From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60874) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W7dBj-0006Wg-On for qemu-devel@nongnu.org; Sun, 26 Jan 2014 22:48:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W7dBd-0003Cw-PN for qemu-devel@nongnu.org; Sun, 26 Jan 2014 22:48:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57649) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W7dBd-0003Cs-HT for qemu-devel@nongnu.org; Sun, 26 Jan 2014 22:48:37 -0500 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s0R3maMr004191 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 26 Jan 2014 22:48:36 -0500 From: Fam Zheng Date: Mon, 27 Jan 2014 11:48:12 +0800 Message-Id: <1390794497-26281-7-git-send-email-famz@redhat.com> In-Reply-To: <1390794497-26281-1-git-send-email-famz@redhat.com> References: <1390794497-26281-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v12 06/11] block: Add backing_blocker in BlockDriverState List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, rjones@redhat.com, armbru@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com This makes use of op_blocker and blocks all the operations except for commit target, on each BlockDriverState->backing_hd. The asserts for op_blocker in bdrv_swap are removed because with this change, the target of block commit has at least the backing blocker of its child, so the assertion is not true. Callers should do their check. Signed-off-by: Fam Zheng --- block.c | 18 ++++++++++++++---- include/block/block_int.h | 3 +++ 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/block.c b/block.c index af8922b..4498ce7 100644 --- a/block.c +++ b/block.c @@ -1075,13 +1075,22 @@ fail: void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) { if (bs->backing_hd) { + assert(error_is_set(&bs->backing_blocker)); + bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker); bdrv_unref(bs->backing_hd); + } else if (backing_hd) { + error_setg(&bs->backing_blocker, + "device is used as backing hd of '%s'", + bs->device_name); } bs->backing_hd = backing_hd; if (!backing_hd) { bs->backing_file[0] = '\0'; bs->backing_format[0] = '\0'; + if (error_is_set(&bs->backing_blocker)) { + error_free(bs->backing_blocker); + } goto out; } pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); @@ -1089,6 +1098,10 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) backing_hd->drv ? backing_hd->drv->format_name : ""); bdrv_ref(bs->backing_hd); + bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); + /* Otherwise we won't be able to commit due to check in bdrv_commit */ + bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, + bs->backing_blocker); pstrcpy(bs->backing_file, sizeof(bs->backing_file), bs->backing_hd->file->filename); pstrcpy(bs->backing_format, sizeof(bs->backing_format), @@ -1680,8 +1693,7 @@ void bdrv_close(BlockDriverState *bs) if (bs->drv) { if (bs->backing_hd) { - bdrv_unref(bs->backing_hd); - bs->backing_hd = NULL; + bdrv_set_backing_hd(bs, NULL); } bs->drv->bdrv_close(bs); g_free(bs->opaque); @@ -1883,7 +1895,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); assert(bs_new->job == NULL); assert(bs_new->dev == NULL); - assert(bdrv_op_blocker_is_empty(bs_new)); assert(bs_new->io_limits_enabled == false); assert(!throttle_have_timer(&bs_new->throttle_state)); @@ -1902,7 +1913,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) /* Check a few fields that should remain attached to the device */ assert(bs_new->dev == NULL); assert(bs_new->job == NULL); - assert(bdrv_op_blocker_is_empty(bs_new)); assert(bs_new->io_limits_enabled == false); assert(!throttle_have_timer(&bs_new->throttle_state)); diff --git a/include/block/block_int.h b/include/block/block_int.h index 1d3f76f..1f4f78b 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -369,6 +369,9 @@ struct BlockDriverState { BlockJob *job; QDict *options; + + /* The error object in use for blocking operations on backing_hd */ + Error *backing_blocker; }; int get_tmp_filename(char *filename, int size); -- 1.8.5.3