From 395c72a707d966b36d5a42fe12c3a237ded3a0d9 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <koverstreet@google.com>
Date: Thu, 6 Sep 2012 15:34:55 -0700
Subject: [PATCH 1/8] block: Generalized bio pool freeing
With the old code, when you allocate a bio from a bio pool you have to
implement your own destructor that knows how to find the bio pool the
bio was originally allocated from.
This adds a new field to struct bio (bi_pool) and changes
bio_alloc_bioset() to use it. This makes various bio destructors
unnecessary, so they're then deleted.
v6: Explain the temporary if statement in bio_put
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: Nicholas Bellinger <nab@linux-iscsi.org>
CC: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/block/drbd/drbd_main.c | 13 +------------
drivers/md/dm-crypt.c | 9 ---------
drivers/md/dm-io.c | 11 -----------
drivers/md/dm.c | 20 --------------------
drivers/md/md.c | 28 ++++------------------------
drivers/target/target_core_iblock.c | 9 ---------
fs/bio.c | 31 +++++++++++++------------------
include/linux/blk_types.h | 3 +++
8 files changed, 21 insertions(+), 103 deletions(-)
Index: linux/drivers/block/drbd/drbd_main.c
===================================================================
--- linux.orig/drivers/block/drbd/drbd_main.c
+++ linux/drivers/block/drbd/drbd_main.c
@@ -162,23 +162,12 @@ static const struct block_device_operati
.release = drbd_release,
};
-static void bio_destructor_drbd(struct bio *bio)
-{
- bio_free(bio, drbd_md_io_bio_set);
-}
-
struct bio *bio_alloc_drbd(gfp_t gfp_mask)
{
- struct bio *bio;
-
if (!drbd_md_io_bio_set)
return bio_alloc(gfp_mask, 1);
- bio = bio_alloc_bioset(gfp_mask, 1, drbd_md_io_bio_set);
- if (!bio)
- return NULL;
- bio->bi_destructor = bio_destructor_drbd;
- return bio;
+ return bio_alloc_bioset(gfp_mask, 1, drbd_md_io_bio_set);
}
#ifdef __CHECKER__
Index: linux/drivers/md/dm-crypt.c
===================================================================
--- linux.orig/drivers/md/dm-crypt.c
+++ linux/drivers/md/dm-crypt.c
@@ -798,14 +798,6 @@ static int crypt_convert(struct crypt_co
return 0;
}
-static void dm_crypt_bio_destructor(struct bio *bio)
-{
- struct dm_crypt_io *io = bio->bi_private;
- struct crypt_config *cc = io->cc;
-
- bio_free(bio, cc->bs);
-}
-
/*
* Generate a new unfragmented bio with the given size
* This should never violate the device limitations
@@ -974,7 +966,6 @@ static void clone_init(struct dm_crypt_i
clone->bi_end_io = crypt_endio;
clone->bi_bdev = cc->dev->bdev;
clone->bi_rw = io->base_bio->bi_rw;
- clone->bi_destructor = dm_crypt_bio_destructor;
}
static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
Index: linux/drivers/md/dm-io.c
===================================================================
--- linux.orig/drivers/md/dm-io.c
+++ linux/drivers/md/dm-io.c
@@ -249,16 +249,6 @@ static void vm_dp_init(struct dpages *dp
dp->context_ptr = data;
}
-static void dm_bio_destructor(struct bio *bio)
-{
- unsigned region;
- struct io *io;
-
- retrieve_io_and_region_from_bio(bio, &io, ®ion);
-
- bio_free(bio, io->client->bios);
-}
-
/*
* Functions for getting the pages from kernel memory.
*/
@@ -317,7 +307,6 @@ static void do_region(int rw, unsigned r
bio->bi_sector = where->sector + (where->count - remaining);
bio->bi_bdev = where->bdev;
bio->bi_end_io = endio;
- bio->bi_destructor = dm_bio_destructor;
store_io_and_region_in_bio(bio, io, region);
if (rw & REQ_DISCARD) {
Index: linux/drivers/md/dm.c
===================================================================
--- linux.orig/drivers/md/dm.c
+++ linux/drivers/md/dm.c
@@ -681,11 +681,6 @@ static void clone_endio(struct bio *bio,
}
}
- /*
- * Store md for cleanup instead of tio which is about to get freed.
- */
- bio->bi_private = md->bs;
-
free_tio(md, tio);
bio_put(bio);
dec_pending(io, error);
@@ -1036,11 +1031,6 @@ static void __map_bio(struct dm_target *
/* error the io and bail out, or requeue it if needed */
md = tio->io->md;
dec_pending(tio->io, r);
- /*
- * Store bio_set for cleanup.
- */
- clone->bi_end_io = NULL;
- clone->bi_private = md->bs;
bio_put(clone);
free_tio(md, tio);
} else if (r) {
@@ -1059,13 +1049,6 @@ struct clone_info {
unsigned short idx;
};
-static void dm_bio_destructor(struct bio *bio)
-{
- struct bio_set *bs = bio->bi_private;
-
- bio_free(bio, bs);
-}
-
/*
* Creates a little bio that just does part of a bvec.
*/
@@ -1077,7 +1060,6 @@ static struct bio *split_bvec(struct bio
struct bio_vec *bv = bio->bi_io_vec + idx;
clone = bio_alloc_bioset(GFP_NOIO, 1, bs);
- clone->bi_destructor = dm_bio_destructor;
*clone->bi_io_vec = *bv;
clone->bi_sector = sector;
@@ -1109,7 +1091,6 @@ static struct bio *clone_bio(struct bio
clone = bio_alloc_bioset(GFP_NOIO, bio->bi_max_vecs, bs);
__bio_clone(clone, bio);
- clone->bi_destructor = dm_bio_destructor;
clone->bi_sector = sector;
clone->bi_idx = idx;
clone->bi_vcnt = idx + bv_count;
@@ -1154,7 +1135,6 @@ static void __issue_target_request(struc
*/
clone = bio_alloc_bioset(GFP_NOIO, ci->bio->bi_max_vecs, ci->md->bs);
__bio_clone(clone, ci->bio);
- clone->bi_destructor = dm_bio_destructor;
if (len) {
clone->bi_sector = ci->sector;
clone->bi_size = to_bytes(len);
Index: linux/drivers/md/md.c
===================================================================
--- linux.orig/drivers/md/md.c
+++ linux/drivers/md/md.c
@@ -155,32 +155,17 @@ static int start_readonly;
* like bio_clone, but with a local bio set
*/
-static void mddev_bio_destructor(struct bio *bio)
-{
- struct mddev *mddev, **mddevp;
-
- mddevp = (void*)bio;
- mddev = mddevp[-1];
-
- bio_free(bio, mddev->bio_set);
-}
-
struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
struct mddev *mddev)
{
struct bio *b;
- struct mddev **mddevp;
if (!mddev || !mddev->bio_set)
return bio_alloc(gfp_mask, nr_iovecs);
- b = bio_alloc_bioset(gfp_mask, nr_iovecs,
- mddev->bio_set);
+ b = bio_alloc_bioset(gfp_mask, nr_iovecs, mddev->bio_set);
if (!b)
return NULL;
- mddevp = (void*)b;
- mddevp[-1] = mddev;
- b->bi_destructor = mddev_bio_destructor;
return b;
}
EXPORT_SYMBOL_GPL(bio_alloc_mddev);
@@ -189,18 +174,14 @@ struct bio *bio_clone_mddev(struct bio *
struct mddev *mddev)
{
struct bio *b;
- struct mddev **mddevp;
if (!mddev || !mddev->bio_set)
return bio_clone(bio, gfp_mask);
- b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs,
- mddev->bio_set);
+ b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, mddev->bio_set);
if (!b)
return NULL;
- mddevp = (void*)b;
- mddevp[-1] = mddev;
- b->bi_destructor = mddev_bio_destructor;
+
__bio_clone(b, bio);
if (bio_integrity(bio)) {
int ret;
@@ -5006,8 +4987,7 @@ int md_run(struct mddev *mddev)
}
if (mddev->bio_set == NULL)
- mddev->bio_set = bioset_create(BIO_POOL_SIZE,
- sizeof(struct mddev *));
+ mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
spin_lock(&pers_lock);
pers = find_pers(mddev->level, mddev->clevel);
Index: linux/drivers/target/target_core_iblock.c
===================================================================
--- linux.orig/drivers/target/target_core_iblock.c
+++ linux/drivers/target/target_core_iblock.c
@@ -556,14 +556,6 @@ static void iblock_complete_cmd(struct s
kfree(ibr);
}
-static void iblock_bio_destructor(struct bio *bio)
-{
- struct se_cmd *cmd = bio->bi_private;
- struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
-
- bio_free(bio, ib_dev->ibd_bio_set);
-}
-
static struct bio *
iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
{
@@ -585,7 +577,6 @@ iblock_get_bio(struct se_cmd *cmd, secto
bio->bi_bdev = ib_dev->ibd_bd;
bio->bi_private = cmd;
- bio->bi_destructor = iblock_bio_destructor;
bio->bi_end_io = &iblock_bio_done;
bio->bi_sector = lba;
return bio;
Index: linux/fs/bio.c
===================================================================
--- linux.orig/fs/bio.c
+++ linux/fs/bio.c
@@ -272,10 +272,6 @@ EXPORT_SYMBOL(bio_init);
* bio_alloc_bioset will try its own mempool to satisfy the allocation.
* If %__GFP_WAIT is set then we will block on the internal pool waiting
* for a &struct bio to become free.
- *
- * Note that the caller must set ->bi_destructor on successful return
- * of a bio, to do the appropriate freeing of the bio once the reference
- * count drops to zero.
**/
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
{
@@ -290,6 +286,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_m
bio = p + bs->front_pad;
bio_init(bio);
+ bio->bi_pool = bs;
if (unlikely(!nr_iovecs))
goto out_set;
@@ -316,11 +313,6 @@ err_free:
}
EXPORT_SYMBOL(bio_alloc_bioset);
-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
@@ -342,12 +334,7 @@ static void bio_fs_destructor(struct bio
*/
struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
{
- struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
-
- if (bio)
- bio->bi_destructor = bio_fs_destructor;
-
- return bio;
+ return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
}
EXPORT_SYMBOL(bio_alloc);
@@ -423,7 +410,16 @@ void bio_put(struct bio *bio)
if (atomic_dec_and_test(&bio->bi_cnt)) {
bio_disassociate_task(bio);
bio->bi_next = NULL;
- bio->bi_destructor(bio);
+
+ /*
+ * This if statement is temporary - bi_pool is replacing
+ * bi_destructor, but bi_destructor will be taken out in another
+ * patch.
+ */
+ if (bio->bi_pool)
+ bio_free(bio, bio->bi_pool);
+ else
+ bio->bi_destructor(bio);
}
}
EXPORT_SYMBOL(bio_put);
@@ -474,12 +470,11 @@ EXPORT_SYMBOL(__bio_clone);
*/
struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
{
- struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
+ struct bio *b = bio_alloc(gfp_mask, bio->bi_max_vecs);
if (!b)
return NULL;
- b->bi_destructor = bio_fs_destructor;
__bio_clone(b, bio);
if (bio_integrity(bio)) {
Index: linux/include/linux/blk_types.h
===================================================================
--- linux.orig/include/linux/blk_types.h
+++ linux/include/linux/blk_types.h
@@ -80,6 +80,9 @@ struct bio {
struct bio_integrity_payload *bi_integrity; /* data integrity */
#endif
+ /* If bi_pool is non NULL, bi_destructor is not called */
+ struct bio_set *bi_pool;
+
bio_destructor_t *bi_destructor; /* destructor */
/*