From ca78cc0370b35e487b8e7884e9032f4c0a0060c8 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 21 Jun 2017 16:35:46 +0200 Subject: [PATCH] scsi: virtio_scsi: let host do exception handling commit e72c9a2a67a6400c8ef3d01d4c461dbbbfa0e1f0 upstream. virtio_scsi tries to do exception handling after the default 30 seconds timeout expires. However, it's better to let the host control the timeout, otherwise with a heavy I/O load it is likely that an abort will also timeout. This leads to fatal errors like filesystems going offline. Disable the 'sd' timeout and allow the host to do exception handling, following the precedent of the storvsc driver. Hannes has a proposal to introduce timeouts in virtio, but this provides an immediate solution for stable kernels too. [mkp: fixed typo] Reported-by: Douglas Miller Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Hannes Reinecke Cc: linux-scsi@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Martin K. Petersen [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/scsi/virtio_scsi.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index 308256b5e4cb..42ecf4c18e2e 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -686,6 +686,16 @@ static void virtscsi_target_destroy(struct scsi_target *starget) kfree(tgt); } +/* + * The host guarantees to respond to each command, although I/O + * latencies might be higher than on bare metal. Reset the timer + * unconditionally to give the host a chance to perform EH. + */ +static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) +{ + return BLK_EH_RESET_TIMER; +} + static struct scsi_host_template virtscsi_host_template_single = { .module = THIS_MODULE, .name = "Virtio SCSI HBA", @@ -695,6 +705,7 @@ static struct scsi_host_template virtscsi_host_template_single = { .queuecommand = virtscsi_queuecommand_single, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, + .eh_timed_out = virtscsi_eh_timed_out, .can_queue = 1024, .dma_boundary = UINT_MAX, @@ -712,6 +723,7 @@ static struct scsi_host_template virtscsi_host_template_multi = { .queuecommand = virtscsi_queuecommand_multi, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, + .eh_timed_out = virtscsi_eh_timed_out, .can_queue = 1024, .dma_boundary = UINT_MAX, -- 2.43.0