert.c
index 9d4785ba24cb..e770c17cbca9 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -2124,6 +2124,9 @@ isert_rdma_rw_ctx_post(struct isert_cmd *cmd, struct =
isert_conn *conn,
 	u32 rkey, offset;
 	int ret;
=20
+	if (cmd->ctx_init_done)
+		goto rdma_ctx_post;
+
 	if (dir =3D=3D DMA_FROM_DEVICE) {
 		addr =3D cmd->write_va;
 		rkey =3D cmd->write_stag;
@@ -2151,11 +2154,15 @@ isert_rdma_rw_ctx_post(struct isert_cmd *cmd, struc=
t isert_conn *conn,
 				se_cmd->t_data_sg, se_cmd->t_data_nents,
 				offset, addr, rkey, dir);
 	}
+
 	if (ret < 0) {
 		isert_err("Cmd: %p failed to prepare RDMA res\n", cmd);
 		return ret;
 	}
=20
+	cmd->ctx_init_done =3D true;
+
+rdma_ctx_post:
 	ret =3D rdma_rw_ctx_post(&cmd->rw, conn->qp, port_num, cqe, chain_wr);
 	if (ret < 0)
 		isert_err("Cmd: %p failed to post RDMA res\n", cmd);
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/u=
lp/isert/ib_isert.h
index d6fd248320ae..3b296bac4f60 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -126,6 +126,7 @@ struct isert_cmd {
 	struct rdma_rw_ctx	rw;
 	struct work_struct	comp_work;
 	struct scatterlist	sg;
+	bool			ctx_init_done;
 };
=20
 static inline struct isert_cmd *tx_desc_to_cmd(struct iser_tx_desc *desc)
--=20
2.14.1