diff options
| author | K. Y. Srinivasan <kys@microsoft.com> | 2014-07-12 09:48:30 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-09-17 09:19:12 -0700 |
| commit | ce87c6acfc090624d218e7d6c5601fd69f4538b9 (patch) | |
| tree | 4eadb14f4895330d6276a0064af663a2e7ec9e84 /drivers/scsi/storvsc_drv.c | |
| parent | 367136a453ce72a17aa3a32153ccc9cd290f004d (diff) | |
Drivers: scsi: storvsc: Implement a eh_timed_out handler
commit 56b26e69c8283121febedd12b3cc193384af46b9 upstream.
On Azure, we have seen instances of unbounded I/O latencies. To deal with
this issue, implement handler that can reset the timeout. Note that the
host gaurantees that it will respond to each command that has been issued.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
[hch: added a better comment explaining the issue]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi/storvsc_drv.c')
| -rw-r--r-- | drivers/scsi/storvsc_drv.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 9969fa1ef7c4..a14a1f7cd577 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -33,6 +33,7 @@ #include <linux/device.h> #include <linux/hyperv.h> #include <linux/mempool.h> +#include <linux/blkdev.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_host.h> @@ -1518,6 +1519,16 @@ static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd) return SUCCESS; } +/* + * The host guarantees to respond to each command, although I/O latencies might + * be unbounded on Azure. Reset the timer unconditionally to give the host a + * chance to perform EH. + */ +static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd) +{ + return BLK_EH_RESET_TIMER; +} + static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd) { bool allowed = true; @@ -1687,6 +1698,7 @@ static struct scsi_host_template scsi_driver = { .bios_param = storvsc_get_chs, .queuecommand = storvsc_queuecommand, .eh_host_reset_handler = storvsc_host_reset_handler, + .eh_timed_out = storvsc_eh_timed_out, .slave_alloc = storvsc_device_alloc, .slave_destroy = storvsc_device_destroy, .slave_configure = storvsc_device_configure, |