> On Jun 22, 2016, at 12:42, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Tue, Jun 21, 2016 at 05:34:52PM -0400, Trond Myklebust wrote: >> Now that we can serialise O_DIRECT and write/truncate using the >> inode->i_rwsem, we no longer need inode->i_dio_count. > > For the AIO case that's not true, we can't hold i_rwsem until > aio completes. So for something that does block allocations we'll > need something like i_dio_count still. This probably includes the > block / scsi layout code. Why can’t we hold the i_rwsem until aio completes? It is only a read lock, so we’re not blocking the aio engine from adding more requests. As long as notify_change() holds the i_rwsem for write, then we have exclusion. Cheers Trond -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
