IB/hfi1: Protect the interval RB tree when cleaning up
authorMitko Haralanov <mitko.haralanov@intel.com>
Tue, 12 Apr 2016 17:46:35 +0000 (10:46 -0700)
committerDoug Ledford <dledford@redhat.com>
Thu, 28 Apr 2016 20:32:26 +0000 (16:32 -0400)
commit782f6697d20d180843565ac93726f5ec6c7ec8ce
treefdb34256820e83a1a21994a628f74c198520c811
parent0ad2d3d05b4a597d1f2e239dcc6ab537cc3eeacb
IB/hfi1: Protect the interval RB tree when cleaning up

The current implementation of the clean up function for
the interval RB trees has two flaws which may cause
problems in cases of concurrent executing of the function
and MMU notifier.

The flaws were due to the fact that deregistration of the
MMU callbacks was done after the tree was emptied and,
furthermore, the tree was not being locked.

This commit fixes both of these flaws by, first, switch the
order of operations, and, second, locking the tree while
traversing it to prevent any other operations.

Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
drivers/staging/rdma/hfi1/mmu_rb.c