[PATCH 2/2] dm: use bioset_init_from_src() to copy bio_set

[Jens Axboe]

We can't just copy and clear a bio_set, use the bio helper to
setup a new bio_set with the settings from another one.

Fixes: 6f1c819c219f ("dm: convert to bioset_init()/mempool_init()")
Signed-off-by: Jens Axboe <ax...@kernel.dk>
---
 drivers/md/dm.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 98dff36b89a3..20a8d63754bf 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1953,9 +1953,10 @@ static void free_dev(struct mapped_device *md)
        kvfree(md);
 }
 
-static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
+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)) {
                /*
@@ -1982,13 +1983,16 @@ static void __bind_mempools(struct mapped_device *md, 
struct dm_table *t)
               bioset_initialized(&md->bs) ||
               bioset_initialized(&md->io_bs));
 
-       md->bs = p->bs;
-       memset(&p->bs, 0, sizeof(p->bs));
-       md->io_bs = p->io_bs;
-       memset(&p->io_bs, 0, sizeof(p->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;
 }
 
 /*
@@ -2033,6 +2037,7 @@ static struct dm_table *__bind(struct mapped_device *md, 
struct dm_table *t,
        struct request_queue *q = md->queue;
        bool request_based = dm_table_request_based(t);
        sector_t size;
+       int ret;
 
        lockdep_assert_held(&md->suspend_lock);
 
@@ -2068,7 +2073,11 @@ static struct dm_table *__bind(struct mapped_device *md, 
struct dm_table *t,
                md->immutable_target = dm_table_get_immutable_target(t);
        }
 
-       __bind_mempools(md, t);
+       ret = __bind_mempools(md, t);
+       if (ret) {
+               old_map = ERR_PTR(ret);
+               goto out;
+       }
 
        old_map = rcu_dereference_protected(md->map, 
lockdep_is_held(&md->suspend_lock));
        rcu_assign_pointer(md->map, (void *)t);
@@ -2078,6 +2087,7 @@ static struct dm_table *__bind(struct mapped_device *md, 
struct dm_table *t,
        if (old_map)
                dm_sync_table(md);
 
+out:
        return old_map;
 }
 
-- 
2.17.1