Re: [PATCH 2/3] block: update the stable_writes flag in bdev_add

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Oct 24, 2023 at 08:44:15AM +0200, Christoph Hellwig wrote:
> Propagate the per-queue stable_write flags into each bdev inode in bdev_add.
> This makes sure devices that require stable writes have it set for I/O
> on the block device node as well.
> 
> Note that this doesn't cover the case of a flag changing on a live device
> yet.  We should handle that as well, but I plan to cover it as part of a
> more general rework of how changing runtime paramters on block devices
> works.

Yessssssssss! :)

> Fixes: 1cb039f3dc16 ("bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag")
> Reported-by: Ilya Dryomov <idryomov@gmail.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Seems sane to me,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  block/bdev.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/block/bdev.c b/block/bdev.c
> index f3b13aa1b7d428..04dba25b0019eb 100644
> --- a/block/bdev.c
> +++ b/block/bdev.c
> @@ -425,6 +425,8 @@ void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors)
>  
>  void bdev_add(struct block_device *bdev, dev_t dev)
>  {
> +	if (bdev_stable_writes(bdev))
> +		mapping_set_stable_writes(bdev->bd_inode->i_mapping);
>  	bdev->bd_dev = dev;
>  	bdev->bd_inode->i_rdev = dev;
>  	bdev->bd_inode->i_ino = dev;
> -- 
> 2.39.2
>