From 30bd7df8ced23eefec87a5cda96dc99b002ed9da Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Fri, 29 Feb 2008 18:25:19 -0600 Subject: [SCSI] scsi_error: add target reset handler The problem is that serveral drivers are sending a target reset from the device reset handler, and if we have multiple devices a target reset gets sent for each device when only one would be sufficient. And if we do a target reset it affects all the commands on the target so the device reset handler code only cleaning up one devices's commands makes programming the driver a little more difficult than it should be. This patch adds a target reset handler, which drivers can use to send a target reset. If successful it cleans up the commands for a devices accessed through that starget. Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/scsi_error.c | 122 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 104 insertions(+), 18 deletions(-) (limited to 'drivers/scsi/scsi_error.c') diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 045a086..1221d2c 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -524,6 +524,41 @@ static int scsi_try_bus_reset(struct scsi_cmnd *scmd) return rtn; } +static void __scsi_report_device_reset(struct scsi_device *sdev, void *data) +{ + sdev->was_reset = 1; + sdev->expecting_cc_ua = 1; +} + +/** + * scsi_try_target_reset - Ask host to perform a target reset + * @scmd: SCSI cmd used to send a target reset + * + * Notes: + * There is no timeout for this operation. if this operation is + * unreliable for a given host, then the host itself needs to put a + * timer on it, and set the host back to a consistent state prior to + * returning. + */ +static int scsi_try_target_reset(struct scsi_cmnd *scmd) +{ + unsigned long flags; + int rtn; + + if (!scmd->device->host->hostt->eh_target_reset_handler) + return FAILED; + + rtn = scmd->device->host->hostt->eh_target_reset_handler(scmd); + if (rtn == SUCCESS) { + spin_lock_irqsave(scmd->device->host->host_lock, flags); + __starget_for_each_device(scsi_target(scmd->device), NULL, + __scsi_report_device_reset); + spin_unlock_irqrestore(scmd->device->host->host_lock, flags); + } + + return rtn; +} + /** * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev * @scmd: SCSI cmd used to send BDR @@ -542,11 +577,8 @@ static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd) return FAILED; rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd); - if (rtn == SUCCESS) { - scmd->device->was_reset = 1; - scmd->device->expecting_cc_ua = 1; - } - + if (rtn == SUCCESS) + __scsi_report_device_reset(scmd->device, NULL); return rtn; } @@ -584,8 +616,9 @@ static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd) { if (__scsi_try_to_abort_cmd(scmd) != SUCCESS) if (scsi_try_bus_device_reset(scmd) != SUCCESS) - if (scsi_try_bus_reset(scmd) != SUCCESS) - scsi_try_host_reset(scmd); + if (scsi_try_target_reset(scmd) != SUCCESS) + if (scsi_try_bus_reset(scmd) != SUCCESS) + scsi_try_host_reset(scmd); } /** @@ -1060,6 +1093,56 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost, } /** + * scsi_eh_target_reset - send target reset if needed + * @shost: scsi host being recovered. + * @work_q: &list_head for pending commands. + * @done_q: &list_head for processed commands. + * + * Notes: + * Try a target reset. + */ +static int scsi_eh_target_reset(struct Scsi_Host *shost, + struct list_head *work_q, + struct list_head *done_q) +{ + struct scsi_cmnd *scmd, *tgtr_scmd, *next; + unsigned int id; + int rtn; + + for (id = 0; id <= shost->max_id; id++) { + tgtr_scmd = NULL; + list_for_each_entry(scmd, work_q, eh_entry) { + if (id == scmd_id(scmd)) { + tgtr_scmd = scmd; + break; + } + } + if (!tgtr_scmd) + continue; + + SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset " + "to target %d\n", + current->comm, id)); + rtn = scsi_try_target_reset(tgtr_scmd); + if (rtn == SUCCESS) { + list_for_each_entry_safe(scmd, next, work_q, eh_entry) { + if (id == scmd_id(scmd)) + if (!scsi_device_online(scmd->device) || + !scsi_eh_tur(tgtr_scmd)) + scsi_eh_finish_cmd(scmd, + done_q); + } + } else + SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset" + " failed target: " + "%d\n", + current->comm, id)); + } + + return list_empty(work_q); +} + +/** * scsi_eh_bus_reset - send a bus reset * @shost: &scsi host being recovered. * @work_q: &list_head for pending commands. @@ -1447,9 +1530,11 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost, { if (!scsi_eh_stu(shost, work_q, done_q)) if (!scsi_eh_bus_device_reset(shost, work_q, done_q)) - if (!scsi_eh_bus_reset(shost, work_q, done_q)) - if (!scsi_eh_host_reset(work_q, done_q)) - scsi_eh_offline_sdevs(work_q, done_q); + if (!scsi_eh_target_reset(shost, work_q, done_q)) + if (!scsi_eh_bus_reset(shost, work_q, done_q)) + if (!scsi_eh_host_reset(work_q, done_q)) + scsi_eh_offline_sdevs(work_q, + done_q); } EXPORT_SYMBOL_GPL(scsi_eh_ready_devs); @@ -1619,10 +1704,8 @@ void scsi_report_bus_reset(struct Scsi_Host *shost, int channel) struct scsi_device *sdev; __shost_for_each_device(sdev, shost) { - if (channel == sdev_channel(sdev)) { - sdev->was_reset = 1; - sdev->expecting_cc_ua = 1; - } + if (channel == sdev_channel(sdev)) + __scsi_report_device_reset(sdev, NULL); } } EXPORT_SYMBOL(scsi_report_bus_reset); @@ -1655,10 +1738,8 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target) __shost_for_each_device(sdev, shost) { if (channel == sdev_channel(sdev) && - target == sdev_id(sdev)) { - sdev->was_reset = 1; - sdev->expecting_cc_ua = 1; - } + target == sdev_id(sdev)) + __scsi_report_device_reset(sdev, NULL); } } EXPORT_SYMBOL(scsi_report_device_reset); @@ -1714,6 +1795,11 @@ scsi_reset_provider(struct scsi_device *dev, int flag) if (rtn == SUCCESS) break; /* FALLTHROUGH */ + case SCSI_TRY_RESET_TARGET: + rtn = scsi_try_target_reset(scmd); + if (rtn == SUCCESS) + break; + /* FALLTHROUGH */ case SCSI_TRY_RESET_BUS: rtn = scsi_try_bus_reset(scmd); if (rtn == SUCCESS) -- cgit v1.1