From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58774) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzGXb-0007Lb-LO for qemu-devel@nongnu.org; Mon, 23 Jun 2014 22:33:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzGXS-000418-Cw for qemu-devel@nongnu.org; Mon, 23 Jun 2014 22:32:59 -0400 Message-ID: <53A8E34B.40607@gmail.com> Date: Tue, 24 Jun 2014 10:32:43 +0800 From: Chen Gang MIME-Version: 1.0 References: <53A84797.9040304@gmail.com> <20140624022547.GC26197@T430.redhat.com> In-Reply-To: <20140624022547.GC26197@T430.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH trivial v2] block.c: Add return value for bdrv_append_temp_snapshot() to avoid incorrect failure processing issue List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: Kevin Wolf , qemu-trivial@nongnu.org, Michael Tokarev , qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com On 06/24/2014 10:25 AM, Fam Zheng wrote: > On Mon, 06/23 23:28, Chen Gang wrote: >> When failure occurs, 'ret' need be set, or may return 0 to indicate success. > > s/need/needs/ > >> And error_propagate() also need be called only one time within a function. > > s/need/needs/ > For a grammar in my learning, in this situation, 'need' is not a verb, "be set" and "be called" are the verb used with passive mode. >> >> It is abnormal to prevent bdrv_append_temp_snapshot() return value but still >> set errp when error occurs -- although it contents return value internally. > > s/contents/has/ > OK, thanks, and excuse me for my poor English. If necessary I shall send patch v2 for it. >> >> So let bdrv_append_temp_snapshot() internal return value outside, and let >> all things normal, then fix the issue too. >> >> >> Signed-off-by: Chen Gang >> --- >> block.c | 7 ++++--- >> include/block/block.h | 2 +- >> 2 files changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/block.c b/block.c >> index 74af8d7..5e4fb60 100644 >> --- a/block.c >> +++ b/block.c >> @@ -1240,7 +1240,7 @@ done: >> return ret; >> } >> >> -void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) >> +int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) >> { >> /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ >> char *tmp_filename = g_malloc0(PATH_MAX + 1); >> @@ -1258,6 +1258,7 @@ void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) >> /* Get the required size from the image */ >> total_size = bdrv_getlength(bs); >> if (total_size < 0) { >> + ret = total_size; >> error_setg_errno(errp, -total_size, "Could not get image size"); >> goto out; >> } >> @@ -1304,6 +1305,7 @@ void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) >> >> out: >> g_free(tmp_filename); >> + return ret; >> } >> >> static QDict *parse_json_filename(const char *filename, Error **errp) >> @@ -1495,9 +1497,8 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, >> /* For snapshot=on, create a temporary qcow2 overlay. bs points to the >> * temporary snapshot afterwards. */ >> if (snapshot_flags) { >> - bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err); >> + ret = bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err); >> if (local_err) { >> - error_propagate(errp, local_err); >> goto close_and_fail; >> } >> } >> diff --git a/include/block/block.h b/include/block/block.h >> index f15b99b..7b3381c 100644 >> --- a/include/block/block.h >> +++ b/include/block/block.h >> @@ -217,7 +217,7 @@ int bdrv_open_image(BlockDriverState **pbs, const char *filename, >> bool allow_none, Error **errp); >> void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd); >> int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp); >> -void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp); >> +int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp); > > Not used outside block.c, but pre-existing. > Yeah, originally, I considered about it, and finally still remained it as pre-existing. > Reviewed-by: Fam Zheng > Thank you for your work. Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed