NFSD: Fix callback decoder status codes

fs/nfsd/nfs4callback.c implements a callback client. Thus its XDR
decoders are decoding replies, not calls.

NFS4ERR_BAD_XDR is an on-the-wire status code that reports that the
client sent a corrupted RPC /call/. It's not used as the internal
error code when a /reply/ can't be decoded, since that kind of
failure is never reported to the sender of that RPC message.

Instead, a reply decoder should return -EIO, as the reply decoders
in the NFS client do.

Fixes: 6487a13b5c6b ("NFSD: add support for CB_GETATTR callback")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 961b1defcb1a59a4970987aabb79ea3fa837ed66..ae4b7b6df47ff054db197bd2f6083905e4149bee 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -101,15 +101,15 @@ static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
 
        if (bitmap[0] & FATTR4_WORD0_CHANGE)
                if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0)
-                       return -NFSERR_BAD_XDR;
+                       return -EIO;
        if (bitmap[0] & FATTR4_WORD0_SIZE)
                if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0)
-                       return -NFSERR_BAD_XDR;
+                       return -EIO;
        if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) {
                fattr4_time_deleg_access access;
 
                if (!xdrgen_decode_fattr4_time_deleg_access(xdr, &access))
-                       return -NFSERR_BAD_XDR;
+                       return -EIO;
                fattr->ncf_cb_atime.tv_sec = access.seconds;
                fattr->ncf_cb_atime.tv_nsec = access.nseconds;
 
@@ -118,7 +118,7 @@ static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
                fattr4_time_deleg_modify modify;
 
                if (!xdrgen_decode_fattr4_time_deleg_modify(xdr, &modify))
-                       return -NFSERR_BAD_XDR;
+                       return -EIO;
                fattr->ncf_cb_mtime.tv_sec = modify.seconds;
                fattr->ncf_cb_mtime.tv_nsec = modify.nseconds;
 
@@ -682,15 +682,15 @@ static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
        if (unlikely(status || cb->cb_status))
                return status;
        if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0)
-               return -NFSERR_BAD_XDR;
+               return -EIO;
        if (xdr_stream_decode_u32(xdr, &attrlen) < 0)
-               return -NFSERR_BAD_XDR;
+               return -EIO;
        maxlen = sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize);
        if (bitmap[2] != 0)
                maxlen += (sizeof(ncf->ncf_cb_mtime.tv_sec) +
                           sizeof(ncf->ncf_cb_mtime.tv_nsec)) * 2;
        if (attrlen > maxlen)
-               return -NFSERR_BAD_XDR;
+               return -EIO;
        status = decode_cb_fattr4(xdr, bitmap, ncf);
        return status;
 }