On Mon, Jan 20, 2014 at 05:58:55AM -0800, Christoph Hellwig wrote: > On Thu, Jan 16, 2014 at 09:07:21AM +1100, Dave Chinner wrote: > > Yes, I think it can be done relatively simply. We'd have to change > > the code in xfs_file_aio_write_checks() to check whether EOF zeroing > > was required rather than always taking an exclusive lock (for block > > aligned IO at EOF sub-block zeroing isn't required), > > That's not even required for supporting aio appends, just a further > optimization for it. Oh, right, I got an off-by-one when reading the code - the EOF zeroing only occurs when the offset is beyond EOF, not at or beyond EOF... > > and then we'd > > have to modify the direct IO code to set the is_async flag > > appropriately. We'd probably need a new flag to say tell the DIO > > code that AIO beyond EOF is OK, but that isn't hard to do.... > > Yep, need a flag to allow appending writes and then defer them. > > > Christoph, are you going to get any time to look at doing this in > > the next few days? > > I'll probably need at least another week before I can get to it. If you > wanna pick it up before than feel free. I'm probably not going to get to it before then, either, so check back in a week? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
