block: pass a block_device and opf to bio_alloc_kiocb

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_kiocb to optimize the assigment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-17-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/bio.c

@@ -1731,7 +1731,9 @@ EXPORT_SYMBOL(bioset_init_from_src);
 /**
  * bio_alloc_kiocb - Allocate a bio from bio_set based on kiocb
  * @kiocb:	kiocb describing the IO
+ * @bdev:	block device to allocate the bio for (can be %NULL)
  * @nr_vecs:	number of iovecs to pre-allocate
+ * @opf:	operation and flags for bio
  * @bs:		bio_set to allocate from
  *
  * Description:
@@ -1742,14 +1744,14 @@ EXPORT_SYMBOL(bioset_init_from_src);
  *    MUST be done from process context, not hard/soft IRQ.
  *
  */
-struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs,
-			    struct bio_set *bs)
+struct bio *bio_alloc_kiocb(struct kiocb *kiocb, struct block_device *bdev,
+		unsigned short nr_vecs, unsigned int opf, struct bio_set *bs)
 {
 	struct bio_alloc_cache *cache;
 	struct bio *bio;
 
 	if (!(kiocb->ki_flags & IOCB_ALLOC_CACHE) || nr_vecs > BIO_INLINE_VECS)
-		return bio_alloc_bioset(NULL, nr_vecs, 0, GFP_KERNEL, bs);
+		return bio_alloc_bioset(bdev, nr_vecs, opf, GFP_KERNEL, bs);
 
 	cache = per_cpu_ptr(bs->cache, get_cpu());
 	if (cache->free_list) {
@@ -1758,12 +1760,14 @@ struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs,
 		cache->nr--;
 		put_cpu();
 		bio_init(bio, nr_vecs ? bio->bi_inline_vecs : NULL, nr_vecs);
+		bio_set_dev(bio, bdev);
+		bio->bi_opf = opf;
 		bio->bi_pool = bs;
 		bio_set_flag(bio, BIO_PERCPU_CACHE);
 		return bio;
 	}
 	put_cpu();
-	bio = bio_alloc_bioset(NULL, nr_vecs, 0, GFP_KERNEL, bs);
+	bio = bio_alloc_bioset(bdev, nr_vecs, opf, GFP_KERNEL, bs);
 	bio_set_flag(bio, BIO_PERCPU_CACHE);
 	return bio;
 }

block/fops.c

@@ -190,6 +190,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	struct blkdev_dio *dio;
 	struct bio *bio;
 	bool is_read = (iov_iter_rw(iter) == READ), is_sync;
+	unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb);
 	loff_t pos = iocb->ki_pos;
 	int ret = 0;
 
@@ -197,7 +198,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	    (bdev_logical_block_size(bdev) - 1))
 		return -EINVAL;
 
-	bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
+	bio = bio_alloc_kiocb(iocb, bdev, nr_pages, opf, &blkdev_dio_pool);
 
 	dio = container_of(bio, struct blkdev_dio, bio);
 	atomic_set(&dio->ref, 1);
@@ -223,7 +224,6 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	blk_start_plug(&plug);
 
 	for (;;) {
-		bio_set_dev(bio, bdev);
 		bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
 		bio->bi_write_hint = iocb->ki_hint;
 		bio->bi_private = dio;
@@ -238,11 +238,9 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		}
 
 		if (is_read) {
-			bio->bi_opf = REQ_OP_READ;
 			if (dio->flags & DIO_SHOULD_DIRTY)
 				bio_set_pages_dirty(bio);
 		} else {
-			bio->bi_opf = dio_bio_write_op(iocb);
 			task_io_account_write(bio->bi_iter.bi_size);
 		}
 		if (iocb->ki_flags & IOCB_NOWAIT)
@@ -259,6 +257,8 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		atomic_inc(&dio->ref);
 		submit_bio(bio);
 		bio = bio_alloc(GFP_KERNEL, nr_pages);
+		bio_set_dev(bio, bdev);
+		bio->bi_opf = opf;
 	}
 
 	blk_finish_plug(&plug);
@@ -311,6 +311,8 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 					unsigned int nr_pages)
 {
 	struct block_device *bdev = iocb->ki_filp->private_data;
+	bool is_read = iov_iter_rw(iter) == READ;
+	unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb);
 	struct blkdev_dio *dio;
 	struct bio *bio;
 	loff_t pos = iocb->ki_pos;
@@ -320,11 +322,10 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 	    (bdev_logical_block_size(bdev) - 1))
 		return -EINVAL;
 
-	bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
+	bio = bio_alloc_kiocb(iocb, bdev, nr_pages, opf, &blkdev_dio_pool);
 	dio = container_of(bio, struct blkdev_dio, bio);
 	dio->flags = 0;
 	dio->iocb = iocb;
-	bio_set_dev(bio, bdev);
 	bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
 	bio->bi_write_hint = iocb->ki_hint;
 	bio->bi_end_io = blkdev_bio_end_io_async;
@@ -347,14 +348,12 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 	}
 	dio->size = bio->bi_iter.bi_size;
 
-	if (iov_iter_rw(iter) == READ) {
-		bio->bi_opf = REQ_OP_READ;
+	if (is_read) {
 		if (iter_is_iovec(iter)) {
 			dio->flags |= DIO_SHOULD_DIRTY;
 			bio_set_pages_dirty(bio);
 		}
 	} else {
-		bio->bi_opf = dio_bio_write_op(iocb);
 		task_io_account_write(bio->bi_iter.bi_size);
 	}
 

include/linux/bio.h

@@ -408,8 +408,8 @@ extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
 struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
 			     unsigned int opf, gfp_t gfp_mask,
 			     struct bio_set *bs);
-struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs,
-		struct bio_set *bs);
+struct bio *bio_alloc_kiocb(struct kiocb *kiocb, struct block_device *bdev,
+		unsigned short nr_vecs, unsigned int opf, struct bio_set *bs);
 struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs);
 extern void bio_put(struct bio *);