2002-10-06 20:55:59

by Bart Trojanowski

[permalink] [raw]
Subject: [PATCH] [2.4.19] fix for fuzzy hash <linux/ghash.h> [Attempt 2]

[ Originally posted on 2002/09/11; I just looked in 2.4.20-pre9 and it
was not there, hence the repost. ]

The DEF_HASH_FUZZY macro allows the user to template their hash; it
takes on a paramter for the hashing-function, namely HASHFN. When used
with a hashing-function named anything other than 'hashfn()', a module
using the kernel's fuzzy hash implementation will not compile.

None of the in-kernel 2.4.x drivers use this primitive (yet) so it's no
wonder no one has spotted it. The patch is very trivial and makes me
think that I am the very first user of the include/linux/ghash.h
hash-table primitive. ;)

Bart.

---
diff -ruN linux-2.4.19/include/linux/ghash.h linux-2.4.19+ghash-fix/include/linux/ghash.h
--- linux-2.4.19/include/linux/ghash.h Wed Sep 11 10:09:57 2002
+++ linux-2.4.19+ghash-fix/include/linux/ghash.h Wed Sep 11 10:12:52 2002
@@ -106,7 +106,7 @@
\
LINKAGE TYPE * find_##NAME##_hash(struct NAME##_table * tbl, KEYTYPE pos)\
{\
- int ix = hashfn(pos);\
+ int ix = HASHFN(pos);\
TYPE * ptr = tbl->hashtable[ix];\
while(ptr && KEYCMP(ptr->KEY, pos))\
ptr = ptr->PTRS.next_hash;\
@@ -206,7 +206,7 @@
\
LINKAGE TYPE * find_##NAME##_hash(struct NAME##_table * tbl, KEYTYPE pos)\
{\
- int ix = hashfn(pos);\
+ int ix = HASHFN(pos);\
TYPE * ptr = tbl->hashtable[ix];\
while(ptr && KEYCMP(ptr->KEY, pos))\
ptr = ptr->PTRS.next_hash;\


Attachments:
(No filename) (1.34 kB)
(No filename) (189.00 B)
Download all attachments

2002-10-07 05:17:35

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH] [2.4.19] fix for fuzzy hash <linux/ghash.h> [Attempt 2]

Em Sun, Oct 06, 2002 at 05:01:24PM -0400, Bart Trojanowski escreveu:
> wonder no one has spotted it. The patch is very trivial and makes me
> think that I am the very first user of the include/linux/ghash.h
> hash-table primitive. ;)

Somebody told me that this was used in when dentry was introduced to the
kernel, but then after rewrites it stopped being used, I was even thinking
about submitting a patch removing it from the tree, but now there is one user,
you :-)

- Arnaldo

2002-10-10 19:13:23

by Daniel Phillips

[permalink] [raw]
Subject: Re: [PATCH] [2.4.19] fix for fuzzy hash <linux/ghash.h> [Attempt 2]

On Monday 07 October 2002 07:22, Arnaldo Carvalho de Melo wrote:
> Em Sun, Oct 06, 2002 at 05:01:24PM -0400, Bart Trojanowski escreveu:
> > wonder no one has spotted it. The patch is very trivial and makes me
> > think that I am the very first user of the include/linux/ghash.h
> > hash-table primitive. ;)
>
> Somebody told me that this was used in when dentry was introduced to the
> kernel, but then after rewrites it stopped being used, I was even thinking
> about submitting a patch removing it from the tree, but now there is one user,
> you :-)

Too bad, should have acted faster ;-)

This attempt is much like the single linked lists: it looks like something you
ought to be able to generalize, but somehow it never quite works. Writing
the code out in full gives you a more efficient, more compact result every
time.

--
Daniel