LU-12538 lod: Add missed qos_rr_init

[fs/lustre-release.git] / lustre / obdclass / lu_qos.c

diff --git a/lustre/obdclass/lu_qos.c b/lustre/obdclass/lu_qos.c
index 0e04bdd..f84954c 100644 (file)
--- a/lustre/obdclass/lu_qos.c
+++ b/lustre/obdclass/lu_qos.c
@@ -34,6 +34,7 @@
 
 #include <linux/module.h>
 #include <linux/list.h>
+#include <linux/random.h>
 #include <libcfs/libcfs.h>
 #include <libcfs/libcfs_hash.h> /* hash_long() */
 #include <libcfs/linux/linux-mem.h>
@@ -43,6 +44,13 @@
 #include <lustre_fid.h>
 #include <lu_object.h>
 
+void lu_qos_rr_init(struct lu_qos_rr *lqr)
+{
+       spin_lock_init(&lqr->lqr_alloc);
+       lqr->lqr_dirty = 1;
+}
+EXPORT_SYMBOL(lu_qos_rr_init);
+
 /**
  * Add a new target to Quality of Service (QoS) target table.
  *
@@ -166,3 +174,38 @@ out:
        RETURN(rc);
 }
 EXPORT_SYMBOL(lqos_del_tgt);
+
+/**
+ * lu_prandom_u64_max - returns a pseudo-random u64 number in interval
+ * [0, ep_ro)
+ *
+ * \param[in] ep_ro    right open interval endpoint
+ *
+ * \retval a pseudo-random 64-bit number that is in interval [0, ep_ro).
+ */
+u64 lu_prandom_u64_max(u64 ep_ro)
+{
+       u64 rand = 0;
+
+       if (ep_ro) {
+#if BITS_PER_LONG == 32
+               /*
+                * If ep_ro > 32-bit, first generate the high
+                * 32 bits of the random number, then add in the low
+                * 32 bits (truncated to the upper limit, if needed)
+                */
+               if (ep_ro > 0xffffffffULL)
+                       rand = prandom_u32_max((u32)(ep_ro >> 32)) << 32;
+
+               if (rand == (ep_ro & 0xffffffff00000000ULL))
+                       rand |= prandom_u32_max((u32)ep_ro);
+               else
+                       rand |= prandom_u32();
+#else
+               rand = ((u64)prandom_u32() << 32 | prandom_u32()) % ep_ro;
+#endif
+       }
+
+       return rand;
+}
+EXPORT_SYMBOL(lu_prandom_u64_max);