dm: abstract dm_in_flight function
This patch adds md_in_flight() to get the number of in_flight I/Os.
No functional change.
This patch is a preparation for a later patch in this series, which
changes I/O counter to md->pending from q->in_flight in request-based dm.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 473f0c3..73b89af 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -452,6 +452,12 @@
mempool_free(info, info->tio->md->io_pool);
}
+static int md_in_flight(struct mapped_device *md)
+{
+ return atomic_read(&md->pending[READ]) +
+ atomic_read(&md->pending[WRITE]);
+}
+
static void start_io_acct(struct dm_io *io)
{
struct mapped_device *md = io->md;
@@ -2100,8 +2106,7 @@
break;
}
spin_unlock_irqrestore(q->queue_lock, flags);
- } else if (!atomic_read(&md->pending[0]) &&
- !atomic_read(&md->pending[1]))
+ } else if (!md_in_flight(md))
break;
if (interruptible == TASK_INTERRUPTIBLE &&