On Wed 31 Jan 2018 08:48:08 PM CET, Max Reitz wrote: > On 2018-01-26 15:59, Alberto Garcia wrote: >> The BDRVQcow2State structure contains an l2_size field, which stores >> the number of 64-bit entries in an L2 table. >> >> For efficiency reasons we want to be able to load slices instead of >> full L2 tables, so we need to know how many entries an L2 slice can >> hold. >> >> An L2 slice is the portion of an L2 table that is loaded by the qcow2 >> cache. At the moment that cache can only load complete tables, >> therefore an L2 slice has the same size as an L2 table (one cluster) >> and l2_size == l2_slice_size. >> >> Later we'll allow smaller slices, but until then we have to use this >> new l2_slice_size field to make the rest of the code ready for that. >> >> Signed-off-by: Alberto Garcia <be...@igalia.com> >> Reviewed-by: Eric Blake <ebl...@redhat.com> >> --- >> block/qcow2.c | 3 +++ >> block/qcow2.h | 1 + >> 2 files changed, 4 insertions(+) > > Am I missing something or does this patch miss setting l2_slice_size > in qcow2_do_open()?
qcow2_do_open() calls qcow2_update_options() which is what reads l2-cache-entry-size and sets s->l2_slice_size. Berto
