From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59752) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WWx0K-0001uN-35 for qemu-devel@nongnu.org; Sun, 06 Apr 2014 20:01:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WWx0D-0003XF-TE for qemu-devel@nongnu.org; Sun, 06 Apr 2014 20:01:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49225) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WWx0D-0003X8-Kz for qemu-devel@nongnu.org; Sun, 06 Apr 2014 20:01:29 -0400 Date: Sun, 6 Apr 2014 20:01:23 -0400 From: Jeff Cody Message-ID: <20140407000123.GC6752@localhost.localdomain> References: <1394436370-8908-1-git-send-email-famz@redhat.com> <1394436370-8908-6-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1394436370-8908-6-git-send-email-famz@redhat.com> Subject: Re: [Qemu-devel] [PATCH v17 05/14] block: Add bdrv_set_backing_hd() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, benoit.canet@irqsave.net, rjones@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org, ptoscano@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com On Mon, Mar 10, 2014 at 03:26:01PM +0800, Fam Zheng wrote: > This is the common but non-trivial steps to assign or change the > backing_hd of BDS. > > Signed-off-by: Fam Zheng Reviewed-by: Jeff Cody > --- > block.c | 39 +++++++++++++++++++++++++-------------- > include/block/block.h | 1 + > 2 files changed, 26 insertions(+), 14 deletions(-) > > diff --git a/block.c b/block.c > index c79d5dc..64738dc 100644 > --- a/block.c > +++ b/block.c > @@ -1047,6 +1047,23 @@ fail: > return ret; > } > > +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) > +{ > + > + bs->backing_hd = backing_hd; > + if (!backing_hd) { > + bs->backing_file[0] = '\0'; > + bs->backing_format[0] = '\0'; > + goto out; > + } > + bs->open_flags &= ~BDRV_O_NO_BACKING; > + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); > + pstrcpy(bs->backing_format, sizeof(bs->backing_format), > + backing_hd->drv ? backing_hd->drv->format_name : ""); > +out: > + bdrv_refresh_limits(bs); > +} > + > /* > * Opens the backing file for a BlockDriverState if not yet open > * > @@ -1060,6 +1077,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) > char backing_filename[PATH_MAX]; > int back_flags, ret; > BlockDriver *back_drv = NULL; > + BlockDriverState *backing_hd; > Error *local_err = NULL; > > if (bs->backing_hd != NULL) { > @@ -1083,6 +1101,8 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) > sizeof(backing_filename)); > } > > + backing_hd = bdrv_new(""); > + > if (bs->backing_format[0] != '\0') { > back_drv = bdrv_find_format(bs->backing_format); > } > @@ -1091,23 +1111,19 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) > back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | > BDRV_O_COPY_ON_READ); > > - assert(bs->backing_hd == NULL); > - ret = bdrv_open(&bs->backing_hd, > + ret = bdrv_open(&backing_hd, > *backing_filename ? backing_filename : NULL, NULL, options, > back_flags, back_drv, &local_err); > if (ret < 0) { > - bs->backing_hd = NULL; > + bdrv_unref(backing_hd); > + backing_hd = NULL; > bs->open_flags |= BDRV_O_NO_BACKING; > error_setg(errp, "Could not open backing file: %s", > error_get_pretty(local_err)); > error_free(local_err); > return ret; > } > - > - if (bs->backing_hd->file) { > - pstrcpy(bs->backing_file, sizeof(bs->backing_file), > - bs->backing_hd->file->filename); > - } > + bdrv_set_backing_hd(bs, backing_hd); > > /* Recalculate the BlockLimits with the backing file */ > bdrv_refresh_limits(bs); > @@ -1944,12 +1960,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) > > /* The contents of 'tmp' will become bs_top, as we are > * swapping bs_new and bs_top contents. */ > - bs_top->backing_hd = bs_new; > - bs_top->open_flags &= ~BDRV_O_NO_BACKING; > - pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file), > - bs_new->filename); > - pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format), > - bs_new->drv ? bs_new->drv->format_name : ""); > + bdrv_set_backing_hd(bs_top, bs_new); > } > > static void bdrv_delete(BlockDriverState *bs) > diff --git a/include/block/block.h b/include/block/block.h > index a46f70a..ee1582d 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -208,6 +208,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags); > int bdrv_open_image(BlockDriverState **pbs, const char *filename, > QDict *options, const char *bdref_key, int flags, > 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); > int bdrv_open(BlockDriverState **pbs, const char *filename, > const char *reference, QDict *options, int flags, > -- > 1.9.0 > >