qemu-ga: execute hook to quiesce the guest on fsfreeze-freeze/thaw
authorTomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Wed, 12 Dec 2012 03:55:55 +0000 (12:55 +0900)
committerMichael Roth <mdroth@linux.vnet.ibm.com>
Tue, 8 Jan 2013 22:38:12 +0000 (16:38 -0600)
commitec0f694c11e8e0958d727e40e0759ab99e5908d6
tree6167bf79990fcde0edf3c0fe862fd7c62619b764
parent7b3760879bf323a0d9654a5158d5b3ed51882505
qemu-ga: execute hook to quiesce the guest on fsfreeze-freeze/thaw

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.

If --fsfreeze-hook option is specified, the hook is executed with
"freeze" argument before the filesystem is frozen by fsfreeze-freeze
command. As for fsfreeze-thaw command, the hook is executed with "thaw"
argument after the filesystem is thawed.

This patch depends on patchset to improve error reporting by Luiz Capitulino:
  http://lists.gnu.org/archive/html/qemu-devel/2012-11/msg03016.html

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
*clarified usage in help output

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
qga/commands-posix.c
qga/guest-agent-core.h
qga/main.c