On Fri, Aug 26, 2016 at 02:06:29PM +0300, Anatoly Pugachev wrote: > On Thu, Aug 18, 2016 at 11:33 PM, Omar Sandoval <osandov@xxxxxxxxxxx> wrote: > > On Tue, Jul 19, 2016 at 03:25:16PM -0400, Chris Mason wrote: > >> On 07/19/2016 12:06 PM, Chandan Rajendra wrote: > >> > >> Omar, looks like we need to make the patched kernel refuse to mount free > >> space trees without a new incompat bit set. That way there won't be any > >> surprises for the people that have managed to get a free space tree saved. > >> Can it please printk a message about clearing the tree and mounting again? > >> > > Sorry it took me a month to get around to this, I tried to implement > > this a couple of ways but I really don't like it. Basically, when we see > > that we're missing the compat bit, we have to assume that the free space > > tree was created with the same endianness that we're running on now. > > That could lead to a false positive if, say, we created the filesystem > > on a little-endian machine with an old kernel but are using it on a > > big-endian system, or a false negative if it was created on a big-endian > > machine with an old kernel but we're using it on a little-endian > > machine. > > > > There's also the question of making it a compat bit vs an incompat bit. > > An incompat bit makes sure that we don't break the filesystem by > > mounting it on an old big-endian kernel, but needlessly breaks > > backwards-compatibility for little-endian. > > > > I'd be much happier if we could just pretend this never happened. Here's > > the patch, anyways, for the sake of completeness. Chris, what do you > > think? > > Omar, > > I can't load btrfs module with this patch applied to 4.8.0-rc3+ (git > v4.8-rc3-39-g61c0457) > on "modprobe btrfs" i'm getting the following in the logs and module > does not load: > > Btrfs loaded, crc32c=crc32c-generic, debug=on, assert=on > BTRFS: selftest: sectorsize: 8192 nodesize: 8192 > BTRFS: selftest: Running btrfs free space cache tests > BTRFS: selftest: Running extent only tests > BTRFS: selftest: Running bitmap only tests > BTRFS: selftest: Running bitmap and extent tests > BTRFS: selftest: Running space stealing from bitmap to extent > BTRFS: selftest: Free space cache tests finished > BTRFS: selftest: Running extent buffer operation tests > BTRFS: selftest: Running btrfs_split_item tests > BTRFS: selftest: Running extent I/O tests > BTRFS: selftest: Running find delalloc tests > BTRFS: selftest: Running extent buffer bitmap tests > BTRFS: selftest: Setting straddling pages failed > BTRFS: selftest: Extent I/O tests finished Is this with the whole patchset + this patch? You still need the patch set for this to actually work, the extra patch is just some extra checks. -- Omar -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
