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

From: Omar Sandoval
Date: Mon Dec 15 2014 - 00:28:57 EST

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@xxxxxxxxxxx>
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,
- ret = mapping->a_ops->direct_IO(ITER_BVEC | WRITE,
- &kiocb, &from,
+ ret = mapping->a_ops->direct_IO(WRITE, &kiocb, &from,
if (ret == PAGE_SIZE) {

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