diff options
| author | Robin H. Johnson <robbat2@gentoo.org> | 2011-01-18 01:26:34 +0000 |
|---|---|---|
| committer | Robin H. Johnson <robbat2@gentoo.org> | 2011-01-18 01:29:09 +0000 |
| commit | 80853f5dbc3a42419ac359ee035ebc76de86d3b3 (patch) | |
| tree | d99200248b7e427d3f1c85a5d9d0b639859afe80 /sh | |
| parent | 9ce957c3e722e3851a191b901bb377c13a1bbec1 (diff) | |
sh/init: Detect a mounted /proc without sleeping
Previously we checked if /proc was alive by reading /proc/uptime twice
with a 1 second sleep between calls, so that it had time to update.
This got a complaint of an entire 1 second delay, so we improve the
check to be much faster without sleep. We cannot continue to use
/proc/uptime as it only has a 10ms resolution.
X-Gentoo-Bug: 348416
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=348416
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Diffstat (limited to 'sh')
| -rw-r--r-- | sh/init.sh.Linux.in | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/sh/init.sh.Linux.in b/sh/init.sh.Linux.in index ad48585d..9b045570 100644 --- a/sh/init.sh.Linux.in +++ b/sh/init.sh.Linux.in @@ -65,19 +65,27 @@ mount_svcdir() # By default VServer already has /proc mounted, but OpenVZ does not! # However, some of our users have an old proc image in /proc # NFC how they managed that, but the end result means we have to test if -# /proc actually works or not. We to this by comparing uptime to one a second -# ago +# /proc actually works or not. We to this by comparing two reads of +# /proc/self/stat. They will not match, because at least the minor fault count +# field (field 10) should have changed. +# +# We can use any file here that fills the following requirements: +# - changes between sequential reads +# - is world-readable (not blocked in hardened kernel) +# - Is only a single line (ergo entire check is doable with no forks) mountproc=true -if [ -e /proc/uptime ]; then - up="$(cat /proc/uptime)" - sleep 1 - if [ "$up" = "$(cat /proc/uptime)" ]; then +f=/proc/self/stat +if [ -e $f ]; then + exec 9<$f ; read a <&9 ; exec 9<&- + exec 9<$f ; read b <&9 ; exec 9<&- + if [ "$a" = "$b" ]; then eerror "You have cruft in /proc that should be deleted" else einfo "/proc is already mounted, skipping" mountproc=false fi fi +unset a b f if $mountproc; then procfs="proc" |