[SCSI] iscsi class: export pid of process that created
There could be multiple userspace entities creating/destroying/
recoverying sessions and also the kernel's iscsi drivers could
be doing this too. If the userspace apps do try to manage the kernel
ones it can get the driver/fw out of sync and cause the user to
loose the root disk, oopses or ping ponging becasue userspace
wants to do one thing but the kernel manager thought we
are trying to do another.
This patch fixes the problem by just exporting the pid of
the entity that created the session. Userspace programs like
iscsid, iscsiadm, iscsistart, qlogic's tools, etc, can then
figure out which sessions they own and only manage them.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 96029e6..c1b172b 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1030,6 +1030,7 @@
return NULL;
session->transport = transport;
+ session->creator = -1;
session->recovery_tmo = 120;
session->state = ISCSI_SESSION_FREE;
INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
@@ -1634,8 +1635,9 @@
static int
iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
- struct iscsi_uevent *ev, uint32_t initial_cmdsn,
- uint16_t cmds_max, uint16_t queue_depth)
+ struct iscsi_uevent *ev, pid_t pid,
+ uint32_t initial_cmdsn, uint16_t cmds_max,
+ uint16_t queue_depth)
{
struct iscsi_transport *transport = priv->iscsi_transport;
struct iscsi_cls_session *session;
@@ -1646,6 +1648,7 @@
if (!session)
return -ENOMEM;
+ session->creator = pid;
shost = iscsi_session_to_shost(session);
ev->r.c_session_ret.host_no = shost->host_no;
ev->r.c_session_ret.sid = session->sid;
@@ -1938,6 +1941,7 @@
switch (nlh->nlmsg_type) {
case ISCSI_UEVENT_CREATE_SESSION:
err = iscsi_if_create_session(priv, ep, ev,
+ NETLINK_CREDS(skb)->pid,
ev->u.c_session.initial_cmdsn,
ev->u.c_session.cmds_max,
ev->u.c_session.queue_depth);
@@ -1950,6 +1954,7 @@
}
err = iscsi_if_create_session(priv, ep, ev,
+ NETLINK_CREDS(skb)->pid,
ev->u.c_bound_session.initial_cmdsn,
ev->u.c_bound_session.cmds_max,
ev->u.c_bound_session.queue_depth);
@@ -2298,6 +2303,15 @@
}
static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
NULL);
+static ssize_t
+show_priv_session_creator(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
+ return sprintf(buf, "%d\n", session->creator);
+}
+static ISCSI_CLASS_ATTR(priv_sess, creator, S_IRUGO, show_priv_session_creator,
+ NULL);
#define iscsi_priv_session_attr_show(field, format) \
static ssize_t \
@@ -2367,6 +2381,7 @@
&dev_attr_sess_targetalias.attr,
&dev_attr_priv_sess_recovery_tmo.attr,
&dev_attr_priv_sess_state.attr,
+ &dev_attr_priv_sess_creator.attr,
NULL,
};
@@ -2424,6 +2439,8 @@
return S_IRUGO | S_IWUSR;
else if (attr == &dev_attr_priv_sess_state.attr)
return S_IRUGO;
+ else if (attr == &dev_attr_priv_sess_creator.attr)
+ return S_IRUGO;
else {
WARN_ONCE(1, "Invalid session attr");
return 0;