From 3d8b7aed60e792bf2a9237cf689b13368f09ecc2 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 8 Jun 2015 13:56:10 +0800 Subject: [PATCH] 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 (cherry picked from commit 508249952c0ea7472c62e17bf8132295dab4912d) Conflicts: block/io.c * applied manually to avoid dependency on 61007b316 * squashed in 6e82e4b bdrv_reset_dirty() is static in 2.3.0 and becomes unused as of this patch Signed-off-by: Michael Roth --- block.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) diff --git a/block.c b/block.c index 63dd460c96..4f52d7a31d 100644 --- a/block.c +++ b/block.c @@ -99,8 +99,6 @@ static QLIST_HEAD(, BlockDriver) bdrv_drivers = static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors); -static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, - int nr_sectors); /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; @@ -5299,8 +5297,6 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, return -EROFS; } - bdrv_reset_dirty(bs, sector_num, nb_sectors); - /* Do nothing if disabled. */ if (!(bs->open_flags & BDRV_O_UNMAP)) { return 0; @@ -5310,6 +5306,8 @@ 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; @@ -5620,15 +5618,6 @@ static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, } } -static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, - int nr_sectors) -{ - BdrvDirtyBitmap *bitmap; - QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { - hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); - } -} - int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) { return hbitmap_count(bitmap->bitmap); -- GitLab