dax: bdev_direct_access() may sleep
The brd driver is the only in-tree driver that may sleep currently.
After some discussion on linux-fsdevel, we decided that any driver
may choose to sleep in its ->direct_access method. To ensure that all
callers of bdev_direct_access() are prepared for this, add a call
to might_sleep().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 5dde6df..12b22dd 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -445,6 +445,12 @@
long avail;
const struct block_device_operations *ops = bdev->bd_disk->fops;
+ /*
+ * The device driver is allowed to sleep, in order to make the
+ * memory directly accessible.
+ */
+ might_sleep();
+
if (size < 0)
return size;
if (!ops->direct_access)