This is a note to let you know that I've just added the patch titled scsi: hpsa: limit outstanding rescans to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-hpsa-limit-outstanding-rescans.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Mon Dec 18 14:47:43 CET 2017 From: Don Brace <don.brace@xxxxxxxxxxxxx> Date: Fri, 10 Mar 2017 14:35:17 -0600 Subject: scsi: hpsa: limit outstanding rescans From: Don Brace <don.brace@xxxxxxxxxxxxx> [ Upstream commit 87b9e6aa87d9411f1059aa245c0c79976bc557ac ] Avoid rescan storms. No need to queue another if one is pending. Reviewed-by: Scott Benesh <scott.benesh@xxxxxxxxxxxxx> Reviewed-by: Scott Teel <scott.teel@xxxxxxxxxxxxx> Reviewed-by: Tomas Henzl <thenzl@xxxxxxxxxx> Signed-off-by: Don Brace <don.brace@xxxxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/hpsa.c | 16 +++++++++++++++- drivers/scsi/hpsa.h | 1 + 2 files changed, 16 insertions(+), 1 deletion(-) --- a/drivers/scsi/hpsa.c +++ b/drivers/scsi/hpsa.c @@ -5254,7 +5254,7 @@ static void hpsa_scan_complete(struct ct spin_lock_irqsave(&h->scan_lock, flags); h->scan_finished = 1; - wake_up_all(&h->scan_wait_queue); + wake_up(&h->scan_wait_queue); spin_unlock_irqrestore(&h->scan_lock, flags); } @@ -5272,11 +5272,23 @@ static void hpsa_scan_start(struct Scsi_ if (unlikely(lockup_detected(h))) return hpsa_scan_complete(h); + /* + * If a scan is already waiting to run, no need to add another + */ + spin_lock_irqsave(&h->scan_lock, flags); + if (h->scan_waiting) { + spin_unlock_irqrestore(&h->scan_lock, flags); + return; + } + + spin_unlock_irqrestore(&h->scan_lock, flags); + /* wait until any scan already in progress is finished. */ while (1) { spin_lock_irqsave(&h->scan_lock, flags); if (h->scan_finished) break; + h->scan_waiting = 1; spin_unlock_irqrestore(&h->scan_lock, flags); wait_event(h->scan_wait_queue, h->scan_finished); /* Note: We don't need to worry about a race between this @@ -5286,6 +5298,7 @@ static void hpsa_scan_start(struct Scsi_ */ } h->scan_finished = 0; /* mark scan as in progress */ + h->scan_waiting = 0; spin_unlock_irqrestore(&h->scan_lock, flags); if (unlikely(lockup_detected(h))) @@ -8502,6 +8515,7 @@ reinit_after_soft_reset: init_waitqueue_head(&h->event_sync_wait_queue); mutex_init(&h->reset_mutex); h->scan_finished = 1; /* no scan currently in progress */ + h->scan_waiting = 0; pci_set_drvdata(pdev, h); h->ndevices = 0; --- a/drivers/scsi/hpsa.h +++ b/drivers/scsi/hpsa.h @@ -200,6 +200,7 @@ struct ctlr_info { dma_addr_t errinfo_pool_dhandle; unsigned long *cmd_pool_bits; int scan_finished; + u8 scan_waiting : 1; spinlock_t scan_lock; wait_queue_head_t scan_wait_queue; Patches currently in stable-queue which might be from don.brace@xxxxxxxxxxxxx are queue-4.4/scsi-hpsa-limit-outstanding-rescans.patch queue-4.4/scsi-hpsa-cleanup-sas_phy-structures-in-sysfs-when-unloading.patch queue-4.4/scsi-hpsa-destroy-sas-transport-properties-before-scsi_host.patch queue-4.4/scsi-hpsa-update-check-for-logical-volume-status.patch