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Commit cea9c228 authored by NeilBrown's avatar NeilBrown
Browse files

md: add explicit method to signal the end of a reshape. 



Currently raid5 (the only module that supports restriping)
notices that the reshape has finished be sync_request being
given a large value, and handles any cleanup them.

This patch changes it so md_check_recovery calls into an
explicit finish_reshape method as well.

The clean-up from sync_request can do things that need to be
done promptly, typically things local to the raid5_conf_t
structure.

The "finish_reshape" method is called under the mddev_lock
so it can do things involving reconfiguring the device.

This allows us to get rid of md_set_array_sectors_locked, which
would have caused a deadlock if you tried to stop and array
while a reshape was happening.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 7ec05478

drivers/md/md.c

+3 −8
Original line number Diff line number Diff line
@@ -5073,14 +5073,6 @@ void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors) 
}

EXPORT_SYMBOL(md_set_array_sectors);



void md_set_array_sectors_lock(mddev_t *mddev, sector_t array_sectors)

{

	mddev_lock(mddev);

	md_set_array_sectors(mddev, array_sectors);

	mddev_unlock(mddev);

}

EXPORT_SYMBOL(md_set_array_sectors_lock);



static int update_size(mddev_t *mddev, sector_t num_sectors)

{

	mdk_rdev_t *rdev;
@@ -6641,6 +6633,9 @@ void md_check_recovery(mddev_t *mddev) 
					sysfs_notify(&mddev->kobj, NULL,

						     "degraded");

			}

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

			    mddev->pers->finish_reshape)

				mddev->pers->finish_reshape(mddev);

			md_update_sb(mddev, 1);



			/* if array is no-longer degraded, then any saved_raid_disk

drivers/md/md.h

+1 −1
Original line number Diff line number Diff line
@@ -317,6 +317,7 @@ struct mdk_personality 
	sector_t (*size) (mddev_t *mddev, sector_t sectors, int raid_disks);

	int (*check_reshape) (mddev_t *mddev);

	int (*start_reshape) (mddev_t *mddev);

	void (*finish_reshape) (mddev_t *mddev);

	int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);

	/* quiesce moves between quiescence states

	 * 0 - fully active
@@ -433,4 +434,3 @@ extern void md_new_event(mddev_t *mddev); 
extern int md_allow_write(mddev_t *mddev);

extern void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev);

extern void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors);
 
extern void md_set_array_sectors_lock(mddev_t *mddev, sector_t array_sectors);

drivers/md/raid5.c

+30 −20
Original line number Diff line number Diff line
@@ -3850,6 +3850,7 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski 
	if (sector_nr >= max_sector) {

		/* just being told to finish up .. nothing much to do */

		unplug_slaves(mddev);



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

			end_reshape(conf);

			return 0;
@@ -4836,43 +4837,49 @@ static int raid5_start_reshape(mddev_t *mddev) 


static void end_reshape(raid5_conf_t *conf)

{

	struct block_device *bdev;



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

		mddev_t *mddev = conf->mddev;



		md_set_array_sectors_lock(mddev, raid5_size(mddev, 0,

						       conf->raid_disks));

		set_capacity(mddev->gendisk, mddev->array_sectors);

		mddev->changed = 1;

		conf->previous_raid_disks = conf->raid_disks;



		bdev = bdget_disk(conf->mddev->gendisk, 0);

		if (bdev) {

			mutex_lock(&bdev->bd_inode->i_mutex);

			i_size_write(bdev->bd_inode,

				     (loff_t)conf->mddev->array_sectors << 9);

			mutex_unlock(&bdev->bd_inode->i_mutex);

			bdput(bdev);

		}

		spin_lock_irq(&conf->device_lock);

		conf->previous_raid_disks = conf->raid_disks;

		conf->expand_progress = MaxSector;

		spin_unlock_irq(&conf->device_lock);

		conf->mddev->reshape_position = MaxSector;



		/* read-ahead size must cover two whole stripes, which is

		 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices

		 */

		{

			int data_disks = conf->previous_raid_disks - conf->max_degraded;

			int stripe = data_disks *

				(conf->mddev->chunk_size / PAGE_SIZE);

			int data_disks = conf->raid_disks - conf->max_degraded;

			int stripe = data_disks * (conf->chunk_size

						   / PAGE_SIZE);

			if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)

				conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;

		}

	}

}



static void raid5_finish_reshape(mddev_t *mddev)

{

	struct block_device *bdev;



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



		md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));

		set_capacity(mddev->gendisk, mddev->array_sectors);

		mddev->changed = 1;

		mddev->reshape_position = MaxSector;



		bdev = bdget_disk(mddev->gendisk, 0);

		if (bdev) {

			mutex_lock(&bdev->bd_inode->i_mutex);

			i_size_write(bdev->bd_inode,

				     (loff_t)mddev->array_sectors << 9);

			mutex_unlock(&bdev->bd_inode->i_mutex);

			bdput(bdev);

		}

	}

}



static void raid5_quiesce(mddev_t *mddev, int state)

{

	raid5_conf_t *conf = mddev_to_conf(mddev);
@@ -5098,6 +5105,7 @@ static struct mdk_personality raid6_personality = 
#ifdef CONFIG_MD_RAID5_RESHAPE

	.check_reshape	= raid5_check_reshape,

	.start_reshape  = raid5_start_reshape,

	.finish_reshape = raid5_finish_reshape,

#endif

	.quiesce	= raid5_quiesce,

	.takeover	= raid6_takeover,
@@ -5121,6 +5129,7 @@ static struct mdk_personality raid5_personality = 
#ifdef CONFIG_MD_RAID5_RESHAPE

	.check_reshape	= raid5_check_reshape,

	.start_reshape  = raid5_start_reshape,

	.finish_reshape = raid5_finish_reshape,

#endif

	.quiesce	= raid5_quiesce,

	.takeover	= raid5_takeover,
@@ -5146,6 +5155,7 @@ static struct mdk_personality raid4_personality = 
#ifdef CONFIG_MD_RAID5_RESHAPE

	.check_reshape	= raid5_check_reshape,

	.start_reshape  = raid5_start_reshape,

	.finish_reshape = raid5_finish_reshape,

#endif

	.quiesce	= raid5_quiesce,

};