Ceph » CephFS

Description of problem:
In Firefly, the userspace version of the cephfs client does not support POSIX file locking.

The lack of POSIX lock creates various issues, for example, when VM ephemeral disk is created by Nova on a cephfs shared folder, it is possible that many nova-compute services will try to write into the same _base file due to the lock not being implemented.

This request is to check the possibility top backport POSIX locks which have been introduced with 0.88 - http://ceph.com/releases/v0-88-released/

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This is the first development release after Giant. The two main features merged this round are the new AsyncMessenger (an alternative implementation of the network layer) from Haomai Wang at UnitedStack, and support for POSIX file locks in ceph-fuse and libcephfs from Yan, Zheng. There is also a big pile of smaller items that re merged while we were stabilizing Giant, including a range of smaller performance and bug fixes and some new tracepoints for LTTNG. - See more at: http://ceph.com/releases/v0-88-released/#sthash.O8ce6HyX.dpuf}
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