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: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fs_context.c b/fs/fs_context.c
index 138b5b4..9097421 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -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, ¶m);