2022-03-17 18:50 GMT+09:00, Vasant Karasulli <vkarasulli@xxxxxxx>: > The Linux kernel exfat driver currently unconditionally strips > trailing periods '.' from path components. This isdone intentionally, > loosely following Windows behaviour and specifications > which state: > > #exFAT > The concatenated file name has the same set of illegal characters as > other FAT-based file systems (see Table 31). > > #FAT > ... > Leading and trailing spaces in a long name are ignored. > Leading and embedded periods are allowed in a name and are stored in > the long name. Trailing periods are ignored. > > Note: Leading and trailing space ' ' characters are currently retained > by Linux kernel exfat, in conflict with the above specification. > On Windows 10, trailing and leading space ' ' characters are stripped > from the filenames. > Some implementations, such as fuse-exfat, don't perform path trailer > removal. When mounting images which contain trailing-dot paths, these > paths are unreachable, e.g.: > > + mount.exfat-fuse /dev/zram0 /mnt/test/ > FUSE exfat 1.3.0 > + cd /mnt/test/ > + touch fuse_created_dots... ' fuse_created_spaces ' > + ls -l > total 0 > -rwxrwxrwx 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces ' > -rwxrwxrwx 1 root 0 0 Aug 18 09:45 fuse_created_dots... > + cd / > + umount /mnt/test/ > + mount -t exfat /dev/zram0 /mnt/test > + cd /mnt/test > + ls -l > ls: cannot access 'fuse_created_dots...': No such file or directory > total 0 > -rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces ' > -????????? ? ? ? ? ? fuse_created_dots... > + touch kexfat_created_dots... ' kexfat_created_spaces ' > + ls -l > ls: cannot access 'fuse_created_dots...': No such file or directory > total 0 > -rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' fuse_created_spaces ' > -rwxr-xr-x 1 root 0 0 Aug 18 09:45 ' kexfat_created_spaces ' > -????????? ? ? ? ? ? fuse_created_dots... > -rwxr-xr-x 1 root 0 0 Aug 18 09:45 kexfat_created_dots > + cd / > + umount /mnt/test/ > > This commit adds "keep_last_dots" mount option that controls whether or > not trailing periods '.' are stripped > from path components during file lookup or file creation. > This mount option can be used to access > paths with trailing periods and disallow creating files with names with > trailing periods. E.g. continuing from the previous example: > > + mount -t exfat -o keep_last_dots /dev/zram0 /mnt/test > + cd /mnt/test > + ls -l > total 0 > -rwxr-xr-x 1 root 0 0 Aug 18 10:32 ' fuse_created_spaces ' > -rwxr-xr-x 1 root 0 0 Aug 18 10:32 ' kexfat_created_spaces ' > -rwxr-xr-x 1 root 0 0 Aug 18 10:32 fuse_created_dots... > -rwxr-xr-x 1 root 0 0 Aug 18 10:32 kexfat_created_dots > > + echo > kexfat_created_dots_again... > sh: kexfat_created_dots_again...: Invalid argument > > Link: https://bugzilla.suse.com/show_bug.cgi?id=1188964 > Link: https://lore.kernel.org/linux-fsdevel/003b01d755e4$31fb0d80$95f12880$ > @samsung.com/ > Link: > https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification > Suggested-by: Takashi Iwai <tiwai@xxxxxxx> > Signed-off-by: Vasant Karasulli <vkarasulli@xxxxxxx> > Co-developed-by: David Disseldorp <ddiss@xxxxxxx> > Signed-off-by: David Disseldorp <ddiss@xxxxxxx> Applied, Thanks for your patch!
