From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42817) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0k3F-00020J-B8 for qemu-devel@nongnu.org; Tue, 07 Jan 2014 22:43:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W0k39-0002Xx-Bm for qemu-devel@nongnu.org; Tue, 07 Jan 2014 22:43:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:63887) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0k38-0002Xt-TS for qemu-devel@nongnu.org; Tue, 07 Jan 2014 22:43:23 -0500 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s083hMV9020148 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 7 Jan 2014 22:43:22 -0500 From: Fam Zheng Date: Wed, 8 Jan 2014 11:42:44 +0800 Message-Id: <1389152570-1815-6-git-send-email-famz@redhat.com> In-Reply-To: <1389152570-1815-1-git-send-email-famz@redhat.com> References: <1389152570-1815-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v10 05/11] block: Add bdrv_set_backing_hd() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, rjones@redhat.com, armbru@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com This is the common but non-trivial steps to assign or change the backing_hd of BDS. Signed-off-by: Fam Zheng --- block.c | 34 ++++++++++++++++++++++++++++------ include/block/block.h | 1 + 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/block.c b/block.c index b122154..ff25749 100644 --- a/block.c +++ b/block.c @@ -958,6 +958,29 @@ fail: return ret; } +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) +{ + if (bs->backing_hd) { + bdrv_unref(bs->backing_hd); + } + + bs->backing_hd = backing_hd; + if (!backing_hd) { + bs->backing_file[0] = '\0'; + bs->backing_format[0] = '\0'; + return; + } + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); + pstrcpy(bs->backing_format, sizeof(bs->backing_file), + backing_hd->drv ? backing_hd->drv->format_name : ""); + bdrv_ref(bs->backing_hd); + + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + bs->backing_hd->file->filename); + pstrcpy(bs->backing_format, sizeof(bs->backing_format), + bs->backing_hd->drv->format_name); +} + /* * Opens the backing file for a BlockDriverState if not yet open * @@ -971,6 +994,7 @@ 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) { @@ -994,7 +1018,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) sizeof(backing_filename)); } - bs->backing_hd = bdrv_new(""); + backing_hd = bdrv_new(""); if (bs->backing_format[0] != '\0') { back_drv = bdrv_find_format(bs->backing_format); @@ -1004,20 +1028,18 @@ 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); - ret = bdrv_open(bs->backing_hd, + ret = bdrv_open(backing_hd, *backing_filename ? backing_filename : NULL, options, back_flags, back_drv, &local_err); if (ret < 0) { - bdrv_unref(bs->backing_hd); - bs->backing_hd = NULL; + bdrv_unref(backing_hd); 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; } - pstrcpy(bs->backing_file, sizeof(bs->backing_file), - bs->backing_hd->file->filename); + bdrv_set_backing_hd(bs, backing_hd); return 0; } diff --git a/include/block/block.h b/include/block/block.h index 5339f92..4ec0069 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -204,6 +204,7 @@ int bdrv_parse_cache_flags(const char *mode, int *flags); int bdrv_parse_discard_flags(const char *mode, int *flags); int bdrv_file_open(BlockDriverState **pbs, const char *filename, QDict *options, int flags, 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 *bs, const char *filename, QDict *options, int flags, BlockDriver *drv, Error **errp); -- 1.8.5.1