NFSv4: Fix an Oops in the open recovery code
The open recovery code does not need to request a new value for the
mdsthreshold, and so does not allocate a struct nfs4_threshold.
The problem is that encode_getfattr_open() will still request an
mdsthreshold, and so we end up Oopsing in decode_attr_mdsthreshold.
This patch fixes encode_getfattr_open so that it doesn't request an
mdsthreshold when the caller isn't asking for one. It also fixes
decode_attr_mdsthreshold so that it errors if the server returns
an mdsthreshold that we didn't ask for (instead of Oopsing).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Andy Adamson <andros@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index ee4a74d..9ca1428 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1198,12 +1198,13 @@
}
static void encode_getfattr_open(struct xdr_stream *xdr, const u32 *bitmask,
+ const u32 *open_bitmap,
struct compound_hdr *hdr)
{
encode_getattr_three(xdr,
- bitmask[0] & nfs4_fattr_bitmap[0],
- bitmask[1] & nfs4_fattr_bitmap[1],
- bitmask[2] & FATTR4_WORD2_MDSTHRESHOLD,
+ bitmask[0] & open_bitmap[0],
+ bitmask[1] & open_bitmap[1],
+ bitmask[2] & open_bitmap[2],
hdr);
}
@@ -2221,7 +2222,7 @@
encode_putfh(xdr, args->fh, &hdr);
encode_open(xdr, args, &hdr);
encode_getfh(xdr, &hdr);
- encode_getfattr_open(xdr, args->bitmask, &hdr);
+ encode_getfattr_open(xdr, args->bitmask, args->open_bitmap, &hdr);
encode_nops(&hdr);
}
@@ -4360,6 +4361,9 @@
if (unlikely(bitmap[2] & (FATTR4_WORD2_MDSTHRESHOLD - 1U)))
return -EIO;
if (likely(bitmap[2] & FATTR4_WORD2_MDSTHRESHOLD)) {
+ /* Did the server return an unrequested attribute? */
+ if (unlikely(res == NULL))
+ return -EREMOTEIO;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;