From patchwork Wed Feb 5 14:01:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Coddington X-Patchwork-Id: 11366355 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 479BA1395 for ; Wed, 5 Feb 2020 14:02:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 271E6217BA for ; Wed, 5 Feb 2020 14:02:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XYgLZuz9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728028AbgBEOCC (ORCPT ); Wed, 5 Feb 2020 09:02:02 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:25100 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726748AbgBEOCC (ORCPT ); Wed, 5 Feb 2020 09:02:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580911321; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=F8hnRB/54ocr4XYqnIxMCt/VDo0InYWo8HeIlSXK7Uo=; b=XYgLZuz9QfwKtOmNa/hVehd1QRhpV221IerltuwZIskPVdxyXeSdBbsYssjMKtgi8xohFF tEatyWodXkdc056NmPDq7NPFriPucoeVgWzXNjGhCbS8Zol+g+S/9WGki+lS45+o8AOh1j 6YiUQGxokx23vNOXe2GKqX6LV/DFBd0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-31-ZmhBepeZPbOpSFsZ16aiyw-1; Wed, 05 Feb 2020 09:01:57 -0500 X-MC-Unique: ZmhBepeZPbOpSFsZ16aiyw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BC22B108838B; Wed, 5 Feb 2020 14:01:55 +0000 (UTC) Received: from bcodding.csb (ovpn-64-2.rdu2.redhat.com [10.10.64.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6424D5D9E2; Wed, 5 Feb 2020 14:01:55 +0000 (UTC) Received: by bcodding.csb (Postfix, from userid 24008) id E7EB010C1FC8; Wed, 5 Feb 2020 09:01:54 -0500 (EST) From: Benjamin Coddington To: Anna Schumaker , Trond Myklebust Cc: linux-nfs@vger.kernel.org Subject: [PATCH 1/3] NFS: Fix up directory verifier races Date: Wed, 5 Feb 2020 09:01:52 -0500 Message-Id: <1fb737c85fdfc56abe19cac56c04b6b9bf4287d8.1580910601.git.bcodding@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust In order to avoid having our dentry revalidation race with an update of the directory on the server, we need to store the verifier before the RPC calls to LOOKUP and READDIR. Signed-off-by: Trond Myklebust Reviewed-by: Benjamin Coddington Tested-by: Benjamin Coddington --- fs/nfs/dir.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 1320288ff9ec..b4e7558e42ab 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -155,6 +155,7 @@ typedef struct { loff_t current_index; decode_dirent_t decode; + unsigned long dir_verifier; unsigned long timestamp; unsigned long gencount; unsigned int cache_entry_index; @@ -353,6 +354,7 @@ int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc, again: timestamp = jiffies; gencount = nfs_inc_attr_generation_counter(); + desc->dir_verifier = nfs_save_change_attribute(inode); error = NFS_PROTO(inode)->readdir(file_dentry(file), cred, entry->cookie, pages, NFS_SERVER(inode)->dtsize, desc->plus); if (error < 0) { @@ -455,13 +457,13 @@ void nfs_force_use_readdirplus(struct inode *dir) } static -void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) +void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry, + unsigned long dir_verifier) { struct qstr filename = QSTR_INIT(entry->name, entry->len); DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); struct dentry *dentry; struct dentry *alias; - struct inode *dir = d_inode(parent); struct inode *inode; int status; @@ -500,7 +502,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) if (nfs_same_file(dentry, entry)) { if (!entry->fh->size) goto out; - nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); + nfs_set_verifier(dentry, dir_verifier); status = nfs_refresh_inode(d_inode(dentry), entry->fattr); if (!status) nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label); @@ -526,7 +528,7 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) dput(dentry); dentry = alias; } - nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); + nfs_set_verifier(dentry, dir_verifier); out: dput(dentry); } @@ -564,7 +566,8 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en count++; if (desc->plus) - nfs_prime_dcache(file_dentry(desc->file), entry); + nfs_prime_dcache(file_dentry(desc->file), entry, + desc->dir_verifier); status = nfs_readdir_add_to_array(entry, page); if (status != 0) @@ -1159,6 +1162,7 @@ nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry, struct nfs_fh *fhandle; struct nfs_fattr *fattr; struct nfs4_label *label; + unsigned long dir_verifier; int ret; ret = -ENOMEM; @@ -1168,6 +1172,7 @@ nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry, if (fhandle == NULL || fattr == NULL || IS_ERR(label)) goto out; + dir_verifier = nfs_save_change_attribute(dir); ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label); if (ret < 0) { switch (ret) { @@ -1188,7 +1193,7 @@ nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry, goto out; nfs_setsecurity(inode, fattr, label); - nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); + nfs_set_verifier(dentry, dir_verifier); /* set a readdirplus hint that we had a cache miss */ nfs_force_use_readdirplus(dir); @@ -1415,6 +1420,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in struct nfs_fh *fhandle = NULL; struct nfs_fattr *fattr = NULL; struct nfs4_label *label = NULL; + unsigned long dir_verifier; int error; dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry); @@ -1440,6 +1446,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in if (IS_ERR(label)) goto out; + dir_verifier = nfs_save_change_attribute(dir); trace_nfs_lookup_enter(dir, dentry, flags); error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label); if (error == -ENOENT) @@ -1463,7 +1470,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in goto out_label; dentry = res; } - nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); + nfs_set_verifier(dentry, dir_verifier); out_label: trace_nfs_lookup_exit(dir, dentry, flags, error); nfs4_label_free(label);