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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 | ||
1da177e4 LT |
23 | #include "linux/module.h" |
24 | #include "linux/blkdev.h" | |
25 | #include "linux/hdreg.h" | |
26 | #include "linux/init.h" | |
1da177e4 LT |
27 | #include "linux/cdrom.h" |
28 | #include "linux/proc_fs.h" | |
29 | #include "linux/ctype.h" | |
30 | #include "linux/capability.h" | |
31 | #include "linux/mm.h" | |
32 | #include "linux/vmalloc.h" | |
33 | #include "linux/blkpg.h" | |
34 | #include "linux/genhd.h" | |
35 | #include "linux/spinlock.h" | |
d052d1be | 36 | #include "linux/platform_device.h" |
1da177e4 LT |
37 | #include "asm/segment.h" |
38 | #include "asm/uaccess.h" | |
39 | #include "asm/irq.h" | |
40 | #include "asm/types.h" | |
41 | #include "asm/tlbflush.h" | |
42 | #include "user_util.h" | |
43 | #include "mem_user.h" | |
44 | #include "kern_util.h" | |
45 | #include "kern.h" | |
46 | #include "mconsole_kern.h" | |
47 | #include "init.h" | |
48 | #include "irq_user.h" | |
49 | #include "irq_kern.h" | |
50 | #include "ubd_user.h" | |
1da177e4 LT |
51 | #include "os.h" |
52 | #include "mem.h" | |
53 | #include "mem_kern.h" | |
54 | #include "cow.h" | |
55 | ||
7b9014c1 | 56 | enum ubd_req { UBD_READ, UBD_WRITE }; |
1da177e4 LT |
57 | |
58 | struct io_thread_req { | |
91acb21f | 59 | enum ubd_req op; |
1da177e4 LT |
60 | int fds[2]; |
61 | unsigned long offsets[2]; | |
62 | unsigned long long offset; | |
63 | unsigned long length; | |
64 | char *buffer; | |
65 | int sectorsize; | |
91acb21f JD |
66 | unsigned long sector_mask; |
67 | unsigned long long cow_offset; | |
68 | unsigned long bitmap_words[2]; | |
1da177e4 LT |
69 | int error; |
70 | }; | |
71 | ||
6c29256c | 72 | extern int open_ubd_file(char *file, struct openflags *openflags, int shared, |
1da177e4 LT |
73 | char **backing_file_out, int *bitmap_offset_out, |
74 | unsigned long *bitmap_len_out, int *data_offset_out, | |
75 | int *create_cow_out); | |
76 | extern int create_cow_file(char *cow_file, char *backing_file, | |
77 | struct openflags flags, int sectorsize, | |
78 | int alignment, int *bitmap_offset_out, | |
79 | unsigned long *bitmap_len_out, | |
80 | int *data_offset_out); | |
81 | extern int read_cow_bitmap(int fd, void *buf, int offset, int len); | |
91acb21f | 82 | extern void do_io(struct io_thread_req *req); |
1da177e4 | 83 | |
91acb21f | 84 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
85 | { |
86 | __u64 n; | |
87 | int bits, off; | |
88 | ||
91acb21f | 89 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
90 | n = bit / bits; |
91 | off = bit % bits; | |
91acb21f | 92 | return((data[n] & (1 << off)) != 0); |
1da177e4 LT |
93 | } |
94 | ||
91acb21f | 95 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
96 | { |
97 | __u64 n; | |
98 | int bits, off; | |
99 | ||
91acb21f | 100 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
101 | n = bit / bits; |
102 | off = bit % bits; | |
91acb21f | 103 | data[n] |= (1 << off); |
1da177e4 LT |
104 | } |
105 | /*End stuff from ubd_user.h*/ | |
106 | ||
107 | #define DRIVER_NAME "uml-blkdev" | |
108 | ||
33f775ee PBG |
109 | /* Can be taken in interrupt context, and is passed to the block layer to lock |
110 | * the request queue. Kernel side code knows that. */ | |
1da177e4 | 111 | static DEFINE_SPINLOCK(ubd_io_lock); |
d7fb2c38 PBG |
112 | |
113 | static DEFINE_MUTEX(ubd_lock); | |
1da177e4 | 114 | |
2fe30a34 PBG |
115 | /* XXX - this made sense in 2.4 days, now it's only used as a boolean, and |
116 | * probably it doesn't make sense even for that. */ | |
117 | static int do_ubd; | |
91acb21f | 118 | |
1da177e4 LT |
119 | static int ubd_open(struct inode * inode, struct file * filp); |
120 | static int ubd_release(struct inode * inode, struct file * file); | |
121 | static int ubd_ioctl(struct inode * inode, struct file * file, | |
122 | unsigned int cmd, unsigned long arg); | |
a885c8c4 | 123 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
1da177e4 | 124 | |
97d88ac8 | 125 | #define MAX_DEV (16) |
1da177e4 | 126 | |
1da177e4 LT |
127 | static struct block_device_operations ubd_blops = { |
128 | .owner = THIS_MODULE, | |
129 | .open = ubd_open, | |
130 | .release = ubd_release, | |
131 | .ioctl = ubd_ioctl, | |
a885c8c4 | 132 | .getgeo = ubd_getgeo, |
1da177e4 LT |
133 | }; |
134 | ||
135 | /* Protected by the queue_lock */ | |
136 | static request_queue_t *ubd_queue; | |
137 | ||
138 | /* Protected by ubd_lock */ | |
139 | static int fake_major = MAJOR_NR; | |
140 | ||
141 | static struct gendisk *ubd_gendisk[MAX_DEV]; | |
142 | static struct gendisk *fake_gendisk[MAX_DEV]; | |
6c29256c | 143 | |
1da177e4 LT |
144 | #ifdef CONFIG_BLK_DEV_UBD_SYNC |
145 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
146 | .cl = 1 }) | |
147 | #else | |
148 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
149 | .cl = 1 }) | |
150 | #endif | |
151 | ||
152 | /* Not protected - changed only in ubd_setup_common and then only to | |
153 | * to enable O_SYNC. | |
154 | */ | |
155 | static struct openflags global_openflags = OPEN_FLAGS; | |
156 | ||
157 | struct cow { | |
2a9d32f6 | 158 | /* backing file name */ |
1da177e4 | 159 | char *file; |
2a9d32f6 | 160 | /* backing file fd */ |
1da177e4 LT |
161 | int fd; |
162 | unsigned long *bitmap; | |
163 | unsigned long bitmap_len; | |
164 | int bitmap_offset; | |
165 | int data_offset; | |
166 | }; | |
167 | ||
168 | struct ubd { | |
2a9d32f6 PBG |
169 | /* name (and fd, below) of the file opened for writing, either the |
170 | * backing or the cow file. */ | |
1da177e4 LT |
171 | char *file; |
172 | int count; | |
173 | int fd; | |
174 | __u64 size; | |
175 | struct openflags boot_openflags; | |
176 | struct openflags openflags; | |
84e945e3 PBG |
177 | unsigned shared:1; |
178 | unsigned no_cow:1; | |
1da177e4 LT |
179 | struct cow cow; |
180 | struct platform_device pdev; | |
1da177e4 LT |
181 | }; |
182 | ||
183 | #define DEFAULT_COW { \ | |
184 | .file = NULL, \ | |
185 | .fd = -1, \ | |
186 | .bitmap = NULL, \ | |
187 | .bitmap_offset = 0, \ | |
188 | .data_offset = 0, \ | |
189 | } | |
190 | ||
191 | #define DEFAULT_UBD { \ | |
192 | .file = NULL, \ | |
193 | .count = 0, \ | |
194 | .fd = -1, \ | |
195 | .size = -1, \ | |
196 | .boot_openflags = OPEN_FLAGS, \ | |
197 | .openflags = OPEN_FLAGS, \ | |
198 | .no_cow = 0, \ | |
6c29256c | 199 | .shared = 0, \ |
1da177e4 | 200 | .cow = DEFAULT_COW, \ |
1da177e4 LT |
201 | } |
202 | ||
7d314e34 | 203 | struct ubd ubd_devs[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; |
1da177e4 | 204 | |
1da177e4 LT |
205 | /* Only changed by fake_ide_setup which is a setup */ |
206 | static int fake_ide = 0; | |
207 | static struct proc_dir_entry *proc_ide_root = NULL; | |
208 | static struct proc_dir_entry *proc_ide = NULL; | |
209 | ||
210 | static void make_proc_ide(void) | |
211 | { | |
212 | proc_ide_root = proc_mkdir("ide", NULL); | |
213 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
214 | } | |
215 | ||
216 | static int proc_ide_read_media(char *page, char **start, off_t off, int count, | |
217 | int *eof, void *data) | |
218 | { | |
219 | int len; | |
220 | ||
221 | strcpy(page, "disk\n"); | |
222 | len = strlen("disk\n"); | |
223 | len -= off; | |
224 | if (len < count){ | |
225 | *eof = 1; | |
226 | if (len <= 0) return 0; | |
227 | } | |
228 | else len = count; | |
229 | *start = page + off; | |
230 | return len; | |
231 | } | |
232 | ||
233 | static void make_ide_entries(char *dev_name) | |
234 | { | |
235 | struct proc_dir_entry *dir, *ent; | |
236 | char name[64]; | |
237 | ||
238 | if(proc_ide_root == NULL) make_proc_ide(); | |
239 | ||
240 | dir = proc_mkdir(dev_name, proc_ide); | |
241 | if(!dir) return; | |
242 | ||
243 | ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); | |
244 | if(!ent) return; | |
245 | ent->nlink = 1; | |
246 | ent->data = NULL; | |
247 | ent->read_proc = proc_ide_read_media; | |
248 | ent->write_proc = NULL; | |
249 | sprintf(name,"ide0/%s", dev_name); | |
250 | proc_symlink(dev_name, proc_ide_root, name); | |
251 | } | |
252 | ||
253 | static int fake_ide_setup(char *str) | |
254 | { | |
255 | fake_ide = 1; | |
256 | return(1); | |
257 | } | |
258 | ||
259 | __setup("fake_ide", fake_ide_setup); | |
260 | ||
261 | __uml_help(fake_ide_setup, | |
262 | "fake_ide\n" | |
263 | " Create ide0 entries that map onto ubd devices.\n\n" | |
264 | ); | |
265 | ||
266 | static int parse_unit(char **ptr) | |
267 | { | |
268 | char *str = *ptr, *end; | |
269 | int n = -1; | |
270 | ||
271 | if(isdigit(*str)) { | |
272 | n = simple_strtoul(str, &end, 0); | |
273 | if(end == str) | |
274 | return(-1); | |
275 | *ptr = end; | |
276 | } | |
97d88ac8 | 277 | else if (('a' <= *str) && (*str <= 'z')) { |
1da177e4 LT |
278 | n = *str - 'a'; |
279 | str++; | |
280 | *ptr = str; | |
281 | } | |
282 | return(n); | |
283 | } | |
284 | ||
d8d7c28e PBG |
285 | /* If *index_out == -1 at exit, the passed option was a general one; |
286 | * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it | |
287 | * should not be freed on exit. | |
288 | */ | |
f28169d2 | 289 | static int ubd_setup_common(char *str, int *index_out, char **error_out) |
1da177e4 | 290 | { |
7d314e34 | 291 | struct ubd *ubd_dev; |
1da177e4 LT |
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); | |
f28169d2 | 305 | return 0; |
1da177e4 LT |
306 | } |
307 | major = simple_strtoul(str, &end, 0); | |
308 | if((*end != '\0') || (end == str)){ | |
f28169d2 JD |
309 | *error_out = "Didn't parse major number"; |
310 | return -EINVAL; | |
1da177e4 LT |
311 | } |
312 | ||
f28169d2 JD |
313 | err = -EINVAL; |
314 | mutex_lock(&ubd_lock); | |
315 | if(fake_major != MAJOR_NR){ | |
316 | *error_out = "Can't assign a fake major twice"; | |
317 | goto out1; | |
318 | } | |
6c29256c | 319 | |
f28169d2 | 320 | fake_major = major; |
1da177e4 LT |
321 | |
322 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
323 | major); | |
f28169d2 JD |
324 | err = 0; |
325 | out1: | |
326 | mutex_unlock(&ubd_lock); | |
327 | return err; | |
1da177e4 LT |
328 | } |
329 | ||
330 | n = parse_unit(&str); | |
331 | if(n < 0){ | |
f28169d2 JD |
332 | *error_out = "Couldn't parse device number"; |
333 | return -EINVAL; | |
1da177e4 LT |
334 | } |
335 | if(n >= MAX_DEV){ | |
f28169d2 JD |
336 | *error_out = "Device number out of range"; |
337 | return 1; | |
1da177e4 LT |
338 | } |
339 | ||
f28169d2 | 340 | err = -EBUSY; |
d7fb2c38 | 341 | mutex_lock(&ubd_lock); |
1da177e4 | 342 | |
7d314e34 PBG |
343 | ubd_dev = &ubd_devs[n]; |
344 | if(ubd_dev->file != NULL){ | |
f28169d2 | 345 | *error_out = "Device is already configured"; |
1da177e4 LT |
346 | goto out; |
347 | } | |
348 | ||
349 | if (index_out) | |
350 | *index_out = n; | |
351 | ||
f28169d2 | 352 | err = -EINVAL; |
6c29256c | 353 | for (i = 0; i < sizeof("rscd="); i++) { |
1da177e4 LT |
354 | switch (*str) { |
355 | case 'r': | |
356 | flags.w = 0; | |
357 | break; | |
358 | case 's': | |
359 | flags.s = 1; | |
360 | break; | |
361 | case 'd': | |
7d314e34 | 362 | ubd_dev->no_cow = 1; |
1da177e4 | 363 | break; |
6c29256c | 364 | case 'c': |
7d314e34 | 365 | ubd_dev->shared = 1; |
6c29256c | 366 | break; |
1da177e4 LT |
367 | case '=': |
368 | str++; | |
369 | goto break_loop; | |
370 | default: | |
f28169d2 JD |
371 | *error_out = "Expected '=' or flag letter " |
372 | "(r, s, c, or d)"; | |
1da177e4 LT |
373 | goto out; |
374 | } | |
375 | str++; | |
376 | } | |
377 | ||
f28169d2 JD |
378 | if (*str == '=') |
379 | *error_out = "Too many flags specified"; | |
380 | else | |
381 | *error_out = "Missing '='"; | |
1da177e4 LT |
382 | goto out; |
383 | ||
384 | break_loop: | |
1da177e4 LT |
385 | backing_file = strchr(str, ','); |
386 | ||
f28169d2 | 387 | if (backing_file == NULL) |
1da177e4 | 388 | backing_file = strchr(str, ':'); |
1da177e4 | 389 | |
f28169d2 JD |
390 | if(backing_file != NULL){ |
391 | if(ubd_dev->no_cow){ | |
392 | *error_out = "Can't specify both 'd' and a cow file"; | |
393 | goto out; | |
394 | } | |
1da177e4 LT |
395 | else { |
396 | *backing_file = '\0'; | |
397 | backing_file++; | |
398 | } | |
399 | } | |
f28169d2 | 400 | err = 0; |
7d314e34 PBG |
401 | ubd_dev->file = str; |
402 | ubd_dev->cow.file = backing_file; | |
403 | ubd_dev->boot_openflags = flags; | |
1da177e4 | 404 | out: |
d7fb2c38 | 405 | mutex_unlock(&ubd_lock); |
f28169d2 | 406 | return err; |
1da177e4 LT |
407 | } |
408 | ||
409 | static int ubd_setup(char *str) | |
410 | { | |
f28169d2 JD |
411 | char *error; |
412 | int err; | |
413 | ||
414 | err = ubd_setup_common(str, NULL, &error); | |
415 | if(err) | |
416 | printk(KERN_ERR "Failed to initialize device with \"%s\" : " | |
417 | "%s\n", str, error); | |
418 | return 1; | |
1da177e4 LT |
419 | } |
420 | ||
421 | __setup("ubd", ubd_setup); | |
422 | __uml_help(ubd_setup, | |
423 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
424 | " This is used to associate a device with a file in the underlying\n" | |
425 | " filesystem. When specifying two filenames, the first one is the\n" | |
426 | " COW name and the second is the backing file name. As separator you can\n" | |
427 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
428 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
429 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
f28169d2 | 430 | " When using only one filename, UML will detect whether to treat it like\n" |
1da177e4 LT |
431 | " a COW file or a backing file. To override this detection, add the 'd'\n" |
432 | " flag:\n" | |
433 | " ubd0d=BackingFile\n" | |
434 | " Usually, there is a filesystem in the file, but \n" | |
435 | " that's not required. Swap devices containing swap files can be\n" | |
436 | " specified like this. Also, a file which doesn't contain a\n" | |
437 | " filesystem can have its contents read in the virtual \n" | |
438 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
439 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
440 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
441 | " an 's' will cause data to be written to disk on the host immediately.\n\n" | |
442 | ); | |
443 | ||
444 | static int udb_setup(char *str) | |
445 | { | |
446 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
447 | "udb TYPO\n", str); | |
448 | return(1); | |
449 | } | |
450 | ||
451 | __setup("udb", udb_setup); | |
452 | __uml_help(udb_setup, | |
453 | "udb\n" | |
0894e27e JD |
454 | " This option is here solely to catch ubd -> udb typos, which can be\n" |
455 | " to impossible to catch visually unless you specifically look for\n" | |
456 | " them. The only result of any option starting with 'udb' is an error\n" | |
1da177e4 LT |
457 | " in the boot output.\n\n" |
458 | ); | |
459 | ||
460 | static int fakehd_set = 0; | |
461 | static int fakehd(char *str) | |
462 | { | |
463 | printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); | |
464 | fakehd_set = 1; | |
465 | return 1; | |
466 | } | |
467 | ||
468 | __setup("fakehd", fakehd); | |
469 | __uml_help(fakehd, | |
470 | "fakehd\n" | |
471 | " Change the ubd device name to \"hd\".\n\n" | |
472 | ); | |
473 | ||
474 | static void do_ubd_request(request_queue_t * q); | |
91acb21f JD |
475 | |
476 | /* Only changed by ubd_init, which is an initcall. */ | |
477 | int thread_fd = -1; | |
1da177e4 LT |
478 | |
479 | /* Changed by ubd_handler, which is serialized because interrupts only | |
480 | * happen on CPU 0. | |
d8d7c28e | 481 | * XXX: currently unused. |
1da177e4 | 482 | */ |
d8d7c28e | 483 | static int intr_count = 0; |
1da177e4 | 484 | |
91acb21f JD |
485 | /* call ubd_finish if you need to serialize */ |
486 | static void __ubd_finish(struct request *req, int error) | |
1da177e4 | 487 | { |
91acb21f JD |
488 | int nsect; |
489 | ||
490 | if(error){ | |
491 | end_request(req, 0); | |
492 | return; | |
1da177e4 | 493 | } |
91acb21f JD |
494 | nsect = req->current_nr_sectors; |
495 | req->sector += nsect; | |
496 | req->buffer += nsect << 9; | |
497 | req->errors = 0; | |
498 | req->nr_sectors -= nsect; | |
499 | req->current_nr_sectors = 0; | |
500 | end_request(req, 1); | |
1da177e4 LT |
501 | } |
502 | ||
33f775ee PBG |
503 | /* Callable only from interrupt context - otherwise you need to do |
504 | * spin_lock_irq()/spin_lock_irqsave() */ | |
91acb21f | 505 | static inline void ubd_finish(struct request *req, int error) |
1da177e4 | 506 | { |
91acb21f JD |
507 | spin_lock(&ubd_io_lock); |
508 | __ubd_finish(req, error); | |
509 | spin_unlock(&ubd_io_lock); | |
1da177e4 LT |
510 | } |
511 | ||
2fe30a34 | 512 | /* XXX - move this inside ubd_intr. */ |
33f775ee | 513 | /* Called without ubd_io_lock held, and only in interrupt context. */ |
91acb21f | 514 | static void ubd_handler(void) |
1da177e4 | 515 | { |
91acb21f JD |
516 | struct io_thread_req req; |
517 | struct request *rq = elv_next_request(ubd_queue); | |
518 | int n; | |
519 | ||
2fe30a34 | 520 | do_ubd = 0; |
91acb21f JD |
521 | intr_count++; |
522 | n = os_read_file(thread_fd, &req, sizeof(req)); | |
523 | if(n != sizeof(req)){ | |
524 | printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " | |
525 | "err = %d\n", os_getpid(), -n); | |
526 | spin_lock(&ubd_io_lock); | |
527 | end_request(rq, 0); | |
528 | spin_unlock(&ubd_io_lock); | |
529 | return; | |
530 | } | |
6c29256c | 531 | |
91acb21f JD |
532 | ubd_finish(rq, req.error); |
533 | reactivate_fd(thread_fd, UBD_IRQ); | |
33f775ee | 534 | spin_lock(&ubd_io_lock); |
91acb21f | 535 | do_ubd_request(ubd_queue); |
33f775ee | 536 | spin_unlock(&ubd_io_lock); |
1da177e4 LT |
537 | } |
538 | ||
7bea96fd | 539 | static irqreturn_t ubd_intr(int irq, void *dev) |
1da177e4 | 540 | { |
91acb21f JD |
541 | ubd_handler(); |
542 | return(IRQ_HANDLED); | |
543 | } | |
09ace81c | 544 | |
91acb21f JD |
545 | /* Only changed by ubd_init, which is an initcall. */ |
546 | static int io_pid = -1; | |
09ace81c | 547 | |
91acb21f JD |
548 | void kill_io_thread(void) |
549 | { | |
6c29256c | 550 | if(io_pid != -1) |
91acb21f | 551 | os_kill_process(io_pid, 1); |
09ace81c | 552 | } |
1da177e4 | 553 | |
91acb21f JD |
554 | __uml_exitcall(kill_io_thread); |
555 | ||
d8d7c28e | 556 | static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) |
1da177e4 LT |
557 | { |
558 | char *file; | |
559 | ||
7d314e34 | 560 | file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; |
1da177e4 LT |
561 | return(os_file_size(file, size_out)); |
562 | } | |
563 | ||
5f75a4f8 | 564 | static void ubd_close_dev(struct ubd *ubd_dev) |
1da177e4 | 565 | { |
7d314e34 PBG |
566 | os_close_file(ubd_dev->fd); |
567 | if(ubd_dev->cow.file == NULL) | |
1da177e4 LT |
568 | return; |
569 | ||
7d314e34 PBG |
570 | os_close_file(ubd_dev->cow.fd); |
571 | vfree(ubd_dev->cow.bitmap); | |
572 | ubd_dev->cow.bitmap = NULL; | |
1da177e4 LT |
573 | } |
574 | ||
7d314e34 | 575 | static int ubd_open_dev(struct ubd *ubd_dev) |
1da177e4 LT |
576 | { |
577 | struct openflags flags; | |
578 | char **back_ptr; | |
579 | int err, create_cow, *create_ptr; | |
0bf16bff | 580 | int fd; |
1da177e4 | 581 | |
7d314e34 | 582 | ubd_dev->openflags = ubd_dev->boot_openflags; |
1da177e4 | 583 | create_cow = 0; |
7d314e34 PBG |
584 | create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; |
585 | back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; | |
0bf16bff PBG |
586 | |
587 | fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, | |
7d314e34 PBG |
588 | back_ptr, &ubd_dev->cow.bitmap_offset, |
589 | &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, | |
6c29256c | 590 | create_ptr); |
1da177e4 | 591 | |
0bf16bff PBG |
592 | if((fd == -ENOENT) && create_cow){ |
593 | fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, | |
7d314e34 PBG |
594 | ubd_dev->openflags, 1 << 9, PAGE_SIZE, |
595 | &ubd_dev->cow.bitmap_offset, | |
596 | &ubd_dev->cow.bitmap_len, | |
597 | &ubd_dev->cow.data_offset); | |
0bf16bff | 598 | if(fd >= 0){ |
1da177e4 | 599 | printk(KERN_INFO "Creating \"%s\" as COW file for " |
7d314e34 | 600 | "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); |
1da177e4 LT |
601 | } |
602 | } | |
603 | ||
0bf16bff | 604 | if(fd < 0){ |
7d314e34 | 605 | printk("Failed to open '%s', errno = %d\n", ubd_dev->file, |
0bf16bff PBG |
606 | -fd); |
607 | return fd; | |
1da177e4 | 608 | } |
0bf16bff | 609 | ubd_dev->fd = fd; |
1da177e4 | 610 | |
7d314e34 | 611 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 612 | err = -ENOMEM; |
7d314e34 PBG |
613 | ubd_dev->cow.bitmap = (void *) vmalloc(ubd_dev->cow.bitmap_len); |
614 | if(ubd_dev->cow.bitmap == NULL){ | |
1da177e4 LT |
615 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); |
616 | goto error; | |
617 | } | |
618 | flush_tlb_kernel_vm(); | |
619 | ||
7d314e34 PBG |
620 | err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, |
621 | ubd_dev->cow.bitmap_offset, | |
622 | ubd_dev->cow.bitmap_len); | |
1da177e4 LT |
623 | if(err < 0) |
624 | goto error; | |
625 | ||
7d314e34 | 626 | flags = ubd_dev->openflags; |
1da177e4 | 627 | flags.w = 0; |
7d314e34 | 628 | err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, |
6c29256c | 629 | NULL, NULL, NULL, NULL); |
1da177e4 | 630 | if(err < 0) goto error; |
7d314e34 | 631 | ubd_dev->cow.fd = err; |
1da177e4 LT |
632 | } |
633 | return(0); | |
634 | error: | |
7d314e34 | 635 | os_close_file(ubd_dev->fd); |
1da177e4 LT |
636 | return(err); |
637 | } | |
638 | ||
5f75a4f8 | 639 | static int ubd_disk_register(int major, u64 size, int unit, |
1da177e4 LT |
640 | struct gendisk **disk_out) |
641 | ||
642 | { | |
643 | struct gendisk *disk; | |
1da177e4 LT |
644 | |
645 | disk = alloc_disk(1 << UBD_SHIFT); | |
646 | if(disk == NULL) | |
647 | return(-ENOMEM); | |
648 | ||
649 | disk->major = major; | |
650 | disk->first_minor = unit << UBD_SHIFT; | |
651 | disk->fops = &ubd_blops; | |
652 | set_capacity(disk, size / 512); | |
ce7b0f46 | 653 | if(major == MAJOR_NR) |
1da177e4 | 654 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); |
ce7b0f46 | 655 | else |
1da177e4 | 656 | sprintf(disk->disk_name, "ubd_fake%d", unit); |
1da177e4 LT |
657 | |
658 | /* sysfs register (not for ide fake devices) */ | |
659 | if (major == MAJOR_NR) { | |
7d314e34 PBG |
660 | ubd_devs[unit].pdev.id = unit; |
661 | ubd_devs[unit].pdev.name = DRIVER_NAME; | |
662 | platform_device_register(&ubd_devs[unit].pdev); | |
663 | disk->driverfs_dev = &ubd_devs[unit].pdev.dev; | |
1da177e4 LT |
664 | } |
665 | ||
7d314e34 | 666 | disk->private_data = &ubd_devs[unit]; |
1da177e4 LT |
667 | disk->queue = ubd_queue; |
668 | add_disk(disk); | |
669 | ||
670 | *disk_out = disk; | |
671 | return 0; | |
672 | } | |
673 | ||
674 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
675 | ||
f28169d2 | 676 | static int ubd_add(int n, char **error_out) |
1da177e4 | 677 | { |
7d314e34 | 678 | struct ubd *ubd_dev = &ubd_devs[n]; |
f28169d2 | 679 | int err = 0; |
1da177e4 | 680 | |
7d314e34 | 681 | if(ubd_dev->file == NULL) |
ec7cf783 | 682 | goto out; |
1da177e4 | 683 | |
7d314e34 | 684 | err = ubd_file_size(ubd_dev, &ubd_dev->size); |
f28169d2 JD |
685 | if(err < 0){ |
686 | *error_out = "Couldn't determine size of device's file"; | |
80c13749 | 687 | goto out; |
f28169d2 | 688 | } |
1da177e4 | 689 | |
7d314e34 | 690 | ubd_dev->size = ROUND_BLOCK(ubd_dev->size); |
1da177e4 | 691 | |
5f75a4f8 | 692 | err = ubd_disk_register(MAJOR_NR, ubd_dev->size, n, &ubd_gendisk[n]); |
6c29256c | 693 | if(err) |
80c13749 | 694 | goto out; |
6c29256c | 695 | |
1da177e4 | 696 | if(fake_major != MAJOR_NR) |
5f75a4f8 | 697 | ubd_disk_register(fake_major, ubd_dev->size, n, |
1da177e4 LT |
698 | &fake_gendisk[n]); |
699 | ||
700 | /* perhaps this should also be under the "if (fake_major)" above */ | |
701 | /* using the fake_disk->disk_name and also the fakehd_set name */ | |
702 | if (fake_ide) | |
703 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
704 | ||
ec7cf783 | 705 | err = 0; |
ec7cf783 JD |
706 | out: |
707 | return err; | |
1da177e4 LT |
708 | } |
709 | ||
f28169d2 | 710 | static int ubd_config(char *str, char **error_out) |
1da177e4 | 711 | { |
e7f6552f | 712 | int n, ret; |
1da177e4 | 713 | |
f28169d2 JD |
714 | /* This string is possibly broken up and stored, so it's only |
715 | * freed if ubd_setup_common fails, or if only general options | |
716 | * were set. | |
717 | */ | |
970d6e3a | 718 | str = kstrdup(str, GFP_KERNEL); |
e7f6552f | 719 | if (str == NULL) { |
f28169d2 JD |
720 | *error_out = "Failed to allocate memory"; |
721 | return -ENOMEM; | |
1da177e4 | 722 | } |
f28169d2 JD |
723 | |
724 | ret = ubd_setup_common(str, &n, error_out); | |
725 | if (ret) | |
e7f6552f | 726 | goto err_free; |
f28169d2 | 727 | |
e7f6552f PBG |
728 | if (n == -1) { |
729 | ret = 0; | |
d8d7c28e | 730 | goto err_free; |
1da177e4 | 731 | } |
1da177e4 | 732 | |
d7fb2c38 | 733 | mutex_lock(&ubd_lock); |
f28169d2 | 734 | ret = ubd_add(n, error_out); |
e7f6552f | 735 | if (ret) |
7d314e34 | 736 | ubd_devs[n].file = NULL; |
d7fb2c38 | 737 | mutex_unlock(&ubd_lock); |
1da177e4 | 738 | |
e7f6552f PBG |
739 | out: |
740 | return ret; | |
741 | ||
742 | err_free: | |
743 | kfree(str); | |
744 | goto out; | |
1da177e4 LT |
745 | } |
746 | ||
747 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
748 | { | |
7d314e34 | 749 | struct ubd *ubd_dev; |
1da177e4 LT |
750 | int n, len = 0; |
751 | ||
752 | n = parse_unit(&name); | |
753 | if((n >= MAX_DEV) || (n < 0)){ | |
754 | *error_out = "ubd_get_config : device number out of range"; | |
755 | return(-1); | |
756 | } | |
757 | ||
7d314e34 | 758 | ubd_dev = &ubd_devs[n]; |
d7fb2c38 | 759 | mutex_lock(&ubd_lock); |
1da177e4 | 760 | |
7d314e34 | 761 | if(ubd_dev->file == NULL){ |
1da177e4 LT |
762 | CONFIG_CHUNK(str, size, len, "", 1); |
763 | goto out; | |
764 | } | |
765 | ||
7d314e34 | 766 | CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); |
1da177e4 | 767 | |
7d314e34 | 768 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 769 | CONFIG_CHUNK(str, size, len, ",", 0); |
7d314e34 | 770 | CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); |
1da177e4 LT |
771 | } |
772 | else CONFIG_CHUNK(str, size, len, "", 1); | |
773 | ||
774 | out: | |
d7fb2c38 | 775 | mutex_unlock(&ubd_lock); |
1da177e4 LT |
776 | return(len); |
777 | } | |
778 | ||
29d56cfe JD |
779 | static int ubd_id(char **str, int *start_out, int *end_out) |
780 | { | |
781 | int n; | |
782 | ||
783 | n = parse_unit(str); | |
784 | *start_out = 0; | |
785 | *end_out = MAX_DEV - 1; | |
786 | return n; | |
787 | } | |
788 | ||
f28169d2 | 789 | static int ubd_remove(int n, char **error_out) |
1da177e4 | 790 | { |
7d314e34 | 791 | struct ubd *ubd_dev; |
29d56cfe | 792 | int err = -ENODEV; |
1da177e4 | 793 | |
d7fb2c38 | 794 | mutex_lock(&ubd_lock); |
1da177e4 | 795 | |
29d56cfe JD |
796 | if(ubd_gendisk[n] == NULL) |
797 | goto out; | |
1da177e4 | 798 | |
7d314e34 | 799 | ubd_dev = &ubd_devs[n]; |
1da177e4 | 800 | |
7d314e34 | 801 | if(ubd_dev->file == NULL) |
29d56cfe | 802 | goto out; |
1da177e4 | 803 | |
29d56cfe JD |
804 | /* you cannot remove a open disk */ |
805 | err = -EBUSY; | |
7d314e34 | 806 | if(ubd_dev->count > 0) |
1da177e4 LT |
807 | goto out; |
808 | ||
809 | del_gendisk(ubd_gendisk[n]); | |
810 | put_disk(ubd_gendisk[n]); | |
811 | ubd_gendisk[n] = NULL; | |
812 | ||
813 | if(fake_gendisk[n] != NULL){ | |
814 | del_gendisk(fake_gendisk[n]); | |
815 | put_disk(fake_gendisk[n]); | |
816 | fake_gendisk[n] = NULL; | |
817 | } | |
818 | ||
7d314e34 PBG |
819 | platform_device_unregister(&ubd_dev->pdev); |
820 | *ubd_dev = ((struct ubd) DEFAULT_UBD); | |
1da177e4 | 821 | err = 0; |
29d56cfe | 822 | out: |
d7fb2c38 | 823 | mutex_unlock(&ubd_lock); |
29d56cfe | 824 | return err; |
1da177e4 LT |
825 | } |
826 | ||
f28169d2 JD |
827 | /* All these are called by mconsole in process context and without |
828 | * ubd-specific locks. | |
829 | */ | |
1da177e4 LT |
830 | static struct mc_device ubd_mc = { |
831 | .name = "ubd", | |
832 | .config = ubd_config, | |
833 | .get_config = ubd_get_config, | |
29d56cfe | 834 | .id = ubd_id, |
1da177e4 LT |
835 | .remove = ubd_remove, |
836 | }; | |
837 | ||
d8d7c28e | 838 | static int __init ubd_mc_init(void) |
1da177e4 LT |
839 | { |
840 | mconsole_register_dev(&ubd_mc); | |
841 | return 0; | |
842 | } | |
843 | ||
844 | __initcall(ubd_mc_init); | |
845 | ||
d8d7c28e PBG |
846 | static int __init ubd0_init(void) |
847 | { | |
848 | struct ubd *ubd_dev = &ubd_devs[0]; | |
849 | ||
850 | if(ubd_dev->file == NULL) | |
851 | ubd_dev->file = "root_fs"; | |
852 | return(0); | |
853 | } | |
854 | ||
855 | __initcall(ubd0_init); | |
856 | ||
3ae5eaec RK |
857 | static struct platform_driver ubd_driver = { |
858 | .driver = { | |
859 | .name = DRIVER_NAME, | |
860 | }, | |
1da177e4 LT |
861 | }; |
862 | ||
d8d7c28e | 863 | static int __init ubd_init(void) |
1da177e4 | 864 | { |
f28169d2 JD |
865 | char *error; |
866 | int i, err; | |
1da177e4 | 867 | |
1da177e4 LT |
868 | if (register_blkdev(MAJOR_NR, "ubd")) |
869 | return -1; | |
870 | ||
871 | ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock); | |
872 | if (!ubd_queue) { | |
873 | unregister_blkdev(MAJOR_NR, "ubd"); | |
874 | return -1; | |
875 | } | |
876 | ||
877 | if (fake_major != MAJOR_NR) { | |
878 | char name[sizeof("ubd_nnn\0")]; | |
879 | ||
880 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
1da177e4 LT |
881 | if (register_blkdev(fake_major, "ubd")) |
882 | return -1; | |
883 | } | |
3ae5eaec | 884 | platform_driver_register(&ubd_driver); |
f28169d2 JD |
885 | for (i = 0; i < MAX_DEV; i++){ |
886 | err = ubd_add(i, &error); | |
887 | if(err) | |
888 | printk(KERN_ERR "Failed to initialize ubd device %d :" | |
889 | "%s\n", i, error); | |
890 | } | |
1da177e4 LT |
891 | return 0; |
892 | } | |
893 | ||
894 | late_initcall(ubd_init); | |
895 | ||
d8d7c28e | 896 | static int __init ubd_driver_init(void){ |
91acb21f JD |
897 | unsigned long stack; |
898 | int err; | |
899 | ||
900 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
901 | if(global_openflags.s){ | |
902 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
903 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
904 | * enough. So use anyway the io thread. */ | |
905 | } | |
906 | stack = alloc_stack(0, 0); | |
6c29256c | 907 | io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), |
91acb21f JD |
908 | &thread_fd); |
909 | if(io_pid < 0){ | |
6c29256c | 910 | printk(KERN_ERR |
91acb21f JD |
911 | "ubd : Failed to start I/O thread (errno = %d) - " |
912 | "falling back to synchronous I/O\n", -io_pid); | |
913 | io_pid = -1; | |
914 | return(0); | |
915 | } | |
6c29256c | 916 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, |
7d314e34 | 917 | IRQF_DISABLED, "ubd", ubd_devs); |
91acb21f JD |
918 | if(err != 0) |
919 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); | |
f4c57a78 | 920 | return 0; |
91acb21f JD |
921 | } |
922 | ||
923 | device_initcall(ubd_driver_init); | |
924 | ||
1da177e4 LT |
925 | static int ubd_open(struct inode *inode, struct file *filp) |
926 | { | |
927 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
7d314e34 | 928 | struct ubd *ubd_dev = disk->private_data; |
1da177e4 LT |
929 | int err = 0; |
930 | ||
7d314e34 PBG |
931 | if(ubd_dev->count == 0){ |
932 | err = ubd_open_dev(ubd_dev); | |
1da177e4 LT |
933 | if(err){ |
934 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
7d314e34 | 935 | disk->disk_name, ubd_dev->file, -err); |
1da177e4 LT |
936 | goto out; |
937 | } | |
938 | } | |
7d314e34 PBG |
939 | ubd_dev->count++; |
940 | set_disk_ro(disk, !ubd_dev->openflags.w); | |
2c49be99 PBG |
941 | |
942 | /* This should no more be needed. And it didn't work anyway to exclude | |
943 | * read-write remounting of filesystems.*/ | |
7d314e34 | 944 | /*if((filp->f_mode & FMODE_WRITE) && !ubd_dev->openflags.w){ |
5f75a4f8 | 945 | if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); |
1da177e4 | 946 | err = -EROFS; |
2c49be99 | 947 | }*/ |
1da177e4 LT |
948 | out: |
949 | return(err); | |
950 | } | |
951 | ||
952 | static int ubd_release(struct inode * inode, struct file * file) | |
953 | { | |
954 | struct gendisk *disk = inode->i_bdev->bd_disk; | |
7d314e34 | 955 | struct ubd *ubd_dev = disk->private_data; |
1da177e4 | 956 | |
7d314e34 | 957 | if(--ubd_dev->count == 0) |
5f75a4f8 | 958 | ubd_close_dev(ubd_dev); |
1da177e4 LT |
959 | return(0); |
960 | } | |
961 | ||
91acb21f JD |
962 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, |
963 | __u64 *cow_offset, unsigned long *bitmap, | |
964 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
965 | __u64 bitmap_len) | |
1da177e4 | 966 | { |
91acb21f JD |
967 | __u64 sector = io_offset >> 9; |
968 | int i, update_bitmap = 0; | |
969 | ||
970 | for(i = 0; i < length >> 9; i++){ | |
971 | if(cow_mask != NULL) | |
972 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
973 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
974 | continue; | |
1da177e4 | 975 | |
91acb21f JD |
976 | update_bitmap = 1; |
977 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
978 | } | |
979 | ||
980 | if(!update_bitmap) | |
981 | return; | |
1da177e4 | 982 | |
91acb21f | 983 | *cow_offset = sector / (sizeof(unsigned long) * 8); |
1da177e4 | 984 | |
91acb21f JD |
985 | /* This takes care of the case where we're exactly at the end of the |
986 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
987 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
988 | * for the original diagnosis. | |
989 | */ | |
990 | if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / | |
991 | sizeof(unsigned long) - 1)) | |
992 | (*cow_offset)--; | |
993 | ||
994 | bitmap_words[0] = bitmap[*cow_offset]; | |
995 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
996 | ||
997 | *cow_offset *= sizeof(unsigned long); | |
998 | *cow_offset += bitmap_offset; | |
999 | } | |
1000 | ||
1001 | static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, | |
1002 | __u64 bitmap_offset, __u64 bitmap_len) | |
1003 | { | |
1004 | __u64 sector = req->offset >> 9; | |
1005 | int i; | |
1006 | ||
1007 | if(req->length > (sizeof(req->sector_mask) * 8) << 9) | |
1008 | panic("Operation too long"); | |
1009 | ||
1010 | if(req->op == UBD_READ) { | |
1011 | for(i = 0; i < req->length >> 9; i++){ | |
1012 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
6c29256c | 1013 | ubd_set_bit(i, (unsigned char *) |
91acb21f JD |
1014 | &req->sector_mask); |
1015 | } | |
1016 | } | |
1017 | else cowify_bitmap(req->offset, req->length, &req->sector_mask, | |
1018 | &req->cow_offset, bitmap, bitmap_offset, | |
1019 | req->bitmap_words, bitmap_len); | |
1da177e4 LT |
1020 | } |
1021 | ||
1da177e4 | 1022 | /* Called with ubd_io_lock held */ |
91acb21f | 1023 | static int prepare_request(struct request *req, struct io_thread_req *io_req) |
1da177e4 LT |
1024 | { |
1025 | struct gendisk *disk = req->rq_disk; | |
7d314e34 | 1026 | struct ubd *ubd_dev = disk->private_data; |
91acb21f JD |
1027 | __u64 offset; |
1028 | int len; | |
1029 | ||
2c49be99 | 1030 | /* This should be impossible now */ |
7d314e34 | 1031 | if((rq_data_dir(req) == WRITE) && !ubd_dev->openflags.w){ |
6c29256c | 1032 | printk("Write attempted on readonly ubd device %s\n", |
1da177e4 | 1033 | disk->disk_name); |
91acb21f | 1034 | end_request(req, 0); |
1da177e4 LT |
1035 | return(1); |
1036 | } | |
1037 | ||
91acb21f JD |
1038 | offset = ((__u64) req->sector) << 9; |
1039 | len = req->current_nr_sectors << 9; | |
1040 | ||
7d314e34 PBG |
1041 | io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : ubd_dev->fd; |
1042 | io_req->fds[1] = ubd_dev->fd; | |
91acb21f | 1043 | io_req->cow_offset = -1; |
1da177e4 LT |
1044 | io_req->offset = offset; |
1045 | io_req->length = len; | |
1046 | io_req->error = 0; | |
91acb21f JD |
1047 | io_req->sector_mask = 0; |
1048 | ||
1049 | io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; | |
1da177e4 | 1050 | io_req->offsets[0] = 0; |
7d314e34 | 1051 | io_req->offsets[1] = ubd_dev->cow.data_offset; |
91acb21f | 1052 | io_req->buffer = req->buffer; |
1da177e4 LT |
1053 | io_req->sectorsize = 1 << 9; |
1054 | ||
7d314e34 PBG |
1055 | if(ubd_dev->cow.file != NULL) |
1056 | cowify_req(io_req, ubd_dev->cow.bitmap, ubd_dev->cow.bitmap_offset, | |
1057 | ubd_dev->cow.bitmap_len); | |
91acb21f | 1058 | |
1da177e4 LT |
1059 | return(0); |
1060 | } | |
1061 | ||
1062 | /* Called with ubd_io_lock held */ | |
1063 | static void do_ubd_request(request_queue_t *q) | |
1064 | { | |
1065 | struct io_thread_req io_req; | |
1066 | struct request *req; | |
91acb21f JD |
1067 | int err, n; |
1068 | ||
1069 | if(thread_fd == -1){ | |
1070 | while((req = elv_next_request(q)) != NULL){ | |
1071 | err = prepare_request(req, &io_req); | |
1072 | if(!err){ | |
1073 | do_io(&io_req); | |
1074 | __ubd_finish(req, io_req.error); | |
1075 | } | |
1076 | } | |
1077 | } | |
1078 | else { | |
1079 | if(do_ubd || (req = elv_next_request(q)) == NULL) | |
1080 | return; | |
1081 | err = prepare_request(req, &io_req); | |
1082 | if(!err){ | |
2fe30a34 | 1083 | do_ubd = 1; |
91acb21f JD |
1084 | n = os_write_file(thread_fd, (char *) &io_req, |
1085 | sizeof(io_req)); | |
1086 | if(n != sizeof(io_req)) | |
1087 | printk("write to io thread failed, " | |
1088 | "errno = %d\n", -n); | |
1da177e4 LT |
1089 | } |
1090 | } | |
1091 | } | |
1092 | ||
a885c8c4 CH |
1093 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1094 | { | |
7d314e34 | 1095 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
a885c8c4 CH |
1096 | |
1097 | geo->heads = 128; | |
1098 | geo->sectors = 32; | |
7d314e34 | 1099 | geo->cylinders = ubd_dev->size / (128 * 32 * 512); |
a885c8c4 CH |
1100 | return 0; |
1101 | } | |
1102 | ||
1da177e4 LT |
1103 | static int ubd_ioctl(struct inode * inode, struct file * file, |
1104 | unsigned int cmd, unsigned long arg) | |
1105 | { | |
7d314e34 | 1106 | struct ubd *ubd_dev = inode->i_bdev->bd_disk->private_data; |
1da177e4 LT |
1107 | struct hd_driveid ubd_id = { |
1108 | .cyls = 0, | |
1109 | .heads = 128, | |
1110 | .sectors = 32, | |
1111 | }; | |
1112 | ||
1113 | switch (cmd) { | |
1da177e4 | 1114 | struct cdrom_volctrl volume; |
1da177e4 | 1115 | case HDIO_GET_IDENTITY: |
7d314e34 | 1116 | ubd_id.cyls = ubd_dev->size / (128 * 32 * 512); |
1da177e4 LT |
1117 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, |
1118 | sizeof(ubd_id))) | |
1119 | return(-EFAULT); | |
1120 | return(0); | |
1121 | ||
1122 | case CDROMVOLREAD: | |
1123 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
1124 | return(-EFAULT); | |
1125 | volume.channel0 = 255; | |
1126 | volume.channel1 = 255; | |
1127 | volume.channel2 = 255; | |
1128 | volume.channel3 = 255; | |
1129 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
1130 | return(-EFAULT); | |
1131 | return(0); | |
1132 | } | |
1133 | return(-EINVAL); | |
1134 | } | |
1135 | ||
4833aff7 | 1136 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) |
1da177e4 LT |
1137 | { |
1138 | struct uml_stat buf1, buf2; | |
1139 | int err; | |
1140 | ||
4833aff7 PBG |
1141 | if(from_cmdline == NULL) |
1142 | return 0; | |
1143 | if(!strcmp(from_cmdline, from_cow)) | |
1144 | return 0; | |
1da177e4 LT |
1145 | |
1146 | err = os_stat_file(from_cmdline, &buf1); | |
1147 | if(err < 0){ | |
1148 | printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); | |
4833aff7 | 1149 | return 0; |
1da177e4 LT |
1150 | } |
1151 | err = os_stat_file(from_cow, &buf2); | |
1152 | if(err < 0){ | |
1153 | printk("Couldn't stat '%s', err = %d\n", from_cow, -err); | |
4833aff7 | 1154 | return 1; |
1da177e4 LT |
1155 | } |
1156 | if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
4833aff7 | 1157 | return 0; |
1da177e4 LT |
1158 | |
1159 | printk("Backing file mismatch - \"%s\" requested,\n" | |
1160 | "\"%s\" specified in COW header of \"%s\"\n", | |
1161 | from_cmdline, from_cow, cow); | |
4833aff7 | 1162 | return 1; |
1da177e4 LT |
1163 | } |
1164 | ||
1165 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
1166 | { | |
1167 | unsigned long modtime; | |
fe1db50c | 1168 | unsigned long long actual; |
1da177e4 LT |
1169 | int err; |
1170 | ||
1171 | err = os_file_modtime(file, &modtime); | |
1172 | if(err < 0){ | |
1173 | printk("Failed to get modification time of backing file " | |
1174 | "\"%s\", err = %d\n", file, -err); | |
1175 | return(err); | |
1176 | } | |
1177 | ||
1178 | err = os_file_size(file, &actual); | |
1179 | if(err < 0){ | |
1180 | printk("Failed to get size of backing file \"%s\", " | |
1181 | "err = %d\n", file, -err); | |
1182 | return(err); | |
1183 | } | |
1184 | ||
1185 | if(actual != size){ | |
1186 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
1187 | * the typecast.*/ | |
1188 | printk("Size mismatch (%llu vs %llu) of COW header vs backing " | |
1189 | "file\n", (unsigned long long) size, actual); | |
1190 | return(-EINVAL); | |
1191 | } | |
1192 | if(modtime != mtime){ | |
1193 | printk("mtime mismatch (%ld vs %ld) of COW header vs backing " | |
1194 | "file\n", mtime, modtime); | |
1195 | return(-EINVAL); | |
1196 | } | |
1197 | return(0); | |
1198 | } | |
1199 | ||
1200 | int read_cow_bitmap(int fd, void *buf, int offset, int len) | |
1201 | { | |
1202 | int err; | |
1203 | ||
1204 | err = os_seek_file(fd, offset); | |
1205 | if(err < 0) | |
1206 | return(err); | |
1207 | ||
1208 | err = os_read_file(fd, buf, len); | |
1209 | if(err < 0) | |
1210 | return(err); | |
1211 | ||
1212 | return(0); | |
1213 | } | |
1214 | ||
6c29256c | 1215 | int open_ubd_file(char *file, struct openflags *openflags, int shared, |
1da177e4 LT |
1216 | char **backing_file_out, int *bitmap_offset_out, |
1217 | unsigned long *bitmap_len_out, int *data_offset_out, | |
1218 | int *create_cow_out) | |
1219 | { | |
1220 | time_t mtime; | |
1221 | unsigned long long size; | |
1222 | __u32 version, align; | |
1223 | char *backing_file; | |
4833aff7 | 1224 | int fd, err, sectorsize, asked_switch, mode = 0644; |
1da177e4 LT |
1225 | |
1226 | fd = os_open_file(file, *openflags, mode); | |
a374a48f PBG |
1227 | if (fd < 0) { |
1228 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
1da177e4 | 1229 | *create_cow_out = 1; |
a374a48f PBG |
1230 | if (!openflags->w || |
1231 | ((fd != -EROFS) && (fd != -EACCES))) | |
1232 | return fd; | |
1da177e4 LT |
1233 | openflags->w = 0; |
1234 | fd = os_open_file(file, *openflags, mode); | |
a374a48f PBG |
1235 | if (fd < 0) |
1236 | return fd; | |
1da177e4 LT |
1237 | } |
1238 | ||
6c29256c JD |
1239 | if(shared) |
1240 | printk("Not locking \"%s\" on the host\n", file); | |
1241 | else { | |
1242 | err = os_lock_file(fd, openflags->w); | |
1243 | if(err < 0){ | |
1244 | printk("Failed to lock '%s', err = %d\n", file, -err); | |
1245 | goto out_close; | |
1246 | } | |
1da177e4 LT |
1247 | } |
1248 | ||
d6e05edc | 1249 | /* Successful return case! */ |
a374a48f PBG |
1250 | if(backing_file_out == NULL) |
1251 | return(fd); | |
1da177e4 LT |
1252 | |
1253 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
1254 | &size, §orsize, &align, bitmap_offset_out); | |
1255 | if(err && (*backing_file_out != NULL)){ | |
1256 | printk("Failed to read COW header from COW file \"%s\", " | |
1257 | "errno = %d\n", file, -err); | |
1258 | goto out_close; | |
1259 | } | |
a374a48f PBG |
1260 | if(err) |
1261 | return(fd); | |
1da177e4 | 1262 | |
4833aff7 | 1263 | asked_switch = path_requires_switch(*backing_file_out, backing_file, file); |
1da177e4 | 1264 | |
4833aff7 PBG |
1265 | /* Allow switching only if no mismatch. */ |
1266 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, mtime)) { | |
1da177e4 LT |
1267 | printk("Switching backing file to '%s'\n", *backing_file_out); |
1268 | err = write_cow_header(file, fd, *backing_file_out, | |
1269 | sectorsize, align, &size); | |
a374a48f | 1270 | if (err) { |
1da177e4 | 1271 | printk("Switch failed, errno = %d\n", -err); |
4833aff7 | 1272 | goto out_close; |
1da177e4 | 1273 | } |
a374a48f | 1274 | } else { |
1da177e4 LT |
1275 | *backing_file_out = backing_file; |
1276 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
a374a48f PBG |
1277 | if (err) |
1278 | goto out_close; | |
1da177e4 LT |
1279 | } |
1280 | ||
1281 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
1282 | bitmap_len_out, data_offset_out); | |
1283 | ||
a374a48f | 1284 | return fd; |
1da177e4 LT |
1285 | out_close: |
1286 | os_close_file(fd); | |
a374a48f | 1287 | return err; |
1da177e4 LT |
1288 | } |
1289 | ||
1290 | int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, | |
1291 | int sectorsize, int alignment, int *bitmap_offset_out, | |
1292 | unsigned long *bitmap_len_out, int *data_offset_out) | |
1293 | { | |
1294 | int err, fd; | |
1295 | ||
1296 | flags.c = 1; | |
6c29256c | 1297 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); |
1da177e4 LT |
1298 | if(fd < 0){ |
1299 | err = fd; | |
1300 | printk("Open of COW file '%s' failed, errno = %d\n", cow_file, | |
1301 | -err); | |
1302 | goto out; | |
1303 | } | |
1304 | ||
1305 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
1306 | bitmap_offset_out, bitmap_len_out, | |
1307 | data_offset_out); | |
1308 | if(!err) | |
1309 | return(fd); | |
1310 | os_close_file(fd); | |
1311 | out: | |
1312 | return(err); | |
1313 | } | |
1314 | ||
91acb21f | 1315 | static int update_bitmap(struct io_thread_req *req) |
1da177e4 | 1316 | { |
91acb21f | 1317 | int n; |
1da177e4 | 1318 | |
91acb21f JD |
1319 | if(req->cow_offset == -1) |
1320 | return(0); | |
1da177e4 | 1321 | |
91acb21f JD |
1322 | n = os_seek_file(req->fds[1], req->cow_offset); |
1323 | if(n < 0){ | |
1324 | printk("do_io - bitmap lseek failed : err = %d\n", -n); | |
1325 | return(1); | |
1326 | } | |
1da177e4 | 1327 | |
91acb21f JD |
1328 | n = os_write_file(req->fds[1], &req->bitmap_words, |
1329 | sizeof(req->bitmap_words)); | |
1330 | if(n != sizeof(req->bitmap_words)){ | |
1331 | printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, | |
1332 | req->fds[1]); | |
1333 | return(1); | |
1334 | } | |
1da177e4 | 1335 | |
91acb21f JD |
1336 | return(0); |
1337 | } | |
1da177e4 | 1338 | |
91acb21f JD |
1339 | void do_io(struct io_thread_req *req) |
1340 | { | |
1341 | char *buf; | |
1342 | unsigned long len; | |
1343 | int n, nsectors, start, end, bit; | |
1344 | int err; | |
1345 | __u64 off; | |
1346 | ||
1347 | nsectors = req->length / req->sectorsize; | |
1348 | start = 0; | |
1349 | do { | |
1350 | bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); | |
1351 | end = start; | |
1352 | while((end < nsectors) && | |
1353 | (ubd_test_bit(end, (unsigned char *) | |
1354 | &req->sector_mask) == bit)) | |
1355 | end++; | |
1356 | ||
1357 | off = req->offset + req->offsets[bit] + | |
1358 | start * req->sectorsize; | |
1359 | len = (end - start) * req->sectorsize; | |
1360 | buf = &req->buffer[start * req->sectorsize]; | |
1361 | ||
1362 | err = os_seek_file(req->fds[bit], off); | |
1363 | if(err < 0){ | |
1364 | printk("do_io - lseek failed : err = %d\n", -err); | |
1365 | req->error = 1; | |
1366 | return; | |
1367 | } | |
1368 | if(req->op == UBD_READ){ | |
1369 | n = 0; | |
1370 | do { | |
1371 | buf = &buf[n]; | |
1372 | len -= n; | |
1373 | n = os_read_file(req->fds[bit], buf, len); | |
1374 | if (n < 0) { | |
1375 | printk("do_io - read failed, err = %d " | |
1376 | "fd = %d\n", -n, req->fds[bit]); | |
1377 | req->error = 1; | |
1378 | return; | |
1379 | } | |
1380 | } while((n < len) && (n != 0)); | |
1381 | if (n < len) memset(&buf[n], 0, len - n); | |
1382 | } else { | |
1383 | n = os_write_file(req->fds[bit], buf, len); | |
1384 | if(n != len){ | |
1385 | printk("do_io - write failed err = %d " | |
1386 | "fd = %d\n", -n, req->fds[bit]); | |
1387 | req->error = 1; | |
1388 | return; | |
1389 | } | |
1390 | } | |
1391 | ||
1392 | start = end; | |
1393 | } while(start < nsectors); | |
1da177e4 | 1394 | |
91acb21f | 1395 | req->error = update_bitmap(req); |
1da177e4 | 1396 | } |
91acb21f JD |
1397 | |
1398 | /* Changed in start_io_thread, which is serialized by being called only | |
1399 | * from ubd_init, which is an initcall. | |
1400 | */ | |
1401 | int kernel_fd = -1; | |
1402 | ||
d8d7c28e PBG |
1403 | /* Only changed by the io thread. XXX: currently unused. */ |
1404 | static int io_count = 0; | |
91acb21f JD |
1405 | |
1406 | int io_thread(void *arg) | |
1407 | { | |
1408 | struct io_thread_req req; | |
1409 | int n; | |
1410 | ||
1411 | ignore_sigwinch_sig(); | |
1412 | while(1){ | |
1413 | n = os_read_file(kernel_fd, &req, sizeof(req)); | |
1414 | if(n != sizeof(req)){ | |
1415 | if(n < 0) | |
1416 | printk("io_thread - read failed, fd = %d, " | |
1417 | "err = %d\n", kernel_fd, -n); | |
1418 | else { | |
1419 | printk("io_thread - short read, fd = %d, " | |
1420 | "length = %d\n", kernel_fd, n); | |
1421 | } | |
1422 | continue; | |
1423 | } | |
1424 | io_count++; | |
1425 | do_io(&req); | |
1426 | n = os_write_file(kernel_fd, &req, sizeof(req)); | |
1427 | if(n != sizeof(req)) | |
1428 | printk("io_thread - write failed, fd = %d, err = %d\n", | |
1429 | kernel_fd, -n); | |
1430 | } | |
91acb21f | 1431 | |
1b57e9c2 JD |
1432 | return 0; |
1433 | } |