| Message ID | 20250228132656.2838008-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | block: fix 'kmem_cache of name 'bio-108' already exists' | expand |
| Context | Check | Description |
|---|---|---|
| shin/vmtest-linus-master-PR | success | PR summary |
| shin/vmtest-linus-master-VM_Test-0 | success | Logs for build-kernel |
On Fri, 28 Feb 2025 21:26:56 +0800, Ming Lei wrote: > 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 > > [...] Applied, thanks! [1/1] block: fix 'kmem_cache of name 'bio-108' already exists' (no commit info) Best regards,
On Fri, Feb 28, 2025 at 09:26:56PM +0800, Ming Lei wrote: > 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 <guazhang@redhat.com> > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/bio.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/bio.c b/block/bio.c > index f0c416e5931d..6ac5983ba51e 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -77,7 +77,7 @@ struct bio_slab { > struct kmem_cache *slab; > unsigned int slab_ref; > unsigned int slab_size; > - char name[8]; > + char name[12]; Can you please turn this into a pointer and use kasprintf to fill it? That way we fix the string overflow problem for real and don't need to doctor around it the next time someone uses names with a longer name.
On Mon, Mar 03, 2025 at 07:39:34AM -0800, Christoph Hellwig wrote: > On Fri, Feb 28, 2025 at 09:26:56PM +0800, Ming Lei wrote: > > 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 <guazhang@redhat.com> > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > --- > > block/bio.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/block/bio.c b/block/bio.c > > index f0c416e5931d..6ac5983ba51e 100644 > > --- a/block/bio.c > > +++ b/block/bio.c > > @@ -77,7 +77,7 @@ struct bio_slab { > > struct kmem_cache *slab; > > unsigned int slab_ref; > > unsigned int slab_size; > > - char name[8]; > > + char name[12]; > > Can you please turn this into a pointer and use kasprintf to fill > it? That way we fix the string overflow problem for real and don't > need to doctor around it the next time someone uses names with a > longer name. There isn't the overflow problem, please see create_bio_slab(), which calls snprintf() to fill the ->name[]. Also extra 4byte can support bio size of ~10^7, which is big enough as block layer API. Thanks, Ming
diff --git a/block/bio.c b/block/bio.c index f0c416e5931d..6ac5983ba51e 100644 --- a/block/bio.c +++ b/block/bio.c @@ -77,7 +77,7 @@ 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);
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 <guazhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/bio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)