fs: add O_DIRECT and aio support for sending down write life time hints

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/aio.c

@@ -1568,6 +1568,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 	req->common.ki_pos = iocb->aio_offset;
 	req->common.ki_complete = aio_complete;
 	req->common.ki_flags = iocb_flags(req->common.ki_filp);
+	req->common.ki_hint = file_write_hint(file);
 
 	if (iocb->aio_flags & IOCB_FLAG_RESFD) {
 		/*

fs/block_dev.c

@@ -225,6 +225,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 	bio_init(&bio, vecs, nr_pages);
 	bio.bi_bdev = bdev;
 	bio.bi_iter.bi_sector = pos >> 9;
+	bio.bi_write_hint = iocb->ki_hint;
 	bio.bi_private = current;
 	bio.bi_end_io = blkdev_bio_end_io_simple;
 
@@ -360,6 +361,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 	for (;;) {
 		bio->bi_bdev = bdev;
 		bio->bi_iter.bi_sector = pos >> 9;
+		bio->bi_write_hint = iocb->ki_hint;
 		bio->bi_private = dio;
 		bio->bi_end_io = blkdev_bio_end_io;
 

fs/direct-io.c

@@ -385,6 +385,8 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 	else
 		bio->bi_end_io = dio_bio_end_io;
 
+	bio->bi_write_hint = dio->iocb->ki_hint;
+
 	sdio->bio = bio;
 	sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;
 }

fs/iomap.c

@@ -793,6 +793,7 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
 		bio->bi_bdev = iomap->bdev;
 		bio->bi_iter.bi_sector =
 			iomap->blkno + ((pos - iomap->offset) >> 9);
+		bio->bi_write_hint = dio->iocb->ki_hint;
 		bio->bi_private = dio;
 		bio->bi_end_io = iomap_dio_bio_end_io;