2018-03-10 06:55:05

by Dan Williams

[permalink] [raw]
Subject: [PATCH v5 03/11] ext4, dax: introduce ext4_dax_aops

In preparation for the dax implementation to start associating dax pages
to inodes via page->mapping, we need to provide a 'struct
address_space_operations' instance for dax. Otherwise, direct-I/O
triggers incorrect page cache assumptions and warnings.

Cc: "Theodore Ts'o" <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: [email protected]
Cc: Jan Kara <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
---
fs/ext4/inode.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c94780075b04..ef21f0ad38ff 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3946,6 +3946,13 @@ static const struct address_space_operations ext4_da_aops = {
.error_remove_page = generic_error_remove_page,
};

+static const struct address_space_operations ext4_dax_aops = {
+ .writepages = ext4_writepages,
+ .direct_IO = ext4_direct_IO,
+ .set_page_dirty = dax_set_page_dirty,
+ .invalidatepage = dax_invalidatepage,
+};
+
void ext4_set_aops(struct inode *inode)
{
switch (ext4_inode_journal_mode(inode)) {
@@ -3958,7 +3965,9 @@ void ext4_set_aops(struct inode *inode)
default:
BUG();
}
- if (test_opt(inode->i_sb, DELALLOC))
+ if (IS_DAX(inode))
+ inode->i_mapping->a_ops = &ext4_dax_aops;
+ else if (test_opt(inode->i_sb, DELALLOC))
inode->i_mapping->a_ops = &ext4_da_aops;
else
inode->i_mapping->a_ops = &ext4_aops;