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authorNeilBrown <neilb@suse.de>2010-12-09 16:36:28 +1100
committerGreg Kroah-Hartman <gregkh@suse.de>2011-01-07 14:43:09 -0800
commit21f29a80fc8f7c399cb6f068ef01ec05a305ecfd (patch)
tree2d91c6877dc2926ef8788747e0bfbfaad193b05c /drivers/md
parente1d55a0e3057b076a178af8438de1bda06ad3a2b (diff)
md: fix bug with re-adding of partially recovered device.
commit 1a855a0606653d2d82506281e2c686bacb4b2f45 upstream. With v0.90 metadata, a hot-spare does not become a full member of the array until recovery is complete. So if we re-add such a device to the array, we know that all of it is as up-to-date as the event count would suggest, and so it a bitmap-based recovery is possible. However with v1.x metadata, the hot-spare immediately becomes a full member of the array, but it record how much of the device has been recovered. If the array is stopped and re-assembled recovery starts from this point. When such a device is hot-added to an array we currently lose the 'how much is recovered' information and incorrectly included it as a full in-sync member (after bitmap-based fixup). This is wrong and unsafe and could corrupt data. So be more careful about setting saved_raid_disk - which is what guides the re-adding of devices back into an array. The new code matches the code in slot_store which does a similar thing, which is encouraging. This is suitable for any -stable kernel. Reported-by: "Dailey, Nate" <Nate.Dailey@stratus.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/md.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 035274682459..81bdfd810e3d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4802,7 +4802,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
PTR_ERR(rdev));
return PTR_ERR(rdev);
}
- /* set save_raid_disk if appropriate */
+ /* set saved_raid_disk if appropriate */
if (!mddev->persistent) {
if (info->state & (1<<MD_DISK_SYNC) &&
info->raid_disk < mddev->raid_disks)
@@ -4812,7 +4812,10 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
} else
super_types[mddev->major_version].
validate_super(mddev, rdev);
- rdev->saved_raid_disk = rdev->raid_disk;
+ if (test_bit(In_sync, &rdev->flags))
+ rdev->saved_raid_disk = rdev->raid_disk;
+ else
+ rdev->saved_raid_disk = -1;
clear_bit(In_sync, &rdev->flags); /* just to be sure */
if (info->state & (1<<MD_DISK_WRITEMOSTLY))