On 30/03/2025 13:50, Corinna Vinschen wrote:
Hi Paul,
thanks for the patch.
On Mar 29 10:31, Paul Eggert via Cygwin wrote:
On 3/29/25 04:30, Corinna Vinschen wrote:
What it should do if only the POSIX.1e draft 17 functions are available
is something along these lines:
Yes, that sounds like a better approach. However, shouldn't it use O_PATH
not O_RDONLY? We might lack read access.
Does the attached Gnulib patch work for you? I haven't tested or installed
it (I don't use Cygwin).
From e245ab6ac865c7ff723837645886eb717c53a754 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 29 Mar 2025 10:27:01 -0600
Subject: [PATCH] file-has-acl: port symlink code to Cygwin
Problem reported by Corinna Vinschen in:
https://lists.gnu.org/r/bug-gnulib/2025-03/msg00112.html
* lib/file-has-acl.c (acl_get_link_np): New static function,
defined only if needed.
(HAVE_ACL_GET_LINK_NP): Define this if defining acl_get_link_np.
---
ChangeLog | 9 +++++++++
lib/file-has-acl.c | 21 ++++++++++++++++++++-
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/ChangeLog b/ChangeLog
index 58195260cf..a7fa40dc33 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2025-03-29 Paul Eggert <egg...@cs.ucla.edu>
+
+ file-has-acl: port symlink code to Cygwin
+ Problem reported by Corinna Vinschen in:
+ https://lists.gnu.org/r/bug-gnulib/2025-03/msg00112.html
+ * lib/file-has-acl.c (acl_get_link_np): New static function,
+ defined only if needed.
+ (HAVE_ACL_GET_LINK_NP): Define this if defining acl_get_link_np.
+
2025-03-29 Bruno Haible <br...@clisp.org>
acl-permissions: Update comments regarding NetBSD.
diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c
index 179e805bd4..2538b61944 100644
--- a/lib/file-has-acl.c
+++ b/lib/file-has-acl.c
@@ -362,6 +362,25 @@ acl_nfs4_nontrivial (uint32_t *xattr, ssize_t nbytes)
}
#endif
+#if (!USE_LINUX_XATTR && USE_ACL && HAVE_ACL_GET_FD \
+ && !HAVE_ACL_EXTENDED_FILE && !HAVE_ACL_TYPE_EXTENDED \
+ && !HAVE_ACL_GET_LINK_NP && defined O_PATH)
The definition of O_PATH requires an additional
#include <fcntl.h>
Adding that to gllib/file-has-acl.c, the patch works as desired on
Cygwin.
However, assuming not only Cygwin is affected, shouldn't the patch
rather use O_PATH if it's available, O_RDONLY if not?
-# if HAVE_ACL_GET_LINK_NP /* FreeBSD, NetBSD >= 10 */
+# if HAVE_ACL_GET_LINK_NP /* FreeBSD, NetBSD >= 10, Cygwin >= 2.5 */
Changing the comment is wrong, IMHO. We're adding a local version of
HAVE_ACL_GET_LINK_NP specificially because Cygwin (or, FWIW, any system
only providing the POSIX.1e draft 17 function) does not provide
acl_get_link_np, isn't it?
For Cygwin, I will add this function nevertheless, but it will only be
available in some upcoming version, either 3.6.1 or 3.7.0.
In terms of coreutils, I think either ls(1) gobble_file() or
file_has_aclinfo_cache() should still handle ENOENT from
file_has_aclinfo() and not print any error message. After all, due to
the preconditions for building acl_get_link_np, we can't be sure
acl_get_link_np has really been built into file-has-acl.c, and the
problem persists.
I tend to agree. I'll apply this later:
commit 88385a0d6d56197d3c180432c8a4bca07241e90b (HEAD -> master)
Author: Pádraig Brady <p...@draigbrady.com>
Date: Sun Mar 30 15:16:54 2025 +0100
ls: suppress ENOENT errors when reading ACL info
* src/ls.c (gobble_file): Indicating unknown ACL info with '?'
suffices for the edge case of a file being removed while reading,
or older cygwin when reading through dangling symlinks.
Reported by Corinna Vinschen.
diff --git a/src/ls.c b/src/ls.c
index 46ec42037..2cf4ee444 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -3538,8 +3538,14 @@ gobble_file (char const *name, enum filetype type, ino_t
inode,
/* Let the user know via '?' if errno is EACCES, which can
happen with Linux kernel 6.12 on an NFS file system.
- That's better than a longwinded diagnostic. */
- bool cannot_access_acl = n < 0 && errno == EACCES;
+ That's better than a longwinded diagnostic.
+
+ Similarly, ignore ENOENT which may happen on some versions
+ of cygwin when processing dangling symlinks for example.
+ Also if a file is removed while we're reading ACL info,
+ ACL_T_UNKNOWN is sufficient indication for that edge case. */
+ bool cannot_access_acl = n < 0
+ && (errno == EACCES || errno == ENOENT);
f->acl_type = (!have_scontext && !have_acl
? (cannot_access_acl ? ACL_T_UNKNOWN : ACL_T_NONE)
cheers,
Pádraig.
