git-commit-vandalism/write-or-die.c
Junio C Hamano cccdfd2243 fsync(): be prepared to see EINTR
Some platforms, like NonStop do not automatically restart fsync()
when interrupted by a signal, even when that signal is setup with
SA_RESTART.

This can lead to test breakage, e.g., where "--progress" is used,
thus SIGALRM is sent often, and can interrupt an fsync() syscall.

Make sure we deal with such a case by retrying the syscall
ourselves.  Luckily, we call fsync() fron a single wrapper,
fsync_or_die(), so the fix is fairly isolated.

Reported-by: Randall S. Becker <randall.becker@nexbridge.ca>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Taylor Blau <me@ttaylorr.com>
[jc: the above two did most of the work---I just tied the loose end]
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-05 22:13:40 +09:00

73 lines
1.6 KiB
C

#include "cache.h"
#include "run-command.h"
/*
* Some cases use stdio, but want to flush after the write
* to get error handling (and to get better interactive
* behaviour - not buffering excessively).
*
* Of course, if the flush happened within the write itself,
* we've already lost the error code, and cannot report it any
* more. So we just ignore that case instead (and hope we get
* the right error code on the flush).
*
* If the file handle is stdout, and stdout is a file, then skip the
* flush entirely since it's not needed.
*/
void maybe_flush_or_die(FILE *f, const char *desc)
{
static int skip_stdout_flush = -1;
struct stat st;
char *cp;
if (f == stdout) {
if (skip_stdout_flush < 0) {
cp = getenv("GIT_FLUSH");
if (cp)
skip_stdout_flush = (atoi(cp) == 0);
else if ((fstat(fileno(stdout), &st) == 0) &&
S_ISREG(st.st_mode))
skip_stdout_flush = 1;
else
skip_stdout_flush = 0;
}
if (skip_stdout_flush && !ferror(f))
return;
}
if (fflush(f)) {
check_pipe(errno);
die_errno("write failure on '%s'", desc);
}
}
void fprintf_or_die(FILE *f, const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
ret = vfprintf(f, fmt, ap);
va_end(ap);
if (ret < 0) {
check_pipe(errno);
die_errno("write error");
}
}
void fsync_or_die(int fd, const char *msg)
{
while (fsync(fd) < 0) {
if (errno != EINTR)
die_errno("fsync error on '%s'", msg);
}
}
void write_or_die(int fd, const void *buf, size_t count)
{
if (write_in_full(fd, buf, count) < 0) {
check_pipe(errno);
die_errno("write error");
}
}