From 43c3dd08da890e458f670b4fc0630513fb405620 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Fri, 3 Jul 2015 10:40:43 -0400 Subject: [PATCH] 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 Signed-off-by: Al Viro --- fs/block_dev.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/block_dev.c b/fs/block_dev.c index 5dde6dff4940..12b22ddb22ef 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -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)