block: fix 'kmem_cache of name 'bio-108' already exists'

mainline inclusion
from mainline-v6.14-rc5
category: bugfix

Device mapper bioset often has big bio_slab size, which can be more than
1000, then 8byte can't hold the slab name any more, cause the kmem_cache
allocation warning of 'kmem_cache of name 'bio-108' already exists'.

Fix the warning by extending bio_slab->name to 12 bytes, but fix output
of /proc/slabinfo

Reported-by: Guangwu Zhang <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
(cherry picked from commit b654f7a51ffb386131de42aa98ed831f8c126546)
Signed-off-by: Wentao Guan <[email protected]>

block/bio.c

@@ -78,7 +78,7 @@ struct bio_slab {
 	struct kmem_cache *slab;
 	unsigned int slab_ref;
 	unsigned int slab_size;
-	char name[8];
+	char name[12];
 };
 static DEFINE_MUTEX(bio_slab_lock);
 static DEFINE_XARRAY(bio_slabs);