[PATCH v2 1/4] libfrog: add wrappers for file_getattr/file_setattr syscalls

[Andrey Albershteyn <aalbersh@redhat.com>]

Add wrappers for new file_getattr/file_setattr inode syscalls which will
be used by xfs_quota and xfs_io.

Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
---
 configure.ac          |   1 +
 include/builddefs.in  |   5 +++
 include/linux.h       |  20 +++++++++
 libfrog/Makefile      |   2 +
 libfrog/file_attr.c   | 122 ++++++++++++++++++++++++++++++++++++++++++++++++++
 libfrog/file_attr.h   |  35 +++++++++++++++
 m4/package_libcdev.m4 |  19 ++++++++
 7 files changed, 204 insertions(+)

diff --git a/configure.ac b/configure.ac
index 195ee6dddf61..a3206d53e7e0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -156,6 +156,7 @@ AC_PACKAGE_NEED_RCU_INIT
 AC_HAVE_PWRITEV2
 AC_HAVE_COPY_FILE_RANGE
 AC_HAVE_CACHESTAT
+AC_HAVE_FILE_ATTR
 AC_NEED_INTERNAL_FSXATTR
 AC_NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG
 AC_NEED_INTERNAL_FSCRYPT_POLICY_V2
diff --git a/include/builddefs.in b/include/builddefs.in
index 04b4e0880a84..d727b55b854f 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -97,6 +97,7 @@ HAVE_ZIPPED_MANPAGES = @have_zipped_manpages@
 HAVE_PWRITEV2 = @have_pwritev2@
 HAVE_COPY_FILE_RANGE = @have_copy_file_range@
 HAVE_CACHESTAT = @have_cachestat@
+HAVE_FILE_ATTR = @have_file_attr@
 NEED_INTERNAL_FSXATTR = @need_internal_fsxattr@
 NEED_INTERNAL_FSCRYPT_ADD_KEY_ARG = @need_internal_fscrypt_add_key_arg@
 NEED_INTERNAL_FSCRYPT_POLICY_V2 = @need_internal_fscrypt_policy_v2@
@@ -169,6 +170,10 @@ ifeq ($(ENABLE_GETTEXT),yes)
 GCFLAGS += -DENABLE_GETTEXT
 endif
 
+ifeq ($(HAVE_FILE_ATTR),yes)
+LCFLAGS += -DHAVE_FILE_ATTR
+endif
+
 # Override these if C++ needs other options
 SANITIZER_CXXFLAGS = $(SANITIZER_CFLAGS)
 GCXXFLAGS = $(GCFLAGS)
diff --git a/include/linux.h b/include/linux.h
index 6e83e073aa2e..993789f01b3a 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -16,6 +16,7 @@
 #include <sys/param.h>
 #include <sys/sysmacros.h>
 #include <sys/stat.h>
+#include <sys/syscall.h>
 #include <inttypes.h>
 #include <malloc.h>
 #include <getopt.h>
@@ -202,6 +203,25 @@ struct fsxattr {
 };
 #endif
 
+/*
+ * Use FILE_ATTR_SIZE_VER0 (linux/fs.h) instead of build system HAVE_FILE_ATTR
+ * as this header could be included in other places where HAVE_FILE_ATTR is not
+ * defined (e.g. xfstests's conftest.c in ./configure)
+ */
+#ifndef FILE_ATTR_SIZE_VER0
+/*
+ * We need to define file_attr if it's missing to know how to convert it to
+ * fsxattr
+ */
+struct file_attr {
+	__u32		fa_xflags;
+	__u32		fa_extsize;
+	__u32		fa_nextents;
+	__u32		fa_projid;
+	__u32		fa_cowextsize;
+};
+#endif
+
 #ifndef FS_IOC_FSGETXATTR
 /*
  * Flags for the fsx_xflags field
diff --git a/libfrog/Makefile b/libfrog/Makefile
index 560bad417ee4..268fa26638d7 100644
--- a/libfrog/Makefile
+++ b/libfrog/Makefile
@@ -24,6 +24,7 @@ fsproperties.c \
 fsprops.c \
 getparents.c \
 histogram.c \
+file_attr.c \
 list_sort.c \
 linux.c \
 logging.c \
@@ -55,6 +56,7 @@ fsprops.h \
 getparents.h \
 handle_priv.h \
 histogram.h \
+file_attr.h \
 logging.h \
 paths.h \
 projects.h \
diff --git a/libfrog/file_attr.c b/libfrog/file_attr.c
new file mode 100644
index 000000000000..1d42895477ae
--- /dev/null
+++ b/libfrog/file_attr.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+
+#include "file_attr.h"
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <asm/types.h>
+#include <fcntl.h>
+
+static void
+file_attr_to_fsxattr(
+	const struct file_attr	*fa,
+	struct fsxattr		*fsxa)
+{
+     memset(fsxa, 0, sizeof(struct fsxattr));
+
+     fsxa->fsx_xflags = fa->fa_xflags;
+     fsxa->fsx_extsize = fa->fa_extsize;
+     fsxa->fsx_nextents = fa->fa_nextents;
+     fsxa->fsx_projid = fa->fa_projid;
+     fsxa->fsx_cowextsize = fa->fa_cowextsize;
+
+}
+
+static void
+fsxattr_to_file_attr(
+	const struct fsxattr	*fsxa,
+	struct file_attr	*fa)
+{
+     memset(fa, 0, sizeof(struct file_attr));
+
+     fa->fa_xflags = fsxa->fsx_xflags;
+     fa->fa_extsize = fsxa->fsx_extsize;
+     fa->fa_nextents = fsxa->fsx_nextents;
+     fa->fa_projid = fsxa->fsx_projid;
+     fa->fa_cowextsize = fsxa->fsx_cowextsize;
+}
+
+int
+xfrog_file_getattr(
+	const int		dfd,
+	const char		*path,
+	const struct stat	*stat,
+	struct file_attr	*fa,
+	const unsigned int	at_flags)
+{
+	int			error;
+	int			fd;
+	struct fsxattr		fsxa;
+
+#ifdef HAVE_FILE_ATTR
+        error = syscall(__NR_file_getattr, dfd, path, fa,
+                        sizeof(struct file_attr), at_flags);
+	if (error && errno != ENOSYS)
+		return error;
+
+	if (!error)
+		return error;
+#endif
+
+	if (SPECIAL_FILE(stat->st_mode)) {
+		errno = EOPNOTSUPP;
+		return -1;
+	}
+
+	fd = open(path, O_RDONLY|O_NOCTTY);
+	if (fd == -1)
+		return fd;
+
+	error = ioctl(fd, FS_IOC_FSGETXATTR, &fsxa);
+	close(fd);
+	if (error)
+		return error;
+
+	fsxattr_to_file_attr(&fsxa, fa);
+
+	return error;
+}
+
+int
+xfrog_file_setattr(
+	const int		dfd,
+	const char		*path,
+	const struct stat	*stat,
+	struct file_attr	*fa,
+	const unsigned int	at_flags)
+{
+	int			error;
+	int			fd;
+	struct fsxattr		fsxa;
+
+#ifdef HAVE_FILE_ATTR
+	error = syscall(__NR_file_setattr, dfd, path, fa,
+			sizeof(struct file_attr), at_flags);
+	if (error && errno != ENOSYS)
+		return error;
+
+	if (!error)
+		return error;
+#endif
+
+	if (SPECIAL_FILE(stat->st_mode)) {
+		errno = EOPNOTSUPP;
+		return -1;
+	}
+
+	fd = open(path, O_RDONLY|O_NOCTTY);
+	if (fd == -1)
+		return fd;
+
+	file_attr_to_fsxattr(fa, &fsxa);
+
+	error = ioctl(fd, FS_IOC_FSSETXATTR, fa);
+	close(fd);
+
+	return error;
+}
diff --git a/libfrog/file_attr.h b/libfrog/file_attr.h
new file mode 100644
index 000000000000..ad33241bbffa
--- /dev/null
+++ b/libfrog/file_attr.h
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+#ifndef __LIBFROG_FILE_ATTR_H__
+#define __LIBFROG_FILE_ATTR_H__
+
+#include "linux.h"
+#include <sys/stat.h>
+
+#define SPECIAL_FILE(x) \
+	   (S_ISCHR((x)) \
+	|| S_ISBLK((x)) \
+	|| S_ISFIFO((x)) \
+	|| S_ISLNK((x)) \
+	|| S_ISSOCK((x)))
+
+int
+xfrog_file_getattr(
+	const int		dfd,
+	const char		*path,
+	const struct stat	*stat,
+	struct file_attr	*fa,
+	const unsigned int	at_flags);
+
+int
+xfrog_file_setattr(
+	const int		dfd,
+	const char		*path,
+	const struct stat	*stat,
+	struct file_attr	*fa,
+	const unsigned int	at_flags);
+
+#endif /* __LIBFROG_FILE_ATTR_H__ */
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index b77ac1a7580a..6a267dab7ab7 100644
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -274,3 +274,22 @@ AC_DEFUN([AC_PACKAGE_CHECK_LTO],
     AC_SUBST(lto_cflags)
     AC_SUBST(lto_ldflags)
   ])
+
+#
+# Check if we have a file_getattr/file_setattr system call (Linux)
+#
+AC_DEFUN([AC_HAVE_FILE_ATTR],
+  [ AC_MSG_CHECKING([for file_getattr/file_setattr syscalls])
+    AC_LINK_IFELSE(
+    [	AC_LANG_PROGRAM([[
+#define _GNU_SOURCE
+#include <sys/syscall.h>
+#include <unistd.h>
+	]], [[
+syscall(__NR_file_getattr, 0, 0, 0, 0, 0);
+	]])
+    ], have_file_attr=yes
+       AC_MSG_RESULT(yes),
+       AC_MSG_RESULT(no))
+    AC_SUBST(have_file_attr)
+  ])

-- 
2.49.0