From patchwork Wed Jun 5 00:38:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronnie Sahlberg X-Patchwork-Id: 10976233 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 BE8D52D49 for ; Wed, 5 Jun 2019 00:38:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A0E5D287EF for ; Wed, 5 Jun 2019 00:38:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8EA312888A; Wed, 5 Jun 2019 00:38:49 +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=ham 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 63579287EF for ; Wed, 5 Jun 2019 00:38:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726317AbfFEAir (ORCPT ); Tue, 4 Jun 2019 20:38:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56464 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726179AbfFEAir (ORCPT ); Tue, 4 Jun 2019 20:38:47 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 431EA5F72C; Wed, 5 Jun 2019 00:38:47 +0000 (UTC) Received: from test1135.test.redhat.com (vpn2-54-17.bne.redhat.com [10.64.54.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id A1E981001DFD; Wed, 5 Jun 2019 00:38:46 +0000 (UTC) From: Ronnie Sahlberg To: linux-cifs Cc: Steve French , Stable , Ronnie Sahlberg Subject: [PATCH] cifs: add spinlock for the openFileList to cifsInodeInfo Date: Wed, 5 Jun 2019 10:38:38 +1000 Message-Id: <20190605003838.13101-1-lsahlber@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 05 Jun 2019 00:38:47 +0000 (UTC) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We can not depend on the tcon->open_file_lock here since in multiuser mode we may have the same file/inode open via multiple different tcons. The current code is race prone and will crash if one user deletes a file at the same time a different user opens/create the file. To avoid this we need to have a spinlock attached to the inode and not the tcon. RHBZ: 1580165 CC: Stable Signed-off-by: Ronnie Sahlberg Reviewed-by: Pavel Shilovsky --- fs/cifs/cifsfs.c | 1 + fs/cifs/cifsglob.h | 1 + fs/cifs/file.c | 8 ++++++-- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index f5fcd6360056..65d9771e49f9 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -303,6 +303,7 @@ cifs_alloc_inode(struct super_block *sb) cifs_inode->uniqueid = 0; cifs_inode->createtime = 0; cifs_inode->epoch = 0; + spin_lock_init(&cifs_inode->open_file_lock); generate_random_uuid(cifs_inode->lease_key); /* diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 334ff5f9c3f3..733ddd5fd480 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1377,6 +1377,7 @@ struct cifsInodeInfo { struct rw_semaphore lock_sem; /* protect the fields above */ /* BB add in lists for dirty pages i.e. write caching info for oplock */ struct list_head openFileList; + spinlock_t open_file_lock; /* protects openFileList */ __u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */ unsigned int oplock; /* oplock/lease level we have */ unsigned int epoch; /* used to track lease state changes */ diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 06e27ac6d82c..97090693d182 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -338,10 +338,12 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, atomic_inc(&tcon->num_local_opens); /* if readable file instance put first in list*/ + spin_lock(&cinode->open_file_lock); if (file->f_mode & FMODE_READ) list_add(&cfile->flist, &cinode->openFileList); else list_add_tail(&cfile->flist, &cinode->openFileList); + spin_unlock(&cinode->open_file_lock); spin_unlock(&tcon->open_file_lock); if (fid->purge_cache) @@ -413,7 +415,9 @@ void _cifsFileInfo_put(struct cifsFileInfo *cifs_file, bool wait_oplock_handler) cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open); /* remove it from the lists */ + spin_lock(&cifsi->open_file_lock); list_del(&cifs_file->flist); + spin_unlock(&cifsi->open_file_lock); list_del(&cifs_file->tlist); atomic_dec(&tcon->num_local_opens); @@ -1950,9 +1954,9 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only, return 0; } - spin_lock(&tcon->open_file_lock); + spin_lock(&cifs_inode->open_file_lock); list_move_tail(&inv_file->flist, &cifs_inode->openFileList); - spin_unlock(&tcon->open_file_lock); + spin_unlock(&cifs_inode->open_file_lock); cifsFileInfo_put(inv_file); ++refind; inv_file = NULL;