On Fri, Mar 25, 2016 at 1:59 PM, Verma, Vishal L <vishal.l.verma@xxxxxxxxx> wrote: > On Fri, 2016-03-25 at 03:45 -0700, Christoph Hellwig wrote: >> On Thu, Mar 24, 2016 at 05:17:30PM -0600, Vishal Verma wrote: >> > >> > dax_do_io (called for read() or write() for a dax file system) may >> > fail >> > in the presence of bad blocks or media errors. Since we expect that >> > a >> > write should clear media errors on nvdimms, make dax_do_io fall >> > back to >> > the direct_IO path, which will send down a bio to the driver, which >> > can >> > then attempt to clear the error. >> Leave the fallback on -EIO to the callers please. They generally >> call >> __blockdev_direct_IO anyway, so it should actually become simpler >> that >> way. > > I thought of this, but made the retrying happen in the wrapper so that > it can be centralized. If the callers were to become responsible for > the retry, then any new callers of dax_do_io might not realize they are > responsible for retrying, and hit problems. That's their prerogative otherwise you are precluding an alternate handling of a dax_do_io() failure. Maybe a fs or upper layer can recover in a different manner than re-submit the I/O to the __blockdev_direct_IO path. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>