Remove legacy cache clearing logic.

It was riddled with funky memory access, and it's been fully replaced
by the new V2 logic.

Test: builds, boots
Bug: 27948817, 36655947
Change-Id: Ic5f0636c414ccf5ccf56eb50fea321b6688a83a0
diff --git a/cmds/installd/InstalldNativeService.cpp b/cmds/installd/InstalldNativeService.cpp
index ca4be0a..381e90c 100644
--- a/cmds/installd/InstalldNativeService.cpp
+++ b/cmds/installd/InstalldNativeService.cpp
@@ -899,30 +899,7 @@
         ATRACE_END();
 
     } else {
-        ATRACE_BEGIN("start");
-        cache_t* cache = start_cache_collection();
-        ATRACE_END();
-
-        ATRACE_BEGIN("add");
-        for (auto user : get_known_users(uuid_)) {
-            add_cache_files(cache, create_data_user_ce_path(uuid_, user));
-            add_cache_files(cache, create_data_user_de_path(uuid_, user));
-            add_cache_files(cache,
-                    StringPrintf("%s/Android/data", create_data_media_path(uuid_, user).c_str()));
-        }
-        // Add files from /data/preloads/file_cache
-        if (uuid == nullptr) {
-            add_preloads_file_cache(cache, uuid_);
-        }
-        ATRACE_END();
-
-        ATRACE_BEGIN("clear");
-        clear_cache_files(data_path, cache, freeStorageSize);
-        ATRACE_END();
-
-        ATRACE_BEGIN("finish");
-        finish_cache_collection(cache);
-        ATRACE_END();
+        return error("Legacy cache logic no longer supported");
     }
 
     free = data_disk_free(data_path);
diff --git a/cmds/installd/utils.cpp b/cmds/installd/utils.cpp
index 03ee23f..fbe6edf 100644
--- a/cmds/installd/utils.cpp
+++ b/cmds/installd/utils.cpp
@@ -38,7 +38,6 @@
 #define LOG_TAG "installd"
 #endif
 
-#define CACHE_NOISY(x) //x
 #define DEBUG_XATTRS 0
 
 using android::base::StringPrintf;
@@ -641,253 +640,6 @@
     }
 }
 
-cache_t* start_cache_collection()
-{
-    cache_t* cache = (cache_t*)calloc(1, sizeof(cache_t));
-    return cache;
-}
-
-#define CACHE_BLOCK_SIZE (512*1024)
-
-static void* _cache_malloc(cache_t* cache, size_t len)
-{
-    len = (len+3)&~3;
-    if (len > (CACHE_BLOCK_SIZE/2)) {
-        // It doesn't make sense to try to put this allocation into one
-        // of our blocks, because it is so big.  Instead, make a new dedicated
-        // block for it.
-        int8_t* res = (int8_t*)malloc(len+sizeof(void*));
-        if (res == NULL) {
-            return NULL;
-        }
-        CACHE_NOISY(ALOGI("Allocated large cache mem block: %p size %zu", res, len));
-        // Link it into our list of blocks, not disrupting the current one.
-        if (cache->memBlocks == NULL) {
-            *(void**)res = NULL;
-            cache->memBlocks = res;
-        } else {
-            *(void**)res = *(void**)cache->memBlocks;
-            *(void**)cache->memBlocks = res;
-        }
-        return res + sizeof(void*);
-    }
-    int8_t* res = cache->curMemBlockAvail;
-    int8_t* nextPos = res + len;
-    if (cache->memBlocks == NULL || nextPos > cache->curMemBlockEnd) {
-        int8_t* newBlock = (int8_t*) malloc(CACHE_BLOCK_SIZE);
-        if (newBlock == NULL) {
-            return NULL;
-        }
-        CACHE_NOISY(ALOGI("Allocated new cache mem block: %p", newBlock));
-        *(void**)newBlock = cache->memBlocks;
-        cache->memBlocks = newBlock;
-        res = cache->curMemBlockAvail = newBlock + sizeof(void*);
-        cache->curMemBlockEnd = newBlock + CACHE_BLOCK_SIZE;
-        nextPos = res + len;
-    }
-    CACHE_NOISY(ALOGI("cache_malloc: ret %p size %zu, block=%p, nextPos=%p",
-            res, len, cache->memBlocks, nextPos));
-    cache->curMemBlockAvail = nextPos;
-    return res;
-}
-
-static void* _cache_realloc(cache_t* cache, void* cur, size_t origLen, size_t len)
-{
-    // This isn't really a realloc, but it is good enough for our purposes here.
-    void* alloc = _cache_malloc(cache, len);
-    if (alloc != NULL && cur != NULL) {
-        memcpy(alloc, cur, origLen < len ? origLen : len);
-    }
-    return alloc;
-}
-
-static void _inc_num_cache_collected(cache_t* cache)
-{
-    cache->numCollected++;
-    if ((cache->numCollected%20000) == 0) {
-        ALOGI("Collected cache so far: %zd directories, %zd files",
-            cache->numDirs, cache->numFiles);
-    }
-}
-
-static cache_dir_t* _add_cache_dir_t(cache_t* cache, cache_dir_t* parent, const char *name)
-{
-    size_t nameLen = strlen(name);
-    cache_dir_t* dir = (cache_dir_t*)_cache_malloc(cache, sizeof(cache_dir_t)+nameLen+1);
-    if (dir != NULL) {
-        dir->parent = parent;
-        dir->childCount = 0;
-        dir->hiddenCount = 0;
-        dir->deleted = 0;
-        strcpy(dir->name, name);
-        if (cache->numDirs >= cache->availDirs) {
-            size_t newAvail = cache->availDirs < 1000 ? 1000 : cache->availDirs*2;
-            cache_dir_t** newDirs = (cache_dir_t**)_cache_realloc(cache, cache->dirs,
-                    cache->availDirs*sizeof(cache_dir_t*), newAvail*sizeof(cache_dir_t*));
-            if (newDirs == NULL) {
-                ALOGE("Failure growing cache dirs array for %s\n", name);
-                return NULL;
-            }
-            cache->availDirs = newAvail;
-            cache->dirs = newDirs;
-        }
-        cache->dirs[cache->numDirs] = dir;
-        cache->numDirs++;
-        if (parent != NULL) {
-            parent->childCount++;
-        }
-        _inc_num_cache_collected(cache);
-    } else {
-        ALOGE("Failure allocating cache_dir_t for %s\n", name);
-    }
-    return dir;
-}
-
-static cache_file_t* _add_cache_file_t(cache_t* cache, cache_dir_t* dir, time_t modTime,
-        const char *name)
-{
-    size_t nameLen = strlen(name);
-    cache_file_t* file = (cache_file_t*)_cache_malloc(cache, sizeof(cache_file_t)+nameLen+1);
-    if (file != NULL) {
-        file->dir = dir;
-        file->modTime = modTime;
-        strcpy(file->name, name);
-        if (cache->numFiles >= cache->availFiles) {
-            size_t newAvail = cache->availFiles < 1000 ? 1000 : cache->availFiles*2;
-            cache_file_t** newFiles = (cache_file_t**)_cache_realloc(cache, cache->files,
-                    cache->availFiles*sizeof(cache_file_t*), newAvail*sizeof(cache_file_t*));
-            if (newFiles == NULL) {
-                ALOGE("Failure growing cache file array for %s\n", name);
-                return NULL;
-            }
-            cache->availFiles = newAvail;
-            cache->files = newFiles;
-        }
-        CACHE_NOISY(ALOGI("Setting file %p at position %zd in array %p", file,
-                cache->numFiles, cache->files));
-        cache->files[cache->numFiles] = file;
-        cache->numFiles++;
-        dir->childCount++;
-        _inc_num_cache_collected(cache);
-    } else {
-        ALOGE("Failure allocating cache_file_t for %s\n", name);
-    }
-    return file;
-}
-
-static int _add_cache_files(cache_t *cache, cache_dir_t *parentDir, const char *dirName,
-        DIR* dir, char *pathBase, char *pathPos, size_t pathAvailLen)
-{
-    struct dirent *de;
-    cache_dir_t* cacheDir = NULL;
-    int dfd;
-
-    CACHE_NOISY(ALOGI("_add_cache_files: parent=%p dirName=%s dir=%p pathBase=%s",
-            parentDir, dirName, dir, pathBase));
-
-    dfd = dirfd(dir);
-
-    if (dfd < 0) return 0;
-
-    // Sub-directories always get added to the data structure, so if they
-    // are empty we will know about them to delete them later.
-    cacheDir = _add_cache_dir_t(cache, parentDir, dirName);
-
-    while ((de = readdir(dir))) {
-        const char *name = de->d_name;
-
-        if (de->d_type == DT_DIR) {
-            int subfd;
-            DIR *subdir;
-
-                /* always skip "." and ".." */
-            if (name[0] == '.') {
-                if (name[1] == 0) continue;
-                if ((name[1] == '.') && (name[2] == 0)) continue;
-            }
-
-            subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
-            if (subfd < 0) {
-                ALOGE("Couldn't openat %s: %s\n", name, strerror(errno));
-                continue;
-            }
-            subdir = fdopendir(subfd);
-            if (subdir == NULL) {
-                ALOGE("Couldn't fdopendir %s: %s\n", name, strerror(errno));
-                close(subfd);
-                continue;
-            }
-            if (cacheDir == NULL) {
-                cacheDir = _add_cache_dir_t(cache, parentDir, dirName);
-            }
-            if (cacheDir != NULL) {
-                // Update pathBase for the new path...  this may change dirName
-                // if that is also pointing to the path, but we are done with it
-                // now.
-                size_t finallen = snprintf(pathPos, pathAvailLen, "/%s", name);
-                CACHE_NOISY(ALOGI("Collecting dir %s\n", pathBase));
-                if (finallen < pathAvailLen) {
-                    _add_cache_files(cache, cacheDir, name, subdir, pathBase,
-                            pathPos+finallen, pathAvailLen-finallen);
-                } else {
-                    // Whoops, the final path is too long!  We'll just delete
-                    // this directory.
-                    ALOGW("Cache dir %s truncated in path %s; deleting dir\n",
-                            name, pathBase);
-                    _delete_dir_contents(subdir, NULL);
-                    if (unlinkat(dfd, name, AT_REMOVEDIR) < 0) {
-                        ALOGE("Couldn't unlinkat %s: %s\n", name, strerror(errno));
-                    }
-                }
-            }
-            closedir(subdir);
-        } else if (de->d_type == DT_REG) {
-            // Skip files that start with '.'; they will be deleted if
-            // their entire directory is deleted.  This allows for metadata
-            // like ".nomedia" to remain in the directory until the entire
-            // directory is deleted.
-            if (cacheDir == NULL) {
-                cacheDir = _add_cache_dir_t(cache, parentDir, dirName);
-            }
-            if (name[0] == '.') {
-                cacheDir->hiddenCount++;
-                continue;
-            }
-            if (cacheDir != NULL) {
-                // Build final full path for file...  this may change dirName
-                // if that is also pointing to the path, but we are done with it
-                // now.
-                size_t finallen = snprintf(pathPos, pathAvailLen, "/%s", name);
-                CACHE_NOISY(ALOGI("Collecting file %s\n", pathBase));
-                if (finallen < pathAvailLen) {
-                    struct stat s;
-                    if (stat(pathBase, &s) >= 0) {
-                        _add_cache_file_t(cache, cacheDir, s.st_mtime, name);
-                    } else {
-                        ALOGW("Unable to stat cache file %s; deleting\n", pathBase);
-                        if (unlink(pathBase) < 0) {
-                            ALOGE("Couldn't unlink %s: %s\n", pathBase, strerror(errno));
-                        }
-                    }
-                } else {
-                    // Whoops, the final path is too long!  We'll just delete
-                    // this file.
-                    ALOGW("Cache file %s truncated in path %s; deleting\n",
-                            name, pathBase);
-                    if (unlinkat(dfd, name, 0) < 0) {
-                        *pathPos = 0;
-                        ALOGE("Couldn't unlinkat %s in %s: %s\n", name, pathBase,
-                                strerror(errno));
-                    }
-                }
-            }
-        } else {
-            cacheDir->hiddenCount++;
-        }
-    }
-    return 0;
-}
-
 int get_path_inode(const std::string& path, ino_t *inode) {
     struct stat buf;
     memset(&buf, 0, sizeof(buf));
@@ -981,187 +733,6 @@
     }
 }
 
-void add_cache_files(cache_t* cache, const std::string& data_path) {
-    DIR *d;
-    struct dirent *de;
-    char dirname[PATH_MAX];
-
-    const char* basepath = data_path.c_str();
-    CACHE_NOISY(ALOGI("add_cache_files: basepath=%s\n", basepath));
-
-    d = opendir(basepath);
-    if (d == NULL) {
-        return;
-    }
-
-    while ((de = readdir(d))) {
-        if (de->d_type == DT_DIR) {
-            DIR* subdir;
-            const char *name = de->d_name;
-
-                /* always skip "." and ".." */
-            if (name[0] == '.') {
-                if (name[1] == 0) continue;
-                if ((name[1] == '.') && (name[2] == 0)) continue;
-            }
-
-            auto parent = StringPrintf("%s/%s", basepath, name);
-            auto resolved = read_path_inode(parent, "cache", kXattrInodeCache);
-            strcpy(dirname, resolved.c_str());
-            CACHE_NOISY(ALOGI("Adding cache files from dir: %s\n", dirname));
-
-            subdir = opendir(dirname);
-            if (subdir != NULL) {
-                size_t dirnameLen = strlen(dirname);
-                _add_cache_files(cache, NULL, dirname, subdir, dirname, dirname+dirnameLen,
-                        PATH_MAX - dirnameLen);
-                closedir(subdir);
-            }
-        }
-    }
-
-    closedir(d);
-}
-
-void add_preloads_file_cache(cache_t* cache, const char* volume_uuid) {
-    char dirname[PATH_MAX];
-    DIR* subdir;
-    auto cache_path = StringPrintf("%s/preloads/file_cache", create_data_path(volume_uuid).c_str());
-    strcpy(dirname, cache_path.c_str());
-    CACHE_NOISY(ALOGI("add_preloads_file_cache: dirname=%s\n", dirname));
-    subdir = opendir(dirname);
-    if (subdir != NULL) {
-        size_t dirnameLen = strlen(dirname);
-        _add_cache_files(cache, NULL, dirname, subdir, dirname, dirname + dirnameLen,
-                PATH_MAX - dirnameLen);
-        closedir(subdir);
-    }
-}
-
-static char *create_dir_path(char path[PATH_MAX], cache_dir_t* dir)
-{
-    char *pos = path;
-    if (dir->parent != NULL) {
-        pos = create_dir_path(path, dir->parent);
-    }
-    // Note that we don't need to worry about going beyond the buffer,
-    // since when we were constructing the cache entries our maximum
-    // buffer size for full paths was PATH_MAX.
-    strcpy(pos, dir->name);
-    pos += strlen(pos);
-    *pos = '/';
-    pos++;
-    *pos = 0;
-    return pos;
-}
-
-static void delete_cache_dir(char path[PATH_MAX], cache_dir_t* dir)
-{
-    if (dir->parent != NULL) {
-        create_dir_path(path, dir);
-        ALOGI("DEL DIR %s\n", path);
-        if (dir->hiddenCount <= 0) {
-            if (rmdir(path)) {
-                ALOGE("Couldn't rmdir %s: %s\n", path, strerror(errno));
-                return;
-            }
-        } else {
-            // The directory contains hidden files so we need to delete
-            // them along with the directory itself.
-            if (delete_dir_contents(path, 1, NULL)) {
-                return;
-            }
-        }
-        dir->parent->childCount--;
-        dir->deleted = 1;
-        if (dir->parent->childCount <= 0) {
-            delete_cache_dir(path, dir->parent);
-        }
-    } else if (dir->hiddenCount > 0) {
-        // This is a root directory, but it has hidden files.  Get rid of
-        // all of those files, but not the directory itself.
-        create_dir_path(path, dir);
-        ALOGI("DEL CONTENTS %s\n", path);
-        delete_dir_contents(path, 0, NULL);
-    }
-}
-
-static int cache_modtime_sort(const void *lhsP, const void *rhsP)
-{
-    const cache_file_t *lhs = *(const cache_file_t**)lhsP;
-    const cache_file_t *rhs = *(const cache_file_t**)rhsP;
-    return lhs->modTime < rhs->modTime ? -1 : (lhs->modTime > rhs->modTime ? 1 : 0);
-}
-
-void clear_cache_files(const std::string& data_path, cache_t* cache, int64_t free_size)
-{
-    size_t i;
-    int skip = 0;
-    char path[PATH_MAX];
-
-    ALOGI("Collected cache files: %zd directories, %zd files",
-        cache->numDirs, cache->numFiles);
-
-    CACHE_NOISY(ALOGI("Sorting files..."));
-    qsort(cache->files, cache->numFiles, sizeof(cache_file_t*),
-            cache_modtime_sort);
-
-    CACHE_NOISY(ALOGI("Cleaning empty directories..."));
-    for (i=cache->numDirs; i>0; i--) {
-        cache_dir_t* dir = cache->dirs[i-1];
-        if (dir->childCount <= 0 && !dir->deleted) {
-            delete_cache_dir(path, dir);
-        }
-    }
-
-    CACHE_NOISY(ALOGI("Trimming files..."));
-    for (i=0; i<cache->numFiles; i++) {
-        skip++;
-        if (skip > 10) {
-            if (data_disk_free(data_path) > free_size) {
-                return;
-            }
-            skip = 0;
-        }
-        cache_file_t* file = cache->files[i];
-        strcpy(create_dir_path(path, file->dir), file->name);
-        ALOGI("DEL (mod %d) %s\n", (int)file->modTime, path);
-        if (unlink(path) < 0) {
-            ALOGE("Couldn't unlink %s: %s\n", path, strerror(errno));
-        }
-        file->dir->childCount--;
-        if (file->dir->childCount <= 0) {
-            delete_cache_dir(path, file->dir);
-        }
-    }
-}
-
-void finish_cache_collection(cache_t* cache)
-{
-    CACHE_NOISY(size_t i;)
-
-    CACHE_NOISY(ALOGI("clear_cache_files: %zu dirs, %zu files\n", cache->numDirs, cache->numFiles));
-    CACHE_NOISY(
-        for (i=0; i<cache->numDirs; i++) {
-            cache_dir_t* dir = cache->dirs[i];
-            ALOGI("dir #%zu: %p %s parent=%p\n", i, dir, dir->name, dir->parent);
-        })
-    CACHE_NOISY(
-        for (i=0; i<cache->numFiles; i++) {
-            cache_file_t* file = cache->files[i];
-            ALOGI("file #%zu: %p %s time=%d dir=%p\n", i, file, file->name,
-                    (int)file->modTime, file->dir);
-        })
-    void* block = cache->memBlocks;
-    while (block != NULL) {
-        void* nextBlock = *(void**)block;
-        CACHE_NOISY(ALOGI("Freeing cache mem block: %p", block));
-        free(block);
-        block = nextBlock;
-    }
-    free(cache);
-}
-
 /**
  * Validate that the path is valid in the context of the provided directory.
  * The path is allowed to have at most one subdirectory and no indirections
diff --git a/cmds/installd/utils.h b/cmds/installd/utils.h
index a4eb1f6..7ebfea2 100644
--- a/cmds/installd/utils.h
+++ b/cmds/installd/utils.h
@@ -37,33 +37,6 @@
 
 struct dir_rec_t;
 
-typedef struct cache_dir_struct {
-    struct cache_dir_struct* parent;
-    int32_t childCount;
-    int32_t hiddenCount;
-    int32_t deleted;
-    char name[];
-} cache_dir_t;
-
-typedef struct {
-    cache_dir_t* dir;
-    time_t modTime;
-    char name[];
-} cache_file_t;
-
-typedef struct {
-    size_t numDirs;
-    size_t availDirs;
-    cache_dir_t** dirs;
-    size_t numFiles;
-    size_t availFiles;
-    cache_file_t** files;
-    size_t numCollected;
-    void* memBlocks;
-    int8_t* curMemBlockAvail;
-    int8_t* curMemBlockEnd;
-} cache_t;
-
 constexpr const char* kXattrInodeCache = "user.inode_cache";
 constexpr const char* kXattrInodeCodeCache = "user.inode_code_cache";
 constexpr const char* kXattrCacheGroup = "user.cache_group";
@@ -139,21 +112,11 @@
 
 int64_t data_disk_free(const std::string& data_path);
 
-cache_t* start_cache_collection();
-
 int get_path_inode(const std::string& path, ino_t *inode);
 
 int write_path_inode(const std::string& parent, const char* name, const char* inode_xattr);
 std::string read_path_inode(const std::string& parent, const char* name, const char* inode_xattr);
 
-void add_cache_files(cache_t* cache, const std::string& data_path);
-
-void add_preloads_file_cache(cache_t* cache, const char* volume_uuid);
-
-void clear_cache_files(const std::string& data_path, cache_t* cache, int64_t free_size);
-
-void finish_cache_collection(cache_t* cache);
-
 int validate_system_app_path(const char* path);
 bool validate_secondary_dex_path(const std::string& pkgname, const std::string& dex_path,
         const char* volume_uuid, int uid, int storage_flag);