nfsd4: it's OK to return nfserr_symlink

The nfsd4 code has a bunch of special exceptions for error returns which
map nfserr_symlink to other errors.

In fact, the spec makes it clear that nfserr_symlink is to be preferred
over less specific errors where possible.

The patch that introduced it back in 2.6.4 is "kNFSd: correct symlink
related error returns.", which claims that these special exceptions are
represent an NFSv4 break from v2/v3 tradition--when in fact the symlink
error was introduced with v4.

I suspect what happened was pynfs tests were written that were overly
faithful to the (known-incomplete) rfc3530 error return lists, and then
code was fixed up mindlessly to make the tests pass.

Delete these unnecessary exceptions.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4proc.c

@@ -488,17 +488,12 @@ static __be32
 nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	     struct nfsd4_commit *commit)
 {
-	__be32 status;
-
 	u32 *p = (u32 *)commit->co_verf.data;
 	*p++ = nfssvc_boot.tv_sec;
 	*p++ = nfssvc_boot.tv_usec;
 
-	status = nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
+	return nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
 			     commit->co_count);
-	if (status == nfserr_symlink)
-		status = nfserr_inval;
-	return status;
 }
 
 static __be32
@@ -513,8 +508,6 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
 	status = fh_verify(rqstp, &cstate->current_fh, S_IFDIR,
 			   NFSD_MAY_CREATE);
-	if (status == nfserr_symlink)
-		status = nfserr_notdir;
 	if (status)
 		return status;
 
@@ -740,8 +733,6 @@ nfsd4_remove(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		return nfserr_grace;
 	status = nfsd_unlink(rqstp, &cstate->current_fh, 0,
 			     remove->rm_name, remove->rm_namelen);
-	if (status == nfserr_symlink)
-		return nfserr_notdir;
 	if (!status) {
 		fh_unlock(&cstate->current_fh);
 		set_change_info(&remove->rm_cinfo, &cstate->current_fh);
@@ -772,8 +763,6 @@ nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                   (S_ISDIR(cstate->save_fh.fh_dentry->d_inode->i_mode) &&
                    S_ISDIR(cstate->current_fh.fh_dentry->d_inode->i_mode)))
 		status = nfserr_exist;
-	else if (status == nfserr_symlink)
-		status = nfserr_notdir;
 
 	if (!status) {
 		set_change_info(&rename->rn_sinfo, &cstate->current_fh);
@@ -913,8 +902,6 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 
 	write->wr_bytes_written = cnt;
 
-	if (status == nfserr_symlink)
-		status = nfserr_inval;
 	return status;
 }
 

fs/nfsd/nfs4state.c

@@ -4179,12 +4179,8 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	if (!nfsd4_has_session(cstate) && STALE_CLIENTID(&lockt->lt_clientid))
 		goto out;
 
-	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0))) {
-		dprintk("NFSD: nfsd4_lockt: fh_verify() failed!\n");
-		if (status == nfserr_symlink)
-			status = nfserr_inval;
+	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0)))
 		goto out;
-	}
 
 	inode = cstate->current_fh.fh_dentry->d_inode;
 	locks_init_lock(&file_lock);

fs/nfsd/nfs4xdr.c

@@ -2778,8 +2778,6 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
 			read->rd_offset, resp->rqstp->rq_vec, read->rd_vlen,
 			&maxcount);
 
-	if (nfserr == nfserr_symlink)
-		nfserr = nfserr_inval;
 	if (nfserr)
 		return nfserr;
 	eof = (read->rd_offset + maxcount >=
@@ -2905,8 +2903,6 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
 	    readdir->common.err == nfserr_toosmall &&
 	    readdir->buffer == page) 
 		nfserr = nfserr_toosmall;
-	if (nfserr == nfserr_symlink)
-		nfserr = nfserr_notdir;
 	if (nfserr)
 		goto err_no_verf;