X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Finclude%2Flustre_fid.h;h=f31c4b5d27416882c6dfa4d7acd311b44b52dc66;hp=fa742e26725ccbb56d7ee611967fba621369efb9;hb=910f68d04916fece5b54137bf78535f5306289f8;hpb=2d8ad415e269efd618f96e24d48e75b8fd8da687

diff --git a/lustre/include/lustre_fid.h b/lustre/include/lustre_fid.h
index fa742e2..f31c4b5 100644
--- a/lustre/include/lustre_fid.h
+++ b/lustre/include/lustre_fid.h
@@ -67,17 +67,14 @@ extern const struct lu_fid LU_DOT_LUSTRE_FID;
 
 enum {
         /*
-         * This is how may FIDs may be allocated in one sequence. 16384 for
-         * now.
+         * This is how may FIDs may be allocated in one sequence(128k)
          */
-        LUSTRE_SEQ_MAX_WIDTH = 0x0000000000000400ULL,
+        LUSTRE_SEQ_MAX_WIDTH = 0x0000000000020000ULL,
 
         /*
-         * How many sequences may be allocate for meta-sequence (this is 128
-         * sequences).
+         * How many sequences to allocate to a client at once.
          */
-        /* changed to 16 to avoid overflow in test11 */
-        LUSTRE_SEQ_META_WIDTH = 0x0000000000000010ULL,
+        LUSTRE_SEQ_META_WIDTH = 0x0000000000000001ULL,
 
          /*
           * seq allocation pool size.
@@ -330,9 +327,59 @@ fid_build_pdo_res_name(const struct lu_fid *f,
         return name;
 }
 
+
+/**
+ * Flatten 128-bit FID values into a 64-bit value for
+ * use as an inode number.  For non-IGIF FIDs this
+ * starts just over 2^32, and continues without conflict
+ * until 2^64, at which point we wrap the high 32 bits
+ * of the SEQ into the range where there may not be many
+ * OID values in use, to minimize the risk of conflict.
+ *
+ * The time between re-used inode numbers is very long -
+ * 2^32 SEQ numbers, or about 2^32 client mounts. */
 static inline __u64 fid_flatten(const struct lu_fid *fid)
 {
-        return (fid_seq(fid) - 1) * LUSTRE_SEQ_MAX_WIDTH + fid_oid(fid);
+        __u64 ino;
+        __u64 seq;
+
+        if (fid_is_igif(fid)) {
+                ino = lu_igif_ino(fid);
+                RETURN(ino);
+        }
+
+        seq = fid_seq(fid);
+
+        ino = (seq << 24) + ((seq >> (64-8)) & 0xffffff0000ULL) + fid_oid(fid);
+
+        RETURN(ino ? ino : fid_oid(fid));
+}
+
+/**
+ * map fid to 32 bit value for ino on 32bit systems. */
+static inline __u32 fid_flatten32(const struct lu_fid *fid)
+{
+        __u32 ino;
+        __u64 seq;
+
+        if (fid_is_igif(fid)) {
+                ino = lu_igif_ino(fid);
+                RETURN(ino);
+        }
+
+        seq = fid_seq(fid) - FID_SEQ_START;
+
+	/*
+          map the high bits of the OID into higher bits of the inode number so that
+          inodes generated at about the same time have a reduced chance of collisions.
+          This will give a period of 1024 clients and 128 k = 128M inodes without collisions.
+	*/
+
+        ino = ((seq & 0x000fffffULL) << 12) + ((seq >> 8) & 0xfffff000) +
+               (seq >> (64 - (40-8)) & 0xffffff00) +
+               (fid_oid(fid) & 0xff000fff) + ((fid_oid(fid) & 0x00fff000) << 16);
+
+        RETURN(ino ? ino : fid_oid(fid));
 }
 
 #define LUSTRE_SEQ_SRV_NAME "seq_srv"