system: Add a 'needed-for-boot?' field to 'mapped-device'.

* gnu/system/file-systems.scm (<mapped-device>)[needed-for-boot?]: New
  field.
* gnu/system.scm (operating-system-user-mapped-devices,
  operating-system-boot-mapped-devices): Use it instead of trying to
  guess.  Guessing doesn't work when one refers to a partition using its
  label, for instance.
* doc/guix.texi (Mapped Devices): Document 'needed-for-boot?'.
This commit is contained in:
Ludovic Courtès 2014-11-29 14:40:26 +01:00
parent 9cd0dfaa46
commit 3b09332adf
3 changed files with 20 additions and 18 deletions

View File

@ -3837,19 +3837,27 @@ detailed below.
Objects of this type represent device mappings that will be made when
the system boots up.
@table @code
@item source
@table @asis
@item @code{source}
This string specifies the name of the block device to be mapped, such as
@code{"/dev/sda3"}.
@item target
@item @code{target}
This string specifies the name of the mapping to be established. For
example, specifying @code{"my-partition"} will lead to the creation of
the @code{"/dev/mapper/my-partition"} device.
@item type
@item @code{type}
This must be a @code{mapped-device-kind} object, which specifies how
@var{source} is mapped to @var{target}.
@item @code{needed-for-boot?} (default: @code{#f})
This Boolean value indicates whether the device mapping must be made at
boot time---i.e., from the initial RAM disk, before any user file
systems are mounted.
You would set it to @code{#t} for instance when the mapped device is
used by the root file system.
@end table
@end deftp

View File

@ -250,23 +250,14 @@ as 'needed-for-boot'."
(define (operating-system-user-mapped-devices os)
"Return the subset of mapped devices that can be installed in
user-land--i.e., those not needed during boot."
(let ((devices (operating-system-mapped-devices os))
(file-systems (operating-system-file-systems os)))
(filter (lambda (md)
(let ((user (mapped-device-user md file-systems)))
(or (not user)
(not (file-system-needed-for-boot? user)))))
devices)))
(remove mapped-device-needed-for-boot?
(operating-system-mapped-devices os)))
(define (operating-system-boot-mapped-devices os)
"Return the subset of mapped devices that must be installed during boot,
from the initrd."
(let ((devices (operating-system-mapped-devices os))
(file-systems (operating-system-file-systems os)))
(filter (lambda (md)
(let ((user (mapped-device-user md file-systems)))
(and user (file-system-needed-for-boot? user))))
devices)))
(filter mapped-device-needed-for-boot?
(operating-system-mapped-devices os)))
(define (device-mapping-services os)
"Return the list of device-mapping services for OS as a monadic list."

View File

@ -45,6 +45,7 @@
mapped-device-source
mapped-device-target
mapped-device-type
mapped-device-needed-for-boot?
mapped-device-kind
mapped-device-kind?
@ -157,7 +158,9 @@ file system."
mapped-device?
(source mapped-device-source) ;string
(target mapped-device-target) ;string
(type mapped-device-type)) ;<mapped-device-kind>
(type mapped-device-type) ;<mapped-device-kind>
(needed-for-boot? mapped-device-needed-for-boot? ;Boolean
(default #f)))
(define-record-type* <mapped-device-type> mapped-device-kind
make-mapped-device-kind