From: Nick Piggin <npiggin@suse.de>
Introduce a new perform_write() address space operation.
This is a single-call, bulk version of write_begin/write_end
operations. It is only used in the buffered write path (write_begin
must still be implemented), and not for in-kernel writes to pagecache.
For some filesystems, using this can provide significant speedups.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
---
Index: linux/include/linux/fs.h
===================================================================
--- linux.orig/include/linux/fs.h 2008-02-04 15:24:03.000000000 +0100
+++ linux/include/linux/fs.h 2008-02-04 16:24:19.000000000 +0100
@@ -469,6 +469,9 @@ struct address_space_operations {
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
+ ssize_t (*perform_write)(struct file *, struct address_space *mapping,
+ struct iov_iter *i, loff_t pos);
+
/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
sector_t (*bmap)(struct address_space *, sector_t);
void (*invalidatepage) (struct page *, unsigned long);
Index: linux/mm/filemap.c
===================================================================
--- linux.orig/mm/filemap.c 2008-02-04 15:24:03.000000000 +0100
+++ linux/mm/filemap.c 2008-02-04 16:22:55.000000000 +0100
@@ -2312,7 +2312,9 @@ generic_file_buffered_write(struct kiocb
struct iov_iter i;
iov_iter_init(&i, iov, nr_segs, count, written);
- if (a_ops->write_begin)
+ if (a_ops->perform_write)
+ status = a_ops->perform_write(file, mapping, &i, pos);
+ else if (a_ops->write_begin)
status = generic_perform_write(file, &i, pos);
else
status = generic_perform_write_2copy(file, &i, pos);
Index: linux/Documentation/filesystems/vfs.txt
===================================================================
--- linux.orig/Documentation/filesystems/vfs.txt 2008-02-04 12:28:50.000000000 +0100
+++ linux/D...
