zio_change_current_trigger: change only if ti is not BUSY

If a trigger instance is busy, so you cannot change the trigger. You must wait until data_done, or diasable the trigger before. Signed-off-by: Federico Vaga <federico.vaga@gmail.com> Acked-by: Alessandro Rubini <rubini@gnudd.com>

zio_change_current_trigger: change only if ti is not BUSY
If a trigger instance is busy, so you cannot change the trigger. You must wait until data_done, or diasable the trigger before. Signed-off-by: Federico Vaga <federico.vaga@gmail.com> Acked-by: Alessandro Rubini <rubini@gnudd.com>
dd69ac64 · Federico Vaga · a6c7e2dd · dd69ac64
Commit dd69ac64 authored Feb 01, 2012 by Federico Vaga
Hide whitespace changes
Inline Side-by-side

Showing with 9 additions and 1 deletion

zio-sys.c zio-sys.c +9 -1

No files found.
--- a/zio-sys.c
+++ b/zio-sys.c
@@ -482,8 +482,16 @@ static int zio_change_current_trigger(struct zio_cset *cset, char *name)
 	struct zio_ti *ti, *ti_old = cset->ti;
 	int err;

-	/* FIXME get all necessary spinlock */
 	pr_debug("%s\n", __func__);
+	spin_lock(&cset->lock);
+	if (ti_old->flags & ZTI_BUSY) {
+		spin_unlock(&cset->lock);
+		return -EBUSY;
+	}
+	/* Set ti BUSY, so it cannot fire */
+	ti_old->flags |= ZTI_BUSY;
+	spin_unlock(&cset->lock);
+
 	if (strlen(name) > ZIO_OBJ_NAME_LEN)
 		return -EINVAL; /* name too long */
 	if (unlikely(strcmp(name, trig_old->head.name) == 0))