If an incremental recovery was interrupted, a subsequent
re-add will result in a full recovery, even though an
incremental should be possible.
This patch handles 99% of possible interruptions of an
incremental recovery (it doesn't handle I/O failure
that occurs immediately after the hot_add_disk(), which
causes the added rdev to become a spare).
Cc: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrei Warkentin <andrey.warkentin@xxxxxxxxx>
---
drivers/md/md.c | 28 +++++++++++++++++++++++++---
include/linux/raid/md_p.h | 6 +++++-
2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5404b22..8002e02 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1701,10 +1701,27 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
break;
default:
if ((le32_to_cpu(sb->feature_map) &
- MD_FEATURE_RECOVERY_OFFSET))
- rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
- else
+ MD_FEATURE_IN_INCREMENTAL)) {
+ /* This rdev had been in an incremental
+ * recovery, which was interrupted, and
+ * can be restarted. Note that we specifically
+ * ignore recovery_offset, as I/O to the degraded
+ * array could have modified data in sectors
+ * below the recovery offset.
+ */
+ char b[BDEVNAME_SIZE];
set_bit(In_sync, &rdev->flags);
+ printk(KERN_NOTICE
+ "md: restarting interrupted incremental resync on %s\n",
+ bdevname(rdev->bdev, b));
+ } else {
+ if ((le32_to_cpu(sb->feature_map) &
+ MD_FEATURE_RECOVERY_OFFSET))
+ rdev->recovery_offset =
+ le64_to_cpu(sb->recovery_offset);
+ else
+ set_bit(In_sync, &rdev->flags);
+ }
rdev->raid_disk = role;
break;
}
@@ -1738,6 +1755,11 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
else
sb->resync_offset = cpu_to_le64(0);
+ if (mddev->bitmap && rdev->saved_raid_disk != -1)
+ sb->feature_map |= cpu_to_le32(MD_FEATURE_IN_INCREMENTAL);
+ else
+ sb->feature_map &= ~cpu_to_le32(MD_FEATURE_IN_INCREMENTAL);
+
sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
sb->raid_disks = cpu_to_le32(mddev->raid_disks);
diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h
index 9e65d9e..8a17446 100644
--- a/include/linux/raid/md_p.h
+++ b/include/linux/raid/md_p.h
@@ -277,7 +277,11 @@ struct mdp_superblock_1 {
*/
#define MD_FEATURE_RESHAPE_ACTIVE 4
#define MD_FEATURE_BAD_BLOCKS 8 /* badblock list is not empty */
+#define MD_FEATURE_IN_INCREMENTAL 16 /* set on disks undergoing incremental
+ * recovery, so that an interrupted
+ * incremental recovery may be restarted
+ */
-#define MD_FEATURE_ALL (1|2|4|8)
+#define MD_FEATURE_ALL (1|2|4|8|16)
#endif
--
1.7.4.1
--
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