pmem_submit_bio() records a REQ_PREFLUSH error, but continues to copy the bio data and can later overwrite the error with a successful REQ_FUA flush. That lets data writes run after a failed preflush and can complete the bio successfully despite the failed ordering barrier.
Run the REQ_PREFLUSH flush synchronously before touching the bio data and complete the bio with the flush error if it fails. Keep asynchronous flush chaining for REQ_FUA. At that point, data copy has completed and the parent bio can wait for the chained flush bio. Signed-off-by: Li Chen <[email protected]> --- drivers/nvdimm/pmem.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 92c67fbbc1c85..05d3de33e2706 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -208,8 +208,14 @@ 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) - ret = nvdimm_flush(nd_region, bio); + if (bio->bi_opf & REQ_PREFLUSH) { + ret = nvdimm_flush(nd_region, NULL); + if (ret) { + bio->bi_status = errno_to_blk_status(ret); + bio_endio(bio); + return; + } + } do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue); if (do_acct) @@ -229,7 +235,7 @@ 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) && !bio->bi_status) ret = nvdimm_flush(nd_region, bio); if (ret) -- 2.52.0
