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-rw-r--r--Makefile.am6
-rw-r--r--guix/store/roots.scm120
-rw-r--r--tests/store-roots.scm53
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")