2017-12-24 00:57:10

by Dan Williams

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Subject: [PATCH v4 13/18] ext4: use DEFINE_FSDAX_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 | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7df2c5644e59..065d11f43cb3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3928,6 +3928,8 @@ static const struct address_space_operations ext4_da_aops = {
.error_remove_page = generic_error_remove_page,
};

+static DEFINE_FSDAX_AOPS(ext4_dax_aops, ext4_writepages);
+
void ext4_set_aops(struct inode *inode)
{
switch (ext4_inode_journal_mode(inode)) {
@@ -3940,7 +3942,9 @@ 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;


2018-01-04 08:29:24

by Christoph Hellwig

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Subject: Re: [PATCH v4 13/18] ext4: use DEFINE_FSDAX_AOPS

Same comment as for XFS applies here as well.