On (02/02/15 12:41), Minchan Kim wrote: > > If we use zram as block device itself(not a fs or swap) and open the > > block device as !FMODE_EXCL, bd_holders will be void. > > > > Another topic: As I didn't see enough fs/block_dev.c bd_holders in zram > > would be mess. I guess we need to study hotplug of device and implement > > it for zram reset rather than strange own konb. It should go TODO. :( > > Actually, I thought bd_mutex use from custom driver was terrible idea > so we should walk around with device hotplug but as I look through > another drivers, they have used the lock for a long time. > Maybe it's okay to use it in zram? > If so, Ganesh's patch is no problem to me although I didn't' review it in detail. > One thing I want to point out is that it would be better to change bd_holders > with bd_openers to filter out because dd test opens block device as !EXCL > so bd_holders will be void. > > What do you think about it? > a quick idea: can we additionally move all bd flush and put work after zram_reset_device(zram, true) and, perhaps, replace ->bd_holders with something else? zram_reset_device() will not return until we have active IOs, pending IOs will be invalidated by ->disksize != 0. -ss -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>