From patchwork Tue Feb 28 12:54:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 9595725 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 732F8601D7 for ; Tue, 28 Feb 2017 14:10:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 66017284D0 for ; Tue, 28 Feb 2017 14:10:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5987328526; Tue, 28 Feb 2017 14:10:28 +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 AA4E2284D0 for ; Tue, 28 Feb 2017 14:10:27 +0000 (UTC) Received: from localhost ([::1]:33066 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciiTw-0005PP-CW for patchwork-qemu-devel@patchwork.kernel.org; Tue, 28 Feb 2017 09:10:24 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44201) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cihK0-0005F4-C1 for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:56:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cihJy-0004e5-Qm for qemu-devel@nongnu.org; Tue, 28 Feb 2017 07:56:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55302) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cihJt-0004ba-Ar; Tue, 28 Feb 2017 07:55:57 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5EFA5C057FA9; Tue, 28 Feb 2017 12:55:57 +0000 (UTC) Received: from noname.redhat.com (ovpn-116-177.ams2.redhat.com [10.36.116.177]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1SCsXQj029713; Tue, 28 Feb 2017 07:55:54 -0500 From: Kevin Wolf To: qemu-block@nongnu.org Date: Tue, 28 Feb 2017 13:54:28 +0100 Message-Id: <1488286469-9381-44-git-send-email-kwolf@redhat.com> In-Reply-To: <1488286469-9381-1-git-send-email-kwolf@redhat.com> References: <1488286469-9381-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 28 Feb 2017 12:55:57 +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 v3 43/44] block: Add Error parameter to bdrv_set_backing_hd() 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: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Not all callers of bdrv_set_backing_hd() know for sure that attaching the backing file will be allowed by the permission system. Return the error from the function rather than aborting. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz --- block.c | 30 +++++++++++++++++++++++------- block/commit.c | 14 +++++++------- block/mirror.c | 7 ++++++- block/stream.c | 9 ++++++++- block/vvfat.c | 2 +- include/block/block.h | 3 ++- 6 files changed, 47 insertions(+), 18 deletions(-) diff --git a/block.c b/block.c index 74ac7dc..6440b61 100644 --- a/block.c +++ b/block.c @@ -1883,7 +1883,8 @@ static void bdrv_parent_cb_resize(BlockDriverState *bs) * Sets the backing file link of a BDS. A new reference is created; callers * which don't need their own reference any more must call bdrv_unref(). */ -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, + Error **errp) { if (backing_hd) { bdrv_ref(backing_hd); @@ -1897,9 +1898,12 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) bs->backing = NULL; goto out; } - /* FIXME Error handling */ + bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing, - &error_abort); + errp); + if (!bs->backing) { + bdrv_unref(backing_hd); + } out: bdrv_refresh_limits(bs, NULL); @@ -1983,8 +1987,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ - bdrv_set_backing_hd(bs, backing_hd); + bdrv_set_backing_hd(bs, backing_hd, &local_err); bdrv_unref(backing_hd); + if (local_err) { + ret = -EINVAL; + goto free_exit; + } qdict_del(parent_options, bdref_key); @@ -2818,7 +2826,7 @@ static void bdrv_close(BlockDriverState *bs) bs->drv->bdrv_close(bs); bs->drv = NULL; - bdrv_set_backing_hd(bs, NULL); + bdrv_set_backing_hd(bs, NULL, &error_abort); if (bs->file != NULL) { bdrv_unref_child(bs, bs->file); @@ -2927,7 +2935,8 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) bdrv_ref(bs_top); change_parent_backing_link(bs_top, bs_new); - bdrv_set_backing_hd(bs_new, bs_top); + /* FIXME Error handling */ + bdrv_set_backing_hd(bs_new, bs_top, &error_abort); bdrv_unref(bs_top); /* bs_new is now referenced by its new parents, we don't need the @@ -3075,6 +3084,7 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, BlockDriverState *base, const char *backing_file_str) { BlockDriverState *new_top_bs = NULL; + Error *local_err = NULL; int ret = -EIO; if (!top->drv || !base->drv) { @@ -3107,7 +3117,13 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, if (ret) { goto exit; } - bdrv_set_backing_hd(new_top_bs, base); + + bdrv_set_backing_hd(new_top_bs, base, &local_err); + if (local_err) { + ret = -EPERM; + error_report_err(local_err); + goto exit; + } ret = 0; exit: diff --git a/block/commit.c b/block/commit.c index 1e0f531..22a0a4d 100644 --- a/block/commit.c +++ b/block/commit.c @@ -121,7 +121,7 @@ static void commit_complete(BlockJob *job, void *opaque) * filter driver from the backing chain. Do this as the final step so that * the 'consistent read' permission can be granted. */ if (remove_commit_top_bs) { - bdrv_set_backing_hd(overlay_bs, top); + bdrv_set_backing_hd(overlay_bs, top, &error_abort); } } @@ -316,8 +316,8 @@ void commit_start(const char *job_id, BlockDriverState *bs, goto fail; } - bdrv_set_backing_hd(commit_top_bs, top); - bdrv_set_backing_hd(overlay_bs, commit_top_bs); + bdrv_set_backing_hd(commit_top_bs, top, &error_abort); + bdrv_set_backing_hd(overlay_bs, commit_top_bs, &error_abort); s->commit_top_bs = commit_top_bs; bdrv_unref(commit_top_bs); @@ -390,7 +390,7 @@ fail: blk_unref(s->top); } if (commit_top_bs) { - bdrv_set_backing_hd(overlay_bs, top); + bdrv_set_backing_hd(overlay_bs, top, &error_abort); } block_job_unref(&s->common); } @@ -451,8 +451,8 @@ int bdrv_commit(BlockDriverState *bs) goto ro_cleanup; } - bdrv_set_backing_hd(commit_top_bs, backing_file_bs); - bdrv_set_backing_hd(bs, commit_top_bs); + bdrv_set_backing_hd(commit_top_bs, backing_file_bs, &error_abort); + bdrv_set_backing_hd(bs, commit_top_bs, &error_abort); ret = blk_insert_bs(backing, backing_file_bs, &local_err); if (ret < 0) { @@ -532,7 +532,7 @@ ro_cleanup: blk_unref(backing); if (backing_file_bs) { - bdrv_set_backing_hd(bs, backing_file_bs); + bdrv_set_backing_hd(bs, backing_file_bs, &error_abort); } bdrv_unref(commit_top_bs); blk_unref(src); diff --git a/block/mirror.c b/block/mirror.c index 9247ad9..e0475b4 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -503,6 +503,7 @@ static void mirror_exit(BlockJob *job, void *opaque) BlockDriverState *src = s->source; BlockDriverState *target_bs = blk_bs(s->target); BlockDriverState *mirror_top_bs = s->mirror_top_bs; + Error *local_err = NULL; /* Make sure that the source BDS doesn't go away before we called * block_job_completed(). */ @@ -516,7 +517,11 @@ static void mirror_exit(BlockJob *job, void *opaque) if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) { BlockDriverState *backing = s->is_none_mode ? src : s->base; if (backing_bs(target_bs) != backing) { - bdrv_set_backing_hd(target_bs, backing); + bdrv_set_backing_hd(target_bs, backing, &local_err); + if (local_err) { + error_report_err(local_err); + data->ret = -EPERM; + } } } diff --git a/block/stream.c b/block/stream.c index b9c2f43..0113710 100644 --- a/block/stream.c +++ b/block/stream.c @@ -68,6 +68,7 @@ static void stream_complete(BlockJob *job, void *opaque) StreamCompleteData *data = opaque; BlockDriverState *bs = blk_bs(job->blk); BlockDriverState *base = s->base; + Error *local_err = NULL; if (!block_job_is_cancelled(&s->common) && data->reached_end && data->ret == 0) { @@ -79,9 +80,15 @@ static void stream_complete(BlockJob *job, void *opaque) } } data->ret = bdrv_change_backing_file(bs, base_id, base_fmt); - bdrv_set_backing_hd(bs, base); + bdrv_set_backing_hd(bs, base, &local_err); + if (local_err) { + error_report_err(local_err); + data->ret = -EPERM; + goto out; + } } +out: /* Reopen the image back in read-only mode if necessary */ if (s->bs_flags != bdrv_get_flags(bs)) { /* Give up write permissions before making it read-only */ diff --git a/block/vvfat.c b/block/vvfat.c index 72b482c..aa61c32 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -3041,7 +3041,7 @@ static int enable_write_target(BlockDriverState *bs, Error **errp) &error_abort); *(void**) backing->opaque = s; - bdrv_set_backing_hd(s->bs, backing); + bdrv_set_backing_hd(s->bs, backing, &error_abort); bdrv_unref(backing); return 0; diff --git a/include/block/block.h b/include/block/block.h index 07f7561..eac2861 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -247,7 +247,8 @@ BdrvChild *bdrv_open_child(const char *filename, BlockDriverState* parent, const BdrvChildRole *child_role, bool allow_none, Error **errp); -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd); +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, + Error **errp); int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, const char *bdref_key, Error **errp); BlockDriverState *bdrv_open(const char *filename, const char *reference,