Attachment 6293 Details for Bug 8010 – Patch with Bob Jenkins hash function to generate inode numbers

[patch] Patch with Bob Jenkins hash function to generate inode numbers

samba-inode-checksum-fix.patch (text/plain), 16.02 KB, created by Nikolay Martynov on 2011-03-15 21:14:54 UTC

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Creator: Nikolay Martynov

Created: 2011-03-15 21:14:54 UTC

Size: 16.02 KB

patch

obsolete

>Description: Upstream changes introduced in version 2:3.5.4~dfsg-1ubuntu8.3kolya1
> This patch has been created by dpkg-source during the package build.
> Here's the last changelog entry, hopefully it gives details on why
> those changes were made:
> .
> samba (2:3.5.4~dfsg-1ubuntu8.3kolya1) maverick; urgency=low
> .
>   * Fix inode generation so nautilus can count total dir size correctly
> .
> The person named in the Author field signed this changelog entry.
>Author: Nikolay Martynov <mar.kolya@gmail.com>
>
>---
>The information above should follow the Patch Tagging Guidelines, please
>checkout http://dep.debian.net/deps/dep3/ to learn about the format. Here
>are templates for supplementary fields that you might want to add:
>
>Origin: <vendor|upstream|other>, <url of original patch>
>Bug: <url in upstream bugtracker>
>Bug-Debian: http://bugs.debian.org/<bugnumber>
>Bug-Ubuntu: https://launchpad.net/bugs/<bugnumber>
>Forwarded: <no|not-needed|url proving that it has been forwarded>
>Reviewed-By: <name and email of someone who approved the patch>
>Last-Update: <YYYY-MM-DD>
>
>--- samba-3.5.4~dfsg.orig/source3/Makefile.in
>+++ samba-3.5.4~dfsg/source3/Makefile.in
>@@ -398,7 +398,7 @@ LIB_OBJ = $(LIBSAMBAUTIL_OBJ) $(UTIL_OBJ
> 	  lib/wins_srv.o \
> 	  lib/util_str.o lib/clobber.o lib/util_sid.o lib/util_uuid.o \
> 	  lib/util_unistr.o lib/util_file.o \
>-	  lib/util.o lib/util_sock.o lib/sock_exec.o lib/util_sec.o \
>+	  lib/util.o lib/hash.o lib/util_sock.o lib/sock_exec.o lib/util_sec.o \
> 	  lib/substitute.o lib/dbwrap_util.o \
> 	  lib/ms_fnmatch.o lib/select.o lib/errmap_unix.o \
> 	  lib/tallocmsg.o lib/dmallocmsg.o \
>--- /dev/null
>+++ samba-3.5.4~dfsg/source3/lib/hash.c
>@@ -0,0 +1,370 @@
>+ /*
>+   Unix SMB/CIFS implementation.
>+
>+   trivial database library
>+
>+   Copyright (C) Rusty Russell		   2010
>+
>+     ** NOTE! The following LGPL license applies to the tdb
>+     ** library. This does NOT imply that all of Samba is released
>+     ** under the LGPL
>+
>+   This library is free software; you can redistribute it and/or
>+   modify it under the terms of the GNU Lesser General Public
>+   License as published by the Free Software Foundation; either
>+   version 3 of the License, or (at your option) any later version.
>+
>+   This library is distributed in the hope that it will be useful,
>+   but WITHOUT ANY WARRANTY; without even the implied warranty of
>+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>+   Lesser General Public License for more details.
>+
>+   You should have received a copy of the GNU Lesser General Public
>+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
>+*/
>+#include "includes.h"
>+
>+/* This is based on the hash algorithm from gdbm */
>+
>+
>+#ifndef WORDS_BIGENDIAN
>+# define HASH_LITTLE_ENDIAN 1
>+# define HASH_BIG_ENDIAN 0
>+#else
>+# define HASH_LITTLE_ENDIAN 0
>+# define HASH_BIG_ENDIAN 1
>+#endif
>+
>+/*
>+-------------------------------------------------------------------------------
>+lookup3.c, by Bob Jenkins, May 2006, Public Domain.
>+
>+These are functions for producing 32-bit hashes for hash table lookup.
>+hash_word(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
>+are externally useful functions.  Routines to test the hash are included
>+if SELF_TEST is defined.  You can use this free for any purpose.  It's in
>+the public domain.  It has no warranty.
>+
>+You probably want to use hashlittle().  hashlittle() and hashbig()
>+hash byte arrays.  hashlittle() is is faster than hashbig() on
>+little-endian machines.  Intel and AMD are little-endian machines.
>+On second thought, you probably want hashlittle2(), which is identical to
>+hashlittle() except it returns two 32-bit hashes for the price of one.
>+You could implement hashbig2() if you wanted but I haven't bothered here.
>+
>+If you want to find a hash of, say, exactly 7 integers, do
>+  a = i1;  b = i2;  c = i3;
>+  mix(a,b,c);
>+  a += i4; b += i5; c += i6;
>+  mix(a,b,c);
>+  a += i7;
>+  final(a,b,c);
>+then use c as the hash value.  If you have a variable length array of
>+4-byte integers to hash, use hash_word().  If you have a byte array (like
>+a character string), use hashlittle().  If you have several byte arrays, or
>+a mix of things, see the comments above hashlittle().
>+
>+Why is this so big?  I read 12 bytes at a time into 3 4-byte integers,
>+then mix those integers.  This is fast (you can do a lot more thorough
>+mixing with 12*3 instructions on 3 integers than you can with 3 instructions
>+on 1 byte), but shoehorning those bytes into integers efficiently is messy.
>+*/
>+
>+#define hashsize(n) ((uint32_t)1<<(n))
>+#define hashmask(n) (hashsize(n)-1)
>+#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
>+
>+/*
>+-------------------------------------------------------------------------------
>+mix -- mix 3 32-bit values reversibly.
>+
>+This is reversible, so any information in (a,b,c) before mix() is
>+still in (a,b,c) after mix().
>+
>+If four pairs of (a,b,c) inputs are run through mix(), or through
>+mix() in reverse, there are at least 32 bits of the output that
>+are sometimes the same for one pair and different for another pair.
>+This was tested for:
>+* pairs that differed by one bit, by two bits, in any combination
>+  of top bits of (a,b,c), or in any combination of bottom bits of
>+  (a,b,c).
>+* "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
>+  the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
>+  is commonly produced by subtraction) look like a single 1-bit
>+  difference.
>+* the base values were pseudorandom, all zero but one bit set, or
>+  all zero plus a counter that starts at zero.
>+
>+Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
>+satisfy this are
>+    4  6  8 16 19  4
>+    9 15  3 18 27 15
>+   14  9  3  7 17  3
>+Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
>+for "differ" defined as + with a one-bit base and a two-bit delta.  I
>+used http://burtleburtle.net/bob/hash/avalanche.html to choose
>+the operations, constants, and arrangements of the variables.
>+
>+This does not achieve avalanche.  There are input bits of (a,b,c)
>+that fail to affect some output bits of (a,b,c), especially of a.  The
>+most thoroughly mixed value is c, but it doesn't really even achieve
>+avalanche in c.
>+
>+This allows some parallelism.  Read-after-writes are good at doubling
>+the number of bits affected, so the goal of mixing pulls in the opposite
>+direction as the goal of parallelism.  I did what I could.  Rotates
>+seem to cost as much as shifts on every machine I could lay my hands
>+on, and rotates are much kinder to the top and bottom bits, so I used
>+rotates.
>+-------------------------------------------------------------------------------
>+*/
>+#define mix(a,b,c) \
>+{ \
>+  a -= c;  a ^= rot(c, 4);  c += b; \
>+  b -= a;  b ^= rot(a, 6);  a += c; \
>+  c -= b;  c ^= rot(b, 8);  b += a; \
>+  a -= c;  a ^= rot(c,16);  c += b; \
>+  b -= a;  b ^= rot(a,19);  a += c; \
>+  c -= b;  c ^= rot(b, 4);  b += a; \
>+}
>+
>+/*
>+-------------------------------------------------------------------------------
>+final -- final mixing of 3 32-bit values (a,b,c) into c
>+
>+Pairs of (a,b,c) values differing in only a few bits will usually
>+produce values of c that look totally different.  This was tested for
>+* pairs that differed by one bit, by two bits, in any combination
>+  of top bits of (a,b,c), or in any combination of bottom bits of
>+  (a,b,c).
>+* "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
>+  the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
>+  is commonly produced by subtraction) look like a single 1-bit
>+  difference.
>+* the base values were pseudorandom, all zero but one bit set, or
>+  all zero plus a counter that starts at zero.
>+
>+These constants passed:
>+ 14 11 25 16 4 14 24
>+ 12 14 25 16 4 14 24
>+and these came close:
>+  4  8 15 26 3 22 24
>+ 10  8 15 26 3 22 24
>+ 11  8 15 26 3 22 24
>+-------------------------------------------------------------------------------
>+*/
>+#define final(a,b,c) \
>+{ \
>+  c ^= b; c -= rot(b,14); \
>+  a ^= c; a -= rot(c,11); \
>+  b ^= a; b -= rot(a,25); \
>+  c ^= b; c -= rot(b,16); \
>+  a ^= c; a -= rot(c,4);  \
>+  b ^= a; b -= rot(a,14); \
>+  c ^= b; c -= rot(b,24); \
>+}
>+
>+
>+/*
>+-------------------------------------------------------------------------------
>+hashlittle() -- hash a variable-length key into a 32-bit value
>+  k       : the key (the unaligned variable-length array of bytes)
>+  length  : the length of the key, counting by bytes
>+  val2    : IN: can be any 4-byte value OUT: second 32 bit hash.
>+Returns a 32-bit value.  Every bit of the key affects every bit of
>+the return value.  Two keys differing by one or two bits will have
>+totally different hash values.  Note that the return value is better
>+mixed than val2, so use that first.
>+
>+The best hash table sizes are powers of 2.  There is no need to do
>+mod a prime (mod is sooo slow!).  If you need less than 32 bits,
>+use a bitmask.  For example, if you need only 10 bits, do
>+  h = (h & hashmask(10));
>+In which case, the hash table should have hashsize(10) elements.
>+
>+If you are hashing n strings (uint8_t **)k, do it like this:
>+  for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h);
>+
>+By Bob Jenkins, 2006.  bob_jenkins@burtleburtle.net.  You may use this
>+code any way you wish, private, educational, or commercial.  It's free.
>+
>+Use for hash table lookup, or anything where one collision in 2^^32 is
>+acceptable.  Do NOT use for cryptographic purposes.
>+-------------------------------------------------------------------------------
>+*/
>+
>+static uint32_t hashlittle( const void *key, size_t length )
>+{
>+  uint32_t a,b,c;                                          /* internal state */
>+  union { const void *ptr; size_t i; } u;     /* needed for Mac Powerbook G4 */
>+
>+  /* Set up the internal state */
>+  a = b = c = 0xdeadbeef + ((uint32_t)length);
>+
>+  u.ptr = key;
>+  if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
>+    const uint32_t *k = (const uint32_t *)key;         /* read 32-bit chunks */
>+#ifdef VALGRIND
>+    const uint8_t  *k8;
>+#endif
>+
>+    /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
>+    while (length > 12)
>+    {
>+      a += k[0];
>+      b += k[1];
>+      c += k[2];
>+      mix(a,b,c);
>+      length -= 12;
>+      k += 3;
>+    }
>+
>+    /*----------------------------- handle the last (probably partial) block */
>+    /*
>+     * "k[2]&0xffffff" actually reads beyond the end of the string, but
>+     * then masks off the part it's not allowed to read.  Because the
>+     * string is aligned, the masked-off tail is in the same word as the
>+     * rest of the string.  Every machine with memory protection I've seen
>+     * does it on word boundaries, so is OK with this.  But VALGRIND will
>+     * still catch it and complain.  The masking trick does make the hash
>+     * noticably faster for short strings (like English words).
>+     */
>+#ifndef VALGRIND
>+
>+    switch(length)
>+    {
>+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
>+    case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
>+    case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
>+    case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
>+    case 8 : b+=k[1]; a+=k[0]; break;
>+    case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
>+    case 6 : b+=k[1]&0xffff; a+=k[0]; break;
>+    case 5 : b+=k[1]&0xff; a+=k[0]; break;
>+    case 4 : a+=k[0]; break;
>+    case 3 : a+=k[0]&0xffffff; break;
>+    case 2 : a+=k[0]&0xffff; break;
>+    case 1 : a+=k[0]&0xff; break;
>+    case 0 : return c;              /* zero length strings require no mixing */
>+    }
>+
>+#else /* make valgrind happy */
>+
>+    k8 = (const uint8_t *)k;
>+    switch(length)
>+    {
>+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
>+    case 11: c+=((uint32_t)k8[10])<<16;  /* fall through */
>+    case 10: c+=((uint32_t)k8[9])<<8;    /* fall through */
>+    case 9 : c+=k8[8];                   /* fall through */
>+    case 8 : b+=k[1]; a+=k[0]; break;
>+    case 7 : b+=((uint32_t)k8[6])<<16;   /* fall through */
>+    case 6 : b+=((uint32_t)k8[5])<<8;    /* fall through */
>+    case 5 : b+=k8[4];                   /* fall through */
>+    case 4 : a+=k[0]; break;
>+    case 3 : a+=((uint32_t)k8[2])<<16;   /* fall through */
>+    case 2 : a+=((uint32_t)k8[1])<<8;    /* fall through */
>+    case 1 : a+=k8[0]; break;
>+    case 0 : return c;
>+    }
>+
>+#endif /* !valgrind */
>+
>+  } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
>+    const uint16_t *k = (const uint16_t *)key;         /* read 16-bit chunks */
>+    const uint8_t  *k8;
>+
>+    /*--------------- all but last block: aligned reads and different mixing */
>+    while (length > 12)
>+    {
>+      a += k[0] + (((uint32_t)k[1])<<16);
>+      b += k[2] + (((uint32_t)k[3])<<16);
>+      c += k[4] + (((uint32_t)k[5])<<16);
>+      mix(a,b,c);
>+      length -= 12;
>+      k += 6;
>+    }
>+
>+    /*----------------------------- handle the last (probably partial) block */
>+    k8 = (const uint8_t *)k;
>+    switch(length)
>+    {
>+    case 12: c+=k[4]+(((uint32_t)k[5])<<16);
>+             b+=k[2]+(((uint32_t)k[3])<<16);
>+             a+=k[0]+(((uint32_t)k[1])<<16);
>+             break;
>+    case 11: c+=((uint32_t)k8[10])<<16;     /* fall through */
>+    case 10: c+=k[4];
>+             b+=k[2]+(((uint32_t)k[3])<<16);
>+             a+=k[0]+(((uint32_t)k[1])<<16);
>+             break;
>+    case 9 : c+=k8[8];                      /* fall through */
>+    case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
>+             a+=k[0]+(((uint32_t)k[1])<<16);
>+             break;
>+    case 7 : b+=((uint32_t)k8[6])<<16;      /* fall through */
>+    case 6 : b+=k[2];
>+             a+=k[0]+(((uint32_t)k[1])<<16);
>+             break;
>+    case 5 : b+=k8[4];                      /* fall through */
>+    case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
>+             break;
>+    case 3 : a+=((uint32_t)k8[2])<<16;      /* fall through */
>+    case 2 : a+=k[0];
>+             break;
>+    case 1 : a+=k8[0];
>+             break;
>+    case 0 : return c;                     /* zero length requires no mixing */
>+    }
>+
>+  } else {                        /* need to read the key one byte at a time */
>+    const uint8_t *k = (const uint8_t *)key;
>+
>+    /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
>+    while (length > 12)
>+    {
>+      a += k[0];
>+      a += ((uint32_t)k[1])<<8;
>+      a += ((uint32_t)k[2])<<16;
>+      a += ((uint32_t)k[3])<<24;
>+      b += k[4];
>+      b += ((uint32_t)k[5])<<8;
>+      b += ((uint32_t)k[6])<<16;
>+      b += ((uint32_t)k[7])<<24;
>+      c += k[8];
>+      c += ((uint32_t)k[9])<<8;
>+      c += ((uint32_t)k[10])<<16;
>+      c += ((uint32_t)k[11])<<24;
>+      mix(a,b,c);
>+      length -= 12;
>+      k += 12;
>+    }
>+
>+    /*-------------------------------- last block: affect all 32 bits of (c) */
>+    switch(length)                   /* all the case statements fall through */
>+    {
>+    case 12: c+=((uint32_t)k[11])<<24;
>+    case 11: c+=((uint32_t)k[10])<<16;
>+    case 10: c+=((uint32_t)k[9])<<8;
>+    case 9 : c+=k[8];
>+    case 8 : b+=((uint32_t)k[7])<<24;
>+    case 7 : b+=((uint32_t)k[6])<<16;
>+    case 6 : b+=((uint32_t)k[5])<<8;
>+    case 5 : b+=k[4];
>+    case 4 : a+=((uint32_t)k[3])<<24;
>+    case 3 : a+=((uint32_t)k[2])<<16;
>+    case 2 : a+=((uint32_t)k[1])<<8;
>+    case 1 : a+=k[0];
>+             break;
>+    case 0 : return c;
>+    }
>+  }
>+
>+  final(a,b,c);
>+  return c;
>+}
>+
>+unsigned int tdb_jenkins_hash(TDB_DATA *key)
>+{
>+	return hashlittle(key->dptr, key->dsize);
>+}
>--- samba-3.5.4~dfsg.orig/source3/lib/util.c
>+++ samba-3.5.4~dfsg/source3/lib/util.c
>@@ -1997,17 +1997,8 @@ const char *tab_depth(int level, int dep
> 
> int str_checksum(const char *s)
> {
>-	int res = 0;
>-	int c;
>-	int i=0;
>-
>-	while(*s) {
>-		c = *s;
>-		res ^= (c << (i % 15)) ^ (c >> (15-(i%15)));
>-		s++;
>-		i++;
>-	}
>-	return(res);
>+	TDB_DATA key = string_tdb_data(s);
>+	return tdb_jenkins_hash(&key);
> }
> 
> /*****************************************************************
>--- samba-3.5.4~dfsg.orig/source3/include/proto.h
>+++ samba-3.5.4~dfsg/source3/include/proto.h
>@@ -1179,6 +1179,7 @@ void set_remote_arch(enum remote_arch_ty
> enum remote_arch_types get_remote_arch(void);
> const char *tab_depth(int level, int depth);
> int str_checksum(const char *s);
>+unsigned int tdb_jenkins_hash(TDB_DATA *key);
> void zero_free(void *p, size_t size);
> int set_maxfiles(int requested_max);
> int smb_mkstemp(char *name_template);
>
>

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Attachments on bug 8010: 6290 | 6291 | 6293 | 6295 | 6297