Commit 6abfaaf1 authored by Lukas Czerner's avatar Lukas Czerner Committed by Theodore Ts'o
Browse files

fs_parse: allow parameter value to be empty 



Allow parameter value to be empty by specifying fs_param_can_be_empty
flag.

Signed-off-by: default avatarLukas Czerner <lczerner@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: default avatarCarlos Maiolino <cmaiolino@redhat.com>
Link: https://lore.kernel.org/r/20211027141857.33657-2-lczerner@redhat.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 0fcfb00b

fs/fs_parser.c

+23 −8
Original line number Diff line number Diff line
@@ -199,6 +199,8 @@ int fs_param_is_bool(struct p_log *log, const struct fs_parameter_spec *p, 
	int b;

	if (param->type != fs_value_is_string)

		return fs_param_bad_value(log, param);

	if (!*param->string && (p->flags & fs_param_can_be_empty))

		return 0;

	b = lookup_constant(bool_names, param->string, -1);

	if (b == -1)

		return fs_param_bad_value(log, param);
@@ -211,8 +213,11 @@ int fs_param_is_u32(struct p_log *log, const struct fs_parameter_spec *p, 
		    struct fs_parameter *param, struct fs_parse_result *result)

{

	int base = (unsigned long)p->data;

	if (param->type != fs_value_is_string ||

	    kstrtouint(param->string, base, &result->uint_32) < 0)

	if (param->type != fs_value_is_string)

		return fs_param_bad_value(log, param);

	if (!*param->string && (p->flags & fs_param_can_be_empty))

		return 0;

	if (kstrtouint(param->string, base, &result->uint_32) < 0)

		return fs_param_bad_value(log, param);

	return 0;

}
@@ -221,8 +226,11 @@ EXPORT_SYMBOL(fs_param_is_u32); 
int fs_param_is_s32(struct p_log *log, const struct fs_parameter_spec *p,

		    struct fs_parameter *param, struct fs_parse_result *result)

{

	if (param->type != fs_value_is_string ||

	    kstrtoint(param->string, 0, &result->int_32) < 0)

	if (param->type != fs_value_is_string)

		return fs_param_bad_value(log, param);

	if (!*param->string && (p->flags & fs_param_can_be_empty))

		return 0;

	if (kstrtoint(param->string, 0, &result->int_32) < 0)

		return fs_param_bad_value(log, param);

	return 0;

}
@@ -231,8 +239,11 @@ EXPORT_SYMBOL(fs_param_is_s32); 
int fs_param_is_u64(struct p_log *log, const struct fs_parameter_spec *p,

		    struct fs_parameter *param, struct fs_parse_result *result)

{

	if (param->type != fs_value_is_string ||

	    kstrtoull(param->string, 0, &result->uint_64) < 0)

	if (param->type != fs_value_is_string)

		return fs_param_bad_value(log, param);

	if (!*param->string && (p->flags & fs_param_can_be_empty))

		return 0;

	if (kstrtoull(param->string, 0, &result->uint_64) < 0)

		return fs_param_bad_value(log, param);

	return 0;

}
@@ -244,6 +255,8 @@ int fs_param_is_enum(struct p_log *log, const struct fs_parameter_spec *p, 
	const struct constant_table *c;

	if (param->type != fs_value_is_string)

		return fs_param_bad_value(log, param);

	if (!*param->string && (p->flags & fs_param_can_be_empty))

		return 0;

	c = __lookup_constant(p->data, param->string);

	if (!c)

		return fs_param_bad_value(log, param);
@@ -255,7 +268,8 @@ EXPORT_SYMBOL(fs_param_is_enum); 
int fs_param_is_string(struct p_log *log, const struct fs_parameter_spec *p,

		       struct fs_parameter *param, struct fs_parse_result *result)

{

	if (param->type != fs_value_is_string || !*param->string)

	if (param->type != fs_value_is_string ||

	    (!*param->string && !(p->flags & fs_param_can_be_empty)))

		return fs_param_bad_value(log, param);

	return 0;

}
@@ -275,7 +289,8 @@ int fs_param_is_fd(struct p_log *log, const struct fs_parameter_spec *p, 
{

	switch (param->type) {

	case fs_value_is_string:

		if (kstrtouint(param->string, 0, &result->uint_32) < 0)

		if ((!*param->string && !(p->flags & fs_param_can_be_empty)) ||

		    kstrtouint(param->string, 0, &result->uint_32) < 0)

			break;

		if (result->uint_32 <= INT_MAX)

			return 0;

include/linux/fs_parser.h

+1 −1
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ struct fs_parameter_spec { 
	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_can_be_empty	0x0004	/* "xxx=" is allowed */

#define fs_param_deprecated	0x0008	/* The param is deprecated */

	const void		*data;

};