On Sun, Apr 07, 2024 at 09:39:28PM -0400, Theodore Ts'o wrote: > On Sat, Apr 06, 2024 at 11:15:36PM +0800, HAN Yuwei wrote: > > > > Sorry, I am not very familiar with Unicode nor kernel. Correct me if wrong. > > > > As to what I have read, kernel seems like using NFD when processing all > > UTF-8 related string. > > If fs is using these helper function, then I can be sure kernel is applying > > NFD to every UTF-8 filenames. > > But I can't find any references to these helper function on Github mirror, > > how are they used by fs code? > > For the most part, the kernel's file stysem code doesn't do anything > special for Unicode. The exception is that the ext4 and f2fs file > systems can have an optional feature which is mostly only used by > Android systems to support case insensitive lookups. This is called > the "casefold" feature, which is not enabled by default by most > desktop or server systems. As I understand it, an important usecase for the casefold feature is running Windows games under WINE. I don't do this myself (sgt-puzzles is more my speed), but there's a pretty important market for this. Wasn't this why Gabriel was funded to work on it (eg commit b886ee3e778e)? Or was that the Android usecase?
