diff options
Diffstat (limited to 'src/core/automount.c')
| -rw-r--r-- | src/core/automount.c | 1135 |
1 files changed, 1135 insertions, 0 deletions
diff --git a/src/core/automount.c b/src/core/automount.c new file mode 100644 index 0000000..a84cddb --- /dev/null +++ b/src/core/automount.c @@ -0,0 +1,1135 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <linux/auto_dev-ioctl.h> +#include <linux/auto_fs4.h> +#include <sys/epoll.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "async.h" +#include "automount.h" +#include "bus-error.h" +#include "bus-util.h" +#include "dbus-automount.h" +#include "dbus-unit.h" +#include "fd-util.h" +#include "format-util.h" +#include "io-util.h" +#include "label.h" +#include "mkdir.h" +#include "mount-util.h" +#include "mount.h" +#include "mountpoint-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "serialize.h" +#include "special.h" +#include "stdio-util.h" +#include "string-table.h" +#include "string-util.h" +#include "unit-name.h" +#include "unit.h" + +static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = { + [AUTOMOUNT_DEAD] = UNIT_INACTIVE, + [AUTOMOUNT_WAITING] = UNIT_ACTIVE, + [AUTOMOUNT_RUNNING] = UNIT_ACTIVE, + [AUTOMOUNT_FAILED] = UNIT_FAILED +}; + +struct expire_data { + int dev_autofs_fd; + int ioctl_fd; +}; + +static void expire_data_free(struct expire_data *data) { + if (!data) + return; + + safe_close(data->dev_autofs_fd); + safe_close(data->ioctl_fd); + free(data); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free); + +static int open_dev_autofs(Manager *m); +static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata); +static int automount_start_expire(Automount *a); +static void automount_stop_expire(Automount *a); +static int automount_send_ready(Automount *a, Set *tokens, int status); + +static void automount_init(Unit *u) { + Automount *a = AUTOMOUNT(u); + + assert(u); + assert(u->load_state == UNIT_STUB); + + a->pipe_fd = -1; + a->directory_mode = 0755; + UNIT(a)->ignore_on_isolate = true; +} + +static void unmount_autofs(Automount *a) { + int r; + + assert(a); + + if (a->pipe_fd < 0) + return; + + a->pipe_event_source = sd_event_source_unref(a->pipe_event_source); + a->pipe_fd = safe_close(a->pipe_fd); + + /* If we reload/reexecute things we keep the mount point around */ + if (!IN_SET(UNIT(a)->manager->objective, MANAGER_RELOAD, MANAGER_REEXECUTE)) { + + automount_send_ready(a, a->tokens, -EHOSTDOWN); + automount_send_ready(a, a->expire_tokens, -EHOSTDOWN); + + if (a->where) { + r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW); + if (r < 0) + log_error_errno(r, "Failed to unmount: %m"); + } + } +} + +static void automount_done(Unit *u) { + Automount *a = AUTOMOUNT(u); + + assert(a); + + unmount_autofs(a); + + a->where = mfree(a->where); + + a->tokens = set_free(a->tokens); + a->expire_tokens = set_free(a->expire_tokens); + + a->expire_event_source = sd_event_source_unref(a->expire_event_source); +} + +static int automount_add_trigger_dependencies(Automount *a) { + Unit *x; + int r; + + assert(a); + + r = unit_load_related_unit(UNIT(a), ".mount", &x); + if (r < 0) + return r; + + return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT); +} + +static int automount_add_mount_dependencies(Automount *a) { + _cleanup_free_ char *parent = NULL; + + assert(a); + + parent = dirname_malloc(a->where); + if (!parent) + return -ENOMEM; + + return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT); +} + +static int automount_add_default_dependencies(Automount *a) { + int r; + + assert(a); + + if (!UNIT(a)->default_dependencies) + return 0; + + if (!MANAGER_IS_SYSTEM(UNIT(a)->manager)) + return 0; + + r = unit_add_dependency_by_name(UNIT(a), UNIT_BEFORE, SPECIAL_LOCAL_FS_TARGET, true, UNIT_DEPENDENCY_DEFAULT); + if (r < 0) + return r; + + r = unit_add_dependency_by_name(UNIT(a), UNIT_AFTER, SPECIAL_LOCAL_FS_PRE_TARGET, true, UNIT_DEPENDENCY_DEFAULT); + if (r < 0) + return r; + + r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, true, UNIT_DEPENDENCY_DEFAULT); + if (r < 0) + return r; + + return 0; +} + +static int automount_verify(Automount *a) { + _cleanup_free_ char *e = NULL; + int r; + + assert(a); + assert(UNIT(a)->load_state == UNIT_LOADED); + + if (path_equal(a->where, "/")) { + log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing."); + return -ENOEXEC; + } + + r = unit_name_from_path(a->where, ".automount", &e); + if (r < 0) + return log_unit_error_errno(UNIT(a), r, "Failed to generate unit name from path: %m"); + + if (!unit_has_name(UNIT(a), e)) { + log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing."); + return -ENOEXEC; + } + + return 0; +} + +static int automount_set_where(Automount *a) { + int r; + + assert(a); + + if (a->where) + return 0; + + r = unit_name_to_path(UNIT(a)->id, &a->where); + if (r < 0) + return r; + + path_simplify(a->where, false); + return 1; +} + +static int automount_add_extras(Automount *a) { + int r; + + r = automount_set_where(a); + if (r < 0) + return r; + + r = automount_add_trigger_dependencies(a); + if (r < 0) + return r; + + r = automount_add_mount_dependencies(a); + if (r < 0) + return r; + + return automount_add_default_dependencies(a); +} + +static int automount_load(Unit *u) { + Automount *a = AUTOMOUNT(u); + int r; + + assert(u); + assert(u->load_state == UNIT_STUB); + + /* Load a .automount file */ + r = unit_load_fragment_and_dropin(u, true); + if (r < 0) + return r; + + if (u->load_state != UNIT_LOADED) + return 0; + + r = automount_add_extras(a); + if (r < 0) + return r; + + return automount_verify(a); +} + +static void automount_set_state(Automount *a, AutomountState state) { + AutomountState old_state; + assert(a); + + if (a->state != state) + bus_unit_send_pending_change_signal(UNIT(a), false); + + old_state = a->state; + a->state = state; + + if (state != AUTOMOUNT_RUNNING) + automount_stop_expire(a); + + if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) + unmount_autofs(a); + + if (state != old_state) + log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state)); + + unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], 0); +} + +static int automount_coldplug(Unit *u) { + Automount *a = AUTOMOUNT(u); + int r; + + assert(a); + assert(a->state == AUTOMOUNT_DEAD); + + if (a->deserialized_state == a->state) + return 0; + + if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) { + + r = automount_set_where(a); + if (r < 0) + return r; + + r = open_dev_autofs(u->manager); + if (r < 0) + return r; + + assert(a->pipe_fd >= 0); + + r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u); + if (r < 0) + return r; + + (void) sd_event_source_set_description(a->pipe_event_source, "automount-io"); + if (a->deserialized_state == AUTOMOUNT_RUNNING) { + r = automount_start_expire(a); + if (r < 0) + log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m"); + } + + automount_set_state(a, a->deserialized_state); + } + + return 0; +} + +static void automount_dump(Unit *u, FILE *f, const char *prefix) { + char time_string[FORMAT_TIMESPAN_MAX]; + Automount *a = AUTOMOUNT(u); + + assert(a); + + fprintf(f, + "%sAutomount State: %s\n" + "%sResult: %s\n" + "%sWhere: %s\n" + "%sDirectoryMode: %04o\n" + "%sTimeoutIdleUSec: %s\n", + prefix, automount_state_to_string(a->state), + prefix, automount_result_to_string(a->result), + prefix, a->where, + prefix, a->directory_mode, + prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC)); +} + +static void automount_enter_dead(Automount *a, AutomountResult f) { + assert(a); + + if (a->result == AUTOMOUNT_SUCCESS) + a->result = f; + + unit_log_result(UNIT(a), a->result == AUTOMOUNT_SUCCESS, automount_result_to_string(a->result)); + automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD); +} + +static int open_dev_autofs(Manager *m) { + struct autofs_dev_ioctl param; + + assert(m); + + if (m->dev_autofs_fd >= 0) + return m->dev_autofs_fd; + + (void) label_fix("/dev/autofs", 0); + + m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY); + if (m->dev_autofs_fd < 0) + return log_error_errno(errno, "Failed to open /dev/autofs: %m"); + + init_autofs_dev_ioctl(¶m); + if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, ¶m) < 0) { + m->dev_autofs_fd = safe_close(m->dev_autofs_fd); + return -errno; + } + + log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor); + + return m->dev_autofs_fd; +} + +static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) { + struct autofs_dev_ioctl *param; + size_t l; + + assert(dev_autofs_fd >= 0); + assert(where); + + l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1; + param = alloca(l); + + init_autofs_dev_ioctl(param); + param->size = l; + param->ioctlfd = -1; + param->openmount.devid = devid; + strcpy(param->path, where); + + if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0) + return -errno; + + if (param->ioctlfd < 0) + return -EIO; + + (void) fd_cloexec(param->ioctlfd, true); + return param->ioctlfd; +} + +static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) { + uint32_t major, minor; + struct autofs_dev_ioctl param; + + assert(dev_autofs_fd >= 0); + assert(ioctl_fd >= 0); + + init_autofs_dev_ioctl(¶m); + param.ioctlfd = ioctl_fd; + + if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, ¶m) < 0) + return -errno; + + major = param.protover.version; + + init_autofs_dev_ioctl(¶m); + param.ioctlfd = ioctl_fd; + + if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, ¶m) < 0) + return -errno; + + minor = param.protosubver.sub_version; + + log_debug("Autofs protocol version %i.%i", major, minor); + return 0; +} + +static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) { + struct autofs_dev_ioctl param; + + assert(dev_autofs_fd >= 0); + assert(ioctl_fd >= 0); + + init_autofs_dev_ioctl(¶m); + param.ioctlfd = ioctl_fd; + + if (usec == USEC_INFINITY) + param.timeout.timeout = 0; + else + /* Convert to seconds, rounding up. */ + param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC); + + if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, ¶m) < 0) + return -errno; + + return 0; +} + +static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) { + struct autofs_dev_ioctl param; + + assert(dev_autofs_fd >= 0); + assert(ioctl_fd >= 0); + + init_autofs_dev_ioctl(¶m); + param.ioctlfd = ioctl_fd; + + if (status != 0) { + param.fail.token = token; + param.fail.status = status; + } else + param.ready.token = token; + + if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, ¶m) < 0) + return -errno; + + return 0; +} + +static int automount_send_ready(Automount *a, Set *tokens, int status) { + _cleanup_close_ int ioctl_fd = -1; + unsigned token; + int r; + + assert(a); + assert(status <= 0); + + if (set_isempty(tokens)) + return 0; + + ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id); + if (ioctl_fd < 0) + return ioctl_fd; + + if (status != 0) + log_unit_debug_errno(UNIT(a), status, "Sending failure: %m"); + else + log_unit_debug(UNIT(a), "Sending success."); + + r = 0; + + /* Autofs thankfully does not hand out 0 as a token */ + while ((token = PTR_TO_UINT(set_steal_first(tokens)))) { + int k; + + /* Autofs fun fact: + * + * if you pass a positive status code here, kernels + * prior to 4.12 will freeze! Yay! */ + + k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd, + ioctl_fd, + token, + status); + if (k < 0) + r = k; + } + + return r; +} + +static void automount_trigger_notify(Unit *u, Unit *other) { + Automount *a = AUTOMOUNT(u); + int r; + + assert(a); + assert(other); + + /* Filter out invocations with bogus state */ + assert(UNIT_IS_LOAD_COMPLETE(other->load_state)); + assert(other->type == UNIT_MOUNT); + + /* Don't propagate state changes from the mount if we are already down */ + if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) + return; + + /* Propagate start limit hit state */ + if (other->start_limit_hit) { + automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT); + return; + } + + /* Don't propagate anything if there's still a job queued */ + if (other->job) + return; + + /* The mount is successfully established */ + if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) { + (void) automount_send_ready(a, a->tokens, 0); + + r = automount_start_expire(a); + if (r < 0) + log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m"); + + automount_set_state(a, AUTOMOUNT_RUNNING); + } + + if (IN_SET(MOUNT(other)->state, + MOUNT_MOUNTING, MOUNT_MOUNTING_DONE, + MOUNT_MOUNTED, MOUNT_REMOUNTING, + MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL, + MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL, + MOUNT_FAILED)) + (void) automount_send_ready(a, a->expire_tokens, -ENODEV); + + if (MOUNT(other)->state == MOUNT_DEAD) + (void) automount_send_ready(a, a->expire_tokens, 0); + + /* The mount is in some unhappy state now, let's unfreeze any waiting clients */ + if (IN_SET(MOUNT(other)->state, + MOUNT_DEAD, MOUNT_UNMOUNTING, + MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL, + MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL, + MOUNT_FAILED)) { + + (void) automount_send_ready(a, a->tokens, -ENODEV); + + automount_set_state(a, AUTOMOUNT_WAITING); + } +} + +static void automount_enter_waiting(Automount *a) { + _cleanup_close_ int ioctl_fd = -1; + int p[2] = { -1, -1 }; + char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1]; + char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct") + + DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1]; + bool mounted = false; + int r, dev_autofs_fd; + struct stat st; + + assert(a); + assert(a->pipe_fd < 0); + assert(a->where); + + set_clear(a->tokens); + + r = unit_fail_if_noncanonical(UNIT(a), a->where); + if (r < 0) + goto fail; + + (void) mkdir_p_label(a->where, a->directory_mode); + + unit_warn_if_dir_nonempty(UNIT(a), a->where); + + dev_autofs_fd = open_dev_autofs(UNIT(a)->manager); + if (dev_autofs_fd < 0) { + r = dev_autofs_fd; + goto fail; + } + + if (pipe2(p, O_CLOEXEC) < 0) { + r = -errno; + goto fail; + } + r = fd_nonblock(p[0], true); + if (r < 0) + goto fail; + + xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp()); + xsprintf(name, "systemd-"PID_FMT, getpid_cached()); + r = mount_nofollow(name, a->where, "autofs", 0, options); + if (r < 0) + goto fail; + + mounted = true; + + p[1] = safe_close(p[1]); + + if (stat(a->where, &st) < 0) { + r = -errno; + goto fail; + } + + ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev); + if (ioctl_fd < 0) { + r = ioctl_fd; + goto fail; + } + + r = autofs_protocol(dev_autofs_fd, ioctl_fd); + if (r < 0) + goto fail; + + r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec); + if (r < 0) + goto fail; + + r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a); + if (r < 0) + goto fail; + + (void) sd_event_source_set_description(a->pipe_event_source, "automount-io"); + + a->pipe_fd = p[0]; + a->dev_id = st.st_dev; + + automount_set_state(a, AUTOMOUNT_WAITING); + + return; + +fail: + log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m"); + + safe_close_pair(p); + + if (mounted) { + r = repeat_unmount(a->where, MNT_DETACH|UMOUNT_NOFOLLOW); + if (r < 0) + log_error_errno(r, "Failed to unmount, ignoring: %m"); + } + + automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES); +} + +static void *expire_thread(void *p) { + struct autofs_dev_ioctl param; + _cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p; + int r; + + assert(data->dev_autofs_fd >= 0); + assert(data->ioctl_fd >= 0); + + init_autofs_dev_ioctl(¶m); + param.ioctlfd = data->ioctl_fd; + + do { + r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, ¶m); + } while (r >= 0); + + if (errno != EAGAIN) + log_warning_errno(errno, "Failed to expire automount, ignoring: %m"); + + return NULL; +} + +static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) { + Automount *a = AUTOMOUNT(userdata); + _cleanup_(expire_data_freep) struct expire_data *data = NULL; + int r; + + assert(a); + assert(source == a->expire_event_source); + + data = new0(struct expire_data, 1); + if (!data) + return log_oom(); + + data->ioctl_fd = -1; + + data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3); + if (data->dev_autofs_fd < 0) + return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m"); + + data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id); + if (data->ioctl_fd < 0) + return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m"); + + r = asynchronous_job(expire_thread, data); + if (r < 0) + return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m"); + + data = NULL; + + return automount_start_expire(a); +} + +static int automount_start_expire(Automount *a) { + usec_t timeout; + int r; + + assert(a); + + if (a->timeout_idle_usec == 0) + return 0; + + timeout = MAX(a->timeout_idle_usec/3, USEC_PER_SEC); + + if (a->expire_event_source) { + r = sd_event_source_set_time_relative(a->expire_event_source, timeout); + if (r < 0) + return r; + + return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT); + } + + r = sd_event_add_time_relative( + UNIT(a)->manager->event, + &a->expire_event_source, + CLOCK_MONOTONIC, timeout, 0, + automount_dispatch_expire, a); + if (r < 0) + return r; + + (void) sd_event_source_set_description(a->expire_event_source, "automount-expire"); + + return 0; +} + +static void automount_stop_expire(Automount *a) { + assert(a); + + if (!a->expire_event_source) + return; + + (void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF); +} + +static void automount_enter_running(Automount *a) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + Unit *trigger; + struct stat st; + int r; + + assert(a); + + /* If the user masked our unit in the meantime, fail */ + if (UNIT(a)->load_state != UNIT_LOADED) { + log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded."); + goto fail; + } + + /* We don't take mount requests anymore if we are supposed to + * shut down anyway */ + if (unit_stop_pending(UNIT(a))) { + log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled."); + automount_send_ready(a, a->tokens, -EHOSTDOWN); + automount_send_ready(a, a->expire_tokens, -EHOSTDOWN); + return; + } + + (void) mkdir_p_label(a->where, a->directory_mode); + + /* Before we do anything, let's see if somebody is playing games with us? */ + if (lstat(a->where, &st) < 0) { + log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m"); + goto fail; + } + + /* The mount unit may have been explicitly started before we got the + * autofs request. Ack it to unblock anything waiting on the mount point. */ + if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) { + log_unit_info(UNIT(a), "Automount point already active?"); + automount_send_ready(a, a->tokens, 0); + return; + } + + trigger = UNIT_TRIGGER(UNIT(a)); + if (!trigger) { + log_unit_error(UNIT(a), "Unit to trigger vanished."); + goto fail; + } + + r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, NULL, &error, NULL); + if (r < 0) { + log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r)); + goto fail; + } + + automount_set_state(a, AUTOMOUNT_RUNNING); + return; + +fail: + automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES); +} + +static int automount_start(Unit *u) { + Automount *a = AUTOMOUNT(u); + int r; + + assert(a); + assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED)); + + if (path_is_mount_point(a->where, NULL, 0) > 0) { + log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where); + return -EEXIST; + } + + r = unit_test_trigger_loaded(u); + if (r < 0) + return r; + + r = unit_test_start_limit(u); + if (r < 0) { + automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT); + return r; + } + + r = unit_acquire_invocation_id(u); + if (r < 0) + return r; + + a->result = AUTOMOUNT_SUCCESS; + automount_enter_waiting(a); + return 1; +} + +static int automount_stop(Unit *u) { + Automount *a = AUTOMOUNT(u); + + assert(a); + assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)); + + automount_enter_dead(a, AUTOMOUNT_SUCCESS); + return 1; +} + +static int automount_serialize(Unit *u, FILE *f, FDSet *fds) { + Automount *a = AUTOMOUNT(u); + void *p; + int r; + + assert(a); + assert(f); + assert(fds); + + (void) serialize_item(f, "state", automount_state_to_string(a->state)); + (void) serialize_item(f, "result", automount_result_to_string(a->result)); + (void) serialize_item_format(f, "dev-id", "%lu", (unsigned long) a->dev_id); + + SET_FOREACH(p, a->tokens) + (void) serialize_item_format(f, "token", "%u", PTR_TO_UINT(p)); + SET_FOREACH(p, a->expire_tokens) + (void) serialize_item_format(f, "expire-token", "%u", PTR_TO_UINT(p)); + + r = serialize_fd(f, fds, "pipe-fd", a->pipe_fd); + if (r < 0) + return r; + + return 0; +} + +static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { + Automount *a = AUTOMOUNT(u); + int r; + + assert(a); + assert(fds); + + if (streq(key, "state")) { + AutomountState state; + + state = automount_state_from_string(value); + if (state < 0) + log_unit_debug(u, "Failed to parse state value: %s", value); + else + a->deserialized_state = state; + } else if (streq(key, "result")) { + AutomountResult f; + + f = automount_result_from_string(value); + if (f < 0) + log_unit_debug(u, "Failed to parse result value: %s", value); + else if (f != AUTOMOUNT_SUCCESS) + a->result = f; + + } else if (streq(key, "dev-id")) { + unsigned long d; + + if (safe_atolu(value, &d) < 0) + log_unit_debug(u, "Failed to parse dev-id value: %s", value); + else + a->dev_id = (dev_t) d; + + } else if (streq(key, "token")) { + unsigned token; + + if (safe_atou(value, &token) < 0) + log_unit_debug(u, "Failed to parse token value: %s", value); + else { + r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(token)); + if (r < 0) + log_unit_error_errno(u, r, "Failed to add token to set: %m"); + } + } else if (streq(key, "expire-token")) { + unsigned token; + + if (safe_atou(value, &token) < 0) + log_unit_debug(u, "Failed to parse token value: %s", value); + else { + r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(token)); + if (r < 0) + log_unit_error_errno(u, r, "Failed to add expire token to set: %m"); + } + } else if (streq(key, "pipe-fd")) { + int fd; + + if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd)) + log_unit_debug(u, "Failed to parse pipe-fd value: %s", value); + else { + safe_close(a->pipe_fd); + a->pipe_fd = fdset_remove(fds, fd); + } + } else + log_unit_debug(u, "Unknown serialization key: %s", key); + + return 0; +} + +static UnitActiveState automount_active_state(Unit *u) { + assert(u); + + return state_translation_table[AUTOMOUNT(u)->state]; +} + +static const char *automount_sub_state_to_string(Unit *u) { + assert(u); + + return automount_state_to_string(AUTOMOUNT(u)->state); +} + +static bool automount_may_gc(Unit *u) { + Unit *t; + + assert(u); + + t = UNIT_TRIGGER(u); + if (!t) + return true; + + return UNIT_VTABLE(t)->may_gc(t); +} + +static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + union autofs_v5_packet_union packet; + Automount *a = AUTOMOUNT(userdata); + Unit *trigger; + int r; + + assert(a); + assert(fd == a->pipe_fd); + + if (events & (EPOLLHUP|EPOLLERR)) { + log_unit_error(UNIT(a), "Got hangup/error on autofs pipe from kernel. Likely our automount point has been unmounted by someone or something else?"); + automount_enter_dead(a, AUTOMOUNT_FAILURE_UNMOUNTED); + return 0; + } + + if (events != EPOLLIN) { + log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd); + goto fail; + } + + r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true); + if (r < 0) { + log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m"); + goto fail; + } + + switch (packet.hdr.type) { + + case autofs_ptype_missing_direct: + + if (packet.v5_packet.pid > 0) { + _cleanup_free_ char *p = NULL; + + (void) get_process_comm(packet.v5_packet.pid, &p); + log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p)); + } else + log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where); + + r = set_ensure_put(&a->tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token)); + if (r < 0) { + log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m"); + goto fail; + } + + automount_enter_running(a); + break; + + case autofs_ptype_expire_direct: + log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where); + + automount_stop_expire(a); + + r = set_ensure_put(&a->expire_tokens, NULL, UINT_TO_PTR(packet.v5_packet.wait_queue_token)); + if (r < 0) { + log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m"); + goto fail; + } + + trigger = UNIT_TRIGGER(UNIT(a)); + if (!trigger) { + log_unit_error(UNIT(a), "Unit to trigger vanished."); + goto fail; + } + + r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, NULL, &error, NULL); + if (r < 0) { + log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r)); + goto fail; + } + break; + + default: + log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type); + break; + } + + return 0; + +fail: + automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES); + return 0; +} + +static void automount_shutdown(Manager *m) { + assert(m); + + m->dev_autofs_fd = safe_close(m->dev_autofs_fd); +} + +static void automount_reset_failed(Unit *u) { + Automount *a = AUTOMOUNT(u); + + assert(a); + + if (a->state == AUTOMOUNT_FAILED) + automount_set_state(a, AUTOMOUNT_DEAD); + + a->result = AUTOMOUNT_SUCCESS; +} + +static bool automount_supported(void) { + static int supported = -1; + + if (supported < 0) + supported = access("/dev/autofs", F_OK) >= 0; + + return supported; +} + +static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = { + [AUTOMOUNT_SUCCESS] = "success", + [AUTOMOUNT_FAILURE_RESOURCES] = "resources", + [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit", + [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit", + [AUTOMOUNT_FAILURE_UNMOUNTED] = "unmounted", +}; + +DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult); + +const UnitVTable automount_vtable = { + .object_size = sizeof(Automount), + + .sections = + "Unit\0" + "Automount\0" + "Install\0", + .private_section = "Automount", + + .can_transient = true, + .can_fail = true, + .can_trigger = true, + + .init = automount_init, + .load = automount_load, + .done = automount_done, + + .coldplug = automount_coldplug, + + .dump = automount_dump, + + .start = automount_start, + .stop = automount_stop, + + .serialize = automount_serialize, + .deserialize_item = automount_deserialize_item, + + .active_state = automount_active_state, + .sub_state_to_string = automount_sub_state_to_string, + + .may_gc = automount_may_gc, + + .trigger_notify = automount_trigger_notify, + + .reset_failed = automount_reset_failed, + + .bus_set_property = bus_automount_set_property, + + .shutdown = automount_shutdown, + .supported = automount_supported, + + .status_message_formats = { + .finished_start_job = { + [JOB_DONE] = "Set up automount %s.", + [JOB_FAILED] = "Failed to set up automount %s.", + }, + .finished_stop_job = { + [JOB_DONE] = "Unset automount %s.", + [JOB_FAILED] = "Failed to unset automount %s.", + }, + }, +}; |