[PATCH 5.18 140/141] dm: fix bio_set allocation

Greg Kroah-Hartman
2022-06-20T13:08:24Z

From: Christoph Hellwig <hch@lst.de>

commit 29dec90a0f1d961b93f34f910e9319d8cb23edbd upstream.

The use of bioset_init_from_src mean that the pre-allocated pools weren't
used for anything except parameter passing, and the integrity pool
creation got completely lost for the actual live mapped_device. Fix that
by assigning the actual preallocated dm_md_mempools to the mapped_device
and using that for I/O instead of creating new mempools.

Fixes: 2a2a4c510b76 ("dm: use bioset_init_from_src() to copy bio_set")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/dm-core.h | 11 +++++-
drivers/md/dm-rq.c | 2 -
drivers/md/dm-table.c | 11 ------
drivers/md/dm.c | 83 ++++++++++++++------------------------------------
drivers/md/dm.h | 2 -
5 files changed, 34 insertions(+), 75 deletions(-)

--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -32,6 +32,14 @@ struct dm_kobject_holder {
* access their members!
*/

+/*
+ * For mempools pre-allocation at the table loading time.
+ */
+struct dm_md_mempools {
+ struct bio_set bs;
+ struct bio_set io_bs;
+};
+
struct mapped_device {
struct mutex suspend_lock;

@@ -109,8 +117,7 @@ struct mapped_device {
/*
* io objects are allocated from here.
*/
- struct bio_set io_bs;
- struct bio_set bs;
+ struct dm_md_mempools *mempools;

/* kobject and completion */
struct dm_kobject_holder kobj_holder;
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -319,7 +319,7 @@ static int setup_clone(struct request *c
{
int r;

- r = blk_rq_prep_clone(clone, rq, &tio->md->bs, gfp_mask,
+ r = blk_rq_prep_clone(clone, rq, &tio->md->mempools->bs, gfp_mask,
dm_rq_bio_constructor, tio);
if (r)
return r;
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1030,17 +1030,6 @@ static int dm_table_alloc_md_mempools(st
return 0;
}

-void dm_table_free_md_mempools(struct dm_table *t)
-{
- dm_free_md_mempools(t->mempools);
- t->mempools = NULL;
-}
-
-struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
-{
- return t->mempools;
-}
-
static int setup_indexes(struct dm_table *t)
{
int i;
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -131,14 +131,6 @@ static int get_swap_bios(void)
return latch;
}

-/*
- * For mempools pre-allocation at the table loading time.
- */
-struct dm_md_mempools {
- struct bio_set bs;
- struct bio_set io_bs;
-};
-
struct table_device {
struct list_head list;
refcount_t count;
@@ -573,7 +565,7 @@ static struct dm_io *alloc_io(struct map
struct dm_target_io *tio;
struct bio *clone;

- clone = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, &md->io_bs);
+ clone = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, &md->mempools->io_bs);

tio = clone_to_tio(clone);
tio->flags = 0;
@@ -615,7 +607,7 @@ static struct bio *alloc_tio(struct clon
clone = &tio->clone;
} else {
clone = bio_alloc_clone(ci->bio->bi_bdev, ci->bio,
- gfp_mask, &ci->io->md->bs);
+ gfp_mask, &ci->io->md->mempools->bs);
if (!clone)
return NULL;

@@ -1775,8 +1767,7 @@ static void cleanup_mapped_device(struct
{
if (md->wq)
destroy_workqueue(md->wq);
- bioset_exit(&md->bs);
- bioset_exit(&md->io_bs);
+ dm_free_md_mempools(md->mempools);

if (md->dax_dev) {
dax_remove_host(md->disk);
@@ -1948,48 +1939,6 @@ static void free_dev(struct mapped_devic
kvfree(md);
}

-static int __bind_mempools(struct mapped_device *md, struct dm_table *t)
-{
- struct dm_md_mempools *p = dm_table_get_md_mempools(t);
- int ret = 0;
-
- if (dm_table_bio_based(t)) {
- /*
- * The md may already have mempools that need changing.
- * If so, reload bioset because front_pad may have changed
- * because a different table was loaded.
- */
- bioset_exit(&md->bs);
- bioset_exit(&md->io_bs);
-
- } else if (bioset_initialized(&md->bs)) {
- /*
- * There's no need to reload with request-based dm
- * because the size of front_pad doesn't change.
- * Note for future: If you are to reload bioset,
- * prep-ed requests in the queue may refer
- * to bio from the old bioset, so you must walk
- * through the queue to unprep.
- */
- goto out;
- }
-
- BUG_ON(!p ||
- bioset_initialized(&md->bs) ||
- bioset_initialized(&md->io_bs));
-
- ret = bioset_init_from_src(&md->bs, &p->bs);
- if (ret)
- goto out;
- ret = bioset_init_from_src(&md->io_bs, &p->io_bs);
- if (ret)
- bioset_exit(&md->bs);
-out:
- /* mempool bind completed, no longer need any mempools in the table */
- dm_table_free_md_mempools(t);
- return ret;
-}
-
/*
* Bind a table to the device.
*/
@@ -2043,12 +1992,28 @@ static struct dm_table *__bind(struct ma
* immutable singletons - used to optimize dm_mq_queue_rq.
*/
md->immutable_target = dm_table_get_immutable_target(t);
- }

- ret = __bind_mempools(md, t);
- if (ret) {
- old_map = ERR_PTR(ret);
- goto out;
+ /*
+ * There is no need to reload with request-based dm because the
+ * size of front_pad doesn't change.
+ *
+ * Note for future: If you are to reload bioset, prep-ed
+ * requests in the queue may refer to bio from the old bioset,
+ * so you must walk through the queue to unprep.
+ */
+ if (!md->mempools) {
+ md->mempools = t->mempools;
+ t->mempools = NULL;
+ }
+ } else {
+ /*
+ * The md may already have mempools that need changing.
+ * If so, reload bioset because front_pad may have changed
+ * because a different table was loaded.
+ */
+ dm_free_md_mempools(md->mempools);
+ md->mempools = t->mempools;
+ t->mempools = NULL;
}

ret = dm_table_set_restrictions(t, md->queue, limits);
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -71,8 +71,6 @@ struct dm_target *dm_table_get_immutable
struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
bool dm_table_bio_based(struct dm_table *t);
bool dm_table_request_based(struct dm_table *t);
-void dm_table_free_md_mempools(struct dm_table *t);
-struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);

void dm_lock_md_type(struct mapped_device *md);
void dm_unlock_md_type(struct mapped_device *md);