Generic wear-leveling algorithm (#16996)

* Initial import of wear-leveling algorithm.

* Alignment.

* Docs tweaks.

* Lock/unlock.

* Update quantum/wear_leveling/wear_leveling_internal.h

Co-authored-by: Stefan Kerkmann <karlk90@pm.me>

* More tests, fix issue with consolidation when unlocked.

* More tests.

* Review comments.

* Add plumbing for FNV1a.

* Another test checking that checksum mismatch clears the cache.

* Check that the write log still gets played back.

Co-authored-by: Stefan Kerkmann <karlk90@pm.me>

1 files changed, 249 insertions, 0 deletions

diff --git a/lib/fnv/fnv.h b/lib/fnv/fnv.h
new file mode 100644
index 0000000000..2083a4aa23
--- /dev/null
+++ b/lib/fnv/fnv.h
@@ -0,0 +1,249 @@
+/*
+ * fnv - Fowler/Noll/Vo- hash code
+ *
+ * @(#) $Revision: 5.4 $
+ * @(#) $Id: fnv.h,v 5.4 2009/07/30 22:49:13 chongo Exp $
+ * @(#) $Source: /usr/local/src/cmd/fnv/RCS/fnv.h,v $
+ *
+ ***
+ *
+ * Fowler/Noll/Vo- hash
+ *
+ * The basis of this hash algorithm was taken from an idea sent
+ * as reviewer comments to the IEEE POSIX P1003.2 committee by:
+ *
+ *      Phong Vo (http://www.research.att.com/info/kpv/)
+ *      Glenn Fowler (http://www.research.att.com/~gsf/)
+ *
+ * In a subsequent ballot round:
+ *
+ *      Landon Curt Noll (http://www.isthe.com/chongo/)
+ *
+ * improved on their algorithm.  Some people tried this hash
+ * and found that it worked rather well.  In an EMail message
+ * to Landon, they named it the ``Fowler/Noll/Vo'' or FNV hash.
+ *
+ * FNV hashes are designed to be fast while maintaining a low
+ * collision rate. The FNV speed allows one to quickly hash lots
+ * of data while maintaining a reasonable collision rate.  See:
+ *
+ *      http://www.isthe.com/chongo/tech/comp/fnv/index.html
+ *
+ * for more details as well as other forms of the FNV hash.
+ *
+ ***
+ *
+ * NOTE: The FNV-0 historic hash is not recommended.  One should use
+ *	 the FNV-1 hash instead.
+ *
+ * To use the 32 bit FNV-0 historic hash, pass FNV0_32_INIT as the
+ * Fnv32_t hashval argument to fnv_32_buf() or fnv_32_str().
+ *
+ * To use the 64 bit FNV-0 historic hash, pass FNV0_64_INIT as the
+ * Fnv64_t hashval argument to fnv_64_buf() or fnv_64_str().
+ *
+ * To use the recommended 32 bit FNV-1 hash, pass FNV1_32_INIT as the
+ * Fnv32_t hashval argument to fnv_32_buf() or fnv_32_str().
+ *
+ * To use the recommended 64 bit FNV-1 hash, pass FNV1_64_INIT as the
+ * Fnv64_t hashval argument to fnv_64_buf() or fnv_64_str().
+ *
+ * To use the recommended 32 bit FNV-1a hash, pass FNV1_32A_INIT as the
+ * Fnv32_t hashval argument to fnv_32a_buf() or fnv_32a_str().
+ *
+ * To use the recommended 64 bit FNV-1a hash, pass FNV1A_64_INIT as the
+ * Fnv64_t hashval argument to fnv_64a_buf() or fnv_64a_str().
+ *
+ ***
+ *
+ * Please do not copyright this code.  This code is in the public domain.
+ *
+ * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+ * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ *
+ * By:
+ *	chongo <Landon Curt Noll> /\oo/\
+ *      http://www.isthe.com/chongo/
+ *
+ * Share and Enjoy!	:-)
+ */
+
+#if !defined(__FNV_H__)
+#define __FNV_H__
+
+#include <sys/types.h>
+
+#define FNV_VERSION "5.0.2"	/* @(#) FNV Version */
+
+
+/*
+ * 32 bit FNV-0 hash type
+ */
+typedef u_int32_t Fnv32_t;
+
+
+/*
+ * 32 bit FNV-0 zero initial basis
+ *
+ * This historic hash is not recommended.  One should use
+ * the FNV-1 hash and initial basis instead.
+ */
+#define FNV0_32_INIT ((Fnv32_t)0)
+
+
+/*
+ * 32 bit FNV-1 and FNV-1a non-zero initial basis
+ *
+ * The FNV-1 initial basis is the FNV-0 hash of the following 32 octets:
+ *
+ *              chongo <Landon Curt Noll> /\../\
+ *
+ * NOTE: The \'s above are not back-slashing escape characters.
+ * They are literal ASCII  backslash 0x5c characters.
+ *
+ * NOTE: The FNV-1a initial basis is the same value as FNV-1 by definition.
+ */
+#define FNV1_32_INIT ((Fnv32_t)0x811c9dc5)
+#define FNV1_32A_INIT FNV1_32_INIT
+
+
+/*
+ * determine how 64 bit unsigned values are represented
+ */
+#include "longlong.h"
+
+
+/*
+ * 64 bit FNV-0 hash
+ */
+#if defined(HAVE_64BIT_LONG_LONG)
+typedef u_int64_t Fnv64_t;
+#else /* HAVE_64BIT_LONG_LONG */
+typedef struct {
+    u_int32_t w32[2]; /* w32[0] is low order, w32[1] is high order word */
+} Fnv64_t;
+#endif /* HAVE_64BIT_LONG_LONG */
+
+
+/*
+ * 64 bit FNV-0 zero initial basis
+ *
+ * This historic hash is not recommended.  One should use
+ * the FNV-1 hash and initial basis instead.
+ */
+#if defined(HAVE_64BIT_LONG_LONG)
+#define FNV0_64_INIT ((Fnv64_t)0)
+#else /* HAVE_64BIT_LONG_LONG */
+extern const Fnv64_t fnv0_64_init;
+#define FNV0_64_INIT (fnv0_64_init)
+#endif /* HAVE_64BIT_LONG_LONG */
+
+
+/*
+ * 64 bit FNV-1 non-zero initial basis
+ *
+ * The FNV-1 initial basis is the FNV-0 hash of the following 32 octets:
+ *
+ *              chongo <Landon Curt Noll> /\../\
+ *
+ * NOTE: The \'s above are not back-slashing escape characters.
+ * They are literal ASCII  backslash 0x5c characters.
+ *
+ * NOTE: The FNV-1a initial basis is the same value as FNV-1 by definition.
+ */
+#if defined(HAVE_64BIT_LONG_LONG)
+#define FNV1_64_INIT ((Fnv64_t)0xcbf29ce484222325ULL)
+#define FNV1A_64_INIT FNV1_64_INIT
+#else /* HAVE_64BIT_LONG_LONG */
+extern const fnv1_64_init;
+extern const Fnv64_t fnv1a_64_init;
+#define FNV1_64_INIT (fnv1_64_init)
+#define FNV1A_64_INIT (fnv1a_64_init)
+#endif /* HAVE_64BIT_LONG_LONG */
+
+
+/*
+ * hash types
+ */
+enum fnv_type {
+    FNV_NONE = 0,	/* invalid FNV hash type */
+    FNV0_32 = 1,	/* FNV-0 32 bit hash */
+    FNV1_32 = 2,	/* FNV-1 32 bit hash */
+    FNV1a_32 = 3,	/* FNV-1a 32 bit hash */
+    FNV0_64 = 4,	/* FNV-0 64 bit hash */
+    FNV1_64 = 5,	/* FNV-1 64 bit hash */
+    FNV1a_64 = 6,	/* FNV-1a 64 bit hash */
+};
+
+
+/*
+ * these test vectors are used as part o the FNV test suite
+ */
+struct test_vector {
+    void *buf;		/* start of test vector buffer */
+    int len;		/* length of test vector */
+};
+struct fnv0_32_test_vector {
+    struct test_vector *test;	/* test vector buffer to hash */
+    Fnv32_t fnv0_32;		/* expected FNV-0 32 bit hash value */
+};
+struct fnv1_32_test_vector {
+    struct test_vector *test;	/* test vector buffer to hash */
+    Fnv32_t fnv1_32;		/* expected FNV-1 32 bit hash value */
+};
+struct fnv1a_32_test_vector {
+    struct test_vector *test;	/* test vector buffer to hash */
+    Fnv32_t fnv1a_32;		/* expected FNV-1a 32 bit hash value */
+};
+struct fnv0_64_test_vector {
+    struct test_vector *test;	/* test vector buffer to hash */
+    Fnv64_t fnv0_64;		/* expected FNV-0 64 bit hash value */
+};
+struct fnv1_64_test_vector {
+    struct test_vector *test;	/* test vector buffer to hash */
+    Fnv64_t fnv1_64;		/* expected FNV-1 64 bit hash value */
+};
+struct fnv1a_64_test_vector {
+    struct test_vector *test;	/* test vector buffer to hash */
+    Fnv64_t fnv1a_64;		/* expected FNV-1a 64 bit hash value */
+};
+
+
+/*
+ * external functions
+ */
+/* hash_32.c */
+extern Fnv32_t fnv_32_buf(void *buf, size_t len, Fnv32_t hashval);
+extern Fnv32_t fnv_32_str(char *buf, Fnv32_t hashval);
+
+/* hash_32a.c */
+extern Fnv32_t fnv_32a_buf(void *buf, size_t len, Fnv32_t hashval);
+extern Fnv32_t fnv_32a_str(char *buf, Fnv32_t hashval);
+
+/* hash_64.c */
+extern Fnv64_t fnv_64_buf(void *buf, size_t len, Fnv64_t hashval);
+extern Fnv64_t fnv_64_str(char *buf, Fnv64_t hashval);
+
+/* hash_64a.c */
+extern Fnv64_t fnv_64a_buf(void *buf, size_t len, Fnv64_t hashval);
+extern Fnv64_t fnv_64a_str(char *buf, Fnv64_t hashval);
+
+/* test_fnv.c */
+extern struct test_vector fnv_test_str[];
+extern struct fnv0_32_test_vector fnv0_32_vector[];
+extern struct fnv1_32_test_vector fnv1_32_vector[];
+extern struct fnv1a_32_test_vector fnv1a_32_vector[];
+extern struct fnv0_64_test_vector fnv0_64_vector[];
+extern struct fnv1_64_test_vector fnv1_64_vector[];
+extern struct fnv1a_64_test_vector fnv1a_64_vector[];
+extern void unknown_hash_type(char *prog, enum fnv_type type, int code);
+extern void print_fnv32(Fnv32_t hval, Fnv32_t mask, int verbose, char *arg);
+extern void print_fnv64(Fnv64_t hval, Fnv64_t mask, int verbose, char *arg);
+
+
+#endif /* __FNV_H__ */