md: override md superblock recovery_offset for journal device
Journal device stores data in a log structure. We need record the log
start. Here we override md superblock recovery_offset for this purpose.
This field of a journal device is meaningless otherwise.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 391341a..3592beb 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1646,6 +1646,7 @@
return -EINVAL;
}
set_bit(Journal, &rdev->flags);
+ rdev->journal_tail = le64_to_cpu(sb->journal_tail);
break;
default:
rdev->saved_raid_disk = role;
@@ -1721,6 +1722,9 @@
sb->feature_map |=
cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
}
+ /* Note: recovery_offset and journal_tail share space */
+ if (test_bit(Journal, &rdev->flags))
+ sb->journal_tail = cpu_to_le64(rdev->journal_tail);
if (test_bit(Replacement, &rdev->flags))
sb->feature_map |=
cpu_to_le32(MD_FEATURE_REPLACEMENT);
@@ -8097,6 +8101,8 @@
continue;
if (test_bit(Faulty, &rdev->flags))
continue;
+ if (test_bit(Journal, &rdev->flags))
+ continue;
if (mddev->ro &&
! (rdev->saved_raid_disk >= 0 &&
!test_bit(Bitmap_sync, &rdev->flags)))
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 88dc6312..2b0f62fb 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -87,10 +87,16 @@
* array and could again if we did a partial
* resync from the bitmap
*/
- sector_t recovery_offset;/* If this device has been partially
+ union {
+ sector_t recovery_offset;/* If this device has been partially
* recovered, this is where we were
* up to.
*/
+ sector_t journal_tail; /* If this device is a journal device,
+ * this is the journal tail (journal
+ * recovery start point)
+ */
+ };
atomic_t nr_pending; /* number of pending requests.
* only maintained for arrays that
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index eaaab52..a5f54ff 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -258,7 +258,10 @@
__le64 data_offset; /* sector start of data, often 0 */
__le64 data_size; /* sectors in this device that can be used for data */
__le64 super_offset; /* sector start of this superblock */
- __le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
+ union {
+ __le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
+ __le64 journal_tail;/* journal tail of journal device (from data_offset) */
+ };
__le32 dev_number; /* permanent identifier of this device - not role in raid */
__le32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */
__u8 device_uuid[16]; /* user-space setable, ignored by kernel */