Return-Path: Received: from mail-qt0-f194.google.com ([209.85.216.194]:34983 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753999AbcITQ4S (ORCPT ); Tue, 20 Sep 2016 12:56:18 -0400 Received: by mail-qt0-f194.google.com with SMTP id 38so722891qte.2 for ; Tue, 20 Sep 2016 09:56:18 -0700 (PDT) From: Trond Myklebust To: anna.schumaker@netapp.com Cc: linux-nfs@vger.kernel.org, Oleg Drokin Subject: [PATCH v6 02/29] NFS: Fix inode corruption in nfs_prime_dcache() Date: Tue, 20 Sep 2016 12:55:44 -0400 Message-Id: <1474390571-17106-3-git-send-email-trond.myklebust@primarydata.com> In-Reply-To: <1474390571-17106-2-git-send-email-trond.myklebust@primarydata.com> References: <1474390571-17106-1-git-send-email-trond.myklebust@primarydata.com> <1474390571-17106-2-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Due to inode number reuse in filesystems, we can end up corrupting the inode on our client if we apply the file attributes without ensuring that the filehandle matches. Typical symptoms include spurious "mode changed" reports in the syslog. We still do want to ensure that we don't invalidate the dentry if the inode number matches, but we don't have a filehandle. Fixes: fa9233699cc1 ("NFS: Don't require a filehandle to refresh...") Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org # v4.0+ --- fs/nfs/dir.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 177fefb26c18..578c8ce1aca1 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -435,11 +435,11 @@ int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) return 0; nfsi = NFS_I(inode); - if (entry->fattr->fileid == nfsi->fileid) - return 1; - if (nfs_compare_fh(entry->fh, &nfsi->fh) == 0) - return 1; - return 0; + if (entry->fattr->fileid != nfsi->fileid) + return 0; + if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0) + return 0; + return 1; } static @@ -517,6 +517,8 @@ again: &entry->fattr->fsid)) goto out; if (nfs_same_file(dentry, entry)) { + if (!entry->fh->size) + goto out; nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); status = nfs_refresh_inode(d_inode(dentry), entry->fattr); if (!status) @@ -529,6 +531,8 @@ again: goto again; } } + if (!entry->fh->size) + goto out; inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label); alias = d_splice_alias(inode, dentry); -- 2.7.4