Re: [PATCH] staging/lustre/llite: fix O_TMPFILE/O_LOV_DELAY_CREATE conflict

[Greg KH <greg@kroah.com>]

On Mon, Feb 03, 2014 at 04:07:57PM -0700, Andreas Dilger wrote:
> In kernel 3.11 O_TMPFILE was introduced, but the open flag value
> conflicts with the O_LOV_DELAY_CREATE flag 020000000 previously used
> by Lustre-aware applications.  O_LOV_DELAY_CREATE allows applications
> to defer file layout and object creation from open time (the default)
> until it can instead be specified by the application using an ioctl.
> 
> Instead of trying to find a non-conflicting O_LOV_DELAY_CREATE flag
> or define a Lustre-specific flag that isn't of use to most/any other
> filesystems, use (O_NOCTTY|FASYNC) as the new value.  These flag
> are not meaningful for newly-created regular files and should be
> OK since O_LOV_DELAY_CREATE is only meaningful for new files.
> 
> I looked into using O_ACCMODE/FMODE_WRITE_IOCTL, which allows calling
> ioctl() on the minimally-opened fd and is close to what is needed,
> but that doesn't allow specifying the actual read or write mode for
> the file, and fcntl(F_SETFL) doesn't allow O_RDONLY/O_WRONLY/O_RDWR
> to be set after the file is opened.
> 
> Lustre-change: http://review.whamcloud.com/8312
> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4209
> Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
> Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
> Signed-off-by: Peng Tao <bergwolf@gmail.com>
> ---
>  .../lustre/lustre/include/lustre/lustre_user.h     |   12 ++++------
>  drivers/staging/lustre/lustre/include/lustre_mdc.h |   11 ++++++++++
>  drivers/staging/lustre/lustre/llite/file.c         |   21 ++++++++++---------
>  drivers/staging/lustre/lustre/mdc/mdc_lib.c        |    2 +-
>  4 files changed, 28 insertions(+), 18 deletions(-)

As you are abusing well known file flags, I can't accept any patch that
doesn't get accepted by the linux-fsdev developers as well, please
repost this there and cc: me for the fun discussion :)

thanks,

greg k-h