From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42125) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agCGH-0003AY-Ph for qemu-devel@nongnu.org; Wed, 16 Mar 2016 10:17:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1agCGG-000658-6v for qemu-devel@nongnu.org; Wed, 16 Mar 2016 10:17:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35778) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1agCGG-000653-1a for qemu-devel@nongnu.org; Wed, 16 Mar 2016 10:17:20 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id BF8CA7F0B0 for ; Wed, 16 Mar 2016 14:17:19 +0000 (UTC) From: Paolo Bonzini Date: Wed, 16 Mar 2016 15:16:52 +0100 Message-Id: <1458137817-15383-12-git-send-email-pbonzini@redhat.com> In-Reply-To: <1458137817-15383-1-git-send-email-pbonzini@redhat.com> References: <1458137817-15383-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH v2 11/16] sheepdog: disable dataplane List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: famz@redhat.com, stefanha@redhat.com sheepdog has some calls to aio_poll that are hard to eliminate, for example in sd_sheepdog_goto's call to do_req. Since I don't have means to test sheepdog well, disable dataplane altogether for this driver. Reviewed-by: Fam Zheng Signed-off-by: Paolo Bonzini --- block/sheepdog.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/block/sheepdog.c b/block/sheepdog.c index a6e98a5..8ced3e5 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -364,6 +364,7 @@ struct SheepdogAIOCB { typedef struct BDRVSheepdogState { BlockDriverState *bs; AioContext *aio_context; + Error *blocker; SheepdogInode inode; @@ -1422,6 +1423,21 @@ static int sd_open(BlockDriverState *bs, QDict *options, int flags, Error *local_err = NULL; const char *filename; + /* sd_snapshot_goto does blocking operations that call aio_poll + * (through do_req). This can cause races with iothread: + * + * main thread I/O thread + * ----------------- ------------------ + * while(srco.finished == false) + * aio_poll(..., true) + * srco.finished = true + * aio_poll(..., true) + * + * Now aio_poll potentially blocks forever. + */ + error_setg(&s->blocker, "sheepdog does not support iothreads"); + bdrv_op_block(bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker); + s->bs = bs; s->aio_context = bdrv_get_aio_context(bs); @@ -1962,6 +1978,9 @@ static void sd_close(BlockDriverState *bs) false, NULL, NULL, NULL); closesocket(s->fd); g_free(s->host_spec); + + bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker); + error_free(s->blocker); } static int64_t sd_getlength(BlockDriverState *bs) -- 1.8.3.1