tree 3ee74b07ce43cdb0b637c3747fadbb1f2ba59eb6
parent 6d4c1a30b32a377083900f39c42bcacb633f99a1
author Al Viro <viro@zeniv.linux.org.uk> 1458950194 -0400
committer Mike Marshall <hubcap@omnibond.com> 1458991320 -0400

orangefs: fix orangefs_superblock locking

* switch orangefs_remount() to taking ORANGEFS_SB(sb) instead of sb
* remove from the list _before_ orangefs_unmount() - request_mutex
in the latter will make sure that nothing observed in the loop in
ORANGEFS_DEV_REMOUNT_ALL handling will get freed until the end
of loop
* on removal, keep the forward pointer and zero the back one.  That
way we can drop and regain the spinlock in the loop body (again,
ORANGEFS_DEV_REMOUNT_ALL one) and still be able to get to the
rest of the list.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>