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 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
