On Tue, Jul 23, 2019 at 04:55:53PM +0200, David Sterba wrote: > On Wed, Jun 26, 2019 at 04:34:02PM +0800, Anand Jain wrote: > > Introduces devid readmirror property, to direct read IO to the specified > > device(s). > > > > The readmirror property is stored as extended attribute on the root > > inode. > > So this is permanently stored on the filesystem, is the policy applied > at mount time? Found in some previous version that it's not permanently stored, so scratch that. > > The readmirror input format is devid1,2,3.. etc. And for the > > each devid provided, a new flag BTRFS_DEV_STATE_READ_OPTIMISED is set. > > I'd say it should be called PREFERRED, and the format specifier could > add ":" between devid and the numbers, like "devid:1,2,3", we'll > probably want more types in the future. > > This is the first whole-filesystem property so we can't follow a naming > scheme, so we'll have to decide if we go with flat or hierarchical > naming with more generic categories like policy.mirror.read and similar. I'll have to go through the past discussions again, there was some feedback regarding this I did not take into account.
