[PATCH] 2.4.19 fix for fuzzy hash <linux/ghash.h>

[PATCH] 2.4.19 fix for fuzzy hash <linux/ghash.h>

[Bart Trojanowski]

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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;\
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 10:09:49 2002
+++ linux-2.4.19+ghash-fix/include/linux/ghash.h~	Wed Sep 11 10:10:57 2002
@@ -1,4 +1,3 @@
-
 /*
  * include/linux/ghash.h -- generic hashing with fuzzy retrieval
  *

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Re: [PATCH] 2.4.19 fix for fuzzy hash <linux/ghash.h>

[Bart Trojanowski]

* Bart Trojanowski <bart@jukie.net> [020911 14:04]:
> 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.

Please ignore the garbage at the end of the last patch.

Here is a cleaned up one.

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;\

Re: [PATCH] 2.4.19 fix for fuzzy hash <linux/ghash.h>

[Rusty Russell]

On Wed, 11 Sep 2002 14:02:32 -0400
Bart Trojanowski <bart@jukie.net> wrote:

> 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.   ;)

That's why I was going to submit a patch to turf it out in 2.5.
2.5's include/hash.h provides a hashing function: did you really want ghash.h?

Cheers,
Rusty.
-- 
   there are those who do and those who hang on and you don't see too
   many doers quoting their contemporaries.  -- Larry McVoy