Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qg0-f41.google.com ([209.85.192.41]:38551 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932498AbaE3NJ4 (ORCPT ); Fri, 30 May 2014 09:09:56 -0400 Received: by mail-qg0-f41.google.com with SMTP id j5so5165522qga.14 for ; Fri, 30 May 2014 06:09:56 -0700 (PDT) From: Jeff Layton To: bfields@fieldses.org Cc: trond.myklebust@primarydata.com, bhalevy@primarydata.com, linux-nfs@vger.kernel.org Subject: [PATCH 8/9] NFSd: Protect addition to the file_hashtbl Date: Fri, 30 May 2014 09:09:32 -0400 Message-Id: <1401455373-18207-9-git-send-email-jlayton@primarydata.com> In-Reply-To: <1401455373-18207-1-git-send-email-jlayton@primarydata.com> References: <1401455373-18207-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: Trond Myklebust Ensure that we only can have a single struct nfs4_file per inode in the file_hashtbl and make addition atomic with respect to lookup. Signed-off-by: Trond Myklebust --- fs/nfsd/nfs4state.c | 46 +++++++++++++++++++++++++++++++++++----------- 1 file changed, 35 insertions(+), 11 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a500033a2f87..553c2d6d48dc 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2519,6 +2519,8 @@ static void nfsd4_init_file(struct nfs4_file *fp, struct inode *ino) { unsigned int hashval = file_hashval(ino); + lockdep_assert_held(&state_lock); + atomic_set(&fp->fi_ref, 1); INIT_LIST_HEAD(&fp->fi_stateids); INIT_LIST_HEAD(&fp->fi_delegations); @@ -2527,9 +2529,7 @@ static void nfsd4_init_file(struct nfs4_file *fp, struct inode *ino) fp->fi_lease = NULL; memset(fp->fi_fds, 0, sizeof(fp->fi_fds)); memset(fp->fi_access, 0, sizeof(fp->fi_access)); - spin_lock(&state_lock); hlist_add_head(&fp->fi_hash, &file_hashtbl[hashval]); - spin_unlock(&state_lock); } void @@ -2695,23 +2695,49 @@ find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open, /* search file_hashtbl[] for file */ static struct nfs4_file * -find_file(struct inode *ino) +find_file_locked(struct inode *ino) { unsigned int hashval = file_hashval(ino); struct nfs4_file *fp; - spin_lock(&state_lock); + lockdep_assert_held(&state_lock); + hlist_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) { if (fp->fi_inode == ino) { get_nfs4_file(fp); - spin_unlock(&state_lock); return fp; } } - spin_unlock(&state_lock); return NULL; } +static struct nfs4_file * +find_file(struct inode *ino) +{ + struct nfs4_file *fp; + + spin_lock(&state_lock); + fp = find_file_locked(ino); + spin_unlock(&state_lock); + return fp; +} + +static struct nfs4_file * +find_or_add_file(struct inode *ino, struct nfs4_file *new) +{ + struct nfs4_file *fp; + + spin_lock(&state_lock); + fp = find_file_locked(ino); + if (fp == NULL) { + nfsd4_init_file(new, ino); + fp = new; + } + spin_unlock(&state_lock); + + return fp; +} + /* * Called to check deny when READ with all zero stateid or * WRITE with all zero or all one stateid @@ -3230,21 +3256,19 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf * and check for delegations in the process of being recalled. * If not found, create the nfs4_file struct */ - fp = find_file(ino); - if (fp) { + fp = find_or_add_file(ino, open->op_file); + if (fp != open->op_file) { if ((status = nfs4_check_open(fp, open, &stp))) goto out; status = nfs4_check_deleg(cl, open, &dp); if (status) goto out; } else { + open->op_file = NULL; status = nfserr_bad_stateid; if (nfsd4_is_deleg_cur(open)) goto out; status = nfserr_jukebox; - fp = open->op_file; - open->op_file = NULL; - nfsd4_init_file(fp, ino); } /* -- 1.9.3