From: Li Chen <me@linux.beauty>
To: Pankaj Gupta <pankaj.gupta.linux@gmail.com>,
Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Alison Schofield <alison.schofield@intel.com>,
virtualization@lists.linux.dev, nvdimm@lists.linux.dev
Cc: linux-kernel@vger.kernel.org, Li Chen <me@linux.beauty>
Subject: [PATCH v6 03/12] nvdimm: pmem: guard data loop for dataless bios
Date: Sun, 21 Jun 2026 21:02:34 +0800 [thread overview]
Message-ID: <20260621130246.2973254-4-me@linux.beauty> (raw)
In-Reply-To: <20260621130246.2973254-1-me@linux.beauty>
pmem_submit_bio() handles flush-only bios before and after the data
loop. Keep dataless bios out of bio_for_each_segment() so the data path
only walks bios that actually carry bvec data.
Signed-off-by: Li Chen <me@linux.beauty>
---
Changes in v6:
- New patch.
drivers/nvdimm/pmem.c | 36 +++++++++++++++++++++---------------
1 file changed, 21 insertions(+), 15 deletions(-)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 05d3de33e2706..82ee1ddb3a445 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -217,23 +217,29 @@ static void pmem_submit_bio(struct bio *bio)
}
}
- do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
- if (do_acct)
- start = bio_start_io_acct(bio);
- bio_for_each_segment(bvec, bio, iter) {
- if (op_is_write(bio_op(bio)))
- rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset,
- iter.bi_sector, bvec.bv_len);
- else
- rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset,
- iter.bi_sector, bvec.bv_len);
- if (rc) {
- bio->bi_status = rc;
- break;
+ if (bio_has_data(bio)) {
+ do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
+ if (do_acct)
+ start = bio_start_io_acct(bio);
+ bio_for_each_segment(bvec, bio, iter) {
+ if (op_is_write(bio_op(bio)))
+ rc = pmem_do_write(pmem, bvec.bv_page,
+ bvec.bv_offset,
+ iter.bi_sector,
+ bvec.bv_len);
+ else
+ rc = pmem_do_read(pmem, bvec.bv_page,
+ bvec.bv_offset,
+ iter.bi_sector,
+ bvec.bv_len);
+ if (rc) {
+ bio->bi_status = rc;
+ break;
+ }
}
+ if (do_acct)
+ bio_end_io_acct(bio, start);
}
- if (do_acct)
- bio_end_io_acct(bio, start);
if ((bio->bi_opf & REQ_FUA) && !bio->bi_status)
ret = nvdimm_flush(nd_region, bio);
--
2.52.0
next prev parent reply other threads:[~2026-06-21 13:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-21 13:02 [PATCH v6 00/12] nvdimm: virtio_pmem: fix request lifetime and converge broken queue failures Li Chen
2026-06-21 13:02 ` [PATCH v6 01/12] nvdimm: preserve flush callback errors Li Chen
2026-06-23 9:46 ` Pankaj Gupta
2026-06-21 13:02 ` [PATCH v6 02/12] nvdimm: pmem: keep PREFLUSH before data writes Li Chen
2026-06-21 13:02 ` Li Chen [this message]
2026-06-21 13:02 ` [PATCH v6 04/12] nvdimm: virtio_pmem: stop allocating child flush bio Li Chen
2026-06-24 17:22 ` Pankaj Gupta
2026-06-21 13:02 ` [PATCH v6 05/12] nvdimm: virtio_pmem: use GFP_NOIO for flush requests Li Chen
2026-06-21 13:02 ` [PATCH v6 06/12] nvdimm: virtio_pmem: always wake -ENOSPC waiters Li Chen
2026-06-21 13:02 ` [PATCH v6 07/12] nvdimm: virtio_pmem: use READ_ONCE()/WRITE_ONCE() for wait flags Li Chen
2026-06-23 8:34 ` Pankaj Gupta
2026-06-21 13:02 ` [PATCH v6 08/12] nvdimm: virtio_pmem: refcount requests for token lifetime Li Chen
2026-06-21 13:02 ` [PATCH v6 09/12] nvdimm: virtio_pmem: publish done with release/acquire Li Chen
2026-06-21 13:02 ` [PATCH v6 10/12] nvdimm: virtio_pmem: isolate DMA request buffers Li Chen
2026-06-21 13:02 ` [PATCH v6 11/12] nvdimm: virtio_pmem: converge broken virtqueue to -EIO Li Chen
2026-06-21 13:02 ` [PATCH v6 12/12] nvdimm: virtio_pmem: drain requests in freeze Li Chen
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