On Tue, Jan 11, 2022 at 8:21 AM Pankaj Gupta
<pankaj.gupta.linux@xxxxxxxxx> wrote:
>
> Return from "pmem_submit_bio" when asynchronous flush is
> still in progress in other context.
>
> Signed-off-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
> ---
> drivers/nvdimm/pmem.c | 15 ++++++++++++---
> drivers/nvdimm/region_devs.c | 4 +++-
> 2 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index fe7ece1534e1..f20e30277a68 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -201,8 +201,12 @@ static void pmem_submit_bio(struct bio *bio)
> struct pmem_device *pmem = bio->bi_bdev->bd_disk->private_data;
> struct nd_region *nd_region = to_region(pmem);
>
> - if (bio->bi_opf & REQ_PREFLUSH)
> + if (bio->bi_opf & REQ_PREFLUSH) {
> ret = nvdimm_flush(nd_region, bio);
> + /* asynchronous flush completes in other context */
I think a negative error code is a confusing way to capture the case
of "bio successfully coalesced to previously pending flush request.
Perhaps reserve negative codes for failure, 0 for synchronously
completed, and > 0 for coalesced flush request.
> + if (ret == -EINPROGRESS)
> + return;
> + }
>
> do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
> if (do_acct)
> @@ -222,13 +226,18 @@ static void pmem_submit_bio(struct bio *bio)
> if (do_acct)
> bio_end_io_acct(bio, start);
>
> - if (bio->bi_opf & REQ_FUA)
> + if (bio->bi_opf & REQ_FUA) {
> ret = nvdimm_flush(nd_region, bio);
> + /* asynchronous flush completes in other context */
> + if (ret == -EINPROGRESS)
> + return;
> + }
>
> if (ret)
> bio->bi_status = errno_to_blk_status(ret);
>
> - bio_endio(bio);
> + if (bio)
> + bio_endio(bio);
> }
>
> static int pmem_rw_page(struct block_device *bdev, sector_t sector,
> diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
> index 9ccf3d608799..8512d2eaed4e 100644
> --- a/drivers/nvdimm/region_devs.c
> +++ b/drivers/nvdimm/region_devs.c
> @@ -1190,7 +1190,9 @@ int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
> if (!nd_region->flush)
> rc = generic_nvdimm_flush(nd_region);
> else {
> - if (nd_region->flush(nd_region, bio))
> + rc = nd_region->flush(nd_region, bio);
> + /* ongoing flush in other context */
> + if (rc && rc != -EINPROGRESS)
> rc = -EIO;
Why change this to -EIO vs just let the error code through untranslated?
> }
>
> --
> 2.25.1
>
>
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