Bug 1309247 - df -l hangs on nfs share when autofs is involved
df -l hangs on nfs share when autofs is involved
Status: CLOSED ERRATA
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: coreutils (Show other bugs)
7.2
All Linux
unspecified Severity medium
: rc
: ---
Assigned To: Ondrej Vasik
Jakub Prokes
Petr Bokoc
: Patch
Depends On:
Blocks:
  Show dependency treegraph
 
Reported: 2016-02-17 05:27 EST by Dmitry Zhukovski
Modified: 2017-11-10 08:33 EST (History)
8 users (show)

See Also:
Fixed In Version: coreutils-8.22-17.el7
Doc Type: Bug Fix
Doc Text:
*NFS* shares mounted by *autofs* no longer cause timeouts when listing local mounts using "df" A bug in "df" could previously cause *NFS* shares mounted by *autofs* to be detected as local mounts. Attempts to list only local mounts using the "-l" option then timed out, because "df" was attempting to list these incorrectly detected shares. This bug has been fixed, and listing local mounts now works as expected.
Story Points: ---
Clone Of:
Environment:
Last Closed: 2016-11-04 03:40:12 EDT
Type: Bug
Regression: ---
Mount Type: ---
Documentation: ---
CRM:
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---


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Description Dmitry Zhukovski 2016-02-17 05:27:32 EST
Description of problem:
df -l hangs on nfs share when autofs is involved

Version-Release number of selected component (if applicable):
coreutils-8.22-15.el7.x86_64

How reproducible:
Everytime


Steps to Reproduce:
1. define any export on rhel7 server
# cat /etc/exports
/var/export	*(rw,no_root_squash)

2. Configure /net automount entry
# cat /etc/auto.master
/net	-hosts

3. check that you can browse nfs share 
# ls -l /net/rhel7-1/var/export/
total 0
-rw-r--r--. 1 root root 0 Feb 16 09:03 1

4. stop nfs on server 
# systemctl stop nfs-server

5. run df -l <- local filesystems

Actual results:
df hangs

Expected results:
df shows local file systems

Additional info:
if nfs share mounted directly then df -l filters it out and does not hang.
Comment 2 Kamil Dudka 2016-02-17 06:34:40 EST
It hangs on a stat() call in filter_mount_list().  The autofs file system is not recognized as a remote file system (for which the stat() call is avoided) because there is no ':' in the mounted file (as in the case of NFS mounts).  This behavior does not anyhow differ from the latest upstream version of df.
Comment 6 Kamil Dudka 2016-02-19 04:44:21 EST
Fix proposed to gnulib upstream:

http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/35708
Comment 7 Kamil Dudka 2016-02-20 03:17:40 EST
upstream commit:

http://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commitdiff;h=781788ee
Comment 10 Frank Sorenson 2016-05-12 16:43:00 EDT
Note that this bz will also result in all exported filesystems from a particular nfs server becoming mounted, and can cause problems even if the nfs server is still running (such as when the nfs server is remote and has a large number of exports).
Comment 24 errata-xmlrpc 2016-11-04 03:40:12 EDT
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-2497.html

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