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author | Trond Myklebust <trond.myklebust@primarydata.com> | 2014-11-19 12:47:50 -0500 |
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committer | J. Bruce Fields <bfields@redhat.com> | 2014-11-19 15:45:44 -0500 |
commit | c6c15e1ed303ffc47e696ea1c9a9df1761c1f603 (patch) | |
tree | 14422719ae15d5d0cf05393169e485c4ac645fca /mm/percpu-vm.c | |
parent | 093a1468b6edb0e568be7311b8d2228d205702db (diff) | |
download | op-kernel-dev-c6c15e1ed303ffc47e696ea1c9a9df1761c1f603.zip op-kernel-dev-c6c15e1ed303ffc47e696ea1c9a9df1761c1f603.tar.gz |
nfsd: Fix slot wake up race in the nfsv4.1 callback code
The currect code for nfsd41_cb_get_slot() and nfsd4_cb_done() has no
locking in order to guarantee atomicity, and so allows for races of
the form.
Task 1 Task 2
====== ======
if (test_and_set_bit(0) != 0) {
clear_bit(0)
rpc_wake_up_next(queue)
rpc_sleep_on(queue)
return false;
}
This patch breaks the race condition by adding a retest of the bit
after the call to rpc_sleep_on().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'mm/percpu-vm.c')
0 files changed, 0 insertions, 0 deletions