[PATCH 5/7] xfs: honor the O_SYNC flag for aysnchronous direct I/O requests

[Jeff Moyer]

Hi, Dave,

Thanks for the review!

> or better still, factor xfs_file_fsync() so that it calls a helper
> that doesn't wait for data IO completion, and call that helper here
> too. The semantics of fsync/fdatasync are too complex to have to
> implement and maintain in multiple locations....

I definitely agree with consolidating things.  However, there are four
blocking calls in xfs_file_fsync (filemap_write_and_wait_range,
xfs_blkdev_issue_flush, _xfs_log_force_lsn, and another call to
xfs_blkdev_issue_flush).  How would you propose to make that
non-blocking given that those steps have to happen in sequence?

Cheers,
Jeff