From 18594a87ba4095e60ec2838610f82b31b73632fd Mon Sep 17 00:00:00 2001
From: Taylor Hutt <thutt@chromium.org>
Date: Thu, 28 Jul 2011 11:45:50 -0700
Subject: [PATCH] chromium-os:17680 : Establish Syncer PID file invariants

Details

  This change updates the use of '-s' to have the proper polarity to
  see if the syncer PID file is zero bytes in size.

  As a bit of other cleanup, if a file of size zero is found, it's
  removed.  This allows the second size test of the syncer PID file to
  be removed.

Testing

  o Created zero-length PID file: saw warning message on console.  Saw
    that the file contains a valid pin while the chroot is entered,
    and verified the PID file is deleted after exiting chroot.

       INFO    : You may have suffered from chromium-os:17680 and
       INFO    : could have stray 'enter_chroot.sh' processes running.
       INFO    : Erroneous PID file will be cleaned up.

  o Entered chroot with multiple terminals, saw that the PID file is
    removed & the syncer process is killed when the last client exits
    the chroot.

  o Executed './enter_chroot.sh --verbose', changed ownership of PID file to
    'root'.

    Exited and did not see the following diagnostic message:

       INFO    : Unable to clean up syncer process.

    The message should not be printed because the file is removed
    under 'sudo'.

BUG=chromium-os:17680
TEST=See above.
Signed-off-by: Taylor Hutt <thutt@chromium.org>

Change-Id: I055fe72b9322acee8c774401b3452ef502b30970
Reviewed-on: http://gerrit.chromium.org/gerrit/4936
Tested-by: Taylor Hutt <thutt@chromium.org>
Reviewed-by: David James <davidjames@chromium.org>
---
 enter_chroot.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/enter_chroot.sh b/enter_chroot.sh
index 14ef354004..1f2039749f 100755
--- a/enter_chroot.sh
+++ b/enter_chroot.sh
@@ -217,15 +217,15 @@ function setup_env {
     #           restart.
     #
     # The daemon is killed by the enter_chroot that exits last.
-    if [ -f "${SYNCERPIDFILE}" ] && [ -s "${SYNCERPIDFILE}" ] ; then
+    if [ -f "${SYNCERPIDFILE}" ] && [ ! -s "${SYNCERPIDFILE}" ] ; then
         info "You may have suffered from chromium-os:17680 and";
         info "could have stray 'enter_chroot.sh' processes running.";
         info "You must manually kill any such stray processes.";
         info "Exit all chroot shells; remaining 'enter_chroot.sh'";
         info "processes are probably stray.";
+        sudo rm -f "${SYNCERPIDFILE}";
     fi;
     if ! [ -f "${SYNCERPIDFILE}" ] || \
-         [ -s "${SYNCERPIDFILE}" ] || \
        ! [ -d /proc/$(cat "${SYNCERPIDFILE}") ]; then
       debug "Starting sync process"
       env_sync_proc &
@@ -387,7 +387,7 @@ function teardown_env {
       # starting the syncer process when this occurs by deleting the
       # PID file.
       kill $(cat "${SYNCERPIDFILE}") && \
-          rm -f "${SYNCERPIDFILE}"   || \
+          sudo rm -f "${SYNCERPIDFILE}" || \
           debug "Unable to clean up syncer process.";
 
       MOUNTED_PATH=$(readlink -f "$FLAGS_chroot")