Build errors in mainline due to "fs/namei.c:,Add hashlen_string() function"

From: Guenter Roeck
Date: Sun May 29 2016 - 01:18:14 EST

I see:

fs/dcache.c:1673: undefined reference to `hashlen_string'

total: 148 pass: 22 fail: 126

I didn't bisect, but I strongly suspect commit fcfd2fbf22d2 ("fs/namei.c:
Add hashlen_string() function") because the new function is not provided
if DCACHE_WORD_ACCESS is not enabled. This affects almost all architectures.

Reverting 468a9428521e, 2a18da7a9c78, and fcfd2fbf22d2 fixed the problem
for me in a couple of test builds, but I don't know if all three patches
need to be reverted, or if reverting those patches fixes the problem for
all builds, or if the revert is sufficient.