From c805a6ed281279ef0ccc4e6e084d52a725260e09 Mon Sep 17 00:00:00 2001 From: Scott Garman Date: Fri, 8 Oct 2010 14:40:47 -0700 Subject: poky-qemu-internal: implement file locking in bash There does not appear to be a universal lockfile utility that meets our needs. For example: * 'lockfile' is part of the procmail pacakge in Ubuntu, a requirement we don't want to impose on our users * lockfile-[create|remove] from the Ubuntu lockfile-progs package does not appear to be available in Fedora/openSUSE So, the most portable way to do this is just to implement it in bash. The likelihood of race conditions is minimal for what we need this for. Signed-off-by: Scott Garman --- scripts/poky-qemu-internal | 83 +++++++++++++++++++++++++++++----------------- 1 file changed, 53 insertions(+), 30 deletions(-) (limited to 'scripts') diff --git a/scripts/poky-qemu-internal b/scripts/poky-qemu-internal index 01c92ee980..834624dede 100755 --- a/scripts/poky-qemu-internal +++ b/scripts/poky-qemu-internal @@ -60,12 +60,39 @@ QEMUIFDOWN=`which poky-qemu-ifdown` NFSRUNNING="false" -LOCKUTIL=`which lockfile-create` -if [ -z "$LOCKUTIL" ]; then - echo "Error: Unable to find the lockfile-create utility" - echo "On Ubuntu systems this is included in the lockfile-progs package" - return -fi +acquire_lock() { + lockfile=$1 + if [ -z "$lockfile" ]; then + echo "Error: missing lockfile arg passed to acquire_lock()" + return 1 + fi + + if [ -e "$lockfile.lock" ]; then + # Check that the lockfile is not stale + ps=`ps -ewwo pid | grep $(cat $lockfile.lock)` + if [ -z "$ps" ]; then + echo "Warning: Stale lock file detected, deleting $lockfile.lock" + rm -f $lockfile.lock + echo $$ > $lockfile.lock + else + return 1 + fi + else + echo $$ > $lockfile.lock + fi + + return 0 +} + +release_lock() { + lockfile=$1 + if [ -z "$lockfile" ]; then + echo "Error: missing lockfile arg passed to release_lock()" + return 1 + fi + + rm -f $lockfile.lock +} LOCKDIR="/tmp/qemu-tap-locks" [ ! -d "$LOCKDIR" ] && mkdir $LOCKDIR @@ -76,10 +103,8 @@ LOCKFILE="" for tap in $POSSIBLE; do LOCKFILE="$LOCKDIR/$tap" echo "Acquiring lockfile for $tap..." - if lockfile-create --use-pid -r 1 $LOCKFILE; then - # the --use-pid option to lockfile-create will give use - # the subshell's pid, so override it with the shell's pid: - echo $$ > $LOCKFILE.lock + acquire_lock $LOCKFILE + if [ $? -eq 0 ]; then TAP=$tap break fi @@ -94,7 +119,7 @@ if [ "$TAP" = "" ]; then fi GROUPID=`id -g` - echo 'Setting up tap interface under sudo' + echo "Setting up tap interface under sudo" tap=`sudo $QEMUIFUP $GROUPID $POKY_NATIVE_SYSROOT` if [ $? -ne 0 ]; then # Re-run standalone to see verbose errors @@ -103,22 +128,20 @@ if [ "$TAP" = "" ]; then fi LOCKFILE="$LOCKDIR/$tap" echo "Acquiring lockfile for $tap..." - if lockfile-create --use-pid -r 1 $LOCKFILE; then - # the --use-pid option to lockfile-create will give us - # the subshell's pid, so override it with the shell's pid: - echo $$ > $LOCKFILE.lock + acquire_lock $LOCKFILE + if [ $? -eq 0 ]; then TAP=$tap fi else echo "Using preconfigured tap device '$TAP'" fi -release_lock() { +cleanup() { if [ ! -e "$NOSUDO_FLAG" ]; then sudo $QEMUIFDOWN $TAP $POKY_NATIVE_SYSROOT fi echo "Releasing lockfile of preconfigured tap device '$TAP'" - lockfile-remove $LOCKFILE + release_lock $LOCKFILE if [ "$NFSRUNNING" = "true" ]; then echo "Shutting down the userspace NFS server..." @@ -162,13 +185,13 @@ esac if [ ! -f "$KERNEL" ]; then echo "Error: Kernel image file $KERNEL doesn't exist" - release_lock + cleanup return fi if [ "$FSTYPE" != "nfs" -a ! -f "$ROOTFS" ]; then echo "Error: Image file $ROOTFS doesn't exist" - release_lock + cleanup return fi @@ -186,7 +209,7 @@ if [ "$FSTYPE" = "nfs" ]; then portmap_running=`ps ax | grep portmap | grep -v grep | wc -l` if [[ $rpcbind_running == 0 && $portmap_running == 0 ]]; then echo "You need to be running either rpcbind or portmap to continue" - release_lock + cleanup return fi @@ -194,7 +217,7 @@ if [ "$FSTYPE" = "nfs" ]; then echo "poky-export-rootfs restart $ROOTFS" poky-export-rootfs restart $ROOTFS if [ $? != 0 ]; then - release_lock + cleanup return fi NFSRUNNING="true" @@ -224,7 +247,7 @@ if [ "$MACHINE" = "qemuarm" -o "$MACHINE" = "qemuarmv6" -o "$MACHINE" = "qemuarm if [ "$FSTYPE" = "nfs" ]; then if [ "$NFS_SERVER" = "192.168.7.1" -a ! -d "$NFS_DIR" ]; then echo "Error: NFS mount point $ROOTFS doesn't exist" - release_lock + cleanup return fi KERNCMDLINE="root=/dev/nfs nfsroot=$NFS_SERVER:$NFS_DIR,$UNFS_OPTS rw $KERNEL_NETWORK_CMD mem=$QEMU_MEMORY" @@ -248,7 +271,7 @@ if [ "$MACHINE" = "qemux86" ]; then if [ "$FSTYPE" = "nfs" ]; then if [ "$NFS_SERVER" = "192.168.7.1" -a ! -d "$NFS_DIR" ]; then echo "Error: NFS mount point $ROOTFS doesn't exist." - release_lock + cleanup return fi KERNCMDLINE="root=/dev/nfs nfsroot=$NFS_SERVER:$NFS_DIR,$UNFS_OPTS rw $KERNEL_NETWORK_CMD mem=$QEMU_MEMORY" @@ -269,7 +292,7 @@ if [ "$MACHINE" = "qemux86-64" ]; then fi if [ ! -d "$ROOTFS" ]; then echo "Error: NFS mount point $ROOTFS doesn't exist." - release_lock + cleanup return fi KERNCMDLINE="root=/dev/nfs nfsroot=$NFS_SERVER:$NFS_DIR,$UNFS_OPTS rw $KERNEL_NETWORK_CMD mem=$QEMU_MEMORY" @@ -303,7 +326,7 @@ if [ "$MACHINE" = "qemumips" ]; then if [ "$FSTYPE" = "nfs" ]; then if [ "$NFS_SERVER" = "192.168.7.1" -a ! -d "$NFS_DIR" ]; then echo "Error: NFS mount point $ROOTFS doesn't exist" - release_lock + cleanup return fi KERNCMDLINE="root=/dev/nfs console=ttyS0 console=tty nfsroot=$NFS_SERVER:$NFS_DIR,$UNFS_OPTS rw $KERNEL_NETWORK_CMD mem=$QEMU_MEMORY" @@ -324,7 +347,7 @@ if [ "$MACHINE" = "qemuppc" ]; then if [ "$FSTYPE" = "nfs" ]; then if [ "$NFS_SERVER" = "192.168.7.1" -a ! -d "$NFS_DIR" ]; then echo "Error: NFS mount point $ROOTFS doesn't exist" - release_lock + cleanup return fi KERNCMDLINE="root=/dev/nfs console=ttyS0 console=tty0 nfsroot=$NFS_SERVER:$NFS_DIR,$UNFS_OPTS rw $KERNEL_NETWORK_CMD mem=$QEMU_MEMORY" @@ -346,7 +369,7 @@ fi if [ "x$QEMUOPTIONS" = "x" ]; then echo "Error: Unable to support this combination of options" - release_lock + cleanup return fi @@ -369,7 +392,7 @@ QEMUBIN=`which $QEMU` if [ ! -x "$QEMUBIN" ]; then echo "Error: No QEMU binary '$QEMU' could be found." - release_lock + cleanup return fi @@ -378,7 +401,7 @@ function _quit() { #echo kill `cat $PIDFILE` kill `cat $PIDFILE` fi - release_lock + cleanup return } @@ -399,7 +422,7 @@ echo "Running $QEMU..." echo $QEMUBIN -kernel $KERNEL $QEMUOPTIONS $SERIALOPTS $SCRIPT_QEMU_CMDLINE_OPT --append '"'$KERNCMDLINE $SCRIPT_KERNEL_OPT'"' $QEMUBIN -kernel $KERNEL $QEMUOPTIONS $SERIALOPTS $SCRIPT_QEMU_OPT --append "$KERNCMDLINE $SCRIPT_KERNEL_OPT" || /bin/true -release_lock +cleanup trap - INT TERM QUIT return -- cgit v1.2.3-54-g00ecf