On Thu, 2007-03-15 at 20:21 -0700, Randy Dunlap wrote: > On Mon, 12 Mar 2007 13:23:07 -0400 Ming Zhang wrote: > > > Hi All > > > > I know sometime we need ERR_PTR and PTR_ERR, but why we need to write > > code like this line 356 in quotactl_block() > > > > 353 bdev = lookup_bdev(tmp); > > 354 putname(tmp); > > 355 if (IS_ERR(bdev)) > > 356 return ERR_PTR(PTR_ERR(bdev)) > > > > instead of > > > > return bdev > > > > it convert a PTR to ERR and then back to PTR. any idea why? > > Did you test what happens when you change that return line to be only > return bdev; > ? Please do so. sorry i should be more accurate. ERR_PTR(PTR_ERR(bdev)) is like to return (void *)(long)bdev; then what is the difference between this and return (void *)bdev; from speed, this 2 should have no difference. then any other consideration? > > --- > ~Randy > *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
