From 273752c9ff03eb83856601b2a3458218bb949e46 Mon Sep 17 00:00:00 2001
From: Vivek Goyal <vgoyal@redhat.com>
Date: Wed, 26 Jul 2017 09:35:09 -0400
Subject: dm, dax: Make sure dm_dax_flush() is called if device supports it
Currently dm_dax_flush() is not being called, even if underlying dax
device supports write cache, because DAXDEV_WRITE_CACHE is not being
propagated up to the DM dax device.
If the underlying dax device supports write cache, set
DAXDEV_WRITE_CACHE on the DM dax device. This will cause dm_dax_flush()
to be called.
Fixes: abebfbe2f7 ("dm: add ->flush() dax operation support")
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-table.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
(limited to 'drivers/md')
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index a39bcd9b982a..28a4071cdf85 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -20,6 +20,7 @@
#include <linux/atomic.h>
#include <linux/blk-mq.h>
#include <linux/mount.h>
+#include <linux/dax.h>
#define DM_MSG_PREFIX "table"
@@ -1630,6 +1631,37 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
return false;
}
+static int device_dax_write_cache_enabled(struct dm_target *ti,
+ struct dm_dev *dev, sector_t start,
+ sector_t len, void *data)
+{
+ struct dax_device *dax_dev = dev->dax_dev;
+
+ if (!dax_dev)
+ return false;
+
+ if (dax_write_cache_enabled(dax_dev))
+ return true;
+ return false;
+}
+
+static int dm_table_supports_dax_write_cache(struct dm_table *t)
+{
+ struct dm_target *ti;
+ unsigned i;
+
+ for (i = 0; i < dm_table_get_num_targets(t); i++) {
+ ti = dm_table_get_target(t, i);
+
+ if (ti->type->iterate_devices &&
+ ti->type->iterate_devices(ti,
+ device_dax_write_cache_enabled, NULL))
+ return true;
+ }
+
+ return false;
+}
+
static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
@@ -1785,6 +1817,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
}
blk_queue_write_cache(q, wc, fua);
+ if (dm_table_supports_dax_write_cache(t))
+ dax_write_cache(t->md->dax_dev, true);
+
/* Ensure that all underlying devices are non-rotational. */
if (dm_table_all_devices_attribute(t, device_is_nonrot))
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
--
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