From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59800) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VoyPb-0007pD-HL for qemu-devel@nongnu.org; Fri, 06 Dec 2013 11:38:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VoyPV-0003Sq-HI for qemu-devel@nongnu.org; Fri, 06 Dec 2013 11:37:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45820) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VoyPV-0003Sm-7a for qemu-devel@nongnu.org; Fri, 06 Dec 2013 11:37:49 -0500 From: Stefan Hajnoczi Date: Fri, 6 Dec 2013 17:36:22 +0100 Message-Id: <1386347807-27359-24-git-send-email-stefanha@redhat.com> In-Reply-To: <1386347807-27359-1-git-send-email-stefanha@redhat.com> References: <1386347807-27359-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PULL 23/48] block: Close backing file early in bdrv_img_create List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Anthony Liguori , Max Reitz From: Max Reitz Leaving the backing file open although it is not needed anymore can cause problems if it is opened through a block driver which allows exclusive access only and if the create function of the block driver used for the top image (the one being created) tries to close and reopen the image file (which will include opening the backing file a second time). In particular, this will happen with a backing file opened through qemu-nbd and using qcow2 as the top image file format (which reopens the image to flush it to disk). In addition, the BlockDriverState in bdrv_img_create() is used for the backing file only; it should therefore be made local to the respective block. Signed-off-by: Max Reitz Reviewed-by: Kevin Wolf Reviewed-by: Wenchao Xia Signed-off-by: Stefan Hajnoczi --- block.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block.c b/block.c index 831c150..1c83ef1 100644 --- a/block.c +++ b/block.c @@ -4713,7 +4713,6 @@ void bdrv_img_create(const char *filename, const char *fmt, { QEMUOptionParameter *param = NULL, *create_options = NULL; QEMUOptionParameter *backing_fmt, *backing_file, *size; - BlockDriverState *bs = NULL; BlockDriver *drv, *proto_drv; BlockDriver *backing_drv = NULL; Error *local_err = NULL; @@ -4792,6 +4791,7 @@ void bdrv_img_create(const char *filename, const char *fmt, size = get_option_parameter(param, BLOCK_OPT_SIZE); if (size && size->value.n == -1) { if (backing_file && backing_file->value.s) { + BlockDriverState *bs; uint64_t size; char buf[32]; int back_flags; @@ -4810,6 +4810,7 @@ void bdrv_img_create(const char *filename, const char *fmt, error_get_pretty(local_err)); error_free(local_err); local_err = NULL; + bdrv_unref(bs); goto out; } bdrv_get_geometry(bs, &size); @@ -4817,6 +4818,8 @@ void bdrv_img_create(const char *filename, const char *fmt, snprintf(buf, sizeof(buf), "%" PRId64, size); set_option_parameter(param, BLOCK_OPT_SIZE, buf); + + bdrv_unref(bs); } else { error_setg(errp, "Image creation needs a size parameter"); goto out; @@ -4847,9 +4850,6 @@ out: free_option_parameters(create_options); free_option_parameters(param); - if (bs) { - bdrv_unref(bs); - } if (error_is_set(&local_err)) { error_propagate(errp, local_err); } -- 1.8.4.2