From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43276) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcY1N-0000VY-6l for qemu-devel@nongnu.org; Tue, 01 Aug 2017 10:19:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcY1K-0002WM-9S for qemu-devel@nongnu.org; Tue, 01 Aug 2017 10:19:41 -0400 From: Anton Nefedov Date: Tue, 1 Aug 2017 17:19:08 +0300 Message-Id: <1501597152-25342-12-git-send-email-anton.nefedov@virtuozzo.com> In-Reply-To: <1501597152-25342-1-git-send-email-anton.nefedov@virtuozzo.com> References: <1501597152-25342-1-git-send-email-anton.nefedov@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v4 11/15] qcow2: move is_zero() up List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, den@virtuozzo.com, kwolf@redhat.com, mreitz@redhat.com, eblake@redhat.com, Anton Nefedov To be used in the following commit without a forward declaration. Signed-off-by: Anton Nefedov --- block/qcow2.c | 45 ++++++++++++++++++++++----------------------- 1 file changed, 22 insertions(+), 23 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index f522ba9..2ec8b03 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1946,6 +1946,28 @@ static bool merge_cow(uint64_t offset, unsigned bytes, return false; } +static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) +{ + int64_t nr; + int64_t res; + int64_t start; + + /* Widen to sector boundaries, then clamp to image length, before + * checking status of underlying sectors */ + start = QEMU_ALIGN_DOWN(offset, BDRV_SECTOR_SIZE); + bytes = QEMU_ALIGN_UP(offset + bytes, BDRV_SECTOR_SIZE) - start; + + if (start + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { + bytes = bs->total_sectors * BDRV_SECTOR_SIZE - start; + } + + if (!bytes) { + return true; + } + res = bdrv_block_status_above(bs, NULL, start, bytes, &nr, NULL); + return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes; +} + /* * If the specified area is beyond EOF, allocates it + prealloc_size * bytes ahead. @@ -3088,29 +3110,6 @@ finish: return ret; } - -static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes) -{ - int64_t nr; - int64_t res; - int64_t start; - - /* Widen to sector boundaries, then clamp to image length, before - * checking status of underlying sectors */ - start = QEMU_ALIGN_DOWN(offset, BDRV_SECTOR_SIZE); - bytes = QEMU_ALIGN_UP(offset + bytes, BDRV_SECTOR_SIZE) - start; - - if (start + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) { - bytes = bs->total_sectors * BDRV_SECTOR_SIZE - start; - } - - if (!bytes) { - return true; - } - res = bdrv_block_status_above(bs, NULL, start, bytes, &nr, NULL); - return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes; -} - static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags) { -- 2.7.4