Using the right linux-fsdevel this time also, this was the second reply. Luis On Tue, Jun 06, 2017 at 06:47:34PM +0200, Luis R. Rodriguez wrote: > Adding fsdevel folks. > > On Tue, Jun 06, 2017 at 03:53:16PM +0100, Alan Cox wrote: > > > "Unix tradition (and thus almost all applications) believe file store > > > writes to > > > be non signal interruptible. It would not be safe or practical to > > > change that > > > guarantee." > > > > Yep everyone codes > > > > write(disk_file, "foo", 3); > > > > not while(..) blah around it. > > Thanks for the confirmation! That's a simple enough explanation. > > > > For these two reasons then it would seem best we do two things > > > actually: > > > > > > 1) return -EINTR instead of -EAGAIN when we detect > > > swait_event_interruptible_timeout() > > > got interrupted by a signal (it returns -ERESTARTSYS) > > > 2) Do as you note below and add wait_event_killable_timeout() > > > > Pedantic detail that I don't think affects you > > > > If you have completed a part of the I/O then you should return the byte > > processed count not EINTR, but -1,EINTR if no progress was made. > > You are right with some new exceptions and with regards to the future: > > The syfs loading interface for firmware currently goes through the > data file exposed on syfs, the respective write op firmware_data_write() > only checks for signals at the beginning. After that its a full one > swoop try to write if you are following the old tradition and are using > a buffer allocated by the firmware API. > > If you are using the relatively new request_firmware_into_buf() added > by Stephen Boyd which lets the driver provide the allocated buffer then > we have a loop in firmware_rw() which should be fixed to: > > 1) Check for signals > 2) Do what you noted above. > > Furthermore Yi Li over at Intel is adding some new API calls which would > re-use some of this for FPGA firmwares which are also very large, that > work should consider the above and fix appropriately as well. > > Luis > -- Luis Rodriguez, SUSE LINUX GmbH Maxfeldstrasse 5; D-90409 Nuernberg
