LU-3345 llapi: add user space method for lov_user_md

[fs/lustre-release.git] / lustre / include / obd_lov.h

diff --git a/lustre/include/obd_lov.h b/lustre/include/obd_lov.h
index 9983197..dfb2631 100644 (file)
--- a/lustre/include/obd_lov.h
+++ b/lustre/include/obd_lov.h
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
@@ -16,8 +14,8 @@
  * in the LICENSE file that accompanied this code).
  *
  * You should have received a copy of the GNU General Public License
- * version 2 along with this program; If not, see [sun.com URL with a
- * copy of GPLv2].
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
@@ -26,8 +24,10 @@
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2012, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -37,18 +37,74 @@
 #ifndef _OBD_LOV_H__
 #define _OBD_LOV_H__
 
-static inline int lov_stripe_md_size(int stripes)
+#define LOV_DEFAULT_STRIPE_SIZE (1 << LNET_MTU_BITS)
+
+static inline int lov_stripe_md_size(__u16 stripes)
 {
         return sizeof(struct lov_stripe_md) + stripes*sizeof(struct lov_oinfo*);
 }
 
-#define lov_mds_md_size(stripes) lov_mds_md_v1_size(stripes)
-static inline int lov_mds_md_v1_size(int stripes)
+struct lov_version_size {
+        __u32   lvs_magic;
+        size_t  lvs_lmm_size;
+        size_t  lvs_lod_size;
+};
+
+static inline __u32 lov_mds_md_stripecnt(int ea_size, __u32 lmm_magic)
 {
-        return sizeof(struct lov_mds_md_v1) +
-                stripes * sizeof(struct lov_ost_data_v1);
+        static const struct lov_version_size lmm_ver_size[] = {
+                        { .lvs_magic = LOV_MAGIC_V3,
+                          .lvs_lmm_size = sizeof(struct lov_mds_md_v3),
+                          .lvs_lod_size = sizeof(struct lov_ost_data_v1) },
+                        { .lvs_magic = LOV_MAGIC_V1,
+                          .lvs_lmm_size = sizeof(struct lov_mds_md_v1),
+                          .lvs_lod_size = sizeof(struct lov_ost_data_v1)} };
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(lmm_ver_size); i++) {
+                if (lmm_magic == lmm_ver_size[i].lvs_magic) {
+                        if (ea_size <= lmm_ver_size[i].lvs_lmm_size)
+                                return 0;
+                        return (ea_size - lmm_ver_size[i].lvs_lmm_size) /
+                                lmm_ver_size[i].lvs_lod_size;
+                }
+        }
+
+        /* Invalid LOV magic, so no stripes could fit */
+        return 0;
 }
 
+/* lov_do_div64(a, b) returns a % b, and a = a / b.
+ * The 32-bit code is LOV-specific due to knowing about stripe limits in
+ * order to reduce the divisor to a 32-bit number.  If the divisor is
+ * already a 32-bit value the compiler handles this directly. */
+#if BITS_PER_LONG > 32
+# define lov_do_div64(n,base) ({                                       \
+       uint64_t __base = (base);                                       \
+       uint64_t __rem;                                                 \
+       __rem = ((uint64_t)(n)) % __base;                               \
+       (n) = ((uint64_t)(n)) / __base;                                 \
+       __rem;                                                          \
+  })
+#else
+# define lov_do_div64(n,base) ({                                       \
+       uint64_t __rem;                                                 \
+       if ((sizeof(base) > 4) && (((base) & 0xffffffff00000000ULL) != 0)) {  \
+               int __remainder;                                              \
+               LASSERTF(!((base) & (LOV_MIN_STRIPE_SIZE - 1)), "64 bit lov " \
+                        "division %llu / %llu\n", (n), (uint64_t)(base));    \
+               __remainder = (n) & (LOV_MIN_STRIPE_SIZE - 1);          \
+               (n) >>= LOV_MIN_STRIPE_BITS;                            \
+               __rem = do_div(n, (base) >> LOV_MIN_STRIPE_BITS);       \
+               __rem <<= LOV_MIN_STRIPE_BITS;                          \
+               __rem += __remainder;                                   \
+       } else {                                                        \
+               __rem = do_div(n, base);                                \
+       }                                                               \
+       __rem;                                                          \
+  })
+#endif
+
 #define IOC_LOV_TYPE                   'g'
 #define IOC_LOV_MIN_NR                 50
 #define IOC_LOV_SET_OSC_ACTIVE         _IOWR('g', 50, long)