| Message ID | 8a87fb9b6e73f06dfc1a8aa9f3c0b4c01f2c9fbd.1572125022.git.berto@igalia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add subcluster allocation to qcow2 | expand |
On 26.10.19 23:25, Alberto Garcia wrote: > Setting the QCOW_OFLAG_ZERO bit of the L2 entry is forbidden if an > image has subclusters. Instead, the individual 'all zeroes' bits must > be used. > > Signed-off-by: Alberto Garcia <berto@igalia.com> > --- > block/qcow2-cluster.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c > index 3e4ba8d448..aa3eb727a5 100644 > --- a/block/qcow2-cluster.c > +++ b/block/qcow2-cluster.c > @@ -1772,7 +1772,11 @@ static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset, > > /* First remove L2 entries */ > qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); > - if (!full_discard && s->qcow_version >= 3) { > + if (has_subclusters(s)) { > + set_l2_entry(s, l2_slice, l2_index + i, 0); > + set_l2_bitmap(s, l2_slice, l2_index + i, > + full_discard ? 0 : QCOW_L2_BITMAP_ALL_ZEROES); But only for !full_discard, right? Max > + } else if (!full_discard && s->qcow_version >= 3) { > set_l2_entry(s, l2_slice, l2_index + i, QCOW_OFLAG_ZERO); > } else { > set_l2_entry(s, l2_slice, l2_index + i, 0); >
On Mon 04 Nov 2019 04:07:35 PM CET, Max Reitz wrote: >> /* First remove L2 entries */ >> qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); >> - if (!full_discard && s->qcow_version >= 3) { >> + if (has_subclusters(s)) { >> + set_l2_entry(s, l2_slice, l2_index + i, 0); >> + set_l2_bitmap(s, l2_slice, l2_index + i, >> + full_discard ? 0 : QCOW_L2_BITMAP_ALL_ZEROES); > > But only for !full_discard, right? Hence the conditional operator in my patch, maybe you didn't see it? Berto
On 14.11.19 16:33, Alberto Garcia wrote: > On Mon 04 Nov 2019 04:07:35 PM CET, Max Reitz wrote: >>> /* First remove L2 entries */ >>> qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); >>> - if (!full_discard && s->qcow_version >= 3) { >>> + if (has_subclusters(s)) { >>> + set_l2_entry(s, l2_slice, l2_index + i, 0); >>> + set_l2_bitmap(s, l2_slice, l2_index + i, >>> + full_discard ? 0 : QCOW_L2_BITMAP_ALL_ZEROES); >> >> But only for !full_discard, right? > > Hence the conditional operator in my patch, maybe you didn't see it? Oops, yep, I was just hung up on the if conditional. Max
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 3e4ba8d448..aa3eb727a5 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1772,7 +1772,11 @@ static int discard_in_l2_slice(BlockDriverState *bs, uint64_t offset, /* First remove L2 entries */ qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); - if (!full_discard && s->qcow_version >= 3) { + if (has_subclusters(s)) { + set_l2_entry(s, l2_slice, l2_index + i, 0); + set_l2_bitmap(s, l2_slice, l2_index + i, + full_discard ? 0 : QCOW_L2_BITMAP_ALL_ZEROES); + } else if (!full_discard && s->qcow_version >= 3) { set_l2_entry(s, l2_slice, l2_index + i, QCOW_OFLAG_ZERO); } else { set_l2_entry(s, l2_slice, l2_index + i, 0);
Setting the QCOW_OFLAG_ZERO bit of the L2 entry is forbidden if an image has subclusters. Instead, the individual 'all zeroes' bits must be used. Signed-off-by: Alberto Garcia <berto@igalia.com> --- block/qcow2-cluster.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)