diff options
| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2016-09-22 13:38:52 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-28 03:45:25 -0400 |
| commit | 78ee5302854aef3b95a69b807d179ea57e6608d7 (patch) | |
| tree | 2e88f15450adba01c77988269d5463517a8ac2ba | |
| parent | 73839f59c07cbfda7167093e1d69cbc592dd1b96 (diff) | |
| download | lwn-78ee5302854aef3b95a69b807d179ea57e6608d7.tar.gz lwn-78ee5302854aef3b95a69b807d179ea57e6608d7.zip | |
NFS: Fix inode corruption in nfs_prime_dcache()
commit 7dc72d5f7a0ec97a53e126c46e2cbd2560757955 upstream.
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 <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/nfs/dir.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 177fefb26c18..6bc5a68e39f1 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 +531,10 @@ again: goto again; } } + if (!entry->fh->size) { + d_lookup_done(dentry); + goto out; + } inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label); alias = d_splice_alias(inode, dentry); |