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.
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"