patch-1.3.69 linux/drivers/block/linear.c

• Lines: 242
• Date: Mon Feb 26 13:51:45 1996
• Orig file: v1.3.68/linux/drivers/block/linear.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.68/linux/drivers/block/linear.c linux/drivers/block/linear.c
@@ -0,0 +1,241 @@
+
+/*
+   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/md.h>
+#include <linux/linear.h>
+#include <linux/malloc.h>
+
+#define MAJOR_NR MD_MAJOR
+#define MD_DRIVER
+#define MD_PERSONALITY
+
+#include <linux/blk.h>
+
+static int linear_run (int minor, struct md_dev *mddev)
+{
+  int cur=0, i, size, dev0_size, nb_zone;
+  struct linear_data *data;
+
+  MOD_INC_USE_COUNT;
+  
+  mddev->private=kmalloc (sizeof (struct linear_data), GFP_KERNEL);
+  data=(struct linear_data *) mddev->private;
+
+  /*
+     Find out the smallest device. This was previously done
+     at registery time, but since it violates modularity,
+     I moved it here... Any comment ? ;-)
+   */
+
+  data->smallest=devices[minor];
+  for (i=1; i<mddev->nb_dev; i++)
+    if (data->smallest->size > devices[minor][i].size)
+      data->smallest=devices[minor]+i;
+  
+  nb_zone=data->nr_zones=
+    md_size[minor]/data->smallest->size +
+    (md_size[minor]%data->smallest->size ? 1 : 0);
+  
+  data->hash_table=kmalloc (sizeof (struct linear_hash)*nb_zone, GFP_KERNEL);
+
+  size=devices[minor][cur].size;
+
+  i=0;
+  while (cur<mddev->nb_dev)
+  {
+    data->hash_table[i].dev0=devices[minor]+cur;
+
+    if (size>=data->smallest->size) /* If we completly fill the slot */
+    {
+      data->hash_table[i++].dev1=NULL;
+      size-=data->smallest->size;
+
+      if (!size)
+      {
+	if (++cur==mddev->nb_dev) continue;
+	size=devices[minor][cur].size;
+      }
+
+      continue;
+    }
+
+    if (++cur==mddev->nb_dev) /* Last dev, set dev1 as NULL */
+    {
+      data->hash_table[i].dev1=NULL;
+      continue;
+    }
+
+    dev0_size=size;		/* Here, we use a 2nd dev to fill the slot */
+    size=devices[minor][cur].size;
+    data->hash_table[i++].dev1=devices[minor]+cur;
+    size-=(data->smallest->size - dev0_size);
+  }
+
+  return 0;
+}
+
+static int linear_stop (int minor, struct md_dev *mddev)
+{
+  struct linear_data *data=(struct linear_data *) mddev->private;
+  
+  kfree (data->hash_table);
+  kfree (data);
+
+  MOD_DEC_USE_COUNT;
+
+  return 0;
+}
+
+
+static int linear_map (int minor, struct md_dev *mddev, struct request *req)
+{
+  struct linear_data *data=(struct linear_data *) mddev->private;
+  struct linear_hash *hash;
+  struct real_dev *tmp_dev;
+  long block, rblock;
+  struct buffer_head *bh, *bh2;
+  int queue, nblk;
+  static struct request pending[MAX_REAL]={{0, }, };
+
+  while (req->nr_sectors)
+  {
+    block=req->sector >> 1;
+    hash=data->hash_table+(block/data->smallest->size);
+    
+    if (block >= (hash->dev0->size + hash->dev0->offset))
+    {
+      if (!hash->dev1)
+	printk ("linear_map : hash->dev1==NULL for block %ld\n", block);
+      tmp_dev=hash->dev1;
+    }
+    else
+      tmp_dev=hash->dev0;
+    
+    if (block >= (tmp_dev->size + tmp_dev->offset) || block < tmp_dev->offset)
+      printk ("Block %ld out of bounds on dev %04x size %d offset %d\n", block, tmp_dev->dev, tmp_dev->size, tmp_dev->offset);
+    
+    rblock=(block-(tmp_dev->offset));
+    
+    if (req->sem)				/* This is a paging request */
+    {
+      req->rq_dev=tmp_dev->dev;
+      req->sector=rblock << 1;
+      add_request (blk_dev+MAJOR (tmp_dev->dev), req);
+      
+      return REDIRECTED_REQ;
+    }
+
+    queue=tmp_dev - devices[minor];
+
+    for (nblk=0, bh=bh2=req->bh;
+	 bh && rblock + nblk + (bh->b_size >> 10) <= tmp_dev->size;
+	 nblk+=bh->b_size >> 10, bh2=bh, bh=bh->b_reqnext)
+    {
+      if (!buffer_locked(bh))
+	printk("md%d: block %ld not locked\n", minor, bh->b_blocknr);
+      
+      bh->b_rdev=tmp_dev->dev;
+    }
+
+    pending[queue].rq_dev=tmp_dev->dev;
+    pending[queue].cmd=req->cmd;
+    pending[queue].sector=rblock << 1;
+    pending[queue].nr_sectors=nblk << 1;
+    pending[queue].current_nr_sectors=req->bh->b_size >> 9;
+    pending[queue].bh=req->bh;
+    pending[queue].bhtail=bh2;
+    bh2->b_reqnext=NULL;
+    
+    req->bh=bh;
+    req->sector+=nblk << 1;
+    req->nr_sectors-=nblk << 1;
+  }
+
+  req->rq_status=RQ_INACTIVE;
+  wake_up (&wait_for_request);
+  make_md_request (pending, mddev->nb_dev);
+  return REDIRECTED_REQ;
+}
+
+
+static int linear_status (char *page, int minor, struct md_dev *mddev)
+{
+  int sz=0;
+
+#undef MD_DEBUG
+#ifdef MD_DEBUG
+  int j;
+  struct linear_data *data=(struct linear_data *) mddev->private;
+  
+  sz+=sprintf (page+sz, "      ");
+  for (j=0; j<data->nr_zones; j++)
+  {
+    sz+=sprintf (page+sz, "[%s",
+		 partition_name (data->hash_table[j].dev0->dev));
+
+    if (data->hash_table[j].dev1)
+      sz+=sprintf (page+sz, "/%s] ",
+		   partition_name(data->hash_table[j].dev1->dev));
+    else
+      sz+=sprintf (page+sz, "] ");
+  }
+
+  sz+=sprintf (page+sz, "\n");
+#endif
+  return sz;
+}
+
+
+static struct md_personality linear_personality=
+{
+  "linear",
+  linear_map,
+  linear_run,
+  linear_stop,
+  linear_status,
+  NULL,				/* no ioctls */
+  0
+};
+
+
+#ifndef MODULE
+
+void 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)
+{
+  if (MOD_IN_USE)
+    printk ("md linear : module still busy...\n");
+  else
+    unregister_md_personality (LINEAR);
+}
+
+#endif