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'.
This commit is contained in:
Ludovic Courtès 2018-05-18 13:43:07 +02:00
parent 25816c4306
commit a5acc17a3c
No known key found for this signature in database
GPG key ID: 090B11993D9AEBB5
13 changed files with 201 additions and 133 deletions

View file

@ -9210,20 +9210,31 @@ This is a string specifying the type of the file system---e.g.,
This designates the place where the file system is to be mounted.
@item @code{device}
This names the ``source'' of the file system. By default it is the name
of a node under @file{/dev}, but its meaning depends on the @code{title}
field described below.
This names the ``source'' of the file system. It can be one of three
things: a file system label, a file system UUID, or the name of a
@file{/dev} node. Labels and UUIDs offer a way to refer to file
systems without having to hard-code their actual device
name@footnote{Note that, while it is tempting to use
@file{/dev/disk/by-uuid} and similar device names to achieve the same
result, this is not recommended: These special device nodes are created
by the udev daemon and may be unavailable at the time the device is
mounted.}.
@item @code{title} (default: @code{'device})
This is a symbol that specifies how the @code{device} field is to be
interpreted.
@findex file-system-label
File system labels are created using the @code{file-system-label}
procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
plain strings. Here's an example of a file system referred to by its
label, as shown by the @command{e2label} command:
When it is the symbol @code{device}, then the @code{device} field is
interpreted as a file name; when it is @code{label}, then @code{device}
is interpreted as a file system label name; when it is @code{uuid},
@code{device} is interpreted as a file system unique identifier (UUID).
@example
(file-system
(mount-point "/home")
(type "ext4")
(device (file-system-label "my-home")))
@end example
UUIDs may be converted from their string representation (as shown by the
@findex uuid
UUIDs are converted from their string representation (as shown by the
@command{tune2fs -l} command) using the @code{uuid} form@footnote{The
@code{uuid} form expects 16-byte UUIDs as defined in
@uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
@ -9235,22 +9246,13 @@ like this:
(file-system
(mount-point "/home")
(type "ext4")
(title 'uuid)
(device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
@end example
The @code{label} and @code{uuid} options offer a way to refer to file
systems without having to hard-code their actual device
name@footnote{Note that, while it is tempting to use
@file{/dev/disk/by-uuid} and similar device names to achieve the same
result, this is not recommended: These special device nodes are created
by the udev daemon and may be unavailable at the time the device is
mounted.}.
However, when the source of a file system is a mapped device (@pxref{Mapped
When the source of a file system is a mapped device (@pxref{Mapped
Devices}), its @code{device} field @emph{must} refer to the mapped
device name---e.g., @file{/dev/mapper/root-partition}---and consequently
@code{title} must be set to @code{'device}. This is required so that
device name---e.g., @file{"/dev/mapper/root-partition"}.
This is required so that
the system knows that mounting the file system depends on having the
corresponding device mapping established.

View file

@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com>
;;; Copyright © 2017 Leo Famulari <leo@famulari.name>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
@ -31,6 +31,7 @@ (define-module (gnu bootloader grub)
#:use-module (gnu system)
#:use-module (gnu bootloader)
#:use-module (gnu system uuid)
#:use-module (gnu system file-systems)
#:autoload (gnu packages bootloaders) (grub)
#:autoload (gnu packages compression) (gzip)
#:autoload (gnu packages gtk) (guile-cairo guile-rsvg)
@ -303,9 +304,10 @@ (define (grub-root-search device file)
((? uuid? uuid)
(format #f "search --fs-uuid --set ~a"
(uuid->string device)))
((? string? label)
(format #f "search --label --set ~a" label))
(#f
((? file-system-label? label)
(format #f "search --label --set ~a"
(file-system-label->string label)))
((or #f (? string?))
#~(format #f "search --file --set ~a" #$file)))))
(define* (grub-configuration-file config entries

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@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016, 2017 David Craven <david@craven.ch>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;;
@ -473,17 +473,9 @@ (define find-partition-by-luks-uuid
(find-partition luks-partition-uuid-predicate))
(define* (canonicalize-device-spec spec #:optional (title 'any))
"Return the device name corresponding to SPEC. TITLE is a symbol, one of
the following:
'device', in which case SPEC is known to designate a device node--e.g.,
\"/dev/sda1\";
'label', in which case SPEC is known to designate a partition label--e.g.,
\"my-root-part\";
'uuid', in which case SPEC must be a UUID designating a partition;
'any', in which case SPEC can be anything.
"
(define (canonicalize-device-spec spec)
"Return the device name corresponding to SPEC, which can be a <uuid>, a
<file-system-label>, or a string (typically a /dev file name)."
(define max-trials
;; Number of times we retry partition label resolution, 1 second per
;; trial. Note: somebody reported a delay of 16 seconds (!) before their
@ -491,19 +483,6 @@ (define max-trials
;; this long.
20)
(define canonical-title
;; The realm of canonicalization.
(if (eq? title 'any)
(if (string? spec)
;; The "--root=SPEC" kernel command-line option always provides a
;; string, but the string can represent a device, a UUID, or a
;; label. So check for all three.
(cond ((string-prefix? "/" spec) 'device)
((string->uuid spec) 'uuid)
(else 'label))
'uuid)
title))
(define (resolve find-partition spec fmt)
(let loop ((count 0))
(let ((device (find-partition spec)))
@ -518,23 +497,19 @@ (define (resolve find-partition spec fmt)
(sleep 1)
(loop (+ 1 count))))))))
(case canonical-title
((device)
(match spec
((? string?)
;; Nothing to do.
spec)
((label)
((? file-system-label?)
;; Resolve the label.
(resolve find-partition-by-label spec identity))
((uuid)
(resolve find-partition-by-label
(file-system-label->string spec)
identity))
((? uuid?)
(resolve find-partition-by-uuid
(cond ((string? spec)
(string->uuid spec))
((uuid? spec)
(uuid-bytevector spec))
(else spec))
uuid->string))
(else
(error "unknown device title" title))))
(uuid-bytevector spec)
uuid->string))))
(define (check-file-system device type)
"Run a file system check of TYPE on DEVICE."
@ -615,8 +590,7 @@ (define (mount-nfs source mount-point type flags options)
"")))))
(let ((type (file-system-type fs))
(options (file-system-options fs))
(source (canonicalize-device-spec (file-system-device fs)
(file-system-title fs)))
(source (canonicalize-device-spec (file-system-device fs)))
(mount-point (string-append root "/"
(file-system-mount-point fs)))
(flags (mount-flags->bit-mask (file-system-flags fs))))

View file

@ -507,9 +507,15 @@ (define (lookup-module name)
(error "pre-mount actions failed")))
(if root
;; The "--root=SPEC" kernel command-line option always provides a
;; string, but the string can represent a device, a UUID, or a
;; label. So check for all three.
(let ((root (cond ((string-prefix? "/" root) root)
((uuid root) => identity)
(else (file-system-label root)))))
(mount-root-file-system (canonicalize-device-spec root)
root-fs-type
#:volatile-root? volatile-root?)
#:volatile-root? volatile-root?))
(mount "none" "/root" "tmpfs"))
;; Mount the specified file systems.

View file

@ -303,15 +303,14 @@ (define user-processes-service-type
(define (file-system->fstab-entry file-system)
"Return a @file{/etc/fstab} entry for @var{file-system}."
(string-append (case (file-system-title file-system)
((label)
(string-append "LABEL=" (file-system-device file-system)))
((uuid)
(string-append
"UUID="
(uuid->string (file-system-device file-system))))
(else
(file-system-device file-system)))
(string-append (match (file-system-device file-system)
((? file-system-label? label)
(string-append "LABEL="
(file-system-label->string file-system)))
((? uuid? uuid)
(string-append "UUID=" (uuid->string uuid)))
((? string? device)
device))
"\t"
(file-system-mount-point file-system) "\t"
(file-system-type file-system) "\t"

View file

@ -131,13 +131,16 @@ (define (bootable-kernel-arguments kernel-arguments system.drv root-device)
"Prepend extra arguments to KERNEL-ARGUMENTS that allow SYSTEM.DRV to be
booted from ROOT-DEVICE"
(cons* (string-append "--root="
(if (uuid? root-device)
(cond ((uuid? root-device)
;; Note: Always use the DCE format because that's
;; what (gnu build linux-boot) expects for the
;; '--root' kernel command-line option.
(uuid->string (uuid-bytevector root-device) 'dce)
root-device))
(uuid->string (uuid-bytevector root-device)
'dce))
((file-system-label? root-device)
(file-system-label->string root-device))
(else root-device)))
#~(string-append "--system=" #$system.drv)
#~(string-append "--load=" #$system.drv "/boot")
kernel-arguments))
@ -251,10 +254,16 @@ (define device-sexp->device
(match-lambda
(('uuid (? symbol? type) (? bytevector? bv))
(bytevector->uuid bv type))
(('file-system-label (? string? label))
(file-system-label label))
((? bytevector? bv) ;old format
(bytevector->uuid bv 'dce))
((? string? device)
device)))
;; It used to be that we would not distinguish between labels and
;; device names. Try to infer the right thing here.
(if (string-prefix? "/dev/" device)
device
(file-system-label device)))))
(match (read port)
(('boot-parameters ('version 0)
@ -377,7 +386,7 @@ (define (mapped-device-user device file-systems)
(let ((target (string-append "/dev/mapper/" (mapped-device-target device))))
(find (lambda (fs)
(or (member device (file-system-dependencies fs))
(and (eq? 'device (file-system-title fs))
(and (string? (file-system-device fs))
(string=? (file-system-device fs) target))))
file-systems)))
@ -934,13 +943,6 @@ (define* (operating-system-bootcfg os #:optional (old-entries '()))
(bootloader-configuration-bootloader bootloader-conf))
bootloader-conf (list entry) #:old-entries old-entries)))
(define (fs->boot-device fs)
"Given FS, a <file-system> object, return a value suitable for use as the
device in a <menu-entry>."
(case (file-system-title fs)
((uuid label device) (file-system-device fs))
(else #f)))
(define (operating-system-boot-parameters os system.drv root-device)
"Return a monadic <boot-parameters> record that describes the boot parameters
of OS. SYSTEM.DRV is either a derivation or #f. If it's a derivation, adds
@ -962,7 +964,7 @@ (define (operating-system-boot-parameters os system.drv root-device)
(operating-system-user-kernel-arguments os)))
(initrd initrd)
(bootloader-name bootloader-name)
(store-device (ensure-not-/dev (fs->boot-device store)))
(store-device (ensure-not-/dev (file-system-device store)))
(store-mount-point (file-system-mount-point store))))))
(define (device->sexp device)
@ -970,6 +972,8 @@ (define (device->sexp device)
(match device
((? uuid? uuid)
`(uuid ,(uuid-type uuid) ,(uuid-bytevector uuid)))
((? file-system-label? label)
`(file-system-label ,(file-system-label->string label)))
(_
device)))

View file

@ -16,8 +16,7 @@
(bootloader grub-bootloader)
(target "/dev/sdX")))
(file-systems (cons (file-system
(device "my-root")
(title 'label)
(device (file-system-label "my-root"))
(mount-point "/")
(type "ext4"))
%base-file-systems))

View file

@ -20,8 +20,7 @@
(initrd-modules (cons "omap_hsmmc" %base-initrd-modules))
(file-systems (cons (file-system
(device "my-root")
(title 'label)
(device (file-system-label "my-root"))
(mount-point "/")
(type "ext4"))
%base-file-systems))

View file

@ -20,13 +20,11 @@
;; Assume the target root file system is labelled "my-root",
;; and the EFI System Partition has UUID 1234-ABCD.
(file-systems (cons* (file-system
(device "my-root")
(title 'label)
(device (file-system-label "my-root"))
(mount-point "/")
(type "ext4"))
(file-system
(device (uuid "1234-ABCD" 'fat))
(title 'uuid)
(mount-point "/boot/efi")
(type "vfat"))
%base-file-systems))

View file

@ -31,8 +31,7 @@ partprobe, and then 2) resizing the filesystem with resize2fs.\n"))
(target "/dev/sda")
(terminal-outputs '(console))))
(file-systems (cons (file-system
(device "my-root")
(title 'label)
(device (file-system-label "my-root"))
(mount-point "/")
(type "ext4"))
%base-file-systems))

View file

@ -20,6 +20,8 @@ (define-module (gnu system file-systems)
#:use-module (ice-9 match)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-9 gnu)
#:use-module (guix records)
#:use-module (gnu system uuid)
#:re-export (uuid ;backward compatibility
@ -28,7 +30,7 @@ (define-module (gnu system file-systems)
#:export (file-system
file-system?
file-system-device
file-system-title
file-system-title ;deprecated
file-system-mount-point
file-system-type
file-system-needed-for-boot?
@ -42,6 +44,10 @@ (define-module (gnu system file-systems)
file-system-type-predicate
file-system-label
file-system-label?
file-system-label->string
file-system->spec
spec->file-system
specification->file-system-mapping
@ -82,12 +88,10 @@ (define-module (gnu system file-systems)
;;; Code:
;; File system declaration.
(define-record-type* <file-system> file-system
(define-record-type* <file-system> %file-system
make-file-system
file-system?
(device file-system-device) ; string
(title file-system-title ; 'device | 'label | 'uuid
(default 'device))
(device file-system-device) ; string | <uuid> | <file-system-label>
(mount-point file-system-mount-point) ; string
(type file-system-type) ; string
(flags file-system-flags ; list of symbols
@ -108,6 +112,83 @@ (define-record-type* <file-system> file-system
(default (current-source-location))
(innate)))
;; A file system label for use in the 'device' field.
(define-record-type <file-system-label>
(file-system-label label)
file-system-label?
(label file-system-label->string))
(set-record-type-printer! <file-system-label>
(lambda (obj port)
(format port "#<file-system-label ~s>"
(file-system-label->string obj))))
(define-syntax report-deprecation
(lambda (s)
"Report the use of the now-deprecated 'title' field."
(syntax-case s ()
((_ field)
(let* ((source (syntax-source #'field))
(file (and source (assq-ref source 'filename)))
(line (and source
(and=> (assq-ref source 'line) 1+)))
(column (and source (assq-ref source 'column))))
(format (current-error-port)
"~a:~a:~a: warning: 'title' field is deprecated~%"
file line column)
#t)))))
;; Helper for 'process-file-system-declaration'.
(define-syntax device-expression
(syntax-rules (quote label uuid device)
((_ (quote label) dev)
(file-system-label dev))
((_ (quote uuid) dev)
(if (uuid? dev) dev (uuid dev)))
((_ (quote device) dev)
dev)
((_ title dev)
(case title
((label) (file-system-label dev))
((uuid) (uuid dev))
(else dev)))))
;; Helper to interpret the now-deprecated 'title' field. Detect forms like
;; (title 'label), remove them, and adjust the 'device' field accordingly.
;; TODO: Remove this once 'title' has been deprecated long enough.
(define-syntax process-file-system-declaration
(syntax-rules (device title)
((_ () (rest ...) #f #f) ;no 'title' and no 'device' field
(%file-system rest ...))
((_ () (rest ...) dev #f) ;no 'title' field
(%file-system rest ... (device dev)))
((_ () (rest ...) dev titl) ;got a 'title' field
(%file-system rest ...
(device (device-expression titl dev))))
((_ ((title titl) rest ...) (previous ...) dev _)
(begin
(report-deprecation (title titl))
(process-file-system-declaration (rest ...)
(previous ...)
dev titl)))
((_ ((device dev) rest ...) (previous ...) _ titl)
(process-file-system-declaration (rest ...)
(previous ...)
dev titl))
((_ (field rest ...) (previous ...) dev titl)
(process-file-system-declaration (rest ...)
(previous ... field)
dev titl))))
(define-syntax-rule (file-system fields ...)
(process-file-system-declaration (fields ...) () #f #f))
(define (file-system-title fs) ;deprecated
(match (file-system-device fs)
((? file-system-label?) 'label)
((? uuid?) 'uuid)
((? string?) 'device)))
;; Note: This module is used both on the build side and on the host side.
;; Arrange not to pull (guix store) and (guix config) because the latter
;; differs from user to user.
@ -160,23 +241,26 @@ (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 title mount-point type flags options _ _ check?)
(list (if (uuid? device)
`(uuid ,(uuid-type device) ,(uuid-bytevector device))
device)
title mount-point type flags options check?))))
(($ <file-system> device mount-point type flags options _ _ check?)
(list (cond ((uuid? device)
`(uuid ,(uuid-type device) ,(uuid-bytevector device)))
((file-system-label? device)
`(file-system-label ,(file-system-label->string device)))
(else device))
mount-point type flags options check?))))
(define (spec->file-system sexp)
"Deserialize SEXP, a list, to the corresponding <file-system> object."
(match sexp
((device title mount-point type flags options check?)
((device mount-point type flags options check?)
(file-system
(device (match device
(('uuid (? symbol? type) (? bytevector? bv))
(bytevector->uuid bv type))
(('file-system-label (? string? label))
(file-system-label label))
(_
device)))
(title title)
(mount-point mount-point) (type type)
(flags flags) (options options)
(check? check?)))))

View file

@ -693,13 +693,12 @@ (define user-file-systems
(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)))

View file

@ -590,17 +590,17 @@ (define relevant
(define labeled
(filter (lambda (fs)
(eq? (file-system-title fs) 'label))
(file-system-label? (file-system-device fs)))
relevant))
(define literal
(filter (lambda (fs)
(eq? (file-system-title fs) 'device))
(string? (file-system-device fs)))
relevant))
(define uuid
(filter (lambda (fs)
(eq? (file-system-title fs) 'uuid))
(uuid? (file-system-device fs)))
relevant))
(define fail? #f)
@ -628,15 +628,15 @@ (define (file-system-location* fs)
(strerror errno))
(unless (string-prefix? "/" device)
(display-hint (format #f (G_ "If '~a' is a file system
label, you need to add @code{(title 'label)} to your @code{file-system}
definition.")
device)))))))
label, write @code{(file-system-label ~s)} in your @code{device} field.")
device device)))))))
literal)
(for-each (lambda (fs)
(unless (find-partition-by-label (file-system-device fs))
(error (G_ "~a: error: file system with label '~a' not found~%")
(file-system-location* fs)
(let ((label (file-system-label->string
(file-system-device fs))))
(unless (find-partition-by-label label)
(error (G_ "~a: error: file system with label '~a' not found~%")
(file-system-location* fs) label))))
labeled)
(for-each (lambda (fs)
(unless (find-partition-by-uuid (file-system-device fs))
@ -677,10 +677,13 @@ (define (check-initrd-modules os)
checking this by themselves in their 'check' procedure."
(define (file-system-/dev fs)
(let ((device (file-system-device fs)))
(match (file-system-title fs)
('device device)
('uuid (find-partition-by-uuid device))
('label (find-partition-by-label device)))))
(match device
((? string?)
device)
((? uuid?)
(find-partition-by-uuid device))
((? file-system-label?)
(find-partition-by-label (file-system-label->string device))))))
(define file-systems
(filter file-system-needed-for-boot?