From patchwork Tue Apr 26 14:49:36 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jes Sorensen X-Patchwork-Id: 92930 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E4AD9B6EF0 for ; Wed, 27 Apr 2011 00:50:35 +1000 (EST) Received: from localhost ([::1]:49683 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QEjaz-0002RX-AO for incoming@patchwork.ozlabs.org; Tue, 26 Apr 2011 10:50:33 -0400 Received: from eggs.gnu.org ([140.186.70.92]:56563) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QEjaq-0002RG-SK for qemu-devel@nongnu.org; Tue, 26 Apr 2011 10:50:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QEjap-0001IW-Kl for qemu-devel@nongnu.org; Tue, 26 Apr 2011 10:50:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47690) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QEjap-0001IL-4M for qemu-devel@nongnu.org; Tue, 26 Apr 2011 10:50:23 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p3QEoIVZ029909 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 26 Apr 2011 10:50:18 -0400 Received: from red-feather.redhat.com (ovpn-113-47.phx2.redhat.com [10.3.113.47]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p3QEoGBG006162; Tue, 26 Apr 2011 10:50:17 -0400 From: Jes.Sorensen@redhat.com To: mdroth@linux.vnet.ibm.com Date: Tue, 26 Apr 2011 16:49:36 +0200 Message-Id: <1303829376-23844-1-git-send-email-Jes.Sorensen@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH] Add QMP fsfreeze support X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Jes Sorensen This patch adds the following QMP commands: qga-guest-fsfreeze: - Freezes all local file systems in the guest. Command will return the number of file systems that were frozen. qga-guest-fsthaw: - Thaws all local file systems in the guest. Command will return the number of file systems that were thawed. Signed-off-by: Jes Sorensen --- qapi-schema.json | 24 ++++++ qga/guest-agent-commands.c | 177 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 201 insertions(+), 0 deletions(-) diff --git a/qapi-schema.json b/qapi-schema.json index e2f209d..2c86cec 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1562,6 +1562,30 @@ { 'option': 'blockdev', 'data': 'BlockdevConfig', 'implicit': 'id' } ## +# @guest-fsfreeze: +# +# json gibberish for guest-fsfreeze command +# +# Returns: Number of file systems frozen +# +# Since: 0.15.0 +## +{ 'command': 'guest-fsfreeze', + 'returns': 'int' } + +## +# @guest-fsthaw: +# +# json gibberish for guest-fsthaw command +# +# Returns: Number of file systems thawed +# +# Since: 0.15.0 +## +{ 'command': 'guest-fsthaw', + 'returns': 'int' } + +## # @VncConfig: # # Configuration options for the built-in VNC server. diff --git a/qga/guest-agent-commands.c b/qga/guest-agent-commands.c index 843ef36..4bc2c57 100644 --- a/qga/guest-agent-commands.c +++ b/qga/guest-agent-commands.c @@ -11,6 +11,10 @@ */ #include +#include +#include +#include +#include #include "guest-agent.h" static bool enable_syslog = true; @@ -262,6 +266,179 @@ struct GuestFileSeek *qga_guest_file_seek(int64_t filehandle, int64_t offset, return seek_data; } +/* + * Walk the mount table and build a list of local file systems + */ +struct direntry { + char *dirname; + char *devtype; + struct direntry *next; +}; + +struct va_freezestate { + struct direntry *mount_list; + int status; +}; + +/* + * This should be in a header file, but we have none :( + */ +enum va_fsfreeze_status { + FREEZE_ERROR = -1, + FREEZE_THAWED = 0, + FREEZE_INPROGRESS = 1, + FREEZE_FROZEN = 2, + FREEZE_THAWINPROGRESS = 3, +}; + +static struct va_freezestate freezestate; + +static int build_mount_list(void) +{ + struct mntent *mnt; + struct direntry *entry; + struct direntry *next; + char const *mtab = MOUNTED; + FILE *fp; + + fp = setmntent(mtab, "r"); + if (!fp) { + fprintf(stderr, "unable to read mtab\n"); + goto fail; + } + + while ((mnt = getmntent(fp))) { + /* + * An entry which device name doesn't start with a '/' is + * either a dummy file system or a network file system. + * Add special handling for smbfs and cifs as is done by + * coreutils as well. + */ + if ((mnt->mnt_fsname[0] != '/') || + (strcmp(mnt->mnt_type, "smbfs") == 0) || + (strcmp(mnt->mnt_type, "cifs") == 0)) { + continue; + } + + entry = qemu_malloc(sizeof(struct direntry)); + entry->dirname = qemu_strdup(mnt->mnt_dir); + entry->devtype = qemu_strdup(mnt->mnt_type); + entry->next = freezestate.mount_list; + + freezestate.mount_list = entry; + } + + endmntent(fp); + + return 0; + +fail: + while(freezestate.mount_list) { + next = freezestate.mount_list->next; + qemu_free(freezestate.mount_list->dirname); + qemu_free(freezestate.mount_list->devtype); + qemu_free(freezestate.mount_list); + freezestate.mount_list = next; + } + + return -1; +} + +/* + * qga_guest_fsfreeze(): Walk list of mounted file systems in the + * guest, and freeze the ones which are real local file systems. + * return values: Number of file systems frozen, -1 on error. + */ +int64_t qga_guest_fsfreeze(Error **err) +{ + struct direntry *entry; + int fd, i = 0; + int64_t ret; + SLOG("va_fsfreeze()"); + + if (freezestate.status != FREEZE_THAWED) { + ret = 0; + goto out; + } + + ret = build_mount_list(); + if (ret < 0) { + goto out; + } + + freezestate.status = FREEZE_INPROGRESS; + + entry = freezestate.mount_list; + while(entry) { + fd = qemu_open(entry->dirname, O_RDONLY); + if (fd == -1) { + ret = errno; + goto error; + } + ret = ioctl(fd, FIFREEZE); + close(fd); + if (ret < 0 && ret != EOPNOTSUPP) { + goto error; + } + + entry = entry->next; + i++; + } + + freezestate.status = FREEZE_FROZEN; + ret = i; +out: + return ret; +error: + if (i > 0) { + freezestate.status = FREEZE_ERROR; + } + goto out; +} + +/* + * qga_guest_fsthaw(): Walk list of frozen file systems in the guest, and + * thaw them. + * return values: Number of file systems thawed on success, -1 on error. + */ +int64_t qga_guest_fsthaw(Error **err) +{ + struct direntry *entry; + int fd, i = 0; + int64_t ret; + SLOG("va_fsthaw()"); + + if (freezestate.status != FREEZE_FROZEN) { + ret = 0; + goto out; + } + + while((entry = freezestate.mount_list)) { + fd = qemu_open(entry->dirname, O_RDONLY); + if (fd == -1) { + ret = -1; + goto out; + } + ret = ioctl(fd, FITHAW); + close(fd); + if (ret < 0 && ret != EOPNOTSUPP) { + ret = -1; + goto out; + } + + freezestate.mount_list = entry->next; + qemu_free(entry->dirname); + qemu_free(entry->devtype); + qemu_free(entry); + i++; + } + + freezestate.status = FREEZE_THAWED; + ret = i; +out: + return ret; +} + void qga_guest_file_close(int64_t filehandle, Error **err) { FILE *fh = guest_file_handle_find(filehandle);