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Commit | Line | Data |
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c444a71b | 1 | |
10ee5932 | 2 | /* |
0f23ee0c KZ |
3 | * No copyright is claimed. This code is in the public domain; do with |
4 | * it what you wish. | |
5 | * | |
6 | * Written by Karel Zak <kzak@redhat.com> | |
10ee5932 KZ |
7 | * |
8 | * -- based on mount/losetup.c | |
9 | * | |
10 | * Simple library for work with loop devices. | |
11 | * | |
12 | * - requires kernel 2.6.x | |
13 | * - reads info from /sys/block/loop<N>/loop/<attr> (new kernels) | |
14 | * - reads info by ioctl | |
15 | * - supports *unlimited* number of loop devices | |
16 | * - supports /dev/loop<N> as well as /dev/loop/<N> | |
17 | * - minimize overhead (fd, loopinfo, ... are shared for all operations) | |
18 | * - setup (associate device and backing file) | |
19 | * - delete (dis-associate file) | |
20 | * - old LOOP_{SET,GET}_STATUS (32bit) ioctls are unsupported | |
21 | * - extendible | |
22 | */ | |
23 | #include <stdio.h> | |
24 | #include <stdint.h> | |
25 | #include <string.h> | |
26 | #include <ctype.h> | |
27 | #include <fcntl.h> | |
10ee5932 KZ |
28 | #include <stdlib.h> |
29 | #include <unistd.h> | |
30 | #include <sys/ioctl.h> | |
31 | #include <sys/stat.h> | |
32 | #include <sys/mman.h> | |
10ee5932 KZ |
33 | #include <inttypes.h> |
34 | #include <dirent.h> | |
10ee5932 KZ |
35 | |
36 | #include "linux_version.h" | |
37 | #include "c.h" | |
38 | #include "sysfs.h" | |
39 | #include "pathnames.h" | |
40 | #include "loopdev.h" | |
41 | #include "canonicalize.h" | |
293714c0 | 42 | #include "blkdev.h" |
0bf03740 | 43 | #include "debug.h" |
10ee5932 | 44 | |
0bf03740 KZ |
45 | /* |
46 | * Debug stuff (based on include/debug.h) | |
47 | */ | |
2ba641e5 | 48 | static UL_DEBUG_DEFINE_MASK(loopdev); |
0bf03740 | 49 | UL_DEBUG_DEFINE_MASKNAMES(loopdev) = UL_DEBUG_EMPTY_MASKNAMES; |
aee31ddc | 50 | |
0bf03740 KZ |
51 | #define LOOPDEV_DEBUG_INIT (1 << 1) |
52 | #define LOOPDEV_DEBUG_CXT (1 << 2) | |
53 | #define LOOPDEV_DEBUG_ITER (1 << 3) | |
54 | #define LOOPDEV_DEBUG_SETUP (1 << 4) | |
aee31ddc | 55 | |
0bf03740 KZ |
56 | #define DBG(m, x) __UL_DBG(loopdev, LOOPDEV_DEBUG_, m, x) |
57 | #define ON_DBG(m, x) __UL_DBG_CALL(loopdev, LOOPDEV_DEBUG_, m, x) | |
aee31ddc | 58 | |
6d00cfb2 KZ |
59 | #define UL_DEBUG_CURRENT_MASK UL_DEBUG_MASK(loopdev) |
60 | #include "debugobj.h" | |
61 | ||
0bf03740 | 62 | static void loopdev_init_debug(void) |
aee31ddc | 63 | { |
0bf03740 KZ |
64 | if (loopdev_debug_mask) |
65 | return; | |
a15dca2f | 66 | __UL_INIT_DEBUG_FROM_ENV(loopdev, LOOPDEV_DEBUG_, 0, LOOPDEV_DEBUG); |
aee31ddc KZ |
67 | } |
68 | ||
e4062c72 KZ |
69 | /* |
70 | * see loopcxt_init() | |
71 | */ | |
10ee5932 | 72 | #define loopcxt_ioctl_enabled(_lc) (!((_lc)->flags & LOOPDEV_FL_NOIOCTL)) |
e4062c72 KZ |
73 | #define loopcxt_sysfs_available(_lc) (!((_lc)->flags & LOOPDEV_FL_NOSYSFS)) \ |
74 | && !loopcxt_ioctl_enabled(_lc) | |
10ee5932 KZ |
75 | |
76 | /* | |
77 | * @lc: context | |
78 | * @device: device name, absolute device path or NULL to reset the current setting | |
79 | * | |
80 | * Sets device, absolute paths (e.g. "/dev/loop<N>") are unchanged, device | |
81 | * names ("loop<N>") are converted to the path (/dev/loop<N> or to | |
82 | * /dev/loop/<N>) | |
83 | * | |
85794fb0 KZ |
84 | * This sets the device name, but does not check if the device exists! |
85 | * | |
10ee5932 KZ |
86 | * Returns: <0 on error, 0 on success |
87 | */ | |
88 | int loopcxt_set_device(struct loopdev_cxt *lc, const char *device) | |
89 | { | |
90 | if (!lc) | |
91 | return -EINVAL; | |
92 | ||
f4bf9592 | 93 | if (lc->fd >= 0) { |
10ee5932 | 94 | close(lc->fd); |
0bf03740 | 95 | DBG(CXT, ul_debugobj(lc, "closing old open fd")); |
f4bf9592 | 96 | } |
10ee5932 | 97 | lc->fd = -1; |
fd7f0718 | 98 | lc->mode = 0; |
75d239ff | 99 | lc->blocksize = 0; |
10ee5932 | 100 | lc->has_info = 0; |
6c224de1 | 101 | lc->info_failed = 0; |
10ee5932 | 102 | *lc->device = '\0'; |
fd7f0718 | 103 | memset(&lc->info, 0, sizeof(lc->info)); |
10ee5932 KZ |
104 | |
105 | /* set new */ | |
106 | if (device) { | |
107 | if (*device != '/') { | |
108 | const char *dir = _PATH_DEV; | |
109 | ||
110 | /* compose device name for /dev/loop<n> or /dev/loop/<n> */ | |
111 | if (lc->flags & LOOPDEV_FL_DEVSUBDIR) { | |
112 | if (strlen(device) < 5) | |
113 | return -1; | |
114 | device += 4; | |
115 | dir = _PATH_DEV_LOOP "/"; /* _PATH_DEV uses tailing slash */ | |
116 | } | |
117 | snprintf(lc->device, sizeof(lc->device), "%s%s", | |
118 | dir, device); | |
119 | } else { | |
120 | strncpy(lc->device, device, sizeof(lc->device)); | |
121 | lc->device[sizeof(lc->device) - 1] = '\0'; | |
122 | } | |
0bf03740 | 123 | DBG(CXT, ul_debugobj(lc, "%s name assigned", device)); |
10ee5932 KZ |
124 | } |
125 | ||
7604f85f KZ |
126 | ul_unref_path(lc->sysfs); |
127 | lc->sysfs = NULL; | |
10ee5932 KZ |
128 | return 0; |
129 | } | |
130 | ||
c7e0925d KZ |
131 | int loopcxt_has_device(struct loopdev_cxt *lc) |
132 | { | |
133 | return lc && *lc->device; | |
134 | } | |
135 | ||
10ee5932 KZ |
136 | /* |
137 | * @lc: context | |
138 | * @flags: LOOPDEV_FL_* flags | |
139 | * | |
3fd1f771 | 140 | * Initialize loop handler. |
10ee5932 | 141 | * |
fd7f0718 KZ |
142 | * We have two sets of the flags: |
143 | * | |
144 | * * LOOPDEV_FL_* flags control loopcxt_* API behavior | |
145 | * | |
146 | * * LO_FLAGS_* are kernel flags used for LOOP_{SET,GET}_STAT64 ioctls | |
147 | * | |
148 | * Note about LOOPDEV_FL_{RDONLY,RDWR} flags. These flags are used for open(2) | |
149 | * syscall to open loop device. By default is the device open read-only. | |
150 | * | |
73afd3f8 | 151 | * The exception is loopcxt_setup_device(), where the device is open read-write |
fd7f0718 KZ |
152 | * if LO_FLAGS_READ_ONLY flags is not set (see loopcxt_set_flags()). |
153 | * | |
10ee5932 KZ |
154 | * Returns: <0 on error, 0 on success. |
155 | */ | |
156 | int loopcxt_init(struct loopdev_cxt *lc, int flags) | |
157 | { | |
defa0710 | 158 | int rc; |
0b14bf7a | 159 | struct stat st; |
6219c25e | 160 | struct loopdev_cxt dummy = UL_LOOPDEVCXT_EMPTY; |
0b14bf7a | 161 | |
10ee5932 KZ |
162 | if (!lc) |
163 | return -EINVAL; | |
164 | ||
0bf03740 KZ |
165 | loopdev_init_debug(); |
166 | DBG(CXT, ul_debugobj(lc, "initialize context")); | |
167 | ||
6219c25e | 168 | memcpy(lc, &dummy, sizeof(dummy)); |
10ee5932 | 169 | lc->flags = flags; |
defa0710 KZ |
170 | |
171 | rc = loopcxt_set_device(lc, NULL); | |
172 | if (rc) | |
173 | return rc; | |
10ee5932 | 174 | |
df0f2ad7 KZ |
175 | if (stat(_PATH_SYS_BLOCK, &st) || !S_ISDIR(st.st_mode)) { |
176 | lc->flags |= LOOPDEV_FL_NOSYSFS; | |
177 | lc->flags &= ~LOOPDEV_FL_NOIOCTL; | |
0bf03740 | 178 | DBG(CXT, ul_debugobj(lc, "init: disable /sys usage")); |
df0f2ad7 KZ |
179 | } |
180 | ||
82b4082e | 181 | if (!(lc->flags & LOOPDEV_FL_NOSYSFS) && |
f4bf9592 | 182 | get_linux_version() >= KERNEL_VERSION(2,6,37)) { |
10ee5932 KZ |
183 | /* |
184 | * Use only sysfs for basic information about loop devices | |
185 | */ | |
186 | lc->flags |= LOOPDEV_FL_NOIOCTL; | |
0bf03740 | 187 | DBG(CXT, ul_debugobj(lc, "init: ignore ioctls")); |
f4bf9592 | 188 | } |
10ee5932 | 189 | |
f4bf9592 | 190 | if (!(lc->flags & LOOPDEV_FL_CONTROL) && !stat(_PATH_DEV_LOOPCTL, &st)) { |
0b14bf7a | 191 | lc->flags |= LOOPDEV_FL_CONTROL; |
0bf03740 | 192 | DBG(CXT, ul_debugobj(lc, "init: loop-control detected ")); |
f4bf9592 | 193 | } |
0b14bf7a | 194 | |
10ee5932 KZ |
195 | return 0; |
196 | } | |
197 | ||
198 | /* | |
199 | * @lc: context | |
200 | * | |
201 | * Deinitialize loop context | |
202 | */ | |
203 | void loopcxt_deinit(struct loopdev_cxt *lc) | |
204 | { | |
82756a74 KZ |
205 | int errsv = errno; |
206 | ||
10ee5932 KZ |
207 | if (!lc) |
208 | return; | |
209 | ||
0bf03740 | 210 | DBG(CXT, ul_debugobj(lc, "de-initialize")); |
aee31ddc | 211 | |
10ee5932 KZ |
212 | free(lc->filename); |
213 | lc->filename = NULL; | |
214 | ||
defa0710 | 215 | ignore_result( loopcxt_set_device(lc, NULL) ); |
10ee5932 | 216 | loopcxt_deinit_iterator(lc); |
82756a74 KZ |
217 | |
218 | errno = errsv; | |
10ee5932 KZ |
219 | } |
220 | ||
221 | /* | |
222 | * @lc: context | |
223 | * | |
224 | * Returns newly allocated device path. | |
225 | */ | |
226 | char *loopcxt_strdup_device(struct loopdev_cxt *lc) | |
227 | { | |
cba69bb5 | 228 | if (!lc || !*lc->device) |
10ee5932 KZ |
229 | return NULL; |
230 | return strdup(lc->device); | |
231 | } | |
232 | ||
233 | /* | |
234 | * @lc: context | |
235 | * | |
236 | * Returns pointer device name in the @lc struct. | |
237 | */ | |
238 | const char *loopcxt_get_device(struct loopdev_cxt *lc) | |
239 | { | |
cba69bb5 | 240 | return lc && *lc->device ? lc->device : NULL; |
10ee5932 KZ |
241 | } |
242 | ||
243 | /* | |
244 | * @lc: context | |
245 | * | |
246 | * Returns pointer to the sysfs context (see lib/sysfs.c) | |
247 | */ | |
7604f85f | 248 | static struct path_cxt *loopcxt_get_sysfs(struct loopdev_cxt *lc) |
10ee5932 KZ |
249 | { |
250 | if (!lc || !*lc->device || (lc->flags & LOOPDEV_FL_NOSYSFS)) | |
251 | return NULL; | |
252 | ||
7604f85f KZ |
253 | if (!lc->sysfs) { |
254 | dev_t devno = sysfs_devname_to_devno(lc->device); | |
aee31ddc | 255 | if (!devno) { |
0bf03740 | 256 | DBG(CXT, ul_debugobj(lc, "sysfs: failed devname to devno")); |
10ee5932 | 257 | return NULL; |
aee31ddc | 258 | } |
7604f85f KZ |
259 | |
260 | lc->sysfs = ul_new_sysfs_path(devno, NULL, NULL); | |
261 | if (!lc->sysfs) | |
0bf03740 | 262 | DBG(CXT, ul_debugobj(lc, "sysfs: init failed")); |
10ee5932 | 263 | } |
aee31ddc | 264 | |
7604f85f | 265 | return lc->sysfs; |
10ee5932 KZ |
266 | } |
267 | ||
268 | /* | |
269 | * @lc: context | |
270 | * | |
271 | * Returns: file descriptor to the open loop device or <0 on error. The mode | |
272 | * depends on LOOPDEV_FL_{RDWR,RDONLY} context flags. Default is | |
273 | * read-only. | |
274 | */ | |
275 | int loopcxt_get_fd(struct loopdev_cxt *lc) | |
276 | { | |
277 | if (!lc || !*lc->device) | |
fd7f0718 | 278 | return -EINVAL; |
10ee5932 | 279 | |
fd7f0718 KZ |
280 | if (lc->fd < 0) { |
281 | lc->mode = lc->flags & LOOPDEV_FL_RDWR ? O_RDWR : O_RDONLY; | |
b1fa3e22 | 282 | lc->fd = open(lc->device, lc->mode | O_CLOEXEC); |
0bf03740 | 283 | DBG(CXT, ul_debugobj(lc, "open %s [%s]: %m", lc->device, |
663bf040 | 284 | lc->flags & LOOPDEV_FL_RDWR ? "rw" : "ro")); |
fd7f0718 | 285 | } |
10ee5932 KZ |
286 | return lc->fd; |
287 | } | |
288 | ||
fd7f0718 KZ |
289 | int loopcxt_set_fd(struct loopdev_cxt *lc, int fd, int mode) |
290 | { | |
291 | if (!lc) | |
292 | return -EINVAL; | |
293 | ||
294 | lc->fd = fd; | |
295 | lc->mode = mode; | |
296 | return 0; | |
297 | } | |
298 | ||
10ee5932 KZ |
299 | /* |
300 | * @lc: context | |
301 | * @flags: LOOPITER_FL_* flags | |
302 | * | |
303 | * Iterator allows to scan list of the free or used loop devices. | |
304 | * | |
305 | * Returns: <0 on error, 0 on success | |
306 | */ | |
307 | int loopcxt_init_iterator(struct loopdev_cxt *lc, int flags) | |
308 | { | |
309 | struct loopdev_iter *iter; | |
310 | struct stat st; | |
311 | ||
312 | if (!lc) | |
313 | return -EINVAL; | |
314 | ||
aee31ddc | 315 | |
10ee5932 | 316 | iter = &lc->iter; |
0bf03740 | 317 | DBG(ITER, ul_debugobj(iter, "initialize")); |
10ee5932 KZ |
318 | |
319 | /* always zeroize | |
320 | */ | |
321 | memset(iter, 0, sizeof(*iter)); | |
322 | iter->ncur = -1; | |
323 | iter->flags = flags; | |
324 | iter->default_check = 1; | |
325 | ||
326 | if (!lc->extra_check) { | |
327 | /* | |
328 | * Check for /dev/loop/<N> subdirectory | |
329 | */ | |
82b4082e | 330 | if (!(lc->flags & LOOPDEV_FL_DEVSUBDIR) && |
10ee5932 KZ |
331 | stat(_PATH_DEV_LOOP, &st) == 0 && S_ISDIR(st.st_mode)) |
332 | lc->flags |= LOOPDEV_FL_DEVSUBDIR; | |
333 | ||
334 | lc->extra_check = 1; | |
335 | } | |
336 | return 0; | |
337 | } | |
338 | ||
339 | /* | |
340 | * @lc: context | |
341 | * | |
342 | * Returns: <0 on error, 0 on success | |
343 | */ | |
344 | int loopcxt_deinit_iterator(struct loopdev_cxt *lc) | |
345 | { | |
7552258a | 346 | struct loopdev_iter *iter; |
10ee5932 KZ |
347 | |
348 | if (!lc) | |
349 | return -EINVAL; | |
350 | ||
351 | iter = &lc->iter; | |
0bf03740 | 352 | DBG(ITER, ul_debugobj(iter, "de-initialize")); |
10ee5932 KZ |
353 | |
354 | free(iter->minors); | |
355 | if (iter->proc) | |
356 | fclose(iter->proc); | |
e4062c72 KZ |
357 | if (iter->sysblock) |
358 | closedir(iter->sysblock); | |
9a94b634 KZ |
359 | |
360 | memset(iter, 0, sizeof(*iter)); | |
10ee5932 KZ |
361 | return 0; |
362 | } | |
363 | ||
364 | /* | |
365 | * Same as loopcxt_set_device, but also checks if the device is | |
11026083 | 366 | * associated with any file. |
10ee5932 KZ |
367 | * |
368 | * Returns: <0 on error, 0 on success, 1 device does not match with | |
369 | * LOOPITER_FL_{USED,FREE} flags. | |
370 | */ | |
371 | static int loopiter_set_device(struct loopdev_cxt *lc, const char *device) | |
372 | { | |
373 | int rc = loopcxt_set_device(lc, device); | |
374 | int used; | |
375 | ||
376 | if (rc) | |
377 | return rc; | |
378 | ||
379 | if (!(lc->iter.flags & LOOPITER_FL_USED) && | |
380 | !(lc->iter.flags & LOOPITER_FL_FREE)) | |
381 | return 0; /* caller does not care about device status */ | |
382 | ||
85794fb0 | 383 | if (!is_loopdev(lc->device)) { |
0bf03740 | 384 | DBG(ITER, ul_debugobj(&lc->iter, "%s does not exist", lc->device)); |
85794fb0 KZ |
385 | return -errno; |
386 | } | |
387 | ||
0bf03740 | 388 | DBG(ITER, ul_debugobj(&lc->iter, "%s exist", lc->device)); |
85794fb0 | 389 | |
10ee5932 KZ |
390 | used = loopcxt_get_offset(lc, NULL) == 0; |
391 | ||
392 | if ((lc->iter.flags & LOOPITER_FL_USED) && used) | |
393 | return 0; | |
394 | ||
395 | if ((lc->iter.flags & LOOPITER_FL_FREE) && !used) | |
396 | return 0; | |
397 | ||
0bf03740 KZ |
398 | DBG(ITER, ul_debugobj(&lc->iter, "failed to use %s device", lc->device)); |
399 | ||
defa0710 | 400 | ignore_result( loopcxt_set_device(lc, NULL) ); |
10ee5932 KZ |
401 | return 1; |
402 | } | |
403 | ||
404 | static int cmpnum(const void *p1, const void *p2) | |
405 | { | |
0145c00a KZ |
406 | return (((* (const int *) p1) > (* (const int *) p2)) - |
407 | ((* (const int *) p1) < (* (const int *) p2))); | |
10ee5932 KZ |
408 | } |
409 | ||
410 | /* | |
411 | * The classic scandir() is more expensive and less portable. | |
412 | * We needn't full loop device names -- loop numbers (loop<N>) | |
413 | * are enough. | |
414 | */ | |
415 | static int loop_scandir(const char *dirname, int **ary, int hasprefix) | |
416 | { | |
417 | DIR *dir; | |
418 | struct dirent *d; | |
419 | unsigned int n, count = 0, arylen = 0; | |
420 | ||
421 | if (!dirname || !ary) | |
422 | return 0; | |
0bf03740 KZ |
423 | |
424 | DBG(ITER, ul_debug("scan dir: %s", dirname)); | |
425 | ||
10ee5932 KZ |
426 | dir = opendir(dirname); |
427 | if (!dir) | |
428 | return 0; | |
10ee5932 KZ |
429 | free(*ary); |
430 | *ary = NULL; | |
431 | ||
432 | while((d = readdir(dir))) { | |
433 | #ifdef _DIRENT_HAVE_D_TYPE | |
434 | if (d->d_type != DT_BLK && d->d_type != DT_UNKNOWN && | |
435 | d->d_type != DT_LNK) | |
436 | continue; | |
437 | #endif | |
438 | if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, "..")) | |
439 | continue; | |
440 | ||
441 | if (hasprefix) { | |
442 | /* /dev/loop<N> */ | |
443 | if (sscanf(d->d_name, "loop%u", &n) != 1) | |
444 | continue; | |
445 | } else { | |
446 | /* /dev/loop/<N> */ | |
447 | char *end = NULL; | |
448 | ||
f0fe8ab5 | 449 | errno = 0; |
10ee5932 KZ |
450 | n = strtol(d->d_name, &end, 10); |
451 | if (d->d_name == end || (end && *end) || errno) | |
452 | continue; | |
453 | } | |
454 | if (n < LOOPDEV_DEFAULT_NNODES) | |
455 | continue; /* ignore loop<0..7> */ | |
456 | ||
457 | if (count + 1 > arylen) { | |
458 | int *tmp; | |
459 | ||
460 | arylen += 1; | |
461 | ||
462 | tmp = realloc(*ary, arylen * sizeof(int)); | |
463 | if (!tmp) { | |
464 | free(*ary); | |
34f6177a | 465 | *ary = NULL; |
2e566efd | 466 | closedir(dir); |
10ee5932 KZ |
467 | return -1; |
468 | } | |
469 | *ary = tmp; | |
470 | } | |
fc8b1f36 KZ |
471 | if (*ary) |
472 | (*ary)[count++] = n; | |
10ee5932 | 473 | } |
fc8b1f36 | 474 | if (count && *ary) |
10ee5932 KZ |
475 | qsort(*ary, count, sizeof(int), cmpnum); |
476 | ||
477 | closedir(dir); | |
478 | return count; | |
479 | } | |
480 | ||
e4062c72 KZ |
481 | /* |
482 | * Set the next *used* loop device according to /proc/partitions. | |
483 | * | |
484 | * Loop devices smaller than 512 bytes are invisible for this function. | |
485 | */ | |
486 | static int loopcxt_next_from_proc(struct loopdev_cxt *lc) | |
487 | { | |
488 | struct loopdev_iter *iter = &lc->iter; | |
489 | char buf[BUFSIZ]; | |
490 | ||
0bf03740 | 491 | DBG(ITER, ul_debugobj(iter, "scan /proc/partitions")); |
e4062c72 KZ |
492 | |
493 | if (!iter->proc) | |
b1fa3e22 | 494 | iter->proc = fopen(_PATH_PROC_PARTITIONS, "r" UL_CLOEXECSTR); |
e4062c72 KZ |
495 | if (!iter->proc) |
496 | return 1; | |
497 | ||
498 | while (fgets(buf, sizeof(buf), iter->proc)) { | |
499 | unsigned int m; | |
657d9adb | 500 | char name[128 + 1]; |
e4062c72 KZ |
501 | |
502 | ||
503 | if (sscanf(buf, " %u %*s %*s %128[^\n ]", | |
504 | &m, name) != 2 || m != LOOPDEV_MAJOR) | |
505 | continue; | |
506 | ||
0bf03740 | 507 | DBG(ITER, ul_debugobj(iter, "checking %s", name)); |
e4062c72 KZ |
508 | |
509 | if (loopiter_set_device(lc, name) == 0) | |
510 | return 0; | |
511 | } | |
512 | ||
513 | return 1; | |
514 | } | |
515 | ||
516 | /* | |
517 | * Set the next *used* loop device according to | |
518 | * /sys/block/loopN/loop/backing_file (kernel >= 2.6.37 is required). | |
519 | * | |
520 | * This is preferred method. | |
521 | */ | |
522 | static int loopcxt_next_from_sysfs(struct loopdev_cxt *lc) | |
523 | { | |
524 | struct loopdev_iter *iter = &lc->iter; | |
525 | struct dirent *d; | |
526 | int fd; | |
527 | ||
0bf03740 | 528 | DBG(ITER, ul_debugobj(iter, "scanning /sys/block")); |
e4062c72 KZ |
529 | |
530 | if (!iter->sysblock) | |
531 | iter->sysblock = opendir(_PATH_SYS_BLOCK); | |
532 | ||
533 | if (!iter->sysblock) | |
534 | return 1; | |
535 | ||
536 | fd = dirfd(iter->sysblock); | |
537 | ||
538 | while ((d = readdir(iter->sysblock))) { | |
acecab61 | 539 | char name[NAME_MAX + 18 + 1]; |
e4062c72 KZ |
540 | struct stat st; |
541 | ||
0bf03740 | 542 | DBG(ITER, ul_debugobj(iter, "check %s", d->d_name)); |
e4062c72 KZ |
543 | |
544 | if (strcmp(d->d_name, ".") == 0 | |
545 | || strcmp(d->d_name, "..") == 0 | |
546 | || strncmp(d->d_name, "loop", 4) != 0) | |
547 | continue; | |
548 | ||
549 | snprintf(name, sizeof(name), "%s/loop/backing_file", d->d_name); | |
2208b3cc | 550 | if (fstatat(fd, name, &st, 0) != 0) |
e4062c72 KZ |
551 | continue; |
552 | ||
553 | if (loopiter_set_device(lc, d->d_name) == 0) | |
554 | return 0; | |
555 | } | |
556 | ||
557 | return 1; | |
558 | } | |
559 | ||
10ee5932 KZ |
560 | /* |
561 | * @lc: context, has to initialized by loopcxt_init_iterator() | |
562 | * | |
563 | * Returns: 0 on success, -1 on error, 1 at the end of scanning. The details | |
564 | * about the current loop device are available by | |
565 | * loopcxt_get_{fd,backing_file,device,offset, ...} functions. | |
566 | */ | |
567 | int loopcxt_next(struct loopdev_cxt *lc) | |
568 | { | |
569 | struct loopdev_iter *iter; | |
570 | ||
571 | if (!lc) | |
572 | return -EINVAL; | |
aee31ddc | 573 | |
aee31ddc | 574 | |
10ee5932 KZ |
575 | iter = &lc->iter; |
576 | if (iter->done) | |
577 | return 1; | |
578 | ||
0bf03740 KZ |
579 | DBG(ITER, ul_debugobj(iter, "next")); |
580 | ||
10ee5932 KZ |
581 | /* A) Look for used loop devices in /proc/partitions ("losetup -a" only) |
582 | */ | |
583 | if (iter->flags & LOOPITER_FL_USED) { | |
e4062c72 KZ |
584 | int rc; |
585 | ||
586 | if (loopcxt_sysfs_available(lc)) | |
587 | rc = loopcxt_next_from_sysfs(lc); | |
588 | else | |
589 | rc = loopcxt_next_from_proc(lc); | |
590 | if (rc == 0) | |
591 | return 0; | |
10ee5932 KZ |
592 | goto done; |
593 | } | |
594 | ||
595 | /* B) Classic way, try first eight loop devices (default number | |
596 | * of loop devices). This is enough for 99% of all cases. | |
597 | */ | |
598 | if (iter->default_check) { | |
0bf03740 | 599 | DBG(ITER, ul_debugobj(iter, "next: default check")); |
10ee5932 KZ |
600 | for (++iter->ncur; iter->ncur < LOOPDEV_DEFAULT_NNODES; |
601 | iter->ncur++) { | |
602 | char name[16]; | |
603 | snprintf(name, sizeof(name), "loop%d", iter->ncur); | |
604 | ||
605 | if (loopiter_set_device(lc, name) == 0) | |
606 | return 0; | |
607 | } | |
608 | iter->default_check = 0; | |
609 | } | |
610 | ||
611 | /* C) the worst possibility, scan whole /dev or /dev/loop/<N> | |
612 | */ | |
613 | if (!iter->minors) { | |
0bf03740 | 614 | DBG(ITER, ul_debugobj(iter, "next: scanning /dev")); |
10ee5932 KZ |
615 | iter->nminors = (lc->flags & LOOPDEV_FL_DEVSUBDIR) ? |
616 | loop_scandir(_PATH_DEV_LOOP, &iter->minors, 0) : | |
617 | loop_scandir(_PATH_DEV, &iter->minors, 1); | |
618 | iter->ncur = -1; | |
619 | } | |
620 | for (++iter->ncur; iter->ncur < iter->nminors; iter->ncur++) { | |
621 | char name[16]; | |
622 | snprintf(name, sizeof(name), "loop%d", iter->minors[iter->ncur]); | |
623 | ||
624 | if (loopiter_set_device(lc, name) == 0) | |
625 | return 0; | |
626 | } | |
627 | done: | |
628 | loopcxt_deinit_iterator(lc); | |
629 | return 1; | |
630 | } | |
631 | ||
632 | /* | |
633 | * @device: path to device | |
634 | */ | |
635 | int is_loopdev(const char *device) | |
636 | { | |
637 | struct stat st; | |
638 | ||
cb129d9c | 639 | if (device && stat(device, &st) == 0 && |
10ee5932 | 640 | S_ISBLK(st.st_mode) && |
cb129d9c TS |
641 | major(st.st_rdev) == LOOPDEV_MAJOR) |
642 | return 1; | |
643 | ||
644 | errno = ENODEV; | |
645 | return 0; | |
10ee5932 KZ |
646 | } |
647 | ||
648 | /* | |
649 | * @lc: context | |
650 | * | |
651 | * Returns result from LOOP_GET_STAT64 ioctl or NULL on error. | |
652 | */ | |
653 | struct loop_info64 *loopcxt_get_info(struct loopdev_cxt *lc) | |
654 | { | |
655 | int fd; | |
656 | ||
85794fb0 KZ |
657 | if (!lc || lc->info_failed) { |
658 | errno = EINVAL; | |
10ee5932 | 659 | return NULL; |
85794fb0 KZ |
660 | } |
661 | errno = 0; | |
10ee5932 KZ |
662 | if (lc->has_info) |
663 | return &lc->info; | |
664 | ||
665 | fd = loopcxt_get_fd(lc); | |
666 | if (fd < 0) | |
667 | return NULL; | |
668 | ||
669 | if (ioctl(fd, LOOP_GET_STATUS64, &lc->info) == 0) { | |
670 | lc->has_info = 1; | |
6c224de1 | 671 | lc->info_failed = 0; |
0bf03740 | 672 | DBG(CXT, ul_debugobj(lc, "reading loop_info64 OK")); |
10ee5932 KZ |
673 | return &lc->info; |
674 | } | |
675 | ||
85794fb0 | 676 | lc->info_failed = 1; |
0bf03740 | 677 | DBG(CXT, ul_debugobj(lc, "reading loop_info64 FAILED")); |
85794fb0 | 678 | |
10ee5932 KZ |
679 | return NULL; |
680 | } | |
681 | ||
682 | /* | |
683 | * @lc: context | |
684 | * | |
685 | * Returns (allocated) string with path to the file assicieted | |
686 | * with the current loop device. | |
687 | */ | |
688 | char *loopcxt_get_backing_file(struct loopdev_cxt *lc) | |
689 | { | |
7604f85f | 690 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
10ee5932 KZ |
691 | char *res = NULL; |
692 | ||
693 | if (sysfs) | |
fd7f0718 | 694 | /* |
11026083 | 695 | * This is always preferred, the loop_info64 |
fd7f0718 KZ |
696 | * has too small buffer for the filename. |
697 | */ | |
7604f85f | 698 | ul_path_read_string(sysfs, &res, "loop/backing_file"); |
10ee5932 KZ |
699 | |
700 | if (!res && loopcxt_ioctl_enabled(lc)) { | |
701 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
702 | ||
703 | if (lo) { | |
704 | lo->lo_file_name[LO_NAME_SIZE - 2] = '*'; | |
705 | lo->lo_file_name[LO_NAME_SIZE - 1] = '\0'; | |
706 | res = strdup((char *) lo->lo_file_name); | |
707 | } | |
708 | } | |
aee31ddc | 709 | |
0bf03740 | 710 | DBG(CXT, ul_debugobj(lc, "get_backing_file [%s]", res)); |
10ee5932 KZ |
711 | return res; |
712 | } | |
713 | ||
714 | /* | |
715 | * @lc: context | |
716 | * @offset: returns offset number for the given device | |
717 | * | |
718 | * Returns: <0 on error, 0 on success | |
719 | */ | |
720 | int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset) | |
721 | { | |
7604f85f | 722 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
10ee5932 KZ |
723 | int rc = -EINVAL; |
724 | ||
725 | if (sysfs) | |
7604f85f | 726 | rc = ul_path_read_u64(sysfs, offset, "loop/offset"); |
10ee5932 KZ |
727 | |
728 | if (rc && loopcxt_ioctl_enabled(lc)) { | |
729 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
730 | if (lo) { | |
731 | if (offset) | |
732 | *offset = lo->lo_offset; | |
6c224de1 | 733 | rc = 0; |
85794fb0 KZ |
734 | } else |
735 | rc = -errno; | |
10ee5932 KZ |
736 | } |
737 | ||
0bf03740 | 738 | DBG(CXT, ul_debugobj(lc, "get_offset [rc=%d]", rc)); |
10ee5932 KZ |
739 | return rc; |
740 | } | |
741 | ||
a1a41597 SB |
742 | /* |
743 | * @lc: context | |
744 | * @blocksize: returns logical blocksize for the given device | |
745 | * | |
746 | * Returns: <0 on error, 0 on success | |
747 | */ | |
748 | int loopcxt_get_blocksize(struct loopdev_cxt *lc, uint64_t *blocksize) | |
749 | { | |
7604f85f | 750 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
a1a41597 SB |
751 | int rc = -EINVAL; |
752 | ||
753 | if (sysfs) | |
7604f85f | 754 | rc = ul_path_read_u64(sysfs, blocksize, "queue/logical_block_size"); |
a1a41597 SB |
755 | |
756 | /* Fallback based on BLKSSZGET ioctl */ | |
757 | if (rc) { | |
758 | int fd = loopcxt_get_fd(lc); | |
759 | int sz = 0; | |
760 | ||
761 | if (fd < 0) | |
762 | return -EINVAL; | |
763 | rc = blkdev_get_sector_size(fd, &sz); | |
764 | if (rc) | |
765 | return rc; | |
766 | ||
767 | *blocksize = sz; | |
768 | } | |
769 | ||
770 | DBG(CXT, ul_debugobj(lc, "get_blocksize [rc=%d]", rc)); | |
771 | return rc; | |
772 | } | |
773 | ||
10ee5932 KZ |
774 | /* |
775 | * @lc: context | |
776 | * @sizelimit: returns size limit for the given device | |
777 | * | |
778 | * Returns: <0 on error, 0 on success | |
779 | */ | |
780 | int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size) | |
781 | { | |
7604f85f | 782 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
10ee5932 KZ |
783 | int rc = -EINVAL; |
784 | ||
785 | if (sysfs) | |
7604f85f | 786 | rc = ul_path_read_u64(sysfs, size, "loop/sizelimit"); |
10ee5932 KZ |
787 | |
788 | if (rc && loopcxt_ioctl_enabled(lc)) { | |
789 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
790 | if (lo) { | |
791 | if (size) | |
792 | *size = lo->lo_sizelimit; | |
6c224de1 | 793 | rc = 0; |
85794fb0 KZ |
794 | } else |
795 | rc = -errno; | |
10ee5932 KZ |
796 | } |
797 | ||
0bf03740 | 798 | DBG(CXT, ul_debugobj(lc, "get_sizelimit [rc=%d]", rc)); |
6c224de1 KZ |
799 | return rc; |
800 | } | |
801 | ||
802 | /* | |
803 | * @lc: context | |
804 | * @devno: returns encryption type | |
805 | * | |
806 | * Cryptoloop is DEPRECATED! | |
807 | * | |
808 | * Returns: <0 on error, 0 on success | |
809 | */ | |
810 | int loopcxt_get_encrypt_type(struct loopdev_cxt *lc, uint32_t *type) | |
811 | { | |
812 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
85794fb0 | 813 | int rc; |
6c224de1 | 814 | |
85794fb0 | 815 | /* not provided by sysfs */ |
6c224de1 KZ |
816 | if (lo) { |
817 | if (type) | |
818 | *type = lo->lo_encrypt_type; | |
819 | rc = 0; | |
85794fb0 KZ |
820 | } else |
821 | rc = -errno; | |
822 | ||
0bf03740 | 823 | DBG(CXT, ul_debugobj(lc, "get_encrypt_type [rc=%d]", rc)); |
6c224de1 KZ |
824 | return rc; |
825 | } | |
826 | ||
827 | /* | |
828 | * @lc: context | |
829 | * @devno: returns crypt name | |
830 | * | |
831 | * Cryptoloop is DEPRECATED! | |
832 | * | |
833 | * Returns: <0 on error, 0 on success | |
834 | */ | |
835 | const char *loopcxt_get_crypt_name(struct loopdev_cxt *lc) | |
836 | { | |
837 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
838 | ||
839 | if (lo) | |
840 | return (char *) lo->lo_crypt_name; | |
841 | ||
0bf03740 | 842 | DBG(CXT, ul_debugobj(lc, "get_crypt_name failed")); |
6c224de1 KZ |
843 | return NULL; |
844 | } | |
845 | ||
846 | /* | |
847 | * @lc: context | |
848 | * @devno: returns backing file devno | |
849 | * | |
850 | * Returns: <0 on error, 0 on success | |
851 | */ | |
852 | int loopcxt_get_backing_devno(struct loopdev_cxt *lc, dev_t *devno) | |
853 | { | |
854 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
85794fb0 | 855 | int rc; |
6c224de1 KZ |
856 | |
857 | if (lo) { | |
858 | if (devno) | |
859 | *devno = lo->lo_device; | |
860 | rc = 0; | |
85794fb0 KZ |
861 | } else |
862 | rc = -errno; | |
863 | ||
0bf03740 | 864 | DBG(CXT, ul_debugobj(lc, "get_backing_devno [rc=%d]", rc)); |
6c224de1 KZ |
865 | return rc; |
866 | } | |
867 | ||
868 | /* | |
869 | * @lc: context | |
870 | * @ino: returns backing file inode | |
871 | * | |
872 | * Returns: <0 on error, 0 on success | |
873 | */ | |
874 | int loopcxt_get_backing_inode(struct loopdev_cxt *lc, ino_t *ino) | |
875 | { | |
876 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
85794fb0 | 877 | int rc; |
6c224de1 KZ |
878 | |
879 | if (lo) { | |
880 | if (ino) | |
881 | *ino = lo->lo_inode; | |
882 | rc = 0; | |
85794fb0 KZ |
883 | } else |
884 | rc = -errno; | |
885 | ||
0bf03740 | 886 | DBG(CXT, ul_debugobj(lc, "get_backing_inode [rc=%d]", rc)); |
10ee5932 KZ |
887 | return rc; |
888 | } | |
889 | ||
59d749c3 KZ |
890 | /* |
891 | * Check if the kernel supports partitioned loop devices. | |
892 | * | |
893 | * Notes: | |
894 | * - kernels < 3.2 support partitioned loop devices and PT scanning | |
9e930041 | 895 | * only if max_part= module parameter is non-zero |
59d749c3 KZ |
896 | * |
897 | * - kernels >= 3.2 always support partitioned loop devices | |
898 | * | |
899 | * - kernels >= 3.2 always support BLKPG_{ADD,DEL}_PARTITION ioctls | |
900 | * | |
901 | * - kernels >= 3.2 enable PT scanner only if max_part= is non-zero or if the | |
902 | * LO_FLAGS_PARTSCAN flag is set for the device. The PT scanner is disabled | |
903 | * by default. | |
904 | * | |
905 | * See kernel commit e03c8dd14915fabc101aa495828d58598dc5af98. | |
906 | */ | |
907 | int loopmod_supports_partscan(void) | |
908 | { | |
909 | int rc, ret = 0; | |
910 | FILE *f; | |
911 | ||
912 | if (get_linux_version() >= KERNEL_VERSION(3,2,0)) | |
913 | return 1; | |
914 | ||
b1fa3e22 | 915 | f = fopen("/sys/module/loop/parameters/max_part", "r" UL_CLOEXECSTR); |
59d749c3 KZ |
916 | if (!f) |
917 | return 0; | |
918 | rc = fscanf(f, "%d", &ret); | |
919 | fclose(f); | |
8b04761d | 920 | return rc == 1 ? ret : 0; |
59d749c3 KZ |
921 | } |
922 | ||
10ee5932 KZ |
923 | /* |
924 | * @lc: context | |
925 | * | |
59d749c3 | 926 | * Returns: 1 if the partscan flags is set *or* (for old kernels) partitions |
9e930041 | 927 | * scanning is enabled for all loop devices. |
59d749c3 KZ |
928 | */ |
929 | int loopcxt_is_partscan(struct loopdev_cxt *lc) | |
930 | { | |
7604f85f | 931 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
59d749c3 KZ |
932 | |
933 | if (sysfs) { | |
934 | /* kernel >= 3.2 */ | |
935 | int fl; | |
7604f85f | 936 | if (ul_path_read_s32(sysfs, &fl, "loop/partscan") == 0) |
59d749c3 KZ |
937 | return fl; |
938 | } | |
939 | ||
940 | /* old kernels (including kernels without loopN/loop/<flags> directory */ | |
941 | return loopmod_supports_partscan(); | |
942 | } | |
943 | ||
944 | /* | |
945 | * @lc: context | |
946 | * | |
947 | * Returns: 1 if the autoclear flags is set. | |
10ee5932 KZ |
948 | */ |
949 | int loopcxt_is_autoclear(struct loopdev_cxt *lc) | |
950 | { | |
7604f85f | 951 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
10ee5932 KZ |
952 | |
953 | if (sysfs) { | |
954 | int fl; | |
7604f85f | 955 | if (ul_path_read_s32(sysfs, &fl, "loop/autoclear") == 0) |
10ee5932 KZ |
956 | return fl; |
957 | } | |
958 | ||
959 | if (loopcxt_ioctl_enabled(lc)) { | |
960 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
961 | if (lo) | |
962 | return lo->lo_flags & LO_FLAGS_AUTOCLEAR; | |
963 | } | |
964 | return 0; | |
965 | } | |
966 | ||
fd7f0718 KZ |
967 | /* |
968 | * @lc: context | |
969 | * | |
59d749c3 | 970 | * Returns: 1 if the readonly flags is set. |
fd7f0718 KZ |
971 | */ |
972 | int loopcxt_is_readonly(struct loopdev_cxt *lc) | |
973 | { | |
7604f85f | 974 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
fd7f0718 KZ |
975 | |
976 | if (sysfs) { | |
977 | int fl; | |
7604f85f | 978 | if (ul_path_read_s32(sysfs, &fl, "ro") == 0) |
fd7f0718 KZ |
979 | return fl; |
980 | } | |
981 | ||
982 | if (loopcxt_ioctl_enabled(lc)) { | |
983 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
984 | if (lo) | |
985 | return lo->lo_flags & LO_FLAGS_READ_ONLY; | |
986 | } | |
987 | return 0; | |
988 | } | |
989 | ||
faeef4d2 ML |
990 | /* |
991 | * @lc: context | |
992 | * | |
993 | * Returns: 1 if the dio flags is set. | |
994 | */ | |
995 | int loopcxt_is_dio(struct loopdev_cxt *lc) | |
996 | { | |
7604f85f | 997 | struct path_cxt *sysfs = loopcxt_get_sysfs(lc); |
faeef4d2 ML |
998 | |
999 | if (sysfs) { | |
1000 | int fl; | |
7604f85f | 1001 | if (ul_path_read_s32(sysfs, &fl, "loop/dio") == 0) |
faeef4d2 ML |
1002 | return fl; |
1003 | } | |
1004 | if (loopcxt_ioctl_enabled(lc)) { | |
1005 | struct loop_info64 *lo = loopcxt_get_info(lc); | |
1006 | if (lo) | |
1007 | return lo->lo_flags & LO_FLAGS_DIRECT_IO; | |
1008 | } | |
1009 | return 0; | |
1010 | } | |
1011 | ||
6c224de1 KZ |
1012 | /* |
1013 | * @lc: context | |
1014 | * @st: backing file stat or NULL | |
1015 | * @backing_file: filename | |
c444a71b KZ |
1016 | * @offset: offset (use LOOPDEV_FL_OFFSET if specified) |
1017 | * @sizelimit: size limit (use LOOPDEV_FL_SIZELIMIT if specified) | |
1018 | * @flags: LOOPDEV_FL_{OFFSET,SIZELIMIT} | |
6c224de1 KZ |
1019 | * |
1020 | * Returns 1 if the current @lc loopdev is associated with the given backing | |
1021 | * file. Note that the preferred way is to use devno and inode number rather | |
1022 | * than filename. The @backing_file filename is poor solution usable in case | |
1023 | * that you don't have rights to call stat(). | |
1024 | * | |
74a4705a SB |
1025 | * LOOPDEV_FL_SIZELIMIT requires LOOPDEV_FL_OFFSET being set as well. |
1026 | * | |
6c224de1 KZ |
1027 | * Don't forget that old kernels provide very restricted (in size) backing |
1028 | * filename by LOOP_GET_STAT64 ioctl only. | |
1029 | */ | |
1030 | int loopcxt_is_used(struct loopdev_cxt *lc, | |
1031 | struct stat *st, | |
1032 | const char *backing_file, | |
1033 | uint64_t offset, | |
74a4705a | 1034 | uint64_t sizelimit, |
6c224de1 KZ |
1035 | int flags) |
1036 | { | |
1037 | ino_t ino; | |
1038 | dev_t dev; | |
1039 | ||
1040 | if (!lc) | |
1041 | return 0; | |
1042 | ||
0bf03740 | 1043 | DBG(CXT, ul_debugobj(lc, "checking %s vs. %s", |
6c224de1 KZ |
1044 | loopcxt_get_device(lc), |
1045 | backing_file)); | |
1046 | ||
1047 | if (st && loopcxt_get_backing_inode(lc, &ino) == 0 && | |
1048 | loopcxt_get_backing_devno(lc, &dev) == 0) { | |
1049 | ||
1050 | if (ino == st->st_ino && dev == st->st_dev) | |
1051 | goto found; | |
1052 | ||
1053 | /* don't use filename if we have devno and inode */ | |
1054 | return 0; | |
1055 | } | |
1056 | ||
1057 | /* poor man's solution */ | |
1058 | if (backing_file) { | |
1059 | char *name = loopcxt_get_backing_file(lc); | |
1060 | int rc = name && strcmp(name, backing_file) == 0; | |
1061 | ||
1062 | free(name); | |
1063 | if (rc) | |
1064 | goto found; | |
1065 | } | |
1066 | ||
1067 | return 0; | |
1068 | found: | |
1069 | if (flags & LOOPDEV_FL_OFFSET) { | |
1070 | uint64_t off; | |
1071 | ||
74a4705a SB |
1072 | int rc = loopcxt_get_offset(lc, &off) == 0 && off == offset; |
1073 | ||
1074 | if (rc && flags & LOOPDEV_FL_SIZELIMIT) { | |
1075 | uint64_t sz; | |
1076 | ||
1077 | return loopcxt_get_sizelimit(lc, &sz) == 0 && sz == sizelimit; | |
c444a71b | 1078 | } else |
74a4705a | 1079 | return rc; |
6c224de1 KZ |
1080 | } |
1081 | return 1; | |
1082 | } | |
1083 | ||
fd7f0718 KZ |
1084 | /* |
1085 | * The setting is removed by loopcxt_set_device() loopcxt_next()! | |
1086 | */ | |
10ee5932 KZ |
1087 | int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset) |
1088 | { | |
1089 | if (!lc) | |
1090 | return -EINVAL; | |
1091 | lc->info.lo_offset = offset; | |
aee31ddc | 1092 | |
0bf03740 | 1093 | DBG(CXT, ul_debugobj(lc, "set offset=%jd", offset)); |
10ee5932 KZ |
1094 | return 0; |
1095 | } | |
1096 | ||
fd7f0718 KZ |
1097 | /* |
1098 | * The setting is removed by loopcxt_set_device() loopcxt_next()! | |
1099 | */ | |
10ee5932 KZ |
1100 | int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit) |
1101 | { | |
1102 | if (!lc) | |
1103 | return -EINVAL; | |
1104 | lc->info.lo_sizelimit = sizelimit; | |
aee31ddc | 1105 | |
0bf03740 | 1106 | DBG(CXT, ul_debugobj(lc, "set sizelimit=%jd", sizelimit)); |
10ee5932 KZ |
1107 | return 0; |
1108 | } | |
1109 | ||
75d239ff KZ |
1110 | /* |
1111 | * The blocksize will be used by loopcxt_set_device(). For already exiting | |
1112 | * devices use loopcxt_ioctl_blocksize(). | |
1113 | * | |
1114 | * The setting is removed by loopcxt_set_device() loopcxt_next()! | |
1115 | */ | |
1116 | int loopcxt_set_blocksize(struct loopdev_cxt *lc, uint64_t blocksize) | |
1117 | { | |
1118 | if (!lc) | |
1119 | return -EINVAL; | |
1120 | lc->blocksize = blocksize; | |
1121 | ||
1122 | DBG(CXT, ul_debugobj(lc, "set blocksize=%jd", blocksize)); | |
1123 | return 0; | |
1124 | } | |
1125 | ||
10ee5932 KZ |
1126 | /* |
1127 | * @lc: context | |
1128 | * @flags: kernel LO_FLAGS_{READ_ONLY,USE_AOPS,AUTOCLEAR} flags | |
1129 | * | |
fd7f0718 KZ |
1130 | * The setting is removed by loopcxt_set_device() loopcxt_next()! |
1131 | * | |
10ee5932 KZ |
1132 | * Returns: 0 on success, <0 on error. |
1133 | */ | |
1134 | int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags) | |
1135 | { | |
1136 | if (!lc) | |
1137 | return -EINVAL; | |
1138 | lc->info.lo_flags = flags; | |
aee31ddc | 1139 | |
0bf03740 | 1140 | DBG(CXT, ul_debugobj(lc, "set flags=%u", (unsigned) flags)); |
10ee5932 KZ |
1141 | return 0; |
1142 | } | |
1143 | ||
1144 | /* | |
1145 | * @lc: context | |
1146 | * @filename: backing file path (the path will be canonicalized) | |
1147 | * | |
fd7f0718 KZ |
1148 | * The setting is removed by loopcxt_set_device() loopcxt_next()! |
1149 | * | |
10ee5932 KZ |
1150 | * Returns: 0 on success, <0 on error. |
1151 | */ | |
1152 | int loopcxt_set_backing_file(struct loopdev_cxt *lc, const char *filename) | |
1153 | { | |
1154 | if (!lc) | |
1155 | return -EINVAL; | |
1156 | ||
1157 | lc->filename = canonicalize_path(filename); | |
1158 | if (!lc->filename) | |
1159 | return -errno; | |
1160 | ||
1161 | strncpy((char *)lc->info.lo_file_name, lc->filename, LO_NAME_SIZE); | |
1162 | lc->info.lo_file_name[LO_NAME_SIZE- 1] = '\0'; | |
1163 | ||
0bf03740 | 1164 | DBG(CXT, ul_debugobj(lc, "set backing file=%s", lc->info.lo_file_name)); |
10ee5932 KZ |
1165 | return 0; |
1166 | } | |
1167 | ||
293714c0 JM |
1168 | /* |
1169 | * In kernels prior to v3.9, if the offset or sizelimit options | |
1170 | * are used, the block device's size won't be synced automatically. | |
1171 | * blockdev --getsize64 and filesystems will use the backing | |
1172 | * file size until the block device has been re-opened or the | |
1173 | * LOOP_SET_CAPACITY ioctl is called to sync the sizes. | |
1174 | * | |
1175 | * Since mount -oloop uses the LO_FLAGS_AUTOCLEAR option and passes | |
1176 | * the open file descriptor to the mount system call, we need to use | |
1177 | * the ioctl. Calling losetup directly doesn't have this problem since | |
1178 | * it closes the device when it exits and whatever consumes the device | |
1179 | * next will re-open it, causing the resync. | |
1180 | */ | |
1181 | static int loopcxt_check_size(struct loopdev_cxt *lc, int file_fd) | |
1182 | { | |
1183 | uint64_t size, expected_size; | |
1184 | int dev_fd; | |
1185 | struct stat st; | |
1186 | ||
1187 | if (!lc->info.lo_offset && !lc->info.lo_sizelimit) | |
1188 | return 0; | |
1189 | ||
01307ecf | 1190 | if (fstat(file_fd, &st)) { |
0bf03740 | 1191 | DBG(CXT, ul_debugobj(lc, "failed to fstat backing file")); |
293714c0 | 1192 | return -errno; |
01307ecf | 1193 | } |
e3b6cb87 KZ |
1194 | if (S_ISBLK(st.st_mode)) { |
1195 | if (blkdev_get_size(file_fd, | |
01307ecf | 1196 | (unsigned long long *) &expected_size)) { |
0bf03740 | 1197 | DBG(CXT, ul_debugobj(lc, "failed to determine device size")); |
e3b6cb87 | 1198 | return -errno; |
01307ecf | 1199 | } |
e3b6cb87 KZ |
1200 | } else |
1201 | expected_size = st.st_size; | |
1202 | ||
1203 | if (expected_size == 0 || expected_size <= lc->info.lo_offset) { | |
0bf03740 | 1204 | DBG(CXT, ul_debugobj(lc, "failed to determine expected size")); |
e3b6cb87 KZ |
1205 | return 0; /* ignore this error */ |
1206 | } | |
293714c0 JM |
1207 | |
1208 | if (lc->info.lo_offset > 0) | |
1209 | expected_size -= lc->info.lo_offset; | |
1210 | ||
1211 | if (lc->info.lo_sizelimit > 0 && lc->info.lo_sizelimit < expected_size) | |
1212 | expected_size = lc->info.lo_sizelimit; | |
1213 | ||
1214 | dev_fd = loopcxt_get_fd(lc); | |
01307ecf | 1215 | if (dev_fd < 0) { |
0bf03740 | 1216 | DBG(CXT, ul_debugobj(lc, "failed to get loop FD")); |
293714c0 | 1217 | return -errno; |
01307ecf | 1218 | } |
293714c0 | 1219 | |
01307ecf | 1220 | if (blkdev_get_size(dev_fd, (unsigned long long *) &size)) { |
0bf03740 | 1221 | DBG(CXT, ul_debugobj(lc, "failed to determine loopdev size")); |
293714c0 | 1222 | return -errno; |
01307ecf | 1223 | } |
293714c0 | 1224 | |
a7d5202b KZ |
1225 | /* It's block device, so, align to 512-byte sectors */ |
1226 | if (expected_size % 512) { | |
0bf03740 | 1227 | DBG(CXT, ul_debugobj(lc, "expected size misaligned to 512-byte sectors")); |
a7d5202b KZ |
1228 | expected_size = (expected_size >> 9) << 9; |
1229 | } | |
1230 | ||
293714c0 | 1231 | if (expected_size != size) { |
0bf03740 | 1232 | DBG(CXT, ul_debugobj(lc, "warning: loopdev and expected " |
9e930041 | 1233 | "size mismatch (%ju/%ju)", |
e3b6cb87 KZ |
1234 | size, expected_size)); |
1235 | ||
9fcc8936 | 1236 | if (loopcxt_ioctl_capacity(lc)) { |
293714c0 JM |
1237 | /* ioctl not available */ |
1238 | if (errno == ENOTTY || errno == EINVAL) | |
1239 | errno = ERANGE; | |
1240 | return -errno; | |
1241 | } | |
1242 | ||
1243 | if (blkdev_get_size(dev_fd, (unsigned long long *) &size)) | |
1244 | return -errno; | |
1245 | ||
01307ecf KZ |
1246 | if (expected_size != size) { |
1247 | errno = ERANGE; | |
0bf03740 | 1248 | DBG(CXT, ul_debugobj(lc, "failed to set loopdev size, " |
01307ecf KZ |
1249 | "size: %ju, expected: %ju", |
1250 | size, expected_size)); | |
1251 | return -errno; | |
1252 | } | |
293714c0 JM |
1253 | } |
1254 | ||
1255 | return 0; | |
1256 | } | |
1257 | ||
10ee5932 | 1258 | /* |
bfd4e1f7 | 1259 | * @lc: context |
10ee5932 KZ |
1260 | * |
1261 | * Associate the current device (see loopcxt_{set,get}_device()) with | |
1262 | * a file (see loopcxt_set_backing_file()). | |
1263 | * | |
fd7f0718 KZ |
1264 | * The device is initialized read-write by default. If you want read-only |
1265 | * device then set LO_FLAGS_READ_ONLY by loopcxt_set_flags(). The LOOPDEV_FL_* | |
1266 | * flags are ignored and modified according to LO_FLAGS_*. | |
1267 | * | |
1268 | * If the device is already open by loopcxt_get_fd() then this setup device | |
1269 | * function will re-open the device to fix read/write mode. | |
1270 | * | |
1271 | * The device is also initialized read-only if the backing file is not | |
1272 | * possible to open read-write (e.g. read-only FS). | |
10ee5932 KZ |
1273 | * |
1274 | * Returns: <0 on error, 0 on success. | |
1275 | */ | |
1276 | int loopcxt_setup_device(struct loopdev_cxt *lc) | |
1277 | { | |
663bf040 | 1278 | int file_fd, dev_fd, mode = O_RDWR, rc = -1, cnt = 0; |
2cde9865 | 1279 | int errsv = 0; |
10ee5932 KZ |
1280 | |
1281 | if (!lc || !*lc->device || !lc->filename) | |
1282 | return -EINVAL; | |
1283 | ||
0bf03740 | 1284 | DBG(SETUP, ul_debugobj(lc, "device setup requested")); |
aee31ddc | 1285 | |
10ee5932 KZ |
1286 | /* |
1287 | * Open backing file and device | |
1288 | */ | |
fd7f0718 KZ |
1289 | if (lc->info.lo_flags & LO_FLAGS_READ_ONLY) |
1290 | mode = O_RDONLY; | |
10ee5932 | 1291 | |
b1fa3e22 | 1292 | if ((file_fd = open(lc->filename, mode | O_CLOEXEC)) < 0) { |
10ee5932 KZ |
1293 | if (mode != O_RDONLY && (errno == EROFS || errno == EACCES)) |
1294 | file_fd = open(lc->filename, mode = O_RDONLY); | |
1295 | ||
aee31ddc | 1296 | if (file_fd < 0) { |
0bf03740 | 1297 | DBG(SETUP, ul_debugobj(lc, "open backing file failed: %m")); |
10ee5932 | 1298 | return -errno; |
aee31ddc | 1299 | } |
10ee5932 | 1300 | } |
0bf03740 | 1301 | DBG(SETUP, ul_debugobj(lc, "backing file open: OK")); |
10ee5932 | 1302 | |
fd7f0718 | 1303 | if (lc->fd != -1 && lc->mode != mode) { |
0bf03740 | 1304 | DBG(SETUP, ul_debugobj(lc, "closing already open device (mode mismatch)")); |
fd7f0718 KZ |
1305 | close(lc->fd); |
1306 | lc->fd = -1; | |
1307 | lc->mode = 0; | |
1308 | } | |
1309 | ||
10ee5932 | 1310 | if (mode == O_RDONLY) { |
fd7f0718 KZ |
1311 | lc->flags |= LOOPDEV_FL_RDONLY; /* open() mode */ |
1312 | lc->info.lo_flags |= LO_FLAGS_READ_ONLY; /* kernel loopdev mode */ | |
1313 | } else { | |
1314 | lc->flags |= LOOPDEV_FL_RDWR; /* open() mode */ | |
1315 | lc->info.lo_flags &= ~LO_FLAGS_READ_ONLY; | |
1316 | lc->flags &= ~LOOPDEV_FL_RDONLY; | |
1317 | } | |
10ee5932 | 1318 | |
663bf040 KZ |
1319 | do { |
1320 | errno = 0; | |
1321 | dev_fd = loopcxt_get_fd(lc); | |
1322 | if (dev_fd >= 0 || lc->control_ok == 0) | |
1323 | break; | |
1324 | if (errno != EACCES && errno != ENOENT) | |
1325 | break; | |
1326 | /* We have permissions to open /dev/loop-control, but open | |
1327 | * /dev/loopN failed with EACCES, it's probably because udevd | |
1328 | * does not applied chown yet. Let's wait a moment. */ | |
1329 | xusleep(25000); | |
1330 | } while (cnt++ < 16); | |
1331 | ||
10ee5932 KZ |
1332 | if (dev_fd < 0) { |
1333 | rc = -errno; | |
1334 | goto err; | |
1335 | } | |
1336 | ||
0bf03740 | 1337 | DBG(SETUP, ul_debugobj(lc, "device open: OK")); |
d356c5d2 | 1338 | |
10ee5932 KZ |
1339 | /* |
1340 | * Set FD | |
1341 | */ | |
1342 | if (ioctl(dev_fd, LOOP_SET_FD, file_fd) < 0) { | |
1343 | rc = -errno; | |
2cde9865 | 1344 | errsv = errno; |
0bf03740 | 1345 | DBG(SETUP, ul_debugobj(lc, "LOOP_SET_FD failed: %m")); |
10ee5932 KZ |
1346 | goto err; |
1347 | } | |
d356c5d2 | 1348 | |
0bf03740 | 1349 | DBG(SETUP, ul_debugobj(lc, "LOOP_SET_FD: OK")); |
d356c5d2 | 1350 | |
75d239ff KZ |
1351 | if (lc->blocksize > 0 |
1352 | && (rc = loopcxt_ioctl_blocksize(lc, lc->blocksize)) < 0) { | |
1353 | errsv = -rc; | |
1354 | goto err; | |
1355 | } | |
1356 | ||
aee31ddc | 1357 | if (ioctl(dev_fd, LOOP_SET_STATUS64, &lc->info)) { |
2cde9865 KZ |
1358 | rc = -errno; |
1359 | errsv = errno; | |
0bf03740 | 1360 | DBG(SETUP, ul_debugobj(lc, "LOOP_SET_STATUS64 failed: %m")); |
10ee5932 | 1361 | goto err; |
aee31ddc | 1362 | } |
d356c5d2 | 1363 | |
0bf03740 | 1364 | DBG(SETUP, ul_debugobj(lc, "LOOP_SET_STATUS64: OK")); |
d356c5d2 | 1365 | |
293714c0 JM |
1366 | if ((rc = loopcxt_check_size(lc, file_fd))) |
1367 | goto err; | |
1368 | ||
1369 | close(file_fd); | |
293714c0 | 1370 | |
10ee5932 KZ |
1371 | memset(&lc->info, 0, sizeof(lc->info)); |
1372 | lc->has_info = 0; | |
6c224de1 | 1373 | lc->info_failed = 0; |
10ee5932 | 1374 | |
0bf03740 | 1375 | DBG(SETUP, ul_debugobj(lc, "success [rc=0]")); |
10ee5932 KZ |
1376 | return 0; |
1377 | err: | |
1378 | if (file_fd >= 0) | |
1379 | close(file_fd); | |
f7e21185 | 1380 | if (dev_fd >= 0 && rc != -EBUSY) |
10ee5932 | 1381 | ioctl(dev_fd, LOOP_CLR_FD, 0); |
2cde9865 KZ |
1382 | if (errsv) |
1383 | errno = errsv; | |
10ee5932 | 1384 | |
0bf03740 | 1385 | DBG(SETUP, ul_debugobj(lc, "failed [rc=%d]", rc)); |
10ee5932 KZ |
1386 | return rc; |
1387 | } | |
1388 | ||
bfd4e1f7 SB |
1389 | /* |
1390 | * @lc: context | |
1391 | * | |
1392 | * Update status of the current device (see loopcxt_{set,get}_device()). | |
1393 | * | |
1394 | * Note that once initialized, kernel accepts only selected changes: | |
1395 | * LO_FLAGS_AUTOCLEAR and LO_FLAGS_PARTSCAN | |
1396 | * For more see linux/drivers/block/loop.c:loop_set_status() | |
1397 | * | |
1398 | * Returns: <0 on error, 0 on success. | |
1399 | */ | |
9fcc8936 | 1400 | int loopcxt_ioctl_status(struct loopdev_cxt *lc) |
bfd4e1f7 SB |
1401 | { |
1402 | int dev_fd, rc = -1; | |
1403 | ||
1404 | errno = 0; | |
1405 | dev_fd = loopcxt_get_fd(lc); | |
1406 | ||
1407 | if (dev_fd < 0) { | |
1408 | rc = -errno; | |
1409 | return rc; | |
1410 | } | |
1411 | DBG(SETUP, ul_debugobj(lc, "device open: OK")); | |
1412 | ||
1413 | if (ioctl(dev_fd, LOOP_SET_STATUS64, &lc->info)) { | |
1414 | rc = -errno; | |
1415 | DBG(SETUP, ul_debugobj(lc, "LOOP_SET_STATUS64 failed: %m")); | |
1416 | return rc; | |
1417 | } | |
1418 | ||
1419 | DBG(SETUP, ul_debugobj(lc, "LOOP_SET_STATUS64: OK")); | |
1420 | return 0; | |
1421 | } | |
1422 | ||
9fcc8936 | 1423 | int loopcxt_ioctl_capacity(struct loopdev_cxt *lc) |
293714c0 JM |
1424 | { |
1425 | int fd = loopcxt_get_fd(lc); | |
1426 | ||
1427 | if (fd < 0) | |
1428 | return -EINVAL; | |
1429 | ||
1430 | /* Kernels prior to v2.6.30 don't support this ioctl */ | |
1431 | if (ioctl(fd, LOOP_SET_CAPACITY, 0) < 0) { | |
1432 | int rc = -errno; | |
0bf03740 | 1433 | DBG(CXT, ul_debugobj(lc, "LOOP_SET_CAPACITY failed: %m")); |
293714c0 JM |
1434 | return rc; |
1435 | } | |
1436 | ||
0bf03740 | 1437 | DBG(CXT, ul_debugobj(lc, "capacity set")); |
293714c0 JM |
1438 | return 0; |
1439 | } | |
1440 | ||
9fcc8936 | 1441 | int loopcxt_ioctl_dio(struct loopdev_cxt *lc, unsigned long use_dio) |
64c3bb3c ML |
1442 | { |
1443 | int fd = loopcxt_get_fd(lc); | |
1444 | ||
1445 | if (fd < 0) | |
1446 | return -EINVAL; | |
1447 | ||
1448 | /* Kernels prior to v4.4 don't support this ioctl */ | |
1449 | if (ioctl(fd, LOOP_SET_DIRECT_IO, use_dio) < 0) { | |
1450 | int rc = -errno; | |
1451 | DBG(CXT, ul_debugobj(lc, "LOOP_SET_DIRECT_IO failed: %m")); | |
1452 | return rc; | |
1453 | } | |
1454 | ||
1455 | DBG(CXT, ul_debugobj(lc, "direct io set")); | |
1456 | return 0; | |
1457 | } | |
1458 | ||
c4e60bc0 KZ |
1459 | /* |
1460 | * Kernel uses "unsigned long" as ioctl arg, but we use u64 for all sizes to | |
1461 | * keep loopdev internal API simple. | |
1462 | */ | |
9fcc8936 | 1463 | int loopcxt_ioctl_blocksize(struct loopdev_cxt *lc, uint64_t blocksize) |
a1a41597 SB |
1464 | { |
1465 | int fd = loopcxt_get_fd(lc); | |
1466 | ||
1467 | if (fd < 0) | |
1468 | return -EINVAL; | |
1469 | ||
1470 | /* Kernels prior to v4.14 don't support this ioctl */ | |
c4e60bc0 | 1471 | if (ioctl(fd, LOOP_SET_BLOCK_SIZE, (unsigned long) blocksize) < 0) { |
a1a41597 SB |
1472 | int rc = -errno; |
1473 | DBG(CXT, ul_debugobj(lc, "LOOP_SET_BLOCK_SIZE failed: %m")); | |
1474 | return rc; | |
1475 | } | |
1476 | ||
1477 | DBG(CXT, ul_debugobj(lc, "logical block size set")); | |
1478 | return 0; | |
1479 | } | |
1480 | ||
10ee5932 KZ |
1481 | int loopcxt_delete_device(struct loopdev_cxt *lc) |
1482 | { | |
1483 | int fd = loopcxt_get_fd(lc); | |
1484 | ||
1485 | if (fd < 0) | |
1486 | return -EINVAL; | |
1487 | ||
aee31ddc | 1488 | if (ioctl(fd, LOOP_CLR_FD, 0) < 0) { |
0bf03740 | 1489 | DBG(CXT, ul_debugobj(lc, "LOOP_CLR_FD failed: %m")); |
10ee5932 | 1490 | return -errno; |
aee31ddc KZ |
1491 | } |
1492 | ||
0bf03740 | 1493 | DBG(CXT, ul_debugobj(lc, "device removed")); |
10ee5932 KZ |
1494 | return 0; |
1495 | } | |
1496 | ||
3cb2413b KZ |
1497 | int loopcxt_add_device(struct loopdev_cxt *lc) |
1498 | { | |
1499 | int rc = -EINVAL; | |
1500 | int ctl, nr = -1; | |
1501 | const char *p, *dev = loopcxt_get_device(lc); | |
1502 | ||
1503 | if (!dev) | |
1504 | goto done; | |
1505 | ||
1506 | if (!(lc->flags & LOOPDEV_FL_CONTROL)) { | |
1507 | rc = -ENOSYS; | |
1508 | goto done; | |
1509 | } | |
1510 | ||
1511 | p = strrchr(dev, '/'); | |
1512 | if (!p || (sscanf(p, "/loop%d", &nr) != 1 && sscanf(p, "/%d", &nr) != 1) | |
1513 | || nr < 0) | |
1514 | goto done; | |
1515 | ||
1516 | ctl = open(_PATH_DEV_LOOPCTL, O_RDWR|O_CLOEXEC); | |
1517 | if (ctl >= 0) { | |
0bf03740 | 1518 | DBG(CXT, ul_debugobj(lc, "add_device %d", nr)); |
3cb2413b KZ |
1519 | rc = ioctl(ctl, LOOP_CTL_ADD, nr); |
1520 | close(ctl); | |
1521 | } | |
663bf040 | 1522 | lc->control_ok = rc >= 0 ? 1 : 0; |
3cb2413b | 1523 | done: |
0bf03740 | 1524 | DBG(CXT, ul_debugobj(lc, "add_device done [rc=%d]", rc)); |
3cb2413b KZ |
1525 | return rc; |
1526 | } | |
1527 | ||
59d749c3 KZ |
1528 | /* |
1529 | * Note that LOOP_CTL_GET_FREE ioctl is supported since kernel 3.1. In older | |
1530 | * kernels we have to check all loop devices to found unused one. | |
1531 | * | |
1532 | * See kernel commit 770fe30a46a12b6fb6b63fbe1737654d28e8484. | |
1533 | */ | |
10ee5932 KZ |
1534 | int loopcxt_find_unused(struct loopdev_cxt *lc) |
1535 | { | |
0b14bf7a | 1536 | int rc = -1; |
10ee5932 | 1537 | |
0bf03740 | 1538 | DBG(CXT, ul_debugobj(lc, "find_unused requested")); |
aee31ddc | 1539 | |
0b14bf7a | 1540 | if (lc->flags & LOOPDEV_FL_CONTROL) { |
9a94b634 KZ |
1541 | int ctl; |
1542 | ||
1543 | DBG(CXT, ul_debugobj(lc, "using loop-control")); | |
10ee5932 | 1544 | |
9a94b634 | 1545 | ctl = open(_PATH_DEV_LOOPCTL, O_RDWR|O_CLOEXEC); |
0b14bf7a KZ |
1546 | if (ctl >= 0) |
1547 | rc = ioctl(ctl, LOOP_CTL_GET_FREE); | |
1548 | if (rc >= 0) { | |
1549 | char name[16]; | |
1550 | snprintf(name, sizeof(name), "loop%d", rc); | |
1551 | ||
1552 | rc = loopiter_set_device(lc, name); | |
1553 | } | |
663bf040 | 1554 | lc->control_ok = ctl >= 0 && rc == 0 ? 1 : 0; |
0b14bf7a KZ |
1555 | if (ctl >= 0) |
1556 | close(ctl); | |
0bf03740 | 1557 | DBG(CXT, ul_debugobj(lc, "find_unused by loop-control [rc=%d]", rc)); |
0b14bf7a KZ |
1558 | } |
1559 | ||
1560 | if (rc < 0) { | |
9a94b634 | 1561 | DBG(CXT, ul_debugobj(lc, "using loop scan")); |
0b14bf7a KZ |
1562 | rc = loopcxt_init_iterator(lc, LOOPITER_FL_FREE); |
1563 | if (rc) | |
1564 | return rc; | |
10ee5932 | 1565 | |
0b14bf7a KZ |
1566 | rc = loopcxt_next(lc); |
1567 | loopcxt_deinit_iterator(lc); | |
0bf03740 | 1568 | DBG(CXT, ul_debugobj(lc, "find_unused by scan [rc=%d]", rc)); |
0b14bf7a | 1569 | } |
10ee5932 KZ |
1570 | return rc; |
1571 | } | |
1572 | ||
1573 | ||
1574 | ||
1575 | /* | |
1576 | * Return: TRUE/FALSE | |
1577 | */ | |
1578 | int loopdev_is_autoclear(const char *device) | |
1579 | { | |
1580 | struct loopdev_cxt lc; | |
1581 | int rc; | |
1582 | ||
1583 | if (!device) | |
1584 | return 0; | |
1585 | ||
defa0710 KZ |
1586 | rc = loopcxt_init(&lc, 0); |
1587 | if (!rc) | |
1588 | rc = loopcxt_set_device(&lc, device); | |
1589 | if (!rc) | |
1590 | rc = loopcxt_is_autoclear(&lc); | |
10ee5932 | 1591 | |
defa0710 | 1592 | loopcxt_deinit(&lc); |
10ee5932 KZ |
1593 | return rc; |
1594 | } | |
1595 | ||
1596 | char *loopdev_get_backing_file(const char *device) | |
1597 | { | |
1598 | struct loopdev_cxt lc; | |
defa0710 | 1599 | char *res = NULL; |
10ee5932 KZ |
1600 | |
1601 | if (!device) | |
1602 | return NULL; | |
defa0710 KZ |
1603 | if (loopcxt_init(&lc, 0)) |
1604 | return NULL; | |
1605 | if (loopcxt_set_device(&lc, device) == 0) | |
1606 | res = loopcxt_get_backing_file(&lc); | |
10ee5932 | 1607 | |
10ee5932 | 1608 | loopcxt_deinit(&lc); |
10ee5932 KZ |
1609 | return res; |
1610 | } | |
1611 | ||
1612 | /* | |
1613 | * Returns: TRUE/FALSE | |
1614 | */ | |
1615 | int loopdev_is_used(const char *device, const char *filename, | |
74a4705a | 1616 | uint64_t offset, uint64_t sizelimit, int flags) |
10ee5932 KZ |
1617 | { |
1618 | struct loopdev_cxt lc; | |
6c224de1 | 1619 | struct stat st; |
10ee5932 KZ |
1620 | int rc = 0; |
1621 | ||
8b470b20 | 1622 | if (!device || !filename) |
10ee5932 KZ |
1623 | return 0; |
1624 | ||
defa0710 KZ |
1625 | rc = loopcxt_init(&lc, 0); |
1626 | if (!rc) | |
1627 | rc = loopcxt_set_device(&lc, device); | |
1628 | if (rc) | |
1629 | return rc; | |
10ee5932 | 1630 | |
6c224de1 | 1631 | rc = !stat(filename, &st); |
74a4705a | 1632 | rc = loopcxt_is_used(&lc, rc ? &st : NULL, filename, offset, sizelimit, flags); |
10ee5932 | 1633 | |
10ee5932 | 1634 | loopcxt_deinit(&lc); |
10ee5932 KZ |
1635 | return rc; |
1636 | } | |
1637 | ||
1638 | int loopdev_delete(const char *device) | |
1639 | { | |
1640 | struct loopdev_cxt lc; | |
1641 | int rc; | |
1642 | ||
8b470b20 KZ |
1643 | if (!device) |
1644 | return -EINVAL; | |
1645 | ||
defa0710 KZ |
1646 | rc = loopcxt_init(&lc, 0); |
1647 | if (!rc) | |
1648 | rc = loopcxt_set_device(&lc, device); | |
10ee5932 KZ |
1649 | if (!rc) |
1650 | rc = loopcxt_delete_device(&lc); | |
1651 | loopcxt_deinit(&lc); | |
1652 | return rc; | |
1653 | } | |
1654 | ||
1655 | /* | |
1656 | * Returns: 0 = success, < 0 error, 1 not found | |
1657 | */ | |
1658 | int loopcxt_find_by_backing_file(struct loopdev_cxt *lc, const char *filename, | |
74a4705a | 1659 | uint64_t offset, uint64_t sizelimit, int flags) |
10ee5932 | 1660 | { |
6c224de1 KZ |
1661 | int rc, hasst; |
1662 | struct stat st; | |
10ee5932 KZ |
1663 | |
1664 | if (!filename) | |
1665 | return -EINVAL; | |
1666 | ||
6c224de1 KZ |
1667 | hasst = !stat(filename, &st); |
1668 | ||
10ee5932 KZ |
1669 | rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED); |
1670 | if (rc) | |
1671 | return rc; | |
1672 | ||
6c224de1 | 1673 | while ((rc = loopcxt_next(lc)) == 0) { |
10ee5932 | 1674 | |
6c224de1 | 1675 | if (loopcxt_is_used(lc, hasst ? &st : NULL, |
74a4705a | 1676 | filename, offset, sizelimit, flags)) |
6c224de1 | 1677 | break; |
10ee5932 KZ |
1678 | } |
1679 | ||
1680 | loopcxt_deinit_iterator(lc); | |
1681 | return rc; | |
1682 | } | |
1683 | ||
211e1d46 | 1684 | /* |
dff7e160 | 1685 | * Returns: 0 = not found, < 0 error, 1 found, 2 found full size and offset match |
211e1d46 | 1686 | */ |
c444a71b | 1687 | int loopcxt_find_overlap(struct loopdev_cxt *lc, const char *filename, |
211e1d46 SB |
1688 | uint64_t offset, uint64_t sizelimit) |
1689 | { | |
1690 | int rc, hasst; | |
1691 | struct stat st; | |
1692 | ||
1693 | if (!filename) | |
1694 | return -EINVAL; | |
1695 | ||
9a94b634 | 1696 | DBG(CXT, ul_debugobj(lc, "find_overlap requested")); |
211e1d46 SB |
1697 | hasst = !stat(filename, &st); |
1698 | ||
1699 | rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED); | |
1700 | if (rc) | |
1701 | return rc; | |
1702 | ||
1703 | while ((rc = loopcxt_next(lc)) == 0) { | |
1704 | uint64_t lc_sizelimit, lc_offset; | |
1705 | ||
1706 | rc = loopcxt_is_used(lc, hasst ? &st : NULL, | |
1707 | filename, offset, sizelimit, 0); | |
1708 | if (!rc) | |
c444a71b | 1709 | continue; /* unused */ |
dff7e160 | 1710 | if (rc < 0) |
c444a71b KZ |
1711 | break; /* error */ |
1712 | ||
211e1d46 SB |
1713 | DBG(CXT, ul_debugobj(lc, "found %s backed by %s", |
1714 | loopcxt_get_device(lc), filename)); | |
c444a71b | 1715 | |
211e1d46 SB |
1716 | rc = loopcxt_get_offset(lc, &lc_offset); |
1717 | if (rc) { | |
1718 | DBG(CXT, ul_debugobj(lc, "failed to get offset for device %s", | |
1719 | loopcxt_get_device(lc))); | |
1720 | break; | |
1721 | } | |
1722 | rc = loopcxt_get_sizelimit(lc, &lc_sizelimit); | |
1723 | if (rc) { | |
1724 | DBG(CXT, ul_debugobj(lc, "failed to get sizelimit for device %s", | |
1725 | loopcxt_get_device(lc))); | |
1726 | break; | |
1727 | } | |
1728 | ||
dff7e160 KZ |
1729 | /* full match */ |
1730 | if (lc_sizelimit == sizelimit && lc_offset == offset) { | |
1731 | DBG(CXT, ul_debugobj(lc, "overlapping loop device %s (full match)", | |
1732 | loopcxt_get_device(lc))); | |
1733 | rc = 2; | |
1734 | goto found; | |
1735 | } | |
1736 | ||
1737 | /* overlap */ | |
211e1d46 SB |
1738 | if (lc_sizelimit != 0 && offset >= lc_offset + lc_sizelimit) |
1739 | continue; | |
1740 | if (sizelimit != 0 && offset + sizelimit <= lc_offset) | |
1741 | continue; | |
dff7e160 | 1742 | |
211e1d46 SB |
1743 | DBG(CXT, ul_debugobj(lc, "overlapping loop device %s", |
1744 | loopcxt_get_device(lc))); | |
dff7e160 KZ |
1745 | rc = 1; |
1746 | goto found; | |
211e1d46 | 1747 | } |
dff7e160 KZ |
1748 | |
1749 | if (rc == 1) | |
1750 | rc = 0; /* not found */ | |
1751 | found: | |
211e1d46 | 1752 | loopcxt_deinit_iterator(lc); |
9a94b634 | 1753 | DBG(CXT, ul_debugobj(lc, "find_overlap done [rc=%d]", rc)); |
211e1d46 SB |
1754 | return rc; |
1755 | } | |
1756 | ||
10ee5932 KZ |
1757 | /* |
1758 | * Returns allocated string with device name | |
1759 | */ | |
74a4705a | 1760 | char *loopdev_find_by_backing_file(const char *filename, uint64_t offset, uint64_t sizelimit, int flags) |
10ee5932 KZ |
1761 | { |
1762 | struct loopdev_cxt lc; | |
1763 | char *res = NULL; | |
1764 | ||
1765 | if (!filename) | |
1766 | return NULL; | |
1767 | ||
defa0710 KZ |
1768 | if (loopcxt_init(&lc, 0)) |
1769 | return NULL; | |
74a4705a | 1770 | if (loopcxt_find_by_backing_file(&lc, filename, offset, sizelimit, flags) == 0) |
10ee5932 KZ |
1771 | res = loopcxt_strdup_device(&lc); |
1772 | loopcxt_deinit(&lc); | |
1773 | ||
1774 | return res; | |
1775 | } | |
1776 | ||
d5688130 KZ |
1777 | /* |
1778 | * Returns number of loop devices associated with @file, if only one loop | |
11026083 | 1779 | * device is associated with the given @filename and @loopdev is not NULL then |
d5688130 KZ |
1780 | * @loopdev returns name of the device. |
1781 | */ | |
1782 | int loopdev_count_by_backing_file(const char *filename, char **loopdev) | |
1783 | { | |
1784 | struct loopdev_cxt lc; | |
defa0710 | 1785 | int count = 0, rc; |
d5688130 KZ |
1786 | |
1787 | if (!filename) | |
1788 | return -1; | |
1789 | ||
defa0710 KZ |
1790 | rc = loopcxt_init(&lc, 0); |
1791 | if (rc) | |
1792 | return rc; | |
d5688130 KZ |
1793 | if (loopcxt_init_iterator(&lc, LOOPITER_FL_USED)) |
1794 | return -1; | |
1795 | ||
1796 | while(loopcxt_next(&lc) == 0) { | |
1797 | char *backing = loopcxt_get_backing_file(&lc); | |
1798 | ||
1799 | if (!backing || strcmp(backing, filename)) { | |
1800 | free(backing); | |
1801 | continue; | |
1802 | } | |
1803 | ||
1804 | free(backing); | |
1805 | if (loopdev && count == 0) | |
1806 | *loopdev = loopcxt_strdup_device(&lc); | |
1807 | count++; | |
1808 | } | |
1809 | ||
1810 | loopcxt_deinit(&lc); | |
1811 | ||
1812 | if (loopdev && count > 1) { | |
1813 | free(*loopdev); | |
1814 | *loopdev = NULL; | |
1815 | } | |
1816 | return count; | |
1817 | } | |
1818 |