From: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxxxxxxxx>
- the bitmap only use in the first_clone clause for raid1_write_request.
- possible we have stale data in bitmap pointer.
Signed-off-by: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxxxxxxxx>
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxxxxxxxx>
---
drivers/md/raid1.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1d54109071cc..727cd5759c83 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1191,7 +1191,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
struct r1conf *conf = mddev->private;
struct raid1_info *mirror;
struct bio *read_bio;
- struct bitmap *bitmap = mddev->bitmap;
+ struct bitmap *bitmap;
const int op = bio_op(bio);
const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
int max_sectors;
@@ -1254,7 +1254,9 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
mdname(mddev),
(unsigned long long)r1_bio->sector,
bdevname(mirror->rdev->bdev, b));
-
+ /* get mddev->bitmap behind wait_barrier()
+ * as it could have been removed before */
+ bitmap = mddev->bitmap;
if (test_bit(WriteMostly, &mirror->rdev->flags) &&
bitmap) {
/*
@@ -1305,7 +1307,6 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
int i, disks;
- struct bitmap *bitmap = mddev->bitmap;
unsigned long flags;
struct md_rdev *blocked_rdev;
struct blk_plug_cb *cb;
@@ -1459,6 +1460,10 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
if (first_clone) {
+ /* get mddev->bitmap behind wait_barrier()
+ * as it could have been removed before */
+ struct bitmap *bitmap = mddev->bitmap;
+
/* do behind I/O ?
* Not if there are too many, or cannot
* allocate memory, or a reader on WriteMostly
--
2.7.4
