On Wednesday 06 April 2011 16:49:31 Kamil Dudka wrote:
> Hello,
>
> the attached patch allows ls(1) from coreutils to eliminate unnecessary
> calls of getxattr() and thus prevents it from triggerring unnecessary
> mounts while listing files. The feature is enabled automatically whenever
> acl_extended_file_nofollow() is available at build-time. See the following
> bug for more details:
>
> https://bugzilla.redhat.com/692823
>
> Thanks in advance for considering the patch!
Attached is a new version with a typo fixed (spotted by Ondrej Vasik).
> Kamil
From 342c1cb354b368a9351aa3b9f1e2f55b2a2ee70b Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdu...@redhat.com>
Date: Wed, 6 Apr 2011 17:41:10 +0200
Subject: [PATCH] file-has-acl: use acl_extended_file_nofollow() if available
* lib/acl-internal.h (HAVE_ACL_EXTENDED_FILE): New macro.
(acl_extended_file): New macro.
* lib/file-has-acl.c (file_has_acl): Use acl_extended_file_nofollow().
* m4/acl.m4 (gl_FUNC_ACL): Check availability of
acl_extended_file_nofollow().
---
ChangeLog | 9 +++++++++
lib/acl-internal.h | 6 ++++++
lib/file-has-acl.c | 9 ++++++++-
m4/acl.m4 | 2 +-
4 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index eee9509..48f1d7a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2011-04-06 Kamil Dudka <kdu...@redhat.com>
+
+ file-has-acl: use acl_extended_file_nofollow() if available
+ * lib/acl-internal.h (HAVE_ACL_EXTENDED_FILE): New macro.
+ (acl_extended_file): New macro.
+ * lib/file-has-acl.c (file_has_acl): Use acl_extended_file_nofollow().
+ * m4/acl.m4 (gl_FUNC_ACL): Check availability of
+ acl_extended_file_nofollow().
+
2011-04-06 Paul Eggert <egg...@cs.ucla.edu>
verify: use _Static_assert if available
diff --git a/lib/acl-internal.h b/lib/acl-internal.h
index 0eb11bc..9a799be 100644
--- a/lib/acl-internal.h
+++ b/lib/acl-internal.h
@@ -124,6 +124,12 @@ rpl_acl_set_fd (int fd, acl_t acl)
# endif
/* Linux-specific */
+# ifndef HAVE_ACL_EXTENDED_FILE_NOFOLLOW
+# define HAVE_ACL_EXTENDED_FILE_NOFOLLOW false
+# define acl_extended_file_nofollow(name) (-1)
+# endif
+
+/* Linux-specific */
# ifndef HAVE_ACL_FROM_MODE
# define HAVE_ACL_FROM_MODE false
# define acl_from_mode(mode) (NULL)
diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c
index a815e4c..0688d8a 100644
--- a/lib/file-has-acl.c
+++ b/lib/file-has-acl.c
@@ -339,12 +339,19 @@ file_has_acl (char const *name, struct stat const *sb)
/* Linux, FreeBSD, MacOS X, IRIX, Tru64 */
int ret;
- if (HAVE_ACL_EXTENDED_FILE) /* Linux */
+ if (HAVE_ACL_EXTENDED_FILE || HAVE_ACL_EXTENDED_FILE_NOFOLLOW) /* Linux */
{
+# if HAVE_ACL_EXTENDED_FILE_NOFOLLOW
+ /* acl_extended_file_nofollow() uses lgetxattr() in order to prevent
+ unnecessary mounts, but it returns the same result as we already
+ know the file is not a symbolic link at this point */
+ ret = acl_extended_file_nofollow (name);
+# else
/* On Linux, acl_extended_file is an optimized function: It only
makes two calls to getxattr(), one for ACL_TYPE_ACCESS, one for
ACL_TYPE_DEFAULT. */
ret = acl_extended_file (name);
+# endif
}
else /* FreeBSD, MacOS X, IRIX, Tru64 */
{
diff --git a/m4/acl.m4 b/m4/acl.m4
index a01382d..9c0f451 100644
--- a/m4/acl.m4
+++ b/m4/acl.m4
@@ -33,7 +33,7 @@ AC_DEFUN([gl_FUNC_ACL],
AC_CHECK_FUNCS(
[acl_get_file acl_get_fd acl_set_file acl_set_fd \
acl_free acl_from_mode acl_from_text \
- acl_delete_def_file acl_extended_file \
+ acl_delete_def_file acl_extended_file acl_extended_file_nofollow \
acl_delete_fd_np acl_delete_file_np \
acl_copy_ext_native acl_create_entry_np \
acl_to_short_text acl_free_text])
--
1.7.4
