* [Qemu-devel] [PATCH v2 0/2] qemu-ga: add hook to quiesce the guest on fsfreeze-freeze/thaw
@ 2012-11-12 9:32 Tomoki Sekiyama
2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 1/2] qemu-ga: execute " Tomoki Sekiyama
2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks Tomoki Sekiyama
0 siblings, 2 replies; 5+ messages in thread
From: Tomoki Sekiyama @ 2012-11-12 9:32 UTC (permalink / raw)
To: qemu-devel; +Cc: mdroth
Hi,
This is version 2 of the qemu-ga fsfreeze hook patchset.
*Changes from v1: ( http://lists.gnu.org/archive/html/qemu-devel/2012-11/msg00685.html )
- Fixed bugs in handling file path which contains spaces.
- Improved error checkings.
- Changed the default hook name to fsfreeze-hook.
This also fixes errors in `make clean'.
---
Tomoki Sekiyama (2):
qemu-ga: execute hook to quiesce the guest on fsfreeze-freeze/thaw
qemu-ga: sample fsfreeze hooks
docs/qemu-guest-agent/fsfreeze-hook | 31 +++++++++++++
.../fsfreeze-hook.d.sample/mysql-flush.sh | 47 ++++++++++++++++++++
qemu-ga.c | 42 +++++++++++++++++-
qga/commands-posix.c | 44 +++++++++++++++++++
qga/guest-agent-core.h | 1
5 files changed, 164 insertions(+), 1 deletion(-)
create mode 100755 docs/qemu-guest-agent/fsfreeze-hook
create mode 100755 docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh
Thanks,
--
Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH v2 1/2] qemu-ga: execute hook to quiesce the guest on fsfreeze-freeze/thaw 2012-11-12 9:32 [Qemu-devel] [PATCH v2 0/2] qemu-ga: add hook to quiesce the guest on fsfreeze-freeze/thaw Tomoki Sekiyama @ 2012-11-12 9:32 ` Tomoki Sekiyama 2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks Tomoki Sekiyama 1 sibling, 0 replies; 5+ messages in thread From: Tomoki Sekiyama @ 2012-11-12 9:32 UTC (permalink / raw) To: qemu-devel; +Cc: mdroth To use the online disk snapshot for online-backup, application-level consistency of the snapshot image is required. However, currently the guest agent can provide only filesystem-level consistency, and the snapshot may contain dirty data, for example, incomplete transactions. This patch provides the opportunity to quiesce applications before snapshot is taken. When the qemu-ga receives fsfreeze-freeze command, the hook script specified in --fsfreeze-hook option is executed with "freeze" argument before the filesystem is frozen. For fsfreeze-thaw command, the hook script is executed with "thaw" argument after the filesystem is thawed. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> --- qemu-ga.c | 42 +++++++++++++++++++++++++++++++++++++++++- qga/commands-posix.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ qga/guest-agent-core.h | 1 + 3 files changed, 86 insertions(+), 1 deletion(-) diff --git a/qemu-ga.c b/qemu-ga.c index 9b59a52..d1d9b89 100644 --- a/qemu-ga.c +++ b/qemu-ga.c @@ -34,6 +34,12 @@ #include "qga/service-win32.h" #include <windows.h> #endif +#ifdef __linux__ +#include <linux/fs.h> +#ifdef FIFREEZE +#define CONFIG_FSFREEZE +#endif +#endif #ifndef _WIN32 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0" @@ -42,6 +48,9 @@ #endif #define QGA_STATEDIR_DEFAULT CONFIG_QEMU_LOCALSTATEDIR "/run" #define QGA_PIDFILE_DEFAULT QGA_STATEDIR_DEFAULT "/qemu-ga.pid" +#ifdef CONFIG_FSFREEZE +#define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook" +#endif #define QGA_SENTINEL_BYTE 0xFF struct GAState { @@ -64,6 +73,9 @@ struct GAState { const char *log_filepath; const char *pid_filepath; } deferred_options; +#ifdef CONFIG_FSFREEZE + const char *fsfreeze_hook; +#endif }; struct GAState *ga_state; @@ -153,6 +165,10 @@ static void usage(const char *cmd) " %s)\n" " -l, --logfile set logfile path, logs to stderr by default\n" " -f, --pidfile specify pidfile (default is %s)\n" +#ifdef CONFIG_FSFREEZE +" -F, --fsfreeze_hook\n" +" specify fsfreeze hook (default is %s)\n" +#endif " -t, --statedir specify dir to store state information (absolute paths\n" " only, default is %s)\n" " -v, --verbose log extra debugging information\n" @@ -167,6 +183,9 @@ static void usage(const char *cmd) "\n" "Report bugs to <mdroth@linux.vnet.ibm.com>\n" , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT, +#ifdef CONFIG_FSFREEZE + QGA_FSFREEZE_HOOK_DEFAULT, +#endif QGA_STATEDIR_DEFAULT); } @@ -401,6 +420,13 @@ void ga_unset_frozen(GAState *s) } } +#ifdef CONFIG_FSFREEZE +const char *ga_fsfreeze_hook(GAState *s) +{ + return s->fsfreeze_hook; +} +#endif + static void become_daemon(const char *pidfile) { #ifndef _WIN32 @@ -678,10 +704,13 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]) int main(int argc, char **argv) { - const char *sopt = "hVvdm:p:l:f:b:s:t:"; + const char *sopt = "hVvdm:p:l:f:F:b:s:t:"; const char *method = NULL, *path = NULL; const char *log_filepath = NULL; const char *pid_filepath = QGA_PIDFILE_DEFAULT; +#ifdef CONFIG_FSFREEZE + const char *fsfreeze_hook = QGA_FSFREEZE_HOOK_DEFAULT; +#endif const char *state_dir = QGA_STATEDIR_DEFAULT; #ifdef _WIN32 const char *service = NULL; @@ -691,6 +720,9 @@ int main(int argc, char **argv) { "version", 0, NULL, 'V' }, { "logfile", 1, NULL, 'l' }, { "pidfile", 1, NULL, 'f' }, +#ifdef CONFIG_FSFREEZE + { "fsfreeze-hook", 1, NULL, 'F' }, +#endif { "verbose", 0, NULL, 'v' }, { "method", 1, NULL, 'm' }, { "path", 1, NULL, 'p' }, @@ -723,6 +755,11 @@ int main(int argc, char **argv) case 'f': pid_filepath = optarg; break; +#ifdef CONFIG_FSFREEZE + case 'F': + fsfreeze_hook = optarg; + break; +#endif case 't': state_dir = optarg; break; @@ -786,6 +823,9 @@ int main(int argc, char **argv) s = g_malloc0(sizeof(GAState)); s->log_level = log_level; s->log_file = stderr; +#ifdef CONFIG_FSFREEZE + s->fsfreeze_hook = fsfreeze_hook; +#endif g_log_set_default_handler(ga_log, s); g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR); ga_enable_logging(s); diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 726930a..8c3e341 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -396,6 +396,45 @@ GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err) return GUEST_FSFREEZE_STATUS_THAWED; } +static void execute_fsfreeze_hook(const char *arg) +{ + int status; + pid_t pid, rpid; + const char *hook; + + hook = ga_fsfreeze_hook(ga_state); + if (!hook || access(hook, X_OK) != 0) { + return; + } + + slog("executing fsfreeze hook with arg `%s'", arg); + pid = fork(); + if (pid == 0) { + setsid(); + reopen_fd_to_null(0); + reopen_fd_to_null(1); + reopen_fd_to_null(2); + + execle(hook, hook, arg, NULL, environ); + _exit(EXIT_FAILURE); + } else if (pid < 0) { + slog("execution of fsfreeze hook failed: %s", strerror(errno)); + return; + } + + do { + rpid = waitpid(pid, &status, 0); + } while (rpid == -1 && errno == EINTR); + if (rpid == pid && WIFEXITED(status)) { + int st = WEXITSTATUS(status); + if (st) { + slog("fsfreeze hook failed with status %d", st); + } + } else if (rpid == pid && WIFSIGNALED(status)) { + slog("fsfreeze hook killed by signal %d", WTERMSIG(status)); + } +} + /* * Walk list of mounted file systems in the guest, and freeze the ones which * are real local file systems. @@ -410,6 +449,8 @@ int64_t qmp_guest_fsfreeze_freeze(Error **err) slog("guest-fsfreeze called"); + execute_fsfreeze_hook("freeze"); + QTAILQ_INIT(&mounts); ret = build_fs_mount_list(&mounts); if (ret < 0) { @@ -513,6 +554,9 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err) ga_unset_frozen(ga_state); free_fs_mount_list(&mounts); + + execute_fsfreeze_hook("thaw"); + return i; } diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h index 49a7abe..c6e8de0 100644 --- a/qga/guest-agent-core.h +++ b/qga/guest-agent-core.h @@ -34,6 +34,7 @@ void ga_set_response_delimited(GAState *s); bool ga_is_frozen(GAState *s); void ga_set_frozen(GAState *s); void ga_unset_frozen(GAState *s); +const char *ga_fsfreeze_hook(GAState *s); #ifndef _WIN32 void reopen_fd_to_null(int fd); ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks 2012-11-12 9:32 [Qemu-devel] [PATCH v2 0/2] qemu-ga: add hook to quiesce the guest on fsfreeze-freeze/thaw Tomoki Sekiyama 2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 1/2] qemu-ga: execute " Tomoki Sekiyama @ 2012-11-12 9:32 ` Tomoki Sekiyama 2012-11-12 22:16 ` Eric Blake 1 sibling, 1 reply; 5+ messages in thread From: Tomoki Sekiyama @ 2012-11-12 9:32 UTC (permalink / raw) To: qemu-devel; +Cc: mdroth Adds sample hook scripts for --fsfreeze-hook option of qemu-ga. - fsfreeze-hook : execute scripts in fsfreeze-hook.d/ - fsfreeze-hook.d.sample/mysql-flush.sh : quiesce MySQL before snapshot Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> --- docs/qemu-guest-agent/fsfreeze-hook | 31 +++++++++++++ .../fsfreeze-hook.d.sample/mysql-flush.sh | 47 ++++++++++++++++++++ 2 files changed, 78 insertions(+) create mode 100755 docs/qemu-guest-agent/fsfreeze-hook create mode 100755 docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh diff --git a/docs/qemu-guest-agent/fsfreeze-hook b/docs/qemu-guest-agent/fsfreeze-hook new file mode 100755 index 0000000..efc9bf2 --- /dev/null +++ b/docs/qemu-guest-agent/fsfreeze-hook @@ -0,0 +1,31 @@ +#!/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 freezed. And for fsfreeze-thaw +# request, it is issued with "thaw" argument after filesystem is thawed. + +LOGFILE=/var/log/qga-fsreeze-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 "$1" in + *~ | *.bak | *.orig | *.rpmnew | *.rpmorig | *.rpmsave) + return 0 ;; + esac + return 1 +} + +# Iterate executables in directory "fsfreeze-hook.d" with the specified args +[ ! -d "$FSFREEZE_D" ] && exit 1 +for file in "$FSFREEZE_D"/* ; do + is_ignored_file "$file" && continue + [ -x "$file" ] || continue + echo $(date) ": execute $file $@" >>$LOGFILE + "$file" "$@" >>$LOGFILE 2>&1 + STATUS=$? + echo $(date) ": $file finished with status=$STATUS" >>$LOGFILE +done diff --git a/docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh b/docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh new file mode 100755 index 0000000..705002e --- /dev/null +++ b/docs/qemu-guest-agent/fsfreeze-hook.d.sample/mysql-flush.sh @@ -0,0 +1,47 @@ +#!/bin/sh + +# Flush MySQL tables to the disk before the filesystem is freezed. +# At the same time, this keeps a read lock while the filesystem is freezed +# in order to avoid write accesses by the other clients. + +MYSQL="mysql -uroot" #"-prootpassword" +FIFO=/tmp/mysql-flush.fifo + +flush_and_wait() { + echo 'FLUSH TABLES WITH READ LOCK \G' + read < $FIFO + echo 'UNLOCK TABLES \G' +} + +case "$1" in + freeze) + mkfifo $FIFO || exit 1 + flush_and_wait | $MYSQL & + # wait until every block is flushed + while [ "$(echo 'SHOW STATUS LIKE "Key_blocks_not_flushed"' |\ + $MYSQL | tail -1 | cut -f 2)" -gt 0 ]; do + sleep 1 + done + # for InnoDB, wait until every log is flushed + INNODB_STATUS=$(mktemp /tmp/mysql-flush.XXXXXX) + [ $? -ne 0 ] && exit 2 + trap "rm -f $INNODB_STATUS" SIGINT + while :; do + echo 'SHOW ENGINE INNODB STATUS \G' | $MYSQL > $INNODB_STATUS + LOG_CURRENT=$(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 + rm $FIFO + ;; +esac + ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks 2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks Tomoki Sekiyama @ 2012-11-12 22:16 ` Eric Blake 2012-11-13 4:49 ` Tomoki Sekiyama 0 siblings, 1 reply; 5+ messages in thread From: Eric Blake @ 2012-11-12 22:16 UTC (permalink / raw) To: Tomoki Sekiyama; +Cc: qemu-devel, mdroth [-- Attachment #1: Type: text/plain, Size: 1434 bytes --] On 11/12/2012 02:32 AM, Tomoki Sekiyama wrote: > Adds sample hook scripts for --fsfreeze-hook option of qemu-ga. > - fsfreeze-hook : execute scripts in fsfreeze-hook.d/ > - fsfreeze-hook.d.sample/mysql-flush.sh : quiesce MySQL before snapshot > > Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> > --- > +LOGFILE=/var/log/qga-fsreeze-hook.log s/fsreeze/fsfreeze/ > +# Iterate executables in directory "fsfreeze-hook.d" with the specified args > +[ ! -d "$FSFREEZE_D" ] && exit 1 > +for file in "$FSFREEZE_D"/* ; do > + is_ignored_file "$file" && continue > + [ -x "$file" ] || continue > + echo $(date) ": execute $file $@" >>$LOGFILE Put $(date) inside the ""; otherwise, single-digit days will be one character shorter due to IFS field splitting eating the double-space; and I don't like unaligned dates in logs. > + "$file" "$@" >>$LOGFILE 2>&1 > + STATUS=$? > + echo $(date) ": $file finished with status=$STATUS" >>$LOGFILE and again. > + INNODB_STATUS=$(mktemp /tmp/mysql-flush.XXXXXX) > + [ $? -ne 0 ] && exit 2 > + trap "rm -f $INNODB_STATUS" SIGINT > + while :; do > + echo 'SHOW ENGINE INNODB STATUS \G' | $MYSQL > $INNODB_STATUS 'echo' cannot portably be used with \. Use 'printf' instead. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 617 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks 2012-11-12 22:16 ` Eric Blake @ 2012-11-13 4:49 ` Tomoki Sekiyama 0 siblings, 0 replies; 5+ messages in thread From: Tomoki Sekiyama @ 2012-11-13 4:49 UTC (permalink / raw) To: eblake; +Cc: qemu-devel, mdroth Hi Eric, thank you for the review again. On 2012/11/13 7:16, Eric Blake wrote: > On 11/12/2012 02:32 AM, Tomoki Sekiyama wrote: >> Adds sample hook scripts for --fsfreeze-hook option of qemu-ga. >> - fsfreeze-hook : execute scripts in fsfreeze-hook.d/ >> - fsfreeze-hook.d.sample/mysql-flush.sh : quiesce MySQL before snapshot >> >> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> >> --- > >> +LOGFILE=/var/log/qga-fsreeze-hook.log > > s/fsreeze/fsfreeze/ Oops... >> +# Iterate executables in directory "fsfreeze-hook.d" with the specified args >> +[ ! -d "$FSFREEZE_D" ] && exit 1 >> +for file in "$FSFREEZE_D"/* ; do >> + is_ignored_file "$file" && continue >> + [ -x "$file" ] || continue >> + echo $(date) ": execute $file $@" >>$LOGFILE > > Put $(date) inside the ""; otherwise, single-digit days will be one > character shorter due to IFS field splitting eating the double-space; > and I don't like unaligned dates in logs. > >> + "$file" "$@" >>$LOGFILE 2>&1 >> + STATUS=$? >> + echo $(date) ": $file finished with status=$STATUS" >>$LOGFILE > > and again. I will fix this. >> + INNODB_STATUS=$(mktemp /tmp/mysql-flush.XXXXXX) >> + [ $? -ne 0 ] && exit 2 >> + trap "rm -f $INNODB_STATUS" SIGINT >> + while :; do >> + echo 'SHOW ENGINE INNODB STATUS \G' | $MYSQL > $INNODB_STATUS > > 'echo' cannot portably be used with \. Use 'printf' instead. OK, I replace this with 'printf' (also in 'flush_and_wait' function). -- Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2012-11-13 4:49 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-11-12 9:32 [Qemu-devel] [PATCH v2 0/2] qemu-ga: add hook to quiesce the guest on fsfreeze-freeze/thaw Tomoki Sekiyama 2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 1/2] qemu-ga: execute " Tomoki Sekiyama 2012-11-12 9:32 ` [Qemu-devel] [PATCH v2 2/2] qemu-ga: sample fsfreeze hooks Tomoki Sekiyama 2012-11-12 22:16 ` Eric Blake 2012-11-13 4:49 ` Tomoki Sekiyama
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