Hi Lauri,
Lauri Tirkkonen via GNU coreutils Bug Reports <[email protected]>
writes:
> saw this on coreutils 9.7 on Alpine Linux, but it also reproduces on
> commit 027855dcad52d718927c3405bc7d605143e2a625.
>
> # mount -t tmpfs -o ro none /mnt
> # ./src/ginstall -d /mnt/foo
> ginstall: cannot change permissions of ‘/mnt/foo’: No such file or
> directory
>
> I would expect the error to be EROFS for creating the directory, not
> changing permissions of the directory that was not able to be created.
> strace confirms mkdir() returns EROFS, but install tries to open() and
> stat() the not-created directory afterward.
Thanks for the report.
It looks like the Gnulib mkdir-p module does not fail when 'mkdir' fails
with EROFS. And it looks like it has always behaved this way.
Paul, you are certainly more familiar with gnulib's mkdir-p and savewd
modules than I am. Can you check that the attached patch is correct
before I commit it?
Here is the new error based on Lauri's example:
$ ./src/ginstall -d /mnt/foo
ginstall: cannot create directory ‘/mnt/foo’: Read-only file system
Thanks,
Collin
>From 822da07feb7862acbade9cb9aa5a9f5fa9cc6458 Mon Sep 17 00:00:00 2001
Message-ID: <822da07feb7862acbade9cb9aa5a9f5fa9cc6458.1753164543.git.collin.fu...@gmail.com>
From: Collin Funk <[email protected]>
Date: Mon, 21 Jul 2025 23:02:55 -0700
Subject: [PATCH] mkdir-p: Diagnose read-only file systems.
* lib/mkdir-p.c (make_dir_parents): Check for 'mkdir' failing on a
read-only file system.
---
ChangeLog | 4 ++++
lib/mkdir-p.c | 4 ++--
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 99ca126183..3948326827 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
2025-07-21 Collin Funk <[email protected]>
+ mkdir-p: Diagnose read-only file systems.
+ * lib/mkdir-p.c (make_dir_parents): Check for 'mkdir' failing on a
+ read-only file system.
+
sys_un-h: Make sure that the 'sys' subdirectory is created.
* modules/sys_un-h (Makefile.am): Make the 'sys' subdirectory. Remove
@NMD@ that is not applicable to subdirectories.
diff --git a/lib/mkdir-p.c b/lib/mkdir-p.c
index f5df9843e4..fc83434655 100644
--- a/lib/mkdir-p.c
+++ b/lib/mkdir-p.c
@@ -182,8 +182,8 @@ make_dir_parents (char *dir,
return true;
if (mkdir_errno == 0
- || (mkdir_errno != ENOENT && make_ancestor
- && errno != ENOTDIR))
+ || (mkdir_errno != ENOENT && mkdir_errno != EROFS
+ && make_ancestor && errno != ENOTDIR))
{
error (0, errno,
_(keep_owner
--
2.50.1
