In the next patches we are going to add FreeBSD support for QEMU Guest
Agent. In the result, code in commands-posix.c will be too cumbersome.
Move Linux-specific FS freeze/thaw code to a separate file commands-linux.c
keeping common POSIX code in commands-posix.c.
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
lgtm,
---
qga/commands-common.h | 35 +++++
qga/commands-linux.c | 286 +++++++++++++++++++++++++++++++++++++++++
qga/commands-posix.c | 289 +++---------------------------------------
qga/meson.build | 3 +
4 files changed, 340 insertions(+), 273 deletions(-)
create mode 100644 qga/commands-linux.c
diff --git a/qga/commands-common.h b/qga/commands-common.h
index d0e4a9696f..181fc330aa 100644
--- a/qga/commands-common.h
+++ b/qga/commands-common.h
@@ -10,6 +10,40 @@
#define QGA_COMMANDS_COMMON_H
#include "qga-qapi-types.h"
+#include "guest-agent-core.h"
+#include "qemu/queue.h"
+
+#if defined(__linux__)
+#include <linux/fs.h>
+#ifdef FIFREEZE
+#define CONFIG_FSFREEZE
+#endif
+#ifdef FITRIM
+#define CONFIG_FSTRIM
+#endif
+#endif /* __linux__ */
+
+#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
+typedef struct FsMount {
+ char *dirname;
+ char *devtype;
+ unsigned int devmajor, devminor;
+ QTAILQ_ENTRY(FsMount) next;
+} FsMount;
+
+typedef QTAILQ_HEAD(FsMountList, FsMount) FsMountList;
+
+bool build_fs_mount_list(FsMountList *mounts, Error **errp);
+void free_fs_mount_list(FsMountList *mounts);
+#endif /* CONFIG_FSFREEZE || CONFIG_FSTRIM */
+
+#if defined(CONFIG_FSFREEZE)
+int64_t qmp_guest_fsfreeze_do_freeze_list(bool has_mountpoints,
+ strList *mountpoints,
+ FsMountList mounts,
+ Error **errp);
+int qmp_guest_fsfreeze_do_thaw(Error **errp);
+#endif /* CONFIG_FSFREEZE */
typedef struct GuestFileHandle GuestFileHandle;
@@ -29,4 +63,5 @@ GuestFileRead *guest_file_read_unsafe(GuestFileHandle *gfh,
*/
char *qga_get_host_name(Error **errp);
+void ga_wait_child(pid_t pid, int *status, Error **errp);
#endif
diff --git a/qga/commands-linux.c b/qga/commands-linux.c
new file mode 100644
index 0000000000..214e408fcd
--- /dev/null
+++ b/qga/commands-linux.c
@@ -0,0 +1,286 @@
+/*
+ * QEMU Guest Agent Linux-specific command implementations
+ *
+ * Copyright IBM Corp. 2011
+ *
+ * Authors:
+ * Michael Roth <mdroth@linux.vnet.ibm.com>
+ * Michal Privoznik <mprivozn@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "commands-common.h"
+#include "cutils.h"
+#include <mntent.h>
+#include <sys/ioctl.h>
+
+#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
+static int dev_major_minor(const char *devpath,
+ unsigned int *devmajor, unsigned int *devminor)
+{
+ struct stat st;
+
+ *devmajor = 0;
+ *devminor = 0;
+
+ if (stat(devpath, &st) < 0) {
+ slog("failed to stat device file '%s': %s", devpath, strerror(errno));
+ return -1;
+ }
+ if (S_ISDIR(st.st_mode)) {
+ /* It is bind mount */
+ return -2;
+ }
+ if (S_ISBLK(st.st_mode)) {
+ *devmajor = major(st.st_rdev);
+ *devminor = minor(st.st_rdev);
+ return 0;
+ }
+ return -1;
+}
+
+static bool build_fs_mount_list_from_mtab(FsMountList *mounts, Error **errp)
+{
+ struct mntent *ment;
+ FsMount *mount;
+ char const *mtab = "/proc/self/mounts";
+ FILE *fp;
+ unsigned int devmajor, devminor;
+
+ fp = setmntent(mtab, "r");
+ if (!fp) {
+ error_setg(errp, "failed to open mtab file: '%s'", mtab);
+ return false;
+ }
+
+ while ((ment = 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 ((ment->mnt_fsname[0] != '/') ||
+ (strcmp(ment->mnt_type, "smbfs") == 0) ||
+ (strcmp(ment->mnt_type, "cifs") == 0)) {
+ continue;
+ }
+ if (dev_major_minor(ment->mnt_fsname, &devmajor, &devminor) == -2) {
+ /* Skip bind mounts */
+ continue;
+ }
+
+ mount = g_new0(FsMount, 1);
+ mount->dirname = g_strdup(ment->mnt_dir);
+ mount->devtype = g_strdup(ment->mnt_type);
+ mount->devmajor = devmajor;
+ mount->devminor = devminor;
+
+ QTAILQ_INSERT_TAIL(mounts, mount, next);
+ }
+
+ endmntent(fp);
+ return true;
+}
+
+static void decode_mntname(char *name, int len)
+{
+ int i, j = 0;
+ for (i = 0; i <= len; i++) {
+ if (name[i] != '\\') {
+ name[j++] = name[i];
+ } else if (name[i + 1] == '\\') {
+ name[j++] = '\\';
+ i++;
+ } else if (name[i + 1] >= '0' && name[i + 1] <= '3' &&
+ name[i + 2] >= '0' && name[i + 2] <= '7' &&
+ name[i + 3] >= '0' && name[i + 3] <= '7') {
+ name[j++] = (name[i + 1] - '0') * 64 +
+ (name[i + 2] - '0') * 8 +
+ (name[i + 3] - '0');
+ i += 3;
+ } else {
+ name[j++] = name[i];
+ }
+ }
+}
+
+/*
+ * Walk the mount table and build a list of local file systems
+ */
+bool build_fs_mount_list(FsMountList *mounts, Error **errp)
+{
+ FsMount *mount;
+ char const *mountinfo = "/proc/self/mountinfo";
+ FILE *fp;
+ char *line = NULL, *dash;
+ size_t n;
+ char check;
+ unsigned int devmajor, devminor;
+ int ret, dir_s, dir_e, type_s, type_e, dev_s, dev_e;
+
+ fp = fopen(mountinfo, "r");
+ if (!fp) {
+ return build_fs_mount_list_from_mtab(mounts, errp);
+ }
+
+ while (getline(&line, &n, fp) != -1) {
+ ret = sscanf(line, "%*u %*u %u:%u %*s %n%*s%n%c",
+ &devmajor, &devminor, &dir_s, &dir_e, &check);
+ if (ret < 3) {
+ continue;
+ }
+ dash = strstr(line + dir_e, " - ");
+ if (!dash) {
+ continue;
+ }
+ ret = sscanf(dash, " - %n%*s%n %n%*s%n%c",
+ &type_s, &type_e, &dev_s, &dev_e, &check);
+ if (ret < 1) {
+ continue;
+ }
+ line[dir_e] = 0;
+ dash[type_e] = 0;
+ dash[dev_e] = 0;
+ decode_mntname(line + dir_s, dir_e - dir_s);
+ decode_mntname(dash + dev_s, dev_e - dev_s);
+ if (devmajor == 0) {
+ /* btrfs reports major number = 0 */
+ if (strcmp("btrfs", dash + type_s) != 0 ||
+ dev_major_minor(dash + dev_s, &devmajor, &devminor) < 0) {
+ continue;
+ }
+ }
+
+ mount = g_new0(FsMount, 1);
+ mount->dirname = g_strdup(line + dir_s);
+ mount->devtype = g_strdup(dash + type_s);
+ mount->devmajor = devmajor;
+ mount->devminor = devminor;
+
+ QTAILQ_INSERT_TAIL(mounts, mount, next);
+ }
+ free(line);
+
+ fclose(fp);
+ return true;
+}
+#endif /* CONFIG_FSFREEZE || CONFIG_FSTRIM */
+
+#ifdef CONFIG_FSFREEZE
+/*
+ * Walk list of mounted file systems in the guest, and freeze the ones which
+ * are real local file systems.
+ */
+int64_t qmp_guest_fsfreeze_do_freeze_list(bool has_mountpoints,
+ strList *mountpoints,
+ FsMountList mounts,
+ Error **errp)
+{
+ struct FsMount *mount;
+ strList *list;
+ int fd, ret, i = 0;
+
+ QTAILQ_FOREACH_REVERSE(mount, &mounts, next) {
+ /* To issue fsfreeze in the reverse order of mounts, check if the
+ * mount is listed in the list here */
+ if (has_mountpoints) {
+ for (list = mountpoints; list; list = list->next) {
+ if (strcmp(list->value, mount->dirname) == 0) {
+ break;
+ }
+ }
+ if (!list) {
+ continue;
+ }
+ }
+
+ fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
+ if (fd == -1) {
+ error_setg_errno(errp, errno, "failed to open %s", mount->dirname);
+ return -1;
+ }
+
+ /* we try to cull filesystems we know won't work in advance, but other
+ * filesystems may not implement fsfreeze for less obvious reasons.
+ * these will report EOPNOTSUPP. we simply ignore these when tallying
+ * the number of frozen filesystems.
+ * if a filesystem is mounted more than once (aka bind mount) a
+ * consecutive attempt to freeze an already frozen filesystem will
+ * return EBUSY.
+ *
+ * any other error means a failure to freeze a filesystem we
+ * expect to be freezable, so return an error in those cases
+ * and return system to thawed state.
+ */
+ ret = ioctl(fd, FIFREEZE);
+ if (ret == -1) {
+ if (errno != EOPNOTSUPP && errno != EBUSY) {
+ error_setg_errno(errp, errno, "failed to freeze %s",
+ mount->dirname);
+ close(fd);
+ return -1;
+ }
+ } else {
+ i++;
+ }
+ close(fd);
+ }
+ return i;
+}
+
+int qmp_guest_fsfreeze_do_thaw(Error **errp)
+{
+ int ret;
+ FsMountList mounts;
+ FsMount *mount;
+ int fd, i = 0, logged;
+ Error *local_err = NULL;
+
+ QTAILQ_INIT(&mounts);
+ if (!build_fs_mount_list(&mounts, &local_err)) {
+ error_propagate(errp, local_err);
+ return -1;
+ }
+
+ QTAILQ_FOREACH(mount, &mounts, next) {
+ logged = false;
+ fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
+ if (fd == -1) {
+ continue;
+ }
+ /* we have no way of knowing whether a filesystem was actually unfrozen
+ * as a result of a successful call to FITHAW, only that if an error
+ * was returned the filesystem was *not* unfrozen by that particular
+ * call.
+ *
+ * since multiple preceding FIFREEZEs require multiple calls to FITHAW
+ * to unfreeze, continuing issuing FITHAW until an error is returned,
+ * in which case either the filesystem is in an unfreezable state, or,
+ * more likely, it was thawed previously (and remains so afterward).
+ *
+ * also, since the most recent successful call is the one that did
+ * the actual unfreeze, we can use this to provide an accurate count
+ * of the number of filesystems unfrozen by guest-fsfreeze-thaw, which
+ * may * be useful for determining whether a filesystem was unfrozen
+ * during the freeze/thaw phase by a process other than qemu-ga.
+ */
+ do {
+ ret = ioctl(fd, FITHAW);
+ if (ret == 0 && !logged) {
+ i++;
+ logged = true;
+ }
+ } while (ret == 0);
+ close(fd);
+ }
+
+ free_fs_mount_list(&mounts);
+
+ return i;
+}
+#endif /* CONFIG_FSFREEZE */
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 16d67e9f6d..9574b83c92 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -16,11 +16,9 @@
#include <sys/utsname.h>
#include <sys/wait.h>
#include <dirent.h>
-#include "guest-agent-core.h"
#include "qga-qapi-commands.h"
#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
-#include "qemu/queue.h"
#include "qemu/host-utils.h"
#include "qemu/sockets.h"
#include "qemu/base64.h"
@@ -70,7 +68,7 @@
#endif
#endif
-static void ga_wait_child(pid_t pid, int *status, Error **errp)
+void ga_wait_child(pid_t pid, int *status, Error **errp)
{
pid_t rpid;
@@ -629,16 +627,7 @@ void qmp_guest_file_flush(int64_t handle, Error **errp)
#if defined(__linux__)
#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
-typedef struct FsMount {
- char *dirname;
- char *devtype;
- unsigned int devmajor, devminor;
- QTAILQ_ENTRY(FsMount) next;
-} FsMount;
-
-typedef QTAILQ_HEAD(FsMountList, FsMount) FsMountList;
-
-static void free_fs_mount_list(FsMountList *mounts)
+void free_fs_mount_list(FsMountList *mounts)
{
FsMount *mount, *temp;
@@ -653,157 +642,6 @@ static void free_fs_mount_list(FsMountList *mounts)
g_free(mount);
}
}
-
-static int dev_major_minor(const char *devpath,
- unsigned int *devmajor, unsigned int *devminor)
-{
- struct stat st;
-
- *devmajor = 0;
- *devminor = 0;
-
- if (stat(devpath, &st) < 0) {
- slog("failed to stat device file '%s': %s", devpath, strerror(errno));
- return -1;
- }
- if (S_ISDIR(st.st_mode)) {
- /* It is bind mount */
- return -2;
- }
- if (S_ISBLK(st.st_mode)) {
- *devmajor = major(st.st_rdev);
- *devminor = minor(st.st_rdev);
- return 0;
- }
- return -1;
-}
-
-/*
- * Walk the mount table and build a list of local file systems
- */
-static bool build_fs_mount_list_from_mtab(FsMountList *mounts, Error **errp)
-{
- struct mntent *ment;
- FsMount *mount;
- char const *mtab = "/proc/self/mounts";
- FILE *fp;
- unsigned int devmajor, devminor;
-
- fp = setmntent(mtab, "r");
- if (!fp) {
- error_setg(errp, "failed to open mtab file: '%s'", mtab);
- return false;
- }
-
- while ((ment = 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 ((ment->mnt_fsname[0] != '/') ||
- (strcmp(ment->mnt_type, "smbfs") == 0) ||
- (strcmp(ment->mnt_type, "cifs") == 0)) {
- continue;
- }
- if (dev_major_minor(ment->mnt_fsname, &devmajor, &devminor) == -2) {
- /* Skip bind mounts */
- continue;
- }
-
- mount = g_new0(FsMount, 1);
- mount->dirname = g_strdup(ment->mnt_dir);
- mount->devtype = g_strdup(ment->mnt_type);
- mount->devmajor = devmajor;
- mount->devminor = devminor;
-
- QTAILQ_INSERT_TAIL(mounts, mount, next);
- }
-
- endmntent(fp);
- return true;
-}
-
-static void decode_mntname(char *name, int len)
-{
- int i, j = 0;
- for (i = 0; i <= len; i++) {
- if (name[i] != '\\') {
- name[j++] = name[i];
- } else if (name[i + 1] == '\\') {
- name[j++] = '\\';
- i++;
- } else if (name[i + 1] >= '0' && name[i + 1] <= '3' &&
- name[i + 2] >= '0' && name[i + 2] <= '7' &&
- name[i + 3] >= '0' && name[i + 3] <= '7') {
- name[j++] = (name[i + 1] - '0') * 64 +
- (name[i + 2] - '0') * 8 +
- (name[i + 3] - '0');
- i += 3;
- } else {
- name[j++] = name[i];
- }
- }
-}
-
-static bool build_fs_mount_list(FsMountList *mounts, Error **errp)
-{
- FsMount *mount;
- char const *mountinfo = "/proc/self/mountinfo";
- FILE *fp;
- char *line = NULL, *dash;
- size_t n;
- char check;
- unsigned int devmajor, devminor;
- int ret, dir_s, dir_e, type_s, type_e, dev_s, dev_e;
-
- fp = fopen(mountinfo, "r");
- if (!fp) {
- return build_fs_mount_list_from_mtab(mounts, errp);
- }
-
- while (getline(&line, &n, fp) != -1) {
- ret = sscanf(line, "%*u %*u %u:%u %*s %n%*s%n%c",
- &devmajor, &devminor, &dir_s, &dir_e, &check);
- if (ret < 3) {
- continue;
- }
- dash = strstr(line + dir_e, " - ");
- if (!dash) {
- continue;
- }
- ret = sscanf(dash, " - %n%*s%n %n%*s%n%c",
- &type_s, &type_e, &dev_s, &dev_e, &check);
- if (ret < 1) {
- continue;
- }
- line[dir_e] = 0;
- dash[type_e] = 0;
- dash[dev_e] = 0;
- decode_mntname(line + dir_s, dir_e - dir_s);
- decode_mntname(dash + dev_s, dev_e - dev_s);
- if (devmajor == 0) {
- /* btrfs reports major number = 0 */
- if (strcmp("btrfs", dash + type_s) != 0 ||
- dev_major_minor(dash + dev_s, &devmajor, &devminor) < 0) {
- continue;
- }
- }
-
- mount = g_new0(FsMount, 1);
- mount->dirname = g_strdup(line + dir_s);
- mount->devtype = g_strdup(dash + type_s);
- mount->devmajor = devmajor;
- mount->devminor = devminor;
-
- QTAILQ_INSERT_TAIL(mounts, mount, next);
- }
- free(line);
-
- fclose(fp);
- return true;
-}
#endif
#if defined(CONFIG_FSFREEZE)
@@ -1708,20 +1546,13 @@ int64_t qmp_guest_fsfreeze_freeze(Error **errp)
return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
}
-/*
- * Walk list of mounted file systems in the guest, and freeze the ones which
- * are real local file systems.
- */
int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
strList *mountpoints,
Error **errp)
{
- int ret = 0, i = 0;
- strList *list;
+ int ret;
FsMountList mounts;
- struct FsMount *mount;
Error *local_err = NULL;
- int fd;
slog("guest-fsfreeze called");
@@ -1740,122 +1571,34 @@ int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
/* cannot risk guest agent blocking itself on a write in this state */
ga_set_frozen(ga_state);
- QTAILQ_FOREACH_REVERSE(mount, &mounts, next) {
- /* To issue fsfreeze in the reverse order of mounts, check if the
- * mount is listed in the list here */
- if (has_mountpoints) {
- for (list = mountpoints; list; list = list->next) {
- if (strcmp(list->value, mount->dirname) == 0) {
- break;
- }
- }
- if (!list) {
- continue;
- }
- }
-
- fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
- if (fd == -1) {
- error_setg_errno(errp, errno, "failed to open %s", mount->dirname);
- goto error;
- }
-
- /* we try to cull filesystems we know won't work in advance, but other
- * filesystems may not implement fsfreeze for less obvious reasons.
- * these will report EOPNOTSUPP. we simply ignore these when tallying
- * the number of frozen filesystems.
- * if a filesystem is mounted more than once (aka bind mount) a
- * consecutive attempt to freeze an already frozen filesystem will
- * return EBUSY.
- *
- * any other error means a failure to freeze a filesystem we
- * expect to be freezable, so return an error in those cases
- * and return system to thawed state.
- */
- ret = ioctl(fd, FIFREEZE);
- if (ret == -1) {
- if (errno != EOPNOTSUPP && errno != EBUSY) {
- error_setg_errno(errp, errno, "failed to freeze %s",
- mount->dirname);
- close(fd);
- goto error;
- }
- } else {
- i++;
- }
- close(fd);
- }
+ ret = qmp_guest_fsfreeze_do_freeze_list(has_mountpoints, mountpoints,
+ mounts, errp);
free_fs_mount_list(&mounts);
/* We may not issue any FIFREEZE here.
* Just unset ga_state here and ready for the next call.
*/
- if (i == 0) {
+ if (ret == 0) {
ga_unset_frozen(ga_state);
+ } else if (ret < 0) {
+ qmp_guest_fsfreeze_thaw(NULL);
}
- return i;
-
-error:
- free_fs_mount_list(&mounts);
- qmp_guest_fsfreeze_thaw(NULL);
- return 0;
+ return ret;
}
-/*
- * Walk list of frozen file systems in the guest, and thaw them.
- */
int64_t qmp_guest_fsfreeze_thaw(Error **errp)
{
int ret;
- FsMountList mounts;
- FsMount *mount;
- int fd, i = 0, logged;
- Error *local_err = NULL;
- QTAILQ_INIT(&mounts);
- if (!build_fs_mount_list(&mounts, &local_err)) {
- error_propagate(errp, local_err);
- return 0;
+ ret = qmp_guest_fsfreeze_do_thaw(errp);
+ if (ret >= 0) {
+ ga_unset_frozen(ga_state);
+ execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
+ } else {
+ ret = 0;
}
- QTAILQ_FOREACH(mount, &mounts, next) {
- logged = false;
- fd = qga_open_cloexec(mount->dirname, O_RDONLY, 0);
- if (fd == -1) {
- continue;
- }
- /* we have no way of knowing whether a filesystem was actually unfrozen
- * as a result of a successful call to FITHAW, only that if an error
- * was returned the filesystem was *not* unfrozen by that particular
- * call.
- *
- * since multiple preceding FIFREEZEs require multiple calls to FITHAW
- * to unfreeze, continuing issuing FITHAW until an error is returned,
- * in which case either the filesystem is in an unfreezable state, or,
- * more likely, it was thawed previously (and remains so afterward).
- *
- * also, since the most recent successful call is the one that did
- * the actual unfreeze, we can use this to provide an accurate count
- * of the number of filesystems unfrozen by guest-fsfreeze-thaw, which
- * may * be useful for determining whether a filesystem was unfrozen
- * during the freeze/thaw phase by a process other than qemu-ga.
- */
- do {
- ret = ioctl(fd, FITHAW);
- if (ret == 0 && !logged) {
- i++;
- logged = true;
- }
- } while (ret == 0);
- close(fd);
- }
-
- ga_unset_frozen(ga_state);
- free_fs_mount_list(&mounts);
-
- execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
-
- return i;
+ return ret;
}
static void guest_fsfreeze_cleanup(void)
diff --git a/qga/meson.build b/qga/meson.build
index 65c1e93846..409f49a000 100644
--- a/qga/meson.build
+++ b/qga/meson.build
@@ -72,6 +72,9 @@ qga_ss.add(when: 'CONFIG_POSIX', if_true: files(
'commands-posix.c',
'commands-posix-ssh.c',
))
+qga_ss.add(when: 'CONFIG_LINUX', if_true: files(
+ 'commands-linux.c',
+))
qga_ss.add(when: 'CONFIG_WIN32', if_true: files(
'channel-win32.c',
'commands-win32.c',
--
2.34.1