From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E353C433B4 for ; Fri, 16 Apr 2021 18:00:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1732B611AB for ; Fri, 16 Apr 2021 18:00:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235514AbhDPSAs (ORCPT ); Fri, 16 Apr 2021 14:00:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236045AbhDPSAr (ORCPT ); Fri, 16 Apr 2021 14:00:47 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 96950C061756 for ; Fri, 16 Apr 2021 11:00:21 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 0559B6D25; Fri, 16 Apr 2021 14:00:19 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 0559B6D25 From: "J. Bruce Fields" To: Chuck Lever Cc: linux-nfs@vger.kernel.org, "J. Bruce Fields" Subject: [PATCH 3/5] nfsd: track filehandle aliasing in nfs4_files Date: Fri, 16 Apr 2021 14:00:16 -0400 Message-Id: <1618596018-9899-3-git-send-email-bfields@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1618596018-9899-1-git-send-email-bfields@redhat.com> References: <1618596018-9899-1-git-send-email-bfields@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: "J. Bruce Fields" It's unusual but possible for multiple filehandles to point to the same file. In that case, we may end up with multiple nfs4_files referencing the same inode. For delegation purposes it will turn out to be useful to flag those cases. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 37 ++++++++++++++++++++++++++++--------- fs/nfsd/state.h | 2 ++ 2 files changed, 30 insertions(+), 9 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index b0c74dbde07b..c1ba60db671a 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4075,6 +4075,8 @@ static void nfsd4_init_file(struct svc_fh *fh, unsigned int hashval, fp->fi_share_deny = 0; memset(fp->fi_fds, 0, sizeof(fp->fi_fds)); memset(fp->fi_access, 0, sizeof(fp->fi_access)); + fp->fi_aliased = false; + fp->fi_inode = d_inode(fh->fh_dentry); #ifdef CONFIG_NFSD_PNFS INIT_LIST_HEAD(&fp->fi_lo_states); atomic_set(&fp->fi_lo_recalls, 0); @@ -4427,6 +4429,31 @@ find_file_locked(struct svc_fh *fh, unsigned int hashval) return NULL; } +static struct nfs4_file *insert_file(struct nfs4_file *new, struct svc_fh *fh, + unsigned int hashval) +{ + struct nfs4_file *fp; + struct nfs4_file *ret = NULL; + bool alias_found = false; + + spin_lock(&state_lock); + hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash, + lockdep_is_held(&state_lock)) { + if (fh_match(&fp->fi_fhandle, &fh->fh_handle)) { + if (refcount_inc_not_zero(&fp->fi_ref)) + ret = fp; + } else if (d_inode(fh->fh_dentry) == fp->fi_inode) + fp->fi_aliased = alias_found = true; + } + if (likely(ret == NULL)) { + nfsd4_init_file(fh, hashval, new); + new->fi_aliased = alias_found; + ret = new; + } + spin_unlock(&state_lock); + return ret; +} + static struct nfs4_file * find_file(struct svc_fh *fh) { struct nfs4_file *fp; @@ -4450,15 +4477,7 @@ find_or_add_file(struct nfs4_file *new, struct svc_fh *fh) if (fp) return fp; - spin_lock(&state_lock); - fp = find_file_locked(fh, hashval); - if (likely(fp == NULL)) { - nfsd4_init_file(fh, hashval, new); - fp = new; - } - spin_unlock(&state_lock); - - return fp; + return insert_file(new, fh, hashval); } /* diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index af1d9f2e373e..7b10b3eaaa5c 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -512,6 +512,8 @@ struct nfs4_clnt_odstate { */ struct nfs4_file { refcount_t fi_ref; + struct inode * fi_inode; + bool fi_aliased; spinlock_t fi_lock; struct hlist_node fi_hash; /* hash on fi_fhandle */ struct list_head fi_stateids; -- 2.30.2