diff options
| -rw-r--r-- | Makefile.am | 6 | ||||
| -rw-r--r-- | guix/store/roots.scm | 120 | ||||
| -rw-r--r-- | tests/store-roots.scm | 53 |
3 files changed, 177 insertions, 2 deletions
diff --git a/Makefile.am b/Makefile.am index 87682b4949..704f2451c3 100644 --- a/Makefile.am +++ b/Makefile.am @@ -277,7 +277,8 @@ endif BUILD_DAEMON_OFFLOAD # Scheme implementation of the build daemon and related functionality. STORE_MODULES = \ guix/store/database.scm \ - guix/store/deduplication.scm + guix/store/deduplication.scm \ + guix/store/roots.scm MODULES += $(STORE_MODULES) @@ -408,7 +409,8 @@ SCM_TESTS = \ tests/pypi.scm \ tests/import-utils.scm \ tests/store-database.scm \ - tests/store-deduplication.scm + tests/store-deduplication.scm \ + tests/store-roots.scm SH_TESTS = \ tests/guix-build.sh \ diff --git a/guix/store/roots.scm b/guix/store/roots.scm new file mode 100644 index 0000000000..4f23ae34e8 --- /dev/null +++ b/guix/store/roots.scm @@ -0,0 +1,120 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2019 Ludovic Courtès <ludo@gnu.org> +;;; +;;; This file is part of GNU Guix. +;;; +;;; GNU Guix is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or (at +;;; your option) any later version. +;;; +;;; GNU Guix is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. + +(define-module (guix store roots) + #:use-module (guix config) + #:use-module ((guix store) #:select (store-path? %gc-roots-directory)) + #:use-module (guix sets) + #:use-module (guix build syscalls) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-11) + #:use-module (srfi srfi-26) + #:use-module (ice-9 match) + #:use-module (ice-9 regex) + #:re-export (%gc-roots-directory) + #:export (gc-roots + user-owned?)) + +;;; Commentary: +;;; +;;; This module provides tools to list and access garbage collector roots ("GC +;;; roots"). +;;; +;;; Code: + +(define %profile-directory + ;; Directory where user profiles are stored. + ;; XXX: This is redundant with the definition in (guix profiles) and not + ;; entirely needed since in practice /var/guix/gcroots/profiles links to + ;; it. + (string-append %state-directory "/profiles")) + +(define (gc-roots) + "Return the list of garbage collector roots (\"GC roots\"). This includes +\"regular\" roots fount in %GC-ROOTS-DIRECTORY as well as indirect roots that +are user-controlled symlinks stored anywhere on the file system." + (define (regular? file) + (match file + (((or "." "..") . _) #f) + (_ #t))) + + (define (file-type=? type) + (match-lambda + ((file . properties) + (match (assq-ref properties 'type) + ('unknown + (let ((stat (lstat file))) + (eq? type (stat:type stat)))) + (actual-type + (eq? type actual-type)))))) + + (define directory? + (file-type=? 'directory)) + + (define symlink? + (file-type=? 'symlink)) + + (define canonical-root + (match-lambda + ((file . properties) + (let ((target (readlink file))) + (cond ((store-path? target) + ;; Regular root: FILE points to the store. + file) + + ;; Indirect root: FILE points to a user-controlled file outside + ;; the store. + ((string-prefix? "/" target) + target) + (else + (string-append (dirname file) "/" target))))))) + + (let loop ((directories (list %gc-roots-directory + %profile-directory)) + (roots '()) + (visited (set))) + (match directories + (() + roots) + ((directory . rest) + (if (set-contains? visited directory) + (loop rest roots visited) + (let*-values (((scope) + (cut string-append directory "/" <>)) + ((sub-directories files) + (partition directory? + (map (match-lambda + ((file . properties) + (cons (scope file) properties))) + (scandir* directory regular?))))) + (loop (append rest (map first sub-directories)) + (append (map canonical-root (filter symlink? files)) + roots) + (set-insert directory visited)))))))) + +(define* (user-owned? root #:optional (uid (getuid))) + "Return true if ROOT exists and is owned by UID, false otherwise." + ;; If ROOT is an indirect root, then perhaps it no longer exists. Thus, + ;; catch 'system-error' exceptions. + (catch 'system-error + (lambda () + (define stat + (lstat root)) + + (= (stat:uid stat) uid)) + (const #f))) diff --git a/tests/store-roots.scm b/tests/store-roots.scm new file mode 100644 index 0000000000..5bcf1bc87e --- /dev/null +++ b/tests/store-roots.scm @@ -0,0 +1,53 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2019 Ludovic Courtès <ludo@gnu.org> +;;; +;;; This file is part of GNU Guix. +;;; +;;; GNU Guix is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or (at +;;; your option) any later version. +;;; +;;; GNU Guix is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. + +(define-module (test-store-deduplication) + #:use-module (guix tests) + #:use-module (guix store) + #:use-module (guix store roots) + #:use-module ((guix utils) #:select (call-with-temporary-directory)) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-64)) + +(define %store + (open-connection)) + +(test-begin "store-roots") + +(test-assert "gc-roots, regular root" + (let* ((item (add-text-to-store %store "something" + (random-text))) + (root (string-append %gc-roots-directory "/test-gc-root"))) + (symlink item root) + (let ((result (member root (gc-roots)))) + (delete-file root) + result))) + +(test-assert "gc-roots, indirect root" + (call-with-temporary-directory + (lambda (directory) + (let* ((item (add-text-to-store %store "something" + (random-text))) + (root (string-append directory "/gc-root"))) + (symlink item root) + (add-indirect-root %store root) + (let ((result (member root (gc-roots)))) + (delete-file root) + result))))) + +(test-end "store-roots") |