summaryrefslogtreecommitdiffstats
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.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
new file mode 100644
index 0000000000..ac021ae6e6
--- /dev/null
+++ b/init/do_mounts_rd.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0
+#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>
+
+static struct file *in_file, *out_file;
+static loff_t in_pos, out_pos;
+
+static int __init prompt_ramdisk(char *str)
+{
+ pr_warn("ignoring the deprecated prompt_ramdisk= option\n");
+ 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(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(struct file *file, loff_t pos,
+ 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;
+ int start_block = rd_image_start;
+
+ 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
+ */
+ pos = start_block * BLOCK_SIZE;
+ kernel_read(file, buf, size, &pos);
+
+ *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
+ */
+ pos = start_block * BLOCK_SIZE + 0x200;
+ kernel_read(file, buf, size, &pos);
+
+ 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
+ */
+ pos = (start_block + 1) * BLOCK_SIZE;
+ kernel_read(file, buf, size, &pos);
+
+ /* 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:
+ kfree(buf);
+ return nblocks;
+}
+
+static unsigned long nr_blocks(struct file *file)
+{
+ struct inode *inode = file->f_mapping->host;
+
+ if (!S_ISBLK(inode->i_mode))
+ return 0;
+ return i_size_read(inode) >> 10;
+}
+
+int __init rd_load_image(char *from)
+{
+ int res = 0;
+ unsigned long rd_blocks, devblocks;
+ int nblocks, i;
+ char *buf = NULL;
+ unsigned short rotate = 0;
+ decompress_fn decompressor = NULL;
+#if !defined(CONFIG_S390)
+ char rotator[4] = { '|' , '/' , '-' , '\\' };
+#endif
+
+ out_file = filp_open("/dev/ram", O_RDWR, 0);
+ if (IS_ERR(out_file))
+ goto out;
+
+ in_file = filp_open(from, O_RDONLY, 0);
+ if (IS_ERR(in_file))
+ goto noclose_input;
+
+ in_pos = rd_image_start * BLOCK_SIZE;
+ nblocks = identify_ramdisk_image(in_file, in_pos, &decompressor);
+ if (nblocks < 0)
+ goto done;
+
+ if (nblocks == 0) {
+ if (crd_load(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.
+ */
+ rd_blocks = nr_blocks(out_file);
+ 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 (strcmp(from, "/initrd.image") == 0)
+ devblocks = nblocks;
+ else
+ devblocks = nr_blocks(in_file);
+
+ 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; i < nblocks; i++) {
+ if (i && (i % devblocks == 0)) {
+ pr_cont("done disk #1.\n");
+ rotate = 0;
+ fput(in_file);
+ break;
+ }
+ kernel_read(in_file, buf, BLOCK_SIZE, &in_pos);
+ kernel_write(out_file, buf, BLOCK_SIZE, &out_pos);
+#if !defined(CONFIG_S390)
+ if (!(i % 16)) {
+ pr_cont("%c\b", rotator[rotate & 0x3]);
+ rotate++;
+ }
+#endif
+ }
+ pr_cont("done.\n");
+
+successful_load:
+ res = 1;
+done:
+ fput(in_file);
+noclose_input:
+ fput(out_file);
+out:
+ kfree(buf);
+ init_unlink("/dev/ram");
+ return res;
+}
+
+int __init rd_load_disk(int n)
+{
+ 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 long __init compr_fill(void *buf, unsigned long len)
+{
+ long r = kernel_read(in_file, buf, len, &in_pos);
+ 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 = kernel_write(out_file, window, outcnt, &out_pos);
+ 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(decompress_fn deco)
+{
+ int result;
+
+ 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;
+}