Re: [ext2] Mislabeled quadratic probing?

[Sean Anderson <seanga2@gmail.com>]

[-- Attachment #1.1: Type: text/plain, Size: 728 bytes --]

> The biggest danger I see here is that we're only going to test 32
> groups before falling back to linear probing (we'll shift the single
> '1' bit out of 'i' in 32 steps).  That might be a performance problem,
> but it should hit quite rarely.

Actually, because the loop condition is `i < ngroups`, we test even less
than that . For example, on a 1T disk with 4K blocks there are 8192
block groups, and the maximum iterations are 13. It seems then that
simply creating a directory and creating at least 15 files and writing
at least 128M between each would cause a fall back to a linear search.
This doesn't seem all that uncommon of use case: any directory over 2GB
or so with many files would be susceptible.


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 618 bytes --]