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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zWMM/5S4dFOu/WD5ECEAYdeBKl4z45VntP0JWXoYfUw=; b=e+ybJQjU/6m2HEFmrmd3VxI2rrMJP7gEm11t5dneEJSdX+H/JcTn1SwGLvbpDPVTmH Bh5tLfu/+Yfn2HWF+X+X11iUz/WRwcR3T2SwwYJolQy1ElVq3nfYmuwZ3VQk6tNyFihX A0B7Xhp+0hXHxZuTt274fCWl/z51uF9ES8Lx5UrEiwOYvcXa1q0xE7kUk5ezjXNcfvz/ TtUM9u3aE3Jt7uIFDZCkkBonEJsUPki/bCHrLhuO/WY2L1ZPeXnFCzf0GUSCuHwGM4q5 dGcehHuGZvtb+gJUybow+oS/1/C8s2CtVUVMbUmaw9CvDOxQY5jtb7Fiho8M5GpLJQbp ZxrQ== X-Gm-Message-State: AOAM532IcWkloAvWEgf8qWL+Jdoh1jGwnuuReZR6GJ6NZE4v97KOjkl2 jjzaKasu9xCJhuphfUN6fWBYkhI+krGJFfkWjkU= X-Google-Smtp-Source: ABdhPJzOk9dUXsN4s4KGdaDemx/wIgj5uCLKt6CfKvzXNaaMS+7QqZjwN6w29MmItaj9l67c72f3RtIl+DIu84YdWEM= X-Received: by 2002:a02:7a15:: with SMTP id a21mr14609694jac.128.1629470627371; Fri, 20 Aug 2021 07:43:47 -0700 (PDT) MIME-Version: 1.0 References: <20210819194102.1491495-1-agruenba@redhat.com> <20210819194102.1491495-11-agruenba@redhat.com> <5e8a20a8d45043e88013c6004636eae5dadc9be3.camel@redhat.com> In-Reply-To: From: =?UTF-8?Q?Andreas_Gr=C3=BCnbacher?= Date: Fri, 20 Aug 2021 16:43:34 +0200 Message-ID: To: Steven Whitehouse X-Source-IP: 209.85.166.41 X-ServerName: mail-io1-f41.google.com X-Proofpoint-SPF-Result: pass X-Proofpoint-SPF-Record: v=spf1 redirect=_spf.google.com X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10082 signatures=668682 X-Proofpoint-Spam-Details: rule=tap_notspam policy=tap score=0 malwarescore=0 bulkscore=0 mlxlogscore=999 lowpriorityscore=0 impostorscore=0 mlxscore=0 phishscore=0 spamscore=0 priorityscore=357 clxscore=183 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108200082 X-Spam: Clean X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10082 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 spamscore=0 suspectscore=0 phishscore=0 malwarescore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108200081 Cc: cluster-devel , Jan Kara , Andreas Gruenbacher , LKML , Christoph Hellwig , Alexander Viro , linux-fsdevel , Linus Torvalds , ocfs2-devel@oss.oracle.com Subject: Re: [Ocfs2-devel] [Cluster-devel] [PATCH v6 10/19] gfs2: Introduce flag for glock holder auto-demotion X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10082 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 spamscore=0 suspectscore=0 phishscore=0 malwarescore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108200082 X-Proofpoint-GUID: eVZ3R-p7lSJaNi9JqAZr15GWm1BJjRcY X-Proofpoint-ORIG-GUID: eVZ3R-p7lSJaNi9JqAZr15GWm1BJjRcY Am Fr., 20. Aug. 2021 um 15:49 Uhr schrieb Steven Whitehouse : > We always used to manage to avoid holding fs locks when copying to/from userspace > to avoid these complications. I realize the intent, but that goal has never actually been achieved. Direct I/O has *always* been calling get_user_pages() while holding the inode glock in deferred mode. The situation is slightly different for buffered I/O, but we have the same problem there at least since switching to iomap. (And it's a fundamental property of iomap that we want to hold the inode glock across multi-page mappings, not an implementation deficit.) Here's a slightly outdated version of a test case that makes all versions of gfs2 prior to this patch queue unhappy: https://lore.kernel.org/fstests/20210531152604.240462-1-agruenba@redhat.com/ Thanks, Andreas _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel