From 7a6613810785872b7c028fba22fc0bae1c91733d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 31 Mar 2009 15:21:40 +1100 Subject: [PATCH] md/raid5: reshape using largest of old and new chunk size This ensures that even when old and new stripes are overlapping, we will try to read all of the old before having to write any of the new. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 80ec9a6..f7fb2b8 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3738,6 +3738,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped int dd_idx; sector_t writepos, safepos, gap; sector_t stripe_addr; + int reshape_sectors; if (sector_nr == 0) { /* If restarting in the middle, skip the initial sectors */ @@ -3755,6 +3756,15 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped } } + /* We need to process a full chunk at a time. + * If old and new chunk sizes differ, we need to process the + * largest of these + */ + if (mddev->new_chunk > mddev->chunk_size) + reshape_sectors = mddev->new_chunk / 512; + else + reshape_sectors = mddev->chunk_size / 512; + /* we update the metadata when there is more than 3Meg * in the block range (that is rather arbitrary, should * probably be time based) or when the data about to be @@ -3768,12 +3778,12 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped safepos = conf->reshape_safe; sector_div(safepos, data_disks); if (mddev->delta_disks < 0) { - writepos -= conf->chunk_size/512; - safepos += conf->chunk_size/512; + writepos -= reshape_sectors; + safepos += reshape_sectors; gap = conf->reshape_safe - conf->reshape_progress; } else { - writepos += conf->chunk_size/512; - safepos -= conf->chunk_size/512; + writepos += reshape_sectors; + safepos -= reshape_sectors; gap = conf->reshape_progress - conf->reshape_safe; } @@ -3799,14 +3809,14 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped BUG_ON(conf->reshape_progress == 0); stripe_addr = writepos; BUG_ON((mddev->dev_sectors & - ~((sector_t)conf->chunk_size / 512 - 1)) - - (conf->chunk_size / 512) - stripe_addr + ~((sector_t)reshape_sectors - 1)) + - reshape_sectors - stripe_addr != sector_nr); } else { - BUG_ON(writepos != sector_nr + conf->chunk_size / 512); + BUG_ON(writepos != sector_nr + reshape_sectors); stripe_addr = sector_nr; } - for (i=0; i < conf->chunk_size/512; i+= STRIPE_SECTORS) { + for (i = 0; i < reshape_sectors; i += STRIPE_SECTORS) { int j; int skipped = 0; sh = get_active_stripe(conf, stripe_addr+i, 0, 0); @@ -3839,9 +3849,9 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped } spin_lock_irq(&conf->device_lock); if (mddev->delta_disks < 0) - conf->reshape_progress -= i * new_data_disks; + conf->reshape_progress -= reshape_sectors * new_data_disks; else - conf->reshape_progress += i * new_data_disks; + conf->reshape_progress += reshape_sectors * new_data_disks; spin_unlock_irq(&conf->device_lock); /* Ok, those stripe are ready. We can start scheduling * reads on the source stripes. @@ -3867,7 +3877,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped /* If this takes us to the resync_max point where we have to pause, * then we need to write out the superblock. */ - sector_nr += conf->chunk_size>>9; + sector_nr += reshape_sectors; if (sector_nr >= mddev->resync_max) { /* Cannot proceed until we've updated the superblock... */ wait_event(conf->wait_for_overlap, @@ -3883,7 +3893,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped spin_unlock_irq(&conf->device_lock); wake_up(&conf->wait_for_overlap); } - return conf->chunk_size>>9; + return reshape_sectors; } /* FIXME go_faster isn't used */ -- 1.8.2.3