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From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To: Mikulas Patocka <mpatocka@redhat.com>, Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>, Christoph Hellwig <hch@lst.de>,
	LKML <linux-kernel@vger.kernel.org>,
	DMML <dm-devel@lists.linux.dev>,
	Uladzislau Rezki <urezki@gmail.com>
Subject: [RESEND PATCH] dm-ebs: Mark full buffer dirty even on partial write
Date: Tue, 14 Oct 2025 16:47:31 +0200	[thread overview]
Message-ID: <20251014144731.164120-1-urezki@gmail.com> (raw)

When performing a read-modify-write(RMW) operation, any modification
to a buffered block must cause the entire buffer to be marked dirty.

Marking only a subrange as dirty is incorrect because the underlying
device block size(ubs) defines the minimum read/write granularity. A
lower device can perform I/O only on regions which are fully aligned
and sized to ubs.

This change ensures that write-back operations always occur in full
ubs-sized chunks, matching the intended emulation semantics of the
EBS target.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
 drivers/md/dm-ebs-target.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-ebs-target.c b/drivers/md/dm-ebs-target.c
index 6abb31ca9662..b354e74a670e 100644
--- a/drivers/md/dm-ebs-target.c
+++ b/drivers/md/dm-ebs-target.c
@@ -103,7 +103,7 @@ static int __ebs_rw_bvec(struct ebs_c *ec, enum req_op op, struct bio_vec *bv,
 			} else {
 				flush_dcache_page(bv->bv_page);
 				memcpy(ba, pa, cur_len);
-				dm_bufio_mark_partial_buffer_dirty(b, buf_off, buf_off + cur_len);
+				dm_bufio_mark_buffer_dirty(b);
 			}
 
 			dm_bufio_release(b);
-- 
2.47.3


             reply	other threads:[~2025-10-14 14:47 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-14 14:47 Uladzislau Rezki (Sony) [this message]
2025-10-16 19:59 ` [RESEND PATCH] dm-ebs: Mark full buffer dirty even on partial write Andrew Morton
2025-10-17 15:55   ` Uladzislau Rezki
  -- strict thread matches above, loose matches on Subject: below --
2025-11-17 10:59 Uladzislau Rezki (Sony)
2025-11-17 20:48 ` Mikulas Patocka
2025-11-18 11:39   ` Uladzislau Rezki
2025-11-18 12:00     ` Mikulas Patocka
2025-11-18 12:40       ` Uladzislau Rezki
2025-11-18 12:46         ` Christoph Hellwig
2025-11-18 14:15       ` Benjamin Marzinski
2025-11-18 17:21         ` Mikulas Patocka
2025-11-19  5:46           ` Christoph Hellwig
2025-11-19  8:43             ` Uladzislau Rezki
2025-11-19  8:53               ` Christoph Hellwig
2025-11-19  8:57                 ` Uladzislau Rezki
2025-11-19  9:00                   ` Christoph Hellwig
2025-11-19  9:01                     ` Uladzislau Rezki
2025-11-19  9:05                       ` Christoph Hellwig
2025-11-19  9:13                         ` Uladzislau Rezki
2025-11-19  9:17                           ` Christoph Hellwig
2025-11-19 17:26             ` Mikulas Patocka
2025-11-20  6:21               ` Christoph Hellwig
2025-11-20 12:08                 ` Uladzislau Rezki
2025-11-20 12:40                   ` Uladzislau Rezki
2025-11-21  7:25                     ` Christoph Hellwig
2025-11-21  7:24                   ` Christoph Hellwig
2025-11-21 13:21                     ` Uladzislau Rezki
2025-11-21 16:48                       ` Benjamin Marzinski
2025-11-24 10:43                         ` Uladzislau Rezki
2025-11-24 14:30                       ` Christoph Hellwig
2025-11-24 15:30                         ` Uladzislau Rezki
2025-11-24 17:00                           ` Christoph Hellwig
2025-11-24 18:05                             ` Uladzislau Rezki

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