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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) | |
3 | * Licensed under the GPL | |
4 | */ | |
5 | ||
6 | /* 2001-09-28...2002-04-17 | |
7 | * Partition stuff by James_McMechan@hotmail.com | |
8 | * old style ubd by setting UBD_SHIFT to 0 | |
9 | * 2002-09-27...2002-10-18 massive tinkering for 2.5 | |
10 | * partitions have changed in 2.5 | |
11 | * 2003-01-29 more tinkering for 2.5.59-1 | |
12 | * This should now address the sysfs problems and has | |
13 | * the symlink for devfs to allow for booting with | |
14 | * the common /dev/ubd/discX/... names rather than | |
15 | * only /dev/ubdN/discN this version also has lots of | |
16 | * clean ups preparing for ubd-many. | |
17 | * James McMechan | |
18 | */ | |
19 | ||
20 | #define MAJOR_NR UBD_MAJOR | |
21 | #define UBD_SHIFT 4 | |
22 | ||
23 | #include "linux/config.h" | |
24 | #include "linux/module.h" | |
25 | #include "linux/blkdev.h" | |
26 | #include "linux/hdreg.h" | |
27 | #include "linux/init.h" | |
28 | #include "linux/devfs_fs_kernel.h" | |
29 | #include "linux/cdrom.h" | |
30 | #include "linux/proc_fs.h" | |
31 | #include "linux/ctype.h" | |
32 | #include "linux/capability.h" | |
33 | #include "linux/mm.h" | |
34 | #include "linux/vmalloc.h" | |
35 | #include "linux/blkpg.h" | |
36 | #include "linux/genhd.h" | |
37 | #include "linux/spinlock.h" | |
38 | #include "asm/segment.h" | |
39 | #include "asm/uaccess.h" | |
40 | #include "asm/irq.h" | |
41 | #include "asm/types.h" | |
42 | #include "asm/tlbflush.h" | |
43 | #include "user_util.h" | |
44 | #include "mem_user.h" | |
45 | #include "kern_util.h" | |
46 | #include "kern.h" | |
47 | #include "mconsole_kern.h" | |
48 | #include "init.h" | |
49 | #include "irq_user.h" | |
50 | #include "irq_kern.h" | |
51 | #include "ubd_user.h" | |
1da177e4 LT |
52 | #include "os.h" |
53 | #include "mem.h" | |
54 | #include "mem_kern.h" | |
55 | #include "cow.h" | |
56 | ||
7b9014c1 | 57 | enum ubd_req { UBD_READ, UBD_WRITE }; |
1da177e4 LT |
58 | |
59 | struct io_thread_req { | |
60 | enum ubd_req op; | |
61 | int fds[2]; | |
62 | unsigned long offsets[2]; | |
63 | unsigned long long offset; | |
64 | unsigned long length; | |
65 | char *buffer; | |
66 | int sectorsize; | |
67 | unsigned long sector_mask; | |
68 | unsigned long long cow_offset; | |
69 | unsigned long bitmap_words[2]; | |
1da177e4 LT |
70 | int error; |
71 | }; | |
72 | ||
73 | extern int open_ubd_file(char *file, struct openflags *openflags, | |
74 | char **backing_file_out, int *bitmap_offset_out, | |
75 | unsigned long *bitmap_len_out, int *data_offset_out, | |
76 | int *create_cow_out); | |
77 | extern int create_cow_file(char *cow_file, char *backing_file, | |
78 | struct openflags flags, int sectorsize, | |
79 | int alignment, int *bitmap_offset_out, | |
80 | unsigned long *bitmap_len_out, | |
81 | int *data_offset_out); | |
82 | extern int read_cow_bitmap(int fd, void *buf, int offset, int len); | |
83 | extern void do_io(struct io_thread_req *req); | |
84 | ||
85 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) | |
86 | { | |
87 | __u64 n; | |
88 | int bits, off; | |
89 | ||
90 | bits = sizeof(data[0]) * 8; | |
91 | n = bit / bits; | |
92 | off = bit % bits; | |
93 | return((data[n] & (1 << off)) != 0); | |
94 | } | |
95 | ||
96 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) | |
97 | { | |
98 | __u64 n; | |
99 | int bits, off; | |
100 | ||
101 | bits = sizeof(data[0]) * 8; | |
102 | n = bit / bits; | |
103 | off = bit % bits; | |
104 | data[n] |= (1 << off); | |
105 | } | |
106 | /*End stuff from ubd_user.h*/ | |
107 | ||
108 | #define DRIVER_NAME "uml-blkdev" | |
109 | ||
110 | static DEFINE_SPINLOCK(ubd_io_lock); | |
111 | static DEFINE_SPINLOCK(ubd_lock); | |
112 | ||
113 | static void (*do_ubd)(void); | |
114 | ||
115 | static int ubd_open(struct inode * inode, struct file * filp); | |
116 | static int ubd_release(struct inode * inode, struct file * file); | |
117 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
118 | unsigned int cmd, unsigned long arg); | |
119 | ||
120 | #define MAX_DEV (8) | |
121 | ||
1da177e4 LT |
122 | static struct block_device_operations ubd_blops = { |
123 | .owner = THIS_MODULE, | |
124 | .open = ubd_open, | |
125 | .release = ubd_release, | |
126 | .ioctl = ubd_ioctl, | |
127 | }; | |
128 | ||
129 | /* Protected by the queue_lock */ | |
130 | static request_queue_t *ubd_queue; | |
131 | ||
132 | /* Protected by ubd_lock */ | |
133 | static int fake_major = MAJOR_NR; | |
134 | ||
135 | static struct gendisk *ubd_gendisk[MAX_DEV]; | |
136 | static struct gendisk *fake_gendisk[MAX_DEV]; | |
137 | ||
138 | #ifdef CONFIG_BLK_DEV_UBD_SYNC | |
139 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
140 | .cl = 1 }) | |
141 | #else | |
142 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
143 | .cl = 1 }) | |
144 | #endif | |
145 | ||
146 | /* Not protected - changed only in ubd_setup_common and then only to | |
147 | * to enable O_SYNC. | |
148 | */ | |
149 | static struct openflags global_openflags = OPEN_FLAGS; | |
150 | ||
151 | struct cow { | |
2c49be99 | 152 | /* This is the backing file, actually */ |
1da177e4 LT |
153 | char *file; |
154 | int fd; | |
155 | unsigned long *bitmap; | |
156 | unsigned long bitmap_len; | |
157 | int bitmap_offset; | |
158 | int data_offset; | |
159 | }; | |
160 | ||
161 | struct ubd { | |
162 | char *file; | |
163 | int count; | |
164 | int fd; | |
165 | __u64 size; | |
166 | struct openflags boot_openflags; | |
167 | struct openflags openflags; | |
168 | int no_cow; | |
169 | struct cow cow; | |
170 | struct platform_device pdev; | |
1da177e4 LT |
171 | }; |
172 | ||
173 | #define DEFAULT_COW { \ | |
174 | .file = NULL, \ | |
175 | .fd = -1, \ | |
176 | .bitmap = NULL, \ | |
177 | .bitmap_offset = 0, \ | |
178 | .data_offset = 0, \ | |
179 | } | |
180 | ||
181 | #define DEFAULT_UBD { \ | |
182 | .file = NULL, \ | |
183 | .count = 0, \ | |
184 | .fd = -1, \ | |
185 | .size = -1, \ | |
186 | .boot_openflags = OPEN_FLAGS, \ | |
187 | .openflags = OPEN_FLAGS, \ | |
188 | .no_cow = 0, \ | |
189 | .cow = DEFAULT_COW, \ | |
1da177e4 LT |
190 | } |
191 | ||
192 | struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; | |
193 | ||
194 | static int ubd0_init(void) | |
195 | { | |
196 | struct ubd *dev = &ubd_dev[0]; | |
197 | ||
198 | if(dev->file == NULL) | |
199 | dev->file = "root_fs"; | |
200 | return(0); | |
201 | } | |
202 | ||
203 | __initcall(ubd0_init); | |
204 | ||
205 | /* Only changed by fake_ide_setup which is a setup */ | |
206 | static int fake_ide = 0; | |
207 | static struct proc_dir_entry *proc_ide_root = NULL; | |
208 | static struct proc_dir_entry *proc_ide = NULL; | |
209 | ||
210 | static void make_proc_ide(void) | |
211 | { | |
212 | proc_ide_root = proc_mkdir("ide", NULL); | |
213 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
214 | } | |
215 | ||
216 | static int proc_ide_read_media(char *page, char **start, off_t off, int count, | |
217 | int *eof, void *data) | |
218 | { | |
219 | int len; | |
220 | ||
221 | strcpy(page, "disk\n"); | |
222 | len = strlen("disk\n"); | |
223 | len -= off; | |
224 | if (len < count){ | |
225 | *eof = 1; | |
226 | if (len <= 0) return 0; | |
227 | } | |
228 | else len = count; | |
229 | *start = page + off; | |
230 | return len; | |
231 | } | |
232 | ||
233 | static void make_ide_entries(char *dev_name) | |
234 | { | |
235 | struct proc_dir_entry *dir, *ent; | |
236 | char name[64]; | |
237 | ||
238 | if(proc_ide_root == NULL) make_proc_ide(); | |
239 | ||
240 | dir = proc_mkdir(dev_name, proc_ide); | |
241 | if(!dir) return; | |
242 | ||
243 | ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); | |
244 | if(!ent) return; | |
245 | ent->nlink = 1; | |
246 | ent->data = NULL; | |
247 | ent->read_proc = proc_ide_read_media; | |
248 | ent->write_proc = NULL; | |
249 | sprintf(name,"ide0/%s", dev_name); | |
250 | proc_symlink(dev_name, proc_ide_root, name); | |
251 | } | |
252 | ||
253 | static int fake_ide_setup(char *str) | |
254 | { | |
255 | fake_ide = 1; | |
256 | return(1); | |
257 | } | |
258 | ||
259 | __setup("fake_ide", fake_ide_setup); | |
260 | ||
261 | __uml_help(fake_ide_setup, | |
262 | "fake_ide\n" | |
263 | " Create ide0 entries that map onto ubd devices.\n\n" | |
264 | ); | |
265 | ||
266 | static int parse_unit(char **ptr) | |
267 | { | |
268 | char *str = *ptr, *end; | |
269 | int n = -1; | |
270 | ||
271 | if(isdigit(*str)) { | |
272 | n = simple_strtoul(str, &end, 0); | |
273 | if(end == str) | |
274 | return(-1); | |
275 | *ptr = end; | |
276 | } | |
277 | else if (('a' <= *str) && (*str <= 'h')) { | |
278 | n = *str - 'a'; | |
279 | str++; | |
280 | *ptr = str; | |
281 | } | |
282 | return(n); | |
283 | } | |
284 | ||
285 | static int ubd_setup_common(char *str, int *index_out) | |
286 | { | |
287 | struct ubd *dev; | |
288 | struct openflags flags = global_openflags; | |
289 | char *backing_file; | |
290 | int n, err, i; | |
291 | ||
292 | if(index_out) *index_out = -1; | |
293 | n = *str; | |
294 | if(n == '='){ | |
295 | char *end; | |
296 | int major; | |
297 | ||
298 | str++; | |
1da177e4 LT |
299 | if(!strcmp(str, "sync")){ |
300 | global_openflags = of_sync(global_openflags); | |
301 | return(0); | |
302 | } | |
303 | major = simple_strtoul(str, &end, 0); | |
304 | if((*end != '\0') || (end == str)){ | |
305 | printk(KERN_ERR | |
306 | "ubd_setup : didn't parse major number\n"); | |
307 | return(1); | |
308 | } | |
309 | ||
310 | err = 1; | |
311 | spin_lock(&ubd_lock); | |
312 | if(fake_major != MAJOR_NR){ | |
313 | printk(KERN_ERR "Can't assign a fake major twice\n"); | |
314 | goto out1; | |
315 | } | |
316 | ||
317 | fake_major = major; | |
318 | ||
319 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
320 | major); | |
321 | err = 0; | |
322 | out1: | |
323 | spin_unlock(&ubd_lock); | |
324 | return(err); | |
325 | } | |
326 | ||
327 | n = parse_unit(&str); | |
328 | if(n < 0){ | |
329 | printk(KERN_ERR "ubd_setup : couldn't parse unit number " | |
330 | "'%s'\n", str); | |
331 | return(1); | |
332 | } | |
333 | if(n >= MAX_DEV){ | |
334 | printk(KERN_ERR "ubd_setup : index %d out of range " | |
335 | "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1); | |
336 | return(1); | |
337 | } | |
338 | ||
339 | err = 1; | |
340 | spin_lock(&ubd_lock); | |
341 | ||
342 | dev = &ubd_dev[n]; | |
343 | if(dev->file != NULL){ | |
344 | printk(KERN_ERR "ubd_setup : device already configured\n"); | |
345 | goto out; | |
346 | } | |
347 | ||
348 | if (index_out) | |
349 | *index_out = n; | |
350 | ||
351 | for (i = 0; i < 4; i++) { | |
352 | switch (*str) { | |
353 | case 'r': | |
354 | flags.w = 0; | |
355 | break; | |
356 | case 's': | |
357 | flags.s = 1; | |
358 | break; | |
359 | case 'd': | |
360 | dev->no_cow = 1; | |
361 | break; | |
362 | case '=': | |
363 | str++; | |
364 | goto break_loop; | |
365 | default: | |
366 | printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r,s or d)\n"); | |
367 | goto out; | |
368 | } | |
369 | str++; | |
370 | } | |
371 | ||
372 | if (*str == '=') | |
373 | printk(KERN_ERR "ubd_setup : Too many flags specified\n"); | |
374 | else | |
375 | printk(KERN_ERR "ubd_setup : Expected '='\n"); | |
376 | goto out; | |
377 | ||
378 | break_loop: | |
379 | err = 0; | |
380 | backing_file = strchr(str, ','); | |
381 | ||
382 | if (!backing_file) { | |
383 | backing_file = strchr(str, ':'); | |
384 | } | |
385 | ||
386 | if(backing_file){ | |
387 | if(dev->no_cow) | |
388 | printk(KERN_ERR "Can't specify both 'd' and a " | |
389 | "cow file\n"); | |
390 | else { | |
391 | *backing_file = '\0'; | |
392 | backing_file++; | |
393 | } | |
394 | } | |
395 | dev->file = str; | |
396 | dev->cow.file = backing_file; | |
397 | dev->boot_openflags = flags; | |
398 | out: | |
399 | spin_unlock(&ubd_lock); | |
400 | return(err); | |
401 | } | |
402 | ||
403 | static int ubd_setup(char *str) | |
404 | { | |
405 | ubd_setup_common(str, NULL); | |
406 | return(1); | |
407 | } | |
408 | ||
409 | __setup("ubd", ubd_setup); | |
410 | __uml_help(ubd_setup, | |
411 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
412 | " This is used to associate a device with a file in the underlying\n" | |
413 | " filesystem. When specifying two filenames, the first one is the\n" | |
414 | " COW name and the second is the backing file name. As separator you can\n" | |
415 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
416 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
417 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
418 | " When using only one filename, UML will detect whether to thread it like\n" | |
419 | " a COW file or a backing file. To override this detection, add the 'd'\n" | |
420 | " flag:\n" | |
421 | " ubd0d=BackingFile\n" | |
422 | " Usually, there is a filesystem in the file, but \n" | |
423 | " that's not required. Swap devices containing swap files can be\n" | |
424 | " specified like this. Also, a file which doesn't contain a\n" | |
425 | " filesystem can have its contents read in the virtual \n" | |
426 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
427 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
428 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
429 | " an 's' will cause data to be written to disk on the host immediately.\n\n" | |
430 | ); | |
431 | ||
432 | static int udb_setup(char *str) | |
433 | { | |
434 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
435 | "udb TYPO\n", str); | |
436 | return(1); | |
437 | } | |
438 | ||
439 | __setup("udb", udb_setup); | |
440 | __uml_help(udb_setup, | |
441 | "udb\n" | |
0894e27e JD |
442 | " This option is here solely to catch ubd -> udb typos, which can be\n" |
443 | " to impossible to catch visually unless you specifically look for\n" | |
444 | " them. The only result of any option starting with 'udb' is an error\n" | |
1da177e4 LT |
445 | " in the boot output.\n\n" |
446 | ); | |
447 | ||
448 | static int fakehd_set = 0; | |
449 | static int fakehd(char *str) | |
450 | { | |
451 | printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); | |
452 | fakehd_set = 1; | |
453 | return 1; | |
454 | } | |
455 | ||
456 | __setup("fakehd", fakehd); | |
457 | __uml_help(fakehd, | |
458 | "fakehd\n" | |
459 | " Change the ubd device name to \"hd\".\n\n" | |
460 | ); | |
461 | ||
462 | static void do_ubd_request(request_queue_t * q); | |
463 | ||
464 | /* Only changed by ubd_init, which is an initcall. */ | |
465 | int thread_fd = -1; | |
466 | ||
467 | /* Changed by ubd_handler, which is serialized because interrupts only | |
468 | * happen on CPU 0. | |
469 | */ | |
470 | int intr_count = 0; | |
471 | ||
472 | /* call ubd_finish if you need to serialize */ | |
473 | static void __ubd_finish(struct request *req, int error) | |
474 | { | |
475 | int nsect; | |
476 | ||
477 | if(error){ | |
478 | end_request(req, 0); | |
479 | return; | |
480 | } | |
481 | nsect = req->current_nr_sectors; | |
482 | req->sector += nsect; | |
483 | req->buffer += nsect << 9; | |
484 | req->errors = 0; | |
485 | req->nr_sectors -= nsect; | |
486 | req->current_nr_sectors = 0; | |
487 | end_request(req, 1); | |
488 | } | |
489 | ||
490 | static inline void ubd_finish(struct request *req, int error) | |
491 | { | |
492 | spin_lock(&ubd_io_lock); | |
493 | __ubd_finish(req, error); | |
494 | spin_unlock(&ubd_io_lock); | |
495 | } | |
496 | ||
497 | /* Called without ubd_io_lock held */ | |
498 | static void ubd_handler(void) | |
499 | { | |
500 | struct io_thread_req req; | |
501 | struct request *rq = elv_next_request(ubd_queue); | |
7b9014c1 | 502 | int n; |
1da177e4 LT |
503 | |
504 | do_ubd = NULL; | |
505 | intr_count++; | |
506 | n = os_read_file(thread_fd, &req, sizeof(req)); | |
507 | if(n != sizeof(req)){ | |
508 | printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " | |
509 | "err = %d\n", os_getpid(), -n); | |
510 | spin_lock(&ubd_io_lock); | |
511 | end_request(rq, 0); | |
512 | spin_unlock(&ubd_io_lock); | |
513 | return; | |
514 | } | |
515 | ||
1da177e4 LT |
516 | ubd_finish(rq, req.error); |
517 | reactivate_fd(thread_fd, UBD_IRQ); | |
518 | do_ubd_request(ubd_queue); | |
519 | } | |
520 | ||
521 | static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) | |
522 | { | |
523 | ubd_handler(); | |
524 | return(IRQ_HANDLED); | |
525 | } | |
526 | ||
527 | /* Only changed by ubd_init, which is an initcall. */ | |
528 | static int io_pid = -1; | |
529 | ||
530 | void kill_io_thread(void) | |
531 | { | |
532 | if(io_pid != -1) | |
533 | os_kill_process(io_pid, 1); | |
534 | } | |
535 | ||
536 | __uml_exitcall(kill_io_thread); | |
537 | ||
538 | static int ubd_file_size(struct ubd *dev, __u64 *size_out) | |
539 | { | |
540 | char *file; | |
541 | ||
542 | file = dev->cow.file ? dev->cow.file : dev->file; | |
543 | return(os_file_size(file, size_out)); | |
544 | } | |
545 | ||
546 | static void ubd_close(struct ubd *dev) | |
547 | { | |
1da177e4 LT |
548 | os_close_file(dev->fd); |
549 | if(dev->cow.file == NULL) | |
550 | return; | |
551 | ||
1da177e4 LT |
552 | os_close_file(dev->cow.fd); |
553 | vfree(dev->cow.bitmap); | |
554 | dev->cow.bitmap = NULL; | |
555 | } | |
556 | ||
557 | static int ubd_open_dev(struct ubd *dev) | |
558 | { | |
559 | struct openflags flags; | |
560 | char **back_ptr; | |
561 | int err, create_cow, *create_ptr; | |
562 | ||
563 | dev->openflags = dev->boot_openflags; | |
564 | create_cow = 0; | |
565 | create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL; | |
566 | back_ptr = dev->no_cow ? NULL : &dev->cow.file; | |
567 | dev->fd = open_ubd_file(dev->file, &dev->openflags, back_ptr, | |
568 | &dev->cow.bitmap_offset, &dev->cow.bitmap_len, | |
569 | &dev->cow.data_offset, create_ptr); | |
570 | ||
571 | if((dev->fd == -ENOENT) && create_cow){ | |
572 | dev->fd = create_cow_file(dev->file, dev->cow.file, | |
573 | dev->openflags, 1 << 9, PAGE_SIZE, | |
574 | &dev->cow.bitmap_offset, | |
575 | &dev->cow.bitmap_len, | |
576 | &dev->cow.data_offset); | |
577 | if(dev->fd >= 0){ | |
578 | printk(KERN_INFO "Creating \"%s\" as COW file for " | |
579 | "\"%s\"\n", dev->file, dev->cow.file); | |
580 | } | |
581 | } | |
582 | ||
583 | if(dev->fd < 0){ | |
584 | printk("Failed to open '%s', errno = %d\n", dev->file, | |
585 | -dev->fd); | |
586 | return(dev->fd); | |
587 | } | |
588 | ||
589 | if(dev->cow.file != NULL){ | |
590 | err = -ENOMEM; | |
591 | dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len); | |
592 | if(dev->cow.bitmap == NULL){ | |
593 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); | |
594 | goto error; | |
595 | } | |
596 | flush_tlb_kernel_vm(); | |
597 | ||
598 | err = read_cow_bitmap(dev->fd, dev->cow.bitmap, | |
599 | dev->cow.bitmap_offset, | |
600 | dev->cow.bitmap_len); | |
601 | if(err < 0) | |
602 | goto error; | |
603 | ||
604 | flags = dev->openflags; | |
605 | flags.w = 0; | |
606 | err = open_ubd_file(dev->cow.file, &flags, NULL, NULL, NULL, | |
607 | NULL, NULL); | |
608 | if(err < 0) goto error; | |
609 | dev->cow.fd = err; | |
610 | } | |
611 | return(0); | |
612 | error: | |
613 | os_close_file(dev->fd); | |
614 | return(err); | |
615 | } | |
616 | ||
617 | static int ubd_new_disk(int major, u64 size, int unit, | |
618 | struct gendisk **disk_out) | |
619 | ||
620 | { | |
621 | struct gendisk *disk; | |
622 | char from[sizeof("ubd/nnnnn\0")], to[sizeof("discnnnnn/disc\0")]; | |
623 | int err; | |
624 | ||
625 | disk = alloc_disk(1 << UBD_SHIFT); | |
626 | if(disk == NULL) | |
627 | return(-ENOMEM); | |
628 | ||
629 | disk->major = major; | |
630 | disk->first_minor = unit << UBD_SHIFT; | |
631 | disk->fops = &ubd_blops; | |
632 | set_capacity(disk, size / 512); | |
633 | if(major == MAJOR_NR){ | |
634 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); | |
635 | sprintf(disk->devfs_name, "ubd/disc%d", unit); | |
636 | sprintf(from, "ubd/%d", unit); | |
637 | sprintf(to, "disc%d/disc", unit); | |
638 | err = devfs_mk_symlink(from, to); | |
639 | if(err) | |
640 | printk("ubd_new_disk failed to make link from %s to " | |
641 | "%s, error = %d\n", from, to, err); | |
642 | } | |
643 | else { | |
644 | sprintf(disk->disk_name, "ubd_fake%d", unit); | |
645 | sprintf(disk->devfs_name, "ubd_fake/disc%d", unit); | |
646 | } | |
647 | ||
648 | /* sysfs register (not for ide fake devices) */ | |
649 | if (major == MAJOR_NR) { | |
650 | ubd_dev[unit].pdev.id = unit; | |
651 | ubd_dev[unit].pdev.name = DRIVER_NAME; | |
652 | platform_device_register(&ubd_dev[unit].pdev); | |
653 | disk->driverfs_dev = &ubd_dev[unit].pdev.dev; | |
654 | } | |
655 | ||
656 | disk->private_data = &ubd_dev[unit]; | |
657 | disk->queue = ubd_queue; | |
658 | add_disk(disk); | |
659 | ||
660 | *disk_out = disk; | |
661 | return 0; | |
662 | } | |
663 | ||
664 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
665 | ||
666 | static int ubd_add(int n) | |
667 | { | |
668 | struct ubd *dev = &ubd_dev[n]; | |
669 | int err; | |
670 | ||
ec7cf783 | 671 | err = -ENODEV; |
1da177e4 | 672 | if(dev->file == NULL) |
ec7cf783 | 673 | goto out; |
1da177e4 LT |
674 | |
675 | if (ubd_open_dev(dev)) | |
ec7cf783 | 676 | goto out; |
1da177e4 LT |
677 | |
678 | err = ubd_file_size(dev, &dev->size); | |
679 | if(err < 0) | |
ec7cf783 | 680 | goto out_close; |
1da177e4 LT |
681 | |
682 | dev->size = ROUND_BLOCK(dev->size); | |
683 | ||
684 | err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]); | |
685 | if(err) | |
ec7cf783 | 686 | goto out_close; |
1da177e4 LT |
687 | |
688 | if(fake_major != MAJOR_NR) | |
689 | ubd_new_disk(fake_major, dev->size, n, | |
690 | &fake_gendisk[n]); | |
691 | ||
692 | /* perhaps this should also be under the "if (fake_major)" above */ | |
693 | /* using the fake_disk->disk_name and also the fakehd_set name */ | |
694 | if (fake_ide) | |
695 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
696 | ||
ec7cf783 JD |
697 | err = 0; |
698 | out_close: | |
1da177e4 | 699 | ubd_close(dev); |
ec7cf783 JD |
700 | out: |
701 | return err; | |
1da177e4 LT |
702 | } |
703 | ||
704 | static int ubd_config(char *str) | |
705 | { | |
706 | int n, err; | |
707 | ||
708 | str = uml_strdup(str); | |
709 | if(str == NULL){ | |
710 | printk(KERN_ERR "ubd_config failed to strdup string\n"); | |
711 | return(1); | |
712 | } | |
713 | err = ubd_setup_common(str, &n); | |
714 | if(err){ | |
715 | kfree(str); | |
716 | return(-1); | |
717 | } | |
718 | if(n == -1) return(0); | |
719 | ||
720 | spin_lock(&ubd_lock); | |
721 | err = ubd_add(n); | |
722 | if(err) | |
723 | ubd_dev[n].file = NULL; | |
724 | spin_unlock(&ubd_lock); | |
725 | ||
726 | return(err); | |
727 | } | |
728 | ||
729 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
730 | { | |
731 | struct ubd *dev; | |
732 | int n, len = 0; | |
733 | ||
734 | n = parse_unit(&name); | |
735 | if((n >= MAX_DEV) || (n < 0)){ | |
736 | *error_out = "ubd_get_config : device number out of range"; | |
737 | return(-1); | |
738 | } | |
739 | ||
740 | dev = &ubd_dev[n]; | |
741 | spin_lock(&ubd_lock); | |
742 | ||
743 | if(dev->file == NULL){ | |
744 | CONFIG_CHUNK(str, size, len, "", 1); | |
745 | goto out; | |
746 | } | |
747 | ||
748 | CONFIG_CHUNK(str, size, len, dev->file, 0); | |
749 | ||
750 | if(dev->cow.file != NULL){ | |
751 | CONFIG_CHUNK(str, size, len, ",", 0); | |
752 | CONFIG_CHUNK(str, size, len, dev->cow.file, 1); | |
753 | } | |
754 | else CONFIG_CHUNK(str, size, len, "", 1); | |
755 | ||
756 | out: | |
757 | spin_unlock(&ubd_lock); | |
758 | return(len); | |
759 | } | |
760 | ||
29d56cfe JD |
761 | static int ubd_id(char **str, int *start_out, int *end_out) |
762 | { | |
763 | int n; | |
764 | ||
765 | n = parse_unit(str); | |
766 | *start_out = 0; | |
767 | *end_out = MAX_DEV - 1; | |
768 | return n; | |
769 | } | |
770 | ||
771 | static int ubd_remove(int n) | |
1da177e4 LT |
772 | { |
773 | struct ubd *dev; | |
29d56cfe | 774 | int err = -ENODEV; |
1da177e4 | 775 | |
29d56cfe | 776 | spin_lock(&ubd_lock); |
1da177e4 | 777 | |
29d56cfe JD |
778 | if(ubd_gendisk[n] == NULL) |
779 | goto out; | |
1da177e4 LT |
780 | |
781 | dev = &ubd_dev[n]; | |
1da177e4 | 782 | |
29d56cfe JD |
783 | if(dev->file == NULL) |
784 | goto out; | |
1da177e4 | 785 | |
29d56cfe JD |
786 | /* you cannot remove a open disk */ |
787 | err = -EBUSY; | |
788 | if(dev->count > 0) | |
1da177e4 LT |
789 | goto out; |
790 | ||
791 | del_gendisk(ubd_gendisk[n]); | |
792 | put_disk(ubd_gendisk[n]); | |
793 | ubd_gendisk[n] = NULL; | |
794 | ||
795 | if(fake_gendisk[n] != NULL){ | |
796 | del_gendisk(fake_gendisk[n]); | |
797 | put_disk(fake_gendisk[n]); | |
798 | fake_gendisk[n] = NULL; | |
799 | } | |
800 | ||
801 | platform_device_unregister(&dev->pdev); | |
802 | *dev = ((struct ubd) DEFAULT_UBD); | |
803 | err = 0; | |
29d56cfe JD |
804 | out: |
805 | spin_unlock(&ubd_lock); | |
806 | return err; | |
1da177e4 LT |
807 | } |
808 | ||
809 | static struct mc_device ubd_mc = { | |
810 | .name = "ubd", | |
811 | .config = ubd_config, | |
812 | .get_config = ubd_get_config, | |
29d56cfe | 813 | .id = ubd_id, |
1da177e4 LT |
814 | .remove = ubd_remove, |
815 | }; | |
816 | ||
817 | static int ubd_mc_init(void) | |
818 | { | |
819 | mconsole_register_dev(&ubd_mc); | |
820 | return 0; | |
821 | } | |
822 | ||
823 | __initcall(ubd_mc_init); | |
824 | ||
825 | static struct device_driver ubd_driver = { | |
826 | .name = DRIVER_NAME, | |
827 | .bus = &platform_bus_type, | |
828 | }; | |
829 | ||
830 | int ubd_init(void) | |
831 | { | |
832 | int i; | |
833 | ||
834 | devfs_mk_dir("ubd"); | |
835 | if (register_blkdev(MAJOR_NR, "ubd")) | |
836 | return -1; | |
837 | ||
838 | ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock); | |
839 | if (!ubd_queue) { | |
840 | unregister_blkdev(MAJOR_NR, "ubd"); | |
841 | return -1; | |
842 | } | |
843 | ||
844 | if (fake_major != MAJOR_NR) { | |
845 | char name[sizeof("ubd_nnn\0")]; | |
846 | ||
847 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
848 | devfs_mk_dir(name); | |
849 | if (register_blkdev(fake_major, "ubd")) | |
850 | return -1; | |
851 | } | |
852 | driver_register(&ubd_driver); | |
853 | for (i = 0; i < MAX_DEV; i++) | |
854 | ubd_add(i); | |
855 | return 0; | |
856 | } | |
857 | ||
858 | late_initcall(ubd_init); | |
859 | ||
860 | int ubd_driver_init(void){ | |
861 | unsigned long stack; | |
862 | int err; | |
863 | ||
864 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
865 | if(global_openflags.s){ | |
866 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
867 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
868 | * enough. So use anyway the io thread. */ | |
869 | } | |
870 | stack = alloc_stack(0, 0); | |
871 | io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), | |
872 | &thread_fd); | |
873 | if(io_pid < 0){ | |
874 | printk(KERN_ERR | |
875 | "ubd : Failed to start I/O thread (errno = %d) - " | |
876 | "falling back to synchronous I/O\n", -io_pid); | |
877 | io_pid = -1; | |
878 | return(0); | |
879 | } | |
880 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, | |
881 | SA_INTERRUPT, "ubd", ubd_dev); | |
882 | if(err != 0) | |
883 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); | |
884 | return(err); | |
885 | } | |
886 | ||
887 | device_initcall(ubd_driver_init); | |
888 | ||
889 | static int ubd_open(struct inode *inode, struct file *filp) | |
890 | { | |
891 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
892 | struct ubd *dev = disk->private_data; | |
893 | int err = 0; | |
894 | ||
895 | if(dev->count == 0){ | |
896 | err = ubd_open_dev(dev); | |
897 | if(err){ | |
898 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
899 | disk->disk_name, dev->file, -err); | |
900 | goto out; | |
901 | } | |
902 | } | |
903 | dev->count++; | |
2c49be99 PBG |
904 | set_disk_ro(disk, !dev->openflags.w); |
905 | ||
906 | /* This should no more be needed. And it didn't work anyway to exclude | |
907 | * read-write remounting of filesystems.*/ | |
908 | /*if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ | |
1da177e4 LT |
909 | if(--dev->count == 0) ubd_close(dev); |
910 | err = -EROFS; | |
2c49be99 | 911 | }*/ |
1da177e4 LT |
912 | out: |
913 | return(err); | |
914 | } | |
915 | ||
916 | static int ubd_release(struct inode * inode, struct file * file) | |
917 | { | |
918 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
919 | struct ubd *dev = disk->private_data; | |
920 | ||
921 | if(--dev->count == 0) | |
922 | ubd_close(dev); | |
923 | return(0); | |
924 | } | |
925 | ||
926 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, | |
927 | __u64 *cow_offset, unsigned long *bitmap, | |
928 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
929 | __u64 bitmap_len) | |
930 | { | |
931 | __u64 sector = io_offset >> 9; | |
932 | int i, update_bitmap = 0; | |
933 | ||
934 | for(i = 0; i < length >> 9; i++){ | |
935 | if(cow_mask != NULL) | |
936 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
937 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
938 | continue; | |
939 | ||
940 | update_bitmap = 1; | |
941 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
942 | } | |
943 | ||
944 | if(!update_bitmap) | |
945 | return; | |
946 | ||
947 | *cow_offset = sector / (sizeof(unsigned long) * 8); | |
948 | ||
949 | /* This takes care of the case where we're exactly at the end of the | |
950 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
951 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
952 | * for the original diagnosis. | |
953 | */ | |
954 | if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / | |
955 | sizeof(unsigned long) - 1)) | |
956 | (*cow_offset)--; | |
957 | ||
958 | bitmap_words[0] = bitmap[*cow_offset]; | |
959 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
960 | ||
961 | *cow_offset *= sizeof(unsigned long); | |
962 | *cow_offset += bitmap_offset; | |
963 | } | |
964 | ||
965 | static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, | |
966 | __u64 bitmap_offset, __u64 bitmap_len) | |
967 | { | |
968 | __u64 sector = req->offset >> 9; | |
969 | int i; | |
970 | ||
971 | if(req->length > (sizeof(req->sector_mask) * 8) << 9) | |
972 | panic("Operation too long"); | |
973 | ||
974 | if(req->op == UBD_READ) { | |
975 | for(i = 0; i < req->length >> 9; i++){ | |
976 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
977 | ubd_set_bit(i, (unsigned char *) | |
978 | &req->sector_mask); | |
979 | } | |
980 | } | |
981 | else cowify_bitmap(req->offset, req->length, &req->sector_mask, | |
982 | &req->cow_offset, bitmap, bitmap_offset, | |
983 | req->bitmap_words, bitmap_len); | |
984 | } | |
985 | ||
1da177e4 LT |
986 | /* Called with ubd_io_lock held */ |
987 | static int prepare_request(struct request *req, struct io_thread_req *io_req) | |
988 | { | |
989 | struct gendisk *disk = req->rq_disk; | |
990 | struct ubd *dev = disk->private_data; | |
991 | __u64 offset; | |
7b9014c1 | 992 | int len; |
1da177e4 LT |
993 | |
994 | if(req->rq_status == RQ_INACTIVE) return(1); | |
995 | ||
2c49be99 | 996 | /* This should be impossible now */ |
1da177e4 LT |
997 | if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ |
998 | printk("Write attempted on readonly ubd device %s\n", | |
999 | disk->disk_name); | |
1000 | end_request(req, 0); | |
1001 | return(1); | |
1002 | } | |
1003 | ||
1004 | offset = ((__u64) req->sector) << 9; | |
1005 | len = req->current_nr_sectors << 9; | |
1006 | ||
1007 | io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; | |
1008 | io_req->fds[1] = dev->fd; | |
1da177e4 LT |
1009 | io_req->cow_offset = -1; |
1010 | io_req->offset = offset; | |
1011 | io_req->length = len; | |
1012 | io_req->error = 0; | |
1013 | io_req->sector_mask = 0; | |
1014 | ||
1da177e4 LT |
1015 | io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; |
1016 | io_req->offsets[0] = 0; | |
1017 | io_req->offsets[1] = dev->cow.data_offset; | |
1018 | io_req->buffer = req->buffer; | |
1019 | io_req->sectorsize = 1 << 9; | |
1020 | ||
1021 | if(dev->cow.file != NULL) | |
1022 | cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, | |
1023 | dev->cow.bitmap_len); | |
1024 | ||
1025 | return(0); | |
1026 | } | |
1027 | ||
1028 | /* Called with ubd_io_lock held */ | |
1029 | static void do_ubd_request(request_queue_t *q) | |
1030 | { | |
1031 | struct io_thread_req io_req; | |
1032 | struct request *req; | |
1033 | int err, n; | |
1034 | ||
1035 | if(thread_fd == -1){ | |
1036 | while((req = elv_next_request(q)) != NULL){ | |
1037 | err = prepare_request(req, &io_req); | |
1038 | if(!err){ | |
1039 | do_io(&io_req); | |
1040 | __ubd_finish(req, io_req.error); | |
1041 | } | |
1042 | } | |
1043 | } | |
1044 | else { | |
1045 | if(do_ubd || (req = elv_next_request(q)) == NULL) | |
1046 | return; | |
1047 | err = prepare_request(req, &io_req); | |
1048 | if(!err){ | |
1049 | do_ubd = ubd_handler; | |
1050 | n = os_write_file(thread_fd, (char *) &io_req, | |
1051 | sizeof(io_req)); | |
1052 | if(n != sizeof(io_req)) | |
1053 | printk("write to io thread failed, " | |
1054 | "errno = %d\n", -n); | |
1055 | } | |
1056 | } | |
1057 | } | |
1058 | ||
1059 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
1060 | unsigned int cmd, unsigned long arg) | |
1061 | { | |
1062 | struct hd_geometry __user *loc = (struct hd_geometry __user *) arg; | |
1063 | struct ubd *dev = inode->i_bdev->bd_disk->private_data; | |
1064 | struct hd_driveid ubd_id = { | |
1065 | .cyls = 0, | |
1066 | .heads = 128, | |
1067 | .sectors = 32, | |
1068 | }; | |
1069 | ||
1070 | switch (cmd) { | |
1071 | struct hd_geometry g; | |
1072 | struct cdrom_volctrl volume; | |
1073 | case HDIO_GETGEO: | |
1074 | if(!loc) return(-EINVAL); | |
1075 | g.heads = 128; | |
1076 | g.sectors = 32; | |
1077 | g.cylinders = dev->size / (128 * 32 * 512); | |
1078 | g.start = get_start_sect(inode->i_bdev); | |
1079 | return(copy_to_user(loc, &g, sizeof(g)) ? -EFAULT : 0); | |
1080 | ||
1081 | case HDIO_GET_IDENTITY: | |
1082 | ubd_id.cyls = dev->size / (128 * 32 * 512); | |
1083 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, | |
1084 | sizeof(ubd_id))) | |
1085 | return(-EFAULT); | |
1086 | return(0); | |
1087 | ||
1088 | case CDROMVOLREAD: | |
1089 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
1090 | return(-EFAULT); | |
1091 | volume.channel0 = 255; | |
1092 | volume.channel1 = 255; | |
1093 | volume.channel2 = 255; | |
1094 | volume.channel3 = 255; | |
1095 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
1096 | return(-EFAULT); | |
1097 | return(0); | |
1098 | } | |
1099 | return(-EINVAL); | |
1100 | } | |
1101 | ||
1da177e4 LT |
1102 | static int same_backing_files(char *from_cmdline, char *from_cow, char *cow) |
1103 | { | |
1104 | struct uml_stat buf1, buf2; | |
1105 | int err; | |
1106 | ||
1107 | if(from_cmdline == NULL) return(1); | |
1108 | if(!strcmp(from_cmdline, from_cow)) return(1); | |
1109 | ||
1110 | err = os_stat_file(from_cmdline, &buf1); | |
1111 | if(err < 0){ | |
1112 | printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); | |
1113 | return(1); | |
1114 | } | |
1115 | err = os_stat_file(from_cow, &buf2); | |
1116 | if(err < 0){ | |
1117 | printk("Couldn't stat '%s', err = %d\n", from_cow, -err); | |
1118 | return(1); | |
1119 | } | |
1120 | if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
1121 | return(1); | |
1122 | ||
1123 | printk("Backing file mismatch - \"%s\" requested,\n" | |
1124 | "\"%s\" specified in COW header of \"%s\"\n", | |
1125 | from_cmdline, from_cow, cow); | |
1126 | return(0); | |
1127 | } | |
1128 | ||
1129 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
1130 | { | |
1131 | unsigned long modtime; | |
1132 | long long actual; | |
1133 | int err; | |
1134 | ||
1135 | err = os_file_modtime(file, &modtime); | |
1136 | if(err < 0){ | |
1137 | printk("Failed to get modification time of backing file " | |
1138 | "\"%s\", err = %d\n", file, -err); | |
1139 | return(err); | |
1140 | } | |
1141 | ||
1142 | err = os_file_size(file, &actual); | |
1143 | if(err < 0){ | |
1144 | printk("Failed to get size of backing file \"%s\", " | |
1145 | "err = %d\n", file, -err); | |
1146 | return(err); | |
1147 | } | |
1148 | ||
1149 | if(actual != size){ | |
1150 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
1151 | * the typecast.*/ | |
1152 | printk("Size mismatch (%llu vs %llu) of COW header vs backing " | |
1153 | "file\n", (unsigned long long) size, actual); | |
1154 | return(-EINVAL); | |
1155 | } | |
1156 | if(modtime != mtime){ | |
1157 | printk("mtime mismatch (%ld vs %ld) of COW header vs backing " | |
1158 | "file\n", mtime, modtime); | |
1159 | return(-EINVAL); | |
1160 | } | |
1161 | return(0); | |
1162 | } | |
1163 | ||
1164 | int read_cow_bitmap(int fd, void *buf, int offset, int len) | |
1165 | { | |
1166 | int err; | |
1167 | ||
1168 | err = os_seek_file(fd, offset); | |
1169 | if(err < 0) | |
1170 | return(err); | |
1171 | ||
1172 | err = os_read_file(fd, buf, len); | |
1173 | if(err < 0) | |
1174 | return(err); | |
1175 | ||
1176 | return(0); | |
1177 | } | |
1178 | ||
1179 | int open_ubd_file(char *file, struct openflags *openflags, | |
1180 | char **backing_file_out, int *bitmap_offset_out, | |
1181 | unsigned long *bitmap_len_out, int *data_offset_out, | |
1182 | int *create_cow_out) | |
1183 | { | |
1184 | time_t mtime; | |
1185 | unsigned long long size; | |
1186 | __u32 version, align; | |
1187 | char *backing_file; | |
1188 | int fd, err, sectorsize, same, mode = 0644; | |
1189 | ||
1190 | fd = os_open_file(file, *openflags, mode); | |
1191 | if(fd < 0){ | |
1192 | if((fd == -ENOENT) && (create_cow_out != NULL)) | |
1193 | *create_cow_out = 1; | |
1194 | if(!openflags->w || | |
1195 | ((fd != -EROFS) && (fd != -EACCES))) return(fd); | |
1196 | openflags->w = 0; | |
1197 | fd = os_open_file(file, *openflags, mode); | |
1198 | if(fd < 0) | |
1199 | return(fd); | |
1200 | } | |
1201 | ||
1202 | err = os_lock_file(fd, openflags->w); | |
1203 | if(err < 0){ | |
1204 | printk("Failed to lock '%s', err = %d\n", file, -err); | |
1205 | goto out_close; | |
1206 | } | |
1207 | ||
1208 | if(backing_file_out == NULL) return(fd); | |
1209 | ||
1210 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
1211 | &size, §orsize, &align, bitmap_offset_out); | |
1212 | if(err && (*backing_file_out != NULL)){ | |
1213 | printk("Failed to read COW header from COW file \"%s\", " | |
1214 | "errno = %d\n", file, -err); | |
1215 | goto out_close; | |
1216 | } | |
1217 | if(err) return(fd); | |
1218 | ||
1219 | if(backing_file_out == NULL) return(fd); | |
1220 | ||
1221 | same = same_backing_files(*backing_file_out, backing_file, file); | |
1222 | ||
1223 | if(!same && !backing_file_mismatch(*backing_file_out, size, mtime)){ | |
1224 | printk("Switching backing file to '%s'\n", *backing_file_out); | |
1225 | err = write_cow_header(file, fd, *backing_file_out, | |
1226 | sectorsize, align, &size); | |
1227 | if(err){ | |
1228 | printk("Switch failed, errno = %d\n", -err); | |
1229 | return(err); | |
1230 | } | |
1231 | } | |
1232 | else { | |
1233 | *backing_file_out = backing_file; | |
1234 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
1235 | if(err) goto out_close; | |
1236 | } | |
1237 | ||
1238 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
1239 | bitmap_len_out, data_offset_out); | |
1240 | ||
1241 | return(fd); | |
1242 | out_close: | |
1243 | os_close_file(fd); | |
1244 | return(err); | |
1245 | } | |
1246 | ||
1247 | int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, | |
1248 | int sectorsize, int alignment, int *bitmap_offset_out, | |
1249 | unsigned long *bitmap_len_out, int *data_offset_out) | |
1250 | { | |
1251 | int err, fd; | |
1252 | ||
1253 | flags.c = 1; | |
1254 | fd = open_ubd_file(cow_file, &flags, NULL, NULL, NULL, NULL, NULL); | |
1255 | if(fd < 0){ | |
1256 | err = fd; | |
1257 | printk("Open of COW file '%s' failed, errno = %d\n", cow_file, | |
1258 | -err); | |
1259 | goto out; | |
1260 | } | |
1261 | ||
1262 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
1263 | bitmap_offset_out, bitmap_len_out, | |
1264 | data_offset_out); | |
1265 | if(!err) | |
1266 | return(fd); | |
1267 | os_close_file(fd); | |
1268 | out: | |
1269 | return(err); | |
1270 | } | |
1271 | ||
1272 | static int update_bitmap(struct io_thread_req *req) | |
1273 | { | |
1274 | int n; | |
1275 | ||
1276 | if(req->cow_offset == -1) | |
1277 | return(0); | |
1278 | ||
1279 | n = os_seek_file(req->fds[1], req->cow_offset); | |
1280 | if(n < 0){ | |
1281 | printk("do_io - bitmap lseek failed : err = %d\n", -n); | |
1282 | return(1); | |
1283 | } | |
1284 | ||
1285 | n = os_write_file(req->fds[1], &req->bitmap_words, | |
1286 | sizeof(req->bitmap_words)); | |
1287 | if(n != sizeof(req->bitmap_words)){ | |
1288 | printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, | |
1289 | req->fds[1]); | |
1290 | return(1); | |
1291 | } | |
1292 | ||
1293 | return(0); | |
1294 | } | |
1295 | ||
1296 | void do_io(struct io_thread_req *req) | |
1297 | { | |
1298 | char *buf; | |
1299 | unsigned long len; | |
1300 | int n, nsectors, start, end, bit; | |
1301 | int err; | |
1302 | __u64 off; | |
1303 | ||
1da177e4 LT |
1304 | nsectors = req->length / req->sectorsize; |
1305 | start = 0; | |
1306 | do { | |
1307 | bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); | |
1308 | end = start; | |
1309 | while((end < nsectors) && | |
1310 | (ubd_test_bit(end, (unsigned char *) | |
1311 | &req->sector_mask) == bit)) | |
1312 | end++; | |
1313 | ||
1314 | off = req->offset + req->offsets[bit] + | |
1315 | start * req->sectorsize; | |
1316 | len = (end - start) * req->sectorsize; | |
1317 | buf = &req->buffer[start * req->sectorsize]; | |
1318 | ||
1319 | err = os_seek_file(req->fds[bit], off); | |
1320 | if(err < 0){ | |
1321 | printk("do_io - lseek failed : err = %d\n", -err); | |
1322 | req->error = 1; | |
1323 | return; | |
1324 | } | |
1325 | if(req->op == UBD_READ){ | |
1326 | n = 0; | |
1327 | do { | |
1328 | buf = &buf[n]; | |
1329 | len -= n; | |
1330 | n = os_read_file(req->fds[bit], buf, len); | |
1331 | if (n < 0) { | |
1332 | printk("do_io - read failed, err = %d " | |
1333 | "fd = %d\n", -n, req->fds[bit]); | |
1334 | req->error = 1; | |
1335 | return; | |
1336 | } | |
1337 | } while((n < len) && (n != 0)); | |
1338 | if (n < len) memset(&buf[n], 0, len - n); | |
2c49be99 | 1339 | } else { |
1da177e4 LT |
1340 | n = os_write_file(req->fds[bit], buf, len); |
1341 | if(n != len){ | |
1342 | printk("do_io - write failed err = %d " | |
1343 | "fd = %d\n", -n, req->fds[bit]); | |
1344 | req->error = 1; | |
1345 | return; | |
1346 | } | |
1347 | } | |
1348 | ||
1349 | start = end; | |
1350 | } while(start < nsectors); | |
1351 | ||
1352 | req->error = update_bitmap(req); | |
1353 | } | |
1354 | ||
1355 | /* Changed in start_io_thread, which is serialized by being called only | |
1356 | * from ubd_init, which is an initcall. | |
1357 | */ | |
1358 | int kernel_fd = -1; | |
1359 | ||
1360 | /* Only changed by the io thread */ | |
1361 | int io_count = 0; | |
1362 | ||
1363 | int io_thread(void *arg) | |
1364 | { | |
1365 | struct io_thread_req req; | |
1366 | int n; | |
1367 | ||
1368 | ignore_sigwinch_sig(); | |
1369 | while(1){ | |
1370 | n = os_read_file(kernel_fd, &req, sizeof(req)); | |
1371 | if(n != sizeof(req)){ | |
1372 | if(n < 0) | |
1373 | printk("io_thread - read failed, fd = %d, " | |
1374 | "err = %d\n", kernel_fd, -n); | |
1375 | else { | |
1376 | printk("io_thread - short read, fd = %d, " | |
1377 | "length = %d\n", kernel_fd, n); | |
1378 | } | |
1379 | continue; | |
1380 | } | |
1381 | io_count++; | |
1382 | do_io(&req); | |
1383 | n = os_write_file(kernel_fd, &req, sizeof(req)); | |
1384 | if(n != sizeof(req)) | |
1385 | printk("io_thread - write failed, fd = %d, err = %d\n", | |
1386 | kernel_fd, -n); | |
1387 | } | |
1388 | } | |
1389 | ||
1390 | /* | |
1391 | * Overrides for Emacs so that we follow Linus's tabbing style. | |
1392 | * Emacs will notice this stuff at the end of the file and automatically | |
1393 | * adjust the settings for this buffer only. This must remain at the end | |
1394 | * of the file. | |
1395 | * --------------------------------------------------------------------------- | |
1396 | * Local variables: | |
1397 | * c-file-style: "linux" | |
1398 | * End: | |
1399 | */ |