Description: dead lock in dcache
References:
 https://lkml.org/lkml/2014/10/25/171
 https://lkml.org/lkml/2014/10/25/179
 https://lkml.org/lkml/2014/10/25/180
 https://lkml.org/lkml/2014/10/26/101
 https://lkml.org/lkml/2014/10/26/116
 https://lkml.org/lkml/2014/10/26/129
Notes:
 According to https://lkml.org/lkml/2014/10/25/179 this was introduced
 by "fs: dcache avoid starvation in dcache multi-step operations", i.e.
 commit 58db63d08679 in 2.6.38-rc1.
Bugs:
upstream: released (3.19-rc1) [946e51f2bf37f1656916eb75bd0742ba33983c28, ca5358ef75fc69fee5322a38a340f5739d997c10]
2.6.32-upstream-stable: N/A
sid: released (3.16.7-ckt4-1)
3.2-wheezy-security: released (3.2.65-1+deb7u2) [bugfix/all/move-d_rcu-from-overlapping-d_child-to-overlapping-d_alias.patch, bugfix/all/deal-with-deadlock-in-d_walk.patch, bugfix/all/dcache-fix-locking-bugs-in-backported-deal-with-deadlock-in-d_walk.patch]
2.6.32-squeeze-security: N/A
3.16-upstream-stable: released (3.16.7-ckt4)
3.2-upstream-stable: released (3.2.66) [move-d_rcu-from-overlapping-d_child-to-overlapping-d_alias.patch, deal-with-deadlock-in-d_walk.patch]