opnsense-src/share/man
Konstantin Belousov f9b1e711f0 fdescfs: add an option to return underlying file vnode on lookup
The 'nodup' option forces fdescfs to return real vnode behind file
descriptor instead of the fdescfs fd vnode, on lookup. The end result
is that e.g. stat("/dev/fd/3") returns the stat data for the underlying
vnode, if any.  Similarly, fchdir(2) works in the expected way.

For open(2), if applied over file descriptor opened with O_PATH, it
effectively re-open that vnode into normal file descriptor which has the
specified access mode, assuming the current vnode permissions allow it.

If the file descriptor does not reference vnode, the behavior is unchanged.

This is done by a mount option, because permission check on open(2) breaks
established fdescfs open semantic of dup(2)-ing the descriptor.  So it
is not suitable for /dev/fd mount.

Tested by:	Andrew Walker <awalker@ixsystems.com>
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D30140
2021-06-04 03:30:12 +03:00
..
man1 pkgbase: move man pages from runtime-manual to runtime 2019-07-19 15:12:20 +00:00
man3 assert.3: Document static_assert and _Static_assert 2021-04-20 11:17:44 +02:00
man3lua flua: Add a libjail module 2020-10-24 17:08:59 +00:00
man4 iwn(4): Remove duplicate device entry 2021-05-30 15:40:33 +02:00
man5 fdescfs: add an option to return underlying file vnode on lookup 2021-06-04 03:30:12 +03:00
man6 pkgbase: move man pages from runtime-manual to runtime 2019-07-19 15:12:20 +00:00
man7 sys/*/conf/*, docs: fix links to handbook 2021-05-20 09:27:10 +01:00
man8 uefi: Add riscv to historical details 2021-02-22 22:27:00 +00:00
man9 kern: ether_gen_addr: randomize on default hostuuid, too 2021-06-01 22:59:21 -05:00
Makefile flua: Add a libjail module 2020-10-24 17:08:59 +00:00