vfs: make O_PATH file descriptors usable for 'fchdir()'
We already use them for openat() and friends, but fchdir() also wants to be able to use O_PATH file descriptors. This should make it comparable to the O_SEARCH of Solaris. In particular, O_PATH allows you to access (not-quite-open) a directory you don't have read persmission to, only execute permission. Noticed during development of multithread support for ksh93. Reported-by: ольга крыжановская <firstname.lastname@example.org> Cc: Al Viro <email@example.com> Cc: firstname.lastname@example.org # O_PATH introduced in 3.0+ Signed-off-by: Linus Torvalds <email@example.com>