On 2020/9/17 上午8:13, Neal Gompa wrote: > On Wed, Sep 16, 2020 at 8:03 PM Qu Wenruo wrote: >> >> >> >> On 2020/9/17 上午12:18, Neal Gompa wrote: >>> On Tue, Sep 15, 2020 at 1:36 AM Qu Wenruo wrote: >>>> >>>> Patches can be fetched from github: >>>> https://github.com/adam900710/linux/tree/subpage >>>> >>>> Currently btrfs only allows to mount fs with sectorsize == PAGE_SIZE. >>>> >>>> That means, for 64K page size system, they can only use 64K sector size >>>> fs. >>>> This brings a big compatible problem for btrfs. >>>> >>>> This patch is going to slightly solve the problem by, allowing 64K >>>> system to mount 4K sectorsize fs in read-only mode. >>>> >>>> The main objective here, is to remove the blockage in the code base, and >>>> pave the road to full RW mount support. >>>> >>> >>> Is there a reason we don't include a patch in here to just hardwire >>> the block size to 4K going forward? >>> >> >> Did you mean to make 4K sector size the hard requirement? >> >> That would make existing 64K sector size fs unable to be mounted then. >> > > I mean, make the 64K variant a legacy one and force 4K for all new > filesystems. That then simplifies this work to making it mountable and > usable as a legacy filesystem format. That's the plan. But not for now, since currently the subpage support is only read-only. > > I guess that would be an incompat flag, no? No need for incompat flag. For older kernel they just can't mount subpage fs. Thanks, Qu > > > > -- > 真実はいつも一つ！/ Always, there's only one truth! >