patch-1.3.48 linux/drivers/block/ramdisk.c

• Lines: 233
• Date: Thu Jan 1 02:00:00 1970
• Orig file: v1.3.47/linux/drivers/block/ramdisk.c
• Orig date: Mon Oct 23 18:02:03 1995

diff -u --recursive --new-file v1.3.47/linux/drivers/block/ramdisk.c linux/drivers/block/ramdisk.c
@@ -1,232 +0,0 @@
-/*
- *  linux/kernel/blk_drv/ramdisk.c
- *
- *  Written by Theodore Ts'o, 12/2/91
- *
- * Modifications by Fred N. van Kempen to allow for bootable root
- * disks (which are used in LINUX/Pro).  Also some cleanups.  03/03/93
- */
-
-
-#include <linux/sched.h>
-#include <linux/minix_fs.h>
-#include <linux/ext2_fs.h>
-#include <linux/fs.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-
-#include <asm/system.h>
-#include <asm/segment.h>
-
-#define MAJOR_NR  MEM_MAJOR
-#include <linux/blk.h>
-
-#define RAMDISK_MINOR	1
-
-extern void wait_for_keypress(void);
-
-char	*rd_start;
-int	rd_length = 0;
-static int rd_blocksizes[2] = {0, 0};
-
-static void do_rd_request(void)
-{
-	int	len;
-	char	*addr;
-
-repeat:
-	INIT_REQUEST;
-	addr = rd_start + (CURRENT->sector << 9);
-	len = CURRENT->current_nr_sectors << 9;
-
-	if ((MINOR(CURRENT->rq_dev) != RAMDISK_MINOR) ||
-	    (addr+len > rd_start+rd_length)) {
-		end_request(0);
-		goto repeat;
-	}
-	if (CURRENT-> cmd == WRITE) {
-		(void ) memcpy(addr,
-			      CURRENT->buffer,
-			      len);
-	} else if (CURRENT->cmd == READ) {
-		(void) memcpy(CURRENT->buffer, 
-			      addr,
-			      len);
-	} else
-		panic("RAMDISK: unknown RAM disk command !\n");
-	end_request(1);
-	goto repeat;
-}
-
-static struct file_operations rd_fops = {
-	NULL,			/* lseek - default */
-	block_read,		/* read - general block-dev read */
-	block_write,		/* write - general block-dev write */
-	NULL,			/* readdir - bad */
-	NULL,			/* select */
-	NULL,			/* ioctl */
-	NULL,			/* mmap */
-	NULL,			/* no special open code */
-	NULL,			/* no special release code */
-	block_fsync		/* fsync */
-};
-
-/*
- * Returns amount of memory which needs to be reserved.
- */
-long rd_init(long mem_start, int length)
-{
-	int	i;
-	char	*cp;
-
-	if (register_blkdev(MEM_MAJOR,"rd",&rd_fops)) {
-		printk("RAMDISK: Unable to get major %d.\n", MEM_MAJOR);
-		return 0;
-	}
-	blk_dev[MEM_MAJOR].request_fn = DEVICE_REQUEST;
-	rd_start = (char *) mem_start;
-	rd_length = length;
-	cp = rd_start;
-	for (i=0; i < length; i++)
-		*cp++ = '\0';
-
-	for(i=0;i<2;i++) rd_blocksizes[i] = 1024;
-	blksize_size[MAJOR_NR] = rd_blocksizes;
-
-	return(length);
-}
-
-static void do_load(void)
-{
-	struct buffer_head *bh;
-	struct super_block {
-	  union
-	  {
-	    char minix [sizeof (struct minix_super_block)];
-	    char ext2 [sizeof (struct ext2_super_block)];
-	  } record;
-	} sb;
-	struct minix_super_block *minixsb =
-		(struct minix_super_block *)&sb;
-	struct ext2_super_block *ext2sb =
-		(struct ext2_super_block *)&sb;
-	int		block, tries;
-	int		i = 1;
-	int		nblocks;
-	char		*cp;
-	
-	/*
-	 * Check for a super block on the diskette.
-	 * The old-style boot/root diskettes had their RAM image
-	 * starting at block 512 of the boot diskette.  LINUX/Pro
-	 * uses the entire diskette as a file system, so in that
-	 * case, we have to look at block 0.  Be intelligent about
-	 * this, and check both... - FvK
-	 */
-	for (tries = 0; tries < 1000; tries += 512) {
-		block = tries;
-		bh = breada(ROOT_DEV,block+1,BLOCK_SIZE, 0,  PAGE_SIZE);
-		if (!bh) {
-			printk("RAMDISK: I/O error while looking for super block!\n");
-			return;
-		}
-
-		/* This is silly- why do we require it to be a MINIX FS? */
-		*((struct super_block *) &sb) =
-			*((struct super_block *) bh->b_data);
-		brelse(bh);
-
-
-		/* Try Minix */
-		nblocks = -1;
-		if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
-		    minixsb->s_magic == MINIX_SUPER_MAGIC2) {
-			printk("RAMDISK: Minix filesystem found at block %d\n",
-				block);
-			nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
-		}
-
-		/* Try ext2 */
-		if (nblocks == -1 && ext2sb->s_magic == EXT2_SUPER_MAGIC)
-	        {
-			printk("RAMDISK: Ext2 filesystem found at block %d\n",
-				block);
-			nblocks = ext2sb->s_blocks_count;
-		}
-
-		if (nblocks == -1)
-		{
-			printk("RAMDISK: trying old-style RAM image.\n");
-			continue;
-		}
-
-		if (nblocks > (rd_length >> BLOCK_SIZE_BITS)) {
-			printk("RAMDISK: image too big! (%d/%d blocks)\n",
-					nblocks, rd_length >> BLOCK_SIZE_BITS);
-			return;
-		}
-		printk("RAMDISK: Loading %d blocks into RAM disk", nblocks);
-
-		/* We found an image file system.  Load it into core! */
-		cp = rd_start;
-		while (nblocks) {
-			if (nblocks > 2) 
-			        bh = breada(ROOT_DEV, block, BLOCK_SIZE, 0,  PAGE_SIZE);
-			else
-				bh = bread(ROOT_DEV, block, BLOCK_SIZE);
-			if (!bh) {
-				printk("RAMDISK: I/O error on block %d, aborting!\n", 
-				block);
-				return;
-			}
-			(void) memcpy(cp, bh->b_data, BLOCK_SIZE);
-			brelse(bh);
-			if (!(nblocks-- & 15)) printk(".");
-			cp += BLOCK_SIZE;
-			block++;
-			i++;
-		}
-		printk("\ndone\n");
-
-		/* We loaded the file system image.  Prepare for mounting it. */
-		ROOT_DEV = MKDEV(MEM_MAJOR, RAMDISK_MINOR);
-		return;
-	}
-}
-
-/*
- * If the root device is the RAM disk, try to load it.
- * In order to do this, the root device is originally set to the
- * floppy, and we later change it to be RAM disk.
- */
-void rd_load(void)
-{
-	struct inode inode;
-	struct file filp;
-
-	/* If no RAM disk specified, give up early. */
-	if (!rd_length)
-		return;
-	printk("RAMDISK: %d bytes, starting at 0x%p\n",
-			rd_length, rd_start);
-
-	/* If we are doing a diskette boot, we might have to pre-load it. */
-	if (MAJOR(ROOT_DEV) != FLOPPY_MAJOR)
-		return;
-
-	/* for Slackware install disks */
-	printk(KERN_NOTICE "VFS: Insert root floppy to be loaded into ramdisk and press ENTER\n");
-	wait_for_keypress();
-
-	memset(&filp, 0, sizeof(filp));
-	memset(&inode, 0, sizeof(inode));
-	inode.i_rdev = ROOT_DEV;
-	filp.f_mode = 1; /* read only */
-	filp.f_inode = &inode;
-	if(blkdev_open(&inode, &filp) == 0 ){
-		do_load();
-		if(filp.f_op && filp.f_op->release)
-			filp.f_op->release(&inode,&filp);
-	}
-}