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Commit | Line | Data |
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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" | |
1da177e4 LT |
28 | #include "linux/cdrom.h" |
29 | #include "linux/proc_fs.h" | |
30 | #include "linux/ctype.h" | |
31 | #include "linux/capability.h" | |
32 | #include "linux/mm.h" | |
33 | #include "linux/vmalloc.h" | |
34 | #include "linux/blkpg.h" | |
35 | #include "linux/genhd.h" | |
36 | #include "linux/spinlock.h" | |
d052d1be | 37 | #include "linux/platform_device.h" |
1da177e4 LT |
38 | #include "asm/segment.h" |
39 | #include "asm/uaccess.h" | |
40 | #include "asm/irq.h" | |
41 | #include "asm/types.h" | |
42 | #include "asm/tlbflush.h" | |
43 | #include "user_util.h" | |
44 | #include "mem_user.h" | |
45 | #include "kern_util.h" | |
46 | #include "kern.h" | |
47 | #include "mconsole_kern.h" | |
48 | #include "init.h" | |
49 | #include "irq_user.h" | |
50 | #include "irq_kern.h" | |
51 | #include "ubd_user.h" | |
1da177e4 LT |
52 | #include "os.h" |
53 | #include "mem.h" | |
54 | #include "mem_kern.h" | |
55 | #include "cow.h" | |
56 | ||
7b9014c1 | 57 | enum ubd_req { UBD_READ, UBD_WRITE }; |
1da177e4 LT |
58 | |
59 | struct io_thread_req { | |
91acb21f | 60 | enum ubd_req op; |
1da177e4 LT |
61 | int fds[2]; |
62 | unsigned long offsets[2]; | |
63 | unsigned long long offset; | |
64 | unsigned long length; | |
65 | char *buffer; | |
66 | int sectorsize; | |
91acb21f JD |
67 | unsigned long sector_mask; |
68 | unsigned long long cow_offset; | |
69 | unsigned long bitmap_words[2]; | |
1da177e4 LT |
70 | int error; |
71 | }; | |
72 | ||
6c29256c | 73 | extern int open_ubd_file(char *file, struct openflags *openflags, int shared, |
1da177e4 LT |
74 | char **backing_file_out, int *bitmap_offset_out, |
75 | unsigned long *bitmap_len_out, int *data_offset_out, | |
76 | int *create_cow_out); | |
77 | extern int create_cow_file(char *cow_file, char *backing_file, | |
78 | struct openflags flags, int sectorsize, | |
79 | int alignment, int *bitmap_offset_out, | |
80 | unsigned long *bitmap_len_out, | |
81 | int *data_offset_out); | |
82 | extern int read_cow_bitmap(int fd, void *buf, int offset, int len); | |
91acb21f | 83 | extern void do_io(struct io_thread_req *req); |
1da177e4 | 84 | |
91acb21f | 85 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
86 | { |
87 | __u64 n; | |
88 | int bits, off; | |
89 | ||
91acb21f | 90 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
91 | n = bit / bits; |
92 | off = bit % bits; | |
91acb21f | 93 | return((data[n] & (1 << off)) != 0); |
1da177e4 LT |
94 | } |
95 | ||
91acb21f | 96 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
97 | { |
98 | __u64 n; | |
99 | int bits, off; | |
100 | ||
91acb21f | 101 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
102 | n = bit / bits; |
103 | off = bit % bits; | |
91acb21f | 104 | data[n] |= (1 << off); |
1da177e4 LT |
105 | } |
106 | /*End stuff from ubd_user.h*/ | |
107 | ||
108 | #define DRIVER_NAME "uml-blkdev" | |
109 | ||
110 | static DEFINE_SPINLOCK(ubd_io_lock); | |
111 | static DEFINE_SPINLOCK(ubd_lock); | |
112 | ||
91acb21f JD |
113 | static void (*do_ubd)(void); |
114 | ||
1da177e4 LT |
115 | static int ubd_open(struct inode * inode, struct file * filp); |
116 | static int ubd_release(struct inode * inode, struct file * file); | |
117 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
118 | unsigned int cmd, unsigned long arg); | |
a885c8c4 | 119 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
1da177e4 LT |
120 | |
121 | #define MAX_DEV (8) | |
122 | ||
1da177e4 LT |
123 | static struct block_device_operations ubd_blops = { |
124 | .owner = THIS_MODULE, | |
125 | .open = ubd_open, | |
126 | .release = ubd_release, | |
127 | .ioctl = ubd_ioctl, | |
a885c8c4 | 128 | .getgeo = ubd_getgeo, |
1da177e4 LT |
129 | }; |
130 | ||
131 | /* Protected by the queue_lock */ | |
132 | static request_queue_t *ubd_queue; | |
133 | ||
134 | /* Protected by ubd_lock */ | |
135 | static int fake_major = MAJOR_NR; | |
136 | ||
137 | static struct gendisk *ubd_gendisk[MAX_DEV]; | |
138 | static struct gendisk *fake_gendisk[MAX_DEV]; | |
6c29256c | 139 | |
1da177e4 LT |
140 | #ifdef CONFIG_BLK_DEV_UBD_SYNC |
141 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
142 | .cl = 1 }) | |
143 | #else | |
144 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
145 | .cl = 1 }) | |
146 | #endif | |
147 | ||
148 | /* Not protected - changed only in ubd_setup_common and then only to | |
149 | * to enable O_SYNC. | |
150 | */ | |
151 | static struct openflags global_openflags = OPEN_FLAGS; | |
152 | ||
153 | struct cow { | |
2c49be99 | 154 | /* This is the backing file, actually */ |
1da177e4 LT |
155 | char *file; |
156 | int fd; | |
157 | unsigned long *bitmap; | |
158 | unsigned long bitmap_len; | |
159 | int bitmap_offset; | |
160 | int data_offset; | |
161 | }; | |
162 | ||
163 | struct ubd { | |
164 | char *file; | |
165 | int count; | |
166 | int fd; | |
167 | __u64 size; | |
168 | struct openflags boot_openflags; | |
169 | struct openflags openflags; | |
6c29256c | 170 | int shared; |
1da177e4 LT |
171 | int no_cow; |
172 | struct cow cow; | |
173 | struct platform_device pdev; | |
1da177e4 LT |
174 | }; |
175 | ||
176 | #define DEFAULT_COW { \ | |
177 | .file = NULL, \ | |
178 | .fd = -1, \ | |
179 | .bitmap = NULL, \ | |
180 | .bitmap_offset = 0, \ | |
181 | .data_offset = 0, \ | |
182 | } | |
183 | ||
184 | #define DEFAULT_UBD { \ | |
185 | .file = NULL, \ | |
186 | .count = 0, \ | |
187 | .fd = -1, \ | |
188 | .size = -1, \ | |
189 | .boot_openflags = OPEN_FLAGS, \ | |
190 | .openflags = OPEN_FLAGS, \ | |
191 | .no_cow = 0, \ | |
6c29256c | 192 | .shared = 0, \ |
1da177e4 | 193 | .cow = DEFAULT_COW, \ |
1da177e4 LT |
194 | } |
195 | ||
196 | struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; | |
197 | ||
198 | static int ubd0_init(void) | |
199 | { | |
200 | struct ubd *dev = &ubd_dev[0]; | |
201 | ||
202 | if(dev->file == NULL) | |
203 | dev->file = "root_fs"; | |
204 | return(0); | |
205 | } | |
206 | ||
207 | __initcall(ubd0_init); | |
208 | ||
209 | /* Only changed by fake_ide_setup which is a setup */ | |
210 | static int fake_ide = 0; | |
211 | static struct proc_dir_entry *proc_ide_root = NULL; | |
212 | static struct proc_dir_entry *proc_ide = NULL; | |
213 | ||
214 | static void make_proc_ide(void) | |
215 | { | |
216 | proc_ide_root = proc_mkdir("ide", NULL); | |
217 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
218 | } | |
219 | ||
220 | static int proc_ide_read_media(char *page, char **start, off_t off, int count, | |
221 | int *eof, void *data) | |
222 | { | |
223 | int len; | |
224 | ||
225 | strcpy(page, "disk\n"); | |
226 | len = strlen("disk\n"); | |
227 | len -= off; | |
228 | if (len < count){ | |
229 | *eof = 1; | |
230 | if (len <= 0) return 0; | |
231 | } | |
232 | else len = count; | |
233 | *start = page + off; | |
234 | return len; | |
235 | } | |
236 | ||
237 | static void make_ide_entries(char *dev_name) | |
238 | { | |
239 | struct proc_dir_entry *dir, *ent; | |
240 | char name[64]; | |
241 | ||
242 | if(proc_ide_root == NULL) make_proc_ide(); | |
243 | ||
244 | dir = proc_mkdir(dev_name, proc_ide); | |
245 | if(!dir) return; | |
246 | ||
247 | ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); | |
248 | if(!ent) return; | |
249 | ent->nlink = 1; | |
250 | ent->data = NULL; | |
251 | ent->read_proc = proc_ide_read_media; | |
252 | ent->write_proc = NULL; | |
253 | sprintf(name,"ide0/%s", dev_name); | |
254 | proc_symlink(dev_name, proc_ide_root, name); | |
255 | } | |
256 | ||
257 | static int fake_ide_setup(char *str) | |
258 | { | |
259 | fake_ide = 1; | |
260 | return(1); | |
261 | } | |
262 | ||
263 | __setup("fake_ide", fake_ide_setup); | |
264 | ||
265 | __uml_help(fake_ide_setup, | |
266 | "fake_ide\n" | |
267 | " Create ide0 entries that map onto ubd devices.\n\n" | |
268 | ); | |
269 | ||
270 | static int parse_unit(char **ptr) | |
271 | { | |
272 | char *str = *ptr, *end; | |
273 | int n = -1; | |
274 | ||
275 | if(isdigit(*str)) { | |
276 | n = simple_strtoul(str, &end, 0); | |
277 | if(end == str) | |
278 | return(-1); | |
279 | *ptr = end; | |
280 | } | |
281 | else if (('a' <= *str) && (*str <= 'h')) { | |
282 | n = *str - 'a'; | |
283 | str++; | |
284 | *ptr = str; | |
285 | } | |
286 | return(n); | |
287 | } | |
288 | ||
289 | static int ubd_setup_common(char *str, int *index_out) | |
290 | { | |
291 | struct ubd *dev; | |
292 | struct openflags flags = global_openflags; | |
293 | char *backing_file; | |
294 | int n, err, i; | |
295 | ||
296 | if(index_out) *index_out = -1; | |
297 | n = *str; | |
298 | if(n == '='){ | |
299 | char *end; | |
300 | int major; | |
301 | ||
302 | str++; | |
1da177e4 LT |
303 | if(!strcmp(str, "sync")){ |
304 | global_openflags = of_sync(global_openflags); | |
305 | return(0); | |
306 | } | |
307 | major = simple_strtoul(str, &end, 0); | |
308 | if((*end != '\0') || (end == str)){ | |
6c29256c | 309 | printk(KERN_ERR |
1da177e4 LT |
310 | "ubd_setup : didn't parse major number\n"); |
311 | return(1); | |
312 | } | |
313 | ||
314 | err = 1; | |
315 | spin_lock(&ubd_lock); | |
316 | if(fake_major != MAJOR_NR){ | |
317 | printk(KERN_ERR "Can't assign a fake major twice\n"); | |
318 | goto out1; | |
319 | } | |
6c29256c | 320 | |
1da177e4 LT |
321 | fake_major = major; |
322 | ||
323 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
324 | major); | |
325 | err = 0; | |
326 | out1: | |
327 | spin_unlock(&ubd_lock); | |
328 | return(err); | |
329 | } | |
330 | ||
331 | n = parse_unit(&str); | |
332 | if(n < 0){ | |
333 | printk(KERN_ERR "ubd_setup : couldn't parse unit number " | |
334 | "'%s'\n", str); | |
335 | return(1); | |
336 | } | |
337 | if(n >= MAX_DEV){ | |
338 | printk(KERN_ERR "ubd_setup : index %d out of range " | |
339 | "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1); | |
340 | return(1); | |
341 | } | |
342 | ||
343 | err = 1; | |
344 | spin_lock(&ubd_lock); | |
345 | ||
346 | dev = &ubd_dev[n]; | |
347 | if(dev->file != NULL){ | |
348 | printk(KERN_ERR "ubd_setup : device already configured\n"); | |
349 | goto out; | |
350 | } | |
351 | ||
352 | if (index_out) | |
353 | *index_out = n; | |
354 | ||
6c29256c | 355 | for (i = 0; i < sizeof("rscd="); i++) { |
1da177e4 LT |
356 | switch (*str) { |
357 | case 'r': | |
358 | flags.w = 0; | |
359 | break; | |
360 | case 's': | |
361 | flags.s = 1; | |
362 | break; | |
363 | case 'd': | |
364 | dev->no_cow = 1; | |
365 | break; | |
6c29256c JD |
366 | case 'c': |
367 | dev->shared = 1; | |
368 | break; | |
1da177e4 LT |
369 | case '=': |
370 | str++; | |
371 | goto break_loop; | |
372 | default: | |
6c29256c | 373 | printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r, s, c, or d)\n"); |
1da177e4 LT |
374 | goto out; |
375 | } | |
376 | str++; | |
377 | } | |
378 | ||
379 | if (*str == '=') | |
380 | printk(KERN_ERR "ubd_setup : Too many flags specified\n"); | |
381 | else | |
382 | printk(KERN_ERR "ubd_setup : Expected '='\n"); | |
383 | goto out; | |
384 | ||
385 | break_loop: | |
386 | err = 0; | |
387 | backing_file = strchr(str, ','); | |
388 | ||
389 | if (!backing_file) { | |
390 | backing_file = strchr(str, ':'); | |
391 | } | |
392 | ||
393 | if(backing_file){ | |
394 | if(dev->no_cow) | |
395 | printk(KERN_ERR "Can't specify both 'd' and a " | |
396 | "cow file\n"); | |
397 | else { | |
398 | *backing_file = '\0'; | |
399 | backing_file++; | |
400 | } | |
401 | } | |
402 | dev->file = str; | |
403 | dev->cow.file = backing_file; | |
404 | dev->boot_openflags = flags; | |
405 | out: | |
406 | spin_unlock(&ubd_lock); | |
407 | return(err); | |
408 | } | |
409 | ||
410 | static int ubd_setup(char *str) | |
411 | { | |
412 | ubd_setup_common(str, NULL); | |
413 | return(1); | |
414 | } | |
415 | ||
416 | __setup("ubd", ubd_setup); | |
417 | __uml_help(ubd_setup, | |
418 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
419 | " This is used to associate a device with a file in the underlying\n" | |
420 | " filesystem. When specifying two filenames, the first one is the\n" | |
421 | " COW name and the second is the backing file name. As separator you can\n" | |
422 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
423 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
424 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
425 | " When using only one filename, UML will detect whether to thread it like\n" | |
426 | " a COW file or a backing file. To override this detection, add the 'd'\n" | |
427 | " flag:\n" | |
428 | " ubd0d=BackingFile\n" | |
429 | " Usually, there is a filesystem in the file, but \n" | |
430 | " that's not required. Swap devices containing swap files can be\n" | |
431 | " specified like this. Also, a file which doesn't contain a\n" | |
432 | " filesystem can have its contents read in the virtual \n" | |
433 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
434 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
435 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
436 | " an 's' will cause data to be written to disk on the host immediately.\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" | |
0894e27e JD |
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" | |
1da177e4 LT |
452 | " in the boot output.\n\n" |
453 | ); | |
454 | ||
455 | static int fakehd_set = 0; | |
456 | static int fakehd(char *str) | |
457 | { | |
458 | printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); | |
459 | fakehd_set = 1; | |
460 | return 1; | |
461 | } | |
462 | ||
463 | __setup("fakehd", fakehd); | |
464 | __uml_help(fakehd, | |
465 | "fakehd\n" | |
466 | " Change the ubd device name to \"hd\".\n\n" | |
467 | ); | |
468 | ||
469 | static void do_ubd_request(request_queue_t * q); | |
91acb21f JD |
470 | |
471 | /* Only changed by ubd_init, which is an initcall. */ | |
472 | int thread_fd = -1; | |
1da177e4 LT |
473 | |
474 | /* Changed by ubd_handler, which is serialized because interrupts only | |
475 | * happen on CPU 0. | |
476 | */ | |
477 | int intr_count = 0; | |
478 | ||
91acb21f JD |
479 | /* call ubd_finish if you need to serialize */ |
480 | static void __ubd_finish(struct request *req, int error) | |
1da177e4 | 481 | { |
91acb21f JD |
482 | int nsect; |
483 | ||
484 | if(error){ | |
485 | end_request(req, 0); | |
486 | return; | |
1da177e4 | 487 | } |
91acb21f JD |
488 | nsect = req->current_nr_sectors; |
489 | req->sector += nsect; | |
490 | req->buffer += nsect << 9; | |
491 | req->errors = 0; | |
492 | req->nr_sectors -= nsect; | |
493 | req->current_nr_sectors = 0; | |
494 | end_request(req, 1); | |
1da177e4 LT |
495 | } |
496 | ||
91acb21f | 497 | static inline void ubd_finish(struct request *req, int error) |
1da177e4 | 498 | { |
91acb21f JD |
499 | spin_lock(&ubd_io_lock); |
500 | __ubd_finish(req, error); | |
501 | spin_unlock(&ubd_io_lock); | |
1da177e4 LT |
502 | } |
503 | ||
91acb21f JD |
504 | /* Called without ubd_io_lock held */ |
505 | static void ubd_handler(void) | |
1da177e4 | 506 | { |
91acb21f JD |
507 | struct io_thread_req req; |
508 | struct request *rq = elv_next_request(ubd_queue); | |
509 | int n; | |
510 | ||
511 | do_ubd = NULL; | |
512 | intr_count++; | |
513 | n = os_read_file(thread_fd, &req, sizeof(req)); | |
514 | if(n != sizeof(req)){ | |
515 | printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " | |
516 | "err = %d\n", os_getpid(), -n); | |
517 | spin_lock(&ubd_io_lock); | |
518 | end_request(rq, 0); | |
519 | spin_unlock(&ubd_io_lock); | |
520 | return; | |
521 | } | |
6c29256c | 522 | |
91acb21f JD |
523 | ubd_finish(rq, req.error); |
524 | reactivate_fd(thread_fd, UBD_IRQ); | |
525 | do_ubd_request(ubd_queue); | |
1da177e4 LT |
526 | } |
527 | ||
528 | static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) | |
529 | { | |
91acb21f JD |
530 | ubd_handler(); |
531 | return(IRQ_HANDLED); | |
532 | } | |
09ace81c | 533 | |
91acb21f JD |
534 | /* Only changed by ubd_init, which is an initcall. */ |
535 | static int io_pid = -1; | |
09ace81c | 536 | |
91acb21f JD |
537 | void kill_io_thread(void) |
538 | { | |
6c29256c | 539 | if(io_pid != -1) |
91acb21f | 540 | os_kill_process(io_pid, 1); |
09ace81c | 541 | } |
1da177e4 | 542 | |
91acb21f JD |
543 | __uml_exitcall(kill_io_thread); |
544 | ||
1da177e4 LT |
545 | static int ubd_file_size(struct ubd *dev, __u64 *size_out) |
546 | { | |
547 | char *file; | |
548 | ||
549 | file = dev->cow.file ? dev->cow.file : dev->file; | |
550 | return(os_file_size(file, size_out)); | |
551 | } | |
552 | ||
553 | static void ubd_close(struct ubd *dev) | |
554 | { | |
1da177e4 LT |
555 | os_close_file(dev->fd); |
556 | if(dev->cow.file == NULL) | |
557 | return; | |
558 | ||
1da177e4 LT |
559 | os_close_file(dev->cow.fd); |
560 | vfree(dev->cow.bitmap); | |
561 | dev->cow.bitmap = NULL; | |
562 | } | |
563 | ||
564 | static int ubd_open_dev(struct ubd *dev) | |
565 | { | |
566 | struct openflags flags; | |
567 | char **back_ptr; | |
568 | int err, create_cow, *create_ptr; | |
569 | ||
570 | dev->openflags = dev->boot_openflags; | |
571 | create_cow = 0; | |
572 | create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL; | |
573 | back_ptr = dev->no_cow ? NULL : &dev->cow.file; | |
6c29256c JD |
574 | dev->fd = open_ubd_file(dev->file, &dev->openflags, dev->shared, |
575 | back_ptr, &dev->cow.bitmap_offset, | |
576 | &dev->cow.bitmap_len, &dev->cow.data_offset, | |
577 | create_ptr); | |
1da177e4 LT |
578 | |
579 | if((dev->fd == -ENOENT) && create_cow){ | |
6c29256c | 580 | dev->fd = create_cow_file(dev->file, dev->cow.file, |
1da177e4 | 581 | dev->openflags, 1 << 9, PAGE_SIZE, |
6c29256c | 582 | &dev->cow.bitmap_offset, |
1da177e4 LT |
583 | &dev->cow.bitmap_len, |
584 | &dev->cow.data_offset); | |
585 | if(dev->fd >= 0){ | |
586 | printk(KERN_INFO "Creating \"%s\" as COW file for " | |
587 | "\"%s\"\n", dev->file, dev->cow.file); | |
588 | } | |
589 | } | |
590 | ||
591 | if(dev->fd < 0){ | |
592 | printk("Failed to open '%s', errno = %d\n", dev->file, | |
593 | -dev->fd); | |
594 | return(dev->fd); | |
595 | } | |
596 | ||
597 | if(dev->cow.file != NULL){ | |
598 | err = -ENOMEM; | |
599 | dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len); | |
600 | if(dev->cow.bitmap == NULL){ | |
601 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); | |
602 | goto error; | |
603 | } | |
604 | flush_tlb_kernel_vm(); | |
605 | ||
6c29256c JD |
606 | err = read_cow_bitmap(dev->fd, dev->cow.bitmap, |
607 | dev->cow.bitmap_offset, | |
1da177e4 LT |
608 | dev->cow.bitmap_len); |
609 | if(err < 0) | |
610 | goto error; | |
611 | ||
612 | flags = dev->openflags; | |
613 | flags.w = 0; | |
6c29256c JD |
614 | err = open_ubd_file(dev->cow.file, &flags, dev->shared, NULL, |
615 | NULL, NULL, NULL, NULL); | |
1da177e4 LT |
616 | if(err < 0) goto error; |
617 | dev->cow.fd = err; | |
618 | } | |
619 | return(0); | |
620 | error: | |
621 | os_close_file(dev->fd); | |
622 | return(err); | |
623 | } | |
624 | ||
625 | static int ubd_new_disk(int major, u64 size, int unit, | |
626 | struct gendisk **disk_out) | |
627 | ||
628 | { | |
629 | struct gendisk *disk; | |
1da177e4 LT |
630 | |
631 | disk = alloc_disk(1 << UBD_SHIFT); | |
632 | if(disk == NULL) | |
633 | return(-ENOMEM); | |
634 | ||
635 | disk->major = major; | |
636 | disk->first_minor = unit << UBD_SHIFT; | |
637 | disk->fops = &ubd_blops; | |
638 | set_capacity(disk, size / 512); | |
ce7b0f46 | 639 | if(major == MAJOR_NR) |
1da177e4 | 640 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); |
ce7b0f46 | 641 | else |
1da177e4 | 642 | sprintf(disk->disk_name, "ubd_fake%d", unit); |
1da177e4 LT |
643 | |
644 | /* sysfs register (not for ide fake devices) */ | |
645 | if (major == MAJOR_NR) { | |
646 | ubd_dev[unit].pdev.id = unit; | |
647 | ubd_dev[unit].pdev.name = DRIVER_NAME; | |
648 | platform_device_register(&ubd_dev[unit].pdev); | |
649 | disk->driverfs_dev = &ubd_dev[unit].pdev.dev; | |
650 | } | |
651 | ||
652 | disk->private_data = &ubd_dev[unit]; | |
653 | disk->queue = ubd_queue; | |
654 | add_disk(disk); | |
655 | ||
656 | *disk_out = disk; | |
657 | return 0; | |
658 | } | |
659 | ||
660 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
661 | ||
662 | static int ubd_add(int n) | |
663 | { | |
664 | struct ubd *dev = &ubd_dev[n]; | |
665 | int err; | |
666 | ||
ec7cf783 | 667 | err = -ENODEV; |
1da177e4 | 668 | if(dev->file == NULL) |
ec7cf783 | 669 | goto out; |
1da177e4 LT |
670 | |
671 | if (ubd_open_dev(dev)) | |
ec7cf783 | 672 | goto out; |
1da177e4 LT |
673 | |
674 | err = ubd_file_size(dev, &dev->size); | |
675 | if(err < 0) | |
ec7cf783 | 676 | goto out_close; |
1da177e4 LT |
677 | |
678 | dev->size = ROUND_BLOCK(dev->size); | |
679 | ||
680 | err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]); | |
6c29256c | 681 | if(err) |
ec7cf783 | 682 | goto out_close; |
6c29256c | 683 | |
1da177e4 | 684 | if(fake_major != MAJOR_NR) |
6c29256c | 685 | ubd_new_disk(fake_major, dev->size, n, |
1da177e4 LT |
686 | &fake_gendisk[n]); |
687 | ||
688 | /* perhaps this should also be under the "if (fake_major)" above */ | |
689 | /* using the fake_disk->disk_name and also the fakehd_set name */ | |
690 | if (fake_ide) | |
691 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
692 | ||
ec7cf783 JD |
693 | err = 0; |
694 | out_close: | |
1da177e4 | 695 | ubd_close(dev); |
ec7cf783 JD |
696 | out: |
697 | return err; | |
1da177e4 LT |
698 | } |
699 | ||
700 | static int ubd_config(char *str) | |
701 | { | |
702 | int n, err; | |
703 | ||
970d6e3a | 704 | str = kstrdup(str, GFP_KERNEL); |
1da177e4 LT |
705 | if(str == NULL){ |
706 | printk(KERN_ERR "ubd_config failed to strdup string\n"); | |
707 | return(1); | |
708 | } | |
709 | err = ubd_setup_common(str, &n); | |
710 | if(err){ | |
711 | kfree(str); | |
712 | return(-1); | |
713 | } | |
714 | if(n == -1) return(0); | |
715 | ||
716 | spin_lock(&ubd_lock); | |
717 | err = ubd_add(n); | |
718 | if(err) | |
719 | ubd_dev[n].file = NULL; | |
720 | spin_unlock(&ubd_lock); | |
721 | ||
722 | return(err); | |
723 | } | |
724 | ||
725 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
726 | { | |
727 | struct ubd *dev; | |
728 | int n, len = 0; | |
729 | ||
730 | n = parse_unit(&name); | |
731 | if((n >= MAX_DEV) || (n < 0)){ | |
732 | *error_out = "ubd_get_config : device number out of range"; | |
733 | return(-1); | |
734 | } | |
735 | ||
736 | dev = &ubd_dev[n]; | |
737 | spin_lock(&ubd_lock); | |
738 | ||
739 | if(dev->file == NULL){ | |
740 | CONFIG_CHUNK(str, size, len, "", 1); | |
741 | goto out; | |
742 | } | |
743 | ||
744 | CONFIG_CHUNK(str, size, len, dev->file, 0); | |
745 | ||
746 | if(dev->cow.file != NULL){ | |
747 | CONFIG_CHUNK(str, size, len, ",", 0); | |
748 | CONFIG_CHUNK(str, size, len, dev->cow.file, 1); | |
749 | } | |
750 | else CONFIG_CHUNK(str, size, len, "", 1); | |
751 | ||
752 | out: | |
753 | spin_unlock(&ubd_lock); | |
754 | return(len); | |
755 | } | |
756 | ||
29d56cfe JD |
757 | static int ubd_id(char **str, int *start_out, int *end_out) |
758 | { | |
759 | int n; | |
760 | ||
761 | n = parse_unit(str); | |
762 | *start_out = 0; | |
763 | *end_out = MAX_DEV - 1; | |
764 | return n; | |
765 | } | |
766 | ||
767 | static int ubd_remove(int n) | |
1da177e4 LT |
768 | { |
769 | struct ubd *dev; | |
29d56cfe | 770 | int err = -ENODEV; |
1da177e4 | 771 | |
29d56cfe | 772 | spin_lock(&ubd_lock); |
1da177e4 | 773 | |
29d56cfe JD |
774 | if(ubd_gendisk[n] == NULL) |
775 | goto out; | |
1da177e4 LT |
776 | |
777 | dev = &ubd_dev[n]; | |
1da177e4 | 778 | |
29d56cfe JD |
779 | if(dev->file == NULL) |
780 | goto out; | |
1da177e4 | 781 | |
29d56cfe JD |
782 | /* you cannot remove a open disk */ |
783 | err = -EBUSY; | |
784 | if(dev->count > 0) | |
1da177e4 LT |
785 | goto out; |
786 | ||
787 | del_gendisk(ubd_gendisk[n]); | |
788 | put_disk(ubd_gendisk[n]); | |
789 | ubd_gendisk[n] = NULL; | |
790 | ||
791 | if(fake_gendisk[n] != NULL){ | |
792 | del_gendisk(fake_gendisk[n]); | |
793 | put_disk(fake_gendisk[n]); | |
794 | fake_gendisk[n] = NULL; | |
795 | } | |
796 | ||
797 | platform_device_unregister(&dev->pdev); | |
798 | *dev = ((struct ubd) DEFAULT_UBD); | |
799 | err = 0; | |
29d56cfe JD |
800 | out: |
801 | spin_unlock(&ubd_lock); | |
802 | return err; | |
1da177e4 LT |
803 | } |
804 | ||
805 | static struct mc_device ubd_mc = { | |
806 | .name = "ubd", | |
807 | .config = ubd_config, | |
808 | .get_config = ubd_get_config, | |
29d56cfe | 809 | .id = ubd_id, |
1da177e4 LT |
810 | .remove = ubd_remove, |
811 | }; | |
812 | ||
813 | static int ubd_mc_init(void) | |
814 | { | |
815 | mconsole_register_dev(&ubd_mc); | |
816 | return 0; | |
817 | } | |
818 | ||
819 | __initcall(ubd_mc_init); | |
820 | ||
3ae5eaec RK |
821 | static struct platform_driver ubd_driver = { |
822 | .driver = { | |
823 | .name = DRIVER_NAME, | |
824 | }, | |
1da177e4 LT |
825 | }; |
826 | ||
827 | int ubd_init(void) | |
828 | { | |
829 | int i; | |
830 | ||
1da177e4 LT |
831 | if (register_blkdev(MAJOR_NR, "ubd")) |
832 | return -1; | |
833 | ||
834 | ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock); | |
835 | if (!ubd_queue) { | |
836 | unregister_blkdev(MAJOR_NR, "ubd"); | |
837 | return -1; | |
838 | } | |
839 | ||
840 | if (fake_major != MAJOR_NR) { | |
841 | char name[sizeof("ubd_nnn\0")]; | |
842 | ||
843 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
1da177e4 LT |
844 | if (register_blkdev(fake_major, "ubd")) |
845 | return -1; | |
846 | } | |
3ae5eaec | 847 | platform_driver_register(&ubd_driver); |
6c29256c | 848 | for (i = 0; i < MAX_DEV; i++) |
1da177e4 LT |
849 | ubd_add(i); |
850 | return 0; | |
851 | } | |
852 | ||
853 | late_initcall(ubd_init); | |
854 | ||
91acb21f JD |
855 | int ubd_driver_init(void){ |
856 | unsigned long stack; | |
857 | int err; | |
858 | ||
859 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
860 | if(global_openflags.s){ | |
861 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
862 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
863 | * enough. So use anyway the io thread. */ | |
864 | } | |
865 | stack = alloc_stack(0, 0); | |
6c29256c | 866 | io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), |
91acb21f JD |
867 | &thread_fd); |
868 | if(io_pid < 0){ | |
6c29256c | 869 | printk(KERN_ERR |
91acb21f JD |
870 | "ubd : Failed to start I/O thread (errno = %d) - " |
871 | "falling back to synchronous I/O\n", -io_pid); | |
872 | io_pid = -1; | |
873 | return(0); | |
874 | } | |
6c29256c | 875 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, |
bd6aa650 | 876 | IRQF_DISABLED, "ubd", ubd_dev); |
91acb21f JD |
877 | if(err != 0) |
878 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); | |
f4c57a78 | 879 | return 0; |
91acb21f JD |
880 | } |
881 | ||
882 | device_initcall(ubd_driver_init); | |
883 | ||
1da177e4 LT |
884 | static int ubd_open(struct inode *inode, struct file *filp) |
885 | { | |
886 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
887 | struct ubd *dev = disk->private_data; | |
888 | int err = 0; | |
889 | ||
890 | if(dev->count == 0){ | |
891 | err = ubd_open_dev(dev); | |
892 | if(err){ | |
893 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
894 | disk->disk_name, dev->file, -err); | |
895 | goto out; | |
896 | } | |
897 | } | |
898 | dev->count++; | |
2c49be99 PBG |
899 | set_disk_ro(disk, !dev->openflags.w); |
900 | ||
901 | /* This should no more be needed. And it didn't work anyway to exclude | |
902 | * read-write remounting of filesystems.*/ | |
903 | /*if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ | |
1da177e4 LT |
904 | if(--dev->count == 0) ubd_close(dev); |
905 | err = -EROFS; | |
2c49be99 | 906 | }*/ |
1da177e4 LT |
907 | out: |
908 | return(err); | |
909 | } | |
910 | ||
911 | static int ubd_release(struct inode * inode, struct file * file) | |
912 | { | |
913 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
914 | struct ubd *dev = disk->private_data; | |
915 | ||
916 | if(--dev->count == 0) | |
917 | ubd_close(dev); | |
918 | return(0); | |
919 | } | |
920 | ||
91acb21f JD |
921 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, |
922 | __u64 *cow_offset, unsigned long *bitmap, | |
923 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
924 | __u64 bitmap_len) | |
1da177e4 | 925 | { |
91acb21f JD |
926 | __u64 sector = io_offset >> 9; |
927 | int i, update_bitmap = 0; | |
928 | ||
929 | for(i = 0; i < length >> 9; i++){ | |
930 | if(cow_mask != NULL) | |
931 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
932 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
933 | continue; | |
1da177e4 | 934 | |
91acb21f JD |
935 | update_bitmap = 1; |
936 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
937 | } | |
938 | ||
939 | if(!update_bitmap) | |
940 | return; | |
1da177e4 | 941 | |
91acb21f | 942 | *cow_offset = sector / (sizeof(unsigned long) * 8); |
1da177e4 | 943 | |
91acb21f JD |
944 | /* This takes care of the case where we're exactly at the end of the |
945 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
946 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
947 | * for the original diagnosis. | |
948 | */ | |
949 | if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / | |
950 | sizeof(unsigned long) - 1)) | |
951 | (*cow_offset)--; | |
952 | ||
953 | bitmap_words[0] = bitmap[*cow_offset]; | |
954 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
955 | ||
956 | *cow_offset *= sizeof(unsigned long); | |
957 | *cow_offset += bitmap_offset; | |
958 | } | |
959 | ||
960 | static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, | |
961 | __u64 bitmap_offset, __u64 bitmap_len) | |
962 | { | |
963 | __u64 sector = req->offset >> 9; | |
964 | int i; | |
965 | ||
966 | if(req->length > (sizeof(req->sector_mask) * 8) << 9) | |
967 | panic("Operation too long"); | |
968 | ||
969 | if(req->op == UBD_READ) { | |
970 | for(i = 0; i < req->length >> 9; i++){ | |
971 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
6c29256c | 972 | ubd_set_bit(i, (unsigned char *) |
91acb21f JD |
973 | &req->sector_mask); |
974 | } | |
975 | } | |
976 | else cowify_bitmap(req->offset, req->length, &req->sector_mask, | |
977 | &req->cow_offset, bitmap, bitmap_offset, | |
978 | req->bitmap_words, bitmap_len); | |
1da177e4 LT |
979 | } |
980 | ||
1da177e4 | 981 | /* Called with ubd_io_lock held */ |
91acb21f | 982 | static int prepare_request(struct request *req, struct io_thread_req *io_req) |
1da177e4 LT |
983 | { |
984 | struct gendisk *disk = req->rq_disk; | |
985 | struct ubd *dev = disk->private_data; | |
91acb21f JD |
986 | __u64 offset; |
987 | int len; | |
988 | ||
989 | if(req->rq_status == RQ_INACTIVE) return(1); | |
1da177e4 | 990 | |
2c49be99 | 991 | /* This should be impossible now */ |
1da177e4 | 992 | if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ |
6c29256c | 993 | printk("Write attempted on readonly ubd device %s\n", |
1da177e4 | 994 | disk->disk_name); |
91acb21f | 995 | end_request(req, 0); |
1da177e4 LT |
996 | return(1); |
997 | } | |
998 | ||
91acb21f JD |
999 | offset = ((__u64) req->sector) << 9; |
1000 | len = req->current_nr_sectors << 9; | |
1001 | ||
1da177e4 LT |
1002 | io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; |
1003 | io_req->fds[1] = dev->fd; | |
91acb21f | 1004 | io_req->cow_offset = -1; |
1da177e4 LT |
1005 | io_req->offset = offset; |
1006 | io_req->length = len; | |
1007 | io_req->error = 0; | |
91acb21f JD |
1008 | io_req->sector_mask = 0; |
1009 | ||
1010 | io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; | |
1da177e4 LT |
1011 | io_req->offsets[0] = 0; |
1012 | io_req->offsets[1] = dev->cow.data_offset; | |
91acb21f | 1013 | io_req->buffer = req->buffer; |
1da177e4 LT |
1014 | io_req->sectorsize = 1 << 9; |
1015 | ||
91acb21f JD |
1016 | if(dev->cow.file != NULL) |
1017 | cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, | |
1018 | dev->cow.bitmap_len); | |
1019 | ||
1da177e4 LT |
1020 | return(0); |
1021 | } | |
1022 | ||
1023 | /* Called with ubd_io_lock held */ | |
1024 | static void do_ubd_request(request_queue_t *q) | |
1025 | { | |
1026 | struct io_thread_req io_req; | |
1027 | struct request *req; | |
91acb21f JD |
1028 | int err, n; |
1029 | ||
1030 | if(thread_fd == -1){ | |
1031 | while((req = elv_next_request(q)) != NULL){ | |
1032 | err = prepare_request(req, &io_req); | |
1033 | if(!err){ | |
1034 | do_io(&io_req); | |
1035 | __ubd_finish(req, io_req.error); | |
1036 | } | |
1037 | } | |
1038 | } | |
1039 | else { | |
1040 | if(do_ubd || (req = elv_next_request(q)) == NULL) | |
1041 | return; | |
1042 | err = prepare_request(req, &io_req); | |
1043 | if(!err){ | |
1044 | do_ubd = ubd_handler; | |
1045 | n = os_write_file(thread_fd, (char *) &io_req, | |
1046 | sizeof(io_req)); | |
1047 | if(n != sizeof(io_req)) | |
1048 | printk("write to io thread failed, " | |
1049 | "errno = %d\n", -n); | |
1da177e4 LT |
1050 | } |
1051 | } | |
1052 | } | |
1053 | ||
a885c8c4 CH |
1054 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1055 | { | |
1056 | struct ubd *dev = bdev->bd_disk->private_data; | |
1057 | ||
1058 | geo->heads = 128; | |
1059 | geo->sectors = 32; | |
1060 | geo->cylinders = dev->size / (128 * 32 * 512); | |
1061 | return 0; | |
1062 | } | |
1063 | ||
1da177e4 LT |
1064 | static int ubd_ioctl(struct inode * inode, struct file * file, |
1065 | unsigned int cmd, unsigned long arg) | |
1066 | { | |
1da177e4 LT |
1067 | struct ubd *dev = inode->i_bdev->bd_disk->private_data; |
1068 | struct hd_driveid ubd_id = { | |
1069 | .cyls = 0, | |
1070 | .heads = 128, | |
1071 | .sectors = 32, | |
1072 | }; | |
1073 | ||
1074 | switch (cmd) { | |
1da177e4 | 1075 | struct cdrom_volctrl volume; |
1da177e4 LT |
1076 | case HDIO_GET_IDENTITY: |
1077 | ubd_id.cyls = dev->size / (128 * 32 * 512); | |
1078 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, | |
1079 | sizeof(ubd_id))) | |
1080 | return(-EFAULT); | |
1081 | return(0); | |
1082 | ||
1083 | case CDROMVOLREAD: | |
1084 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
1085 | return(-EFAULT); | |
1086 | volume.channel0 = 255; | |
1087 | volume.channel1 = 255; | |
1088 | volume.channel2 = 255; | |
1089 | volume.channel3 = 255; | |
1090 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
1091 | return(-EFAULT); | |
1092 | return(0); | |
1093 | } | |
1094 | return(-EINVAL); | |
1095 | } | |
1096 | ||
4833aff7 | 1097 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) |
1da177e4 LT |
1098 | { |
1099 | struct uml_stat buf1, buf2; | |
1100 | int err; | |
1101 | ||
4833aff7 PBG |
1102 | if(from_cmdline == NULL) |
1103 | return 0; | |
1104 | if(!strcmp(from_cmdline, from_cow)) | |
1105 | return 0; | |
1da177e4 LT |
1106 | |
1107 | err = os_stat_file(from_cmdline, &buf1); | |
1108 | if(err < 0){ | |
1109 | printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); | |
4833aff7 | 1110 | return 0; |
1da177e4 LT |
1111 | } |
1112 | err = os_stat_file(from_cow, &buf2); | |
1113 | if(err < 0){ | |
1114 | printk("Couldn't stat '%s', err = %d\n", from_cow, -err); | |
4833aff7 | 1115 | return 1; |
1da177e4 LT |
1116 | } |
1117 | if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
4833aff7 | 1118 | return 0; |
1da177e4 LT |
1119 | |
1120 | printk("Backing file mismatch - \"%s\" requested,\n" | |
1121 | "\"%s\" specified in COW header of \"%s\"\n", | |
1122 | from_cmdline, from_cow, cow); | |
4833aff7 | 1123 | return 1; |
1da177e4 LT |
1124 | } |
1125 | ||
1126 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
1127 | { | |
1128 | unsigned long modtime; | |
fe1db50c | 1129 | unsigned long long actual; |
1da177e4 LT |
1130 | int err; |
1131 | ||
1132 | err = os_file_modtime(file, &modtime); | |
1133 | if(err < 0){ | |
1134 | printk("Failed to get modification time of backing file " | |
1135 | "\"%s\", err = %d\n", file, -err); | |
1136 | return(err); | |
1137 | } | |
1138 | ||
1139 | err = os_file_size(file, &actual); | |
1140 | if(err < 0){ | |
1141 | printk("Failed to get size of backing file \"%s\", " | |
1142 | "err = %d\n", file, -err); | |
1143 | return(err); | |
1144 | } | |
1145 | ||
1146 | if(actual != size){ | |
1147 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
1148 | * the typecast.*/ | |
1149 | printk("Size mismatch (%llu vs %llu) of COW header vs backing " | |
1150 | "file\n", (unsigned long long) size, actual); | |
1151 | return(-EINVAL); | |
1152 | } | |
1153 | if(modtime != mtime){ | |
1154 | printk("mtime mismatch (%ld vs %ld) of COW header vs backing " | |
1155 | "file\n", mtime, modtime); | |
1156 | return(-EINVAL); | |
1157 | } | |
1158 | return(0); | |
1159 | } | |
1160 | ||
1161 | int read_cow_bitmap(int fd, void *buf, int offset, int len) | |
1162 | { | |
1163 | int err; | |
1164 | ||
1165 | err = os_seek_file(fd, offset); | |
1166 | if(err < 0) | |
1167 | return(err); | |
1168 | ||
1169 | err = os_read_file(fd, buf, len); | |
1170 | if(err < 0) | |
1171 | return(err); | |
1172 | ||
1173 | return(0); | |
1174 | } | |
1175 | ||
6c29256c | 1176 | int open_ubd_file(char *file, struct openflags *openflags, int shared, |
1da177e4 LT |
1177 | char **backing_file_out, int *bitmap_offset_out, |
1178 | unsigned long *bitmap_len_out, int *data_offset_out, | |
1179 | int *create_cow_out) | |
1180 | { | |
1181 | time_t mtime; | |
1182 | unsigned long long size; | |
1183 | __u32 version, align; | |
1184 | char *backing_file; | |
4833aff7 | 1185 | int fd, err, sectorsize, asked_switch, mode = 0644; |
1da177e4 LT |
1186 | |
1187 | fd = os_open_file(file, *openflags, mode); | |
a374a48f PBG |
1188 | if (fd < 0) { |
1189 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
1da177e4 | 1190 | *create_cow_out = 1; |
a374a48f PBG |
1191 | if (!openflags->w || |
1192 | ((fd != -EROFS) && (fd != -EACCES))) | |
1193 | return fd; | |
1da177e4 LT |
1194 | openflags->w = 0; |
1195 | fd = os_open_file(file, *openflags, mode); | |
a374a48f PBG |
1196 | if (fd < 0) |
1197 | return fd; | |
1da177e4 LT |
1198 | } |
1199 | ||
6c29256c JD |
1200 | if(shared) |
1201 | printk("Not locking \"%s\" on the host\n", file); | |
1202 | else { | |
1203 | err = os_lock_file(fd, openflags->w); | |
1204 | if(err < 0){ | |
1205 | printk("Failed to lock '%s', err = %d\n", file, -err); | |
1206 | goto out_close; | |
1207 | } | |
1da177e4 LT |
1208 | } |
1209 | ||
d6e05edc | 1210 | /* Successful return case! */ |
a374a48f PBG |
1211 | if(backing_file_out == NULL) |
1212 | return(fd); | |
1da177e4 LT |
1213 | |
1214 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
1215 | &size, §orsize, &align, bitmap_offset_out); | |
1216 | if(err && (*backing_file_out != NULL)){ | |
1217 | printk("Failed to read COW header from COW file \"%s\", " | |
1218 | "errno = %d\n", file, -err); | |
1219 | goto out_close; | |
1220 | } | |
a374a48f PBG |
1221 | if(err) |
1222 | return(fd); | |
1da177e4 | 1223 | |
4833aff7 | 1224 | asked_switch = path_requires_switch(*backing_file_out, backing_file, file); |
1da177e4 | 1225 | |
4833aff7 PBG |
1226 | /* Allow switching only if no mismatch. */ |
1227 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { | |
1da177e4 LT |
1228 | printk("Switching backing file to '%s'\n", *backing_file_out); |
1229 | err = write_cow_header(file, fd, *backing_file_out, | |
1230 | sectorsize, align, &size); | |
a374a48f | 1231 | if (err) { |
1da177e4 | 1232 | printk("Switch failed, errno = %d\n", -err); |
4833aff7 | 1233 | goto out_close; |
1da177e4 | 1234 | } |
a374a48f | 1235 | } else { |
1da177e4 LT |
1236 | *backing_file_out = backing_file; |
1237 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
a374a48f PBG |
1238 | if (err) |
1239 | goto out_close; | |
1da177e4 LT |
1240 | } |
1241 | ||
1242 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
1243 | bitmap_len_out, data_offset_out); | |
1244 | ||
a374a48f | 1245 | return fd; |
1da177e4 LT |
1246 | out_close: |
1247 | os_close_file(fd); | |
a374a48f | 1248 | return err; |
1da177e4 LT |
1249 | } |
1250 | ||
1251 | int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, | |
1252 | int sectorsize, int alignment, int *bitmap_offset_out, | |
1253 | unsigned long *bitmap_len_out, int *data_offset_out) | |
1254 | { | |
1255 | int err, fd; | |
1256 | ||
1257 | flags.c = 1; | |
6c29256c | 1258 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); |
1da177e4 LT |
1259 | if(fd < 0){ |
1260 | err = fd; | |
1261 | printk("Open of COW file '%s' failed, errno = %d\n", cow_file, | |
1262 | -err); | |
1263 | goto out; | |
1264 | } | |
1265 | ||
1266 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
1267 | bitmap_offset_out, bitmap_len_out, | |
1268 | data_offset_out); | |
1269 | if(!err) | |
1270 | return(fd); | |
1271 | os_close_file(fd); | |
1272 | out: | |
1273 | return(err); | |
1274 | } | |
1275 | ||
91acb21f | 1276 | static int update_bitmap(struct io_thread_req *req) |
1da177e4 | 1277 | { |
91acb21f | 1278 | int n; |
1da177e4 | 1279 | |
91acb21f JD |
1280 | if(req->cow_offset == -1) |
1281 | return(0); | |
1da177e4 | 1282 | |
91acb21f JD |
1283 | n = os_seek_file(req->fds[1], req->cow_offset); |
1284 | if(n < 0){ | |
1285 | printk("do_io - bitmap lseek failed : err = %d\n", -n); | |
1286 | return(1); | |
1287 | } | |
1da177e4 | 1288 | |
91acb21f JD |
1289 | n = os_write_file(req->fds[1], &req->bitmap_words, |
1290 | sizeof(req->bitmap_words)); | |
1291 | if(n != sizeof(req->bitmap_words)){ | |
1292 | printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, | |
1293 | req->fds[1]); | |
1294 | return(1); | |
1295 | } | |
1da177e4 | 1296 | |
91acb21f JD |
1297 | return(0); |
1298 | } | |
1da177e4 | 1299 | |
91acb21f JD |
1300 | void do_io(struct io_thread_req *req) |
1301 | { | |
1302 | char *buf; | |
1303 | unsigned long len; | |
1304 | int n, nsectors, start, end, bit; | |
1305 | int err; | |
1306 | __u64 off; | |
1307 | ||
1308 | nsectors = req->length / req->sectorsize; | |
1309 | start = 0; | |
1310 | do { | |
1311 | bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); | |
1312 | end = start; | |
1313 | while((end < nsectors) && | |
1314 | (ubd_test_bit(end, (unsigned char *) | |
1315 | &req->sector_mask) == bit)) | |
1316 | end++; | |
1317 | ||
1318 | off = req->offset + req->offsets[bit] + | |
1319 | start * req->sectorsize; | |
1320 | len = (end - start) * req->sectorsize; | |
1321 | buf = &req->buffer[start * req->sectorsize]; | |
1322 | ||
1323 | err = os_seek_file(req->fds[bit], off); | |
1324 | if(err < 0){ | |
1325 | printk("do_io - lseek failed : err = %d\n", -err); | |
1326 | req->error = 1; | |
1327 | return; | |
1328 | } | |
1329 | if(req->op == UBD_READ){ | |
1330 | n = 0; | |
1331 | do { | |
1332 | buf = &buf[n]; | |
1333 | len -= n; | |
1334 | n = os_read_file(req->fds[bit], buf, len); | |
1335 | if (n < 0) { | |
1336 | printk("do_io - read failed, err = %d " | |
1337 | "fd = %d\n", -n, req->fds[bit]); | |
1338 | req->error = 1; | |
1339 | return; | |
1340 | } | |
1341 | } while((n < len) && (n != 0)); | |
1342 | if (n < len) memset(&buf[n], 0, len - n); | |
1343 | } else { | |
1344 | n = os_write_file(req->fds[bit], buf, len); | |
1345 | if(n != len){ | |
1346 | printk("do_io - write failed err = %d " | |
1347 | "fd = %d\n", -n, req->fds[bit]); | |
1348 | req->error = 1; | |
1349 | return; | |
1350 | } | |
1351 | } | |
1352 | ||
1353 | start = end; | |
1354 | } while(start < nsectors); | |
1da177e4 | 1355 | |
91acb21f | 1356 | req->error = update_bitmap(req); |
1da177e4 | 1357 | } |
91acb21f JD |
1358 | |
1359 | /* Changed in start_io_thread, which is serialized by being called only | |
1360 | * from ubd_init, which is an initcall. | |
1361 | */ | |
1362 | int kernel_fd = -1; | |
1363 | ||
1364 | /* Only changed by the io thread */ | |
1365 | int io_count = 0; | |
1366 | ||
1367 | int io_thread(void *arg) | |
1368 | { | |
1369 | struct io_thread_req req; | |
1370 | int n; | |
1371 | ||
1372 | ignore_sigwinch_sig(); | |
1373 | while(1){ | |
1374 | n = os_read_file(kernel_fd, &req, sizeof(req)); | |
1375 | if(n != sizeof(req)){ | |
1376 | if(n < 0) | |
1377 | printk("io_thread - read failed, fd = %d, " | |
1378 | "err = %d\n", kernel_fd, -n); | |
1379 | else { | |
1380 | printk("io_thread - short read, fd = %d, " | |
1381 | "length = %d\n", kernel_fd, n); | |
1382 | } | |
1383 | continue; | |
1384 | } | |
1385 | io_count++; | |
1386 | do_io(&req); | |
1387 | n = os_write_file(kernel_fd, &req, sizeof(req)); | |
1388 | if(n != sizeof(req)) | |
1389 | printk("io_thread - write failed, fd = %d, err = %d\n", | |
1390 | kernel_fd, -n); | |
1391 | } | |
91acb21f | 1392 | |
1b57e9c2 JD |
1393 | return 0; |
1394 | } |