block: mark bio_split_pool static

Since all bio_split calls refer the same single bio_split_pool, the bio_split
function can use bio_split_pool directly instead of the mempool_t parameter;

then the mempool_t parameter can be removed from bio_split param list, and
bio_split_pool is only referred in fs/bio.c file, can be marked static.

Signed-off-by: Denis ChengRq <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/block/pktcdvd.c

···
 		if (last_zone != zone) {
 			BUG_ON(last_zone != zone + pd->settings.size);
 			first_sectors = last_zone - bio->bi_sector;
-			bp = bio_split(bio, bio_split_pool, first_sectors);
+			bp = bio_split(bio, first_sectors);
 			BUG_ON(!bp);
 			pkt_make_request(q, &bp->bio1);
 			pkt_make_request(q, &bp->bio2);

drivers/md/linear.c

···
 		 * split it.
 		 */
 		struct bio_pair *bp;
-		bp = bio_split(bio, bio_split_pool,
+		bp = bio_split(bio,
 			       ((tmp_dev->offset + tmp_dev->size)<<1) - bio->bi_sector);
 		if (linear_make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);

drivers/md/raid0.c

···
 		/* This is a one page bio that upper layers
 		 * refuse to split for us, so we need to split it.
 		 */
-		bp = bio_split(bio, bio_split_pool, chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
+		bp = bio_split(bio, chunk_sects - (bio->bi_sector & (chunk_sects - 1)));
 		if (raid0_make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);
 		if (raid0_make_request(q, &bp->bio2))

drivers/md/raid10.c

···
 		/* This is a one page bio that upper layers
 		 * refuse to split for us, so we need to split it.
 		 */
-		bp = bio_split(bio, bio_split_pool,
+		bp = bio_split(bio,
 			       chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
 		if (make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);

fs/bio.c

···
 
 static struct kmem_cache *bio_slab __read_mostly;
 
-mempool_t *bio_split_pool __read_mostly;
+static mempool_t *bio_split_pool __read_mostly;
 
 /*
  * if you change this list, also change bvec_alloc or things will
···
  * split a bio - only worry about a bio with a single page
  * in it's iovec
  */
-struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
+struct bio_pair *bio_split(struct bio *bi, int first_sectors)
 {
-	struct bio_pair *bp = mempool_alloc(pool, GFP_NOIO);
+	struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
 
 	if (!bp)
 		return bp;
···
 	bp->bio2.bi_end_io = bio_pair_end_2;
 
 	bp->bio1.bi_private = bi;
-	bp->bio2.bi_private = pool;
+	bp->bio2.bi_private = bio_split_pool;
 
 	if (bio_integrity(bi))
 		bio_integrity_split(bi, bp, first_sectors);
···
 EXPORT_SYMBOL(bio_copy_kern);
 EXPORT_SYMBOL(bio_pair_release);
 EXPORT_SYMBOL(bio_split);
-EXPORT_SYMBOL(bio_split_pool);
 EXPORT_SYMBOL(bio_copy_user);
 EXPORT_SYMBOL(bio_uncopy_user);
 EXPORT_SYMBOL(bioset_create);

include/linux/bio.h

···
 	atomic_t			cnt;
 	int				error;
 };
-extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool,
-				  int first_sectors);
-extern mempool_t *bio_split_pool;
+extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
 extern void bio_pair_release(struct bio_pair *dbio);
 
 extern struct bio_set *bioset_create(int, int);