Commit | Line | Data |
---|---|---|
6c29256c | 1 | /* |
1da177e4 LT |
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" | |
d052d1be | 38 | #include "linux/platform_device.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" | |
57 | ||
7b9014c1 | 58 | enum ubd_req { UBD_READ, UBD_WRITE }; |
1da177e4 LT |
59 | |
60 | struct io_thread_req { | |
91acb21f | 61 | enum ubd_req op; |
1da177e4 LT |
62 | int fds[2]; |
63 | unsigned long offsets[2]; | |
64 | unsigned long long offset; | |
65 | unsigned long length; | |
66 | char *buffer; | |
67 | int sectorsize; | |
91acb21f JD |
68 | unsigned long sector_mask; |
69 | unsigned long long cow_offset; | |
70 | unsigned long bitmap_words[2]; | |
1da177e4 LT |
71 | int error; |
72 | }; | |
73 | ||
6c29256c | 74 | extern int open_ubd_file(char *file, struct openflags *openflags, int shared, |
1da177e4 LT |
75 | char **backing_file_out, int *bitmap_offset_out, |
76 | unsigned long *bitmap_len_out, int *data_offset_out, | |
77 | int *create_cow_out); | |
78 | extern int create_cow_file(char *cow_file, char *backing_file, | |
79 | struct openflags flags, int sectorsize, | |
80 | int alignment, int *bitmap_offset_out, | |
81 | unsigned long *bitmap_len_out, | |
82 | int *data_offset_out); | |
83 | extern int read_cow_bitmap(int fd, void *buf, int offset, int len); | |
91acb21f | 84 | extern void do_io(struct io_thread_req *req); |
1da177e4 | 85 | |
91acb21f | 86 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
87 | { |
88 | __u64 n; | |
89 | int bits, off; | |
90 | ||
91acb21f | 91 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
92 | n = bit / bits; |
93 | off = bit % bits; | |
91acb21f | 94 | return((data[n] & (1 << off)) != 0); |
1da177e4 LT |
95 | } |
96 | ||
91acb21f | 97 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
98 | { |
99 | __u64 n; | |
100 | int bits, off; | |
101 | ||
91acb21f | 102 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
103 | n = bit / bits; |
104 | off = bit % bits; | |
91acb21f | 105 | data[n] |= (1 << off); |
1da177e4 LT |
106 | } |
107 | /*End stuff from ubd_user.h*/ | |
108 | ||
109 | #define DRIVER_NAME "uml-blkdev" | |
110 | ||
111 | static DEFINE_SPINLOCK(ubd_io_lock); | |
112 | static DEFINE_SPINLOCK(ubd_lock); | |
113 | ||
91acb21f JD |
114 | static void (*do_ubd)(void); |
115 | ||
1da177e4 LT |
116 | static int ubd_open(struct inode * inode, struct file * filp); |
117 | static int ubd_release(struct inode * inode, struct file * file); | |
118 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
119 | unsigned int cmd, unsigned long arg); | |
a885c8c4 | 120 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
1da177e4 LT |
121 | |
122 | #define MAX_DEV (8) | |
123 | ||
1da177e4 LT |
124 | static struct block_device_operations ubd_blops = { |
125 | .owner = THIS_MODULE, | |
126 | .open = ubd_open, | |
127 | .release = ubd_release, | |
128 | .ioctl = ubd_ioctl, | |
a885c8c4 | 129 | .getgeo = ubd_getgeo, |
1da177e4 LT |
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]; | |
6c29256c | 140 | |
1da177e4 LT |
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 | ||
164 | struct ubd { | |
165 | char *file; | |
166 | int count; | |
167 | int fd; | |
168 | __u64 size; | |
169 | struct openflags boot_openflags; | |
170 | struct openflags openflags; | |
6c29256c | 171 | int shared; |
1da177e4 LT |
172 | int no_cow; |
173 | struct cow cow; | |
174 | struct platform_device pdev; | |
1da177e4 LT |
175 | }; |
176 | ||
177 | #define DEFAULT_COW { \ | |
178 | .file = NULL, \ | |
179 | .fd = -1, \ | |
180 | .bitmap = NULL, \ | |
181 | .bitmap_offset = 0, \ | |
182 | .data_offset = 0, \ | |
183 | } | |
184 | ||
185 | #define DEFAULT_UBD { \ | |
186 | .file = NULL, \ | |
187 | .count = 0, \ | |
188 | .fd = -1, \ | |
189 | .size = -1, \ | |
190 | .boot_openflags = OPEN_FLAGS, \ | |
191 | .openflags = OPEN_FLAGS, \ | |
192 | .no_cow = 0, \ | |
6c29256c | 193 | .shared = 0, \ |
1da177e4 | 194 | .cow = DEFAULT_COW, \ |
1da177e4 LT |
195 | } |
196 | ||
197 | struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; | |
198 | ||
199 | static int ubd0_init(void) | |
200 | { | |
201 | struct ubd *dev = &ubd_dev[0]; | |
202 | ||
203 | if(dev->file == NULL) | |
204 | dev->file = "root_fs"; | |
205 | return(0); | |
206 | } | |
207 | ||
208 | __initcall(ubd0_init); | |
209 | ||
210 | /* Only changed by fake_ide_setup which is a setup */ | |
211 | static int fake_ide = 0; | |
212 | static struct proc_dir_entry *proc_ide_root = NULL; | |
213 | static struct proc_dir_entry *proc_ide = NULL; | |
214 | ||
215 | static void make_proc_ide(void) | |
216 | { | |
217 | proc_ide_root = proc_mkdir("ide", NULL); | |
218 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
219 | } | |
220 | ||
221 | static int proc_ide_read_media(char *page, char **start, off_t off, int count, | |
222 | int *eof, void *data) | |
223 | { | |
224 | int len; | |
225 | ||
226 | strcpy(page, "disk\n"); | |
227 | len = strlen("disk\n"); | |
228 | len -= off; | |
229 | if (len < count){ | |
230 | *eof = 1; | |
231 | if (len <= 0) return 0; | |
232 | } | |
233 | else len = count; | |
234 | *start = page + off; | |
235 | return len; | |
236 | } | |
237 | ||
238 | static void make_ide_entries(char *dev_name) | |
239 | { | |
240 | struct proc_dir_entry *dir, *ent; | |
241 | char name[64]; | |
242 | ||
243 | if(proc_ide_root == NULL) make_proc_ide(); | |
244 | ||
245 | dir = proc_mkdir(dev_name, proc_ide); | |
246 | if(!dir) return; | |
247 | ||
248 | ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); | |
249 | if(!ent) return; | |
250 | ent->nlink = 1; | |
251 | ent->data = NULL; | |
252 | ent->read_proc = proc_ide_read_media; | |
253 | ent->write_proc = NULL; | |
254 | sprintf(name,"ide0/%s", dev_name); | |
255 | proc_symlink(dev_name, proc_ide_root, name); | |
256 | } | |
257 | ||
258 | static int fake_ide_setup(char *str) | |
259 | { | |
260 | fake_ide = 1; | |
261 | return(1); | |
262 | } | |
263 | ||
264 | __setup("fake_ide", fake_ide_setup); | |
265 | ||
266 | __uml_help(fake_ide_setup, | |
267 | "fake_ide\n" | |
268 | " Create ide0 entries that map onto ubd devices.\n\n" | |
269 | ); | |
270 | ||
271 | static int parse_unit(char **ptr) | |
272 | { | |
273 | char *str = *ptr, *end; | |
274 | int n = -1; | |
275 | ||
276 | if(isdigit(*str)) { | |
277 | n = simple_strtoul(str, &end, 0); | |
278 | if(end == str) | |
279 | return(-1); | |
280 | *ptr = end; | |
281 | } | |
282 | else if (('a' <= *str) && (*str <= 'h')) { | |
283 | n = *str - 'a'; | |
284 | str++; | |
285 | *ptr = str; | |
286 | } | |
287 | return(n); | |
288 | } | |
289 | ||
290 | static int ubd_setup_common(char *str, int *index_out) | |
291 | { | |
292 | struct ubd *dev; | |
293 | struct openflags flags = global_openflags; | |
294 | char *backing_file; | |
295 | int n, err, i; | |
296 | ||
297 | if(index_out) *index_out = -1; | |
298 | n = *str; | |
299 | if(n == '='){ | |
300 | char *end; | |
301 | int major; | |
302 | ||
303 | str++; | |
1da177e4 LT |
304 | if(!strcmp(str, "sync")){ |
305 | global_openflags = of_sync(global_openflags); | |
306 | return(0); | |
307 | } | |
308 | major = simple_strtoul(str, &end, 0); | |
309 | if((*end != '\0') || (end == str)){ | |
6c29256c | 310 | printk(KERN_ERR |
1da177e4 LT |
311 | "ubd_setup : didn't parse major number\n"); |
312 | return(1); | |
313 | } | |
314 | ||
315 | err = 1; | |
316 | spin_lock(&ubd_lock); | |
317 | if(fake_major != MAJOR_NR){ | |
318 | printk(KERN_ERR "Can't assign a fake major twice\n"); | |
319 | goto out1; | |
320 | } | |
6c29256c | 321 | |
1da177e4 LT |
322 | fake_major = major; |
323 | ||
324 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
325 | major); | |
326 | err = 0; | |
327 | out1: | |
328 | spin_unlock(&ubd_lock); | |
329 | return(err); | |
330 | } | |
331 | ||
332 | n = parse_unit(&str); | |
333 | if(n < 0){ | |
334 | printk(KERN_ERR "ubd_setup : couldn't parse unit number " | |
335 | "'%s'\n", str); | |
336 | return(1); | |
337 | } | |
338 | if(n >= MAX_DEV){ | |
339 | printk(KERN_ERR "ubd_setup : index %d out of range " | |
340 | "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1); | |
341 | return(1); | |
342 | } | |
343 | ||
344 | err = 1; | |
345 | spin_lock(&ubd_lock); | |
346 | ||
347 | dev = &ubd_dev[n]; | |
348 | if(dev->file != NULL){ | |
349 | printk(KERN_ERR "ubd_setup : device already configured\n"); | |
350 | goto out; | |
351 | } | |
352 | ||
353 | if (index_out) | |
354 | *index_out = n; | |
355 | ||
6c29256c | 356 | for (i = 0; i < sizeof("rscd="); i++) { |
1da177e4 LT |
357 | switch (*str) { |
358 | case 'r': | |
359 | flags.w = 0; | |
360 | break; | |
361 | case 's': | |
362 | flags.s = 1; | |
363 | break; | |
364 | case 'd': | |
365 | dev->no_cow = 1; | |
366 | break; | |
6c29256c JD |
367 | case 'c': |
368 | dev->shared = 1; | |
369 | break; | |
1da177e4 LT |
370 | case '=': |
371 | str++; | |
372 | goto break_loop; | |
373 | default: | |
6c29256c | 374 | printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r, s, c, or d)\n"); |
1da177e4 LT |
375 | goto out; |
376 | } | |
377 | str++; | |
378 | } | |
379 | ||
380 | if (*str == '=') | |
381 | printk(KERN_ERR "ubd_setup : Too many flags specified\n"); | |
382 | else | |
383 | printk(KERN_ERR "ubd_setup : Expected '='\n"); | |
384 | goto out; | |
385 | ||
386 | break_loop: | |
387 | err = 0; | |
388 | backing_file = strchr(str, ','); | |
389 | ||
390 | if (!backing_file) { | |
391 | backing_file = strchr(str, ':'); | |
392 | } | |
393 | ||
394 | if(backing_file){ | |
395 | if(dev->no_cow) | |
396 | printk(KERN_ERR "Can't specify both 'd' and a " | |
397 | "cow file\n"); | |
398 | else { | |
399 | *backing_file = '\0'; | |
400 | backing_file++; | |
401 | } | |
402 | } | |
403 | dev->file = str; | |
404 | dev->cow.file = backing_file; | |
405 | dev->boot_openflags = flags; | |
406 | out: | |
407 | spin_unlock(&ubd_lock); | |
408 | return(err); | |
409 | } | |
410 | ||
411 | static int ubd_setup(char *str) | |
412 | { | |
413 | ubd_setup_common(str, NULL); | |
414 | return(1); | |
415 | } | |
416 | ||
417 | __setup("ubd", ubd_setup); | |
418 | __uml_help(ubd_setup, | |
419 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
420 | " This is used to associate a device with a file in the underlying\n" | |
421 | " filesystem. When specifying two filenames, the first one is the\n" | |
422 | " COW name and the second is the backing file name. As separator you can\n" | |
423 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
424 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
425 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
426 | " When using only one filename, UML will detect whether to thread it like\n" | |
427 | " a COW file or a backing file. To override this detection, add the 'd'\n" | |
428 | " flag:\n" | |
429 | " ubd0d=BackingFile\n" | |
430 | " Usually, there is a filesystem in the file, but \n" | |
431 | " that's not required. Swap devices containing swap files can be\n" | |
432 | " specified like this. Also, a file which doesn't contain a\n" | |
433 | " filesystem can have its contents read in the virtual \n" | |
434 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
435 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
436 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
437 | " an 's' will cause data to be written to disk on the host immediately.\n\n" | |
438 | ); | |
439 | ||
440 | static int udb_setup(char *str) | |
441 | { | |
442 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
443 | "udb TYPO\n", str); | |
444 | return(1); | |
445 | } | |
446 | ||
447 | __setup("udb", udb_setup); | |
448 | __uml_help(udb_setup, | |
449 | "udb\n" | |
0894e27e JD |
450 | " This option is here solely to catch ubd -> udb typos, which can be\n" |
451 | " to impossible to catch visually unless you specifically look for\n" | |
452 | " them. The only result of any option starting with 'udb' is an error\n" | |
1da177e4 LT |
453 | " in the boot output.\n\n" |
454 | ); | |
455 | ||
456 | static int fakehd_set = 0; | |
457 | static int fakehd(char *str) | |
458 | { | |
459 | printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); | |
460 | fakehd_set = 1; | |
461 | return 1; | |
462 | } | |
463 | ||
464 | __setup("fakehd", fakehd); | |
465 | __uml_help(fakehd, | |
466 | "fakehd\n" | |
467 | " Change the ubd device name to \"hd\".\n\n" | |
468 | ); | |
469 | ||
470 | static void do_ubd_request(request_queue_t * q); | |
91acb21f JD |
471 | |
472 | /* Only changed by ubd_init, which is an initcall. */ | |
473 | int thread_fd = -1; | |
1da177e4 LT |
474 | |
475 | /* Changed by ubd_handler, which is serialized because interrupts only | |
476 | * happen on CPU 0. | |
477 | */ | |
478 | int intr_count = 0; | |
479 | ||
91acb21f JD |
480 | /* call ubd_finish if you need to serialize */ |
481 | static void __ubd_finish(struct request *req, int error) | |
1da177e4 | 482 | { |
91acb21f JD |
483 | int nsect; |
484 | ||
485 | if(error){ | |
486 | end_request(req, 0); | |
487 | return; | |
1da177e4 | 488 | } |
91acb21f JD |
489 | nsect = req->current_nr_sectors; |
490 | req->sector += nsect; | |
491 | req->buffer += nsect << 9; | |
492 | req->errors = 0; | |
493 | req->nr_sectors -= nsect; | |
494 | req->current_nr_sectors = 0; | |
495 | end_request(req, 1); | |
1da177e4 LT |
496 | } |
497 | ||
91acb21f | 498 | static inline void ubd_finish(struct request *req, int error) |
1da177e4 | 499 | { |
91acb21f JD |
500 | spin_lock(&ubd_io_lock); |
501 | __ubd_finish(req, error); | |
502 | spin_unlock(&ubd_io_lock); | |
1da177e4 LT |
503 | } |
504 | ||
91acb21f JD |
505 | /* Called without ubd_io_lock held */ |
506 | static void ubd_handler(void) | |
1da177e4 | 507 | { |
91acb21f JD |
508 | struct io_thread_req req; |
509 | struct request *rq = elv_next_request(ubd_queue); | |
510 | int n; | |
511 | ||
512 | do_ubd = NULL; | |
513 | intr_count++; | |
514 | n = os_read_file(thread_fd, &req, sizeof(req)); | |
515 | if(n != sizeof(req)){ | |
516 | printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " | |
517 | "err = %d\n", os_getpid(), -n); | |
518 | spin_lock(&ubd_io_lock); | |
519 | end_request(rq, 0); | |
520 | spin_unlock(&ubd_io_lock); | |
521 | return; | |
522 | } | |
6c29256c | 523 | |
91acb21f JD |
524 | ubd_finish(rq, req.error); |
525 | reactivate_fd(thread_fd, UBD_IRQ); | |
526 | do_ubd_request(ubd_queue); | |
1da177e4 LT |
527 | } |
528 | ||
529 | static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) | |
530 | { | |
91acb21f JD |
531 | ubd_handler(); |
532 | return(IRQ_HANDLED); | |
533 | } | |
09ace81c | 534 | |
91acb21f JD |
535 | /* Only changed by ubd_init, which is an initcall. */ |
536 | static int io_pid = -1; | |
09ace81c | 537 | |
91acb21f JD |
538 | void kill_io_thread(void) |
539 | { | |
6c29256c | 540 | if(io_pid != -1) |
91acb21f | 541 | os_kill_process(io_pid, 1); |
09ace81c | 542 | } |
1da177e4 | 543 | |
91acb21f JD |
544 | __uml_exitcall(kill_io_thread); |
545 | ||
1da177e4 LT |
546 | static int ubd_file_size(struct ubd *dev, __u64 *size_out) |
547 | { | |
548 | char *file; | |
549 | ||
550 | file = dev->cow.file ? dev->cow.file : dev->file; | |
551 | return(os_file_size(file, size_out)); | |
552 | } | |
553 | ||
554 | static void ubd_close(struct ubd *dev) | |
555 | { | |
1da177e4 LT |
556 | os_close_file(dev->fd); |
557 | if(dev->cow.file == NULL) | |
558 | return; | |
559 | ||
1da177e4 LT |
560 | os_close_file(dev->cow.fd); |
561 | vfree(dev->cow.bitmap); | |
562 | dev->cow.bitmap = NULL; | |
563 | } | |
564 | ||
565 | static int ubd_open_dev(struct ubd *dev) | |
566 | { | |
567 | struct openflags flags; | |
568 | char **back_ptr; | |
569 | int err, create_cow, *create_ptr; | |
570 | ||
571 | dev->openflags = dev->boot_openflags; | |
572 | create_cow = 0; | |
573 | create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL; | |
574 | back_ptr = dev->no_cow ? NULL : &dev->cow.file; | |
6c29256c JD |
575 | dev->fd = open_ubd_file(dev->file, &dev->openflags, dev->shared, |
576 | back_ptr, &dev->cow.bitmap_offset, | |
577 | &dev->cow.bitmap_len, &dev->cow.data_offset, | |
578 | create_ptr); | |
1da177e4 LT |
579 | |
580 | if((dev->fd == -ENOENT) && create_cow){ | |
6c29256c | 581 | dev->fd = create_cow_file(dev->file, dev->cow.file, |
1da177e4 | 582 | dev->openflags, 1 << 9, PAGE_SIZE, |
6c29256c | 583 | &dev->cow.bitmap_offset, |
1da177e4 LT |
584 | &dev->cow.bitmap_len, |
585 | &dev->cow.data_offset); | |
586 | if(dev->fd >= 0){ | |
587 | printk(KERN_INFO "Creating \"%s\" as COW file for " | |
588 | "\"%s\"\n", dev->file, dev->cow.file); | |
589 | } | |
590 | } | |
591 | ||
592 | if(dev->fd < 0){ | |
593 | printk("Failed to open '%s', errno = %d\n", dev->file, | |
594 | -dev->fd); | |
595 | return(dev->fd); | |
596 | } | |
597 | ||
598 | if(dev->cow.file != NULL){ | |
599 | err = -ENOMEM; | |
600 | dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len); | |
601 | if(dev->cow.bitmap == NULL){ | |
602 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); | |
603 | goto error; | |
604 | } | |
605 | flush_tlb_kernel_vm(); | |
606 | ||
6c29256c JD |
607 | err = read_cow_bitmap(dev->fd, dev->cow.bitmap, |
608 | dev->cow.bitmap_offset, | |
1da177e4 LT |
609 | dev->cow.bitmap_len); |
610 | if(err < 0) | |
611 | goto error; | |
612 | ||
613 | flags = dev->openflags; | |
614 | flags.w = 0; | |
6c29256c JD |
615 | err = open_ubd_file(dev->cow.file, &flags, dev->shared, NULL, |
616 | NULL, NULL, NULL, NULL); | |
1da177e4 LT |
617 | if(err < 0) goto error; |
618 | dev->cow.fd = err; | |
619 | } | |
620 | return(0); | |
621 | error: | |
622 | os_close_file(dev->fd); | |
623 | return(err); | |
624 | } | |
625 | ||
626 | static int ubd_new_disk(int major, u64 size, int unit, | |
627 | struct gendisk **disk_out) | |
628 | ||
629 | { | |
630 | struct gendisk *disk; | |
631 | char from[sizeof("ubd/nnnnn\0")], to[sizeof("discnnnnn/disc\0")]; | |
632 | int err; | |
633 | ||
634 | disk = alloc_disk(1 << UBD_SHIFT); | |
635 | if(disk == NULL) | |
636 | return(-ENOMEM); | |
637 | ||
638 | disk->major = major; | |
639 | disk->first_minor = unit << UBD_SHIFT; | |
640 | disk->fops = &ubd_blops; | |
641 | set_capacity(disk, size / 512); | |
642 | if(major == MAJOR_NR){ | |
643 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); | |
644 | sprintf(disk->devfs_name, "ubd/disc%d", unit); | |
645 | sprintf(from, "ubd/%d", unit); | |
646 | sprintf(to, "disc%d/disc", unit); | |
647 | err = devfs_mk_symlink(from, to); | |
648 | if(err) | |
649 | printk("ubd_new_disk failed to make link from %s to " | |
650 | "%s, error = %d\n", from, to, err); | |
651 | } | |
652 | else { | |
653 | sprintf(disk->disk_name, "ubd_fake%d", unit); | |
654 | sprintf(disk->devfs_name, "ubd_fake/disc%d", unit); | |
655 | } | |
656 | ||
657 | /* sysfs register (not for ide fake devices) */ | |
658 | if (major == MAJOR_NR) { | |
659 | ubd_dev[unit].pdev.id = unit; | |
660 | ubd_dev[unit].pdev.name = DRIVER_NAME; | |
661 | platform_device_register(&ubd_dev[unit].pdev); | |
662 | disk->driverfs_dev = &ubd_dev[unit].pdev.dev; | |
663 | } | |
664 | ||
665 | disk->private_data = &ubd_dev[unit]; | |
666 | disk->queue = ubd_queue; | |
667 | add_disk(disk); | |
668 | ||
669 | *disk_out = disk; | |
670 | return 0; | |
671 | } | |
672 | ||
673 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
674 | ||
675 | static int ubd_add(int n) | |
676 | { | |
677 | struct ubd *dev = &ubd_dev[n]; | |
678 | int err; | |
679 | ||
ec7cf783 | 680 | err = -ENODEV; |
1da177e4 | 681 | if(dev->file == NULL) |
ec7cf783 | 682 | goto out; |
1da177e4 LT |
683 | |
684 | if (ubd_open_dev(dev)) | |
ec7cf783 | 685 | goto out; |
1da177e4 LT |
686 | |
687 | err = ubd_file_size(dev, &dev->size); | |
688 | if(err < 0) | |
ec7cf783 | 689 | goto out_close; |
1da177e4 LT |
690 | |
691 | dev->size = ROUND_BLOCK(dev->size); | |
692 | ||
693 | err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]); | |
6c29256c | 694 | if(err) |
ec7cf783 | 695 | goto out_close; |
6c29256c | 696 | |
1da177e4 | 697 | if(fake_major != MAJOR_NR) |
6c29256c | 698 | ubd_new_disk(fake_major, dev->size, n, |
1da177e4 LT |
699 | &fake_gendisk[n]); |
700 | ||
701 | /* perhaps this should also be under the "if (fake_major)" above */ | |
702 | /* using the fake_disk->disk_name and also the fakehd_set name */ | |
703 | if (fake_ide) | |
704 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
705 | ||
ec7cf783 JD |
706 | err = 0; |
707 | out_close: | |
1da177e4 | 708 | ubd_close(dev); |
ec7cf783 JD |
709 | out: |
710 | return err; | |
1da177e4 LT |
711 | } |
712 | ||
713 | static int ubd_config(char *str) | |
714 | { | |
715 | int n, err; | |
716 | ||
970d6e3a | 717 | str = kstrdup(str, GFP_KERNEL); |
1da177e4 LT |
718 | if(str == NULL){ |
719 | printk(KERN_ERR "ubd_config failed to strdup string\n"); | |
720 | return(1); | |
721 | } | |
722 | err = ubd_setup_common(str, &n); | |
723 | if(err){ | |
724 | kfree(str); | |
725 | return(-1); | |
726 | } | |
727 | if(n == -1) return(0); | |
728 | ||
729 | spin_lock(&ubd_lock); | |
730 | err = ubd_add(n); | |
731 | if(err) | |
732 | ubd_dev[n].file = NULL; | |
733 | spin_unlock(&ubd_lock); | |
734 | ||
735 | return(err); | |
736 | } | |
737 | ||
738 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
739 | { | |
740 | struct ubd *dev; | |
741 | int n, len = 0; | |
742 | ||
743 | n = parse_unit(&name); | |
744 | if((n >= MAX_DEV) || (n < 0)){ | |
745 | *error_out = "ubd_get_config : device number out of range"; | |
746 | return(-1); | |
747 | } | |
748 | ||
749 | dev = &ubd_dev[n]; | |
750 | spin_lock(&ubd_lock); | |
751 | ||
752 | if(dev->file == NULL){ | |
753 | CONFIG_CHUNK(str, size, len, "", 1); | |
754 | goto out; | |
755 | } | |
756 | ||
757 | CONFIG_CHUNK(str, size, len, dev->file, 0); | |
758 | ||
759 | if(dev->cow.file != NULL){ | |
760 | CONFIG_CHUNK(str, size, len, ",", 0); | |
761 | CONFIG_CHUNK(str, size, len, dev->cow.file, 1); | |
762 | } | |
763 | else CONFIG_CHUNK(str, size, len, "", 1); | |
764 | ||
765 | out: | |
766 | spin_unlock(&ubd_lock); | |
767 | return(len); | |
768 | } | |
769 | ||
29d56cfe JD |
770 | static int ubd_id(char **str, int *start_out, int *end_out) |
771 | { | |
772 | int n; | |
773 | ||
774 | n = parse_unit(str); | |
775 | *start_out = 0; | |
776 | *end_out = MAX_DEV - 1; | |
777 | return n; | |
778 | } | |
779 | ||
780 | static int ubd_remove(int n) | |
1da177e4 LT |
781 | { |
782 | struct ubd *dev; | |
29d56cfe | 783 | int err = -ENODEV; |
1da177e4 | 784 | |
29d56cfe | 785 | spin_lock(&ubd_lock); |
1da177e4 | 786 | |
29d56cfe JD |
787 | if(ubd_gendisk[n] == NULL) |
788 | goto out; | |
1da177e4 LT |
789 | |
790 | dev = &ubd_dev[n]; | |
1da177e4 | 791 | |
29d56cfe JD |
792 | if(dev->file == NULL) |
793 | goto out; | |
1da177e4 | 794 | |
29d56cfe JD |
795 | /* you cannot remove a open disk */ |
796 | err = -EBUSY; | |
797 | if(dev->count > 0) | |
1da177e4 LT |
798 | goto out; |
799 | ||
800 | del_gendisk(ubd_gendisk[n]); | |
801 | put_disk(ubd_gendisk[n]); | |
802 | ubd_gendisk[n] = NULL; | |
803 | ||
804 | if(fake_gendisk[n] != NULL){ | |
805 | del_gendisk(fake_gendisk[n]); | |
806 | put_disk(fake_gendisk[n]); | |
807 | fake_gendisk[n] = NULL; | |
808 | } | |
809 | ||
810 | platform_device_unregister(&dev->pdev); | |
811 | *dev = ((struct ubd) DEFAULT_UBD); | |
812 | err = 0; | |
29d56cfe JD |
813 | out: |
814 | spin_unlock(&ubd_lock); | |
815 | return err; | |
1da177e4 LT |
816 | } |
817 | ||
818 | static struct mc_device ubd_mc = { | |
819 | .name = "ubd", | |
820 | .config = ubd_config, | |
821 | .get_config = ubd_get_config, | |
29d56cfe | 822 | .id = ubd_id, |
1da177e4 LT |
823 | .remove = ubd_remove, |
824 | }; | |
825 | ||
826 | static int ubd_mc_init(void) | |
827 | { | |
828 | mconsole_register_dev(&ubd_mc); | |
829 | return 0; | |
830 | } | |
831 | ||
832 | __initcall(ubd_mc_init); | |
833 | ||
3ae5eaec RK |
834 | static struct platform_driver ubd_driver = { |
835 | .driver = { | |
836 | .name = DRIVER_NAME, | |
837 | }, | |
1da177e4 LT |
838 | }; |
839 | ||
840 | int ubd_init(void) | |
841 | { | |
842 | int i; | |
843 | ||
844 | devfs_mk_dir("ubd"); | |
845 | if (register_blkdev(MAJOR_NR, "ubd")) | |
846 | return -1; | |
847 | ||
848 | ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock); | |
849 | if (!ubd_queue) { | |
850 | unregister_blkdev(MAJOR_NR, "ubd"); | |
851 | return -1; | |
852 | } | |
853 | ||
854 | if (fake_major != MAJOR_NR) { | |
855 | char name[sizeof("ubd_nnn\0")]; | |
856 | ||
857 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
858 | devfs_mk_dir(name); | |
859 | if (register_blkdev(fake_major, "ubd")) | |
860 | return -1; | |
861 | } | |
3ae5eaec | 862 | platform_driver_register(&ubd_driver); |
6c29256c | 863 | for (i = 0; i < MAX_DEV; i++) |
1da177e4 LT |
864 | ubd_add(i); |
865 | return 0; | |
866 | } | |
867 | ||
868 | late_initcall(ubd_init); | |
869 | ||
91acb21f JD |
870 | int ubd_driver_init(void){ |
871 | unsigned long stack; | |
872 | int err; | |
873 | ||
874 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
875 | if(global_openflags.s){ | |
876 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
877 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
878 | * enough. So use anyway the io thread. */ | |
879 | } | |
880 | stack = alloc_stack(0, 0); | |
6c29256c | 881 | io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), |
91acb21f JD |
882 | &thread_fd); |
883 | if(io_pid < 0){ | |
6c29256c | 884 | printk(KERN_ERR |
91acb21f JD |
885 | "ubd : Failed to start I/O thread (errno = %d) - " |
886 | "falling back to synchronous I/O\n", -io_pid); | |
887 | io_pid = -1; | |
888 | return(0); | |
889 | } | |
6c29256c | 890 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, |
91acb21f JD |
891 | SA_INTERRUPT, "ubd", ubd_dev); |
892 | if(err != 0) | |
893 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); | |
894 | return(err); | |
895 | } | |
896 | ||
897 | device_initcall(ubd_driver_init); | |
898 | ||
1da177e4 LT |
899 | static int ubd_open(struct inode *inode, struct file *filp) |
900 | { | |
901 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
902 | struct ubd *dev = disk->private_data; | |
903 | int err = 0; | |
904 | ||
905 | if(dev->count == 0){ | |
906 | err = ubd_open_dev(dev); | |
907 | if(err){ | |
908 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
909 | disk->disk_name, dev->file, -err); | |
910 | goto out; | |
911 | } | |
912 | } | |
913 | dev->count++; | |
2c49be99 PBG |
914 | set_disk_ro(disk, !dev->openflags.w); |
915 | ||
916 | /* This should no more be needed. And it didn't work anyway to exclude | |
917 | * read-write remounting of filesystems.*/ | |
918 | /*if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ | |
1da177e4 LT |
919 | if(--dev->count == 0) ubd_close(dev); |
920 | err = -EROFS; | |
2c49be99 | 921 | }*/ |
1da177e4 LT |
922 | out: |
923 | return(err); | |
924 | } | |
925 | ||
926 | static int ubd_release(struct inode * inode, struct file * file) | |
927 | { | |
928 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
929 | struct ubd *dev = disk->private_data; | |
930 | ||
931 | if(--dev->count == 0) | |
932 | ubd_close(dev); | |
933 | return(0); | |
934 | } | |
935 | ||
91acb21f JD |
936 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, |
937 | __u64 *cow_offset, unsigned long *bitmap, | |
938 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
939 | __u64 bitmap_len) | |
1da177e4 | 940 | { |
91acb21f JD |
941 | __u64 sector = io_offset >> 9; |
942 | int i, update_bitmap = 0; | |
943 | ||
944 | for(i = 0; i < length >> 9; i++){ | |
945 | if(cow_mask != NULL) | |
946 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
947 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
948 | continue; | |
1da177e4 | 949 | |
91acb21f JD |
950 | update_bitmap = 1; |
951 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
952 | } | |
953 | ||
954 | if(!update_bitmap) | |
955 | return; | |
1da177e4 | 956 | |
91acb21f | 957 | *cow_offset = sector / (sizeof(unsigned long) * 8); |
1da177e4 | 958 | |
91acb21f JD |
959 | /* This takes care of the case where we're exactly at the end of the |
960 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
961 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
962 | * for the original diagnosis. | |
963 | */ | |
964 | if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / | |
965 | sizeof(unsigned long) - 1)) | |
966 | (*cow_offset)--; | |
967 | ||
968 | bitmap_words[0] = bitmap[*cow_offset]; | |
969 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
970 | ||
971 | *cow_offset *= sizeof(unsigned long); | |
972 | *cow_offset += bitmap_offset; | |
973 | } | |
974 | ||
975 | static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, | |
976 | __u64 bitmap_offset, __u64 bitmap_len) | |
977 | { | |
978 | __u64 sector = req->offset >> 9; | |
979 | int i; | |
980 | ||
981 | if(req->length > (sizeof(req->sector_mask) * 8) << 9) | |
982 | panic("Operation too long"); | |
983 | ||
984 | if(req->op == UBD_READ) { | |
985 | for(i = 0; i < req->length >> 9; i++){ | |
986 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
6c29256c | 987 | ubd_set_bit(i, (unsigned char *) |
91acb21f JD |
988 | &req->sector_mask); |
989 | } | |
990 | } | |
991 | else cowify_bitmap(req->offset, req->length, &req->sector_mask, | |
992 | &req->cow_offset, bitmap, bitmap_offset, | |
993 | req->bitmap_words, bitmap_len); | |
1da177e4 LT |
994 | } |
995 | ||
1da177e4 | 996 | /* Called with ubd_io_lock held */ |
91acb21f | 997 | static int prepare_request(struct request *req, struct io_thread_req *io_req) |
1da177e4 LT |
998 | { |
999 | struct gendisk *disk = req->rq_disk; | |
1000 | struct ubd *dev = disk->private_data; | |
91acb21f JD |
1001 | __u64 offset; |
1002 | int len; | |
1003 | ||
1004 | if(req->rq_status == RQ_INACTIVE) return(1); | |
1da177e4 | 1005 | |
2c49be99 | 1006 | /* This should be impossible now */ |
1da177e4 | 1007 | if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ |
6c29256c | 1008 | printk("Write attempted on readonly ubd device %s\n", |
1da177e4 | 1009 | disk->disk_name); |
91acb21f | 1010 | end_request(req, 0); |
1da177e4 LT |
1011 | return(1); |
1012 | } | |
1013 | ||
91acb21f JD |
1014 | offset = ((__u64) req->sector) << 9; |
1015 | len = req->current_nr_sectors << 9; | |
1016 | ||
1da177e4 LT |
1017 | io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; |
1018 | io_req->fds[1] = dev->fd; | |
91acb21f | 1019 | io_req->cow_offset = -1; |
1da177e4 LT |
1020 | io_req->offset = offset; |
1021 | io_req->length = len; | |
1022 | io_req->error = 0; | |
91acb21f JD |
1023 | io_req->sector_mask = 0; |
1024 | ||
1025 | io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; | |
1da177e4 LT |
1026 | io_req->offsets[0] = 0; |
1027 | io_req->offsets[1] = dev->cow.data_offset; | |
91acb21f | 1028 | io_req->buffer = req->buffer; |
1da177e4 LT |
1029 | io_req->sectorsize = 1 << 9; |
1030 | ||
91acb21f JD |
1031 | if(dev->cow.file != NULL) |
1032 | cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, | |
1033 | dev->cow.bitmap_len); | |
1034 | ||
1da177e4 LT |
1035 | return(0); |
1036 | } | |
1037 | ||
1038 | /* Called with ubd_io_lock held */ | |
1039 | static void do_ubd_request(request_queue_t *q) | |
1040 | { | |
1041 | struct io_thread_req io_req; | |
1042 | struct request *req; | |
91acb21f JD |
1043 | int err, n; |
1044 | ||
1045 | if(thread_fd == -1){ | |
1046 | while((req = elv_next_request(q)) != NULL){ | |
1047 | err = prepare_request(req, &io_req); | |
1048 | if(!err){ | |
1049 | do_io(&io_req); | |
1050 | __ubd_finish(req, io_req.error); | |
1051 | } | |
1052 | } | |
1053 | } | |
1054 | else { | |
1055 | if(do_ubd || (req = elv_next_request(q)) == NULL) | |
1056 | return; | |
1057 | err = prepare_request(req, &io_req); | |
1058 | if(!err){ | |
1059 | do_ubd = ubd_handler; | |
1060 | n = os_write_file(thread_fd, (char *) &io_req, | |
1061 | sizeof(io_req)); | |
1062 | if(n != sizeof(io_req)) | |
1063 | printk("write to io thread failed, " | |
1064 | "errno = %d\n", -n); | |
1da177e4 LT |
1065 | } |
1066 | } | |
1067 | } | |
1068 | ||
a885c8c4 CH |
1069 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1070 | { | |
1071 | struct ubd *dev = bdev->bd_disk->private_data; | |
1072 | ||
1073 | geo->heads = 128; | |
1074 | geo->sectors = 32; | |
1075 | geo->cylinders = dev->size / (128 * 32 * 512); | |
1076 | return 0; | |
1077 | } | |
1078 | ||
1da177e4 LT |
1079 | static int ubd_ioctl(struct inode * inode, struct file * file, |
1080 | unsigned int cmd, unsigned long arg) | |
1081 | { | |
1da177e4 LT |
1082 | struct ubd *dev = inode->i_bdev->bd_disk->private_data; |
1083 | struct hd_driveid ubd_id = { | |
1084 | .cyls = 0, | |
1085 | .heads = 128, | |
1086 | .sectors = 32, | |
1087 | }; | |
1088 | ||
1089 | switch (cmd) { | |
1da177e4 | 1090 | struct cdrom_volctrl volume; |
1da177e4 LT |
1091 | case HDIO_GET_IDENTITY: |
1092 | ubd_id.cyls = dev->size / (128 * 32 * 512); | |
1093 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, | |
1094 | sizeof(ubd_id))) | |
1095 | return(-EFAULT); | |
1096 | return(0); | |
1097 | ||
1098 | case CDROMVOLREAD: | |
1099 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
1100 | return(-EFAULT); | |
1101 | volume.channel0 = 255; | |
1102 | volume.channel1 = 255; | |
1103 | volume.channel2 = 255; | |
1104 | volume.channel3 = 255; | |
1105 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
1106 | return(-EFAULT); | |
1107 | return(0); | |
1108 | } | |
1109 | return(-EINVAL); | |
1110 | } | |
1111 | ||
4833aff7 | 1112 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) |
1da177e4 LT |
1113 | { |
1114 | struct uml_stat buf1, buf2; | |
1115 | int err; | |
1116 | ||
4833aff7 PBG |
1117 | if(from_cmdline == NULL) |
1118 | return 0; | |
1119 | if(!strcmp(from_cmdline, from_cow)) | |
1120 | return 0; | |
1da177e4 LT |
1121 | |
1122 | err = os_stat_file(from_cmdline, &buf1); | |
1123 | if(err < 0){ | |
1124 | printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); | |
4833aff7 | 1125 | return 0; |
1da177e4 LT |
1126 | } |
1127 | err = os_stat_file(from_cow, &buf2); | |
1128 | if(err < 0){ | |
1129 | printk("Couldn't stat '%s', err = %d\n", from_cow, -err); | |
4833aff7 | 1130 | return 1; |
1da177e4 LT |
1131 | } |
1132 | if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
4833aff7 | 1133 | return 0; |
1da177e4 LT |
1134 | |
1135 | printk("Backing file mismatch - \"%s\" requested,\n" | |
1136 | "\"%s\" specified in COW header of \"%s\"\n", | |
1137 | from_cmdline, from_cow, cow); | |
4833aff7 | 1138 | return 1; |
1da177e4 LT |
1139 | } |
1140 | ||
1141 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
1142 | { | |
1143 | unsigned long modtime; | |
fe1db50c | 1144 | unsigned long long actual; |
1da177e4 LT |
1145 | int err; |
1146 | ||
1147 | err = os_file_modtime(file, &modtime); | |
1148 | if(err < 0){ | |
1149 | printk("Failed to get modification time of backing file " | |
1150 | "\"%s\", err = %d\n", file, -err); | |
1151 | return(err); | |
1152 | } | |
1153 | ||
1154 | err = os_file_size(file, &actual); | |
1155 | if(err < 0){ | |
1156 | printk("Failed to get size of backing file \"%s\", " | |
1157 | "err = %d\n", file, -err); | |
1158 | return(err); | |
1159 | } | |
1160 | ||
1161 | if(actual != size){ | |
1162 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
1163 | * the typecast.*/ | |
1164 | printk("Size mismatch (%llu vs %llu) of COW header vs backing " | |
1165 | "file\n", (unsigned long long) size, actual); | |
1166 | return(-EINVAL); | |
1167 | } | |
1168 | if(modtime != mtime){ | |
1169 | printk("mtime mismatch (%ld vs %ld) of COW header vs backing " | |
1170 | "file\n", mtime, modtime); | |
1171 | return(-EINVAL); | |
1172 | } | |
1173 | return(0); | |
1174 | } | |
1175 | ||
1176 | int read_cow_bitmap(int fd, void *buf, int offset, int len) | |
1177 | { | |
1178 | int err; | |
1179 | ||
1180 | err = os_seek_file(fd, offset); | |
1181 | if(err < 0) | |
1182 | return(err); | |
1183 | ||
1184 | err = os_read_file(fd, buf, len); | |
1185 | if(err < 0) | |
1186 | return(err); | |
1187 | ||
1188 | return(0); | |
1189 | } | |
1190 | ||
6c29256c | 1191 | int open_ubd_file(char *file, struct openflags *openflags, int shared, |
1da177e4 LT |
1192 | char **backing_file_out, int *bitmap_offset_out, |
1193 | unsigned long *bitmap_len_out, int *data_offset_out, | |
1194 | int *create_cow_out) | |
1195 | { | |
1196 | time_t mtime; | |
1197 | unsigned long long size; | |
1198 | __u32 version, align; | |
1199 | char *backing_file; | |
4833aff7 | 1200 | int fd, err, sectorsize, asked_switch, mode = 0644; |
1da177e4 LT |
1201 | |
1202 | fd = os_open_file(file, *openflags, mode); | |
a374a48f PBG |
1203 | if (fd < 0) { |
1204 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
1da177e4 | 1205 | *create_cow_out = 1; |
a374a48f PBG |
1206 | if (!openflags->w || |
1207 | ((fd != -EROFS) && (fd != -EACCES))) | |
1208 | return fd; | |
1da177e4 LT |
1209 | openflags->w = 0; |
1210 | fd = os_open_file(file, *openflags, mode); | |
a374a48f PBG |
1211 | if (fd < 0) |
1212 | return fd; | |
1da177e4 LT |
1213 | } |
1214 | ||
6c29256c JD |
1215 | if(shared) |
1216 | printk("Not locking \"%s\" on the host\n", file); | |
1217 | else { | |
1218 | err = os_lock_file(fd, openflags->w); | |
1219 | if(err < 0){ | |
1220 | printk("Failed to lock '%s', err = %d\n", file, -err); | |
1221 | goto out_close; | |
1222 | } | |
1da177e4 LT |
1223 | } |
1224 | ||
4833aff7 | 1225 | /* Succesful return case! */ |
a374a48f PBG |
1226 | if(backing_file_out == NULL) |
1227 | return(fd); | |
1da177e4 LT |
1228 | |
1229 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
1230 | &size, §orsize, &align, bitmap_offset_out); | |
1231 | if(err && (*backing_file_out != NULL)){ | |
1232 | printk("Failed to read COW header from COW file \"%s\", " | |
1233 | "errno = %d\n", file, -err); | |
1234 | goto out_close; | |
1235 | } | |
a374a48f PBG |
1236 | if(err) |
1237 | return(fd); | |
1da177e4 | 1238 | |
4833aff7 | 1239 | asked_switch = path_requires_switch(*backing_file_out, backing_file, file); |
1da177e4 | 1240 | |
4833aff7 PBG |
1241 | /* Allow switching only if no mismatch. */ |
1242 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { | |
1da177e4 LT |
1243 | printk("Switching backing file to '%s'\n", *backing_file_out); |
1244 | err = write_cow_header(file, fd, *backing_file_out, | |
1245 | sectorsize, align, &size); | |
a374a48f | 1246 | if (err) { |
1da177e4 | 1247 | printk("Switch failed, errno = %d\n", -err); |
4833aff7 | 1248 | goto out_close; |
1da177e4 | 1249 | } |
a374a48f | 1250 | } else { |
1da177e4 LT |
1251 | *backing_file_out = backing_file; |
1252 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
a374a48f PBG |
1253 | if (err) |
1254 | goto out_close; | |
1da177e4 LT |
1255 | } |
1256 | ||
1257 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
1258 | bitmap_len_out, data_offset_out); | |
1259 | ||
a374a48f | 1260 | return fd; |
1da177e4 LT |
1261 | out_close: |
1262 | os_close_file(fd); | |
a374a48f | 1263 | return err; |
1da177e4 LT |
1264 | } |
1265 | ||
1266 | int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, | |
1267 | int sectorsize, int alignment, int *bitmap_offset_out, | |
1268 | unsigned long *bitmap_len_out, int *data_offset_out) | |
1269 | { | |
1270 | int err, fd; | |
1271 | ||
1272 | flags.c = 1; | |
6c29256c | 1273 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); |
1da177e4 LT |
1274 | if(fd < 0){ |
1275 | err = fd; | |
1276 | printk("Open of COW file '%s' failed, errno = %d\n", cow_file, | |
1277 | -err); | |
1278 | goto out; | |
1279 | } | |
1280 | ||
1281 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
1282 | bitmap_offset_out, bitmap_len_out, | |
1283 | data_offset_out); | |
1284 | if(!err) | |
1285 | return(fd); | |
1286 | os_close_file(fd); | |
1287 | out: | |
1288 | return(err); | |
1289 | } | |
1290 | ||
91acb21f | 1291 | static int update_bitmap(struct io_thread_req *req) |
1da177e4 | 1292 | { |
91acb21f | 1293 | int n; |
1da177e4 | 1294 | |
91acb21f JD |
1295 | if(req->cow_offset == -1) |
1296 | return(0); | |
1da177e4 | 1297 | |
91acb21f JD |
1298 | n = os_seek_file(req->fds[1], req->cow_offset); |
1299 | if(n < 0){ | |
1300 | printk("do_io - bitmap lseek failed : err = %d\n", -n); | |
1301 | return(1); | |
1302 | } | |
1da177e4 | 1303 | |
91acb21f JD |
1304 | n = os_write_file(req->fds[1], &req->bitmap_words, |
1305 | sizeof(req->bitmap_words)); | |
1306 | if(n != sizeof(req->bitmap_words)){ | |
1307 | printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, | |
1308 | req->fds[1]); | |
1309 | return(1); | |
1310 | } | |
1da177e4 | 1311 | |
91acb21f JD |
1312 | return(0); |
1313 | } | |
1da177e4 | 1314 | |
91acb21f JD |
1315 | void do_io(struct io_thread_req *req) |
1316 | { | |
1317 | char *buf; | |
1318 | unsigned long len; | |
1319 | int n, nsectors, start, end, bit; | |
1320 | int err; | |
1321 | __u64 off; | |
1322 | ||
1323 | nsectors = req->length / req->sectorsize; | |
1324 | start = 0; | |
1325 | do { | |
1326 | bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); | |
1327 | end = start; | |
1328 | while((end < nsectors) && | |
1329 | (ubd_test_bit(end, (unsigned char *) | |
1330 | &req->sector_mask) == bit)) | |
1331 | end++; | |
1332 | ||
1333 | off = req->offset + req->offsets[bit] + | |
1334 | start * req->sectorsize; | |
1335 | len = (end - start) * req->sectorsize; | |
1336 | buf = &req->buffer[start * req->sectorsize]; | |
1337 | ||
1338 | err = os_seek_file(req->fds[bit], off); | |
1339 | if(err < 0){ | |
1340 | printk("do_io - lseek failed : err = %d\n", -err); | |
1341 | req->error = 1; | |
1342 | return; | |
1343 | } | |
1344 | if(req->op == UBD_READ){ | |
1345 | n = 0; | |
1346 | do { | |
1347 | buf = &buf[n]; | |
1348 | len -= n; | |
1349 | n = os_read_file(req->fds[bit], buf, len); | |
1350 | if (n < 0) { | |
1351 | printk("do_io - read failed, err = %d " | |
1352 | "fd = %d\n", -n, req->fds[bit]); | |
1353 | req->error = 1; | |
1354 | return; | |
1355 | } | |
1356 | } while((n < len) && (n != 0)); | |
1357 | if (n < len) memset(&buf[n], 0, len - n); | |
1358 | } else { | |
1359 | n = os_write_file(req->fds[bit], buf, len); | |
1360 | if(n != len){ | |
1361 | printk("do_io - write failed err = %d " | |
1362 | "fd = %d\n", -n, req->fds[bit]); | |
1363 | req->error = 1; | |
1364 | return; | |
1365 | } | |
1366 | } | |
1367 | ||
1368 | start = end; | |
1369 | } while(start < nsectors); | |
1da177e4 | 1370 | |
91acb21f | 1371 | req->error = update_bitmap(req); |
1da177e4 | 1372 | } |
91acb21f JD |
1373 | |
1374 | /* Changed in start_io_thread, which is serialized by being called only | |
1375 | * from ubd_init, which is an initcall. | |
1376 | */ | |
1377 | int kernel_fd = -1; | |
1378 | ||
1379 | /* Only changed by the io thread */ | |
1380 | int io_count = 0; | |
1381 | ||
1382 | int io_thread(void *arg) | |
1383 | { | |
1384 | struct io_thread_req req; | |
1385 | int n; | |
1386 | ||
1387 | ignore_sigwinch_sig(); | |
1388 | while(1){ | |
1389 | n = os_read_file(kernel_fd, &req, sizeof(req)); | |
1390 | if(n != sizeof(req)){ | |
1391 | if(n < 0) | |
1392 | printk("io_thread - read failed, fd = %d, " | |
1393 | "err = %d\n", kernel_fd, -n); | |
1394 | else { | |
1395 | printk("io_thread - short read, fd = %d, " | |
1396 | "length = %d\n", kernel_fd, n); | |
1397 | } | |
1398 | continue; | |
1399 | } | |
1400 | io_count++; | |
1401 | do_io(&req); | |
1402 | n = os_write_file(kernel_fd, &req, sizeof(req)); | |
1403 | if(n != sizeof(req)) | |
1404 | printk("io_thread - write failed, fd = %d, err = %d\n", | |
1405 | kernel_fd, -n); | |
1406 | } | |
91acb21f | 1407 | |
1b57e9c2 JD |
1408 | return 0; |
1409 | } |