From 9aa6ffb22b712d4e928604e291f954b02237e8cd Mon Sep 17 00:00:00 2001 From: Joshua Judson Rosen Date: Tue, 20 May 2014 01:02:20 -0400 Subject: syslogd: Unify unlink/truncate + unlock log-rotation logic Always unlink + reopen, rather than sometimes using ftruncate(); using a single code-path reduces the opportunity for either mistakes or duplicate code. Signed-off-by: Joshua Judson Rosen Signed-off-by: Denys Vlasenko --- sysklogd/syslogd.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-) diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c index d77fc9475..f75851085 100644 --- a/sysklogd/syslogd.c +++ b/sysklogd/syslogd.c @@ -648,32 +648,24 @@ static void log_locally(time_t now, char *msg, logFile_t *log_file) } /* newFile == "f.0" now */ rename(log_file->path, newFile); - /* Incredibly, if F and F.0 are hardlinks, POSIX - * _demands_ that rename returns 0 but does not - * remove F!!! - * (hardlinked F/F.0 pair was observed after - * power failure during rename()). - * Ensure old file is gone: - */ - unlink(log_file->path); -#ifdef SYSLOGD_WRLOCK - fl.l_type = F_UNLCK; - fcntl(log_file->fd, F_SETLKW, &fl); -#endif - close(log_file->fd); - goto reopen; } - /* We don't get here unless G.logFileRotate == 0; - * in which case don't bother unlinking and reopening, - * just truncate and reset size to match: + /* We may or may not have just renamed the file away; + * if we didn't rename because we aren't keeping any backlog, + * then it's time to clobber the file. If we did rename it..., + * incredibly, if F and F.0 are hardlinks, POSIX _demands_ + * that rename returns 0 but does not remove F!!! + * (hardlinked F/F.0 pair was observed after + * power failure during rename()). + * So ensure old file is gone in any case: */ - ftruncate(log_file->fd, 0); - log_file->size = 0; + unlink(log_file->path); #ifdef SYSLOGD_WRLOCK fl.l_type = F_UNLCK; fcntl(log_file->fd, F_SETLKW, &fl); #endif + close(log_file->fd); + goto reopen; } log_file->size += #endif -- cgit v1.2.3