[DLM] canceling deadlocked lock
Add a function that can be used through libdlm by a system daemon to cancel
another process's deadlocked lock. A completion ast with EDEADLK is returned
to the process waiting for the lock.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index df91578..de943af 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -300,6 +300,11 @@
rv = -ETIMEDOUT;
}
+ if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_DEADLOCK_CANCEL)) {
+ lkb->lkb_flags &= ~DLM_IFL_DEADLOCK_CANCEL;
+ rv = -EDEADLK;
+ }
+
lkb->lkb_lksb->sb_status = rv;
lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
@@ -4450,6 +4455,54 @@
return error;
}
+int dlm_user_deadlock(struct dlm_ls *ls, uint32_t flags, uint32_t lkid)
+{
+ struct dlm_lkb *lkb;
+ struct dlm_args args;
+ struct dlm_user_args *ua;
+ struct dlm_rsb *r;
+ int error;
+
+ dlm_lock_recovery(ls);
+
+ error = find_lkb(ls, lkid, &lkb);
+ if (error)
+ goto out;
+
+ ua = (struct dlm_user_args *)lkb->lkb_astparam;
+
+ error = set_unlock_args(flags, ua, &args);
+ if (error)
+ goto out_put;
+
+ /* same as cancel_lock(), but set DEADLOCK_CANCEL after lock_rsb */
+
+ r = lkb->lkb_resource;
+ hold_rsb(r);
+ lock_rsb(r);
+
+ error = validate_unlock_args(lkb, &args);
+ if (error)
+ goto out_r;
+ lkb->lkb_flags |= DLM_IFL_DEADLOCK_CANCEL;
+
+ error = _cancel_lock(r, lkb);
+ out_r:
+ unlock_rsb(r);
+ put_rsb(r);
+
+ if (error == -DLM_ECANCEL)
+ error = 0;
+ /* from validate_unlock_args() */
+ if (error == -EBUSY)
+ error = 0;
+ out_put:
+ dlm_put_lkb(lkb);
+ out:
+ dlm_unlock_recovery(ls);
+ return error;
+}
+
/* lkb's that are removed from the waiters list by revert are just left on the
orphans list with the granted orphan locks, to be freed by purge */