From patchwork Wed May 15 19:26:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 10945235 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 206B392A for ; Wed, 15 May 2019 19:30:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 11B3528658 for ; Wed, 15 May 2019 19:30:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 066E6288F1; Wed, 15 May 2019 19:30:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 912D328658 for ; Wed, 15 May 2019 19:30:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727986AbfEOTak (ORCPT ); Wed, 15 May 2019 15:30:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34990 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727009AbfEOT1d (ORCPT ); Wed, 15 May 2019 15:27:33 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 56312C0624A1; Wed, 15 May 2019 19:27:33 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id C759519C71; Wed, 15 May 2019 19:27:32 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 9F35D22547E; Wed, 15 May 2019 15:27:29 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-nvdimm@lists.01.org Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, swhiteho@redhat.com Subject: [PATCH v2 10/30] fuse: Separate fuse device allocation and installation in fuse_conn Date: Wed, 15 May 2019 15:26:55 -0400 Message-Id: <20190515192715.18000-11-vgoyal@redhat.com> In-Reply-To: <20190515192715.18000-1-vgoyal@redhat.com> References: <20190515192715.18000-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 15 May 2019 19:27:33 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP As of now fuse_dev_alloc() both allocates a fuse device and installs it in fuse_conn list. fuse_dev_alloc() can fail if fuse_device allocation fails. virtio-fs needs to initialize multiple fuse devices (one per virtio queue). It initializes one fuse device as part of call to fuse_fill_super_common() and rest of the devices are allocated and installed after that. But, we can't affort to fail after calling fuse_fill_super_common() as we don't have a way to undo all the actions done by fuse_fill_super_common(). So to avoid failures after the call to fuse_fill_super_common(), pre-allocate all fuse devices early and install them into fuse connection later. This patch provides two separate helpers for fuse device allocation and fuse device installation in fuse_conn. Signed-off-by: Vivek Goyal --- fs/fuse/cuse.c | 2 +- fs/fuse/dev.c | 2 +- fs/fuse/fuse_i.h | 4 +++- fs/fuse/inode.c | 25 ++++++++++++++++++++----- 4 files changed, 25 insertions(+), 8 deletions(-) diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c index a6ed7a036b50..a509747153a7 100644 --- a/fs/fuse/cuse.c +++ b/fs/fuse/cuse.c @@ -506,7 +506,7 @@ static int cuse_channel_open(struct inode *inode, struct file *file) */ fuse_conn_init(&cc->fc, file->f_cred->user_ns, &fuse_dev_fiq_ops, NULL); - fud = fuse_dev_alloc(&cc->fc); + fud = fuse_dev_alloc_install(&cc->fc); if (!fud) { kfree(cc); return -ENOMEM; diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index ef489beadf58..ee9dd38bc0f0 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2318,7 +2318,7 @@ static int fuse_device_clone(struct fuse_conn *fc, struct file *new) if (new->private_data) return -EINVAL; - fud = fuse_dev_alloc(fc); + fud = fuse_dev_alloc_install(fc); if (!fud) return -ENOMEM; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 0b578e07156d..4008ed65a48d 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1050,7 +1050,9 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns, */ void fuse_conn_put(struct fuse_conn *fc); -struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc); +struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc); +struct fuse_dev *fuse_dev_alloc(void); +void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc); void fuse_dev_free(struct fuse_dev *fud); void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 126e77854dac..9b0114437a14 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1027,8 +1027,7 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb) return 0; } -struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc) -{ +struct fuse_dev *fuse_dev_alloc(void) { struct fuse_dev *fud; struct list_head *pq; @@ -1043,16 +1042,32 @@ struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc) } fud->pq.processing = pq; - fud->fc = fuse_conn_get(fc); fuse_pqueue_init(&fud->pq); + return fud; +} +EXPORT_SYMBOL_GPL(fuse_dev_alloc); + +void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc) { + fud->fc = fuse_conn_get(fc); spin_lock(&fc->lock); list_add_tail(&fud->entry, &fc->devices); spin_unlock(&fc->lock); +} +EXPORT_SYMBOL_GPL(fuse_dev_install); +struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc) +{ + struct fuse_dev *fud; + + fud = fuse_dev_alloc(); + if (!fud) + return NULL; + + fuse_dev_install(fud, fc); return fud; } -EXPORT_SYMBOL_GPL(fuse_dev_alloc); +EXPORT_SYMBOL_GPL(fuse_dev_alloc_install); void fuse_dev_free(struct fuse_dev *fud) { @@ -1122,7 +1137,7 @@ int fuse_fill_super_common(struct super_block *sb, mount_data->fiq_priv); fc->release = fuse_free_conn; - fud = fuse_dev_alloc(fc); + fud = fuse_dev_alloc_install(fc); if (!fud) goto err_put_conn;