From 2c6e755b49d273243431f5f1184654e71221fc78 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 11 Jul 2022 16:30:52 -0400 Subject: [PATCH] dm writecache: count number of blocks read, not number of read bios 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 --- Documentation/admin-guide/device-mapper/writecache.rst | 4 ++-- drivers/md/dm-writecache.c | 1 + 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index 2104812f0281..1fab82408ef1 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -80,8 +80,8 @@ 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 9e14717c46a9..a551be5f9b4b 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -1365,6 +1365,7 @@ 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; }