On Sun, Aug 29, 2021 at 02:25:29PM +0000, Caleb D.S. Brzezinski wrote: > Implement the main msdos_format_name() filename cache. If used as a > module, all memory allocated for the cache is freed when the module is > de-registered. > > Signed-off-by: Caleb D.S. Brzezinski <calebdsb@xxxxxxxxxxxxxx> > --- > fs/fat/namei_msdos.c | 35 +++++++++++++++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > > diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c > index 7561674b1..f9d4f63c3 100644 > --- a/fs/fat/namei_msdos.c > +++ b/fs/fat/namei_msdos.c > @@ -124,6 +124,16 @@ static int msdos_format_name(const unsigned char *name, int len, > unsigned char *walk; > unsigned char c; > int space; > + u64 hash; > + struct msdos_name_node *node; > + > + /* check if the name is already in the cache */ > + > + hash = msdos_fname_hash(name); > + if (find_fname_in_cache(res, hash)) > + return 0; Huh? How could that possibly work, seeing that * your hash function only looks at the first 8 characters * your find_fname_in_cache() assumes that hash collisions are impossible, which is... unlikely, considering the nature of that hash function * find_fname_in_cache(res, hash) copies at most 8 characters into res in case of match. Where does the extension come from? Out of curiosity, how have you tested that thing?
