diff options
Diffstat (limited to 'refs')
| -rw-r--r-- | refs/files-backend.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c index d8b3f73..b040bb3 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -370,6 +370,18 @@ static void files_ref_path(struct files_ref_store *refs, } /* + * Check that the packed refs cache (if any) still reflects the + * contents of the file. If not, clear the cache. + */ +static void validate_packed_ref_cache(struct files_ref_store *refs) +{ + if (refs->packed && + !stat_validity_check(&refs->packed->validity, + files_packed_refs_path(refs))) + clear_packed_ref_cache(refs); +} + +/* * Get the packed_ref_cache for the specified files_ref_store, * creating and populating it if it hasn't been read before or if the * file has been changed (according to its `validity` field) since it @@ -381,10 +393,8 @@ static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *ref { const char *packed_refs_file = files_packed_refs_path(refs); - if (refs->packed && - !is_lock_file_locked(&refs->packed_refs_lock) && - !stat_validity_check(&refs->packed->validity, packed_refs_file)) - clear_packed_ref_cache(refs); + if (!is_lock_file_locked(&refs->packed_refs_lock)) + validate_packed_ref_cache(refs); if (!refs->packed) refs->packed = read_packed_refs(packed_refs_file); @@ -1311,13 +1321,17 @@ static int lock_packed_refs(struct files_ref_store *refs, int flags) &refs->packed_refs_lock, files_packed_refs_path(refs), flags, timeout_value) < 0) return -1; + /* - * Get the current packed-refs while holding the lock. It is - * important that we call `get_packed_ref_cache()` before - * setting `packed_ref_cache->lock`, because otherwise the - * former will see that the file is locked and assume that the - * cache can't be stale. + * Now that we hold the `packed-refs` lock, make sure that our + * cache matches the current version of the file. Normally + * `get_packed_ref_cache()` does that for us, but that + * function assumes that when the file is locked, any existing + * cache is still valid. We've just locked the file, but it + * might have changed the moment *before* we locked it. */ + validate_packed_ref_cache(refs); + packed_ref_cache = get_packed_ref_cache(refs); /* Increment the reference count to prevent it from being freed: */ acquire_packed_ref_cache(packed_ref_cache); |