2018-09-14 14:51:13

by Toshi Kani

Subject: [PATCH v2 2/3] ext4, dax: set ext4_dax_aops for dax files

Sync syscall to DAX file needs to flush processor cache, but it
currently does not flush to existing DAX files. This is because
'ext4_da_aops' is set to address_space_operations of existing DAX
files, instead of 'ext4_dax_aops', since S_DAX flag is set after
ext4_set_aops() in the open path.

New file
--------
lookup_open
ext4_create
__ext4_new_inode
ext4_set_inode_flags // Set S_DAX flag
ext4_set_aops // Set aops to ext4_dax_aops

Existing file
-------------
lookup_open
ext4_lookup
ext4_iget
ext4_set_aops // Set aops to ext4_da_aops
ext4_set_inode_flags // Set S_DAX flag

Change ext4_iget() to initialize i_flags before ext4_set_aops().

Fixes: 5f0663bb4a64 ("ext4, dax: introduce ext4_dax_aops")
Signed-off-by: Toshi Kani <[email protected]>
Suggested-by: Jan Kara <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: "Theodore Ts'o" <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: <[email protected]>
---
fs/ext4/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index e4acaa980467..b19387b75f2b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4896,6 +4896,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
* not initialized on a new filesystem. */
}
ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+ ext4_set_inode_flags(inode);
inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
if (ext4_has_feature_64bit(sb))
@@ -5042,7 +5043,6 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
goto bad_inode;
}
brelse(iloc.bh);
- ext4_set_inode_flags(inode);

unlock_new_inode(inode);
return inode;

2018-09-16 01:56:46

by Theodore Y. Ts'o

Subject: Re: [PATCH v2 2/3] ext4, dax: set ext4_dax_aops for dax files

On Fri, Sep 14, 2018 at 08:51:13AM -0600, Toshi Kani wrote:
> Sync syscall to DAX file needs to flush processor cache, but it
> currently does not flush to existing DAX files. This is because
> 'ext4_da_aops' is set to address_space_operations of existing DAX
> files, instead of 'ext4_dax_aops', since S_DAX flag is set after
> ext4_set_aops() in the open path.
>
> New file
> --------
> lookup_open
> ext4_create
> __ext4_new_inode
> ext4_set_inode_flags // Set S_DAX flag
> ext4_set_aops // Set aops to ext4_dax_aops
>
> Existing file
> -------------
> lookup_open
> ext4_lookup
> ext4_iget
> ext4_set_aops // Set aops to ext4_da_aops
> ext4_set_inode_flags // Set S_DAX flag
>
> Change ext4_iget() to initialize i_flags before ext4_set_aops().
>
> Fixes: 5f0663bb4a64 ("ext4, dax: introduce ext4_dax_aops")
> Signed-off-by: Toshi Kani <[email protected]>
> Suggested-by: Jan Kara <[email protected]>
> Cc: Jan Kara <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: "Theodore Ts'o" <[email protected]>
> Cc: Andreas Dilger <[email protected]>
> Cc: <[email protected]>

Thanks, applied.

- Ted