summaryrefslogtreecommitdiffstats
path: root/fs/ceph/ceph_fs.c
diff options
context:
space:
mode:
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 /fs/ceph/ceph_fs.c
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>
Diffstat (limited to 'fs/ceph/ceph_fs.c')
-rw-r--r--fs/ceph/ceph_fs.c77
1 files changed, 0 insertions, 77 deletions
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;
-}
-