/* * Many of the syscalls used in this file expect some of the arguments * to be __user pointers not __kernel pointers.  To limit the sparse * noise, turn off sparse checking for this file. */#ifdef __CHECKER__#undef __CHECKER__#warning "Sparse checking disabled for this file"#endif #include <linux/kernel.h>#include <linux/fs.h>#include <linux/minix_fs.h>#include <linux/ext2_fs.h>#include <linux/romfs_fs.h>#include <linux/cramfs_fs.h>#include <linux/initrd.h>#include <linux/string.h>#include <linux/slab.h> #include "do_mounts.h"#include "../fs/squashfs/squashfs_fs.h" #include <linux/decompress/generic.h>  int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ static int __init prompt_ramdisk(char *str){	rd_prompt = simple_strtol(str,NULL,0) & 1;	return 1;}__setup("prompt_ramdisk=", prompt_ramdisk); int __initdata rd_image_start;		/* starting block # of image */ static int __init ramdisk_start_setup(char *str){	rd_image_start = simple_strtol(str,NULL,0);	return 1;}__setup("ramdisk_start=", ramdisk_start_setup); static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); /* * This routine tries to find a RAM disk image to load, and returns the * number of blocks to read for a non-compressed image, 0 if the image * is a compressed image, and -1 if an image with the right magic * numbers could not be found. * * We currently check for the following magic numbers: *	minix *	ext2 *	romfs *	cramfs *	squashfs *	gzip */static int __initidentify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor){	const int size = 512;	struct minix_super_block *minixsb;	struct romfs_super_block *romfsb;	struct cramfs_super *cramfsb;	struct squashfs_super_block *squashfsb;	int nblocks = -1;	unsigned char *buf;	const char *compress_name;	unsigned long n; 	buf = kmalloc(size, GFP_KERNEL);	if (!buf)		return -ENOMEM; 	minixsb = (struct minix_super_block *) buf;	romfsb = (struct romfs_super_block *) buf;	cramfsb = (struct cramfs_super *) buf;	squashfsb = (struct squashfs_super_block *) buf;	memset(buf, 0xe5, size); 	/*	 * Read block 0 to test for compressed kernel	 */	sys_lseek(fd, start_block * BLOCK_SIZE, 0);	sys_read(fd, buf, size); 	*decompressor = decompress_method(buf, size, &compress_name);	if (compress_name) {		printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",		       compress_name, start_block);		if (!*decompressor)			printk(KERN_EMERG			       "RAMDISK: %s decompressor not configured!\n",			       compress_name);		nblocks = 0;		goto done;	} 	/* romfs is at block zero too */	if (romfsb->word0 == ROMSB_WORD0 &&	    romfsb->word1 == ROMSB_WORD1) {		printk(KERN_NOTICE		       "RAMDISK: romfs filesystem found at block %d\n",		       start_block);		nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;		goto done;	} 	if (cramfsb->magic == CRAMFS_MAGIC) {		printk(KERN_NOTICE		       "RAMDISK: cramfs filesystem found at block %d\n",		       start_block);		nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;		goto done;	} 	/* squashfs is at block zero too */	if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {		printk(KERN_NOTICE		       "RAMDISK: squashfs filesystem found at block %d\n",		       start_block);		nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)			 >> BLOCK_SIZE_BITS;		goto done;	} 	/*	 * Read 512 bytes further to check if cramfs is padded	 */	sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0);	sys_read(fd, buf, size); 	if (cramfsb->magic == CRAMFS_MAGIC) {		printk(KERN_NOTICE		       "RAMDISK: cramfs filesystem found at block %d\n",		       start_block);		nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;		goto done;	} 	/*	 * Read block 1 to test for minix and ext2 superblock	 */	sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0);	sys_read(fd, buf, size); 	/* Try minix */	if (minixsb->s_magic == MINIX_SUPER_MAGIC ||	    minixsb->s_magic == MINIX_SUPER_MAGIC2) {		printk(KERN_NOTICE		       "RAMDISK: Minix filesystem found at block %d\n",		       start_block);		nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;		goto done;	} 	/* Try ext2 */	n = ext2_image_size(buf);	if (n) {		printk(KERN_NOTICE		       "RAMDISK: ext2 filesystem found at block %d\n",		       start_block);		nblocks = n;		goto done;	} 	printk(KERN_NOTICE	       "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",	       start_block); done:	sys_lseek(fd, start_block * BLOCK_SIZE, 0);	kfree(buf);	return nblocks;} int __init rd_load_image(char *from){	int res = 0;	int in_fd, out_fd;	unsigned long rd_blocks, devblocks;	int nblocks, i, disk;	char *buf = NULL;	unsigned short rotate = 0;	decompress_fn decompressor = NULL;#if !defined(CONFIG_S390)	char rotator[4] = { '|' , '/' , '-' , '\\' };#endif 	out_fd = sys_open("/dev/ram", O_RDWR, 0);	if (out_fd < 0)		goto out; 	in_fd = sys_open(from, O_RDONLY, 0);	if (in_fd < 0)		goto noclose_input; 	nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);	if (nblocks < 0)		goto done; 	if (nblocks == 0) {		if (crd_load(in_fd, out_fd, decompressor) == 0)			goto successful_load;		goto done;	} 	/*	 * NOTE NOTE: nblocks is not actually blocks but	 * the number of kibibytes of data to load into a ramdisk.	 * So any ramdisk block size that is a multiple of 1KiB should	 * work when the appropriate ramdisk_blocksize is specified	 * on the command line.	 *	 * The default ramdisk_blocksize is 1KiB and it is generally	 * silly to use anything else, so make sure to use 1KiB	 * blocksize while generating ext2fs ramdisk-images.	 */	if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0)		rd_blocks = 0;	else		rd_blocks >>= 1; 	if (nblocks > rd_blocks) {		printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",		       nblocks, rd_blocks);		goto done;	} 	/*	 * OK, time to copy in the data	 */	if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0)		devblocks = 0;	else		devblocks >>= 1; 	if (strcmp(from, "/initrd.image") == 0)		devblocks = nblocks; 	if (devblocks == 0) {		printk(KERN_ERR "RAMDISK: could not determine device size\n");		goto done;	} 	buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);	if (!buf) {		printk(KERN_ERR "RAMDISK: could not allocate buffer\n");		goto done;	} 	printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",		nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "");	for (i = 0, disk = 1; i < nblocks; i++) {		if (i && (i % devblocks == 0)) {			printk("done disk #%d.\n", disk++);			rotate = 0;			if (sys_close(in_fd)) {				printk("Error closing the disk.\n");				goto noclose_input;			}			change_floppy("disk #%d", disk);			in_fd = sys_open(from, O_RDONLY, 0);			if (in_fd < 0)  {				printk("Error opening disk.\n");				goto noclose_input;			}			printk("Loading disk #%d... ", disk);		}		sys_read(in_fd, buf, BLOCK_SIZE);		sys_write(out_fd, buf, BLOCK_SIZE);#if !defined(CONFIG_S390)		if (!(i % 16)) {			printk("%c\b", rotator[rotate & 0x3]);			rotate++;		}#endif	}	printk("done.\n"); successful_load:	res = 1;done:	sys_close(in_fd);noclose_input:	sys_close(out_fd);out:	kfree(buf);	sys_unlink("/dev/ram");	return res;} int __init rd_load_disk(int n){	if (rd_prompt)		change_floppy("root floppy disk to be loaded into RAM disk");	create_dev("/dev/root", ROOT_DEV);	create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));	return rd_load_image("/dev/root");} static int exit_code;static int decompress_error;static int crd_infd, crd_outfd; static int __init compr_fill(void *buf, unsigned int len){	int r = sys_read(crd_infd, buf, len);	if (r < 0)		printk(KERN_ERR "RAMDISK: error while reading compressed data");	else if (r == 0)		printk(KERN_ERR "RAMDISK: EOF while reading compressed data");	return r;} static int __init compr_flush(void *window, unsigned int outcnt){	int written = sys_write(crd_outfd, window, outcnt);	if (written != outcnt) {		if (decompress_error == 0)			printk(KERN_ERR			       "RAMDISK: incomplete write (%d != %d)\n",			       written, outcnt);		decompress_error = 1;		return -1;	}	return outcnt;} static void __init error(char *x){	printk(KERN_ERR "%s\n", x);	exit_code = 1;	decompress_error = 1;} static int __init crd_load(int in_fd, int out_fd, decompress_fn deco){	int result;	crd_infd = in_fd;	crd_outfd = out_fd;	result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);	if (decompress_error)		result = 1;	return result;}