The patch titled
md: fix possible oops when removing a bitmap from an active array
has been added to the -mm tree. Its filename is
md-fix-possible-oops-when-removing-a-bitmap-from-an-active-array.patch
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------------------------------------------------------
Subject: md: fix possible oops when removing a bitmap from an active array
From: NeilBrown <neilb@xxxxxxx>
It is possible to add a write-intent bitmap to an active array, or remove
the bitmap that is there.
When we do with the 'quiesce' the array, which causes make_request to
block in "wait_barrier()".
However we are sampling the value of "mddev->bitmap" before the
wait_barrier call, and using it afterwards. This can result in using a
bitmap structure that has been freed.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/md/raid1.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN drivers/md/raid1.c~md-fix-possible-oops-when-removing-a-bitmap-from-an-active-array drivers/md/raid1.c
--- a/drivers/md/raid1.c~md-fix-possible-oops-when-removing-a-bitmap-from-an-active-array
+++ a/drivers/md/raid1.c
@@ -773,7 +773,7 @@ static int make_request(struct request_q
r1bio_t *r1_bio;
struct bio *read_bio;
int i, targets = 0, disks;
- struct bitmap *bitmap = mddev->bitmap;
+ struct bitmap *bitmap;
unsigned long flags;
struct bio_list bl;
struct page **behind_pages = NULL;
@@ -802,6 +802,8 @@ static int make_request(struct request_q
wait_barrier(conf);
+ bitmap = mddev->bitmap;
+
disk_stat_inc(mddev->gendisk, ios[rw]);
disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
_
Patches currently in -mm which might be from neilb@xxxxxxx are
origin.patch
linux-next.patch
md-fix-possible-oops-when-removing-a-bitmap-from-an-active-array.patch
md-proper-extern-for-mdp_major.patch
md-kill-file_path-wrapper.patch
md-md-raid5-rate-limit-error-printk.patch
md-raid1-fix-restoration-of-bio-between-failed-read-and-write.patch
md-notify-userspace-on-write-pending-changes-to-array_state.patch
md-notify-userspace-on-stop-events.patch
md-improve-setting-of-events_cleared-for-write-intent-bitmaps.patch
md-allow-parallel-resync-of-md-devices.patch
md-restart-recovery-cleanly-after-device-failure.patch
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