On Wed, Dec 13, 2017 at 01:50:07PM +0200, Nikolay Borisov wrote:
> Commit e0ae99941423 ("btrfs: preallocate device flush bio") reworked
> the way the flush bio is allocated and used. Concretely it allocates
> the bio in __alloc_device and then re-uses it multiple times with a
> very simple endio routine that just calls complete() without consuming
> a reference. Allocated bios by default come with a ref count of 1,
> which is then consumed by the endio routine (or not, in which case they
> should be bio_put by the caller). The way the impleementation works now
> is that the flush bio has a refcount of 2 and we only ever bio_put it
> once, leaving it to hang indefinitely. Fix this by removing the extra
> bio_get in __alloc_device.
>
Reviewed-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
Thanks,
-liubo
> Fixes: e0ae99941423 ("btrfs: preallocate device flush bio")
> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/volumes.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 132966950f5f..3690822d469a 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -312,7 +312,6 @@ static struct btrfs_device *__alloc_device(void)
> kfree(dev);
> return ERR_PTR(-ENOMEM);
> }
> - bio_get(dev->flush_bio);
>
> INIT_LIST_HEAD(&dev->dev_list);
> INIT_LIST_HEAD(&dev->dev_alloc_list);
> --
> 2.7.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
