From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59316) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGmnm-0003bn-10 for qemu-devel@nongnu.org; Mon, 20 Nov 2017 09:12:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eGmnl-0004de-1u for qemu-devel@nongnu.org; Mon, 20 Nov 2017 09:11:58 -0500 From: Kevin Wolf Date: Mon, 20 Nov 2017 15:11:41 +0100 Message-Id: <20171120141141.24626-3-kwolf@redhat.com> In-Reply-To: <20171120141141.24626-1-kwolf@redhat.com> References: <20171120141141.24626-1-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH for-2.11 2/2] block: Don't request I/O permission with BDRV_O_NO_IO List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, famz@redhat.com, eblake@redhat.com, qemu-devel@nongnu.org 'qemu-img info' makes sense even when BLK_PERM_CONSISTENT_READ cannot be granted because of a block job in a running qemu process. It already sets BDRV_O_NO_IO to indicate that it doesn't access the guest visible data at all. Check the BDRV_O_NO_IO flags in blk_new_open(), so that I/O related permissions are not unnecessarily requested and 'qemu-img info' can work even if BLK_PERM_CONSISTENT_READ cannot be granted. Signed-off-by: Kevin Wolf --- block/block-backend.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 5836cb3087..baef8e7abc 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -299,7 +299,7 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, { BlockBackend *blk; BlockDriverState *bs; - uint64_t perm; + uint64_t perm = 0; /* blk_new_open() is mainly used in .bdrv_create implementations and the * tools where sharing isn't a concern because the BDS stays private, so we @@ -309,9 +309,11 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, * caller of blk_new_open() doesn't make use of the permissions, but they * shouldn't hurt either. We can still share everything here because the * guest devices will add their own blockers if they can't share. */ - perm = BLK_PERM_CONSISTENT_READ; - if (flags & BDRV_O_RDWR) { - perm |= BLK_PERM_WRITE; + if ((flags & BDRV_O_NO_IO) == 0) { + perm |= BLK_PERM_CONSISTENT_READ; + if (flags & BDRV_O_RDWR) { + perm |= BLK_PERM_WRITE; + } } if (flags & BDRV_O_RESIZE) { perm |= BLK_PERM_RESIZE; -- 2.13.6