On 2.07.20 г. 16:36 ч., David Sterba wrote: > On Thu, Jul 02, 2020 at 09:25:30AM -0400, Josef Bacik wrote: >> On 7/2/20 8:23 AM, Nikolay Borisov wrote: >>> Since BTRFS uses a private bdi it makes sense to create a link to this >>> bdi under /sys/fs/btrfs/<UUID>/bdi. This allows size of read ahead to >>> be controlled. Without this patch it's not possible to uniquely identify >>> which bdi pertains to which btrfs filesystem in the fase of multiple >>> btrfs filesystem. >>> >>> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx> >> >> Was confused why we needed to make sure the link existed before removing it, >> since other things sysfs is smart enough to figure out. Apparently it has a >> WARN_ON() if the parent isn't initialized, so the check is necessary, albeit >> annoying. > > There must be a better way, this is just too weird. We can check if > objects have been initialized by peeking to kobject::state_initialized > and we use that already for fsid_kobj in __btrfs_sysfs_remove_fsid or > btrfs_sysfs_feature_update. > Awesome, will use this for v2.
