From: Mikulas Patocka Date: Mon, 11 Jul 2022 20:30:52 +0000 (-0400) Subject: dm writecache: count number of blocks read, not number of read bios X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3a2500b73a1792671ad00f332d0fc56730a301c1;p=linux.git dm writecache: count number of blocks read, not number of read bios [ Upstream commit 2c6e755b49d273243431f5f1184654e71221fc78 ] Change dm-writecache, so that it counts the number of blocks read instead of the number of read bios. Bios can be split and requeued using the dm_accept_partial_bio function, so counting bios caused inaccurate results. Fixes: e3a35d03407c ("dm writecache: add event counters") Reported-by: Yu Kuai Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index 10429779a91ab..7bead3b52690c 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -78,8 +78,8 @@ Status: 2. the number of blocks 3. the number of free blocks 4. the number of blocks under writeback -5. the number of read requests -6. the number of read requests that hit the cache +5. the number of read blocks +6. the number of read blocks that hit the cache 7. the number of write requests 8. the number of write requests that hit uncommitted block 9. the number of write requests that hit committed block diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index e3d0a9bb27b54..9d6b7b706a650 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -1364,6 +1364,7 @@ read_next_block: } } else { writecache_map_remap_origin(wc, bio, e); + wc->stats.reads += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits; map_op = WC_MAP_REMAP_ORIGIN; }