diff options
author | Yehuda Sadeh <yehuda@hq.newdream.net> | 2010-04-06 15:14:15 -0700 |
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committer | Sage Weil <sage@newdream.net> | 2010-10-20 15:37:28 -0700 |
commit | 3d14c5d2b6e15c21d8e5467dc62d33127c23a644 (patch) | |
tree | 7d123c47847df9d1e865b6b78dc7da3fe739b704 /net/ceph/crush/hash.c | |
parent | ae1533b62b3369e6ae32338f4a77d64d0e88f676 (diff) |
ceph: factor out libceph from Ceph file system
This factors out protocol and low-level storage parts of ceph into a
separate libceph module living in net/ceph and include/linux/ceph. This
is mostly a matter of moving files around. However, a few key pieces
of the interface change as well:
- ceph_client becomes ceph_fs_client and ceph_client, where the latter
captures the mon and osd clients, and the fs_client gets the mds client
and file system specific pieces.
- Mount option parsing and debugfs setup is correspondingly broken into
two pieces.
- The mon client gets a generic handler callback for otherwise unknown
messages (mds map, in this case).
- The basic supported/required feature bits can be expanded (and are by
ceph_fs_client).
No functional change, aside from some subtle error handling cases that got
cleaned up in the refactoring process.
Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'net/ceph/crush/hash.c')
-rw-r--r-- | net/ceph/crush/hash.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/net/ceph/crush/hash.c b/net/ceph/crush/hash.c new file mode 100644 index 000000000000..5bb63e37a8a1 --- /dev/null +++ b/net/ceph/crush/hash.c @@ -0,0 +1,149 @@ + +#include <linux/types.h> +#include <linux/crush/hash.h> + +/* + * Robert Jenkins' function for mixing 32-bit values + * http://burtleburtle.net/bob/hash/evahash.html + * a, b = random bits, c = input and output + */ +#define crush_hashmix(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) + +#define crush_hash_seed 1315423911 + +static __u32 crush_hash32_rjenkins1(__u32 a) +{ + __u32 hash = crush_hash_seed ^ a; + __u32 b = a; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(b, x, hash); + crush_hashmix(y, a, hash); + return hash; +} + +static __u32 crush_hash32_rjenkins1_2(__u32 a, __u32 b) +{ + __u32 hash = crush_hash_seed ^ a ^ b; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(x, a, hash); + crush_hashmix(b, y, hash); + return hash; +} + +static __u32 crush_hash32_rjenkins1_3(__u32 a, __u32 b, __u32 c) +{ + __u32 hash = crush_hash_seed ^ a ^ b ^ c; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(c, x, hash); + crush_hashmix(y, a, hash); + crush_hashmix(b, x, hash); + crush_hashmix(y, c, hash); + return hash; +} + +static __u32 crush_hash32_rjenkins1_4(__u32 a, __u32 b, __u32 c, __u32 d) +{ + __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(c, d, hash); + crush_hashmix(a, x, hash); + crush_hashmix(y, b, hash); + crush_hashmix(c, x, hash); + crush_hashmix(y, d, hash); + return hash; +} + +static __u32 crush_hash32_rjenkins1_5(__u32 a, __u32 b, __u32 c, __u32 d, + __u32 e) +{ + __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d ^ e; + __u32 x = 231232; + __u32 y = 1232; + crush_hashmix(a, b, hash); + crush_hashmix(c, d, hash); + crush_hashmix(e, x, hash); + crush_hashmix(y, a, hash); + crush_hashmix(b, x, hash); + crush_hashmix(y, c, hash); + crush_hashmix(d, x, hash); + crush_hashmix(y, e, hash); + return hash; +} + + +__u32 crush_hash32(int type, __u32 a) +{ + switch (type) { + case CRUSH_HASH_RJENKINS1: + return crush_hash32_rjenkins1(a); + default: + return 0; + } +} + +__u32 crush_hash32_2(int type, __u32 a, __u32 b) +{ + switch (type) { + case CRUSH_HASH_RJENKINS1: + return crush_hash32_rjenkins1_2(a, b); + default: + return 0; + } +} + +__u32 crush_hash32_3(int type, __u32 a, __u32 b, __u32 c) +{ + switch (type) { + case CRUSH_HASH_RJENKINS1: + return crush_hash32_rjenkins1_3(a, b, c); + default: + return 0; + } +} + +__u32 crush_hash32_4(int type, __u32 a, __u32 b, __u32 c, __u32 d) +{ + switch (type) { + case CRUSH_HASH_RJENKINS1: + return crush_hash32_rjenkins1_4(a, b, c, d); + default: + return 0; + } +} + +__u32 crush_hash32_5(int type, __u32 a, __u32 b, __u32 c, __u32 d, __u32 e) +{ + switch (type) { + case CRUSH_HASH_RJENKINS1: + return crush_hash32_rjenkins1_5(a, b, c, d, e); + default: + return 0; + } +} + +const char *crush_hash_name(int type) +{ + switch (type) { + case CRUSH_HASH_RJENKINS1: + return "rjenkins1"; + default: + return "unknown"; + } +} |