On Sat, Aug 31, 2019 at 10:32:41AM +0200, Christoph Hellwig wrote: > On Mon, Aug 26, 2019 at 08:28:19PM +0100, Al Viro wrote: > > For configfs bin_attr it won't work, simply because it wants the entire > > thing to be present - callback parses the data. For SCSI tape... Maybe, > > but you'll need to take care of the overlaps with ->write(). Right now > > it can't happen (the last reference, about to be dropped right after > > st_flush() returns); if we do that on each ->flush(), we will have to > > cope with that fun and we'll need to keep an error (if any) for the > > next call of st_flush() to pick and return. I'm not saying it can't > > be done, but that's really a question for SCSI folks. > > So for the one real life example of the configfs attribute life > actually is simpler. acpi_table_aml_write verifies early on that > the size matches what it expects. So if we document that any future > instance needs to be able to do that as well we should be able to > get away with just writing it from ->flush. I'm not sure I understand what you mean... Do you want them to recognize incomplete data and quietly bugger off when called on too early ->flush()?
