Re: [PATCH V2] fs/ntfs3: Add missing direct_IO in ntfs_aops_cmpr

[Lizhi Xu]

On Tue, 15 Apr 2025 23:05:56 -0700, Christoph Hellwig wrote:
> > In the reproducer, the second file passed in by the system call sendfile()
> > sets the file flag O_DIRECT when opening the file, which bypasses the page
> > cache and accesses the direct io interface of the ntfs3 file system.
> > However, ntfs3 does not set direct_IO for compressed files in ntfs_aops_cmpr.
> 
> Not allowing direct I/O is perfectly fine.  If you think you need to
> support direct I/O for this case it is also fine.  But none of this
> has anything to do with 'can use the page cache' and there are also
The "The ntfs3 can use the page cache directly" I mentioned in the patch
is to explain that the calltrace is the direct I/O of ntfs3 called from
generic_file_read_iter().