1 files changed, 8 insertions, 1 deletions
diff --git a/fs/dax.c b/fs/dax.c
index a86d3cc2b389..8e17b371aeb8 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -29,6 +29,11 @@
 #include <linux/uio.h>
 #include <linux/vmstat.h>
 
+/*
+ * dax_clear_blocks() is called from within transaction context from XFS,
+ * and hence this means the stack from this point must follow GFP_NOFS
+ * semantics for all operations.
+ */
 int dax_clear_blocks(struct inode *inode, sector_t block, long size)
 {
 	struct block_device *bdev = inode->i_sb->s_bdev;
@@ -169,8 +174,10 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 		else
 			len = iov_iter_zero(max - pos, iter);
 
-		if (!len)
+		if (!len) {
+			retval = -EFAULT;
 			break;
+		}
 
 		pos += len;
 		addr += len;