diff options
| -rw-r--r-- | fs/ocfs2/dlmglue.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index ebc4a49801b..9e8ed607173 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -119,6 +119,18 @@ struct ocfs2_lock_res_ops { void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *); /* + * Allow a lock type to add checks to determine whether it is + * safe to downconvert a lock. Return 0 to re-queue the + * downconvert at a later time, nonzero to continue. + * + * For most locks, the default checks that there are no + * incompatible holders are sufficient. + * + * Called with the lockres spinlock held. + */ + int (*check_downconvert)(struct ocfs2_lock_res *, int); + + /* * LOCK_TYPE_* flags which describe the specific requirements * of a lock type. Descriptions of each individual flag follow. */ @@ -2657,6 +2669,12 @@ recheck: && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) goto leave_requeue; + new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); + + if (lockres->l_ops->check_downconvert + && !lockres->l_ops->check_downconvert(lockres, new_level)) + goto leave_requeue; + /* If we get here, then we know that there are no more * incompatible holders (and anyone asking for an incompatible * lock is blocked). We can now downconvert the lock */ @@ -2684,7 +2702,6 @@ recheck: downconvert: ctl->requeue = 0; - new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking); ocfs2_prepare_downconvert(lockres, new_level); spin_unlock_irqrestore(&lockres->l_lock, flags); |