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author | Fred Isaman <iisaman@netapp.com> | 2011-02-03 18:28:52 +0000 |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-03-11 15:38:40 -0500 |
commit | f49f9baac8f63de9cbc17a0a84e04060496e8e76 (patch) | |
tree | e3e544247ec5e85c47915d34737f278772d15c73 /net/sunrpc/sched.c | |
parent | 9f52c2525e09854ed6aa4cbd83915a56226d86c1 (diff) | |
download | op-kernel-dev-f49f9baac8f63de9cbc17a0a84e04060496e8e76.zip op-kernel-dev-f49f9baac8f63de9cbc17a0a84e04060496e8e76.tar.gz |
pnfs: fix pnfs lock inversion of i_lock and cl_lock
The pnfs code was using throughout the lock order i_lock, cl_lock.
This conflicts with the nfs delegation code. Rework the pnfs code
to avoid taking both locks simultaneously.
Currently the code takes the double lock to add/remove the layout to a
nfs_client list, while atomically checking that the list of lsegs is
empty. To avoid this, we rely on existing serializations. When a
layout is initialized with lseg count equal zero, LAYOUTGET's
openstateid serialization is in effect, making it safe to assume it
stays zero unless we change it. And once a layout's lseg count drops
to zero, it is set as DESTROYED and so will stay at zero.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net/sunrpc/sched.c')
0 files changed, 0 insertions, 0 deletions