Ian Pilcher <arequipeno <at> gmail.com> writes: > I suspect that the most significant difference is that my backing device > is a partition on a RAID device, rather than the device itself. > In reality, however, I don't think it's worth spending a lot of time > figuring out exactly what else is accessing the device. If I understand > udev correctly, this sort of "conflict" is an inevitable consequence of > its asynchronous nature, and helper programs like bcache-register need > to be robust enough to deal with them. > > (If I'm wrong about this, then I guess this is a udev bug?) > > BTW, this is what the bcache-related dmesg entries look like when I hit > the conflict with my patches applied: > > > [ 1.761932] bcache: bch_journal_replay() journal replay done, 1972 keys in 75 entries, seq 312536 > > [ 1.762043] bcache: register_cache() registered cache device sda2 > > [ 1.762631] bcache: register_bcache() error opening /dev/md126p5: device busy > > [ 1.862949] bcache: register_bdev() registered backing device md126p5 > > [ 1.864268] bcache: bch_cached_dev_attach() Caching md126p5 as bcache0 on set fb8d253b-6144-4b48-8ed6-7b1724ed83a7 > > [ 3.553053] bcache: register_bcache() error opening /dev/sda2: device already registered > > [ 4.182180] bcache: register_bcache() error opening /dev/md126p5: device already registered > > You can see that the backing device is busy when it first tries to > register it, but it succeeds 1/10th of a second later. (I'm assuming > the last two "already registered" messages occur when udev replays > its events later in the boot process.) To me your assumption makes sense. I would be good though if Gabriel (bcache userspace) and/or Kent (bcache kernel) would respond to this. I'll add some retries to bcache tools (in case of any error) and see if that works and add a pull request here: https://github.com/g2p/bcache-tools -- 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
