From e494f6a728394ab0df194342549ee20e6f0752df Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Mon, 11 Nov 2013 13:44:54 +0100 Subject: [SCSI] improved eh timeout handler When a command runs into a timeout we need to send an 'ABORT TASK' TMF. This is typically done by the 'eh_abort_handler' LLDD callback. Conceptually, however, this function is a normal SCSI command, so there is no need to enter the error handler. This patch implements a new scsi_abort_command() function which invokes an asynchronous function scsi_eh_abort_handler() to abort the commands via the usual 'eh_abort_handler'. If abort succeeds the command is either retried or terminated, depending on the number of allowed retries. However, 'eh_eflags' records the abort, so if the retry would fail again the command is pushed onto the error handler without trying to abort it (again); it'll be cleared up from SCSI EH. [hare: smatch detected stray switch fixed] Signed-off-by: Hannes Reinecke Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index f2c5005..c3ab093 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -169,6 +169,7 @@ void scsi_remove_host(struct Scsi_Host *shost) spin_unlock_irqrestore(shost->host_lock, flags); scsi_autopm_get_host(shost); + flush_workqueue(shost->tmf_work_q); scsi_forget_host(shost); mutex_unlock(&shost->scan_mutex); scsi_proc_host_rm(shost); @@ -294,6 +295,8 @@ static void scsi_host_dev_release(struct device *dev) scsi_proc_hostdir_rm(shost->hostt); + if (shost->tmf_work_q) + destroy_workqueue(shost->tmf_work_q); if (shost->ehandler) kthread_stop(shost->ehandler); if (shost->work_q) @@ -360,7 +363,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) INIT_LIST_HEAD(&shost->eh_cmd_q); INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); - mutex_init(&shost->scan_mutex); /* @@ -444,9 +446,19 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) goto fail_kfree; } + shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", + WQ_UNBOUND | WQ_MEM_RECLAIM, + 1, shost->host_no); + if (!shost->tmf_work_q) { + printk(KERN_WARNING "scsi%d: failed to create tmf workq\n", + shost->host_no); + goto fail_kthread; + } scsi_proc_hostdir_add(shost->hostt); return shost; + fail_kthread: + kthread_stop(shost->ehandler); fail_kfree: kfree(shost); return NULL; -- cgit v1.1