From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: [PATCH 03/30] NFS: Add options for finer control of the lookup cache Date: Tue, 07 Oct 2008 18:19:53 -0400 Message-ID: <20081007221953.20945.4355.stgit@localhost.localdomain> References: <20081007221952.20945.69529.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" To: linux-nfs@vger.kernel.org Return-path: Received: from mx2.netapp.com ([216.240.18.37]:4712 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756174AbYJGWcu (ORCPT ); Tue, 7 Oct 2008 18:32:50 -0400 Received: from sacexrs02.hq.netapp.com (sacexrs02.hq.netapp.com [10.99.190.106]) by smtp1.corp.netapp.com (8.13.1/8.13.1/NTAP-1.6) with ESMTP id m97MWkw2026300 for ; Tue, 7 Oct 2008 15:32:47 -0700 (PDT) In-Reply-To: <20081007221952.20945.69529.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: Add the flag NFS_MOUNT_LOOKUP_CACHE_NONEG to turn off the caching of negative dentries. In reality what we do is to force nfs_lookup_revalidate() to always discard negative dentries. Add the flag NFS_MOUNT_LOOKUP_CACHE_NONE for enforcing stricter revalidation of dentries. It forces the revalidate code to always do a lookup instead of just checking the cached mtime of the parent directory. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 4 ++++ include/linux/nfs_mount.h | 4 ++++ 2 files changed, 8 insertions(+), 0 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 74f92b7..49d5654 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -667,6 +667,8 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) { if (IS_ROOT(dentry)) return 1; + if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) + return 0; if (!nfs_verify_change_attribute(dir, dentry->d_time)) return 0; /* Revalidate nfsi->cache_change_attribute before we declare a match */ @@ -750,6 +752,8 @@ int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, /* Don't revalidate a negative dentry if we're creating a new file */ if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) return 0; + if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) + return 1; return !nfs_check_verifier(dir, dentry); } diff --git a/include/linux/nfs_mount.h b/include/linux/nfs_mount.h index df7c6b7..6549a06 100644 --- a/include/linux/nfs_mount.h +++ b/include/linux/nfs_mount.h @@ -65,4 +65,8 @@ struct nfs_mount_data { #define NFS_MOUNT_UNSHARED 0x8000 /* 5 */ #define NFS_MOUNT_FLAGMASK 0xFFFF +/* The following are for internal use only */ +#define NFS_MOUNT_LOOKUP_CACHE_NONEG 0x10000 +#define NFS_MOUNT_LOOKUP_CACHE_NONE 0x20000 + #endif