[PATCH] xfs: don't return 0 if generic_segment_checks() find nothing to write

[Ben Myers]

Hey Jeff,

On Fri, Apr 12, 2013 at 11:48:28PM +0800, Jeff Liu wrote:
> From: Jie Liu <jeff.liu at oracle.com>
> 
> At xfs_file_aio_write(), we just return 0 which means a successfully operation if the ocount
> is evaluated to 0 at generic_segment_checks().  Generally, it'll occurred if the specified
> write count is 0 from the user space.  However, for example, if the given offset is over the
> maximum file size limitation although nothing would be written into the file, in this case,
> the underlying file system should detect this issue and return a proper errno instead.
> Hence, the beginning pre-checking up against ocount would conceal some real cause and confuse
> the user space program maybe.
> 
> To fix it, we can delay the write count verification until xfs_file_aio_write_checks() is done.

Could you wrap these around 72 columns or so in the future?  Don't worry
about reposting this one unless something technical comes up.

Thanks,
	Ben