From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56211) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WY524-0003WN-8U for qemu-devel@nongnu.org; Wed, 09 Apr 2014 22:48:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WY51w-00073Z-F7 for qemu-devel@nongnu.org; Wed, 09 Apr 2014 22:48:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36941) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WY51w-00073S-6X for qemu-devel@nongnu.org; Wed, 09 Apr 2014 22:47:56 -0400 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 s3A2ltPR014779 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 9 Apr 2014 22:47:55 -0400 From: Fam Zheng Date: Thu, 10 Apr 2014 10:47:07 +0800 Message-Id: <1397098036-20605-7-git-send-email-famz@redhat.com> In-Reply-To: <1397098036-20605-1-git-send-email-famz@redhat.com> References: <1397098036-20605-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v18 06/15] 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, jcody@redhat.com, hbrock@redhat.com, rjones@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 | 24 ++++++++++++++++++++---- block/mirror.c | 1 + include/block/block_int.h | 3 +++ 3 files changed, 24 insertions(+), 4 deletions(-) diff --git a/block.c b/block.c index 7859340..6f803fa 100644 --- a/block.c +++ b/block.c @@ -1055,14 +1055,31 @@ 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); + } 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) { + if (error_is_set(&bs->backing_blocker)) { + error_free(bs->backing_blocker); + } goto out; } bs->open_flags &= ~BDRV_O_NO_BACKING; pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_hd->drv ? backing_hd->drv->format_name : ""); + + 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); out: bdrv_refresh_limits(bs); } @@ -1717,8 +1734,9 @@ void bdrv_close(BlockDriverState *bs) if (bs->drv) { if (bs->backing_hd) { - bdrv_unref(bs->backing_hd); - bs->backing_hd = NULL; + BlockDriverState *backing_hd = bs->backing_hd; + bdrv_set_backing_hd(bs, NULL); + bdrv_unref(backing_hd); } bs->drv->bdrv_close(bs); g_free(bs->opaque); @@ -1926,7 +1944,6 @@ 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)); @@ -1945,7 +1962,6 @@ 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/block/mirror.c b/block/mirror.c index 0ef41f9..22ec5be 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -496,6 +496,7 @@ immediate_exit: * trigger the unref from the top one */ BlockDriverState *p = s->base->backing_hd; s->base->backing_hd = NULL; + bdrv_op_unblock_all(p, s->base->backing_blocker); bdrv_unref(p); } } diff --git a/include/block/block_int.h b/include/block/block_int.h index 025ee02..594df74 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); -- 1.9.1