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 of bios provided inaccurate results.
Signed-off-by: Mikulas Patocka <[email protected]> Reported-by: Yu Kuai <[email protected]> Index: linux-2.6/drivers/md/dm-writecache.c =================================================================== --- linux-2.6.orig/drivers/md/dm-writecache.c +++ linux-2.6/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; } Index: linux-2.6/Documentation/admin-guide/device-mapper/writecache.rst =================================================================== --- linux-2.6.orig/Documentation/admin-guide/device-mapper/writecache.rst +++ linux-2.6/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 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
