store-copy: 'populate-store' can optionally deduplicate files.

Until now deduplication was performed as an additional pass after
copying files, which involve re-traversing all the files that had just
been copied.

* guix/store/deduplication.scm (copy-file/deduplicate): New procedure.
* tests/store-deduplication.scm ("copy-file/deduplicate"): New test.
* guix/build/store-copy.scm (populate-store): Add #:deduplicate?
parameter and honor it.
* tests/gexp.scm ("gexp->derivation, store copy"): Pass #:deduplicate? #f
to 'populate-store'.
* gnu/build/image.scm (initialize-root-partition): Pass #:deduplicate?
to 'populate-store'.  Pass #:deduplicate? #f to 'register-closure'.
* gnu/build/vm.scm (root-partition-initializer): Likewise.
* gnu/build/install.scm (populate-single-profile-directory): Pass
 #:deduplicate? #f to 'populate-store'.
* gnu/build/linux-initrd.scm (build-initrd): Likewise.
* guix/scripts/pack.scm (self-contained-tarball)[import-module?]: New
procedure.
[build]: Pass it as an argument to 'source-module-closure'.
* guix/scripts/pack.scm (squashfs-image)[build]: Wrap in
'with-extensions'.
* gnu/system/linux-initrd.scm (expression->initrd)[import-module?]: New
procedure.
[builder]: Pass it to 'source-module-closure'.
* gnu/system/install.scm (cow-store-service-type)[import-module?]: New
procedure.  Pass it to 'source-module-closure'.

6 files changed, 29 insertions, 9 deletions

diff --git a/gnu/build/image.scm b/gnu/build/image.scm
index 0deea10a9d5..8f50f27f78a 100644
--- a/gnu/build/image.scm
+++ b/gnu/build/image.scm
@@ -186,7 +186,8 @@ rest of the store when registering the closures.  SYSTEM-DIRECTORY is the name
 of the directory of the 'system' derivation.  Pass WAL-MODE? to
 register-closure."
   (populate-root-file-system system-directory root)
-  (populate-store references-graphs root)
+  (populate-store references-graphs root
+                  #:deduplicate? deduplicate?)
 
   ;; Populate /dev.
   (when make-device-nodes
@@ -195,7 +196,7 @@ register-closure."
   (when register-closures?
     (for-each (lambda (closure)
                 (register-closure root closure
-                                  #:deduplicate? deduplicate?
+                                  #:deduplicate? #f
                                   #:wal-mode? wal-mode?))
               references-graphs))
 
diff --git a/gnu/build/install.scm b/gnu/build/install.scm
index 63995e1d09f..f5c8407b894 100644
--- a/gnu/build/install.scm
+++ b/gnu/build/install.scm
@@ -214,7 +214,8 @@ This is used to create the self-contained tarballs with 'guix pack'."
     (symlink old (scope new)))
 
   ;; Populate the store.
-  (populate-store (list closure) directory)
+  (populate-store (list closure) directory
+                  #:deduplicate? #f)
 
   (when database
     (install-database-and-gc-roots directory database profile
diff --git a/gnu/build/linux-initrd.scm b/gnu/build/linux-initrd.scm
index 99796adba65..bb2ed0db0c7 100644
--- a/gnu/build/linux-initrd.scm
+++ b/gnu/build/linux-initrd.scm
@@ -127,7 +127,8 @@ REFERENCES-GRAPHS."
   (mkdir "contents")
 
   ;; Copy the closures of all the items referenced in REFERENCES-GRAPHS.
-  (populate-store references-graphs "contents")
+  (populate-store references-graphs "contents"
+                  #:deduplicate? #f)
 
   (with-directory-excursion "contents"
     ;; Make '/init'.
diff --git a/gnu/build/vm.scm b/gnu/build/vm.scm
index abb0317faf6..03be5697b75 100644
--- a/gnu/build/vm.scm
+++ b/gnu/build/vm.scm
@@ -395,7 +395,8 @@ system that is passed to 'populate-root-file-system'."
     (when copy-closures?
       ;; Populate the store.
       (populate-store (map (cut string-append "/xchg/" <>) closures)
-                      target))
+                      target
+                      #:deduplicate? deduplicate?))
 
     ;; Populate /dev.
     (make-device-nodes target)
@@ -412,7 +413,7 @@ system that is passed to 'populate-root-file-system'."
       (for-each (lambda (closure)
                   (register-closure target
                                     (string-append "/xchg/" closure)
-                                    #:deduplicate? deduplicate?))
+                                    #:deduplicate? #f))
                 closures)
       (unless copy-closures?
         (umount target-store)))
diff --git a/gnu/system/install.scm b/gnu/system/install.scm
index a6b9e3d9523..e7534634739 100644
--- a/gnu/system/install.scm
+++ b/gnu/system/install.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2016 Andreas Enge <andreas@enge.fr>
 ;;; Copyright © 2017 Marius Bakke <mbakke@fastmail.com>
@@ -176,6 +176,13 @@ manual."
   (shepherd-service-type
    'cow-store
    (lambda _
+     (define (import-module? module)
+       ;; Since we don't use deduplication support in 'populate-store', don't
+       ;; import (guix store deduplication) and its dependencies, which
+       ;; includes Guile-Gcrypt.
+       (and (guix-module-name? module)
+            (not (equal? module '(guix store deduplication)))))
+
      (shepherd-service
       (requirement '(root-file-system user-processes))
       (provision '(cow-store))
@@ -190,7 +197,8 @@ the given target.")
                  ,@%default-modules))
       (start
        (with-imported-modules (source-module-closure
-                               '((gnu build install)))
+                               '((gnu build install))
+                               #:select? import-module?)
          #~(case-lambda
              ((target)
               (mount-cow-store target #$%backing-directory)
diff --git a/gnu/system/linux-initrd.scm b/gnu/system/linux-initrd.scm
index 4fb1d863c9d..c6ba9bb5605 100644
--- a/gnu/system/linux-initrd.scm
+++ b/gnu/system/linux-initrd.scm
@@ -76,12 +76,20 @@ the derivations referenced by EXP are automatically copied to the initrd."
   (define init
     (program-file "init" exp #:guile guile))
 
+  (define (import-module? module)
+    ;; Since we don't use deduplication support in 'populate-store', don't
+    ;; import (guix store deduplication) and its dependencies, which includes
+    ;; Guile-Gcrypt.  That way we can run tests with '--bootstrap'.
+    (and (guix-module-name? module)
+         (not (equal? module '(guix store deduplication)))))
+
   (define builder
     ;; Do not use "guile-zlib" extension here, otherwise it would drag the
     ;; non-static "zlib" package to the initrd closure.  It is not needed
     ;; anyway because the modules are stored uncompressed within the initrd.
     (with-imported-modules (source-module-closure
-                            '((gnu build linux-initrd)))
+                            '((gnu build linux-initrd))
+                            #:select? import-module?)
       #~(begin
           (use-modules (gnu build linux-initrd))