diff options
Diffstat (limited to 'src/libsystemd/sd-event/sd-event.c')
| -rw-r--r-- | src/libsystemd/sd-event/sd-event.c | 180 |
1 files changed, 151 insertions, 29 deletions
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c index b06e00fae2..37efe3f425 100644 --- a/src/libsystemd/sd-event/sd-event.c +++ b/src/libsystemd/sd-event/sd-event.c @@ -1820,6 +1820,29 @@ static void event_free_inode_data( free(d); } +static void event_gc_inotify_data( + sd_event *e, + struct inotify_data *d) { + + assert(e); + + /* GCs the inotify data object if we don't need it anymore. That's the case if we don't want to watch + * any inode with it anymore, which in turn happens if no event source of this priority is interested + * in any inode any longer. That said, we maintain an extra busy counter: if non-zero we'll delay GC + * (under the expectation that the GC is called again once the counter is decremented). */ + + if (!d) + return; + + if (!hashmap_isempty(d->inodes)) + return; + + if (d->n_busy > 0) + return; + + event_free_inotify_data(e, d); +} + static void event_gc_inode_data( sd_event *e, struct inode_data *d) { @@ -1837,8 +1860,7 @@ static void event_gc_inode_data( inotify_data = d->inotify_data; event_free_inode_data(e, d); - if (inotify_data && hashmap_isempty(inotify_data->inodes)) - event_free_inotify_data(e, inotify_data); + event_gc_inotify_data(e, inotify_data); } static int event_make_inode_data( @@ -1967,24 +1989,25 @@ static int inotify_exit_callback(sd_event_source *s, const struct inotify_event return sd_event_exit(sd_event_source_get_event(s), PTR_TO_INT(userdata)); } -_public_ int sd_event_add_inotify( +static int event_add_inotify_fd_internal( sd_event *e, sd_event_source **ret, - const char *path, + int fd, + bool donate, uint32_t mask, sd_event_inotify_handler_t callback, void *userdata) { + _cleanup_close_ int donated_fd = donate ? fd : -1; + _cleanup_(source_freep) sd_event_source *s = NULL; struct inotify_data *inotify_data = NULL; struct inode_data *inode_data = NULL; - _cleanup_close_ int fd = -1; - _cleanup_(source_freep) sd_event_source *s = NULL; struct stat st; int r; assert_return(e, -EINVAL); assert_return(e = event_resolve(e), -ENOPKG); - assert_return(path, -EINVAL); + assert_return(fd >= 0, -EBADF); assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); assert_return(!event_pid_changed(e), -ECHILD); @@ -1997,12 +2020,6 @@ _public_ int sd_event_add_inotify( if (mask & IN_MASK_ADD) return -EINVAL; - fd = open(path, O_PATH|O_CLOEXEC| - (mask & IN_ONLYDIR ? O_DIRECTORY : 0)| - (mask & IN_DONT_FOLLOW ? O_NOFOLLOW : 0)); - if (fd < 0) - return -errno; - if (fstat(fd, &st) < 0) return -errno; @@ -2022,14 +2039,24 @@ _public_ int sd_event_add_inotify( r = event_make_inode_data(e, inotify_data, st.st_dev, st.st_ino, &inode_data); if (r < 0) { - event_free_inotify_data(e, inotify_data); + event_gc_inotify_data(e, inotify_data); return r; } /* Keep the O_PATH fd around until the first iteration of the loop, so that we can still change the priority of * the event source, until then, for which we need the original inode. */ if (inode_data->fd < 0) { - inode_data->fd = TAKE_FD(fd); + if (donated_fd >= 0) + inode_data->fd = TAKE_FD(donated_fd); + else { + inode_data->fd = fcntl(fd, F_DUPFD_CLOEXEC, 3); + if (inode_data->fd < 0) { + r = -errno; + event_gc_inode_data(e, inode_data); + return r; + } + } + LIST_PREPEND(to_close, e->inode_data_to_close, inode_data); } @@ -2042,8 +2069,6 @@ _public_ int sd_event_add_inotify( if (r < 0) return r; - (void) sd_event_source_set_description(s, path); - if (ret) *ret = s; TAKE_PTR(s); @@ -2051,6 +2076,48 @@ _public_ int sd_event_add_inotify( return 0; } +_public_ int sd_event_add_inotify_fd( + sd_event *e, + sd_event_source **ret, + int fd, + uint32_t mask, + sd_event_inotify_handler_t callback, + void *userdata) { + + return event_add_inotify_fd_internal(e, ret, fd, /* donate= */ false, mask, callback, userdata); +} + +_public_ int sd_event_add_inotify( + sd_event *e, + sd_event_source **ret, + const char *path, + uint32_t mask, + sd_event_inotify_handler_t callback, + void *userdata) { + + sd_event_source *s; + int fd, r; + + assert_return(path, -EINVAL); + + fd = open(path, O_PATH|O_CLOEXEC| + (mask & IN_ONLYDIR ? O_DIRECTORY : 0)| + (mask & IN_DONT_FOLLOW ? O_NOFOLLOW : 0)); + if (fd < 0) + return -errno; + + r = event_add_inotify_fd_internal(e, &s, fd, /* donate= */ true, mask, callback, userdata); + if (r < 0) + return r; + + (void) sd_event_source_set_description(s, path); + + if (ret) + *ret = s; + + return r; +} + static sd_event_source* event_source_free(sd_event_source *s) { if (!s) return NULL; @@ -2841,7 +2908,7 @@ fail: return r; } -static int event_source_leave_ratelimit(sd_event_source *s) { +static int event_source_leave_ratelimit(sd_event_source *s, bool run_callback) { int r; assert(s); @@ -2873,6 +2940,30 @@ static int event_source_leave_ratelimit(sd_event_source *s) { ratelimit_reset(&s->rate_limit); log_debug("Event source %p (%s) left rate limit state.", s, strna(s->description)); + + if (run_callback && s->ratelimit_expire_callback) { + s->dispatching = true; + r = s->ratelimit_expire_callback(s, s->userdata); + s->dispatching = false; + + if (r < 0) { + log_debug_errno(r, "Ratelimit expiry callback of event source %s (type %s) returned error, %s: %m", + strna(s->description), + event_source_type_to_string(s->type), + s->exit_on_failure ? "exiting" : "disabling"); + + if (s->exit_on_failure) + (void) sd_event_exit(s->event, r); + } + + if (s->n_ref == 0) + source_free(s); + else if (r < 0) + sd_event_source_set_enabled(s, SD_EVENT_OFF); + + return 1; + } + return 0; fail: @@ -3072,6 +3163,7 @@ static int process_timer( struct clock_data *d) { sd_event_source *s; + bool callback_invoked = false; int r; assert(e); @@ -3089,9 +3181,11 @@ static int process_timer( * again. */ assert(s->ratelimited); - r = event_source_leave_ratelimit(s); + r = event_source_leave_ratelimit(s, /* run_callback */ true); if (r < 0) return r; + else if (r == 1) + callback_invoked = true; continue; } @@ -3106,7 +3200,7 @@ static int process_timer( event_source_time_prioq_reshuffle(s); } - return 0; + return callback_invoked; } static int process_child(sd_event *e, int64_t threshold, int64_t *ret_min_priority) { @@ -3556,13 +3650,23 @@ static int source_dispatch(sd_event_source *s) { sz = offsetof(struct inotify_event, name) + d->buffer.ev.len; assert(d->buffer_filled >= sz); + /* If the inotify callback destroys the event source then this likely means we don't need to + * watch the inode anymore, and thus also won't need the inotify object anymore. But if we'd + * free it immediately, then we couldn't drop the event from the inotify event queue without + * memory corruption anymore, as below. Hence, let's not free it immediately, but mark it + * "busy" with a counter (which will ensure it's not GC'ed away prematurely). Let's then + * explicitly GC it after we are done dropping the inotify event from the buffer. */ + d->n_busy++; r = s->inotify.callback(s, &d->buffer.ev, s->userdata); + d->n_busy--; - /* When no event is pending anymore on this inotify object, then let's drop the event from the - * buffer. */ + /* When no event is pending anymore on this inotify object, then let's drop the event from + * the inotify event queue buffer. */ if (d->n_pending == 0) event_inotify_data_drop(e, d, sz); + /* Now we don't want to access 'd' anymore, it's OK to GC now. */ + event_gc_inotify_data(e, d); break; } @@ -3587,7 +3691,7 @@ static int source_dispatch(sd_event_source *s) { if (s->n_ref == 0) source_free(s); else if (r < 0) - sd_event_source_set_enabled(s, SD_EVENT_OFF); + assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0); return 1; } @@ -3628,7 +3732,7 @@ static int event_prepare(sd_event *e) { if (s->n_ref == 0) source_free(s); else if (r < 0) - sd_event_source_set_enabled(s, SD_EVENT_OFF); + assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0); } return 0; @@ -4020,15 +4124,15 @@ _public_ int sd_event_wait(sd_event *e, uint64_t timeout) { if (r < 0) goto finish; - r = process_timer(e, e->timestamp.realtime, &e->realtime); + r = process_inotify(e); if (r < 0) goto finish; - r = process_timer(e, e->timestamp.boottime, &e->boottime); + r = process_timer(e, e->timestamp.realtime, &e->realtime); if (r < 0) goto finish; - r = process_timer(e, e->timestamp.monotonic, &e->monotonic); + r = process_timer(e, e->timestamp.boottime, &e->boottime); if (r < 0) goto finish; @@ -4040,9 +4144,20 @@ _public_ int sd_event_wait(sd_event *e, uint64_t timeout) { if (r < 0) goto finish; - r = process_inotify(e); + r = process_timer(e, e->timestamp.monotonic, &e->monotonic); if (r < 0) goto finish; + else if (r == 1) { + /* Ratelimit expiry callback was called. Let's postpone processing pending sources and + * put loop in the initial state in order to evaluate (in the next iteration) also sources + * there were potentially re-enabled by the callback. + * + * Wondering why we treat only this invocation of process_timer() differently? Once event + * source is ratelimited we essentially transform it into CLOCK_MONOTONIC timer hence + * ratelimit expiry callback is never called for any other timer type. */ + r = 0; + goto finish; + } if (event_next_pending(e)) { e->state = SD_EVENT_PENDING; @@ -4411,7 +4526,7 @@ _public_ int sd_event_source_set_ratelimit(sd_event_source *s, uint64_t interval /* When ratelimiting is configured we'll always reset the rate limit state first and start fresh, * non-ratelimited. */ - r = event_source_leave_ratelimit(s); + r = event_source_leave_ratelimit(s, /* run_callback */ false); if (r < 0) return r; @@ -4419,6 +4534,13 @@ _public_ int sd_event_source_set_ratelimit(sd_event_source *s, uint64_t interval return 0; } +_public_ int sd_event_source_set_ratelimit_expire_callback(sd_event_source *s, sd_event_handler_t callback) { + assert_return(s, -EINVAL); + + s->ratelimit_expire_callback = callback; + return 0; +} + _public_ int sd_event_source_get_ratelimit(sd_event_source *s, uint64_t *ret_interval, unsigned *ret_burst) { assert_return(s, -EINVAL); |