From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "K. Y. Srinivasan" , Hannes Reinecke , Christoph Hellwig Subject: [PATCH 3.14 031/114] Drivers: scsi: storvsc: Implement a eh_timed_out handler Date: Mon, 15 Sep 2014 12:25:31 -0700 Message-Id: <20140915192642.407804937@linuxfoundation.org> In-Reply-To: <20140915192641.428509513@linuxfoundation.org> References: <20140915192641.428509513@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: "K. Y. Srinivasan" 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 Reviewed-by: Hannes Reinecke [hch: added a better comment explaining the issue] Signed-off-by: Christoph Hellwig Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/storvsc_drv.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -1518,6 +1519,16 @@ static int storvsc_host_reset_handler(st 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_dr .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,