Make index preloading check the whole path to the file

This uses the new thread-safe 'threaded_has_symlink_leading_path()'
function to efficiently verify that the whole path leading up to the
filename is a proper path, and does not contain symlinks.

This makes 'ce_uptodate()' a much stronger guarantee: it no longer just
guarantees that the 'lstat()' of the path would match, it also means
that we know that people haven't played games with moving directories
around and covered it up with symlinks.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/preload-index.c b/preload-index.c
index 88edc5f8a9d5384e19426e6adb40e08b34d3adf2..14d52811832d8f2a3f6c1e1e5502c51ce73da82e 100644 (file)
--- a/preload-index.c
+++ b/preload-index.c
@@ -34,7 +34,9 @@ static void *preload_thread(void *_data)
        struct thread_data *p = _data;
        struct index_state *index = p->index;
        struct cache_entry **cep = index->cache + p->offset;
+       struct cache_def cache;
 
+       memset(&cache, 0, sizeof(cache));
        nr = p->nr;
        if (nr + p->offset > index->cache_nr)
                nr = index->cache_nr - p->offset;
@@ -49,6 +51,8 @@ static void *preload_thread(void *_data)
                        continue;
                if (!ce_path_match(ce, p->pathspec))
                        continue;
+               if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
+                       continue;
                if (lstat(ce->name, &st))
                        continue;
                if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY))