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| author | Vladimir Neyelov <vladimirn@mellanox.com> | 2017-05-21 19:17:31 +0300 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2017-07-17 11:45:25 -0400 |
| commit | c8c16d3bae967f1c7af541e8d016e5c51e4f010a (patch) | |
| tree | e77bbefab15af2e4e1bb08090c6447aebf697f88 /drivers/infiniband/ulp/iser/iscsi_iser.c | |
| parent | 28b5b3a23ba67970f4f534b15c4e4d687136605a (diff) | |
| download | linux-c8c16d3bae967f1c7af541e8d016e5c51e4f010a.tar.gz linux-c8c16d3bae967f1c7af541e8d016e5c51e4f010a.tar.bz2 linux-c8c16d3bae967f1c7af541e8d016e5c51e4f010a.zip | |
IB/iser: Fix connection teardown race condition
Under heavy iser target(scst) start/stop stress during login/logout
on iser intitiator side happened trace call provided below.
The function iscsi_iser_slave_alloc iser_conn pointer could be NULL,
due to the fact that function iscsi_iser_conn_stop can be called before
and free iser connection. Let's protect that flow by introducing global mutex.
BUG: unable to handle kernel paging request at 0000000000001018
IP: [<ffffffffc0426f7e>] iscsi_iser_slave_alloc+0x1e/0x50 [ib_iser]
Call Trace:
? scsi_alloc_sdev+0x242/0x300
scsi_probe_and_add_lun+0x9e1/0xea0
? kfree_const+0x21/0x30
? kobject_set_name_vargs+0x76/0x90
? __pm_runtime_resume+0x5b/0x70
__scsi_scan_target+0xf6/0x250
scsi_scan_target+0xea/0x100
iscsi_user_scan_session.part.13+0x101/0x130 [scsi_transport_iscsi]
? iscsi_user_scan_session.part.13+0x130/0x130 [scsi_transport_iscsi]
iscsi_user_scan_session+0x1e/0x30 [scsi_transport_iscsi]
device_for_each_child+0x50/0x90
iscsi_user_scan+0x44/0x60 [scsi_transport_iscsi]
store_scan+0xa8/0x100
? common_file_perm+0x5d/0x1c0
dev_attr_store+0x18/0x30
sysfs_kf_write+0x37/0x40
kernfs_fop_write+0x12c/0x1c0
__vfs_write+0x18/0x40
vfs_write+0xb5/0x1a0
SyS_write+0x55/0xc0
Fixes: 318d311e8f01 ("iser: Accept arbitrary sg lists mapping if the device supports it")
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Vladimir Neyelov <vladimirn@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimbeg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/ulp/iser/iscsi_iser.c')
| -rw-r--r-- | drivers/infiniband/ulp/iser/iscsi_iser.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c index 5a887efb4bdf..37b33d708c2d 100644 --- a/drivers/infiniband/ulp/iser/iscsi_iser.c +++ b/drivers/infiniband/ulp/iser/iscsi_iser.c @@ -83,6 +83,7 @@ static struct scsi_host_template iscsi_iser_sht; static struct iscsi_transport iscsi_iser_transport; static struct scsi_transport_template *iscsi_iser_scsi_transport; static struct workqueue_struct *release_wq; +static DEFINE_MUTEX(unbind_iser_conn_mutex); struct iser_global ig; int iser_debug_level = 0; @@ -550,12 +551,14 @@ iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) */ if (iser_conn) { mutex_lock(&iser_conn->state_mutex); + mutex_lock(&unbind_iser_conn_mutex); iser_conn_terminate(iser_conn); iscsi_conn_stop(cls_conn, flag); /* unbind */ iser_conn->iscsi_conn = NULL; conn->dd_data = NULL; + mutex_unlock(&unbind_iser_conn_mutex); complete(&iser_conn->stop_completion); mutex_unlock(&iser_conn->state_mutex); @@ -977,13 +980,21 @@ static int iscsi_iser_slave_alloc(struct scsi_device *sdev) struct iser_conn *iser_conn; struct ib_device *ib_dev; + mutex_lock(&unbind_iser_conn_mutex); + session = starget_to_session(scsi_target(sdev))->dd_data; iser_conn = session->leadconn->dd_data; + if (!iser_conn) { + mutex_unlock(&unbind_iser_conn_mutex); + return -ENOTCONN; + } ib_dev = iser_conn->ib_conn.device->ib_device; if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)) blk_queue_virt_boundary(sdev->request_queue, ~MASK_4K); + mutex_unlock(&unbind_iser_conn_mutex); + return 0; } |