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 6efab1c455e158a71a2792c07d9b6d3fadc7595c..7a1a39a4817ca6bd8d9bf4cb85f02b64ffd0411f 100644 (file)
--- 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 fb17f57a65e695fddafb92743fd132892a288079..a24b810407ab3c4c2fd762be956d588aff9bb3c3 100644 (file)
--- 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 a4c9336811d17b14fe7c06e2171de329cf077b7b..7109f3d5b03b10b1fe0688e8979fabd1f36af94a 100644 (file)
--- 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
 };
 
 /*