From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38F1146D543 for ; Thu, 27 Aug 2026 13:43:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787838218; cv=none; b=dSno7A30Z2bw9Fz1ydsmUNR0kpQOsbcoL+O+1xlwMmSWwZXYn2wS6FaFqiewgalqFSY0BgpHVjii/GHqM/x+1Dj/o3K00T+Kpt73MwYrFsUt+upbctQzITJfC9aglGC/hLelWdtjZIAOXyLRaEYExJz3w/7KrI8ZMCfFPXeQRHg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787838218; c=relaxed/simple; bh=FzRo1GPNzAWelnrKwWW+888gA+zU/UXIf9GDxf2VjrM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BPpVSpTpY27pzzyHEepzAgYGDkYtIT5SRxxCZ36RtYnquj6UadFnT8kyTl3u3bgnI2VWDBbzK3mPdFlEKkrQr3YdHICv9ELrSofVk2XEs/5ov8J9LzocHzB9AKvSNWSaqsnrGpDcxpXb+2W1Z01nESNbWpLf7bKyhwv2SjjD3T4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=iJyxD68v; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iJyxD68v" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1787838215; 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=M/Qxd7N6jCXPKHznu5KtiQXyFK2J5SiupV4se6oGxR0=; b=iJyxD68v5SGjdnaz9kClzJaMMJnqNo8DGblAYjNR+k58LCY4IELS6p5KE8dGMCdVdHu7Vm snFCgLkGZ8LHRDGbMQcf6J19gWCpIKa/EPi7Ku+MssE3RQ8Vl1ehHaEj0BX24e/4cmm7xx HIfKttFfB7MmZSFDFeESlRcUX9Rj8AQ= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-61-O9VHSz7CMhm4q9U19GEbqg-1; Thu, 27 Aug 2026 09:43:31 -0400 X-MC-Unique: O9VHSz7CMhm4q9U19GEbqg-1 X-Mimecast-MFC-AGG-ID: O9VHSz7CMhm4q9U19GEbqg_1787838210 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2D45B1933EAE; Thu, 27 Aug 2026 13:43:30 +0000 (UTC) Received: from warthog.com (unknown [10.22.88.47]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0DA6F1800346; Thu, 27 Aug 2026 13:43:27 +0000 (UTC) From: David Howells To: Christian Brauner Cc: David Howells , Paulo Alcantara , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 05/10] netfs: Fix subreq ref leak Date: Thu, 27 Aug 2026 14:42:58 +0100 Message-ID: <20260827134304.2075713-6-dhowells@redhat.com> In-Reply-To: <20260827134304.2075713-1-dhowells@redhat.com> References: <20260827134304.2075713-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Fix a subrequest ref leak in netfs_unbuffered_write() in the event that subreq->io_iter ends up zero length during preparation. Fixes: a0b4c7a49137e ("netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence") Link: https://sashiko.dev/#/patchset/20260824120224.504575-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Paulo Alcantara cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org --- fs/netfs/direct_write.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c index f33ccddaa826..fbcfadb232ee 100644 --- a/fs/netfs/direct_write.c +++ b/fs/netfs/direct_write.c @@ -121,8 +121,14 @@ static int netfs_unbuffered_write(struct netfs_io_request *wreq) } iov_iter_truncate(&subreq->io_iter, wreq->len - wreq->transferred); - if (!iov_iter_count(&subreq->io_iter)) + if (!iov_iter_count(&subreq->io_iter)) { + pr_warn("netfs: Unexpected zero-length iterator R=%08x\n", + wreq->debug_id); + __set_bit(NETFS_SREQ_FAILED, &subreq->flags); + netfs_write_subrequest_terminated(subreq, -EIO); + wreq->error = -EIO; break; + } subreq->len = netfs_limit_iter(&subreq->io_iter, 0, stream->sreq_max_len,