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qemu/qga/commands-posix.c
Tomoki Sekiyama e5d9adbdab qemu-ga: execute fsfreeze-freeze in reverse order of mounts 
Currently, fsfreeze-freeze may cause deadlock if a guest has loopback mounts
of image files in its disk; e.g.:

    # mount | grep ^/
    /dev/vda1 / type ext4 (rw,noatime,seclabel,data=ordered)
    /tmp/disk.img on /mnt type ext4 (rw,relatime,seclabel)

To avoid the deadlock, this freezes filesystems in reverse order of mounts.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
*fix up commit msg
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-10-10 14:52:37 -05:00

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/*
* QEMU Guest Agent POSIX-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 <glib.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <inttypes.h>
#include "qga/guest-agent-core.h"
#include "qga-qmp-commands.h"
#include "qapi/qmp/qerror.h"
#include "qemu/queue.h"
#include "qemu/host-utils.h"
#ifndef CONFIG_HAS_ENVIRON
#ifdef __APPLE__
#include <crt_externs.h>
#define environ (*_NSGetEnviron())
#else
extern char **environ;
#endif
#endif
#if defined(__linux__)
#include <mntent.h>
#include <linux/fs.h>
#include <ifaddrs.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <net/if.h>
#ifdef FIFREEZE
#define CONFIG_FSFREEZE
#endif
#ifdef FITRIM
#define CONFIG_FSTRIM
#endif
#endif
static void ga_wait_child(pid_t pid, int *status, Error **err)
{
pid_t rpid;
*status = 0;
do {
rpid = waitpid(pid, status, 0);
} while (rpid == -1 && errno == EINTR);
if (rpid == -1) {
error_setg_errno(err, errno, "failed to wait for child (pid: %d)", pid);
return;
}
g_assert(rpid == pid);
}
void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
{
const char *shutdown_flag;
Error *local_err = NULL;
pid_t pid;
int status;
slog("guest-shutdown called, mode: %s", mode);
if (!has_mode || strcmp(mode, "powerdown") == 0) {
shutdown_flag = "-P";
} else if (strcmp(mode, "halt") == 0) {
shutdown_flag = "-H";
} else if (strcmp(mode, "reboot") == 0) {
shutdown_flag = "-r";
} else {
error_setg(err,
"mode is invalid (valid values are: halt|powerdown|reboot");
return;
}
pid = fork();
if (pid == 0) {
/* child, start the shutdown */
setsid();
reopen_fd_to_null(0);
reopen_fd_to_null(1);
reopen_fd_to_null(2);
execle("/sbin/shutdown", "shutdown", shutdown_flag, "+0",
"hypervisor initiated shutdown", (char*)NULL, environ);
_exit(EXIT_FAILURE);
} else if (pid < 0) {
error_setg_errno(err, errno, "failed to create child process");
return;
}
ga_wait_child(pid, &status, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
return;
}
if (!WIFEXITED(status)) {
error_setg(err, "child process has terminated abnormally");
return;
}
if (WEXITSTATUS(status)) {
error_setg(err, "child process has failed to shutdown");
return;
}
/* succeeded */
}
int64_t qmp_guest_get_time(Error **errp)
{
int ret;
qemu_timeval tq;
int64_t time_ns;
ret = qemu_gettimeofday(&tq);
if (ret < 0) {
error_setg_errno(errp, errno, "Failed to get time");
return -1;
}
time_ns = tq.tv_sec * 1000000000LL + tq.tv_usec * 1000;
return time_ns;
}
void qmp_guest_set_time(int64_t time_ns, Error **errp)
{
int ret;
int status;
pid_t pid;
Error *local_err = NULL;
struct timeval tv;
/* year-2038 will overflow in case time_t is 32bit */
if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) {
error_setg(errp, "Time %" PRId64 " is too large", time_ns);
return;
}
tv.tv_sec = time_ns / 1000000000;
tv.tv_usec = (time_ns % 1000000000) / 1000;
ret = settimeofday(&tv, NULL);
if (ret < 0) {
error_setg_errno(errp, errno, "Failed to set time to guest");
return;
}
/* Set the Hardware Clock to the current System Time. */
pid = fork();
if (pid == 0) {
setsid();
reopen_fd_to_null(0);
reopen_fd_to_null(1);
reopen_fd_to_null(2);
execle("/sbin/hwclock", "hwclock", "-w", NULL, environ);
_exit(EXIT_FAILURE);
} else if (pid < 0) {
error_setg_errno(errp, errno, "failed to create child process");
return;
}
ga_wait_child(pid, &status, &local_err);
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
return;
}
if (!WIFEXITED(status)) {
error_setg(errp, "child process has terminated abnormally");
return;
}
if (WEXITSTATUS(status)) {
error_setg(errp, "hwclock failed to set hardware clock to system time");
return;
}
}
typedef struct GuestFileHandle {
uint64_t id;
FILE *fh;
QTAILQ_ENTRY(GuestFileHandle) next;
} GuestFileHandle;
static struct {
QTAILQ_HEAD(, GuestFileHandle) filehandles;
} guest_file_state;
static int64_t guest_file_handle_add(FILE *fh, Error **errp)
{
GuestFileHandle *gfh;
int64_t handle;
handle = ga_get_fd_handle(ga_state, errp);
if (error_is_set(errp)) {
return 0;
}
gfh = g_malloc0(sizeof(GuestFileHandle));
gfh->id = handle;
gfh->fh = fh;
QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
return handle;
}
static GuestFileHandle *guest_file_handle_find(int64_t id, Error **err)
{
GuestFileHandle *gfh;
QTAILQ_FOREACH(gfh, &guest_file_state.filehandles, next)
{
if (gfh->id == id) {
return gfh;
}
}
error_setg(err, "handle '%" PRId64 "' has not been found", id);
return NULL;
}
typedef const char * const ccpc;
#ifndef O_BINARY
#define O_BINARY 0
#endif
/* http://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html */
static const struct {
ccpc *forms;
int oflag_base;
} guest_file_open_modes[] = {
{ (ccpc[]){ "r", NULL }, O_RDONLY },
{ (ccpc[]){ "rb", NULL }, O_RDONLY | O_BINARY },
{ (ccpc[]){ "w", NULL }, O_WRONLY | O_CREAT | O_TRUNC },
{ (ccpc[]){ "wb", NULL }, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY },
{ (ccpc[]){ "a", NULL }, O_WRONLY | O_CREAT | O_APPEND },
{ (ccpc[]){ "ab", NULL }, O_WRONLY | O_CREAT | O_APPEND | O_BINARY },
{ (ccpc[]){ "r+", NULL }, O_RDWR },
{ (ccpc[]){ "rb+", "r+b", NULL }, O_RDWR | O_BINARY },
{ (ccpc[]){ "w+", NULL }, O_RDWR | O_CREAT | O_TRUNC },
{ (ccpc[]){ "wb+", "w+b", NULL }, O_RDWR | O_CREAT | O_TRUNC | O_BINARY },
{ (ccpc[]){ "a+", NULL }, O_RDWR | O_CREAT | O_APPEND },
{ (ccpc[]){ "ab+", "a+b", NULL }, O_RDWR | O_CREAT | O_APPEND | O_BINARY }
};
static int
find_open_flag(const char *mode_str, Error **err)
{
unsigned mode;
for (mode = 0; mode < ARRAY_SIZE(guest_file_open_modes); ++mode) {
ccpc *form;
form = guest_file_open_modes[mode].forms;
while (*form != NULL && strcmp(*form, mode_str) != 0) {
++form;
}
if (*form != NULL) {
break;
}
}
if (mode == ARRAY_SIZE(guest_file_open_modes)) {
error_setg(err, "invalid file open mode '%s'", mode_str);
return -1;
}
return guest_file_open_modes[mode].oflag_base | O_NOCTTY | O_NONBLOCK;
}
#define DEFAULT_NEW_FILE_MODE (S_IRUSR | S_IWUSR | \
S_IRGRP | S_IWGRP | \
S_IROTH | S_IWOTH)
static FILE *
safe_open_or_create(const char *path, const char *mode, Error **err)
{
Error *local_err = NULL;
int oflag;
oflag = find_open_flag(mode, &local_err);
if (local_err == NULL) {
int fd;
/* If the caller wants / allows creation of a new file, we implement it
* with a two step process: open() + (open() / fchmod()).
*
* First we insist on creating the file exclusively as a new file. If
* that succeeds, we're free to set any file-mode bits on it. (The
* motivation is that we want to set those file-mode bits independently
* of the current umask.)
*
* If the exclusive creation fails because the file already exists
* (EEXIST is not possible for any other reason), we just attempt to
* open the file, but in this case we won't be allowed to change the
* file-mode bits on the preexistent file.
*
* The pathname should never disappear between the two open()s in
* practice. If it happens, then someone very likely tried to race us.
* In this case just go ahead and report the ENOENT from the second
* open() to the caller.
*
* If the caller wants to open a preexistent file, then the first
* open() is decisive and its third argument is ignored, and the second
* open() and the fchmod() are never called.
*/
fd = open(path, oflag | ((oflag & O_CREAT) ? O_EXCL : 0), 0);
if (fd == -1 && errno == EEXIST) {
oflag &= ~(unsigned)O_CREAT;
fd = open(path, oflag);
}
if (fd == -1) {
error_setg_errno(&local_err, errno, "failed to open file '%s' "
"(mode: '%s')", path, mode);
} else {
qemu_set_cloexec(fd);
if ((oflag & O_CREAT) && fchmod(fd, DEFAULT_NEW_FILE_MODE) == -1) {
error_setg_errno(&local_err, errno, "failed to set permission "
"0%03o on new file '%s' (mode: '%s')",
(unsigned)DEFAULT_NEW_FILE_MODE, path, mode);
} else {
FILE *f;
f = fdopen(fd, mode);
if (f == NULL) {
error_setg_errno(&local_err, errno, "failed to associate "
"stdio stream with file descriptor %d, "
"file '%s' (mode: '%s')", fd, path, mode);
} else {
return f;
}
}
close(fd);
if (oflag & O_CREAT) {
unlink(path);
}
}
}
error_propagate(err, local_err);
return NULL;
}
int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, Error **err)
{
FILE *fh;
Error *local_err = NULL;
int fd;
int64_t ret = -1, handle;
if (!has_mode) {
mode = "r";
}
slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
fh = safe_open_or_create(path, mode, &local_err);
if (local_err != NULL) {
error_propagate(err, local_err);
return -1;
}
/* set fd non-blocking to avoid common use cases (like reading from a
* named pipe) from hanging the agent
*/
fd = fileno(fh);
ret = fcntl(fd, F_GETFL);
ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK);
if (ret == -1) {
error_setg_errno(err, errno, "failed to make file '%s' non-blocking",
path);
fclose(fh);
return -1;
}
handle = guest_file_handle_add(fh, err);
if (error_is_set(err)) {
fclose(fh);
return -1;
}
slog("guest-file-open, handle: %d", handle);
return handle;
}
void qmp_guest_file_close(int64_t handle, Error **err)
{
GuestFileHandle *gfh = guest_file_handle_find(handle, err);
int ret;
slog("guest-file-close called, handle: %ld", handle);
if (!gfh) {
return;
}
ret = fclose(gfh->fh);
if (ret == EOF) {
error_setg_errno(err, errno, "failed to close handle");
return;
}
QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
g_free(gfh);
}
struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
int64_t count, Error **err)
{
GuestFileHandle *gfh = guest_file_handle_find(handle, err);
GuestFileRead *read_data = NULL;
guchar *buf;
FILE *fh;
size_t read_count;
if (!gfh) {
return NULL;
}
if (!has_count) {
count = QGA_READ_COUNT_DEFAULT;
} else if (count < 0) {
error_setg(err, "value '%" PRId64 "' is invalid for argument count",
count);
return NULL;
}
fh = gfh->fh;
buf = g_malloc0(count+1);
read_count = fread(buf, 1, count, fh);
if (ferror(fh)) {
error_setg_errno(err, errno, "failed to read file");
slog("guest-file-read failed, handle: %ld", handle);
} else {
buf[read_count] = 0;
read_data = g_malloc0(sizeof(GuestFileRead));
read_data->count = read_count;
read_data->eof = feof(fh);
if (read_count) {
read_data->buf_b64 = g_base64_encode(buf, read_count);
}
}
g_free(buf);
clearerr(fh);
return read_data;
}
GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
bool has_count, int64_t count, Error **err)
{
GuestFileWrite *write_data = NULL;
guchar *buf;
gsize buf_len;
int write_count;
GuestFileHandle *gfh = guest_file_handle_find(handle, err);
FILE *fh;
if (!gfh) {
return NULL;
}
fh = gfh->fh;
buf = g_base64_decode(buf_b64, &buf_len);
if (!has_count) {
count = buf_len;
} else if (count < 0 || count > buf_len) {
error_setg(err, "value '%" PRId64 "' is invalid for argument count",
count);
g_free(buf);
return NULL;
}
write_count = fwrite(buf, 1, count, fh);
if (ferror(fh)) {
error_setg_errno(err, errno, "failed to write to file");
slog("guest-file-write failed, handle: %ld", handle);
} else {
write_data = g_malloc0(sizeof(GuestFileWrite));
write_data->count = write_count;
write_data->eof = feof(fh);
}
g_free(buf);
clearerr(fh);
return write_data;
}
struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
int64_t whence, Error **err)
{
GuestFileHandle *gfh = guest_file_handle_find(handle, err);
GuestFileSeek *seek_data = NULL;
FILE *fh;
int ret;
if (!gfh) {
return NULL;
}
fh = gfh->fh;
ret = fseek(fh, offset, whence);
if (ret == -1) {
error_setg_errno(err, errno, "failed to seek file");
} else {
seek_data = g_malloc0(sizeof(GuestFileRead));
seek_data->position = ftell(fh);
seek_data->eof = feof(fh);
}
clearerr(fh);
return seek_data;
}
void qmp_guest_file_flush(int64_t handle, Error **err)
{
GuestFileHandle *gfh = guest_file_handle_find(handle, err);
FILE *fh;
int ret;
if (!gfh) {
return;
}
fh = gfh->fh;
ret = fflush(fh);
if (ret == EOF) {
error_setg_errno(err, errno, "failed to flush file");
}
}
static void guest_file_init(void)
{
QTAILQ_INIT(&guest_file_state.filehandles);
}
/* linux-specific implementations. avoid this if at all possible. */
#if defined(__linux__)
#if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
typedef struct FsMount {
char *dirname;
char *devtype;
QTAILQ_ENTRY(FsMount) next;
} FsMount;
typedef QTAILQ_HEAD(FsMountList, FsMount) FsMountList;
static void free_fs_mount_list(FsMountList *mounts)
{
FsMount *mount, *temp;
if (!mounts) {
return;
}
QTAILQ_FOREACH_SAFE(mount, mounts, next, temp) {
QTAILQ_REMOVE(mounts, mount, next);
g_free(mount->dirname);
g_free(mount->devtype);
g_free(mount);
}
}
/*
* Walk the mount table and build a list of local file systems
*/
static void build_fs_mount_list(FsMountList *mounts, Error **err)
{
struct mntent *ment;
FsMount *mount;
char const *mtab = "/proc/self/mounts";
FILE *fp;
fp = setmntent(mtab, "r");
if (!fp) {
error_setg(err, "failed to open mtab file: '%s'", mtab);
return;
}
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;
}
mount = g_malloc0(sizeof(FsMount));
mount->dirname = g_strdup(ment->mnt_dir);
mount->devtype = g_strdup(ment->mnt_type);
QTAILQ_INSERT_TAIL(mounts, mount, next);
}
endmntent(fp);
}
#endif
#if defined(CONFIG_FSFREEZE)
typedef enum {
FSFREEZE_HOOK_THAW = 0,
FSFREEZE_HOOK_FREEZE,
} FsfreezeHookArg;
const char *fsfreeze_hook_arg_string[] = {
"thaw",
"freeze",
};
static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **err)
{
int status;
pid_t pid;
const char *hook;
const char *arg_str = fsfreeze_hook_arg_string[arg];
Error *local_err = NULL;
hook = ga_fsfreeze_hook(ga_state);
if (!hook) {
return;
}
if (access(hook, X_OK) != 0) {
error_setg_errno(err, errno, "can't access fsfreeze hook '%s'", hook);
return;
}
slog("executing fsfreeze hook with arg '%s'", arg_str);
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_str, NULL, environ);
_exit(EXIT_FAILURE);
} else if (pid < 0) {
error_setg_errno(err, errno, "failed to create child process");
return;
}
ga_wait_child(pid, &status, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
return;
}
if (!WIFEXITED(status)) {
error_setg(err, "fsfreeze hook has terminated abnormally");
return;
}
status = WEXITSTATUS(status);
if (status) {
error_setg(err, "fsfreeze hook has failed with status %d", status);
return;
}
}
/*
* Return status of freeze/thaw
*/
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
{
if (ga_is_frozen(ga_state)) {
return GUEST_FSFREEZE_STATUS_FROZEN;
}
return GUEST_FSFREEZE_STATUS_THAWED;
}
/*
* 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(Error **err)
{
int ret = 0, i = 0;
FsMountList mounts;
struct FsMount *mount;
Error *local_err = NULL;
int fd;
slog("guest-fsfreeze called");
execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
return -1;
}
QTAILQ_INIT(&mounts);
build_fs_mount_list(&mounts, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
return -1;
}
/* cannot risk guest agent blocking itself on a write in this state */
ga_set_frozen(ga_state);
QTAILQ_FOREACH_REVERSE(mount, &mounts, FsMountList, next) {
fd = qemu_open(mount->dirname, O_RDONLY);
if (fd == -1) {
error_setg_errno(err, errno, "failed to open %s", mount->dirname);
goto error;
}
/* we try to cull filesytems we know won't work in advance, but other
* filesytems may not implement fsfreeze for less obvious reasons.
* these will report EOPNOTSUPP. we simply ignore these when tallying
* the number of frozen filesystems.
*
* 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) {
error_setg_errno(err, errno, "failed to freeze %s",
mount->dirname);
close(fd);
goto error;
}
} else {
i++;
}
close(fd);
}
free_fs_mount_list(&mounts);
return i;
error:
free_fs_mount_list(&mounts);
qmp_guest_fsfreeze_thaw(NULL);
return 0;
}
/*
* Walk list of frozen file systems in the guest, and thaw them.
*/
int64_t qmp_guest_fsfreeze_thaw(Error **err)
{
int ret;
FsMountList mounts;
FsMount *mount;
int fd, i = 0, logged;
Error *local_err = NULL;
QTAILQ_INIT(&mounts);
build_fs_mount_list(&mounts, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
return 0;
}
QTAILQ_FOREACH(mount, &mounts, next) {
logged = false;
fd = qemu_open(mount->dirname, O_RDONLY);
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, err);
return i;
}
static void guest_fsfreeze_cleanup(void)
{
Error *err = NULL;
if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) {
qmp_guest_fsfreeze_thaw(&err);
if (err) {
slog("failed to clean up frozen filesystems: %s",
error_get_pretty(err));
error_free(err);
}
}
}
#endif /* CONFIG_FSFREEZE */
#if defined(CONFIG_FSTRIM)
/*
* Walk list of mounted file systems in the guest, and trim them.
*/
void qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **err)
{
int ret = 0;
FsMountList mounts;
struct FsMount *mount;
int fd;
Error *local_err = NULL;
struct fstrim_range r = {
.start = 0,
.len = -1,
.minlen = has_minimum ? minimum : 0,
};
slog("guest-fstrim called");
QTAILQ_INIT(&mounts);
build_fs_mount_list(&mounts, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
return;
}
QTAILQ_FOREACH(mount, &mounts, next) {
fd = qemu_open(mount->dirname, O_RDONLY);
if (fd == -1) {
error_setg_errno(err, errno, "failed to open %s", mount->dirname);
goto error;
}
/* We try to cull filesytems we know won't work in advance, but other
* filesytems may not implement fstrim for less obvious reasons. These
* will report EOPNOTSUPP; we simply ignore these errors. Any other
* error means an unexpected error, so return it in those cases. In
* some other cases ENOTTY will be reported (e.g. CD-ROMs).
*/
ret = ioctl(fd, FITRIM, &r);
if (ret == -1) {
if (errno != ENOTTY && errno != EOPNOTSUPP) {
error_setg_errno(err, errno, "failed to trim %s",
mount->dirname);
close(fd);
goto error;
}
}
close(fd);
}
error:
free_fs_mount_list(&mounts);
}
#endif /* CONFIG_FSTRIM */
#define LINUX_SYS_STATE_FILE "/sys/power/state"
#define SUSPEND_SUPPORTED 0
#define SUSPEND_NOT_SUPPORTED 1
static void bios_supports_mode(const char *pmutils_bin, const char *pmutils_arg,
const char *sysfile_str, Error **err)
{
Error *local_err = NULL;
char *pmutils_path;
pid_t pid;
int status;
pmutils_path = g_find_program_in_path(pmutils_bin);
pid = fork();
if (!pid) {
char buf[32]; /* hopefully big enough */
ssize_t ret;
int fd;
setsid();
reopen_fd_to_null(0);
reopen_fd_to_null(1);
reopen_fd_to_null(2);
if (pmutils_path) {
execle(pmutils_path, pmutils_bin, pmutils_arg, NULL, environ);
}
/*
* If we get here either pm-utils is not installed or execle() has
* failed. Let's try the manual method if the caller wants it.
*/
if (!sysfile_str) {
_exit(SUSPEND_NOT_SUPPORTED);
}
fd = open(LINUX_SYS_STATE_FILE, O_RDONLY);
if (fd < 0) {
_exit(SUSPEND_NOT_SUPPORTED);
}
ret = read(fd, buf, sizeof(buf)-1);
if (ret <= 0) {
_exit(SUSPEND_NOT_SUPPORTED);
}
buf[ret] = '\0';
if (strstr(buf, sysfile_str)) {
_exit(SUSPEND_SUPPORTED);
}
_exit(SUSPEND_NOT_SUPPORTED);
} else if (pid < 0) {
error_setg_errno(err, errno, "failed to create child process");
goto out;
}
ga_wait_child(pid, &status, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
goto out;
}
if (!WIFEXITED(status)) {
error_setg(err, "child process has terminated abnormally");
goto out;
}
switch (WEXITSTATUS(status)) {
case SUSPEND_SUPPORTED:
goto out;
case SUSPEND_NOT_SUPPORTED:
error_setg(err,
"the requested suspend mode is not supported by the guest");
goto out;
default:
error_setg(err,
"the helper program '%s' returned an unexpected exit status"
" code (%d)", pmutils_path, WEXITSTATUS(status));
goto out;
}
out:
g_free(pmutils_path);
}
static void guest_suspend(const char *pmutils_bin, const char *sysfile_str,
Error **err)
{
Error *local_err = NULL;
char *pmutils_path;
pid_t pid;
int status;
pmutils_path = g_find_program_in_path(pmutils_bin);
pid = fork();
if (pid == 0) {
/* child */
int fd;
setsid();
reopen_fd_to_null(0);
reopen_fd_to_null(1);
reopen_fd_to_null(2);
if (pmutils_path) {
execle(pmutils_path, pmutils_bin, NULL, environ);
}
/*
* If we get here either pm-utils is not installed or execle() has
* failed. Let's try the manual method if the caller wants it.
*/
if (!sysfile_str) {
_exit(EXIT_FAILURE);
}
fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
if (fd < 0) {
_exit(EXIT_FAILURE);
}
if (write(fd, sysfile_str, strlen(sysfile_str)) < 0) {
_exit(EXIT_FAILURE);
}
_exit(EXIT_SUCCESS);
} else if (pid < 0) {
error_setg_errno(err, errno, "failed to create child process");
goto out;
}
ga_wait_child(pid, &status, &local_err);
if (error_is_set(&local_err)) {
error_propagate(err, local_err);
goto out;
}
if (!WIFEXITED(status)) {
error_setg(err, "child process has terminated abnormally");
goto out;
}
if (WEXITSTATUS(status)) {
error_setg(err, "child process has failed to suspend");
goto out;
}
out:
g_free(pmutils_path);
}
void qmp_guest_suspend_disk(Error **err)
{
bios_supports_mode("pm-is-supported", "--hibernate", "disk", err);
if (error_is_set(err)) {
return;
}
guest_suspend("pm-hibernate", "disk", err);
}
void qmp_guest_suspend_ram(Error **err)
{
bios_supports_mode("pm-is-supported", "--suspend", "mem", err);
if (error_is_set(err)) {
return;
}
guest_suspend("pm-suspend", "mem", err);
}
void qmp_guest_suspend_hybrid(Error **err)
{
bios_supports_mode("pm-is-supported", "--suspend-hybrid", NULL, err);
if (error_is_set(err)) {
return;
}
guest_suspend("pm-suspend-hybrid", NULL, err);
}
static GuestNetworkInterfaceList *
guest_find_interface(GuestNetworkInterfaceList *head,
const char *name)
{
for (; head; head = head->next) {
if (strcmp(head->value->name, name) == 0) {
break;
}
}
return head;
}
/*
* Build information about guest interfaces
*/
GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
{
GuestNetworkInterfaceList *head = NULL, *cur_item = NULL;
struct ifaddrs *ifap, *ifa;
if (getifaddrs(&ifap) < 0) {
error_setg_errno(errp, errno, "getifaddrs failed");
goto error;
}
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
GuestNetworkInterfaceList *info;
GuestIpAddressList **address_list = NULL, *address_item = NULL;
char addr4[INET_ADDRSTRLEN];
char addr6[INET6_ADDRSTRLEN];
int sock;
struct ifreq ifr;
unsigned char *mac_addr;
void *p;
g_debug("Processing %s interface", ifa->ifa_name);
info = guest_find_interface(head, ifa->ifa_name);
if (!info) {
info = g_malloc0(sizeof(*info));
info->value = g_malloc0(sizeof(*info->value));
info->value->name = g_strdup(ifa->ifa_name);
if (!cur_item) {
head = cur_item = info;
} else {
cur_item->next = info;
cur_item = info;
}
}
if (!info->value->has_hardware_address &&
ifa->ifa_flags & SIOCGIFHWADDR) {
/* we haven't obtained HW address yet */
sock = socket(PF_INET, SOCK_STREAM, 0);
if (sock == -1) {
error_setg_errno(errp, errno, "failed to create socket");
goto error;
}
memset(&ifr, 0, sizeof(ifr));
pstrcpy(ifr.ifr_name, IF_NAMESIZE, info->value->name);
if (ioctl(sock, SIOCGIFHWADDR, &ifr) == -1) {
error_setg_errno(errp, errno,
"failed to get MAC address of %s",
ifa->ifa_name);
close(sock);
goto error;
}
close(sock);
mac_addr = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
info->value->hardware_address =
g_strdup_printf("%02x:%02x:%02x:%02x:%02x:%02x",
(int) mac_addr[0], (int) mac_addr[1],
(int) mac_addr[2], (int) mac_addr[3],
(int) mac_addr[4], (int) mac_addr[5]);
info->value->has_hardware_address = true;
}
if (ifa->ifa_addr &&
ifa->ifa_addr->sa_family == AF_INET) {
/* interface with IPv4 address */
p = &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
if (!inet_ntop(AF_INET, p, addr4, sizeof(addr4))) {
error_setg_errno(errp, errno, "inet_ntop failed");
goto error;
}
address_item = g_malloc0(sizeof(*address_item));
address_item->value = g_malloc0(sizeof(*address_item->value));
address_item->value->ip_address = g_strdup(addr4);
address_item->value->ip_address_type = GUEST_IP_ADDRESS_TYPE_IPV4;
if (ifa->ifa_netmask) {
/* Count the number of set bits in netmask.
* This is safe as '1' and '0' cannot be shuffled in netmask. */
p = &((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr;
address_item->value->prefix = ctpop32(((uint32_t *) p)[0]);
}
} else if (ifa->ifa_addr &&
ifa->ifa_addr->sa_family == AF_INET6) {
/* interface with IPv6 address */
p = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
if (!inet_ntop(AF_INET6, p, addr6, sizeof(addr6))) {
error_setg_errno(errp, errno, "inet_ntop failed");
goto error;
}
address_item = g_malloc0(sizeof(*address_item));
address_item->value = g_malloc0(sizeof(*address_item->value));
address_item->value->ip_address = g_strdup(addr6);
address_item->value->ip_address_type = GUEST_IP_ADDRESS_TYPE_IPV6;
if (ifa->ifa_netmask) {
/* Count the number of set bits in netmask.
* This is safe as '1' and '0' cannot be shuffled in netmask. */
p = &((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_addr;
address_item->value->prefix =
ctpop32(((uint32_t *) p)[0]) +
ctpop32(((uint32_t *) p)[1]) +
ctpop32(((uint32_t *) p)[2]) +
ctpop32(((uint32_t *) p)[3]);
}
}
if (!address_item) {
continue;
}
address_list = &info->value->ip_addresses;
while (*address_list && (*address_list)->next) {
address_list = &(*address_list)->next;
}
if (!*address_list) {
*address_list = address_item;
} else {
(*address_list)->next = address_item;
}
info->value->has_ip_addresses = true;
}
freeifaddrs(ifap);
return head;
error:
freeifaddrs(ifap);
qapi_free_GuestNetworkInterfaceList(head);
return NULL;
}
#define SYSCONF_EXACT(name, err) sysconf_exact((name), #name, (err))
static long sysconf_exact(int name, const char *name_str, Error **err)
{
long ret;
errno = 0;
ret = sysconf(name);
if (ret == -1) {
if (errno == 0) {
error_setg(err, "sysconf(%s): value indefinite", name_str);
} else {
error_setg_errno(err, errno, "sysconf(%s)", name_str);
}
}
return ret;
}
/* Transfer online/offline status between @vcpu and the guest system.
*
* On input either @errp or *@errp must be NULL.
*
* In system-to-@vcpu direction, the following @vcpu fields are accessed:
* - R: vcpu->logical_id
* - W: vcpu->online
* - W: vcpu->can_offline
*
* In @vcpu-to-system direction, the following @vcpu fields are accessed:
* - R: vcpu->logical_id
* - R: vcpu->online
*
* Written members remain unmodified on error.
*/
static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu,
Error **errp)
{
char *dirpath;
int dirfd;
dirpath = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
vcpu->logical_id);
dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
if (dirfd == -1) {
error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
} else {
static const char fn[] = "online";
int fd;
int res;
fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR);
if (fd == -1) {
if (errno != ENOENT) {
error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn);
} else if (sys2vcpu) {
vcpu->online = true;
vcpu->can_offline = false;
} else if (!vcpu->online) {
error_setg(errp, "logical processor #%" PRId64 " can't be "
"offlined", vcpu->logical_id);
} /* otherwise pretend successful re-onlining */
} else {
unsigned char status;
res = pread(fd, &status, 1, 0);
if (res == -1) {
error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn);
} else if (res == 0) {
error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath,
fn);
} else if (sys2vcpu) {
vcpu->online = (status != '0');
vcpu->can_offline = true;
} else if (vcpu->online != (status != '0')) {
status = '0' + vcpu->online;
if (pwrite(fd, &status, 1, 0) == -1) {
error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath,
fn);
}
} /* otherwise pretend successful re-(on|off)-lining */
res = close(fd);
g_assert(res == 0);
}
res = close(dirfd);
g_assert(res == 0);
}
g_free(dirpath);
}
GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
{
int64_t current;
GuestLogicalProcessorList *head, **link;
long sc_max;
Error *local_err = NULL;
current = 0;
head = NULL;
link = &head;
sc_max = SYSCONF_EXACT(_SC_NPROCESSORS_CONF, &local_err);
while (local_err == NULL && current < sc_max) {
GuestLogicalProcessor *vcpu;
GuestLogicalProcessorList *entry;
vcpu = g_malloc0(sizeof *vcpu);
vcpu->logical_id = current++;
vcpu->has_can_offline = true; /* lolspeak ftw */
transfer_vcpu(vcpu, true, &local_err);
entry = g_malloc0(sizeof *entry);
entry->value = vcpu;
*link = entry;
link = &entry->next;
}
if (local_err == NULL) {
/* there's no guest with zero VCPUs */
g_assert(head != NULL);
return head;
}
qapi_free_GuestLogicalProcessorList(head);
error_propagate(errp, local_err);
return NULL;
}
int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
{
int64_t processed;
Error *local_err = NULL;
processed = 0;
while (vcpus != NULL) {
transfer_vcpu(vcpus->value, false, &local_err);
if (local_err != NULL) {
break;
}
++processed;
vcpus = vcpus->next;
}
if (local_err != NULL) {
if (processed == 0) {
error_propagate(errp, local_err);
} else {
error_free(local_err);
}
}
return processed;
}
#else /* defined(__linux__) */
void qmp_guest_suspend_disk(Error **err)
{
error_set(err, QERR_UNSUPPORTED);
}
void qmp_guest_suspend_ram(Error **err)
{
error_set(err, QERR_UNSUPPORTED);
}
void qmp_guest_suspend_hybrid(Error **err)
{
error_set(err, QERR_UNSUPPORTED);
}
GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
{
error_set(errp, QERR_UNSUPPORTED);
return NULL;
}
GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
{
error_set(errp, QERR_UNSUPPORTED);
return NULL;
}
int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
{
error_set(errp, QERR_UNSUPPORTED);
return -1;
}
#endif
#if !defined(CONFIG_FSFREEZE)
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
{
error_set(err, QERR_UNSUPPORTED);
return 0;
}
int64_t qmp_guest_fsfreeze_freeze(Error **err)
{
error_set(err, QERR_UNSUPPORTED);
return 0;
}
int64_t qmp_guest_fsfreeze_thaw(Error **err)
{
error_set(err, QERR_UNSUPPORTED);
return 0;
}
#endif /* CONFIG_FSFREEZE */
#if !defined(CONFIG_FSTRIM)
void qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **err)
{
error_set(err, QERR_UNSUPPORTED);
}
#endif
/* register init/cleanup routines for stateful command groups */
void ga_command_state_init(GAState *s, GACommandState *cs)
{
#if defined(CONFIG_FSFREEZE)
ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup);
#endif
ga_command_state_add(cs, guest_file_init, NULL);
}
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