linux-boot: Remove verbose output for module loads.

* gnu/build/linux-boot.scm (boot-system): Leave
'current-module-debugging-port' unchanged.
* gnu/build/linux-modules.scm (load-linux-module*): Update comment about
'mmap'.

system: Allow the root file system to be named by UUID.

* gnu/build/file-systems.scm (canonicalize-device-spec)[canonical-title]:
Use 'string->uuid' to check whether SPEC is a UUID.
When SPEC is a string and CANONICAL-TITLE is 'uuid, call 'string->uuid'.
* gnu/system.scm (operating-system-grub.cfg): Add 'root-device'
variable and use it for the "--root=" argument.

file-systems: Move 'string->uuid' to the build side.

* gnu/system/file-systems.scm (%uuid-rx, string->uuid): Move to...
* gnu/build/file-systems.scm (%uuid-rx, string->uuid): ... here.  New
variables.

build: container: Add feature test predicates.

* gnu/build/linux-container.scm (user-namespace-supported?,
  unprivileged-user-namespace-supported?, setgroups-supported?): New
  procedures.
* tests/container.scm: Use predicates.
* tests/syscalls.scm: Likewise.

Merge branch 'master' into dbus-update

container: Remove unnecessary CLONE_CHILD_* flags.

* gnu/build/linux-container.scm (namespaces->bit-mask): Remove
  CLONE_CHILD_CLEARTID and CLONE_CHILD_SETTID, which are unneeded.
  Discussed at <http://bugs.gnu.org/21694>.

Merge branch 'master' into dbus-update

file-systems: Do not truncate mount points that already exist.

Reported by David Thompson <dthompson2@worcester.edu>
at <https://lists.gnu.org/archive/html/guix-devel/2015-10/msg00284.html>.

* gnu/build/file-systems.scm (mount-file-system): When SOURCE matches
  'regular-file?', do not create MOUNT-POINT if it already exists.  This
  fixes a bug whereby we would be truncating MOUNT-POINT if it already
  existed.

build: container: Fix call-with-clean-exit.

Before, call-with-clean-exit would *always* return an exit code of 1.

* gnu/build/linux-container.scm (call-with-clean-exit): Exit with status
  code of 0 if thunk does not throw an exception.
* tests/containers.scm: Add test.

Merge branch 'master' into core-updates

linux-boot: Mount /dev as a devtmpfs from the start.

Suggested by Petter <petter@mykolab.ch>
and Mark H Weaver <mhw@netris.org>.
Reported by Duncan Keall <duncan@duncankeall.com>.

Partly fixes <http://bugs.gnu.org/19190> by populating /dev/mapper
early enough.

* gnu/build/linux-boot.scm (mount-essential-file-systems): Mount /dev as
  a devtmpfs.
  (move-essential-file-systems): Add /dev.
  (mount-root-file-system): Mount /rw-root/dev as a devtmpfs instead of
  calling 'make-essential-device-nodes'.
  (boot-system): Remove call to 'make-essential-device-nodes'.
* gnu/system/file-systems.scm (%devtmpfs-file-system): Remove.
* doc/guix.texi (File Systems): Adjust accordingly.

Merge branch 'master' into core-updates

linux-initrd: Compress cpio archives deterministically.

* gnu/build/linux-initrd.scm (write-cpio-archive): Use '--no-name'.

build: container: Use the same clone flags as fork(3).

The intent is to make 'clone' behave a lot more like 'primitive-fork', which
calls clone(2) with SIGCHLD, CLONE_CHILD_CLEARTID, and CLONE_CHILD_SETTID
flags.  Notably, running 'clone' at the REPL without these flags would break
the REPL beyond repair.

* guix/build/syscalls.scm (CLONE_CHILD_CLEARTID, CLONE_CHILD_SETTID): New
  variables.
* gnu/build/linux-container.scm (namespaces->bit-mask): Add
  CLONE_CHILD_CLEARTID and CLONE_CHILD_SETTID to bit mask.

build: container: Setup /dev/console.

* gnu/build/linux-container.scm (mount-file-systems): Bind mount the
  controlling terminal as /dev/console.

build: container: Add #:host-uids argument to call-with-container.

It's not always possible to map 65536 uids when creating a container as the
root user within another user namespace.  This is true when building Guix
within the build daemon's container.  By using a uid range of 1 by default,
even as the root user, the tests now pass.

* gnu/build/linux-container.scm (initialize-user-namespace, run-container):
  Add 'host-uids' argument.
  (call-with-container): Add #:host-uids keyword argument.
* tests/containers.scm ("container-excursion"): Update 'run-container' call.

build: file-systems: Allow for bind mounting regular files.

* gnu/build/file-systems.scm (regular-file?): New procedure.
  (mount-file-system): Create a regular file instead of a directory when bind
  mounting a regular file.

vm: Make the list of partitions to build a parameter.

* gnu/build/vm.scm (<partition>): New record type.
  (fold2): New procedure.
  (initialize-partition-table): Remove #:bootable? and
  'partition-size' parameters.  Add 'partitions' parameter.  Invoke 'parted'
  with '--script'.
  (initialize-root-partition): Remove.
  (initialize-partition, root-partition-initializer): New procedures.
  (initialize-hard-disk): Remove #:system-directory, #:disk-image-size,
  #:file-system-type, #:file-system-label, #:closures, #:copy-closures?,
  #:bootable?, and #:register-closures? parameters.  Add #:partitions.
  Rewrite to use 'initialize-partition' for each item of PARTITIONS.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Add (guix records)
  to #:modules default value.
  (qemu-image): Adjust accordingly.

vm: Use the 'umount' procedure instead of util-linux's 'umount' command.

* gnu/build/vm.scm (initialize-root-partition, initialize-hard-disk): Use the
  'umount' procedure instead of invoking the 'umount' command.
* gnu/system/vm.scm (qemu-image): Remove UTIL-LINUX from INPUTS.

Merge branch 'master' into core-updates