From fc73648a5026dcf228aadc6ab8ca4b868d91c159 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Thu, 25 Apr 2013 08:10:00 +0200 Subject: [PATCH] [SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmnd scsi_send_eh_cmnd() is calling queuecommand() directly, so it needs to check the return value here. The only valid return codes for queuecommand() are 'busy' states, so we need to wait for a bit to allow the LLDD to recover. Based on an earlier patch from Wen Xiong. [jejb: fix confusion between msec and jiffies values and other issues] [bvanassche: correct stall_for interval] Cc: Wen Xiong Cc: Brian King Signed-off-by: Hannes Reinecke Signed-off-by: James Bottomley --- drivers/scsi/scsi_error.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index c1b05a83d403..f43de1e56420 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -791,32 +792,48 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd, struct scsi_device *sdev = scmd->device; struct Scsi_Host *shost = sdev->host; DECLARE_COMPLETION_ONSTACK(done); - unsigned long timeleft; + unsigned long timeleft = timeout; struct scsi_eh_save ses; + const unsigned long stall_for = msecs_to_jiffies(100); int rtn; +retry: scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes); shost->eh_action = &done; scsi_log_send(scmd); scmd->scsi_done = scsi_eh_done; - shost->hostt->queuecommand(shost, scmd); - - timeleft = wait_for_completion_timeout(&done, timeout); + rtn = shost->hostt->queuecommand(shost, scmd); + if (rtn) { + if (timeleft > stall_for) { + scsi_eh_restore_cmnd(scmd, &ses); + timeleft -= stall_for; + msleep(jiffies_to_msecs(stall_for)); + goto retry; + } + /* signal not to enter either branch of the if () below */ + timeleft = 0; + rtn = NEEDS_RETRY; + } else { + timeleft = wait_for_completion_timeout(&done, timeout); + } shost->eh_action = NULL; - scsi_log_completion(scmd, SUCCESS); + scsi_log_completion(scmd, rtn); SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, timeleft: %ld\n", __func__, scmd, timeleft)); /* - * If there is time left scsi_eh_done got called, and we will - * examine the actual status codes to see whether the command - * actually did complete normally, else tell the host to forget - * about this command. + * If there is time left scsi_eh_done got called, and we will examine + * the actual status codes to see whether the command actually did + * complete normally, else if we have a zero return and no time left, + * the command must still be pending, so abort it and return FAILED. + * If we never actually managed to issue the command, because + * ->queuecommand() kept returning non zero, use the rtn = FAILED + * value above (so don't execute either branch of the if) */ if (timeleft) { rtn = scsi_eh_completed_normally(scmd); @@ -837,7 +854,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd, rtn = FAILED; break; } - } else { + } else if (!rtn) { scsi_abort_eh_cmnd(scmd); rtn = FAILED; } -- 2.20.1