From 1c96c1bbabb9646aba2a3860cac02157f56c4dd1 Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Mon, 14 Apr 2014 23:59:08 +0200 Subject: linux-initrd: Mount / as a unionfs when asking for a volatile root. * guix/build/linux-initrd.scm (make-essential-device-nodes): Make /dev/fuse. (boot-system): Add #:unionfs parameter. Invoke UNIONFS instead of copying files over when VOLATILE-ROOT? is true. * gnu/system/linux-initrd.scm (expression->initrd): Add #:inputs parameter. [files-to-copy]: New procedure. [builder]: Add 'to-copy' parameter; honor it. (qemu-initrd)[linux-modules]: Add 'fuse.ko' when VOLATILE-ROOT?. Pass UNIONFS-FUSE/STATIC as #:inputs; change builder to pass #:unionfs to 'boot-system'. --- guix/build/linux-initrd.scm | 38 +++++++++++++++++--------------------- 1 file changed, 17 insertions(+), 21 deletions(-) (limited to 'guix') diff --git a/guix/build/linux-initrd.scm b/guix/build/linux-initrd.scm index 61d4304b65..5d4446e720 100644 --- a/guix/build/linux-initrd.scm +++ b/guix/build/linux-initrd.scm @@ -143,7 +143,10 @@ (symlink "/proc/self/fd" (scope "dev/fd")) (symlink "/proc/self/fd/0" (scope "dev/stdin")) (symlink "/proc/self/fd/1" (scope "dev/stdout")) - (symlink "/proc/self/fd/2" (scope "dev/stderr"))) + (symlink "/proc/self/fd/2" (scope "dev/stderr")) + + ;; File systems in user space (FUSE). + (mknod (scope "dev/fuse") 'char-special #o666 (device-number 10 229))) (define %host-qemu-ipv4-address (inet-pton AF_INET "10.0.2.10")) @@ -212,7 +215,7 @@ the last argument of `mknod'." (linux-modules '()) qemu-guest-networking? guile-modules-in-chroot? - volatile-root? + volatile-root? unionfs (mounts '())) "This procedure is meant to be called from an initrd. Boot a system by first loading LINUX-MODULES, then setting up QEMU guest networking if @@ -277,27 +280,20 @@ to it are lost." (lambda () (if volatile-root? (begin - ;; XXX: For lack of a union file system... (mkdir-p "/real-root") (mount root "/real-root" "ext3" MS_RDONLY) - (mount "none" "/root" "tmpfs") - - ;; XXX: 'copy-recursively' cannot deal with device nodes, so - ;; explicitly avoid /dev. - (for-each (lambda (file) - (unless (string=? "dev" file) - (copy-recursively (string-append "/real-root/" - file) - (string-append "/root/" - file) - #:log (%make-void-port - "w")))) - (scandir "/real-root" - (lambda (file) - (not (member file '("." "..")))))) - - ;; TODO: Unmount /real-root. - ) + (mkdir-p "/rw-root") + (mount "none" "/rw-root" "tmpfs") + + ;; We want read-write /dev nodes. + (make-essential-device-nodes #:root "/rw-root") + + ;; Make /root a union of the tmpfs and the actual root. + (unless (zero? (system* unionfs "-o" + "cow,allow_other,use_ino,dev" + "/rw-root=RW:/real-root=RO" + "/root")) + (error "unionfs failed"))) (mount root "/root" "ext3"))) (lambda args (format (current-error-port) "exception while mounting '~a': ~s~%" -- cgit v1.2.3