From patchwork Thu Jun 25 15:22:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 279437 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2312FC433E0 for ; Thu, 25 Jun 2020 15:44:06 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DDF1A20706 for ; Thu, 25 Jun 2020 15:44:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DF6OJmWg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDF1A20706 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36764 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1joU2n-0002VU-5N for qemu-devel@archiver.kernel.org; Thu, 25 Jun 2020 11:44:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37936) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joTj9-0006hW-41 for qemu-devel@nongnu.org; Thu, 25 Jun 2020 11:23:47 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:27852 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1joTj7-0001Pc-AZ for qemu-devel@nongnu.org; Thu, 25 Jun 2020 11:23:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593098624; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pfZPe2A0gMy19xNoNvyJo6Hg83Fvr4rLDGbzuj1bsDg=; b=DF6OJmWg0PD1Q/3HaD1T/dMMiIKgId/NczHkuKT+wEO1p6aFqBBZAUXWmW33Pf/KcUMZ81 OzWGW8OB/KmvZ+O81zENhbk/WbGu1ZjkI7V0di7cB9+o+pddHQkFUWqQ1BGDaxdB1si+3s /X8pm5oGeDfuET8nmPhgSSMR54sblKQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-349--APkIY4yOJi1zkscek-RaA-1; Thu, 25 Jun 2020 11:23:39 -0400 X-MC-Unique: -APkIY4yOJi1zkscek-RaA-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 46C40464; Thu, 25 Jun 2020 15:23:36 +0000 (UTC) Received: from localhost (ovpn-113-182.ams2.redhat.com [10.36.113.182]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B3A961DC; Thu, 25 Jun 2020 15:23:35 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v7 35/47] commit: Deal with filters Date: Thu, 25 Jun 2020 17:22:03 +0200 Message-Id: <20200625152215.941773-36-mreitz@redhat.com> In-Reply-To: <20200625152215.941773-1-mreitz@redhat.com> References: <20200625152215.941773-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/25 02:30:11 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This includes some permission limiting (for example, we only need to take the RESIZE permission if the base is smaller than the top). Signed-off-by: Max Reitz --- block/block-backend.c | 9 +++- block/commit.c | 96 +++++++++++++++++++++++++--------- block/monitor/block-hmp-cmds.c | 2 +- blockdev.c | 4 +- 4 files changed, 81 insertions(+), 30 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index 6936b25c83..7f2c7dbccc 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -2271,8 +2271,13 @@ int blk_commit_all(void) AioContext *aio_context = blk_get_aio_context(blk); aio_context_acquire(aio_context); - if (blk_is_inserted(blk) && blk->root->bs->backing) { - int ret = bdrv_commit(blk->root->bs); + if (blk_is_inserted(blk)) { + BlockDriverState *non_filter; + int ret; + + /* Legacy function, so skip implicit filters */ + non_filter = bdrv_skip_implicit_filters(blk->root->bs); + ret = bdrv_commit(non_filter); if (ret < 0) { aio_context_release(aio_context); return ret; diff --git a/block/commit.c b/block/commit.c index 7732d02dfe..4122b6736d 100644 --- a/block/commit.c +++ b/block/commit.c @@ -37,6 +37,7 @@ typedef struct CommitBlockJob { BlockBackend *top; BlockBackend *base; BlockDriverState *base_bs; + BlockDriverState *base_overlay; BlockdevOnError on_error; bool base_read_only; bool chain_frozen; @@ -89,7 +90,7 @@ static void commit_abort(Job *job) * XXX Can (or should) we somehow keep 'consistent read' blocked even * after the failed/cancelled commit job is gone? If we already wrote * something to base, the intermediate images aren't valid any more. */ - bdrv_replace_node(s->commit_top_bs, backing_bs(s->commit_top_bs), + bdrv_replace_node(s->commit_top_bs, s->commit_top_bs->backing->bs, &error_abort); bdrv_unref(s->commit_top_bs); @@ -153,7 +154,7 @@ static int coroutine_fn commit_run(Job *job, Error **errp) break; } /* Copy if allocated above the base */ - ret = bdrv_is_allocated_above(blk_bs(s->top), blk_bs(s->base), false, + ret = bdrv_is_allocated_above(blk_bs(s->top), s->base_overlay, true, offset, COMMIT_BUFFER_SIZE, &n); copy = (ret == 1); trace_commit_one_iteration(s, offset, n, ret); @@ -253,15 +254,35 @@ void commit_start(const char *job_id, BlockDriverState *bs, CommitBlockJob *s; BlockDriverState *iter; BlockDriverState *commit_top_bs = NULL; + BlockDriverState *filtered_base; Error *local_err = NULL; + int64_t base_size, top_size; + uint64_t perms, iter_shared_perms; int ret; assert(top != bs); - if (top == base) { + if (bdrv_skip_filters(top) == bdrv_skip_filters(base)) { error_setg(errp, "Invalid files for merge: top and base are the same"); return; } + base_size = bdrv_getlength(base); + if (base_size < 0) { + error_setg_errno(errp, -base_size, "Could not inquire base image size"); + return; + } + + top_size = bdrv_getlength(top); + if (top_size < 0) { + error_setg_errno(errp, -top_size, "Could not inquire top image size"); + return; + } + + perms = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE; + if (base_size < top_size) { + perms |= BLK_PERM_RESIZE; + } + s = block_job_create(job_id, &commit_job_driver, NULL, bs, 0, BLK_PERM_ALL, speed, creation_flags, NULL, NULL, errp); if (!s) { @@ -301,17 +322,43 @@ void commit_start(const char *job_id, BlockDriverState *bs, s->commit_top_bs = commit_top_bs; - /* Block all nodes between top and base, because they will - * disappear from the chain after this operation. */ - assert(bdrv_chain_contains(top, base)); - for (iter = top; iter != base; iter = backing_bs(iter)) { - /* XXX BLK_PERM_WRITE needs to be allowed so we don't block ourselves - * at s->base (if writes are blocked for a node, they are also blocked - * for its backing file). The other options would be a second filter - * driver above s->base. */ + /* + * Block all nodes between top and base, because they will + * disappear from the chain after this operation. + * Note that this assumes that the user is fine with removing all + * nodes (including R/W filters) between top and base. Assuring + * this is the responsibility of the interface (i.e. whoever calls + * commit_start()). + */ + s->base_overlay = bdrv_find_overlay(top, base); + assert(s->base_overlay); + + /* + * The topmost node with + * bdrv_skip_filters(filtered_base) == bdrv_skip_filters(base) + */ + filtered_base = bdrv_cow_bs(s->base_overlay); + assert(bdrv_skip_filters(filtered_base) == bdrv_skip_filters(base)); + + /* + * XXX BLK_PERM_WRITE needs to be allowed so we don't block ourselves + * at s->base (if writes are blocked for a node, they are also blocked + * for its backing file). The other options would be a second filter + * driver above s->base. + */ + iter_shared_perms = BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE; + + for (iter = top; iter != base; iter = bdrv_filter_or_cow_bs(iter)) { + if (iter == filtered_base) { + /* + * From here on, all nodes are filters on the base. This + * allows us to share BLK_PERM_CONSISTENT_READ. + */ + iter_shared_perms |= BLK_PERM_CONSISTENT_READ; + } + ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0, - BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE, - errp); + iter_shared_perms, errp); if (ret < 0) { goto fail; } @@ -328,9 +375,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, } s->base = blk_new(s->common.job.aio_context, - BLK_PERM_CONSISTENT_READ - | BLK_PERM_WRITE - | BLK_PERM_RESIZE, + perms, BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | BLK_PERM_WRITE_UNCHANGED); @@ -398,19 +443,22 @@ int bdrv_commit(BlockDriverState *bs) if (!drv) return -ENOMEDIUM; - if (!bs->backing) { + backing_file_bs = bdrv_cow_bs(bs); + + if (!backing_file_bs) { return -ENOTSUP; } if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) || - bdrv_op_is_blocked(bs->backing->bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) { + bdrv_op_is_blocked(backing_file_bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) + { return -EBUSY; } - ro = bs->backing->bs->read_only; + ro = backing_file_bs->read_only; if (ro) { - if (bdrv_reopen_set_read_only(bs->backing->bs, false, NULL)) { + if (bdrv_reopen_set_read_only(backing_file_bs, false, NULL)) { return -EACCES; } } @@ -428,8 +476,6 @@ int bdrv_commit(BlockDriverState *bs) } /* Insert commit_top block node above backing, so we can write to it */ - backing_file_bs = backing_bs(bs); - commit_top_bs = bdrv_new_open_driver(&bdrv_commit_top, NULL, BDRV_O_RDWR, &local_err); if (commit_top_bs == NULL) { @@ -515,15 +561,13 @@ ro_cleanup: qemu_vfree(buf); blk_unref(backing); - if (backing_file_bs) { - bdrv_set_backing_hd(bs, backing_file_bs, &error_abort); - } + bdrv_set_backing_hd(bs, backing_file_bs, &error_abort); bdrv_unref(commit_top_bs); blk_unref(src); if (ro) { /* ignoring error return here */ - bdrv_reopen_set_read_only(bs->backing->bs, true, NULL); + bdrv_reopen_set_read_only(backing_file_bs, true, NULL); } return ret; diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index 4c8c375172..4d3db5ed3c 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -217,7 +217,7 @@ void hmp_commit(Monitor *mon, const QDict *qdict) return; } - bs = blk_bs(blk); + bs = bdrv_skip_implicit_filters(blk_bs(blk)); aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); diff --git a/blockdev.c b/blockdev.c index 9ce99b9cbc..402f1d1df1 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2690,7 +2690,9 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device, assert(bdrv_get_aio_context(base_bs) == aio_context); - for (iter = top_bs; iter != backing_bs(base_bs); iter = backing_bs(iter)) { + for (iter = top_bs; iter != bdrv_filter_or_cow_bs(base_bs); + iter = bdrv_filter_or_cow_bs(iter)) + { if (bdrv_op_is_blocked(iter, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) { goto out; }