Re: umount -l <path>, getcwd and /proc/<pid>/cwd inconsistent

From: Bauke Jan Douma
Date: Mon Jan 07 2008 - 03:30:18 EST


Ian Kent wrote on 07-01-08 04:17:
Hi all,

Could someone please help me understand what's happening with, what
looks like inconsistent behavior, between getpwd and procfs readlink.

Basically, from a bash shell, setting working directory to a mounted
directory all is fine with "pwd" and "/proc/<pid>/cwd". Following a
"umount - l" on the mount "pwd" continues to return the expected string
but "/proc/<pid>/cwd" returns an empty string.

What I'm really after is why this happens because sys_getcwd and
proc_pid_readlink appear to do essentially the same thing to get the
string.

[snip]

What does `/bin/pwd' return, when you do that instead of
plain `pwd' (after the umount)?

bjd


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