From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57942) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzGQW-0005ES-Br for qemu-devel@nongnu.org; Mon, 23 Jun 2014 22:25:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzGQQ-0002GQ-4G for qemu-devel@nongnu.org; Mon, 23 Jun 2014 22:25:40 -0400 Date: Tue, 24 Jun 2014 10:25:47 +0800 From: Fam Zheng Message-ID: <20140624022547.GC26197@T430.redhat.com> References: <53A84797.9040304@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53A84797.9040304@gmail.com> 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: Chen Gang Cc: Kevin Wolf , qemu-trivial@nongnu.org, Michael Tokarev , qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com 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/ > > 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/ > > 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. Reviewed-by: Fam Zheng Fam > int bdrv_open(BlockDriverState **pbs, const char *filename, > const char *reference, QDict *options, int flags, > BlockDriver *drv, Error **errp); > -- > 1.7.11.7