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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 UBD_SHIFT 4 | |
21 | ||
22 | #include "linux/kernel.h" | |
23 | #include "linux/module.h" | |
24 | #include "linux/blkdev.h" | |
25 | #include "linux/ata.h" | |
26 | #include "linux/hdreg.h" | |
27 | #include "linux/init.h" | |
28 | #include "linux/cdrom.h" | |
29 | #include "linux/proc_fs.h" | |
30 | #include "linux/seq_file.h" | |
31 | #include "linux/ctype.h" | |
32 | #include "linux/capability.h" | |
33 | #include "linux/mm.h" | |
34 | #include "linux/slab.h" | |
35 | #include "linux/vmalloc.h" | |
36 | #include "linux/mutex.h" | |
37 | #include "linux/blkpg.h" | |
38 | #include "linux/genhd.h" | |
39 | #include "linux/spinlock.h" | |
40 | #include "linux/platform_device.h" | |
41 | #include "linux/scatterlist.h" | |
42 | #include "asm/segment.h" | |
43 | #include "asm/uaccess.h" | |
44 | #include "asm/irq.h" | |
45 | #include "asm/types.h" | |
46 | #include "asm/tlbflush.h" | |
47 | #include "mem_user.h" | |
48 | #include "kern_util.h" | |
49 | #include "kern.h" | |
50 | #include "mconsole_kern.h" | |
51 | #include "init.h" | |
52 | #include "irq_user.h" | |
53 | #include "irq_kern.h" | |
54 | #include "ubd_user.h" | |
55 | #include "os.h" | |
56 | #include "mem.h" | |
57 | #include "mem_kern.h" | |
58 | #include "cow.h" | |
59 | ||
60 | enum ubd_req { UBD_READ, UBD_WRITE }; | |
61 | ||
62 | struct io_thread_req { | |
63 | struct request *req; | |
64 | enum ubd_req op; | |
65 | int fds[2]; | |
66 | unsigned long offsets[2]; | |
67 | unsigned long long offset; | |
68 | unsigned long length; | |
69 | char *buffer; | |
70 | int sectorsize; | |
71 | unsigned long sector_mask; | |
72 | unsigned long long cow_offset; | |
73 | unsigned long bitmap_words[2]; | |
74 | int error; | |
75 | }; | |
76 | ||
77 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) | |
78 | { | |
79 | __u64 n; | |
80 | int bits, off; | |
81 | ||
82 | bits = sizeof(data[0]) * 8; | |
83 | n = bit / bits; | |
84 | off = bit % bits; | |
85 | return (data[n] & (1 << off)) != 0; | |
86 | } | |
87 | ||
88 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) | |
89 | { | |
90 | __u64 n; | |
91 | int bits, off; | |
92 | ||
93 | bits = sizeof(data[0]) * 8; | |
94 | n = bit / bits; | |
95 | off = bit % bits; | |
96 | data[n] |= (1 << off); | |
97 | } | |
98 | /*End stuff from ubd_user.h*/ | |
99 | ||
100 | #define DRIVER_NAME "uml-blkdev" | |
101 | ||
102 | static DEFINE_MUTEX(ubd_lock); | |
103 | static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */ | |
104 | ||
105 | static int ubd_open(struct block_device *bdev, fmode_t mode); | |
106 | static int ubd_release(struct gendisk *disk, fmode_t mode); | |
107 | static int ubd_ioctl(struct block_device *bdev, fmode_t mode, | |
108 | unsigned int cmd, unsigned long arg); | |
109 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); | |
110 | ||
111 | #define MAX_DEV (16) | |
112 | ||
113 | static const struct block_device_operations ubd_blops = { | |
114 | .owner = THIS_MODULE, | |
115 | .open = ubd_open, | |
116 | .release = ubd_release, | |
117 | .ioctl = ubd_ioctl, | |
118 | .getgeo = ubd_getgeo, | |
119 | }; | |
120 | ||
121 | /* Protected by ubd_lock */ | |
122 | static int fake_major = UBD_MAJOR; | |
123 | static struct gendisk *ubd_gendisk[MAX_DEV]; | |
124 | static struct gendisk *fake_gendisk[MAX_DEV]; | |
125 | ||
126 | #ifdef CONFIG_BLK_DEV_UBD_SYNC | |
127 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
128 | .cl = 1 }) | |
129 | #else | |
130 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
131 | .cl = 1 }) | |
132 | #endif | |
133 | static struct openflags global_openflags = OPEN_FLAGS; | |
134 | ||
135 | struct cow { | |
136 | /* backing file name */ | |
137 | char *file; | |
138 | /* backing file fd */ | |
139 | int fd; | |
140 | unsigned long *bitmap; | |
141 | unsigned long bitmap_len; | |
142 | int bitmap_offset; | |
143 | int data_offset; | |
144 | }; | |
145 | ||
146 | #define MAX_SG 64 | |
147 | ||
148 | struct ubd { | |
149 | struct list_head restart; | |
150 | /* name (and fd, below) of the file opened for writing, either the | |
151 | * backing or the cow file. */ | |
152 | char *file; | |
153 | int count; | |
154 | int fd; | |
155 | __u64 size; | |
156 | struct openflags boot_openflags; | |
157 | struct openflags openflags; | |
158 | unsigned shared:1; | |
159 | unsigned no_cow:1; | |
160 | struct cow cow; | |
161 | struct platform_device pdev; | |
162 | struct request_queue *queue; | |
163 | spinlock_t lock; | |
164 | struct scatterlist sg[MAX_SG]; | |
165 | struct request *request; | |
166 | int start_sg, end_sg; | |
167 | sector_t rq_pos; | |
168 | }; | |
169 | ||
170 | #define DEFAULT_COW { \ | |
171 | .file = NULL, \ | |
172 | .fd = -1, \ | |
173 | .bitmap = NULL, \ | |
174 | .bitmap_offset = 0, \ | |
175 | .data_offset = 0, \ | |
176 | } | |
177 | ||
178 | #define DEFAULT_UBD { \ | |
179 | .file = NULL, \ | |
180 | .count = 0, \ | |
181 | .fd = -1, \ | |
182 | .size = -1, \ | |
183 | .boot_openflags = OPEN_FLAGS, \ | |
184 | .openflags = OPEN_FLAGS, \ | |
185 | .no_cow = 0, \ | |
186 | .shared = 0, \ | |
187 | .cow = DEFAULT_COW, \ | |
188 | .lock = SPIN_LOCK_UNLOCKED, \ | |
189 | .request = NULL, \ | |
190 | .start_sg = 0, \ | |
191 | .end_sg = 0, \ | |
192 | .rq_pos = 0, \ | |
193 | } | |
194 | ||
195 | /* Protected by ubd_lock */ | |
196 | static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD }; | |
197 | ||
198 | /* Only changed by fake_ide_setup which is a setup */ | |
199 | static int fake_ide = 0; | |
200 | static struct proc_dir_entry *proc_ide_root = NULL; | |
201 | static struct proc_dir_entry *proc_ide = NULL; | |
202 | ||
203 | static void make_proc_ide(void) | |
204 | { | |
205 | proc_ide_root = proc_mkdir("ide", NULL); | |
206 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
207 | } | |
208 | ||
209 | static int fake_ide_media_proc_show(struct seq_file *m, void *v) | |
210 | { | |
211 | seq_puts(m, "disk\n"); | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static int fake_ide_media_proc_open(struct inode *inode, struct file *file) | |
216 | { | |
217 | return single_open(file, fake_ide_media_proc_show, NULL); | |
218 | } | |
219 | ||
220 | static const struct file_operations fake_ide_media_proc_fops = { | |
221 | .owner = THIS_MODULE, | |
222 | .open = fake_ide_media_proc_open, | |
223 | .read = seq_read, | |
224 | .llseek = seq_lseek, | |
225 | .release = single_release, | |
226 | }; | |
227 | ||
228 | static void make_ide_entries(const char *dev_name) | |
229 | { | |
230 | struct proc_dir_entry *dir, *ent; | |
231 | char name[64]; | |
232 | ||
233 | if(proc_ide_root == NULL) make_proc_ide(); | |
234 | ||
235 | dir = proc_mkdir(dev_name, proc_ide); | |
236 | if(!dir) return; | |
237 | ||
238 | ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops); | |
239 | if(!ent) return; | |
240 | snprintf(name, sizeof(name), "ide0/%s", dev_name); | |
241 | proc_symlink(dev_name, proc_ide_root, name); | |
242 | } | |
243 | ||
244 | static int fake_ide_setup(char *str) | |
245 | { | |
246 | fake_ide = 1; | |
247 | return 1; | |
248 | } | |
249 | ||
250 | __setup("fake_ide", fake_ide_setup); | |
251 | ||
252 | __uml_help(fake_ide_setup, | |
253 | "fake_ide\n" | |
254 | " Create ide0 entries that map onto ubd devices.\n\n" | |
255 | ); | |
256 | ||
257 | static int parse_unit(char **ptr) | |
258 | { | |
259 | char *str = *ptr, *end; | |
260 | int n = -1; | |
261 | ||
262 | if(isdigit(*str)) { | |
263 | n = simple_strtoul(str, &end, 0); | |
264 | if(end == str) | |
265 | return -1; | |
266 | *ptr = end; | |
267 | } | |
268 | else if (('a' <= *str) && (*str <= 'z')) { | |
269 | n = *str - 'a'; | |
270 | str++; | |
271 | *ptr = str; | |
272 | } | |
273 | return n; | |
274 | } | |
275 | ||
276 | /* If *index_out == -1 at exit, the passed option was a general one; | |
277 | * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it | |
278 | * should not be freed on exit. | |
279 | */ | |
280 | static int ubd_setup_common(char *str, int *index_out, char **error_out) | |
281 | { | |
282 | struct ubd *ubd_dev; | |
283 | struct openflags flags = global_openflags; | |
284 | char *backing_file; | |
285 | int n, err = 0, i; | |
286 | ||
287 | if(index_out) *index_out = -1; | |
288 | n = *str; | |
289 | if(n == '='){ | |
290 | char *end; | |
291 | int major; | |
292 | ||
293 | str++; | |
294 | if(!strcmp(str, "sync")){ | |
295 | global_openflags = of_sync(global_openflags); | |
296 | goto out1; | |
297 | } | |
298 | ||
299 | err = -EINVAL; | |
300 | major = simple_strtoul(str, &end, 0); | |
301 | if((*end != '\0') || (end == str)){ | |
302 | *error_out = "Didn't parse major number"; | |
303 | goto out1; | |
304 | } | |
305 | ||
306 | mutex_lock(&ubd_lock); | |
307 | if (fake_major != UBD_MAJOR) { | |
308 | *error_out = "Can't assign a fake major twice"; | |
309 | goto out1; | |
310 | } | |
311 | ||
312 | fake_major = major; | |
313 | ||
314 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
315 | major); | |
316 | err = 0; | |
317 | out1: | |
318 | mutex_unlock(&ubd_lock); | |
319 | return err; | |
320 | } | |
321 | ||
322 | n = parse_unit(&str); | |
323 | if(n < 0){ | |
324 | *error_out = "Couldn't parse device number"; | |
325 | return -EINVAL; | |
326 | } | |
327 | if(n >= MAX_DEV){ | |
328 | *error_out = "Device number out of range"; | |
329 | return 1; | |
330 | } | |
331 | ||
332 | err = -EBUSY; | |
333 | mutex_lock(&ubd_lock); | |
334 | ||
335 | ubd_dev = &ubd_devs[n]; | |
336 | if(ubd_dev->file != NULL){ | |
337 | *error_out = "Device is already configured"; | |
338 | goto out; | |
339 | } | |
340 | ||
341 | if (index_out) | |
342 | *index_out = n; | |
343 | ||
344 | err = -EINVAL; | |
345 | for (i = 0; i < sizeof("rscd="); i++) { | |
346 | switch (*str) { | |
347 | case 'r': | |
348 | flags.w = 0; | |
349 | break; | |
350 | case 's': | |
351 | flags.s = 1; | |
352 | break; | |
353 | case 'd': | |
354 | ubd_dev->no_cow = 1; | |
355 | break; | |
356 | case 'c': | |
357 | ubd_dev->shared = 1; | |
358 | break; | |
359 | case '=': | |
360 | str++; | |
361 | goto break_loop; | |
362 | default: | |
363 | *error_out = "Expected '=' or flag letter " | |
364 | "(r, s, c, or d)"; | |
365 | goto out; | |
366 | } | |
367 | str++; | |
368 | } | |
369 | ||
370 | if (*str == '=') | |
371 | *error_out = "Too many flags specified"; | |
372 | else | |
373 | *error_out = "Missing '='"; | |
374 | goto out; | |
375 | ||
376 | break_loop: | |
377 | backing_file = strchr(str, ','); | |
378 | ||
379 | if (backing_file == NULL) | |
380 | backing_file = strchr(str, ':'); | |
381 | ||
382 | if(backing_file != NULL){ | |
383 | if(ubd_dev->no_cow){ | |
384 | *error_out = "Can't specify both 'd' and a cow file"; | |
385 | goto out; | |
386 | } | |
387 | else { | |
388 | *backing_file = '\0'; | |
389 | backing_file++; | |
390 | } | |
391 | } | |
392 | err = 0; | |
393 | ubd_dev->file = str; | |
394 | ubd_dev->cow.file = backing_file; | |
395 | ubd_dev->boot_openflags = flags; | |
396 | out: | |
397 | mutex_unlock(&ubd_lock); | |
398 | return err; | |
399 | } | |
400 | ||
401 | static int ubd_setup(char *str) | |
402 | { | |
403 | char *error; | |
404 | int err; | |
405 | ||
406 | err = ubd_setup_common(str, NULL, &error); | |
407 | if(err) | |
408 | printk(KERN_ERR "Failed to initialize device with \"%s\" : " | |
409 | "%s\n", str, error); | |
410 | return 1; | |
411 | } | |
412 | ||
413 | __setup("ubd", ubd_setup); | |
414 | __uml_help(ubd_setup, | |
415 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
416 | " This is used to associate a device with a file in the underlying\n" | |
417 | " filesystem. When specifying two filenames, the first one is the\n" | |
418 | " COW name and the second is the backing file name. As separator you can\n" | |
419 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
420 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
421 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
422 | " When using only one filename, UML will detect whether to treat it like\n" | |
423 | " a COW file or a backing file. To override this detection, add the 'd'\n" | |
424 | " flag:\n" | |
425 | " ubd0d=BackingFile\n" | |
426 | " Usually, there is a filesystem in the file, but \n" | |
427 | " that's not required. Swap devices containing swap files can be\n" | |
428 | " specified like this. Also, a file which doesn't contain a\n" | |
429 | " filesystem can have its contents read in the virtual \n" | |
430 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
431 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
432 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
433 | " an 's' will cause data to be written to disk on the host immediately.\n" | |
434 | " 'c' will cause the device to be treated as being shared between multiple\n" | |
435 | " UMLs and file locking will be turned off - this is appropriate for a\n" | |
436 | " cluster filesystem and inappropriate at almost all other times.\n\n" | |
437 | ); | |
438 | ||
439 | static int udb_setup(char *str) | |
440 | { | |
441 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
442 | "udb TYPO\n", str); | |
443 | return 1; | |
444 | } | |
445 | ||
446 | __setup("udb", udb_setup); | |
447 | __uml_help(udb_setup, | |
448 | "udb\n" | |
449 | " This option is here solely to catch ubd -> udb typos, which can be\n" | |
450 | " to impossible to catch visually unless you specifically look for\n" | |
451 | " them. The only result of any option starting with 'udb' is an error\n" | |
452 | " in the boot output.\n\n" | |
453 | ); | |
454 | ||
455 | static void do_ubd_request(struct request_queue * q); | |
456 | ||
457 | /* Only changed by ubd_init, which is an initcall. */ | |
458 | static int thread_fd = -1; | |
459 | static LIST_HEAD(restart); | |
460 | ||
461 | /* XXX - move this inside ubd_intr. */ | |
462 | /* Called without dev->lock held, and only in interrupt context. */ | |
463 | static void ubd_handler(void) | |
464 | { | |
465 | struct io_thread_req *req; | |
466 | struct ubd *ubd; | |
467 | struct list_head *list, *next_ele; | |
468 | unsigned long flags; | |
469 | int n; | |
470 | ||
471 | while(1){ | |
472 | n = os_read_file(thread_fd, &req, | |
473 | sizeof(struct io_thread_req *)); | |
474 | if(n != sizeof(req)){ | |
475 | if(n == -EAGAIN) | |
476 | break; | |
477 | printk(KERN_ERR "spurious interrupt in ubd_handler, " | |
478 | "err = %d\n", -n); | |
479 | return; | |
480 | } | |
481 | ||
482 | blk_end_request(req->req, 0, req->length); | |
483 | kfree(req); | |
484 | } | |
485 | reactivate_fd(thread_fd, UBD_IRQ); | |
486 | ||
487 | list_for_each_safe(list, next_ele, &restart){ | |
488 | ubd = container_of(list, struct ubd, restart); | |
489 | list_del_init(&ubd->restart); | |
490 | spin_lock_irqsave(&ubd->lock, flags); | |
491 | do_ubd_request(ubd->queue); | |
492 | spin_unlock_irqrestore(&ubd->lock, flags); | |
493 | } | |
494 | } | |
495 | ||
496 | static irqreturn_t ubd_intr(int irq, void *dev) | |
497 | { | |
498 | ubd_handler(); | |
499 | return IRQ_HANDLED; | |
500 | } | |
501 | ||
502 | /* Only changed by ubd_init, which is an initcall. */ | |
503 | static int io_pid = -1; | |
504 | ||
505 | static void kill_io_thread(void) | |
506 | { | |
507 | if(io_pid != -1) | |
508 | os_kill_process(io_pid, 1); | |
509 | } | |
510 | ||
511 | __uml_exitcall(kill_io_thread); | |
512 | ||
513 | static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) | |
514 | { | |
515 | char *file; | |
516 | ||
517 | file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; | |
518 | return os_file_size(file, size_out); | |
519 | } | |
520 | ||
521 | static int read_cow_bitmap(int fd, void *buf, int offset, int len) | |
522 | { | |
523 | int err; | |
524 | ||
525 | err = os_seek_file(fd, offset); | |
526 | if (err < 0) | |
527 | return err; | |
528 | ||
529 | err = os_read_file(fd, buf, len); | |
530 | if (err < 0) | |
531 | return err; | |
532 | ||
533 | return 0; | |
534 | } | |
535 | ||
536 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
537 | { | |
538 | unsigned long modtime; | |
539 | unsigned long long actual; | |
540 | int err; | |
541 | ||
542 | err = os_file_modtime(file, &modtime); | |
543 | if (err < 0) { | |
544 | printk(KERN_ERR "Failed to get modification time of backing " | |
545 | "file \"%s\", err = %d\n", file, -err); | |
546 | return err; | |
547 | } | |
548 | ||
549 | err = os_file_size(file, &actual); | |
550 | if (err < 0) { | |
551 | printk(KERN_ERR "Failed to get size of backing file \"%s\", " | |
552 | "err = %d\n", file, -err); | |
553 | return err; | |
554 | } | |
555 | ||
556 | if (actual != size) { | |
557 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
558 | * the typecast.*/ | |
559 | printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header " | |
560 | "vs backing file\n", (unsigned long long) size, actual); | |
561 | return -EINVAL; | |
562 | } | |
563 | if (modtime != mtime) { | |
564 | printk(KERN_ERR "mtime mismatch (%ld vs %ld) of COW header vs " | |
565 | "backing file\n", mtime, modtime); | |
566 | return -EINVAL; | |
567 | } | |
568 | return 0; | |
569 | } | |
570 | ||
571 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) | |
572 | { | |
573 | struct uml_stat buf1, buf2; | |
574 | int err; | |
575 | ||
576 | if (from_cmdline == NULL) | |
577 | return 0; | |
578 | if (!strcmp(from_cmdline, from_cow)) | |
579 | return 0; | |
580 | ||
581 | err = os_stat_file(from_cmdline, &buf1); | |
582 | if (err < 0) { | |
583 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline, | |
584 | -err); | |
585 | return 0; | |
586 | } | |
587 | err = os_stat_file(from_cow, &buf2); | |
588 | if (err < 0) { | |
589 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow, | |
590 | -err); | |
591 | return 1; | |
592 | } | |
593 | if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
594 | return 0; | |
595 | ||
596 | printk(KERN_ERR "Backing file mismatch - \"%s\" requested, " | |
597 | "\"%s\" specified in COW header of \"%s\"\n", | |
598 | from_cmdline, from_cow, cow); | |
599 | return 1; | |
600 | } | |
601 | ||
602 | static int open_ubd_file(char *file, struct openflags *openflags, int shared, | |
603 | char **backing_file_out, int *bitmap_offset_out, | |
604 | unsigned long *bitmap_len_out, int *data_offset_out, | |
605 | int *create_cow_out) | |
606 | { | |
607 | time_t mtime; | |
608 | unsigned long long size; | |
609 | __u32 version, align; | |
610 | char *backing_file; | |
611 | int fd, err, sectorsize, asked_switch, mode = 0644; | |
612 | ||
613 | fd = os_open_file(file, *openflags, mode); | |
614 | if (fd < 0) { | |
615 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
616 | *create_cow_out = 1; | |
617 | if (!openflags->w || | |
618 | ((fd != -EROFS) && (fd != -EACCES))) | |
619 | return fd; | |
620 | openflags->w = 0; | |
621 | fd = os_open_file(file, *openflags, mode); | |
622 | if (fd < 0) | |
623 | return fd; | |
624 | } | |
625 | ||
626 | if (shared) | |
627 | printk(KERN_INFO "Not locking \"%s\" on the host\n", file); | |
628 | else { | |
629 | err = os_lock_file(fd, openflags->w); | |
630 | if (err < 0) { | |
631 | printk(KERN_ERR "Failed to lock '%s', err = %d\n", | |
632 | file, -err); | |
633 | goto out_close; | |
634 | } | |
635 | } | |
636 | ||
637 | /* Successful return case! */ | |
638 | if (backing_file_out == NULL) | |
639 | return fd; | |
640 | ||
641 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
642 | &size, §orsize, &align, bitmap_offset_out); | |
643 | if (err && (*backing_file_out != NULL)) { | |
644 | printk(KERN_ERR "Failed to read COW header from COW file " | |
645 | "\"%s\", errno = %d\n", file, -err); | |
646 | goto out_close; | |
647 | } | |
648 | if (err) | |
649 | return fd; | |
650 | ||
651 | asked_switch = path_requires_switch(*backing_file_out, backing_file, | |
652 | file); | |
653 | ||
654 | /* Allow switching only if no mismatch. */ | |
655 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, | |
656 | mtime)) { | |
657 | printk(KERN_ERR "Switching backing file to '%s'\n", | |
658 | *backing_file_out); | |
659 | err = write_cow_header(file, fd, *backing_file_out, | |
660 | sectorsize, align, &size); | |
661 | if (err) { | |
662 | printk(KERN_ERR "Switch failed, errno = %d\n", -err); | |
663 | goto out_close; | |
664 | } | |
665 | } else { | |
666 | *backing_file_out = backing_file; | |
667 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
668 | if (err) | |
669 | goto out_close; | |
670 | } | |
671 | ||
672 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
673 | bitmap_len_out, data_offset_out); | |
674 | ||
675 | return fd; | |
676 | out_close: | |
677 | os_close_file(fd); | |
678 | return err; | |
679 | } | |
680 | ||
681 | static int create_cow_file(char *cow_file, char *backing_file, | |
682 | struct openflags flags, | |
683 | int sectorsize, int alignment, int *bitmap_offset_out, | |
684 | unsigned long *bitmap_len_out, int *data_offset_out) | |
685 | { | |
686 | int err, fd; | |
687 | ||
688 | flags.c = 1; | |
689 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); | |
690 | if (fd < 0) { | |
691 | err = fd; | |
692 | printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n", | |
693 | cow_file, -err); | |
694 | goto out; | |
695 | } | |
696 | ||
697 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
698 | bitmap_offset_out, bitmap_len_out, | |
699 | data_offset_out); | |
700 | if (!err) | |
701 | return fd; | |
702 | os_close_file(fd); | |
703 | out: | |
704 | return err; | |
705 | } | |
706 | ||
707 | static void ubd_close_dev(struct ubd *ubd_dev) | |
708 | { | |
709 | os_close_file(ubd_dev->fd); | |
710 | if(ubd_dev->cow.file == NULL) | |
711 | return; | |
712 | ||
713 | os_close_file(ubd_dev->cow.fd); | |
714 | vfree(ubd_dev->cow.bitmap); | |
715 | ubd_dev->cow.bitmap = NULL; | |
716 | } | |
717 | ||
718 | static int ubd_open_dev(struct ubd *ubd_dev) | |
719 | { | |
720 | struct openflags flags; | |
721 | char **back_ptr; | |
722 | int err, create_cow, *create_ptr; | |
723 | int fd; | |
724 | ||
725 | ubd_dev->openflags = ubd_dev->boot_openflags; | |
726 | create_cow = 0; | |
727 | create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; | |
728 | back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; | |
729 | ||
730 | fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, | |
731 | back_ptr, &ubd_dev->cow.bitmap_offset, | |
732 | &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, | |
733 | create_ptr); | |
734 | ||
735 | if((fd == -ENOENT) && create_cow){ | |
736 | fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, | |
737 | ubd_dev->openflags, 1 << 9, PAGE_SIZE, | |
738 | &ubd_dev->cow.bitmap_offset, | |
739 | &ubd_dev->cow.bitmap_len, | |
740 | &ubd_dev->cow.data_offset); | |
741 | if(fd >= 0){ | |
742 | printk(KERN_INFO "Creating \"%s\" as COW file for " | |
743 | "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); | |
744 | } | |
745 | } | |
746 | ||
747 | if(fd < 0){ | |
748 | printk("Failed to open '%s', errno = %d\n", ubd_dev->file, | |
749 | -fd); | |
750 | return fd; | |
751 | } | |
752 | ubd_dev->fd = fd; | |
753 | ||
754 | if(ubd_dev->cow.file != NULL){ | |
755 | blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long)); | |
756 | ||
757 | err = -ENOMEM; | |
758 | ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len); | |
759 | if(ubd_dev->cow.bitmap == NULL){ | |
760 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); | |
761 | goto error; | |
762 | } | |
763 | flush_tlb_kernel_vm(); | |
764 | ||
765 | err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, | |
766 | ubd_dev->cow.bitmap_offset, | |
767 | ubd_dev->cow.bitmap_len); | |
768 | if(err < 0) | |
769 | goto error; | |
770 | ||
771 | flags = ubd_dev->openflags; | |
772 | flags.w = 0; | |
773 | err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, | |
774 | NULL, NULL, NULL, NULL); | |
775 | if(err < 0) goto error; | |
776 | ubd_dev->cow.fd = err; | |
777 | } | |
778 | return 0; | |
779 | error: | |
780 | os_close_file(ubd_dev->fd); | |
781 | return err; | |
782 | } | |
783 | ||
784 | static void ubd_device_release(struct device *dev) | |
785 | { | |
786 | struct ubd *ubd_dev = dev_get_drvdata(dev); | |
787 | ||
788 | blk_cleanup_queue(ubd_dev->queue); | |
789 | *ubd_dev = ((struct ubd) DEFAULT_UBD); | |
790 | } | |
791 | ||
792 | static int ubd_disk_register(int major, u64 size, int unit, | |
793 | struct gendisk **disk_out) | |
794 | { | |
795 | struct gendisk *disk; | |
796 | ||
797 | disk = alloc_disk(1 << UBD_SHIFT); | |
798 | if(disk == NULL) | |
799 | return -ENOMEM; | |
800 | ||
801 | disk->major = major; | |
802 | disk->first_minor = unit << UBD_SHIFT; | |
803 | disk->fops = &ubd_blops; | |
804 | set_capacity(disk, size / 512); | |
805 | if (major == UBD_MAJOR) | |
806 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); | |
807 | else | |
808 | sprintf(disk->disk_name, "ubd_fake%d", unit); | |
809 | ||
810 | /* sysfs register (not for ide fake devices) */ | |
811 | if (major == UBD_MAJOR) { | |
812 | ubd_devs[unit].pdev.id = unit; | |
813 | ubd_devs[unit].pdev.name = DRIVER_NAME; | |
814 | ubd_devs[unit].pdev.dev.release = ubd_device_release; | |
815 | dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]); | |
816 | platform_device_register(&ubd_devs[unit].pdev); | |
817 | disk->driverfs_dev = &ubd_devs[unit].pdev.dev; | |
818 | } | |
819 | ||
820 | disk->private_data = &ubd_devs[unit]; | |
821 | disk->queue = ubd_devs[unit].queue; | |
822 | add_disk(disk); | |
823 | ||
824 | *disk_out = disk; | |
825 | return 0; | |
826 | } | |
827 | ||
828 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
829 | ||
830 | static int ubd_add(int n, char **error_out) | |
831 | { | |
832 | struct ubd *ubd_dev = &ubd_devs[n]; | |
833 | int err = 0; | |
834 | ||
835 | if(ubd_dev->file == NULL) | |
836 | goto out; | |
837 | ||
838 | err = ubd_file_size(ubd_dev, &ubd_dev->size); | |
839 | if(err < 0){ | |
840 | *error_out = "Couldn't determine size of device's file"; | |
841 | goto out; | |
842 | } | |
843 | ||
844 | ubd_dev->size = ROUND_BLOCK(ubd_dev->size); | |
845 | ||
846 | INIT_LIST_HEAD(&ubd_dev->restart); | |
847 | sg_init_table(ubd_dev->sg, MAX_SG); | |
848 | ||
849 | err = -ENOMEM; | |
850 | ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock); | |
851 | if (ubd_dev->queue == NULL) { | |
852 | *error_out = "Failed to initialize device queue"; | |
853 | goto out; | |
854 | } | |
855 | ubd_dev->queue->queuedata = ubd_dev; | |
856 | ||
857 | blk_queue_max_segments(ubd_dev->queue, MAX_SG); | |
858 | err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]); | |
859 | if(err){ | |
860 | *error_out = "Failed to register device"; | |
861 | goto out_cleanup; | |
862 | } | |
863 | ||
864 | if (fake_major != UBD_MAJOR) | |
865 | ubd_disk_register(fake_major, ubd_dev->size, n, | |
866 | &fake_gendisk[n]); | |
867 | ||
868 | /* | |
869 | * Perhaps this should also be under the "if (fake_major)" above | |
870 | * using the fake_disk->disk_name | |
871 | */ | |
872 | if (fake_ide) | |
873 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
874 | ||
875 | err = 0; | |
876 | out: | |
877 | return err; | |
878 | ||
879 | out_cleanup: | |
880 | blk_cleanup_queue(ubd_dev->queue); | |
881 | goto out; | |
882 | } | |
883 | ||
884 | static int ubd_config(char *str, char **error_out) | |
885 | { | |
886 | int n, ret; | |
887 | ||
888 | /* This string is possibly broken up and stored, so it's only | |
889 | * freed if ubd_setup_common fails, or if only general options | |
890 | * were set. | |
891 | */ | |
892 | str = kstrdup(str, GFP_KERNEL); | |
893 | if (str == NULL) { | |
894 | *error_out = "Failed to allocate memory"; | |
895 | return -ENOMEM; | |
896 | } | |
897 | ||
898 | ret = ubd_setup_common(str, &n, error_out); | |
899 | if (ret) | |
900 | goto err_free; | |
901 | ||
902 | if (n == -1) { | |
903 | ret = 0; | |
904 | goto err_free; | |
905 | } | |
906 | ||
907 | mutex_lock(&ubd_lock); | |
908 | ret = ubd_add(n, error_out); | |
909 | if (ret) | |
910 | ubd_devs[n].file = NULL; | |
911 | mutex_unlock(&ubd_lock); | |
912 | ||
913 | out: | |
914 | return ret; | |
915 | ||
916 | err_free: | |
917 | kfree(str); | |
918 | goto out; | |
919 | } | |
920 | ||
921 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
922 | { | |
923 | struct ubd *ubd_dev; | |
924 | int n, len = 0; | |
925 | ||
926 | n = parse_unit(&name); | |
927 | if((n >= MAX_DEV) || (n < 0)){ | |
928 | *error_out = "ubd_get_config : device number out of range"; | |
929 | return -1; | |
930 | } | |
931 | ||
932 | ubd_dev = &ubd_devs[n]; | |
933 | mutex_lock(&ubd_lock); | |
934 | ||
935 | if(ubd_dev->file == NULL){ | |
936 | CONFIG_CHUNK(str, size, len, "", 1); | |
937 | goto out; | |
938 | } | |
939 | ||
940 | CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); | |
941 | ||
942 | if(ubd_dev->cow.file != NULL){ | |
943 | CONFIG_CHUNK(str, size, len, ",", 0); | |
944 | CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); | |
945 | } | |
946 | else CONFIG_CHUNK(str, size, len, "", 1); | |
947 | ||
948 | out: | |
949 | mutex_unlock(&ubd_lock); | |
950 | return len; | |
951 | } | |
952 | ||
953 | static int ubd_id(char **str, int *start_out, int *end_out) | |
954 | { | |
955 | int n; | |
956 | ||
957 | n = parse_unit(str); | |
958 | *start_out = 0; | |
959 | *end_out = MAX_DEV - 1; | |
960 | return n; | |
961 | } | |
962 | ||
963 | static int ubd_remove(int n, char **error_out) | |
964 | { | |
965 | struct gendisk *disk = ubd_gendisk[n]; | |
966 | struct ubd *ubd_dev; | |
967 | int err = -ENODEV; | |
968 | ||
969 | mutex_lock(&ubd_lock); | |
970 | ||
971 | ubd_dev = &ubd_devs[n]; | |
972 | ||
973 | if(ubd_dev->file == NULL) | |
974 | goto out; | |
975 | ||
976 | /* you cannot remove a open disk */ | |
977 | err = -EBUSY; | |
978 | if(ubd_dev->count > 0) | |
979 | goto out; | |
980 | ||
981 | ubd_gendisk[n] = NULL; | |
982 | if(disk != NULL){ | |
983 | del_gendisk(disk); | |
984 | put_disk(disk); | |
985 | } | |
986 | ||
987 | if(fake_gendisk[n] != NULL){ | |
988 | del_gendisk(fake_gendisk[n]); | |
989 | put_disk(fake_gendisk[n]); | |
990 | fake_gendisk[n] = NULL; | |
991 | } | |
992 | ||
993 | err = 0; | |
994 | platform_device_unregister(&ubd_dev->pdev); | |
995 | out: | |
996 | mutex_unlock(&ubd_lock); | |
997 | return err; | |
998 | } | |
999 | ||
1000 | /* All these are called by mconsole in process context and without | |
1001 | * ubd-specific locks. The structure itself is const except for .list. | |
1002 | */ | |
1003 | static struct mc_device ubd_mc = { | |
1004 | .list = LIST_HEAD_INIT(ubd_mc.list), | |
1005 | .name = "ubd", | |
1006 | .config = ubd_config, | |
1007 | .get_config = ubd_get_config, | |
1008 | .id = ubd_id, | |
1009 | .remove = ubd_remove, | |
1010 | }; | |
1011 | ||
1012 | static int __init ubd_mc_init(void) | |
1013 | { | |
1014 | mconsole_register_dev(&ubd_mc); | |
1015 | return 0; | |
1016 | } | |
1017 | ||
1018 | __initcall(ubd_mc_init); | |
1019 | ||
1020 | static int __init ubd0_init(void) | |
1021 | { | |
1022 | struct ubd *ubd_dev = &ubd_devs[0]; | |
1023 | ||
1024 | mutex_lock(&ubd_lock); | |
1025 | if(ubd_dev->file == NULL) | |
1026 | ubd_dev->file = "root_fs"; | |
1027 | mutex_unlock(&ubd_lock); | |
1028 | ||
1029 | return 0; | |
1030 | } | |
1031 | ||
1032 | __initcall(ubd0_init); | |
1033 | ||
1034 | /* Used in ubd_init, which is an initcall */ | |
1035 | static struct platform_driver ubd_driver = { | |
1036 | .driver = { | |
1037 | .name = DRIVER_NAME, | |
1038 | }, | |
1039 | }; | |
1040 | ||
1041 | static int __init ubd_init(void) | |
1042 | { | |
1043 | char *error; | |
1044 | int i, err; | |
1045 | ||
1046 | if (register_blkdev(UBD_MAJOR, "ubd")) | |
1047 | return -1; | |
1048 | ||
1049 | if (fake_major != UBD_MAJOR) { | |
1050 | char name[sizeof("ubd_nnn\0")]; | |
1051 | ||
1052 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
1053 | if (register_blkdev(fake_major, "ubd")) | |
1054 | return -1; | |
1055 | } | |
1056 | platform_driver_register(&ubd_driver); | |
1057 | mutex_lock(&ubd_lock); | |
1058 | for (i = 0; i < MAX_DEV; i++){ | |
1059 | err = ubd_add(i, &error); | |
1060 | if(err) | |
1061 | printk(KERN_ERR "Failed to initialize ubd device %d :" | |
1062 | "%s\n", i, error); | |
1063 | } | |
1064 | mutex_unlock(&ubd_lock); | |
1065 | return 0; | |
1066 | } | |
1067 | ||
1068 | late_initcall(ubd_init); | |
1069 | ||
1070 | static int __init ubd_driver_init(void){ | |
1071 | unsigned long stack; | |
1072 | int err; | |
1073 | ||
1074 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
1075 | if(global_openflags.s){ | |
1076 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
1077 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
1078 | * enough. So use anyway the io thread. */ | |
1079 | } | |
1080 | stack = alloc_stack(0, 0); | |
1081 | io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), | |
1082 | &thread_fd); | |
1083 | if(io_pid < 0){ | |
1084 | printk(KERN_ERR | |
1085 | "ubd : Failed to start I/O thread (errno = %d) - " | |
1086 | "falling back to synchronous I/O\n", -io_pid); | |
1087 | io_pid = -1; | |
1088 | return 0; | |
1089 | } | |
1090 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, | |
1091 | IRQF_DISABLED, "ubd", ubd_devs); | |
1092 | if(err != 0) | |
1093 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); | |
1094 | return 0; | |
1095 | } | |
1096 | ||
1097 | device_initcall(ubd_driver_init); | |
1098 | ||
1099 | static int ubd_open(struct block_device *bdev, fmode_t mode) | |
1100 | { | |
1101 | struct gendisk *disk = bdev->bd_disk; | |
1102 | struct ubd *ubd_dev = disk->private_data; | |
1103 | int err = 0; | |
1104 | ||
1105 | mutex_lock(&ubd_mutex); | |
1106 | if(ubd_dev->count == 0){ | |
1107 | err = ubd_open_dev(ubd_dev); | |
1108 | if(err){ | |
1109 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
1110 | disk->disk_name, ubd_dev->file, -err); | |
1111 | goto out; | |
1112 | } | |
1113 | } | |
1114 | ubd_dev->count++; | |
1115 | set_disk_ro(disk, !ubd_dev->openflags.w); | |
1116 | ||
1117 | /* This should no more be needed. And it didn't work anyway to exclude | |
1118 | * read-write remounting of filesystems.*/ | |
1119 | /*if((mode & FMODE_WRITE) && !ubd_dev->openflags.w){ | |
1120 | if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); | |
1121 | err = -EROFS; | |
1122 | }*/ | |
1123 | out: | |
1124 | mutex_unlock(&ubd_mutex); | |
1125 | return err; | |
1126 | } | |
1127 | ||
1128 | static int ubd_release(struct gendisk *disk, fmode_t mode) | |
1129 | { | |
1130 | struct ubd *ubd_dev = disk->private_data; | |
1131 | ||
1132 | mutex_lock(&ubd_mutex); | |
1133 | if(--ubd_dev->count == 0) | |
1134 | ubd_close_dev(ubd_dev); | |
1135 | mutex_unlock(&ubd_mutex); | |
1136 | return 0; | |
1137 | } | |
1138 | ||
1139 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, | |
1140 | __u64 *cow_offset, unsigned long *bitmap, | |
1141 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
1142 | __u64 bitmap_len) | |
1143 | { | |
1144 | __u64 sector = io_offset >> 9; | |
1145 | int i, update_bitmap = 0; | |
1146 | ||
1147 | for(i = 0; i < length >> 9; i++){ | |
1148 | if(cow_mask != NULL) | |
1149 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
1150 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
1151 | continue; | |
1152 | ||
1153 | update_bitmap = 1; | |
1154 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
1155 | } | |
1156 | ||
1157 | if(!update_bitmap) | |
1158 | return; | |
1159 | ||
1160 | *cow_offset = sector / (sizeof(unsigned long) * 8); | |
1161 | ||
1162 | /* This takes care of the case where we're exactly at the end of the | |
1163 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
1164 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
1165 | * for the original diagnosis. | |
1166 | */ | |
1167 | if (*cow_offset == (DIV_ROUND_UP(bitmap_len, | |
1168 | sizeof(unsigned long)) - 1)) | |
1169 | (*cow_offset)--; | |
1170 | ||
1171 | bitmap_words[0] = bitmap[*cow_offset]; | |
1172 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
1173 | ||
1174 | *cow_offset *= sizeof(unsigned long); | |
1175 | *cow_offset += bitmap_offset; | |
1176 | } | |
1177 | ||
1178 | static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, | |
1179 | __u64 bitmap_offset, __u64 bitmap_len) | |
1180 | { | |
1181 | __u64 sector = req->offset >> 9; | |
1182 | int i; | |
1183 | ||
1184 | if(req->length > (sizeof(req->sector_mask) * 8) << 9) | |
1185 | panic("Operation too long"); | |
1186 | ||
1187 | if(req->op == UBD_READ) { | |
1188 | for(i = 0; i < req->length >> 9; i++){ | |
1189 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
1190 | ubd_set_bit(i, (unsigned char *) | |
1191 | &req->sector_mask); | |
1192 | } | |
1193 | } | |
1194 | else cowify_bitmap(req->offset, req->length, &req->sector_mask, | |
1195 | &req->cow_offset, bitmap, bitmap_offset, | |
1196 | req->bitmap_words, bitmap_len); | |
1197 | } | |
1198 | ||
1199 | /* Called with dev->lock held */ | |
1200 | static void prepare_request(struct request *req, struct io_thread_req *io_req, | |
1201 | unsigned long long offset, int page_offset, | |
1202 | int len, struct page *page) | |
1203 | { | |
1204 | struct gendisk *disk = req->rq_disk; | |
1205 | struct ubd *ubd_dev = disk->private_data; | |
1206 | ||
1207 | io_req->req = req; | |
1208 | io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : | |
1209 | ubd_dev->fd; | |
1210 | io_req->fds[1] = ubd_dev->fd; | |
1211 | io_req->cow_offset = -1; | |
1212 | io_req->offset = offset; | |
1213 | io_req->length = len; | |
1214 | io_req->error = 0; | |
1215 | io_req->sector_mask = 0; | |
1216 | ||
1217 | io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; | |
1218 | io_req->offsets[0] = 0; | |
1219 | io_req->offsets[1] = ubd_dev->cow.data_offset; | |
1220 | io_req->buffer = page_address(page) + page_offset; | |
1221 | io_req->sectorsize = 1 << 9; | |
1222 | ||
1223 | if(ubd_dev->cow.file != NULL) | |
1224 | cowify_req(io_req, ubd_dev->cow.bitmap, | |
1225 | ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len); | |
1226 | ||
1227 | } | |
1228 | ||
1229 | /* Called with dev->lock held */ | |
1230 | static void do_ubd_request(struct request_queue *q) | |
1231 | { | |
1232 | struct io_thread_req *io_req; | |
1233 | struct request *req; | |
1234 | int n; | |
1235 | ||
1236 | while(1){ | |
1237 | struct ubd *dev = q->queuedata; | |
1238 | if(dev->end_sg == 0){ | |
1239 | struct request *req = blk_fetch_request(q); | |
1240 | if(req == NULL) | |
1241 | return; | |
1242 | ||
1243 | dev->request = req; | |
1244 | dev->rq_pos = blk_rq_pos(req); | |
1245 | dev->start_sg = 0; | |
1246 | dev->end_sg = blk_rq_map_sg(q, req, dev->sg); | |
1247 | } | |
1248 | ||
1249 | req = dev->request; | |
1250 | while(dev->start_sg < dev->end_sg){ | |
1251 | struct scatterlist *sg = &dev->sg[dev->start_sg]; | |
1252 | ||
1253 | io_req = kmalloc(sizeof(struct io_thread_req), | |
1254 | GFP_ATOMIC); | |
1255 | if(io_req == NULL){ | |
1256 | if(list_empty(&dev->restart)) | |
1257 | list_add(&dev->restart, &restart); | |
1258 | return; | |
1259 | } | |
1260 | prepare_request(req, io_req, | |
1261 | (unsigned long long)dev->rq_pos << 9, | |
1262 | sg->offset, sg->length, sg_page(sg)); | |
1263 | ||
1264 | n = os_write_file(thread_fd, &io_req, | |
1265 | sizeof(struct io_thread_req *)); | |
1266 | if(n != sizeof(struct io_thread_req *)){ | |
1267 | if(n != -EAGAIN) | |
1268 | printk("write to io thread failed, " | |
1269 | "errno = %d\n", -n); | |
1270 | else if(list_empty(&dev->restart)) | |
1271 | list_add(&dev->restart, &restart); | |
1272 | kfree(io_req); | |
1273 | return; | |
1274 | } | |
1275 | ||
1276 | dev->rq_pos += sg->length >> 9; | |
1277 | dev->start_sg++; | |
1278 | } | |
1279 | dev->end_sg = 0; | |
1280 | dev->request = NULL; | |
1281 | } | |
1282 | } | |
1283 | ||
1284 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) | |
1285 | { | |
1286 | struct ubd *ubd_dev = bdev->bd_disk->private_data; | |
1287 | ||
1288 | geo->heads = 128; | |
1289 | geo->sectors = 32; | |
1290 | geo->cylinders = ubd_dev->size / (128 * 32 * 512); | |
1291 | return 0; | |
1292 | } | |
1293 | ||
1294 | static int ubd_ioctl(struct block_device *bdev, fmode_t mode, | |
1295 | unsigned int cmd, unsigned long arg) | |
1296 | { | |
1297 | struct ubd *ubd_dev = bdev->bd_disk->private_data; | |
1298 | u16 ubd_id[ATA_ID_WORDS]; | |
1299 | ||
1300 | switch (cmd) { | |
1301 | struct cdrom_volctrl volume; | |
1302 | case HDIO_GET_IDENTITY: | |
1303 | memset(&ubd_id, 0, ATA_ID_WORDS * 2); | |
1304 | ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512); | |
1305 | ubd_id[ATA_ID_HEADS] = 128; | |
1306 | ubd_id[ATA_ID_SECTORS] = 32; | |
1307 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, | |
1308 | sizeof(ubd_id))) | |
1309 | return -EFAULT; | |
1310 | return 0; | |
1311 | ||
1312 | case CDROMVOLREAD: | |
1313 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
1314 | return -EFAULT; | |
1315 | volume.channel0 = 255; | |
1316 | volume.channel1 = 255; | |
1317 | volume.channel2 = 255; | |
1318 | volume.channel3 = 255; | |
1319 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
1320 | return -EFAULT; | |
1321 | return 0; | |
1322 | } | |
1323 | return -EINVAL; | |
1324 | } | |
1325 | ||
1326 | static int update_bitmap(struct io_thread_req *req) | |
1327 | { | |
1328 | int n; | |
1329 | ||
1330 | if(req->cow_offset == -1) | |
1331 | return 0; | |
1332 | ||
1333 | n = os_seek_file(req->fds[1], req->cow_offset); | |
1334 | if(n < 0){ | |
1335 | printk("do_io - bitmap lseek failed : err = %d\n", -n); | |
1336 | return 1; | |
1337 | } | |
1338 | ||
1339 | n = os_write_file(req->fds[1], &req->bitmap_words, | |
1340 | sizeof(req->bitmap_words)); | |
1341 | if(n != sizeof(req->bitmap_words)){ | |
1342 | printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, | |
1343 | req->fds[1]); | |
1344 | return 1; | |
1345 | } | |
1346 | ||
1347 | return 0; | |
1348 | } | |
1349 | ||
1350 | static void do_io(struct io_thread_req *req) | |
1351 | { | |
1352 | char *buf; | |
1353 | unsigned long len; | |
1354 | int n, nsectors, start, end, bit; | |
1355 | int err; | |
1356 | __u64 off; | |
1357 | ||
1358 | nsectors = req->length / req->sectorsize; | |
1359 | start = 0; | |
1360 | do { | |
1361 | bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); | |
1362 | end = start; | |
1363 | while((end < nsectors) && | |
1364 | (ubd_test_bit(end, (unsigned char *) | |
1365 | &req->sector_mask) == bit)) | |
1366 | end++; | |
1367 | ||
1368 | off = req->offset + req->offsets[bit] + | |
1369 | start * req->sectorsize; | |
1370 | len = (end - start) * req->sectorsize; | |
1371 | buf = &req->buffer[start * req->sectorsize]; | |
1372 | ||
1373 | err = os_seek_file(req->fds[bit], off); | |
1374 | if(err < 0){ | |
1375 | printk("do_io - lseek failed : err = %d\n", -err); | |
1376 | req->error = 1; | |
1377 | return; | |
1378 | } | |
1379 | if(req->op == UBD_READ){ | |
1380 | n = 0; | |
1381 | do { | |
1382 | buf = &buf[n]; | |
1383 | len -= n; | |
1384 | n = os_read_file(req->fds[bit], buf, len); | |
1385 | if (n < 0) { | |
1386 | printk("do_io - read failed, err = %d " | |
1387 | "fd = %d\n", -n, req->fds[bit]); | |
1388 | req->error = 1; | |
1389 | return; | |
1390 | } | |
1391 | } while((n < len) && (n != 0)); | |
1392 | if (n < len) memset(&buf[n], 0, len - n); | |
1393 | } else { | |
1394 | n = os_write_file(req->fds[bit], buf, len); | |
1395 | if(n != len){ | |
1396 | printk("do_io - write failed err = %d " | |
1397 | "fd = %d\n", -n, req->fds[bit]); | |
1398 | req->error = 1; | |
1399 | return; | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | start = end; | |
1404 | } while(start < nsectors); | |
1405 | ||
1406 | req->error = update_bitmap(req); | |
1407 | } | |
1408 | ||
1409 | /* Changed in start_io_thread, which is serialized by being called only | |
1410 | * from ubd_init, which is an initcall. | |
1411 | */ | |
1412 | int kernel_fd = -1; | |
1413 | ||
1414 | /* Only changed by the io thread. XXX: currently unused. */ | |
1415 | static int io_count = 0; | |
1416 | ||
1417 | int io_thread(void *arg) | |
1418 | { | |
1419 | struct io_thread_req *req; | |
1420 | int n; | |
1421 | ||
1422 | ignore_sigwinch_sig(); | |
1423 | while(1){ | |
1424 | n = os_read_file(kernel_fd, &req, | |
1425 | sizeof(struct io_thread_req *)); | |
1426 | if(n != sizeof(struct io_thread_req *)){ | |
1427 | if(n < 0) | |
1428 | printk("io_thread - read failed, fd = %d, " | |
1429 | "err = %d\n", kernel_fd, -n); | |
1430 | else { | |
1431 | printk("io_thread - short read, fd = %d, " | |
1432 | "length = %d\n", kernel_fd, n); | |
1433 | } | |
1434 | continue; | |
1435 | } | |
1436 | io_count++; | |
1437 | do_io(req); | |
1438 | n = os_write_file(kernel_fd, &req, | |
1439 | sizeof(struct io_thread_req *)); | |
1440 | if(n != sizeof(struct io_thread_req *)) | |
1441 | printk("io_thread - write failed, fd = %d, err = %d\n", | |
1442 | kernel_fd, -n); | |
1443 | } | |
1444 | ||
1445 | return 0; | |
1446 | } |