Date: Tue, 29 Jan 2008 21:40:54 GMT From: Juli Mallett <juli@clockworksquid.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/120128: __getcwd erroneously returning ENOENT Message-ID: <200801292140.m0TLesbt083061@www.freebsd.org> Resent-Message-ID: <200801292150.m0TLo11Q089395@freefall.freebsd.org>
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>Number: 120128
>Category: kern
>Synopsis: __getcwd erroneously returning ENOENT
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Tue Jan 29 21:50:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator: Juli Mallett
>Release: 8.0-CURRENT, kern.osreldate: 800008
>Organization:
>Environment:
FreeBSD alala.evergreen.edu 8.0-CURRENT FreeBSD 8.0-CURRENT #7: Tue Jan 8 16:03:13 PST 2008 root@alala.evergreen.edu:/usr/obj/usr/src/sys/ALALA amd64
>Description:
When removing subdirectories, __getcwd is sometimes falsely returning ENOENT, and continues to do so until pwd -L is invoked (it is the stat($PWD) that fixes the problem, presumably this is updating some cached information somewhere?) in a specific configuration (with a few edge-cases). This only occurs with tcsh for me, not sh, because the sh builtin compensates for the problem.
^_^ (mallettj@alala:~)267% cd pwd
^_^ (mallettj@alala:~/pwd)268% mkdir foo ; cd foo ; mkdir bar ; rm -rf bar ; pwd -P ; cd .. ; rm -rf foo
pwd: .: Permission denied
^_^ (mallettj@alala:~/pwd)269% mkdir foo ; cd foo ; mkdir bar ; rm -rf bar ; pwd -L ; cd .. ; rm -rf foo
/home/mallettj/pwd/foo
^_^ (mallettj@alala:~/pwd)270% mkdir foo ; cd foo ; mkdir bar ; rm -rf bar ; ~/pwd/pwd -P ; cd .. ; rm -rf foo
/data/home/mallettj/pwd/foo
^_^ (mallettj@alala:~/pwd)271% ls -lartd .
drwxr-xr-x 3 mallettj mallettj 512 Jan 29 15:38 .
^_^ (mallettj@alala:~/pwd)272% pwd -L
/home/mallettj/pwd
^_^ (mallettj@alala:~/pwd)273% pwd -P
/data/home/mallettj/pwd
^_^ (mallettj@alala:~/pwd)274% ls -lartd /data
drwxr-xr-x 8 root wheel 512 Jul 5 2007 /data
^_^ (mallettj@alala:~/pwd)275% ls -lartd /data/home
drwx--x--x 9 root wheel 512 Jan 23 19:00 /data/home
^_^ (mallettj@alala:~/pwd)276% ls -lartd /data/home/mallettj
drwxr-xr-x 13 mallettj mallettj 1024 Jan 29 15:34 /data/home/mallettj
^_^ (mallettj@alala:~/pwd)277% ls -lartd /data/home/mallettj/pwd
drwxr-xr-x 3 mallettj mallettj 512 Jan 29 15:38 /data/home/mallettj/pwd
^_^ (mallettj@alala:~/pwd)278% ls -lartd /home
lrwxr-xr-x 1 root wheel 10 Jun 21 2007 /home -> /data/home
^_^ (mallettj@alala:~/pwd)279% cvs diff -u pwd.c
socket: Protocol not supported
Index: pwd.c
===================================================================
RCS file: /home/ncvs/src/bin/pwd/pwd.c,v
retrieving revision 1.25
diff -u -r1.25 pwd.c
--- pwd.c 9 Feb 2005 17:37:38 -0000 1.25
+++ pwd.c 29 Jan 2008 21:39:47 -0000
@@ -84,6 +84,8 @@
* If we're trying to find the logical current directory and that
* fails, behave as if -P was specified.
*/
+ struct stat phy;
+ stat(getenv("PWD"), &phy);
if ((!physical && (p = getcwd_logical()) != NULL) ||
(p = getcwd(NULL, 0)) != NULL)
printf("%s\n", p);
>How-To-Repeat:
tcsh -c 'mkdir foo ; cd foo ; mkdir bar ; rm -rf bar ; pwd -P ; cd .. ; rm -rf foo'
>Fix:
Unlikely to have time to dig in to the kernel to figure out the root cause. Want to stress that the patch in the full description (obviously) is not a solution, should someone stumble over this bug and think it is. This affects all callers of getcwd, including my shell:
^_^ (mallettj@alala:~/pwd)286% tcsh -c 'mkdir foo ; cd foo ; mkdir bar ; rm -rf bar ; pwd -P ; cd .. ; rm -rf foo'
tcsh: Permission denied
tcsh: Trying to start from "/home/mallettj"
pwd: .: Permission denied
^_^ (mallettj@alala:~/pwd)287% pwd -L
/home/mallettj/pwd
^_^ (mallettj@alala:~/pwd)288% tcsh -c 'mkdir foo ; cd foo ; mkdir bar ; rm -rf bar ; pwd -P ; cd .. ; rm -rf foo'
pwd: .: Permission denied
>Release-Note:
>Audit-Trail:
>Unformatted:
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