From patchwork Tue Mar 14 07:07:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9622601 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9D0AC60244 for ; Tue, 14 Mar 2017 07:10:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B8F9284DC for ; Tue, 14 Mar 2017 07:10:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8027B284F0; Tue, 14 Mar 2017 07:10:27 +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=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID 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 37CE0284DC for ; Tue, 14 Mar 2017 07:10:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750979AbdCNHHg (ORCPT ); Tue, 14 Mar 2017 03:07:36 -0400 Received: from mga11.intel.com ([192.55.52.93]:34832 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750961AbdCNHHf (ORCPT ); Tue, 14 Mar 2017 03:07:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1489475254; x=1521011254; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=/8vcUhf1sfON90fB7gifCr3p6qtcnN8Jk2Td+hdH6Sk=; b=ncDH+5G3+zZA8ONL7W+wUVSPfbwrQ93xJE+QN6bGec4E08e7VZebplVR O7tiVre0upKWU7HJ/KE7Xb2DtsCG0w==; Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Mar 2017 00:07:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,162,1486454400"; d="scan'208";a="944018193" Received: from elena-thinkpad-x230.fi.intel.com ([10.237.72.51]) by orsmga003.jf.intel.com with ESMTP; 14 Mar 2017 00:07:30 -0700 From: Elena Reshetova To: trond.myklebust@primarydata.com Cc: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, anna.schumaker@netapp.com, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 03/12] fs, nfsd: convert nfs4_file.fi_ref from atomic_t to refcount_t Date: Tue, 14 Mar 2017 09:07:11 +0200 Message-Id: <1489475240-6594-4-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489475240-6594-1-git-send-email-elena.reshetova@intel.com> References: <1489475240-6594-1-git-send-email-elena.reshetova@intel.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- fs/nfsd/nfs4state.c | 6 +++--- fs/nfsd/state.h | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 253fc93..a19f56c 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -359,7 +359,7 @@ put_nfs4_file(struct nfs4_file *fi) { might_lock(&state_lock); - if (atomic_dec_and_lock(&fi->fi_ref, &state_lock)) { + if (refcount_dec_and_lock(&fi->fi_ref, &state_lock)) { hlist_del_rcu(&fi->fi_hash); spin_unlock(&state_lock); WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate)); @@ -3352,7 +3352,7 @@ static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval, { lockdep_assert_held(&state_lock); - atomic_set(&fp->fi_ref, 1); + refcount_set(&fp->fi_ref, 1); spin_lock_init(&fp->fi_lock); INIT_LIST_HEAD(&fp->fi_stateids); INIT_LIST_HEAD(&fp->fi_delegations); @@ -3648,7 +3648,7 @@ find_file_locked(struct knfsd_fh *fh, unsigned int hashval) hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash) { if (fh_match(&fp->fi_fhandle, fh)) { - if (atomic_inc_not_zero(&fp->fi_ref)) + if (refcount_inc_not_zero(&fp->fi_ref)) return fp; } } diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 58eb5f4..4797429 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -482,7 +482,7 @@ struct nfs4_clnt_odstate { * the global state_lock spinlock. */ struct nfs4_file { - atomic_t fi_ref; + refcount_t fi_ref; spinlock_t fi_lock; struct hlist_node fi_hash; /* hash on fi_fhandle */ struct list_head fi_stateids; @@ -635,7 +635,7 @@ struct nfs4_file *find_file(struct knfsd_fh *fh); void put_nfs4_file(struct nfs4_file *fi); static inline void get_nfs4_file(struct nfs4_file *fi) { - atomic_inc(&fi->fi_ref); + refcount_inc(&fi->fi_ref); } struct file *find_any_file(struct nfs4_file *f);