From 508249952c0ea7472c62e17bf8132295dab4912d Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 8 Jun 2015 13:56:10 +0800 Subject: block: Fix dirty bitmap in bdrv_co_discard 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: wangxiaolong@ucloud.cn Signed-off-by: Fam Zheng Reviewed-by: Paolo Bonzini Reviewed-by: Eric Blake Signed-off-by: Stefan Hajnoczi --- block/io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'block') diff --git a/block/io.c b/block/io.c index ccf79c33c5..ad31822b08 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; -- cgit v1.2.3