Commit | Line | Data |
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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> | |
37185b33 | 39 | #include <kern_util.h> |
1da177e4 | 40 | #include "mconsole_kern.h" |
37185b33 AV |
41 | #include <init.h> |
42 | #include <irq_kern.h> | |
8ea3c06a | 43 | #include "ubd.h" |
37185b33 | 44 | #include <os.h> |
1da177e4 LT |
45 | #include "cow.h" |
46 | ||
a43c8316 AI |
47 | /* Max request size is determined by sector mask - 32K */ |
48 | #define UBD_MAX_REQUEST (8 * sizeof(long)) | |
1da177e4 | 49 | |
fc6b6a87 GKB |
50 | struct io_desc { |
51 | char *buffer; | |
52 | unsigned long length; | |
53 | unsigned long sector_mask; | |
54 | unsigned long long cow_offset; | |
55 | unsigned long bitmap_words[2]; | |
56 | }; | |
57 | ||
1da177e4 | 58 | struct io_thread_req { |
62f96cb0 | 59 | struct request *req; |
1da177e4 LT |
60 | int fds[2]; |
61 | unsigned long offsets[2]; | |
62 | unsigned long long offset; | |
1da177e4 | 63 | int sectorsize; |
1da177e4 | 64 | int error; |
fc6b6a87 GKB |
65 | |
66 | int desc_cnt; | |
67 | /* io_desc has to be the last element of the struct */ | |
68 | struct io_desc io_desc[]; | |
1da177e4 LT |
69 | }; |
70 | ||
f88f0bdf AI |
71 | |
72 | static struct io_thread_req * (*irq_req_buffer)[]; | |
73 | static struct io_thread_req *irq_remainder; | |
74 | static int irq_remainder_size; | |
75 | ||
76 | static struct io_thread_req * (*io_req_buffer)[]; | |
77 | static struct io_thread_req *io_remainder; | |
78 | static int io_remainder_size; | |
79 | ||
80 | ||
81 | ||
91acb21f | 82 | static inline int ubd_test_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
83 | { |
84 | __u64 n; | |
85 | int bits, off; | |
86 | ||
91acb21f | 87 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
88 | n = bit / bits; |
89 | off = bit % bits; | |
dc764e50 | 90 | return (data[n] & (1 << off)) != 0; |
1da177e4 LT |
91 | } |
92 | ||
91acb21f | 93 | static inline void ubd_set_bit(__u64 bit, unsigned char *data) |
1da177e4 LT |
94 | { |
95 | __u64 n; | |
96 | int bits, off; | |
97 | ||
91acb21f | 98 | bits = sizeof(data[0]) * 8; |
1da177e4 LT |
99 | n = bit / bits; |
100 | off = bit % bits; | |
91acb21f | 101 | data[n] |= (1 << off); |
1da177e4 LT |
102 | } |
103 | /*End stuff from ubd_user.h*/ | |
104 | ||
105 | #define DRIVER_NAME "uml-blkdev" | |
106 | ||
d7fb2c38 | 107 | static DEFINE_MUTEX(ubd_lock); |
1da177e4 | 108 | |
05bdb996 | 109 | static int ubd_ioctl(struct block_device *bdev, blk_mode_t mode, |
1da177e4 | 110 | unsigned int cmd, unsigned long arg); |
a885c8c4 | 111 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo); |
1da177e4 | 112 | |
97d88ac8 | 113 | #define MAX_DEV (16) |
1da177e4 | 114 | |
83d5cde4 | 115 | static const struct block_device_operations ubd_blops = { |
1da177e4 | 116 | .owner = THIS_MODULE, |
a625c998 | 117 | .ioctl = ubd_ioctl, |
ab0cf1e4 | 118 | .compat_ioctl = blkdev_compat_ptr_ioctl, |
a885c8c4 | 119 | .getgeo = ubd_getgeo, |
1da177e4 LT |
120 | }; |
121 | ||
1da177e4 LT |
122 | #ifdef CONFIG_BLK_DEV_UBD_SYNC |
123 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ | |
124 | .cl = 1 }) | |
125 | #else | |
126 | #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ | |
127 | .cl = 1 }) | |
128 | #endif | |
1da177e4 LT |
129 | static struct openflags global_openflags = OPEN_FLAGS; |
130 | ||
131 | struct cow { | |
2a9d32f6 | 132 | /* backing file name */ |
1da177e4 | 133 | char *file; |
2a9d32f6 | 134 | /* backing file fd */ |
1da177e4 LT |
135 | int fd; |
136 | unsigned long *bitmap; | |
137 | unsigned long bitmap_len; | |
138 | int bitmap_offset; | |
dc764e50 | 139 | int data_offset; |
1da177e4 LT |
140 | }; |
141 | ||
a0044bdf JD |
142 | #define MAX_SG 64 |
143 | ||
1da177e4 | 144 | struct ubd { |
2a9d32f6 PBG |
145 | /* name (and fd, below) of the file opened for writing, either the |
146 | * backing or the cow file. */ | |
1da177e4 | 147 | char *file; |
ef3ba87c | 148 | char *serial; |
1da177e4 LT |
149 | int fd; |
150 | __u64 size; | |
151 | struct openflags boot_openflags; | |
152 | struct openflags openflags; | |
84e945e3 PBG |
153 | unsigned shared:1; |
154 | unsigned no_cow:1; | |
50109b5a | 155 | unsigned no_trim:1; |
1da177e4 LT |
156 | struct cow cow; |
157 | struct platform_device pdev; | |
32621ad7 | 158 | struct gendisk *disk; |
4e6da0fe | 159 | struct blk_mq_tag_set tag_set; |
62f96cb0 | 160 | spinlock_t lock; |
4e6da0fe RW |
161 | }; |
162 | ||
1da177e4 LT |
163 | #define DEFAULT_COW { \ |
164 | .file = NULL, \ | |
dc764e50 JD |
165 | .fd = -1, \ |
166 | .bitmap = NULL, \ | |
1da177e4 | 167 | .bitmap_offset = 0, \ |
dc764e50 | 168 | .data_offset = 0, \ |
1da177e4 LT |
169 | } |
170 | ||
171 | #define DEFAULT_UBD { \ | |
172 | .file = NULL, \ | |
ef3ba87c | 173 | .serial = NULL, \ |
1da177e4 LT |
174 | .fd = -1, \ |
175 | .size = -1, \ | |
176 | .boot_openflags = OPEN_FLAGS, \ | |
177 | .openflags = OPEN_FLAGS, \ | |
dc764e50 | 178 | .no_cow = 0, \ |
50109b5a | 179 | .no_trim = 0, \ |
6c29256c | 180 | .shared = 0, \ |
dc764e50 | 181 | .cow = DEFAULT_COW, \ |
22e65004 | 182 | .lock = __SPIN_LOCK_UNLOCKED(ubd_devs.lock), \ |
1da177e4 LT |
183 | } |
184 | ||
b8831a1d | 185 | /* Protected by ubd_lock */ |
5dc62b1b | 186 | static struct ubd ubd_devs[MAX_DEV] = { [0 ... MAX_DEV - 1] = DEFAULT_UBD }; |
1da177e4 | 187 | |
4e6da0fe RW |
188 | static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, |
189 | const struct blk_mq_queue_data *bd); | |
4e6da0fe | 190 | |
1da177e4 LT |
191 | static int fake_ide_setup(char *str) |
192 | { | |
7eb90f7e | 193 | pr_warn("The fake_ide option has been removed\n"); |
dc764e50 | 194 | return 1; |
1da177e4 | 195 | } |
1da177e4 LT |
196 | __setup("fake_ide", fake_ide_setup); |
197 | ||
198 | __uml_help(fake_ide_setup, | |
199 | "fake_ide\n" | |
7eb90f7e | 200 | " Obsolete stub.\n\n" |
1da177e4 LT |
201 | ); |
202 | ||
203 | static int parse_unit(char **ptr) | |
204 | { | |
205 | char *str = *ptr, *end; | |
206 | int n = -1; | |
207 | ||
208 | if(isdigit(*str)) { | |
209 | n = simple_strtoul(str, &end, 0); | |
210 | if(end == str) | |
dc764e50 | 211 | return -1; |
1da177e4 LT |
212 | *ptr = end; |
213 | } | |
97d88ac8 | 214 | else if (('a' <= *str) && (*str <= 'z')) { |
1da177e4 LT |
215 | n = *str - 'a'; |
216 | str++; | |
217 | *ptr = str; | |
218 | } | |
dc764e50 | 219 | return n; |
1da177e4 LT |
220 | } |
221 | ||
d8d7c28e PBG |
222 | /* If *index_out == -1 at exit, the passed option was a general one; |
223 | * otherwise, the str pointer is used (and owned) inside ubd_devs array, so it | |
224 | * should not be freed on exit. | |
225 | */ | |
f28169d2 | 226 | static int ubd_setup_common(char *str, int *index_out, char **error_out) |
1da177e4 | 227 | { |
7d314e34 | 228 | struct ubd *ubd_dev; |
1da177e4 | 229 | struct openflags flags = global_openflags; |
ef3ba87c | 230 | char *file, *backing_file, *serial; |
b8831a1d | 231 | int n, err = 0, i; |
1da177e4 LT |
232 | |
233 | if(index_out) *index_out = -1; | |
234 | n = *str; | |
235 | if(n == '='){ | |
1da177e4 | 236 | str++; |
1da177e4 LT |
237 | if(!strcmp(str, "sync")){ |
238 | global_openflags = of_sync(global_openflags); | |
9ca55299 | 239 | return err; |
1da177e4 | 240 | } |
b8831a1d | 241 | |
7eb90f7e CH |
242 | pr_warn("fake major not supported any more\n"); |
243 | return 0; | |
1da177e4 LT |
244 | } |
245 | ||
246 | n = parse_unit(&str); | |
247 | if(n < 0){ | |
f28169d2 JD |
248 | *error_out = "Couldn't parse device number"; |
249 | return -EINVAL; | |
1da177e4 LT |
250 | } |
251 | if(n >= MAX_DEV){ | |
f28169d2 JD |
252 | *error_out = "Device number out of range"; |
253 | return 1; | |
1da177e4 LT |
254 | } |
255 | ||
f28169d2 | 256 | err = -EBUSY; |
d7fb2c38 | 257 | mutex_lock(&ubd_lock); |
1da177e4 | 258 | |
7d314e34 PBG |
259 | ubd_dev = &ubd_devs[n]; |
260 | if(ubd_dev->file != NULL){ | |
f28169d2 | 261 | *error_out = "Device is already configured"; |
1da177e4 LT |
262 | goto out; |
263 | } | |
264 | ||
265 | if (index_out) | |
266 | *index_out = n; | |
267 | ||
f28169d2 | 268 | err = -EINVAL; |
50109b5a | 269 | for (i = 0; i < sizeof("rscdt="); i++) { |
1da177e4 LT |
270 | switch (*str) { |
271 | case 'r': | |
272 | flags.w = 0; | |
273 | break; | |
274 | case 's': | |
275 | flags.s = 1; | |
276 | break; | |
277 | case 'd': | |
7d314e34 | 278 | ubd_dev->no_cow = 1; |
1da177e4 | 279 | break; |
6c29256c | 280 | case 'c': |
7d314e34 | 281 | ubd_dev->shared = 1; |
6c29256c | 282 | break; |
50109b5a AI |
283 | case 't': |
284 | ubd_dev->no_trim = 1; | |
285 | break; | |
1da177e4 LT |
286 | case '=': |
287 | str++; | |
288 | goto break_loop; | |
289 | default: | |
f28169d2 | 290 | *error_out = "Expected '=' or flag letter " |
50109b5a | 291 | "(r, s, c, t or d)"; |
1da177e4 LT |
292 | goto out; |
293 | } | |
294 | str++; | |
295 | } | |
296 | ||
f28169d2 JD |
297 | if (*str == '=') |
298 | *error_out = "Too many flags specified"; | |
299 | else | |
300 | *error_out = "Missing '='"; | |
1da177e4 LT |
301 | goto out; |
302 | ||
303 | break_loop: | |
ef3ba87c CO |
304 | file = strsep(&str, ",:"); |
305 | if (*file == '\0') | |
306 | file = NULL; | |
1da177e4 | 307 | |
ef3ba87c | 308 | backing_file = strsep(&str, ",:"); |
94c41b3a | 309 | if (backing_file && *backing_file == '\0') |
ef3ba87c | 310 | backing_file = NULL; |
1da177e4 | 311 | |
ef3ba87c | 312 | serial = strsep(&str, ",:"); |
94c41b3a | 313 | if (serial && *serial == '\0') |
ef3ba87c CO |
314 | serial = NULL; |
315 | ||
316 | if (backing_file && ubd_dev->no_cow) { | |
317 | *error_out = "Can't specify both 'd' and a cow file"; | |
318 | goto out; | |
1da177e4 | 319 | } |
ef3ba87c | 320 | |
f28169d2 | 321 | err = 0; |
ef3ba87c | 322 | ubd_dev->file = file; |
7d314e34 | 323 | ubd_dev->cow.file = backing_file; |
ef3ba87c | 324 | ubd_dev->serial = serial; |
7d314e34 | 325 | ubd_dev->boot_openflags = flags; |
1da177e4 | 326 | out: |
d7fb2c38 | 327 | mutex_unlock(&ubd_lock); |
f28169d2 | 328 | return err; |
1da177e4 LT |
329 | } |
330 | ||
331 | static int ubd_setup(char *str) | |
332 | { | |
f28169d2 JD |
333 | char *error; |
334 | int err; | |
335 | ||
336 | err = ubd_setup_common(str, NULL, &error); | |
337 | if(err) | |
338 | printk(KERN_ERR "Failed to initialize device with \"%s\" : " | |
339 | "%s\n", str, error); | |
340 | return 1; | |
1da177e4 LT |
341 | } |
342 | ||
343 | __setup("ubd", ubd_setup); | |
344 | __uml_help(ubd_setup, | |
ef3ba87c | 345 | "ubd<n><flags>=<filename>[(:|,)<filename2>][(:|,)<serial>]\n" |
1da177e4 LT |
346 | " This is used to associate a device with a file in the underlying\n" |
347 | " filesystem. When specifying two filenames, the first one is the\n" | |
348 | " COW name and the second is the backing file name. As separator you can\n" | |
349 | " use either a ':' or a ',': the first one allows writing things like;\n" | |
350 | " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" | |
351 | " while with a ',' the shell would not expand the 2nd '~'.\n" | |
f28169d2 | 352 | " When using only one filename, UML will detect whether to treat it like\n" |
1da177e4 LT |
353 | " a COW file or a backing file. To override this detection, add the 'd'\n" |
354 | " flag:\n" | |
355 | " ubd0d=BackingFile\n" | |
356 | " Usually, there is a filesystem in the file, but \n" | |
357 | " that's not required. Swap devices containing swap files can be\n" | |
358 | " specified like this. Also, a file which doesn't contain a\n" | |
359 | " filesystem can have its contents read in the virtual \n" | |
360 | " machine by running 'dd' on the device. <n> must be in the range\n" | |
361 | " 0 to 7. Appending an 'r' to the number will cause that device\n" | |
362 | " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" | |
20ede453 JD |
363 | " an 's' will cause data to be written to disk on the host immediately.\n" |
364 | " 'c' will cause the device to be treated as being shared between multiple\n" | |
365 | " UMLs and file locking will be turned off - this is appropriate for a\n" | |
366 | " cluster filesystem and inappropriate at almost all other times.\n\n" | |
50109b5a | 367 | " 't' will disable trim/discard support on the device (enabled by default).\n\n" |
ef3ba87c CO |
368 | " An optional device serial number can be exposed using the serial parameter\n" |
369 | " on the cmdline which is exposed as a sysfs entry. This is particularly\n" | |
370 | " useful when a unique number should be given to the device. Note when\n" | |
371 | " specifying a label, the filename2 must be also presented. It can be\n" | |
372 | " an empty string, in which case the backing file is not used:\n" | |
373 | " ubd0=File,,Serial\n" | |
1da177e4 LT |
374 | ); |
375 | ||
8299ca5c | 376 | static int udb_setup(char *str) |
1da177e4 LT |
377 | { |
378 | printk("udb%s specified on command line is almost certainly a ubd -> " | |
379 | "udb TYPO\n", str); | |
dc764e50 | 380 | return 1; |
1da177e4 LT |
381 | } |
382 | ||
383 | __setup("udb", udb_setup); | |
384 | __uml_help(udb_setup, | |
385 | "udb\n" | |
0894e27e JD |
386 | " This option is here solely to catch ubd -> udb typos, which can be\n" |
387 | " to impossible to catch visually unless you specifically look for\n" | |
388 | " them. The only result of any option starting with 'udb' is an error\n" | |
1da177e4 LT |
389 | " in the boot output.\n\n" |
390 | ); | |
391 | ||
91acb21f | 392 | /* Only changed by ubd_init, which is an initcall. */ |
5dc62b1b | 393 | static int thread_fd = -1; |
a0044bdf | 394 | |
f88f0bdf AI |
395 | /* Function to read several request pointers at a time |
396 | * handling fractional reads if (and as) needed | |
397 | */ | |
398 | ||
399 | static int bulk_req_safe_read( | |
400 | int fd, | |
401 | struct io_thread_req * (*request_buffer)[], | |
402 | struct io_thread_req **remainder, | |
403 | int *remainder_size, | |
404 | int max_recs | |
405 | ) | |
406 | { | |
407 | int n = 0; | |
408 | int res = 0; | |
409 | ||
410 | if (*remainder_size > 0) { | |
411 | memmove( | |
412 | (char *) request_buffer, | |
413 | (char *) remainder, *remainder_size | |
414 | ); | |
415 | n = *remainder_size; | |
416 | } | |
417 | ||
418 | res = os_read_file( | |
419 | fd, | |
420 | ((char *) request_buffer) + *remainder_size, | |
421 | sizeof(struct io_thread_req *)*max_recs | |
422 | - *remainder_size | |
423 | ); | |
424 | if (res > 0) { | |
425 | n += res; | |
426 | if ((n % sizeof(struct io_thread_req *)) > 0) { | |
427 | /* | |
428 | * Read somehow returned not a multiple of dword | |
429 | * theoretically possible, but never observed in the | |
430 | * wild, so read routine must be able to handle it | |
431 | */ | |
432 | *remainder_size = n % sizeof(struct io_thread_req *); | |
433 | WARN(*remainder_size > 0, "UBD IPC read returned a partial result"); | |
434 | memmove( | |
435 | remainder, | |
436 | ((char *) request_buffer) + | |
437 | (n/sizeof(struct io_thread_req *))*sizeof(struct io_thread_req *), | |
438 | *remainder_size | |
439 | ); | |
440 | n = n - *remainder_size; | |
441 | } | |
442 | } else { | |
443 | n = res; | |
444 | } | |
445 | return n; | |
446 | } | |
447 | ||
5db755fb | 448 | static void ubd_end_request(struct io_thread_req *io_req) |
1da177e4 | 449 | { |
31ade7d4 CH |
450 | if (io_req->error == BLK_STS_NOTSUPP) { |
451 | if (req_op(io_req->req) == REQ_OP_DISCARD) | |
73e3715e | 452 | blk_queue_disable_discard(io_req->req->q); |
31ade7d4 | 453 | else if (req_op(io_req->req) == REQ_OP_WRITE_ZEROES) |
73e3715e | 454 | blk_queue_disable_write_zeroes(io_req->req->q); |
a0044bdf | 455 | } |
5db755fb CH |
456 | blk_mq_end_request(io_req->req, io_req->error); |
457 | kfree(io_req); | |
1da177e4 LT |
458 | } |
459 | ||
7bea96fd | 460 | static irqreturn_t ubd_intr(int irq, void *dev) |
1da177e4 | 461 | { |
5db755fb CH |
462 | int len, i; |
463 | ||
464 | while ((len = bulk_req_safe_read(thread_fd, irq_req_buffer, | |
465 | &irq_remainder, &irq_remainder_size, | |
466 | UBD_REQ_BUFFER_SIZE)) >= 0) { | |
467 | for (i = 0; i < len / sizeof(struct io_thread_req *); i++) | |
468 | ubd_end_request((*irq_req_buffer)[i]); | |
469 | } | |
470 | ||
471 | if (len < 0 && len != -EAGAIN) | |
472 | pr_err("spurious interrupt in %s, err = %d\n", __func__, len); | |
dc764e50 | 473 | return IRQ_HANDLED; |
91acb21f | 474 | } |
09ace81c | 475 | |
91acb21f JD |
476 | /* Only changed by ubd_init, which is an initcall. */ |
477 | static int io_pid = -1; | |
09ace81c | 478 | |
5dc62b1b | 479 | static void kill_io_thread(void) |
91acb21f | 480 | { |
6c29256c | 481 | if(io_pid != -1) |
91acb21f | 482 | os_kill_process(io_pid, 1); |
09ace81c | 483 | } |
1da177e4 | 484 | |
91acb21f JD |
485 | __uml_exitcall(kill_io_thread); |
486 | ||
d8d7c28e | 487 | static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out) |
1da177e4 LT |
488 | { |
489 | char *file; | |
85356398 RW |
490 | int fd; |
491 | int err; | |
492 | ||
493 | __u32 version; | |
494 | __u32 align; | |
495 | char *backing_file; | |
853bc0ab | 496 | time64_t mtime; |
85356398 RW |
497 | unsigned long long size; |
498 | int sector_size; | |
499 | int bitmap_offset; | |
500 | ||
501 | if (ubd_dev->file && ubd_dev->cow.file) { | |
502 | file = ubd_dev->cow.file; | |
503 | ||
504 | goto out; | |
505 | } | |
506 | ||
d4afcba9 | 507 | fd = os_open_file(ubd_dev->file, of_read(OPENFLAGS()), 0); |
85356398 RW |
508 | if (fd < 0) |
509 | return fd; | |
510 | ||
511 | err = read_cow_header(file_reader, &fd, &version, &backing_file, \ | |
512 | &mtime, &size, §or_size, &align, &bitmap_offset); | |
513 | os_close_file(fd); | |
1da177e4 | 514 | |
85356398 RW |
515 | if(err == -EINVAL) |
516 | file = ubd_dev->file; | |
517 | else | |
518 | file = backing_file; | |
519 | ||
520 | out: | |
dc764e50 | 521 | return os_file_size(file, size_out); |
1da177e4 LT |
522 | } |
523 | ||
5dc62b1b WC |
524 | static int read_cow_bitmap(int fd, void *buf, int offset, int len) |
525 | { | |
526 | int err; | |
527 | ||
8c6157b6 | 528 | err = os_pread_file(fd, buf, len, offset); |
5dc62b1b WC |
529 | if (err < 0) |
530 | return err; | |
531 | ||
532 | return 0; | |
533 | } | |
534 | ||
853bc0ab | 535 | static int backing_file_mismatch(char *file, __u64 size, time64_t mtime) |
5dc62b1b | 536 | { |
853bc0ab | 537 | time64_t modtime; |
5dc62b1b WC |
538 | unsigned long long actual; |
539 | int err; | |
540 | ||
541 | err = os_file_modtime(file, &modtime); | |
542 | if (err < 0) { | |
543 | printk(KERN_ERR "Failed to get modification time of backing " | |
544 | "file \"%s\", err = %d\n", file, -err); | |
545 | return err; | |
546 | } | |
547 | ||
548 | err = os_file_size(file, &actual); | |
549 | if (err < 0) { | |
550 | printk(KERN_ERR "Failed to get size of backing file \"%s\", " | |
551 | "err = %d\n", file, -err); | |
552 | return err; | |
553 | } | |
554 | ||
555 | if (actual != size) { | |
556 | /*__u64 can be a long on AMD64 and with %lu GCC complains; so | |
557 | * the typecast.*/ | |
558 | printk(KERN_ERR "Size mismatch (%llu vs %llu) of COW header " | |
559 | "vs backing file\n", (unsigned long long) size, actual); | |
560 | return -EINVAL; | |
561 | } | |
562 | if (modtime != mtime) { | |
853bc0ab | 563 | printk(KERN_ERR "mtime mismatch (%lld vs %lld) of COW header vs " |
5dc62b1b WC |
564 | "backing file\n", mtime, modtime); |
565 | return -EINVAL; | |
566 | } | |
567 | return 0; | |
568 | } | |
569 | ||
570 | static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow) | |
571 | { | |
572 | struct uml_stat buf1, buf2; | |
573 | int err; | |
574 | ||
575 | if (from_cmdline == NULL) | |
576 | return 0; | |
577 | if (!strcmp(from_cmdline, from_cow)) | |
578 | return 0; | |
579 | ||
580 | err = os_stat_file(from_cmdline, &buf1); | |
581 | if (err < 0) { | |
582 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cmdline, | |
583 | -err); | |
584 | return 0; | |
585 | } | |
586 | err = os_stat_file(from_cow, &buf2); | |
587 | if (err < 0) { | |
588 | printk(KERN_ERR "Couldn't stat '%s', err = %d\n", from_cow, | |
589 | -err); | |
590 | return 1; | |
591 | } | |
592 | if ((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) | |
593 | return 0; | |
594 | ||
595 | printk(KERN_ERR "Backing file mismatch - \"%s\" requested, " | |
596 | "\"%s\" specified in COW header of \"%s\"\n", | |
597 | from_cmdline, from_cow, cow); | |
598 | return 1; | |
599 | } | |
600 | ||
601 | static int open_ubd_file(char *file, struct openflags *openflags, int shared, | |
602 | char **backing_file_out, int *bitmap_offset_out, | |
603 | unsigned long *bitmap_len_out, int *data_offset_out, | |
604 | int *create_cow_out) | |
605 | { | |
853bc0ab | 606 | time64_t mtime; |
5dc62b1b WC |
607 | unsigned long long size; |
608 | __u32 version, align; | |
609 | char *backing_file; | |
610 | int fd, err, sectorsize, asked_switch, mode = 0644; | |
611 | ||
612 | fd = os_open_file(file, *openflags, mode); | |
613 | if (fd < 0) { | |
614 | if ((fd == -ENOENT) && (create_cow_out != NULL)) | |
615 | *create_cow_out = 1; | |
616 | if (!openflags->w || | |
617 | ((fd != -EROFS) && (fd != -EACCES))) | |
618 | return fd; | |
619 | openflags->w = 0; | |
620 | fd = os_open_file(file, *openflags, mode); | |
621 | if (fd < 0) | |
622 | return fd; | |
623 | } | |
624 | ||
625 | if (shared) | |
626 | printk(KERN_INFO "Not locking \"%s\" on the host\n", file); | |
627 | else { | |
628 | err = os_lock_file(fd, openflags->w); | |
629 | if (err < 0) { | |
630 | printk(KERN_ERR "Failed to lock '%s', err = %d\n", | |
631 | file, -err); | |
632 | goto out_close; | |
633 | } | |
634 | } | |
635 | ||
636 | /* Successful return case! */ | |
637 | if (backing_file_out == NULL) | |
638 | return fd; | |
639 | ||
640 | err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, | |
641 | &size, §orsize, &align, bitmap_offset_out); | |
642 | if (err && (*backing_file_out != NULL)) { | |
643 | printk(KERN_ERR "Failed to read COW header from COW file " | |
644 | "\"%s\", errno = %d\n", file, -err); | |
645 | goto out_close; | |
646 | } | |
647 | if (err) | |
648 | return fd; | |
649 | ||
650 | asked_switch = path_requires_switch(*backing_file_out, backing_file, | |
651 | file); | |
652 | ||
653 | /* Allow switching only if no mismatch. */ | |
654 | if (asked_switch && !backing_file_mismatch(*backing_file_out, size, | |
655 | mtime)) { | |
656 | printk(KERN_ERR "Switching backing file to '%s'\n", | |
657 | *backing_file_out); | |
658 | err = write_cow_header(file, fd, *backing_file_out, | |
659 | sectorsize, align, &size); | |
660 | if (err) { | |
661 | printk(KERN_ERR "Switch failed, errno = %d\n", -err); | |
662 | goto out_close; | |
663 | } | |
664 | } else { | |
665 | *backing_file_out = backing_file; | |
666 | err = backing_file_mismatch(*backing_file_out, size, mtime); | |
667 | if (err) | |
668 | goto out_close; | |
669 | } | |
670 | ||
671 | cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, | |
672 | bitmap_len_out, data_offset_out); | |
673 | ||
674 | return fd; | |
675 | out_close: | |
676 | os_close_file(fd); | |
677 | return err; | |
678 | } | |
679 | ||
680 | static int create_cow_file(char *cow_file, char *backing_file, | |
681 | struct openflags flags, | |
682 | int sectorsize, int alignment, int *bitmap_offset_out, | |
683 | unsigned long *bitmap_len_out, int *data_offset_out) | |
684 | { | |
685 | int err, fd; | |
686 | ||
687 | flags.c = 1; | |
688 | fd = open_ubd_file(cow_file, &flags, 0, NULL, NULL, NULL, NULL, NULL); | |
689 | if (fd < 0) { | |
690 | err = fd; | |
691 | printk(KERN_ERR "Open of COW file '%s' failed, errno = %d\n", | |
692 | cow_file, -err); | |
693 | goto out; | |
694 | } | |
695 | ||
696 | err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, | |
697 | bitmap_offset_out, bitmap_len_out, | |
698 | data_offset_out); | |
699 | if (!err) | |
700 | return fd; | |
701 | os_close_file(fd); | |
702 | out: | |
703 | return err; | |
704 | } | |
705 | ||
5f75a4f8 | 706 | static void ubd_close_dev(struct ubd *ubd_dev) |
1da177e4 | 707 | { |
7d314e34 PBG |
708 | os_close_file(ubd_dev->fd); |
709 | if(ubd_dev->cow.file == NULL) | |
1da177e4 LT |
710 | return; |
711 | ||
7d314e34 PBG |
712 | os_close_file(ubd_dev->cow.fd); |
713 | vfree(ubd_dev->cow.bitmap); | |
714 | ubd_dev->cow.bitmap = NULL; | |
1da177e4 LT |
715 | } |
716 | ||
7d314e34 | 717 | static int ubd_open_dev(struct ubd *ubd_dev) |
1da177e4 LT |
718 | { |
719 | struct openflags flags; | |
720 | char **back_ptr; | |
721 | int err, create_cow, *create_ptr; | |
0bf16bff | 722 | int fd; |
1da177e4 | 723 | |
7d314e34 | 724 | ubd_dev->openflags = ubd_dev->boot_openflags; |
1da177e4 | 725 | create_cow = 0; |
7d314e34 PBG |
726 | create_ptr = (ubd_dev->cow.file != NULL) ? &create_cow : NULL; |
727 | back_ptr = ubd_dev->no_cow ? NULL : &ubd_dev->cow.file; | |
0bf16bff PBG |
728 | |
729 | fd = open_ubd_file(ubd_dev->file, &ubd_dev->openflags, ubd_dev->shared, | |
7d314e34 PBG |
730 | back_ptr, &ubd_dev->cow.bitmap_offset, |
731 | &ubd_dev->cow.bitmap_len, &ubd_dev->cow.data_offset, | |
6c29256c | 732 | create_ptr); |
1da177e4 | 733 | |
0bf16bff PBG |
734 | if((fd == -ENOENT) && create_cow){ |
735 | fd = create_cow_file(ubd_dev->file, ubd_dev->cow.file, | |
a43c8316 | 736 | ubd_dev->openflags, SECTOR_SIZE, PAGE_SIZE, |
7d314e34 PBG |
737 | &ubd_dev->cow.bitmap_offset, |
738 | &ubd_dev->cow.bitmap_len, | |
739 | &ubd_dev->cow.data_offset); | |
0bf16bff | 740 | if(fd >= 0){ |
1da177e4 | 741 | printk(KERN_INFO "Creating \"%s\" as COW file for " |
7d314e34 | 742 | "\"%s\"\n", ubd_dev->file, ubd_dev->cow.file); |
1da177e4 LT |
743 | } |
744 | } | |
745 | ||
0bf16bff | 746 | if(fd < 0){ |
7d314e34 | 747 | printk("Failed to open '%s', errno = %d\n", ubd_dev->file, |
0bf16bff PBG |
748 | -fd); |
749 | return fd; | |
1da177e4 | 750 | } |
0bf16bff | 751 | ubd_dev->fd = fd; |
1da177e4 | 752 | |
7d314e34 | 753 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 754 | err = -ENOMEM; |
da2486ba | 755 | ubd_dev->cow.bitmap = vmalloc(ubd_dev->cow.bitmap_len); |
7d314e34 | 756 | if(ubd_dev->cow.bitmap == NULL){ |
1da177e4 LT |
757 | printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); |
758 | goto error; | |
759 | } | |
1da177e4 | 760 | |
7d314e34 PBG |
761 | err = read_cow_bitmap(ubd_dev->fd, ubd_dev->cow.bitmap, |
762 | ubd_dev->cow.bitmap_offset, | |
763 | ubd_dev->cow.bitmap_len); | |
1da177e4 LT |
764 | if(err < 0) |
765 | goto error; | |
766 | ||
7d314e34 | 767 | flags = ubd_dev->openflags; |
1da177e4 | 768 | flags.w = 0; |
7d314e34 | 769 | err = open_ubd_file(ubd_dev->cow.file, &flags, ubd_dev->shared, NULL, |
6c29256c | 770 | NULL, NULL, NULL, NULL); |
1da177e4 | 771 | if(err < 0) goto error; |
7d314e34 | 772 | ubd_dev->cow.fd = err; |
1da177e4 | 773 | } |
dc764e50 | 774 | return 0; |
1da177e4 | 775 | error: |
7d314e34 | 776 | os_close_file(ubd_dev->fd); |
dc764e50 | 777 | return err; |
1da177e4 LT |
778 | } |
779 | ||
2e3f5251 JD |
780 | static void ubd_device_release(struct device *dev) |
781 | { | |
8691b97b | 782 | struct ubd *ubd_dev = dev_get_drvdata(dev); |
2e3f5251 | 783 | |
4e6da0fe | 784 | blk_mq_free_tag_set(&ubd_dev->tag_set); |
2e3f5251 JD |
785 | *ubd_dev = ((struct ubd) DEFAULT_UBD); |
786 | } | |
787 | ||
ef3ba87c CO |
788 | static ssize_t serial_show(struct device *dev, |
789 | struct device_attribute *attr, char *buf) | |
790 | { | |
791 | struct gendisk *disk = dev_to_disk(dev); | |
792 | struct ubd *ubd_dev = disk->private_data; | |
793 | ||
794 | if (!ubd_dev) | |
795 | return 0; | |
796 | ||
797 | return sprintf(buf, "%s", ubd_dev->serial); | |
798 | } | |
799 | ||
800 | static DEVICE_ATTR_RO(serial); | |
801 | ||
802 | static struct attribute *ubd_attrs[] = { | |
803 | &dev_attr_serial.attr, | |
804 | NULL, | |
805 | }; | |
806 | ||
807 | static umode_t ubd_attrs_are_visible(struct kobject *kobj, | |
808 | struct attribute *a, int n) | |
809 | { | |
810 | return a->mode; | |
811 | } | |
812 | ||
813 | static const struct attribute_group ubd_attr_group = { | |
814 | .attrs = ubd_attrs, | |
815 | .is_visible = ubd_attrs_are_visible, | |
816 | }; | |
817 | ||
818 | static const struct attribute_group *ubd_attr_groups[] = { | |
819 | &ubd_attr_group, | |
820 | NULL, | |
821 | }; | |
822 | ||
a43c8316 | 823 | #define ROUND_BLOCK(n) ((n + (SECTOR_SIZE - 1)) & (-SECTOR_SIZE)) |
1da177e4 | 824 | |
4e6da0fe RW |
825 | static const struct blk_mq_ops ubd_mq_ops = { |
826 | .queue_rq = ubd_queue_rq, | |
4e6da0fe RW |
827 | }; |
828 | ||
f28169d2 | 829 | static int ubd_add(int n, char **error_out) |
1da177e4 | 830 | { |
7d314e34 | 831 | struct ubd *ubd_dev = &ubd_devs[n]; |
5d6789ce CH |
832 | struct queue_limits lim = { |
833 | .max_segments = MAX_SG, | |
834 | .seg_boundary_mask = PAGE_SIZE - 1, | |
1122c0c1 | 835 | .features = BLK_FEAT_WRITE_CACHE, |
5d6789ce | 836 | }; |
35efb594 | 837 | struct gendisk *disk; |
f28169d2 | 838 | int err = 0; |
1da177e4 | 839 | |
7d314e34 | 840 | if(ubd_dev->file == NULL) |
ec7cf783 | 841 | goto out; |
1da177e4 | 842 | |
58ebe3e7 CH |
843 | if (ubd_dev->cow.file) |
844 | lim.max_hw_sectors = 8 * sizeof(long); | |
845 | if (!ubd_dev->no_trim) { | |
846 | lim.max_hw_discard_sectors = UBD_MAX_REQUEST; | |
847 | lim.max_write_zeroes_sectors = UBD_MAX_REQUEST; | |
848 | } | |
849 | ||
7d314e34 | 850 | err = ubd_file_size(ubd_dev, &ubd_dev->size); |
f28169d2 JD |
851 | if(err < 0){ |
852 | *error_out = "Couldn't determine size of device's file"; | |
80c13749 | 853 | goto out; |
f28169d2 | 854 | } |
1da177e4 | 855 | |
fb5d1d38 CH |
856 | err = ubd_open_dev(ubd_dev); |
857 | if (err) { | |
858 | pr_err("ubd%c: Can't open \"%s\": errno = %d\n", | |
859 | 'a' + n, ubd_dev->file, -err); | |
860 | goto out; | |
861 | } | |
862 | ||
7d314e34 | 863 | ubd_dev->size = ROUND_BLOCK(ubd_dev->size); |
1da177e4 | 864 | |
4e6da0fe RW |
865 | ubd_dev->tag_set.ops = &ubd_mq_ops; |
866 | ubd_dev->tag_set.queue_depth = 64; | |
867 | ubd_dev->tag_set.numa_node = NUMA_NO_NODE; | |
868 | ubd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; | |
4e6da0fe RW |
869 | ubd_dev->tag_set.driver_data = ubd_dev; |
870 | ubd_dev->tag_set.nr_hw_queues = 1; | |
a0044bdf | 871 | |
4e6da0fe RW |
872 | err = blk_mq_alloc_tag_set(&ubd_dev->tag_set); |
873 | if (err) | |
fb5d1d38 | 874 | goto out_close; |
4e6da0fe | 875 | |
5d6789ce | 876 | disk = blk_mq_alloc_disk(&ubd_dev->tag_set, &lim, ubd_dev); |
35efb594 CH |
877 | if (IS_ERR(disk)) { |
878 | err = PTR_ERR(disk); | |
aea05eb5 | 879 | goto out_cleanup_tags; |
62f96cb0 | 880 | } |
4e6da0fe | 881 | |
0267e9ca CH |
882 | disk->major = UBD_MAJOR; |
883 | disk->first_minor = n << UBD_SHIFT; | |
884 | disk->minors = 1 << UBD_SHIFT; | |
885 | disk->fops = &ubd_blops; | |
886 | set_capacity(disk, ubd_dev->size / 512); | |
887 | sprintf(disk->disk_name, "ubd%c", 'a' + n); | |
888 | disk->private_data = ubd_dev; | |
5e4e1ff8 | 889 | set_disk_ro(disk, !ubd_dev->openflags.w); |
0267e9ca CH |
890 | |
891 | ubd_dev->pdev.id = n; | |
892 | ubd_dev->pdev.name = DRIVER_NAME; | |
893 | ubd_dev->pdev.dev.release = ubd_device_release; | |
894 | dev_set_drvdata(&ubd_dev->pdev.dev, ubd_dev); | |
895 | platform_device_register(&ubd_dev->pdev); | |
896 | ||
897 | err = device_add_disk(&ubd_dev->pdev.dev, disk, ubd_attr_groups); | |
66638f16 LC |
898 | if (err) |
899 | goto out_cleanup_disk; | |
900 | ||
35efb594 | 901 | return 0; |
62f96cb0 | 902 | |
66638f16 | 903 | out_cleanup_disk: |
8b9ab626 | 904 | put_disk(disk); |
4e6da0fe RW |
905 | out_cleanup_tags: |
906 | blk_mq_free_tag_set(&ubd_dev->tag_set); | |
fb5d1d38 CH |
907 | out_close: |
908 | ubd_close_dev(ubd_dev); | |
35efb594 CH |
909 | out: |
910 | return err; | |
1da177e4 LT |
911 | } |
912 | ||
f28169d2 | 913 | static int ubd_config(char *str, char **error_out) |
1da177e4 | 914 | { |
e7f6552f | 915 | int n, ret; |
1da177e4 | 916 | |
f28169d2 JD |
917 | /* This string is possibly broken up and stored, so it's only |
918 | * freed if ubd_setup_common fails, or if only general options | |
919 | * were set. | |
920 | */ | |
970d6e3a | 921 | str = kstrdup(str, GFP_KERNEL); |
e7f6552f | 922 | if (str == NULL) { |
f28169d2 JD |
923 | *error_out = "Failed to allocate memory"; |
924 | return -ENOMEM; | |
1da177e4 | 925 | } |
f28169d2 JD |
926 | |
927 | ret = ubd_setup_common(str, &n, error_out); | |
928 | if (ret) | |
e7f6552f | 929 | goto err_free; |
f28169d2 | 930 | |
e7f6552f PBG |
931 | if (n == -1) { |
932 | ret = 0; | |
d8d7c28e | 933 | goto err_free; |
1da177e4 | 934 | } |
1da177e4 | 935 | |
dc764e50 | 936 | mutex_lock(&ubd_lock); |
f28169d2 | 937 | ret = ubd_add(n, error_out); |
e7f6552f | 938 | if (ret) |
7d314e34 | 939 | ubd_devs[n].file = NULL; |
dc764e50 | 940 | mutex_unlock(&ubd_lock); |
1da177e4 | 941 | |
e7f6552f | 942 | out: |
dc764e50 | 943 | return ret; |
e7f6552f PBG |
944 | |
945 | err_free: | |
946 | kfree(str); | |
947 | goto out; | |
1da177e4 LT |
948 | } |
949 | ||
950 | static int ubd_get_config(char *name, char *str, int size, char **error_out) | |
951 | { | |
7d314e34 | 952 | struct ubd *ubd_dev; |
1da177e4 LT |
953 | int n, len = 0; |
954 | ||
955 | n = parse_unit(&name); | |
956 | if((n >= MAX_DEV) || (n < 0)){ | |
957 | *error_out = "ubd_get_config : device number out of range"; | |
dc764e50 | 958 | return -1; |
1da177e4 LT |
959 | } |
960 | ||
7d314e34 | 961 | ubd_dev = &ubd_devs[n]; |
d7fb2c38 | 962 | mutex_lock(&ubd_lock); |
1da177e4 | 963 | |
7d314e34 | 964 | if(ubd_dev->file == NULL){ |
1da177e4 LT |
965 | CONFIG_CHUNK(str, size, len, "", 1); |
966 | goto out; | |
967 | } | |
968 | ||
7d314e34 | 969 | CONFIG_CHUNK(str, size, len, ubd_dev->file, 0); |
1da177e4 | 970 | |
7d314e34 | 971 | if(ubd_dev->cow.file != NULL){ |
1da177e4 | 972 | CONFIG_CHUNK(str, size, len, ",", 0); |
7d314e34 | 973 | CONFIG_CHUNK(str, size, len, ubd_dev->cow.file, 1); |
1da177e4 LT |
974 | } |
975 | else CONFIG_CHUNK(str, size, len, "", 1); | |
976 | ||
977 | out: | |
d7fb2c38 | 978 | mutex_unlock(&ubd_lock); |
dc764e50 | 979 | return len; |
1da177e4 LT |
980 | } |
981 | ||
29d56cfe JD |
982 | static int ubd_id(char **str, int *start_out, int *end_out) |
983 | { | |
dc764e50 | 984 | int n; |
29d56cfe JD |
985 | |
986 | n = parse_unit(str); | |
dc764e50 JD |
987 | *start_out = 0; |
988 | *end_out = MAX_DEV - 1; | |
989 | return n; | |
29d56cfe JD |
990 | } |
991 | ||
f28169d2 | 992 | static int ubd_remove(int n, char **error_out) |
1da177e4 | 993 | { |
7d314e34 | 994 | struct ubd *ubd_dev; |
29d56cfe | 995 | int err = -ENODEV; |
1da177e4 | 996 | |
d7fb2c38 | 997 | mutex_lock(&ubd_lock); |
1da177e4 | 998 | |
7d314e34 | 999 | ubd_dev = &ubd_devs[n]; |
1da177e4 | 1000 | |
7d314e34 | 1001 | if(ubd_dev->file == NULL) |
29d56cfe | 1002 | goto out; |
1da177e4 | 1003 | |
32621ad7 | 1004 | if (ubd_dev->disk) { |
fb5d1d38 CH |
1005 | /* you cannot remove a open disk */ |
1006 | err = -EBUSY; | |
1007 | if (disk_openers(ubd_dev->disk)) | |
1008 | goto out; | |
1009 | ||
32621ad7 | 1010 | del_gendisk(ubd_dev->disk); |
fb5d1d38 | 1011 | ubd_close_dev(ubd_dev); |
32621ad7 | 1012 | put_disk(ubd_dev->disk); |
1da177e4 LT |
1013 | } |
1014 | ||
1da177e4 | 1015 | err = 0; |
2e3f5251 | 1016 | platform_device_unregister(&ubd_dev->pdev); |
29d56cfe | 1017 | out: |
d7fb2c38 | 1018 | mutex_unlock(&ubd_lock); |
29d56cfe | 1019 | return err; |
1da177e4 LT |
1020 | } |
1021 | ||
f28169d2 | 1022 | /* All these are called by mconsole in process context and without |
b8831a1d | 1023 | * ubd-specific locks. The structure itself is const except for .list. |
f28169d2 | 1024 | */ |
1da177e4 | 1025 | static struct mc_device ubd_mc = { |
84f48d4f | 1026 | .list = LIST_HEAD_INIT(ubd_mc.list), |
1da177e4 LT |
1027 | .name = "ubd", |
1028 | .config = ubd_config, | |
dc764e50 | 1029 | .get_config = ubd_get_config, |
29d56cfe | 1030 | .id = ubd_id, |
1da177e4 LT |
1031 | .remove = ubd_remove, |
1032 | }; | |
1033 | ||
d8d7c28e | 1034 | static int __init ubd_mc_init(void) |
1da177e4 LT |
1035 | { |
1036 | mconsole_register_dev(&ubd_mc); | |
1037 | return 0; | |
1038 | } | |
1039 | ||
1040 | __initcall(ubd_mc_init); | |
1041 | ||
d8d7c28e PBG |
1042 | static int __init ubd0_init(void) |
1043 | { | |
1044 | struct ubd *ubd_dev = &ubd_devs[0]; | |
1045 | ||
b8831a1d | 1046 | mutex_lock(&ubd_lock); |
d8d7c28e PBG |
1047 | if(ubd_dev->file == NULL) |
1048 | ubd_dev->file = "root_fs"; | |
b8831a1d JD |
1049 | mutex_unlock(&ubd_lock); |
1050 | ||
dc764e50 | 1051 | return 0; |
d8d7c28e PBG |
1052 | } |
1053 | ||
1054 | __initcall(ubd0_init); | |
1055 | ||
b8831a1d | 1056 | /* Used in ubd_init, which is an initcall */ |
3ae5eaec RK |
1057 | static struct platform_driver ubd_driver = { |
1058 | .driver = { | |
1059 | .name = DRIVER_NAME, | |
1060 | }, | |
1da177e4 LT |
1061 | }; |
1062 | ||
d8d7c28e | 1063 | static int __init ubd_init(void) |
1da177e4 | 1064 | { |
f28169d2 JD |
1065 | char *error; |
1066 | int i, err; | |
1da177e4 | 1067 | |
792dd4fc | 1068 | if (register_blkdev(UBD_MAJOR, "ubd")) |
1da177e4 LT |
1069 | return -1; |
1070 | ||
6da2ec56 KC |
1071 | irq_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, |
1072 | sizeof(struct io_thread_req *), | |
1073 | GFP_KERNEL | |
f88f0bdf AI |
1074 | ); |
1075 | irq_remainder = 0; | |
1076 | ||
1077 | if (irq_req_buffer == NULL) { | |
1078 | printk(KERN_ERR "Failed to initialize ubd buffering\n"); | |
31a5990e | 1079 | return -ENOMEM; |
f88f0bdf | 1080 | } |
6da2ec56 KC |
1081 | io_req_buffer = kmalloc_array(UBD_REQ_BUFFER_SIZE, |
1082 | sizeof(struct io_thread_req *), | |
1083 | GFP_KERNEL | |
f88f0bdf AI |
1084 | ); |
1085 | ||
1086 | io_remainder = 0; | |
1087 | ||
1088 | if (io_req_buffer == NULL) { | |
1089 | printk(KERN_ERR "Failed to initialize ubd buffering\n"); | |
31a5990e | 1090 | return -ENOMEM; |
f88f0bdf | 1091 | } |
3ae5eaec | 1092 | platform_driver_register(&ubd_driver); |
dc764e50 | 1093 | mutex_lock(&ubd_lock); |
f28169d2 JD |
1094 | for (i = 0; i < MAX_DEV; i++){ |
1095 | err = ubd_add(i, &error); | |
1096 | if(err) | |
1097 | printk(KERN_ERR "Failed to initialize ubd device %d :" | |
1098 | "%s\n", i, error); | |
1099 | } | |
dc764e50 | 1100 | mutex_unlock(&ubd_lock); |
1da177e4 LT |
1101 | return 0; |
1102 | } | |
1103 | ||
1104 | late_initcall(ubd_init); | |
1105 | ||
d8d7c28e | 1106 | static int __init ubd_driver_init(void){ |
91acb21f JD |
1107 | unsigned long stack; |
1108 | int err; | |
1109 | ||
1110 | /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ | |
1111 | if(global_openflags.s){ | |
1112 | printk(KERN_INFO "ubd: Synchronous mode\n"); | |
1113 | /* Letting ubd=sync be like using ubd#s= instead of ubd#= is | |
1114 | * enough. So use anyway the io thread. */ | |
1115 | } | |
2fcb4090 | 1116 | stack = alloc_stack(0, 0); |
558f9b2f | 1117 | io_pid = start_io_thread(stack + PAGE_SIZE, &thread_fd); |
91acb21f | 1118 | if(io_pid < 0){ |
6c29256c | 1119 | printk(KERN_ERR |
91acb21f JD |
1120 | "ubd : Failed to start I/O thread (errno = %d) - " |
1121 | "falling back to synchronous I/O\n", -io_pid); | |
1122 | io_pid = -1; | |
dc764e50 | 1123 | return 0; |
91acb21f | 1124 | } |
6c29256c | 1125 | err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, |
c0b79a90 | 1126 | 0, "ubd", ubd_devs); |
36d46a59 | 1127 | if(err < 0) |
91acb21f | 1128 | printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); |
f4c57a78 | 1129 | return 0; |
91acb21f JD |
1130 | } |
1131 | ||
1132 | device_initcall(ubd_driver_init); | |
1133 | ||
91acb21f JD |
1134 | static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, |
1135 | __u64 *cow_offset, unsigned long *bitmap, | |
1136 | __u64 bitmap_offset, unsigned long *bitmap_words, | |
1137 | __u64 bitmap_len) | |
1da177e4 | 1138 | { |
a43c8316 | 1139 | __u64 sector = io_offset >> SECTOR_SHIFT; |
91acb21f JD |
1140 | int i, update_bitmap = 0; |
1141 | ||
a43c8316 | 1142 | for (i = 0; i < length >> SECTOR_SHIFT; i++) { |
91acb21f JD |
1143 | if(cow_mask != NULL) |
1144 | ubd_set_bit(i, (unsigned char *) cow_mask); | |
1145 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) | |
1146 | continue; | |
1da177e4 | 1147 | |
91acb21f JD |
1148 | update_bitmap = 1; |
1149 | ubd_set_bit(sector + i, (unsigned char *) bitmap); | |
1150 | } | |
1151 | ||
1152 | if(!update_bitmap) | |
1153 | return; | |
1da177e4 | 1154 | |
91acb21f | 1155 | *cow_offset = sector / (sizeof(unsigned long) * 8); |
1da177e4 | 1156 | |
91acb21f JD |
1157 | /* This takes care of the case where we're exactly at the end of the |
1158 | * device, and *cow_offset + 1 is off the end. So, just back it up | |
1159 | * by one word. Thanks to Lynn Kerby for the fix and James McMechan | |
1160 | * for the original diagnosis. | |
1161 | */ | |
6d074242 JO |
1162 | if (*cow_offset == (DIV_ROUND_UP(bitmap_len, |
1163 | sizeof(unsigned long)) - 1)) | |
91acb21f JD |
1164 | (*cow_offset)--; |
1165 | ||
1166 | bitmap_words[0] = bitmap[*cow_offset]; | |
1167 | bitmap_words[1] = bitmap[*cow_offset + 1]; | |
1168 | ||
1169 | *cow_offset *= sizeof(unsigned long); | |
1170 | *cow_offset += bitmap_offset; | |
1171 | } | |
1172 | ||
fc6b6a87 GKB |
1173 | static void cowify_req(struct io_thread_req *req, struct io_desc *segment, |
1174 | unsigned long offset, unsigned long *bitmap, | |
91acb21f JD |
1175 | __u64 bitmap_offset, __u64 bitmap_len) |
1176 | { | |
fc6b6a87 | 1177 | __u64 sector = offset >> SECTOR_SHIFT; |
91acb21f JD |
1178 | int i; |
1179 | ||
fc6b6a87 | 1180 | if (segment->length > (sizeof(segment->sector_mask) * 8) << SECTOR_SHIFT) |
91acb21f JD |
1181 | panic("Operation too long"); |
1182 | ||
a43c8316 | 1183 | if (req_op(req->req) == REQ_OP_READ) { |
fc6b6a87 | 1184 | for (i = 0; i < segment->length >> SECTOR_SHIFT; i++) { |
91acb21f | 1185 | if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) |
6c29256c | 1186 | ubd_set_bit(i, (unsigned char *) |
fc6b6a87 GKB |
1187 | &segment->sector_mask); |
1188 | } | |
1189 | } else { | |
1190 | cowify_bitmap(offset, segment->length, &segment->sector_mask, | |
1191 | &segment->cow_offset, bitmap, bitmap_offset, | |
1192 | segment->bitmap_words, bitmap_len); | |
1193 | } | |
1194 | } | |
1195 | ||
1196 | static void ubd_map_req(struct ubd *dev, struct io_thread_req *io_req, | |
1197 | struct request *req) | |
1198 | { | |
1199 | struct bio_vec bvec; | |
1200 | struct req_iterator iter; | |
1201 | int i = 0; | |
1202 | unsigned long byte_offset = io_req->offset; | |
7ee1de6e | 1203 | enum req_op op = req_op(req); |
fc6b6a87 GKB |
1204 | |
1205 | if (op == REQ_OP_WRITE_ZEROES || op == REQ_OP_DISCARD) { | |
1206 | io_req->io_desc[0].buffer = NULL; | |
1207 | io_req->io_desc[0].length = blk_rq_bytes(req); | |
1208 | } else { | |
1209 | rq_for_each_segment(bvec, req, iter) { | |
1210 | BUG_ON(i >= io_req->desc_cnt); | |
1211 | ||
25d84545 | 1212 | io_req->io_desc[i].buffer = bvec_virt(&bvec); |
fc6b6a87 GKB |
1213 | io_req->io_desc[i].length = bvec.bv_len; |
1214 | i++; | |
1215 | } | |
1216 | } | |
1217 | ||
1218 | if (dev->cow.file) { | |
1219 | for (i = 0; i < io_req->desc_cnt; i++) { | |
1220 | cowify_req(io_req, &io_req->io_desc[i], byte_offset, | |
1221 | dev->cow.bitmap, dev->cow.bitmap_offset, | |
1222 | dev->cow.bitmap_len); | |
1223 | byte_offset += io_req->io_desc[i].length; | |
dc764e50 | 1224 | } |
fc6b6a87 | 1225 | |
91acb21f | 1226 | } |
1da177e4 LT |
1227 | } |
1228 | ||
fc6b6a87 GKB |
1229 | static struct io_thread_req *ubd_alloc_req(struct ubd *dev, struct request *req, |
1230 | int desc_cnt) | |
1da177e4 | 1231 | { |
ecb0a83e | 1232 | struct io_thread_req *io_req; |
fc6b6a87 | 1233 | int i; |
1da177e4 | 1234 | |
fc6b6a87 GKB |
1235 | io_req = kmalloc(sizeof(*io_req) + |
1236 | (desc_cnt * sizeof(struct io_desc)), | |
1237 | GFP_ATOMIC); | |
ecb0a83e | 1238 | if (!io_req) |
fc6b6a87 | 1239 | return NULL; |
805f11a0 RW |
1240 | |
1241 | io_req->req = req; | |
ecb0a83e CH |
1242 | if (dev->cow.file) |
1243 | io_req->fds[0] = dev->cow.fd; | |
1244 | else | |
1245 | io_req->fds[0] = dev->fd; | |
0033dfd9 | 1246 | io_req->error = 0; |
53766def AI |
1247 | io_req->sectorsize = SECTOR_SIZE; |
1248 | io_req->fds[1] = dev->fd; | |
fc6b6a87 | 1249 | io_req->offset = (u64) blk_rq_pos(req) << SECTOR_SHIFT; |
53766def AI |
1250 | io_req->offsets[0] = 0; |
1251 | io_req->offsets[1] = dev->cow.data_offset; | |
1252 | ||
fc6b6a87 GKB |
1253 | for (i = 0 ; i < desc_cnt; i++) { |
1254 | io_req->io_desc[i].sector_mask = 0; | |
1255 | io_req->io_desc[i].cow_offset = -1; | |
1256 | } | |
1257 | ||
1258 | return io_req; | |
1259 | } | |
1260 | ||
1261 | static int ubd_submit_request(struct ubd *dev, struct request *req) | |
1262 | { | |
1263 | int segs = 0; | |
1264 | struct io_thread_req *io_req; | |
1265 | int ret; | |
7ee1de6e | 1266 | enum req_op op = req_op(req); |
fc6b6a87 GKB |
1267 | |
1268 | if (op == REQ_OP_FLUSH) | |
1269 | segs = 0; | |
1270 | else if (op == REQ_OP_WRITE_ZEROES || op == REQ_OP_DISCARD) | |
1271 | segs = 1; | |
1272 | else | |
1273 | segs = blk_rq_nr_phys_segments(req); | |
1274 | ||
1275 | io_req = ubd_alloc_req(dev, req, segs); | |
1276 | if (!io_req) | |
1277 | return -ENOMEM; | |
1278 | ||
1279 | io_req->desc_cnt = segs; | |
1280 | if (segs) | |
1281 | ubd_map_req(dev, io_req, req); | |
53766def | 1282 | |
ecb0a83e CH |
1283 | ret = os_write_file(thread_fd, &io_req, sizeof(io_req)); |
1284 | if (ret != sizeof(io_req)) { | |
1285 | if (ret != -EAGAIN) | |
1286 | pr_err("write to io thread failed: %d\n", -ret); | |
bc1d72e7 | 1287 | kfree(io_req); |
bc1d72e7 | 1288 | } |
ecb0a83e | 1289 | return ret; |
bc1d72e7 RW |
1290 | } |
1291 | ||
4e6da0fe RW |
1292 | static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, |
1293 | const struct blk_mq_queue_data *bd) | |
1da177e4 | 1294 | { |
6961cd4d | 1295 | struct ubd *ubd_dev = hctx->queue->queuedata; |
4e6da0fe | 1296 | struct request *req = bd->rq; |
53766def | 1297 | int ret = 0, res = BLK_STS_OK; |
a0044bdf | 1298 | |
4e6da0fe RW |
1299 | blk_mq_start_request(req); |
1300 | ||
6961cd4d JA |
1301 | spin_lock_irq(&ubd_dev->lock); |
1302 | ||
53766def | 1303 | switch (req_op(req)) { |
53766def | 1304 | case REQ_OP_FLUSH: |
53766def AI |
1305 | case REQ_OP_READ: |
1306 | case REQ_OP_WRITE: | |
50109b5a AI |
1307 | case REQ_OP_DISCARD: |
1308 | case REQ_OP_WRITE_ZEROES: | |
fc6b6a87 | 1309 | ret = ubd_submit_request(ubd_dev, req); |
50109b5a | 1310 | break; |
53766def AI |
1311 | default: |
1312 | WARN_ON_ONCE(1); | |
1313 | res = BLK_STS_NOTSUPP; | |
4e6da0fe | 1314 | } |
53766def | 1315 | |
6961cd4d JA |
1316 | spin_unlock_irq(&ubd_dev->lock); |
1317 | ||
d848074b AI |
1318 | if (ret < 0) { |
1319 | if (ret == -ENOMEM) | |
1320 | res = BLK_STS_RESOURCE; | |
1321 | else | |
1322 | res = BLK_STS_DEV_RESOURCE; | |
1323 | } | |
6961cd4d | 1324 | |
53766def | 1325 | return res; |
1da177e4 LT |
1326 | } |
1327 | ||
a885c8c4 CH |
1328 | static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1329 | { | |
7d314e34 | 1330 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
a885c8c4 CH |
1331 | |
1332 | geo->heads = 128; | |
1333 | geo->sectors = 32; | |
7d314e34 | 1334 | geo->cylinders = ubd_dev->size / (128 * 32 * 512); |
a885c8c4 CH |
1335 | return 0; |
1336 | } | |
1337 | ||
05bdb996 | 1338 | static int ubd_ioctl(struct block_device *bdev, blk_mode_t mode, |
1da177e4 LT |
1339 | unsigned int cmd, unsigned long arg) |
1340 | { | |
a625c998 | 1341 | struct ubd *ubd_dev = bdev->bd_disk->private_data; |
73855e13 | 1342 | u16 ubd_id[ATA_ID_WORDS]; |
1da177e4 LT |
1343 | |
1344 | switch (cmd) { | |
1da177e4 | 1345 | struct cdrom_volctrl volume; |
1da177e4 | 1346 | case HDIO_GET_IDENTITY: |
73855e13 BZ |
1347 | memset(&ubd_id, 0, ATA_ID_WORDS * 2); |
1348 | ubd_id[ATA_ID_CYLS] = ubd_dev->size / (128 * 32 * 512); | |
1349 | ubd_id[ATA_ID_HEADS] = 128; | |
1350 | ubd_id[ATA_ID_SECTORS] = 32; | |
1da177e4 LT |
1351 | if(copy_to_user((char __user *) arg, (char *) &ubd_id, |
1352 | sizeof(ubd_id))) | |
dc764e50 JD |
1353 | return -EFAULT; |
1354 | return 0; | |
b8831a1d | 1355 | |
1da177e4 LT |
1356 | case CDROMVOLREAD: |
1357 | if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) | |
dc764e50 | 1358 | return -EFAULT; |
1da177e4 LT |
1359 | volume.channel0 = 255; |
1360 | volume.channel1 = 255; | |
1361 | volume.channel2 = 255; | |
1362 | volume.channel3 = 255; | |
1363 | if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) | |
dc764e50 JD |
1364 | return -EFAULT; |
1365 | return 0; | |
1da177e4 | 1366 | } |
dc764e50 | 1367 | return -EINVAL; |
1da177e4 LT |
1368 | } |
1369 | ||
a43c8316 AI |
1370 | static int map_error(int error_code) |
1371 | { | |
1372 | switch (error_code) { | |
1373 | case 0: | |
1374 | return BLK_STS_OK; | |
1375 | case ENOSYS: | |
1376 | case EOPNOTSUPP: | |
1377 | return BLK_STS_NOTSUPP; | |
1378 | case ENOSPC: | |
1379 | return BLK_STS_NOSPC; | |
1380 | } | |
1381 | return BLK_STS_IOERR; | |
1382 | } | |
1383 | ||
a41421ed AI |
1384 | /* |
1385 | * Everything from here onwards *IS NOT PART OF THE KERNEL* | |
1386 | * | |
1387 | * The following functions are part of UML hypervisor code. | |
1388 | * All functions from here onwards are executed as a helper | |
1389 | * thread and are not allowed to execute any kernel functions. | |
1390 | * | |
1391 | * Any communication must occur strictly via shared memory and IPC. | |
1392 | * | |
1393 | * Do not add printks, locks, kernel memory operations, etc - it | |
1394 | * will result in unpredictable behaviour and/or crashes. | |
1395 | */ | |
1396 | ||
fc6b6a87 | 1397 | static int update_bitmap(struct io_thread_req *req, struct io_desc *segment) |
1da177e4 | 1398 | { |
91acb21f | 1399 | int n; |
1da177e4 | 1400 | |
fc6b6a87 | 1401 | if (segment->cow_offset == -1) |
a43c8316 | 1402 | return map_error(0); |
1da177e4 | 1403 | |
fc6b6a87 GKB |
1404 | n = os_pwrite_file(req->fds[1], &segment->bitmap_words, |
1405 | sizeof(segment->bitmap_words), segment->cow_offset); | |
1406 | if (n != sizeof(segment->bitmap_words)) | |
a43c8316 | 1407 | return map_error(-n); |
1da177e4 | 1408 | |
a43c8316 | 1409 | return map_error(0); |
91acb21f | 1410 | } |
1da177e4 | 1411 | |
fc6b6a87 | 1412 | static void do_io(struct io_thread_req *req, struct io_desc *desc) |
91acb21f | 1413 | { |
50109b5a | 1414 | char *buf = NULL; |
91acb21f JD |
1415 | unsigned long len; |
1416 | int n, nsectors, start, end, bit; | |
91acb21f JD |
1417 | __u64 off; |
1418 | ||
50109b5a AI |
1419 | /* FLUSH is really a special case, we cannot "case" it with others */ |
1420 | ||
a43c8316 | 1421 | if (req_op(req->req) == REQ_OP_FLUSH) { |
805f11a0 | 1422 | /* fds[0] is always either the rw image or our cow file */ |
a41421ed | 1423 | req->error = map_error(-os_sync_file(req->fds[0])); |
805f11a0 RW |
1424 | return; |
1425 | } | |
1426 | ||
fc6b6a87 | 1427 | nsectors = desc->length / req->sectorsize; |
91acb21f JD |
1428 | start = 0; |
1429 | do { | |
fc6b6a87 | 1430 | bit = ubd_test_bit(start, (unsigned char *) &desc->sector_mask); |
91acb21f JD |
1431 | end = start; |
1432 | while((end < nsectors) && | |
fc6b6a87 | 1433 | (ubd_test_bit(end, (unsigned char *) &desc->sector_mask) == bit)) |
91acb21f JD |
1434 | end++; |
1435 | ||
1436 | off = req->offset + req->offsets[bit] + | |
1437 | start * req->sectorsize; | |
1438 | len = (end - start) * req->sectorsize; | |
fc6b6a87 GKB |
1439 | if (desc->buffer != NULL) |
1440 | buf = &desc->buffer[start * req->sectorsize]; | |
91acb21f | 1441 | |
50109b5a AI |
1442 | switch (req_op(req->req)) { |
1443 | case REQ_OP_READ: | |
91acb21f JD |
1444 | n = 0; |
1445 | do { | |
1446 | buf = &buf[n]; | |
1447 | len -= n; | |
8c6157b6 | 1448 | n = os_pread_file(req->fds[bit], buf, len, off); |
50109b5a | 1449 | if (n < 0) { |
a43c8316 | 1450 | req->error = map_error(-n); |
91acb21f JD |
1451 | return; |
1452 | } | |
1453 | } while((n < len) && (n != 0)); | |
1454 | if (n < len) memset(&buf[n], 0, len - n); | |
50109b5a AI |
1455 | break; |
1456 | case REQ_OP_WRITE: | |
8c6157b6 | 1457 | n = os_pwrite_file(req->fds[bit], buf, len, off); |
91acb21f | 1458 | if(n != len){ |
a43c8316 | 1459 | req->error = map_error(-n); |
91acb21f JD |
1460 | return; |
1461 | } | |
50109b5a AI |
1462 | break; |
1463 | case REQ_OP_DISCARD: | |
50109b5a AI |
1464 | n = os_falloc_punch(req->fds[bit], off, len); |
1465 | if (n) { | |
1466 | req->error = map_error(-n); | |
1467 | return; | |
1468 | } | |
1469 | break; | |
d2a0a616 FD |
1470 | case REQ_OP_WRITE_ZEROES: |
1471 | n = os_falloc_zeroes(req->fds[bit], off, len); | |
1472 | if (n) { | |
1473 | req->error = map_error(-n); | |
1474 | return; | |
1475 | } | |
1476 | break; | |
50109b5a AI |
1477 | default: |
1478 | WARN_ON_ONCE(1); | |
1479 | req->error = BLK_STS_NOTSUPP; | |
1480 | return; | |
91acb21f JD |
1481 | } |
1482 | ||
1483 | start = end; | |
1484 | } while(start < nsectors); | |
1da177e4 | 1485 | |
fc6b6a87 GKB |
1486 | req->offset += len; |
1487 | req->error = update_bitmap(req, desc); | |
1da177e4 | 1488 | } |
91acb21f JD |
1489 | |
1490 | /* Changed in start_io_thread, which is serialized by being called only | |
1491 | * from ubd_init, which is an initcall. | |
1492 | */ | |
1493 | int kernel_fd = -1; | |
1494 | ||
d8d7c28e | 1495 | /* Only changed by the io thread. XXX: currently unused. */ |
4dc5a328 | 1496 | static int io_count; |
91acb21f JD |
1497 | |
1498 | int io_thread(void *arg) | |
1499 | { | |
f88f0bdf | 1500 | int n, count, written, res; |
91acb21f | 1501 | |
91d44ff8 RW |
1502 | os_fix_helper_signals(); |
1503 | ||
91acb21f | 1504 | while(1){ |
f88f0bdf AI |
1505 | n = bulk_req_safe_read( |
1506 | kernel_fd, | |
1507 | io_req_buffer, | |
1508 | &io_remainder, | |
1509 | &io_remainder_size, | |
1510 | UBD_REQ_BUFFER_SIZE | |
1511 | ); | |
e355b2f5 GKB |
1512 | if (n <= 0) { |
1513 | if (n == -EAGAIN) | |
f88f0bdf | 1514 | ubd_read_poll(-1); |
e355b2f5 GKB |
1515 | |
1516 | continue; | |
91acb21f | 1517 | } |
f88f0bdf AI |
1518 | |
1519 | for (count = 0; count < n/sizeof(struct io_thread_req *); count++) { | |
fc6b6a87 GKB |
1520 | struct io_thread_req *req = (*io_req_buffer)[count]; |
1521 | int i; | |
1522 | ||
f88f0bdf | 1523 | io_count++; |
fc6b6a87 GKB |
1524 | for (i = 0; !req->error && i < req->desc_cnt; i++) |
1525 | do_io(req, &(req->io_desc[i])); | |
1526 | ||
f88f0bdf AI |
1527 | } |
1528 | ||
1529 | written = 0; | |
1530 | ||
1531 | do { | |
6e682d53 GKB |
1532 | res = os_write_file(kernel_fd, |
1533 | ((char *) io_req_buffer) + written, | |
1534 | n - written); | |
ff6a1798 | 1535 | if (res >= 0) { |
f88f0bdf | 1536 | written += res; |
f88f0bdf AI |
1537 | } |
1538 | if (written < n) { | |
1539 | ubd_write_poll(-1); | |
1540 | } | |
1541 | } while (written < n); | |
91acb21f | 1542 | } |
91acb21f | 1543 | |
1b57e9c2 JD |
1544 | return 0; |
1545 | } |