[PATCH 02/13] blk: replace bioset_create_nobvec() with a flags arg to bioset_create()

NeilBrown
2017-05-02T03:42:24Z

"flags" arguments are often seen as good API design as they allow
easy extensibility.
bioset_create_nobvec() is implemented internally as a variation in
flags passed to __bioset_create().

To support future extension, make the internal structure part of the
API.
i.e. add a 'flags' argument to bioset_create() and discard
bioset_create_nobvec().

Note that the bio_split allocations in drivers/md/raid* do not need
the bvec mempool - they should have used bioset_create_nobvec().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NeilBrown <neilb@suse.com>
---
block/bio.c | 60 +++++++++++++----------------------
block/blk-core.c | 2 +
drivers/block/drbd/drbd_main.c | 2 +
drivers/md/bcache/super.c | 4 +-
drivers/md/dm-crypt.c | 2 +
drivers/md/dm-io.c | 2 +
drivers/md/dm.c | 2 +
drivers/md/md.c | 2 +
drivers/md/raid1.c | 2 +
drivers/md/raid10.c | 2 +
drivers/md/raid5-cache.c | 2 +
drivers/md/raid5-ppl.c | 2 +
drivers/md/raid5.c | 2 +
drivers/target/target_core_iblock.c | 2 +
fs/block_dev.c | 2 +
fs/btrfs/extent_io.c | 3 +-
fs/xfs/xfs_super.c | 3 +-
include/linux/bio.h | 6 ++--
18 files changed, 45 insertions(+), 57 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 888e7801c638..3f1286ed301e 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1921,9 +1921,26 @@ void bioset_free(struct bio_set *bs)
}
EXPORT_SYMBOL(bioset_free);

-static struct bio_set *__bioset_create(unsigned int pool_size,
- unsigned int front_pad,
- bool create_bvec_pool)
+/**
+ * bioset_create - Create 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 only %BIOSET_NEED_BVECS
+ *
+ * Description:
+ * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
+ * to ask for a number of bytes to be allocated in front of the bio.
+ * Front pad allocation is useful for embedding the bio inside
+ * another structure, to avoid allocating extra data to go with the bio.
+ * Note that the bio must be embedded at the END of that structure always,
+ * or things will break badly.
+ * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated
+ * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast().
+ *
+ */
+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;
@@ -1948,7 +1965,7 @@ static struct bio_set *__bioset_create(unsigned int pool_size,
if (!bs->bio_pool)
goto bad;

- if (create_bvec_pool) {
+ if (flags & BIOSET_NEED_BVECS) {
bs->bvec_pool = biovec_create_pool(pool_size);
if (!bs->bvec_pool)
goto bad;
@@ -1963,41 +1980,8 @@ static struct bio_set *__bioset_create(unsigned int pool_size,
bioset_free(bs);
return NULL;
}
-
-/**
- * bioset_create - Create 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
- *
- * Description:
- * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
- * to ask for a number of bytes to be allocated in front of the bio.
- * Front pad allocation is useful for embedding the bio inside
- * another structure, to avoid allocating extra data to go with the bio.
- * Note that the bio must be embedded at the END of that structure always,
- * or things will break badly.
- */
-struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
-{
- return __bioset_create(pool_size, front_pad, true);
-}
EXPORT_SYMBOL(bioset_create);

-/**
- * bioset_create_nobvec - Create a bio_set without bio_vec mempool
- * @pool_size: Number of bio to cache in the mempool
- * @front_pad: Number of bytes to allocate in front of the returned bio
- *
- * Description:
- * Same functionality as bioset_create() except that mempool is not
- * created for bio_vecs. Saving some memory for bio_clone_fast() users.
- */
-struct bio_set *bioset_create_nobvec(unsigned int pool_size, unsigned int front_pad)
-{
- return __bioset_create(pool_size, front_pad, false);
-}
-EXPORT_SYMBOL(bioset_create_nobvec);
-
#ifdef CONFIG_BLK_CGROUP

/**
@@ -2112,7 +2096,7 @@ static int __init init_bio(void)
bio_integrity_init();
biovec_init_slabs();

- fs_bio_set = bioset_create(BIO_POOL_SIZE, 0);
+ fs_bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (!fs_bio_set)
panic("bio: can't allocate bios\n");

diff --git a/block/blk-core.c b/block/blk-core.c
index 1a05c505964d..3797753f4085 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -730,7 +730,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
if (q->id < 0)
goto fail_q;

- q->bio_split = bioset_create(BIO_POOL_SIZE, 0);
+ q->bio_split = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (!q->bio_split)
goto fail_id;

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 84455c365f57..b395fe391171 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2165,7 +2165,7 @@ static int drbd_create_mempools(void)
goto Enomem;

/* mempools */
- drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0);
+ drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0, BIOSET_NEED_BVECS);
if (drbd_md_io_bio_set == NULL)
goto Enomem;

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 85e3f21c2514..8b9dae98cc7e 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -786,7 +786,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,

minor *= BCACHE_MINORS;

- if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
+ if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio), BIOSET_NEED_BVECS)) ||
!(d->disk = alloc_disk(BCACHE_MINORS))) {
ida_simple_remove(&bcache_minor, minor);
return -ENOMEM;
@@ -1520,7 +1520,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
sizeof(struct bbio) + sizeof(struct bio_vec) *
bucket_pages(c))) ||
!(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
- !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
+ !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio), BIOSET_NEED_BVECS)) ||
!(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
!(c->moving_gc_wq = alloc_workqueue("bcache_gc",
WQ_MEM_RECLAIM, 0)) ||
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ef1d836bd81b..5a98c1eb87d9 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1936,7 +1936,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad;
}

- cc->bs = bioset_create(MIN_IOS, 0);
+ cc->bs = bioset_create(MIN_IOS, 0, BIOSET_NEED_BVECS);
if (!cc->bs) {
ti->error = "Cannot allocate crypt bioset";
goto bad;
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 3702e502466d..1d86d1d39d48 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -58,7 +58,7 @@ struct dm_io_client *dm_io_client_create(void)
if (!client->pool)
goto bad;

- client->bios = bioset_create(min_ios, 0);
+ client->bios = bioset_create(min_ios, 0, BIOSET_NEED_BVECS);
if (!client->bios)
goto bad;

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8bf397729bbd..e21a7d58c8ef 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2601,7 +2601,7 @@ struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, unsigned t
BUG();
}

- pools->bs = bioset_create_nobvec(pool_size, front_pad);
+ pools->bs = bioset_create(pool_size, front_pad, 0);
if (!pools->bs)
goto out;

diff --git a/drivers/md/md.c b/drivers/md/md.c
index de78e74c8e01..1379fb636de2 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5420,7 +5420,7 @@ int md_run(struct mddev *mddev)
}

if (mddev->bio_set == NULL) {
- mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
+ mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (!mddev->bio_set)
return -ENOMEM;
}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 7ed59351fe97..3f951e4a36ea 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2953,7 +2953,7 @@ static struct r1conf *setup_conf(struct mddev *mddev)
if (!conf->r1bio_pool)
goto abort;

- conf->bio_split = bioset_create(BIO_POOL_SIZE, 0);
+ conf->bio_split = bioset_create(BIO_POOL_SIZE, 0, 0);
if (!conf->bio_split)
goto abort;

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 6b86a0032cf8..9b401a9eae85 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3553,7 +3553,7 @@ static struct r10conf *setup_conf(struct mddev *mddev)
if (!conf->r10bio_pool)
goto out;

- conf->bio_split = bioset_create(BIO_POOL_SIZE, 0);
+ conf->bio_split = bioset_create(BIO_POOL_SIZE, 0, 0);
if (!conf->bio_split)
goto out;

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index b6194e082e48..ea562aa735ac 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -3034,7 +3034,7 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
if (!log->io_pool)
goto io_pool;

- log->bs = bioset_create(R5L_POOL_SIZE, 0);
+ log->bs = bioset_create(R5L_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (!log->bs)
goto io_bs;

diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 5d25bebf3328..3a31e6ef74d5 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -1150,7 +1150,7 @@ int ppl_init_log(struct r5conf *conf)
goto err;
}

- ppl_conf->bs = bioset_create(conf->raid_disks, 0);
+ ppl_conf->bs = bioset_create(conf->raid_disks, 0, 0);
if (!ppl_conf->bs) {
ret = -ENOMEM;
goto err;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2e38cfac5b1d..3da078676503 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6918,7 +6918,7 @@ static struct r5conf *setup_conf(struct mddev *mddev)
goto abort;
}

- conf->bio_split = bioset_create(BIO_POOL_SIZE, 0);
+ conf->bio_split = bioset_create(BIO_POOL_SIZE, 0, 0);
if (!conf->bio_split)
goto abort;
conf->mddev = mddev;
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index d316ed537d59..c7b373dafaf9 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -93,7 +93,7 @@ static int iblock_configure_device(struct se_device *dev)
return -EINVAL;
}

- ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
+ ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (!ib_dev->ibd_bio_set) {
pr_err("IBLOCK: Unable to create bioset\n");
goto out;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9ccabe3bb7de..6e7a4c411cd2 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -436,7 +436,7 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)

static __init int blkdev_init(void)
{
- blkdev_dio_pool = bioset_create(4, offsetof(struct blkdev_dio, bio));
+ blkdev_dio_pool = bioset_create(4, offsetof(struct blkdev_dio, bio), BIOSET_NEED_BVECS);
if (!blkdev_dio_pool)
return -ENOMEM;
return 0;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 27fdb250b446..6897c2cd18d3 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -174,7 +174,8 @@ int __init extent_io_init(void)
goto free_state_cache;

btrfs_bioset = bioset_create(BIO_POOL_SIZE,
- offsetof(struct btrfs_io_bio, bio));
+ offsetof(struct btrfs_io_bio, bio),
+ BIOSET_NEED_BVECS);
if (!btrfs_bioset)
goto free_buffer_cache;

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 685c042a120f..0262063014c6 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1757,7 +1757,8 @@ STATIC int __init
xfs_init_zones(void)
{
xfs_ioend_bioset = bioset_create(4 * MAX_BUF_PER_PAGE,
- offsetof(struct xfs_ioend, io_inline_bio));
+ offsetof(struct xfs_ioend, io_inline_bio),
+ BIOSET_NEED_BVECS);
if (!xfs_ioend_bioset)
goto out;

diff --git a/include/linux/bio.h b/include/linux/bio.h
index d1b04b0e99cf..0975da6bebd9 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -373,8 +373,10 @@ static inline struct bio *bio_next_split(struct bio *bio, int sectors,
return bio_split(bio, sectors, gfp, bs);
}

-extern struct bio_set *bioset_create(unsigned int, unsigned int);
-extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
+extern struct bio_set *bioset_create(unsigned int, unsigned int, int flags);
+enum {
+ BIOSET_NEED_BVECS = BIT(0),
+};
extern void bioset_free(struct bio_set *);
extern mempool_t *biovec_create_pool(int pool_entries);