[PATCH] Streamline generic_file_* interfaces and filemap cleanups

This patch cleans up generic_file_*_read/write() interfaces.  Christoph
Hellwig gave me the idea for this clean ups.

In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods.  This allows us
to cleanup all variants of generic_file_* routines.

Final available interfaces:

generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler

__generic_file_aio_write_nolock() - internal worker routine

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 677139b..bfe5dbf 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -36,8 +36,10 @@
 const struct file_operations ramfs_file_operations = {
 	.mmap			= ramfs_nommu_mmap,
 	.get_unmapped_area	= ramfs_nommu_get_unmapped_area,
-	.read			= generic_file_read,
-	.write			= generic_file_write,
+	.read			= do_sync_read,
+	.aio_read		= generic_file_aio_read,
+	.write			= do_sync_write,
+	.aio_write		= generic_file_aio_write,
 	.fsync			= simple_sync_file,
 	.sendfile		= generic_file_sendfile,
 	.llseek			= generic_file_llseek,