diff options
authorChuck Lever <chuck.lever@oracle.com>2011-01-28 12:41:05 -0500
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-01-28 13:41:35 -0500
commitd1205f87bbb8040c1408bbd9e0a720310b2b0b9b (patch)
parentNFS: Micro-optimize nfs4_decode_dirent() (diff)
NFS: NFSv4 readdir loses entries
On recent 2.6.38-rc kernels, connectathon basic test 6 fails on NFSv4 mounts of OpenSolaris with something like: > ./test6: readdir > ./test6: (/mnt/klimt/matisse.test) didn't read expected 'file.12' dir entry, pass 0 > ./test6: (/mnt/klimt/matisse.test) didn't read expected 'file.82' dir entry, pass 0 > ./test6: (/mnt/klimt/matisse.test) didn't read expected 'file.164' dir entry, pass 0 > ./test6: (/mnt/klimt/matisse.test) Test failed with 3 errors > basic tests failed > Tests failed, leaving /mnt/klimt mounted > [cel@matisse cthon04]$ I narrowed the problem down to nfs4_decode_dirent() reporting that the decode buffer had overflowed while decoding the entries for those missing files. verify_attr_len() assumes both it's pointer arguments reside on the same page. When these arguments point to locations on two different pages, verify_attr_len() can report false errors. This can happen now that a large NFSv4 readdir result can span pages. We have reasonably good checking in nfs4_decode_dirent() anyway, so it should be safe to simply remove the extra checking. At a guess, this was introduced by commit 6650239a, "NFS: Don't use vm_map_ram() in readdir". Cc: stable@kernel.org [2.6.37] Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
1 files changed, 0 insertions, 3 deletions
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 009aef9e12bc..4e2c168b6ee9 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -6132,9 +6132,6 @@ int nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
if (entry->fattr->valid & NFS_ATTR_FATTR_TYPE)
entry->d_type = nfs_umode_to_dtype(entry->fattr->mode);
- if (verify_attr_len(xdr, p, len) < 0)
- goto out_overflow;
return 0;