4.4-stable review patch. If anyone has any objections, please let me know.
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From: Don Brace don.brace@microsemi.com
[ Upstream commit 87b9e6aa87d9411f1059aa245c0c79976bc557ac ]
Avoid rescan storms. No need to queue another if one is pending.
Reviewed-by: Scott Benesh scott.benesh@microsemi.com Reviewed-by: Scott Teel scott.teel@microsemi.com Reviewed-by: Tomas Henzl thenzl@redhat.com Signed-off-by: Don Brace don.brace@microsemi.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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;