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authorNeilBrown <neilb@suse.de>2010-12-09 00:36:28 -0500
committerNeilBrown <neilb@suse.de>2010-12-09 00:36:28 -0500
commit1a855a0606653d2d82506281e2c686bacb4b2f45 (patch)
tree7eeca410e738491318c0d80bd0a0940c392e513f /drivers/md/md.c
parenta035fc3e2531703b539f23bec4ca7943cfc69349 (diff)
md: fix bug with re-adding of partially recovered device.
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> Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/md.c')
-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 d66aaeddf95d..b757da175180 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5159,7 +5159,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
5159 PTR_ERR(rdev)); 5159 PTR_ERR(rdev));
5160 return PTR_ERR(rdev); 5160 return PTR_ERR(rdev);
5161 } 5161 }
5162 /* set save_raid_disk if appropriate */ 5162 /* set saved_raid_disk if appropriate */
5163 if (!mddev->persistent) { 5163 if (!mddev->persistent) {
5164 if (info->state & (1<<MD_DISK_SYNC) && 5164 if (info->state & (1<<MD_DISK_SYNC) &&
5165 info->raid_disk < mddev->raid_disks) 5165 info->raid_disk < mddev->raid_disks)
@@ -5169,7 +5169,10 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
5169 } else 5169 } else
5170 super_types[mddev->major_version]. 5170 super_types[mddev->major_version].
5171 validate_super(mddev, rdev); 5171 validate_super(mddev, rdev);
5172 rdev->saved_raid_disk = rdev->raid_disk; 5172 if (test_bit(In_sync, &rdev->flags))
5173 rdev->saved_raid_disk = rdev->raid_disk;
5174 else
5175 rdev->saved_raid_disk = -1;
5173 5176
5174 clear_bit(In_sync, &rdev->flags); /* just to be sure */ 5177 clear_bit(In_sync, &rdev->flags); /* just to be sure */
5175 if (info->state & (1<<MD_DISK_WRITEMOSTLY)) 5178 if (info->state & (1<<MD_DISK_WRITEMOSTLY))