ocfs2 fix o2dlm dlm run purgelist (rev 3)
authorSrinivas Eeda <srinivas.eeda@oracle.com>
Mon, 19 Jul 2010 23:04:12 +0000 (16:04 -0700)
committerJoel Becker <joel.becker@oracle.com>
Sat, 7 Aug 2010 17:44:40 +0000 (10:44 -0700)
commit7beaf243787f85a2ef9213ccf13ab4a243283fde
tree689e5a447ee2b7b83fcaccf2959ca8dd5b0fb359
parent6d98c3ccb52f692f1a60339dde7c700686a5568b
ocfs2 fix o2dlm dlm run purgelist (rev 3)

This patch fixes two problems in dlm_run_purgelist

1. If a lockres is found to be in use, dlm_run_purgelist keeps trying to purge
the same lockres instead of trying the next lockres.

2. When a lockres is found unused, dlm_run_purgelist releases lockres spinlock
before setting DLM_LOCK_RES_DROPPING_REF and calls dlm_purge_lockres.
spinlock is reacquired but in this window lockres can get reused. This leads
to BUG.

This patch modifies dlm_run_purgelist to skip lockres if it's in use and purge
 next lockres. It also sets DLM_LOCK_RES_DROPPING_REF before releasing the
lockres spinlock protecting it from getting reused.

Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Acked-by: Sunil Mushran <sunil.mushran@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <joel.becker@oracle.com>
fs/ocfs2/dlm/dlmthread.c