NFS: Avoid return code checking in mount XDR encoder functions

Clean up.

The trend in the other XDR encoder functions is to BUG() when encoding
problems occur, since a problem here is always due to a local coding
error.  Then, instead of a status, zero is unconditionally returned.

Update the mount client XDR encoders to behave this way.

To finish the update, use the new-style be32_to_cpup() and
cpu_to_be32() macros, and compute the buffer sizes using raw integers
instead of sizeof().  This matches the conventions used in other XDR
functions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
index 4f981f1f668925cba6bebe6ed4cf485da6a56dbb..c82547e49ba1e26c543ce4e4d43addf1a7db8380 100644 (file)
--- a/fs/nfs/mount_clnt.c
+++ b/fs/nfs/mount_clnt.c
@@ -280,20 +280,14 @@ out_call_err:
  * XDR encode/decode functions for MOUNT
  */
 
-static int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
+static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 {
        const u32 pathname_len = strlen(pathname);
        __be32 *p;
 
-       if (unlikely(pathname_len > MNTPATHLEN))
-               return -EIO;
-
-       p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
-       if (unlikely(p == NULL))
-               return -EIO;
+       BUG_ON(pathname_len > MNTPATHLEN);
+       p = xdr_reserve_space(xdr, 4 + pathname_len);
        xdr_encode_opaque(p, pathname, pathname_len);
-
-       return 0;
 }
 
 static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
@@ -302,7 +296,8 @@ static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
        struct xdr_stream xdr;
 
        xdr_init_encode(&xdr, &req->rq_snd_buf, p);
-       return encode_mntdirpath(&xdr, dirpath);
+       encode_mntdirpath(&xdr, dirpath);
+       return 0;
 }
 
 /*
@@ -320,10 +315,10 @@ static int decode_status(struct xdr_stream *xdr, struct mountres *res)
        u32 status;
        __be32 *p;
 
-       p = xdr_inline_decode(xdr, sizeof(status));
+       p = xdr_inline_decode(xdr, 4);
        if (unlikely(p == NULL))
                return -EIO;
-       status = ntohl(*p);
+       status = be32_to_cpup(p);
 
        for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
                if (mnt_errtbl[i].status == status) {
@@ -371,10 +366,10 @@ static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
        u32 status;
        __be32 *p;
 
-       p = xdr_inline_decode(xdr, sizeof(status));
+       p = xdr_inline_decode(xdr, 4);
        if (unlikely(p == NULL))
                return -EIO;
-       status = ntohl(*p);
+       status = be32_to_cpup(p);
 
        for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
                if (mnt3_errtbl[i].status == status) {
@@ -394,11 +389,11 @@ static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
        u32 size;
        __be32 *p;
 
-       p = xdr_inline_decode(xdr, sizeof(size));
+       p = xdr_inline_decode(xdr, 4);
        if (unlikely(p == NULL))
                return -EIO;
 
-       size = ntohl(*p++);
+       size = be32_to_cpup(p);
        if (size > NFS3_FHSIZE || size == 0)
                return -EIO;
 
@@ -421,15 +416,15 @@ static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
        if (*count == 0)
                return 0;
 
-       p = xdr_inline_decode(xdr, sizeof(entries));
+       p = xdr_inline_decode(xdr, 4);
        if (unlikely(p == NULL))
                return -EIO;
-       entries = ntohl(*p);
+       entries = be32_to_cpup(p);
        dprintk("NFS: received %u auth flavors\n", entries);
        if (entries > NFS_MAX_SECFLAVORS)
                entries = NFS_MAX_SECFLAVORS;
 
-       p = xdr_inline_decode(xdr, sizeof(u32) * entries);
+       p = xdr_inline_decode(xdr, 4 * entries);
        if (unlikely(p == NULL))
                return -EIO;
 
@@ -437,7 +432,7 @@ static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
                entries = *count;
 
        for (i = 0; i < entries; i++) {
-               flavors[i] = ntohl(*p++);
+               flavors[i] = be32_to_cpup(p++);
                dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
        }
        *count = i;