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| author |   Christoph Böhmwalder <christoph.boehmwalder@linbit.com> | 2022-10-20 10:52:05 +0200 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2022-10-20 05:45:21 -0700 |
| commit | 6d42ddf7f27b6723549ee6d4c8b1b418b59bf6b5 (patch) | |
| tree | 8428578275365a3e9a8871bfbce3231c22b2a680 /drivers/block | |
| parent | Merge tag 'nvme-6.1-2022-10-22' of git://git.infradead.org/nvme into block-6.1 (diff) | |
| download | linux-dev-6d42ddf7f27b6723549ee6d4c8b1b418b59bf6b5.tar.xz linux-dev-6d42ddf7f27b6723549ee6d4c8b1b418b59bf6b5.zip | |
drbd: only clone bio if we have a backing device
Commit c347a787e34cb (drbd: set ->bi_bdev in drbd_req_new) moved a
bio_set_dev call (which has since been removed) to "earlier", from
drbd_request_prepare to drbd_req_new.
The problem is that this accesses device->ldev->backing_bdev, which is
not NULL-checked at this point. When we don't have an ldev (i.e. when
the DRBD device is diskless), this leads to a null pointer deref.
So, only allocate the private_bio if we actually have a disk. This is
also a small optimization, since we don't clone the bio to only to
immediately free it again in the diskless case.
Fixes: c347a787e34cb ("drbd: set ->bi_bdev in drbd_req_new")
Co-developed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Co-developed-by: Joel Colledge <joel.colledge@linbit.com>
Signed-off-by: Joel Colledge <joel.colledge@linbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020085205.129090-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 8f7f144e54f3..7f9bcc82fc9c 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -30,11 +30,6 @@ static struct drbd_request *drbd_req_new(struct drbd_device *device, struct bio return NULL; memset(req, 0, sizeof(*req)); - req->private_bio = bio_alloc_clone(device->ldev->backing_bdev, bio_src, - GFP_NOIO, &drbd_io_bio_set); - req->private_bio->bi_private = req; - req->private_bio->bi_end_io = drbd_request_endio; - req->rq_state = (bio_data_dir(bio_src) == WRITE ? RQ_WRITE : 0) | (bio_op(bio_src) == REQ_OP_WRITE_ZEROES ? RQ_ZEROES : 0) | (bio_op(bio_src) == REQ_OP_DISCARD ? RQ_UNMAP : 0); @@ -1219,9 +1214,12 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio) /* Update disk stats */ req->start_jif = bio_start_io_acct(req->master_bio); - if (!get_ldev(device)) { - bio_put(req->private_bio); - req->private_bio = NULL; + if (get_ldev(device)) { + req->private_bio = bio_alloc_clone(device->ldev->backing_bdev, + bio, GFP_NOIO, + &drbd_io_bio_set); + req->private_bio->bi_private = req; + req->private_bio->bi_end_io = drbd_request_endio; } /* process discards always from our submitter thread */ |