V2: Replace retry logic in useradd with flock

From: Kai Kang <[email protected]>

V2:

* Use $SYSROOT/etc as flock file

The following changes since commit da13f0bce5d1b3c52f5716ae8d104372a820e5f9:

buildhistory.bbclass: remove out-dated information on request (2016-02-15 17:47:08 +0000)

are available in the git repository at:

git://git.pokylinux.org/poky-contrib kangkai/flock
http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=kangkai/flock

Kai Kang (1):
useradd_base.bbclass: fix simultaneous with flock

 meta/classes/useradd.bbclass      |   8 +-
 meta/classes/useradd_base.bbclass | 165 ++++++++++----------------------------
 2 files changed, 48 insertions(+), 125 deletions(-)

2.7.0

From: Kai Kang <[email protected]>

When perform useradd during populate sysroot, it locks files passwd.lock and group.lock at same time. And then it meets a dead lock issue randomly.

Use flock to reslove it by using an universal lock file for all the user and group related operations.

[YOCTO #9022]

---
 meta/classes/useradd.bbclass      |   8 +-
 meta/classes/useradd_base.bbclass | 165 ++++++++++----------------------------
 2 files changed, 48 insertions(+), 125 deletions(-)

index c960656..4503020 100644
@@ -38,6 +38,8 @@ if test "x$D" != "x"; then
 	export PSEUDO_PASSWD="$SYSROOT:${STAGING_DIR_NATIVE}"
 fi
 
+FLOCK_FILE=$SYSROOT/etc
+
 # If we're not doing a special SSTATE/SYSROOT install
 # then set the values, otherwise use the environment
 if test "x$UA_SYSROOT" = "x"; then

@@ -57,7 +59,7 @@ if test "x`echo $GROUPADD_PARAM | tr -d '[:space:]'`" != "x"; then
 	opts=`echo "$GROUPADD_PARAM" | cut -d ';' -f 1`
 	remaining=`echo "$GROUPADD_PARAM" | cut -d ';' -f 2-`
 	while test "x$opts" != "x"; do
-		perform_groupadd "$SYSROOT" "$OPT $opts" 10
+		perform_groupadd "$SYSROOT" "$OPT $opts"
 		if test "x$opts" = "x$remaining"; then
 			break
 		fi

@@ -73,7 +75,7 @@ if test "x`echo $USERADD_PARAM | tr -d '[:space:]'`" != "x"; then
 	opts=`echo "$USERADD_PARAM" | cut -d ';' -f 1`
 	remaining=`echo "$USERADD_PARAM" | cut -d ';' -f 2-`
 	while test "x$opts" != "x"; do
-		perform_useradd "$SYSROOT" "$OPT $opts" 10
+		perform_useradd "$SYSROOT" "$OPT $opts"
 		if test "x$opts" = "x$remaining"; then
 			break
 		fi

@@ -89,7 +91,7 @@ if test "x`echo $GROUPMEMS_PARAM | tr -d '[:space:]'`" != "x"; then
 	opts=`echo "$GROUPMEMS_PARAM" | cut -d ';' -f 1`
 	remaining=`echo "$GROUPMEMS_PARAM" | cut -d ';' -f 2-`
 	while test "x$opts" != "x"; do
-		perform_groupmems "$SYSROOT" "$OPT $opts" 10
+		perform_groupmems "$SYSROOT" "$OPT $opts"
 		if test "x$opts" = "x$remaining"; then
 			break
 		fi

2.7.0

useradd_base is also used by extrausers.bbclass, so it would be best if useradd_base decided where to use as a lock ($rootdir/${sysconfdir} sounds sensible) instead of expecting that the caller sets FLOCK_FILE and mysteriously failing if it wasn't set.

Also if we're locking and waiting properly instead of using timeouts and loops, can we remove the "does it exist?" check before the operation (eg groupadd -f will exit 0 if the group exists) and after (with proper locking that shouldn't be happening).

Ross

OK. Sounds good.

I prefer to keep such check. There is more than one case that causes operation error such as pass wrong parameters. The messages are helpful for developers.

Thanks,
Kai

Regards,
Neil | Kai Kang

In that case the groupadd will return an error code. What situations with proper locking will result in groupadd running successfully but the group not being added?

Ross

Sorry for late reply.

I think I understand your meanings. V3 will be sent.

--Kai

Regards,
Neil | Kai Kang