From: Fam Zheng <f...@redhat.com>
Unsetting dirty globally with discard is not very correct. The discard may zero
out sectors (depending on can_write_zeroes_with_unmap), we should replicate
this change to destination side to make sure that the guest sees the same data.
Calling bdrv_reset_dirty also troubles mirror job because the hbitmap iterator
doesn't expect unsetting of bits after current position.
So let's do it the opposite way which fixes both problems: set the dirty bits
if we are to discard it.
Reported-by: wangxiaol...@ucloud.cn
Signed-off-by: Fam Zheng <f...@redhat.com>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
block/io.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/block/io.c b/block/io.c
index ccf79c3..ad31822 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2412,8 +2412,6 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs,
int64_t sector_num,
return -EPERM;
}
- bdrv_reset_dirty(bs, sector_num, nb_sectors);
-
/* Do nothing if disabled. */
if (!(bs->open_flags & BDRV_O_UNMAP)) {
return 0;
@@ -2423,6 +2421,8 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs,
int64_t sector_num,
return 0;
}
+ bdrv_set_dirty(bs, sector_num, nb_sectors);
+
max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
while (nb_sectors > 0) {
int ret;
--
2.4.3
