Don't truncate valid cachefiles

An embarrassing thinko in cgit_check_cache() would truncate valid cachefiles
in the following situation:
  1) process A notices a missing/expired cachefile
  2) process B gets scheduled, locks, fills and unlocks the cachefile
  3) process A gets scheduled, locks the cachefile, notices that the cachefile
     now exist/is not expired anymore, and continues to overwrite it with an
     empty lockfile.

Thanks to Linus for noticing (again).

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
This commit is contained in:
Lars Hjemli
2006-12-11 22:53:50 +01:00
parent 44923f8953
commit fbaf1171b4
3 ha cambiato i file con 16 aggiunte e 4 eliminazioni

14
cgit.c
Vedi File

@ -61,13 +61,19 @@ static void cgit_check_cache(struct cacheitem *item)
sleep(1);
goto top;
}
if (!cache_exist(item))
if (!cache_exist(item)) {
cgit_fill_cache(item);
cache_unlock(item);
cache_unlock(item);
} else {
cache_cancel_lock(item);
}
} else if (cache_expired(item) && cache_lock(item)) {
if (cache_expired(item))
if (cache_expired(item)) {
cgit_fill_cache(item);
cache_unlock(item);
cache_unlock(item);
} else {
cache_cancel_lock(item);
}
}
}