1 files changed, 67 insertions, 79 deletions

diff --git a/block/bio.c b/block/bio.c
index 4259125e16ab..a3893d80dccc 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -224,24 +224,13 @@ EXPORT_SYMBOL(bio_uninit);
 static void bio_free(struct bio *bio)
 {
 	struct bio_set *bs = bio->bi_pool;
-	void *p;
-
-	bio_uninit(bio);
+	void *p = bio;
 
-	if (bs) {
-		bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs);
+	WARN_ON_ONCE(!bs);
 
-		/*
-		 * If we have front padding, adjust the bio pointer before freeing
-		 */
-		p = bio;
-		p -= bs->front_pad;
-
-		mempool_free(p, &bs->bio_pool);
-	} else {
-		/* Bio was allocated by bio_kmalloc() */
-		kfree(bio);
-	}
+	bio_uninit(bio);
+	bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs);
+	mempool_free(p - bs->front_pad, &bs->bio_pool);
 }
 
 /*
@@ -419,6 +408,28 @@ static void punt_bios_to_rescuer(struct bio_set *bs)
 	queue_work(bs->rescue_workqueue, &bs->rescue_work);
 }
 
+static struct bio *bio_alloc_percpu_cache(struct block_device *bdev,
+		unsigned short nr_vecs, unsigned int opf, gfp_t gfp,
+		struct bio_set *bs)
+{
+	struct bio_alloc_cache *cache;
+	struct bio *bio;
+
+	cache = per_cpu_ptr(bs->cache, get_cpu());
+	if (!cache->free_list) {
+		put_cpu();
+		return NULL;
+	}
+	bio = cache->free_list;
+	cache->free_list = bio->bi_next;
+	cache->nr--;
+	put_cpu();
+
+	bio_init(bio, bdev, nr_vecs ? bio->bi_inline_vecs : NULL, nr_vecs, opf);
+	bio->bi_pool = bs;
+	return bio;
+}
+
 /**
  * bio_alloc_bioset - allocate a bio for I/O
  * @bdev:	block device to allocate the bio for (can be %NULL)
@@ -451,6 +462,9 @@ static void punt_bios_to_rescuer(struct bio_set *bs)
  * submit_bio_noacct() should be avoided - instead, use bio_set's front_pad
  * for per bio allocations.
  *
+ * If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done from process
+ * context, not hard/soft IRQ.
+ *
  * Returns: Pointer to new bio on success, NULL on failure.
  */
 struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
@@ -465,6 +479,21 @@ struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
 	if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && nr_vecs > 0))
 		return NULL;
 
+	if (opf & REQ_ALLOC_CACHE) {
+		if (bs->cache && nr_vecs <= BIO_INLINE_VECS) {
+			bio = bio_alloc_percpu_cache(bdev, nr_vecs, opf,
+						     gfp_mask, bs);
+			if (bio)
+				return bio;
+			/*
+			 * No cached bio available, bio returned below marked with
+			 * REQ_ALLOC_CACHE to particpate in per-cpu alloc cache.
+			 */
+		} else {
+			opf &= ~REQ_ALLOC_CACHE;
+		}
+	}
+
 	/*
 	 * submit_bio_noacct() converts recursion to iteration; this means if
 	 * we're running beneath it, any bios we allocate and submit will not be
@@ -528,28 +557,28 @@ err_free:
 EXPORT_SYMBOL(bio_alloc_bioset);
 
 /**
- * bio_kmalloc - kmalloc a bio for I/O
+ * bio_kmalloc - kmalloc a bio
+ * @nr_vecs:	number of bio_vecs to allocate
  * @gfp_mask:   the GFP_* mask given to the slab allocator
- * @nr_iovecs:	number of iovecs to pre-allocate
  *
- * Use kmalloc to allocate and initialize a bio.
+ * Use kmalloc to allocate a bio (including bvecs).  The bio must be initialized
+ * using bio_init() before use.  To free a bio returned from this function use
+ * kfree() after calling bio_uninit().  A bio returned from this function can
+ * be reused by calling bio_uninit() before calling bio_init() again.
+ *
+ * Note that unlike bio_alloc() or bio_alloc_bioset() allocations from this
+ * function are not backed by a mempool can can fail.  Do not use this function
+ * for allocations in the file system I/O path.
  *
  * Returns: Pointer to new bio on success, NULL on failure.
  */
-struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs)
+struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask)
 {
 	struct bio *bio;
 
-	if (nr_iovecs > UIO_MAXIOV)
-		return NULL;
-
-	bio = kmalloc(struct_size(bio, bi_inline_vecs, nr_iovecs), gfp_mask);
-	if (unlikely(!bio))
+	if (nr_vecs > UIO_MAXIOV)
 		return NULL;
-	bio_init(bio, NULL, nr_iovecs ? bio->bi_inline_vecs : NULL, nr_iovecs,
-		 0);
-	bio->bi_pool = NULL;
-	return bio;
+	return kmalloc(struct_size(bio, bi_inline_vecs, nr_vecs), gfp_mask);
 }
 EXPORT_SYMBOL(bio_kmalloc);
 
@@ -711,7 +740,7 @@ void bio_put(struct bio *bio)
 			return;
 	}
 
-	if (bio_flagged(bio, BIO_PERCPU_CACHE)) {
+	if (bio->bi_opf & REQ_ALLOC_CACHE) {
 		struct bio_alloc_cache *cache;
 
 		bio_uninit(bio);
@@ -732,14 +761,15 @@ static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp)
 	bio_set_flag(bio, BIO_CLONED);
 	if (bio_flagged(bio_src, BIO_THROTTLED))
 		bio_set_flag(bio, BIO_THROTTLED);
-	if (bio->bi_bdev == bio_src->bi_bdev &&
-	    bio_flagged(bio_src, BIO_REMAPPED))
-		bio_set_flag(bio, BIO_REMAPPED);
 	bio->bi_ioprio = bio_src->bi_ioprio;
 	bio->bi_iter = bio_src->bi_iter;
 
-	bio_clone_blkg_association(bio, bio_src);
-	blkcg_bio_issue_init(bio);
+	if (bio->bi_bdev) {
+		if (bio->bi_bdev == bio_src->bi_bdev &&
+		    bio_flagged(bio_src, BIO_REMAPPED))
+			bio_set_flag(bio, BIO_REMAPPED);
+		bio_clone_blkg_association(bio, bio_src);
+	}
 
 	if (bio_crypt_clone(bio, bio_src, gfp) < 0)
 		return -ENOMEM;
@@ -1727,55 +1757,13 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src)
 		flags |= BIOSET_NEED_BVECS;
 	if (src->rescue_workqueue)
 		flags |= BIOSET_NEED_RESCUER;
+	if (src->cache)
+		flags |= BIOSET_PERCPU_CACHE;
 
 	return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags);
 }
 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:
- *    Like @bio_alloc_bioset, but pass in the kiocb. The kiocb is only
- *    used to check if we should dip into the per-cpu bio_set allocation
- *    cache. The allocation uses GFP_KERNEL internally. On return, the
- *    bio is marked BIO_PERCPU_CACHEABLE, and the final put of the bio
- *    MUST be done from process context, not hard/soft IRQ.
- *
- */
-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(bdev, nr_vecs, opf, GFP_KERNEL, bs);
-
-	cache = per_cpu_ptr(bs->cache, get_cpu());
-	if (cache->free_list) {
-		bio = cache->free_list;
-		cache->free_list = bio->bi_next;
-		cache->nr--;
-		put_cpu();
-		bio_init(bio, bdev, nr_vecs ? bio->bi_inline_vecs : NULL,
-			 nr_vecs, opf);
-		bio->bi_pool = bs;
-		bio_set_flag(bio, BIO_PERCPU_CACHE);
-		return bio;
-	}
-	put_cpu();
-	bio = bio_alloc_bioset(bdev, nr_vecs, opf, GFP_KERNEL, bs);
-	bio_set_flag(bio, BIO_PERCPU_CACHE);
-	return bio;
-}
-EXPORT_SYMBOL_GPL(bio_alloc_kiocb);
-
 static int __init init_bio(void)
 {
 	int i;