Initial import

1 files changed, 361 insertions, 0 deletions

diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
new file mode 100644
index 000000000..e5d059e8a
--- /dev/null
+++ b/init/do_mounts_rd.c
@@ -0,0 +1,361 @@
+/*
+ * 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 <uapi/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
+ *	bzip2
+ *	lzma
+ *	xz
+ *	lzo
+ *	lz4
+ */
+static int __init
+identify_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 long __init compr_fill(void *buf, unsigned long len)
+{
+	long 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 long __init compr_flush(void *window, unsigned long outcnt)
+{
+	long written = sys_write(crd_outfd, window, outcnt);
+	if (written != outcnt) {
+		if (decompress_error == 0)
+			printk(KERN_ERR
+			       "RAMDISK: incomplete write (%ld != %ld)\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;
+
+	if (!deco) {
+		pr_emerg("Invalid ramdisk decompression routine.  "
+			 "Select appropriate config option.\n");
+		panic("Could not decompress initial ramdisk image.");
+	}
+
+	result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
+	if (decompress_error)
+		result = 1;
+	return result;
+}