Re: [PATCH 5/6] statx: Make windows attributes available for CIFS, NTFS and FAT to use

David Howells
2016-05-03T20:23:44Z

Andreas Dilger <adilger@dilger.ca> wrote:

> > __u32 st_win_attrs;
>
> It seems some of these flags are duplicated with the st_information field,
> and some are duplicate with FS_IOC_GETFLAGS values, and returning the same
> information in multiple ways is confusing.
>
> If these flags are part of the CIFS protocol,

They're part of the Windows API. CIFS/SMB and NTFS have them at the same
values.

> and are directly usable by Samba then I can understand we wouldn't want to
> change them once in the kernel and then convert them back in userspace, but
> I'm a bit reluctant to have flags only for CIFS/NTFS/FAT that might also be
> useful for other filesystems.

Where said "other filesystems" have some support for Windows or OS/2 and have
bits defined that map directly in semantics, if not in value, to these bits.

JFS, for example, has IREADONLY, IHIDDEN, ISYSTEM, IDIRECTORY, IARCHIVE and
ISPARSE.

> Would we want to be able to get translated
> st_win_attrs flags in ext4 attrs when it is being exported by Samba?

Actually, I was thinking of proposing an ext4 patch that stored windows flags
in a separate word in the inode on disk. There isn't sufficient bit space to
map all the windows flags to FS_IOC_GETFLAGS. However, as you say, there is a
certain amount of overlap...

David