Fix iscsi issue (rhbz 1253789)

iSCSI-let-session-recovery_tmo-sysfs-writes-persist.patch

@@ -0,0 +1,89 @@
+From 9c8108a4d3a837c51a29f28229a06d97654eaeb6 Mon Sep 17 00:00:00 2001
+From: Chris Leech <cleech@redhat.com>
+Date: Tue, 16 Jun 2015 16:07:13 -0700
+Subject: iSCSI: let session recovery_tmo sysfs writes persist across recovery
+
+The iSCSI session recovery_tmo setting is writeable in sysfs, but it's
+also set every time a connection is established when parameters are set
+from iscsid over netlink.  That results in the timeout being reset to
+the default value after every recovery.
+
+The DM multipath tools want to use the sysfs interface to lower the
+default timeout when there are multiple paths to fail over.  It has
+caused confusion that we have a writeable sysfs value that seem to keep
+resetting itself.
+
+This patch adds an in-kernel flag that gets set once a sysfs write
+occurs, and then ignores netlink parameter setting once it's been
+modified via the sysfs interface.  My thinking here is that the sysfs
+interface is much simpler for external tools to influence the session
+timeout, but if we're going to allow it to be modified directly we
+should ensure that setting is maintained.
+
+Signed-off-by: Chris Leech <cleech@redhat.com>
+Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
+Signed-off-by: James Bottomley <JBottomley@Odin.com>
+
+diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
+index 55647aa..4c25539 100644
+--- a/drivers/scsi/scsi_transport_iscsi.c
++++ b/drivers/scsi/scsi_transport_iscsi.c
+@@ -2042,6 +2042,7 @@ iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
+ 	session->transport = transport;
+ 	session->creator = -1;
+ 	session->recovery_tmo = 120;
++	session->recovery_tmo_sysfs_override = false;
+ 	session->state = ISCSI_SESSION_FREE;
+ 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
+ 	INIT_LIST_HEAD(&session->sess_list);
+@@ -2786,7 +2787,8 @@ iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
+ 	switch (ev->u.set_param.param) {
+ 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
+ 		sscanf(data, "%d", &value);
+-		session->recovery_tmo = value;
++		if (!session->recovery_tmo_sysfs_override)
++			session->recovery_tmo = value;
+ 		break;
+ 	default:
+ 		err = transport->set_param(conn, ev->u.set_param.param,
+@@ -4049,13 +4051,15 @@ store_priv_session_##field(struct device *dev,				\
+ 	if ((session->state == ISCSI_SESSION_FREE) ||			\
+ 	    (session->state == ISCSI_SESSION_FAILED))			\
+ 		return -EBUSY;						\
+-	if (strncmp(buf, "off", 3) == 0)				\
++	if (strncmp(buf, "off", 3) == 0) {				\
+ 		session->field = -1;					\
+-	else {								\
++		session->field##_sysfs_override = true;			\
++	} else {							\
+ 		val = simple_strtoul(buf, &cp, 0);			\
+ 		if (*cp != '\0' && *cp != '\n')				\
+ 			return -EINVAL;					\
+ 		session->field = val;					\
++		session->field##_sysfs_override = true;			\
+ 	}								\
+ 	return count;							\
+ }
+@@ -4066,6 +4070,7 @@ store_priv_session_##field(struct device *dev,				\
+ static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO | S_IWUSR,		\
+ 			show_priv_session_##field,			\
+ 			store_priv_session_##field)
++
+ iscsi_priv_session_rw_attr(recovery_tmo, "%d");
+ 
+ static struct attribute *iscsi_session_attrs[] = {
+diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
+index 2555ee5..6183d20 100644
+--- a/include/scsi/scsi_transport_iscsi.h
++++ b/include/scsi/scsi_transport_iscsi.h
+@@ -241,6 +241,7 @@ struct iscsi_cls_session {
+ 
+ 	/* recovery fields */
+ 	int recovery_tmo;
++	bool recovery_tmo_sysfs_override;
+ 	struct delayed_work recovery_work;
+ 
+ 	unsigned int target_id;
+-- 
+cgit v0.10.2
+

kernel.spec

@@ -590,6 +590,9 @@ Patch508: kexec-uefi-copy-secure_boot-flag-in-boot-params.patch
 #rhbz 1239050
 Patch509: ideapad-laptop-Add-Lenovo-Yoga-3-14-to-no_hw_rfkill-.patch
 
+#rhbz 1253789
+Patch510: iSCSI-let-session-recovery_tmo-sysfs-writes-persist.patch
+
 Patch904: kdbus.patch
 
 # END OF PATCH DEFINITIONS
@@ -2027,6 +2030,9 @@ fi
 #
 # 
 %changelog
+* Mon Aug 17 2015 Josh Boyer <jwboyer@fedoraproject.org>
+- Fix iscsi issue (rhbz 1253789)
+
 * Mon Aug 17 2015 Josh Boyer <jwboyer@fedoraproject.org> - 4.2.0-0.rc7.git0.1
 - Linux v4.2-rc7