[PATCH 1/2] ext4: replace ext4_io_submit->io_op with ->io_wbc

[Tejun Heo <tj@kernel.org>]

ext4_io_submit_init() takes the pointer to writeback_control to test
its sync_mode and determine between WRITE and WRITE_SYNC and records
the result in ->io_op.  This patch makes it record the pointer
directly and moves the test to ext4_io_submit().

This doesn't cause any noticeable differences now but having
writeback_control available throughout IO submission path will be
depended upon by the planned cgroup writeback support.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/ext4.h    | 2 +-
 fs/ext4/page-io.c | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 009a059..74a4923 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -191,7 +191,7 @@ typedef struct ext4_io_end {
 } ext4_io_end_t;
 
 struct ext4_io_submit {
-	int			io_op;
+	struct writeback_control *io_wbc;
 	struct bio		*io_bio;
 	ext4_io_end_t		*io_end;
 	sector_t		io_next_block;
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index c5d81e8..3f80cb2 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -357,8 +357,10 @@ void ext4_io_submit(struct ext4_io_submit *io)
 	struct bio *bio = io->io_bio;
 
 	if (bio) {
+		int io_op = io->io_wbc->sync_mode == WB_SYNC_ALL ?
+			    WRITE_SYNC : WRITE;
 		bio_get(io->io_bio);
-		submit_bio(io->io_op, io->io_bio);
+		submit_bio(io_op, io->io_bio);
 		bio_put(io->io_bio);
 	}
 	io->io_bio = NULL;
@@ -367,7 +369,7 @@ void ext4_io_submit(struct ext4_io_submit *io)
 void ext4_io_submit_init(struct ext4_io_submit *io,
 			 struct writeback_control *wbc)
 {
-	io->io_op = (wbc->sync_mode == WB_SYNC_ALL ?  WRITE_SYNC : WRITE);
+	io->io_wbc = wbc;
 	io->io_bio = NULL;
 	io->io_end = NULL;
 }
-- 
2.4.3