Re: [PATCH v6 06/12] md/raid1,raid10: keep REQ_NOMERGE on narrow_write_error() retry clones
From: sashiko-bot@kernel.org
Date: 2026-07-26 12:09:03
Also in:
linux-pci
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: Pre-existing issues: - [High] Unconditional assignment to `wbio->bi_opf` destroys all request flags cloned from the master bio, leading to potential data corruption. --
--- Patch [6]: [PATCH v6 06/12] md/raid1,raid10: keep REQ_NOMERGE on narrow_write_error() retry clones ---commit 333e1430f8770afc53cf111be8c36899e6c4c5e3 Author: Mykola Marzhan [off-list ref] md/raid1,raid10: keep REQ_NOMERGE on narrow_write_error() retry clones This commit restores REQ_NOMERGE on P2PDMA retry clones in narrow_write_error() to prevent member queues from improperly merging segments.
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diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index f07edeac6e5a3..19c4dec450de0 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c
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@@ -2561,6 +2561,9 @@ static void narrow_write_error(struct r1bio *r1_bio, int i) } wbio->bi_opf = REQ_OP_WRITE;
[Severity: High] This isn't a bug introduced by this patch, but does this assignment unintentionally overwrite all request flags? Since bio_alloc_clone() copies the original bi_opf, setting it directly to REQ_OP_WRITE zeroes out the upper 24 flag bits, which drops flags like REQ_FUA and REQ_PREFLUSH. Could this result in data corruption on power loss if the original write requested forced unit access?
+ /* Keep P2PDMA retry bios unmergeable, like the original */ + if (md_bio_is_p2pdma(wbio)) + wbio->bi_opf |= REQ_NOMERGE; wbio->bi_iter.bi_sector = r1_bio->sector; wbio->bi_iter.bi_size = r1_bio->sectors << 9;
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diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 5b63175fb3826..428bddddfe71d 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c
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@@ -2823,6 +2823,9 @@ static void narrow_write_error(struct r10bio *r10_bio, int i) wbio->bi_iter.bi_sector = wsector + choose_data_offset(r10_bio, rdev); wbio->bi_opf = REQ_OP_WRITE;
[Severity: High] This is the same pre-existing issue as in raid1.c. Does overwriting bi_opf drop critical data integrity flags like REQ_FUA cloned from the master bio?
+ /* Keep P2PDMA retry bios unmergeable, like the original */
+ if (md_bio_is_p2pdma(wbio))
+ wbio->bi_opf |= REQ_NOMERGE;
if (submit_bio_wait(wbio) &&
!rdev_set_badblocks(rdev, wsector, sectors, 0)) {-- Sashiko AI review · https://sashiko.dev/#/patchset/20260726113229.2154269-1-mykola@meshstor.io?part=6