dm table: fix DAX iterate_devices based device capability checks

Fix dm_table_supports_dax() and invert logic of both
iterate_devices_callout_fn so that all devices' DAX capabilities are
properly checked.

Fixes: 545ed20e6df6 ("dm: add infrastructure for DAX support")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 3e211e6..71f7ec5 100644 (file)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -820,24 +820,24 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 EXPORT_SYMBOL_GPL(dm_table_set_type);
 
 /* validate the dax capability of the target device span */
-int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
+int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
                        sector_t start, sector_t len, void *data)
 {
        int blocksize = *(int *) data, id;
        bool rc;
 
        id = dax_read_lock();
-       rc = dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
+       rc = !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
        dax_read_unlock(id);
 
        return rc;
 }
 
 /* Check devices support synchronous DAX */
-static int device_dax_synchronous(struct dm_target *ti, struct dm_dev *dev,
-                                 sector_t start, sector_t len, void *data)
+static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
+                                             sector_t start, sector_t len, void *data)
 {
-       return dev->dax_dev && dax_synchronous(dev->dax_dev);
+       return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 }
 
 bool dm_table_supports_dax(struct dm_table *t,
@@ -854,7 +854,7 @@ bool dm_table_supports_dax(struct dm_table *t,
                        return false;
 
                if (!ti->type->iterate_devices ||
-                   !ti->type->iterate_devices(ti, iterate_fn, blocksize))
+                   ti->type->iterate_devices(ti, iterate_fn, blocksize))
                        return false;
        }
 
@@ -925,7 +925,7 @@ static int dm_table_determine_type(struct dm_table *t)
 verify_bio_based:
                /* We must use this table as bio-based */
                t->type = DM_TYPE_BIO_BASED;
-               if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
+               if (dm_table_supports_dax(t, device_not_dax_capable, &page_size) ||
                    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
                        t->type = DM_TYPE_DAX_BIO_BASED;
                }
@@ -1618,23 +1618,6 @@ static int device_dax_write_cache_enabled(struct dm_target *ti,
        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_rotational(struct dm_target *ti, struct dm_dev *dev,
                                sector_t start, sector_t len, void *data)
 {
@@ -1839,15 +1822,15 @@ 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(t, device_supports_dax, &page_size)) {
+       if (dm_table_supports_dax(t, device_not_dax_capable, &page_size)) {
                blk_queue_flag_set(QUEUE_FLAG_DAX, q);
-               if (dm_table_supports_dax(t, device_dax_synchronous, NULL))
+               if (dm_table_supports_dax(t, device_not_dax_synchronous_capable, NULL))
                        set_dax_synchronous(t->md->dax_dev);
        }
        else
                blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
 
-       if (dm_table_supports_dax_write_cache(t))
+       if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled))
                dax_write_cache(t->md->dax_dev, true);
 
        /* Ensure that all underlying devices are non-rotational. */

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 65b2115..64fda14 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1133,7 +1133,7 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd
        if (!map)
                goto out;
 
-       ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);
+       ret = dm_table_supports_dax(map, device_not_dax_capable, &blocksize);
 
 out:
        dm_put_live_table(md, srcu_idx);

diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index fffe1e2..b441ad7 100644 (file)
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -73,7 +73,7 @@ void dm_table_free_md_mempools(struct dm_table *t);
 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
 bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
                           int *blocksize);
-int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
+int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
                           sector_t start, sector_t len, void *data);
 
 void dm_lock_md_type(struct mapped_device *md);