On Friday 08 March 2013 12:55:08 Alan Stern wrote: > On Sat, 9 Mar 2013, Alexey Khoroshilov wrote: > > > As it was described by Oliver Neukum in commit acbe2fe > > "USB: Don't use GFP_KERNEL while we cannot reset a storage device": > > > > Memory allocations with GFP_KERNEL can cause IO to a storage device > > which can fail resulting in a need to reset the device. Therefore > > GFP_KERNEL cannot be safely used between usb_lock_device() > > and usb_unlock_device(). Replace by GFP_NOIO. > > > > The patch fixes the same issue in usb/core/devio.c. > > All the allocations fixed are under usb_lock_device() from usbdev_do_ioctl(). > > > > Found by Linux Driver Verification project (linuxtesting.org). > > I don't know if this is a good idea. People can and do submit > transfers requiring a lot of buffer space. Switching to GFP_NOIO > will make those allocations a lot more likely to fail. > > Oliver, what do you think? Ideally we'd split memory allocation and use, by it fixes a bug. Better allocation failure than deadlock. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
