vdev_file: unify FreeBSD and Linux implementations

Kernel & userspace specifics are in zfs_file_os.c, so there's no
particular reason these have to be separate.

The one platform-specific part is in the Linux kernel part, to offload
flushes to a taskq if we're already inside a filesystem transaction.
This would be normally be an unsatisfying wart, but I'm intending to
remove this shortly, so I'm content to leave it gated for the moment.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Signed-off-by: Rob Norris <[email protected]>

lib/libzpool/Makefile.am

@@ -46,7 +46,6 @@ nodist_libzpool_la_SOURCES = \
 	module/lua/lvm.c \
 	module/lua/lzio.c \
 	\
-	module/os/linux/zfs/vdev_file.c \
 	module/os/linux/zfs/zio_crypt.c \
 	\
 	module/zcommon/cityhash.c \
@@ -143,6 +142,7 @@ nodist_libzpool_la_SOURCES = \
 	module/zfs/vdev.c \
 	module/zfs/vdev_draid.c \
 	module/zfs/vdev_draid_rand.c \
+	module/zfs/vdev_file.c \
 	module/zfs/vdev_indirect.c \
 	module/zfs/vdev_indirect_births.c \
 	module/zfs/vdev_indirect_mapping.c \

module/Kbuild.in

@@ -385,6 +385,7 @@ ZFS_OBJS := \
 	vdev.o \
 	vdev_draid.o \
 	vdev_draid_rand.o \
+	vdev_file.o \
 	vdev_indirect.o \
 	vdev_indirect_births.o \
 	vdev_indirect_mapping.o \
@@ -446,7 +447,6 @@ ZFS_OBJS_OS := \
 	spa_misc_os.o \
 	trace.o \
 	vdev_disk.o \
-	vdev_file.o \
 	vdev_raidz.o \
 	vdev_label_os.o \
 	zfs_acl.o \

module/Makefile.bsd

@@ -199,7 +199,6 @@ SRCS+=	abd_os.c \
 	kmod_core.c \
 	spa_os.c \
 	sysctl_os.c \
-	vdev_file.c \
 	vdev_geom.c \
 	vdev_label_os.c \
 	zfs_acl.c \
@@ -313,6 +312,7 @@ SRCS+=	abd.c \
 	vdev.c \
 	vdev_draid.c \
 	vdev_draid_rand.c \
+	vdev_file.c \
 	vdev_indirect_births.c \
 	vdev_indirect.c \
 	vdev_indirect_mapping.c \