[PATCH v2 4/5] ext2: call dax_get_unmapped_area() for DAX pmd mappings

From: Toshi Kani
Date: Tue Apr 12 2016 - 16:49:40 EST


To support DAX pmd mappings with unmodified applications,
filesystems need to align an mmap address by the pmd size.

Call dax_get_unmapped_area() from f_op->get_unmapped_area.

Note, there is no change in behavior for a non-DAX file.

Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Cc: <linux-ext4@xxxxxxxxxxxxxxx>
---
fs/ext2/file.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index c1400b1..f1b8006 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -172,6 +172,9 @@ const struct file_operations ext2_file_operations = {
.open = dquot_file_open,
.release = ext2_release_file,
.fsync = ext2_fsync,
+#ifdef CONFIG_FS_DAX
+ .get_unmapped_area = dax_get_unmapped_area,
+#endif
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
};