The patch below does not apply to the 3.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8313b8e57f55b15e5b7f7fc5d1630bbf686a9a97 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@xxxxxxx>
Date: Thu, 12 Dec 2013 10:13:33 +1100
Subject: [PATCH] md: fix problem when adding device to read-only array with
bitmap.
If an array is started degraded, and then the missing device
is found it can be re-added and a minimal bitmap-based recovery
will bring it fully up-to-date.
If the array is read-only a recovery would not be allowed.
But also if the array is read-only and the missing device was
present very recently, then there could be no need for any
recovery at all, so we simply include the device in the read-only
array without any recovery.
However... if the missing device was removed a little longer ago
it could be missing some updates, but if a bitmap is present it will
be conditionally accepted pending a bitmap-based update. We don't
currently detect this case properly and will include that old
device into the read-only array with no recovery even though it really
needs a recovery.
This patch keeps track of whether a bitmap-based-recovery is really
needed or not in the new Bitmap_sync rdev flag. If that is set,
then the device will not be added to a read-only array.
Cc: Andrei Warkentin <andreiw@xxxxxxxxxx>
Fixes: d70ed2e4fafdbef0800e73942482bb075c21578b
Cc: stable@xxxxxxxxxxxxxxx (3.2+)
Signed-off-by: NeilBrown <neilb@xxxxxxx>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index e60cebf3f519..2a456a5d59a8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1087,6 +1087,7 @@ static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
rdev->raid_disk = -1;
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
+ clear_bit(Bitmap_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
if (mddev->raid_disks == 0) {
@@ -1165,6 +1166,8 @@ static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
*/
if (ev1 < mddev->bitmap->events_cleared)
return 0;
+ if (ev1 < mddev->events)
+ set_bit(Bitmap_sync, &rdev->flags);
} else {
if (ev1 < mddev->events)
/* just a hot-add of a new device, leave raid_disk at -1 */
@@ -1573,6 +1576,7 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
rdev->raid_disk = -1;
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
+ clear_bit(Bitmap_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
if (mddev->raid_disks == 0) {
@@ -1655,6 +1659,8 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
*/
if (ev1 < mddev->bitmap->events_cleared)
return 0;
+ if (ev1 < mddev->events)
+ set_bit(Bitmap_sync, &rdev->flags);
} else {
if (ev1 < mddev->events)
/* just a hot-add of a new device, leave raid_disk at -1 */
@@ -2798,6 +2804,7 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len)
else
rdev->saved_raid_disk = -1;
clear_bit(In_sync, &rdev->flags);
+ clear_bit(Bitmap_sync, &rdev->flags);
err = rdev->mddev->pers->
hot_add_disk(rdev->mddev, rdev);
if (err) {
@@ -5770,6 +5777,7 @@ static int add_new_disk(struct mddev * mddev, mdu_disk_info_t *info)
info->raid_disk < mddev->raid_disks) {
rdev->raid_disk = info->raid_disk;
set_bit(In_sync, &rdev->flags);
+ clear_bit(Bitmap_sync, &rdev->flags);
} else
rdev->raid_disk = -1;
} else
@@ -7716,7 +7724,8 @@ static int remove_and_add_spares(struct mddev *mddev,
if (test_bit(Faulty, &rdev->flags))
continue;
if (mddev->ro &&
- rdev->saved_raid_disk < 0)
+ ! (rdev->saved_raid_disk >= 0 &&
+ !test_bit(Bitmap_sync, &rdev->flags)))
continue;
rdev->recovery_offset = 0;
@@ -7797,9 +7806,12 @@ void md_check_recovery(struct mddev *mddev)
* As we only add devices that are already in-sync,
* we can activate the spares immediately.
*/
- clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
remove_and_add_spares(mddev, NULL);
- mddev->pers->spare_active(mddev);
+ /* There is no thread, but we need to call
+ * ->spare_active and clear saved_raid_disk
+ */
+ md_reap_sync_thread(mddev);
+ clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
goto unlock;
}
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 2f5cc8a7ef3e..0095ec84ffc7 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -129,6 +129,9 @@ struct md_rdev {
enum flag_bits {
Faulty, /* device is known to have a fault */
In_sync, /* device is in_sync with rest of array */
+ Bitmap_sync, /* ..actually, not quite In_sync. Need a
+ * bitmap-based recovery to get fully in sync
+ */
Unmerged, /* device is being added to array and should
* be considerred for bvec_merge_fn but not
* yet for actual IO
--
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