Re: [RFC] [PATCH 1/2] fs: introduce inode operation ->update_time

[Josef Bacik <josef@redhat.com>]

On Mon, Apr 30, 2012 at 11:21:47AM -0400, Christoph Hellwig wrote:
> On Mon, Mar 26, 2012 at 10:10:30AM -0400, Josef Bacik wrote:
> > Btrfs has to make sure we have space to allocate new blocks in order to modify
> > the inode, so updating time can fail.  We've gotten around this by having our
> > own file_update_time but this is kind of a pain, and Christoph has indicated he
> > would like to make xfs do something different with atime updates.  So introduce
> > ->update_time, where we will deal with i_version an a/m/c time updates and
> > indicate which changes need to be made.  The normal version just does what it
> > has always done, updates the time and marks the inode dirty, and then
> > filesystems can choose to do something different.
> > 
> > I've gone through all of the users of file_update_time and made them check for
> > errors with the exception of the fault code since it's complicated and I wasn't
> > quite sure what to do there, also Jan is going to be pushing the file time
> > updates into page_mkwrite for those who have it so that should satisfy btrfs and
> > make it not a big deal to check the file_update_time() return code in the
> > generic fault path. Thanks,
> 
> Any reason that atime updates ignore the return value?
> 
> Otherwise looks fine,
> 

Yeah I figure it's not nice to return ENOSPC when somebody is doing a lookup,
I'm open to other suggestions, but btrfs especially hits this with some of the
ENOSPC xfstests and I think that could lead to unhappy users.  Thanks,

Josef