From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59331) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdKLw-0003E6-Kh for qemu-devel@nongnu.org; Mon, 13 Feb 2017 12:23:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cdKLt-000680-Vu for qemu-devel@nongnu.org; Mon, 13 Feb 2017 12:23:52 -0500 From: Kevin Wolf Date: Mon, 13 Feb 2017 18:22:39 +0100 Message-Id: <1487006583-24350-18-git-send-email-kwolf@redhat.com> In-Reply-To: <1487006583-24350-1-git-send-email-kwolf@redhat.com> References: <1487006583-24350-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [RFC PATCH 17/41] block: Request real permissions in blk_new_open() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-devel@nongnu.org We can figure out the necessary permissions from the flags that the caller passed. Signed-off-by: Kevin Wolf --- block/block-backend.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 1f80854..e10a278 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -160,6 +160,7 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, { BlockBackend *blk; BlockDriverState *bs; + uint64_t perm; blk = blk_new(0, BLK_PERM_ALL); bs = bdrv_open(filename, reference, options, flags, errp); @@ -168,9 +169,20 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, return NULL; } - /* FIXME Use real permissions */ + /* 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 + * just request permission according to the flags. + * + * The exceptions are xen_disk and blockdev_init(); in these cases, the + * 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; + } blk->root = bdrv_root_attach_child(bs, "root", &child_root, - 0, BLK_PERM_ALL, blk, &error_abort); + perm, BLK_PERM_ALL, blk, &error_abort); return blk; } -- 1.8.3.1