4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Toshi Kani <toshi.kani@xxxxxxx>
commit cce6c9f7e6029caee45c459db5b3e78fec6973cb upstream.
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 <toshi.kani@xxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Suggested-by: Jan Kara <jack@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4861,6 +4861,7 @@ struct inode *ext4_iget(struct super_blo
* 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))
@@ -5010,7 +5011,6 @@ struct inode *ext4_iget(struct super_blo
goto bad_inode;
}
brelse(iloc.bh);
- ext4_set_inode_flags(inode);
unlock_new_inode(inode);
return inode;
