diff options
| -rw-r--r-- | libsysfs/sysfs.h | 4 | ||||
| -rw-r--r-- | udevd.c | 167 | ||||
| -rw-r--r-- | udevstart.c | 2 |
3 files changed, 140 insertions, 33 deletions
diff --git a/libsysfs/sysfs.h b/libsysfs/sysfs.h index 1b800ddcd2..0fdb38af19 100644 --- a/libsysfs/sysfs.h +++ b/libsysfs/sysfs.h @@ -37,9 +37,7 @@ #ifdef DEBUG #include "../logging.h" #define dprintf(format, arg...) \ - do { \ - log_message (LOG_DEBUG , "%s: " format , __FUNCTION__ , ## arg); \ - } while (0) + dbg(format, ##arg) #else #define dprintf(format, arg...) do { } while (0) #endif @@ -33,6 +33,7 @@ #include <sys/socket.h> #include <sys/un.h> #include <sys/time.h> +#include <fcntl.h> #include "list.h" #include "udev.h" @@ -41,9 +42,12 @@ #include "udevd.h" #include "logging.h" +static int pipefds[2]; static int expected_seqnum = 0; volatile static int children_waiting; -volatile static int msg_q_timeout; +volatile static int run_msg_q; +volatile static int sig_flag; +static int run_exec_q; static LIST_HEAD(msg_list); static LIST_HEAD(exec_list); @@ -51,6 +55,8 @@ static LIST_HEAD(running_list); static void exec_queue_manager(void); static void msg_queue_manager(void); +static void user_sighandler(void); +static void reap_kids(void); #ifdef LOG unsigned char logname[LOGNAME_SIZE]; @@ -66,10 +72,12 @@ void log_message (int level, const char *format, ...) static void msg_dump_queue(void) { +#ifdef DEBUG struct hotplug_msg *msg; list_for_each_entry(msg, &msg_list, list) dbg("sequence %d in queue", msg->seqnum); +#endif } static void msg_dump(struct hotplug_msg *msg) @@ -92,7 +100,6 @@ static void run_queue_delete(struct hotplug_msg *msg) { list_del(&msg->list); free(msg); - exec_queue_manager(); } /* orders the message in the queue by sequence number */ @@ -100,18 +107,20 @@ static void msg_queue_insert(struct hotplug_msg *msg) { struct hotplug_msg *loop_msg; - /* sort message by sequence number into list*/ - list_for_each_entry(loop_msg, &msg_list, list) - if (loop_msg->seqnum > msg->seqnum) + /* sort message by sequence number into list. events + * will tend to come in order, so scan the list backwards + */ + list_for_each_entry_reverse(loop_msg, &msg_list, list) + if (loop_msg->seqnum < msg->seqnum) break; - list_add_tail(&msg->list, &loop_msg->list); + list_add(&msg->list, &loop_msg->list); dbg("queued message seq %d", msg->seqnum); /* store timestamp of queuing */ msg->queue_time = time(NULL); /* run msg queue manager */ - msg_queue_manager(); + run_msg_q = 1; return ; } @@ -138,6 +147,9 @@ static void udev_run(struct hotplug_msg *msg) case -1: dbg("fork of child failed"); run_queue_delete(msg); + /* note: we never managed to run, so we had no impact on + * running_with_devpath(), so don't bother setting run_exec_q + */ break; default: /* get SIGCHLD in main loop */ @@ -180,7 +192,7 @@ static void exec_queue_manager() static void msg_move_exec(struct hotplug_msg *msg) { list_move_tail(&msg->list, &exec_list); - exec_queue_manager(); + run_exec_q = 1; expected_seqnum = msg->seqnum+1; dbg("moved seq %d to exec, next expected is %d", msg->seqnum, expected_seqnum); @@ -276,7 +288,7 @@ static void handle_msg(int sock) /* if no seqnum is given, we move straight to exec queue */ if (msg->seqnum == -1) { list_add(&msg->list, &exec_list); - exec_queue_manager(); + run_exec_q = 1; } else { msg_queue_insert(msg); } @@ -289,19 +301,37 @@ skip: static void sig_handler(int signum) { + int rc; switch (signum) { case SIGINT: case SIGTERM: exit(20 + signum); break; case SIGALRM: - msg_q_timeout = 1; + /* set flag, then write to pipe if needed */ + run_msg_q = 1; + goto do_write; break; case SIGCHLD: + /* set flag, then write to pipe if needed */ children_waiting = 1; + goto do_write; break; default: dbg("unhandled signal"); + return; + } + +do_write: + /* if pipe is empty, write to pipe to force select to return + * immediately when it gets called + */ + if (!sig_flag) { + rc = write(pipefds[1],&signum,sizeof(signum)); + if (rc < 0) + dbg("unable to write to pipe"); + else + sig_flag = 1; } } @@ -314,19 +344,53 @@ static void udev_done(int pid) if (msg->pid == pid) { dbg("<== exec seq %d came back", msg->seqnum); run_queue_delete(msg); + + /* we want to run the exec queue manager since there may + * be events waiting with the devpath of the one that + * just finished + */ + run_exec_q = 1; return; } } } +static void reap_kids() +{ + /* reap all dead children */ + while(1) { + int pid = waitpid(-1, 0, WNOHANG); + if ((pid == -1) || (pid == 0)) + break; + udev_done(pid); + } +} + +/* just read everything from the pipe and clear the flag, + * the useful flags were set in the signal handler + */ +static void user_sighandler() +{ + int sig; + while(1) { + int rc = read(pipefds[0],&sig,sizeof(sig)); + if (rc < 0) + break; + + sig_flag = 0; + } +} + + int main(int argc, char *argv[]) { - int ssock; + int ssock, maxsockplus; struct sockaddr_un saddr; socklen_t addrlen; int retval; const int on = 1; struct sigaction act; + fd_set readfds; init_logging("udevd"); dbg("version %s", UDEV_VERSION); @@ -335,16 +399,32 @@ int main(int argc, char *argv[]) dbg("need to be root, exit"); exit(1); } - - /* set signal handler */ + + /* setup signal handler pipe */ + retval = pipe(pipefds); + if (retval < 0) { + dbg("error getting pipes: %s", strerror(errno)); + exit(1); + } + + retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK); + if (retval < 0) { + dbg("fcntl on read pipe: %s", strerror(errno)); + exit(1); + } + + retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK); + if (retval < 0) { + dbg("fcntl on write pipe: %s", strerror(errno)); + exit(1); + } + + /* set signal handlers */ act.sa_handler = sig_handler; - sigemptyset (&act.sa_mask); + sigemptyset(&act.sa_mask); act.sa_flags = SA_RESTART; sigaction(SIGINT, &act, NULL); sigaction(SIGTERM, &act, NULL); - - /* we want these two to interrupt system calls */ - act.sa_flags = 0; sigaction(SIGALRM, &act, NULL); sigaction(SIGCHLD, &act, NULL); @@ -370,23 +450,50 @@ int main(int argc, char *argv[]) /* enable receiving of the sender credentials */ setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + FD_ZERO(&readfds); + FD_SET(ssock, &readfds); + FD_SET(pipefds[0], &readfds); + maxsockplus = ssock+1; while (1) { - handle_msg(ssock); - - while(msg_q_timeout) { - msg_q_timeout = 0; - msg_queue_manager(); + fd_set workreadfds = readfds; + retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL); + + if (retval < 0) { + dbg("error in select: %s", strerror(errno)); + continue; } - - while(children_waiting) { + + if (FD_ISSET(ssock, &workreadfds)) + handle_msg(ssock); + + if (FD_ISSET(pipefds[0], &workreadfds)) + user_sighandler(); + + if (children_waiting) { children_waiting = 0; - /* reap all dead children */ - while(1) { - int pid = waitpid(-1, 0, WNOHANG); - if ((pid == -1) || (pid == 0)) - break; - udev_done(pid); + reap_kids(); + } + + if (run_msg_q) { + run_msg_q = 0; + msg_queue_manager(); + } + + if (run_exec_q) { + + /* this is tricky. exec_queue_manager() loops over exec_list, and + * calls running_with_devpath(), which loops over running_list. This gives + * O(N*M), which can get *nasty*. Clean up running_list before + * calling exec_queue_manager(). + */ + + if (children_waiting) { + children_waiting = 0; + reap_kids(); } + + run_exec_q = 0; + exec_queue_manager(); } } exit: diff --git a/udevstart.c b/udevstart.c index 40dbaf2475..eda6355b53 100644 --- a/udevstart.c +++ b/udevstart.c @@ -29,6 +29,8 @@ #include <ctype.h> #include <dirent.h> #include <sys/wait.h> +#include <sys/types.h> +#include <unistd.h> #include "logging.h" |