patch-2.4.0-test9 linux/drivers/md/linear.c

• Lines: 214
• Date: Thu Aug 10 12:35:50 2000
• Orig file: v2.4.0-test8/linux/drivers/md/linear.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test8/linux/drivers/md/linear.c linux/drivers/md/linear.c
@@ -0,0 +1,213 @@
+/*
+   linear.c : Multiple Devices driver for Linux
+              Copyright (C) 1994-96 Marc ZYNGIER
+	      <zyngier@ufr-info-p7.ibp.fr> or
+	      <maz@gloups.fdn.fr>
+
+   Linear mode management functions.
+
+   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, or (at your option)
+   any later version.
+   
+   You should have received a copy of the GNU General Public License
+   (for example /usr/src/linux/COPYING); if not, write to the Free
+   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  
+*/
+
+#include <linux/module.h>
+
+#include <linux/raid/md.h>
+#include <linux/malloc.h>
+
+#include <linux/raid/linear.h>
+
+#define MAJOR_NR MD_MAJOR
+#define MD_DRIVER
+#define MD_PERSONALITY
+
+static int linear_run (mddev_t *mddev)
+{
+	linear_conf_t *conf;
+	struct linear_hash *table;
+	mdk_rdev_t *rdev;
+	int size, i, j, nb_zone;
+	unsigned int curr_offset;
+
+	MOD_INC_USE_COUNT;
+
+	conf = kmalloc (sizeof (*conf), GFP_KERNEL);
+	if (!conf)
+		goto out;
+	mddev->private = conf;
+
+	if (md_check_ordering(mddev)) {
+		printk("linear: disks are not ordered, aborting!\n");
+		goto out;
+	}
+	/*
+	 * Find the smallest device.
+	 */
+
+	conf->smallest = NULL;
+	curr_offset = 0;
+	ITERATE_RDEV_ORDERED(mddev,rdev,j) {
+		dev_info_t *disk = conf->disks + j;
+
+		disk->dev = rdev->dev;
+		disk->size = rdev->size;
+		disk->offset = curr_offset;
+
+		curr_offset += disk->size;
+
+		if (!conf->smallest || (disk->size < conf->smallest->size))
+			conf->smallest = disk;
+	}
+
+	nb_zone = conf->nr_zones =
+		md_size[mdidx(mddev)] / conf->smallest->size +
+		((md_size[mdidx(mddev)] % conf->smallest->size) ? 1 : 0);
+  
+	conf->hash_table = kmalloc (sizeof (struct linear_hash) * nb_zone,
+					GFP_KERNEL);
+	if (!conf->hash_table)
+		goto out;
+
+	/*
+	 * Here we generate the linear hash table
+	 */
+	table = conf->hash_table;
+	i = 0;
+	size = 0;
+	for (j = 0; j < mddev->nb_dev; j++) {
+		dev_info_t *disk = conf->disks + j;
+
+		if (size < 0) {
+			table->dev1 = disk;
+			table++;
+		}
+		size += disk->size;
+
+		while (size) {
+			table->dev0 = disk;
+			size -= conf->smallest->size;
+			if (size < 0)
+				break;
+			table->dev1 = NULL;
+			table++;
+		}
+	}
+	table->dev1 = NULL;
+
+	return 0;
+
+out:
+	if (conf)
+		kfree(conf);
+	MOD_DEC_USE_COUNT;
+	return 1;
+}
+
+static int linear_stop (mddev_t *mddev)
+{
+	linear_conf_t *conf = mddev_to_conf(mddev);
+  
+	kfree(conf->hash_table);
+	kfree(conf);
+
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+static int linear_make_request (mddev_t *mddev,
+			int rw, struct buffer_head * bh)
+{
+        linear_conf_t *conf = mddev_to_conf(mddev);
+        struct linear_hash *hash;
+        dev_info_t *tmp_dev;
+        long block;
+
+	block = bh->b_rsector >> 1;
+	hash = conf->hash_table + (block / conf->smallest->size);
+  
+	if (block >= (hash->dev0->size + hash->dev0->offset)) {
+		if (!hash->dev1) {
+			printk ("linear_make_request : hash->dev1==NULL for block %ld\n",
+						block);
+			return -1;
+		}
+		tmp_dev = hash->dev1;
+	} else
+		tmp_dev = hash->dev0;
+    
+	if (block >= (tmp_dev->size + tmp_dev->offset)
+				|| block < tmp_dev->offset) {
+		printk ("linear_make_request: Block %ld out of bounds on dev %s size %ld offset %ld\n", block, kdevname(tmp_dev->dev), tmp_dev->size, tmp_dev->offset);
+		return -1;
+	}
+	bh->b_rdev = tmp_dev->dev;
+	bh->b_rsector = bh->b_rsector - (tmp_dev->offset << 1);
+
+	return 1;
+}
+
+static int linear_status (char *page, mddev_t *mddev)
+{
+	int sz = 0;
+
+#undef MD_DEBUG
+#ifdef MD_DEBUG
+	int j;
+	linear_conf_t *conf = mddev_to_conf(mddev);
+  
+	sz += sprintf(page+sz, "      ");
+	for (j = 0; j < conf->nr_zones; j++)
+	{
+		sz += sprintf(page+sz, "[%s",
+			partition_name(conf->hash_table[j].dev0->dev));
+
+		if (conf->hash_table[j].dev1)
+			sz += sprintf(page+sz, "/%s] ",
+			  partition_name(conf->hash_table[j].dev1->dev));
+		else
+			sz += sprintf(page+sz, "] ");
+	}
+	sz += sprintf(page+sz, "\n");
+#endif
+	sz += sprintf(page+sz, " %dk rounding", mddev->param.chunk_size/1024);
+	return sz;
+}
+
+
+static mdk_personality_t linear_personality=
+{
+	name:		"linear",
+	make_request:	linear_make_request,
+	run:		linear_run,
+	stop:		linear_stop,
+	status:		linear_status,
+};
+
+#ifndef MODULE
+
+void md__init linear_init (void)
+{
+	register_md_personality (LINEAR, &linear_personality);
+}
+
+#else
+
+int init_module (void)
+{
+	return (register_md_personality (LINEAR, &linear_personality));
+}
+
+void cleanup_module (void)
+{
+	unregister_md_personality (LINEAR);
+}
+
+#endif
+