dax: move the dax_read_lock() locking into dax_supported

Move the dax_read_lock/dax_read_unlock pair from the callers into
dax_supported to make it a little easier to use.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20210826135510.6293-6-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index e13fde5..0f74f83 100644 (file)
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -219,7 +219,6 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
        struct request_queue *q;
        char buf[BDEVNAME_SIZE];
        bool ret;
-       int id;
 
        q = bdev_get_queue(bdev);
        if (!q || !blk_queue_dax(q)) {
@@ -235,10 +234,8 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
                return false;
        }
 
-       id = dax_read_lock();
        ret = dax_supported(dax_dev, bdev, blocksize, 0,
                        i_size_read(bdev->bd_inode) / 512);
-       dax_read_unlock(id);
 
        put_dax(dax_dev);
 
@@ -356,13 +353,18 @@ EXPORT_SYMBOL_GPL(dax_direct_access);
 bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
                int blocksize, sector_t start, sector_t len)
 {
-       if (!dax_dev)
-               return false;
+       bool ret = false;
+       int id;
 
-       if (!dax_alive(dax_dev))
+       if (!dax_dev)
                return false;
 
-       return dax_dev->ops->dax_supported(dax_dev, bdev, blocksize, start, len);
+       id = dax_read_lock();
+       if (dax_alive(dax_dev))
+               ret = dax_dev->ops->dax_supported(dax_dev, bdev, blocksize,
+                                                 start, len);
+       dax_read_unlock(id);
+       return ret;
 }
 EXPORT_SYMBOL_GPL(dax_supported);
 

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 0543cdf..b53acca 100644 (file)
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -809,14 +809,9 @@ EXPORT_SYMBOL_GPL(dm_table_set_type);
 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;
+       int blocksize = *(int *) data;
 
-       id = dax_read_lock();
-       rc = !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
-       dax_read_unlock(id);
-
-       return rc;
+       return !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
 }
 
 /* Check devices support synchronous DAX */