staging/lustre/llite: lock i_lock before __d_drop()
authorBruno Faccini <bruno.faccini@intel.com>
Mon, 20 Jun 2016 20:55:27 +0000 (16:55 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 20 Jun 2016 21:28:39 +0000 (14:28 -0700)
commitc9cc8d0f6f770635b206784686a16157db3d43b8
treef96ac61072f315556f6479783957fde99bb6f95a
parent2bbec0ed2c957541f22ba99202827b004267ab58
staging/lustre/llite: lock i_lock before __d_drop()

There has been several Lustre Client crashes reported by sites
running with Lustre versions 2.1/2.5, all showing the same
dentry->d_hash->next corrupted pointer cause.

This patch fixes a regression that has been introduced since a
long time by commit :
(LU-506 kernel: FC15 - support dcache scalability changes.)

where i_lock protection usage has been removed and
that is likely to cause racy condition during dentry [un]hashing
and to be the root cause of these crashes.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Reviewed-on: http://review.whamcloud.com/19287
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7973
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/lustre/lustre/llite/file.c