[PATCH] Correctly handle d_path error returns

There's some minor bug in the d_path handling (the nfsd one may not the the
correct fix, there's no failure path for it, so I just terminate the
string, and the last one in the audit subsystem is just a robustness
cleanup if somebody will extend d_path in the future, right now it's a
noop).
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/compat.c

@@ -429,6 +429,8 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
 			       		fn = d_path(filp->f_dentry,
 						filp->f_vfsmnt, path,
 						PAGE_SIZE);
+					if (IS_ERR(fn))
+						fn = "?";
 				}
 
 				sprintf(buf,"'%c'", (cmd>>24) & 0x3f);

fs/nfsd/export.c

@@ -294,6 +294,11 @@ void svc_export_request(struct cache_detail *cd,
 
 	qword_add(bpp, blen, exp->ex_client->name);
 	pth = d_path(exp->ex_dentry, exp->ex_mnt, *bpp, *blen);
+	if (IS_ERR(pth)) {
+		/* is this correct? */
+		(*bpp)[0] = '\n';
+		return;
+	}
 	qword_add(bpp, blen, pth);
 	(*bpp)[-1] = '\n';
 }

kernel/audit.c

@@ -708,7 +708,7 @@ void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
 		audit_log_move(ab);
 	avail = sizeof(ab->tmp) - ab->len;
 	p = d_path(dentry, vfsmnt, ab->tmp + ab->len, avail);
-	if (p == ERR_PTR(-ENAMETOOLONG)) {
+	if (IS_ERR(p)) {
 		/* FIXME: can we save some information here? */
 		audit_log_format(ab, "<toolong>");
 	} else {