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path: root/include/linux/fs_parser.h
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2024-07-02fs_parse: add uid & gid option option parsing helpersEric Sandeen
Multiple filesystems take uid and gid as options, and the code to create the ID from an integer and validate it is standard boilerplate that can be moved into common helper functions, so do that for consistency and less cut&paste. This also helps avoid the buggy pattern noted by Seth Jenkins at https://lore.kernel.org/lkml/CALxfFW4BXhEwxR0Q5LSkg-8Vb4r2MONKCcUCVioehXQKr35eHg@mail.gmail.com/ because uid/gid parsing will fail before any assignment in most filesystems. Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Link: https://lore.kernel.org/r/de859d0a-feb9-473d-a5e2-c195a3d47abb@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-03-26fs_parser: move fsparam_string_empty() helper into headerLuis Henriques (SUSE)
Since both ext4 and overlayfs define the same macro to specify string parameters that may allow empty values, define it in an header file so that this helper can be shared. Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev> Link: https://lore.kernel.org/r/20240312104757.27333-1-luis.henriques@linux.dev Signed-off-by: Christian Brauner <brauner@kernel.org>
2022-12-01ext4: journal_path mount options should follow linksLukas Czerner
Before the commit 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter") ext4 mount option journal_path did follow links in the provided path. Bring this behavior back by allowing to pass pathwalk flags to fs_lookup_param(). Fixes: 461c3af045d3 ("ext4: Change handle_mount_opt() to use fs_parameter") Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20221004135803.32283-1-lczerner@redhat.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2021-12-09fs_parse: allow parameter value to be emptyLukas Czerner
Allow parameter value to be empty by specifying fs_param_can_be_empty flag. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Link: https://lore.kernel.org/r/20211027141857.33657-2-lczerner@redhat.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-09-16fs: fix cast in fsparam_u32hex() macroAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07turn fs_param_is_... into functionsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07fs_parse: handle optional arguments sanelyAl Viro
Don't bother with "mixed" options that would allow both the form with and without argument (i.e. both -o foo and -o foo=bar). Rather than trying to shove both into a single fs_parameter_spec, allow having with-argument and no-argument specs with the same name and teach fs_parse to handle that. There are very few options of that sort, and they are actually easier to handle that way - callers end up with less postprocessing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07fs_parse: fold fs_parameter_desc/fs_parameter_specAl Viro
The former contains nothing but a pointer to an array of the latter... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07fs_parser: remove fs_parameter_description name fieldEric Sandeen
Unused now. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07add prefix to fs_context->logAl Viro
... turning it into struct p_log embedded into fs_context. Initialize the prefix with fs_type->name, turning fs_parse() into a trivial inline wrapper for __fs_parse(). This makes fs_parameter_description->name completely unused. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07new primitive: __fs_parse()Al Viro
fs_parse() analogue taking p_log instead of fs_context. fs_parse() turned into a wrapper, callers in ceph_common and rbd switched to __fs_parse(). As the result, fs_parse() never gets NULL fs_context and neither do fs_context-based logging primitives Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07don't bother with explicit length argument for __lookup_constant()Al Viro
Have the arrays of constant_table self-terminated (by NULL ->name in the final entry). Simplifies lookup_constant() and allows to reuse the search for enum params as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07fold struct fs_parameter_enum into struct constant_tableAl Viro
no real difference now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07fs_parse: get rid of ->enumsAl Viro
Don't do a single array; attach them to fsparam_enum() entry instead. And don't bother trying to embed the names into those - it actually loses memory, with no real speedup worth mentioning. Simplifies validation as well. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07Pass consistent param->type to fs_parse()Al Viro
As it is, vfs_parse_fs_string() makes "foo" and "foo=" indistinguishable; both get fs_value_is_string for ->type and NULL for ->string. To make it even more unpleasant, that combination is impossible to produce with fsconfig(). Much saner rules would be "foo" => fs_value_is_flag, NULL "foo=" => fs_value_is_string, "" "foo=bar" => fs_value_is_string, "bar" All cases are distinguishable, all results are expressable by fsconfig(), ->has_value checks are much simpler that way (to the point of the field being useless) and quite a few regressions go away (gfs2 has no business accepting -o nodebug=, for example). Partially based upon patches from Miklos. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public licence as published by the free software foundation either version 2 of the licence or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-28vfs: Add configuration parser helpersDavid Howells
Because the new API passes in key,value parameters, match_token() cannot be used with it. Instead, provide three new helpers to aid with parsing: (1) fs_parse(). This takes a parameter and a simple static description of all the parameters and maps the key name to an ID. It returns 1 on a match, 0 on no match if unknowns should be ignored and some other negative error code on a parse error. The parameter description includes a list of key names to IDs, desired parameter types and a list of enumeration name -> ID mappings. [!] Note that for the moment I've required that the key->ID mapping array is expected to be sorted and unterminated. The size of the array is noted in the fsconfig_parser struct. This allows me to use bsearch(), but I'm not sure any performance gain is worth the hassle of requiring people to keep the array sorted. The parameter type array is sized according to the number of parameter IDs and is indexed directly. The optional enum mapping array is an unterminated, unsorted list and the size goes into the fsconfig_parser struct. The function can do some additional things: (a) If it's not ambiguous and no value is given, the prefix "no" on a key name is permitted to indicate that the parameter should be considered negatory. (b) If the desired type is a single simple integer, it will perform an appropriate conversion and store the result in a union in the parse result. (c) If the desired type is an enumeration, {key ID, name} will be looked up in the enumeration list and the matching value will be stored in the parse result union. (d) Optionally generate an error if the key is unrecognised. This is called something like: enum rdt_param { Opt_cdp, Opt_cdpl2, Opt_mba_mpbs, nr__rdt_params }; const struct fs_parameter_spec rdt_param_specs[nr__rdt_params] = { [Opt_cdp] = { fs_param_is_bool }, [Opt_cdpl2] = { fs_param_is_bool }, [Opt_mba_mpbs] = { fs_param_is_bool }, }; const const char *const rdt_param_keys[nr__rdt_params] = { [Opt_cdp] = "cdp", [Opt_cdpl2] = "cdpl2", [Opt_mba_mpbs] = "mba_mbps", }; const struct fs_parameter_description rdt_parser = { .name = "rdt", .nr_params = nr__rdt_params, .keys = rdt_param_keys, .specs = rdt_param_specs, .no_source = true, }; int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct fs_parse_result parse; struct rdt_fs_context *ctx = rdt_fc2context(fc); int ret; ret = fs_parse(fc, &rdt_parser, param, &parse); if (ret < 0) return ret; switch (parse.key) { case Opt_cdp: ctx->enable_cdpl3 = true; return 0; case Opt_cdpl2: ctx->enable_cdpl2 = true; return 0; case Opt_mba_mpbs: ctx->enable_mba_mbps = true; return 0; } return -EINVAL; } (2) fs_lookup_param(). This takes a { dirfd, path, LOOKUP_EMPTY? } or string value and performs an appropriate path lookup to convert it into a path object, which it will then return. If the desired type was a blockdev, the type of the looked up inode will be checked to make sure it is one. This can be used like: enum foo_param { Opt_source, nr__foo_params }; const struct fs_parameter_spec foo_param_specs[nr__foo_params] = { [Opt_source] = { fs_param_is_blockdev }, }; const char *char foo_param_keys[nr__foo_params] = { [Opt_source] = "source", }; const struct constant_table foo_param_alt_keys[] = { { "device", Opt_source }, }; const struct fs_parameter_description foo_parser = { .name = "foo", .nr_params = nr__foo_params, .nr_alt_keys = ARRAY_SIZE(foo_param_alt_keys), .keys = foo_param_keys, .alt_keys = foo_param_alt_keys, .specs = foo_param_specs, }; int foo_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct fs_parse_result parse; struct foo_fs_context *ctx = foo_fc2context(fc); int ret; ret = fs_parse(fc, &foo_parser, param, &parse); if (ret < 0) return ret; switch (parse.key) { case Opt_source: return fs_lookup_param(fc, &foo_parser, param, &parse, &ctx->source); default: return -EINVAL; } } (3) lookup_constant(). This takes a table of named constants and looks up the given name within it. The table is expected to be sorted such that bsearch() be used upon it. Possibly I should require the table be terminated and just use a for-loop to scan it instead of using bsearch() to reduce hassle. Tables look something like: static const struct constant_table bool_names[] = { { "0", false }, { "1", true }, { "false", false }, { "no", false }, { "true", true }, { "yes", true }, }; and a lookup is done with something like: b = lookup_constant(bool_names, param->string, -1); Additionally, optional validation routines for the parameter description are provided that can be enabled at compile time. A later patch will invoke these when a filesystem is registered. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>