Bug 487653 - Using a large number of direct mounts causes autofs to hang
Summary: Using a large number of direct mounts causes autofs to hang
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: autofs
Version: 5.3
Hardware: All
OS: Linux
low
medium
Target Milestone: rc
: ---
Assignee: Ian Kent
QA Contact: BaseOS QE
URL:
Whiteboard:
Depends On:
Blocks: 527377
TreeView+ depends on / blocked
 
Reported: 2009-02-27 09:51 UTC by Ian Kent
Modified: 2010-03-14 21:32 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Previously, autofs used the select() function to process direct-mount maps and was therefore limited by the file descriptor limit (by default, 1024). As a consequence, autofs was not able to use direct-mount maps with numbers of entries larger than the limit, and would stop responding when it used up all available file descriptors. Now, autofs uses poll() instead of select() and is therefore no longer limited by the available file descriptors. Freed of this limitation, autofs can use large direct-mount maps.
Clone Of:
: 527377 (view as bug list)
Environment:
Last Closed: 2009-09-02 11:59:39 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2009:1397 0 normal SHIPPED_LIVE autofs bug fix update 2009-09-01 12:02:15 UTC

Description Ian Kent 2009-02-27 09:51:05 UTC
Description of problem:
Using a large number of direct mounts causes autofs to hang.

How reproducible:
always

Steps to Reproduce:
1. Create a large direct mount map with:
#!/bin/bash
DIRECT_MAP="auto.direct.many"
DIR="/usr/local/tmp"
rm -f $DIRECT_MAP
mkdir -p $DIR
for i in `seq 1 2025`; do
	if [ ! -d ${DIR}/mnt${i} ]; then
		mkdir ${DIR}/mnt${i}
	fi
	echo "/test/mnt${i} :${DIR}/mnt${i}" >> $DIRECT_MAP
done

2. Configure autofs to use this map and start autofs.
3. Run find /test -maxdepth 2
  
Actual results:
autofs hangs at just less than 1024 mounts.

Expected results:
All 2024 mounts should succeed.

Comment 2 Ian Kent 2009-05-21 02:52:06 UTC
This issue has been fixed in the latest autofs package
autofs-5.0.1-0.rc2.125.

The autofs RHTS test bubzillas/bz487653 can be used to verify
the correction.

Comment 6 Ruediger Landmann 2009-08-31 22:49:08 UTC
Release note added. If any revisions are required, please set the 
"requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly.
All revisions will be proofread by the Engineering Content Services team.

New Contents:
Previously, autofs used the select() function to process direct-mount maps and was therefore limited by the file descriptor limit (by default, 1024). As a consequence, autofs was not able to use direct-mount maps with numbers of entries larger than the limit, and would stop responding when it used up all available file descriptors. Now, autofs uses poll() instead of select() and is therefore no longer limited by the available file descriptors. Freed of this limitation, autofs can use large direct-mount maps.

Comment 7 errata-xmlrpc 2009-09-02 11:59:39 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2009-1397.html


Note You need to log in before you can comment on or make changes to this bug.