module: reduce symbol table for loaded modules (v2)
[linux-block.git] / init / do_mounts_rd.c
CommitLineData
1da177e4
LT
1
2#include <linux/kernel.h>
3#include <linux/fs.h>
4#include <linux/minix_fs.h>
5#include <linux/ext2_fs.h>
6#include <linux/romfs_fs.h>
7#include <linux/cramfs_fs.h>
8#include <linux/initrd.h>
9#include <linux/string.h>
10
11#include "do_mounts.h"
b8fed87d 12#include "../fs/squashfs/squashfs_fs.h"
1da177e4 13
30d65dbf
AK
14#include <linux/decompress/generic.h>
15
30d65dbf 16
1da177e4
LT
17int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */
18
19static int __init prompt_ramdisk(char *str)
20{
21 rd_prompt = simple_strtol(str,NULL,0) & 1;
22 return 1;
23}
24__setup("prompt_ramdisk=", prompt_ramdisk);
25
26int __initdata rd_image_start; /* starting block # of image */
27
28static int __init ramdisk_start_setup(char *str)
29{
30 rd_image_start = simple_strtol(str,NULL,0);
31 return 1;
32}
33__setup("ramdisk_start=", ramdisk_start_setup);
34
30d65dbf 35static int __init crd_load(int in_fd, int out_fd, decompress_fn deco);
1da177e4
LT
36
37/*
38 * This routine tries to find a RAM disk image to load, and returns the
39 * number of blocks to read for a non-compressed image, 0 if the image
40 * is a compressed image, and -1 if an image with the right magic
41 * numbers could not be found.
42 *
43 * We currently check for the following magic numbers:
b172fd88
PA
44 * minix
45 * ext2
1da177e4
LT
46 * romfs
47 * cramfs
b8fed87d 48 * squashfs
b172fd88 49 * gzip
1da177e4 50 */
b172fd88 51static int __init
30d65dbf 52identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
1da177e4
LT
53{
54 const int size = 512;
55 struct minix_super_block *minixsb;
56 struct ext2_super_block *ext2sb;
57 struct romfs_super_block *romfsb;
58 struct cramfs_super *cramfsb;
b8fed87d 59 struct squashfs_super_block *squashfsb;
1da177e4
LT
60 int nblocks = -1;
61 unsigned char *buf;
889c92d2 62 const char *compress_name;
1da177e4
LT
63
64 buf = kmalloc(size, GFP_KERNEL);
c80544dc 65 if (!buf)
1da177e4
LT
66 return -1;
67
68 minixsb = (struct minix_super_block *) buf;
69 ext2sb = (struct ext2_super_block *) buf;
70 romfsb = (struct romfs_super_block *) buf;
71 cramfsb = (struct cramfs_super *) buf;
b8fed87d 72 squashfsb = (struct squashfs_super_block *) buf;
1da177e4
LT
73 memset(buf, 0xe5, size);
74
75 /*
b172fd88 76 * Read block 0 to test for compressed kernel
1da177e4
LT
77 */
78 sys_lseek(fd, start_block * BLOCK_SIZE, 0);
79 sys_read(fd, buf, size);
80
889c92d2 81 *decompressor = decompress_method(buf, size, &compress_name);
23a22d57 82 if (compress_name) {
889c92d2
PA
83 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
84 compress_name, start_block);
23a22d57 85 if (!*decompressor)
73310a16
PA
86 printk(KERN_EMERG
87 "RAMDISK: %s decompressor not configured!\n",
23a22d57 88 compress_name);
889c92d2
PA
89 nblocks = 0;
90 goto done;
1da177e4
LT
91 }
92
93 /* romfs is at block zero too */
94 if (romfsb->word0 == ROMSB_WORD0 &&
95 romfsb->word1 == ROMSB_WORD1) {
96 printk(KERN_NOTICE
97 "RAMDISK: romfs filesystem found at block %d\n",
98 start_block);
99 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS;
100 goto done;
101 }
102
103 if (cramfsb->magic == CRAMFS_MAGIC) {
104 printk(KERN_NOTICE
105 "RAMDISK: cramfs filesystem found at block %d\n",
106 start_block);
107 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
108 goto done;
109 }
110
b8fed87d
PL
111 /* squashfs is at block zero too */
112 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) {
113 printk(KERN_NOTICE
114 "RAMDISK: squashfs filesystem found at block %d\n",
115 start_block);
116 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1)
117 >> BLOCK_SIZE_BITS;
118 goto done;
119 }
120
1da177e4
LT
121 /*
122 * Read block 1 to test for minix and ext2 superblock
123 */
124 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0);
125 sys_read(fd, buf, size);
126
127 /* Try minix */
128 if (minixsb->s_magic == MINIX_SUPER_MAGIC ||
129 minixsb->s_magic == MINIX_SUPER_MAGIC2) {
130 printk(KERN_NOTICE
131 "RAMDISK: Minix filesystem found at block %d\n",
132 start_block);
133 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size;
134 goto done;
135 }
136
137 /* Try ext2 */
138 if (ext2sb->s_magic == cpu_to_le16(EXT2_SUPER_MAGIC)) {
139 printk(KERN_NOTICE
140 "RAMDISK: ext2 filesystem found at block %d\n",
141 start_block);
142 nblocks = le32_to_cpu(ext2sb->s_blocks_count) <<
143 le32_to_cpu(ext2sb->s_log_block_size);
144 goto done;
145 }
146
147 printk(KERN_NOTICE
148 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n",
149 start_block);
b172fd88 150
1da177e4
LT
151done:
152 sys_lseek(fd, start_block * BLOCK_SIZE, 0);
153 kfree(buf);
154 return nblocks;
155}
156
157int __init rd_load_image(char *from)
158{
159 int res = 0;
160 int in_fd, out_fd;
161 unsigned long rd_blocks, devblocks;
162 int nblocks, i, disk;
163 char *buf = NULL;
164 unsigned short rotate = 0;
30d65dbf 165 decompress_fn decompressor = NULL;
347a8dc3 166#if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES)
1da177e4
LT
167 char rotator[4] = { '|' , '/' , '-' , '\\' };
168#endif
169
170 out_fd = sys_open("/dev/ram", O_RDWR, 0);
171 if (out_fd < 0)
172 goto out;
173
174 in_fd = sys_open(from, O_RDONLY, 0);
175 if (in_fd < 0)
176 goto noclose_input;
177
30d65dbf 178 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);
1da177e4
LT
179 if (nblocks < 0)
180 goto done;
181
182 if (nblocks == 0) {
30d65dbf 183 if (crd_load(in_fd, out_fd, decompressor) == 0)
1da177e4 184 goto successful_load;
1da177e4
LT
185 goto done;
186 }
187
188 /*
189 * NOTE NOTE: nblocks is not actually blocks but
190 * the number of kibibytes of data to load into a ramdisk.
191 * So any ramdisk block size that is a multiple of 1KiB should
192 * work when the appropriate ramdisk_blocksize is specified
193 * on the command line.
194 *
195 * The default ramdisk_blocksize is 1KiB and it is generally
196 * silly to use anything else, so make sure to use 1KiB
197 * blocksize while generating ext2fs ramdisk-images.
198 */
199 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0)
200 rd_blocks = 0;
201 else
202 rd_blocks >>= 1;
203
204 if (nblocks > rd_blocks) {
205 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n",
206 nblocks, rd_blocks);
207 goto done;
208 }
b172fd88 209
1da177e4
LT
210 /*
211 * OK, time to copy in the data
212 */
213 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0)
214 devblocks = 0;
215 else
216 devblocks >>= 1;
217
218 if (strcmp(from, "/initrd.image") == 0)
219 devblocks = nblocks;
220
221 if (devblocks == 0) {
222 printk(KERN_ERR "RAMDISK: could not determine device size\n");
223 goto done;
224 }
225
226 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL);
d613c3e2 227 if (!buf) {
1da177e4
LT
228 printk(KERN_ERR "RAMDISK: could not allocate buffer\n");
229 goto done;
230 }
231
232 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ",
233 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : "");
234 for (i = 0, disk = 1; i < nblocks; i++) {
235 if (i && (i % devblocks == 0)) {
236 printk("done disk #%d.\n", disk++);
237 rotate = 0;
238 if (sys_close(in_fd)) {
239 printk("Error closing the disk.\n");
240 goto noclose_input;
241 }
242 change_floppy("disk #%d", disk);
243 in_fd = sys_open(from, O_RDONLY, 0);
244 if (in_fd < 0) {
245 printk("Error opening disk.\n");
246 goto noclose_input;
247 }
248 printk("Loading disk #%d... ", disk);
249 }
250 sys_read(in_fd, buf, BLOCK_SIZE);
251 sys_write(out_fd, buf, BLOCK_SIZE);
347a8dc3 252#if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES)
1da177e4
LT
253 if (!(i % 16)) {
254 printk("%c\b", rotator[rotate & 0x3]);
255 rotate++;
256 }
257#endif
258 }
259 printk("done.\n");
260
261successful_load:
262 res = 1;
263done:
264 sys_close(in_fd);
265noclose_input:
266 sys_close(out_fd);
267out:
268 kfree(buf);
269 sys_unlink("/dev/ram");
270 return res;
271}
272
273int __init rd_load_disk(int n)
274{
275 if (rd_prompt)
276 change_floppy("root floppy disk to be loaded into RAM disk");
bdaf8529
GKH
277 create_dev("/dev/root", ROOT_DEV);
278 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
1da177e4
LT
279 return rd_load_image("/dev/root");
280}
281
1da177e4 282static int exit_code;
30d65dbf 283static int decompress_error;
1da177e4
LT
284static int crd_infd, crd_outfd;
285
30d65dbf 286static int __init compr_fill(void *buf, unsigned int len)
1da177e4 287{
30d65dbf
AK
288 int r = sys_read(crd_infd, buf, len);
289 if (r < 0)
290 printk(KERN_ERR "RAMDISK: error while reading compressed data");
291 else if (r == 0)
292 printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
293 return r;
1da177e4
LT
294}
295
30d65dbf 296static int __init compr_flush(void *window, unsigned int outcnt)
1da177e4 297{
30d65dbf
AK
298 int written = sys_write(crd_outfd, window, outcnt);
299 if (written != outcnt) {
300 if (decompress_error == 0)
301 printk(KERN_ERR
302 "RAMDISK: incomplete write (%d != %d)\n",
303 written, outcnt);
304 decompress_error = 1;
305 return -1;
306 }
307 return outcnt;
1da177e4
LT
308}
309
310static void __init error(char *x)
311{
312 printk(KERN_ERR "%s\n", x);
313 exit_code = 1;
30d65dbf 314 decompress_error = 1;
1da177e4
LT
315}
316
30d65dbf 317static int __init crd_load(int in_fd, int out_fd, decompress_fn deco)
1da177e4
LT
318{
319 int result;
1da177e4
LT
320 crd_infd = in_fd;
321 crd_outfd = out_fd;
30d65dbf
AK
322 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
323 if (decompress_error)
1da177e4 324 result = 1;
1da177e4
LT
325 return result;
326}