Re: [PATCH v6 6/6] loop: Add support for REQ_ALLOCATE

Darrick J. Wong
2020-02-12T20:45:51Z

On Wed, Feb 12, 2020 at 11:00:15PM +0300, Kirill Tkhai wrote:
> On 12.02.2020 20:01, Darrick J. Wong wrote:
> > On Mon, Feb 10, 2020 at 12:34:04PM +0300, Kirill Tkhai wrote:
> >> Support for new modifier of REQ_OP_WRITE_ZEROES command.
> >> This results in allocation extents in backing file instead
> >> of actual blocks zeroing.
> >>
> >> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> >> Reviewed-by: Bob Liu <bob.liu@oracle.com>
> >> ---
> >> drivers/block/loop.c | 15 ++++++++++++---
> >> 1 file changed, 12 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> >> index 739b372a5112..bfe76d9adf09 100644
> >> --- a/drivers/block/loop.c
> >> +++ b/drivers/block/loop.c
> >> @@ -581,6 +581,15 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
> >> return 0;
> >> }
> >>
> >> +static unsigned int write_zeroes_to_fallocate_mode(unsigned int flags)
> >> +{
> >> + if (flags & REQ_ALLOCATE)
> >> + return 0;
> >> + if (flags & REQ_NOUNMAP)
> >> + return FALLOC_FL_ZERO_RANGE;
> >> + return FALLOC_FL_PUNCH_HOLE;
> >> +}
> >> +
> >> static int do_req_filebacked(struct loop_device *lo, struct request *rq)
> >> {
> >> struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
> >> @@ -604,9 +613,7 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
> >> * write zeroes the range. Otherwise, punch them out.
> >> */
> >
> > Please update this comment to reflect the new REQ_ALLOCATE mode, and
> > move it to where you define write_zeroes_to_fallocate_mode().
> >
> > With that fixed,
> >
> > Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
>
> Just to clarify. Is this "Reviewed-by:" tag for this patch or for the whole series?

Only that patch.

--D

> Kirill