Re: Changes to the filesystem while find is running - comments?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



(Because I'm so sick of the broken autoresponders bugtraq is full of,
I've set the From: on this mail to a black-hole address.  Please use
the address in the signature if you actually want to reach me.)

>> Before a chdir to "foo", take stock:
>> - record stat(".");  DOTFD = open("."); (get a fd to ".")

This is not possible if . is a search-only directory.  (While find will
not work very well in such a directory, care should be taken that it
not fall over just because someone happened to chmod the read bits away
from a directory just when find happens to be in it.)

More generally, I've wanted to do this - use file descriptors as
handles onto directories - and often wished for an O_NOACCESS mode to
open() in consequence.

> Of course, open(2) will follow a symlink, if the directory we
> originally stat()ed is replaced by a symlink just before we issue the
> open() call.  We of course can guard against that by issuing an
> lstat() on the fd once we have opened it.

ITYPM fstat(), not lstat(), in the last line.

/~\ The ASCII				der Mouse
\ / Ribbon Campaign
 X  Against HTML	       mouse@xxxxxxxxxxxxxxxxxxxxxx
/ \ Email!	     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

[Index of Archives]     [Linux Security]     [Netfilter]     [PHP]     [Yosemite News]     [Linux Kernel]

  Powered by Linux