[PATCH] v9fs: debug and support routines

This part of the patch contains debug and other misc routines.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/9p/error.c b/fs/9p/error.c
new file mode 100644
index 0000000..fee5d19
--- /dev/null
+++ b/fs/9p/error.c
@@ -0,0 +1,93 @@
+/*
+ * linux/fs/9p/error.c
+ *
+ * Error string handling
+ *
+ * Plan 9 uses error strings, Unix uses error numbers.  These functions
+ * try to help manage that and provide for dynamically adding error
+ * mappings.
+ *
+ *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/list.h>
+#include <linux/jhash.h>
+
+#include "debug.h"
+#include "error.h"
+
+/**
+ * v9fs_error_init - preload
+ * @errstr: error string
+ *
+ */
+
+int v9fs_error_init(void)
+{
+	struct errormap *c;
+	int bucket;
+
+	/* initialize hash table */
+	for (bucket = 0; bucket < ERRHASHSZ; bucket++)
+		INIT_HLIST_HEAD(&hash_errmap[bucket]);
+
+	/* load initial error map into hash table */
+	for (c = errmap; c->name != NULL; c++) {
+		bucket = jhash(c->name, strlen(c->name), 0) % ERRHASHSZ;
+		INIT_HLIST_NODE(&c->list);
+		hlist_add_head(&c->list, &hash_errmap[bucket]);
+	}
+
+	return 1;
+}
+
+/**
+ * errstr2errno - convert error string to error number
+ * @errstr: error string
+ *
+ */
+
+int v9fs_errstr2errno(char *errstr)
+{
+	int errno = 0;
+	struct hlist_node *p = NULL;
+	struct errormap *c = NULL;
+	int bucket = jhash(errstr, strlen(errstr), 0) % ERRHASHSZ;
+
+	hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
+		if (!strcmp(c->name, errstr)) {
+			errno = c->val;
+			break;
+		}
+	}
+
+	if (errno == 0) {
+		/* TODO: if error isn't found, add it dynamically */
+		printk(KERN_ERR "%s: errstr :%s: not found\n", __FUNCTION__,
+		       errstr);
+		errno = 1;
+	}
+
+	return -errno;
+}