scsi: make asynchronous aborts mandatory (a0658632) · Commits · e / devices / android_kernel_fairphone_FP4

Documentation/scsi/scsi_eh.txt

+6 −12

Original line number	Diff line number	Diff line
		@@ -70,7 +70,7 @@ with the command.
		scmd is requeued to blk queue.

		- otherwise
		scsi_eh_scmd_add(scmd, 0) is invoked for the command. See
		scsi_eh_scmd_add(scmd) is invoked for the command. See
		[1-3] for details of this function.


		@@ -103,9 +103,7 @@ function
		eh_timed_out() callback did not handle the command.
		Step #2 is taken.

		2. If the host supports asynchronous completion (as indicated by the
		no_async_abort setting in the host template) scsi_abort_command()
		is invoked to schedule an asynchrous abort.
		2. scsi_abort_command() is invoked to schedule an asynchrous abort.
		Asynchronous abort are not invoked for commands which the
		SCSI_EH_ABORT_SCHEDULED flag is set (this indicates that the command
		already had been aborted once, and this is a retry which failed),
		@@ -127,16 +125,13 @@ function

		scmds enter EH via scsi_eh_scmd_add(), which does the following.

		1. Turns on scmd->eh_eflags as requested. It's 0 for error
		completions and SCSI_EH_CANCEL_CMD for timeouts.
		1. Links scmd->eh_entry to shost->eh_cmd_q

		2. Links scmd->eh_entry to shost->eh_cmd_q
		2. Sets SHOST_RECOVERY bit in shost->shost_state

		3. Sets SHOST_RECOVERY bit in shost->shost_state
		3. Increments shost->host_failed

		4. Increments shost->host_failed

		5. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed
		4. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed

		As can be seen above, once any scmd is added to shost->eh_cmd_q,
		SHOST_RECOVERY shost_state bit is turned on. This prevents any new
		@@ -252,7 +247,6 @@ scmd->allowed.

		1. Error completion / time out
		ACTION: scsi_eh_scmd_add() is invoked for scmd
		- set scmd->eh_eflags
		- add scmd to shost->eh_cmd_q
		- set SHOST_RECOVERY
		- shost->host_failed++

drivers/scsi/scsi_error.c

+7 −74

Original line number	Diff line number	Diff line
		@@ -162,7 +162,7 @@ scmd_eh_abort_handler(struct work_struct *work)
		}
		}

		scsi_eh_scmd_add(scmd, 0);
		scsi_eh_scmd_add(scmd);
		}

		/**
		@@ -221,9 +221,8 @@ static void scsi_eh_reset(struct scsi_cmnd *scmd)
		/**
		* scsi_eh_scmd_add - add scsi cmd to error handling.
		* @scmd: scmd to run eh on.
		* @eh_flag: optional SCSI_EH flag.
		*/
		void scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
		void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
		{
		struct Scsi_Host *shost = scmd->device->host;
		unsigned long flags;
		@@ -239,9 +238,6 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
		if (shost->eh_deadline != -1 && !shost->last_reset)
		shost->last_reset = jiffies;

		if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
		eh_flag &= ~SCSI_EH_CANCEL_CMD;
		scmd->eh_eflags \|= eh_flag;
		scsi_eh_reset(scmd);
		list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
		shost->host_failed++;
		@@ -275,10 +271,9 @@ enum blk_eh_timer_return scsi_times_out(struct request *req)
		rtn = host->hostt->eh_timed_out(scmd);

		if (rtn == BLK_EH_NOT_HANDLED) {
		if (host->hostt->no_async_abort \|\|
		scsi_abort_command(scmd) != SUCCESS) {
		if (scsi_abort_command(scmd) != SUCCESS) {
		set_host_byte(scmd, DID_TIME_OUT);
		scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD);
		scsi_eh_scmd_add(scmd);
		}
		}

		@@ -331,7 +326,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
		list_for_each_entry(scmd, work_q, eh_entry) {
		if (scmd->device == sdev) {
		++total_failures;
		if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
		if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
		++cmd_cancel;
		else
		++cmd_failed;
		@@ -1154,8 +1149,7 @@ int scsi_eh_get_sense(struct list_head *work_q,
		* should not get sense.
		*/
		list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
		if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) \|\|
		(scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) \|\|
		if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) \|\|
		SCSI_SENSE_VALID(scmd))
		continue;

		@@ -1295,61 +1289,6 @@ static int scsi_eh_test_devices(struct list_head *cmd_list,
		return list_empty(work_q);
		}


		/**
		* scsi_eh_abort_cmds - abort pending commands.
		* @work_q: &list_head for pending commands.
		* @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;
		LIST_HEAD(check_list);
		int rtn;
		struct Scsi_Host *shost;

		list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
		if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
		continue;
		shost = scmd->device->host;
		if (scsi_host_eh_past_deadline(shost)) {
		list_splice_init(&check_list, work_q);
		SCSI_LOG_ERROR_RECOVERY(3,
		scmd_printk(KERN_INFO, scmd,
		"%s: skip aborting cmd, past eh deadline\n",
		current->comm));
		return list_empty(work_q);
		}
		SCSI_LOG_ERROR_RECOVERY(3,
		scmd_printk(KERN_INFO, scmd,
		"%s: aborting cmd\n", current->comm));
		rtn = scsi_try_to_abort_cmd(shost->hostt, scmd);
		if (rtn == FAILED) {
		SCSI_LOG_ERROR_RECOVERY(3,
		scmd_printk(KERN_INFO, scmd,
		"%s: aborting cmd failed\n",
		current->comm));
		list_splice_init(&check_list, work_q);
		return list_empty(work_q);
		}
		scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
		if (rtn == FAST_IO_FAIL)
		scsi_eh_finish_cmd(scmd, done_q);
		else
		list_move_tail(&scmd->eh_entry, &check_list);
		}

		return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
		}

		/**
		* scsi_eh_try_stu - Send START_UNIT to device.
		* @scmd: &scsi_cmnd to send START_UNIT
		@@ -1692,11 +1631,6 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
		sdev_printk(KERN_INFO, scmd->device, "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;
		@@ -2140,7 +2074,6 @@ static void scsi_unjam_host(struct Scsi_Host *shost)
		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);

		spin_lock_irqsave(shost->host_lock, flags);

drivers/scsi/scsi_lib.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1593,7 +1593,7 @@ static void scsi_softirq_done(struct request *rq)
		scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
		break;
		default:
		scsi_eh_scmd_add(cmd, 0);
		scsi_eh_scmd_add(cmd);
		break;
		}
		}

drivers/scsi/scsi_priv.h

+1 −2

Original line number	Diff line number	Diff line
		@@ -18,7 +18,6 @@ struct scsi_nl_hdr;
		/*
		* Scsi Error Handler Flags
		*/
		#define SCSI_EH_CANCEL_CMD 0x0001 /* Cancel this cmd */
		#define SCSI_EH_ABORT_SCHEDULED 0x0002 /* Abort has been scheduled */

		#define SCSI_SENSE_VALID(scmd) \
		@@ -72,7 +71,7 @@ extern enum blk_eh_timer_return scsi_times_out(struct request *req);
		extern int scsi_error_handler(void *host);
		extern int scsi_decide_disposition(struct scsi_cmnd *cmd);
		extern void scsi_eh_wakeup(struct Scsi_Host *shost);
		extern void scsi_eh_scmd_add(struct scsi_cmnd *, int);
		extern void scsi_eh_scmd_add(struct scsi_cmnd *);
		void scsi_eh_ready_devs(struct Scsi_Host *shost,
		struct list_head *work_q,
		struct list_head *done_q);

include/scsi/scsi_host.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -451,11 +451,6 @@ struct scsi_host_template {
		/* True if the controller does not support WRITE SAME */
		unsigned no_write_same:1;

		/*
		* True if asynchronous aborts are not supported
		*/
		unsigned no_async_abort:1;

		/*
		* Countdown for host blocking with no commands outstanding.
		*/