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| 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/sw/rxe/rxe_recv.c | |
| parent | IDR: Expose the XArray lock (diff) | |
| download | linux-dev-9a41e38a467c06a0c48369970ce5a9f790edd64d.tar.xz linux-dev-9a41e38a467c06a0c48369970ce5a9f790edd64d.zip | |
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/sw/rxe/rxe_recv.c')
0 files changed, 0 insertions, 0 deletions