[dm-devel] [PATCH v2 08/11] dm: Forbid requeue of writes to zones

[Hannes Reinecke]

On 5/20/21 6:22 AM, Damien Le Moal wrote:
> A target map method requesting the requeue of a bio with
> DM_MAPIO_REQUEUE or completing it with DM_ENDIO_REQUEUE can cause
> unaligned write errors if the bio is a write operation targeting a
> sequential zone. If a zoned target request such a requeue, warn about
> it and kill the IO.
> 
> The function dm_is_zone_write() is introduced to detect write operations
> to zoned targets.
> 
> This change does not affect the target drivers supporting zoned devices
> and exposing a zoned device, namely dm-crypt, dm-linear and dm-flakey as
> none of these targets ever request a requeue.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
> ---
>   drivers/md/dm-zone.c | 17 +++++++++++++++++
>   drivers/md/dm.c      | 18 +++++++++++++++---
>   drivers/md/dm.h      |  5 +++++
>   3 files changed, 37 insertions(+), 3 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare at suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
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