Messages in this thread | | | Subject | Re: pivot_root(".", ".") and the fchdir() dance | From | "Michael Kerrisk (man-pages)" <> | Date | Tue, 10 Sep 2019 13:21:16 +0200 |
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Hello Christian,
>> All: I plan to add the following text to the manual page: >> >> new_root and put_old may be the same directory. In particular, >> the following sequence allows a pivot-root operation without need‐ >> ing to create and remove a temporary directory: >> >> chdir(new_root); >> pivot_root(".", "."); >> umount2(".", MNT_DETACH); > > Hm, should we mention that MS_PRIVATE or MS_SLAVE is usually needed > before the umount2()? Especially for the container case... I think we > discussed this briefly yesterday in person. Thanks for noticing. That detail (more precisely: not MS_SHARED) is already covered in the numerous other changes that I have pending for this page:
The following restrictions apply: ... - The propagation type of new_root and its parent mount must not be MS_SHARED; similarly, if put_old is an existing mount point, its propagation type must not be MS_SHARED.
Thanks,
Michael
-- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
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