Commit 96610da2 authored by Tomoki Sekiyama's avatar Tomoki Sekiyama Committed by Michael Roth
Browse files

qemu-ga: sample fsfreeze hooks 



Adds sample hook scripts for --fsfreeze-hook option of qemu-ga.
  - fsfreeze-hook : execute scripts in fsfreeze-hook.d/
  - fsfreeze-hook.d/mysql-flush.sh.sample : quiesce MySQL before snapshot

Signed-off-by: default avatarTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Reviewed-by: default avatarMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Roth <mdroth@linux.vnet.ibm.com>
parent ec0f694c

.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ fsdev/virtfs-proxy-helper.pod 
*.tp

*.vr

*.d

!scripts/qemu-guest-agent/fsfreeze-hook.d

*.o

*.lo

*.la

Makefile

+1 −1
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@@ -232,7 +232,7 @@ clean: 
# avoid old build problems by removing potentially incorrect old files

	rm -f config.mak op-i386.h opc-i386.h gen-op-i386.h op-arm.h opc-arm.h gen-op-arm.h

	rm -f qemu-options.def

	find . -name '*.[od]' -exec rm -f {} +

	find . -name '*.[od]' -type f -exec rm -f {} +

	rm -f *.a *.lo $(TOOLS) $(HELPERS-y) qemu-ga TAGS cscope.* *.pod *~ */*~

	rm -Rf .libs

	rm -f qemu-img-cmds.h

scripts/qemu-guest-agent/fsfreeze-hook

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#!/bin/sh



# This script is executed when a guest agent receives fsfreeze-freeze and

# fsfreeze-thaw command, if it is specified in --fsfreeze-hook (-F)

# option of qemu-ga or placed in default path (/etc/qemu/fsfreeze-hook).

# When the agent receives fsfreeze-freeze request, this script is issued with

# "freeze" argument before the filesystem is frozen. And for fsfreeze-thaw

# request, it is issued with "thaw" argument after filesystem is thawed.



LOGFILE=/var/log/qga-fsfreeze-hook.log

FSFREEZE_D=$(dirname -- "$0")/fsfreeze-hook.d



# Check whether file $1 is a backup or rpm-generated file and should be ignored

is_ignored_file() {

    case "$1" in

        *~ | *.bak | *.orig | *.rpmnew | *.rpmorig | *.rpmsave | *.sample)

            return 0 ;;

    esac

    return 1

}



# Iterate executables in directory "fsfreeze-hook.d" with the specified args

[ ! -d "$FSFREEZE_D" ] && exit 0

for file in "$FSFREEZE_D"/* ; do

    is_ignored_file "$file" && continue

    [ -x "$file" ] || continue

    printf "$(date): execute $file $@\n" >>$LOGFILE

    "$file" "$@" >>$LOGFILE 2>&1

    STATUS=$?

    printf "$(date): $file finished with status=$STATUS\n" >>$LOGFILE

done



exit 0

scripts/qemu-guest-agent/fsfreeze-hook.d/mysql-flush.sh.sample

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#!/bin/sh



# Flush MySQL tables to the disk before the filesystem is frozen.

# At the same time, this keeps a read lock in order to avoid write accesses

# from the other clients until the filesystem is thawed.



MYSQL="/usr/bin/mysql"

MYSQL_OPTS="-uroot" #"-prootpassword"

FIFO=/var/run/mysql-flush.fifo



# Check mysql is installed and the server running

[ -x "$MYSQL" ] && "$MYSQL" $MYSQL_OPTS < /dev/null || exit 0



flush_and_wait() {

    printf "FLUSH TABLES WITH READ LOCK \\G\n"

    trap 'printf "$(date): $0 is killed\n">&2' HUP INT QUIT ALRM TERM

    read < $FIFO

    printf "UNLOCK TABLES \\G\n"

    rm -f $FIFO

}



case "$1" in

    freeze)

        mkfifo $FIFO || exit 1

        flush_and_wait | "$MYSQL" $MYSQL_OPTS &

        # wait until every block is flushed

        while [ "$(echo 'SHOW STATUS LIKE "Key_blocks_not_flushed"' |\

                 "$MYSQL" $MYSQL_OPTS | tail -1 | cut -f 2)" -gt 0 ]; do

            sleep 1

        done

        # for InnoDB, wait until every log is flushed

        INNODB_STATUS=$(mktemp /tmp/mysql-flush.XXXXXX)

        [ $? -ne 0 ] && exit 2

        trap "rm -f $INNODB_STATUS; exit 1" HUP INT QUIT ALRM TERM

        while :; do

            printf "SHOW ENGINE INNODB STATUS \\G" |\

                "$MYSQL" $MYSQL_OPTS > $INNODB_STATUS

            LOG_CURRENT=$(grep 'Log sequence number' $INNODB_STATUS |\

                          tr -s ' ' | cut -d' ' -f4)

            LOG_FLUSHED=$(grep 'Log flushed up to' $INNODB_STATUS |\

                          tr -s ' ' | cut -d' ' -f5)

            [ "$LOG_CURRENT" = "$LOG_FLUSHED" ] && break

            sleep 1

        done

        rm -f $INNODB_STATUS

        ;;



    thaw)

        [ ! -p $FIFO ] && exit 1

        echo > $FIFO

        ;;



    *)

        exit 1

        ;;

esac