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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 | ||
1da177e4 LT |
20 | #define UBD_SHIFT 4 |
21 | ||
e16f5350 | 22 | #include "linux/kernel.h" |
1da177e4 LT |
23 | #include "linux/module.h" |
24 | #include "linux/blkdev.h" | |
73855e13 | 25 | #include "linux/ata.h" |
1da177e4 LT |
26 | #include "linux/hdreg.h" |
27 | #include "linux/init.h" | |
1da177e4 LT |
28 | #include "linux/cdrom.h" |
29 | #include "linux/proc_fs.h" | |
6613c5e8 | 30 | #include "linux/seq_file.h" |
1da177e4 LT |
31 | #include "linux/ctype.h" |
32 | #include "linux/capability.h" | |
33 | #include "linux/mm.h" | |
5a0e3ad6 | 34 | #include "linux/slab.h" |
1da177e4 | 35 | #include "linux/vmalloc.h" |
9a181c58 | 36 | #include "linux/mutex.h" |
1da177e4 LT |
37 | #include "linux/blkpg.h" |
38 | #include "linux/genhd.h" | |
39 | #include "linux/spinlock.h" | |
d052d1be | 40 | #include "linux/platform_device.h" |
23464ffa | 41 | #include "linux/scatterlist.h" |
1da177e4 LT |
42 | #include "asm/segment.h" |
43 | #include "asm/uaccess.h" | |
44 | #include "asm/irq.h" | |
45 | #include "asm/types.h" | |
46 | #include "asm/tlbflush.h" | |
1da177e4 LT |
47 | #include "mem_user.h" |
48 | #include "kern_util.h" | |
49 | #include "kern.h" | |
50 | #include "mconsole_kern.h" | |
51 | #include "init.h" | |
52 | #include "irq_user.h" | |
53 | #include "irq_kern.h" | |
54 | #include "ubd_user.h" | |
1da177e4 LT |
55 | #include "os.h" |
56 | #include "mem.h" | |
57 | #include "mem_kern.h" | |
58 | #include "cow.h" | |
59 | ||
7b9014c1 | 60 | enum ubd_req { UBD_READ, UBD_WRITE }; |
1da177e4 LT |
61 | |
62 | struct io_thread_req { | |
62f96cb0 | 63 | struct request *req; |
91acb21f | 64 | enum ubd_req op; |
1da177e4 LT |
65 | int fds[2]; |
66 | unsigned long offsets[2]; | |
67 | unsigned long long offset; | |
68 | unsigned long length; | |
69 | char *buffer; | |
70 | int sectorsize; | |
91acb21f JD |
71 | unsigned long sector_mask; |
72 | unsigned long long cow_offset; | |
73 | unsigned long bitmap_words[2]; | |
1da177e4 LT |
74 | int error; |
75 | }; | |
76 | ||
91acb21f | 77 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
78 | { |
79 | __u64 n; | |
80 | int bits, off; | |
81 | ||
91acb21f | 82 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
83 | n = bit / bits; |
84 | off = bit % bits; | |
dc764e50 | 85 | return (data[n] & (1 << off)) != 0; |
1da177e4 LT |
86 | } |
87 | ||
91acb21f | 88 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
89 | { |
90 | __u64 n; | |
91 | int bits, off; | |
92 | ||
91acb21f | 93 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
94 | n = bit / bits; |
95 | off = bit % bits; | |
91acb21f | 96 | data[n] |= (1 << off); |
1da177e4 LT |
97 | } |
98 | /*End stuff from ubd_user.h*/ | |
99 | ||
100 | #define DRIVER_NAME "uml-blkdev" | |
101 | ||
d7fb2c38 | 102 | static DEFINE_MUTEX(ubd_lock); |
9a181c58 | 103 | static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */ |
1da177e4 | 104 | |
a625c998 AV |
105 | static int ubd_open(struct block_device *bdev, fmode_t mode); |
106 | static int ubd_release(struct gendisk *disk, fmode_t mode); | |
107 | static int ubd_ioctl(struct block_device *bdev, fmode_t mode, | |
1da177e4 | 108 | unsigned int cmd, unsigned long arg); |
a885c8c4 | 109 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
1da177e4 | 110 | |
97d88ac8 | 111 | #define MAX_DEV (16) |
1da177e4 | 112 | |
83d5cde4 | 113 | static const struct block_device_operations ubd_blops = { |
1da177e4 | 114 | .owner = THIS_MODULE, |
a625c998 AV |
115 | .open = ubd_open, |
116 | .release = ubd_release, | |
117 | .ioctl = ubd_ioctl, | |
a885c8c4 | 118 | .getgeo = ubd_getgeo, |
1da177e4 LT |
119 | }; |
120 | ||
1da177e4 | 121 | /* Protected by ubd_lock */ |
792dd4fc | 122 | static int fake_major = UBD_MAJOR; |
1da177e4 LT |
123 | static struct gendisk *ubd_gendisk[MAX_DEV]; |
124 | static struct gendisk *fake_gendisk[MAX_DEV]; | |
6c29256c | 125 | |
1da177e4 LT |
126 | #ifdef CONFIG_BLK_DEV_UBD_SYNC |
127 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
128 | .cl = 1 }) | |
129 | #else | |
130 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
131 | .cl = 1 }) | |
132 | #endif | |
1da177e4 LT |
133 | static struct openflags global_openflags = OPEN_FLAGS; |
134 | ||
135 | struct cow { | |
2a9d32f6 | 136 | /* backing file name */ |
1da177e4 | 137 | char *file; |
2a9d32f6 | 138 | /* backing file fd */ |
1da177e4 LT |
139 | int fd; |
140 | unsigned long *bitmap; | |
141 | unsigned long bitmap_len; | |
142 | int bitmap_offset; | |
dc764e50 | 143 | int data_offset; |
1da177e4 LT |
144 | }; |
145 | ||
a0044bdf JD |
146 | #define MAX_SG 64 |
147 | ||
1da177e4 | 148 | struct ubd { |
a0044bdf | 149 | struct list_head restart; |
2a9d32f6 PBG |
150 | /* name (and fd, below) of the file opened for writing, either the |
151 | * backing or the cow file. */ | |
1da177e4 LT |
152 | char *file; |
153 | int count; | |
154 | int fd; | |
155 | __u64 size; | |
156 | struct openflags boot_openflags; | |
157 | struct openflags openflags; | |
84e945e3 PBG |
158 | unsigned shared:1; |
159 | unsigned no_cow:1; | |
1da177e4 LT |
160 | struct cow cow; |
161 | struct platform_device pdev; | |
62f96cb0 JD |
162 | struct request_queue *queue; |
163 | spinlock_t lock; | |
a0044bdf JD |
164 | struct scatterlist sg[MAX_SG]; |
165 | struct request *request; | |
166 | int start_sg, end_sg; | |
47526903 | 167 | sector_t rq_pos; |
1da177e4 LT |
168 | }; |
169 | ||
170 | #define DEFAULT_COW { \ | |
171 | .file = NULL, \ | |
dc764e50 JD |
172 | .fd = -1, \ |
173 | .bitmap = NULL, \ | |
1da177e4 | 174 | .bitmap_offset = 0, \ |
dc764e50 | 175 | .data_offset = 0, \ |
1da177e4 LT |
176 | } |
177 | ||
178 | #define DEFAULT_UBD { \ | |
179 | .file = NULL, \ | |
180 | .count = 0, \ | |
181 | .fd = -1, \ | |
182 | .size = -1, \ | |
183 | .boot_openflags = OPEN_FLAGS, \ | |
184 | .openflags = OPEN_FLAGS, \ | |
dc764e50 | 185 | .no_cow = 0, \ |
6c29256c | 186 | .shared = 0, \ |
dc764e50 | 187 | .cow = DEFAULT_COW, \ |
62f96cb0 | 188 | .lock = SPIN_LOCK_UNLOCKED, \ |
a0044bdf JD |
189 | .request = NULL, \ |
190 | .start_sg = 0, \ | |
191 | .end_sg = 0, \ | |
47526903 | 192 | .rq_pos = 0, \ |
1da177e4 LT |
193 | } |
194 | ||
b8831a1d | 195 | /* Protected by ubd_lock */ |
5dc62b1b | 196 | static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD }; |
1da177e4 | 197 | |
1da177e4 LT |
198 | /* Only changed by fake_ide_setup which is a setup */ |
199 | static int fake_ide = 0; | |
200 | static struct proc_dir_entry *proc_ide_root = NULL; | |
201 | static struct proc_dir_entry *proc_ide = NULL; | |
202 | ||
203 | static void make_proc_ide(void) | |
204 | { | |
205 | proc_ide_root = proc_mkdir("ide", NULL); | |
206 | proc_ide = proc_mkdir("ide0", proc_ide_root); | |
207 | } | |
208 | ||
6613c5e8 | 209 | static int fake_ide_media_proc_show(struct seq_file *m, void *v) |
1da177e4 | 210 | { |
6613c5e8 AD |
211 | seq_puts(m, "disk\n"); |
212 | return 0; | |
213 | } | |
214 | ||
215 | static int fake_ide_media_proc_open(struct inode *inode, struct file *file) | |
216 | { | |
217 | return single_open(file, fake_ide_media_proc_show, NULL); | |
1da177e4 LT |
218 | } |
219 | ||
6613c5e8 AD |
220 | static const struct file_operations fake_ide_media_proc_fops = { |
221 | .owner = THIS_MODULE, | |
222 | .open = fake_ide_media_proc_open, | |
223 | .read = seq_read, | |
224 | .llseek = seq_lseek, | |
225 | .release = single_release, | |
226 | }; | |
227 | ||
c0a9290e | 228 | static void make_ide_entries(const char *dev_name) |
1da177e4 LT |
229 | { |
230 | struct proc_dir_entry *dir, *ent; | |
231 | char name[64]; | |
232 | ||
233 | if(proc_ide_root == NULL) make_proc_ide(); | |
234 | ||
235 | dir = proc_mkdir(dev_name, proc_ide); | |
236 | if(!dir) return; | |
237 | ||
6613c5e8 | 238 | ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops); |
1da177e4 | 239 | if(!ent) return; |
c0a9290e | 240 | snprintf(name, sizeof(name), "ide0/%s", dev_name); |
1da177e4 LT |
241 | proc_symlink(dev_name, proc_ide_root, name); |
242 | } | |
243 | ||
244 | static int fake_ide_setup(char *str) | |
245 | { | |
246 | fake_ide = 1; | |
dc764e50 | 247 | return 1; |
1da177e4 LT |
248 | } |
249 | ||
250 | __setup("fake_ide", fake_ide_setup); | |
251 | ||
252 | __uml_help(fake_ide_setup, | |
253 | "fake_ide\n" | |
254 | " Create ide0 entries that map onto ubd devices.\n\n" | |
255 | ); | |
256 | ||
257 | static int parse_unit(char **ptr) | |
258 | { | |
259 | char *str = *ptr, *end; | |
260 | int n = -1; | |
261 | ||
262 | if(isdigit(*str)) { | |
263 | n = simple_strtoul(str, &end, 0); | |
264 | if(end == str) | |
dc764e50 | 265 | return -1; |
1da177e4 LT |
266 | *ptr = end; |
267 | } | |
97d88ac8 | 268 | else if (('a' <= *str) && (*str <= 'z')) { |
1da177e4 LT |
269 | n = *str - 'a'; |
270 | str++; | |
271 | *ptr = str; | |
272 | } | |
dc764e50 | 273 | return n; |
1da177e4 LT |
274 | } |
275 | ||
d8d7c28e PBG |
276 | /* If *index_out == -1 at exit, the passed option was a general one; |
277 | * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it | |
278 | * should not be freed on exit. | |
279 | */ | |
f28169d2 | 280 | static int ubd_setup_common(char *str, int *index_out, char **error_out) |
1da177e4 | 281 | { |
7d314e34 | 282 | struct ubd *ubd_dev; |
1da177e4 LT |
283 | struct openflags flags = global_openflags; |
284 | char *backing_file; | |
b8831a1d | 285 | int n, err = 0, i; |
1da177e4 LT |
286 | |
287 | if(index_out) *index_out = -1; | |
288 | n = *str; | |
289 | if(n == '='){ | |
290 | char *end; | |
291 | int major; | |
292 | ||
293 | str++; | |
1da177e4 LT |
294 | if(!strcmp(str, "sync")){ |
295 | global_openflags = of_sync(global_openflags); | |
b8831a1d | 296 | goto out1; |
1da177e4 | 297 | } |
b8831a1d JD |
298 | |
299 | err = -EINVAL; | |
1da177e4 LT |
300 | major = simple_strtoul(str, &end, 0); |
301 | if((*end != '\0') || (end == str)){ | |
f28169d2 | 302 | *error_out = "Didn't parse major number"; |
b8831a1d | 303 | goto out1; |
1da177e4 LT |
304 | } |
305 | ||
f28169d2 | 306 | mutex_lock(&ubd_lock); |
792dd4fc | 307 | if (fake_major != UBD_MAJOR) { |
f28169d2 JD |
308 | *error_out = "Can't assign a fake major twice"; |
309 | goto out1; | |
310 | } | |
6c29256c | 311 | |
f28169d2 | 312 | fake_major = major; |
1da177e4 LT |
313 | |
314 | printk(KERN_INFO "Setting extra ubd major number to %d\n", | |
315 | major); | |
f28169d2 JD |
316 | err = 0; |
317 | out1: | |
318 | mutex_unlock(&ubd_lock); | |
319 | return err; | |
1da177e4 LT |
320 | } |
321 | ||
322 | n = parse_unit(&str); | |
323 | if(n < 0){ | |
f28169d2 JD |
324 | *error_out = "Couldn't parse device number"; |
325 | return -EINVAL; | |
1da177e4 LT |
326 | } |
327 | if(n >= MAX_DEV){ | |
f28169d2 JD |
328 | *error_out = "Device number out of range"; |
329 | return 1; | |
1da177e4 LT |
330 | } |
331 | ||
f28169d2 | 332 | err = -EBUSY; |
d7fb2c38 | 333 | mutex_lock(&ubd_lock); |
1da177e4 | 334 | |
7d314e34 PBG |
335 | ubd_dev = &ubd_devs[n]; |
336 | if(ubd_dev->file != NULL){ | |
f28169d2 | 337 | *error_out = "Device is already configured"; |
1da177e4 LT |
338 | goto out; |
339 | } | |
340 | ||
341 | if (index_out) | |
342 | *index_out = n; | |
343 | ||
f28169d2 | 344 | err = -EINVAL; |
6c29256c | 345 | for (i = 0; i < sizeof("rscd="); i++) { |
1da177e4 LT |
346 | switch (*str) { |
347 | case 'r': | |
348 | flags.w = 0; | |
349 | break; | |
350 | case 's': | |
351 | flags.s = 1; | |
352 | break; | |
353 | case 'd': | |
7d314e34 | 354 | ubd_dev->no_cow = 1; |
1da177e4 | 355 | break; |
6c29256c | 356 | case 'c': |
7d314e34 | 357 | ubd_dev->shared = 1; |
6c29256c | 358 | break; |
1da177e4 LT |
359 | case '=': |
360 | str++; | |
361 | goto break_loop; | |
362 | default: | |
f28169d2 JD |
363 | *error_out = "Expected '=' or flag letter " |
364 | "(r, s, c, or d)"; | |
1da177e4 LT |
365 | goto out; |
366 | } | |
367 | str++; | |
368 | } | |
369 | ||
f28169d2 JD |
370 | if (*str == '=') |
371 | *error_out = "Too many flags specified"; | |
372 | else | |
373 | *error_out = "Missing '='"; | |
1da177e4 LT |
374 | goto out; |
375 | ||
376 | break_loop: | |
1da177e4 LT |
377 | backing_file = strchr(str, ','); |
378 | ||
f28169d2 | 379 | if (backing_file == NULL) |
1da177e4 | 380 | backing_file = strchr(str, ':'); |
1da177e4 | 381 | |
f28169d2 JD |
382 | if(backing_file != NULL){ |
383 | if(ubd_dev->no_cow){ | |
384 | *error_out = "Can't specify both 'd' and a cow file"; | |
385 | goto out; | |
386 | } | |
1da177e4 LT |
387 | else { |
388 | *backing_file = '\0'; | |
389 | backing_file++; | |
390 | } | |
391 | } | |
f28169d2 | 392 | err = 0; |
7d314e34 PBG |
393 | ubd_dev->file = str; |
394 | ubd_dev->cow.file = backing_file; | |
395 | ubd_dev->boot_openflags = flags; | |
1da177e4 | 396 | out: |
d7fb2c38 | 397 | mutex_unlock(&ubd_lock); |
f28169d2 | 398 | return err; |
1da177e4 LT |
399 | } |
400 | ||
401 | static int ubd_setup(char *str) | |
402 | { | |
f28169d2 JD |
403 | char *error; |
404 | int err; | |
405 | ||
406 | err = ubd_setup_common(str, NULL, &error); | |
407 | if(err) | |
408 | printk(KERN_ERR "Failed to initialize device with \"%s\" : " | |
409 | "%s\n", str, error); | |
410 | return 1; | |
1da177e4 LT |
411 | } |
412 | ||
413 | __setup("ubd", ubd_setup); | |
414 | __uml_help(ubd_setup, | |
415 | "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" | |
416 | " This is used to associate a device with a file in the underlying\n" | |
417 | " filesystem. When specifying two filenames, the first one is the\n" | |
418 | " COW name and the second is the backing file name. As separator you can\n" | |
419 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
420 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
421 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
f28169d2 | 422 | " When using only one filename, UML will detect whether to treat it like\n" |
1da177e4 LT |
423 | " a COW file or a backing file. To override this detection, add the 'd'\n" |
424 | " flag:\n" | |
425 | " ubd0d=BackingFile\n" | |
426 | " Usually, there is a filesystem in the file, but \n" | |
427 | " that's not required. Swap devices containing swap files can be\n" | |
428 | " specified like this. Also, a file which doesn't contain a\n" | |
429 | " filesystem can have its contents read in the virtual \n" | |
430 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
431 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
432 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
20ede453 JD |
433 | " an 's' will cause data to be written to disk on the host immediately.\n" |
434 | " 'c' will cause the device to be treated as being shared between multiple\n" | |
435 | " UMLs and file locking will be turned off - this is appropriate for a\n" | |
436 | " cluster filesystem and inappropriate at almost all other times.\n\n" | |
1da177e4 LT |
437 | ); |
438 | ||
8299ca5c | 439 | static int udb_setup(char *str) |
1da177e4 LT |
440 | { |
441 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
442 | "udb TYPO\n", str); | |
dc764e50 | 443 | return 1; |
1da177e4 LT |
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 | ||
165125e1 | 455 | static void do_ubd_request(struct request_queue * q); |
91acb21f JD |
456 | |
457 | /* Only changed by ubd_init, which is an initcall. */ | |
5dc62b1b | 458 | static int thread_fd = -1; |
a0044bdf JD |
459 | static LIST_HEAD(restart); |
460 | ||
2fe30a34 | 461 | /* XXX - move this inside ubd_intr. */ |
62f96cb0 | 462 | /* Called without dev->lock held, and only in interrupt context. */ |
91acb21f | 463 | static void ubd_handler(void) |
1da177e4 | 464 | { |
2adcec21 | 465 | struct io_thread_req *req; |
a0044bdf JD |
466 | struct ubd *ubd; |
467 | struct list_head *list, *next_ele; | |
468 | unsigned long flags; | |
91acb21f JD |
469 | int n; |
470 | ||
a0044bdf | 471 | while(1){ |
a6ea4cce JD |
472 | n = os_read_file(thread_fd, &req, |
473 | sizeof(struct io_thread_req *)); | |
a0044bdf JD |
474 | if(n != sizeof(req)){ |
475 | if(n == -EAGAIN) | |
476 | break; | |
477 | printk(KERN_ERR "spurious interrupt in ubd_handler, " | |
478 | "err = %d\n", -n); | |
479 | return; | |
480 | } | |
62f96cb0 | 481 | |
4d6c84d9 | 482 | blk_end_request(req->req, 0, req->length); |
2adcec21 | 483 | kfree(req); |
a0044bdf | 484 | } |
62f96cb0 | 485 | reactivate_fd(thread_fd, UBD_IRQ); |
a0044bdf JD |
486 | |
487 | list_for_each_safe(list, next_ele, &restart){ | |
488 | ubd = container_of(list, struct ubd, restart); | |
489 | list_del_init(&ubd->restart); | |
490 | spin_lock_irqsave(&ubd->lock, flags); | |
491 | do_ubd_request(ubd->queue); | |
492 | spin_unlock_irqrestore(&ubd->lock, flags); | |
493 | } | |
1da177e4 LT |
494 | } |
495 | ||
7bea96fd | 496 | static irqreturn_t ubd_intr(int irq, void *dev) |
1da177e4 | 497 | { |
91acb21f | 498 | ubd_handler(); |
dc764e50 | 499 | return IRQ_HANDLED; |
91acb21f | 500 | } |
09ace81c | 501 | |
91acb21f JD |
502 | /* Only changed by ubd_init, which is an initcall. */ |
503 | static int io_pid = -1; | |
09ace81c | 504 | |
5dc62b1b | 505 | static void kill_io_thread(void) |
91acb21f | 506 | { |
6c29256c | 507 | if(io_pid != -1) |
91acb21f | 508 | os_kill_process(io_pid, 1); |
09ace81c | 509 | } |
1da177e4 | 510 | |
91acb21f JD |
511 | __uml_exitcall(kill_io_thread); |
512 | ||
d8d7c28e | 513 | static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) |
1da177e4 LT |
514 | { |
515 | char *file; | |
516 | ||
7d314e34 | 517 | file = ubd_dev->cow.file ? ubd_dev->cow.file : ubd_dev->file; |
dc764e50 | 518 | return os_file_size(file, size_out); |
1da177e4 LT |
519 | } |
520 | ||
5dc62b1b WC |
521 | static int read_cow_bitmap(int fd, void *buf, int offset, int len) |
522 | { | |
523 | int err; | |
524 | ||
525 | err = os_seek_file(fd, offset); | |
526 | if (err < 0) | |
527 | return err; | |
528 | ||
529 | err = os_read_file(fd, buf, len); | |
530 | if (err < 0) | |
531 | return err; | |
532 | ||
533 | return 0; | |
534 | } | |
535 | ||
536 | static int backing_file_mismatch(char *file, __u64 size, time_t mtime) | |
537 | { | |
538 | unsigned long modtime; | |
539 | unsigned long long actual; | |
540 | int err; | |
541 | ||
542 | err = os_file_modtime(file, &modtime); | |
543 | if (err < 0) { | |
544 | printk(KERN_ERR "Failed to get modification time of backing " | |
545 | "file \"%s\", err = %d\n", file, -err); | |
546 | return err; | |
547 | } | |
548 | ||
549 | err = os_file_size(file, &actual); | |
550 | if (err < 0) { | |
551 | printk(KERN_ERR "Failed to get size of backing file \"%s\", " | |
552 | "err = %d\n", file, -err); | |
553 | return err; | |
554 | } | |
555 | ||
556 | if (actual != size) { | |
557 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
558 | * the typecast.*/ | |
559 | printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header " | |
560 | "vs backing file\n", (unsigned long long) size, actual); | |
561 | return -EINVAL; | |
562 | } | |
563 | if (modtime != mtime) { | |
564 | printk(KERN_ERR "mtime mismatch (%ld vs %ld) of COW header vs " | |
565 | "backing file\n", mtime, modtime); | |
566 | return -EINVAL; | |
567 | } | |
568 | return 0; | |
569 | } | |
570 | ||
571 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) | |
572 | { | |
573 | struct uml_stat buf1, buf2; | |
574 | int err; | |
575 | ||
576 | if (from_cmdline == NULL) | |
577 | return 0; | |
578 | if (!strcmp(from_cmdline, from_cow)) | |
579 | return 0; | |
580 | ||
581 | err = os_stat_file(from_cmdline, &buf1); | |
582 | if (err < 0) { | |
583 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline, | |
584 | -err); | |
585 | return 0; | |
586 | } | |
587 | err = os_stat_file(from_cow, &buf2); | |
588 | if (err < 0) { | |
589 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow, | |
590 | -err); | |
591 | return 1; | |
592 | } | |
593 | if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
594 | return 0; | |
595 | ||
596 | printk(KERN_ERR "Backing file mismatch - \"%s\" requested, " | |
597 | "\"%s\" specified in COW header of \"%s\"\n", | |
598 | from_cmdline, from_cow, cow); | |
599 | return 1; | |
600 | } | |
601 | ||
602 | static int open_ubd_file(char *file, struct openflags *openflags, int shared, | |
603 | char **backing_file_out, int *bitmap_offset_out, | |
604 | unsigned long *bitmap_len_out, int *data_offset_out, | |
605 | int *create_cow_out) | |
606 | { | |
607 | time_t mtime; | |
608 | unsigned long long size; | |
609 | __u32 version, align; | |
610 | char *backing_file; | |
611 | int fd, err, sectorsize, asked_switch, mode = 0644; | |
612 | ||
613 | fd = os_open_file(file, *openflags, mode); | |
614 | if (fd < 0) { | |
615 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
616 | *create_cow_out = 1; | |
617 | if (!openflags->w || | |
618 | ((fd != -EROFS) && (fd != -EACCES))) | |
619 | return fd; | |
620 | openflags->w = 0; | |
621 | fd = os_open_file(file, *openflags, mode); | |
622 | if (fd < 0) | |
623 | return fd; | |
624 | } | |
625 | ||
626 | if (shared) | |
627 | printk(KERN_INFO "Not locking \"%s\" on the host\n", file); | |
628 | else { | |
629 | err = os_lock_file(fd, openflags->w); | |
630 | if (err < 0) { | |
631 | printk(KERN_ERR "Failed to lock '%s', err = %d\n", | |
632 | file, -err); | |
633 | goto out_close; | |
634 | } | |
635 | } | |
636 | ||
637 | /* Successful return case! */ | |
638 | if (backing_file_out == NULL) | |
639 | return fd; | |
640 | ||
641 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
642 | &size, §orsize, &align, bitmap_offset_out); | |
643 | if (err && (*backing_file_out != NULL)) { | |
644 | printk(KERN_ERR "Failed to read COW header from COW file " | |
645 | "\"%s\", errno = %d\n", file, -err); | |
646 | goto out_close; | |
647 | } | |
648 | if (err) | |
649 | return fd; | |
650 | ||
651 | asked_switch = path_requires_switch(*backing_file_out, backing_file, | |
652 | file); | |
653 | ||
654 | /* Allow switching only if no mismatch. */ | |
655 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, | |
656 | mtime)) { | |
657 | printk(KERN_ERR "Switching backing file to '%s'\n", | |
658 | *backing_file_out); | |
659 | err = write_cow_header(file, fd, *backing_file_out, | |
660 | sectorsize, align, &size); | |
661 | if (err) { | |
662 | printk(KERN_ERR "Switch failed, errno = %d\n", -err); | |
663 | goto out_close; | |
664 | } | |
665 | } else { | |
666 | *backing_file_out = backing_file; | |
667 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
668 | if (err) | |
669 | goto out_close; | |
670 | } | |
671 | ||
672 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
673 | bitmap_len_out, data_offset_out); | |
674 | ||
675 | return fd; | |
676 | out_close: | |
677 | os_close_file(fd); | |
678 | return err; | |
679 | } | |
680 | ||
681 | static int create_cow_file(char *cow_file, char *backing_file, | |
682 | struct openflags flags, | |
683 | int sectorsize, int alignment, int *bitmap_offset_out, | |
684 | unsigned long *bitmap_len_out, int *data_offset_out) | |
685 | { | |
686 | int err, fd; | |
687 | ||
688 | flags.c = 1; | |
689 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); | |
690 | if (fd < 0) { | |
691 | err = fd; | |
692 | printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n", | |
693 | cow_file, -err); | |
694 | goto out; | |
695 | } | |
696 | ||
697 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
698 | bitmap_offset_out, bitmap_len_out, | |
699 | data_offset_out); | |
700 | if (!err) | |
701 | return fd; | |
702 | os_close_file(fd); | |
703 | out: | |
704 | return err; | |
705 | } | |
706 | ||
5f75a4f8 | 707 | static void ubd_close_dev(struct ubd *ubd_dev) |
1da177e4 | 708 | { |
7d314e34 PBG |
709 | os_close_file(ubd_dev->fd); |
710 | if(ubd_dev->cow.file == NULL) | |
1da177e4 LT |
711 | return; |
712 | ||
7d314e34 PBG |
713 | os_close_file(ubd_dev->cow.fd); |
714 | vfree(ubd_dev->cow.bitmap); | |
715 | ubd_dev->cow.bitmap = NULL; | |
1da177e4 LT |
716 | } |
717 | ||
7d314e34 | 718 | static int ubd_open_dev(struct ubd *ubd_dev) |
1da177e4 LT |
719 | { |
720 | struct openflags flags; | |
721 | char **back_ptr; | |
722 | int err, create_cow, *create_ptr; | |
0bf16bff | 723 | int fd; |
1da177e4 | 724 | |
7d314e34 | 725 | ubd_dev->openflags = ubd_dev->boot_openflags; |
1da177e4 | 726 | create_cow = 0; |
7d314e34 PBG |
727 | create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; |
728 | back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; | |
0bf16bff PBG |
729 | |
730 | fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, | |
7d314e34 PBG |
731 | back_ptr, &ubd_dev->cow.bitmap_offset, |
732 | &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, | |
6c29256c | 733 | create_ptr); |
1da177e4 | 734 | |
0bf16bff PBG |
735 | if((fd == -ENOENT) && create_cow){ |
736 | fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, | |
7d314e34 PBG |
737 | ubd_dev->openflags, 1 << 9, PAGE_SIZE, |
738 | &ubd_dev->cow.bitmap_offset, | |
739 | &ubd_dev->cow.bitmap_len, | |
740 | &ubd_dev->cow.data_offset); | |
0bf16bff | 741 | if(fd >= 0){ |
1da177e4 | 742 | printk(KERN_INFO "Creating \"%s\" as COW file for " |
7d314e34 | 743 | "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); |
1da177e4 LT |
744 | } |
745 | } | |
746 | ||
0bf16bff | 747 | if(fd < 0){ |
7d314e34 | 748 | printk("Failed to open '%s', errno = %d\n", ubd_dev->file, |
0bf16bff PBG |
749 | -fd); |
750 | return fd; | |
1da177e4 | 751 | } |
0bf16bff | 752 | ubd_dev->fd = fd; |
1da177e4 | 753 | |
7d314e34 | 754 | if(ubd_dev->cow.file != NULL){ |
086fa5ff | 755 | blk_queue_max_hw_sectors(ubd_dev->queue, 8 * sizeof(long)); |
f4768ffd | 756 | |
1da177e4 | 757 | err = -ENOMEM; |
da2486ba | 758 | ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len); |
7d314e34 | 759 | if(ubd_dev->cow.bitmap == NULL){ |
1da177e4 LT |
760 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); |
761 | goto error; | |
762 | } | |
763 | flush_tlb_kernel_vm(); | |
764 | ||
7d314e34 PBG |
765 | err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, |
766 | ubd_dev->cow.bitmap_offset, | |
767 | ubd_dev->cow.bitmap_len); | |
1da177e4 LT |
768 | if(err < 0) |
769 | goto error; | |
770 | ||
7d314e34 | 771 | flags = ubd_dev->openflags; |
1da177e4 | 772 | flags.w = 0; |
7d314e34 | 773 | err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, |
6c29256c | 774 | NULL, NULL, NULL, NULL); |
1da177e4 | 775 | if(err < 0) goto error; |
7d314e34 | 776 | ubd_dev->cow.fd = err; |
1da177e4 | 777 | } |
dc764e50 | 778 | return 0; |
1da177e4 | 779 | error: |
7d314e34 | 780 | os_close_file(ubd_dev->fd); |
dc764e50 | 781 | return err; |
1da177e4 LT |
782 | } |
783 | ||
2e3f5251 JD |
784 | static void ubd_device_release(struct device *dev) |
785 | { | |
8691b97b | 786 | struct ubd *ubd_dev = dev_get_drvdata(dev); |
2e3f5251 JD |
787 | |
788 | blk_cleanup_queue(ubd_dev->queue); | |
789 | *ubd_dev = ((struct ubd) DEFAULT_UBD); | |
790 | } | |
791 | ||
5f75a4f8 | 792 | static int ubd_disk_register(int major, u64 size, int unit, |
b8831a1d | 793 | struct gendisk **disk_out) |
1da177e4 LT |
794 | { |
795 | struct gendisk *disk; | |
1da177e4 LT |
796 | |
797 | disk = alloc_disk(1 << UBD_SHIFT); | |
798 | if(disk == NULL) | |
dc764e50 | 799 | return -ENOMEM; |
1da177e4 LT |
800 | |
801 | disk->major = major; | |
802 | disk->first_minor = unit << UBD_SHIFT; | |
803 | disk->fops = &ubd_blops; | |
804 | set_capacity(disk, size / 512); | |
792dd4fc | 805 | if (major == UBD_MAJOR) |
1da177e4 | 806 | sprintf(disk->disk_name, "ubd%c", 'a' + unit); |
ce7b0f46 | 807 | else |
1da177e4 | 808 | sprintf(disk->disk_name, "ubd_fake%d", unit); |
1da177e4 LT |
809 | |
810 | /* sysfs register (not for ide fake devices) */ | |
792dd4fc | 811 | if (major == UBD_MAJOR) { |
7d314e34 PBG |
812 | ubd_devs[unit].pdev.id = unit; |
813 | ubd_devs[unit].pdev.name = DRIVER_NAME; | |
2e3f5251 | 814 | ubd_devs[unit].pdev.dev.release = ubd_device_release; |
8691b97b | 815 | dev_set_drvdata(&ubd_devs[unit].pdev.dev, &ubd_devs[unit]); |
7d314e34 PBG |
816 | platform_device_register(&ubd_devs[unit].pdev); |
817 | disk->driverfs_dev = &ubd_devs[unit].pdev.dev; | |
1da177e4 LT |
818 | } |
819 | ||
7d314e34 | 820 | disk->private_data = &ubd_devs[unit]; |
62f96cb0 | 821 | disk->queue = ubd_devs[unit].queue; |
1da177e4 LT |
822 | add_disk(disk); |
823 | ||
824 | *disk_out = disk; | |
825 | return 0; | |
826 | } | |
827 | ||
828 | #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) | |
829 | ||
f28169d2 | 830 | static int ubd_add(int n, char **error_out) |
1da177e4 | 831 | { |
7d314e34 | 832 | struct ubd *ubd_dev = &ubd_devs[n]; |
f28169d2 | 833 | int err = 0; |
1da177e4 | 834 | |
7d314e34 | 835 | if(ubd_dev->file == NULL) |
ec7cf783 | 836 | goto out; |
1da177e4 | 837 | |
7d314e34 | 838 | err = ubd_file_size(ubd_dev, &ubd_dev->size); |
f28169d2 JD |
839 | if(err < 0){ |
840 | *error_out = "Couldn't determine size of device's file"; | |
80c13749 | 841 | goto out; |
f28169d2 | 842 | } |
1da177e4 | 843 | |
7d314e34 | 844 | ubd_dev->size = ROUND_BLOCK(ubd_dev->size); |
1da177e4 | 845 | |
a0044bdf | 846 | INIT_LIST_HEAD(&ubd_dev->restart); |
4f40c055 | 847 | sg_init_table(ubd_dev->sg, MAX_SG); |
a0044bdf | 848 | |
62f96cb0 JD |
849 | err = -ENOMEM; |
850 | ubd_dev->queue = blk_init_queue(do_ubd_request, &ubd_dev->lock); | |
851 | if (ubd_dev->queue == NULL) { | |
852 | *error_out = "Failed to initialize device queue"; | |
80c13749 | 853 | goto out; |
62f96cb0 JD |
854 | } |
855 | ubd_dev->queue->queuedata = ubd_dev; | |
856 | ||
8a78362c | 857 | blk_queue_max_segments(ubd_dev->queue, MAX_SG); |
792dd4fc | 858 | err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, &ubd_gendisk[n]); |
62f96cb0 JD |
859 | if(err){ |
860 | *error_out = "Failed to register device"; | |
861 | goto out_cleanup; | |
862 | } | |
6c29256c | 863 | |
792dd4fc | 864 | if (fake_major != UBD_MAJOR) |
5f75a4f8 | 865 | ubd_disk_register(fake_major, ubd_dev->size, n, |
62f96cb0 | 866 | &fake_gendisk[n]); |
1da177e4 | 867 | |
83380cc1 JD |
868 | /* |
869 | * Perhaps this should also be under the "if (fake_major)" above | |
870 | * using the fake_disk->disk_name | |
871 | */ | |
1da177e4 LT |
872 | if (fake_ide) |
873 | make_ide_entries(ubd_gendisk[n]->disk_name); | |
874 | ||
ec7cf783 | 875 | err = 0; |
ec7cf783 JD |
876 | out: |
877 | return err; | |
62f96cb0 JD |
878 | |
879 | out_cleanup: | |
880 | blk_cleanup_queue(ubd_dev->queue); | |
881 | goto out; | |
1da177e4 LT |
882 | } |
883 | ||
f28169d2 | 884 | static int ubd_config(char *str, char **error_out) |
1da177e4 | 885 | { |
e7f6552f | 886 | int n, ret; |
1da177e4 | 887 | |
f28169d2 JD |
888 | /* This string is possibly broken up and stored, so it's only |
889 | * freed if ubd_setup_common fails, or if only general options | |
890 | * were set. | |
891 | */ | |
970d6e3a | 892 | str = kstrdup(str, GFP_KERNEL); |
e7f6552f | 893 | if (str == NULL) { |
f28169d2 JD |
894 | *error_out = "Failed to allocate memory"; |
895 | return -ENOMEM; | |
1da177e4 | 896 | } |
f28169d2 JD |
897 | |
898 | ret = ubd_setup_common(str, &n, error_out); | |
899 | if (ret) | |
e7f6552f | 900 | goto err_free; |
f28169d2 | 901 | |
e7f6552f PBG |
902 | if (n == -1) { |
903 | ret = 0; | |
d8d7c28e | 904 | goto err_free; |
1da177e4 | 905 | } |
1da177e4 | 906 | |
dc764e50 | 907 | mutex_lock(&ubd_lock); |
f28169d2 | 908 | ret = ubd_add(n, error_out); |
e7f6552f | 909 | if (ret) |
7d314e34 | 910 | ubd_devs[n].file = NULL; |
dc764e50 | 911 | mutex_unlock(&ubd_lock); |
1da177e4 | 912 | |
e7f6552f | 913 | out: |
dc764e50 | 914 | return ret; |
e7f6552f PBG |
915 | |
916 | err_free: | |
917 | kfree(str); | |
918 | goto out; | |
1da177e4 LT |
919 | } |
920 | ||
921 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
922 | { | |
7d314e34 | 923 | struct ubd *ubd_dev; |
1da177e4 LT |
924 | int n, len = 0; |
925 | ||
926 | n = parse_unit(&name); | |
927 | if((n >= MAX_DEV) || (n < 0)){ | |
928 | *error_out = "ubd_get_config : device number out of range"; | |
dc764e50 | 929 | return -1; |
1da177e4 LT |
930 | } |
931 | ||
7d314e34 | 932 | ubd_dev = &ubd_devs[n]; |
d7fb2c38 | 933 | mutex_lock(&ubd_lock); |
1da177e4 | 934 | |
7d314e34 | 935 | if(ubd_dev->file == NULL){ |
1da177e4 LT |
936 | CONFIG_CHUNK(str, size, len, "", 1); |
937 | goto out; | |
938 | } | |
939 | ||
7d314e34 | 940 | CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); |
1da177e4 | 941 | |
7d314e34 | 942 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 943 | CONFIG_CHUNK(str, size, len, ",", 0); |
7d314e34 | 944 | CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); |
1da177e4 LT |
945 | } |
946 | else CONFIG_CHUNK(str, size, len, "", 1); | |
947 | ||
948 | out: | |
d7fb2c38 | 949 | mutex_unlock(&ubd_lock); |
dc764e50 | 950 | return len; |
1da177e4 LT |
951 | } |
952 | ||
29d56cfe JD |
953 | static int ubd_id(char **str, int *start_out, int *end_out) |
954 | { | |
dc764e50 | 955 | int n; |
29d56cfe JD |
956 | |
957 | n = parse_unit(str); | |
dc764e50 JD |
958 | *start_out = 0; |
959 | *end_out = MAX_DEV - 1; | |
960 | return n; | |
29d56cfe JD |
961 | } |
962 | ||
f28169d2 | 963 | static int ubd_remove(int n, char **error_out) |
1da177e4 | 964 | { |
2e3f5251 | 965 | struct gendisk *disk = ubd_gendisk[n]; |
7d314e34 | 966 | struct ubd *ubd_dev; |
29d56cfe | 967 | int err = -ENODEV; |
1da177e4 | 968 | |
d7fb2c38 | 969 | mutex_lock(&ubd_lock); |
1da177e4 | 970 | |
7d314e34 | 971 | ubd_dev = &ubd_devs[n]; |
1da177e4 | 972 | |
7d314e34 | 973 | if(ubd_dev->file == NULL) |
29d56cfe | 974 | goto out; |
1da177e4 | 975 | |
29d56cfe JD |
976 | /* you cannot remove a open disk */ |
977 | err = -EBUSY; | |
7d314e34 | 978 | if(ubd_dev->count > 0) |
1da177e4 LT |
979 | goto out; |
980 | ||
dc764e50 | 981 | ubd_gendisk[n] = NULL; |
b47d2deb JD |
982 | if(disk != NULL){ |
983 | del_gendisk(disk); | |
984 | put_disk(disk); | |
985 | } | |
1da177e4 LT |
986 | |
987 | if(fake_gendisk[n] != NULL){ | |
988 | del_gendisk(fake_gendisk[n]); | |
989 | put_disk(fake_gendisk[n]); | |
990 | fake_gendisk[n] = NULL; | |
991 | } | |
992 | ||
1da177e4 | 993 | err = 0; |
2e3f5251 | 994 | platform_device_unregister(&ubd_dev->pdev); |
29d56cfe | 995 | out: |
d7fb2c38 | 996 | mutex_unlock(&ubd_lock); |
29d56cfe | 997 | return err; |
1da177e4 LT |
998 | } |
999 | ||
f28169d2 | 1000 | /* All these are called by mconsole in process context and without |
b8831a1d | 1001 | * ubd-specific locks. The structure itself is const except for .list. |
f28169d2 | 1002 | */ |
1da177e4 | 1003 | static struct mc_device ubd_mc = { |
84f48d4f | 1004 | .list = LIST_HEAD_INIT(ubd_mc.list), |
1da177e4 LT |
1005 | .name = "ubd", |
1006 | .config = ubd_config, | |
dc764e50 | 1007 | .get_config = ubd_get_config, |
29d56cfe | 1008 | .id = ubd_id, |
1da177e4 LT |
1009 | .remove = ubd_remove, |
1010 | }; | |
1011 | ||
d8d7c28e | 1012 | static int __init ubd_mc_init(void) |
1da177e4 LT |
1013 | { |
1014 | mconsole_register_dev(&ubd_mc); | |
1015 | return 0; | |
1016 | } | |
1017 | ||
1018 | __initcall(ubd_mc_init); | |
1019 | ||
d8d7c28e PBG |
1020 | static int __init ubd0_init(void) |
1021 | { | |
1022 | struct ubd *ubd_dev = &ubd_devs[0]; | |
1023 | ||
b8831a1d | 1024 | mutex_lock(&ubd_lock); |
d8d7c28e PBG |
1025 | if(ubd_dev->file == NULL) |
1026 | ubd_dev->file = "root_fs"; | |
b8831a1d JD |
1027 | mutex_unlock(&ubd_lock); |
1028 | ||
dc764e50 | 1029 | return 0; |
d8d7c28e PBG |
1030 | } |
1031 | ||
1032 | __initcall(ubd0_init); | |
1033 | ||
b8831a1d | 1034 | /* Used in ubd_init, which is an initcall */ |
3ae5eaec RK |
1035 | static struct platform_driver ubd_driver = { |
1036 | .driver = { | |
1037 | .name = DRIVER_NAME, | |
1038 | }, | |
1da177e4 LT |
1039 | }; |
1040 | ||
d8d7c28e | 1041 | static int __init ubd_init(void) |
1da177e4 | 1042 | { |
f28169d2 JD |
1043 | char *error; |
1044 | int i, err; | |
1da177e4 | 1045 | |
792dd4fc | 1046 | if (register_blkdev(UBD_MAJOR, "ubd")) |
1da177e4 LT |
1047 | return -1; |
1048 | ||
792dd4fc | 1049 | if (fake_major != UBD_MAJOR) { |
1da177e4 LT |
1050 | char name[sizeof("ubd_nnn\0")]; |
1051 | ||
1052 | snprintf(name, sizeof(name), "ubd_%d", fake_major); | |
1da177e4 LT |
1053 | if (register_blkdev(fake_major, "ubd")) |
1054 | return -1; | |
1055 | } | |
3ae5eaec | 1056 | platform_driver_register(&ubd_driver); |
dc764e50 | 1057 | mutex_lock(&ubd_lock); |
f28169d2 JD |
1058 | for (i = 0; i < MAX_DEV; i++){ |
1059 | err = ubd_add(i, &error); | |
1060 | if(err) | |
1061 | printk(KERN_ERR "Failed to initialize ubd device %d :" | |
1062 | "%s\n", i, error); | |
1063 | } | |
dc764e50 | 1064 | mutex_unlock(&ubd_lock); |
1da177e4 LT |
1065 | return 0; |
1066 | } | |
1067 | ||
1068 | late_initcall(ubd_init); | |
1069 | ||
d8d7c28e | 1070 | static int __init ubd_driver_init(void){ |
91acb21f JD |
1071 | unsigned long stack; |
1072 | int err; | |
1073 | ||
1074 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
1075 | if(global_openflags.s){ | |
1076 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
1077 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
1078 | * enough. So use anyway the io thread. */ | |
1079 | } | |
1080 | stack = alloc_stack(0, 0); | |
6c29256c | 1081 | io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), |
91acb21f JD |
1082 | &thread_fd); |
1083 | if(io_pid < 0){ | |
6c29256c | 1084 | printk(KERN_ERR |
91acb21f JD |
1085 | "ubd : Failed to start I/O thread (errno = %d) - " |
1086 | "falling back to synchronous I/O\n", -io_pid); | |
1087 | io_pid = -1; | |
dc764e50 | 1088 | return 0; |
91acb21f | 1089 | } |
6c29256c | 1090 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, |
7d314e34 | 1091 | IRQF_DISABLED, "ubd", ubd_devs); |
91acb21f JD |
1092 | if(err != 0) |
1093 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); | |
f4c57a78 | 1094 | return 0; |
91acb21f JD |
1095 | } |
1096 | ||
1097 | device_initcall(ubd_driver_init); | |
1098 | ||
a625c998 | 1099 | static int ubd_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 1100 | { |
a625c998 | 1101 | struct gendisk *disk = bdev->bd_disk; |
7d314e34 | 1102 | struct ubd *ubd_dev = disk->private_data; |
1da177e4 LT |
1103 | int err = 0; |
1104 | ||
9a181c58 | 1105 | mutex_lock(&ubd_mutex); |
7d314e34 PBG |
1106 | if(ubd_dev->count == 0){ |
1107 | err = ubd_open_dev(ubd_dev); | |
1da177e4 LT |
1108 | if(err){ |
1109 | printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", | |
7d314e34 | 1110 | disk->disk_name, ubd_dev->file, -err); |
1da177e4 LT |
1111 | goto out; |
1112 | } | |
1113 | } | |
7d314e34 PBG |
1114 | ubd_dev->count++; |
1115 | set_disk_ro(disk, !ubd_dev->openflags.w); | |
2c49be99 PBG |
1116 | |
1117 | /* This should no more be needed. And it didn't work anyway to exclude | |
1118 | * read-write remounting of filesystems.*/ | |
a625c998 | 1119 | /*if((mode & FMODE_WRITE) && !ubd_dev->openflags.w){ |
5f75a4f8 | 1120 | if(--ubd_dev->count == 0) ubd_close_dev(ubd_dev); |
1da177e4 | 1121 | err = -EROFS; |
2c49be99 | 1122 | }*/ |
6e9624b8 | 1123 | out: |
9a181c58 | 1124 | mutex_unlock(&ubd_mutex); |
dc764e50 | 1125 | return err; |
1da177e4 LT |
1126 | } |
1127 | ||
a625c998 | 1128 | static int ubd_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 1129 | { |
7d314e34 | 1130 | struct ubd *ubd_dev = disk->private_data; |
1da177e4 | 1131 | |
9a181c58 | 1132 | mutex_lock(&ubd_mutex); |
7d314e34 | 1133 | if(--ubd_dev->count == 0) |
5f75a4f8 | 1134 | ubd_close_dev(ubd_dev); |
9a181c58 | 1135 | mutex_unlock(&ubd_mutex); |
dc764e50 | 1136 | return 0; |
1da177e4 LT |
1137 | } |
1138 | ||
91acb21f JD |
1139 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, |
1140 | __u64 *cow_offset, unsigned long *bitmap, | |
1141 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
1142 | __u64 bitmap_len) | |
1da177e4 | 1143 | { |
91acb21f JD |
1144 | __u64 sector = io_offset >> 9; |
1145 | int i, update_bitmap = 0; | |
1146 | ||
1147 | for(i = 0; i < length >> 9; i++){ | |
1148 | if(cow_mask != NULL) | |
1149 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
1150 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
1151 | continue; | |
1da177e4 | 1152 | |
91acb21f JD |
1153 | update_bitmap = 1; |
1154 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
1155 | } | |
1156 | ||
1157 | if(!update_bitmap) | |
1158 | return; | |
1da177e4 | 1159 | |
91acb21f | 1160 | *cow_offset = sector / (sizeof(unsigned long) * 8); |
1da177e4 | 1161 | |
91acb21f JD |
1162 | /* This takes care of the case where we're exactly at the end of the |
1163 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
1164 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
1165 | * for the original diagnosis. | |
1166 | */ | |
6d074242 JO |
1167 | if (*cow_offset == (DIV_ROUND_UP(bitmap_len, |
1168 | sizeof(unsigned long)) - 1)) | |
91acb21f JD |
1169 | (*cow_offset)--; |
1170 | ||
1171 | bitmap_words[0] = bitmap[*cow_offset]; | |
1172 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
1173 | ||
1174 | *cow_offset *= sizeof(unsigned long); | |
1175 | *cow_offset += bitmap_offset; | |
1176 | } | |
1177 | ||
1178 | static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, | |
1179 | __u64 bitmap_offset, __u64 bitmap_len) | |
1180 | { | |
1181 | __u64 sector = req->offset >> 9; | |
1182 | int i; | |
1183 | ||
1184 | if(req->length > (sizeof(req->sector_mask) * 8) << 9) | |
1185 | panic("Operation too long"); | |
1186 | ||
1187 | if(req->op == UBD_READ) { | |
1188 | for(i = 0; i < req->length >> 9; i++){ | |
1189 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
6c29256c | 1190 | ubd_set_bit(i, (unsigned char *) |
91acb21f | 1191 | &req->sector_mask); |
dc764e50 | 1192 | } |
91acb21f JD |
1193 | } |
1194 | else cowify_bitmap(req->offset, req->length, &req->sector_mask, | |
1195 | &req->cow_offset, bitmap, bitmap_offset, | |
1196 | req->bitmap_words, bitmap_len); | |
1da177e4 LT |
1197 | } |
1198 | ||
62f96cb0 | 1199 | /* Called with dev->lock held */ |
a0044bdf JD |
1200 | static void prepare_request(struct request *req, struct io_thread_req *io_req, |
1201 | unsigned long long offset, int page_offset, | |
1202 | int len, struct page *page) | |
1da177e4 LT |
1203 | { |
1204 | struct gendisk *disk = req->rq_disk; | |
7d314e34 | 1205 | struct ubd *ubd_dev = disk->private_data; |
91acb21f | 1206 | |
62f96cb0 | 1207 | io_req->req = req; |
a0044bdf JD |
1208 | io_req->fds[0] = (ubd_dev->cow.file != NULL) ? ubd_dev->cow.fd : |
1209 | ubd_dev->fd; | |
7d314e34 | 1210 | io_req->fds[1] = ubd_dev->fd; |
91acb21f | 1211 | io_req->cow_offset = -1; |
1da177e4 LT |
1212 | io_req->offset = offset; |
1213 | io_req->length = len; | |
1214 | io_req->error = 0; | |
91acb21f JD |
1215 | io_req->sector_mask = 0; |
1216 | ||
1217 | io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; | |
1da177e4 | 1218 | io_req->offsets[0] = 0; |
7d314e34 | 1219 | io_req->offsets[1] = ubd_dev->cow.data_offset; |
a0044bdf | 1220 | io_req->buffer = page_address(page) + page_offset; |
1da177e4 LT |
1221 | io_req->sectorsize = 1 << 9; |
1222 | ||
7d314e34 | 1223 | if(ubd_dev->cow.file != NULL) |
a0044bdf JD |
1224 | cowify_req(io_req, ubd_dev->cow.bitmap, |
1225 | ubd_dev->cow.bitmap_offset, ubd_dev->cow.bitmap_len); | |
91acb21f | 1226 | |
1da177e4 LT |
1227 | } |
1228 | ||
62f96cb0 | 1229 | /* Called with dev->lock held */ |
165125e1 | 1230 | static void do_ubd_request(struct request_queue *q) |
1da177e4 | 1231 | { |
2adcec21 | 1232 | struct io_thread_req *io_req; |
1da177e4 | 1233 | struct request *req; |
f81f2f7c | 1234 | int n; |
a0044bdf JD |
1235 | |
1236 | while(1){ | |
2a9529a0 | 1237 | struct ubd *dev = q->queuedata; |
a0044bdf | 1238 | if(dev->end_sg == 0){ |
9934c8c0 | 1239 | struct request *req = blk_fetch_request(q); |
a0044bdf JD |
1240 | if(req == NULL) |
1241 | return; | |
1242 | ||
1243 | dev->request = req; | |
47526903 | 1244 | dev->rq_pos = blk_rq_pos(req); |
a0044bdf JD |
1245 | dev->start_sg = 0; |
1246 | dev->end_sg = blk_rq_map_sg(q, req, dev->sg); | |
1247 | } | |
1248 | ||
1249 | req = dev->request; | |
1250 | while(dev->start_sg < dev->end_sg){ | |
1251 | struct scatterlist *sg = &dev->sg[dev->start_sg]; | |
1252 | ||
2adcec21 | 1253 | io_req = kmalloc(sizeof(struct io_thread_req), |
990c5587 | 1254 | GFP_ATOMIC); |
2adcec21 JD |
1255 | if(io_req == NULL){ |
1256 | if(list_empty(&dev->restart)) | |
1257 | list_add(&dev->restart, &restart); | |
1258 | return; | |
1259 | } | |
1260 | prepare_request(req, io_req, | |
47526903 | 1261 | (unsigned long long)dev->rq_pos << 9, |
45711f1a | 1262 | sg->offset, sg->length, sg_page(sg)); |
a0044bdf | 1263 | |
a6ea4cce JD |
1264 | n = os_write_file(thread_fd, &io_req, |
1265 | sizeof(struct io_thread_req *)); | |
2adcec21 | 1266 | if(n != sizeof(struct io_thread_req *)){ |
a0044bdf JD |
1267 | if(n != -EAGAIN) |
1268 | printk("write to io thread failed, " | |
1269 | "errno = %d\n", -n); | |
1270 | else if(list_empty(&dev->restart)) | |
1271 | list_add(&dev->restart, &restart); | |
12429bf9 | 1272 | kfree(io_req); |
a0044bdf JD |
1273 | return; |
1274 | } | |
1275 | ||
47526903 | 1276 | dev->rq_pos += sg->length >> 9; |
a0044bdf | 1277 | dev->start_sg++; |
1da177e4 | 1278 | } |
a0044bdf JD |
1279 | dev->end_sg = 0; |
1280 | dev->request = NULL; | |
1da177e4 LT |
1281 | } |
1282 | } | |
1283 | ||
a885c8c4 CH |
1284 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1285 | { | |
7d314e34 | 1286 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
a885c8c4 CH |
1287 | |
1288 | geo->heads = 128; | |
1289 | geo->sectors = 32; | |
7d314e34 | 1290 | geo->cylinders = ubd_dev->size / (128 * 32 * 512); |
a885c8c4 CH |
1291 | return 0; |
1292 | } | |
1293 | ||
a625c998 | 1294 | static int ubd_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
1295 | unsigned int cmd, unsigned long arg) |
1296 | { | |
a625c998 | 1297 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
73855e13 | 1298 | u16 ubd_id[ATA_ID_WORDS]; |
1da177e4 LT |
1299 | |
1300 | switch (cmd) { | |
1da177e4 | 1301 | struct cdrom_volctrl volume; |
1da177e4 | 1302 | case HDIO_GET_IDENTITY: |
73855e13 BZ |
1303 | memset(&ubd_id, 0, ATA_ID_WORDS * 2); |
1304 | ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512); | |
1305 | ubd_id[ATA_ID_HEADS] = 128; | |
1306 | ubd_id[ATA_ID_SECTORS] = 32; | |
1da177e4 LT |
1307 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, |
1308 | sizeof(ubd_id))) | |
dc764e50 JD |
1309 | return -EFAULT; |
1310 | return 0; | |
b8831a1d | 1311 | |
1da177e4 LT |
1312 | case CDROMVOLREAD: |
1313 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
dc764e50 | 1314 | return -EFAULT; |
1da177e4 LT |
1315 | volume.channel0 = 255; |
1316 | volume.channel1 = 255; | |
1317 | volume.channel2 = 255; | |
1318 | volume.channel3 = 255; | |
1319 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
dc764e50 JD |
1320 | return -EFAULT; |
1321 | return 0; | |
1da177e4 | 1322 | } |
dc764e50 | 1323 | return -EINVAL; |
1da177e4 LT |
1324 | } |
1325 | ||
91acb21f | 1326 | static int update_bitmap(struct io_thread_req *req) |
1da177e4 | 1327 | { |
91acb21f | 1328 | int n; |
1da177e4 | 1329 | |
91acb21f | 1330 | if(req->cow_offset == -1) |
dc764e50 | 1331 | return 0; |
1da177e4 | 1332 | |
91acb21f JD |
1333 | n = os_seek_file(req->fds[1], req->cow_offset); |
1334 | if(n < 0){ | |
1335 | printk("do_io - bitmap lseek failed : err = %d\n", -n); | |
dc764e50 | 1336 | return 1; |
91acb21f | 1337 | } |
1da177e4 | 1338 | |
a6ea4cce JD |
1339 | n = os_write_file(req->fds[1], &req->bitmap_words, |
1340 | sizeof(req->bitmap_words)); | |
91acb21f JD |
1341 | if(n != sizeof(req->bitmap_words)){ |
1342 | printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, | |
1343 | req->fds[1]); | |
dc764e50 | 1344 | return 1; |
91acb21f | 1345 | } |
1da177e4 | 1346 | |
dc764e50 | 1347 | return 0; |
91acb21f | 1348 | } |
1da177e4 | 1349 | |
5dc62b1b | 1350 | static void do_io(struct io_thread_req *req) |
91acb21f JD |
1351 | { |
1352 | char *buf; | |
1353 | unsigned long len; | |
1354 | int n, nsectors, start, end, bit; | |
1355 | int err; | |
1356 | __u64 off; | |
1357 | ||
1358 | nsectors = req->length / req->sectorsize; | |
1359 | start = 0; | |
1360 | do { | |
1361 | bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); | |
1362 | end = start; | |
1363 | while((end < nsectors) && | |
1364 | (ubd_test_bit(end, (unsigned char *) | |
1365 | &req->sector_mask) == bit)) | |
1366 | end++; | |
1367 | ||
1368 | off = req->offset + req->offsets[bit] + | |
1369 | start * req->sectorsize; | |
1370 | len = (end - start) * req->sectorsize; | |
1371 | buf = &req->buffer[start * req->sectorsize]; | |
1372 | ||
1373 | err = os_seek_file(req->fds[bit], off); | |
1374 | if(err < 0){ | |
1375 | printk("do_io - lseek failed : err = %d\n", -err); | |
1376 | req->error = 1; | |
1377 | return; | |
1378 | } | |
1379 | if(req->op == UBD_READ){ | |
1380 | n = 0; | |
1381 | do { | |
1382 | buf = &buf[n]; | |
1383 | len -= n; | |
a6ea4cce | 1384 | n = os_read_file(req->fds[bit], buf, len); |
91acb21f JD |
1385 | if (n < 0) { |
1386 | printk("do_io - read failed, err = %d " | |
1387 | "fd = %d\n", -n, req->fds[bit]); | |
1388 | req->error = 1; | |
1389 | return; | |
1390 | } | |
1391 | } while((n < len) && (n != 0)); | |
1392 | if (n < len) memset(&buf[n], 0, len - n); | |
1393 | } else { | |
a6ea4cce | 1394 | n = os_write_file(req->fds[bit], buf, len); |
91acb21f JD |
1395 | if(n != len){ |
1396 | printk("do_io - write failed err = %d " | |
1397 | "fd = %d\n", -n, req->fds[bit]); | |
1398 | req->error = 1; | |
1399 | return; | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | start = end; | |
1404 | } while(start < nsectors); | |
1da177e4 | 1405 | |
91acb21f | 1406 | req->error = update_bitmap(req); |
1da177e4 | 1407 | } |
91acb21f JD |
1408 | |
1409 | /* Changed in start_io_thread, which is serialized by being called only | |
1410 | * from ubd_init, which is an initcall. | |
1411 | */ | |
1412 | int kernel_fd = -1; | |
1413 | ||
d8d7c28e PBG |
1414 | /* Only changed by the io thread. XXX: currently unused. */ |
1415 | static int io_count = 0; | |
91acb21f JD |
1416 | |
1417 | int io_thread(void *arg) | |
1418 | { | |
2adcec21 | 1419 | struct io_thread_req *req; |
91acb21f JD |
1420 | int n; |
1421 | ||
1422 | ignore_sigwinch_sig(); | |
1423 | while(1){ | |
a6ea4cce | 1424 | n = os_read_file(kernel_fd, &req, |
2adcec21 JD |
1425 | sizeof(struct io_thread_req *)); |
1426 | if(n != sizeof(struct io_thread_req *)){ | |
91acb21f JD |
1427 | if(n < 0) |
1428 | printk("io_thread - read failed, fd = %d, " | |
1429 | "err = %d\n", kernel_fd, -n); | |
1430 | else { | |
1431 | printk("io_thread - short read, fd = %d, " | |
1432 | "length = %d\n", kernel_fd, n); | |
1433 | } | |
1434 | continue; | |
1435 | } | |
1436 | io_count++; | |
2adcec21 | 1437 | do_io(req); |
a6ea4cce | 1438 | n = os_write_file(kernel_fd, &req, |
2adcec21 JD |
1439 | sizeof(struct io_thread_req *)); |
1440 | if(n != sizeof(struct io_thread_req *)) | |
91acb21f JD |
1441 | printk("io_thread - write failed, fd = %d, err = %d\n", |
1442 | kernel_fd, -n); | |
1443 | } | |
91acb21f | 1444 | |
1b57e9c2 JD |
1445 | return 0; |
1446 | } |