From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34322) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YqNzr-00046m-6N for qemu-devel@nongnu.org; Thu, 07 May 2015 11:46:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YqNzl-0001dZ-AK for qemu-devel@nongnu.org; Thu, 07 May 2015 11:45:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53678) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YqNzl-0001cR-3P for qemu-devel@nongnu.org; Thu, 07 May 2015 11:45:53 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t47Fjpce006260 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 7 May 2015 11:45:52 -0400 From: Paolo Bonzini Date: Thu, 7 May 2015 17:45:48 +0200 Message-Id: <1431013548-22492-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH] block: return EPERM on writes or discards to read-only devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, mreitz@redhat.com This is the behavior in the operating system, for example Linux's blkdev_write_iter has the following: if (bdev_read_only(I_BDEV(bd_inode))) return -EPERM; This does not apply to opening a device for read/write, when the device only supports read-only operation. In this case any of EACCES, EPERM or EROFS is acceptable depending on why writing is not possible. Signed-off-by: Paolo Bonzini --- block/io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 1ce62c4..a05ad67 100644 --- a/block/io.c +++ b/block/io.c @@ -1205,7 +1205,7 @@ static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, return -ENOMEDIUM; } if (bs->read_only) { - return -EACCES; + return -EPERM; } ret = bdrv_check_byte_request(bs, offset, bytes); @@ -2340,7 +2340,7 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, if (ret < 0) { return ret; } else if (bs->read_only) { - return -EROFS; + return -EPERM; } bdrv_reset_dirty(bs, sector_num, nb_sectors); -- 2.3.5