X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=6e27c8a0d141779edfe2f8e3420c0d4b927a1bdf;hp=f1e28d9ca3de7ba9e72d87ab5054159a7ebfb840;hb=7f7ae03a6290ccc1e4ca57416fe871dae4b865d2;hpb=f15515b59ff373c3b9524a0842e96c1d105f5a62 diff --git a/udevd.c b/udevd.c index f1e28d9ca..6e27c8a0d 100644 --- a/udevd.c +++ b/udevd.c @@ -1,7 +1,7 @@ /* * udevd.c - hotplug event serializer * - * Copyright (C) 2004 Kay Sievers + * Copyright (C) 2004-2005 Kay Sievers * Copyright (C) 2004 Chris Friesen * * @@ -21,22 +21,26 @@ */ #include -#include #include #include #include #include #include #include +#include +#include +#include +#include +#include #include #include #include #include -#include #include #include #include "list.h" +#include "udev_libc_wrapper.h" #include "udev.h" #include "udev_version.h" #include "udev_utils.h" @@ -45,6 +49,7 @@ /* global variables*/ static int udevsendsock; +static pid_t sid; static int pipefds[2]; static long startup_time; @@ -64,7 +69,7 @@ static void user_sighandler(void); static void reap_sigchilds(void); char *udev_bin; -#ifdef LOG +#ifdef USE_LOG void log_message (int level, const char *format, ...) { va_list args; @@ -84,14 +89,14 @@ static void msg_dump_queue(void) #ifdef DEBUG struct hotplug_msg *msg; - list_for_each_entry(msg, &msg_list, list) + list_for_each_entry(msg, &msg_list, node) dbg("sequence %llu in queue", msg->seqnum); #endif } static void run_queue_delete(struct hotplug_msg *msg) { - list_del(&msg->list); + list_del(&msg->node); free(msg); } @@ -103,27 +108,41 @@ static void msg_queue_insert(struct hotplug_msg *msg) if (msg->seqnum == 0) { dbg("no SEQNUM, move straight to the exec queue"); - list_add(&msg->list, &exec_list); + list_add(&msg->node, &exec_list); + run_exec_q = 1; + return; + } + + /* don't delay messages with timeout set */ + if (msg->timeout) { + dbg("move seq %llu with timeout %u to exec queue", msg->seqnum, msg->timeout); + list_add(&msg->node, &exec_list); run_exec_q = 1; return; } /* sort message by sequence number into list */ - list_for_each_entry_reverse(loop_msg, &msg_list, list) + list_for_each_entry_reverse(loop_msg, &msg_list, node) { if (loop_msg->seqnum < msg->seqnum) break; + if (loop_msg->seqnum == msg->seqnum) { + dbg("ignoring duplicate message seq %llu", msg->seqnum); + return; + } + } + /* store timestamp of queuing */ sysinfo(&info); msg->queue_time = info.uptime; - list_add(&msg->list, &loop_msg->list); + list_add(&msg->node, &loop_msg->node); dbg("queued message seq %llu", msg->seqnum); /* run msg queue manager */ run_msg_q = 1; - return ; + return; } /* forks event and removes event from run queue when finished */ @@ -138,6 +157,8 @@ static void udev_run(struct hotplug_msg *msg) /* child */ close(udevsendsock); logging_close(); + + setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY); execve(udev_bin, argv, msg->envp); dbg("exec of child failed"); _exit(1); @@ -145,9 +166,6 @@ 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 */ @@ -156,11 +174,105 @@ static void udev_run(struct hotplug_msg *msg) } } +static int running_processes(void) +{ + int f; + static char buf[4096]; + int len; + int running; + const char *pos; + + f = open("/proc/stat", O_RDONLY); + if (f == -1) + return -1; + + len = read(f, buf, sizeof(buf)); + close(f); + + if (len <= 0) + return -1; + else + buf[len] = '\0'; + + pos = strstr(buf, "procs_running "); + if (pos == NULL) + return -1; + + if (sscanf(pos, "procs_running %u", &running) != 1) + return -1; + + return running; +} + +/* return the number of process es in our session, count only until limit */ +static int running_processes_in_session(pid_t session, int limit) +{ + DIR *dir; + struct dirent *dent; + int running = 0; + + dir = opendir("/proc"); + if (!dir) + return -1; + + /* read process info from /proc */ + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + int f; + char procdir[64]; + char line[256]; + const char *pos; + char state; + pid_t ppid, pgrp, sess; + int len; + + if (!isdigit(dent->d_name[0])) + continue; + + snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name); + procdir[sizeof(procdir)-1] = '\0'; + + f = open(procdir, O_RDONLY); + if (f == -1) + continue; + + len = read(f, line, sizeof(line)); + close(f); + + if (len <= 0) + continue; + else + line[len] = '\0'; + + /* skip ugly program name */ + pos = strrchr(line, ')') + 2; + if (pos == NULL) + continue; + + if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4) + continue; + + /* count only processes in our session */ + if (sess != session) + continue; + + /* count only running, no sleeping processes */ + if (state != 'R') + continue; + + running++; + if (limit > 0 && running >= limit) + break; + } + closedir(dir); + + return running; +} + static int compare_devpath(const char *running, const char *waiting) { int i; - for (i = 0; i < DEVPATH_SIZE; i++) { + for (i = 0; i < PATH_SIZE; i++) { /* identical device event found */ if (running[i] == '\0' && waiting[i] == '\0') return 1; @@ -189,7 +301,11 @@ static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg) if (msg->devpath == NULL) return NULL; - list_for_each_entry(loop_msg, &running_list, list) { + /* skip any events with a timeout set */ + if (msg->timeout) + return NULL; + + list_for_each_entry(loop_msg, &running_list, node) { if (loop_msg->devpath == NULL) continue; @@ -212,13 +328,30 @@ static void exec_queue_manager(void) struct hotplug_msg *loop_msg; struct hotplug_msg *tmp_msg; struct hotplug_msg *msg; + int running; + + running = running_processes(); + dbg("%d processes runnning on system", running); + if (running < 0) + running = THROTTLE_MAX_RUNNING_CHILDS; + + list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) { + /* check running processes in our session and possibly throttle */ + if (running >= THROTTLE_MAX_RUNNING_CHILDS) { + running = running_processes_in_session(sid, THROTTLE_MAX_RUNNING_CHILDS+10); + dbg("%d processes running in session", running); + if (running >= THROTTLE_MAX_RUNNING_CHILDS) { + dbg("delay seq %llu, cause too many processes already running", loop_msg->seqnum); + return; + } + } - list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) { msg = running_with_devpath(loop_msg); if (!msg) { /* move event to run list */ - list_move_tail(&loop_msg->list, &running_list); + list_move_tail(&loop_msg->node, &running_list); udev_run(loop_msg); + running++; dbg("moved seq %llu to running list", loop_msg->seqnum); } else { dbg("delay seq %llu (%s), cause seq %llu (%s) is still running", @@ -229,7 +362,7 @@ static void exec_queue_manager(void) static void msg_move_exec(struct hotplug_msg *msg) { - list_move_tail(&msg->list, &exec_list); + list_move_tail(&msg->node, &exec_list); run_exec_q = 1; expected_seqnum = msg->seqnum+1; dbg("moved seq %llu to exec, next expected is %llu", @@ -248,7 +381,7 @@ static void msg_queue_manager(void) dbg("msg queue manager, next expected is %llu", expected_seqnum); recheck: - list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) { + list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, node) { /* move event with expected sequence to the exec list */ if (loop_msg->seqnum == expected_seqnum) { msg_move_exec(loop_msg); @@ -369,6 +502,9 @@ static struct hotplug_msg *get_udevsend_msg(void) if (strncmp(key, "PHYSDEVPATH=", 12) == 0) msg->physdevpath = &key[12]; + + if (strncmp(key, "TIMEOUT=", 8) == 0) + msg->timeout = strtoull(&key[8], NULL, 10); } msg->envp[i++] = "UDEVD_EVENT=1"; msg->envp[i] = NULL; @@ -413,7 +549,7 @@ static void udev_done(int pid) /* find msg associated with pid and delete it */ struct hotplug_msg *msg; - list_for_each_entry(msg, &running_list, list) { + list_for_each_entry(msg, &running_list, node) { if (msg->pid == pid) { dbg("<== exec seq %llu came back", msg->seqnum); run_queue_delete(msg); @@ -444,6 +580,7 @@ static void reap_sigchilds(void) static void user_sighandler(void) { int sig; + while(1) { int rc = read(pipefds[0], &sig, sizeof(sig)); if (rc < 0) @@ -453,16 +590,48 @@ static void user_sighandler(void) } } -int main(int argc, char *argv[], char *envp[]) +static int init_udevsend_socket(void) { - struct sysinfo info; - int maxsockplus; struct sockaddr_un saddr; socklen_t addrlen; - int retval, fd; const int feature_on = 1; + int retval; + + memset(&saddr, 0x00, sizeof(saddr)); + saddr.sun_family = AF_LOCAL; + /* use abstract namespace for socket path */ + strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH); + addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; + + udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0); + if (udevsendsock == -1) { + dbg("error getting socket, %s", strerror(errno)); + return -1; + } + + /* the bind takes care of ensuring only one copy running */ + retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen); + if (retval < 0) { + dbg("bind failed, %s", strerror(errno)); + close(udevsendsock); + return -1; + } + + /* enable receiving of the sender credentials */ + setsockopt(udevsendsock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on)); + + return 0; +} + +int main(int argc, char *argv[], char *envp[]) +{ + struct sysinfo info; + int maxsockplus; + int retval; + int fd; struct sigaction act; fd_set readfds; + const char *udevd_expected_seqnum; logging_init("udevd"); dbg("version %s", UDEV_VERSION); @@ -490,24 +659,27 @@ int main(int argc, char *argv[], char *envp[]) } } + /* become session leader */ + sid = setsid(); + dbg("our session is %d", sid); + /* make sure we don't lock any path */ chdir("/"); umask(umask(077) | 022); + /*set a reasonable scheduling priority for the daemon */ + setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY); + /* Set fds to dev/null */ fd = open( "/dev/null", O_RDWR ); - if ( fd < 0 ) { + if (fd >= 0) { + dup2(fd, 0); + dup2(fd, 1); + dup2(fd, 2); + if (fd > 2) + close(fd); + } else dbg("error opening /dev/null %s", strerror(errno)); - goto exit; - } - dup2(fd, 0); - dup2(fd, 1); - dup2(fd, 2); - if (fd > 2) - close(fd); - - /* become session leader */ - setsid(); /* setup signal handler pipe */ retval = pipe(pipefds); @@ -522,10 +694,8 @@ int main(int argc, char *argv[], char *envp[]) goto exit; } retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC); - if (retval < 0) { + if (retval < 0) dbg("error fcntl on read pipe: %s", strerror(errno)); - goto exit; - } retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK); if (retval < 0) { @@ -533,12 +703,11 @@ int main(int argc, char *argv[], char *envp[]) goto exit; } retval = fcntl(pipefds[1], F_SETFD, FD_CLOEXEC); - if (retval < 0) { + if (retval < 0) dbg("error fcntl on write pipe: %s", strerror(errno)); - goto exit; - } /* set signal handlers */ + memset(&act, 0x00, sizeof(struct sigaction)); act.sa_handler = (void (*) (int))sig_handler; sigemptyset(&act.sa_mask); act.sa_flags = SA_RESTART; @@ -547,29 +716,15 @@ int main(int argc, char *argv[], char *envp[]) sigaction(SIGALRM, &act, NULL); sigaction(SIGCHLD, &act, NULL); - memset(&saddr, 0x00, sizeof(saddr)); - saddr.sun_family = AF_LOCAL; - /* use abstract namespace for socket path */ - strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH); - addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; - - udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0); - if (udevsendsock == -1) { - dbg("error getting socket, exit"); - goto exit; - } + if (init_udevsend_socket() < 0) { + if (errno == EADDRINUSE) + dbg("another udevd running, exit"); + else + dbg("error initialising udevsend socket: %s", strerror(errno)); - /* the bind takes care of ensuring only one copy running */ - retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen); - if (retval < 0) { - dbg("bind failed, exit"); - close(udevsendsock); goto exit; } - /* enable receiving of the sender credentials */ - setsockopt(udevsendsock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on)); - /* possible override of udev binary, used for testing */ udev_bin = getenv("UDEV_BIN"); if (udev_bin != NULL) @@ -577,7 +732,14 @@ int main(int argc, char *argv[], char *envp[]) else udev_bin = UDEV_BIN; - /* handle special startup timeout*/ + /* possible init of expected_seqnum value */ + udevd_expected_seqnum = getenv("UDEVD_EXPECTED_SEQNUM"); + if (udevd_expected_seqnum != NULL) { + expected_seqnum = strtoull(udevd_expected_seqnum, NULL, 10); + dbg("initialize expected_seqnum to %llu", expected_seqnum); + } + + /* get current time to provide shorter timeout on startup */ sysinfo(&info); startup_time = info.uptime;