2022-03-11 5:06 GMT+09:00, David Disseldorp <ddiss@xxxxxxx>: > Thanks for reworking these changes, Vasant. > > Please trim the 1/2 and 2/2 patch subjects down to around 50 chars > (including a "exfat: " prefix), with the details moved into the commit > message body... > > On Thu, 10 Mar 2022 15:24:55 +0100, Vasant Karasulli wrote: > >> #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. > > I think it makes sense to mention your findings from the Windows tests > here. E.g. "Windows 10 also retains leading and trailing space > characters". Windows 10 do also strip them. So you can make another patch to strip it as well as trailing periods. > >> 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/ >> >> With this change, the "keep_last_dots" 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 > > It'd be nice to demonstrate "keep_last_dots" creation here as well, e.g. > > + echo > kexfat_created_dots_again... > sh: kexfat_created_dots_again...: Invalid argument > > @Namjae: not sure whether this is what you had in mind for preventing > creation of invalid paths. What's your preference? Look like what I wanted. Thanks! > > Cheers, David >
