Re: [PATCH net-next 7/9] net: ipmr: remove SLAB_PANIC

On 11/21/2015 03:23 PM, Eric Dumazet wrote:

On Sat, 2015-11-21 at 14:01 +0100, Nikolay Aleksandrov wrote:

quoted

From: Nikolay Aleksandrov <redacted>

It's not necessary to panic upon allocation failure, returning an error
at that point is okay because user-space won't be able to use any of the
ops since they didn't get registered and the default table is null.

Signed-off-by: Nikolay Aleksandrov <redacted>
---
 net/ipv4/ipmr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index a006d96d6cd9..2c7fa584a274 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c

@@ -2675,7 +2675,7 @@ int __init ip_mr_init(void)
 
 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
 				       sizeof(struct mfc_cache),
-				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
+				       0, SLAB_HWCACHE_ALIGN,
 				       NULL);
 	if (!mrt_cachep)
 		return -ENOMEM;

This runs at boot time.

I very much prefer a panic instead of having to deal with a host with a
probable bug in mm layer at this point.

Right, I was unsure about this one, I tried to rely on the ipmr_get_table() returning NULL but
I guess it's better to be safe than sorry.
I'll respin with the panic in place and removed null check.

For IPv6, it is a different matter as it might be a module, thus
ip6_mr_init() does not use SLAB_PANIC

Yep, I saw. It wasn't the reason I removed this one.

Thanks for the review!