> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Wednesday, June 14, 2023 9:38 PM > > On Wed, Jun 14, 2023 at 01:05:45PM +0000, Liu, Yi L wrote: > > > -EAGAIN basically means the kernel internally malfunctioned - eg it > > > allocated too little space for the actual size of devices. That is no > > > longer possible in this version so it should never return -EAGAIN. > > > > I still have one doubt. Per my understanding, this is to handle newly > > plugged devices during the info reporting path. I don’t think holding > > dev_set lock can prevent it. but maybe -ENOSPC is enough. @Alex, > > what about your opinion? > > If the device was plug instantly before we computed the size we returned > ENOSPC > > If it was plugged instantly after we computed the size we returned > EAGAIN Yes. > Here we just resolve this race consistently to always return ENOSPC, > which always means we ran out of space in the user provided buffer. This makes sense. > > > - kfree(devices); > > > - return ret; > > > + if (fill.count != fill.devices - arg->devices) > > > > Should be "if (fill.count != (fill.devices - arg->devices) / sizeof(arg->devices[0]))" 😊 > > devices is already a typed pointer so the compiler computes the > /sizeof() itself > > Your version above is needed if it was void * Got it. Regards, Yi Liu
