Commit Graph

6 Commits

Author SHA1 Message Date
David Howells 74983ac20a vfs: Make fs_parse() handle fs_param_is_fd-type params better
Make fs_parse() handle fs_param_is_fd-type parameters that are passed a
string by converting it to an integer (in addition to handling direct fd
specification).

Also range check the integer.

[fix from  Yin Fengwei folded]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-12 21:06:14 -04:00
Linus Torvalds 933a90bf4f Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...
2019-07-19 10:42:02 -07:00
David Howells 7cdfa44227 vfs: Fix refcounting of filenames in fs_parser
Fix an overput in which filename_lookup() unconditionally drops a ref to
the filename it was given, but this isn't taken account of in the caller,
fs_lookup_param().

Addresses-Coverity-ID: 1443811 ("Use after free")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-25 18:00:02 -04:00
Thomas Gleixner b4d0d230cc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36
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>
2019-05-24 17:27:11 +02:00
Randy Dunlap 2620327852 fs: fs_parser: fix printk format warning
Fix printk format warning (seen on i386 builds) by using ptrdiff format
specifier (%t):

  fs/fs_parser.c:413:6: warning: format `%lu' expects argument of type `long unsigned int', but argument 3 has type `int' [-Wformat=]

Link: http://lkml.kernel.org/r/19432668-ffd3-fbb2-af4f-1c8e48f6cc81@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-29 10:01:38 -07:00
David Howells 31d921c7fb vfs: Add configuration parser helpers
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>
2019-02-28 03:28:53 -05:00