[PATCH 4/4] xfstests: Add support for btrfs in 079

[Christoph Hellwig]

On Fri, Jul 29, 2011 at 02:24:30PM +0200, Stefan Behrens wrote:
> I changed it according to your suggestion:
> - Get rid of the check for the specific filesystem type.
> - Always use FS_IOC_GETFLAGS/FS_IOC_SETFLAGS. This code is inside an
>   '#ifdef FS_IOC_SETFLAGS" block in order to never fail compilation.
> - Without support for FS_IOC_SETFLAGS, the test completes with _notrun.

Thanks!

> One issue is that the file is there (the creation did succeed but
> the open for writing did not) what IEEE 1003.1-2004 prohibits
> (open() must not create or modify any files if -1 is returned).

That sounds like something we need to fix, and it seems like we'll
need to fix it in the VFS.  Can you start a thread about that particular
issue on fsdevel?

> The difference between the filesystems is whether the append-only
> flag from the directory is inherited to the newly create file inside
> that directory. XFS does not inherit that append-only flag, ext2,
> ext3, ext4 and btrfs do inherit it.
> Test 079 fails when the open("/mnt3/foo/append-only.d/newfile-0",
> O_RDWR|O_CREAT, 0666) fails due to the O_RDWR flag. The O_RDWR
> flag lets the open() fail when the file has the append-only flag
> set. On one type of filesystem the flag is inherited from the
> directory, on the other type it is not. Test 079 expects that flag
> to not be inherited.
> 
> What is your opinion? I would prefer to either change the test to
> detect whether the append-only flag is inherited and then interpret
> the following system call result depending on the state of the flag,
> or to force the flag to a defined state to be independent of the
> inheritance behaviour.

Having different behaviour for different filesystems is a bad thing,
and given that XFS is the lonely one out there I think we should
remove the inheritance.  I'll preparate a patch for it.