git/lockfile.c
Junio C Hamano 40aaae88ad Better error message when we are unable to lock the index file
Most of the callers except the one in refs.c use the function to
update the index file.  Among the index writers, everybody
except write-tree dies if they cannot open it for writing.

This gives the function an extra argument, to tell it to die
when it cannot create a new file as the lockfile.

The only caller that does not have to die is write-tree, because
updating the index for the cache-tree part is optional and not
being able to do so does not affect the correctness.  I think we
do not have to be so careful and make the failure into die() the
same way as other callers, but that would be a different patch.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-12 17:08:25 -07:00

71 lines
1.5 KiB
C

/*
* Copyright (c) 2005, Junio C Hamano
*/
#include <signal.h>
#include "cache.h"
static struct lock_file *lock_file_list;
static void remove_lock_file(void)
{
while (lock_file_list) {
if (lock_file_list->filename[0])
unlink(lock_file_list->filename);
lock_file_list = lock_file_list->next;
}
}
static void remove_lock_file_on_signal(int signo)
{
remove_lock_file();
signal(SIGINT, SIG_DFL);
raise(signo);
}
static int lock_file(struct lock_file *lk, const char *path)
{
int fd;
sprintf(lk->filename, "%s.lock", path);
fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
if (0 <= fd) {
if (!lk->next) {
lk->next = lock_file_list;
lock_file_list = lk;
signal(SIGINT, remove_lock_file_on_signal);
atexit(remove_lock_file);
}
if (adjust_shared_perm(lk->filename))
return error("cannot fix permission bits on %s",
lk->filename);
}
return fd;
}
int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
{
int fd = lock_file(lk, path);
if (fd < 0 && die_on_error)
die("unable to create '%s': %s", path, strerror(errno));
return fd;
}
int commit_lock_file(struct lock_file *lk)
{
char result_file[PATH_MAX];
int i;
strcpy(result_file, lk->filename);
i = strlen(result_file) - 5; /* .lock */
result_file[i] = 0;
i = rename(lk->filename, result_file);
lk->filename[0] = 0;
return i;
}
void rollback_lock_file(struct lock_file *lk)
{
if (lk->filename[0])
unlink(lk->filename);
lk->filename[0] = 0;
}