From patchwork Mon Nov 20 20:09:50 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 10067195 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 57B6D603FA for ; Mon, 20 Nov 2017 20:17:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 49CD0292FA for ; Mon, 20 Nov 2017 20:17:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3E74829323; Mon, 20 Nov 2017 20:17:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C3CB6292FA for ; Mon, 20 Nov 2017 20:17:34 +0000 (UTC) Received: from localhost ([::1]:59526 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGsVZ-0004s6-SG for patchwork-qemu-devel@patchwork.kernel.org; Mon, 20 Nov 2017 15:17:33 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35197) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGsPM-0008Qh-9q for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:11:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eGsPH-00079X-Ve for qemu-devel@nongnu.org; Mon, 20 Nov 2017 15:11:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43360) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eGsPF-00078B-BY; Mon, 20 Nov 2017 15:11:01 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 897D7680EE; Mon, 20 Nov 2017 20:11:00 +0000 (UTC) Received: from localhost (ovpn-204-75.brq.redhat.com [10.40.204.75]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 631D560171; Mon, 20 Nov 2017 20:10:58 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Mon, 20 Nov 2017 21:09:50 +0100 Message-Id: <20171120201004.14999-12-mreitz@redhat.com> In-Reply-To: <20171120201004.14999-1-mreitz@redhat.com> References: <20171120201004.14999-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 20 Nov 2017 20:11:00 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v7 for-2.12 11/25] block: Add bdrv_dirname() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Alberto Garcia , John Snow , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP This function may be implemented by block drivers to derive a directory name from a BDS. Concatenating this g_free()-able string with a relative filename must result in a valid (not necessarily existing) filename, so this is a function that should generally be not implemented by format drivers, because this is protocol-specific. If a BDS's driver does not implement this function, bdrv_dirname() will fall through to the BDS's file if it exists. If it does not, the exact_filename field will be used to generate a directory name. Signed-off-by: Max Reitz Reviewed-by: Alberto Garcia --- include/block/block.h | 1 + include/block/block_int.h | 7 +++++++ block.c | 26 ++++++++++++++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/include/block/block.h b/include/block/block.h index 3e2ea6c879..a053a27148 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -485,6 +485,7 @@ char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp); char *bdrv_get_full_backing_filename_from_filename(const char *backed, const char *backing, Error **errp); +char *bdrv_dirname(BlockDriverState *bs, Error **errp); int path_has_protocol(const char *path); int path_is_absolute(const char *path); diff --git a/include/block/block_int.h b/include/block/block_int.h index 5e9734d8b5..c07882962d 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -135,6 +135,13 @@ struct BlockDriver { void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options); + /* + * Returns an allocated string which is the directory name of this BDS: It + * will be used to make relative filenames absolute by prepending this + * function's return value to them. + */ + char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp); + /* aio */ BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, diff --git a/block.c b/block.c index ecea78dae0..20e45c85c6 100644 --- a/block.c +++ b/block.c @@ -5098,6 +5098,32 @@ void bdrv_refresh_filename(BlockDriverState *bs) } } +char *bdrv_dirname(BlockDriverState *bs, Error **errp) +{ + BlockDriver *drv = bs->drv; + + if (!drv) { + error_setg(errp, "Node '%s' is ejected", bs->node_name); + return NULL; + } + + if (drv->bdrv_dirname) { + return drv->bdrv_dirname(bs, errp); + } + + if (bs->file) { + return bdrv_dirname(bs->file->bs, errp); + } + + if (bs->exact_filename[0] != '\0') { + return path_combine(bs->exact_filename, ""); + } + + error_setg(errp, "Cannot generate a base directory for %s nodes", + drv->format_name); + return NULL; +} + /* * Hot add/remove a BDS's child. So the user can take a child offline when * it is broken and take a new child online