summaryrefslogtreecommitdiff
path: root/init/do_mounts_rd.c
diff options
context:
space:
mode:
Diffstat (limited to 'init/do_mounts_rd.c')
-rw-r--r--init/do_mounts_rd.c361
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;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-04 21:45:07 +0000