diff options
| -rw-r--r-- | src/or/conscache.c | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/src/or/conscache.c b/src/or/conscache.c index 350a05b0f2..9e13ce8e43 100644 --- a/src/or/conscache.c +++ b/src/or/conscache.c @@ -10,7 +10,10 @@ #define CCE_MAGIC 0x17162253 #ifdef _WIN32 -/* On Windows, unlink won't work if there's an active mmap. */ +/* On Windows, unlink won't work on a file if the file is actively mmap()ed. + * That forces us to be less aggressive about unlinking files, and causes other + * changes throughout our logic. + */ #define MUST_UNMAP_TO_UNLINK #endif @@ -74,13 +77,26 @@ static void consensus_cache_entry_unmap(consensus_cache_entry_t *ent); consensus_cache_t * consensus_cache_open(const char *subdir, int max_entries) { + int storagedir_max_entries; consensus_cache_t *cache = tor_malloc_zero(sizeof(consensus_cache_t)); char *directory = get_datadir_fname(subdir); cache->max_entries = max_entries; + #ifdef MUST_UNMAP_TO_UNLINK - max_entries = 1000000; + /* If we can't unlink the files that we're still using, then we need to + * tell the storagedir backend to allow far more files than this consensus + * cache actually wants, so that it can hold files which, from this cache's + * perspective, have become useless. + */ +#define VERY_LARGE_STORAGEDIR_LIMIT (1000*1000) + storagedir_max_entries = VERY_LARGE_STORAGEDIR_LIMIT; +#else + /* Otherwise, we can just tell the storagedir to use the same limits + * as this cache. */ + storagedir_max_entries = max_entries; #endif - cache->dir = storage_dir_new(directory, max_entries); + + cache->dir = storage_dir_new(directory, storagedir_max_entries); tor_free(directory); if (!cache->dir) { tor_free(cache); @@ -92,7 +108,12 @@ consensus_cache_open(const char *subdir, int max_entries) } /** Return true if it's okay to put more entries in this cache than - * its official file limit. */ + * its official file limit. + * + * (We need this method on Windows, where we can't unlink files that are still + * in use, and therefore might need to temporarily exceed the file limit until + * the no-longer-wanted files are deletable.) + */ int consensus_cache_may_overallocate(consensus_cache_t *cache) { @@ -113,7 +134,15 @@ consensus_cache_register_with_sandbox(consensus_cache_t *cache, struct sandbox_cfg_elem **cfg) { #ifdef MUST_UNMAP_TO_UNLINK - /* Our sandbox doesn't support huge limits like we use here. + /* Our Linux sandbox doesn't support huge file lists like the one that would + * be generated by using VERY_LARGE_STORAGEDIR_LIMIT above in + * consensus_cache_open(). Since the Linux sandbox is the only one we have + * right now, we just assert that we never reach this point when we've had + * to use VERY_LARGE_STORAGEDIR_LIMIT. + * + * If at some point in the future we have a different sandbox mechanism that + * can handle huge file lists, we can remove this assertion or make it + * conditional. */ tor_assert_nonfatal_unreached(); #endif |