Kai Krakow posted on Sun, 01 May 2016 18:54:18 +0200 as excerpted: > It affects all file systems. The "btrfs fi sync" is used to finish my > rsync backup and ensure everything is written before I'm trying to > unmount it or the system goes back to sleep. > > "df" and friends also freeze on tmp (ramdisk) fs and vfat fs (my EFI > boot partition).
That's just weird, there. df on tmpfs triggers a stall as well? Weird to the point I wonder if you're seeing a general block layer bug... only involving btrfs if btrfs is somehow fowling up the block layer for everyone else as well. Whatever it is, it's obviously far different than my first guess, which now looks ridiculously wrong. Oh, well... But given that I've seen no other reports of it, I'd consider the things that are unique to your kernel config compared to others running btrfs. The first thing off the top of my head, bcache. Do you happen to follow the bcache list (presuming it has one) as well? Given this new information and the contrast with others running btrfs, I'd wonder if they've had similar reported. If I understand correctly, with bcache, you can't entirely turn it off or bypass it as the filesystems are installed on top of it. Have you tried tinkering with its writeback settings? Alternatively, if you have the space/time to test, try creating a new btrfs with the same options, etc, but without the bcache layer, and see if it gives you similar behavior in terms of even df of a tmpfs hanging like that, of course without the positive effects of bcache as well, tho. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
