On Aug 28, 2015 2:54 PM, "Andreas Grünbacher"
[off-list ref] wrote:

2015-08-28 23:36 GMT+02:00 Andy Lutomirski [off-list ref]:

quoted

Silly question from the peanut gallery: is there any such thing as
opening an fd pointing at a file such that the "open file description"
(i.e. the struct file) captures the right to delete the file?

IOW do we need FMODE_DELETE_SELF?

When would that permission be checked, what syscall would you use to
unlink an open file descriptor?

Good point.  It's remotely plausible that there's some trick with bind
mounts, it's likely possible to unlink a directory by fd (using
unlinkat), and you can *link* a file (with linkat or /proc), but
unlinkat doesn't appear to allow you to unlink a file by fd.

--Andy

Thanks,
Andreas