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dbddf429 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6c29256c | 2 | /* |
a41421ed | 3 | * Copyright (C) 2018 Cambridge Greys Ltd |
f88f0bdf | 4 | * Copyright (C) 2015-2016 Anton Ivanov (aivanov@brocade.com) |
1da177e4 | 5 | * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) |
1da177e4 LT |
6 | */ |
7 | ||
8 | /* 2001-09-28...2002-04-17 | |
9 | * Partition stuff by James_McMechan@hotmail.com | |
10 | * old style ubd by setting UBD_SHIFT to 0 | |
11 | * 2002-09-27...2002-10-18 massive tinkering for 2.5 | |
12 | * partitions have changed in 2.5 | |
13 | * 2003-01-29 more tinkering for 2.5.59-1 | |
14 | * This should now address the sysfs problems and has | |
15 | * the symlink for devfs to allow for booting with | |
16 | * the common /dev/ubd/discX/... names rather than | |
17 | * only /dev/ubdN/discN this version also has lots of | |
18 | * clean ups preparing for ubd-many. | |
19 | * James McMechan | |
20 | */ | |
21 | ||
1da177e4 LT |
22 | #define UBD_SHIFT 4 |
23 | ||
8ea3c06a AV |
24 | #include <linux/module.h> |
25 | #include <linux/init.h> | |
26 | #include <linux/blkdev.h> | |
4e6da0fe | 27 | #include <linux/blk-mq.h> |
8ea3c06a AV |
28 | #include <linux/ata.h> |
29 | #include <linux/hdreg.h> | |
b81e0c23 | 30 | #include <linux/major.h> |
8ea3c06a AV |
31 | #include <linux/cdrom.h> |
32 | #include <linux/proc_fs.h> | |
33 | #include <linux/seq_file.h> | |
34 | #include <linux/ctype.h> | |
35 | #include <linux/slab.h> | |
36 | #include <linux/vmalloc.h> | |
37 | #include <linux/platform_device.h> | |
38 | #include <linux/scatterlist.h> | |
39 | #include <asm/tlbflush.h> | |
37185b33 | 40 | #include <kern_util.h> |
1da177e4 | 41 | #include "mconsole_kern.h" |
37185b33 AV |
42 | #include <init.h> |
43 | #include <irq_kern.h> | |
8ea3c06a | 44 | #include "ubd.h" |
37185b33 | 45 | #include <os.h> |
1da177e4 LT |
46 | #include "cow.h" |
47 | ||
a43c8316 AI |
48 | /* Max request size is determined by sector mask - 32K */ |
49 | #define UBD_MAX_REQUEST (8 * sizeof(long)) | |
1da177e4 | 50 | |
fc6b6a87 GKB |
51 | struct io_desc { |
52 | char *buffer; | |
53 | unsigned long length; | |
54 | unsigned long sector_mask; | |
55 | unsigned long long cow_offset; | |
56 | unsigned long bitmap_words[2]; | |
57 | }; | |
58 | ||
1da177e4 | 59 | struct io_thread_req { |
62f96cb0 | 60 | struct request *req; |
1da177e4 LT |
61 | int fds[2]; |
62 | unsigned long offsets[2]; | |
63 | unsigned long long offset; | |
1da177e4 | 64 | int sectorsize; |
1da177e4 | 65 | int error; |
fc6b6a87 GKB |
66 | |
67 | int desc_cnt; | |
68 | /* io_desc has to be the last element of the struct */ | |
69 | struct io_desc io_desc[]; | |
1da177e4 LT |
70 | }; |
71 | ||
f88f0bdf AI |
72 | |
73 | static struct io_thread_req * (*irq_req_buffer)[]; | |
74 | static struct io_thread_req *irq_remainder; | |
75 | static int irq_remainder_size; | |
76 | ||
77 | static struct io_thread_req * (*io_req_buffer)[]; | |
78 | static struct io_thread_req *io_remainder; | |
79 | static int io_remainder_size; | |
80 | ||
81 | ||
82 | ||
91acb21f | 83 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
84 | { |
85 | __u64 n; | |
86 | int bits, off; | |
87 | ||
91acb21f | 88 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
89 | n = bit / bits; |
90 | off = bit % bits; | |
dc764e50 | 91 | return (data[n] & (1 << off)) != 0; |
1da177e4 LT |
92 | } |
93 | ||
91acb21f | 94 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
95 | { |
96 | __u64 n; | |
97 | int bits, off; | |
98 | ||
91acb21f | 99 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
100 | n = bit / bits; |
101 | off = bit % bits; | |
91acb21f | 102 | data[n] |= (1 << off); |
1da177e4 LT |
103 | } |
104 | /*End stuff from ubd_user.h*/ | |
105 | ||
106 | #define DRIVER_NAME "uml-blkdev" | |
107 | ||
d7fb2c38 | 108 | static DEFINE_MUTEX(ubd_lock); |
9a181c58 | 109 | static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */ |
1da177e4 | 110 | |
05bdb996 | 111 | static int ubd_ioctl(struct block_device *bdev, blk_mode_t mode, |
1da177e4 | 112 | unsigned int cmd, unsigned long arg); |
a885c8c4 | 113 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
1da177e4 | 114 | |
97d88ac8 | 115 | #define MAX_DEV (16) |
1da177e4 | 116 | |
83d5cde4 | 117 | static const struct block_device_operations ubd_blops = { |
1da177e4 | 118 | .owner = THIS_MODULE, |
a625c998 | 119 | .ioctl = ubd_ioctl, |
ab0cf1e4 | 120 | .compat_ioctl = blkdev_compat_ptr_ioctl, |
a885c8c4 | 121 | .getgeo = ubd_getgeo, |
1da177e4 LT |
122 | }; |
123 | ||
1da177e4 LT |
124 | #ifdef CONFIG_BLK_DEV_UBD_SYNC |
125 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
126 | .cl = 1 }) | |
127 | #else | |
128 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
129 | .cl = 1 }) | |
130 | #endif | |
1da177e4 LT |
131 | static struct openflags global_openflags = OPEN_FLAGS; |
132 | ||
133 | struct cow { | |
2a9d32f6 | 134 | /* backing file name */ |
1da177e4 | 135 | char *file; |
2a9d32f6 | 136 | /* backing file fd */ |
1da177e4 LT |
137 | int fd; |
138 | unsigned long *bitmap; | |
139 | unsigned long bitmap_len; | |
140 | int bitmap_offset; | |
dc764e50 | 141 | int data_offset; |
1da177e4 LT |
142 | }; |
143 | ||
a0044bdf JD |
144 | #define MAX_SG 64 |
145 | ||
1da177e4 | 146 | struct ubd { |
2a9d32f6 PBG |
147 | /* name (and fd, below) of the file opened for writing, either the |
148 | * backing or the cow file. */ | |
1da177e4 | 149 | char *file; |
ef3ba87c | 150 | char *serial; |
1da177e4 LT |
151 | int fd; |
152 | __u64 size; | |
153 | struct openflags boot_openflags; | |
154 | struct openflags openflags; | |
84e945e3 PBG |
155 | unsigned shared:1; |
156 | unsigned no_cow:1; | |
50109b5a | 157 | unsigned no_trim:1; |
1da177e4 LT |
158 | struct cow cow; |
159 | struct platform_device pdev; | |
32621ad7 | 160 | struct gendisk *disk; |
4e6da0fe | 161 | struct blk_mq_tag_set tag_set; |
62f96cb0 | 162 | spinlock_t lock; |
4e6da0fe RW |
163 | }; |
164 | ||
1da177e4 LT |
165 | #define DEFAULT_COW { \ |
166 | .file = NULL, \ | |
dc764e50 JD |
167 | .fd = -1, \ |
168 | .bitmap = NULL, \ | |
1da177e4 | 169 | .bitmap_offset = 0, \ |
dc764e50 | 170 | .data_offset = 0, \ |
1da177e4 LT |
171 | } |
172 | ||
173 | #define DEFAULT_UBD { \ | |
174 | .file = NULL, \ | |
ef3ba87c | 175 | .serial = NULL, \ |
1da177e4 LT |
176 | .fd = -1, \ |
177 | .size = -1, \ | |
178 | .boot_openflags = OPEN_FLAGS, \ | |
179 | .openflags = OPEN_FLAGS, \ | |
dc764e50 | 180 | .no_cow = 0, \ |
50109b5a | 181 | .no_trim = 0, \ |
6c29256c | 182 | .shared = 0, \ |
dc764e50 | 183 | .cow = DEFAULT_COW, \ |
22e65004 | 184 | .lock = __SPIN_LOCK_UNLOCKED(ubd_devs.lock), \ |
1da177e4 LT |
185 | } |
186 | ||
b8831a1d | 187 | /* Protected by ubd_lock */ |
5dc62b1b | 188 | static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD }; |
1da177e4 | 189 | |
4e6da0fe RW |
190 | static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, |
191 | const struct blk_mq_queue_data *bd); | |
4e6da0fe | 192 | |
1da177e4 LT |
193 | static int fake_ide_setup(char *str) |
194 | { | |
7eb90f7e | 195 | pr_warn("The fake_ide option has been removed\n"); |
dc764e50 | 196 | return 1; |
1da177e4 | 197 | } |
1da177e4 LT |
198 | __setup("fake_ide", fake_ide_setup); |
199 | ||
200 | __uml_help(fake_ide_setup, | |
201 | "fake_ide\n" | |
7eb90f7e | 202 | " Obsolete stub.\n\n" |
1da177e4 LT |
203 | ); |
204 | ||
205 | static int parse_unit(char **ptr) | |
206 | { | |
207 | char *str = *ptr, *end; | |
208 | int n = -1; | |
209 | ||
210 | if(isdigit(*str)) { | |
211 | n = simple_strtoul(str, &end, 0); | |
212 | if(end == str) | |
dc764e50 | 213 | return -1; |
1da177e4 LT |
214 | *ptr = end; |
215 | } | |
97d88ac8 | 216 | else if (('a' <= *str) && (*str <= 'z')) { |
1da177e4 LT |
217 | n = *str - 'a'; |
218 | str++; | |
219 | *ptr = str; | |
220 | } | |
dc764e50 | 221 | return n; |
1da177e4 LT |
222 | } |
223 | ||
d8d7c28e PBG |
224 | /* If *index_out == -1 at exit, the passed option was a general one; |
225 | * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it | |
226 | * should not be freed on exit. | |
227 | */ | |
f28169d2 | 228 | static int ubd_setup_common(char *str, int *index_out, char **error_out) |
1da177e4 | 229 | { |
7d314e34 | 230 | struct ubd *ubd_dev; |
1da177e4 | 231 | struct openflags flags = global_openflags; |
ef3ba87c | 232 | char *file, *backing_file, *serial; |
b8831a1d | 233 | int n, err = 0, i; |
1da177e4 LT |
234 | |
235 | if(index_out) *index_out = -1; | |
236 | n = *str; | |
237 | if(n == '='){ | |
1da177e4 | 238 | str++; |
1da177e4 LT |
239 | if(!strcmp(str, "sync")){ |
240 | global_openflags = of_sync(global_openflags); | |
9ca55299 | 241 | return err; |
1da177e4 | 242 | } |
b8831a1d | 243 | |
7eb90f7e CH |
244 | pr_warn("fake major not supported any more\n"); |
245 | return 0; | |
1da177e4 LT |
246 | } |
247 | ||
248 | n = parse_unit(&str); | |
249 | if(n < 0){ | |
f28169d2 JD |
250 | *error_out = "Couldn't parse device number"; |
251 | return -EINVAL; | |
1da177e4 LT |
252 | } |
253 | if(n >= MAX_DEV){ | |
f28169d2 JD |
254 | *error_out = "Device number out of range"; |
255 | return 1; | |
1da177e4 LT |
256 | } |
257 | ||
f28169d2 | 258 | err = -EBUSY; |
d7fb2c38 | 259 | mutex_lock(&ubd_lock); |
1da177e4 | 260 | |
7d314e34 PBG |
261 | ubd_dev = &ubd_devs[n]; |
262 | if(ubd_dev->file != NULL){ | |
f28169d2 | 263 | *error_out = "Device is already configured"; |
1da177e4 LT |
264 | goto out; |
265 | } | |
266 | ||
267 | if (index_out) | |
268 | *index_out = n; | |
269 | ||
f28169d2 | 270 | err = -EINVAL; |
50109b5a | 271 | for (i = 0; i < sizeof("rscdt="); i++) { |
1da177e4 LT |
272 | switch (*str) { |
273 | case 'r': | |
274 | flags.w = 0; | |
275 | break; | |
276 | case 's': | |
277 | flags.s = 1; | |
278 | break; | |
279 | case 'd': | |
7d314e34 | 280 | ubd_dev->no_cow = 1; |
1da177e4 | 281 | break; |
6c29256c | 282 | case 'c': |
7d314e34 | 283 | ubd_dev->shared = 1; |
6c29256c | 284 | break; |
50109b5a AI |
285 | case 't': |
286 | ubd_dev->no_trim = 1; | |
287 | break; | |
1da177e4 LT |
288 | case '=': |
289 | str++; | |
290 | goto break_loop; | |
291 | default: | |
f28169d2 | 292 | *error_out = "Expected '=' or flag letter " |
50109b5a | 293 | "(r, s, c, t or d)"; |
1da177e4 LT |
294 | goto out; |
295 | } | |
296 | str++; | |
297 | } | |
298 | ||
f28169d2 JD |
299 | if (*str == '=') |
300 | *error_out = "Too many flags specified"; | |
301 | else | |
302 | *error_out = "Missing '='"; | |
1da177e4 LT |
303 | goto out; |
304 | ||
305 | break_loop: | |
ef3ba87c CO |
306 | file = strsep(&str, ",:"); |
307 | if (*file == '\0') | |
308 | file = NULL; | |
1da177e4 | 309 | |
ef3ba87c | 310 | backing_file = strsep(&str, ",:"); |
94c41b3a | 311 | if (backing_file && *backing_file == '\0') |
ef3ba87c | 312 | backing_file = NULL; |
1da177e4 | 313 | |
ef3ba87c | 314 | serial = strsep(&str, ",:"); |
94c41b3a | 315 | if (serial && *serial == '\0') |
ef3ba87c CO |
316 | serial = NULL; |
317 | ||
318 | if (backing_file && ubd_dev->no_cow) { | |
319 | *error_out = "Can't specify both 'd' and a cow file"; | |
320 | goto out; | |
1da177e4 | 321 | } |
ef3ba87c | 322 | |
f28169d2 | 323 | err = 0; |
ef3ba87c | 324 | ubd_dev->file = file; |
7d314e34 | 325 | ubd_dev->cow.file = backing_file; |
ef3ba87c | 326 | ubd_dev->serial = serial; |
7d314e34 | 327 | ubd_dev->boot_openflags = flags; |
1da177e4 | 328 | out: |
d7fb2c38 | 329 | mutex_unlock(&ubd_lock); |
f28169d2 | 330 | return err; |
1da177e4 LT |
331 | } |
332 | ||
333 | static int ubd_setup(char *str) | |
334 | { | |
f28169d2 JD |
335 | char *error; |
336 | int err; | |
337 | ||
338 | err = ubd_setup_common(str, NULL, &error); | |
339 | if(err) | |
340 | printk(KERN_ERR "Failed to initialize device with \"%s\" : " | |
341 | "%s\n", str, error); | |
342 | return 1; | |
1da177e4 LT |
343 | } |
344 | ||
345 | __setup("ubd", ubd_setup); | |
346 | __uml_help(ubd_setup, | |
ef3ba87c | 347 | "ubd<n><flags>=<filename>[(:|,)<filename2>][(:|,)<serial>]\n" |
1da177e4 LT |
348 | " This is used to associate a device with a file in the underlying\n" |
349 | " filesystem. When specifying two filenames, the first one is the\n" | |
350 | " COW name and the second is the backing file name. As separator you can\n" | |
351 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
352 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
353 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
f28169d2 | 354 | " When using only one filename, UML will detect whether to treat it like\n" |
1da177e4 LT |
355 | " a COW file or a backing file. To override this detection, add the 'd'\n" |
356 | " flag:\n" | |
357 | " ubd0d=BackingFile\n" | |
358 | " Usually, there is a filesystem in the file, but \n" | |
359 | " that's not required. Swap devices containing swap files can be\n" | |
360 | " specified like this. Also, a file which doesn't contain a\n" | |
361 | " filesystem can have its contents read in the virtual \n" | |
362 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
363 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
364 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
20ede453 JD |
365 | " an 's' will cause data to be written to disk on the host immediately.\n" |
366 | " 'c' will cause the device to be treated as being shared between multiple\n" | |
367 | " UMLs and file locking will be turned off - this is appropriate for a\n" | |
368 | " cluster filesystem and inappropriate at almost all other times.\n\n" | |
50109b5a | 369 | " 't' will disable trim/discard support on the device (enabled by default).\n\n" |
ef3ba87c CO |
370 | " An optional device serial number can be exposed using the serial parameter\n" |
371 | " on the cmdline which is exposed as a sysfs entry. This is particularly\n" | |
372 | " useful when a unique number should be given to the device. Note when\n" | |
373 | " specifying a label, the filename2 must be also presented. It can be\n" | |
374 | " an empty string, in which case the backing file is not used:\n" | |
375 | " ubd0=File,,Serial\n" | |
1da177e4 LT |
376 | ); |
377 | ||
8299ca5c | 378 | static int udb_setup(char *str) |
1da177e4 LT |
379 | { |
380 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
381 | "udb TYPO\n", str); | |
dc764e50 | 382 | return 1; |
1da177e4 LT |
383 | } |
384 | ||
385 | __setup("udb", udb_setup); | |
386 | __uml_help(udb_setup, | |
387 | "udb\n" | |
0894e27e JD |
388 | " This option is here solely to catch ubd -> udb typos, which can be\n" |
389 | " to impossible to catch visually unless you specifically look for\n" | |
390 | " them. The only result of any option starting with 'udb' is an error\n" | |
1da177e4 LT |
391 | " in the boot output.\n\n" |
392 | ); | |
393 | ||
91acb21f | 394 | /* Only changed by ubd_init, which is an initcall. */ |
5dc62b1b | 395 | static int thread_fd = -1; |
a0044bdf | 396 | |
f88f0bdf AI |
397 | /* Function to read several request pointers at a time |
398 | * handling fractional reads if (and as) needed | |
399 | */ | |
400 | ||
401 | static int bulk_req_safe_read( | |
402 | int fd, | |
403 | struct io_thread_req * (*request_buffer)[], | |
404 | struct io_thread_req **remainder, | |
405 | int *remainder_size, | |
406 | int max_recs | |
407 | ) | |
408 | { | |
409 | int n = 0; | |
410 | int res = 0; | |
411 | ||
412 | if (*remainder_size > 0) { | |
413 | memmove( | |
414 | (char *) request_buffer, | |
415 | (char *) remainder, *remainder_size | |
416 | ); | |
417 | n = *remainder_size; | |
418 | } | |
419 | ||
420 | res = os_read_file( | |
421 | fd, | |
422 | ((char *) request_buffer) + *remainder_size, | |
423 | sizeof(struct io_thread_req *)*max_recs | |
424 | - *remainder_size | |
425 | ); | |
426 | if (res > 0) { | |
427 | n += res; | |
428 | if ((n % sizeof(struct io_thread_req *)) > 0) { | |
429 | /* | |
430 | * Read somehow returned not a multiple of dword | |
431 | * theoretically possible, but never observed in the | |
432 | * wild, so read routine must be able to handle it | |
433 | */ | |
434 | *remainder_size = n % sizeof(struct io_thread_req *); | |
435 | WARN(*remainder_size > 0, "UBD IPC read returned a partial result"); | |
436 | memmove( | |
437 | remainder, | |
438 | ((char *) request_buffer) + | |
439 | (n/sizeof(struct io_thread_req *))*sizeof(struct io_thread_req *), | |
440 | *remainder_size | |
441 | ); | |
442 | n = n - *remainder_size; | |
443 | } | |
444 | } else { | |
445 | n = res; | |
446 | } | |
447 | return n; | |
448 | } | |
449 | ||
62f96cb0 | 450 | /* Called without dev->lock held, and only in interrupt context. */ |
91acb21f | 451 | static void ubd_handler(void) |
1da177e4 | 452 | { |
91acb21f | 453 | int n; |
f88f0bdf | 454 | int count; |
91acb21f | 455 | |
a0044bdf | 456 | while(1){ |
f88f0bdf AI |
457 | n = bulk_req_safe_read( |
458 | thread_fd, | |
459 | irq_req_buffer, | |
460 | &irq_remainder, | |
461 | &irq_remainder_size, | |
462 | UBD_REQ_BUFFER_SIZE | |
463 | ); | |
464 | if (n < 0) { | |
a0044bdf JD |
465 | if(n == -EAGAIN) |
466 | break; | |
467 | printk(KERN_ERR "spurious interrupt in ubd_handler, " | |
468 | "err = %d\n", -n); | |
469 | return; | |
470 | } | |
f88f0bdf | 471 | for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { |
4e6da0fe | 472 | struct io_thread_req *io_req = (*irq_req_buffer)[count]; |
4e6da0fe | 473 | |
50109b5a AI |
474 | if ((io_req->error == BLK_STS_NOTSUPP) && (req_op(io_req->req) == REQ_OP_DISCARD)) { |
475 | blk_queue_max_discard_sectors(io_req->req->q, 0); | |
476 | blk_queue_max_write_zeroes_sectors(io_req->req->q, 0); | |
50109b5a | 477 | } |
fc6b6a87 | 478 | blk_mq_end_request(io_req->req, io_req->error); |
4e6da0fe | 479 | kfree(io_req); |
f88f0bdf | 480 | } |
a0044bdf | 481 | } |
1da177e4 LT |
482 | } |
483 | ||
7bea96fd | 484 | static irqreturn_t ubd_intr(int irq, void *dev) |
1da177e4 | 485 | { |
91acb21f | 486 | ubd_handler(); |
dc764e50 | 487 | return IRQ_HANDLED; |
91acb21f | 488 | } |
09ace81c | 489 | |
91acb21f JD |
490 | /* Only changed by ubd_init, which is an initcall. */ |
491 | static int io_pid = -1; | |
09ace81c | 492 | |
5dc62b1b | 493 | static void kill_io_thread(void) |
91acb21f | 494 | { |
6c29256c | 495 | if(io_pid != -1) |
91acb21f | 496 | os_kill_process(io_pid, 1); |
09ace81c | 497 | } |
1da177e4 | 498 | |
91acb21f JD |
499 | __uml_exitcall(kill_io_thread); |
500 | ||
d8d7c28e | 501 | static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) |
1da177e4 LT |
502 | { |
503 | char *file; | |
85356398 RW |
504 | int fd; |
505 | int err; | |
506 | ||
507 | __u32 version; | |
508 | __u32 align; | |
509 | char *backing_file; | |
853bc0ab | 510 | time64_t mtime; |
85356398 RW |
511 | unsigned long long size; |
512 | int sector_size; | |
513 | int bitmap_offset; | |
514 | ||
515 | if (ubd_dev->file && ubd_dev->cow.file) { | |
516 | file = ubd_dev->cow.file; | |
517 | ||
518 | goto out; | |
519 | } | |
520 | ||
d4afcba9 | 521 | fd = os_open_file(ubd_dev->file, of_read(OPENFLAGS()), 0); |
85356398 RW |
522 | if (fd < 0) |
523 | return fd; | |
524 | ||
525 | err = read_cow_header(file_reader, &fd, &version, &backing_file, \ | |
526 | &mtime, &size, §or_size, &align, &bitmap_offset); | |
527 | os_close_file(fd); | |
1da177e4 | 528 | |
85356398 RW |
529 | if(err == -EINVAL) |
530 | file = ubd_dev->file; | |
531 | else | |
532 | file = backing_file; | |
533 | ||
534 | out: | |
dc764e50 | 535 | return os_file_size(file, size_out); |
1da177e4 LT |
536 | } |
537 | ||
5dc62b1b WC |
538 | static int read_cow_bitmap(int fd, void *buf, int offset, int len) |
539 | { | |
540 | int err; | |
541 | ||
8c6157b6 | 542 | err = os_pread_file(fd, buf, len, offset); |
5dc62b1b WC |
543 | if (err < 0) |
544 | return err; | |
545 | ||
546 | return 0; | |
547 | } | |
548 | ||
853bc0ab | 549 | static int backing_file_mismatch(char *file, __u64 size, time64_t mtime) |
5dc62b1b | 550 | { |
853bc0ab | 551 | time64_t modtime; |
5dc62b1b WC |
552 | unsigned long long actual; |
553 | int err; | |
554 | ||
555 | err = os_file_modtime(file, &modtime); | |
556 | if (err < 0) { | |
557 | printk(KERN_ERR "Failed to get modification time of backing " | |
558 | "file \"%s\", err = %d\n", file, -err); | |
559 | return err; | |
560 | } | |
561 | ||
562 | err = os_file_size(file, &actual); | |
563 | if (err < 0) { | |
564 | printk(KERN_ERR "Failed to get size of backing file \"%s\", " | |
565 | "err = %d\n", file, -err); | |
566 | return err; | |
567 | } | |
568 | ||
569 | if (actual != size) { | |
570 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
571 | * the typecast.*/ | |
572 | printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header " | |
573 | "vs backing file\n", (unsigned long long) size, actual); | |
574 | return -EINVAL; | |
575 | } | |
576 | if (modtime != mtime) { | |
853bc0ab | 577 | printk(KERN_ERR "mtime mismatch (%lld vs %lld) of COW header vs " |
5dc62b1b WC |
578 | "backing file\n", mtime, modtime); |
579 | return -EINVAL; | |
580 | } | |
581 | return 0; | |
582 | } | |
583 | ||
584 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) | |
585 | { | |
586 | struct uml_stat buf1, buf2; | |
587 | int err; | |
588 | ||
589 | if (from_cmdline == NULL) | |
590 | return 0; | |
591 | if (!strcmp(from_cmdline, from_cow)) | |
592 | return 0; | |
593 | ||
594 | err = os_stat_file(from_cmdline, &buf1); | |
595 | if (err < 0) { | |
596 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline, | |
597 | -err); | |
598 | return 0; | |
599 | } | |
600 | err = os_stat_file(from_cow, &buf2); | |
601 | if (err < 0) { | |
602 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow, | |
603 | -err); | |
604 | return 1; | |
605 | } | |
606 | if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
607 | return 0; | |
608 | ||
609 | printk(KERN_ERR "Backing file mismatch - \"%s\" requested, " | |
610 | "\"%s\" specified in COW header of \"%s\"\n", | |
611 | from_cmdline, from_cow, cow); | |
612 | return 1; | |
613 | } | |
614 | ||
615 | static int open_ubd_file(char *file, struct openflags *openflags, int shared, | |
616 | char **backing_file_out, int *bitmap_offset_out, | |
617 | unsigned long *bitmap_len_out, int *data_offset_out, | |
618 | int *create_cow_out) | |
619 | { | |
853bc0ab | 620 | time64_t mtime; |
5dc62b1b WC |
621 | unsigned long long size; |
622 | __u32 version, align; | |
623 | char *backing_file; | |
624 | int fd, err, sectorsize, asked_switch, mode = 0644; | |
625 | ||
626 | fd = os_open_file(file, *openflags, mode); | |
627 | if (fd < 0) { | |
628 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
629 | *create_cow_out = 1; | |
630 | if (!openflags->w || | |
631 | ((fd != -EROFS) && (fd != -EACCES))) | |
632 | return fd; | |
633 | openflags->w = 0; | |
634 | fd = os_open_file(file, *openflags, mode); | |
635 | if (fd < 0) | |
636 | return fd; | |
637 | } | |
638 | ||
639 | if (shared) | |
640 | printk(KERN_INFO "Not locking \"%s\" on the host\n", file); | |
641 | else { | |
642 | err = os_lock_file(fd, openflags->w); | |
643 | if (err < 0) { | |
644 | printk(KERN_ERR "Failed to lock '%s', err = %d\n", | |
645 | file, -err); | |
646 | goto out_close; | |
647 | } | |
648 | } | |
649 | ||
650 | /* Successful return case! */ | |
651 | if (backing_file_out == NULL) | |
652 | return fd; | |
653 | ||
654 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
655 | &size, §orsize, &align, bitmap_offset_out); | |
656 | if (err && (*backing_file_out != NULL)) { | |
657 | printk(KERN_ERR "Failed to read COW header from COW file " | |
658 | "\"%s\", errno = %d\n", file, -err); | |
659 | goto out_close; | |
660 | } | |
661 | if (err) | |
662 | return fd; | |
663 | ||
664 | asked_switch = path_requires_switch(*backing_file_out, backing_file, | |
665 | file); | |
666 | ||
667 | /* Allow switching only if no mismatch. */ | |
668 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, | |
669 | mtime)) { | |
670 | printk(KERN_ERR "Switching backing file to '%s'\n", | |
671 | *backing_file_out); | |
672 | err = write_cow_header(file, fd, *backing_file_out, | |
673 | sectorsize, align, &size); | |
674 | if (err) { | |
675 | printk(KERN_ERR "Switch failed, errno = %d\n", -err); | |
676 | goto out_close; | |
677 | } | |
678 | } else { | |
679 | *backing_file_out = backing_file; | |
680 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
681 | if (err) | |
682 | goto out_close; | |
683 | } | |
684 | ||
685 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
686 | bitmap_len_out, data_offset_out); | |
687 | ||
688 | return fd; | |
689 | out_close: | |
690 | os_close_file(fd); | |
691 | return err; | |
692 | } | |
693 | ||
694 | static int create_cow_file(char *cow_file, char *backing_file, | |
695 | struct openflags flags, | |
696 | int sectorsize, int alignment, int *bitmap_offset_out, | |
697 | unsigned long *bitmap_len_out, int *data_offset_out) | |
698 | { | |
699 | int err, fd; | |
700 | ||
701 | flags.c = 1; | |
702 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); | |
703 | if (fd < 0) { | |
704 | err = fd; | |
705 | printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n", | |
706 | cow_file, -err); | |
707 | goto out; | |
708 | } | |
709 | ||
710 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
711 | bitmap_offset_out, bitmap_len_out, | |
712 | data_offset_out); | |
713 | if (!err) | |
714 | return fd; | |
715 | os_close_file(fd); | |
716 | out: | |
717 | return err; | |
718 | } | |
719 | ||
5f75a4f8 | 720 | static void ubd_close_dev(struct ubd *ubd_dev) |
1da177e4 | 721 | { |
7d314e34 PBG |
722 | os_close_file(ubd_dev->fd); |
723 | if(ubd_dev->cow.file == NULL) | |
1da177e4 LT |
724 | return; |
725 | ||
7d314e34 PBG |
726 | os_close_file(ubd_dev->cow.fd); |
727 | vfree(ubd_dev->cow.bitmap); | |
728 | ubd_dev->cow.bitmap = NULL; | |
1da177e4 LT |
729 | } |
730 | ||
7d314e34 | 731 | static int ubd_open_dev(struct ubd *ubd_dev) |
1da177e4 LT |
732 | { |
733 | struct openflags flags; | |
734 | char **back_ptr; | |
735 | int err, create_cow, *create_ptr; | |
0bf16bff | 736 | int fd; |
1da177e4 | 737 | |
7d314e34 | 738 | ubd_dev->openflags = ubd_dev->boot_openflags; |
1da177e4 | 739 | create_cow = 0; |
7d314e34 PBG |
740 | create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; |
741 | back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; | |
0bf16bff PBG |
742 | |
743 | fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, | |
7d314e34 PBG |
744 | back_ptr, &ubd_dev->cow.bitmap_offset, |
745 | &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, | |
6c29256c | 746 | create_ptr); |
1da177e4 | 747 | |
0bf16bff PBG |
748 | if((fd == -ENOENT) && create_cow){ |
749 | fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, | |
a43c8316 | 750 | ubd_dev->openflags, SECTOR_SIZE, PAGE_SIZE, |
7d314e34 PBG |
751 | &ubd_dev->cow.bitmap_offset, |
752 | &ubd_dev->cow.bitmap_len, | |
753 | &ubd_dev->cow.data_offset); | |
0bf16bff | 754 | if(fd >= 0){ |
1da177e4 | 755 | printk(KERN_INFO "Creating \"%s\" as COW file for " |
7d314e34 | 756 | "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); |
1da177e4 LT |
757 | } |
758 | } | |
759 | ||
0bf16bff | 760 | if(fd < 0){ |
7d314e34 | 761 | printk("Failed to open '%s', errno = %d\n", ubd_dev->file, |
0bf16bff PBG |
762 | -fd); |
763 | return fd; | |
1da177e4 | 764 | } |
0bf16bff | 765 | ubd_dev->fd = fd; |
1da177e4 | 766 | |
7d314e34 | 767 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 768 | err = -ENOMEM; |
da2486ba | 769 | ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len); |
7d314e34 | 770 | if(ubd_dev->cow.bitmap == NULL){ |
1da177e4 LT |
771 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); |
772 | goto error; | |
773 | } | |
774 | flush_tlb_kernel_vm(); | |
775 | ||
7d314e34 PBG |
776 | err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, |
777 | ubd_dev->cow.bitmap_offset, | |
778 | ubd_dev->cow.bitmap_len); | |
1da177e4 LT |
779 | if(err < 0) |
780 | goto error; | |
781 | ||
7d314e34 | 782 | flags = ubd_dev->openflags; |
1da177e4 | 783 | flags.w = 0; |
7d314e34 | 784 | err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, |
6c29256c | 785 | NULL, NULL, NULL, NULL); |
1da177e4 | 786 | if(err < 0) goto error; |
7d314e34 | 787 | ubd_dev->cow.fd = err; |
1da177e4 | 788 | } |
dc764e50 | 789 | return 0; |
1da177e4 | 790 | error: |
7d314e34 | 791 | os_close_file(ubd_dev->fd); |
dc764e50 | 792 | return err; |
1da177e4 LT |
793 | } |
794 | ||
2e3f5251 JD |
795 | static void ubd_device_release(struct device *dev) |
796 | { | |
8691b97b | 797 | struct ubd *ubd_dev = dev_get_drvdata(dev); |
2e3f5251 | 798 | |
4e6da0fe | 799 | blk_mq_free_tag_set(&ubd_dev->tag_set); |
2e3f5251 JD |
800 | *ubd_dev = ((struct ubd) DEFAULT_UBD); |
801 | } | |
802 | ||
ef3ba87c CO |
803 | static ssize_t serial_show(struct device *dev, |
804 | struct device_attribute *attr, char *buf) | |
805 | { | |
806 | struct gendisk *disk = dev_to_disk(dev); | |
807 | struct ubd *ubd_dev = disk->private_data; | |
808 | ||
809 | if (!ubd_dev) | |
810 | return 0; | |
811 | ||
812 | return sprintf(buf, "%s", ubd_dev->serial); | |
813 | } | |
814 | ||
815 | static DEVICE_ATTR_RO(serial); | |
816 | ||
817 | static struct attribute *ubd_attrs[] = { | |
818 | &dev_attr_serial.attr, | |
819 | NULL, | |
820 | }; | |
821 | ||
822 | static umode_t ubd_attrs_are_visible(struct kobject *kobj, | |
823 | struct attribute *a, int n) | |
824 | { | |
825 | return a->mode; | |
826 | } | |
827 | ||
828 | static const struct attribute_group ubd_attr_group = { | |
829 | .attrs = ubd_attrs, | |
830 | .is_visible = ubd_attrs_are_visible, | |
831 | }; | |
832 | ||
833 | static const struct attribute_group *ubd_attr_groups[] = { | |
834 | &ubd_attr_group, | |
835 | NULL, | |
836 | }; | |
837 | ||
a43c8316 | 838 | #define ROUND_BLOCK(n) ((n + (SECTOR_SIZE - 1)) & (-SECTOR_SIZE)) |
1da177e4 | 839 | |
4e6da0fe RW |
840 | static const struct blk_mq_ops ubd_mq_ops = { |
841 | .queue_rq = ubd_queue_rq, | |
4e6da0fe RW |
842 | }; |
843 | ||
f28169d2 | 844 | static int ubd_add(int n, char **error_out) |
1da177e4 | 845 | { |
7d314e34 | 846 | struct ubd *ubd_dev = &ubd_devs[n]; |
5d6789ce CH |
847 | struct queue_limits lim = { |
848 | .max_segments = MAX_SG, | |
849 | .seg_boundary_mask = PAGE_SIZE - 1, | |
850 | }; | |
35efb594 | 851 | struct gendisk *disk; |
f28169d2 | 852 | int err = 0; |
1da177e4 | 853 | |
7d314e34 | 854 | if(ubd_dev->file == NULL) |
ec7cf783 | 855 | goto out; |
1da177e4 | 856 | |
58ebe3e7 CH |
857 | if (ubd_dev->cow.file) |
858 | lim.max_hw_sectors = 8 * sizeof(long); | |
859 | if (!ubd_dev->no_trim) { | |
860 | lim.max_hw_discard_sectors = UBD_MAX_REQUEST; | |
861 | lim.max_write_zeroes_sectors = UBD_MAX_REQUEST; | |
862 | } | |
863 | ||
7d314e34 | 864 | err = ubd_file_size(ubd_dev, &ubd_dev->size); |
f28169d2 JD |
865 | if(err < 0){ |
866 | *error_out = "Couldn't determine size of device's file"; | |
80c13749 | 867 | goto out; |
f28169d2 | 868 | } |
1da177e4 | 869 | |
fb5d1d38 CH |
870 | err = ubd_open_dev(ubd_dev); |
871 | if (err) { | |
872 | pr_err("ubd%c: Can't open \"%s\": errno = %d\n", | |
873 | 'a' + n, ubd_dev->file, -err); | |
874 | goto out; | |
875 | } | |
876 | ||
7d314e34 | 877 | ubd_dev->size = ROUND_BLOCK(ubd_dev->size); |
1da177e4 | 878 | |
4e6da0fe RW |
879 | ubd_dev->tag_set.ops = &ubd_mq_ops; |
880 | ubd_dev->tag_set.queue_depth = 64; | |
881 | ubd_dev->tag_set.numa_node = NUMA_NO_NODE; | |
882 | ubd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; | |
4e6da0fe RW |
883 | ubd_dev->tag_set.driver_data = ubd_dev; |
884 | ubd_dev->tag_set.nr_hw_queues = 1; | |
a0044bdf | 885 | |
4e6da0fe RW |
886 | err = blk_mq_alloc_tag_set(&ubd_dev->tag_set); |
887 | if (err) | |
fb5d1d38 | 888 | goto out_close; |
4e6da0fe | 889 | |
5d6789ce | 890 | disk = blk_mq_alloc_disk(&ubd_dev->tag_set, &lim, ubd_dev); |
35efb594 CH |
891 | if (IS_ERR(disk)) { |
892 | err = PTR_ERR(disk); | |
aea05eb5 | 893 | goto out_cleanup_tags; |
62f96cb0 | 894 | } |
4e6da0fe | 895 | |
b8b364d2 | 896 | blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); |
f3c17dcc | 897 | blk_queue_write_cache(disk->queue, true, false); |
0267e9ca CH |
898 | disk->major = UBD_MAJOR; |
899 | disk->first_minor = n << UBD_SHIFT; | |
900 | disk->minors = 1 << UBD_SHIFT; | |
901 | disk->fops = &ubd_blops; | |
902 | set_capacity(disk, ubd_dev->size / 512); | |
903 | sprintf(disk->disk_name, "ubd%c", 'a' + n); | |
904 | disk->private_data = ubd_dev; | |
5e4e1ff8 | 905 | set_disk_ro(disk, !ubd_dev->openflags.w); |
0267e9ca CH |
906 | |
907 | ubd_dev->pdev.id = n; | |
908 | ubd_dev->pdev.name = DRIVER_NAME; | |
909 | ubd_dev->pdev.dev.release = ubd_device_release; | |
910 | dev_set_drvdata(&ubd_dev->pdev.dev, ubd_dev); | |
911 | platform_device_register(&ubd_dev->pdev); | |
912 | ||
913 | err = device_add_disk(&ubd_dev->pdev.dev, disk, ubd_attr_groups); | |
66638f16 LC |
914 | if (err) |
915 | goto out_cleanup_disk; | |
916 | ||
35efb594 | 917 | return 0; |
62f96cb0 | 918 | |
66638f16 | 919 | out_cleanup_disk: |
8b9ab626 | 920 | put_disk(disk); |
4e6da0fe RW |
921 | out_cleanup_tags: |
922 | blk_mq_free_tag_set(&ubd_dev->tag_set); | |
fb5d1d38 CH |
923 | out_close: |
924 | ubd_close_dev(ubd_dev); | |
35efb594 CH |
925 | out: |
926 | return err; | |
1da177e4 LT |
927 | } |
928 | ||
f28169d2 | 929 | static int ubd_config(char *str, char **error_out) |
1da177e4 | 930 | { |
e7f6552f | 931 | int n, ret; |
1da177e4 | 932 | |
f28169d2 JD |
933 | /* This string is possibly broken up and stored, so it's only |
934 | * freed if ubd_setup_common fails, or if only general options | |
935 | * were set. | |
936 | */ | |
970d6e3a | 937 | str = kstrdup(str, GFP_KERNEL); |
e7f6552f | 938 | if (str == NULL) { |
f28169d2 JD |
939 | *error_out = "Failed to allocate memory"; |
940 | return -ENOMEM; | |
1da177e4 | 941 | } |
f28169d2 JD |
942 | |
943 | ret = ubd_setup_common(str, &n, error_out); | |
944 | if (ret) | |
e7f6552f | 945 | goto err_free; |
f28169d2 | 946 | |
e7f6552f PBG |
947 | if (n == -1) { |
948 | ret = 0; | |
d8d7c28e | 949 | goto err_free; |
1da177e4 | 950 | } |
1da177e4 | 951 | |
dc764e50 | 952 | mutex_lock(&ubd_lock); |
f28169d2 | 953 | ret = ubd_add(n, error_out); |
e7f6552f | 954 | if (ret) |
7d314e34 | 955 | ubd_devs[n].file = NULL; |
dc764e50 | 956 | mutex_unlock(&ubd_lock); |
1da177e4 | 957 | |
e7f6552f | 958 | out: |
dc764e50 | 959 | return ret; |
e7f6552f PBG |
960 | |
961 | err_free: | |
962 | kfree(str); | |
963 | goto out; | |
1da177e4 LT |
964 | } |
965 | ||
966 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
967 | { | |
7d314e34 | 968 | struct ubd *ubd_dev; |
1da177e4 LT |
969 | int n, len = 0; |
970 | ||
971 | n = parse_unit(&name); | |
972 | if((n >= MAX_DEV) || (n < 0)){ | |
973 | *error_out = "ubd_get_config : device number out of range"; | |
dc764e50 | 974 | return -1; |
1da177e4 LT |
975 | } |
976 | ||
7d314e34 | 977 | ubd_dev = &ubd_devs[n]; |
d7fb2c38 | 978 | mutex_lock(&ubd_lock); |
1da177e4 | 979 | |
7d314e34 | 980 | if(ubd_dev->file == NULL){ |
1da177e4 LT |
981 | CONFIG_CHUNK(str, size, len, "", 1); |
982 | goto out; | |
983 | } | |
984 | ||
7d314e34 | 985 | CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); |
1da177e4 | 986 | |
7d314e34 | 987 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 988 | CONFIG_CHUNK(str, size, len, ",", 0); |
7d314e34 | 989 | CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); |
1da177e4 LT |
990 | } |
991 | else CONFIG_CHUNK(str, size, len, "", 1); | |
992 | ||
993 | out: | |
d7fb2c38 | 994 | mutex_unlock(&ubd_lock); |
dc764e50 | 995 | return len; |
1da177e4 LT |
996 | } |
997 | ||
29d56cfe JD |
998 | static int ubd_id(char **str, int *start_out, int *end_out) |
999 | { | |
dc764e50 | 1000 | int n; |
29d56cfe JD |
1001 | |
1002 | n = parse_unit(str); | |
dc764e50 JD |
1003 | *start_out = 0; |
1004 | *end_out = MAX_DEV - 1; | |
1005 | return n; | |
29d56cfe JD |
1006 | } |
1007 | ||
f28169d2 | 1008 | static int ubd_remove(int n, char **error_out) |
1da177e4 | 1009 | { |
7d314e34 | 1010 | struct ubd *ubd_dev; |
29d56cfe | 1011 | int err = -ENODEV; |
1da177e4 | 1012 | |
d7fb2c38 | 1013 | mutex_lock(&ubd_lock); |
1da177e4 | 1014 | |
7d314e34 | 1015 | ubd_dev = &ubd_devs[n]; |
1da177e4 | 1016 | |
7d314e34 | 1017 | if(ubd_dev->file == NULL) |
29d56cfe | 1018 | goto out; |
1da177e4 | 1019 | |
32621ad7 | 1020 | if (ubd_dev->disk) { |
fb5d1d38 CH |
1021 | /* you cannot remove a open disk */ |
1022 | err = -EBUSY; | |
1023 | if (disk_openers(ubd_dev->disk)) | |
1024 | goto out; | |
1025 | ||
32621ad7 | 1026 | del_gendisk(ubd_dev->disk); |
fb5d1d38 | 1027 | ubd_close_dev(ubd_dev); |
32621ad7 | 1028 | put_disk(ubd_dev->disk); |
1da177e4 LT |
1029 | } |
1030 | ||
1da177e4 | 1031 | err = 0; |
2e3f5251 | 1032 | platform_device_unregister(&ubd_dev->pdev); |
29d56cfe | 1033 | out: |
d7fb2c38 | 1034 | mutex_unlock(&ubd_lock); |
29d56cfe | 1035 | return err; |
1da177e4 LT |
1036 | } |
1037 | ||
f28169d2 | 1038 | /* All these are called by mconsole in process context and without |
b8831a1d | 1039 | * ubd-specific locks. The structure itself is const except for .list. |
f28169d2 | 1040 | */ |
1da177e4 | 1041 | static struct mc_device ubd_mc = { |
84f48d4f | 1042 | .list = LIST_HEAD_INIT(ubd_mc.list), |
1da177e4 LT |
1043 | .name = "ubd", |
1044 | .config = ubd_config, | |
dc764e50 | 1045 | .get_config = ubd_get_config, |
29d56cfe | 1046 | .id = ubd_id, |
1da177e4 LT |
1047 | .remove = ubd_remove, |
1048 | }; | |
1049 | ||
d8d7c28e | 1050 | static int __init ubd_mc_init(void) |
1da177e4 LT |
1051 | { |
1052 | mconsole_register_dev(&ubd_mc); | |
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | __initcall(ubd_mc_init); | |
1057 | ||
d8d7c28e PBG |
1058 | static int __init ubd0_init(void) |
1059 | { | |
1060 | struct ubd *ubd_dev = &ubd_devs[0]; | |
1061 | ||
b8831a1d | 1062 | mutex_lock(&ubd_lock); |
d8d7c28e PBG |
1063 | if(ubd_dev->file == NULL) |
1064 | ubd_dev->file = "root_fs"; | |
b8831a1d JD |
1065 | mutex_unlock(&ubd_lock); |
1066 | ||
dc764e50 | 1067 | return 0; |
d8d7c28e PBG |
1068 | } |
1069 | ||
1070 | __initcall(ubd0_init); | |
1071 | ||
b8831a1d | 1072 | /* Used in ubd_init, which is an initcall */ |
3ae5eaec RK |
1073 | static struct platform_driver ubd_driver = { |
1074 | .driver = { | |
1075 | .name = DRIVER_NAME, | |
1076 | }, | |
1da177e4 LT |
1077 | }; |
1078 | ||
d8d7c28e | 1079 | static int __init ubd_init(void) |
1da177e4 | 1080 | { |
f28169d2 JD |
1081 | char *error; |
1082 | int i, err; | |
1da177e4 | 1083 | |
792dd4fc | 1084 | if (register_blkdev(UBD_MAJOR, "ubd")) |
1da177e4 LT |
1085 | return -1; |
1086 | ||
6da2ec56 KC |
1087 | irq_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, |
1088 | sizeof(struct io_thread_req *), | |
1089 | GFP_KERNEL | |
f88f0bdf AI |
1090 | ); |
1091 | irq_remainder = 0; | |
1092 | ||
1093 | if (irq_req_buffer == NULL) { | |
1094 | printk(KERN_ERR "Failed to initialize ubd buffering\n"); | |
1095 | return -1; | |
1096 | } | |
6da2ec56 KC |
1097 | io_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, |
1098 | sizeof(struct io_thread_req *), | |
1099 | GFP_KERNEL | |
f88f0bdf AI |
1100 | ); |
1101 | ||
1102 | io_remainder = 0; | |
1103 | ||
1104 | if (io_req_buffer == NULL) { | |
1105 | printk(KERN_ERR "Failed to initialize ubd buffering\n"); | |
1106 | return -1; | |
1107 | } | |
3ae5eaec | 1108 | platform_driver_register(&ubd_driver); |
dc764e50 | 1109 | mutex_lock(&ubd_lock); |
f28169d2 JD |
1110 | for (i = 0; i < MAX_DEV; i++){ |
1111 | err = ubd_add(i, &error); | |
1112 | if(err) | |
1113 | printk(KERN_ERR "Failed to initialize ubd device %d :" | |
1114 | "%s\n", i, error); | |
1115 | } | |
dc764e50 | 1116 | mutex_unlock(&ubd_lock); |
1da177e4 LT |
1117 | return 0; |
1118 | } | |
1119 | ||
1120 | late_initcall(ubd_init); | |
1121 | ||
d8d7c28e | 1122 | static int __init ubd_driver_init(void){ |
91acb21f JD |
1123 | unsigned long stack; |
1124 | int err; | |
1125 | ||
1126 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
1127 | if(global_openflags.s){ | |
1128 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
1129 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
1130 | * enough. So use anyway the io thread. */ | |
1131 | } | |
2fcb4090 | 1132 | stack = alloc_stack(0, 0); |
558f9b2f | 1133 | io_pid = start_io_thread(stack + PAGE_SIZE, &thread_fd); |
91acb21f | 1134 | if(io_pid < 0){ |
6c29256c | 1135 | printk(KERN_ERR |
91acb21f JD |
1136 | "ubd : Failed to start I/O thread (errno = %d) - " |
1137 | "falling back to synchronous I/O\n", -io_pid); | |
1138 | io_pid = -1; | |
dc764e50 | 1139 | return 0; |
91acb21f | 1140 | } |
6c29256c | 1141 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, |
c0b79a90 | 1142 | 0, "ubd", ubd_devs); |
36d46a59 | 1143 | if(err < 0) |
91acb21f | 1144 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); |
f4c57a78 | 1145 | return 0; |
91acb21f JD |
1146 | } |
1147 | ||
1148 | device_initcall(ubd_driver_init); | |
1149 | ||
91acb21f JD |
1150 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, |
1151 | __u64 *cow_offset, unsigned long *bitmap, | |
1152 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
1153 | __u64 bitmap_len) | |
1da177e4 | 1154 | { |
a43c8316 | 1155 | __u64 sector = io_offset >> SECTOR_SHIFT; |
91acb21f JD |
1156 | int i, update_bitmap = 0; |
1157 | ||
a43c8316 | 1158 | for (i = 0; i < length >> SECTOR_SHIFT; i++) { |
91acb21f JD |
1159 | if(cow_mask != NULL) |
1160 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
1161 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
1162 | continue; | |
1da177e4 | 1163 | |
91acb21f JD |
1164 | update_bitmap = 1; |
1165 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
1166 | } | |
1167 | ||
1168 | if(!update_bitmap) | |
1169 | return; | |
1da177e4 | 1170 | |
91acb21f | 1171 | *cow_offset = sector / (sizeof(unsigned long) * 8); |
1da177e4 | 1172 | |
91acb21f JD |
1173 | /* This takes care of the case where we're exactly at the end of the |
1174 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
1175 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
1176 | * for the original diagnosis. | |
1177 | */ | |
6d074242 JO |
1178 | if (*cow_offset == (DIV_ROUND_UP(bitmap_len, |
1179 | sizeof(unsigned long)) - 1)) | |
91acb21f JD |
1180 | (*cow_offset)--; |
1181 | ||
1182 | bitmap_words[0] = bitmap[*cow_offset]; | |
1183 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
1184 | ||
1185 | *cow_offset *= sizeof(unsigned long); | |
1186 | *cow_offset += bitmap_offset; | |
1187 | } | |
1188 | ||
fc6b6a87 GKB |
1189 | static void cowify_req(struct io_thread_req *req, struct io_desc *segment, |
1190 | unsigned long offset, unsigned long *bitmap, | |
91acb21f JD |
1191 | __u64 bitmap_offset, __u64 bitmap_len) |
1192 | { | |
fc6b6a87 | 1193 | __u64 sector = offset >> SECTOR_SHIFT; |
91acb21f JD |
1194 | int i; |
1195 | ||
fc6b6a87 | 1196 | if (segment->length > (sizeof(segment->sector_mask) * 8) << SECTOR_SHIFT) |
91acb21f JD |
1197 | panic("Operation too long"); |
1198 | ||
a43c8316 | 1199 | if (req_op(req->req) == REQ_OP_READ) { |
fc6b6a87 | 1200 | for (i = 0; i < segment->length >> SECTOR_SHIFT; i++) { |
91acb21f | 1201 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) |
6c29256c | 1202 | ubd_set_bit(i, (unsigned char *) |
fc6b6a87 GKB |
1203 | &segment->sector_mask); |
1204 | } | |
1205 | } else { | |
1206 | cowify_bitmap(offset, segment->length, &segment->sector_mask, | |
1207 | &segment->cow_offset, bitmap, bitmap_offset, | |
1208 | segment->bitmap_words, bitmap_len); | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | static void ubd_map_req(struct ubd *dev, struct io_thread_req *io_req, | |
1213 | struct request *req) | |
1214 | { | |
1215 | struct bio_vec bvec; | |
1216 | struct req_iterator iter; | |
1217 | int i = 0; | |
1218 | unsigned long byte_offset = io_req->offset; | |
7ee1de6e | 1219 | enum req_op op = req_op(req); |
fc6b6a87 GKB |
1220 | |
1221 | if (op == REQ_OP_WRITE_ZEROES || op == REQ_OP_DISCARD) { | |
1222 | io_req->io_desc[0].buffer = NULL; | |
1223 | io_req->io_desc[0].length = blk_rq_bytes(req); | |
1224 | } else { | |
1225 | rq_for_each_segment(bvec, req, iter) { | |
1226 | BUG_ON(i >= io_req->desc_cnt); | |
1227 | ||
25d84545 | 1228 | io_req->io_desc[i].buffer = bvec_virt(&bvec); |
fc6b6a87 GKB |
1229 | io_req->io_desc[i].length = bvec.bv_len; |
1230 | i++; | |
1231 | } | |
1232 | } | |
1233 | ||
1234 | if (dev->cow.file) { | |
1235 | for (i = 0; i < io_req->desc_cnt; i++) { | |
1236 | cowify_req(io_req, &io_req->io_desc[i], byte_offset, | |
1237 | dev->cow.bitmap, dev->cow.bitmap_offset, | |
1238 | dev->cow.bitmap_len); | |
1239 | byte_offset += io_req->io_desc[i].length; | |
dc764e50 | 1240 | } |
fc6b6a87 | 1241 | |
91acb21f | 1242 | } |
1da177e4 LT |
1243 | } |
1244 | ||
fc6b6a87 GKB |
1245 | static struct io_thread_req *ubd_alloc_req(struct ubd *dev, struct request *req, |
1246 | int desc_cnt) | |
1da177e4 | 1247 | { |
ecb0a83e | 1248 | struct io_thread_req *io_req; |
fc6b6a87 | 1249 | int i; |
1da177e4 | 1250 | |
fc6b6a87 GKB |
1251 | io_req = kmalloc(sizeof(*io_req) + |
1252 | (desc_cnt * sizeof(struct io_desc)), | |
1253 | GFP_ATOMIC); | |
ecb0a83e | 1254 | if (!io_req) |
fc6b6a87 | 1255 | return NULL; |
805f11a0 RW |
1256 | |
1257 | io_req->req = req; | |
ecb0a83e CH |
1258 | if (dev->cow.file) |
1259 | io_req->fds[0] = dev->cow.fd; | |
1260 | else | |
1261 | io_req->fds[0] = dev->fd; | |
0033dfd9 | 1262 | io_req->error = 0; |
53766def AI |
1263 | io_req->sectorsize = SECTOR_SIZE; |
1264 | io_req->fds[1] = dev->fd; | |
fc6b6a87 | 1265 | io_req->offset = (u64) blk_rq_pos(req) << SECTOR_SHIFT; |
53766def AI |
1266 | io_req->offsets[0] = 0; |
1267 | io_req->offsets[1] = dev->cow.data_offset; | |
1268 | ||
fc6b6a87 GKB |
1269 | for (i = 0 ; i < desc_cnt; i++) { |
1270 | io_req->io_desc[i].sector_mask = 0; | |
1271 | io_req->io_desc[i].cow_offset = -1; | |
1272 | } | |
1273 | ||
1274 | return io_req; | |
1275 | } | |
1276 | ||
1277 | static int ubd_submit_request(struct ubd *dev, struct request *req) | |
1278 | { | |
1279 | int segs = 0; | |
1280 | struct io_thread_req *io_req; | |
1281 | int ret; | |
7ee1de6e | 1282 | enum req_op op = req_op(req); |
fc6b6a87 GKB |
1283 | |
1284 | if (op == REQ_OP_FLUSH) | |
1285 | segs = 0; | |
1286 | else if (op == REQ_OP_WRITE_ZEROES || op == REQ_OP_DISCARD) | |
1287 | segs = 1; | |
1288 | else | |
1289 | segs = blk_rq_nr_phys_segments(req); | |
1290 | ||
1291 | io_req = ubd_alloc_req(dev, req, segs); | |
1292 | if (!io_req) | |
1293 | return -ENOMEM; | |
1294 | ||
1295 | io_req->desc_cnt = segs; | |
1296 | if (segs) | |
1297 | ubd_map_req(dev, io_req, req); | |
53766def | 1298 | |
ecb0a83e CH |
1299 | ret = os_write_file(thread_fd, &io_req, sizeof(io_req)); |
1300 | if (ret != sizeof(io_req)) { | |
1301 | if (ret != -EAGAIN) | |
1302 | pr_err("write to io thread failed: %d\n", -ret); | |
bc1d72e7 | 1303 | kfree(io_req); |
bc1d72e7 | 1304 | } |
ecb0a83e | 1305 | return ret; |
bc1d72e7 RW |
1306 | } |
1307 | ||
4e6da0fe RW |
1308 | static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, |
1309 | const struct blk_mq_queue_data *bd) | |
1da177e4 | 1310 | { |
6961cd4d | 1311 | struct ubd *ubd_dev = hctx->queue->queuedata; |
4e6da0fe | 1312 | struct request *req = bd->rq; |
53766def | 1313 | int ret = 0, res = BLK_STS_OK; |
a0044bdf | 1314 | |
4e6da0fe RW |
1315 | blk_mq_start_request(req); |
1316 | ||
6961cd4d JA |
1317 | spin_lock_irq(&ubd_dev->lock); |
1318 | ||
53766def | 1319 | switch (req_op(req)) { |
53766def | 1320 | case REQ_OP_FLUSH: |
53766def AI |
1321 | case REQ_OP_READ: |
1322 | case REQ_OP_WRITE: | |
50109b5a AI |
1323 | case REQ_OP_DISCARD: |
1324 | case REQ_OP_WRITE_ZEROES: | |
fc6b6a87 | 1325 | ret = ubd_submit_request(ubd_dev, req); |
50109b5a | 1326 | break; |
53766def AI |
1327 | default: |
1328 | WARN_ON_ONCE(1); | |
1329 | res = BLK_STS_NOTSUPP; | |
4e6da0fe | 1330 | } |
53766def | 1331 | |
6961cd4d JA |
1332 | spin_unlock_irq(&ubd_dev->lock); |
1333 | ||
d848074b AI |
1334 | if (ret < 0) { |
1335 | if (ret == -ENOMEM) | |
1336 | res = BLK_STS_RESOURCE; | |
1337 | else | |
1338 | res = BLK_STS_DEV_RESOURCE; | |
1339 | } | |
6961cd4d | 1340 | |
53766def | 1341 | return res; |
1da177e4 LT |
1342 | } |
1343 | ||
a885c8c4 CH |
1344 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1345 | { | |
7d314e34 | 1346 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
a885c8c4 CH |
1347 | |
1348 | geo->heads = 128; | |
1349 | geo->sectors = 32; | |
7d314e34 | 1350 | geo->cylinders = ubd_dev->size / (128 * 32 * 512); |
a885c8c4 CH |
1351 | return 0; |
1352 | } | |
1353 | ||
05bdb996 | 1354 | static int ubd_ioctl(struct block_device *bdev, blk_mode_t mode, |
1da177e4 LT |
1355 | unsigned int cmd, unsigned long arg) |
1356 | { | |
a625c998 | 1357 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
73855e13 | 1358 | u16 ubd_id[ATA_ID_WORDS]; |
1da177e4 LT |
1359 | |
1360 | switch (cmd) { | |
1da177e4 | 1361 | struct cdrom_volctrl volume; |
1da177e4 | 1362 | case HDIO_GET_IDENTITY: |
73855e13 BZ |
1363 | memset(&ubd_id, 0, ATA_ID_WORDS * 2); |
1364 | ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512); | |
1365 | ubd_id[ATA_ID_HEADS] = 128; | |
1366 | ubd_id[ATA_ID_SECTORS] = 32; | |
1da177e4 LT |
1367 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, |
1368 | sizeof(ubd_id))) | |
dc764e50 JD |
1369 | return -EFAULT; |
1370 | return 0; | |
b8831a1d | 1371 | |
1da177e4 LT |
1372 | case CDROMVOLREAD: |
1373 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
dc764e50 | 1374 | return -EFAULT; |
1da177e4 LT |
1375 | volume.channel0 = 255; |
1376 | volume.channel1 = 255; | |
1377 | volume.channel2 = 255; | |
1378 | volume.channel3 = 255; | |
1379 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
dc764e50 JD |
1380 | return -EFAULT; |
1381 | return 0; | |
1da177e4 | 1382 | } |
dc764e50 | 1383 | return -EINVAL; |
1da177e4 LT |
1384 | } |
1385 | ||
a43c8316 AI |
1386 | static int map_error(int error_code) |
1387 | { | |
1388 | switch (error_code) { | |
1389 | case 0: | |
1390 | return BLK_STS_OK; | |
1391 | case ENOSYS: | |
1392 | case EOPNOTSUPP: | |
1393 | return BLK_STS_NOTSUPP; | |
1394 | case ENOSPC: | |
1395 | return BLK_STS_NOSPC; | |
1396 | } | |
1397 | return BLK_STS_IOERR; | |
1398 | } | |
1399 | ||
a41421ed AI |
1400 | /* |
1401 | * Everything from here onwards *IS NOT PART OF THE KERNEL* | |
1402 | * | |
1403 | * The following functions are part of UML hypervisor code. | |
1404 | * All functions from here onwards are executed as a helper | |
1405 | * thread and are not allowed to execute any kernel functions. | |
1406 | * | |
1407 | * Any communication must occur strictly via shared memory and IPC. | |
1408 | * | |
1409 | * Do not add printks, locks, kernel memory operations, etc - it | |
1410 | * will result in unpredictable behaviour and/or crashes. | |
1411 | */ | |
1412 | ||
fc6b6a87 | 1413 | static int update_bitmap(struct io_thread_req *req, struct io_desc *segment) |
1da177e4 | 1414 | { |
91acb21f | 1415 | int n; |
1da177e4 | 1416 | |
fc6b6a87 | 1417 | if (segment->cow_offset == -1) |
a43c8316 | 1418 | return map_error(0); |
1da177e4 | 1419 | |
fc6b6a87 GKB |
1420 | n = os_pwrite_file(req->fds[1], &segment->bitmap_words, |
1421 | sizeof(segment->bitmap_words), segment->cow_offset); | |
1422 | if (n != sizeof(segment->bitmap_words)) | |
a43c8316 | 1423 | return map_error(-n); |
1da177e4 | 1424 | |
a43c8316 | 1425 | return map_error(0); |
91acb21f | 1426 | } |
1da177e4 | 1427 | |
fc6b6a87 | 1428 | static void do_io(struct io_thread_req *req, struct io_desc *desc) |
91acb21f | 1429 | { |
50109b5a | 1430 | char *buf = NULL; |
91acb21f JD |
1431 | unsigned long len; |
1432 | int n, nsectors, start, end, bit; | |
91acb21f JD |
1433 | __u64 off; |
1434 | ||
50109b5a AI |
1435 | /* FLUSH is really a special case, we cannot "case" it with others */ |
1436 | ||
a43c8316 | 1437 | if (req_op(req->req) == REQ_OP_FLUSH) { |
805f11a0 | 1438 | /* fds[0] is always either the rw image or our cow file */ |
a41421ed | 1439 | req->error = map_error(-os_sync_file(req->fds[0])); |
805f11a0 RW |
1440 | return; |
1441 | } | |
1442 | ||
fc6b6a87 | 1443 | nsectors = desc->length / req->sectorsize; |
91acb21f JD |
1444 | start = 0; |
1445 | do { | |
fc6b6a87 | 1446 | bit = ubd_test_bit(start, (unsigned char *) &desc->sector_mask); |
91acb21f JD |
1447 | end = start; |
1448 | while((end < nsectors) && | |
fc6b6a87 | 1449 | (ubd_test_bit(end, (unsigned char *) &desc->sector_mask) == bit)) |
91acb21f JD |
1450 | end++; |
1451 | ||
1452 | off = req->offset + req->offsets[bit] + | |
1453 | start * req->sectorsize; | |
1454 | len = (end - start) * req->sectorsize; | |
fc6b6a87 GKB |
1455 | if (desc->buffer != NULL) |
1456 | buf = &desc->buffer[start * req->sectorsize]; | |
91acb21f | 1457 | |
50109b5a AI |
1458 | switch (req_op(req->req)) { |
1459 | case REQ_OP_READ: | |
91acb21f JD |
1460 | n = 0; |
1461 | do { | |
1462 | buf = &buf[n]; | |
1463 | len -= n; | |
8c6157b6 | 1464 | n = os_pread_file(req->fds[bit], buf, len, off); |
50109b5a | 1465 | if (n < 0) { |
a43c8316 | 1466 | req->error = map_error(-n); |
91acb21f JD |
1467 | return; |
1468 | } | |
1469 | } while((n < len) && (n != 0)); | |
1470 | if (n < len) memset(&buf[n], 0, len - n); | |
50109b5a AI |
1471 | break; |
1472 | case REQ_OP_WRITE: | |
8c6157b6 | 1473 | n = os_pwrite_file(req->fds[bit], buf, len, off); |
91acb21f | 1474 | if(n != len){ |
a43c8316 | 1475 | req->error = map_error(-n); |
91acb21f JD |
1476 | return; |
1477 | } | |
50109b5a AI |
1478 | break; |
1479 | case REQ_OP_DISCARD: | |
50109b5a AI |
1480 | n = os_falloc_punch(req->fds[bit], off, len); |
1481 | if (n) { | |
1482 | req->error = map_error(-n); | |
1483 | return; | |
1484 | } | |
1485 | break; | |
d2a0a616 FD |
1486 | case REQ_OP_WRITE_ZEROES: |
1487 | n = os_falloc_zeroes(req->fds[bit], off, len); | |
1488 | if (n) { | |
1489 | req->error = map_error(-n); | |
1490 | return; | |
1491 | } | |
1492 | break; | |
50109b5a AI |
1493 | default: |
1494 | WARN_ON_ONCE(1); | |
1495 | req->error = BLK_STS_NOTSUPP; | |
1496 | return; | |
91acb21f JD |
1497 | } |
1498 | ||
1499 | start = end; | |
1500 | } while(start < nsectors); | |
1da177e4 | 1501 | |
fc6b6a87 GKB |
1502 | req->offset += len; |
1503 | req->error = update_bitmap(req, desc); | |
1da177e4 | 1504 | } |
91acb21f JD |
1505 | |
1506 | /* Changed in start_io_thread, which is serialized by being called only | |
1507 | * from ubd_init, which is an initcall. | |
1508 | */ | |
1509 | int kernel_fd = -1; | |
1510 | ||
d8d7c28e | 1511 | /* Only changed by the io thread. XXX: currently unused. */ |
4dc5a328 | 1512 | static int io_count; |
91acb21f JD |
1513 | |
1514 | int io_thread(void *arg) | |
1515 | { | |
f88f0bdf | 1516 | int n, count, written, res; |
91acb21f | 1517 | |
91d44ff8 RW |
1518 | os_fix_helper_signals(); |
1519 | ||
91acb21f | 1520 | while(1){ |
f88f0bdf AI |
1521 | n = bulk_req_safe_read( |
1522 | kernel_fd, | |
1523 | io_req_buffer, | |
1524 | &io_remainder, | |
1525 | &io_remainder_size, | |
1526 | UBD_REQ_BUFFER_SIZE | |
1527 | ); | |
e355b2f5 GKB |
1528 | if (n <= 0) { |
1529 | if (n == -EAGAIN) | |
f88f0bdf | 1530 | ubd_read_poll(-1); |
e355b2f5 GKB |
1531 | |
1532 | continue; | |
91acb21f | 1533 | } |
f88f0bdf AI |
1534 | |
1535 | for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { | |
fc6b6a87 GKB |
1536 | struct io_thread_req *req = (*io_req_buffer)[count]; |
1537 | int i; | |
1538 | ||
f88f0bdf | 1539 | io_count++; |
fc6b6a87 GKB |
1540 | for (i = 0; !req->error && i < req->desc_cnt; i++) |
1541 | do_io(req, &(req->io_desc[i])); | |
1542 | ||
f88f0bdf AI |
1543 | } |
1544 | ||
1545 | written = 0; | |
1546 | ||
1547 | do { | |
6e682d53 GKB |
1548 | res = os_write_file(kernel_fd, |
1549 | ((char *) io_req_buffer) + written, | |
1550 | n - written); | |
ff6a1798 | 1551 | if (res >= 0) { |
f88f0bdf | 1552 | written += res; |
f88f0bdf AI |
1553 | } |
1554 | if (written < n) { | |
1555 | ubd_write_poll(-1); | |
1556 | } | |
1557 | } while (written < n); | |
91acb21f | 1558 | } |
91acb21f | 1559 | |
1b57e9c2 JD |
1560 | return 0; |
1561 | } |