From 7c4ea599b0d44e46c4f96bf955b62d96126b53ff Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 17 Nov 2008 09:01:20 -0800 Subject: [PATCH] Fix index preloading for racy dirty case In the threaded index preloading case, we must be sure to always use the CE_MATCH_RACY_IS_DIRTY flag when calling ie_match_stat(), in order to make sure that we only ever look at the stat() data, and don't try to do anything fancy. Because most of git internals are not thread-safe, and must not be called in parallel. Otherwise, what happens is that if the timestamps indicate that an entry _might_ be dirty, we might start actually comparing filesystem data with the object database. And we mustn't do that, because that would involve looking up and creating the object structure, and that whole code sequence with read_sha1_file() where we look up and add objects to the hashes is definitely not thread-safe. Nor do we want to add locking, because the whole point of the preload was to be simple and not affect anything else. With CE_MATCH_RACY_IS_DIRTY, we get what we wanted, and we'll just leave the hard cases well alone, to be done later in the much simpler serial case. Signed-off-by: Linus Torvalds Signed-off-by: Junio C Hamano --- preload-index.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/preload-index.c b/preload-index.c index 6253578c9..a6855837a 100644 --- a/preload-index.c +++ b/preload-index.c @@ -43,7 +43,7 @@ static void *preload_thread(void *_data) continue; if (lstat(ce->name, &st)) continue; - if (ie_match_stat(index, ce, &st, 0)) + if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY)) continue; ce_mark_uptodate(ce); } while (--nr > 0); -- 2.30.2