Comment 18 for bug 556621

On 6/13/2010 6:23 PM, Theodore Ts'o wrote:
> there are inodes which are created back in the 1900's? A patch to
> e2fsck which unceremoniously offers to clear them is likely going to
> cause Unbuntu users to go up in arms.

Couldn't/shouldn't systems with broken real time clocks be fixed to
force the system clock up to mkfs time before mounting the root fs, and
wouldn't that take care of that and other problems?

> I suppose we could code in some hard-coded dates. (If the time is
> before when Linux was invented, clearly it's bogus.) However, I'm
> concerned that such hueristics aren't going to catch them all.

That would tell you that the time is broken, but would not tell you
whether the inode belongs to this fs or not.

> The best way to fix this is to have a kernel patch which clears
> uninitialized inodes in the background, so it's not done as a blocking
> activity during mke2fs. That is a much safer thing to do, IMHO.

I'd rather avoid the need to zero the table completely since that has
negative consequences other than just using up disk IO in the
background. For instance, if the fs is on a snapshot, thin provisioned
san disk, or SSD, the writes cause allocations that aren't needed just
to hold zeroes, which reads there would already return.