On Fri, 2011-01-28 at 12:41 -0500, Chuck Lever wrote: > 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_direct() 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@xxxxxxxxxx [2.6.37] > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > --- > > fs/nfs/nfs4xdr.c | 3 --- > 1 files changed, 0 insertions(+), 3 deletions(-) > > diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c > index 009aef9..4e2c168 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; > > out_overflow: > I'm assuming that this is 'Cc: stable@xxxxxxxxxx [2.6.37]'? -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
