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| author | Mikulas Patocka <mpatocka@redhat.com> | 2021-06-21 20:48:29 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2021-06-21 22:15:10 +0200 |
| commit | 867de40c4c23e6d7f89f9ce4272a5d1b1484c122 (patch) | |
| tree | ebd3f7cb8dd216e4ab3f0ec96fc19565f52f35dc /drivers/md/dm-writecache.c | |
| parent | dm writecache: flush origin device when writing and cache is full (diff) | |
| download | linux-867de40c4c23e6d7f89f9ce4272a5d1b1484c122.tar.xz linux-867de40c4c23e6d7f89f9ce4272a5d1b1484c122.zip | |
dm writecache: write at least 4k when committing
SSDs perform badly with sub-4k writes (because they perfrorm
read-modify-write internally), so make sure writecache writes at least
4k when committing.
Fixes: 991bd8d7bc78 ("dm writecache: commit just one block, not a full page")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-writecache.c')
| -rw-r--r-- | drivers/md/dm-writecache.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index ddd368e0491d..558d39764e6d 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -532,7 +532,11 @@ static void ssd_commit_superblock(struct dm_writecache *wc) region.bdev = wc->ssd_dev->bdev; region.sector = 0; - region.count = wc->block_size >> SECTOR_SHIFT; + region.count = max(4096U, wc->block_size) >> SECTOR_SHIFT; + + if (unlikely(region.sector + region.count > wc->metadata_sectors)) + region.count = wc->metadata_sectors - region.sector; + region.sector += wc->start_sector; req.bi_op = REQ_OP_WRITE; |