[PATCH 03/10] block: Add bioset_init()/bioset_exit()

Kent Overstreet
2018-05-09T01:33:51Z

Similarly to mempool_init()/mempool_exit(), take a pointer indirection
out of allocation/freeing by allowing biosets to be embedded in other
structs.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
---
block/bio.c | 93 +++++++++++++++++++++++++++++++--------------
include/linux/bio.h | 2 +
2 files changed, 67 insertions(+), 28 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 360e9bcea5..980befd919 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1856,21 +1856,83 @@ int biovec_init_pool(mempool_t *pool, int pool_entries)
return mempool_init_slab_pool(pool, pool_entries, bp->slab);
}

-void bioset_free(struct bio_set *bs)
+/*
+ * bioset_exit - exit a bioset initialized with bioset_init()
+ *
+ * May be called on a zeroed but uninitialized bioset (i.e. allocated with
+ * kzalloc()).
+ */
+void bioset_exit(struct bio_set *bs)
{
if (bs->rescue_workqueue)
destroy_workqueue(bs->rescue_workqueue);
+ bs->rescue_workqueue = NULL;

mempool_exit(&bs->bio_pool);
mempool_exit(&bs->bvec_pool);

bioset_integrity_free(bs);
- bio_put_slab(bs);
+ if (bs->bio_slab)
+ bio_put_slab(bs);
+ bs->bio_slab = NULL;
+}
+EXPORT_SYMBOL(bioset_exit);

+void bioset_free(struct bio_set *bs)
+{
+ bioset_exit(bs);
kfree(bs);
}
EXPORT_SYMBOL(bioset_free);

+/**
+ * bioset_init - Initialize a bio_set
+ * @pool_size: Number of bio and bio_vecs to cache in the mempool
+ * @front_pad: Number of bytes to allocate in front of the returned bio
+ * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS
+ * and %BIOSET_NEED_RESCUER
+ *
+ * Similar to bioset_create(), but initializes a passed-in bioset instead of
+ * separately allocating it.
+ */
+int bioset_init(struct bio_set *bs,
+ unsigned int pool_size,
+ unsigned int front_pad,
+ int flags)
+{
+ unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
+
+ bs->front_pad = front_pad;
+
+ spin_lock_init(&bs->rescue_lock);
+ bio_list_init(&bs->rescue_list);
+ INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
+
+ bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
+ if (!bs->bio_slab)
+ return -ENOMEM;
+
+ if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab))
+ goto bad;
+
+ if ((flags & BIOSET_NEED_BVECS) &&
+ biovec_init_pool(&bs->bvec_pool, pool_size))
+ goto bad;
+
+ if (!(flags & BIOSET_NEED_RESCUER))
+ return 0;
+
+ bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
+ if (!bs->rescue_workqueue)
+ goto bad;
+
+ return 0;
+bad:
+ bioset_exit(bs);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL(bioset_init);
+
/**
* bioset_create - Create a bio_set
* @pool_size: Number of bio and bio_vecs to cache in the mempool
@@ -1895,43 +1957,18 @@ struct bio_set *bioset_create(unsigned int pool_size,
unsigned int front_pad,
int flags)
{
- unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
struct bio_set *bs;

bs = kzalloc(sizeof(*bs), GFP_KERNEL);
if (!bs)
return NULL;

- bs->front_pad = front_pad;
-
- spin_lock_init(&bs->rescue_lock);
- bio_list_init(&bs->rescue_list);
- INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
-
- bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
- if (!bs->bio_slab) {
+ if (bioset_init(bs, pool_size, front_pad, flags)) {
kfree(bs);
return NULL;
}

- if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab))
- goto bad;
-
- if ((flags & BIOSET_NEED_BVECS) &&
- biovec_init_pool(&bs->bvec_pool, pool_size))
- goto bad;
-
- if (!(flags & BIOSET_NEED_RESCUER))
- return bs;
-
- bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
- if (!bs->rescue_workqueue)
- goto bad;
-
return bs;
-bad:
- bioset_free(bs);
- return NULL;
}
EXPORT_SYMBOL(bioset_create);

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 720f7261d0..fa3cf94a50 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -406,6 +406,8 @@ static inline struct bio *bio_next_split(struct bio *bio, int sectors,
return bio_split(bio, sectors, gfp, bs);
}

+extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
+extern void bioset_exit(struct bio_set *);
extern struct bio_set *bioset_create(unsigned int, unsigned int, int flags);
enum {
BIOSET_NEED_BVECS = BIT(0),
--
2.17.0