This is a note to let you know that I've just added the patch titled
vhost-scsi: Take configfs group dependency during VHOST_SCSI_SET_ENDPOINT
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vhost-scsi-take-configfs-group-dependency-during-vhost_scsi_set_endpoint.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From nab@xxxxxxxxxxxxxxx Tue Feb 3 15:07:28 2015
From: "Nicholas A. Bellinger" <nab@xxxxxxxxxxxxxxx>
Date: Fri, 30 Jan 2015 22:17:22 +0000
Subject: vhost-scsi: Take configfs group dependency during VHOST_SCSI_SET_ENDPOINT
To: target-devel <target-devel@xxxxxxxxxxxxxxx>
Cc: Greg-KH <gregkh@xxxxxxxxxxxxxxxxxxx>, stable <stable@xxxxxxxxxxxxxxx>, Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>, "Michael S. Tsirkin" <mst@xxxxxxxxxx>, Paolo Bonzini <pbonzini@xxxxxxxxxx>, Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Message-ID: <1422656251-29468-4-git-send-email-nab@xxxxxxxxxxxxxxx>
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
commit ab8edab132829b26dd13db6caca3c242cce35dc1 upstream.
This patch addresses a bug where individual vhost-scsi configfs endpoint
groups can be removed from below while active exports to QEMU userspace
still exist, resulting in an OOPs.
It adds a configfs_depend_item() in vhost_scsi_set_endpoint() to obtain
an explicit dependency on se_tpg->tpg_group in order to prevent individual
vhost-scsi WWPN endpoints from being released via normal configfs methods
while an QEMU ioctl reference still exists.
Also, add matching configfs_undepend_item() in vhost_scsi_clear_endpoint()
to release the dependency, once QEMU's reference to the individual group
at /sys/kernel/config/target/vhost/$WWPN/$TPGT is released.
(Fix up vhost_scsi_clear_endpoint() error path - DanC)
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vhost/scsi.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1150,6 +1150,7 @@ static int vhost_scsi_set_endpoint(
struct vhost_scsi *vs,
struct vhost_scsi_target *t)
{
+ struct se_portal_group *se_tpg;
struct tcm_vhost_tport *tv_tport;
struct tcm_vhost_tpg *tv_tpg;
struct tcm_vhost_tpg **vs_tpg;
@@ -1197,6 +1198,21 @@ static int vhost_scsi_set_endpoint(
ret = -EEXIST;
goto out;
}
+ /*
+ * In order to ensure individual vhost-scsi configfs
+ * groups cannot be removed while in use by vhost ioctl,
+ * go ahead and take an explicit se_tpg->tpg_group.cg_item
+ * dependency now.
+ */
+ se_tpg = &tv_tpg->se_tpg;
+ ret = configfs_depend_item(se_tpg->se_tpg_tfo->tf_subsys,
+ &se_tpg->tpg_group.cg_item);
+ if (ret) {
+ pr_warn("configfs_depend_item() failed: %d\n", ret);
+ kfree(vs_tpg);
+ mutex_unlock(&tv_tpg->tv_tpg_mutex);
+ goto out;
+ }
tv_tpg->tv_tpg_vhost_count++;
tv_tpg->vhost_scsi = vs;
vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
@@ -1240,6 +1256,7 @@ static int vhost_scsi_clear_endpoint(
struct vhost_scsi *vs,
struct vhost_scsi_target *t)
{
+ struct se_portal_group *se_tpg;
struct tcm_vhost_tport *tv_tport;
struct tcm_vhost_tpg *tv_tpg;
struct vhost_virtqueue *vq;
@@ -1288,6 +1305,13 @@ static int vhost_scsi_clear_endpoint(
vs->vs_tpg[target] = NULL;
match = true;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
+ /*
+ * Release se_tpg->tpg_group.cg_item configfs dependency now
+ * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
+ */
+ se_tpg = &tv_tpg->se_tpg;
+ configfs_undepend_item(se_tpg->se_tpg_tfo->tf_subsys,
+ &se_tpg->tpg_group.cg_item);
}
if (match) {
for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
Patches currently in stable-queue which might be from nab@xxxxxxxxxxxxxxx are
queue-3.10/iser-target-fix-connected_handler-teardown-flow-race.patch
queue-3.10/iscsi-iser-target-initiate-termination-only-once.patch
queue-3.10/ib_isert-add-max_send_sge-2-minimum-for-control-pdu-responses.patch
queue-3.10/iser-target-fix-implicit-termination-of-connections.patch
queue-3.10/iser-target-parallelize-cm-connection-establishment.patch
queue-3.10/vhost-scsi-take-configfs-group-dependency-during-vhost_scsi_set_endpoint.patch
queue-3.10/ib-isert-adjust-cq-size-to-hw-limits.patch
queue-3.10/iser-target-handle-addr_change-event-for-listener-cm_id.patch
queue-3.10/vhost-scsi-add-missing-virtio-scsi-tcm-attribute-conversion.patch
queue-3.10/target-drop-arbitrary-maximum-i-o-size-limit.patch
queue-3.10/tcm_loop-fix-wrong-i_t-nexus-association.patch
queue-3.10/iser-target-fix-flush-disconnect-completion-handling.patch
--
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