abd_os: break out platform-specific header parts

Removing the platform #ifdefs from shared headers in favour of
per-platform headers. Makes abd_t much leaner, among other things.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16253

config/Rules.am

@@ -10,7 +10,8 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/module/icp/include \
 	-I$(top_srcdir)/lib/libspl/include \
-	-I$(top_srcdir)/lib/libspl/include/os/@ac_system_l@
+	-I$(top_srcdir)/lib/libspl/include/os/@ac_system_l@ \
+	-I$(top_srcdir)/lib/libzpool/include
 
 AM_LIBTOOLFLAGS = --silent
 

include/os/freebsd/Makefile.am

@@ -77,6 +77,8 @@ noinst_HEADERS = \
 	%D%/spl/sys/zmod.h \
 	%D%/spl/sys/zone.h \
 	\
+	%D%/zfs/sys/abd_os.h \
+	%D%/zfs/sys/abd_impl_os.h \
 	%D%/zfs/sys/arc_os.h \
 	%D%/zfs/sys/freebsd_crypto.h \
 	%D%/zfs/sys/freebsd_event.h \

include/os/freebsd/zfs/sys/abd_impl_os.h

@@ -0,0 +1,41 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
+ * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2023, 2024, Klara Inc.
+ */
+
+#ifndef _ABD_IMPL_OS_H
+#define	_ABD_IMPL_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define	abd_enter_critical(flags)	critical_enter()
+#define	abd_exit_critical(flags)	critical_exit()
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _ABD_IMPL_OS_H */

include/os/freebsd/zfs/sys/abd_os.h

@@ -0,0 +1,46 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
+ * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ */
+
+#ifndef _ABD_OS_H
+#define	_ABD_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct abd_scatter {
+	uint_t		abd_offset;
+	void		*abd_chunks[1]; /* actually variable-length */
+};
+
+struct abd_linear {
+	void		*abd_buf;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _ABD_H */

include/os/linux/Makefile.am

@@ -20,6 +20,8 @@ kernel_linux_HEADERS = \
 
 kernel_sysdir = $(kerneldir)/sys
 kernel_sys_HEADERS = \
+	%D%/zfs/sys/abd_os.h \
+	%D%/zfs/sys/abd_impl_os.h \
 	%D%/zfs/sys/policy.h \
 	%D%/zfs/sys/trace_acl.h \
 	%D%/zfs/sys/trace_arc.h \

include/os/linux/zfs/sys/abd_impl_os.h

@@ -0,0 +1,41 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
+ * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2023, 2024, Klara Inc.
+ */
+
+#ifndef _ABD_IMPL_OS_H
+#define	_ABD_IMPL_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define	abd_enter_critical(flags)	local_irq_save(flags)
+#define	abd_exit_critical(flags)	local_irq_restore(flags)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _ABD_IMPL_OS_H */

include/os/linux/zfs/sys/abd_os.h

@@ -0,0 +1,62 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
+ * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ */
+
+#ifndef _ABD_OS_H
+#define	_ABD_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct abd_scatter {
+	uint_t		abd_offset;
+	uint_t		abd_nents;
+	struct scatterlist *abd_sgl;
+};
+
+struct abd_linear {
+	void		*abd_buf;
+	struct scatterlist *abd_sgl; /* for LINEAR_PAGE */
+};
+
+typedef struct abd abd_t;
+
+typedef int abd_iter_page_func_t(struct page *, size_t, size_t, void *);
+int abd_iterate_page_func(abd_t *, size_t, size_t, abd_iter_page_func_t *,
+    void *);
+
+/*
+ * Linux ABD bio functions
+ * Note: these are only needed to support vdev_classic. See comment in
+ * vdev_disk.c.
+ */
+unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t);
+unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _ABD_H */

include/sys/abd.h

@@ -30,6 +30,7 @@
 #include <sys/debug.h>
 #include <sys/zfs_refcount.h>
 #include <sys/uio.h>
+#include <sys/abd_os.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -57,21 +58,8 @@ typedef struct abd {
 #endif
 	kmutex_t	abd_mtx;
 	union {
-		struct abd_scatter {
+		struct abd_scatter	abd_scatter;
-			uint_t		abd_offset;
+		struct abd_linear	abd_linear;
-#if defined(__FreeBSD__) && defined(_KERNEL)
-			void    *abd_chunks[1]; /* actually variable-length */
-#else
-			uint_t		abd_nents;
-			struct scatterlist *abd_sgl;
-#endif
-		} abd_scatter;
-		struct abd_linear {
-			void		*abd_buf;
-#if defined(__linux__) && defined(_KERNEL)
-			struct scatterlist *abd_sgl; /* for LINEAR_PAGE */
-#endif
-		} abd_linear;
 		struct abd_gang {
 			list_t abd_gang_chain;
 		} abd_gang;
@@ -80,9 +68,6 @@ typedef struct abd {
 
 typedef int abd_iter_func_t(void *buf, size_t len, void *priv);
 typedef int abd_iter_func2_t(void *bufa, void *bufb, size_t len, void *priv);
-#if defined(__linux__) && defined(_KERNEL)
-typedef int abd_iter_page_func_t(struct page *, size_t, size_t, void *);
-#endif
 
 extern int zfs_abd_scatter_enabled;
 
@@ -129,10 +114,6 @@ void abd_release_ownership_of_buf(abd_t *);
 int abd_iterate_func(abd_t *, size_t, size_t, abd_iter_func_t *, void *);
 int abd_iterate_func2(abd_t *, abd_t *, size_t, size_t, size_t,
     abd_iter_func2_t *, void *);
-#if defined(__linux__) && defined(_KERNEL)
-int abd_iterate_page_func(abd_t *, size_t, size_t, abd_iter_page_func_t *,
-    void *);
-#endif
 void abd_copy_off(abd_t *, abd_t *, size_t, size_t, size_t);
 void abd_copy_from_buf_off(abd_t *, const void *, size_t, size_t);
 void abd_copy_to_buf_off(void *, abd_t *, size_t, size_t);
@@ -226,16 +207,6 @@ abd_get_size(abd_t *abd)
 void abd_init(void);
 void abd_fini(void);
 
-/*
- * Linux ABD bio functions
- * Note: these are only needed to support vdev_classic. See comment in
- * vdev_disk.c.
- */
-#if defined(__linux__) && defined(_KERNEL)
-unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t);
-unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t);
-#endif
-
 #ifdef __cplusplus
 }
 #endif

include/sys/abd_impl.h

@@ -28,6 +28,7 @@
 #define	_ABD_IMPL_H
 
 #include <sys/abd.h>
+#include <sys/abd_impl_os.h>
 #include <sys/wmsum.h>
 
 #ifdef __cplusplus
@@ -111,19 +112,6 @@ void abd_iter_page(struct abd_iter *);
 #define	ABD_LINEAR_BUF(abd)	(abd->abd_u.abd_linear.abd_buf)
 #define	ABD_GANG(abd)		(abd->abd_u.abd_gang)
 
-#if defined(_KERNEL)
-#if defined(__FreeBSD__)
-#define	abd_enter_critical(flags)	critical_enter()
-#define	abd_exit_critical(flags)	critical_exit()
-#else
-#define	abd_enter_critical(flags)	local_irq_save(flags)
-#define	abd_exit_critical(flags)	local_irq_restore(flags)
-#endif
-#else /* !_KERNEL */
-#define	abd_enter_critical(flags)	((void)0)
-#define	abd_exit_critical(flags)	((void)0)
-#endif
-
 #ifdef __cplusplus
 }
 #endif

lib/libzpool/Makefile.am

@@ -1,3 +1,5 @@
+include $(srcdir)/%D%/include/Makefile.am
+
 libzpool_la_CFLAGS  = $(AM_CFLAGS) $(KERNEL_CFLAGS) $(LIBRARY_CFLAGS)
 libzpool_la_CFLAGS += $(ZLIB_CFLAGS)
 

lib/libzpool/include/Makefile.am

@@ -0,0 +1,4 @@
+libzpooldir = $(includedir)/libzpool
+libzpool_HEADERS = \
+	%D%/sys/abd_os.h \
+	%D%/sys/abd_impl_os.h

lib/libzpool/include/sys/abd_impl_os.h

@@ -0,0 +1,41 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
+ * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2023, 2024, Klara Inc.
+ */
+
+#ifndef _ABD_IMPL_OS_H
+#define	_ABD_IMPL_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define	abd_enter_critical(flags)	((void)0)
+#define	abd_exit_critical(flags)	((void)0)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _ABD_IMPL_OS_H */

lib/libzpool/include/sys/abd_os.h

@@ -0,0 +1,47 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2014 by Chunwei Chen. All rights reserved.
+ * Copyright (c) 2016, 2019 by Delphix. All rights reserved.
+ */
+
+#ifndef _ABD_OS_H
+#define	_ABD_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct abd_scatter {
+	uint_t		abd_offset;
+	uint_t		abd_nents;
+	struct scatterlist *abd_sgl;
+};
+
+struct abd_linear {
+	void		*abd_buf;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _ABD_H */

module/os/freebsd/zfs/abd_os.c

@@ -95,14 +95,12 @@ struct {
  */
 static size_t zfs_abd_scatter_min_size = PAGE_SIZE + 1;
 
-#if defined(_KERNEL)
 SYSCTL_DECL(_vfs_zfs);
 
 SYSCTL_INT(_vfs_zfs, OID_AUTO, abd_scatter_enabled, CTLFLAG_RWTUN,
 	&zfs_abd_scatter_enabled, 0, "Enable scattered ARC data buffers");
 SYSCTL_ULONG(_vfs_zfs, OID_AUTO, abd_scatter_min_size, CTLFLAG_RWTUN,
 	&zfs_abd_scatter_min_size, 0, "Minimum size of scatter allocations.");
-#endif
 
 kmem_cache_t *abd_chunk_cache;
 static kstat_t *abd_ksp;