module/zfs/include/sys/sa_impl.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24
  25 #ifndef _SYS_SA_IMPL_H
  26 #define _SYS_SA_IMPL_H
  27
  28 #include <sys/dmu.h>
  29 #include <sys/refcount.h>
  30 #include <sys/list.h>
  31
  32 /*
  33  * Array of known attributes and their
  34  * various characteristics.
  35  */
  36 typedef struct sa_attr_table {
  37         sa_attr_type_t  sa_attr;
  38         uint8_t sa_registered;
  39         uint16_t sa_length;
  40         sa_bswap_type_t sa_byteswap;
  41         char *sa_name;
  42 } sa_attr_table_t;
  43
  44 /*
  45  * Zap attribute format for attribute registration
  46  *
  47  * 64      56      48      40      32      24      16      8       0
  48  * +-------+-------+-------+-------+-------+-------+-------+-------+
  49  * |        unused         |      len      | bswap |   attr num    |
  50  * +-------+-------+-------+-------+-------+-------+-------+-------+
  51  *
  52  * Zap attribute format for layout information.
  53  *
  54  * layout information is stored as an array of attribute numbers
  55  * The name of the attribute is the layout number (0, 1, 2, ...)
  56  *
  57  * 16       0
  58  * +---- ---+
  59  * | attr # |
  60  * +--------+
  61  * | attr # |
  62  * +--- ----+
  63  *  ......
  64  *
  65  */
  66
  67 #define ATTR_BSWAP(x)   BF32_GET(x, 16, 8)
  68 #define ATTR_LENGTH(x)  BF32_GET(x, 24, 16)
  69 #define ATTR_NUM(x)     BF32_GET(x, 0, 16)
  70 #define ATTR_ENCODE(x, attr, length, bswap) \
  71 { \
  72         BF64_SET(x, 24, 16, length); \
  73         BF64_SET(x, 16, 8, bswap); \
  74         BF64_SET(x, 0, 16, attr); \
  75 }
  76
  77 #define TOC_OFF(x)              BF32_GET(x, 0, 23)
  78 #define TOC_ATTR_PRESENT(x)     BF32_GET(x, 31, 1)
  79 #define TOC_LEN_IDX(x)          BF32_GET(x, 24, 4)
  80 #define TOC_ATTR_ENCODE(x, len_idx, offset) \
  81 { \
  82         BF32_SET(x, 31, 1, 1); \
  83         BF32_SET(x, 24, 7, len_idx); \
  84         BF32_SET(x, 0, 24, offset); \
  85 }
  86
  87 #define SA_LAYOUTS      "LAYOUTS"
  88 #define SA_REGISTRY     "REGISTRY"
  89
  90 /*
  91  * Each unique layout will have their own table
  92  * sa_lot (layout_table)
  93  */
  94 typedef struct sa_lot {
  95         avl_node_t lot_num_node;
  96         avl_node_t lot_hash_node;
  97         uint64_t lot_num;
  98         uint64_t lot_hash;
  99         sa_attr_type_t *lot_attrs;      /* array of attr #'s */
 100         uint32_t lot_var_sizes; /* how many aren't fixed size */
 101         uint32_t lot_attr_count;        /* total attr count */
 102         list_t  lot_idx_tab;    /* should be only a couple of entries */
 103         int     lot_instance;   /* used with lot_hash to identify entry */
 104 } sa_lot_t;
 105
 106 /* index table of offsets */
 107 typedef struct sa_idx_tab {
 108         list_node_t     sa_next;
 109         sa_lot_t        *sa_layout;
 110         uint16_t        *sa_variable_lengths;
 111         refcount_t      sa_refcount;
 112         uint32_t        *sa_idx_tab;    /* array of offsets */
 113 } sa_idx_tab_t;
 114
 115 /*
 116  * Since the offset/index information into the actual data
 117  * will usually be identical we can share that information with
 118  * all handles that have the exact same offsets.
 119  *
 120  * You would typically only have a large number of different table of
 121  * contents if you had a several variable sized attributes.
 122  *
 123  * Two AVL trees are used to track the attribute layout numbers.
 124  * one is keyed by number and will be consulted when a DMU_OT_SA
 125  * object is first read.  The second tree is keyed by the hash signature
 126  * of the attributes and will be consulted when an attribute is added
 127  * to determine if we already have an instance of that layout.  Both
 128  * of these tree's are interconnected.  The only difference is that
 129  * when an entry is found in the "hash" tree the list of attributes will
 130  * need to be compared against the list of attributes you have in hand.
 131  * The assumption is that typically attributes will just be updated and
 132  * adding a completely new attribute is a very rare operation.
 133  */
 134 struct sa_os {
 135         kmutex_t        sa_lock;
 136         boolean_t       sa_need_attr_registration;
 137         boolean_t       sa_force_spill;
 138         uint64_t        sa_master_obj;
 139         uint64_t        sa_reg_attr_obj;
 140         uint64_t        sa_layout_attr_obj;
 141         int             sa_num_attrs;
 142         sa_attr_table_t *sa_attr_table;  /* private attr table */
 143         sa_update_cb_t  *sa_update_cb;
 144         avl_tree_t      sa_layout_num_tree;  /* keyed by layout number */
 145         avl_tree_t      sa_layout_hash_tree; /* keyed by layout hash value */
 146         int             sa_user_table_sz;
 147         sa_attr_type_t  *sa_user_table; /* user name->attr mapping table */
 148 };
 149
 150 /*
 151  * header for all bonus and spill buffers.
 152  * The header has a fixed portion with a variable number
 153  * of "lengths" depending on the number of variable sized
 154  * attribues which are determined by the "layout number"
 155  */
 156
 157 #define SA_MAGIC        0x2F505A  /* ZFS SA */
 158 typedef struct sa_hdr_phys {
 159         uint32_t sa_magic;
 160         uint16_t sa_layout_info;  /* Encoded with hdrsize and layout number */
 161         uint16_t sa_lengths[1]; /* optional sizes for variable length attrs */
 162         /* ... Data follows the lengths.  */
 163 } sa_hdr_phys_t;
 164
 165 /*
 166  * sa_hdr_phys -> sa_layout_info
 167  *
 168  * 16      10       0
 169  * +--------+-------+
 170  * | hdrsz  |layout |
 171  * +--------+-------+
 172  *
 173  * Bits 0-10 are the layout number
 174  * Bits 11-16 are the size of the header.
 175  * The hdrsize is the number * 8
 176  *
 177  * For example.
 178  * hdrsz of 1 ==> 8 byte header
 179  *          2 ==> 16 byte header
 180  *
 181  */
 182
 183 #define SA_HDR_LAYOUT_NUM(hdr) BF32_GET(hdr->sa_layout_info, 0, 10)
 184 #define SA_HDR_SIZE(hdr) BF32_GET_SB(hdr->sa_layout_info, 10, 16, 3, 0)
 185 #define SA_HDR_LAYOUT_INFO_ENCODE(x, num, size) \
 186 { \
 187         BF32_SET_SB(x, 10, 6, 3, 0, size); \
 188         BF32_SET(x, 0, 10, num); \
 189 }
 190
 191 typedef enum sa_buf_type {
 192         SA_BONUS = 1,
 193         SA_SPILL = 2
 194 } sa_buf_type_t;
 195
 196 typedef enum sa_data_op {
 197         SA_LOOKUP,
 198         SA_UPDATE,
 199         SA_ADD,
 200         SA_REPLACE,
 201         SA_REMOVE
 202 } sa_data_op_t;
 203
 204 /*
 205  * Opaque handle used for most sa functions
 206  *
 207  * This needs to be kept as small as possible.
 208  */
 209
 210 struct sa_handle {
 211         kmutex_t        sa_lock;
 212         dmu_buf_t       *sa_bonus;
 213         dmu_buf_t       *sa_spill;
 214         objset_t        *sa_os;
 215         void            *sa_userp;
 216         sa_idx_tab_t    *sa_bonus_tab;   /* idx of bonus */
 217         sa_idx_tab_t    *sa_spill_tab; /* only present if spill activated */
 218 };
 219
 220 #define SA_GET_DB(hdl, type)    \
 221         (dmu_buf_impl_t *)((type == SA_BONUS) ? hdl->sa_bonus : hdl->sa_spill)
 222
 223 #define SA_GET_HDR(hdl, type) \
 224         ((sa_hdr_phys_t *)((dmu_buf_impl_t *)(SA_GET_DB(hdl, \
 225         type))->db.db_data))
 226
 227 #define SA_IDX_TAB_GET(hdl, type) \
 228         (type == SA_BONUS ? hdl->sa_bonus_tab : hdl->sa_spill_tab)
 229
 230 #define IS_SA_BONUSTYPE(a)      \
 231         ((a == DMU_OT_SA) ? B_TRUE : B_FALSE)
 232
 233 #define SA_BONUSTYPE_FROM_DB(db) \
 234         (dmu_get_bonustype((dmu_buf_t *)db))
 235
 236 #define SA_BLKPTR_SPACE (DN_MAX_BONUSLEN - sizeof (blkptr_t))
 237
 238 #define SA_LAYOUT_NUM(x, type) \
 239         ((!IS_SA_BONUSTYPE(type) ? 0 : (((IS_SA_BONUSTYPE(type)) && \
 240         ((SA_HDR_LAYOUT_NUM(x)) == 0)) ? 1 : SA_HDR_LAYOUT_NUM(x))))
 241
 242
 243 #define SA_REGISTERED_LEN(sa, attr) sa->sa_attr_table[attr].sa_length
 244
 245 #define SA_ATTR_LEN(sa, idx, attr, hdr) ((SA_REGISTERED_LEN(sa, attr) == 0) ?\
 246         hdr->sa_lengths[TOC_LEN_IDX(idx->sa_idx_tab[attr])] : \
 247         SA_REGISTERED_LEN(sa, attr))
 248
 249 #define SA_SET_HDR(hdr, num, size) \
 250         { \
 251                 hdr->sa_magic = SA_MAGIC; \
 252                 SA_HDR_LAYOUT_INFO_ENCODE(hdr->sa_layout_info, num, size); \
 253         }
 254
 255 #define SA_ATTR_INFO(sa, idx, hdr, attr, bulk, type, hdl) \
 256         { \
 257                 bulk.sa_size = SA_ATTR_LEN(sa, idx, attr, hdr); \
 258                 bulk.sa_buftype = type; \
 259                 bulk.sa_addr = \
 260                     (void *)((uintptr_t)TOC_OFF(idx->sa_idx_tab[attr]) + \
 261                     (uintptr_t)hdr); \
 262 }
 263
 264 #define SA_HDR_SIZE_MATCH_LAYOUT(hdr, tb) \
 265         (SA_HDR_SIZE(hdr) == (sizeof (sa_hdr_phys_t) + \
 266         (tb->lot_var_sizes > 1 ? P2ROUNDUP((tb->lot_var_sizes - 1) * \
 267         sizeof (uint16_t), 8) : 0)))
 268
 269 int sa_add_impl(sa_handle_t *, sa_attr_type_t,
 270     uint32_t, sa_data_locator_t, void *, dmu_tx_t *);
 271
 272 void sa_register_update_callback_locked(objset_t *, sa_update_cb_t *);
 273 int sa_size_locked(sa_handle_t *, sa_attr_type_t, int *);
 274
 275 void sa_default_locator(void **, uint32_t *, uint32_t, boolean_t, void *);
 276 int sa_attr_size(sa_os_t *, sa_idx_tab_t *, sa_attr_type_t,
 277     uint16_t *, sa_hdr_phys_t *);
 278
 279 #ifdef  __cplusplus
 280 extern "C" {
 281 #endif
 282
 283 #ifdef  __cplusplus
 284 }
 285 #endif
 286
 287 #endif  /* _SYS_SA_IMPL_H */