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
*
* Bart Trojanowski <[email protected]> [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;\
On Wed, 11 Sep 2002 14:02:32 -0400
Bart Trojanowski <[email protected]> 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