commit 8a23393eda00c7b7448b4d84157c5d06ba40c01c Author: teor teor@torproject.org Date: Wed Feb 12 13:11:57 2020 +1000
log: Stop duplicating error file fds
Since we're not closing these fds, they don't need to be duplicated any more.
Cleanup after 33087. --- src/lib/log/log.c | 41 ++++++++++++----------------------------- 1 file changed, 12 insertions(+), 29 deletions(-)
diff --git a/src/lib/log/log.c b/src/lib/log/log.c index 4813a4fae..cfb8f5b42 100644 --- a/src/lib/log/log.c +++ b/src/lib/log/log.c @@ -665,21 +665,15 @@ tor_log_update_sigsafe_err_fds(void) const logfile_t *lf; int found_real_stderr = 0;
- /* log_fds and err_fds contain matching entries: log_fds are the fds used by - * the log module, and err_fds are the fds used by the err module. - * For stdio logs, the log_fd and err_fd values are identical. - * For file logs, the err_fd is a dup() of the log_fd. - * Both the log and err modules flush these fds on shutdown. - */ - int log_fds[TOR_SIGSAFE_LOG_MAX_FDS]; - int err_fds[TOR_SIGSAFE_LOG_MAX_FDS]; + /* The fds are the file descriptors of tor's stdout, stderr, and file + * logs. The log and err modules flush these fds during their shutdowns. */ + int fds[TOR_SIGSAFE_LOG_MAX_FDS]; int n_fds;
LOCK_LOGS(); /* Reserve the first one for stderr. This is safe because when we daemonize, - * we dup2 /dev/null to stderr. - * For stderr, log_fds and err_fds are the same. */ - log_fds[0] = err_fds[0] = STDERR_FILENO; + * we dup2 /dev/null to stderr. */ + fds[0] = STDERR_FILENO; n_fds = 1;
for (lf = logfiles; lf; lf = lf->next) { @@ -694,21 +688,11 @@ tor_log_update_sigsafe_err_fds(void) (LD_BUG|LD_GENERAL)) { if (lf->fd == STDERR_FILENO) found_real_stderr = 1; - /* Avoid duplicates by checking the log module fd against log_fds */ - if (int_array_contains(log_fds, n_fds, lf->fd)) + /* Avoid duplicates by checking the log module fd against fds */ + if (int_array_contains(fds, n_fds, lf->fd)) continue; - /* Update log_fds using the log module's fd */ - log_fds[n_fds] = lf->fd; - if (lf->needs_close) { - /* File log fds are duplicated, because close_log() closes the log - * module's fd, and tor_log_flush_sigsafe_err_fds() closes the err - * module's fd. Both refer to the same file. */ - err_fds[n_fds] = dup(lf->fd); - } else { - /* stdio log fds are not closed by the log module. - * tor_log_flush_sigsafe_err_fds() closes stdio logs. */ - err_fds[n_fds] = lf->fd; - } + /* Update fds using the log module's fd */ + fds[n_fds] = lf->fd; n_fds++; if (n_fds == TOR_SIGSAFE_LOG_MAX_FDS) break; @@ -716,20 +700,19 @@ tor_log_update_sigsafe_err_fds(void) }
if (!found_real_stderr && - int_array_contains(log_fds, n_fds, STDOUT_FILENO)) { + int_array_contains(fds, n_fds, STDOUT_FILENO)) { /* Don't use a virtual stderr when we're also logging to stdout. * If we reached max_fds logs, we'll now have (max_fds - 1) logs. * That's ok, max_fds is large enough that most tor instances don't exceed * it. */ raw_assert(n_fds >= 2); /* Don't tor_assert inside log fns */ --n_fds; - log_fds[0] = log_fds[n_fds]; - err_fds[0] = err_fds[n_fds]; + fds[0] = fds[n_fds]; }
UNLOCK_LOGS();
- tor_log_set_sigsafe_err_fds(err_fds, n_fds); + tor_log_set_sigsafe_err_fds(fds, n_fds); }
/** Add to <b>out</b> a copy of every currently configured log file name. Used