NFSv4.1: Fix a potential layoutget/layoutrecall deadlock
authorTrond Myklebust <trond.myklebust@hammerspace.com>
Thu, 12 Jul 2018 18:19:03 +0000 (14:19 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 19 Sep 2018 20:43:44 +0000 (22:43 +0200)
commit1181e8687a8d075841b1e8876ec6cc503219e207
tree70b47a478e4ca32b50cf5889d9e957dd96cafbfa
parent0983ef553d8fbda2d7bd1fb4783b567f7d563151
NFSv4.1: Fix a potential layoutget/layoutrecall deadlock

[ Upstream commit bd3d16a887b0c19a2a20d35ffed499e3a3637feb ]

If the client is sending a layoutget, but the server issues a callback
to recall what it thinks may be an outstanding layout, then we may find
an uninitialised layout attached to the inode due to the layoutget.
In that case, it is appropriate to return NFS4ERR_NOMATCHING_LAYOUT
rather than NFS4ERR_DELAY, as the latter can end up deadlocking.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/nfs/callback_proc.c