X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Fobdclass%2Fmea.c;h=15f15d895ce2e3059efbde90a34a14e4ae32a3f1;hb=6957329b064f72db289ae93d0a7776cb9faa3961;hp=fa9ce2aa7ba4253e928135b07f5d6fc4e6f2472e;hpb=fc4de168e941017bce61765080c15982cb33dd88;p=fs%2Flustre-release.git

diff --git a/lustre/obdclass/mea.c b/lustre/obdclass/mea.c
index fa9ce2a..15f15d8 100644
--- a/lustre/obdclass/mea.c
+++ b/lustre/obdclass/mea.c
@@ -20,57 +20,162 @@
  */
 
 #define DEBUG_SUBSYSTEM S_CLASS
+#include <obd_class.h>
 #ifdef __KERNEL__
 #include <linux/kmod.h>   /* for request_module() */
 #include <linux/module.h>
-#include <linux/obd_class.h>
 #include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/pagemap.h>
-#else 
+#else
 #include <liblustre.h>
-#include <linux/obd_class.h>
-#include <linux/obd.h>
+#include <obd.h>
 #endif
-#include <linux/lprocfs_status.h>
+#include <lprocfs_status.h>
+#include <lustre/lustre_idl.h>
 
-
-int mea_name2idx(struct mea *mea, char *name, int namelen)
+#ifdef __KERNEL__
+#include <linux/jbd.h>
+#ifdef HAVE_SERVER_SUPPORT
+/* LDISKFS_SB() */
+#include <linux/ldiskfs_fs.h>
+#endif
+#endif
+static int mea_last_char_hash(int count, char *name, int namelen)
 {
         unsigned int c;
 
-	/* just to simplify caller code */
-       	if (mea == NULL)
-		return 0;
-
-        if (mea->mea_count == 0)
-                return 0;
-
-        /* FIXME: real hash calculation here */
         c = name[namelen - 1];
         if (c == 0)
                 CWARN("looks like wrong len is passed\n");
-        c = c % mea->mea_count;
-	
-	LASSERT(c < mea->mea_count);
+        c = c % count;
         return c;
 }
 
-int raw_name2idx(int count, const char *name, int namelen)
+static int mea_all_chars_hash(int count, char *name, int namelen)
 {
-        unsigned int c;
+        unsigned int c = 0;
+
+        while (--namelen >= 0)
+                c += name[namelen];
+        c = c % count;
+        return c;
+}
+
+#ifdef __KERNEL__
+/* This hash calculate method must be same as the lvar hash method */
+
+#define LVAR_HASH_SANDWICH  (0)
+#define LVAR_HASH_TEA       (1)
+#define LVAR_HASH_R5        (0)
+#define LVAR_HASH_PREFIX    (0)
+
+static __u32 hash_build0(const char *name, int namelen)
+{
+        __u32 result;
+
+        if (namelen == 0)
+                return 0;
+        if (strncmp(name, ".", 1) == 0 && namelen == 1)
+                return 1;
+        if (strncmp(name, "..", 2) == 0 && namelen == 2)
+                return 2;
+
+        if (LVAR_HASH_PREFIX) {
+                result = 0;
+                strncpy((void *)&result,
+                        name, min(namelen, (int)sizeof result));
+        } else {
+                struct ldiskfs_dx_hash_info hinfo;
+
+                if (LVAR_HASH_TEA)
+                        hinfo.hash_version = LDISKFS_DX_HASH_TEA;
+                else
+                        hinfo.hash_version = LDISKFS_DX_HASH_R5;
+                hinfo.seed = 0;
+                ldiskfsfs_dirhash(name, namelen, &hinfo);
+                result = hinfo.hash;
+                if (LVAR_HASH_SANDWICH) {
+                        __u32 result2;
+
+                        hinfo.hash_version = LDISKFS_DX_HASH_TEA;
+                        hinfo.seed = 0;
+                        ldiskfsfs_dirhash(name, namelen, &hinfo);
+                        result2 = hinfo.hash;
+                        result = (0xfc000000 & result2) | (0x03ffffff & result);
+                }
+        }
+
+        return result;
+}
+
+enum {
+        HASH_GRAY_AREA = 1024
+};
+
+static __u32 hash_build(const char *name, int namelen)
+{
+        __u32 hash;
+
+        hash = (hash_build0(name, namelen) << 1) & MAX_HASH_SIZE;
+        if (hash > MAX_HASH_SIZE - HASH_GRAY_AREA)
+                hash &= HASH_GRAY_AREA - 1;
+        return hash;
+}
+
+static int mea_hash_segment(int count, const char *name, int namelen)
+{
+        __u32 hash;
+
+        LASSERT(IS_PO2(MAX_HASH_SIZE + 1));
+
+        hash = hash_build(name, namelen) / (MAX_HASH_SIZE / count);
+        LASSERTF(hash < count, "hash %x count %d \n", hash, count);
+
+        return hash;
+}
+#else
+static int mea_hash_segment(int count, char *name, int namelen)
+{
+#warning "fix for liblustre"
+        return 0;
+}
+#endif
+int raw_name2idx(int hashtype, int count, const char *name, int namelen)
+{
+        unsigned int c = 0;
 
         LASSERT(namelen > 0);
         if (count <= 1)
                 return 0;
 
-
-        /* FIXME: real hash calculation here */
-        c = name[namelen - 1];
-        if (c == 0)
-                CWARN("looks like wrong len is passed\n");
-        c = c % count;
+        switch (hashtype) {
+                case MEA_MAGIC_LAST_CHAR:
+                        c = mea_last_char_hash(count, (char *)name, namelen);
+                        break;
+                case MEA_MAGIC_ALL_CHARS:
+                        c = mea_all_chars_hash(count, (char *)name, namelen);
+                        break;
+                case MEA_MAGIC_HASH_SEGMENT:
+                        c = mea_hash_segment(count, (char *)name, namelen);
+                        break;
+                default:
+                        CERROR("Unknown hash type 0x%x\n", hashtype);
+        }
 	
+        LASSERT(c < count);
+        return c;
+}
+
+int mea_name2idx(struct lmv_stripe_md *mea, const char *name, int namelen)
+{
+        unsigned int c;
+
+        LASSERT(mea && mea->mea_count);
+
+	c = raw_name2idx(mea->mea_magic, mea->mea_count, name, namelen);
+
+        LASSERT(c < mea->mea_count);
         return c;
 }