From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47620) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vl9uY-0007Sl-Ra for qemu-devel@nongnu.org; Mon, 25 Nov 2013 23:06:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Vl9uS-00011K-0q for qemu-devel@nongnu.org; Mon, 25 Nov 2013 23:06:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:4554) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vl9uR-000117-Oi for qemu-devel@nongnu.org; Mon, 25 Nov 2013 23:05:59 -0500 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 rAQ45xoL014910 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 25 Nov 2013 23:05:59 -0500 From: Fam Zheng Date: Tue, 26 Nov 2013 12:05:26 +0800 Message-Id: <1385438728-17924-6-git-send-email-famz@redhat.com> In-Reply-To: <1385438728-17924-1-git-send-email-famz@redhat.com> References: <1385438728-17924-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v5 5/7] block: Parse "backing" option to reference existing BDS List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, hbrock@redhat.com, rjones@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Signed-off-by: Fam Zheng --- block.c | 31 ++++++++++++++++++++++++++++--- block/mirror.c | 2 +- include/block/block.h | 3 ++- include/block/block_int.h | 3 +++ 4 files changed, 34 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index c2ab6d8..d633f2b 100644 --- a/block.c +++ b/block.c @@ -959,18 +959,39 @@ fail: /* * Opens the backing file for a BlockDriverState if not yet open * + * If backing_bs is not NULL or empty, find the BDS by name and reference it as + * the backing_hd, in this case options is ignored. + * * options is a QDict of options to pass to the block drivers, or NULL for an * empty set of options. The reference to the QDict is transferred to this * function (even on failure), so if the caller intends to reuse the dictionary, * it needs to use QINCREF() before calling bdrv_file_open. */ -int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) +int bdrv_open_backing_file(BlockDriverState *bs, const char *backing_bs, + QDict *options, Error **errp) { char backing_filename[PATH_MAX]; int back_flags, ret; BlockDriver *back_drv = NULL; Error *local_err = NULL; + if (backing_bs && *backing_bs != '\0') { + bs->backing_hd = bdrv_find(backing_bs); + if (!bs->backing_hd) { + error_setg(errp, "Backing device not found: %s", backing_bs); + return -ENOENT; + } + bdrv_ref(bs->backing_hd); + assert(!bs->backing_blocker); + error_setg(&bs->backing_blocker, + "device is used as backing hd of '%s'", + bs->device_name); + bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); + pstrcpy(bs->backing_file, sizeof(bs->backing_file), + bs->backing_hd->filename); + pstrcpy(bs->backing_format, sizeof(bs->backing_format), + bs->backing_hd->drv->format_name); + } if (bs->backing_hd != NULL) { QDECREF(options); return 0; @@ -1166,9 +1187,11 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, /* If there is a backing file, use it */ if ((flags & BDRV_O_NO_BACKING) == 0) { QDict *backing_options; - qdict_extract_subqdict(options, &backing_options, "backing."); - ret = bdrv_open_backing_file(bs, backing_options, &local_err); + ret = bdrv_open_backing_file(bs, qdict_get_try_str(options, "backing"), + backing_options, &local_err); + + qdict_del(options, "backing"); if (ret < 0) { goto close_and_fail; } @@ -1461,6 +1484,8 @@ void bdrv_close(BlockDriverState *bs) if (bs->drv) { if (bs->backing_hd) { + bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker); + error_free(bs->backing_blocker); bdrv_unref(bs->backing_hd); bs->backing_hd = NULL; } diff --git a/block/mirror.c b/block/mirror.c index 7b95acf..ce0103a 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -508,7 +508,7 @@ static void mirror_complete(BlockJob *job, Error **errp) Error *local_err = NULL; int ret; - ret = bdrv_open_backing_file(s->target, NULL, &local_err); + ret = bdrv_open_backing_file(s->target, NULL, NULL, &local_err); if (ret < 0) { char backing_filename[PATH_MAX]; bdrv_get_full_backing_filename(s->target, backing_filename, diff --git a/include/block/block.h b/include/block/block.h index 173c09a..e6ec03e 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -157,7 +157,8 @@ 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); -int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp); +int bdrv_open_backing_file(BlockDriverState *bs, const char *backing_bs, + QDict *options, Error **errp); int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, int flags, BlockDriver *drv, Error **errp); BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, diff --git a/include/block/block_int.h b/include/block/block_int.h index 60edc80..6db30c9 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -316,6 +316,9 @@ struct BlockDriverState { BlockJob *job; QDict *options; + + /* For backing reference, block the operations of named backing device */ + Error *backing_blocker; }; int get_tmp_filename(char *filename, int size); -- 1.8.4.2