file-systems: Remove 'title' field and add <file-system-label>.

The 'title' field was easily overlooked and was an endless source of
confusion.  Now, the value of the 'device' field is self-contained.

* gnu/system/file-systems.scm (<file-system>): Change constructor name
to '%file-system'.
[title]: Remove.
(<file-system-label>): New record type with printer.
(report-deprecation, device-expression)
(process-file-system-declaration, file-system): New macros.
(file-system-title): New procedure.
(file-system->spec, spec->file-system): Adjust to handle
<file-system-label>.
* gnu/system.scm (bootable-kernel-arguments): Add case for
'file-system-label?'.
(read-boot-parameters): Likewise.
(mapped-device-user): Avoid 'file-system-title'.
(fs->boot-device): Remove.
(operating-system-boot-parameters): Use 'file-system-device' instead of
'fs->boot-device'.
(device->sexp): Add case for 'file-system-label?'.
* gnu/bootloader/grub.scm (grub-root-search): Add case for
'file-system-label?'.
* gnu/system/examples/bare-bones.tmpl,
gnu/system/examples/beaglebone-black.tmpl,
gnu/system/examples/lightweight-desktop.tmpl,
gnu/system/examples/vm-image.tmpl: Remove uses of 'title'.
* gnu/system/vm.scm (virtualized-operating-system): Remove uses of
'file-system-title'.
* guix/scripts/system.scm (check-file-system-availability): Likewise,
and adjust fix-it hint.
(check-initrd-modules)[file-system-/dev]: Likewise.
* gnu/build/file-systems.scm (canonicalize-device-spec): Remove 'title'
parameter.
[canonical-title]: Remove.
Match on SPEC's type rather than on CANONICAL-TITLE.
(mount-file-system): Adjust caller.
* gnu/build/linux-boot.scm (boot-system): Interpret ROOT here.
* gnu/services/base.scm (file-system->fstab-entry): Remove use of
'file-system-title'.
* doc/guix.texi (File Systems): Remove documentation of the 'title'
field.  Rewrite documentation of 'device' and document
'file-system-label'.

1 files changed, 2 insertions, 3 deletions

diff --git a/gnu/system/vm.scm b/gnu/system/vm.scm
index eb73b5ca7a..7f80147150 100644
--- a/gnu/system/vm.scm
+++ b/gnu/system/vm.scm
@@ -693,13 +693,12 @@ environment with the store shared with the host.  MAPPINGS is a list of
                     (source (file-system-device fs)))
                 (or (string=? target (%store-prefix))
                     (string=? target "/")
-                    (and (eq? 'device (file-system-title fs))
+                    (and (string? source)
                          (string-prefix? "/dev/" source))
 
                     ;; Labels and UUIDs are necessarily invalid in the VM.
                     (and (file-system-mount? fs)
-                         (or (eq? 'label (file-system-title fs))
-                             (eq? 'uuid (file-system-title fs))
+                         (or (file-system-label? source)
                              (uuid? source))))))
             (operating-system-file-systems os)))