diff options
Diffstat (limited to 'fs/bio.c')
| -rw-r--r-- | fs/bio.c | 122 |
1 files changed, 65 insertions, 57 deletions
@@ -175,14 +175,6 @@ struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, 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! */ switch (nr) { @@ -260,21 +252,6 @@ void bio_free(struct bio *bio, struct bio_set *bs) 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)); @@ -301,21 +278,15 @@ void bio_init(struct bio *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); @@ -332,22 +303,33 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) 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); @@ -358,19 +340,45 @@ struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) 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; } @@ -814,7 +822,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, 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; @@ -938,7 +946,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q, 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); @@ -1122,7 +1130,7 @@ static struct bio *__bio_map_kern(struct request_queue *q, void *data, 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); |