| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Mike Anderson | 1573 | 18.05% | 12 | 3.73% |
| Hannes Reinecke | 1085 | 12.45% | 29 | 9.01% |
| Linus Torvalds (pre-git) | 769 | 8.82% | 36 | 11.18% |
| Christoph Hellwig | 724 | 8.31% | 58 | 18.01% |
| Brian King | 685 | 7.86% | 4 | 1.24% |
| Michael Christie | 482 | 5.53% | 11 | 3.42% |
| James Bottomley | 465 | 5.34% | 34 | 10.56% |
| Ewan D. Milne | 404 | 4.64% | 3 | 0.93% |
| Bart Van Assche | 320 | 3.67% | 17 | 5.28% |
| Boaz Harrosh | 272 | 3.12% | 5 | 1.55% |
| David Jeffery | 206 | 2.36% | 1 | 0.31% |
| Douglas Gilbert | 196 | 2.25% | 3 | 0.93% |
| Niklas Svensson (Niklas Cassel) | 140 | 1.61% | 2 | 0.62% |
| Vasu Dev | 106 | 1.22% | 1 | 0.31% |
| Alan Cox | 100 | 1.15% | 1 | 0.31% |
| Jesper Juhl | 92 | 1.06% | 1 | 0.31% |
| Alan Stern | 82 | 0.94% | 8 | 2.48% |
| FUJITA Tomonori | 76 | 0.87% | 4 | 1.24% |
| James Smart | 72 | 0.83% | 2 | 0.62% |
| Muneendra Kumar M | 67 | 0.77% | 2 | 0.62% |
| Martin K. Petersen | 65 | 0.75% | 6 | 1.86% |
| Chandra Seetharaman | 56 | 0.64% | 1 | 0.31% |
| Martin Wilck | 48 | 0.55% | 3 | 0.93% |
| Damien Le Moal | 43 | 0.49% | 2 | 0.62% |
| Tejun Heo | 43 | 0.49% | 5 | 1.55% |
| Patrick Mansfield | 38 | 0.44% | 5 | 1.55% |
| Luben Tuikov | 35 | 0.40% | 3 | 0.93% |
| Mike Snitzer | 34 | 0.39% | 1 | 0.31% |
| Jeff Garzik | 31 | 0.36% | 4 | 1.24% |
| Ren Mingxin | 30 | 0.34% | 1 | 0.31% |
| Gustavo A. R. Silva | 28 | 0.32% | 1 | 0.31% |
| Linus Torvalds | 23 | 0.26% | 4 | 1.24% |
| Christof Schmitt | 23 | 0.26% | 1 | 0.31% |
| Randy Dunlap | 20 | 0.23% | 3 | 0.93% |
| Michael Reed | 18 | 0.21% | 2 | 0.62% |
| TARUISI Hiroaki | 17 | 0.20% | 1 | 0.31% |
| Willem Riede | 16 | 0.18% | 1 | 0.31% |
| Li Zhong | 15 | 0.17% | 1 | 0.31% |
| Keith Busch | 14 | 0.16% | 2 | 0.62% |
| Jens Axboe | 14 | 0.16% | 2 | 0.62% |
| Doug Ledford | 14 | 0.16% | 1 | 0.31% |
| Keiichiro Tokunaga | 13 | 0.15% | 1 | 0.31% |
| Lin Ming | 12 | 0.14% | 1 | 0.31% |
| Ulrich Obergfell | 12 | 0.14% | 1 | 0.31% |
| Bo Wu | 10 | 0.11% | 1 | 0.31% |
| Wenchao Hao | 10 | 0.11% | 1 | 0.31% |
| Dan J Williams | 9 | 0.10% | 1 | 0.31% |
| Joe Lawrence | 8 | 0.09% | 2 | 0.62% |
| Tony Battersby | 8 | 0.09% | 1 | 0.31% |
| Michal Hocko | 8 | 0.09% | 1 | 0.31% |
| Adrian Hunter | 8 | 0.09% | 1 | 0.31% |
| Wei Fang | 7 | 0.08% | 1 | 0.31% |
| Shyam Iyer | 7 | 0.08% | 1 | 0.31% |
| Harvey Harrison | 7 | 0.08% | 1 | 0.31% |
| Naveen Burmi | 6 | 0.07% | 1 | 0.31% |
| Vladislav Bolkhovitin | 5 | 0.06% | 1 | 0.31% |
| Darrick J. Wong | 5 | 0.06% | 1 | 0.31% |
| Jiang Biao | 4 | 0.05% | 1 | 0.31% |
| Andrew Morton | 3 | 0.03% | 1 | 0.31% |
| Ming Lei | 3 | 0.03% | 1 | 0.31% |
| Babu Moger | 3 | 0.03% | 1 | 0.31% |
| Adrian Bunk | 3 | 0.03% | 1 | 0.31% |
| Andries E. Brouwer | 3 | 0.03% | 2 | 0.62% |
| John Garry | 3 | 0.03% | 2 | 0.62% |
| Avi Kivity | 3 | 0.03% | 1 | 0.31% |
| Matthew Wilcox | 2 | 0.02% | 1 | 0.31% |
| Santosh Yaraganavi | 2 | 0.02% | 1 | 0.31% |
| Steven Cole | 2 | 0.02% | 1 | 0.31% |
| Chunguang Xu | 1 | 0.01% | 1 | 0.31% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.31% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.31% |
| Petros Koutoupis | 1 | 0.01% | 1 | 0.31% |
| Uladzislau Rezki | 1 | 0.01% | 1 | 0.31% |
| Frederik Schwarzer | 1 | 0.01% | 1 | 0.31% |
| Geert Uytterhoeven | 1 | 0.01% | 1 | 0.31% |
| Li Zhijian | 1 | 0.01% | 1 | 0.31% |
| Total | 8715 | 322 |
// SPDX-License-Identifier: GPL-2.0-only /* * 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/gfp.h> #include <linux/timer.h> #include <linux/string.h> #include <linux/kernel.h> #include <linux/freezer.h> #include <linux/kthread.h> #include <linux/interrupt.h> #include <linux/blkdev.h> #include <linux/delay.h> #include <linux/jiffies.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_dbg.h> #include <scsi/scsi_device.h> #include <scsi/scsi_driver.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_common.h> #include <scsi/scsi_transport.h> #include <scsi/scsi_host.h> #include <scsi/scsi_ioctl.h> #include <scsi/scsi_dh.h> #include <scsi/scsi_devinfo.h> #include <scsi/sg.h> #include "scsi_priv.h" #include "scsi_logging.h" #include "scsi_transport_api.h" #include <trace/events/scsi.h> #include <asm/unaligned.h> /* * 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) static int scsi_eh_try_stu(struct scsi_cmnd *scmd); static enum scsi_disposition scsi_try_to_abort_cmd(const struct scsi_host_template *, struct scsi_cmnd *); void scsi_eh_wakeup(struct Scsi_Host *shost) { lockdep_assert_held(shost->host_lock); if (scsi_host_busy(shost) == shost->host_failed) { trace_scsi_eh_wakeup(shost); wake_up_process(shost->ehandler); SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost, "Waking error handler thread\n")); } } /** * scsi_schedule_eh - schedule EH for SCSI host * @shost: SCSI host to invoke error handling on. * * Schedule SCSI EH without scmd. */ void scsi_schedule_eh(struct Scsi_Host *shost) { unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 || scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) { shost->host_eh_scheduled++; scsi_eh_wakeup(shost); } spin_unlock_irqrestore(shost->host_lock, flags); } EXPORT_SYMBOL_GPL(scsi_schedule_eh); static int scsi_host_eh_past_deadline(struct Scsi_Host *shost) { if (!shost->last_reset || shost->eh_deadline == -1) return 0; /* * 32bit accesses are guaranteed to be atomic * (on all supported architectures), so instead * of using a spinlock we can as well double check * if eh_deadline has been set to 'off' during the * time_before call. */ if (time_before(jiffies, shost->last_reset + shost->eh_deadline) && shost->eh_deadline > -1) return 0; return 1; } static bool scsi_cmd_retry_allowed(struct scsi_cmnd *cmd) { if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT) return true; return ++cmd->retries <= cmd->allowed; } static bool scsi_eh_should_retry_cmd(struct scsi_cmnd *cmd) { struct scsi_device *sdev = cmd->device; struct Scsi_Host *host = sdev->host; if (host->hostt->eh_should_retry_cmd) return host->hostt->eh_should_retry_cmd(cmd); return true; } /** * scmd_eh_abort_handler - Handle command aborts * @work: command to be aborted. * * Note: this function must be called only for a command that has timed out. * Because the block layer marks a request as complete before it calls * scsi_timeout(), a .scsi_done() call from the LLD for a command that has * timed out do not have any effect. Hence it is safe to call * scsi_finish_command() from this function. */ void scmd_eh_abort_handler(struct work_struct *work) { struct scsi_cmnd *scmd = container_of(work, struct scsi_cmnd, abort_work.work); struct scsi_device *sdev = scmd->device; struct Scsi_Host *shost = sdev->host; enum scsi_disposition rtn; unsigned long flags; if (scsi_host_eh_past_deadline(shost)) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "eh timeout, not aborting\n")); goto out; } SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "aborting command\n")); rtn = scsi_try_to_abort_cmd(shost->hostt, scmd); if (rtn != SUCCESS) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "cmd abort %s\n", (rtn == FAST_IO_FAIL) ? "not send" : "failed")); goto out; } set_host_byte(scmd, DID_TIME_OUT); if (scsi_host_eh_past_deadline(shost)) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "eh timeout, not retrying " "aborted command\n")); goto out; } spin_lock_irqsave(shost->host_lock, flags); list_del_init(&scmd->eh_entry); /* * If the abort succeeds, and there is no further * EH action, clear the ->last_reset time. */ if (list_empty(&shost->eh_abort_list) && list_empty(&shost->eh_cmd_q)) if (shost->eh_deadline != -1) shost->last_reset = 0; spin_unlock_irqrestore(shost->host_lock, flags); if (!scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd) && scsi_eh_should_retry_cmd(scmd)) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_WARNING, scmd, "retry aborted command\n")); scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY); } else { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_WARNING, scmd, "finish aborted command\n")); scsi_finish_command(scmd); } return; out: spin_lock_irqsave(shost->host_lock, flags); list_del_init(&scmd->eh_entry); spin_unlock_irqrestore(shost->host_lock, flags); scsi_eh_scmd_add(scmd); } /** * scsi_abort_command - schedule a command abort * @scmd: scmd to abort. * * We only need to abort commands after a command timeout */ static int scsi_abort_command(struct scsi_cmnd *scmd) { struct scsi_device *sdev = scmd->device; struct Scsi_Host *shost = sdev->host; unsigned long flags; if (!shost->hostt->eh_abort_handler) { /* No abort handler, fail command directly */ return FAILED; } if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) { /* * Retry after abort failed, escalate to next level. */ SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "previous abort failed\n")); BUG_ON(delayed_work_pending(&scmd->abort_work)); return FAILED; } spin_lock_irqsave(shost->host_lock, flags); if (shost->eh_deadline != -1 && !shost->last_reset) shost->last_reset = jiffies; BUG_ON(!list_empty(&scmd->eh_entry)); list_add_tail(&scmd->eh_entry, &shost->eh_abort_list); spin_unlock_irqrestore(shost->host_lock, flags); scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED; SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "abort scheduled\n")); queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100); return SUCCESS; } /** * scsi_eh_reset - call into ->eh_action to reset internal counters * @scmd: scmd to run eh on. * * The scsi driver might be carrying internal state about the * devices, so we need to call into the driver to reset the * internal state once the error handler is started. */ static void scsi_eh_reset(struct scsi_cmnd *scmd) { if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) { struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd); if (sdrv->eh_reset) sdrv->eh_reset(scmd); } } static void scsi_eh_inc_host_failed(struct rcu_head *head) { struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu); struct Scsi_Host *shost = scmd->device->host; unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); shost->host_failed++; scsi_eh_wakeup(shost); spin_unlock_irqrestore(shost->host_lock, flags); } /** * scsi_eh_scmd_add - add scsi cmd to error handling. * @scmd: scmd to run eh on. */ void scsi_eh_scmd_add(struct scsi_cmnd *scmd) { struct Scsi_Host *shost = scmd->device->host; unsigned long flags; int ret; WARN_ON_ONCE(!shost->ehandler); spin_lock_irqsave(shost->host_lock, flags); if (scsi_host_set_state(shost, SHOST_RECOVERY)) { ret = scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY); WARN_ON_ONCE(ret); } if (shost->eh_deadline != -1 && !shost->last_reset) shost->last_reset = jiffies; scsi_eh_reset(scmd); list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q); spin_unlock_irqrestore(shost->host_lock, flags); /* * Ensure that all tasks observe the host state change before the * host_failed change. */ call_rcu_hurry(&scmd->rcu, scsi_eh_inc_host_failed); } /** * scsi_timeout - Timeout function for normal scsi commands. * @req: request 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. */ enum blk_eh_timer_return scsi_timeout(struct request *req) { struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req); struct Scsi_Host *host = scmd->device->host; trace_scsi_dispatch_cmd_timeout(scmd); scsi_log_completion(scmd, TIMEOUT_ERROR); atomic_inc(&scmd->device->iotmo_cnt); if (host->eh_deadline != -1 && !host->last_reset) host->last_reset = jiffies; if (host->hostt->eh_timed_out) { switch (host->hostt->eh_timed_out(scmd)) { case SCSI_EH_DONE: return BLK_EH_DONE; case SCSI_EH_RESET_TIMER: return BLK_EH_RESET_TIMER; case SCSI_EH_NOT_HANDLED: break; } } /* * If scsi_done() has already set SCMD_STATE_COMPLETE, do not modify * *scmd. */ if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state)) return BLK_EH_DONE; atomic_inc(&scmd->device->iodone_cnt); if (scsi_abort_command(scmd) != SUCCESS) { set_host_byte(scmd, DID_TIME_OUT); scsi_eh_scmd_add(scmd); } return BLK_EH_DONE; } /** * 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); 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_ABORT_SCHEDULED) ++cmd_cancel; else ++cmd_failed; } } if (cmd_cancel || cmd_failed) { SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: cmds failed: %d, cancel: %d\n", __func__, cmd_failed, cmd_cancel)); cmd_cancel = 0; cmd_failed = 0; ++devices_failed; } } SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO, shost, "Total of %d commands on %d" " devices require eh work\n", total_failures, devices_failed)); } #endif /** * scsi_report_lun_change - Set flag on all *other* devices on the same target * to indicate that a UNIT ATTENTION is expected. * @sdev: Device reporting the UNIT ATTENTION */ static void scsi_report_lun_change(struct scsi_device *sdev) { sdev->sdev_target->expecting_lun_change = 1; } /** * scsi_report_sense - Examine scsi sense information and log messages for * certain conditions, also issue uevents for some of them. * @sdev: Device reporting the sense code * @sshdr: sshdr to be examined */ static void scsi_report_sense(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr) { enum scsi_device_event evt_type = SDEV_EVT_MAXBITS; /* i.e. none */ if (sshdr->sense_key == UNIT_ATTENTION) { if (sshdr->asc == 0x3f && sshdr->ascq == 0x03) { evt_type = SDEV_EVT_INQUIRY_CHANGE_REPORTED; sdev_printk(KERN_WARNING, sdev, "Inquiry data has changed"); } else if (sshdr->asc == 0x3f && sshdr->ascq == 0x0e) { evt_type = SDEV_EVT_LUN_CHANGE_REPORTED; scsi_report_lun_change(sdev); sdev_printk(KERN_WARNING, sdev, "LUN assignments on this target have " "changed. The Linux SCSI layer does not " "automatically remap LUN assignments.\n"); } else if (sshdr->asc == 0x3f) sdev_printk(KERN_WARNING, sdev, "Operating parameters on this target have " "changed. The Linux SCSI layer does not " "automatically adjust these parameters.\n"); if (sshdr->asc == 0x38 && sshdr->ascq == 0x07) { evt_type = SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED; sdev_printk(KERN_WARNING, sdev, "Warning! Received an indication that the " "LUN reached a thin provisioning soft " "threshold.\n"); } if (sshdr->asc == 0x29) { evt_type = SDEV_EVT_POWER_ON_RESET_OCCURRED; /* * Do not print message if it is an expected side-effect * of runtime PM. */ if (!sdev->silence_suspend) sdev_printk(KERN_WARNING, sdev, "Power-on or device reset occurred\n"); } if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) { evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED; sdev_printk(KERN_WARNING, sdev, "Mode parameters changed"); } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x06) { evt_type = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED; sdev_printk(KERN_WARNING, sdev, "Asymmetric access state changed"); } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x09) { evt_type = SDEV_EVT_CAPACITY_CHANGE_REPORTED; sdev_printk(KERN_WARNING, sdev, "Capacity data has changed"); } else if (sshdr->asc == 0x2a) sdev_printk(KERN_WARNING, sdev, "Parameters changed"); } if (evt_type != SDEV_EVT_MAXBITS) { set_bit(evt_type, sdev->pending_events); schedule_work(&sdev->event_work); } } static inline void set_scsi_ml_byte(struct scsi_cmnd *cmd, u8 status) { cmd->result = (cmd->result & 0xffff00ff) | (status << 8); } /** * scsi_check_sense - Examine scsi cmd sense * @scmd: Cmd to have sense checked. * * Return value: * SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE * * Notes: * When a deferred error is detected the current command has * not been executed and needs retrying. */ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd) { struct request *req = scsi_cmd_to_rq(scmd); struct scsi_device *sdev = scmd->device; struct scsi_sense_hdr sshdr; if (! scsi_command_normalize_sense(scmd, &sshdr)) return FAILED; /* no valid sense data */ scsi_report_sense(sdev, &sshdr); if (scsi_sense_is_deferred(&sshdr)) return NEEDS_RETRY; if (sdev->handler && sdev->handler->check_sense) { enum scsi_disposition rc; rc = sdev->handler->check_sense(sdev, &sshdr); if (rc != SCSI_RETURN_NOT_HANDLED) return rc; /* handler does not care. Drop down to default handling */ } if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->submitter != SUBMITTED_BY_SCSI_ERROR_HANDLER) /* * nasty: for mid-layer issued TURs, we need to return the * actual sense data without any recovery attempt. For eh * issued ones, we need to try to recover and interpret */ return SUCCESS; /* * 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: if (sshdr.asc == 0x10) /* DIF */ return SUCCESS; /* * Check aborts due to command duration limit policy: * ABORTED COMMAND additional sense code with the * COMMAND TIMEOUT BEFORE PROCESSING or * COMMAND TIMEOUT DURING PROCESSING or * COMMAND TIMEOUT DURING PROCESSING DUE TO ERROR RECOVERY * additional sense code qualifiers. */ if (sshdr.asc == 0x2e && sshdr.ascq >= 0x01 && sshdr.ascq <= 0x03) { set_scsi_ml_byte(scmd, SCSIML_STAT_DL_TIMEOUT); req->cmd_flags |= REQ_FAILFAST_DEV; req->rq_flags |= RQF_QUIET; return SUCCESS; } if (sshdr.asc == 0x44 && sdev->sdev_bflags & BLIST_RETRY_ITF) return ADD_TO_MLQUEUE; if (sshdr.asc == 0xc1 && sshdr.ascq == 0x01 && sdev->sdev_bflags & BLIST_RETRY_ASC_C1) return ADD_TO_MLQUEUE; 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) { /* * Because some device does not queue unit * attentions correctly, we carefully check * additional sense code and qualifier so as * not to squash media change unit attention. */ if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) { scmd->device->expecting_cc_ua = 0; return NEEDS_RETRY; } } /* * we might also expect a cc/ua if another LUN on the target * reported a UA with an ASC/ASCQ of 3F 0E - * REPORTED LUNS DATA HAS CHANGED. */ if (scmd->device->sdev_target->expecting_lun_change && sshdr.asc == 0x3f && sshdr.ascq == 0x0e) 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; /* * Pass the UA upwards for a determination in the completion * functions. */ return SUCCESS; /* these are not supported */ case DATA_PROTECT: if (sshdr.asc == 0x27 && sshdr.ascq == 0x07) { /* Thin provisioning hard threshold reached */ set_scsi_ml_byte(scmd, SCSIML_STAT_NOSPC); return SUCCESS; } fallthrough; case COPY_ABORTED: case VOLUME_OVERFLOW: case MISCOMPARE: case BLANK_CHECK: set_scsi_ml_byte(scmd, SCSIML_STAT_TGT_FAILURE); return SUCCESS; case MEDIUM_ERROR: if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */ sshdr.asc == 0x13 || /* AMNF DATA FIELD */ sshdr.asc == 0x14) { /* RECORD NOT FOUND */ set_scsi_ml_byte(scmd, SCSIML_STAT_MED_ERROR); return SUCCESS; } return NEEDS_RETRY; case HARDWARE_ERROR: if (scmd->device->retry_hwerror) return ADD_TO_MLQUEUE; else set_scsi_ml_byte(scmd, SCSIML_STAT_TGT_FAILURE); fallthrough; case ILLEGAL_REQUEST: if (sshdr.asc == 0x20 || /* Invalid command operation code */ sshdr.asc == 0x21 || /* Logical block address out of range */ sshdr.asc == 0x22 || /* Invalid function */ sshdr.asc == 0x24 || /* Invalid field in cdb */ sshdr.asc == 0x26 || /* Parameter value invalid */ sshdr.asc == 0x27) { /* Write protected */ set_scsi_ml_byte(scmd, SCSIML_STAT_TGT_FAILURE); } return SUCCESS; case COMPLETED: if (sshdr.asc == 0x55 && sshdr.ascq == 0x0a) { set_scsi_ml_byte(scmd, SCSIML_STAT_DL_TIMEOUT); req->cmd_flags |= REQ_FAILFAST_DEV; req->rq_flags |= RQF_QUIET; } return SUCCESS; default: return SUCCESS; } } EXPORT_SYMBOL_GPL(scsi_check_sense); static void scsi_handle_queue_ramp_up(struct scsi_device *sdev) { const struct scsi_host_template *sht = sdev->host->hostt; struct scsi_device *tmp_sdev; if (!sht->track_queue_depth || sdev->queue_depth >= sdev->max_queue_depth) return; if (time_before(jiffies, sdev->last_queue_ramp_up + sdev->queue_ramp_up_period)) return; if (time_before(jiffies, sdev->last_queue_full_time + sdev->queue_ramp_up_period)) return; /* * Walk all devices of a target and do * ramp up on them. */ shost_for_each_device(tmp_sdev, sdev->host) { if (tmp_sdev->channel != sdev->channel || tmp_sdev->id != sdev->id || tmp_sdev->queue_depth == sdev->max_queue_depth) continue; scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1); sdev->last_queue_ramp_up = jiffies; } } static void scsi_handle_queue_full(struct scsi_device *sdev) { const struct scsi_host_template *sht = sdev->host->hostt; struct scsi_device *tmp_sdev; if (!sht->track_queue_depth) return; shost_for_each_device(tmp_sdev, sdev->host) { if (tmp_sdev->channel != sdev->channel || tmp_sdev->id != sdev->id) continue; /* * We do not know the number of commands that were at * the device when we got the queue full so we start * from the highest possible value and work our way down. */ scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1); } } /** * 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 enum scsi_disposition 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; /* * now, check the status byte to see if this indicates * anything special. */ switch (get_status_byte(scmd)) { case SAM_STAT_GOOD: scsi_handle_queue_ramp_up(scmd->device); if (scmd->sense_buffer && SCSI_SENSE_VALID(scmd)) /* * If we have sense data, call scsi_check_sense() in * order to set the correct SCSI ML byte (if any). * No point in checking the return value, since the * command has already completed successfully. */ scsi_check_sense(scmd); fallthrough; case SAM_STAT_COMMAND_TERMINATED: return SUCCESS; case SAM_STAT_CHECK_CONDITION: return scsi_check_sense(scmd); case SAM_STAT_CONDITION_MET: case SAM_STAT_INTERMEDIATE: case SAM_STAT_INTERMEDIATE_CONDITION_MET: /* * who knows? FIXME(eric) */ return SUCCESS; case SAM_STAT_RESERVATION_CONFLICT: if (scmd->cmnd[0] == TEST_UNIT_READY) /* it is a success, we probed the device and * found it */ return SUCCESS; /* otherwise, we failed to send the command */ return FAILED; case SAM_STAT_TASK_SET_FULL: scsi_handle_queue_full(scmd->device); fallthrough; case SAM_STAT_BUSY: return NEEDS_RETRY; default: return FAILED; } return FAILED; } /** * scsi_eh_done - Completion function for error handling. * @scmd: Cmd that is done. */ void scsi_eh_done(struct scsi_cmnd *scmd) { struct completion *eh_action; SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s result: %x\n", __func__, scmd->result)); eh_action = scmd->device->host->eh_action; if (eh_action) complete(eh_action); } /** * scsi_try_host_reset - ask host adapter to reset itself * @scmd: SCSI cmd to send host reset. */ static enum scsi_disposition scsi_try_host_reset(struct scsi_cmnd *scmd) { unsigned long flags; enum scsi_disposition rtn; struct Scsi_Host *host = scmd->device->host; const struct scsi_host_template *hostt = host->hostt; SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, host, "Snd Host RST\n")); if (!hostt->eh_host_reset_handler) return FAILED; rtn = hostt->eh_host_reset_handler(scmd); if (rtn == SUCCESS) { if (!hostt->skip_settle_delay) ssleep(HOST_RESET_SETTLE_TIME); spin_lock_irqsave(host->host_lock, flags); scsi_report_bus_reset(host, scmd_channel(scmd)); spin_unlock_irqrestore(host->host_lock, flags); } return rtn; } /** * scsi_try_bus_reset - ask host to perform a bus reset * @scmd: SCSI cmd to send bus reset. */ static enum scsi_disposition scsi_try_bus_reset(struct scsi_cmnd *scmd) { unsigned long flags; enum scsi_disposition rtn; struct Scsi_Host *host = scmd->device->host; const struct scsi_host_template *hostt = host->hostt; SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s: Snd Bus RST\n", __func__)); if (!hostt->eh_bus_reset_handler) return FAILED; rtn = hostt->eh_bus_reset_handler(scmd); if (rtn == SUCCESS) { if (!hostt->skip_settle_delay) ssleep(BUS_RESET_SETTLE_TIME); spin_lock_irqsave(host->host_lock, flags); scsi_report_bus_reset(host, scmd_channel(scmd)); spin_unlock_irqrestore(host->host_lock, flags); } 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 enum scsi_disposition scsi_try_target_reset(struct scsi_cmnd *scmd) { unsigned long flags; enum scsi_disposition rtn; struct Scsi_Host *host = scmd->device->host; const struct scsi_host_template *hostt = host->hostt; if (!hostt->eh_target_reset_handler) return FAILED; rtn = hostt->eh_target_reset_handler(scmd); if (rtn == SUCCESS) { spin_lock_irqsave(host->host_lock, flags); __starget_for_each_device(scsi_target(scmd->device), NULL, __scsi_report_device_reset); spin_unlock_irqrestore(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 * * 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 enum scsi_disposition scsi_try_bus_device_reset(struct scsi_cmnd *scmd) { enum scsi_disposition rtn; const struct scsi_host_template *hostt = scmd->device->host->hostt; if (!hostt->eh_device_reset_handler) return FAILED; rtn = hostt->eh_device_reset_handler(scmd); if (rtn == SUCCESS) __scsi_report_device_reset(scmd->device, NULL); return rtn; } /** * scsi_try_to_abort_cmd - Ask host to abort a SCSI command * @hostt: SCSI driver host template * @scmd: SCSI cmd used to send a target reset * * Return value: * SUCCESS, FAILED, or FAST_IO_FAIL * * Notes: * SUCCESS does not necessarily indicate that the command * has been aborted; it only indicates that the LLDDs * has cleared all references to that command. * LLDDs should return FAILED only if an abort was required * but could not be executed. LLDDs should return FAST_IO_FAIL * if the device is temporarily unavailable (eg due to a * link down on FibreChannel) */ static enum scsi_disposition scsi_try_to_abort_cmd(const struct scsi_host_template *hostt, struct scsi_cmnd *scmd) { if (!hostt->eh_abort_handler) return FAILED; return hostt->eh_abort_handler(scmd); } static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd) { if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS) if (scsi_try_bus_device_reset(scmd) != SUCCESS) if (scsi_try_target_reset(scmd) != SUCCESS) if (scsi_try_bus_reset(scmd) != SUCCESS) scsi_try_host_reset(scmd); } /** * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery * @scmd: SCSI command structure to hijack * @ses: structure to save restore information * @cmnd: CDB to send. Can be NULL if no new cmnd is needed * @cmnd_size: size in bytes of @cmnd (must be <= MAX_COMMAND_SIZE) * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored) * * This function is used to save a scsi command information before re-execution * as part of the error recovery process. If @sense_bytes is 0 the command * sent must be one that does not transfer any data. If @sense_bytes != 0 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer. */ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses, unsigned char *cmnd, int cmnd_size, unsigned sense_bytes) { struct scsi_device *sdev = scmd->device; /* * We need saved copies of a number of fields - this is because * error handling may need to overwrite these with different values * to run different commands, and once error handling is complete, * we will need to restore these values prior to running the actual * command. */ ses->cmd_len = scmd->cmd_len; ses->data_direction = scmd->sc_data_direction; ses->sdb = scmd->sdb; ses->result = scmd->result; ses->resid_len = scmd->resid_len; ses->underflow = scmd->underflow; ses->prot_op = scmd->prot_op; ses->eh_eflags = scmd->eh_eflags; scmd->prot_op = SCSI_PROT_NORMAL; scmd->eh_eflags = 0; memcpy(ses->cmnd, scmd->cmnd, sizeof(ses->cmnd)); memset(scmd->cmnd, 0, sizeof(scmd->cmnd)); memset(&scmd->sdb, 0, sizeof(scmd->sdb)); scmd->result = 0; scmd->resid_len = 0; if (sense_bytes) { scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE, sense_bytes); sg_init_one(&ses->sense_sgl, scmd->sense_buffer, scmd->sdb.length); scmd->sdb.table.sgl = &ses->sense_sgl; scmd->sc_data_direction = DMA_FROM_DEVICE; scmd->sdb.table.nents = scmd->sdb.table.orig_nents = 1; scmd->cmnd[0] = REQUEST_SENSE; scmd->cmnd[4] = scmd->sdb.length; scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); } else { scmd->sc_data_direction = DMA_NONE; if (cmnd) { BUG_ON(cmnd_size > sizeof(scmd->cmnd)); memcpy(scmd->cmnd, cmnd, cmnd_size); scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); } } scmd->underflow = 0; if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN) scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) | (sdev->lun << 5 & 0xe0); /* * Zero the sense buffer. The scsi spec mandates that any * untransferred sense data should be interpreted as being zero. */ memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); } EXPORT_SYMBOL(scsi_eh_prep_cmnd); /** * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery * @scmd: SCSI command structure to restore * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd * * Undo any damage done by above scsi_eh_prep_cmnd(). */ void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses) { /* * Restore original data */ scmd->cmd_len = ses->cmd_len; memcpy(scmd->cmnd, ses->cmnd, sizeof(ses->cmnd)); scmd->sc_data_direction = ses->data_direction; scmd->sdb = ses->sdb; scmd->result = ses->result; scmd->resid_len = ses->resid_len; scmd->underflow = ses->underflow; scmd->prot_op = ses->prot_op; scmd->eh_eflags = ses->eh_eflags; } EXPORT_SYMBOL(scsi_eh_restore_cmnd); /** * scsi_send_eh_cmnd - submit a scsi command as part of error recovery * @scmd: SCSI command structure to hijack * @cmnd: CDB to send * @cmnd_size: size in bytes of @cmnd * @timeout: timeout for this request * @sense_bytes: size of sense data to copy or 0 * * This function is used to send a scsi command down to a target device * as part of the error recovery process. See also scsi_eh_prep_cmnd() above. * * Return value: * SUCCESS or FAILED or NEEDS_RETRY */ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd, int cmnd_size, int timeout, unsigned sense_bytes) { struct scsi_device *sdev = scmd->device; struct Scsi_Host *shost = sdev->host; DECLARE_COMPLETION_ONSTACK(done); unsigned long timeleft = timeout, delay; 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->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER; /* * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can * change the SCSI device state after we have examined it and before * .queuecommand() is called. */ mutex_lock(&sdev->state_mutex); while (sdev->sdev_state == SDEV_BLOCK && timeleft > 0) { mutex_unlock(&sdev->state_mutex); SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_DEBUG, sdev, "%s: state %d <> %d\n", __func__, sdev->sdev_state, SDEV_BLOCK)); delay = min(timeleft, stall_for); timeleft -= delay; msleep(jiffies_to_msecs(delay)); mutex_lock(&sdev->state_mutex); } if (sdev->sdev_state != SDEV_BLOCK) rtn = shost->hostt->queuecommand(shost, scmd); else rtn = FAILED; mutex_unlock(&sdev->state_mutex); 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 = FAILED; } else { timeleft = wait_for_completion_timeout(&done, timeout); rtn = SUCCESS; } shost->eh_action = NULL; scsi_log_completion(scmd, rtn); SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s timeleft: %ld\n", __func__, 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 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); SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s: scsi_eh_completed_normally %x\n", __func__, rtn)); switch (rtn) { case SUCCESS: case NEEDS_RETRY: case FAILED: break; case ADD_TO_MLQUEUE: rtn = NEEDS_RETRY; break; default: rtn = FAILED; break; } } else if (rtn != FAILED) { scsi_abort_eh_cmnd(scmd); rtn = FAILED; } scsi_eh_restore_cmnd(scmd, &ses); 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 enum scsi_disposition scsi_request_sense(struct scsi_cmnd *scmd) { return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0); } static enum scsi_disposition scsi_eh_action(struct scsi_cmnd *scmd, enum scsi_disposition rtn) { if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) { struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd); if (sdrv->eh_action) rtn = sdrv->eh_action(scmd, rtn); } 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. */ void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q) { list_move_tail(&scmd->eh_entry, done_q); } EXPORT_SYMBOL(scsi_eh_finish_cmd); /** * scsi_eh_get_sense - Get device sense data. * @work_q: Queue of commands to process. * @done_q: Queue of processed 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, 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. */ int scsi_eh_get_sense(struct list_head *work_q, struct list_head *done_q) { struct scsi_cmnd *scmd, *next; struct Scsi_Host *shost; enum scsi_disposition rtn; /* * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO, * should not get sense. */ list_for_each_entry_safe(scmd, next, work_q, eh_entry) { if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) || SCSI_SENSE_VALID(scmd)) continue; shost = scmd->device->host; if (scsi_host_eh_past_deadline(shost)) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s: skip request sense, past eh deadline\n", current->comm)); break; } if (!scsi_status_is_check_condition(scmd->result)) /* * don't request sense if there's no check condition * status because the error we're processing isn't one * that has a sense code (and some devices get * confused by sense requests out of the blue) */ 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, scmd_printk(KERN_INFO, scmd, "sense requested, result %x\n", scmd->result)); SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(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. If the user * has requested infinite retries, we also want to * finish this command, so force completion by setting * retries and allowed to the same value. */ if (scmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT) scmd->retries = scmd->allowed = 1; else scmd->retries = scmd->allowed; else if (rtn != NEEDS_RETRY) continue; scsi_eh_finish_cmd(scmd, done_q); } return list_empty(work_q); } EXPORT_SYMBOL_GPL(scsi_eh_get_sense); /** * scsi_eh_tur - Send TUR to device. * @scmd: &scsi_cmnd 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; enum scsi_disposition rtn; retry_tur: rtn = scsi_send_eh_cmnd(scmd, tur_command, 6, scmd->device->eh_timeout, 0); SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s return: %x\n", __func__, rtn)); switch (rtn) { case NEEDS_RETRY: if (retry_cnt--) goto retry_tur; fallthrough; case SUCCESS: return 0; default: return 1; } } /** * scsi_eh_test_devices - check if devices are responding from error recovery. * @cmd_list: scsi commands in error recovery. * @work_q: queue for commands which still need more error recovery * @done_q: queue for commands which are finished * @try_stu: boolean on if a STU command should be tried in addition to TUR. * * Decription: * Tests if devices are in a working state. Commands to devices now in * a working state are sent to the done_q while commands to devices which * are still failing to respond are returned to the work_q for more * processing. **/ static int scsi_eh_test_devices(struct list_head *cmd_list, struct list_head *work_q, struct list_head *done_q, int try_stu) { struct scsi_cmnd *scmd, *next; struct scsi_device *sdev; int finish_cmds; while (!list_empty(cmd_list)) { scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry); sdev = scmd->device; if (!try_stu) { if (scsi_host_eh_past_deadline(sdev->host)) { /* Push items back onto work_q */ list_splice_init(cmd_list, work_q); SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev, "%s: skip test device, past eh deadline", current->comm)); break; } } finish_cmds = !scsi_device_online(scmd->device) || (try_stu && !scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) || !scsi_eh_tur(scmd); list_for_each_entry_safe(scmd, next, cmd_list, eh_entry) if (scmd->device == sdev) { if (finish_cmds && (try_stu || scsi_eh_action(scmd, SUCCESS) == SUCCESS)) scsi_eh_finish_cmd(scmd, done_q); else list_move_tail(&scmd->eh_entry, work_q); } } return list_empty(work_q); } /** * scsi_eh_try_stu - Send START_UNIT to device. * @scmd: &scsi_cmnd 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}; if (scmd->device->allow_restart) { int i; enum scsi_disposition rtn = NEEDS_RETRY; for (i = 0; rtn == NEEDS_RETRY && i < 2; i++) rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->eh_timeout, 0); if (rtn == SUCCESS) return 0; } return 1; } /** * scsi_eh_stu - send START_UNIT if needed * @shost: &scsi host being recovered. * @work_q: &list_head for pending commands. * @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) { if (scsi_host_eh_past_deadline(shost)) { SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev, "%s: skip START_UNIT, past eh deadline\n", current->comm)); scsi_device_put(sdev); break; } 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, sdev_printk(KERN_INFO, sdev, "%s: Sending START_UNIT\n", current->comm)); 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_action(scmd, SUCCESS) == SUCCESS) scsi_eh_finish_cmd(scmd, done_q); } } } else { SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev, "%s: START_UNIT failed\n", current->comm)); } } return list_empty(work_q); } /** * scsi_eh_bus_device_reset - send bdr if needed * @shost: scsi host being recovered. * @work_q: &list_head for pending commands. * @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; enum scsi_disposition rtn; shost_for_each_device(sdev, shost) { if (scsi_host_eh_past_deadline(shost)) { SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev, "%s: skip BDR, past eh deadline\n", current->comm)); scsi_device_put(sdev); break; } 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, sdev_printk(KERN_INFO, sdev, "%s: Sending BDR\n", current->comm)); rtn = scsi_try_bus_device_reset(bdr_scmd); if (rtn == SUCCESS || rtn == FAST_IO_FAIL) { if (!scsi_device_online(sdev) || rtn == FAST_IO_FAIL || !scsi_eh_tur(bdr_scmd)) { list_for_each_entry_safe(scmd, next, work_q, eh_entry) { if (scmd->device == sdev && scsi_eh_action(scmd, rtn) != FAILED) scsi_eh_finish_cmd(scmd, done_q); } } } else { SCSI_LOG_ERROR_RECOVERY(3, sdev_printk(KERN_INFO, sdev, "%s: BDR failed\n", current->comm)); } } return list_empty(work_q); } /** * 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) { LIST_HEAD(tmp_list); LIST_HEAD(check_list); list_splice_init(work_q, &tmp_list); while (!list_empty(&tmp_list)) { struct scsi_cmnd *next, *scmd; enum scsi_disposition rtn; unsigned int id; if (scsi_host_eh_past_deadline(shost)) { /* push back on work queue for further processing */ list_splice_init(&check_list, work_q); list_splice_init(&tmp_list, work_q); SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: Skip target reset, past eh deadline\n", current->comm)); return list_empty(work_q); } scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry); id = scmd_id(scmd); SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: Sending target reset to target %d\n", current->comm, id)); rtn = scsi_try_target_reset(scmd); if (rtn != SUCCESS && rtn != FAST_IO_FAIL) SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: Target reset failed" " target: %d\n", current->comm, id)); list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) { if (scmd_id(scmd) != id) continue; if (rtn == SUCCESS) list_move_tail(&scmd->eh_entry, &check_list); else if (rtn == FAST_IO_FAIL) scsi_eh_finish_cmd(scmd, done_q); else /* push back on work queue for further processing */ list_move(&scmd->eh_entry, work_q); } } return scsi_eh_test_devices(&check_list, work_q, done_q, 0); } /** * scsi_eh_bus_reset - send a bus reset * @shost: &scsi host being recovered. * @work_q: &list_head for pending commands. * @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; LIST_HEAD(check_list); unsigned int channel; enum scsi_disposition 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++) { if (scsi_host_eh_past_deadline(shost)) { list_splice_init(&check_list, work_q); SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: skip BRST, past eh deadline\n", current->comm)); return list_empty(work_q); } 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, shost_printk(KERN_INFO, shost, "%s: Sending BRST chan: %d\n", current->comm, channel)); rtn = scsi_try_bus_reset(chan_scmd); if (rtn == SUCCESS || rtn == FAST_IO_FAIL) { list_for_each_entry_safe(scmd, next, work_q, eh_entry) { if (channel == scmd_channel(scmd)) { if (rtn == FAST_IO_FAIL) scsi_eh_finish_cmd(scmd, done_q); else list_move_tail(&scmd->eh_entry, &check_list); } } } else { SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: BRST failed chan: %d\n", current->comm, channel)); } } return scsi_eh_test_devices(&check_list, work_q, done_q, 0); } /** * scsi_eh_host_reset - send a host reset * @shost: host to be reset. * @work_q: &list_head for pending commands. * @done_q: &list_head for processed commands. */ static int scsi_eh_host_reset(struct Scsi_Host *shost, struct list_head *work_q, struct list_head *done_q) { struct scsi_cmnd *scmd, *next; LIST_HEAD(check_list); enum scsi_disposition rtn; if (!list_empty(work_q)) { scmd = list_entry(work_q->next, struct scsi_cmnd, eh_entry); SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: Sending HRST\n", current->comm)); rtn = scsi_try_host_reset(scmd); if (rtn == SUCCESS) { list_splice_init(work_q, &check_list); } else if (rtn == FAST_IO_FAIL) { list_for_each_entry_safe(scmd, next, work_q, eh_entry) { scsi_eh_finish_cmd(scmd, done_q); } } else { SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "%s: HRST failed\n", current->comm)); } } return scsi_eh_test_devices(&check_list, work_q, done_q, 1); } /** * scsi_eh_offline_sdevs - offline scsi devices that fail to recover * @work_q: &list_head for pending 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; struct scsi_device *sdev; list_for_each_entry_safe(scmd, next, work_q, eh_entry) { sdev_printk(KERN_INFO, scmd->device, "Device offlined - " "not ready after error recovery\n"); sdev = scmd->device; mutex_lock(&sdev->state_mutex); scsi_device_set_state(sdev, SDEV_OFFLINE); mutex_unlock(&sdev->state_mutex); scsi_eh_finish_cmd(scmd, done_q); } return; } /** * scsi_noretry_cmd - determine if command should be failed fast * @scmd: SCSI cmd to examine. */ bool scsi_noretry_cmd(struct scsi_cmnd *scmd) { struct request *req = scsi_cmd_to_rq(scmd); switch (host_byte(scmd->result)) { case DID_OK: break; case DID_TIME_OUT: goto check_type; case DID_BUS_BUSY: return !!(req->cmd_flags & REQ_FAILFAST_TRANSPORT); case DID_PARITY: return !!(req->cmd_flags & REQ_FAILFAST_DEV); case DID_ERROR: if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT) return false; fallthrough; case DID_SOFT_ERROR: return !!(req->cmd_flags & REQ_FAILFAST_DRIVER); } /* Never retry commands aborted due to a duration limit timeout */ if (scsi_ml_byte(scmd->result) == SCSIML_STAT_DL_TIMEOUT) return true; if (!scsi_status_is_check_condition(scmd->result)) return false; check_type: /* * assume caller has checked sense and determined * the check condition was retryable. */ if (req->cmd_flags & REQ_FAILFAST_DEV || blk_rq_is_passthrough(req)) return true; return false; } /** * 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. */ enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd) { enum scsi_disposition 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, scmd_printk(KERN_INFO, scmd, "%s: device offline - report as SUCCESS\n", __func__)); 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_ABORT: if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) { set_host_byte(scmd, DID_TIME_OUT); return SUCCESS; } fallthrough; case DID_NO_CONNECT: case DID_BAD_TARGET: /* * 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; case DID_SOFT_ERROR: /* * 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) */ goto maybe_retry; case DID_IMM_RETRY: return NEEDS_RETRY; case DID_REQUEUE: return ADD_TO_MLQUEUE; case DID_TRANSPORT_DISRUPTED: /* * LLD/transport was disrupted during processing of the IO. * The transport class is now blocked/blocking, * and the transport will decide what to do with the IO * based on its timers and recovery capablilities if * there are enough retries. */ goto maybe_retry; case DID_TRANSPORT_FAILFAST: /* * The transport decided to failfast the IO (most likely * the fast io fail tmo fired), so send IO directly upwards. */ return SUCCESS; case DID_TRANSPORT_MARGINAL: /* * caller has decided not to do retries on * abort success, so send IO directly upwards */ return SUCCESS; case DID_ERROR: if (get_status_byte(scmd) == SAM_STAT_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; } /* * check the status byte to see if this indicates anything special. */ switch (get_status_byte(scmd)) { case SAM_STAT_TASK_SET_FULL: scsi_handle_queue_full(scmd->device); /* * the case of trying to send too many commands to a * tagged queueing device. */ fallthrough; case SAM_STAT_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 SAM_STAT_GOOD: if (scmd->cmnd[0] == REPORT_LUNS) scmd->device->sdev_target->expecting_lun_change = 0; scsi_handle_queue_ramp_up(scmd->device); if (scmd->sense_buffer && SCSI_SENSE_VALID(scmd)) /* * If we have sense data, call scsi_check_sense() in * order to set the correct SCSI ML byte (if any). * No point in checking the return value, since the * command has already completed successfully. */ scsi_check_sense(scmd); fallthrough; case SAM_STAT_COMMAND_TERMINATED: return SUCCESS; case SAM_STAT_TASK_ABORTED: goto maybe_retry; case SAM_STAT_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 SAM_STAT_CONDITION_MET: case SAM_STAT_INTERMEDIATE: case SAM_STAT_INTERMEDIATE_CONDITION_MET: case SAM_STAT_ACA_ACTIVE: /* * who knows? FIXME(eric) */ return SUCCESS; case SAM_STAT_RESERVATION_CONFLICT: sdev_printk(KERN_INFO, scmd->device, "reservation conflict\n"); set_scsi_ml_byte(scmd, SCSIML_STAT_RESV_CONFLICT); return SUCCESS; /* causes immediate i/o error */ } 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 (scsi_cmd_retry_allowed(scmd) && !scsi_noretry_cmd(scmd)) { return NEEDS_RETRY; } else { /* * no more retries - report this one back to upper level. */ return SUCCESS; } } static enum rq_end_io_ret eh_lock_door_done(struct request *req, blk_status_t status) { blk_mq_free_request(req); return RQ_END_IO_NONE; } /** * 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. * * Notes: * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the * head of the devices request queue, and continue. */ static void scsi_eh_lock_door(struct scsi_device *sdev) { struct scsi_cmnd *scmd; struct request *req; req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN, 0); if (IS_ERR(req)) return; scmd = blk_mq_rq_to_pdu(req); scmd->cmnd[0] = ALLOW_MEDIUM_REMOVAL; scmd->cmnd[1] = 0; scmd->cmnd[2] = 0; scmd->cmnd[3] = 0; scmd->cmnd[4] = SCSI_REMOVAL_PREVENT; scmd->cmnd[5] = 0; scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); scmd->allowed = 5; req->rq_flags |= RQF_QUIET; req->timeout = 10 * HZ; req->end_io = eh_lock_door_done; blk_execute_rq_nowait(req, true); } /** * 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->was_reset && sdev->locked) { scsi_eh_lock_door(sdev); sdev->was_reset = 0; } } /* * 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, shost_printk(KERN_INFO, shost, "waking up host to restart\n")); 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); /* * if eh is active and host_eh_scheduled is pending we need to re-run * recovery. we do this check after scsi_run_host_queues() to allow * everything pent up since the last eh run a chance to make forward * progress before we sync again. Either we'll immediately re-run * recovery or scsi_device_unbusy() will wake us again when these * pending commands complete. */ spin_lock_irqsave(shost->host_lock, flags); if (shost->host_eh_scheduled) if (scsi_host_set_state(shost, SHOST_RECOVERY)) WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)); spin_unlock_irqrestore(shost->host_lock, flags); } /** * scsi_eh_ready_devs - check device ready state and recover if not. * @shost: host to be recovered. * @work_q: &list_head for pending commands. * @done_q: &list_head for processed commands. */ 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_target_reset(shost, work_q, done_q)) if (!scsi_eh_bus_reset(shost, work_q, done_q)) if (!scsi_eh_host_reset(shost, work_q, done_q)) scsi_eh_offline_sdevs(work_q, done_q); } EXPORT_SYMBOL_GPL(scsi_eh_ready_devs); /** * scsi_eh_flush_done_q - finish processed commands or retry them. * @done_q: list_head of processed commands. */ 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) && !scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd) && scsi_eh_should_retry_cmd(scmd)) { SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s: flush retry cmd\n", current->comm)); 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 DID_TIME_OUT. */ if (!scmd->result && !(scmd->flags & SCMD_FORCE_EH_SUCCESS)) scmd->result |= (DID_TIME_OUT << 16); SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd, "%s: flush finish cmd\n", current->comm)); scsi_finish_command(scmd); } } } EXPORT_SYMBOL(scsi_eh_flush_done_q); /** * 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)) scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q); spin_lock_irqsave(shost->host_lock, flags); if (shost->eh_deadline != -1) shost->last_reset = 0; spin_unlock_irqrestore(shost->host_lock, flags); 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; /* * 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 signal delivery for the created thread. */ while (true) { /* * The sequence in kthread_stop() sets the stop flag first * then wakes the process. To avoid missed wakeups, the task * should always be in a non running state before the stop * flag is checked */ set_current_state(TASK_INTERRUPTIBLE); if (kthread_should_stop()) break; if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) || shost->host_failed != scsi_host_busy(shost)) { SCSI_LOG_ERROR_RECOVERY(1, shost_printk(KERN_INFO, shost, "scsi_eh_%d: sleeping\n", shost->host_no)); schedule(); continue; } __set_current_state(TASK_RUNNING); SCSI_LOG_ERROR_RECOVERY(1, shost_printk(KERN_INFO, shost, "scsi_eh_%d: waking up %d/%d/%d\n", shost->host_no, shost->host_eh_scheduled, shost->host_failed, scsi_host_busy(shost))); /* * 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->eh_noresume && scsi_autopm_get_host(shost) != 0) { SCSI_LOG_ERROR_RECOVERY(1, shost_printk(KERN_ERR, shost, "scsi_eh_%d: unable to autoresume\n", shost->host_no)); continue; } if (shost->transportt->eh_strategy_handler) shost->transportt->eh_strategy_handler(shost); else scsi_unjam_host(shost); /* All scmds have been handled */ shost->host_failed = 0; /* * 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); if (!shost->eh_noresume) scsi_autopm_put_host(shost); } __set_current_state(TASK_RUNNING); SCSI_LOG_ERROR_RECOVERY(1, shost_printk(KERN_INFO, shost, "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)) __scsi_report_device_reset(sdev, NULL); } } 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)) __scsi_report_device_reset(sdev, NULL); } } EXPORT_SYMBOL(scsi_report_device_reset); /** * scsi_ioctl_reset: explicitly reset a host/bus/target/device * @dev: scsi_device to operate on * @arg: reset type (see sg.h) */ int scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) { struct scsi_cmnd *scmd; struct Scsi_Host *shost = dev->host; struct request *rq; unsigned long flags; int error = 0, val; enum scsi_disposition rtn; if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) return -EACCES; error = get_user(val, arg); if (error) return error; if (scsi_autopm_get_host(shost) < 0) return -EIO; error = -EIO; rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size, GFP_KERNEL); if (!rq) goto out_put_autopm_host; blk_rq_init(NULL, rq); scmd = (struct scsi_cmnd *)(rq + 1); scsi_init_command(dev, scmd); scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL; memset(&scmd->sdb, 0, sizeof(scmd->sdb)); scmd->cmd_len = 0; scmd->sc_data_direction = DMA_BIDIRECTIONAL; spin_lock_irqsave(shost->host_lock, flags); shost->tmf_in_progress = 1; spin_unlock_irqrestore(shost->host_lock, flags); switch (val & ~SG_SCSI_RESET_NO_ESCALATE) { case SG_SCSI_RESET_NOTHING: rtn = SUCCESS; break; case SG_SCSI_RESET_DEVICE: rtn = scsi_try_bus_device_reset(scmd); if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE)) break; fallthrough; case SG_SCSI_RESET_TARGET: rtn = scsi_try_target_reset(scmd); if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE)) break; fallthrough; case SG_SCSI_RESET_BUS: rtn = scsi_try_bus_reset(scmd); if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE)) break; fallthrough; case SG_SCSI_RESET_HOST: rtn = scsi_try_host_reset(scmd); if (rtn == SUCCESS) break; fallthrough; default: rtn = FAILED; break; } error = (rtn == SUCCESS) ? 0 : -EIO; spin_lock_irqsave(shost->host_lock, flags); shost->tmf_in_progress = 0; spin_unlock_irqrestore(shost->host_lock, flags); /* * be sure to wake up anyone who was sleeping or had their queue * suspended while we performed the TMF. */ SCSI_LOG_ERROR_RECOVERY(3, shost_printk(KERN_INFO, shost, "waking up host to restart after TMF\n")); wake_up(&shost->host_wait); scsi_run_host_queues(shost); kfree(rq); out_put_autopm_host: scsi_autopm_put_host(shost); return error; } bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd, struct scsi_sense_hdr *sshdr) { return scsi_normalize_sense(cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE, sshdr); } EXPORT_SYMBOL(scsi_command_normalize_sense); /** * scsi_get_sense_info_fld - 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: * true if information field found, false if not found. */ bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len, u64 *info_out) { const u8 * ucp; if (sb_len < 7) return false; switch (sense_buffer[0] & 0x7f) { case 0x70: case 0x71: if (sense_buffer[0] & 0x80) { *info_out = get_unaligned_be32(&sense_buffer[3]); return true; } return false; case 0x72: case 0x73: ucp = scsi_sense_desc_find(sense_buffer, sb_len, 0 /* info desc */); if (ucp && (0xa == ucp[1])) { *info_out = get_unaligned_be64(&ucp[4]); return true; } return false; default: return false; } } EXPORT_SYMBOL(scsi_get_sense_info_fld);
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