<snip> >> The worst thing is that i don't think users can master this magic >> concept very well. > > Normally users don't need very sophisticated scenarios. In fact, they > don't even need higher level quota groups, the basic tracking is > enough. In this case, everything just works as expected for the user. > If you start creating and assigning qgroups manually, prepare to handle > the complexity. > Considering this case:
a subvolume related to a user, we limit the space by limiting every subvolume qgroup, but we also want to limit the total space all the users can use. So we create a parent qgroup(1/1 for example) and assign all subvolume group to this parent group. The above case is regularly used i think, What's more, many snapshots may be done. So i think what i am concerning is not a corner case.. Thanks, Wang > >> >>> >>>> If so, i think it really confusing and too complex for users to do >>>> such work, is't it?... >>> >>> It is complex. That is why I always point anyone asking to do some work >>> on btrfs or qgroups to writing an enhanced interface to simplify this >>> task for the user. I don't think the kernel should handle this. >>> And that's why I took the effort to write a pdf to explain the >>> concepts :) >> >> I don't have any good ideas about this yet.. >> >>> But the current interface is not only complex, it also is very powerful. >>> You can solve problems with it that no other quota system I know of can >>> solve. >>> >>>> >>>> BTW, i have a question about the function btrfs_qgroup_inherit(), >>>> when copying exclusive value from src_qgroup to dst_qgroup: >>>> >>>> dst_qgroup->exclusive = src_qgroup->exclusive + level_size >>>> >>>> while copying referenced value from src_qgroup to dot_qgroup: >>>> >>>> dst_qgroup->referenced = src_qgroup->referenced -level_size >>>> >>>> I can't really figure out...~_~ >>> >>> level_size is just a small correction for the space the tree root >>> occupies. The tree root is never shared between sub volumes. >> >> O.K. I got it.. >> >> Thanks, >> Wang >> >>> >>> -Arne >>> >>>> >>>> Thanks, >>>> Wang >>> >> > -- 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
