ocfs2:dlm: avoid dlm->ast_lock lockres->spinlock dependency break

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Currently we process a dirty lockres with the lockres->spinlock taken. While
during the process, we may need to lock on dlm->ast_lock. This breaks the
dependency of dlm->ast_lock(lock first) and lockres->spinlock(lock second).

This patch fixes the problem.
Since we can't release lockres->spinlock, we have to take dlm->ast_lock
just before taking the lockres->spinlock and release it after lockres->spinlock
is released. And use __dlm_queue_bast()/__dlm_queue_ast(), the nolock version,
in dlm_shuffle_lists(). There are no too many locks on a lockres, so there is no
performance harm.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

...

This commit is contained in:

Wengang Wang 2010-05-17 20:20:44 +08:00 • committed by Joel Becker

parent d5a7df0649

commit d9ef75221a

3 changed files with 14 additions and 8 deletions

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4

fs/ocfs2/dlm/dlmast.c

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2

fs/ocfs2/dlm/dlmcommon.h

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16

fs/ocfs2/dlm/dlmthread.c

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