linux-master/fs/fs_context.c

39 static int legacy_init_fs_context(struct fs_context *fc);
61 static int vfs_parse_sb_flag(struct fs_context *fc, const char *key)
67 		fc->sb_flags |= token;
68 		fc->sb_flags_mask |= token;
74 		fc->sb_flags &= ~token;
75 		fc->sb_flags_mask |= token;
84  * @fc: The filesystem context to modify
94 int vfs_parse_fs_param_source(struct fs_context *fc, struct fs_parameter *param)
100 		return invalf(fc, "Non-string source");
102 	if (fc->source)
103 		return invalf(fc, "Multiple sources");
105 	fc->source = param->string;
113  * @fc: The filesystem context to modify
127 int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
132 		return invalf(fc, "Unnamed parameter\n");
134 	ret = vfs_parse_sb_flag(fc, param->key);
138 	ret = security_fs_context_parse_param(fc, param);
145 	if (fc->ops->parse_param) {
146 		ret = fc->ops->parse_param(fc, param);
154 	ret = vfs_parse_fs_param_source(fc, param);
158 	return invalf(fc, "%s: Unknown parameter '%s'",
159 		      fc->fs_type->name, param->key);
165  * @fc: Filesystem context.
170 int vfs_parse_fs_string(struct fs_context *fc, const char *key,
188 	ret = vfs_parse_fs_param(fc, &param);
196  * @fc: The superblock configuration to fill in.
206 int vfs_parse_monolithic_sep(struct fs_context *fc, void *data,
215 	ret = security_sb_eat_lsm_opts(options, &fc->security);
230 			ret = vfs_parse_fs_string(fc, key, value, v_len);
247  * @fc: The superblock configuration to fill in.
256 int generic_parse_monolithic(struct fs_context *fc, void *data)
258 	return vfs_parse_monolithic_sep(fc, data, vfs_parse_comma_sep);
282 	struct fs_context *fc;
285 	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL_ACCOUNT);
286 	if (!fc)
289 	fc->purpose	= purpose;
290 	fc->sb_flags	= sb_flags;
291 	fc->sb_flags_mask = sb_flags_mask;
292 	fc->fs_type	= get_filesystem(fs_type);
293 	fc->cred	= get_current_cred();
294 	fc->net_ns	= get_net(current->nsproxy->net_ns);
295 	fc->log.prefix	= fs_type->name;
297 	mutex_init(&fc->uapi_mutex);
301 		fc->user_ns = get_user_ns(fc->cred->user_ns);
304 		fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
308 		fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
309 		fc->root = dget(reference);
314 	init_fs_context = fc->fs_type->init_fs_context;
318 	ret = init_fs_context(fc);
321 	fc->need_free = true;
322 	return fc;
325 	put_fs_context(fc);
352  * the fc->security object is inherited from @reference (if needed).
357 	struct fs_context *fc;
360 	fc = alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT);
361 	if (IS_ERR(fc))
362 		return fc;
364 	ret = security_fs_context_submount(fc, reference->d_sb);
366 		put_fs_context(fc);
370 	return fc;
374 void fc_drop_locked(struct fs_context *fc)
376 	struct super_block *sb = fc->root->d_sb;
377 	dput(fc->root);
378 	fc->root = NULL;
382 static void legacy_fs_context_free(struct fs_context *fc);
390 	struct fs_context *fc;
396 	fc = kmemdup(src_fc, sizeof(struct fs_context), GFP_KERNEL);
397 	if (!fc)
400 	mutex_init(&fc->uapi_mutex);
402 	fc->fs_private	= NULL;
403 	fc->s_fs_info	= NULL;
404 	fc->source	= NULL;
405 	fc->security	= NULL;
406 	get_filesystem(fc->fs_type);
407 	get_net(fc->net_ns);
408 	get_user_ns(fc->user_ns);
409 	get_cred(fc->cred);
410 	if (fc->log.log)
411 		refcount_inc(&fc->log.log->usage);
414 	ret = fc->ops->dup(fc, src_fc);
418 	ret = security_fs_context_dup(fc, src_fc);
421 	return fc;
424 	put_fs_context(fc);
488 static void put_fc_log(struct fs_context *fc)
490 	struct fc_log *log = fc->log.log;
495 			fc->log.log = NULL;
506  * @fc: The context to dispose of.
508 void put_fs_context(struct fs_context *fc)
512 	if (fc->root) {
513 		sb = fc->root->d_sb;
514 		dput(fc->root);
515 		fc->root = NULL;
519 	if (fc->need_free && fc->ops && fc->ops->free)
520 		fc->ops->free(fc);
522 	security_free_mnt_opts(&fc->security);
523 	put_net(fc->net_ns);
524 	put_user_ns(fc->user_ns);
525 	put_cred(fc->cred);
526 	put_fc_log(fc);
527 	put_filesystem(fc->fs_type);
528 	kfree(fc->source);
529 	kfree(fc);
536 static void legacy_fs_context_free(struct fs_context *fc)
538 	struct legacy_fs_context *ctx = fc->fs_private;
550 static int legacy_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
568 	fc->fs_private = ctx;
576 static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param)
578 	struct legacy_fs_context *ctx = fc->fs_private;
583 	ret = vfs_parse_fs_param_source(fc, param);
588 		return invalf(fc, "VFS: Legacy: Can't mix monolithic and individual options");
598 		return invalf(fc, "VFS: Legacy: Parameter type for '%s' not supported",
603 		return invalf(fc, "VFS: Legacy: Cumulative options too large");
607 		return invalf(fc, "VFS: Legacy: Option '%s' contained comma",
634 static int legacy_parse_monolithic(struct fs_context *fc, void *data)
636 	struct legacy_fs_context *ctx = fc->fs_private;
648 	if (fc->fs_type->fs_flags & FS_BINARY_MOUNTDATA)
650 	return security_sb_eat_lsm_opts(ctx->legacy_data, &fc->security);
656 static int legacy_get_tree(struct fs_context *fc)
658 	struct legacy_fs_context *ctx = fc->fs_private;
662 	root = fc->fs_type->mount(fc->fs_type, fc->sb_flags,
663 				      fc->source, ctx->legacy_data);
670 	fc->root = root;
677 static int legacy_reconfigure(struct fs_context *fc)
679 	struct legacy_fs_context *ctx = fc->fs_private;
680 	struct super_block *sb = fc->root->d_sb;
685 	return sb->s_op->remount_fs(sb, &fc->sb_flags,
702 static int legacy_init_fs_context(struct fs_context *fc)
704 	fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL_ACCOUNT);
705 	if (!fc->fs_private)
707 	fc->ops = &legacy_fs_context_ops;
711 int parse_monolithic_mount_data(struct fs_context *fc, void *data)
715 	monolithic_mount_data = fc->ops->parse_monolithic;
719 	return monolithic_mount_data(fc, data);
735 void vfs_clean_context(struct fs_context *fc)
737 	if (fc->need_free && fc->ops && fc->ops->free)
738 		fc->ops->free(fc);
739 	fc->need_free = false;
740 	fc->fs_private = NULL;
741 	fc->s_fs_info = NULL;
742 	fc->sb_flags = 0;
743 	security_free_mnt_opts(&fc->security);
744 	kfree(fc->source);
745 	fc->source = NULL;
746 	fc->exclusive = false;
748 	fc->purpose = FS_CONTEXT_FOR_RECONFIGURE;
749 	fc->phase = FS_CONTEXT_AWAITING_RECONF;
752 int finish_clean_context(struct fs_context *fc)
756 	if (fc->phase != FS_CONTEXT_AWAITING_RECONF)
759 	if (fc->fs_type->init_fs_context)
760 		error = fc->fs_type->init_fs_context(fc);
762 		error = legacy_init_fs_context(fc);
764 		fc->phase = FS_CONTEXT_FAILED;
767 	fc->need_free = true;
768 	fc->phase = FS_CONTEXT_RECONF_PARAMS;