Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /* Provide a way to create a superblock configuration context within the kernel
3 : * that allows a superblock to be set up prior to mounting.
4 : *
5 : * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
6 : * Written by David Howells (dhowells@redhat.com)
7 : */
8 :
9 : #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 : #include <linux/module.h>
11 : #include <linux/fs_context.h>
12 : #include <linux/fs_parser.h>
13 : #include <linux/fs.h>
14 : #include <linux/mount.h>
15 : #include <linux/nsproxy.h>
16 : #include <linux/slab.h>
17 : #include <linux/magic.h>
18 : #include <linux/security.h>
19 : #include <linux/mnt_namespace.h>
20 : #include <linux/pid_namespace.h>
21 : #include <linux/user_namespace.h>
22 : #include <net/net_namespace.h>
23 : #include <asm/sections.h>
24 : #include "mount.h"
25 : #include "internal.h"
26 :
27 : enum legacy_fs_param {
28 : LEGACY_FS_UNSET_PARAMS,
29 : LEGACY_FS_MONOLITHIC_PARAMS,
30 : LEGACY_FS_INDIVIDUAL_PARAMS,
31 : };
32 :
33 : struct legacy_fs_context {
34 : char *legacy_data; /* Data page for legacy filesystems */
35 : size_t data_size;
36 : enum legacy_fs_param param_type;
37 : };
38 :
39 : static int legacy_init_fs_context(struct fs_context *fc);
40 :
41 : static const struct constant_table common_set_sb_flag[] = {
42 : { "dirsync", SB_DIRSYNC },
43 : { "lazytime", SB_LAZYTIME },
44 : { "mand", SB_MANDLOCK },
45 : { "ro", SB_RDONLY },
46 : { "sync", SB_SYNCHRONOUS },
47 : { },
48 : };
49 :
50 : static const struct constant_table common_clear_sb_flag[] = {
51 : { "async", SB_SYNCHRONOUS },
52 : { "nolazytime", SB_LAZYTIME },
53 : { "nomand", SB_MANDLOCK },
54 : { "rw", SB_RDONLY },
55 : { },
56 : };
57 :
58 : /*
59 : * Check for a common mount option that manipulates s_flags.
60 : */
61 332 : static int vfs_parse_sb_flag(struct fs_context *fc, const char *key)
62 : {
63 332 : unsigned int token;
64 :
65 332 : token = lookup_constant(common_set_sb_flag, key, 0);
66 332 : if (token) {
67 0 : fc->sb_flags |= token;
68 0 : fc->sb_flags_mask |= token;
69 0 : return 0;
70 : }
71 :
72 332 : token = lookup_constant(common_clear_sb_flag, key, 0);
73 332 : if (token) {
74 0 : fc->sb_flags &= ~token;
75 0 : fc->sb_flags_mask |= token;
76 0 : return 0;
77 : }
78 :
79 : return -ENOPARAM;
80 : }
81 :
82 : /**
83 : * vfs_parse_fs_param - Add a single parameter to a superblock config
84 : * @fc: The filesystem context to modify
85 : * @param: The parameter
86 : *
87 : * A single mount option in string form is applied to the filesystem context
88 : * being set up. Certain standard options (for example "ro") are translated
89 : * into flag bits without going to the filesystem. The active security module
90 : * is allowed to observe and poach options. Any other options are passed over
91 : * to the filesystem to parse.
92 : *
93 : * This may be called multiple times for a context.
94 : *
95 : * Returns 0 on success and a negative error code on failure. In the event of
96 : * failure, supplementary error information may have been set.
97 : */
98 332 : int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
99 : {
100 332 : int ret;
101 :
102 332 : if (!param->key)
103 0 : return invalf(fc, "Unnamed parameter\n");
104 :
105 332 : ret = vfs_parse_sb_flag(fc, param->key);
106 332 : if (ret != -ENOPARAM)
107 : return ret;
108 :
109 332 : ret = security_fs_context_parse_param(fc, param);
110 332 : if (ret != -ENOPARAM)
111 : /* Param belongs to the LSM or is disallowed by the LSM; so
112 : * don't pass to the FS.
113 : */
114 : return ret;
115 :
116 332 : if (fc->ops->parse_param) {
117 323 : ret = fc->ops->parse_param(fc, param);
118 323 : if (ret != -ENOPARAM)
119 : return ret;
120 : }
121 :
122 : /* If the filesystem doesn't take any arguments, give it the
123 : * default handling of source.
124 : */
125 115 : if (strcmp(param->key, "source") == 0) {
126 115 : if (param->type != fs_value_is_string)
127 0 : return invalf(fc, "VFS: Non-string source");
128 115 : if (fc->source)
129 0 : return invalf(fc, "VFS: Multiple sources");
130 115 : fc->source = param->string;
131 115 : param->string = NULL;
132 115 : return 0;
133 : }
134 :
135 0 : return invalf(fc, "%s: Unknown parameter '%s'",
136 : fc->fs_type->name, param->key);
137 : }
138 : EXPORT_SYMBOL(vfs_parse_fs_param);
139 :
140 : /**
141 : * vfs_parse_fs_string - Convenience function to just parse a string.
142 : */
143 332 : int vfs_parse_fs_string(struct fs_context *fc, const char *key,
144 : const char *value, size_t v_size)
145 : {
146 332 : int ret;
147 :
148 332 : struct fs_parameter param = {
149 : .key = key,
150 : .type = fs_value_is_flag,
151 : .size = v_size,
152 : };
153 :
154 332 : if (value) {
155 329 : param.string = kmemdup_nul(value, v_size, GFP_KERNEL);
156 329 : if (!param.string)
157 : return -ENOMEM;
158 329 : param.type = fs_value_is_string;
159 : }
160 :
161 332 : ret = vfs_parse_fs_param(fc, ¶m);
162 332 : kfree(param.string);
163 332 : return ret;
164 : }
165 : EXPORT_SYMBOL(vfs_parse_fs_string);
166 :
167 : /**
168 : * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data
169 : * @ctx: The superblock configuration to fill in.
170 : * @data: The data to parse
171 : *
172 : * Parse a blob of data that's in key[=val][,key[=val]]* form. This can be
173 : * called from the ->monolithic_mount_data() fs_context operation.
174 : *
175 : * Returns 0 on success or the error returned by the ->parse_option() fs_context
176 : * operation on failure.
177 : */
178 14 : int generic_parse_monolithic(struct fs_context *fc, void *data)
179 : {
180 14 : char *options = data, *key;
181 14 : int ret = 0;
182 :
183 14 : if (!options)
184 : return 0;
185 :
186 2 : ret = security_sb_eat_lsm_opts(options, &fc->security);
187 2 : if (ret)
188 : return ret;
189 :
190 6 : while ((key = strsep(&options, ",")) != NULL) {
191 4 : if (*key) {
192 4 : size_t v_len = 0;
193 4 : char *value = strchr(key, '=');
194 :
195 4 : if (value) {
196 1 : if (value == key)
197 0 : continue;
198 1 : *value++ = 0;
199 1 : v_len = strlen(value);
200 : }
201 4 : ret = vfs_parse_fs_string(fc, key, value, v_len);
202 4 : if (ret < 0)
203 : break;
204 : }
205 : }
206 :
207 : return ret;
208 : }
209 : EXPORT_SYMBOL(generic_parse_monolithic);
210 :
211 : /**
212 : * alloc_fs_context - Create a filesystem context.
213 : * @fs_type: The filesystem type.
214 : * @reference: The dentry from which this one derives (or NULL)
215 : * @sb_flags: Filesystem/superblock flags (SB_*)
216 : * @sb_flags_mask: Applicable members of @sb_flags
217 : * @purpose: The purpose that this configuration shall be used for.
218 : *
219 : * Open a filesystem and create a mount context. The mount context is
220 : * initialised with the supplied flags and, if a submount/automount from
221 : * another superblock (referred to by @reference) is supplied, may have
222 : * parameters such as namespaces copied across from that superblock.
223 : */
224 131 : static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
225 : struct dentry *reference,
226 : unsigned int sb_flags,
227 : unsigned int sb_flags_mask,
228 : enum fs_context_purpose purpose)
229 : {
230 131 : int (*init_fs_context)(struct fs_context *);
231 131 : struct fs_context *fc;
232 131 : int ret = -ENOMEM;
233 :
234 131 : fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
235 131 : if (!fc)
236 131 : return ERR_PTR(-ENOMEM);
237 :
238 131 : fc->purpose = purpose;
239 131 : fc->sb_flags = sb_flags;
240 131 : fc->sb_flags_mask = sb_flags_mask;
241 131 : fc->fs_type = get_filesystem(fs_type);
242 131 : fc->cred = get_current_cred();
243 131 : fc->net_ns = get_net(current->nsproxy->net_ns);
244 131 : fc->log.prefix = fs_type->name;
245 :
246 131 : mutex_init(&fc->uapi_mutex);
247 :
248 131 : switch (purpose) {
249 128 : case FS_CONTEXT_FOR_MOUNT:
250 128 : fc->user_ns = get_user_ns(fc->cred->user_ns);
251 128 : break;
252 0 : case FS_CONTEXT_FOR_SUBMOUNT:
253 0 : fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
254 0 : break;
255 3 : case FS_CONTEXT_FOR_RECONFIGURE:
256 3 : atomic_inc(&reference->d_sb->s_active);
257 3 : fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
258 3 : fc->root = dget(reference);
259 3 : break;
260 : }
261 :
262 : /* TODO: Make all filesystems support this unconditionally */
263 131 : init_fs_context = fc->fs_type->init_fs_context;
264 131 : if (!init_fs_context)
265 12 : init_fs_context = legacy_init_fs_context;
266 :
267 131 : ret = init_fs_context(fc);
268 131 : if (ret < 0)
269 0 : goto err_fc;
270 131 : fc->need_free = true;
271 131 : return fc;
272 :
273 0 : err_fc:
274 0 : put_fs_context(fc);
275 0 : return ERR_PTR(ret);
276 : }
277 :
278 128 : struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
279 : unsigned int sb_flags)
280 : {
281 128 : return alloc_fs_context(fs_type, NULL, sb_flags, 0,
282 : FS_CONTEXT_FOR_MOUNT);
283 : }
284 : EXPORT_SYMBOL(fs_context_for_mount);
285 :
286 3 : struct fs_context *fs_context_for_reconfigure(struct dentry *dentry,
287 : unsigned int sb_flags,
288 : unsigned int sb_flags_mask)
289 : {
290 3 : return alloc_fs_context(dentry->d_sb->s_type, dentry, sb_flags,
291 : sb_flags_mask, FS_CONTEXT_FOR_RECONFIGURE);
292 : }
293 : EXPORT_SYMBOL(fs_context_for_reconfigure);
294 :
295 0 : struct fs_context *fs_context_for_submount(struct file_system_type *type,
296 : struct dentry *reference)
297 : {
298 0 : return alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT);
299 : }
300 : EXPORT_SYMBOL(fs_context_for_submount);
301 :
302 0 : void fc_drop_locked(struct fs_context *fc)
303 : {
304 0 : struct super_block *sb = fc->root->d_sb;
305 0 : dput(fc->root);
306 0 : fc->root = NULL;
307 0 : deactivate_locked_super(sb);
308 0 : }
309 :
310 : static void legacy_fs_context_free(struct fs_context *fc);
311 :
312 : /**
313 : * vfs_dup_fc_config: Duplicate a filesystem context.
314 : * @src_fc: The context to copy.
315 : */
316 0 : struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc)
317 : {
318 0 : struct fs_context *fc;
319 0 : int ret;
320 :
321 0 : if (!src_fc->ops->dup)
322 0 : return ERR_PTR(-EOPNOTSUPP);
323 :
324 0 : fc = kmemdup(src_fc, sizeof(struct fs_context), GFP_KERNEL);
325 0 : if (!fc)
326 0 : return ERR_PTR(-ENOMEM);
327 :
328 0 : mutex_init(&fc->uapi_mutex);
329 :
330 0 : fc->fs_private = NULL;
331 0 : fc->s_fs_info = NULL;
332 0 : fc->source = NULL;
333 0 : fc->security = NULL;
334 0 : get_filesystem(fc->fs_type);
335 0 : get_net(fc->net_ns);
336 0 : get_user_ns(fc->user_ns);
337 0 : get_cred(fc->cred);
338 0 : if (fc->log.log)
339 0 : refcount_inc(&fc->log.log->usage);
340 :
341 : /* Can't call put until we've called ->dup */
342 0 : ret = fc->ops->dup(fc, src_fc);
343 0 : if (ret < 0)
344 0 : goto err_fc;
345 :
346 0 : ret = security_fs_context_dup(fc, src_fc);
347 0 : if (ret < 0)
348 0 : goto err_fc;
349 : return fc;
350 :
351 0 : err_fc:
352 0 : put_fs_context(fc);
353 0 : return ERR_PTR(ret);
354 : }
355 : EXPORT_SYMBOL(vfs_dup_fs_context);
356 :
357 : /**
358 : * logfc - Log a message to a filesystem context
359 : * @fc: The filesystem context to log to.
360 : * @fmt: The format of the buffer.
361 : */
362 0 : void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...)
363 : {
364 0 : va_list va;
365 0 : struct va_format vaf = {.fmt = fmt, .va = &va};
366 :
367 0 : va_start(va, fmt);
368 0 : if (!log) {
369 0 : switch (level) {
370 0 : case 'w':
371 0 : printk(KERN_WARNING "%s%s%pV\n", prefix ? prefix : "",
372 : prefix ? ": " : "", &vaf);
373 0 : break;
374 0 : case 'e':
375 0 : printk(KERN_ERR "%s%s%pV\n", prefix ? prefix : "",
376 : prefix ? ": " : "", &vaf);
377 0 : break;
378 0 : default:
379 0 : printk(KERN_NOTICE "%s%s%pV\n", prefix ? prefix : "",
380 : prefix ? ": " : "", &vaf);
381 0 : break;
382 : }
383 : } else {
384 0 : unsigned int logsize = ARRAY_SIZE(log->buffer);
385 0 : u8 index;
386 0 : char *q = kasprintf(GFP_KERNEL, "%c %s%s%pV\n", level,
387 : prefix ? prefix : "",
388 : prefix ? ": " : "", &vaf);
389 :
390 0 : index = log->head & (logsize - 1);
391 0 : BUILD_BUG_ON(sizeof(log->head) != sizeof(u8) ||
392 : sizeof(log->tail) != sizeof(u8));
393 0 : if ((u8)(log->head - log->tail) == logsize) {
394 : /* The buffer is full, discard the oldest message */
395 0 : if (log->need_free & (1 << index))
396 0 : kfree(log->buffer[index]);
397 0 : log->tail++;
398 : }
399 :
400 0 : log->buffer[index] = q ? q : "OOM: Can't store error string";
401 0 : if (q)
402 0 : log->need_free |= 1 << index;
403 : else
404 0 : log->need_free &= ~(1 << index);
405 0 : log->head++;
406 : }
407 0 : va_end(va);
408 0 : }
409 : EXPORT_SYMBOL(logfc);
410 :
411 : /*
412 : * Free a logging structure.
413 : */
414 131 : static void put_fc_log(struct fs_context *fc)
415 : {
416 131 : struct fc_log *log = fc->log.log;
417 131 : int i;
418 :
419 131 : if (log) {
420 0 : if (refcount_dec_and_test(&log->usage)) {
421 0 : fc->log.log = NULL;
422 0 : for (i = 0; i <= 7; i++)
423 0 : if (log->need_free & (1 << i))
424 0 : kfree(log->buffer[i]);
425 0 : kfree(log);
426 : }
427 : }
428 131 : }
429 :
430 : /**
431 : * put_fs_context - Dispose of a superblock configuration context.
432 : * @fc: The context to dispose of.
433 : */
434 131 : void put_fs_context(struct fs_context *fc)
435 : {
436 131 : struct super_block *sb;
437 :
438 131 : if (fc->root) {
439 130 : sb = fc->root->d_sb;
440 130 : dput(fc->root);
441 130 : fc->root = NULL;
442 130 : deactivate_super(sb);
443 : }
444 :
445 131 : if (fc->need_free && fc->ops && fc->ops->free)
446 131 : fc->ops->free(fc);
447 :
448 131 : security_free_mnt_opts(&fc->security);
449 131 : put_net(fc->net_ns);
450 131 : put_user_ns(fc->user_ns);
451 131 : put_cred(fc->cred);
452 131 : put_fc_log(fc);
453 131 : put_filesystem(fc->fs_type);
454 131 : kfree(fc->source);
455 131 : kfree(fc);
456 131 : }
457 : EXPORT_SYMBOL(put_fs_context);
458 :
459 : /*
460 : * Free the config for a filesystem that doesn't support fs_context.
461 : */
462 12 : static void legacy_fs_context_free(struct fs_context *fc)
463 : {
464 12 : struct legacy_fs_context *ctx = fc->fs_private;
465 :
466 12 : if (ctx) {
467 12 : if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS)
468 0 : kfree(ctx->legacy_data);
469 12 : kfree(ctx);
470 : }
471 12 : }
472 :
473 : /*
474 : * Duplicate a legacy config.
475 : */
476 0 : static int legacy_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
477 : {
478 0 : struct legacy_fs_context *ctx;
479 0 : struct legacy_fs_context *src_ctx = src_fc->fs_private;
480 :
481 0 : ctx = kmemdup(src_ctx, sizeof(*src_ctx), GFP_KERNEL);
482 0 : if (!ctx)
483 : return -ENOMEM;
484 :
485 0 : if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS) {
486 0 : ctx->legacy_data = kmemdup(src_ctx->legacy_data,
487 : src_ctx->data_size, GFP_KERNEL);
488 0 : if (!ctx->legacy_data) {
489 0 : kfree(ctx);
490 0 : return -ENOMEM;
491 : }
492 : }
493 :
494 0 : fc->fs_private = ctx;
495 0 : return 0;
496 : }
497 :
498 : /*
499 : * Add a parameter to a legacy config. We build up a comma-separated list of
500 : * options.
501 : */
502 10 : static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param)
503 : {
504 10 : struct legacy_fs_context *ctx = fc->fs_private;
505 10 : unsigned int size = ctx->data_size;
506 10 : size_t len = 0;
507 :
508 10 : if (strcmp(param->key, "source") == 0) {
509 10 : if (param->type != fs_value_is_string)
510 0 : return invalf(fc, "VFS: Legacy: Non-string source");
511 10 : if (fc->source)
512 0 : return invalf(fc, "VFS: Legacy: Multiple sources");
513 10 : fc->source = param->string;
514 10 : param->string = NULL;
515 10 : return 0;
516 : }
517 :
518 0 : if (ctx->param_type == LEGACY_FS_MONOLITHIC_PARAMS)
519 0 : return invalf(fc, "VFS: Legacy: Can't mix monolithic and individual options");
520 :
521 0 : switch (param->type) {
522 0 : case fs_value_is_string:
523 0 : len = 1 + param->size;
524 0 : fallthrough;
525 0 : case fs_value_is_flag:
526 0 : len += strlen(param->key);
527 0 : break;
528 0 : default:
529 0 : return invalf(fc, "VFS: Legacy: Parameter type for '%s' not supported",
530 : param->key);
531 : }
532 :
533 0 : if (len > PAGE_SIZE - 2 - size)
534 0 : return invalf(fc, "VFS: Legacy: Cumulative options too large");
535 0 : if (strchr(param->key, ',') ||
536 0 : (param->type == fs_value_is_string &&
537 0 : memchr(param->string, ',', param->size)))
538 0 : return invalf(fc, "VFS: Legacy: Option '%s' contained comma",
539 : param->key);
540 0 : if (!ctx->legacy_data) {
541 0 : ctx->legacy_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
542 0 : if (!ctx->legacy_data)
543 : return -ENOMEM;
544 : }
545 :
546 0 : ctx->legacy_data[size++] = ',';
547 0 : len = strlen(param->key);
548 0 : memcpy(ctx->legacy_data + size, param->key, len);
549 0 : size += len;
550 0 : if (param->type == fs_value_is_string) {
551 0 : ctx->legacy_data[size++] = '=';
552 0 : memcpy(ctx->legacy_data + size, param->string, param->size);
553 0 : size += param->size;
554 : }
555 0 : ctx->legacy_data[size] = '\0';
556 0 : ctx->data_size = size;
557 0 : ctx->param_type = LEGACY_FS_INDIVIDUAL_PARAMS;
558 0 : return 0;
559 : }
560 :
561 : /*
562 : * Add monolithic mount data.
563 : */
564 12 : static int legacy_parse_monolithic(struct fs_context *fc, void *data)
565 : {
566 12 : struct legacy_fs_context *ctx = fc->fs_private;
567 :
568 12 : if (ctx->param_type != LEGACY_FS_UNSET_PARAMS) {
569 0 : pr_warn("VFS: Can't mix monolithic and individual options\n");
570 0 : return -EINVAL;
571 : }
572 :
573 12 : ctx->legacy_data = data;
574 12 : ctx->param_type = LEGACY_FS_MONOLITHIC_PARAMS;
575 12 : if (!ctx->legacy_data)
576 : return 0;
577 :
578 4 : if (fc->fs_type->fs_flags & FS_BINARY_MOUNTDATA)
579 : return 0;
580 4 : return security_sb_eat_lsm_opts(ctx->legacy_data, &fc->security);
581 : }
582 :
583 : /*
584 : * Get a mountable root with the legacy mount command.
585 : */
586 10 : static int legacy_get_tree(struct fs_context *fc)
587 : {
588 10 : struct legacy_fs_context *ctx = fc->fs_private;
589 10 : struct super_block *sb;
590 10 : struct dentry *root;
591 :
592 20 : root = fc->fs_type->mount(fc->fs_type, fc->sb_flags,
593 10 : fc->source, ctx->legacy_data);
594 10 : if (IS_ERR(root))
595 1 : return PTR_ERR(root);
596 :
597 9 : sb = root->d_sb;
598 9 : BUG_ON(!sb);
599 :
600 9 : fc->root = root;
601 9 : return 0;
602 : }
603 :
604 : /*
605 : * Handle remount.
606 : */
607 2 : static int legacy_reconfigure(struct fs_context *fc)
608 : {
609 2 : struct legacy_fs_context *ctx = fc->fs_private;
610 2 : struct super_block *sb = fc->root->d_sb;
611 :
612 2 : if (!sb->s_op->remount_fs)
613 : return 0;
614 :
615 2 : return sb->s_op->remount_fs(sb, &fc->sb_flags,
616 : ctx ? ctx->legacy_data : NULL);
617 : }
618 :
619 : const struct fs_context_operations legacy_fs_context_ops = {
620 : .free = legacy_fs_context_free,
621 : .dup = legacy_fs_context_dup,
622 : .parse_param = legacy_parse_param,
623 : .parse_monolithic = legacy_parse_monolithic,
624 : .get_tree = legacy_get_tree,
625 : .reconfigure = legacy_reconfigure,
626 : };
627 :
628 : /*
629 : * Initialise a legacy context for a filesystem that doesn't support
630 : * fs_context.
631 : */
632 12 : static int legacy_init_fs_context(struct fs_context *fc)
633 : {
634 12 : fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL);
635 12 : if (!fc->fs_private)
636 : return -ENOMEM;
637 12 : fc->ops = &legacy_fs_context_ops;
638 12 : return 0;
639 : }
640 :
641 130 : int parse_monolithic_mount_data(struct fs_context *fc, void *data)
642 : {
643 130 : int (*monolithic_mount_data)(struct fs_context *, void *);
644 :
645 130 : monolithic_mount_data = fc->ops->parse_monolithic;
646 130 : if (!monolithic_mount_data)
647 14 : monolithic_mount_data = generic_parse_monolithic;
648 :
649 130 : return monolithic_mount_data(fc, data);
650 : }
651 :
652 : /*
653 : * Clean up a context after performing an action on it and put it into a state
654 : * from where it can be used to reconfigure a superblock.
655 : *
656 : * Note that here we do only the parts that can't fail; the rest is in
657 : * finish_clean_context() below and in between those fs_context is marked
658 : * FS_CONTEXT_AWAITING_RECONF. The reason for splitup is that after
659 : * successful mount or remount we need to report success to userland.
660 : * Trying to do full reinit (for the sake of possible subsequent remount)
661 : * and failing to allocate memory would've put us into a nasty situation.
662 : * So here we only discard the old state and reinitialization is left
663 : * until we actually try to reconfigure.
664 : */
665 0 : void vfs_clean_context(struct fs_context *fc)
666 : {
667 0 : if (fc->need_free && fc->ops && fc->ops->free)
668 0 : fc->ops->free(fc);
669 0 : fc->need_free = false;
670 0 : fc->fs_private = NULL;
671 0 : fc->s_fs_info = NULL;
672 0 : fc->sb_flags = 0;
673 0 : security_free_mnt_opts(&fc->security);
674 0 : kfree(fc->source);
675 0 : fc->source = NULL;
676 :
677 0 : fc->purpose = FS_CONTEXT_FOR_RECONFIGURE;
678 0 : fc->phase = FS_CONTEXT_AWAITING_RECONF;
679 0 : }
680 :
681 0 : int finish_clean_context(struct fs_context *fc)
682 : {
683 0 : int error;
684 :
685 0 : if (fc->phase != FS_CONTEXT_AWAITING_RECONF)
686 : return 0;
687 :
688 0 : if (fc->fs_type->init_fs_context)
689 0 : error = fc->fs_type->init_fs_context(fc);
690 : else
691 0 : error = legacy_init_fs_context(fc);
692 0 : if (unlikely(error)) {
693 0 : fc->phase = FS_CONTEXT_FAILED;
694 0 : return error;
695 : }
696 0 : fc->need_free = true;
697 0 : fc->phase = FS_CONTEXT_RECONF_PARAMS;
698 0 : return 0;
699 : }
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