Red Hat Bugzilla – Bug 173194
race condition when expiring ghosted autofs mounts
Last modified: 2007-11-30 17:07:21 EST
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Description of problem:
For browsable autofs maps, a mount request that arrives at the same time
an expire is happening can fail to perform the needed mount.
This happens becuase the directory exists and so the revalidate succeeds
when we need it to fail so that lookup is called on the same dentry to do
the mount. Instead lookup is called on the next path component which
should be whithin the mount, but the parent isn't mounted.
The solution is to allow the revalidate to continue and perform the mount
as no directory creation (at mount time) is needed for browsable mount
Version-Release number of selected component (if applicable):
Steps to Reproduce:
I put together the following reproducer for this:
/multi /etc/auto.multi --timeout=4 --ghost
and auto.multi contains
dir / segfault:/export/multi \
Then, I simply run the following script:
cat /segfault/multi/foo/bar > /dev/null
if [ $? -ne 0 ]; then
Once we get a mount request at the same time as a pending expiry, we will
trigger this bug. In my testing, this typically occurs withing the first 3
iterations of the loop.
committed in -22.25
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 the 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.