From: jiangyiwen <jiangyiwen@huawei.com>
Date: Mon, 23 Jun 2014 20:22:09 +0000 (-0700)
Subject: ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during... 
X-Git-Tag: omap-for-v3.16/fixes-rc4~63^2~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b9aaac5a6b7d228435fcb80963d41c274406011b;p=pandora-kernel.git

ocfs2: do not return DLM_MIGRATE_RESPONSE_MASTERY_REF to avoid endless,loop during umount

The following case may lead to endless loop during umount.

node A         node B               node C       node D
umount volume,
migrate lockres1
to B
                                                 want to lock lockres1,
                                                 send
                                                 MASTER_REQUEST_MSG
                                                 to C
                                    init block mle
               send
               MIGRATE_REQUEST_MSG
               to C
                                    find a block
                                    mle, and then
                                    return
                                    DLM_MIGRATE_RESPONSE_MASTERY_REF
                                    to B
               set C in refmap
                                    umount successfully
               try to umount, endless
               loop occurs when migrate
               lockres1 since C is in
               refmap

So we can fix this endless loop case by only returning
DLM_MIGRATE_RESPONSE_MASTERY_REF if it has a mastery mle when receiving
MIGRATE_REQUEST_MSG.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Xue jiufei <xuejiufei@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

Reading git-diff-tree failed