[PATCH 1/2] ibmvscsi: Protect ibmvscsi_head from concurrent modificaiton
From: Tyrel Datwyler <hidden>
Date: 2019-03-20 18:41:50
Also in:
linux-scsi, stable
Subsystem:
ibm power virtual scsi device drivers, linux for powerpc (32-bit and 64-bit), scsi subsystem, the rest · Maintainers:
Tyrel Datwyler, Madhavan Srinivasan, "James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
For each ibmvscsi host created during a probe or destroyed during a
remove we either add or remove that host to/from the global ibmvscsi_head
list. This runs the risk of concurrent modification.
This patch adds a simple spinlock around the list modification calls to
prevent concurrent updates as is done similarly in the ibmvfc driver and
ipr driver.
Fixes: 32d6e4b6e4ea ("scsi: ibmvscsi: add vscsi hosts to global list_head")
Cc: <redacted> # v4.10+
Signed-off-by: Tyrel Datwyler <redacted>
---
drivers/scsi/ibmvscsi/ibmvscsi.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 1135e74646e2..2b22969f3f63 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c@@ -96,6 +96,7 @@ static int client_reserve = 1; static char partition_name[96] = "UNKNOWN"; static unsigned int partition_number = -1; static LIST_HEAD(ibmvscsi_head); +static DEFINE_SPINLOCK(ibmvscsi_driver_lock); static struct scsi_transport_template *ibmvscsi_transport_template;
@@ -2270,7 +2271,9 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id) } dev_set_drvdata(&vdev->dev, hostdata); + spin_lock(&ibmvscsi_driver_lock); list_add_tail(&hostdata->host_list, &ibmvscsi_head); + spin_unlock(&ibmvscsi_driver_lock); return 0; add_srp_port_failed:
@@ -2292,7 +2295,9 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id) static int ibmvscsi_remove(struct vio_dev *vdev) { struct ibmvscsi_host_data *hostdata = dev_get_drvdata(&vdev->dev); + spin_lock(&ibmvscsi_driver_lock); list_del(&hostdata->host_list); + spin_unlock(&ibmvscsi_driver_lock); unmap_persist_bufs(hostdata); release_event_pool(&hostdata->pool, hostdata); ibmvscsi_release_crq_queue(&hostdata->queue, hostdata,
--
2.12.3