From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751698AbdH3P26 (ORCPT ); Wed, 30 Aug 2017 11:28:58 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:44534 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751332AbdH3P25 (ORCPT ); Wed, 30 Aug 2017 11:28:57 -0400 Date: Wed, 30 Aug 2017 16:28:55 +0100 From: Al Viro To: Christoph Hellwig Cc: arve@android.com, riandrews@android.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/16] ashmem: switch to ->read_iter Message-ID: <20170830152855.GL5426@ZenIV.linux.org.uk> References: <20170830150007.3953-1-hch@lst.de> <20170830150007.3953-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170830150007.3953-2-hch@lst.de> User-Agent: Mutt/1.8.3 (2017-05-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 30, 2017 at 04:59:52PM +0200, Christoph Hellwig wrote: > And use the proper VFS helper for using the backing file. Actually, I wonder if that update of ->f_pos of the underlying file is correct. That's unrelated to this patch, but might be worth sorting out while we are at it. How about mutex_unlock(&ashmem_mutex); /* * asma and asma->file are used outside the lock here. We assume * once asma->file is set it will never be changed, and will not * be destroyed until all references to the file are dropped and * ashmem_release is called. */ ret = vfs_iter_read(asma->file, iter, &iocb->ki_pos, 0); mutex_lock(&ashmem_mutex); if (ret >= 0) asma->file->f_pos = *pos; out_unlock: mutex_unlock(&ashmem_mutex); return ret; in there?