This is a note to let you know that I've just added the patch titled
dm writecache: commit just one block, not a full page
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-writecache-commit-just-one-block-not-a-full-page.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 34c42101d30248b21181761b44e16ec8c2b7f908
Author: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Date: Sun Jun 6 16:13:16 2021 -0400
dm writecache: commit just one block, not a full page
[ Upstream commit 991bd8d7bc78966b4dc427b53a144f276bffcd52 ]
Some architectures have pages larger than 4k and committing a full
page causes needless overhead.
Fix this by writing a single block when committing the superblock.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 64c2980aaa54..894b58bbe56e 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -532,11 +532,7 @@ static void ssd_commit_superblock(struct dm_writecache *wc)
region.bdev = wc->ssd_dev->bdev;
region.sector = 0;
- region.count = PAGE_SIZE >> SECTOR_SHIFT;
-
- if (unlikely(region.sector + region.count > wc->metadata_sectors))
- region.count = wc->metadata_sectors - region.sector;
-
+ region.count = wc->block_size >> SECTOR_SHIFT;
region.sector += wc->start_sector;
req.bi_op = REQ_OP_WRITE;
