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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" | |
09ace81c | 38 | #include "asm/atomic.h" |
1da177e4 LT |
39 | #include "asm/segment.h" |
40 | #include "asm/uaccess.h" | |
41 | #include "asm/irq.h" | |
42 | #include "asm/types.h" | |
43 | #include "asm/tlbflush.h" | |
44 | #include "user_util.h" | |
45 | #include "mem_user.h" | |
46 | #include "kern_util.h" | |
47 | #include "kern.h" | |
48 | #include "mconsole_kern.h" | |
49 | #include "init.h" | |
50 | #include "irq_user.h" | |
51 | #include "irq_kern.h" | |
52 | #include "ubd_user.h" | |
1da177e4 LT |
53 | #include "os.h" |
54 | #include "mem.h" | |
55 | #include "mem_kern.h" | |
56 | #include "cow.h" | |
09ace81c | 57 | #include "aio.h" |
1da177e4 | 58 | |
7b9014c1 | 59 | enum ubd_req { UBD_READ, UBD_WRITE }; |
1da177e4 LT |
60 | |
61 | struct io_thread_req { | |
09ace81c | 62 | enum aio_type op; |
1da177e4 LT |
63 | int fds[2]; |
64 | unsigned long offsets[2]; | |
65 | unsigned long long offset; | |
66 | unsigned long length; | |
67 | char *buffer; | |
68 | int sectorsize; | |
09ace81c JD |
69 | int bitmap_offset; |
70 | long bitmap_start; | |
71 | long bitmap_end; | |
1da177e4 LT |
72 | int error; |
73 | }; | |
74 | ||
75 | extern int open_ubd_file(char *file, struct openflags *openflags, | |
76 | char **backing_file_out, int *bitmap_offset_out, | |
77 | unsigned long *bitmap_len_out, int *data_offset_out, | |
78 | int *create_cow_out); | |
79 | extern int create_cow_file(char *cow_file, char *backing_file, | |
80 | struct openflags flags, int sectorsize, | |
81 | int alignment, int *bitmap_offset_out, | |
82 | unsigned long *bitmap_len_out, | |
83 | int *data_offset_out); | |
84 | extern int read_cow_bitmap(int fd, void *buf, int offset, int len); | |
09ace81c JD |
85 | extern void do_io(struct io_thread_req *req, struct request *r, |
86 | unsigned long *bitmap); | |
1da177e4 | 87 | |
09ace81c | 88 | static inline int ubd_test_bit(__u64 bit, void *data) |
1da177e4 | 89 | { |
09ace81c | 90 | unsigned char *buffer = data; |
1da177e4 LT |
91 | __u64 n; |
92 | int bits, off; | |
93 | ||
09ace81c | 94 | bits = sizeof(buffer[0]) * 8; |
1da177e4 LT |
95 | n = bit / bits; |
96 | off = bit % bits; | |
09ace81c | 97 | return((buffer[n] & (1 << off)) != 0); |
1da177e4 LT |
98 | } |
99 | ||
09ace81c | 100 | static inline void ubd_set_bit(__u64 bit, void *data) |
1da177e4 | 101 | { |
09ace81c | 102 | unsigned char *buffer = data; |
1da177e4 LT |
103 | __u64 n; |
104 | int bits, off; | |
105 | ||
09ace81c | 106 | bits = sizeof(buffer[0]) * 8; |
1da177e4 LT |
107 | n = bit / bits; |
108 | off = bit % bits; | |
09ace81c | 109 | buffer[n] |= (1 << off); |
1da177e4 LT |
110 | } |
111 | /*End stuff from ubd_user.h*/ | |
112 | ||
113 | #define DRIVER_NAME "uml-blkdev" | |
114 | ||
115 | static DEFINE_SPINLOCK(ubd_io_lock); | |
116 | static DEFINE_SPINLOCK(ubd_lock); | |
117 | ||
1da177e4 LT |
118 | static int ubd_open(struct inode * inode, struct file * filp); |
119 | static int ubd_release(struct inode * inode, struct file * file); | |
120 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
121 | unsigned int cmd, unsigned long arg); | |
122 | ||
123 | #define MAX_DEV (8) | |
124 | ||
1da177e4 LT |
125 | static struct block_device_operations ubd_blops = { |
126 | .owner = THIS_MODULE, | |
127 | .open = ubd_open, | |
128 | .release = ubd_release, | |
129 | .ioctl = ubd_ioctl, | |
130 | }; | |
131 | ||
132 | /* Protected by the queue_lock */ | |
133 | static request_queue_t *ubd_queue; | |
134 | ||
135 | /* Protected by ubd_lock */ | |
136 | static int fake_major = MAJOR_NR; | |
137 | ||
138 | static struct gendisk *ubd_gendisk[MAX_DEV]; | |
139 | static struct gendisk *fake_gendisk[MAX_DEV]; | |
140 | ||
141 | #ifdef CONFIG_BLK_DEV_UBD_SYNC | |
142 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
143 | .cl = 1 }) | |
144 | #else | |
145 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
146 | .cl = 1 }) | |
147 | #endif | |
148 | ||
149 | /* Not protected - changed only in ubd_setup_common and then only to | |
150 | * to enable O_SYNC. | |
151 | */ | |
152 | static struct openflags global_openflags = OPEN_FLAGS; | |
153 | ||
154 | struct cow { | |
2c49be99 | 155 | /* This is the backing file, actually */ |
1da177e4 LT |
156 | char *file; |
157 | int fd; | |
158 | unsigned long *bitmap; | |
159 | unsigned long bitmap_len; | |
160 | int bitmap_offset; | |
161 | int data_offset; | |
162 | }; | |
163 | ||
09ace81c JD |
164 | #define MAX_SG 64 |
165 | ||
1da177e4 LT |
166 | struct ubd { |
167 | char *file; | |
168 | int count; | |
169 | int fd; | |
170 | __u64 size; | |
171 | struct openflags boot_openflags; | |
172 | struct openflags openflags; | |
173 | int no_cow; | |
174 | struct cow cow; | |
175 | struct platform_device pdev; | |
09ace81c | 176 | struct scatterlist sg[MAX_SG]; |
1da177e4 LT |
177 | }; |
178 | ||
179 | #define DEFAULT_COW { \ | |
180 | .file = NULL, \ | |
181 | .fd = -1, \ | |
182 | .bitmap = NULL, \ | |
183 | .bitmap_offset = 0, \ | |
184 | .data_offset = 0, \ | |
185 | } | |
186 | ||
187 | #define DEFAULT_UBD { \ | |
188 | .file = NULL, \ | |
189 | .count = 0, \ | |
190 | .fd = -1, \ | |
191 | .size = -1, \ | |
192 | .boot_openflags = OPEN_FLAGS, \ | |
193 | .openflags = OPEN_FLAGS, \ | |
194 | .no_cow = 0, \ | |
195 | .cow = DEFAULT_COW, \ | |
1da177e4 LT |
196 | } |
197 | ||
198 | struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; | |
199 | ||
200 | static int ubd0_init(void) | |
201 | { | |
202 | struct ubd *dev = &ubd_dev[0]; | |
203 | ||
204 | if(dev->file == NULL) | |
205 | dev->file = "root_fs"; | |
206 | return(0); | |
207 | } | |
208 | ||
209 | __initcall(ubd0_init); | |
210 | ||
211 | /* Only changed by fake_ide_setup which is a setup */ | |
212 | static int fake_ide = 0; | |
213 | static struct proc_dir_entry *proc_ide_root = NULL; | |
214 | static struct proc_dir_entry *proc_ide = NULL; | |
215 | ||
216 | static void make_proc_ide(void) | |
217 | { | |
218 | proc_ide_root = proc_mkdir("ide", NULL); | |
219 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
220 | } | |
221 | ||
222 | static int proc_ide_read_media(char *page, char **start, off_t off, int count, | |
223 | int *eof, void *data) | |
224 | { | |
225 | int len; | |
226 | ||
227 | strcpy(page, "disk\n"); | |
228 | len = strlen("disk\n"); | |
229 | len -= off; | |
230 | if (len < count){ | |
231 | *eof = 1; | |
232 | if (len <= 0) return 0; | |
233 | } | |
234 | else len = count; | |
235 | *start = page + off; | |
236 | return len; | |
237 | } | |
238 | ||
239 | static void make_ide_entries(char *dev_name) | |
240 | { | |
241 | struct proc_dir_entry *dir, *ent; | |
242 | char name[64]; | |
243 | ||
244 | if(proc_ide_root == NULL) make_proc_ide(); | |
245 | ||
246 | dir = proc_mkdir(dev_name, proc_ide); | |
247 | if(!dir) return; | |
248 | ||
249 | ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); | |
250 | if(!ent) return; | |
251 | ent->nlink = 1; | |
252 | ent->data = NULL; | |
253 | ent->read_proc = proc_ide_read_media; | |
254 | ent->write_proc = NULL; | |
255 | sprintf(name,"ide0/%s", dev_name); | |
256 | proc_symlink(dev_name, proc_ide_root, name); | |
257 | } | |
258 | ||
259 | static int fake_ide_setup(char *str) | |
260 | { | |
261 | fake_ide = 1; | |
262 | return(1); | |
263 | } | |
264 | ||
265 | __setup("fake_ide", fake_ide_setup); | |
266 | ||
267 | __uml_help(fake_ide_setup, | |
268 | "fake_ide\n" | |
269 | " Create ide0 entries that map onto ubd devices.\n\n" | |
270 | ); | |
271 | ||
272 | static int parse_unit(char **ptr) | |
273 | { | |
274 | char *str = *ptr, *end; | |
275 | int n = -1; | |
276 | ||
277 | if(isdigit(*str)) { | |
278 | n = simple_strtoul(str, &end, 0); | |
279 | if(end == str) | |
280 | return(-1); | |
281 | *ptr = end; | |
282 | } | |
283 | else if (('a' <= *str) && (*str <= 'h')) { | |
284 | n = *str - 'a'; | |
285 | str++; | |
286 | *ptr = str; | |
287 | } | |
288 | return(n); | |
289 | } | |
290 | ||
291 | static int ubd_setup_common(char *str, int *index_out) | |
292 | { | |
293 | struct ubd *dev; | |
294 | struct openflags flags = global_openflags; | |
295 | char *backing_file; | |
296 | int n, err, i; | |
297 | ||
298 | if(index_out) *index_out = -1; | |
299 | n = *str; | |
300 | if(n == '='){ | |
301 | char *end; | |
302 | int major; | |
303 | ||
304 | str++; | |
1da177e4 LT |
305 | if(!strcmp(str, "sync")){ |
306 | global_openflags = of_sync(global_openflags); | |
307 | return(0); | |
308 | } | |
309 | major = simple_strtoul(str, &end, 0); | |
310 | if((*end != '\0') || (end == str)){ | |
311 | printk(KERN_ERR | |
312 | "ubd_setup : didn't parse major number\n"); | |
313 | return(1); | |
314 | } | |
315 | ||
316 | err = 1; | |
317 | spin_lock(&ubd_lock); | |
318 | if(fake_major != MAJOR_NR){ | |
319 | printk(KERN_ERR "Can't assign a fake major twice\n"); | |
320 | goto out1; | |
321 | } | |
322 | ||
323 | fake_major = major; | |
324 | ||
325 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
326 | major); | |
327 | err = 0; | |
328 | out1: | |
329 | spin_unlock(&ubd_lock); | |
330 | return(err); | |
331 | } | |
332 | ||
333 | n = parse_unit(&str); | |
334 | if(n < 0){ | |
335 | printk(KERN_ERR "ubd_setup : couldn't parse unit number " | |
336 | "'%s'\n", str); | |
337 | return(1); | |
338 | } | |
339 | if(n >= MAX_DEV){ | |
340 | printk(KERN_ERR "ubd_setup : index %d out of range " | |
341 | "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1); | |
342 | return(1); | |
343 | } | |
344 | ||
345 | err = 1; | |
346 | spin_lock(&ubd_lock); | |
347 | ||
348 | dev = &ubd_dev[n]; | |
349 | if(dev->file != NULL){ | |
350 | printk(KERN_ERR "ubd_setup : device already configured\n"); | |
351 | goto out; | |
352 | } | |
353 | ||
354 | if (index_out) | |
355 | *index_out = n; | |
356 | ||
357 | for (i = 0; i < 4; i++) { | |
358 | switch (*str) { | |
359 | case 'r': | |
360 | flags.w = 0; | |
361 | break; | |
362 | case 's': | |
363 | flags.s = 1; | |
364 | break; | |
365 | case 'd': | |
366 | dev->no_cow = 1; | |
367 | break; | |
368 | case '=': | |
369 | str++; | |
370 | goto break_loop; | |
371 | default: | |
372 | printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r,s or d)\n"); | |
373 | goto out; | |
374 | } | |
375 | str++; | |
376 | } | |
377 | ||
378 | if (*str == '=') | |
379 | printk(KERN_ERR "ubd_setup : Too many flags specified\n"); | |
380 | else | |
381 | printk(KERN_ERR "ubd_setup : Expected '='\n"); | |
382 | goto out; | |
383 | ||
384 | break_loop: | |
385 | err = 0; | |
386 | backing_file = strchr(str, ','); | |
387 | ||
388 | if (!backing_file) { | |
389 | backing_file = strchr(str, ':'); | |
390 | } | |
391 | ||
392 | if(backing_file){ | |
393 | if(dev->no_cow) | |
394 | printk(KERN_ERR "Can't specify both 'd' and a " | |
395 | "cow file\n"); | |
396 | else { | |
397 | *backing_file = '\0'; | |
398 | backing_file++; | |
399 | } | |
400 | } | |
401 | dev->file = str; | |
402 | dev->cow.file = backing_file; | |
403 | dev->boot_openflags = flags; | |
404 | out: | |
405 | spin_unlock(&ubd_lock); | |
406 | return(err); | |
407 | } | |
408 | ||
409 | static int ubd_setup(char *str) | |
410 | { | |
411 | ubd_setup_common(str, NULL); | |
412 | return(1); | |
413 | } | |
414 | ||
415 | __setup("ubd", ubd_setup); | |
416 | __uml_help(ubd_setup, | |
417 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
418 | " This is used to associate a device with a file in the underlying\n" | |
419 | " filesystem. When specifying two filenames, the first one is the\n" | |
420 | " COW name and the second is the backing file name. As separator you can\n" | |
421 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
422 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
423 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
424 | " When using only one filename, UML will detect whether to thread it like\n" | |
425 | " a COW file or a backing file. To override this detection, add the 'd'\n" | |
426 | " flag:\n" | |
427 | " ubd0d=BackingFile\n" | |
428 | " Usually, there is a filesystem in the file, but \n" | |
429 | " that's not required. Swap devices containing swap files can be\n" | |
430 | " specified like this. Also, a file which doesn't contain a\n" | |
431 | " filesystem can have its contents read in the virtual \n" | |
432 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
433 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
434 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
435 | " an 's' will cause data to be written to disk on the host immediately.\n\n" | |
436 | ); | |
437 | ||
438 | static int udb_setup(char *str) | |
439 | { | |
440 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
441 | "udb TYPO\n", str); | |
442 | return(1); | |
443 | } | |
444 | ||
445 | __setup("udb", udb_setup); | |
446 | __uml_help(udb_setup, | |
447 | "udb\n" | |
0894e27e JD |
448 | " This option is here solely to catch ubd -> udb typos, which can be\n" |
449 | " to impossible to catch visually unless you specifically look for\n" | |
450 | " them. The only result of any option starting with 'udb' is an error\n" | |
1da177e4 LT |
451 | " in the boot output.\n\n" |
452 | ); | |
453 | ||
454 | static int fakehd_set = 0; | |
455 | static int fakehd(char *str) | |
456 | { | |
457 | printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); | |
458 | fakehd_set = 1; | |
459 | return 1; | |
460 | } | |
461 | ||
462 | __setup("fakehd", fakehd); | |
463 | __uml_help(fakehd, | |
464 | "fakehd\n" | |
465 | " Change the ubd device name to \"hd\".\n\n" | |
466 | ); | |
467 | ||
468 | static void do_ubd_request(request_queue_t * q); | |
09ace81c | 469 | static int in_ubd; |
1da177e4 LT |
470 | |
471 | /* Changed by ubd_handler, which is serialized because interrupts only | |
472 | * happen on CPU 0. | |
473 | */ | |
474 | int intr_count = 0; | |
475 | ||
09ace81c | 476 | static void ubd_end_request(struct request *req, int bytes, int uptodate) |
1da177e4 | 477 | { |
09ace81c JD |
478 | if (!end_that_request_first(req, uptodate, bytes >> 9)) { |
479 | add_disk_randomness(req->rq_disk); | |
480 | end_that_request_last(req); | |
1da177e4 | 481 | } |
1da177e4 LT |
482 | } |
483 | ||
09ace81c JD |
484 | /* call ubd_finish if you need to serialize */ |
485 | static void __ubd_finish(struct request *req, int bytes) | |
1da177e4 | 486 | { |
09ace81c JD |
487 | if(bytes < 0){ |
488 | ubd_end_request(req, 0, 0); | |
489 | return; | |
490 | } | |
491 | ||
492 | ubd_end_request(req, bytes, 1); | |
1da177e4 LT |
493 | } |
494 | ||
09ace81c | 495 | static inline void ubd_finish(struct request *req, int bytes) |
1da177e4 | 496 | { |
09ace81c JD |
497 | spin_lock(&ubd_io_lock); |
498 | __ubd_finish(req, bytes); | |
499 | spin_unlock(&ubd_io_lock); | |
1da177e4 LT |
500 | } |
501 | ||
09ace81c JD |
502 | struct bitmap_io { |
503 | atomic_t count; | |
504 | struct aio_context aio; | |
505 | }; | |
506 | ||
507 | struct ubd_aio { | |
508 | struct aio_context aio; | |
509 | struct request *req; | |
510 | int len; | |
511 | struct bitmap_io *bitmap; | |
512 | void *bitmap_buf; | |
513 | }; | |
514 | ||
515 | static int ubd_reply_fd = -1; | |
516 | ||
1da177e4 LT |
517 | static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) |
518 | { | |
09ace81c JD |
519 | struct aio_thread_reply reply; |
520 | struct ubd_aio *aio; | |
521 | struct request *req; | |
522 | int err, n, fd = (int) (long) dev; | |
1da177e4 | 523 | |
09ace81c JD |
524 | while(1){ |
525 | err = os_read_file(fd, &reply, sizeof(reply)); | |
526 | if(err == -EAGAIN) | |
527 | break; | |
528 | if(err < 0){ | |
529 | printk("ubd_aio_handler - read returned err %d\n", | |
530 | -err); | |
531 | break; | |
532 | } | |
1da177e4 | 533 | |
09ace81c JD |
534 | aio = container_of(reply.data, struct ubd_aio, aio); |
535 | n = reply.err; | |
536 | ||
537 | if(n == 0){ | |
538 | req = aio->req; | |
539 | req->nr_sectors -= aio->len >> 9; | |
1da177e4 | 540 | |
09ace81c JD |
541 | if((aio->bitmap != NULL) && |
542 | (atomic_dec_and_test(&aio->bitmap->count))){ | |
543 | aio->aio = aio->bitmap->aio; | |
544 | aio->len = 0; | |
545 | kfree(aio->bitmap); | |
546 | aio->bitmap = NULL; | |
547 | submit_aio(&aio->aio); | |
548 | } | |
549 | else { | |
550 | if((req->nr_sectors == 0) && | |
551 | (aio->bitmap == NULL)){ | |
552 | int len = req->hard_nr_sectors << 9; | |
553 | ubd_finish(req, len); | |
554 | } | |
555 | ||
556 | if(aio->bitmap_buf != NULL) | |
557 | kfree(aio->bitmap_buf); | |
558 | kfree(aio); | |
559 | } | |
560 | } | |
561 | else if(n < 0){ | |
562 | ubd_finish(aio->req, n); | |
563 | if(aio->bitmap != NULL) | |
564 | kfree(aio->bitmap); | |
565 | if(aio->bitmap_buf != NULL) | |
566 | kfree(aio->bitmap_buf); | |
567 | kfree(aio); | |
568 | } | |
569 | } | |
570 | reactivate_fd(fd, UBD_IRQ); | |
571 | ||
572 | do_ubd_request(ubd_queue); | |
573 | ||
574 | return(IRQ_HANDLED); | |
575 | } | |
1da177e4 LT |
576 | |
577 | static int ubd_file_size(struct ubd *dev, __u64 *size_out) | |
578 | { | |
579 | char *file; | |
580 | ||
581 | file = dev->cow.file ? dev->cow.file : dev->file; | |
582 | return(os_file_size(file, size_out)); | |
583 | } | |
584 | ||
585 | static void ubd_close(struct ubd *dev) | |
586 | { | |
1da177e4 LT |
587 | os_close_file(dev->fd); |
588 | if(dev->cow.file == NULL) | |
589 | return; | |
590 | ||
1da177e4 LT |
591 | os_close_file(dev->cow.fd); |
592 | vfree(dev->cow.bitmap); | |
593 | dev->cow.bitmap = NULL; | |
594 | } | |
595 | ||
596 | static int ubd_open_dev(struct ubd *dev) | |
597 | { | |
598 | struct openflags flags; | |
599 | char **back_ptr; | |
600 | int err, create_cow, *create_ptr; | |
601 | ||
602 | dev->openflags = dev->boot_openflags; | |
603 | create_cow = 0; | |
604 | create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL; | |
605 | back_ptr = dev->no_cow ? NULL : &dev->cow.file; | |
606 | dev->fd = open_ubd_file(dev->file, &dev->openflags, back_ptr, | |
607 | &dev->cow.bitmap_offset, &dev->cow.bitmap_len, | |
608 | &dev->cow.data_offset, create_ptr); | |
609 | ||
610 | if((dev->fd == -ENOENT) && create_cow){ | |
09ace81c | 611 | dev->fd = create_cow_file(dev->file, dev->cow.file, |
1da177e4 LT |
612 | dev->openflags, 1 << 9, PAGE_SIZE, |
613 | &dev->cow.bitmap_offset, | |
614 | &dev->cow.bitmap_len, | |
615 | &dev->cow.data_offset); | |
616 | if(dev->fd >= 0){ | |
617 | printk(KERN_INFO "Creating \"%s\" as COW file for " | |
618 | "\"%s\"\n", dev->file, dev->cow.file); | |
619 | } | |
620 | } | |
621 | ||
622 | if(dev->fd < 0){ | |
623 | printk("Failed to open '%s', errno = %d\n", dev->file, | |
624 | -dev->fd); | |
625 | return(dev->fd); | |
626 | } | |
627 | ||
628 | if(dev->cow.file != NULL){ | |
629 | err = -ENOMEM; | |
630 | dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len); | |
631 | if(dev->cow.bitmap == NULL){ | |
632 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); | |
633 | goto error; | |
634 | } | |
635 | flush_tlb_kernel_vm(); | |
636 | ||
637 | err = read_cow_bitmap(dev->fd, dev->cow.bitmap, | |
638 | dev->cow.bitmap_offset, | |
639 | dev->cow.bitmap_len); | |
640 | if(err < 0) | |
641 | goto error; | |
642 | ||
643 | flags = dev->openflags; | |
644 | flags.w = 0; | |
645 | err = open_ubd_file(dev->cow.file, &flags, NULL, NULL, NULL, | |
646 | NULL, NULL); | |
647 | if(err < 0) goto error; | |
648 | dev->cow.fd = err; | |
649 | } | |
650 | return(0); | |
651 | error: | |
652 | os_close_file(dev->fd); | |
653 | return(err); | |
654 | } | |
655 | ||
656 | static int ubd_new_disk(int major, u64 size, int unit, | |
657 | struct gendisk **disk_out) | |
658 | ||
659 | { | |
660 | struct gendisk *disk; | |
661 | char from[sizeof("ubd/nnnnn\0")], to[sizeof("discnnnnn/disc\0")]; | |
662 | int err; | |
663 | ||
664 | disk = alloc_disk(1 << UBD_SHIFT); | |
665 | if(disk == NULL) | |
666 | return(-ENOMEM); | |
667 | ||
668 | disk->major = major; | |
669 | disk->first_minor = unit << UBD_SHIFT; | |
670 | disk->fops = &ubd_blops; | |
671 | set_capacity(disk, size / 512); | |
672 | if(major == MAJOR_NR){ | |
673 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); | |
674 | sprintf(disk->devfs_name, "ubd/disc%d", unit); | |
675 | sprintf(from, "ubd/%d", unit); | |
676 | sprintf(to, "disc%d/disc", unit); | |
677 | err = devfs_mk_symlink(from, to); | |
678 | if(err) | |
679 | printk("ubd_new_disk failed to make link from %s to " | |
680 | "%s, error = %d\n", from, to, err); | |
681 | } | |
682 | else { | |
683 | sprintf(disk->disk_name, "ubd_fake%d", unit); | |
684 | sprintf(disk->devfs_name, "ubd_fake/disc%d", unit); | |
685 | } | |
686 | ||
687 | /* sysfs register (not for ide fake devices) */ | |
688 | if (major == MAJOR_NR) { | |
689 | ubd_dev[unit].pdev.id = unit; | |
690 | ubd_dev[unit].pdev.name = DRIVER_NAME; | |
691 | platform_device_register(&ubd_dev[unit].pdev); | |
692 | disk->driverfs_dev = &ubd_dev[unit].pdev.dev; | |
693 | } | |
694 | ||
695 | disk->private_data = &ubd_dev[unit]; | |
696 | disk->queue = ubd_queue; | |
697 | add_disk(disk); | |
698 | ||
699 | *disk_out = disk; | |
700 | return 0; | |
701 | } | |
702 | ||
703 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
704 | ||
705 | static int ubd_add(int n) | |
706 | { | |
707 | struct ubd *dev = &ubd_dev[n]; | |
708 | int err; | |
709 | ||
ec7cf783 | 710 | err = -ENODEV; |
1da177e4 | 711 | if(dev->file == NULL) |
ec7cf783 | 712 | goto out; |
1da177e4 LT |
713 | |
714 | if (ubd_open_dev(dev)) | |
ec7cf783 | 715 | goto out; |
1da177e4 LT |
716 | |
717 | err = ubd_file_size(dev, &dev->size); | |
718 | if(err < 0) | |
ec7cf783 | 719 | goto out_close; |
1da177e4 LT |
720 | |
721 | dev->size = ROUND_BLOCK(dev->size); | |
722 | ||
723 | err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]); | |
724 | if(err) | |
ec7cf783 | 725 | goto out_close; |
1da177e4 LT |
726 | |
727 | if(fake_major != MAJOR_NR) | |
728 | ubd_new_disk(fake_major, dev->size, n, | |
729 | &fake_gendisk[n]); | |
730 | ||
731 | /* perhaps this should also be under the "if (fake_major)" above */ | |
732 | /* using the fake_disk->disk_name and also the fakehd_set name */ | |
733 | if (fake_ide) | |
734 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
735 | ||
ec7cf783 JD |
736 | err = 0; |
737 | out_close: | |
1da177e4 | 738 | ubd_close(dev); |
ec7cf783 JD |
739 | out: |
740 | return err; | |
1da177e4 LT |
741 | } |
742 | ||
743 | static int ubd_config(char *str) | |
744 | { | |
745 | int n, err; | |
746 | ||
747 | str = uml_strdup(str); | |
748 | if(str == NULL){ | |
749 | printk(KERN_ERR "ubd_config failed to strdup string\n"); | |
750 | return(1); | |
751 | } | |
752 | err = ubd_setup_common(str, &n); | |
753 | if(err){ | |
754 | kfree(str); | |
755 | return(-1); | |
756 | } | |
757 | if(n == -1) return(0); | |
758 | ||
759 | spin_lock(&ubd_lock); | |
760 | err = ubd_add(n); | |
761 | if(err) | |
762 | ubd_dev[n].file = NULL; | |
763 | spin_unlock(&ubd_lock); | |
764 | ||
765 | return(err); | |
766 | } | |
767 | ||
768 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
769 | { | |
770 | struct ubd *dev; | |
771 | int n, len = 0; | |
772 | ||
773 | n = parse_unit(&name); | |
774 | if((n >= MAX_DEV) || (n < 0)){ | |
775 | *error_out = "ubd_get_config : device number out of range"; | |
776 | return(-1); | |
777 | } | |
778 | ||
779 | dev = &ubd_dev[n]; | |
780 | spin_lock(&ubd_lock); | |
781 | ||
782 | if(dev->file == NULL){ | |
783 | CONFIG_CHUNK(str, size, len, "", 1); | |
784 | goto out; | |
785 | } | |
786 | ||
787 | CONFIG_CHUNK(str, size, len, dev->file, 0); | |
788 | ||
789 | if(dev->cow.file != NULL){ | |
790 | CONFIG_CHUNK(str, size, len, ",", 0); | |
791 | CONFIG_CHUNK(str, size, len, dev->cow.file, 1); | |
792 | } | |
793 | else CONFIG_CHUNK(str, size, len, "", 1); | |
794 | ||
795 | out: | |
796 | spin_unlock(&ubd_lock); | |
797 | return(len); | |
798 | } | |
799 | ||
29d56cfe JD |
800 | static int ubd_id(char **str, int *start_out, int *end_out) |
801 | { | |
802 | int n; | |
803 | ||
804 | n = parse_unit(str); | |
805 | *start_out = 0; | |
806 | *end_out = MAX_DEV - 1; | |
807 | return n; | |
808 | } | |
809 | ||
810 | static int ubd_remove(int n) | |
1da177e4 LT |
811 | { |
812 | struct ubd *dev; | |
29d56cfe | 813 | int err = -ENODEV; |
1da177e4 | 814 | |
29d56cfe | 815 | spin_lock(&ubd_lock); |
1da177e4 | 816 | |
29d56cfe JD |
817 | if(ubd_gendisk[n] == NULL) |
818 | goto out; | |
1da177e4 LT |
819 | |
820 | dev = &ubd_dev[n]; | |
1da177e4 | 821 | |
29d56cfe JD |
822 | if(dev->file == NULL) |
823 | goto out; | |
1da177e4 | 824 | |
29d56cfe JD |
825 | /* you cannot remove a open disk */ |
826 | err = -EBUSY; | |
827 | if(dev->count > 0) | |
1da177e4 LT |
828 | goto out; |
829 | ||
830 | del_gendisk(ubd_gendisk[n]); | |
831 | put_disk(ubd_gendisk[n]); | |
832 | ubd_gendisk[n] = NULL; | |
833 | ||
834 | if(fake_gendisk[n] != NULL){ | |
835 | del_gendisk(fake_gendisk[n]); | |
836 | put_disk(fake_gendisk[n]); | |
837 | fake_gendisk[n] = NULL; | |
838 | } | |
839 | ||
840 | platform_device_unregister(&dev->pdev); | |
841 | *dev = ((struct ubd) DEFAULT_UBD); | |
842 | err = 0; | |
29d56cfe JD |
843 | out: |
844 | spin_unlock(&ubd_lock); | |
845 | return err; | |
1da177e4 LT |
846 | } |
847 | ||
848 | static struct mc_device ubd_mc = { | |
849 | .name = "ubd", | |
850 | .config = ubd_config, | |
851 | .get_config = ubd_get_config, | |
29d56cfe | 852 | .id = ubd_id, |
1da177e4 LT |
853 | .remove = ubd_remove, |
854 | }; | |
855 | ||
856 | static int ubd_mc_init(void) | |
857 | { | |
858 | mconsole_register_dev(&ubd_mc); | |
859 | return 0; | |
860 | } | |
861 | ||
862 | __initcall(ubd_mc_init); | |
863 | ||
864 | static struct device_driver ubd_driver = { | |
865 | .name = DRIVER_NAME, | |
866 | .bus = &platform_bus_type, | |
867 | }; | |
868 | ||
869 | int ubd_init(void) | |
870 | { | |
871 | int i; | |
872 | ||
09ace81c JD |
873 | ubd_reply_fd = init_aio_irq(UBD_IRQ, "ubd", ubd_intr); |
874 | if(ubd_reply_fd < 0) | |
875 | printk("Setting up ubd AIO failed, err = %d\n", ubd_reply_fd); | |
876 | ||
1da177e4 LT |
877 | devfs_mk_dir("ubd"); |
878 | if (register_blkdev(MAJOR_NR, "ubd")) | |
879 | return -1; | |
880 | ||
881 | ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock); | |
882 | if (!ubd_queue) { | |
883 | unregister_blkdev(MAJOR_NR, "ubd"); | |
884 | return -1; | |
885 | } | |
886 | ||
09ace81c | 887 | blk_queue_max_hw_segments(ubd_queue, MAX_SG); |
1da177e4 LT |
888 | if (fake_major != MAJOR_NR) { |
889 | char name[sizeof("ubd_nnn\0")]; | |
890 | ||
891 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
892 | devfs_mk_dir(name); | |
893 | if (register_blkdev(fake_major, "ubd")) | |
894 | return -1; | |
895 | } | |
896 | driver_register(&ubd_driver); | |
897 | for (i = 0; i < MAX_DEV; i++) | |
898 | ubd_add(i); | |
09ace81c | 899 | |
1da177e4 LT |
900 | return 0; |
901 | } | |
902 | ||
903 | late_initcall(ubd_init); | |
904 | ||
1da177e4 LT |
905 | static int ubd_open(struct inode *inode, struct file *filp) |
906 | { | |
907 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
908 | struct ubd *dev = disk->private_data; | |
909 | int err = 0; | |
910 | ||
911 | if(dev->count == 0){ | |
912 | err = ubd_open_dev(dev); | |
913 | if(err){ | |
914 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
915 | disk->disk_name, dev->file, -err); | |
916 | goto out; | |
917 | } | |
918 | } | |
919 | dev->count++; | |
2c49be99 PBG |
920 | set_disk_ro(disk, !dev->openflags.w); |
921 | ||
922 | /* This should no more be needed. And it didn't work anyway to exclude | |
923 | * read-write remounting of filesystems.*/ | |
924 | /*if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ | |
1da177e4 LT |
925 | if(--dev->count == 0) ubd_close(dev); |
926 | err = -EROFS; | |
2c49be99 | 927 | }*/ |
1da177e4 LT |
928 | out: |
929 | return(err); | |
930 | } | |
931 | ||
932 | static int ubd_release(struct inode * inode, struct file * file) | |
933 | { | |
934 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
935 | struct ubd *dev = disk->private_data; | |
936 | ||
937 | if(--dev->count == 0) | |
938 | ubd_close(dev); | |
939 | return(0); | |
940 | } | |
941 | ||
09ace81c | 942 | static void cowify_bitmap(struct io_thread_req *req, unsigned long *bitmap) |
1da177e4 | 943 | { |
09ace81c JD |
944 | __u64 sector = req->offset / req->sectorsize; |
945 | int i; | |
1da177e4 | 946 | |
09ace81c JD |
947 | for(i = 0; i < req->length / req->sectorsize; i++){ |
948 | if(ubd_test_bit(sector + i, bitmap)) | |
949 | continue; | |
1da177e4 | 950 | |
09ace81c JD |
951 | if(req->bitmap_start == -1) |
952 | req->bitmap_start = sector + i; | |
953 | req->bitmap_end = sector + i + 1; | |
1da177e4 | 954 | |
09ace81c JD |
955 | ubd_set_bit(sector + i, bitmap); |
956 | } | |
1da177e4 LT |
957 | } |
958 | ||
1da177e4 | 959 | /* Called with ubd_io_lock held */ |
09ace81c JD |
960 | static int prepare_request(struct request *req, struct io_thread_req *io_req, |
961 | unsigned long long offset, int page_offset, | |
962 | int len, struct page *page) | |
1da177e4 LT |
963 | { |
964 | struct gendisk *disk = req->rq_disk; | |
965 | struct ubd *dev = disk->private_data; | |
1da177e4 | 966 | |
2c49be99 | 967 | /* This should be impossible now */ |
1da177e4 LT |
968 | if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ |
969 | printk("Write attempted on readonly ubd device %s\n", | |
970 | disk->disk_name); | |
09ace81c | 971 | ubd_end_request(req, 0, 0); |
1da177e4 LT |
972 | return(1); |
973 | } | |
974 | ||
1da177e4 LT |
975 | io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; |
976 | io_req->fds[1] = dev->fd; | |
1da177e4 LT |
977 | io_req->offset = offset; |
978 | io_req->length = len; | |
979 | io_req->error = 0; | |
09ace81c | 980 | io_req->op = (rq_data_dir(req) == READ) ? AIO_READ : AIO_WRITE; |
1da177e4 LT |
981 | io_req->offsets[0] = 0; |
982 | io_req->offsets[1] = dev->cow.data_offset; | |
09ace81c | 983 | io_req->buffer = page_address(page) + page_offset; |
1da177e4 | 984 | io_req->sectorsize = 1 << 9; |
09ace81c JD |
985 | io_req->bitmap_offset = dev->cow.bitmap_offset; |
986 | io_req->bitmap_start = -1; | |
987 | io_req->bitmap_end = -1; | |
1da177e4 | 988 | |
09ace81c JD |
989 | if((dev->cow.file != NULL) && (io_req->op == UBD_WRITE)) |
990 | cowify_bitmap(io_req, dev->cow.bitmap); | |
1da177e4 LT |
991 | return(0); |
992 | } | |
993 | ||
994 | /* Called with ubd_io_lock held */ | |
995 | static void do_ubd_request(request_queue_t *q) | |
996 | { | |
997 | struct io_thread_req io_req; | |
998 | struct request *req; | |
09ace81c JD |
999 | __u64 sector; |
1000 | int err; | |
1001 | ||
1002 | if(in_ubd) | |
1003 | return; | |
1004 | in_ubd = 1; | |
1005 | while((req = elv_next_request(q)) != NULL){ | |
1006 | struct gendisk *disk = req->rq_disk; | |
1007 | struct ubd *dev = disk->private_data; | |
1008 | int n, i; | |
1009 | ||
1010 | blkdev_dequeue_request(req); | |
1011 | ||
1012 | sector = req->sector; | |
1013 | n = blk_rq_map_sg(q, req, dev->sg); | |
1014 | ||
1015 | for(i = 0; i < n; i++){ | |
1016 | struct scatterlist *sg = &dev->sg[i]; | |
1017 | ||
1018 | err = prepare_request(req, &io_req, sector << 9, | |
1019 | sg->offset, sg->length, | |
1020 | sg->page); | |
1021 | if(err) | |
1022 | continue; | |
1023 | ||
1024 | sector += sg->length >> 9; | |
1025 | do_io(&io_req, req, dev->cow.bitmap); | |
1da177e4 LT |
1026 | } |
1027 | } | |
09ace81c | 1028 | in_ubd = 0; |
1da177e4 LT |
1029 | } |
1030 | ||
1031 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
1032 | unsigned int cmd, unsigned long arg) | |
1033 | { | |
1034 | struct hd_geometry __user *loc = (struct hd_geometry __user *) arg; | |
1035 | struct ubd *dev = inode->i_bdev->bd_disk->private_data; | |
1036 | struct hd_driveid ubd_id = { | |
1037 | .cyls = 0, | |
1038 | .heads = 128, | |
1039 | .sectors = 32, | |
1040 | }; | |
1041 | ||
1042 | switch (cmd) { | |
1043 | struct hd_geometry g; | |
1044 | struct cdrom_volctrl volume; | |
1045 | case HDIO_GETGEO: | |
1046 | if(!loc) return(-EINVAL); | |
1047 | g.heads = 128; | |
1048 | g.sectors = 32; | |
1049 | g.cylinders = dev->size / (128 * 32 * 512); | |
1050 | g.start = get_start_sect(inode->i_bdev); | |
1051 | return(copy_to_user(loc, &g, sizeof(g)) ? -EFAULT : 0); | |
1052 | ||
1053 | case HDIO_GET_IDENTITY: | |
1054 | ubd_id.cyls = dev->size / (128 * 32 * 512); | |
1055 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, | |
1056 | sizeof(ubd_id))) | |
1057 | return(-EFAULT); | |
1058 | return(0); | |
1059 | ||
1060 | case CDROMVOLREAD: | |
1061 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
1062 | return(-EFAULT); | |
1063 | volume.channel0 = 255; | |
1064 | volume.channel1 = 255; | |
1065 | volume.channel2 = 255; | |
1066 | volume.channel3 = 255; | |
1067 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
1068 | return(-EFAULT); | |
1069 | return(0); | |
1070 | } | |
1071 | return(-EINVAL); | |
1072 | } | |
1073 | ||
1da177e4 LT |
1074 | static int same_backing_files(char *from_cmdline, char *from_cow, char *cow) |
1075 | { | |
1076 | struct uml_stat buf1, buf2; | |
1077 | int err; | |
1078 | ||
1079 | if(from_cmdline == NULL) return(1); | |
1080 | if(!strcmp(from_cmdline, from_cow)) return(1); | |
1081 | ||
1082 | err = os_stat_file(from_cmdline, &buf1); | |
1083 | if(err < 0){ | |
1084 | printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); | |
1085 | return(1); | |
1086 | } | |
1087 | err = os_stat_file(from_cow, &buf2); | |
1088 | if(err < 0){ | |
1089 | printk("Couldn't stat '%s', err = %d\n", from_cow, -err); | |
1090 | return(1); | |
1091 | } | |
1092 | if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
1093 | return(1); | |
1094 | ||
1095 | printk("Backing file mismatch - \"%s\" requested,\n" | |
1096 | "\"%s\" specified in COW header of \"%s\"\n", | |
1097 | from_cmdline, from_cow, cow); | |
1098 | return(0); | |
1099 | } | |
1100 | ||
1101 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
1102 | { | |
1103 | unsigned long modtime; | |
1104 | long long actual; | |
1105 | int err; | |
1106 | ||
1107 | err = os_file_modtime(file, &modtime); | |
1108 | if(err < 0){ | |
1109 | printk("Failed to get modification time of backing file " | |
1110 | "\"%s\", err = %d\n", file, -err); | |
1111 | return(err); | |
1112 | } | |
1113 | ||
1114 | err = os_file_size(file, &actual); | |
1115 | if(err < 0){ | |
1116 | printk("Failed to get size of backing file \"%s\", " | |
1117 | "err = %d\n", file, -err); | |
1118 | return(err); | |
1119 | } | |
1120 | ||
1121 | if(actual != size){ | |
1122 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
1123 | * the typecast.*/ | |
1124 | printk("Size mismatch (%llu vs %llu) of COW header vs backing " | |
1125 | "file\n", (unsigned long long) size, actual); | |
1126 | return(-EINVAL); | |
1127 | } | |
1128 | if(modtime != mtime){ | |
1129 | printk("mtime mismatch (%ld vs %ld) of COW header vs backing " | |
1130 | "file\n", mtime, modtime); | |
1131 | return(-EINVAL); | |
1132 | } | |
1133 | return(0); | |
1134 | } | |
1135 | ||
1136 | int read_cow_bitmap(int fd, void *buf, int offset, int len) | |
1137 | { | |
1138 | int err; | |
1139 | ||
1140 | err = os_seek_file(fd, offset); | |
1141 | if(err < 0) | |
1142 | return(err); | |
1143 | ||
1144 | err = os_read_file(fd, buf, len); | |
1145 | if(err < 0) | |
1146 | return(err); | |
1147 | ||
1148 | return(0); | |
1149 | } | |
1150 | ||
1151 | int open_ubd_file(char *file, struct openflags *openflags, | |
1152 | char **backing_file_out, int *bitmap_offset_out, | |
1153 | unsigned long *bitmap_len_out, int *data_offset_out, | |
1154 | int *create_cow_out) | |
1155 | { | |
1156 | time_t mtime; | |
1157 | unsigned long long size; | |
1158 | __u32 version, align; | |
1159 | char *backing_file; | |
1160 | int fd, err, sectorsize, same, mode = 0644; | |
1161 | ||
1162 | fd = os_open_file(file, *openflags, mode); | |
1163 | if(fd < 0){ | |
1164 | if((fd == -ENOENT) && (create_cow_out != NULL)) | |
1165 | *create_cow_out = 1; | |
1166 | if(!openflags->w || | |
1167 | ((fd != -EROFS) && (fd != -EACCES))) return(fd); | |
1168 | openflags->w = 0; | |
1169 | fd = os_open_file(file, *openflags, mode); | |
1170 | if(fd < 0) | |
1171 | return(fd); | |
1172 | } | |
1173 | ||
1174 | err = os_lock_file(fd, openflags->w); | |
1175 | if(err < 0){ | |
1176 | printk("Failed to lock '%s', err = %d\n", file, -err); | |
1177 | goto out_close; | |
1178 | } | |
1179 | ||
1180 | if(backing_file_out == NULL) return(fd); | |
1181 | ||
1182 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
1183 | &size, §orsize, &align, bitmap_offset_out); | |
1184 | if(err && (*backing_file_out != NULL)){ | |
1185 | printk("Failed to read COW header from COW file \"%s\", " | |
1186 | "errno = %d\n", file, -err); | |
1187 | goto out_close; | |
1188 | } | |
1189 | if(err) return(fd); | |
1190 | ||
1191 | if(backing_file_out == NULL) return(fd); | |
1192 | ||
1193 | same = same_backing_files(*backing_file_out, backing_file, file); | |
1194 | ||
1195 | if(!same && !backing_file_mismatch(*backing_file_out, size, mtime)){ | |
1196 | printk("Switching backing file to '%s'\n", *backing_file_out); | |
1197 | err = write_cow_header(file, fd, *backing_file_out, | |
1198 | sectorsize, align, &size); | |
1199 | if(err){ | |
1200 | printk("Switch failed, errno = %d\n", -err); | |
1201 | return(err); | |
1202 | } | |
1203 | } | |
1204 | else { | |
1205 | *backing_file_out = backing_file; | |
1206 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
1207 | if(err) goto out_close; | |
1208 | } | |
1209 | ||
1210 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
1211 | bitmap_len_out, data_offset_out); | |
1212 | ||
1213 | return(fd); | |
1214 | out_close: | |
1215 | os_close_file(fd); | |
1216 | return(err); | |
1217 | } | |
1218 | ||
1219 | int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, | |
1220 | int sectorsize, int alignment, int *bitmap_offset_out, | |
1221 | unsigned long *bitmap_len_out, int *data_offset_out) | |
1222 | { | |
1223 | int err, fd; | |
1224 | ||
1225 | flags.c = 1; | |
1226 | fd = open_ubd_file(cow_file, &flags, NULL, NULL, NULL, NULL, NULL); | |
1227 | if(fd < 0){ | |
1228 | err = fd; | |
1229 | printk("Open of COW file '%s' failed, errno = %d\n", cow_file, | |
1230 | -err); | |
1231 | goto out; | |
1232 | } | |
1233 | ||
1234 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
1235 | bitmap_offset_out, bitmap_len_out, | |
1236 | data_offset_out); | |
1237 | if(!err) | |
1238 | return(fd); | |
1239 | os_close_file(fd); | |
1240 | out: | |
1241 | return(err); | |
1242 | } | |
1243 | ||
09ace81c | 1244 | void do_io(struct io_thread_req *req, struct request *r, unsigned long *bitmap) |
1da177e4 | 1245 | { |
09ace81c JD |
1246 | struct ubd_aio *aio; |
1247 | struct bitmap_io *bitmap_io = NULL; | |
1248 | char *buf; | |
1249 | void *bitmap_buf = NULL; | |
1250 | unsigned long len, sector; | |
1251 | int nsectors, start, end, bit, err; | |
1252 | __u64 off; | |
1253 | ||
1254 | if(req->bitmap_start != -1){ | |
1255 | /* Round up to the nearest word */ | |
1256 | int round = sizeof(unsigned long); | |
1257 | len = (req->bitmap_end - req->bitmap_start + | |
1258 | round * 8 - 1) / (round * 8); | |
1259 | len *= round; | |
1260 | ||
1261 | off = req->bitmap_start / (8 * round); | |
1262 | off *= round; | |
1263 | ||
1264 | bitmap_io = kmalloc(sizeof(*bitmap_io), GFP_KERNEL); | |
1265 | if(bitmap_io == NULL){ | |
1266 | printk("Failed to kmalloc bitmap IO\n"); | |
1267 | req->error = 1; | |
1268 | return; | |
1269 | } | |
1da177e4 | 1270 | |
09ace81c JD |
1271 | bitmap_buf = kmalloc(len, GFP_KERNEL); |
1272 | if(bitmap_buf == NULL){ | |
1273 | printk("do_io : kmalloc of bitmap chunk " | |
1274 | "failed\n"); | |
1275 | kfree(bitmap_io); | |
1276 | req->error = 1; | |
1277 | return; | |
1278 | } | |
1279 | memcpy(bitmap_buf, &bitmap[off / sizeof(bitmap[0])], len); | |
1280 | ||
1281 | *bitmap_io = ((struct bitmap_io) | |
1282 | { .count = ATOMIC_INIT(0), | |
1283 | .aio = INIT_AIO(AIO_WRITE, req->fds[1], | |
1284 | bitmap_buf, len, | |
1285 | req->bitmap_offset + off, | |
1286 | ubd_reply_fd) } ); | |
1287 | } | |
1da177e4 | 1288 | |
09ace81c JD |
1289 | nsectors = req->length / req->sectorsize; |
1290 | start = 0; | |
1291 | end = nsectors; | |
1292 | bit = 0; | |
1293 | do { | |
1294 | if(bitmap != NULL){ | |
1295 | sector = req->offset / req->sectorsize; | |
1296 | bit = ubd_test_bit(sector + start, bitmap); | |
1297 | end = start; | |
1298 | while((end < nsectors) && | |
1299 | (ubd_test_bit(sector + end, bitmap) == bit)) | |
1300 | end++; | |
1301 | } | |
1da177e4 | 1302 | |
09ace81c JD |
1303 | off = req->offsets[bit] + req->offset + |
1304 | start * req->sectorsize; | |
1305 | len = (end - start) * req->sectorsize; | |
1306 | buf = &req->buffer[start * req->sectorsize]; | |
1da177e4 | 1307 | |
09ace81c JD |
1308 | aio = kmalloc(sizeof(*aio), GFP_KERNEL); |
1309 | if(aio == NULL){ | |
1310 | req->error = 1; | |
1311 | return; | |
1312 | } | |
1da177e4 | 1313 | |
09ace81c JD |
1314 | *aio = ((struct ubd_aio) |
1315 | { .aio = INIT_AIO(req->op, req->fds[bit], buf, | |
1316 | len, off, ubd_reply_fd), | |
1317 | .len = len, | |
1318 | .req = r, | |
1319 | .bitmap = bitmap_io, | |
1320 | .bitmap_buf = bitmap_buf }); | |
1321 | ||
1322 | if(aio->bitmap != NULL) | |
1323 | atomic_inc(&aio->bitmap->count); | |
1324 | ||
1325 | err = submit_aio(&aio->aio); | |
1326 | if(err){ | |
1327 | printk("do_io - submit_aio failed, " | |
1328 | "err = %d\n", err); | |
1329 | req->error = 1; | |
1330 | return; | |
1331 | } | |
1da177e4 | 1332 | |
09ace81c JD |
1333 | start = end; |
1334 | } while(start < nsectors); | |
1da177e4 | 1335 | } |