{
struct bio_vec *bvl;
- /*
- * If 'bs' is given, lookup the pool and do the mempool alloc.
- * If not, this is a bio_kmalloc() allocation and just do a
- * kzalloc() for the exact number of vecs right away.
- */
- if (!bs)
- bvl = kmalloc(nr * sizeof(struct bio_vec), gfp_mask);
-
/*
* see comment near bvec_array define!
*/
mempool_free(p, bs->bio_pool);
}
-/*
- * default destructor for a bio allocated with bio_alloc_bioset()
- */
-static void bio_fs_destructor(struct bio *bio)
-{
- bio_free(bio, fs_bio_set);
-}
-
-static void bio_kmalloc_destructor(struct bio *bio)
-{
- if (bio_has_allocated_vec(bio))
- kfree(bio->bi_io_vec);
- kfree(bio);
-}
-
void bio_init(struct bio *bio)
{
memset(bio, 0, sizeof(*bio));
**/
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
{
+ unsigned long idx = BIO_POOL_NONE;
struct bio_vec *bvl = NULL;
- struct bio *bio = NULL;
- unsigned long idx = 0;
- void *p = NULL;
-
- if (bs) {
- p = mempool_alloc(bs->bio_pool, gfp_mask);
- if (!p)
- goto err;
- bio = p + bs->front_pad;
- } else {
- bio = kmalloc(sizeof(*bio), gfp_mask);
- if (!bio)
- goto err;
- }
+ struct bio *bio;
+ void *p;
+
+ p = mempool_alloc(bs->bio_pool, gfp_mask);
+ if (unlikely(!p))
+ return NULL;
+ bio = p + bs->front_pad;
bio_init(bio);
nr_iovecs = bvec_nr_vecs(idx);
}
+out_set:
bio->bi_flags |= idx << BIO_POOL_OFFSET;
bio->bi_max_vecs = nr_iovecs;
-out_set:
bio->bi_io_vec = bvl;
-
return bio;
err_free:
- if (bs)
- mempool_free(p, bs->bio_pool);
- else
- kfree(bio);
-err:
+ mempool_free(p, bs->bio_pool);
return NULL;
}
+static void bio_fs_destructor(struct bio *bio)
+{
+ bio_free(bio, fs_bio_set);
+}
+
+/**
+ * bio_alloc - allocate a new bio, memory pool backed
+ * @gfp_mask: allocation mask to use
+ * @nr_iovecs: number of iovecs
+ *
+ * Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask
+ * contains __GFP_WAIT, the allocation is guaranteed to succeed.
+ *
+ * RETURNS:
+ * Pointer to new bio on success, NULL on failure.
+ */
struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
{
struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
return bio;
}
-/*
- * Like bio_alloc(), but doesn't use a mempool backing. This means that
- * it CAN fail, but while bio_alloc() can only be used for allocations
- * that have a short (finite) life span, bio_kmalloc() should be used
- * for more permanent bio allocations (like allocating some bio's for
- * initalization or setup purposes).
- */
+static void bio_kmalloc_destructor(struct bio *bio)
+{
+ if (bio_integrity(bio))
+ bio_integrity_free(bio);
+ kfree(bio);
+}
+
+/**
+ * bio_alloc - allocate a bio for I/O
+ * @gfp_mask: the GFP_ mask given to the slab allocator
+ * @nr_iovecs: number of iovecs to pre-allocate
+ *
+ * Description:
+ * bio_alloc will allocate a bio and associated bio_vec array that can hold
+ * at least @nr_iovecs entries. Allocations will be done from the
+ * fs_bio_set. Also see @bio_alloc_bioset.
+ *
+ * If %__GFP_WAIT is set, then bio_alloc will always be able to allocate
+ * a bio. This is due to the mempool guarantees. To make this work, callers
+ * must never allocate more than 1 bio at the time from this pool. Callers
+ * that need to allocate more than 1 bio must always submit the previously
+ * allocate bio for IO before attempting to allocate a new one. Failure to
+ * do so can cause livelocks under memory pressure.
+ *
+ **/
struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
{
- struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
+ struct bio *bio;
- if (bio)
- bio->bi_destructor = bio_kmalloc_destructor;
+ bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec),
+ gfp_mask);
+ if (unlikely(!bio))
+ return NULL;
+
+ bio_init(bio);
+ bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
+ bio->bi_max_vecs = nr_iovecs;
+ bio->bi_io_vec = bio->bi_inline_vecs;
+ bio->bi_destructor = bio_kmalloc_destructor;
return bio;
}
len += iov[i].iov_len;
}
+ if (offset)
+ nr_pages++;
+
bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask);
if (!bmd)
return ERR_PTR(-ENOMEM);
ret = -ENOMEM;
- bio = bio_alloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, nr_pages);
if (!bio)
goto out_bmd;
if (!nr_pages)
return ERR_PTR(-EINVAL);
- bio = bio_alloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, nr_pages);
if (!bio)
return ERR_PTR(-ENOMEM);
int offset, i;
struct bio *bio;
- bio = bio_alloc(gfp_mask, nr_pages);
+ bio = bio_kmalloc(gfp_mask, nr_pages);
if (!bio)
return ERR_PTR(-ENOMEM);
git.openpandora.org / pandora-kernel.git / blobdiff