Re: Boot regression (was "Re: [PATCH] genhd: Do not hold event lock when scheduling workqueue elements")

From: hch@xxxxxx
Date: Tue Feb 14 2017 - 08:48:28 EST

Hi Dexuan,

can you try the hack below for now? I disable the TUR call from
sd_check_events, which I think your VM is hanging on. The checks
it does on the sense data look a bit fishy, but so far I've not
identified a possible root cause.

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 40b4038c019e..1502e87c2be9 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1457,9 +1457,13 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
retval = -ENODEV;

if (scsi_block_when_processing_errors(sdp)) {
+#if 0
sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
+ retval = 0;

/* failed to execute TUR, assume media not present */