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udevd.c
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udevd.c
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/*
* Copyright (C) 2004-2012 Kay Sievers <kay@vrfy.org>
* Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
* Copyright (C) 2009 Canonical Ltd.
* Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stddef.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <time.h>
#include <getopt.h>
#include <dirent.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/signalfd.h>
#include <sys/epoll.h>
#include <sys/mount.h>
#include <poll.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/inotify.h>
#include <sys/utsname.h>
#include <sys/sysmacros.h>
#include "udev.h"
#include "udev-util.h"
#include "def.h"
#include "dev-setup.h"
#include "fileio.h"
#include "hashmap.h"
static struct udev_rules *rules;
static struct udev_ctrl *udev_ctrl;
static struct udev_ctrl_connection *udev_ctrl_conn;
static struct udev_monitor *monitor;
static int worker_watch[2] = { -1, -1 };
static int fd_signal = -1;
static int fd_ep = -1;
static int fd_inotify = -1;
static bool stop_exec_queue;
static bool reload;
static bool arg_debug = false;
static int arg_daemonize = false;
static int arg_resolve_names = 1;
static unsigned arg_children_max;
static int arg_exec_delay;
static usec_t arg_event_timeout_usec = 180 * USEC_PER_SEC;
static usec_t arg_event_timeout_warn_usec = 180 * USEC_PER_SEC / 3;
static sigset_t sigmask_orig;
static UDEV_LIST(event_list);
Hashmap *workers;
static struct udev_list properties_list;
static bool udev_exit;
enum event_state {
EVENT_UNDEF,
EVENT_QUEUED,
EVENT_RUNNING,
};
struct event {
struct udev_list_node node;
struct udev *udev;
struct udev_device *dev;
struct udev_device *dev_kernel;
struct worker *worker;
enum event_state state;
unsigned long long int delaying_seqnum;
unsigned long long int seqnum;
const char *devpath;
size_t devpath_len;
const char *devpath_old;
dev_t devnum;
int ifindex;
bool is_block;
usec_t start_usec;
bool warned;
};
static inline struct event *node_to_event(struct udev_list_node *node) {
return container_of(node, struct event, node);
}
static void event_queue_cleanup(struct udev *udev, enum event_state type);
enum worker_state {
WORKER_UNDEF,
WORKER_RUNNING,
WORKER_IDLE,
WORKER_KILLED,
};
struct worker {
struct udev_list_node node;
struct udev *udev;
int refcount;
pid_t pid;
struct udev_monitor *monitor;
enum worker_state state;
struct event *event;
};
/* passed from worker to main process */
struct worker_message {
};
static void event_free(struct event *event) {
if (!event)
return;
udev_list_node_remove(&event->node);
udev_device_unref(event->dev);
udev_device_unref(event->dev_kernel);
if (event->worker)
event->worker->event = NULL;
free(event);
}
static void worker_free(struct worker *worker) {
if (!worker)
return;
hashmap_remove(workers, UINT_TO_PTR(worker->pid));
udev_monitor_unref(worker->monitor);
udev_unref(worker->udev);
event_free(worker->event);
free(worker);
}
static void workers_free(void) {
struct worker *worker;
Iterator i;
HASHMAP_FOREACH(worker, workers, i)
worker_free(worker);
hashmap_free(workers);
workers = NULL;
}
static int worker_new(struct worker **ret, struct udev *udev, struct udev_monitor *worker_monitor, pid_t pid) {
_cleanup_free_ struct worker *worker = NULL;
int r;
assert(ret);
assert(udev);
assert(worker_monitor);
assert(pid > 1);
worker = new0(struct worker, 1);
if (!worker)
return -ENOMEM;
worker->refcount = 1;
worker->udev = udev_ref(udev);
/* close monitor, but keep address around */
udev_monitor_disconnect(worker_monitor);
worker->monitor = udev_monitor_ref(worker_monitor);
worker->pid = pid;
r = hashmap_ensure_allocated(&workers, NULL);
if (r < 0)
return r;
r = hashmap_put(workers, UINT_TO_PTR(pid), worker);
if (r < 0)
return r;
*ret = worker;
worker = NULL;
return 0;
}
static void worker_attach_event(struct worker *worker, struct event *event) {
assert(worker);
assert(event);
assert(!event->worker);
assert(!worker->event);
worker->state = WORKER_RUNNING;
worker->event = event;
event->state = EVENT_RUNNING;
event->start_usec = now(CLOCK_MONOTONIC);
event->warned = false;
event->worker = worker;
}
static int worker_send_message(int fd) {
struct worker_message message = {};
return loop_write(fd, &message, sizeof(message), false);
}
static void worker_spawn(struct event *event) {
struct udev *udev = event->udev;
_cleanup_udev_monitor_unref_ struct udev_monitor *worker_monitor = NULL;
pid_t pid;
/* listen for new events */
worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
if (worker_monitor == NULL)
return;
/* allow the main daemon netlink address to send devices to the worker */
udev_monitor_allow_unicast_sender(worker_monitor, monitor);
udev_monitor_enable_receiving(worker_monitor);
pid = fork();
switch (pid) {
case 0: {
struct udev_device *dev = NULL;
int fd_monitor;
struct epoll_event ep_signal, ep_monitor;
sigset_t mask;
int r = 0;
/* take initial device from queue */
dev = event->dev;
event->dev = NULL;
workers_free();
event_queue_cleanup(udev, EVENT_UNDEF);
udev_monitor_unref(monitor);
udev_ctrl_unref(udev_ctrl);
close(fd_signal);
close(fd_ep);
close(worker_watch[READ_END]);
sigfillset(&mask);
fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
if (fd_signal < 0) {
r = log_error_errno(errno, "error creating signalfd %m");
goto out;
}
fd_ep = epoll_create1(EPOLL_CLOEXEC);
if (fd_ep < 0) {
r = log_error_errno(errno, "error creating epoll fd: %m");
goto out;
}
memzero(&ep_signal, sizeof(struct epoll_event));
ep_signal.events = EPOLLIN;
ep_signal.data.fd = fd_signal;
fd_monitor = udev_monitor_get_fd(worker_monitor);
memzero(&ep_monitor, sizeof(struct epoll_event));
ep_monitor.events = EPOLLIN;
ep_monitor.data.fd = fd_monitor;
if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
r = log_error_errno(errno, "fail to add fds to epoll: %m");
goto out;
}
/* request TERM signal if parent exits */
prctl(PR_SET_PDEATHSIG, SIGTERM);
/* reset OOM score, we only protect the main daemon */
write_string_file("/proc/self/oom_score_adj", "0");
for (;;) {
struct udev_event *udev_event;
int fd_lock = -1;
log_debug("seq %llu running", udev_device_get_seqnum(dev));
udev_event = udev_event_new(dev);
if (udev_event == NULL) {
r = -ENOMEM;
goto out;
}
/* needed for SIGCHLD/SIGTERM in spawn() */
udev_event->fd_signal = fd_signal;
if (arg_exec_delay > 0)
udev_event->exec_delay = arg_exec_delay;
/*
* Take a shared lock on the device node; this establishes
* a concept of device "ownership" to serialize device
* access. External processes holding an exclusive lock will
* cause udev to skip the event handling; in the case udev
* acquired the lock, the external process can block until
* udev has finished its event handling.
*/
if (!streq_ptr(udev_device_get_action(dev), "remove") &&
streq_ptr("block", udev_device_get_subsystem(dev)) &&
!startswith(udev_device_get_sysname(dev), "dm-") &&
!startswith(udev_device_get_sysname(dev), "md")) {
struct udev_device *d = dev;
if (streq_ptr("partition", udev_device_get_devtype(d)))
d = udev_device_get_parent(d);
if (d) {
fd_lock = open(udev_device_get_devnode(d), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
if (fd_lock >= 0 && flock(fd_lock, LOCK_SH|LOCK_NB) < 0) {
log_debug_errno(errno, "Unable to flock(%s), skipping event handling: %m", udev_device_get_devnode(d));
fd_lock = safe_close(fd_lock);
r = -EAGAIN;
goto skip;
}
}
}
/* apply rules, create node, symlinks */
udev_event_execute_rules(udev_event,
arg_event_timeout_usec, arg_event_timeout_warn_usec,
&properties_list,
rules,
&sigmask_orig);
udev_event_execute_run(udev_event,
arg_event_timeout_usec, arg_event_timeout_warn_usec,
&sigmask_orig);
/* apply/restore inotify watch */
if (udev_event->inotify_watch) {
udev_watch_begin(udev, dev);
udev_device_update_db(dev);
}
safe_close(fd_lock);
/* send processed event back to libudev listeners */
udev_monitor_send_device(worker_monitor, NULL, dev);
skip:
log_debug("seq %llu processed", udev_device_get_seqnum(dev));
/* send udevd the result of the event execution */
r = worker_send_message(worker_watch[WRITE_END]);
if (r < 0)
log_error_errno(r, "failed to send result of seq %llu to main daemon: %m",
udev_device_get_seqnum(dev));
udev_device_unref(dev);
dev = NULL;
if (udev_event->sigterm) {
udev_event_unref(udev_event);
goto out;
}
udev_event_unref(udev_event);
/* wait for more device messages from main udevd, or term signal */
while (dev == NULL) {
struct epoll_event ev[4];
int fdcount;
int i;
fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
if (fdcount < 0) {
if (errno == EINTR)
continue;
r = log_error_errno(errno, "failed to poll: %m");
goto out;
}
for (i = 0; i < fdcount; i++) {
if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
dev = udev_monitor_receive_device(worker_monitor);
break;
} else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
struct signalfd_siginfo fdsi;
ssize_t size;
size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
if (size != sizeof(struct signalfd_siginfo))
continue;
switch (fdsi.ssi_signo) {
case SIGTERM:
goto out;
}
}
}
}
}
out:
udev_device_unref(dev);
safe_close(fd_signal);
safe_close(fd_ep);
close(fd_inotify);
close(worker_watch[WRITE_END]);
udev_rules_unref(rules);
udev_builtin_exit(udev);
udev_unref(udev);
log_close();
_exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
}
case -1:
event->state = EVENT_QUEUED;
log_error_errno(errno, "fork of child failed: %m");
break;
default:
{
struct worker *worker;
int r;
r = worker_new(&worker, udev, worker_monitor, pid);
if (r < 0)
return;
worker_attach_event(worker, event);
log_debug("seq %llu forked new worker ["PID_FMT"]", udev_device_get_seqnum(event->dev), pid);
break;
}
}
}
static void event_run(struct event *event) {
struct worker *worker;
Iterator i;
HASHMAP_FOREACH(worker, workers, i) {
ssize_t count;
if (worker->state != WORKER_IDLE)
continue;
count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
if (count < 0) {
log_error_errno(errno, "worker ["PID_FMT"] did not accept message %zi (%m), kill it",
worker->pid, count);
kill(worker->pid, SIGKILL);
worker->state = WORKER_KILLED;
continue;
}
worker_attach_event(worker, event);
return;
}
if (hashmap_size(workers) >= arg_children_max) {
if (arg_children_max > 1)
log_debug("maximum number (%i) of children reached", hashmap_size(workers));
return;
}
/* start new worker and pass initial device */
worker_spawn(event);
}
static int event_queue_insert(struct udev_device *dev) {
struct event *event;
event = new0(struct event, 1);
if (event == NULL)
return -1;
event->udev = udev_device_get_udev(dev);
event->dev = dev;
event->dev_kernel = udev_device_shallow_clone(dev);
udev_device_copy_properties(event->dev_kernel, dev);
event->seqnum = udev_device_get_seqnum(dev);
event->devpath = udev_device_get_devpath(dev);
event->devpath_len = strlen(event->devpath);
event->devpath_old = udev_device_get_devpath_old(dev);
event->devnum = udev_device_get_devnum(dev);
event->is_block = streq("block", udev_device_get_subsystem(dev));
event->ifindex = udev_device_get_ifindex(dev);
log_debug("seq %llu queued, '%s' '%s'", udev_device_get_seqnum(dev),
udev_device_get_action(dev), udev_device_get_subsystem(dev));
event->state = EVENT_QUEUED;
udev_list_node_append(&event->node, &event_list);
return 0;
}
static void worker_kill(void) {
struct worker *worker;
Iterator i;
HASHMAP_FOREACH(worker, workers, i) {
if (worker->state == WORKER_KILLED)
continue;
worker->state = WORKER_KILLED;
kill(worker->pid, SIGTERM);
}
}
/* lookup event for identical, parent, child device */
static bool is_devpath_busy(struct event *event) {
struct udev_list_node *loop;
size_t common;
/* check if queue contains events we depend on */
udev_list_node_foreach(loop, &event_list) {
struct event *loop_event = node_to_event(loop);
/* we already found a later event, earlier can not block us, no need to check again */
if (loop_event->seqnum < event->delaying_seqnum)
continue;
/* event we checked earlier still exists, no need to check again */
if (loop_event->seqnum == event->delaying_seqnum)
return true;
/* found ourself, no later event can block us */
if (loop_event->seqnum >= event->seqnum)
break;
/* check major/minor */
if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
return true;
/* check network device ifindex */
if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
return true;
/* check our old name */
if (event->devpath_old != NULL && streq(loop_event->devpath, event->devpath_old)) {
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* compare devpath */
common = MIN(loop_event->devpath_len, event->devpath_len);
/* one devpath is contained in the other? */
if (memcmp(loop_event->devpath, event->devpath, common) != 0)
continue;
/* identical device event found */
if (loop_event->devpath_len == event->devpath_len) {
/* devices names might have changed/swapped in the meantime */
if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
continue;
if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
continue;
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* parent device event found */
if (event->devpath[common] == '/') {
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* child device event found */
if (loop_event->devpath[common] == '/') {
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* no matching device */
continue;
}
return false;
}
static void event_queue_start(struct udev *udev __attribute__((unused))) {
struct udev_list_node *loop;
udev_list_node_foreach(loop, &event_list) {
struct event *event = node_to_event(loop);
if (event->state != EVENT_QUEUED)
continue;
/* do not start event if parent or child event is still running */
if (is_devpath_busy(event))
continue;
event_run(event);
}
}
static void event_queue_cleanup(struct udev *udev __attribute__((unused)), enum event_state match_type) {
struct udev_list_node *loop, *tmp;
udev_list_node_foreach_safe(loop, tmp, &event_list) {
struct event *event = node_to_event(loop);
if (match_type != EVENT_UNDEF && match_type != event->state)
continue;
event_free(event);
}
}
static void worker_returned(int fd_worker) {
for (;;) {
struct worker_message msg;
struct iovec iovec;
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
} control = {};
struct msghdr msghdr;
struct cmsghdr *cmsg;
ssize_t size;
struct ucred *ucred = NULL;
struct worker *worker;
memzero(&iovec, sizeof(struct iovec));
iovec.iov_base = &msg;
iovec.iov_len = sizeof(msg);
memzero(&msghdr, sizeof(struct msghdr));
msghdr.msg_iov = &iovec;
msghdr.msg_iovlen = 1;
msghdr.msg_control = &control;
msghdr.msg_controllen = sizeof(control);
size = recvmsg(fd_worker, &msghdr, MSG_DONTWAIT);
if (size < 0) {
if (errno == EINTR)
continue;
else if (errno == EAGAIN)
/* nothing more to read */
break;
log_error_errno(errno, "failed to receive message: %m");
return;
} else if (size != sizeof(struct worker_message)) {
log_warning_errno(EIO, "ignoring worker message with invalid size %zi bytes", size);
return;
}
for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_CREDENTIALS &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
ucred = (struct ucred*) CMSG_DATA(cmsg);
}
if (!ucred || ucred->pid <= 0) {
log_warning_errno(EIO, "ignoring worker message without valid PID");
continue;
}
/* lookup worker who sent the signal */
worker = hashmap_get(workers, UINT_TO_PTR(ucred->pid));
if (!worker) {
log_debug("worker ["PID_FMT"] returned, but is no longer tracked", ucred->pid);
continue;
}
if (worker->state != WORKER_KILLED)
worker->state = WORKER_IDLE;
/* worker returned */
event_free(worker->event);
}
}
static void event_queue_update(void) {
int r;
if (!udev_list_node_is_empty(&event_list)) {
r = touch("/run/udev/queue");
if (r < 0)
log_warning_errno(r, "could not touch /run/udev/queue: %m");
} else {
r = unlink("/run/udev/queue");
if (r < 0 && errno != ENOENT)
log_warning("could not unlink /run/udev/queue: %m");
}
}
/* receive the udevd message from userspace */
static void handle_ctrl_msg(struct udev_ctrl *uctrl) {
_cleanup_udev_ctrl_connection_unref_ struct udev_ctrl_connection *ctrl_conn = NULL;
_cleanup_udev_ctrl_msg_unref_ struct udev_ctrl_msg *ctrl_msg = NULL;
const char *str;
int i;
assert(uctrl);
ctrl_conn = udev_ctrl_get_connection(uctrl);
if (!ctrl_conn)
return;
ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
if (!ctrl_msg)
return;
i = udev_ctrl_get_set_log_level(ctrl_msg);
if (i >= 0) {
log_debug("udevd message (SET_LOG_LEVEL) received, log_priority=%i", i);
log_set_max_level(i);
worker_kill();
}
if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
log_debug("udevd message (STOP_EXEC_QUEUE) received");
stop_exec_queue = true;
}
if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
log_debug("udevd message (START_EXEC_QUEUE) received");
stop_exec_queue = false;
}
if (udev_ctrl_get_reload(ctrl_msg) > 0) {
log_debug("udevd message (RELOAD) received");
reload = true;
}
str = udev_ctrl_get_set_env(ctrl_msg);
if (str != NULL) {
char *key;
key = strdup(str);
if (key != NULL) {
char *val;
val = strchr(key, '=');
if (val != NULL) {
val[0] = '\0';
val = &val[1];
if (val[0] == '\0') {
log_debug("udevd message (ENV) received, unset '%s'", key);
udev_list_entry_add(&properties_list, key, NULL);
} else {
log_debug("udevd message (ENV) received, set '%s=%s'", key, val);
udev_list_entry_add(&properties_list, key, val);
}
} else {
log_error("wrong key format '%s'", key);
}
free(key);
}
worker_kill();
}
i = udev_ctrl_get_set_children_max(ctrl_msg);
if (i >= 0) {
log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i", i);
arg_children_max = i;
}
if (udev_ctrl_get_ping(ctrl_msg) > 0) {
log_debug("udevd message (SYNC) received");
/* tell settle that we are busy or idle, this needs to be before the
* PING handling
*/
event_queue_update();
}
if (udev_ctrl_get_exit(ctrl_msg) > 0) {
log_debug("udevd message (EXIT) received");
udev_exit = true;
/* keep reference to block the client until we exit */
udev_ctrl_conn = udev_ctrl_connection_ref(ctrl_conn);
}
return;
}
static int synthesize_change(struct udev_device *dev) {
char filename[UTIL_PATH_SIZE];
int r;
if (streq_ptr("block", udev_device_get_subsystem(dev)) &&
streq_ptr("disk", udev_device_get_devtype(dev)) &&
!startswith(udev_device_get_sysname(dev), "dm-")) {
bool part_table_read = false;
bool has_partitions = false;
int fd;
struct udev *udev = udev_device_get_udev(dev);
_cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
struct udev_list_entry *item;
/*
* Try to re-read the partition table. This only succeeds if
* none of the devices is busy. The kernel returns 0 if no
* partition table is found, and we will not get an event for
* the disk.
*/
fd = open(udev_device_get_devnode(dev), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
if (fd >= 0) {
r = flock(fd, LOCK_EX|LOCK_NB);
if (r >= 0)
r = ioctl(fd, BLKRRPART, 0);
close(fd);
if (r >= 0)
part_table_read = true;
}
/* search for partitions */
e = udev_enumerate_new(udev);
if (!e)
return -ENOMEM;
r = udev_enumerate_add_match_parent(e, dev);
if (r < 0)
return r;
r = udev_enumerate_add_match_subsystem(e, "block");
if (r < 0)
return r;
r = udev_enumerate_scan_devices(e);
if (r < 0)
return r;
udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
_cleanup_udev_device_unref_ struct udev_device *d = NULL;
d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
if (!d)
continue;
if (!streq_ptr("partition", udev_device_get_devtype(d)))
continue;
has_partitions = true;
break;
}
/*
* We have partitions and re-read the table, the kernel already sent
* out a "change" event for the disk, and "remove/add" for all
* partitions.
*/
if (part_table_read && has_partitions)
return 0;
/*
* We have partitions but re-reading the partition table did not
* work, synthesize "change" for the disk and all partitions.
*/
log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
write_string_file(filename, "change");
udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
_cleanup_udev_device_unref_ struct udev_device *d = NULL;
d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
if (!d)
continue;
if (!streq_ptr("partition", udev_device_get_devtype(d)))
continue;
log_debug("device %s closed, synthesising partition '%s' 'change'",
udev_device_get_devnode(dev), udev_device_get_devnode(d));
strscpyl(filename, sizeof(filename), udev_device_get_syspath(d), "/uevent", NULL);
write_string_file(filename, "change");
}
return 0;
}
log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
write_string_file(filename, "change");
return 0;
}
static int handle_inotify(struct udev *udev) {
union inotify_event_buffer buffer;
struct inotify_event *e;
ssize_t l;
l = read(fd_inotify, &buffer, sizeof(buffer));
if (l < 0) {
if (errno == EAGAIN || errno == EINTR)
return 0;
return log_error_errno(errno, "Failed to read inotify fd: %m");
}
FOREACH_INOTIFY_EVENT(e, buffer, l) {
struct udev_device *dev;
dev = udev_watch_lookup(udev, e->wd);
if (!dev)
continue;
log_debug("inotify event: %x for %s", e->mask, udev_device_get_devnode(dev));
if (e->mask & IN_CLOSE_WRITE)
synthesize_change(dev);
else if (e->mask & IN_IGNORED)
udev_watch_end(udev, dev);
udev_device_unref(dev);
}
return 0;
}
static void handle_signal(struct udev *udev __attribute__((unused)), int signo) {
switch (signo) {
case SIGINT:
case SIGTERM:
udev_exit = true;
break;
case SIGCHLD:
for (;;) {
pid_t pid;
int status;
struct worker *worker;
pid = waitpid(-1, &status, WNOHANG);
if (pid <= 0)
break;
worker = hashmap_get(workers, UINT_TO_PTR(pid));
if (!worker) {
log_warning("worker ["PID_FMT"] is unknown, ignoring", pid);
continue;
}
if (WIFEXITED(status)) {
if (WEXITSTATUS(status) == 0)
log_debug("worker ["PID_FMT"] exited", pid);
else
log_warning("worker ["PID_FMT"] exited with return code %i", pid, WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
log_warning("worker ["PID_FMT"] terminated by signal %i (%s)",
pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
} else if (WIFSTOPPED(status)) {
log_info("worker ["PID_FMT"] stopped", pid);
break;
} else if (WIFCONTINUED(status)) {
log_info("worker ["PID_FMT"] continued", pid);
break;
} else {
log_warning("worker ["PID_FMT"] exit with status 0x%04x", pid, status);
}
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
if (worker->event) {
log_error("worker ["PID_FMT"] failed while handling '%s'", pid, worker->event->devpath);
/* delete state from disk */
udev_device_delete_db(worker->event->dev);
udev_device_tag_index(worker->event->dev, NULL, false);
/* forward kernel event without amending it */
udev_monitor_send_device(monitor, NULL, worker->event->dev_kernel);
}
}
worker_free(worker);
}
break;
case SIGHUP:
reload = true;
break;
}
}
/*
* read the kernel command line, in case we need to get into debug mode
* udev.log-priority=<level> syslog priority
* udev.children-max=<number of workers> events are fully serialized if set to 1
* udev.exec-delay=<number of seconds> delay execution of every executed program
* udev.event-timeout=<number of seconds> seconds to wait before terminating an event
*/
static int parse_proc_cmdline_item(const char *key, const char *value) {
int r;
assert(key);
if (!value)
return 0;
if (startswith(key, "rd."))
key += strlen("rd.");