file-systems: Support the 'no-atime' flag.

* guix/build/syscalls.scm (MS_NOATIME): New variable.
* gnu/build/file-systems.scm (mount-flags->bit-mask): Support it.
* doc/guix.texi (File Systems): Document it and add cross-references to
the relevant documentation.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 7 insertions, 2 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 8f6e5bc20c..39d2ee476a 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -10753,10 +10753,15 @@ corresponding device mapping established.
 This is a list of symbols denoting mount flags.  Recognized flags
 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
 access to special files), @code{no-suid} (ignore setuid and setgid
-bits), and @code{no-exec} (disallow program execution.)
+bits), @code{no-atime} (do not update file access times), and @code{no-exec}
+(disallow program execution).  @xref{Mount-Unmount-Remount,,, libc, The GNU C
+Library Reference Manual}, for more information on these flags.
 
 @item @code{options} (default: @code{#f})
-This is either @code{#f}, or a string denoting mount options.
+This is either @code{#f}, or a string denoting mount options passed to the
+file system driver.  @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
+Reference Manual}, for details and run @command{man 8 mount} for options for
+various file systems.
 
 @item @code{mount?} (default: @code{#t})
 This value indicates whether to automatically mount the file system when