Re: [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses

[OGAWA Hirofumi]

Jan Kara <jack@xxxxxxx> writes:

>> Isn't it reallocated blocks too, and metadata too?
>   Reallocated blocks - not really. For a block to be freed it cannot be
> under writeback and when it's freed no writeback is started.

Sure for data -> data reallocated case. metadata -> data/metadata is
still there.

> For metadata - yes. But ext3, ext4, xfs, btrfs have to avoid modifying
> metadata under writeback anyway (because of journalling / COW
> constraints) and thus they don't care.

Yes. Those would use better way than just blocking.

> For ext2 or vfat it's a different story. But as I wrote to Darrick,
> I'm not sure about vfat but for ext2 and similar legacy filesystems,
> I'd rather let them live with their unstable pages under IO ;) because
> I see a limited use for that.

If this patches was not going to tackle it, I have no argument here ;)
It would be simply FS specific approach/fixes anymore like journal.

Thanks.
-- 
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/