[PATCH 3/8] swap: don't add ITER_BVEC flag to direct_IO rw

[Omar Sandoval <osandov@osandov.com>]

The rw argument to direct_IO has some ill-defined semantics. Some
filesystems (e.g., ext4, FAT) decide whether they're doing a write with
rw == WRITE, but others (e.g., XFS) check rw & WRITE. Let's set a good
example in the swap file code and say ITER_BVEC belongs in
iov_iter->flags but not in rw. This caters to the least common
denominator and avoids a sweeping change of every direct_IO
implementation for now.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
---
 mm/page_io.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index 1630ac0..c229f88 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -285,8 +285,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
 		set_page_writeback(page);
 		unlock_page(page);
 		mutex_lock(&inode->i_mutex);
-		ret = mapping->a_ops->direct_IO(ITER_BVEC | WRITE,
-						&kiocb, &from,
+		ret = mapping->a_ops->direct_IO(WRITE, &kiocb, &from,
 						kiocb.ki_pos);
 		mutex_unlock(&inode->i_mutex);
 		if (ret == PAGE_SIZE) {
-- 
2.1.3

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>