On Thu, Dec 07, 2017 at 04:19:50PM -0700, Ross Zwisler wrote: > This test creates a file and writes to it via an mmap(), but never syncs > via fsync/msync. This process is tracked via dm-log-writes, then replayed. > > If MAP_SYNC is working the dm-log-writes replay will show the test file > with 1 MiB of on-media block allocations. This is because each allocating > page fault included an implicit metadata sync. If MAP_SYNC isn't working > (which you can test by removing the "-S" flag to xfs_io mmap) the file > will be smaller or missing entirely. > > Note that dm-log-writes doesn't track the data that we write via the > mmap(), so we can't do any data integrity checking. We can only verify > that the metadata writes for the page faults happened. > > Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> > > --- > > Changes since v5: > - Addressed Eryu's comments. Thanks for the review. Thanks for the explanation on the dm-log-writes dax support! I agree that we should keep _require_log_writes_dax for now till dm-log-writes gains full dax support. I added some comments about this above the helper definition and queued the patchset for next fstests update. (Test was re-numbered as generic/470, BTW.) Thanks, Eryu -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
