| /* |
| * scsi_error.c Copyright (C) 1997 Eric Youngdale |
| * |
| * SCSI error/timeout handling |
| * Initial versions: Eric Youngdale. Based upon conversations with |
| * Leonard Zubkoff and David Miller at Linux Expo, |
| * ideas originating from all over the place. |
| * |
| * Restructured scsi_unjam_host and associated functions. |
| * September 04, 2002 Mike Anderson (andmike@us.ibm.com) |
| * |
| * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and |
| * minor cleanups. |
| * September 30, 2002 Mike Anderson (andmike@us.ibm.com) |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/sched.h> |
| #include <linux/timer.h> |
| #include <linux/string.h> |
| #include <linux/slab.h> |
| #include <linux/kernel.h> |
| #include <linux/kthread.h> |
| #include <linux/interrupt.h> |
| #include <linux/blkdev.h> |
| #include <linux/delay.h> |
| |
| #include <scsi/scsi.h> |
| #include <scsi/scsi_dbg.h> |
| #include <scsi/scsi_device.h> |
| #include <scsi/scsi_eh.h> |
| #include <scsi/scsi_host.h> |
| #include <scsi/scsi_ioctl.h> |
| #include <scsi/scsi_request.h> |
| |
| #include "scsi_priv.h" |
| #include "scsi_logging.h" |
| |
| #define SENSE_TIMEOUT (10*HZ) |
| #define START_UNIT_TIMEOUT (30*HZ) |
| |
| /* |
| * These should *probably* be handled by the host itself. |
| * Since it is allowed to sleep, it probably should. |
| */ |
| #define BUS_RESET_SETTLE_TIME (10) |
| #define HOST_RESET_SETTLE_TIME (10) |
| |
| /* called with shost->host_lock held */ |
| void scsi_eh_wakeup(struct Scsi_Host *shost) |
| { |
| if (shost->host_busy == shost->host_failed) { |
| wake_up_process(shost->ehandler); |
| SCSI_LOG_ERROR_RECOVERY(5, |
| printk("Waking error handler thread\n")); |
| } |
| } |
| |
| /** |
| * scsi_eh_scmd_add - add scsi cmd to error handling. |
| * @scmd: scmd to run eh on. |
| * @eh_flag: optional SCSI_EH flag. |
| * |
| * Return value: |
| * 0 on failure. |
| **/ |
| int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag) |
| { |
| struct Scsi_Host *shost = scmd->device->host; |
| unsigned long flags; |
| int ret = 0; |
| |
| if (!shost->ehandler) |
| return 0; |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| if (scsi_host_set_state(shost, SHOST_RECOVERY)) |
| if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) |
| goto out_unlock; |
| |
| ret = 1; |
| scmd->eh_eflags |= eh_flag; |
| list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q); |
| shost->host_failed++; |
| scsi_eh_wakeup(shost); |
| out_unlock: |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| return ret; |
| } |
| |
| /** |
| * scsi_add_timer - Start timeout timer for a single scsi command. |
| * @scmd: scsi command that is about to start running. |
| * @timeout: amount of time to allow this command to run. |
| * @complete: timeout function to call if timer isn't canceled. |
| * |
| * Notes: |
| * This should be turned into an inline function. Each scsi command |
| * has its own timer, and as it is added to the queue, we set up the |
| * timer. When the command completes, we cancel the timer. |
| **/ |
| void scsi_add_timer(struct scsi_cmnd *scmd, int timeout, |
| void (*complete)(struct scsi_cmnd *)) |
| { |
| |
| /* |
| * If the clock was already running for this command, then |
| * first delete the timer. The timer handling code gets rather |
| * confused if we don't do this. |
| */ |
| if (scmd->eh_timeout.function) |
| del_timer(&scmd->eh_timeout); |
| |
| scmd->eh_timeout.data = (unsigned long)scmd; |
| scmd->eh_timeout.expires = jiffies + timeout; |
| scmd->eh_timeout.function = (void (*)(unsigned long)) complete; |
| |
| SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:" |
| " %d, (%p)\n", __FUNCTION__, |
| scmd, timeout, complete)); |
| |
| add_timer(&scmd->eh_timeout); |
| } |
| |
| /** |
| * scsi_delete_timer - Delete/cancel timer for a given function. |
| * @scmd: Cmd that we are canceling timer for |
| * |
| * Notes: |
| * This should be turned into an inline function. |
| * |
| * Return value: |
| * 1 if we were able to detach the timer. 0 if we blew it, and the |
| * timer function has already started to run. |
| **/ |
| int scsi_delete_timer(struct scsi_cmnd *scmd) |
| { |
| int rtn; |
| |
| rtn = del_timer(&scmd->eh_timeout); |
| |
| SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p," |
| " rtn: %d\n", __FUNCTION__, |
| scmd, rtn)); |
| |
| scmd->eh_timeout.data = (unsigned long)NULL; |
| scmd->eh_timeout.function = NULL; |
| |
| return rtn; |
| } |
| |
| /** |
| * scsi_times_out - Timeout function for normal scsi commands. |
| * @scmd: Cmd that is timing out. |
| * |
| * Notes: |
| * We do not need to lock this. There is the potential for a race |
| * only in that the normal completion handling might run, but if the |
| * normal completion function determines that the timer has already |
| * fired, then it mustn't do anything. |
| **/ |
| void scsi_times_out(struct scsi_cmnd *scmd) |
| { |
| scsi_log_completion(scmd, TIMEOUT_ERROR); |
| |
| if (scmd->device->host->hostt->eh_timed_out) |
| switch (scmd->device->host->hostt->eh_timed_out(scmd)) { |
| case EH_HANDLED: |
| __scsi_done(scmd); |
| return; |
| case EH_RESET_TIMER: |
| /* This allows a single retry even of a command |
| * with allowed == 0 */ |
| if (scmd->retries++ > scmd->allowed) |
| break; |
| scsi_add_timer(scmd, scmd->timeout_per_command, |
| scsi_times_out); |
| return; |
| case EH_NOT_HANDLED: |
| break; |
| } |
| |
| if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) { |
| scmd->result |= DID_TIME_OUT << 16; |
| __scsi_done(scmd); |
| } |
| } |
| |
| /** |
| * scsi_block_when_processing_errors - Prevent cmds from being queued. |
| * @sdev: Device on which we are performing recovery. |
| * |
| * Description: |
| * We block until the host is out of error recovery, and then check to |
| * see whether the host or the device is offline. |
| * |
| * Return value: |
| * 0 when dev was taken offline by error recovery. 1 OK to proceed. |
| **/ |
| int scsi_block_when_processing_errors(struct scsi_device *sdev) |
| { |
| int online; |
| |
| wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host)); |
| |
| online = scsi_device_online(sdev); |
| |
| SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__, |
| online)); |
| |
| return online; |
| } |
| EXPORT_SYMBOL(scsi_block_when_processing_errors); |
| |
| #ifdef CONFIG_SCSI_LOGGING |
| /** |
| * scsi_eh_prt_fail_stats - Log info on failures. |
| * @shost: scsi host being recovered. |
| * @work_q: Queue of scsi cmds to process. |
| **/ |
| static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost, |
| struct list_head *work_q) |
| { |
| struct scsi_cmnd *scmd; |
| struct scsi_device *sdev; |
| int total_failures = 0; |
| int cmd_failed = 0; |
| int cmd_cancel = 0; |
| int devices_failed = 0; |
| |
| shost_for_each_device(sdev, shost) { |
| list_for_each_entry(scmd, work_q, eh_entry) { |
| if (scmd->device == sdev) { |
| ++total_failures; |
| if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) |
| ++cmd_cancel; |
| else |
| ++cmd_failed; |
| } |
| } |
| |
| if (cmd_cancel || cmd_failed) { |
| SCSI_LOG_ERROR_RECOVERY(3, |
| sdev_printk(KERN_INFO, sdev, |
| "%s: cmds failed: %d, cancel: %d\n", |
| __FUNCTION__, cmd_failed, |
| cmd_cancel)); |
| cmd_cancel = 0; |
| cmd_failed = 0; |
| ++devices_failed; |
| } |
| } |
| |
| SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d" |
| " devices require eh work\n", |
| total_failures, devices_failed)); |
| } |
| #endif |
| |
| /** |
| * scsi_check_sense - Examine scsi cmd sense |
| * @scmd: Cmd to have sense checked. |
| * |
| * Return value: |
| * SUCCESS or FAILED or NEEDS_RETRY |
| * |
| * Notes: |
| * When a deferred error is detected the current command has |
| * not been executed and needs retrying. |
| **/ |
| static int scsi_check_sense(struct scsi_cmnd *scmd) |
| { |
| struct scsi_sense_hdr sshdr; |
| |
| if (! scsi_command_normalize_sense(scmd, &sshdr)) |
| return FAILED; /* no valid sense data */ |
| |
| if (scsi_sense_is_deferred(&sshdr)) |
| return NEEDS_RETRY; |
| |
| /* |
| * Previous logic looked for FILEMARK, EOM or ILI which are |
| * mainly associated with tapes and returned SUCCESS. |
| */ |
| if (sshdr.response_code == 0x70) { |
| /* fixed format */ |
| if (scmd->sense_buffer[2] & 0xe0) |
| return SUCCESS; |
| } else { |
| /* |
| * descriptor format: look for "stream commands sense data |
| * descriptor" (see SSC-3). Assume single sense data |
| * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG. |
| */ |
| if ((sshdr.additional_length > 3) && |
| (scmd->sense_buffer[8] == 0x4) && |
| (scmd->sense_buffer[11] & 0xe0)) |
| return SUCCESS; |
| } |
| |
| switch (sshdr.sense_key) { |
| case NO_SENSE: |
| return SUCCESS; |
| case RECOVERED_ERROR: |
| return /* soft_error */ SUCCESS; |
| |
| case ABORTED_COMMAND: |
| return NEEDS_RETRY; |
| case NOT_READY: |
| case UNIT_ATTENTION: |
| /* |
| * if we are expecting a cc/ua because of a bus reset that we |
| * performed, treat this just as a retry. otherwise this is |
| * information that we should pass up to the upper-level driver |
| * so that we can deal with it there. |
| */ |
| if (scmd->device->expecting_cc_ua) { |
| scmd->device->expecting_cc_ua = 0; |
| return NEEDS_RETRY; |
| } |
| /* |
| * if the device is in the process of becoming ready, we |
| * should retry. |
| */ |
| if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01)) |
| return NEEDS_RETRY; |
| /* |
| * if the device is not started, we need to wake |
| * the error handler to start the motor |
| */ |
| if (scmd->device->allow_restart && |
| (sshdr.asc == 0x04) && (sshdr.ascq == 0x02)) |
| return FAILED; |
| return SUCCESS; |
| |
| /* these three are not supported */ |
| case COPY_ABORTED: |
| case VOLUME_OVERFLOW: |
| case MISCOMPARE: |
| return SUCCESS; |
| |
| case MEDIUM_ERROR: |
| return NEEDS_RETRY; |
| |
| case HARDWARE_ERROR: |
| if (scmd->device->retry_hwerror) |
| return NEEDS_RETRY; |
| else |
| return SUCCESS; |
| |
| case ILLEGAL_REQUEST: |
| case BLANK_CHECK: |
| case DATA_PROTECT: |
| default: |
| return SUCCESS; |
| } |
| } |
| |
| /** |
| * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD. |
| * @scmd: SCSI cmd to examine. |
| * |
| * Notes: |
| * This is *only* called when we are examining the status of commands |
| * queued during error recovery. the main difference here is that we |
| * don't allow for the possibility of retries here, and we are a lot |
| * more restrictive about what we consider acceptable. |
| **/ |
| static int scsi_eh_completed_normally(struct scsi_cmnd *scmd) |
| { |
| /* |
| * first check the host byte, to see if there is anything in there |
| * that would indicate what we need to do. |
| */ |
| if (host_byte(scmd->result) == DID_RESET) { |
| /* |
| * rats. we are already in the error handler, so we now |
| * get to try and figure out what to do next. if the sense |
| * is valid, we have a pretty good idea of what to do. |
| * if not, we mark it as FAILED. |
| */ |
| return scsi_check_sense(scmd); |
| } |
| if (host_byte(scmd->result) != DID_OK) |
| return FAILED; |
| |
| /* |
| * next, check the message byte. |
| */ |
| if (msg_byte(scmd->result) != COMMAND_COMPLETE) |
| return FAILED; |
| |
| /* |
| * now, check the status byte to see if this indicates |
| * anything special. |
| */ |
| switch (status_byte(scmd->result)) { |
| case GOOD: |
| case COMMAND_TERMINATED: |
| return SUCCESS; |
| case CHECK_CONDITION: |
| return scsi_check_sense(scmd); |
| case CONDITION_GOOD: |
| case INTERMEDIATE_GOOD: |
| case INTERMEDIATE_C_GOOD: |
| /* |
| * who knows? FIXME(eric) |
| */ |
| return SUCCESS; |
| case BUSY: |
| case QUEUE_FULL: |
| case RESERVATION_CONFLICT: |
| default: |
| return FAILED; |
| } |
| return FAILED; |
| } |
| |
| /** |
| * scsi_eh_done - Completion function for error handling. |
| * @scmd: Cmd that is done. |
| **/ |
| static void scsi_eh_done(struct scsi_cmnd *scmd) |
| { |
| SCSI_LOG_ERROR_RECOVERY(3, |
| printk("%s scmd: %p result: %x\n", |
| __FUNCTION__, scmd, scmd->result)); |
| complete(scmd->device->host->eh_action); |
| } |
| |
| /** |
| * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery. |
| * @scmd: SCSI Cmd to send. |
| * @timeout: Timeout for cmd. |
| * |
| * Return value: |
| * SUCCESS or FAILED or NEEDS_RETRY |
| **/ |
| static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout) |
| { |
| struct scsi_device *sdev = scmd->device; |
| struct Scsi_Host *shost = sdev->host; |
| DECLARE_COMPLETION(done); |
| unsigned long timeleft; |
| unsigned long flags; |
| int rtn; |
| |
| if (sdev->scsi_level <= SCSI_2) |
| scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) | |
| (sdev->lun << 5 & 0xe0); |
| |
| shost->eh_action = &done; |
| scmd->request->rq_status = RQ_SCSI_BUSY; |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| scsi_log_send(scmd); |
| shost->hostt->queuecommand(scmd, scsi_eh_done); |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| |
| timeleft = wait_for_completion_timeout(&done, timeout); |
| |
| scmd->request->rq_status = RQ_SCSI_DONE; |
| shost->eh_action = NULL; |
| |
| scsi_log_completion(scmd, SUCCESS); |
| |
| SCSI_LOG_ERROR_RECOVERY(3, |
| printk("%s: scmd: %p, timeleft: %ld\n", |
| __FUNCTION__, 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 (timeleft) { |
| rtn = scsi_eh_completed_normally(scmd); |
| SCSI_LOG_ERROR_RECOVERY(3, |
| printk("%s: scsi_eh_completed_normally %x\n", |
| __FUNCTION__, rtn)); |
| |
| switch (rtn) { |
| case SUCCESS: |
| case NEEDS_RETRY: |
| case FAILED: |
| break; |
| default: |
| rtn = FAILED; |
| break; |
| } |
| } else { |
| /* |
| * FIXME(eric) - we are not tracking whether we could |
| * abort a timed out command or not. not sure how |
| * we should treat them differently anyways. |
| */ |
| if (shost->hostt->eh_abort_handler) |
| shost->hostt->eh_abort_handler(scmd); |
| rtn = FAILED; |
| } |
| |
| return rtn; |
| } |
| |
| /** |
| * scsi_request_sense - Request sense data from a particular target. |
| * @scmd: SCSI cmd for request sense. |
| * |
| * Notes: |
| * Some hosts automatically obtain this information, others require |
| * that we obtain it on our own. This function will *not* return until |
| * the command either times out, or it completes. |
| **/ |
| static int scsi_request_sense(struct scsi_cmnd *scmd) |
| { |
| static unsigned char generic_sense[6] = |
| {REQUEST_SENSE, 0, 0, 0, 252, 0}; |
| unsigned char *scsi_result; |
| int saved_result; |
| int rtn; |
| |
| memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense)); |
| |
| scsi_result = kmalloc(252, GFP_ATOMIC | ((scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0)); |
| |
| |
| if (unlikely(!scsi_result)) { |
| printk(KERN_ERR "%s: cannot allocate scsi_result.\n", |
| __FUNCTION__); |
| return FAILED; |
| } |
| |
| /* |
| * zero the sense buffer. some host adapters automatically always |
| * request sense, so it is not a good idea that |
| * scmd->request_buffer and scmd->sense_buffer point to the same |
| * address (db). 0 is not a valid sense code. |
| */ |
| memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer)); |
| memset(scsi_result, 0, 252); |
| |
| saved_result = scmd->result; |
| scmd->request_buffer = scsi_result; |
| scmd->request_bufflen = 252; |
| scmd->use_sg = 0; |
| scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); |
| scmd->sc_data_direction = DMA_FROM_DEVICE; |
| scmd->underflow = 0; |
| |
| rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT); |
| |
| /* last chance to have valid sense data */ |
| if(!SCSI_SENSE_VALID(scmd)) { |
| memcpy(scmd->sense_buffer, scmd->request_buffer, |
| sizeof(scmd->sense_buffer)); |
| } |
| |
| kfree(scsi_result); |
| |
| /* |
| * when we eventually call scsi_finish, we really wish to complete |
| * the original request, so let's restore the original data. (db) |
| */ |
| scsi_setup_cmd_retry(scmd); |
| scmd->result = saved_result; |
| return rtn; |
| } |
| |
| /** |
| * scsi_eh_finish_cmd - Handle a cmd that eh is finished with. |
| * @scmd: Original SCSI cmd that eh has finished. |
| * @done_q: Queue for processed commands. |
| * |
| * Notes: |
| * We don't want to use the normal command completion while we are are |
| * still handling errors - it may cause other commands to be queued, |
| * and that would disturb what we are doing. thus we really want to |
| * keep a list of pending commands for final completion, and once we |
| * are ready to leave error handling we handle completion for real. |
| **/ |
| static void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, |
| struct list_head *done_q) |
| { |
| scmd->device->host->host_failed--; |
| scmd->eh_eflags = 0; |
| |
| /* |
| * set this back so that the upper level can correctly free up |
| * things. |
| */ |
| scsi_setup_cmd_retry(scmd); |
| list_move_tail(&scmd->eh_entry, done_q); |
| } |
| |
| /** |
| * scsi_eh_get_sense - Get device sense data. |
| * @work_q: Queue of commands to process. |
| * @done_q: Queue of proccessed commands.. |
| * |
| * Description: |
| * See if we need to request sense information. if so, then get it |
| * now, so we have a better idea of what to do. |
| * |
| * Notes: |
| * This has the unfortunate side effect that if a shost adapter does |
| * not automatically request sense information, that we end up shutting |
| * it down before we request it. |
| * |
| * All drivers should request sense information internally these days, |
| * so for now all I have to say is tough noogies if you end up in here. |
| * |
| * XXX: Long term this code should go away, but that needs an audit of |
| * all LLDDs first. |
| **/ |
| static int scsi_eh_get_sense(struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *next; |
| int rtn; |
| |
| list_for_each_entry_safe(scmd, next, work_q, eh_entry) { |
| if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) || |
| SCSI_SENSE_VALID(scmd)) |
| continue; |
| |
| SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd, |
| "%s: requesting sense\n", |
| current->comm)); |
| rtn = scsi_request_sense(scmd); |
| if (rtn != SUCCESS) |
| continue; |
| |
| SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p" |
| " result %x\n", scmd, |
| scmd->result)); |
| SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd)); |
| |
| rtn = scsi_decide_disposition(scmd); |
| |
| /* |
| * if the result was normal, then just pass it along to the |
| * upper level. |
| */ |
| if (rtn == SUCCESS) |
| /* we don't want this command reissued, just |
| * finished with the sense data, so set |
| * retries to the max allowed to ensure it |
| * won't get reissued */ |
| scmd->retries = scmd->allowed; |
| else if (rtn != NEEDS_RETRY) |
| continue; |
| |
| scsi_eh_finish_cmd(scmd, done_q); |
| } |
| |
| return list_empty(work_q); |
| } |
| |
| /** |
| * scsi_try_to_abort_cmd - Ask host to abort a running command. |
| * @scmd: SCSI cmd to abort from Lower Level. |
| * |
| * Notes: |
| * This function will not return until the user's completion function |
| * has been called. there is no timeout on this operation. if the |
| * author of the low-level driver wishes this operation to be timed, |
| * they can provide this facility themselves. helper functions in |
| * scsi_error.c can be supplied to make this easier to do. |
| **/ |
| static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd) |
| { |
| if (!scmd->device->host->hostt->eh_abort_handler) |
| return FAILED; |
| |
| /* |
| * scsi_done was called just after the command timed out and before |
| * we had a chance to process it. (db) |
| */ |
| if (scmd->serial_number == 0) |
| return SUCCESS; |
| return scmd->device->host->hostt->eh_abort_handler(scmd); |
| } |
| |
| /** |
| * scsi_eh_tur - Send TUR to device. |
| * @scmd: Scsi cmd to send TUR |
| * |
| * Return value: |
| * 0 - Device is ready. 1 - Device NOT ready. |
| **/ |
| static int scsi_eh_tur(struct scsi_cmnd *scmd) |
| { |
| static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0}; |
| int retry_cnt = 1, rtn; |
| int saved_result; |
| |
| retry_tur: |
| memcpy(scmd->cmnd, tur_command, sizeof(tur_command)); |
| |
| /* |
| * zero the sense buffer. the scsi spec mandates that any |
| * untransferred sense data should be interpreted as being zero. |
| */ |
| memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer)); |
| |
| saved_result = scmd->result; |
| scmd->request_buffer = NULL; |
| scmd->request_bufflen = 0; |
| scmd->use_sg = 0; |
| scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); |
| scmd->underflow = 0; |
| scmd->sc_data_direction = DMA_NONE; |
| |
| rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT); |
| |
| /* |
| * when we eventually call scsi_finish, we really wish to complete |
| * the original request, so let's restore the original data. (db) |
| */ |
| scsi_setup_cmd_retry(scmd); |
| scmd->result = saved_result; |
| |
| /* |
| * hey, we are done. let's look to see what happened. |
| */ |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n", |
| __FUNCTION__, scmd, rtn)); |
| if (rtn == SUCCESS) |
| return 0; |
| else if (rtn == NEEDS_RETRY) { |
| if (retry_cnt--) |
| goto retry_tur; |
| return 0; |
| } |
| return 1; |
| } |
| |
| /** |
| * scsi_eh_abort_cmds - abort canceled commands. |
| * @shost: scsi host being recovered. |
| * @eh_done_q: list_head for processed commands. |
| * |
| * Decription: |
| * Try and see whether or not it makes sense to try and abort the |
| * running command. this only works out to be the case if we have one |
| * command that has timed out. if the command simply failed, it makes |
| * no sense to try and abort the command, since as far as the shost |
| * adapter is concerned, it isn't running. |
| **/ |
| static int scsi_eh_abort_cmds(struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *next; |
| int rtn; |
| |
| list_for_each_entry_safe(scmd, next, work_q, eh_entry) { |
| if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD)) |
| continue; |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:" |
| "0x%p\n", current->comm, |
| scmd)); |
| rtn = scsi_try_to_abort_cmd(scmd); |
| if (rtn == SUCCESS) { |
| scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD; |
| if (!scsi_device_online(scmd->device) || |
| !scsi_eh_tur(scmd)) { |
| scsi_eh_finish_cmd(scmd, done_q); |
| } |
| |
| } else |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting" |
| " cmd failed:" |
| "0x%p\n", |
| current->comm, |
| scmd)); |
| } |
| |
| return list_empty(work_q); |
| } |
| |
| /** |
| * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev |
| * @scmd: SCSI cmd used to send BDR |
| * |
| * 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_bus_device_reset(struct scsi_cmnd *scmd) |
| { |
| int rtn; |
| |
| if (!scmd->device->host->hostt->eh_device_reset_handler) |
| 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; |
| } |
| |
| return rtn; |
| } |
| |
| /** |
| * scsi_eh_try_stu - Send START_UNIT to device. |
| * @scmd: Scsi cmd to send START_UNIT |
| * |
| * Return value: |
| * 0 - Device is ready. 1 - Device NOT ready. |
| **/ |
| static int scsi_eh_try_stu(struct scsi_cmnd *scmd) |
| { |
| static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0}; |
| int rtn; |
| int saved_result; |
| |
| if (!scmd->device->allow_restart) |
| return 1; |
| |
| memcpy(scmd->cmnd, stu_command, sizeof(stu_command)); |
| |
| /* |
| * zero the sense buffer. the scsi spec mandates that any |
| * untransferred sense data should be interpreted as being zero. |
| */ |
| memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer)); |
| |
| saved_result = scmd->result; |
| scmd->request_buffer = NULL; |
| scmd->request_bufflen = 0; |
| scmd->use_sg = 0; |
| scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); |
| scmd->underflow = 0; |
| scmd->sc_data_direction = DMA_NONE; |
| |
| rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT); |
| |
| /* |
| * when we eventually call scsi_finish, we really wish to complete |
| * the original request, so let's restore the original data. (db) |
| */ |
| scsi_setup_cmd_retry(scmd); |
| scmd->result = saved_result; |
| |
| /* |
| * hey, we are done. let's look to see what happened. |
| */ |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n", |
| __FUNCTION__, scmd, rtn)); |
| if (rtn == SUCCESS) |
| return 0; |
| return 1; |
| } |
| |
| /** |
| * scsi_eh_stu - send START_UNIT if needed |
| * @shost: scsi host being recovered. |
| * @eh_done_q: list_head for processed commands. |
| * |
| * Notes: |
| * If commands are failing due to not ready, initializing command required, |
| * try revalidating the device, which will end up sending a start unit. |
| **/ |
| static int scsi_eh_stu(struct Scsi_Host *shost, |
| struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *stu_scmd, *next; |
| struct scsi_device *sdev; |
| |
| shost_for_each_device(sdev, shost) { |
| stu_scmd = NULL; |
| list_for_each_entry(scmd, work_q, eh_entry) |
| if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) && |
| scsi_check_sense(scmd) == FAILED ) { |
| stu_scmd = scmd; |
| break; |
| } |
| |
| if (!stu_scmd) |
| continue; |
| |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:" |
| " 0x%p\n", current->comm, sdev)); |
| |
| if (!scsi_eh_try_stu(stu_scmd)) { |
| if (!scsi_device_online(sdev) || |
| !scsi_eh_tur(stu_scmd)) { |
| list_for_each_entry_safe(scmd, next, |
| work_q, eh_entry) { |
| if (scmd->device == sdev) |
| scsi_eh_finish_cmd(scmd, done_q); |
| } |
| } |
| } else { |
| SCSI_LOG_ERROR_RECOVERY(3, |
| printk("%s: START_UNIT failed to sdev:" |
| " 0x%p\n", current->comm, sdev)); |
| } |
| } |
| |
| return list_empty(work_q); |
| } |
| |
| |
| /** |
| * scsi_eh_bus_device_reset - send bdr if needed |
| * @shost: scsi host being recovered. |
| * @eh_done_q: list_head for processed commands. |
| * |
| * Notes: |
| * Try a bus device reset. still, look to see whether we have multiple |
| * devices that are jammed or not - if we have multiple devices, it |
| * makes no sense to try bus_device_reset - we really would need to try |
| * a bus_reset instead. |
| **/ |
| static int scsi_eh_bus_device_reset(struct Scsi_Host *shost, |
| struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *bdr_scmd, *next; |
| struct scsi_device *sdev; |
| int rtn; |
| |
| shost_for_each_device(sdev, shost) { |
| bdr_scmd = NULL; |
| list_for_each_entry(scmd, work_q, eh_entry) |
| if (scmd->device == sdev) { |
| bdr_scmd = scmd; |
| break; |
| } |
| |
| if (!bdr_scmd) |
| continue; |
| |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:" |
| " 0x%p\n", current->comm, |
| sdev)); |
| rtn = scsi_try_bus_device_reset(bdr_scmd); |
| if (rtn == SUCCESS) { |
| if (!scsi_device_online(sdev) || |
| !scsi_eh_tur(bdr_scmd)) { |
| list_for_each_entry_safe(scmd, next, |
| work_q, eh_entry) { |
| if (scmd->device == sdev) |
| scsi_eh_finish_cmd(scmd, |
| done_q); |
| } |
| } |
| } else { |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR" |
| " failed sdev:" |
| "0x%p\n", |
| current->comm, |
| sdev)); |
| } |
| } |
| |
| return list_empty(work_q); |
| } |
| |
| /** |
| * scsi_try_bus_reset - ask host to perform a bus reset |
| * @scmd: SCSI cmd to send bus reset. |
| **/ |
| static int scsi_try_bus_reset(struct scsi_cmnd *scmd) |
| { |
| unsigned long flags; |
| int rtn; |
| |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n", |
| __FUNCTION__)); |
| |
| if (!scmd->device->host->hostt->eh_bus_reset_handler) |
| return FAILED; |
| |
| rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd); |
| |
| if (rtn == SUCCESS) { |
| if (!scmd->device->host->hostt->skip_settle_delay) |
| ssleep(BUS_RESET_SETTLE_TIME); |
| spin_lock_irqsave(scmd->device->host->host_lock, flags); |
| scsi_report_bus_reset(scmd->device->host, |
| scmd_channel(scmd)); |
| spin_unlock_irqrestore(scmd->device->host->host_lock, flags); |
| } |
| |
| return rtn; |
| } |
| |
| /** |
| * scsi_try_host_reset - ask host adapter to reset itself |
| * @scmd: SCSI cmd to send hsot reset. |
| **/ |
| static int scsi_try_host_reset(struct scsi_cmnd *scmd) |
| { |
| unsigned long flags; |
| int rtn; |
| |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n", |
| __FUNCTION__)); |
| |
| if (!scmd->device->host->hostt->eh_host_reset_handler) |
| return FAILED; |
| |
| rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd); |
| |
| if (rtn == SUCCESS) { |
| if (!scmd->device->host->hostt->skip_settle_delay) |
| ssleep(HOST_RESET_SETTLE_TIME); |
| spin_lock_irqsave(scmd->device->host->host_lock, flags); |
| scsi_report_bus_reset(scmd->device->host, |
| scmd_channel(scmd)); |
| spin_unlock_irqrestore(scmd->device->host->host_lock, flags); |
| } |
| |
| return rtn; |
| } |
| |
| /** |
| * scsi_eh_bus_reset - send a bus reset |
| * @shost: scsi host being recovered. |
| * @eh_done_q: list_head for processed commands. |
| **/ |
| static int scsi_eh_bus_reset(struct Scsi_Host *shost, |
| struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *chan_scmd, *next; |
| unsigned int channel; |
| int rtn; |
| |
| /* |
| * we really want to loop over the various channels, and do this on |
| * a channel by channel basis. we should also check to see if any |
| * of the failed commands are on soft_reset devices, and if so, skip |
| * the reset. |
| */ |
| |
| for (channel = 0; channel <= shost->max_channel; channel++) { |
| chan_scmd = NULL; |
| list_for_each_entry(scmd, work_q, eh_entry) { |
| if (channel == scmd_channel(scmd)) { |
| chan_scmd = scmd; |
| break; |
| /* |
| * FIXME add back in some support for |
| * soft_reset devices. |
| */ |
| } |
| } |
| |
| if (!chan_scmd) |
| continue; |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:" |
| " %d\n", current->comm, |
| channel)); |
| rtn = scsi_try_bus_reset(chan_scmd); |
| if (rtn == SUCCESS) { |
| list_for_each_entry_safe(scmd, next, work_q, eh_entry) { |
| if (channel == scmd_channel(scmd)) |
| if (!scsi_device_online(scmd->device) || |
| !scsi_eh_tur(scmd)) |
| scsi_eh_finish_cmd(scmd, |
| done_q); |
| } |
| } else { |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST" |
| " failed chan: %d\n", |
| current->comm, |
| channel)); |
| } |
| } |
| return list_empty(work_q); |
| } |
| |
| /** |
| * scsi_eh_host_reset - send a host reset |
| * @work_q: list_head for processed commands. |
| * @done_q: list_head for processed commands. |
| **/ |
| static int scsi_eh_host_reset(struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *next; |
| int rtn; |
| |
| if (!list_empty(work_q)) { |
| scmd = list_entry(work_q->next, |
| struct scsi_cmnd, eh_entry); |
| |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n" |
| , current->comm)); |
| |
| rtn = scsi_try_host_reset(scmd); |
| if (rtn == SUCCESS) { |
| list_for_each_entry_safe(scmd, next, work_q, eh_entry) { |
| if (!scsi_device_online(scmd->device) || |
| (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) || |
| !scsi_eh_tur(scmd)) |
| scsi_eh_finish_cmd(scmd, done_q); |
| } |
| } else { |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST" |
| " failed\n", |
| current->comm)); |
| } |
| } |
| return list_empty(work_q); |
| } |
| |
| /** |
| * scsi_eh_offline_sdevs - offline scsi devices that fail to recover |
| * @work_q: list_head for processed commands. |
| * @done_q: list_head for processed commands. |
| * |
| **/ |
| static void scsi_eh_offline_sdevs(struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *next; |
| |
| list_for_each_entry_safe(scmd, next, work_q, eh_entry) { |
| sdev_printk(KERN_INFO, scmd->device, |
| "scsi: Device offlined - not" |
| " ready after error recovery\n"); |
| scsi_device_set_state(scmd->device, SDEV_OFFLINE); |
| if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) { |
| /* |
| * FIXME: Handle lost cmds. |
| */ |
| } |
| scsi_eh_finish_cmd(scmd, done_q); |
| } |
| return; |
| } |
| |
| /** |
| * scsi_decide_disposition - Disposition a cmd on return from LLD. |
| * @scmd: SCSI cmd to examine. |
| * |
| * Notes: |
| * This is *only* called when we are examining the status after sending |
| * out the actual data command. any commands that are queued for error |
| * recovery (e.g. test_unit_ready) do *not* come through here. |
| * |
| * When this routine returns failed, it means the error handler thread |
| * is woken. In cases where the error code indicates an error that |
| * doesn't require the error handler read (i.e. we don't need to |
| * abort/reset), this function should return SUCCESS. |
| **/ |
| int scsi_decide_disposition(struct scsi_cmnd *scmd) |
| { |
| int rtn; |
| |
| /* |
| * if the device is offline, then we clearly just pass the result back |
| * up to the top level. |
| */ |
| if (!scsi_device_online(scmd->device)) { |
| SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report" |
| " as SUCCESS\n", |
| __FUNCTION__)); |
| return SUCCESS; |
| } |
| |
| /* |
| * first check the host byte, to see if there is anything in there |
| * that would indicate what we need to do. |
| */ |
| switch (host_byte(scmd->result)) { |
| case DID_PASSTHROUGH: |
| /* |
| * no matter what, pass this through to the upper layer. |
| * nuke this special code so that it looks like we are saying |
| * did_ok. |
| */ |
| scmd->result &= 0xff00ffff; |
| return SUCCESS; |
| case DID_OK: |
| /* |
| * looks good. drop through, and check the next byte. |
| */ |
| break; |
| case DID_NO_CONNECT: |
| case DID_BAD_TARGET: |
| case DID_ABORT: |
| /* |
| * note - this means that we just report the status back |
| * to the top level driver, not that we actually think |
| * that it indicates SUCCESS. |
| */ |
| return SUCCESS; |
| /* |
| * when the low level driver returns did_soft_error, |
| * it is responsible for keeping an internal retry counter |
| * in order to avoid endless loops (db) |
| * |
| * actually this is a bug in this function here. we should |
| * be mindful of the maximum number of retries specified |
| * and not get stuck in a loop. |
| */ |
| case DID_SOFT_ERROR: |
| goto maybe_retry; |
| case DID_IMM_RETRY: |
| return NEEDS_RETRY; |
| |
| case DID_REQUEUE: |
| return ADD_TO_MLQUEUE; |
| |
| case DID_ERROR: |
| if (msg_byte(scmd->result) == COMMAND_COMPLETE && |
| status_byte(scmd->result) == RESERVATION_CONFLICT) |
| /* |
| * execute reservation conflict processing code |
| * lower down |
| */ |
| break; |
| /* fallthrough */ |
| |
| case DID_BUS_BUSY: |
| case DID_PARITY: |
| goto maybe_retry; |
| case DID_TIME_OUT: |
| /* |
| * when we scan the bus, we get timeout messages for |
| * these commands if there is no device available. |
| * other hosts report did_no_connect for the same thing. |
| */ |
| if ((scmd->cmnd[0] == TEST_UNIT_READY || |
| scmd->cmnd[0] == INQUIRY)) { |
| return SUCCESS; |
| } else { |
| return FAILED; |
| } |
| case DID_RESET: |
| return SUCCESS; |
| default: |
| return FAILED; |
| } |
| |
| /* |
| * next, check the message byte. |
| */ |
| if (msg_byte(scmd->result) != COMMAND_COMPLETE) |
| return FAILED; |
| |
| /* |
| * check the status byte to see if this indicates anything special. |
| */ |
| switch (status_byte(scmd->result)) { |
| case QUEUE_FULL: |
| /* |
| * the case of trying to send too many commands to a |
| * tagged queueing device. |
| */ |
| case BUSY: |
| /* |
| * device can't talk to us at the moment. Should only |
| * occur (SAM-3) when the task queue is empty, so will cause |
| * the empty queue handling to trigger a stall in the |
| * device. |
| */ |
| return ADD_TO_MLQUEUE; |
| case GOOD: |
| case COMMAND_TERMINATED: |
| case TASK_ABORTED: |
| return SUCCESS; |
| case CHECK_CONDITION: |
| rtn = scsi_check_sense(scmd); |
| if (rtn == NEEDS_RETRY) |
| goto maybe_retry; |
| /* if rtn == FAILED, we have no sense information; |
| * returning FAILED will wake the error handler thread |
| * to collect the sense and redo the decide |
| * disposition */ |
| return rtn; |
| case CONDITION_GOOD: |
| case INTERMEDIATE_GOOD: |
| case INTERMEDIATE_C_GOOD: |
| case ACA_ACTIVE: |
| /* |
| * who knows? FIXME(eric) |
| */ |
| return SUCCESS; |
| |
| case RESERVATION_CONFLICT: |
| sdev_printk(KERN_INFO, scmd->device, |
| "reservation conflict\n"); |
| return SUCCESS; /* causes immediate i/o error */ |
| default: |
| return FAILED; |
| } |
| return FAILED; |
| |
| maybe_retry: |
| |
| /* we requeue for retry because the error was retryable, and |
| * the request was not marked fast fail. Note that above, |
| * even if the request is marked fast fail, we still requeue |
| * for queue congestion conditions (QUEUE_FULL or BUSY) */ |
| if ((++scmd->retries) < scmd->allowed |
| && !blk_noretry_request(scmd->request)) { |
| return NEEDS_RETRY; |
| } else { |
| /* |
| * no more retries - report this one back to upper level. |
| */ |
| return SUCCESS; |
| } |
| } |
| |
| /** |
| * scsi_eh_lock_door - Prevent medium removal for the specified device |
| * @sdev: SCSI device to prevent medium removal |
| * |
| * Locking: |
| * We must be called from process context; scsi_allocate_request() |
| * may sleep. |
| * |
| * Notes: |
| * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the |
| * head of the devices request queue, and continue. |
| * |
| * Bugs: |
| * scsi_allocate_request() may sleep waiting for existing requests to |
| * be processed. However, since we haven't kicked off any request |
| * processing for this host, this may deadlock. |
| * |
| * If scsi_allocate_request() fails for what ever reason, we |
| * completely forget to lock the door. |
| **/ |
| static void scsi_eh_lock_door(struct scsi_device *sdev) |
| { |
| unsigned char cmnd[MAX_COMMAND_SIZE]; |
| |
| cmnd[0] = ALLOW_MEDIUM_REMOVAL; |
| cmnd[1] = 0; |
| cmnd[2] = 0; |
| cmnd[3] = 0; |
| cmnd[4] = SCSI_REMOVAL_PREVENT; |
| cmnd[5] = 0; |
| |
| scsi_execute_async(sdev, cmnd, DMA_NONE, NULL, 0, 0, 10 * HZ, |
| 5, NULL, NULL, GFP_KERNEL); |
| } |
| |
| |
| /** |
| * scsi_restart_operations - restart io operations to the specified host. |
| * @shost: Host we are restarting. |
| * |
| * Notes: |
| * When we entered the error handler, we blocked all further i/o to |
| * this device. we need to 'reverse' this process. |
| **/ |
| static void scsi_restart_operations(struct Scsi_Host *shost) |
| { |
| struct scsi_device *sdev; |
| unsigned long flags; |
| |
| /* |
| * If the door was locked, we need to insert a door lock request |
| * onto the head of the SCSI request queue for the device. There |
| * is no point trying to lock the door of an off-line device. |
| */ |
| shost_for_each_device(sdev, shost) { |
| if (scsi_device_online(sdev) && sdev->locked) |
| scsi_eh_lock_door(sdev); |
| } |
| |
| /* |
| * next free up anything directly waiting upon the host. this |
| * will be requests for character device operations, and also for |
| * ioctls to queued block devices. |
| */ |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n", |
| __FUNCTION__)); |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| if (scsi_host_set_state(shost, SHOST_RUNNING)) |
| if (scsi_host_set_state(shost, SHOST_CANCEL)) |
| BUG_ON(scsi_host_set_state(shost, SHOST_DEL)); |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| |
| wake_up(&shost->host_wait); |
| |
| /* |
| * finally we need to re-initiate requests that may be pending. we will |
| * have had everything blocked while error handling is taking place, and |
| * now that error recovery is done, we will need to ensure that these |
| * requests are started. |
| */ |
| scsi_run_host_queues(shost); |
| } |
| |
| /** |
| * scsi_eh_ready_devs - check device ready state and recover if not. |
| * @shost: host to be recovered. |
| * @eh_done_q: list_head for processed commands. |
| * |
| **/ |
| static void scsi_eh_ready_devs(struct Scsi_Host *shost, |
| struct list_head *work_q, |
| struct list_head *done_q) |
| { |
| 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); |
| } |
| |
| /** |
| * scsi_eh_flush_done_q - finish processed commands or retry them. |
| * @done_q: list_head of processed commands. |
| * |
| **/ |
| static void scsi_eh_flush_done_q(struct list_head *done_q) |
| { |
| struct scsi_cmnd *scmd, *next; |
| |
| list_for_each_entry_safe(scmd, next, done_q, eh_entry) { |
| list_del_init(&scmd->eh_entry); |
| if (scsi_device_online(scmd->device) && |
| !blk_noretry_request(scmd->request) && |
| (++scmd->retries < scmd->allowed)) { |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush" |
| " retry cmd: %p\n", |
| current->comm, |
| scmd)); |
| scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY); |
| } else { |
| /* |
| * If just we got sense for the device (called |
| * scsi_eh_get_sense), scmd->result is already |
| * set, do not set DRIVER_TIMEOUT. |
| */ |
| if (!scmd->result) |
| scmd->result |= (DRIVER_TIMEOUT << 24); |
| SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish" |
| " cmd: %p\n", |
| current->comm, scmd)); |
| scsi_finish_command(scmd); |
| } |
| } |
| } |
| |
| /** |
| * scsi_unjam_host - Attempt to fix a host which has a cmd that failed. |
| * @shost: Host to unjam. |
| * |
| * Notes: |
| * When we come in here, we *know* that all commands on the bus have |
| * either completed, failed or timed out. we also know that no further |
| * commands are being sent to the host, so things are relatively quiet |
| * and we have freedom to fiddle with things as we wish. |
| * |
| * This is only the *default* implementation. it is possible for |
| * individual drivers to supply their own version of this function, and |
| * if the maintainer wishes to do this, it is strongly suggested that |
| * this function be taken as a template and modified. this function |
| * was designed to correctly handle problems for about 95% of the |
| * different cases out there, and it should always provide at least a |
| * reasonable amount of error recovery. |
| * |
| * Any command marked 'failed' or 'timeout' must eventually have |
| * scsi_finish_cmd() called for it. we do all of the retry stuff |
| * here, so when we restart the host after we return it should have an |
| * empty queue. |
| **/ |
| static void scsi_unjam_host(struct Scsi_Host *shost) |
| { |
| unsigned long flags; |
| LIST_HEAD(eh_work_q); |
| LIST_HEAD(eh_done_q); |
| |
| spin_lock_irqsave(shost->host_lock, flags); |
| list_splice_init(&shost->eh_cmd_q, &eh_work_q); |
| spin_unlock_irqrestore(shost->host_lock, flags); |
| |
| SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q)); |
| |
| if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q)) |
| if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q)) |
| scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q); |
| |
| scsi_eh_flush_done_q(&eh_done_q); |
| } |
| |
| /** |
| * scsi_error_handler - SCSI error handler thread |
| * @data: Host for which we are running. |
| * |
| * Notes: |
| * This is the main error handling loop. This is run as a kernel thread |
| * for every SCSI host and handles all error handling activity. |
| **/ |
| int scsi_error_handler(void *data) |
| { |
| struct Scsi_Host *shost = data; |
| |
| current->flags |= PF_NOFREEZE; |
| |
| /* |
| * We use TASK_INTERRUPTIBLE so that the thread is not |
| * counted against the load average as a running process. |
| * We never actually get interrupted because kthread_run |
| * disables singal delivery for the created thread. |
| */ |
| set_current_state(TASK_INTERRUPTIBLE); |
| while (!kthread_should_stop()) { |
| if (shost->host_failed == 0 || |
| shost->host_failed != shost->host_busy) { |
| SCSI_LOG_ERROR_RECOVERY(1, |
| printk("Error handler scsi_eh_%d sleeping\n", |
| shost->host_no)); |
| schedule(); |
| set_current_state(TASK_INTERRUPTIBLE); |
| continue; |
| } |
| |
| __set_current_state(TASK_RUNNING); |
| SCSI_LOG_ERROR_RECOVERY(1, |
| printk("Error handler scsi_eh_%d waking up\n", |
| shost->host_no)); |
| |
| /* |
| * We have a host that is failing for some reason. Figure out |
| * what we need to do to get it up and online again (if we can). |
| * If we fail, we end up taking the thing offline. |
| */ |
| if (shost->hostt->eh_strategy_handler) |
| shost->hostt->eh_strategy_handler(shost); |
| else |
| scsi_unjam_host(shost); |
| |
| /* |
| * Note - if the above fails completely, the action is to take |
| * individual devices offline and flush the queue of any |
| * outstanding requests that may have been pending. When we |
| * restart, we restart any I/O to any other devices on the bus |
| * which are still online. |
| */ |
| scsi_restart_operations(shost); |
| set_current_state(TASK_INTERRUPTIBLE); |
| } |
| __set_current_state(TASK_RUNNING); |
| |
| SCSI_LOG_ERROR_RECOVERY(1, |
| printk("Error handler scsi_eh_%d exiting\n", shost->host_no)); |
| shost->ehandler = NULL; |
| return 0; |
| } |
| |
| /* |
| * Function: scsi_report_bus_reset() |
| * |
| * Purpose: Utility function used by low-level drivers to report that |
| * they have observed a bus reset on the bus being handled. |
| * |
| * Arguments: shost - Host in question |
| * channel - channel on which reset was observed. |
| * |
| * Returns: Nothing |
| * |
| * Lock status: Host lock must be held. |
| * |
| * Notes: This only needs to be called if the reset is one which |
| * originates from an unknown location. Resets originated |
| * by the mid-level itself don't need to call this, but there |
| * should be no harm. |
| * |
| * The main purpose of this is to make sure that a CHECK_CONDITION |
| * is properly treated. |
| */ |
| 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; |
| } |
| } |
| } |
| EXPORT_SYMBOL(scsi_report_bus_reset); |
| |
| /* |
| * Function: scsi_report_device_reset() |
| * |
| * Purpose: Utility function used by low-level drivers to report that |
| * they have observed a device reset on the device being handled. |
| * |
| * Arguments: shost - Host in question |
| * channel - channel on which reset was observed |
| * target - target on which reset was observed |
| * |
| * Returns: Nothing |
| * |
| * Lock status: Host lock must be held |
| * |
| * Notes: This only needs to be called if the reset is one which |
| * originates from an unknown location. Resets originated |
| * by the mid-level itself don't need to call this, but there |
| * should be no harm. |
| * |
| * The main purpose of this is to make sure that a CHECK_CONDITION |
| * is properly treated. |
| */ |
| void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target) |
| { |
| struct scsi_device *sdev; |
| |
| __shost_for_each_device(sdev, shost) { |
| if (channel == sdev_channel(sdev) && |
| target == sdev_id(sdev)) { |
| sdev->was_reset = 1; |
| sdev->expecting_cc_ua = 1; |
| } |
| } |
| } |
| EXPORT_SYMBOL(scsi_report_device_reset); |
| |
| static void |
| scsi_reset_provider_done_command(struct scsi_cmnd *scmd) |
| { |
| } |
| |
| /* |
| * Function: scsi_reset_provider |
| * |
| * Purpose: Send requested reset to a bus or device at any phase. |
| * |
| * Arguments: device - device to send reset to |
| * flag - reset type (see scsi.h) |
| * |
| * Returns: SUCCESS/FAILURE. |
| * |
| * Notes: This is used by the SCSI Generic driver to provide |
| * Bus/Device reset capability. |
| */ |
| int |
| scsi_reset_provider(struct scsi_device *dev, int flag) |
| { |
| struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL); |
| struct request req; |
| int rtn; |
| |
| scmd->request = &req; |
| memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout)); |
| scmd->request->rq_status = RQ_SCSI_BUSY; |
| |
| memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd)); |
| |
| scmd->scsi_done = scsi_reset_provider_done_command; |
| scmd->done = NULL; |
| scmd->buffer = NULL; |
| scmd->bufflen = 0; |
| scmd->request_buffer = NULL; |
| scmd->request_bufflen = 0; |
| |
| scmd->cmd_len = 0; |
| |
| scmd->sc_data_direction = DMA_BIDIRECTIONAL; |
| scmd->sc_request = NULL; |
| scmd->sc_magic = SCSI_CMND_MAGIC; |
| |
| init_timer(&scmd->eh_timeout); |
| |
| /* |
| * Sometimes the command can get back into the timer chain, |
| * so use the pid as an identifier. |
| */ |
| scmd->pid = 0; |
| |
| switch (flag) { |
| case SCSI_TRY_RESET_DEVICE: |
| rtn = scsi_try_bus_device_reset(scmd); |
| if (rtn == SUCCESS) |
| break; |
| /* FALLTHROUGH */ |
| case SCSI_TRY_RESET_BUS: |
| rtn = scsi_try_bus_reset(scmd); |
| if (rtn == SUCCESS) |
| break; |
| /* FALLTHROUGH */ |
| case SCSI_TRY_RESET_HOST: |
| rtn = scsi_try_host_reset(scmd); |
| break; |
| default: |
| rtn = FAILED; |
| } |
| |
| scsi_next_command(scmd); |
| return rtn; |
| } |
| EXPORT_SYMBOL(scsi_reset_provider); |
| |
| /** |
| * scsi_normalize_sense - normalize main elements from either fixed or |
| * descriptor sense data format into a common format. |
| * |
| * @sense_buffer: byte array containing sense data returned by device |
| * @sb_len: number of valid bytes in sense_buffer |
| * @sshdr: pointer to instance of structure that common |
| * elements are written to. |
| * |
| * Notes: |
| * The "main elements" from sense data are: response_code, sense_key, |
| * asc, ascq and additional_length (only for descriptor format). |
| * |
| * Typically this function can be called after a device has |
| * responded to a SCSI command with the CHECK_CONDITION status. |
| * |
| * Return value: |
| * 1 if valid sense data information found, else 0; |
| **/ |
| int scsi_normalize_sense(const u8 *sense_buffer, int sb_len, |
| struct scsi_sense_hdr *sshdr) |
| { |
| if (!sense_buffer || !sb_len) |
| return 0; |
| |
| memset(sshdr, 0, sizeof(struct scsi_sense_hdr)); |
| |
| sshdr->response_code = (sense_buffer[0] & 0x7f); |
| |
| if (!scsi_sense_valid(sshdr)) |
| return 0; |
| |
| if (sshdr->response_code >= 0x72) { |
| /* |
| * descriptor format |
| */ |
| if (sb_len > 1) |
| sshdr->sense_key = (sense_buffer[1] & 0xf); |
| if (sb_len > 2) |
| sshdr->asc = sense_buffer[2]; |
| if (sb_len > 3) |
| sshdr->ascq = sense_buffer[3]; |
| if (sb_len > 7) |
| sshdr->additional_length = sense_buffer[7]; |
| } else { |
| /* |
| * fixed format |
| */ |
| if (sb_len > 2) |
| sshdr->sense_key = (sense_buffer[2] & 0xf); |
| if (sb_len > 7) { |
| sb_len = (sb_len < (sense_buffer[7] + 8)) ? |
| sb_len : (sense_buffer[7] + 8); |
| if (sb_len > 12) |
| sshdr->asc = sense_buffer[12]; |
| if (sb_len > 13) |
| sshdr->ascq = sense_buffer[13]; |
| } |
| } |
| |
| return 1; |
| } |
| EXPORT_SYMBOL(scsi_normalize_sense); |
| |
| int scsi_request_normalize_sense(struct scsi_request *sreq, |
| struct scsi_sense_hdr *sshdr) |
| { |
| return scsi_normalize_sense(sreq->sr_sense_buffer, |
| sizeof(sreq->sr_sense_buffer), sshdr); |
| } |
| EXPORT_SYMBOL(scsi_request_normalize_sense); |
| |
| int scsi_command_normalize_sense(struct scsi_cmnd *cmd, |
| struct scsi_sense_hdr *sshdr) |
| { |
| return scsi_normalize_sense(cmd->sense_buffer, |
| sizeof(cmd->sense_buffer), sshdr); |
| } |
| EXPORT_SYMBOL(scsi_command_normalize_sense); |
| |
| /** |
| * scsi_sense_desc_find - search for a given descriptor type in |
| * descriptor sense data format. |
| * |
| * @sense_buffer: byte array of descriptor format sense data |
| * @sb_len: number of valid bytes in sense_buffer |
| * @desc_type: value of descriptor type to find |
| * (e.g. 0 -> information) |
| * |
| * Notes: |
| * only valid when sense data is in descriptor format |
| * |
| * Return value: |
| * pointer to start of (first) descriptor if found else NULL |
| **/ |
| const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len, |
| int desc_type) |
| { |
| int add_sen_len, add_len, desc_len, k; |
| const u8 * descp; |
| |
| if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7]))) |
| return NULL; |
| if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73)) |
| return NULL; |
| add_sen_len = (add_sen_len < (sb_len - 8)) ? |
| add_sen_len : (sb_len - 8); |
| descp = &sense_buffer[8]; |
| for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) { |
| descp += desc_len; |
| add_len = (k < (add_sen_len - 1)) ? descp[1]: -1; |
| desc_len = add_len + 2; |
| if (descp[0] == desc_type) |
| return descp; |
| if (add_len < 0) // short descriptor ?? |
| break; |
| } |
| return NULL; |
| } |
| EXPORT_SYMBOL(scsi_sense_desc_find); |
| |
| /** |
| * scsi_get_sense_info_fld - attempts to get information field from |
| * sense data (either fixed or descriptor format) |
| * |
| * @sense_buffer: byte array of sense data |
| * @sb_len: number of valid bytes in sense_buffer |
| * @info_out: pointer to 64 integer where 8 or 4 byte information |
| * field will be placed if found. |
| * |
| * Return value: |
| * 1 if information field found, 0 if not found. |
| **/ |
| int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len, |
| u64 * info_out) |
| { |
| int j; |
| const u8 * ucp; |
| u64 ull; |
| |
| if (sb_len < 7) |
| return 0; |
| switch (sense_buffer[0] & 0x7f) { |
| case 0x70: |
| case 0x71: |
| if (sense_buffer[0] & 0x80) { |
| *info_out = (sense_buffer[3] << 24) + |
| (sense_buffer[4] << 16) + |
| (sense_buffer[5] << 8) + sense_buffer[6]; |
| return 1; |
| } else |
| return 0; |
| case 0x72: |
| case 0x73: |
| ucp = scsi_sense_desc_find(sense_buffer, sb_len, |
| 0 /* info desc */); |
| if (ucp && (0xa == ucp[1])) { |
| ull = 0; |
| for (j = 0; j < 8; ++j) { |
| if (j > 0) |
| ull <<= 8; |
| ull |= ucp[4 + j]; |
| } |
| *info_out = ull; |
| return 1; |
| } else |
| return 0; |
| default: |
| return 0; |
| } |
| } |
| EXPORT_SYMBOL(scsi_get_sense_info_fld); |