From 0c70d84b794c9a99f7395b617ecaef34c00d82ec Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Mon, 5 Dec 2011 16:44:01 -0600 Subject: [PATCH] [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 Signed-off-by: James Bottomley --- drivers/scsi/scsi_transport_iscsi.c | 21 +++++++++++++++++++-- include/scsi/scsi_transport_iscsi.h | 5 +++++ 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 96029e6d027f..c1b172b76689 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -1030,6 +1030,7 @@ iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport, 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 @@ EXPORT_SYMBOL_GPL(iscsi_session_event); 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 @@ iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep, 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 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group) 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 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group) } 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 @@ show_priv_session_state(struct device *dev, struct device_attribute *attr, } 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 @@ static struct attribute *iscsi_session_attrs[] = { &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 @@ static mode_t iscsi_session_attr_is_visible(struct kobject *kobj, 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; diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h index 5994bcc1b017..c54cedc196e8 100644 --- a/include/scsi/scsi_transport_iscsi.h +++ b/include/scsi/scsi_transport_iscsi.h @@ -211,6 +211,11 @@ struct iscsi_cls_session { unsigned int target_id; bool ida_used; + /* + * pid of userspace process that created session or -1 if + * created by the kernel. + */ + pid_t creator; int state; int sid; /* session id */ void *dd_data; /* LLD private data */