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authorSage Weil <sage@newdream.net>2009-11-07 06:55:25 +0100
committerSage Weil <sage@newdream.net>2009-11-07 06:55:25 +0100
commit1654dd0cf5ee1827322aca156af7d96d757201c7 (patch)
treeba71b1a1e214b929937f02a1794b3d32b8ff1342
parentceph: use strong hash function for mapping objects to pgs (diff)
downloadlinux-1654dd0cf5ee1827322aca156af7d96d757201c7.tar.xz
linux-1654dd0cf5ee1827322aca156af7d96d757201c7.zip
ceph: make object hash a pg_pool property
The object will be hashed to a placement seed (ps) based on the pg_pool's hash function. This allows new hashes to be introduced into an existing object store, or selection of a hash appropriate to the objects that will be stored in a particular pool. Signed-off-by: Sage Weil <sage@newdream.net>
-rw-r--r--fs/ceph/Makefile2
-rw-r--r--fs/ceph/README2
-rw-r--r--fs/ceph/ceph_fs.c77
-rw-r--r--fs/ceph/ceph_fs.h2
-rw-r--r--fs/ceph/ceph_hash.c118
-rw-r--r--fs/ceph/ceph_hash.h13
-rw-r--r--fs/ceph/osdmap.c2
-rw-r--r--fs/ceph/rados.h1
-rw-r--r--fs/ceph/types.h1
9 files changed, 137 insertions, 81 deletions
diff --git a/fs/ceph/Makefile b/fs/ceph/Makefile
index 8bad70aac363..bdd3e6fc1609 100644
--- a/fs/ceph/Makefile
+++ b/fs/ceph/Makefile
@@ -13,7 +13,7 @@ ceph-objs := super.o inode.o dir.o file.o addr.o ioctl.o \
mon_client.o \
osd_client.o osdmap.o crush/crush.o crush/mapper.o crush/hash.o \
debugfs.o \
- ceph_fs.o ceph_strings.o ceph_frag.o
+ ceph_fs.o ceph_strings.o ceph_hash.o ceph_frag.o
else
#Otherwise we were called directly from the command
diff --git a/fs/ceph/README b/fs/ceph/README
index 660e00074d59..18352fab37c0 100644
--- a/fs/ceph/README
+++ b/fs/ceph/README
@@ -10,6 +10,8 @@ src/include/rados.h fs/ceph/rados.h
src/include/ceph_strings.cc fs/ceph/ceph_strings.c
src/include/ceph_frag.h fs/ceph/ceph_frag.h
src/include/ceph_frag.cc fs/ceph/ceph_frag.c
+src/include/ceph_hash.h fs/ceph/ceph_hash.h
+src/include/ceph_hash.cc fs/ceph/ceph_hash.c
src/crush/crush.c fs/ceph/crush/crush.c
src/crush/crush.h fs/ceph/crush/crush.h
src/crush/mapper.c fs/ceph/crush/mapper.c
diff --git a/fs/ceph/ceph_fs.c b/fs/ceph/ceph_fs.c
index b3ecf1b07521..79d76bc4303f 100644
--- a/fs/ceph/ceph_fs.c
+++ b/fs/ceph/ceph_fs.c
@@ -72,80 +72,3 @@ int ceph_caps_for_mode(int mode)
}
return 0;
}
-
-/*
- * Robert Jenkin's hash function.
- * http://burtleburtle.net/bob/hash/evahash.html
- * This is in the public domain.
- */
-#define mix(a, b, c) \
- do { \
- a = a - b; a = a - c; a = a ^ (c >> 13); \
- b = b - c; b = b - a; b = b ^ (a << 8); \
- c = c - a; c = c - b; c = c ^ (b >> 13); \
- a = a - b; a = a - c; a = a ^ (c >> 12); \
- b = b - c; b = b - a; b = b ^ (a << 16); \
- c = c - a; c = c - b; c = c ^ (b >> 5); \
- a = a - b; a = a - c; a = a ^ (c >> 3); \
- b = b - c; b = b - a; b = b ^ (a << 10); \
- c = c - a; c = c - b; c = c ^ (b >> 15); \
- } while (0)
-
-unsigned int ceph_full_name_hash(const char *str, unsigned int length)
-{
- const unsigned char *k = (const unsigned char *)str;
- __u32 a, b, c; /* the internal state */
- __u32 len; /* how many key bytes still need mixing */
-
- /* Set up the internal state */
- len = length;
- a = 0x9e3779b9; /* the golden ratio; an arbitrary value */
- b = a;
- c = 0; /* variable initialization of internal state */
-
- /* handle most of the key */
- while (len >= 12) {
- a = a + (k[0] + ((__u32)k[1] << 8) + ((__u32)k[2] << 16) +
- ((__u32)k[3] << 24));
- b = b + (k[4] + ((__u32)k[5] << 8) + ((__u32)k[6] << 16) +
- ((__u32)k[7] << 24));
- c = c + (k[8] + ((__u32)k[9] << 8) + ((__u32)k[10] << 16) +
- ((__u32)k[11] << 24));
- mix(a, b, c);
- k = k + 12;
- len = len - 12;
- }
-
- /* handle the last 11 bytes */
- c = c + length;
- switch (len) { /* all the case statements fall through */
- case 11:
- c = c + ((__u32)k[10] << 24);
- case 10:
- c = c + ((__u32)k[9] << 16);
- case 9:
- c = c + ((__u32)k[8] << 8);
- /* the first byte of c is reserved for the length */
- case 8:
- b = b + ((__u32)k[7] << 24);
- case 7:
- b = b + ((__u32)k[6] << 16);
- case 6:
- b = b + ((__u32)k[5] << 8);
- case 5:
- b = b + k[4];
- case 4:
- a = a + ((__u32)k[3] << 24);
- case 3:
- a = a + ((__u32)k[2] << 16);
- case 2:
- a = a + ((__u32)k[1] << 8);
- case 1:
- a = a + k[0];
- /* case 0: nothing left to add */
- }
- mix(a, b, c);
-
- return c;
-}
-
diff --git a/fs/ceph/ceph_fs.h b/fs/ceph/ceph_fs.h
index 25fc537f4140..36becb024788 100644
--- a/fs/ceph/ceph_fs.h
+++ b/fs/ceph/ceph_fs.h
@@ -49,8 +49,6 @@
#define CEPH_MAX_MON 31
-unsigned int ceph_full_name_hash(const char *name, unsigned int len);
-
/*
* ceph_file_layout - describe data layout for a file/inode
diff --git a/fs/ceph/ceph_hash.c b/fs/ceph/ceph_hash.c
new file mode 100644
index 000000000000..ac8be54631fe
--- /dev/null
+++ b/fs/ceph/ceph_hash.c
@@ -0,0 +1,118 @@
+
+#include "types.h"
+
+/*
+ * Robert Jenkin's hash function.
+ * http://burtleburtle.net/bob/hash/evahash.html
+ * This is in the public domain.
+ */
+#define mix(a, b, c) \
+ do { \
+ a = a - b; a = a - c; a = a ^ (c >> 13); \
+ b = b - c; b = b - a; b = b ^ (a << 8); \
+ c = c - a; c = c - b; c = c ^ (b >> 13); \
+ a = a - b; a = a - c; a = a ^ (c >> 12); \
+ b = b - c; b = b - a; b = b ^ (a << 16); \
+ c = c - a; c = c - b; c = c ^ (b >> 5); \
+ a = a - b; a = a - c; a = a ^ (c >> 3); \
+ b = b - c; b = b - a; b = b ^ (a << 10); \
+ c = c - a; c = c - b; c = c ^ (b >> 15); \
+ } while (0)
+
+unsigned ceph_str_hash_rjenkins(const char *str, unsigned length)
+{
+ const unsigned char *k = (const unsigned char *)str;
+ __u32 a, b, c; /* the internal state */
+ __u32 len; /* how many key bytes still need mixing */
+
+ /* Set up the internal state */
+ len = length;
+ a = 0x9e3779b9; /* the golden ratio; an arbitrary value */
+ b = a;
+ c = 0; /* variable initialization of internal state */
+
+ /* handle most of the key */
+ while (len >= 12) {
+ a = a + (k[0] + ((__u32)k[1] << 8) + ((__u32)k[2] << 16) +
+ ((__u32)k[3] << 24));
+ b = b + (k[4] + ((__u32)k[5] << 8) + ((__u32)k[6] << 16) +
+ ((__u32)k[7] << 24));
+ c = c + (k[8] + ((__u32)k[9] << 8) + ((__u32)k[10] << 16) +
+ ((__u32)k[11] << 24));
+ mix(a, b, c);
+ k = k + 12;
+ len = len - 12;
+ }
+
+ /* handle the last 11 bytes */
+ c = c + length;
+ switch (len) { /* all the case statements fall through */
+ case 11:
+ c = c + ((__u32)k[10] << 24);
+ case 10:
+ c = c + ((__u32)k[9] << 16);
+ case 9:
+ c = c + ((__u32)k[8] << 8);
+ /* the first byte of c is reserved for the length */
+ case 8:
+ b = b + ((__u32)k[7] << 24);
+ case 7:
+ b = b + ((__u32)k[6] << 16);
+ case 6:
+ b = b + ((__u32)k[5] << 8);
+ case 5:
+ b = b + k[4];
+ case 4:
+ a = a + ((__u32)k[3] << 24);
+ case 3:
+ a = a + ((__u32)k[2] << 16);
+ case 2:
+ a = a + ((__u32)k[1] << 8);
+ case 1:
+ a = a + k[0];
+ /* case 0: nothing left to add */
+ }
+ mix(a, b, c);
+
+ return c;
+}
+
+/*
+ * linux dcache hash
+ */
+unsigned ceph_str_hash_linux(const char *str, unsigned length)
+{
+ unsigned long hash = 0;
+ unsigned char c;
+
+ while (length-- > 0) {
+ c = *str++;
+ hash = (hash + (c << 4) + (c >> 4)) * 11;
+ }
+ return hash;
+}
+
+
+unsigned ceph_str_hash(int type, const char *s, unsigned len)
+{
+ switch (type) {
+ case CEPH_STR_HASH_LINUX:
+ return ceph_str_hash_linux(s, len);
+ case CEPH_STR_HASH_RJENKINS:
+ return ceph_str_hash_rjenkins(s, len);
+ default:
+ return -1;
+ }
+}
+
+const char *ceph_str_hash_name(int type)
+{
+ switch (type) {
+ case CEPH_STR_HASH_LINUX:
+ return "linux";
+ case CEPH_STR_HASH_RJENKINS:
+ return "rjenkins";
+ default:
+ return "unknown";
+ }
+}
diff --git a/fs/ceph/ceph_hash.h b/fs/ceph/ceph_hash.h
new file mode 100644
index 000000000000..5ac470c433c9
--- /dev/null
+++ b/fs/ceph/ceph_hash.h
@@ -0,0 +1,13 @@
+#ifndef _FS_CEPH_HASH_H
+#define _FS_CEPH_HASH_H
+
+#define CEPH_STR_HASH_LINUX 0x1 /* linux dcache hash */
+#define CEPH_STR_HASH_RJENKINS 0x2 /* robert jenkins' */
+
+extern unsigned ceph_str_hash_linux(const char *s, unsigned len);
+extern unsigned ceph_str_hash_rjenkins(const char *s, unsigned len);
+
+extern unsigned ceph_str_hash(int type, const char *s, unsigned len);
+extern const char *ceph_str_hash_name(int type);
+
+#endif
diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index a025555b70af..68478270ad70 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -809,7 +809,7 @@ int ceph_calc_object_layout(struct ceph_object_layout *ol,
return -EIO;
pool = &osdmap->pg_pool[poolid];
- ps = ceph_full_name_hash(oid, strlen(oid));
+ ps = ceph_str_hash(pool->v.object_hash, oid, strlen(oid));
if (preferred >= 0) {
ps += preferred;
num = le32_to_cpu(pool->v.lpg_num);
diff --git a/fs/ceph/rados.h b/fs/ceph/rados.h
index 85bdef78d142..fb23ff9297c9 100644
--- a/fs/ceph/rados.h
+++ b/fs/ceph/rados.h
@@ -84,6 +84,7 @@ struct ceph_pg_pool {
__u8 type; /* CEPH_PG_TYPE_* */
__u8 size; /* number of osds in each pg */
__u8 crush_ruleset; /* crush placement rule */
+ __u8 object_hash; /* hash mapping object name to ps */
__le32 pg_num, pgp_num; /* number of pg's */
__le32 lpg_num, lpgp_num; /* number of localized pg's */
__le32 last_change; /* most recent epoch changed */
diff --git a/fs/ceph/types.h b/fs/ceph/types.h
index 8a514568cab2..28b35a005ec2 100644
--- a/fs/ceph/types.h
+++ b/fs/ceph/types.h
@@ -9,6 +9,7 @@
#include "ceph_fs.h"
#include "ceph_frag.h"
+#include "ceph_hash.h"
/*
* Identify inodes by both their ino AND snapshot id (a u64).