[PATCH 11/16] block: use SLAB_TYPESAFE_BY_RCU for the bio slab

Christoph Hellwig
2021-06-15T14:32:05Z

This flags ensures that the pages will not be reused for non-bio
allocations before the end of an RCU grace period. With that we can
safely use a RCU lookup for bio polling as long as we are fine with
occasionally polling the wrong device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
---
block/bio.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/bio.c b/block/bio.c
index 44205dfb6b60..de5505d7018e 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -82,7 +82,8 @@ static struct bio_slab *create_bio_slab(unsigned int size)

snprintf(bslab->name, sizeof(bslab->name), "bio-%d", size);
bslab->slab = kmem_cache_create(bslab->name, size,
- ARCH_KMALLOC_MINALIGN, SLAB_HWCACHE_ALIGN, NULL);
+ ARCH_KMALLOC_MINALIGN,
+ SLAB_HWCACHE_ALIGN | SLAB_TYPESAFE_BY_RCU, NULL);
if (!bslab->slab)
goto fail_alloc_slab;