On Thu, 9 Jun 2022 at 06:36, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > On Wed, Jun 8, 2022 at 9:01 PM Andreas Dilger <adilger@xxxxxxxxx> wrote: > > > > On Jun 7, 2022, at 9:31 AM, Christian Göttsche <cgzones@xxxxxxxxxxxxxx> wrote: > > > > > > From: Miklos Szeredi <mszeredi@xxxxxxxxxx> > > > > > > Support file descriptors obtained via O_PATH for extended attribute > > > operations. > > > > > > Extended attributes are for example used by SELinux for the security > > > context of file objects. To avoid time-of-check-time-of-use issues while > > > setting those contexts it is advisable to pin the file in question and > > > operate on a file descriptor instead of the path name. This can be > > > emulated in userspace via /proc/self/fd/NN [1] but requires a procfs, > > > which might not be mounted e.g. inside of chroots, see[2]. > > > > Will this allow get/set xattrs directly on symlinks? That is one problem > > that we have with some of the xattrs that are inherited on symlinks, but > > there is no way to change them. Allowing setxattr directly on a symlink > > would be very useful. > > It is possible. > See: https://github.com/libfuse/libfuse/pull/514 > Does it really? (It should not since xtattr(7) mentions some quota related issues.) In my tests setting extended attributes via O_PATH on symlinks fails with ENOTSUP (even as root), except for special ones, like "security.selinux". > That's why Miklos withdrew this patch: > https://lore.kernel.org/linux-fsdevel/CAOssrKeV7g0wPg4ozspG4R7a+5qARqWdG+GxWtXB-MCfbVM=9A@xxxxxxxxxxxxxx/ > > Thanks, > Amir.
