diff --git a/lib/log/log.c b/lib/log/log.c index 118a3ba42..0b79ed16d 100644 --- a/lib/log/log.c +++ b/lib/log/log.c @@ -217,6 +217,45 @@ void init_log_fn(lvm2_log_fn_t log_fn) _lvm2_log_fn = log_fn; } +/* Read /proc/self/stat to extract pid and starttime */ +static int _get_pid_starttime(int *pid, unsigned long long *starttime) +{ + static const char statfile[] = "/proc/self/stat"; + char buf[1024]; + char *p; + int fd; + int e; + + if ((fd = open(statfile, O_RDONLY)) == -1) { + log_sys_debug("open", statfile); + return 0; + } + + if ((e = read(fd, buf, sizeof(buf) - 1)) <= 0) + log_sys_debug("read", statfile); + + if (!close(fd)) + log_sys_debug("close", statfile); + + if (e <= 0) + return 0; + + buf[e] = '\0'; + if ((sscanf(buf, "%d ", pid) == 1) && + /* Jump past COMM, don't use scanf with '%s' since COMM may contain a space. */ + (p = strrchr(buf, ')')) && + (scanf(++p, " %*c %*d %*d %*d %*d " /* tty_nr */ + "%*d %*u %*u %*u %*u " /* mjflt */ + "%*u %*u %*u %*d %*d " /* cstim */ + "%*d %*d %*d %*d " /* itrealvalue */ + "%llu", &starttime) == 1)) + return 1; + + log_debug("Cannot parse content of %s.", statfile); + + return 0; +} + /* * Support envvar LVM_LOG_FILE_EPOCH and allow to attach * extra keyword (consist of upto 32 alpha chars) to @@ -228,11 +267,9 @@ void init_log_fn(lvm2_log_fn_t log_fn) */ void init_log_file(const char *log_file, int append) { - static const char statfile[] = "/proc/self/stat"; const char *env; - int pid; - unsigned long long starttime; - FILE *st; + int pid = 0; + unsigned long long starttime = 0; int i = 0; _log_file_path[0] = '\0'; @@ -245,27 +282,17 @@ void init_log_file(const char *log_file, int append) goto no_epoch; } - if (!(st = fopen(statfile, "r"))) - log_sys_error("fopen", statfile); - else if (fscanf(st, "%d %*s %*c %*d %*d %*d %*d " /* tty_nr */ - "%*d %*u %*u %*u %*u " /* mjflt */ - "%*u %*u %*u %*d %*d " /* cstim */ - "%*d %*d %*d %*d " /* itrealvalue */ - "%llu", &pid, &starttime) != 2) { - log_warn("WARNING: Cannot parse content of %s.", statfile); - } else { - if (dm_snprintf(_log_file_path, sizeof(_log_file_path), - "%s_%s_%d_%llu", log_file, env, pid, starttime) < 0) { - log_warn("WARNING: Debug log file path is too long for epoch."); - _log_file_path[0] = '\0'; - } else { - log_file = _log_file_path; - append = 1; /* force */ - } - } + if (!_get_pid_starttime(&pid, &starttime)) + log_debug("Failed to obtain pid and starttime."); - if (st && fclose(st)) - log_sys_debug("fclose", statfile); + if (dm_snprintf(_log_file_path, sizeof(_log_file_path), + "%s_%s_%d_%llu", log_file, env, pid, starttime) < 0) { + log_warn("WARNING: Debug log file path is too long for epoch."); + _log_file_path[0] = '\0'; + } else { + log_file = _log_file_path; + append = 1; /* force */ + } if ((env = getenv("LVM_LOG_FILE_MAX_LINES"))) { if (sscanf(env, FMTu64, &_log_file_max_lines) != 1) { @@ -896,4 +923,3 @@ uint32_t log_journal_str_to_val(const char *str) log_warn("Ignoring unrecognized journal value."); return 0; } -