do_mounts_rd.c 8.33 KB
Newer Older
1 2 3 4 5 6 7 8 9
/*
 * 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
Linus Torvalds's avatar
Linus Torvalds committed
10 11 12 13 14 15

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/minix_fs.h>
#include <linux/ext2_fs.h>
#include <linux/romfs_fs.h>
16
#include <uapi/linux/cramfs_fs.h>
Linus Torvalds's avatar
Linus Torvalds committed
17 18
#include <linux/initrd.h>
#include <linux/string.h>
19
#include <linux/slab.h>
Linus Torvalds's avatar
Linus Torvalds committed
20 21

#include "do_mounts.h"
22
#include "../fs/squashfs/squashfs_fs.h"
Linus Torvalds's avatar
Linus Torvalds committed
23

24 25 26
#include <linux/decompress/generic.h>


Linus Torvalds's avatar
Linus Torvalds committed
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
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);

45
static int __init crd_load(int in_fd, int out_fd, decompress_fn deco);
Linus Torvalds's avatar
Linus Torvalds committed
46 47 48 49 50 51 52 53

/*
 * 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:
54 55
 *	minix
 *	ext2
Linus Torvalds's avatar
Linus Torvalds committed
56 57
 *	romfs
 *	cramfs
58
 *	squashfs
59
 *	gzip
60 61 62 63 64
 *	bzip2
 *	lzma
 *	xz
 *	lzo
 *	lz4
Linus Torvalds's avatar
Linus Torvalds committed
65
 */
66
static int __init
67
identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
Linus Torvalds's avatar
Linus Torvalds committed
68 69 70 71 72
{
	const int size = 512;
	struct minix_super_block *minixsb;
	struct romfs_super_block *romfsb;
	struct cramfs_super *cramfsb;
73
	struct squashfs_super_block *squashfsb;
Linus Torvalds's avatar
Linus Torvalds committed
74 75
	int nblocks = -1;
	unsigned char *buf;
76
	const char *compress_name;
Al Viro's avatar
Al Viro committed
77
	unsigned long n;
Linus Torvalds's avatar
Linus Torvalds committed
78 79

	buf = kmalloc(size, GFP_KERNEL);
80
	if (!buf)
81
		return -ENOMEM;
Linus Torvalds's avatar
Linus Torvalds committed
82 83 84 85

	minixsb = (struct minix_super_block *) buf;
	romfsb = (struct romfs_super_block *) buf;
	cramfsb = (struct cramfs_super *) buf;
86
	squashfsb = (struct squashfs_super_block *) buf;
Linus Torvalds's avatar
Linus Torvalds committed
87 88 89
	memset(buf, 0xe5, size);

	/*
90
	 * Read block 0 to test for compressed kernel
Linus Torvalds's avatar
Linus Torvalds committed
91 92 93 94
	 */
	sys_lseek(fd, start_block * BLOCK_SIZE, 0);
	sys_read(fd, buf, size);

95
	*decompressor = decompress_method(buf, size, &compress_name);
96
	if (compress_name) {
97 98
		printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
		       compress_name, start_block);
99
		if (!*decompressor)
100 101
			printk(KERN_EMERG
			       "RAMDISK: %s decompressor not configured!\n",
102
			       compress_name);
103 104
		nblocks = 0;
		goto done;
Linus Torvalds's avatar
Linus Torvalds committed
105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124
	}

	/* 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;
	}

125 126 127 128 129 130 131 132 133 134
	/* 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;
	}

135 136 137 138 139 140 141 142 143 144 145 146 147 148
	/*
	 * 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;
	}

Linus Torvalds's avatar
Linus Torvalds committed
149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165
	/*
	 * 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 */
Al Viro's avatar
Al Viro committed
166 167
	n = ext2_image_size(buf);
	if (n) {
Linus Torvalds's avatar
Linus Torvalds committed
168 169 170
		printk(KERN_NOTICE
		       "RAMDISK: ext2 filesystem found at block %d\n",
		       start_block);
Al Viro's avatar
Al Viro committed
171
		nblocks = n;
Linus Torvalds's avatar
Linus Torvalds committed
172 173 174 175 176 177
		goto done;
	}

	printk(KERN_NOTICE
	       "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
	       start_block);
178

Linus Torvalds's avatar
Linus Torvalds committed
179 180 181 182 183 184 185 186 187 188 189 190 191 192
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;
193
	decompress_fn decompressor = NULL;
194
#if !defined(CONFIG_S390)
Linus Torvalds's avatar
Linus Torvalds committed
195 196 197
	char rotator[4] = { '|' , '/' , '-' , '\\' };
#endif

198
	out_fd = sys_open("/dev/ram", O_RDWR, 0);
Linus Torvalds's avatar
Linus Torvalds committed
199 200 201 202 203 204 205
	if (out_fd < 0)
		goto out;

	in_fd = sys_open(from, O_RDONLY, 0);
	if (in_fd < 0)
		goto noclose_input;

206
	nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);
Linus Torvalds's avatar
Linus Torvalds committed
207 208 209 210
	if (nblocks < 0)
		goto done;

	if (nblocks == 0) {
211
		if (crd_load(in_fd, out_fd, decompressor) == 0)
Linus Torvalds's avatar
Linus Torvalds committed
212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229
			goto successful_load;
		goto done;
	}

	/*
	 * NOTE NOTE: nblocks is not actually blocks but
	 * the number of kibibytes of data to load into a ramdisk.
	 */
	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;
	}
230

Linus Torvalds's avatar
Linus Torvalds committed
231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247
	/*
	 * 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);
248
	if (!buf) {
Linus Torvalds's avatar
Linus Torvalds committed
249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272
		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);
273
#if !defined(CONFIG_S390)
Linus Torvalds's avatar
Linus Torvalds committed
274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289
		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);
290
	sys_unlink("/dev/ram");
Linus Torvalds's avatar
Linus Torvalds committed
291 292 293 294 295 296 297
	return res;
}

int __init rd_load_disk(int n)
{
	if (rd_prompt)
		change_floppy("root floppy disk to be loaded into RAM disk");
298 299
	create_dev("/dev/root", ROOT_DEV);
	create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
Linus Torvalds's avatar
Linus Torvalds committed
300 301 302 303
	return rd_load_image("/dev/root");
}

static int exit_code;
304
static int decompress_error;
Linus Torvalds's avatar
Linus Torvalds committed
305 306
static int crd_infd, crd_outfd;

307
static long __init compr_fill(void *buf, unsigned long len)
Linus Torvalds's avatar
Linus Torvalds committed
308
{
309
	long r = sys_read(crd_infd, buf, len);
310 311 312 313 314
	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;
Linus Torvalds's avatar
Linus Torvalds committed
315 316
}

317
static long __init compr_flush(void *window, unsigned long outcnt)
Linus Torvalds's avatar
Linus Torvalds committed
318
{
319
	long written = sys_write(crd_outfd, window, outcnt);
320 321 322
	if (written != outcnt) {
		if (decompress_error == 0)
			printk(KERN_ERR
323
			       "RAMDISK: incomplete write (%ld != %ld)\n",
324 325 326 327 328
			       written, outcnt);
		decompress_error = 1;
		return -1;
	}
	return outcnt;
Linus Torvalds's avatar
Linus Torvalds committed
329 330 331 332 333 334
}

static void __init error(char *x)
{
	printk(KERN_ERR "%s\n", x);
	exit_code = 1;
335
	decompress_error = 1;
Linus Torvalds's avatar
Linus Torvalds committed
336 337
}

338
static int __init crd_load(int in_fd, int out_fd, decompress_fn deco)
Linus Torvalds's avatar
Linus Torvalds committed
339 340 341 342
{
	int result;
	crd_infd = in_fd;
	crd_outfd = out_fd;
343 344 345 346 347 348 349

	if (!deco) {
		pr_emerg("Invalid ramdisk decompression routine.  "
			 "Select appropriate config option.\n");
		panic("Could not decompress initial ramdisk image.");
	}

350 351
	result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
	if (decompress_error)
Linus Torvalds's avatar
Linus Torvalds committed
352 353 354
		result = 1;
	return result;
}