From: ashok.vairavan <ashok.vairavan@oracle.com>
Date: Sat, 8 Oct 2016 01:47:01 +0000 (-0400)
Subject: scsi: Add intermediate STARGET_REMOVE state to scsi_target_state
X-Git-Tag: v4.1.12-92~66^2~1
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=d008c14d3cbef1ad7ef31e63b2eadd971fdded57;p=users%2Fjedix%2Flinux-maple.git

scsi: Add intermediate STARGET_REMOVE state to scsi_target_state

Add intermediate STARGET_REMOVE state to scsi_target_state to avoid
running into the BUG_ON() in scsi_target_reap(). The STARGET_REMOVE
state is only valid in the path from scsi_remove_target() to
scsi_target_destroy() indicating this target is going to be removed.

This re-fixes the problem introduced in commits bc3f02a795d3 ("[SCSI]
scsi_remove_target: fix softlockup regression on hot remove") and
40998193560d ("scsi: restart list search after unlock in
scsi_remove_target") in a more comprehensive way.

[mkp: Included James' fix for scsi_target_destroy()]

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
Cc: stable@vger.kernel.org
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: James Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Orabug: 24844559
Mainline commit: f05795d3d771f30a7bdc3a138bf714b06d42aa95
Conflicts:
    The following changes are done to fix kabi breakage.

        #ifndef __GENKSYMS__
        STARGET_REMOVE,
        #endif
---

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 6efab1c455e1..7a1a39a4817c 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -313,6 +313,7 @@ static void scsi_target_destroy(struct scsi_target *starget)
 	struct Scsi_Host *shost = dev_to_shost(dev->parent);
 	unsigned long flags;
 
+	BUG_ON(starget->state == STARGET_DEL);
 	starget->state = STARGET_DEL;
 	transport_destroy_device(dev);
 	spin_lock_irqsave(shost->host_lock, flags);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index fb17f57a65e6..a24b810407ab 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1155,11 +1155,13 @@ restart:
 	spin_lock_irqsave(shost->host_lock, flags);
 	list_for_each_entry(starget, &shost->__targets, siblings) {
 		if (starget->state == STARGET_DEL ||
+		    starget->state == STARGET_REMOVE ||
 		    starget == last_target)
 			continue;
 		if (starget->dev.parent == dev || &starget->dev == dev) {
 			kref_get(&starget->reap_ref);
 			last_target = starget;
+			starget->state = STARGET_REMOVE;
 			spin_unlock_irqrestore(shost->host_lock, flags);
 			__scsi_remove_target(starget);
 			scsi_target_reap(starget);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index a4c9336811d1..7109f3d5b03b 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -260,6 +260,9 @@ enum scsi_target_state {
 	STARGET_CREATED = 1,
 	STARGET_RUNNING,
 	STARGET_DEL,
+	#ifndef __GENKSYMS__
+	STARGET_REMOVE,
+	#endif
 };
 
 /*