Commit 78200d45 authored Feb 25, 2009 by NeilBrown

md/raid10: Don't call bitmap_cond_end_sync when we are doing recovery.



For raid1/4/5/6, resync (fixing inconsistencies between devices) is
very similar to recovery (rebuilding a failed device onto a spare).
The both walk through the device addresses in order.

For raid10 it can be quite different.  resync follows the 'array'
address, and makes sure all copies are the same.  Recover walks
through 'device' addresses and recreates each missing block.

The 'bitmap_cond_end_sync' function allows the write-intent-bitmap
(When present) to be updated to reflect a partially completed resync.
It makes assumptions which mean that it does not work correctly for
raid10 recovery at all.

In particularly, it can cause bitmap-directed recovery of a raid10 to
not recovery some of the blocks that need to be recovered.

So move the call to bitmap_cond_end_sync into the resync path, rather
than being in the common "resync or recovery" path.


Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

parent 09b4068a

drivers/md/raid10.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1749,8 +1749,6 @@ static sector_t sync_request(mddev_t mddev, sector_t sector_nr, int skipped, i
		if (!go_faster && conf->nr_waiting)
		msleep_interruptible(1000);

		bitmap_cond_end_sync(mddev->bitmap, sector_nr);

		/* Again, very different code for resync and recovery.
		* Both must result in an r10bio with a list of bios that
		* have bi_end_io, bi_sector, bi_bdev set,
		@@ -1886,6 +1884,8 @@ static sector_t sync_request(mddev_t mddev, sector_t sector_nr, int skipped, i
		/* resync. Schedule a read for every block at this virt offset */
		int count = 0;

		bitmap_cond_end_sync(mddev->bitmap, sector_nr);

		if (!bitmap_start_sync(mddev->bitmap, sector_nr,
		&sync_blocks, mddev->degraded) &&
		!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {

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