cgroup: remove the ns_cgroup
[linux-2.6.git] / init / initramfs.c
1 #include <linux/init.h>
2 #include <linux/fs.h>
3 #include <linux/slab.h>
4 #include <linux/types.h>
5 #include <linux/fcntl.h>
6 #include <linux/delay.h>
7 #include <linux/string.h>
8 #include <linux/dirent.h>
9 #include <linux/syscalls.h>
10 #include <linux/utime.h>
11
12 static __initdata char *message;
13 static void __init error(char *x)
14 {
15         if (!message)
16                 message = x;
17 }
18
19 /* link hash */
20
21 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
22
23 static __initdata struct hash {
24         int ino, minor, major;
25         mode_t mode;
26         struct hash *next;
27         char name[N_ALIGN(PATH_MAX)];
28 } *head[32];
29
30 static inline int hash(int major, int minor, int ino)
31 {
32         unsigned long tmp = ino + minor + (major << 3);
33         tmp += tmp >> 5;
34         return tmp & 31;
35 }
36
37 static char __init *find_link(int major, int minor, int ino,
38                               mode_t mode, char *name)
39 {
40         struct hash **p, *q;
41         for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
42                 if ((*p)->ino != ino)
43                         continue;
44                 if ((*p)->minor != minor)
45                         continue;
46                 if ((*p)->major != major)
47                         continue;
48                 if (((*p)->mode ^ mode) & S_IFMT)
49                         continue;
50                 return (*p)->name;
51         }
52         q = kmalloc(sizeof(struct hash), GFP_KERNEL);
53         if (!q)
54                 panic("can't allocate link hash entry");
55         q->major = major;
56         q->minor = minor;
57         q->ino = ino;
58         q->mode = mode;
59         strcpy(q->name, name);
60         q->next = NULL;
61         *p = q;
62         return NULL;
63 }
64
65 static void __init free_hash(void)
66 {
67         struct hash **p, *q;
68         for (p = head; p < head + 32; p++) {
69                 while (*p) {
70                         q = *p;
71                         *p = q->next;
72                         kfree(q);
73                 }
74         }
75 }
76
77 static long __init do_utime(char __user *filename, time_t mtime)
78 {
79         struct timespec t[2];
80
81         t[0].tv_sec = mtime;
82         t[0].tv_nsec = 0;
83         t[1].tv_sec = mtime;
84         t[1].tv_nsec = 0;
85
86         return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
87 }
88
89 static __initdata LIST_HEAD(dir_list);
90 struct dir_entry {
91         struct list_head list;
92         char *name;
93         time_t mtime;
94 };
95
96 static void __init dir_add(const char *name, time_t mtime)
97 {
98         struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
99         if (!de)
100                 panic("can't allocate dir_entry buffer");
101         INIT_LIST_HEAD(&de->list);
102         de->name = kstrdup(name, GFP_KERNEL);
103         de->mtime = mtime;
104         list_add(&de->list, &dir_list);
105 }
106
107 static void __init dir_utime(void)
108 {
109         struct dir_entry *de, *tmp;
110         list_for_each_entry_safe(de, tmp, &dir_list, list) {
111                 list_del(&de->list);
112                 do_utime(de->name, de->mtime);
113                 kfree(de->name);
114                 kfree(de);
115         }
116 }
117
118 static __initdata time_t mtime;
119
120 /* cpio header parsing */
121
122 static __initdata unsigned long ino, major, minor, nlink;
123 static __initdata mode_t mode;
124 static __initdata unsigned long body_len, name_len;
125 static __initdata uid_t uid;
126 static __initdata gid_t gid;
127 static __initdata unsigned rdev;
128
129 static void __init parse_header(char *s)
130 {
131         unsigned long parsed[12];
132         char buf[9];
133         int i;
134
135         buf[8] = '\0';
136         for (i = 0, s += 6; i < 12; i++, s += 8) {
137                 memcpy(buf, s, 8);
138                 parsed[i] = simple_strtoul(buf, NULL, 16);
139         }
140         ino = parsed[0];
141         mode = parsed[1];
142         uid = parsed[2];
143         gid = parsed[3];
144         nlink = parsed[4];
145         mtime = parsed[5];
146         body_len = parsed[6];
147         major = parsed[7];
148         minor = parsed[8];
149         rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
150         name_len = parsed[11];
151 }
152
153 /* FSM */
154
155 static __initdata enum state {
156         Start,
157         Collect,
158         GotHeader,
159         SkipIt,
160         GotName,
161         CopyFile,
162         GotSymlink,
163         Reset
164 } state, next_state;
165
166 static __initdata char *victim;
167 static __initdata unsigned count;
168 static __initdata loff_t this_header, next_header;
169
170 static inline void __init eat(unsigned n)
171 {
172         victim += n;
173         this_header += n;
174         count -= n;
175 }
176
177 static __initdata char *vcollected;
178 static __initdata char *collected;
179 static __initdata int remains;
180 static __initdata char *collect;
181
182 static void __init read_into(char *buf, unsigned size, enum state next)
183 {
184         if (count >= size) {
185                 collected = victim;
186                 eat(size);
187                 state = next;
188         } else {
189                 collect = collected = buf;
190                 remains = size;
191                 next_state = next;
192                 state = Collect;
193         }
194 }
195
196 static __initdata char *header_buf, *symlink_buf, *name_buf;
197
198 static int __init do_start(void)
199 {
200         read_into(header_buf, 110, GotHeader);
201         return 0;
202 }
203
204 static int __init do_collect(void)
205 {
206         unsigned n = remains;
207         if (count < n)
208                 n = count;
209         memcpy(collect, victim, n);
210         eat(n);
211         collect += n;
212         if ((remains -= n) != 0)
213                 return 1;
214         state = next_state;
215         return 0;
216 }
217
218 static int __init do_header(void)
219 {
220         if (memcmp(collected, "070707", 6)==0) {
221                 error("incorrect cpio method used: use -H newc option");
222                 return 1;
223         }
224         if (memcmp(collected, "070701", 6)) {
225                 error("no cpio magic");
226                 return 1;
227         }
228         parse_header(collected);
229         next_header = this_header + N_ALIGN(name_len) + body_len;
230         next_header = (next_header + 3) & ~3;
231         state = SkipIt;
232         if (name_len <= 0 || name_len > PATH_MAX)
233                 return 0;
234         if (S_ISLNK(mode)) {
235                 if (body_len > PATH_MAX)
236                         return 0;
237                 collect = collected = symlink_buf;
238                 remains = N_ALIGN(name_len) + body_len;
239                 next_state = GotSymlink;
240                 state = Collect;
241                 return 0;
242         }
243         if (S_ISREG(mode) || !body_len)
244                 read_into(name_buf, N_ALIGN(name_len), GotName);
245         return 0;
246 }
247
248 static int __init do_skip(void)
249 {
250         if (this_header + count < next_header) {
251                 eat(count);
252                 return 1;
253         } else {
254                 eat(next_header - this_header);
255                 state = next_state;
256                 return 0;
257         }
258 }
259
260 static int __init do_reset(void)
261 {
262         while(count && *victim == '\0')
263                 eat(1);
264         if (count && (this_header & 3))
265                 error("broken padding");
266         return 1;
267 }
268
269 static int __init maybe_link(void)
270 {
271         if (nlink >= 2) {
272                 char *old = find_link(major, minor, ino, mode, collected);
273                 if (old)
274                         return (sys_link(old, collected) < 0) ? -1 : 1;
275         }
276         return 0;
277 }
278
279 static void __init clean_path(char *path, mode_t mode)
280 {
281         struct stat st;
282
283         if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
284                 if (S_ISDIR(st.st_mode))
285                         sys_rmdir(path);
286                 else
287                         sys_unlink(path);
288         }
289 }
290
291 static __initdata int wfd;
292
293 static int __init do_name(void)
294 {
295         state = SkipIt;
296         next_state = Reset;
297         if (strcmp(collected, "TRAILER!!!") == 0) {
298                 free_hash();
299                 return 0;
300         }
301         clean_path(collected, mode);
302         if (S_ISREG(mode)) {
303                 int ml = maybe_link();
304                 if (ml >= 0) {
305                         int openflags = O_WRONLY|O_CREAT;
306                         if (ml != 1)
307                                 openflags |= O_TRUNC;
308                         wfd = sys_open(collected, openflags, mode);
309
310                         if (wfd >= 0) {
311                                 sys_fchown(wfd, uid, gid);
312                                 sys_fchmod(wfd, mode);
313                                 if (body_len)
314                                         sys_ftruncate(wfd, body_len);
315                                 vcollected = kstrdup(collected, GFP_KERNEL);
316                                 state = CopyFile;
317                         }
318                 }
319         } else if (S_ISDIR(mode)) {
320                 sys_mkdir(collected, mode);
321                 sys_chown(collected, uid, gid);
322                 sys_chmod(collected, mode);
323                 dir_add(collected, mtime);
324         } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
325                    S_ISFIFO(mode) || S_ISSOCK(mode)) {
326                 if (maybe_link() == 0) {
327                         sys_mknod(collected, mode, rdev);
328                         sys_chown(collected, uid, gid);
329                         sys_chmod(collected, mode);
330                         do_utime(collected, mtime);
331                 }
332         }
333         return 0;
334 }
335
336 static int __init do_copy(void)
337 {
338         if (count >= body_len) {
339                 sys_write(wfd, victim, body_len);
340                 sys_close(wfd);
341                 do_utime(vcollected, mtime);
342                 kfree(vcollected);
343                 eat(body_len);
344                 state = SkipIt;
345                 return 0;
346         } else {
347                 sys_write(wfd, victim, count);
348                 body_len -= count;
349                 eat(count);
350                 return 1;
351         }
352 }
353
354 static int __init do_symlink(void)
355 {
356         collected[N_ALIGN(name_len) + body_len] = '\0';
357         clean_path(collected, 0);
358         sys_symlink(collected + N_ALIGN(name_len), collected);
359         sys_lchown(collected, uid, gid);
360         do_utime(collected, mtime);
361         state = SkipIt;
362         next_state = Reset;
363         return 0;
364 }
365
366 static __initdata int (*actions[])(void) = {
367         [Start]         = do_start,
368         [Collect]       = do_collect,
369         [GotHeader]     = do_header,
370         [SkipIt]        = do_skip,
371         [GotName]       = do_name,
372         [CopyFile]      = do_copy,
373         [GotSymlink]    = do_symlink,
374         [Reset]         = do_reset,
375 };
376
377 static int __init write_buffer(char *buf, unsigned len)
378 {
379         count = len;
380         victim = buf;
381
382         while (!actions[state]())
383                 ;
384         return len - count;
385 }
386
387 static int __init flush_buffer(void *bufv, unsigned len)
388 {
389         char *buf = (char *) bufv;
390         int written;
391         int origLen = len;
392         if (message)
393                 return -1;
394         while ((written = write_buffer(buf, len)) < len && !message) {
395                 char c = buf[written];
396                 if (c == '0') {
397                         buf += written;
398                         len -= written;
399                         state = Start;
400                 } else if (c == 0) {
401                         buf += written;
402                         len -= written;
403                         state = Reset;
404                 } else
405                         error("junk in compressed archive");
406         }
407         return origLen;
408 }
409
410 static unsigned my_inptr;   /* index of next byte to be processed in inbuf */
411
412 #include <linux/decompress/generic.h>
413
414 static char * __init unpack_to_rootfs(char *buf, unsigned len)
415 {
416         int written, res;
417         decompress_fn decompress;
418         const char *compress_name;
419         static __initdata char msg_buf[64];
420
421         header_buf = kmalloc(110, GFP_KERNEL);
422         symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
423         name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
424
425         if (!header_buf || !symlink_buf || !name_buf)
426                 panic("can't allocate buffers");
427
428         state = Start;
429         this_header = 0;
430         message = NULL;
431         while (!message && len) {
432                 loff_t saved_offset = this_header;
433                 if (*buf == '0' && !(this_header & 3)) {
434                         state = Start;
435                         written = write_buffer(buf, len);
436                         buf += written;
437                         len -= written;
438                         continue;
439                 }
440                 if (!*buf) {
441                         buf++;
442                         len--;
443                         this_header++;
444                         continue;
445                 }
446                 this_header = 0;
447                 decompress = decompress_method(buf, len, &compress_name);
448                 if (decompress) {
449                         res = decompress(buf, len, NULL, flush_buffer, NULL,
450                                    &my_inptr, error);
451                         if (res)
452                                 error("decompressor failed");
453                 } else if (compress_name) {
454                         if (!message) {
455                                 snprintf(msg_buf, sizeof msg_buf,
456                                          "compression method %s not configured",
457                                          compress_name);
458                                 message = msg_buf;
459                         }
460                 } else
461                         error("junk in compressed archive");
462                 if (state != Reset)
463                         error("junk in compressed archive");
464                 this_header = saved_offset + my_inptr;
465                 buf += my_inptr;
466                 len -= my_inptr;
467         }
468         dir_utime();
469         kfree(name_buf);
470         kfree(symlink_buf);
471         kfree(header_buf);
472         return message;
473 }
474
475 static int __initdata do_retain_initrd;
476
477 static int __init retain_initrd_param(char *str)
478 {
479         if (*str)
480                 return 0;
481         do_retain_initrd = 1;
482         return 1;
483 }
484 __setup("retain_initrd", retain_initrd_param);
485
486 extern char __initramfs_start[];
487 extern unsigned long __initramfs_size;
488 #include <linux/initrd.h>
489 #include <linux/kexec.h>
490
491 static void __init free_initrd(void)
492 {
493 #ifdef CONFIG_KEXEC
494         unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
495         unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
496 #endif
497         if (do_retain_initrd)
498                 goto skip;
499
500 #ifdef CONFIG_KEXEC
501         /*
502          * If the initrd region is overlapped with crashkernel reserved region,
503          * free only memory that is not part of crashkernel region.
504          */
505         if (initrd_start < crashk_end && initrd_end > crashk_start) {
506                 /*
507                  * Initialize initrd memory region since the kexec boot does
508                  * not do.
509                  */
510                 memset((void *)initrd_start, 0, initrd_end - initrd_start);
511                 if (initrd_start < crashk_start)
512                         free_initrd_mem(initrd_start, crashk_start);
513                 if (initrd_end > crashk_end)
514                         free_initrd_mem(crashk_end, initrd_end);
515         } else
516 #endif
517                 free_initrd_mem(initrd_start, initrd_end);
518 skip:
519         initrd_start = 0;
520         initrd_end = 0;
521 }
522
523 #ifdef CONFIG_BLK_DEV_RAM
524 #define BUF_SIZE 1024
525 static void __init clean_rootfs(void)
526 {
527         int fd;
528         void *buf;
529         struct linux_dirent64 *dirp;
530         int num;
531
532         fd = sys_open((const char __user __force *) "/", O_RDONLY, 0);
533         WARN_ON(fd < 0);
534         if (fd < 0)
535                 return;
536         buf = kzalloc(BUF_SIZE, GFP_KERNEL);
537         WARN_ON(!buf);
538         if (!buf) {
539                 sys_close(fd);
540                 return;
541         }
542
543         dirp = buf;
544         num = sys_getdents64(fd, dirp, BUF_SIZE);
545         while (num > 0) {
546                 while (num > 0) {
547                         struct stat st;
548                         int ret;
549
550                         ret = sys_newlstat(dirp->d_name, &st);
551                         WARN_ON_ONCE(ret);
552                         if (!ret) {
553                                 if (S_ISDIR(st.st_mode))
554                                         sys_rmdir(dirp->d_name);
555                                 else
556                                         sys_unlink(dirp->d_name);
557                         }
558
559                         num -= dirp->d_reclen;
560                         dirp = (void *)dirp + dirp->d_reclen;
561                 }
562                 dirp = buf;
563                 memset(buf, 0, BUF_SIZE);
564                 num = sys_getdents64(fd, dirp, BUF_SIZE);
565         }
566
567         sys_close(fd);
568         kfree(buf);
569 }
570 #endif
571
572 static int __init populate_rootfs(void)
573 {
574         char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
575         if (err)
576                 panic(err);     /* Failed to decompress INTERNAL initramfs */
577         if (initrd_start) {
578 #ifdef CONFIG_BLK_DEV_RAM
579                 int fd;
580                 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
581                 err = unpack_to_rootfs((char *)initrd_start,
582                         initrd_end - initrd_start);
583                 if (!err) {
584                         free_initrd();
585                         return 0;
586                 } else {
587                         clean_rootfs();
588                         unpack_to_rootfs(__initramfs_start, __initramfs_size);
589                 }
590                 printk(KERN_INFO "rootfs image is not initramfs (%s)"
591                                 "; looks like an initrd\n", err);
592                 fd = sys_open((const char __user __force *) "/initrd.image",
593                               O_WRONLY|O_CREAT, 0700);
594                 if (fd >= 0) {
595                         sys_write(fd, (char *)initrd_start,
596                                         initrd_end - initrd_start);
597                         sys_close(fd);
598                         free_initrd();
599                 }
600 #else
601                 printk(KERN_INFO "Unpacking initramfs...\n");
602                 err = unpack_to_rootfs((char *)initrd_start,
603                         initrd_end - initrd_start);
604                 if (err)
605                         printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
606                 free_initrd();
607 #endif
608         }
609         return 0;
610 }
611 rootfs_initcall(populate_rootfs);