Re: [patch] ext3: remove btree_dir

[Stephen C. Tweedie]

Hi,

On Thu, 2006-07-13 at 16:05 +0800, Qi Yong wrote:
> Remove support for EXT3_FEATURE_RO_COMPAT_BTREE_DIR, so mount can
> safely fail out when some new feature added using 0x0004. 

I think this is a bad idea.

It's not safe to reuse this existing feature bit: if we do, then any
existing 2.6 kernel prior to the change will mistakenly think that it
understands that feature for read-write, and will therefore be likely to
corrupt data.  And we are not remotely short of feature bits, so there's
no pressure to free up existing bits.

Removing the flag from the tree will remove what is essentially
documentation that this flag cannot be reused.

Cheers,
 Stephen


-
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/