xfs: abstract block export operations from nfsd layouts

Instead of creeping pnfs layout configuration into filesystems, move the
definition of block-based export operations under a more abstract
configuration.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/Kconfig

@@ -67,6 +67,12 @@ config FS_POSIX_ACL
 config EXPORTFS
 	tristate
 
+config EXPORTFS_BLOCK_OPS
+	bool "Enable filesystem export operations for block IO"
+	help
+	  This option enables the export operations for a filesystem to support
+	  external block IO.
+
 config FILE_LOCKING
 	bool "Enable POSIX file locking API" if EXPERT
 	default y

fs/nfsd/Kconfig

@@ -90,6 +90,7 @@ config NFSD_BLOCKLAYOUT
 	bool "NFSv4.1 server support for pNFS block layouts"
 	depends on NFSD_V4 && BLOCK
 	select NFSD_PNFS
+	select EXPORTFS_BLOCK_OPS
 	help
 	  This option enables support for the exporting pNFS block layouts
 	  in the kernel's NFS server. The pNFS block layout enables NFS
@@ -102,6 +103,7 @@ config NFSD_SCSILAYOUT
 	bool "NFSv4.1 server support for pNFS SCSI layouts"
 	depends on NFSD_V4 && BLOCK
 	select NFSD_PNFS
+	select EXPORTFS_BLOCK_OPS
 	help
 	  This option enables support for the exporting pNFS SCSI layouts
 	  in the kernel's NFS server. The pNFS SCSI layout enables NFS

fs/xfs/Makefile

@@ -121,5 +121,4 @@ xfs-$(CONFIG_XFS_RT)		+= xfs_rtalloc.o
 xfs-$(CONFIG_XFS_POSIX_ACL)	+= xfs_acl.o
 xfs-$(CONFIG_SYSCTL)		+= xfs_sysctl.o
 xfs-$(CONFIG_COMPAT)		+= xfs_ioctl32.o
-xfs-$(CONFIG_NFSD_BLOCKLAYOUT)	+= xfs_pnfs.o
-xfs-$(CONFIG_NFSD_SCSILAYOUT)	+= xfs_pnfs.o
+xfs-$(CONFIG_EXPORTFS_BLOCK_OPS)	+= xfs_pnfs.o

fs/xfs/xfs_export.c

@@ -246,7 +246,7 @@ const struct export_operations xfs_export_operations = {
 	.fh_to_parent		= xfs_fs_fh_to_parent,
 	.get_parent		= xfs_fs_get_parent,
 	.commit_metadata	= xfs_fs_nfs_commit_metadata,
-#ifdef CONFIG_NFSD_BLOCKLAYOUT
+#ifdef CONFIG_EXPORTFS_BLOCK_OPS
 	.get_uuid		= xfs_fs_get_uuid,
 	.map_blocks		= xfs_fs_map_blocks,
 	.commit_blocks		= xfs_fs_commit_blocks,

fs/xfs/xfs_pnfs.h

@@ -1,7 +1,7 @@
 #ifndef _XFS_PNFS_H
 #define _XFS_PNFS_H 1
 
-#if defined(CONFIG_NFSD_BLOCKLAYOUT) || defined(CONFIG_NFSD_SCSILAYOUT)
+#ifdef CONFIG_EXPORTFS_BLOCK_OPS
 int xfs_fs_get_uuid(struct super_block *sb, u8 *buf, u32 *len, u64 *offset);
 int xfs_fs_map_blocks(struct inode *inode, loff_t offset, u64 length,
 		struct iomap *iomap, bool write, u32 *device_generation);
@@ -15,5 +15,5 @@ xfs_break_layouts(struct inode *inode, uint *iolock, bool with_imutex)
 {
 	return 0;
 }
-#endif /* CONFIG_NFSD_PNFS */
+#endif /* CONFIG_EXPORTFS_BLOCK_OPS */
 #endif /* _XFS_PNFS_H */