tree d8e67346881f72e06782c08305b88c8ce167b698
parent f4bcbe792b8f434e32487cff9d9e30ab45a3ce02
author George Spelvin <linux@sciencehorizons.net> 1463748097 -0400
committer George Spelvin <linux@sciencehorizons.net> 1464464570 -0400

fs/namei.c: Add hashlen_string() function

We'd like to make more use of the highly-optimized dcache hash functions
throughout the kernel, rather than have every subsystem create its own,
and a function that hashes basic null-terminated strings is required
for that.

(The name is to emphasize that it returns both hash and length.)

It's actually useful in the dcache itself, specifically d_alloc_name().
Other uses in the next patch.

full_name_hash() is also tweaked to make it more generally useful:
1) Take a "char *" rather than "unsigned char *" argument, to
   be consistent with hash_name().
2) Handle zero-length inputs.  If we want more callers, we don't want
   to make them worry about corner cases.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>