On Wed, 2009-07-29 at 14:48 -0500, Eric Sandeen wrote: > Eric Sandeen wrote: > ... > > > Also, IIRC xfs does the conversion to written (vs. unwritten) extents in > > an IO completion handler, just FWIW. > > After talking w/ Jeff Moyer, realized that w/o using the io completion, > there's a race with AIO. > > Userspace will get notified that the write is done before the extents > get flipped to initialized .... Yes, for the AIO case, the DIO submit the IO and returns without waiting for IO to complete. If we do conversion in ext4_direct_IO, then we could convert the extents before the real IO hit to disk. Could cause stale data exposed if crash before the data written to disk. > > -Eric > -- > 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 -- 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
