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file-systems: read-partition-{uuid,label} don't swallow ENOENT & co.

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Previously, (read-partition-uuid "/does/not/exist") would return #f.
With this change, a 'system-error exception is raised as expected.

* gnu/build/file-systems.scm (ENOENT-safe): Clarify docstring.
(partition-field-reader): Remove use of 'ENOENT-safe'.
(partition-predicate): Wrap READER in 'ENOENT-safe'.
This commit is contained in:
Ludovic Courtès 2021-04-22 22:41:01 +02:00
parent 34db952a4b
commit 09ce4568f2
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GPG key ID: 090B11993D9AEBB5
1 changed files with 14 additions and 15 deletions
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15
gnu/build/file-systems.scm
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@ -644,16 +644,13 @@ if DEVICE does not contain a NTFS file system."
(loop parts)))))))))) (loop parts))))))))))
(define (ENOENT-safe proc) (define (ENOENT-safe proc)
"Wrap the one-argument PROC such that ENOENT errors are caught and lead to a "Wrap the one-argument PROC such that ENOENT, EIO, and ENOMEDIUM errors are
warning and #f as the result." caught and lead to a warning and #f as the result."
(lambda (device) (lambda (device)
(catch 'system-error (catch 'system-error
(lambda () (lambda ()
(proc device)) (proc device))
(lambda args (lambda args
;; When running on the hand-made /dev,
;; 'disk-partitions' could return partitions for which
;; we have no /dev node. Handle that gracefully.
(let ((errno (system-error-errno args))) (let ((errno (system-error-errno args)))
(cond ((= ENOENT errno) (cond ((= ENOENT errno)
(format (current-error-port) (format (current-error-port)
@ -671,11 +668,10 @@ warning and #f as the result."
(define (partition-field-reader read field) (define (partition-field-reader read field)
"Return a procedure that takes a device and returns the value of a FIELD in "Return a procedure that takes a device and returns the value of a FIELD in
the partition superblock or #f." the partition superblock or #f."
(let ((read (ENOENT-safe read)))
(lambda (device) (lambda (device)
(let ((sblock (read device))) (let ((sblock (read device)))
(and sblock (and sblock
(field sblock)))))) (field sblock)))))
(define (read-partition-field device partition-field-readers) (define (read-partition-field device partition-field-readers)
"Returns the value of a FIELD in the partition superblock of DEVICE or #f. It "Returns the value of a FIELD in the partition superblock of DEVICE or #f. It
@ -742,11 +738,14 @@ partition field reader that returned a value."
(define (partition-predicate reader =) (define (partition-predicate reader =)
"Return a predicate that returns true if the FIELD of partition header that "Return a predicate that returns true if the FIELD of partition header that
was READ is = to the given value." was READ is = to the given value."
;; When running on the hand-made /dev, 'disk-partitions' could return
;; partitions for which we have no /dev node. Handle that gracefully.
(let ((reader (ENOENT-safe reader)))
(lambda (expected) (lambda (expected)
(lambda (device) (lambda (device)
(let ((actual (reader device))) (let ((actual (reader device)))
(and actual (and actual
(= actual expected)))))) (= actual expected)))))))
(define partition-label-predicate (define partition-label-predicate
(partition-predicate read-partition-label string=?)) (partition-predicate read-partition-label string=?))