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Commit c91abf5a authored by NeilBrown's avatar NeilBrown
Browse files

md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread. 



We currently use kthread_should_stop() in various places in the
sync/reshape code to abort early.
However some places set MD_RECOVERY_INTR but don't immediately call
md_reap_sync_thread() (and we will shortly get another one).
When this happens we are relying on md_check_recovery() to reap the
thread and that only happen when it finishes normally.
So MD_RECOVERY_INTR must lead to a normal finish without the
kthread_should_stop() test.

So replace all relevant tests, and be more careful when the thread is
interrupted not to acknowledge that latest step in a reshape as it may
not be fully committed yet.

Also add a test on MD_RECOVERY_INTR in the 'is_mddev_idle' loop
so we don't wait have to wait for the speed to drop before we can abort.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 29f097c4

drivers/md/md.c

+14 −26
Original line number Diff line number Diff line
@@ -7410,9 +7410,6 @@ void md_do_sync(struct md_thread *thread) 
		mddev->curr_resync = 2;



	try_again:

		if (kthread_should_stop())

			set_bit(MD_RECOVERY_INTR, &mddev->recovery);



		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))

			goto skip;

		for_each_mddev(mddev2, tmp) {
@@ -7437,7 +7434,7 @@ void md_do_sync(struct md_thread *thread) 
				 * be caught by 'softlockup'

				 */

				prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);

				if (!kthread_should_stop() &&

				if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&

				    mddev2->curr_resync >= mddev->curr_resync) {

					printk(KERN_INFO "md: delaying %s of %s"

					       " until %s has finished (they"
@@ -7550,7 +7547,8 @@ void md_do_sync(struct md_thread *thread) 
			sysfs_notify(&mddev->kobj, NULL, "sync_completed");

		}



		while (j >= mddev->resync_max && !kthread_should_stop()) {

		while (j >= mddev->resync_max &&

		       !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {

			/* As this condition is controlled by user-space,

			 * we can block indefinitely, so use '_interruptible'

			 * to avoid triggering warnings.
@@ -7558,17 +7556,18 @@ void md_do_sync(struct md_thread *thread) 
			flush_signals(current); /* just in case */

			wait_event_interruptible(mddev->recovery_wait,

						 mddev->resync_max > j

						 || kthread_should_stop());

						 || test_bit(MD_RECOVERY_INTR,

							     &mddev->recovery));

		}



		if (kthread_should_stop())

			goto interrupted;

		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))

			break;



		sectors = mddev->pers->sync_request(mddev, j, &skipped,

						  currspeed < speed_min(mddev));

		if (sectors == 0) {

			set_bit(MD_RECOVERY_INTR, &mddev->recovery);

			goto out;

			break;

		}



		if (!skipped) { /* actual IO requested */
@@ -7605,10 +7604,8 @@ void md_do_sync(struct md_thread *thread) 
			last_mark = next;

		}





		if (kthread_should_stop())

			goto interrupted;



		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))

			break;



		/*

		 * this loop exits only if either when we are slower than
@@ -7631,11 +7628,12 @@ void md_do_sync(struct md_thread *thread) 
			}

		}

	}

	printk(KERN_INFO "md: %s: %s done.\n",mdname(mddev), desc);

	printk(KERN_INFO "md: %s: %s %s.\n",mdname(mddev), desc,

	       test_bit(MD_RECOVERY_INTR, &mddev->recovery)

	       ? "interrupted" : "done");

	/*

	 * this also signals 'finished resyncing' to md_stop

	 */

 out:

	blk_finish_plug(&plug);

	wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
@@ -7689,16 +7687,6 @@ void md_do_sync(struct md_thread *thread) 
	set_bit(MD_RECOVERY_DONE, &mddev->recovery);

	md_wakeup_thread(mddev->thread);

	return;



 interrupted:

	/*

	 * got a signal, exit.

	 */

	printk(KERN_INFO

	       "md: md_do_sync() got signal ... exiting\n");

	set_bit(MD_RECOVERY_INTR, &mddev->recovery);

	goto out;



}

EXPORT_SYMBOL_GPL(md_do_sync);

drivers/md/raid10.c

+5 −1
Original line number Diff line number Diff line
@@ -4386,7 +4386,11 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, 
		set_bit(MD_CHANGE_DEVS, &mddev->flags);

		md_wakeup_thread(mddev->thread);

		wait_event(mddev->sb_wait, mddev->flags == 0 ||

			   kthread_should_stop());

			   test_bit(MD_RECOVERY_INTR, &mddev->recovery));

		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {

			allow_barrier(conf);

			return sectors_done;

		}

		conf->reshape_safe = mddev->reshape_position;

		allow_barrier(conf);

	}

drivers/md/raid5.c

+15 −4
Original line number Diff line number Diff line
@@ -4842,14 +4842,19 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk 
	    time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {

		/* Cannot proceed until we've updated the superblock... */

		wait_event(conf->wait_for_overlap,

			   atomic_read(&conf->reshape_stripes)==0);

			   atomic_read(&conf->reshape_stripes)==0

			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));

		if (atomic_read(&conf->reshape_stripes) != 0)

			return 0;

		mddev->reshape_position = conf->reshape_progress;

		mddev->curr_resync_completed = sector_nr;

		conf->reshape_checkpoint = jiffies;

		set_bit(MD_CHANGE_DEVS, &mddev->flags);

		md_wakeup_thread(mddev->thread);

		wait_event(mddev->sb_wait, mddev->flags == 0 ||

			   kthread_should_stop());

			   test_bit(MD_RECOVERY_INTR, &mddev->recovery));

		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))

			return 0;

		spin_lock_irq(&conf->device_lock);

		conf->reshape_safe = mddev->reshape_position;

		spin_unlock_irq(&conf->device_lock);
@@ -4932,7 +4937,10 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk 
	    >= mddev->resync_max - mddev->curr_resync_completed) {

		/* Cannot proceed until we've updated the superblock... */

		wait_event(conf->wait_for_overlap,

			   atomic_read(&conf->reshape_stripes) == 0);

			   atomic_read(&conf->reshape_stripes) == 0

			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));

		if (atomic_read(&conf->reshape_stripes) != 0)

			goto ret;

		mddev->reshape_position = conf->reshape_progress;

		mddev->curr_resync_completed = sector_nr;

		conf->reshape_checkpoint = jiffies;
@@ -4940,13 +4948,16 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk 
		md_wakeup_thread(mddev->thread);

		wait_event(mddev->sb_wait,

			   !test_bit(MD_CHANGE_DEVS, &mddev->flags)

			   || kthread_should_stop());

			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));

		if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))

			goto ret;

		spin_lock_irq(&conf->device_lock);

		conf->reshape_safe = mddev->reshape_position;

		spin_unlock_irq(&conf->device_lock);

		wake_up(&conf->wait_for_overlap);

		sysfs_notify(&mddev->kobj, NULL, "sync_completed");

	}

ret:

	return reshape_sectors;

}