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>
This commit is contained in:
Matthew Wilcox 2015-07-03 10:40:43 -04:00 committed by Al Viro
parent bbab37ddc2
commit 43c3dd08da

View File

@ -445,6 +445,12 @@ long bdev_direct_access(struct block_device *bdev, sector_t sector,
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)