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c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738703699; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Yh8r9aazOxh4iudbELqACHjQNqnsLiUCBFbRzvJrGFQ=; b=fypPhFPoffWbUeuaa/klPYreqwwgfyKn2PEGWBAXWO8LBVYML8a8mDUCUok+6BdJicQZh6 s4JHX2wc4GxL1WY28gSqPte7broLJ3Ho2Ed2n+0GG21ubESnPPcEnE+N9wJlxz8jBleG3/ j9JZPUPOliuF10E93HOA9xXN5UZaqYE= X-MC-Unique: rfKFmOtTP2aihKnOOFVjSA-1 X-Mimecast-MFC-AGG-ID: rfKFmOtTP2aihKnOOFVjSA From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, hreitz@redhat.com, stefanha@redhat.com, pkrempa@redhat.com, peterx@redhat.com, farosas@suse.de, qemu-devel@nongnu.org Subject: [PATCH v3 11/16] block: Drain nodes before inactivating them Date: Tue, 4 Feb 2025 22:14:02 +0100 Message-ID: <20250204211407.381505-12-kwolf@redhat.com> In-Reply-To: <20250204211407.381505-1-kwolf@redhat.com> References: <20250204211407.381505-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; 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charset="utf-8" So far the assumption has always been that if we try to inactivate a node, it is already idle. This doesn't hold true any more if we allow inactivating exported nodes because we can't know when new external requests come in. Drain the node around setting BDRV_O_INACTIVE so that requests can't start operating on an active node and then in the middle it suddenly becomes inactive. With this change, it's enough for exports to check for new requests that they operate on an active node (or, like reads, are allowed even on an inactive node). Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- block.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block.c b/block.c index 7eeb8d076e..1601b25f66 100644 --- a/block.c +++ b/block.c @@ -7032,7 +7032,9 @@ bdrv_inactivate_recurse(BlockDriverState *bs, bool to= p_level) return -EPERM; } =20 + bdrv_drained_begin(bs); bs->open_flags |=3D BDRV_O_INACTIVE; + bdrv_drained_end(bs); =20 /* * Update permissions, they may differ for inactive nodes. --=20 2.48.1