scsi: Add intermediate STARGET_REMOVE state to scsi_target_state

commit f05795d3d771f30a7bdc3a138bf714b06d42aa95 upstream.

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
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 97074c91e328fbd96757f89dec8d3b9da4647843..6b5811de6519c77d03aa4b365c627206dcb07f5f 100644 (file)
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -316,6 +316,7 @@ 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 2b642b145be1b8a6be08e7eb3829eb6ee357eb4f..ea13e8fa502f2b5242225e166732d7f8cb7dcda7 100644 (file)
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1373,11 +1373,13 @@ 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 74d79bde70750c717284b34ab77ac5f1dd7774b6..a505079dcf88152569cb34c6f6a391144cff8908 100644 (file)
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -242,6 +242,7 @@ scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
 enum scsi_target_state {
        STARGET_CREATED = 1,
        STARGET_RUNNING,
+       STARGET_REMOVE,
        STARGET_DEL,
 };