fs/reiser4/reiser4.h

   1 /* Copyright 2001, 2002, 2003 by Hans Reiser, licensing governed by
   2  * reiser4/README */
   3
   4 /* definitions of common constants used by reiser4 */
   5
   6 #if !defined(__REISER4_H__)
   7 #define __REISER4_H__
   8
   9 #include <asm/param.h>          /* for HZ */
  10 #include <linux/errno.h>
  11 #include <linux/types.h>
  12 #include <linux/fs.h>
  13 #include <linux/hardirq.h>
  14 #include <linux/sched.h>
  15
  16 /*
  17  * reiser4 compilation options.
  18  */
  19
  20 #if defined(CONFIG_REISER4_DEBUG)
  21 /* turn on assertion checks */
  22 #define REISER4_DEBUG (1)
  23 #else
  24 #define REISER4_DEBUG (0)
  25 #endif
  26
  27 #if defined(CONFIG_ZLIB_INFLATE)
  28 /* turn on zlib */
  29 #define REISER4_ZLIB (1)
  30 #else
  31 #define REISER4_ZLIB (0)
  32 #endif
  33
  34 #if defined(CONFIG_CRYPTO_SHA256)
  35 #define REISER4_SHA256 (1)
  36 #else
  37 #define REISER4_SHA256 (0)
  38 #endif
  39
  40 /*
  41  * Turn on large keys mode. In his mode (which is default), reiser4 key has 4
  42  * 8-byte components. In the old "small key" mode, it's 3 8-byte
  43  * components. Additional component, referred to as "ordering" is used to
  44  * order items from which given object is composed of. As such, ordering is
  45  * placed between locality and objectid. For directory item ordering contains
  46  * initial prefix of the file name this item is for. This sorts all directory
  47  * items within given directory lexicographically (but see
  48  * fibration.[ch]). For file body and stat-data, ordering contains initial
  49  * prefix of the name file was initially created with. In the common case
  50  * (files with single name) this allows to order file bodies and stat-datas in
  51  * the same order as their respective directory entries, thus speeding up
  52  * readdir.
  53  *
  54  * Note, that kernel can only mount file system with the same key size as one
  55  * it is compiled for, so flipping this option may render your data
  56  * inaccessible.
  57  */
  58 #define REISER4_LARGE_KEY (1)
  59 /*#define REISER4_LARGE_KEY (0)*/
  60
  61 /*#define GUESS_EXISTS 1*/
  62
  63 /*
  64  * PLEASE update fs/reiser4/kattr.c:show_options() when adding new compilation
  65  * option
  66  */
  67
  68 extern const char *REISER4_SUPER_MAGIC_STRING;
  69 extern const int REISER4_MAGIC_OFFSET;  /* offset to magic string from the
  70                                          * beginning of device */
  71
  72 /* here go tunable parameters that are not worth special entry in kernel
  73    configuration */
  74
  75 /* default number of slots in coord-by-key caches */
  76 #define CBK_CACHE_SLOTS    (16)
  77 /* how many elementary tree operation to carry on the next level */
  78 #define CARRIES_POOL_SIZE        (5)
  79 /* size of pool of preallocated nodes for carry process. */
  80 #define NODES_LOCKED_POOL_SIZE   (5)
  81
  82 #define REISER4_NEW_NODE_FLAGS (COPI_LOAD_LEFT | COPI_LOAD_RIGHT | COPI_GO_LEFT)
  83 #define REISER4_NEW_EXTENT_FLAGS (COPI_LOAD_LEFT | COPI_LOAD_RIGHT | COPI_GO_LEFT)
  84 #define REISER4_PASTE_FLAGS (COPI_GO_LEFT)
  85 #define REISER4_INSERT_FLAGS (COPI_GO_LEFT)
  86
  87 /* we are supporting reservation of disk space on uid basis */
  88 #define REISER4_SUPPORT_UID_SPACE_RESERVATION (0)
  89 /* we are supporting reservation of disk space for groups */
  90 #define REISER4_SUPPORT_GID_SPACE_RESERVATION (0)
  91 /* we are supporting reservation of disk space for root */
  92 #define REISER4_SUPPORT_ROOT_SPACE_RESERVATION (0)
  93 /* we use rapid flush mode, see flush.c for comments.  */
  94 #define REISER4_USE_RAPID_FLUSH (1)
  95
  96 /*
  97  * set this to 0 if you don't want to use wait-for-flush in ->writepage().
  98  */
  99 #define REISER4_USE_ENTD (1)
 100
 101 /* key allocation is Plan-A */
 102 #define REISER4_PLANA_KEY_ALLOCATION (1)
 103 /* key allocation follows good old 3.x scheme */
 104 #define REISER4_3_5_KEY_ALLOCATION (0)
 105
 106 /* size of hash-table for znodes */
 107 #define REISER4_ZNODE_HASH_TABLE_SIZE (1 << 13)
 108
 109 /* number of buckets in lnode hash-table */
 110 #define LNODE_HTABLE_BUCKETS (1024)
 111
 112 /* some ridiculously high maximal limit on height of znode tree. This
 113     is used in declaration of various per level arrays and
 114     to allocate stattistics gathering array for per-level stats. */
 115 #define REISER4_MAX_ZTREE_HEIGHT     (8)
 116
 117 #define REISER4_PANIC_MSG_BUFFER_SIZE (1024)
 118
 119 /* If array contains less than REISER4_SEQ_SEARCH_BREAK elements then,
 120    sequential search is on average faster than binary. This is because
 121    of better optimization and because sequential search is more CPU
 122    cache friendly. This number (25) was found by experiments on dual AMD
 123    Athlon(tm), 1400MHz.
 124
 125    NOTE: testing in kernel has shown that binary search is more effective than
 126    implied by results of the user level benchmarking. Probably because in the
 127    node keys are separated by other data. So value was adjusted after few
 128    tests. More thorough tuning is needed.
 129 */
 130 #define REISER4_SEQ_SEARCH_BREAK      (3)
 131
 132 /* don't allow tree to be lower than this */
 133 #define REISER4_MIN_TREE_HEIGHT       (TWIG_LEVEL)
 134
 135 /* NOTE NIKITA this is no longer used: maximal atom size is auto-adjusted to
 136  * available memory. */
 137 /* Default value of maximal atom size. Can be ovewritten by
 138    tmgr.atom_max_size mount option. By default infinity. */
 139 #define REISER4_ATOM_MAX_SIZE         ((unsigned)(~0))
 140
 141 /* Default value of maximal atom age (in jiffies). After reaching this age
 142    atom will be forced to commit, either synchronously or asynchronously. Can
 143    be overwritten by tmgr.atom_max_age mount option. */
 144 #define REISER4_ATOM_MAX_AGE          (600 * HZ)
 145
 146 /* sleeping period for ktxnmrgd */
 147 #define REISER4_TXNMGR_TIMEOUT  (5 * HZ)
 148
 149 /* timeout to wait for ent thread in writepage. Default: 3 milliseconds. */
 150 #define REISER4_ENTD_TIMEOUT (3 * HZ / 1000)
 151
 152 /* start complaining after that many restarts in coord_by_key().
 153
 154    This either means incredibly heavy contention for this part of a tree, or
 155    some corruption or bug.
 156 */
 157 #define REISER4_CBK_ITERATIONS_LIMIT  (100)
 158
 159 /* return -EIO after that many iterations in coord_by_key().
 160
 161    I have witnessed more than 800 iterations (in 30 thread test) before cbk
 162    finished. --nikita
 163 */
 164 #define REISER4_MAX_CBK_ITERATIONS    500000
 165
 166 /* put a per-inode limit on maximal number of directory entries with identical
 167    keys in hashed directory.
 168
 169    Disable this until inheritance interfaces stabilize: we need some way to
 170    set per directory limit.
 171 */
 172 #define REISER4_USE_COLLISION_LIMIT    (0)
 173
 174 /* If flush finds more than FLUSH_RELOCATE_THRESHOLD adjacent dirty leaf-level
 175    blocks it will force them to be relocated. */
 176 #define FLUSH_RELOCATE_THRESHOLD 64
 177 /* If flush finds can find a block allocation closer than at most
 178    FLUSH_RELOCATE_DISTANCE from the preceder it will relocate to that position.
 179  */
 180 #define FLUSH_RELOCATE_DISTANCE  64
 181
 182 /* If we have written this much or more blocks before encountering busy jnode
 183    in flush list - abort flushing hoping that next time we get called
 184    this jnode will be clean already, and we will save some seeks. */
 185 #define FLUSH_WRITTEN_THRESHOLD 50
 186
 187 /* The maximum number of nodes to scan left on a level during flush. */
 188 #define FLUSH_SCAN_MAXNODES 10000
 189
 190 /* per-atom limit of flushers */
 191 #define ATOM_MAX_FLUSHERS (1)
 192
 193 /* default tracing buffer size */
 194 #define REISER4_TRACE_BUF_SIZE (1 << 15)
 195
 196 /* what size units of IO we would like cp, etc., to use, in writing to
 197    reiser4. In bytes.
 198
 199    Can be overwritten by optimal_io_size mount option.
 200 */
 201 #define REISER4_OPTIMAL_IO_SIZE (64 * 1024)
 202
 203 /* see comments in inode.c:oid_to_uino() */
 204 #define REISER4_UINO_SHIFT (1 << 30)
 205
 206 /* Mark function argument as unused to avoid compiler warnings. */
 207 #define UNUSED_ARG __attribute__((unused))
 208
 209 #if ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 3)) || (__GNUC__ > 3)
 210 #define NONNULL __attribute__((nonnull))
 211 #else
 212 #define NONNULL
 213 #endif
 214
 215 /* master super block offset in bytes.*/
 216 #define REISER4_MASTER_OFFSET 65536
 217
 218 /* size of VFS block */
 219 #define VFS_BLKSIZE 512
 220 /* number of bits in size of VFS block (512==2^9) */
 221 #define VFS_BLKSIZE_BITS 9
 222
 223 #define REISER4_I reiser4_inode_data
 224
 225 /* implication */
 226 #define ergo(antecedent, consequent) (!(antecedent) || (consequent))
 227 /* logical equivalence */
 228 #define equi(p1, p2) (ergo((p1), (p2)) && ergo((p2), (p1)))
 229
 230 #define sizeof_array(x) ((int) (sizeof(x) / sizeof(x[0])))
 231
 232 #define NOT_YET                       (0)
 233
 234 /** Reiser4 specific error codes **/
 235
 236 #define REISER4_ERROR_CODE_BASE 10000
 237
 238 /* Neighbor is not available (side neighbor or parent) */
 239 #define E_NO_NEIGHBOR  (REISER4_ERROR_CODE_BASE)
 240
 241 /* Node was not found in cache */
 242 #define E_NOT_IN_CACHE (REISER4_ERROR_CODE_BASE + 1)
 243
 244 /* node has no free space enough for completion of balancing operation */
 245 #define E_NODE_FULL    (REISER4_ERROR_CODE_BASE + 2)
 246
 247 /* repeat operation */
 248 #define E_REPEAT       (REISER4_ERROR_CODE_BASE + 3)
 249
 250 /* deadlock happens */
 251 #define E_DEADLOCK     (REISER4_ERROR_CODE_BASE + 4)
 252
 253 /* operation cannot be performed, because it would block and non-blocking mode
 254  * was requested. */
 255 #define E_BLOCK        (REISER4_ERROR_CODE_BASE + 5)
 256
 257 /* wait some event (depends on context), then repeat */
 258 #define E_WAIT         (REISER4_ERROR_CODE_BASE + 6)
 259
 260 #endif                          /* __REISER4_H__ */
 261
 262 /* Make Linus happy.
 263    Local variables:
 264    c-indentation-style: "K&R"
 265    mode-name: "LC"
 266    c-basic-offset: 8
 267    tab-width: 8
 268    fill-column: 120
 269    End:
 270 */