system: Add first-class file system declarations.

* gnu/system.scm (<operating-system>)[initrd]: Default to
  'qemu-initrd'.
  (<file-system>): New record type.
  (operating-system-root-file-system): New procedure.
  (operating-system-derivation): Take the device name for GRUB from
  'operating-system-root-file-system'.  Pass the
  'operating-system-initrd' procedure the list of boot file systems.
* gnu/system/linux-initrd.scm (file-system->spec): New procedure.
  (qemu-initrd): Add 'file-systems' parameter, and remove #:mounts
  parameter.
  [file-system-type-predicate]: New procedure.
  [linux-modules]: Use it.
  Adjust #:mounts argument in 'boot-system' call.
  (gnu-system-initrd): Remove.
* gnu/system/vm.scm (%linux-vm-file-systems): New variable.
  (expression->derivation-in-linux-vm): Adjust call to 'qemu-initrd'.
  (virtualized-operating-system): New procedure.
  (system-qemu-image/shared-store-script)[initrd]: Remove.  Use
  'virtualized-operating-system'.  Get the 'initrd' file from OS-DRV.
* guix/build/linux-initrd.scm (mount-qemu-smb-share, mount-qemu-9p):
  Remove.
  (MS_RDONLY, MS_BIND): New global variables.
  (bind-mount): Remove local 'MS_BIND' definition.
  (mount-root-file-system): New procedure, with code formerly in
  'boot-system'.
  (mount-file-system): New procedure.
  (boot-system): Add #:root-fs-type parameter.  Remove 'MS_RDONLY' local
  variable.  Use 'mount-root-file-system' and 'mount-file-system'.
* doc/guix.texi (Using the Configuration System): Add 'file-system'
  declaration.

1 files changed, 26 insertions, 21 deletions

diff --git a/gnu/system/linux-initrd.scm b/gnu/system/linux-initrd.scm
index 6e04ad150f..8b4ab9c4eb 100644
--- a/gnu/system/linux-initrd.scm
+++ b/gnu/system/linux-initrd.scm
@@ -30,11 +30,12 @@
   #:use-module (gnu packages guile)
   #:use-module ((gnu packages make-bootstrap)
                 #:select (%guile-static-stripped))
+  #:use-module (gnu system)                       ; for 'file-system'
   #:use-module (ice-9 match)
   #:use-module (ice-9 regex)
+  #:use-module (srfi srfi-1)
   #:export (expression->initrd
-            qemu-initrd
-            gnu-system-initrd))
+            qemu-initrd))
 
 
 ;;; Commentary:
@@ -193,24 +194,29 @@ a list of Guile module names to be embedded in the initrd."
    (gexp->derivation name builder
                      #:modules '((guix build utils)))))
 
-(define* (qemu-initrd #:key
+(define (file-system->spec fs)
+  "Return a list corresponding to file-system FS that can be passed to the
+initrd code."
+  (match fs
+    (($ <file-system> device mount-point type flags options)
+     (list device mount-point type flags options))))
+
+(define* (qemu-initrd file-systems
+                      #:key
                       guile-modules-in-chroot?
-                      volatile-root?
-                      (mounts `((cifs "/store" ,(%store-prefix))
-                                (cifs "/xchg" "/xchg"))))
+                      volatile-root?)
   "Return a monadic derivation that builds an initrd for use in a QEMU guest
-where the store is shared with the host.  MOUNTS is a list of file systems to
-be mounted atop the root file system, where each item has the form:
+where the store is shared with the host.  FILE-SYSTEMS is a list of
+file-systems to be mounted by the initrd, possibly in addition to the root
+file system specified on the kernel command line via '--root'.
 
-    (FILE-SYSTEM-TYPE SOURCE TARGET)
+When VOLATILE-ROOT? is true, the root file system is writable but any changes
+to it are lost.
 
 When GUILE-MODULES-IN-CHROOT? is true, make core Guile modules available in
 the new root.  This is necessary is the file specified as '--load' needs
 access to these modules (which is the case if it wants to even just print an
-exception and backtrace!).
-
-When VOLATILE-ROOT? is true, the root file system is writable but any changes
-to it are lost."
+exception and backtrace!)."
   (define cifs-modules
     ;; Modules needed to mount CIFS file systems.
     '("md4.ko" "ecb.ko" "cifs.ko"))
@@ -219,14 +225,18 @@ to it are lost."
     ;; Modules for the 9p paravirtualized file system.
     '("9pnet.ko" "9p.ko" "9pnet_virtio.ko"))
 
+  (define (file-system-type-predicate type)
+    (lambda (fs)
+      (string=? (file-system-type fs) type)))
+
   (define linux-modules
     ;; Modules added to the initrd and loaded from the initrd.
     `("virtio.ko" "virtio_ring.ko" "virtio_pci.ko"
       "virtio_balloon.ko" "virtio_blk.ko" "virtio_net.ko"
-      ,@(if (assoc-ref mounts 'cifs)
+      ,@(if (find (file-system-type-predicate "cifs") file-systems)
             cifs-modules
             '())
-      ,@(if (assoc-ref mounts '9p)
+      ,@(if (find (file-system-type-predicate "9p") file-systems)
             virtio-9p-modules
             '())
       ,@(if volatile-root?
@@ -238,7 +248,7 @@ to it are lost."
        (use-modules (guix build linux-initrd)
                     (srfi srfi-26))
 
-       (boot-system #:mounts '#$mounts
+       (boot-system #:mounts '#$(map file-system->spec file-systems)
                     #:linux-modules '#$linux-modules
                     #:qemu-guest-networking? #t
                     #:guile-modules-in-chroot? '#$guile-modules-in-chroot?
@@ -254,9 +264,4 @@ to it are lost."
    #:linux linux-libre
    #:linux-modules linux-modules))
 
-(define (gnu-system-initrd)
-  "Initrd for the GNU system itself, with nothing QEMU-specific."
-  (qemu-initrd #:guile-modules-in-chroot? #f
-               #:mounts '()))
-
 ;;; linux-initrd.scm ends here