NFSD: Add nfsd4_encode_fattr4_type()

Refactor the encoder for FATTR4_TYPE into a helper. In a subsequent
patch, this helper will be called from a bitmask loop.

In addition, restructure the code so that byte-swapping is done on
constant values rather than at run time. Run-time swapping can be
costly on some platforms, and "type" is a frequently-requested
attribute.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index c8fbfc175dab0d9e12b9a535784583e1e1170036..55fa9f69c1e6b04cf0990619bc88fea72923d979 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2792,20 +2792,6 @@ static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
        return 0;
 }
 
-static u32 nfs4_file_type(umode_t mode)
-{
-       switch (mode & S_IFMT) {
-       case S_IFIFO:   return NF4FIFO;
-       case S_IFCHR:   return NF4CHR;
-       case S_IFDIR:   return NF4DIR;
-       case S_IFBLK:   return NF4BLK;
-       case S_IFLNK:   return NF4LNK;
-       case S_IFREG:   return NF4REG;
-       case S_IFSOCK:  return NF4SOCK;
-       default:        return NF4BAD;
-       }
-}
-
 static inline __be32
 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
                     struct nfs4_ace *ace)
@@ -2978,6 +2964,44 @@ static __be32 nfsd4_encode_fattr4_supported_attrs(struct xdr_stream *xdr,
        return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
 }
 
+static __be32 nfsd4_encode_fattr4_type(struct xdr_stream *xdr,
+                                      const struct nfsd4_fattr_args *args)
+{
+       __be32 *p;
+
+       p = xdr_reserve_space(xdr, XDR_UNIT);
+       if (!p)
+               return nfserr_resource;
+
+       switch (args->stat.mode & S_IFMT) {
+       case S_IFIFO:
+               *p = cpu_to_be32(NF4FIFO);
+               break;
+       case S_IFCHR:
+               *p = cpu_to_be32(NF4CHR);
+               break;
+       case S_IFDIR:
+               *p = cpu_to_be32(NF4DIR);
+               break;
+       case S_IFBLK:
+               *p = cpu_to_be32(NF4BLK);
+               break;
+       case S_IFLNK:
+               *p = cpu_to_be32(NF4LNK);
+               break;
+       case S_IFREG:
+               *p = cpu_to_be32(NF4REG);
+               break;
+       case S_IFSOCK:
+               *p = cpu_to_be32(NF4SOCK);
+               break;
+       default:
+               return nfserr_serverfault;
+       }
+
+       return nfs_ok;
+}
+
 /*
  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
  * ourselves.
@@ -2996,7 +3020,6 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
        __be32 *p, *attrlen_p;
        int starting_len = xdr->buf->len;
        int attrlen_offset;
-       u32 dummy;
        u64 dummy64;
        __be32 status;
        int err;
@@ -3113,15 +3136,9 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
                        goto out;
        }
        if (bmval0 & FATTR4_WORD0_TYPE) {
-               p = xdr_reserve_space(xdr, 4);
-               if (!p)
-                       goto out_resource;
-               dummy = nfs4_file_type(args.stat.mode);
-               if (dummy == NF4BAD) {
-                       status = nfserr_serverfault;
+               status = nfsd4_encode_fattr4_type(xdr, &args);
+               if (status != nfs_ok)
                        goto out;
-               }
-               *p++ = cpu_to_be32(dummy);
        }
        if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
                p = xdr_reserve_space(xdr, 4);