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| author | NeilBrown <neilb@suse.de> | 2010-12-09 16:36:28 +1100 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2011-02-09 22:15:36 +0100 |
| commit | 69b74dfe7cc2022a2f2e0cf920f0c24e72c0d387 (patch) | |
| tree | c84dd5c64f787e31b8f0d025eb7f7afc0ef98f83 /drivers | |
| parent | 685c0cc45ed6d9a6289dee976eb6b9db4f05c5fe (diff) | |
| download | lwn-69b74dfe7cc2022a2f2e0cf920f0c24e72c0d387.tar.gz lwn-69b74dfe7cc2022a2f2e0cf920f0c24e72c0d387.zip | |
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>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/md.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 4d96950c4b2d..2c84cc90c5ed 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4300,7 +4300,7 @@ 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) @@ -4310,7 +4310,10 @@ 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)) |