Messages in this thread | | | Date | Mon, 31 Jan 2022 19:34:53 +0000 | From | Eric Biggers <> | Subject | Re: [RFC PATCH] f2fs: disallow setting unsettable file attributes |
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On Sun, Jan 30, 2022 at 05:21:39PM +0000, Harry Austen wrote: > After Eric kindly pointed out the reasons why my initial kernel patch > attempt was incorrect > (https://lore.kernel.org/lkml/Ye79OLCFLR3H+GnY@gmail.com/), I had a > rethink as to if the current implementation could be improved in any > way. > > I wondered whether something along the lines of the following patch > would be more acceptable? It is intentionally verbose in order to > demonstrate the concept as this is intended purely as an RFC. > > What if SETFLAGS returned EOPNOTSUPP if userspace is actually trying to > *set* one of the unsettable flags (i.e. it isn't set already)? I believe > this would therefore not break chattr(1), as flags that are retrieved > from GETFLAGS can still be passed into SETFLAGS without error. > > If there is some other ABI compatibility that needs to be maintained > that is broken by this, then please let me know. Also, I have not yet > determined whether there are any concerns with calling f2fs_fileattr_get > from inside f2fs_fileattr_set, e.g. speed/performance? so any thoughts > would be greatly appreciated. > > Signed-off-by: Harry Austen <harryausten@hotmail.co.uk> > --- > fs/f2fs/file.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+)
This makes sense, but this ioctl isn't f2fs-specific; it's implemented by other filesystems, most notably ext2/ext4 where it originated. f2fs shouldn't have different behavior for the same ioctl. If you want to change this ioctl, you need to start a wider discussion (including the linux-fsdevel and linux-ext4 mailing lists) where the change is proposed for all filesystems.
- Eric
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