On Sat, 10 Jun 2017, Kai Krakow wrote: > Am Fri, 9 Jun 2017 01:46:24 +0000 (UTC) > schrieb Eric Wheeler <bcache@xxxxxxxxxxxxxxxxxx>: > > > On Fri, 2 Jun 2017, feng D wrote: > > > > > hi: > > > > > > Some time, the online machine will appear disk gone situation, > > > although this is not very common, but we have too many machines, so > > > still will encounter it. > > > > > > That in the case of disk gone, /sys/block/bcache0/bcache/stop is > > > not found, this case how to delete the bcache0? > > > > An interesting question. Is it still available from the cache device > > in /sys/fs/bcache/* somewhere? I'm guessing not, but check. > > > > Do you have a procedure to reproduce this problem > > where /sys/block/bcache0 has been hotplugged into oblivion? > > You easily run into the same situation when you stop the device instead > of detaching it. Bcache then doesn't release its cache device and > cannot be stopped/unregistered, because every interface for shutting > bcache down has vanished: It can only be reached through the backing > devices but the bcache interface below those is gone. > > I think bcache needs a way to force unregister the cache device... > Otherwise the cache device stays busy and cannot be registered, neither > can any devices be attached again in this state. I'm having trouble reproducing: ]# echo /dev/centos/bcache0 > /sys/fs/bcache/register ]# echo /dev/centos/bcache0-cache > /sys/fs/bcache/register ]# ]# echo 1 > /sys/block/bcache0/bcache/stop ]# echo 1 > /sys/fs/bcache/3e57bc2e-4f01-4164-9b6d-54ef288ae394/stop ]# ]# echo /dev/centos/bcache0 > /sys/fs/bcache/register ]# echo /dev/centos/bcache0-cache > /sys/fs/bcache/register also tried swapping the stop order: ]# echo /dev/centos/bcache0 > /sys/fs/bcache/register ]# echo /dev/centos/bcache0-cache > /sys/fs/bcache/register ]# ]# echo 1 > /sys/fs/bcache/3e57bc2e-4f01-4164-9b6d-54ef288ae394/stop ]# echo 1 > /sys/block/bcache0/bcache/stop >>> fails, no such file, but re-registers fine below ]# ]# echo /dev/centos/bcache0 > /sys/fs/bcache/register ]# echo /dev/centos/bcache0-cache > /sys/fs/bcache/register What am I missing here? -- Eric Wheeler > > -- > Regards, > Kai > > Replies to list-only preferred. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
