Commit 92000266 authored by Ian Kent's avatar Ian Kent Committed by Linus Torvalds

autofs: update autofs.txt for strictexpire mount option

A "strictexpire" mount option has been added to the autofs file system.

It is meant to be used in cases where a GUI continually accesses or an
application frquently scans an automount directory tree causing an
accumulation of otherwise unused mounts.

Link: http://lkml.kernel.org/r/155287083000.12593.2722713092537666885.stgit@pluto.themaw.netSigned-off-by: default avatarIan Kent <raven@themaw.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2ad56add
...@@ -240,11 +240,18 @@ Normally the daemon only wants to remove entries which haven't been ...@@ -240,11 +240,18 @@ Normally the daemon only wants to remove entries which haven't been
used for a while. For this purpose autofs maintains a "`last_used`" used for a while. For this purpose autofs maintains a "`last_used`"
time stamp on each directory or symlink. For symlinks it genuinely time stamp on each directory or symlink. For symlinks it genuinely
does record the last time the symlink was "used" or followed to find does record the last time the symlink was "used" or followed to find
out where it points to. For directories the field is a slight out where it points to. For directories the field is used slightly
misnomer. It actually records the last time that autofs checked if differently. The field is updated at mount time and during expire
the directory or one of its descendants was busy and found that it checks if it is found to be in use (ie. open file descriptor or
was. This is just as useful and doesn't require updating the field so process working directory) and during path walks. The update done
often. during path walks prevents frequent expire and immediate mount of
frequently accessed automounts. But in the case where a GUI continually
access or an application frequently scans an autofs directory tree
there can be an accumulation of mounts that aren't actually being
used. To cater for this case the "`strictexpire`" autofs mount option
can be used to avoid the "`last_used`" update on path walk thereby
preventing this apparent inability to expire mounts that aren't
really in use.
The daemon is able to ask autofs if anything is due to be expired, The daemon is able to ask autofs if anything is due to be expired,
using an `ioctl` as discussed later. For a *direct* mount, autofs using an `ioctl` as discussed later. For a *direct* mount, autofs
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment