On Tue 24-11-15 08:07:23, Christoph Hellwig wrote: > On Tue, Nov 24, 2015 at 02:24:21PM +0100, Jan Kara wrote: > > Well, this problem seems to suggest that we have the freeze protection for > > AIO writes wrong. We should call file_end_write() from aio_complete() and > > not from aio_run_iocb()... I believe XFS and other filesystems may have > > problems with this as well (CCed). Attached patch (so far only compile > > tested since my test machine is pondering on something else) should fix > > this. > > Sounds like one way to do it, but we'd really want a vfs_* helper for > this so that it doesn't have to duplicated in other write_iter users > like the loop driver, which seems to be missing file > file_start_write/file_end_write entirely. That is mostly a separate issue, isn't it? I guess you mean a helper like vfs_write_iter() that would get freeze protection and call ->write_iter()? And what about files which have ->write (or ->splice_write()) and don't end up calling ->write_iter? Also there is stuff like __kernel_write() which ends up calling ->write_iter() but e.g. kernel/acct.c: do_acct_process() wants to do it's own thing... So the current status is not ideal but I don't see how to make it substantially better... Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
