diff options
author | willy@infradead.org <willy@infradead.org> | 2018-06-13 05:34:03 -0700 |
---|---|---|
committer | Jason Gunthorpe <jgg@mellanox.com> | 2018-06-18 11:22:54 -0600 |
commit | 9a41e38a467c06a0c48369970ce5a9f790edd64d (patch) | |
tree | 382d5e0923c4a76b8884e5b1407a818b9d5986ac /drivers/infiniband/core/mad_priv.h | |
parent | 3c60e868c31e4ff144776bf53ff0dfe9e9e4ec15 (diff) |
IB/mad: Use IDR for agent IDs
Allocate agent IDs from a global IDR instead of an atomic variable.
This eliminates the possibility of reusing an ID which is already in
use after 4 billion registrations. We limit the assigned ID to be less
than 2^24 as the mlx4 driver uses the most significant byte of the agent
ID to store the slave number. Users unlucky enough to see a collision
between agent numbers and slave numbers see messages like:
mlx4_ib: egress mad has non-null tid msb:1 class:4 slave:0
and the MAD layer stops working.
We look up the agent under protection of the RCU lock, which means we
have to free the agent using kfree_rcu, and only increment the reference
counter if it is not 0.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reported-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
Acked-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Tested-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/core/mad_priv.h')
-rw-r--r-- | drivers/infiniband/core/mad_priv.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/infiniband/core/mad_priv.h b/drivers/infiniband/core/mad_priv.h index 28669f6419e1..d84ae1671898 100644 --- a/drivers/infiniband/core/mad_priv.h +++ b/drivers/infiniband/core/mad_priv.h @@ -89,7 +89,6 @@ struct ib_rmpp_segment { }; struct ib_mad_agent_private { - struct list_head agent_list; struct ib_mad_agent agent; struct ib_mad_reg_req *reg_req; struct ib_mad_qp_info *qp_info; @@ -105,7 +104,10 @@ struct ib_mad_agent_private { struct list_head rmpp_list; atomic_t refcount; - struct completion comp; + union { + struct completion comp; + struct rcu_head rcu; + }; }; struct ib_mad_snoop_private { @@ -203,7 +205,6 @@ struct ib_mad_port_private { spinlock_t reg_lock; struct ib_mad_mgmt_version_table version[MAX_MGMT_VERSION]; - struct list_head agent_list; struct workqueue_struct *wq; struct ib_mad_qp_info qp_info[IB_MAD_QPS_CORE]; }; |