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Diffstat (limited to '')
-rw-r--r-- | include/linux/fs_parser.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/include/linux/fs_parser.h b/include/linux/fs_parser.h new file mode 100644 index 000000000..aab0ffc6b --- /dev/null +++ b/include/linux/fs_parser.h @@ -0,0 +1,134 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Filesystem parameter description and parser + * + * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _LINUX_FS_PARSER_H +#define _LINUX_FS_PARSER_H + +#include <linux/fs_context.h> + +struct path; + +struct constant_table { + const char *name; + int value; +}; + +struct fs_parameter_spec; +struct fs_parse_result; +typedef int fs_param_type(struct p_log *, + const struct fs_parameter_spec *, + struct fs_parameter *, + struct fs_parse_result *); +/* + * The type of parameter expected. + */ +fs_param_type fs_param_is_bool, fs_param_is_u32, fs_param_is_s32, fs_param_is_u64, + fs_param_is_enum, fs_param_is_string, fs_param_is_blob, fs_param_is_blockdev, + fs_param_is_path, fs_param_is_fd; + +/* + * Specification of the type of value a parameter wants. + * + * Note that the fsparam_flag(), fsparam_string(), fsparam_u32(), ... macros + * should be used to generate elements of this type. + */ +struct fs_parameter_spec { + const char *name; + fs_param_type *type; /* The desired parameter type */ + u8 opt; /* Option number (returned by fs_parse()) */ + unsigned short flags; +#define fs_param_neg_with_no 0x0002 /* "noxxx" is negative param */ +#define fs_param_neg_with_empty 0x0004 /* "xxx=" is negative param */ +#define fs_param_deprecated 0x0008 /* The param is deprecated */ + const void *data; +}; + +/* + * Result of parse. + */ +struct fs_parse_result { + bool negated; /* T if param was "noxxx" */ + union { + bool boolean; /* For spec_bool */ + int int_32; /* For spec_s32/spec_enum */ + unsigned int uint_32; /* For spec_u32{,_octal,_hex}/spec_enum */ + u64 uint_64; /* For spec_u64 */ + }; +}; + +extern int __fs_parse(struct p_log *log, + const struct fs_parameter_spec *desc, + struct fs_parameter *value, + struct fs_parse_result *result); + +static inline int fs_parse(struct fs_context *fc, + const struct fs_parameter_spec *desc, + struct fs_parameter *param, + struct fs_parse_result *result) +{ + return __fs_parse(&fc->log, desc, param, result); +} + +extern int fs_lookup_param(struct fs_context *fc, + struct fs_parameter *param, + bool want_bdev, + struct path *_path); + +extern int lookup_constant(const struct constant_table tbl[], const char *name, int not_found); + +#ifdef CONFIG_VALIDATE_FS_PARSER +extern bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, + int low, int high, int special); +extern bool fs_validate_description(const char *name, + const struct fs_parameter_spec *desc); +#else +static inline bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size, + int low, int high, int special) +{ return true; } +static inline bool fs_validate_description(const char *name, + const struct fs_parameter_spec *desc) +{ return true; } +#endif + +/* + * Parameter type, name, index and flags element constructors. Use as: + * + * fsparam_xxxx("foo", Opt_foo) + * + * If existing helpers are not enough, direct use of __fsparam() would + * work, but any such case is probably a sign that new helper is needed. + * Helpers will remain stable; low-level implementation may change. + */ +#define __fsparam(TYPE, NAME, OPT, FLAGS, DATA) \ + { \ + .name = NAME, \ + .opt = OPT, \ + .type = TYPE, \ + .flags = FLAGS, \ + .data = DATA \ + } + +#define fsparam_flag(NAME, OPT) __fsparam(NULL, NAME, OPT, 0, NULL) +#define fsparam_flag_no(NAME, OPT) \ + __fsparam(NULL, NAME, OPT, fs_param_neg_with_no, NULL) +#define fsparam_bool(NAME, OPT) __fsparam(fs_param_is_bool, NAME, OPT, 0, NULL) +#define fsparam_u32(NAME, OPT) __fsparam(fs_param_is_u32, NAME, OPT, 0, NULL) +#define fsparam_u32oct(NAME, OPT) \ + __fsparam(fs_param_is_u32, NAME, OPT, 0, (void *)8) +#define fsparam_u32hex(NAME, OPT) \ + __fsparam(fs_param_is_u32_hex, NAME, OPT, 0, (void *)16) +#define fsparam_s32(NAME, OPT) __fsparam(fs_param_is_s32, NAME, OPT, 0, NULL) +#define fsparam_u64(NAME, OPT) __fsparam(fs_param_is_u64, NAME, OPT, 0, NULL) +#define fsparam_enum(NAME, OPT, array) __fsparam(fs_param_is_enum, NAME, OPT, 0, array) +#define fsparam_string(NAME, OPT) \ + __fsparam(fs_param_is_string, NAME, OPT, 0, NULL) +#define fsparam_blob(NAME, OPT) __fsparam(fs_param_is_blob, NAME, OPT, 0, NULL) +#define fsparam_bdev(NAME, OPT) __fsparam(fs_param_is_blockdev, NAME, OPT, 0, NULL) +#define fsparam_path(NAME, OPT) __fsparam(fs_param_is_path, NAME, OPT, 0, NULL) +#define fsparam_fd(NAME, OPT) __fsparam(fs_param_is_fd, NAME, OPT, 0, NULL) + +#endif /* _LINUX_FS_PARSER_H */ |