Commit 0f89589a authored by Al Viro's avatar Al Viro
Browse files

Pass consistent param->type to fs_parse() 



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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7dc2993a

drivers/block/rbd.c

+2 −5
Original line number Diff line number Diff line
@@ -6433,7 +6433,7 @@ static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx) 
		if (*key) {

			struct fs_parameter param = {

				.key	= key,

				.type	= fs_value_is_string,

				.type	= fs_value_is_flag,

			};

			char *value = strchr(key, '=');

			size_t v_len = 0;
@@ -6443,14 +6443,11 @@ static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx) 
					continue;

				*value++ = 0;

				v_len = strlen(value);

			}





			if (v_len > 0) {

				param.string = kmemdup_nul(value, v_len,

							   GFP_KERNEL);

				if (!param.string)

					return -ENOMEM;

				param.type = fs_value_is_string;

			}

			param.size = v_len;

fs/fs_context.c

+3 −2
Original line number Diff line number Diff line
@@ -175,14 +175,15 @@ int vfs_parse_fs_string(struct fs_context *fc, const char *key, 


	struct fs_parameter param = {

		.key	= key,

		.type	= fs_value_is_string,

		.type	= fs_value_is_flag,

		.size	= v_size,

	};



	if (v_size > 0) {

	if (value) {

		param.string = kmemdup_nul(value, v_size, GFP_KERNEL);

		if (!param.string)

			return -ENOMEM;

		param.type = fs_value_is_string;

	}



	ret = vfs_parse_fs_param(fc, &param);

fs/fs_parser.c

+11 −12
Original line number Diff line number Diff line
@@ -85,7 +85,6 @@ int fs_parse(struct fs_context *fc, 
	const struct fs_parameter_enum *e;

	int ret = -ENOPARAM, b;



	result->has_value = !!param->string;

	result->negated = false;

	result->uint_64 = 0;
@@ -95,7 +94,7 @@ int fs_parse(struct fs_context *fc, 
		 * "xxx" takes the "no"-form negative - but only if there

		 * wasn't an value.

		 */

		if (result->has_value)

		if (param->type != fs_value_is_flag)

			goto unknown_parameter;

		if (param->key[0] != 'n' || param->key[1] != 'o' || !param->key[2])

			goto unknown_parameter;
@@ -127,14 +126,18 @@ int fs_parse(struct fs_context *fc, 
	case fs_param_is_u64:

	case fs_param_is_enum:

	case fs_param_is_string:

		if (param->type != fs_value_is_string)

		if (param->type == fs_value_is_string) {

			if (p->flags & fs_param_v_optional)

				break;

			if (!*param->string)

				goto bad_value;

		if (!result->has_value) {

			break;

		}

		if (param->type == fs_value_is_flag) {

			if (p->flags & fs_param_v_optional)

				goto okay;

			goto bad_value;

		}

		/* Fall through */

		goto bad_value;

	default:

		break;

	}
@@ -144,8 +147,7 @@ int fs_parse(struct fs_context *fc, 
	 */

	switch (p->type) {

	case fs_param_is_flag:

		if (param->type != fs_value_is_flag &&

		    (param->type != fs_value_is_string || result->has_value))

		if (param->type != fs_value_is_flag)

			return invalf(fc, "%s: Unexpected value for '%s'",

				      desc->name, param->key);

		result->boolean = true;
@@ -206,9 +208,6 @@ int fs_parse(struct fs_context *fc, 
	case fs_param_is_fd: {

		switch (param->type) {

		case fs_value_is_string:

			if (!result->has_value)

				goto bad_value;



			ret = kstrtouint(param->string, 0, &result->uint_32);

			break;

		case fs_value_is_file:

include/linux/fs_parser.h

+0 −1
Original line number Diff line number Diff line
@@ -72,7 +72,6 @@ struct fs_parameter_description { 
 */

struct fs_parse_result {

	bool			negated;	/* T if param was "noxxx" */

	bool			has_value;	/* T if value supplied to param */

	union {

		bool		boolean;	/* For spec_bool */

		int		int_32;		/* For spec_s32/spec_enum */

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