From patchwork Wed Aug 21 17:37:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11107627 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 337FD1395 for ; Wed, 21 Aug 2019 17:39:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C1672339E for ; Wed, 21 Aug 2019 17:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730243AbfHURiu (ORCPT ); Wed, 21 Aug 2019 13:38:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41586 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729996AbfHURiV (ORCPT ); Wed, 21 Aug 2019 13:38:21 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1DDBAC0546FF; Wed, 21 Aug 2019 17:38:21 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.158]) by smtp.corp.redhat.com (Postfix) with ESMTP id EFE465C226; Wed, 21 Aug 2019 17:38:20 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id CE477223D06; Wed, 21 Aug 2019 13:38:14 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu Cc: virtio-fs@redhat.com, vgoyal@redhat.com, stefanha@redhat.com, dgilbert@redhat.com Subject: [PATCH 10/13] fuse: Separate fuse device allocation and installation in fuse_conn Date: Wed, 21 Aug 2019 13:37:39 -0400 Message-Id: <20190821173742.24574-11-vgoyal@redhat.com> In-Reply-To: <20190821173742.24574-1-vgoyal@redhat.com> References: <20190821173742.24574-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 21 Aug 2019 17:38:21 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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 7bdab6521469..04727540bdbb 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 fa6794e96811..556e44fa6b20 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2319,7 +2319,7 @@ 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 70c1bde06293..605217552350 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1060,7 +1060,9 @@ 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 226af184a402..0df885d6fa00 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1024,8 +1024,7 @@ 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; @@ -1040,16 +1039,32 @@ 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) { @@ -1119,7 +1134,7 @@ 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;