fs/ocfs2/stack_o2cb.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * stack_o2cb.c
   5  *
   6  * Code which interfaces ocfs2 with the o2cb stack.
   7  *
   8  * Copyright (C) 2007 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation, version 2.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  */
  19
  20 #include <linux/crc32.h>
  21 #include <linux/module.h>
  22
  23 /* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */
  24 #include <linux/fs.h>
  25
  26 #include "cluster/masklog.h"
  27 #include "cluster/nodemanager.h"
  28 #include "cluster/heartbeat.h"
  29
  30 #include "stackglue.h"
  31
  32 struct o2dlm_private {
  33         struct dlm_eviction_cb op_eviction_cb;
  34 };
  35
  36 static struct ocfs2_stack_plugin o2cb_stack;
  37
  38 /* These should be identical */
  39 #if (DLM_LOCK_IV != LKM_IVMODE)
  40 # error Lock modes do not match
  41 #endif
  42 #if (DLM_LOCK_NL != LKM_NLMODE)
  43 # error Lock modes do not match
  44 #endif
  45 #if (DLM_LOCK_CR != LKM_CRMODE)
  46 # error Lock modes do not match
  47 #endif
  48 #if (DLM_LOCK_CW != LKM_CWMODE)
  49 # error Lock modes do not match
  50 #endif
  51 #if (DLM_LOCK_PR != LKM_PRMODE)
  52 # error Lock modes do not match
  53 #endif
  54 #if (DLM_LOCK_PW != LKM_PWMODE)
  55 # error Lock modes do not match
  56 #endif
  57 #if (DLM_LOCK_EX != LKM_EXMODE)
  58 # error Lock modes do not match
  59 #endif
  60 static inline int mode_to_o2dlm(int mode)
  61 {
  62         BUG_ON(mode > LKM_MAXMODE);
  63
  64         return mode;
  65 }
  66
  67 #define map_flag(_generic, _o2dlm)              \
  68         if (flags & (_generic)) {               \
  69                 flags &= ~(_generic);           \
  70                 o2dlm_flags |= (_o2dlm);        \
  71         }
  72 static int flags_to_o2dlm(u32 flags)
  73 {
  74         int o2dlm_flags = 0;
  75
  76         map_flag(DLM_LKF_NOQUEUE, LKM_NOQUEUE);
  77         map_flag(DLM_LKF_CANCEL, LKM_CANCEL);
  78         map_flag(DLM_LKF_CONVERT, LKM_CONVERT);
  79         map_flag(DLM_LKF_VALBLK, LKM_VALBLK);
  80         map_flag(DLM_LKF_IVVALBLK, LKM_INVVALBLK);
  81         map_flag(DLM_LKF_ORPHAN, LKM_ORPHAN);
  82         map_flag(DLM_LKF_FORCEUNLOCK, LKM_FORCE);
  83         map_flag(DLM_LKF_TIMEOUT, LKM_TIMEOUT);
  84         map_flag(DLM_LKF_LOCAL, LKM_LOCAL);
  85
  86         /* map_flag() should have cleared every flag passed in */
  87         BUG_ON(flags != 0);
  88
  89         return o2dlm_flags;
  90 }
  91 #undef map_flag
  92
  93 /*
  94  * Map an o2dlm status to standard errno values.
  95  *
  96  * o2dlm only uses a handful of these, and returns even fewer to the
  97  * caller. Still, we try to assign sane values to each error.
  98  *
  99  * The following value pairs have special meanings to dlmglue, thus
 100  * the right hand side needs to stay unique - never duplicate the
 101  * mapping elsewhere in the table!
 102  *
 103  * DLM_NORMAL:          0
 104  * DLM_NOTQUEUED:       -EAGAIN
 105  * DLM_CANCELGRANT:     -EBUSY
 106  * DLM_CANCEL:          -DLM_ECANCEL
 107  */
 108 /* Keep in sync with dlmapi.h */
 109 static int status_map[] = {
 110         [DLM_NORMAL]                    = 0,            /* Success */
 111         [DLM_GRANTED]                   = -EINVAL,
 112         [DLM_DENIED]                    = -EACCES,
 113         [DLM_DENIED_NOLOCKS]            = -EACCES,
 114         [DLM_WORKING]                   = -EACCES,
 115         [DLM_BLOCKED]                   = -EINVAL,
 116         [DLM_BLOCKED_ORPHAN]            = -EINVAL,
 117         [DLM_DENIED_GRACE_PERIOD]       = -EACCES,
 118         [DLM_SYSERR]                    = -ENOMEM,      /* It is what it is */
 119         [DLM_NOSUPPORT]                 = -EPROTO,
 120         [DLM_CANCELGRANT]               = -EBUSY,       /* Cancel after grant */
 121         [DLM_IVLOCKID]                  = -EINVAL,
 122         [DLM_SYNC]                      = -EINVAL,
 123         [DLM_BADTYPE]                   = -EINVAL,
 124         [DLM_BADRESOURCE]               = -EINVAL,
 125         [DLM_MAXHANDLES]                = -ENOMEM,
 126         [DLM_NOCLINFO]                  = -EINVAL,
 127         [DLM_NOLOCKMGR]                 = -EINVAL,
 128         [DLM_NOPURGED]                  = -EINVAL,
 129         [DLM_BADARGS]                   = -EINVAL,
 130         [DLM_VOID]                      = -EINVAL,
 131         [DLM_NOTQUEUED]                 = -EAGAIN,      /* Trylock failed */
 132         [DLM_IVBUFLEN]                  = -EINVAL,
 133         [DLM_CVTUNGRANT]                = -EPERM,
 134         [DLM_BADPARAM]                  = -EINVAL,
 135         [DLM_VALNOTVALID]               = -EINVAL,
 136         [DLM_REJECTED]                  = -EPERM,
 137         [DLM_ABORT]                     = -EINVAL,
 138         [DLM_CANCEL]                    = -DLM_ECANCEL, /* Successful cancel */
 139         [DLM_IVRESHANDLE]               = -EINVAL,
 140         [DLM_DEADLOCK]                  = -EDEADLK,
 141         [DLM_DENIED_NOASTS]             = -EINVAL,
 142         [DLM_FORWARD]                   = -EINVAL,
 143         [DLM_TIMEOUT]                   = -ETIMEDOUT,
 144         [DLM_IVGROUPID]                 = -EINVAL,
 145         [DLM_VERS_CONFLICT]             = -EOPNOTSUPP,
 146         [DLM_BAD_DEVICE_PATH]           = -ENOENT,
 147         [DLM_NO_DEVICE_PERMISSION]      = -EPERM,
 148         [DLM_NO_CONTROL_DEVICE]         = -ENOENT,
 149         [DLM_RECOVERING]                = -ENOTCONN,
 150         [DLM_MIGRATING]                 = -ERESTART,
 151         [DLM_MAXSTATS]                  = -EINVAL,
 152 };
 153
 154 static int dlm_status_to_errno(enum dlm_status status)
 155 {
 156         BUG_ON(status > (sizeof(status_map) / sizeof(status_map[0])));
 157
 158         return status_map[status];
 159 }
 160
 161 static void o2dlm_lock_ast_wrapper(void *astarg)
 162 {
 163         BUG_ON(o2cb_stack.sp_proto == NULL);
 164
 165         o2cb_stack.sp_proto->lp_lock_ast(astarg);
 166 }
 167
 168 static void o2dlm_blocking_ast_wrapper(void *astarg, int level)
 169 {
 170         BUG_ON(o2cb_stack.sp_proto == NULL);
 171
 172         o2cb_stack.sp_proto->lp_blocking_ast(astarg, level);
 173 }
 174
 175 static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status)
 176 {
 177         int error = dlm_status_to_errno(status);
 178
 179         BUG_ON(o2cb_stack.sp_proto == NULL);
 180
 181         /*
 182          * In o2dlm, you can get both the lock_ast() for the lock being
 183          * granted and the unlock_ast() for the CANCEL failing.  A
 184          * successful cancel sends DLM_NORMAL here.  If the
 185          * lock grant happened before the cancel arrived, you get
 186          * DLM_CANCELGRANT.
 187          *
 188          * There's no need for the double-ast.  If we see DLM_CANCELGRANT,
 189          * we just ignore it.  We expect the lock_ast() to handle the
 190          * granted lock.
 191          */
 192         if (status == DLM_CANCELGRANT)
 193                 return;
 194
 195         o2cb_stack.sp_proto->lp_unlock_ast(astarg, error);
 196 }
 197
 198 static int o2cb_dlm_lock(struct ocfs2_cluster_connection *conn,
 199                          int mode,
 200                          union ocfs2_dlm_lksb *lksb,
 201                          u32 flags,
 202                          void *name,
 203                          unsigned int namelen,
 204                          void *astarg)
 205 {
 206         enum dlm_status status;
 207         int o2dlm_mode = mode_to_o2dlm(mode);
 208         int o2dlm_flags = flags_to_o2dlm(flags);
 209         int ret;
 210
 211         status = dlmlock(conn->cc_lockspace, o2dlm_mode, &lksb->lksb_o2dlm,
 212                          o2dlm_flags, name, namelen,
 213                          o2dlm_lock_ast_wrapper, astarg,
 214                          o2dlm_blocking_ast_wrapper);
 215         ret = dlm_status_to_errno(status);
 216         return ret;
 217 }
 218
 219 static int o2cb_dlm_unlock(struct ocfs2_cluster_connection *conn,
 220                            union ocfs2_dlm_lksb *lksb,
 221                            u32 flags,
 222                            void *astarg)
 223 {
 224         enum dlm_status status;
 225         int o2dlm_flags = flags_to_o2dlm(flags);
 226         int ret;
 227
 228         status = dlmunlock(conn->cc_lockspace, &lksb->lksb_o2dlm,
 229                            o2dlm_flags, o2dlm_unlock_ast_wrapper, astarg);
 230         ret = dlm_status_to_errno(status);
 231         return ret;
 232 }
 233
 234 static int o2cb_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
 235 {
 236         return dlm_status_to_errno(lksb->lksb_o2dlm.status);
 237 }
 238
 239 /*
 240  * o2dlm aways has a "valid" LVB. If the dlm loses track of the LVB
 241  * contents, it will zero out the LVB.  Thus the caller can always trust
 242  * the contents.
 243  */
 244 static int o2cb_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
 245 {
 246         return 1;
 247 }
 248
 249 static void *o2cb_dlm_lvb(union ocfs2_dlm_lksb *lksb)
 250 {
 251         return (void *)(lksb->lksb_o2dlm.lvb);
 252 }
 253
 254 static void o2cb_dump_lksb(union ocfs2_dlm_lksb *lksb)
 255 {
 256         dlm_print_one_lock(lksb->lksb_o2dlm.lockid);
 257 }
 258
 259 /*
 260  * Called from the dlm when it's about to evict a node. This is how the
 261  * classic stack signals node death.
 262  */
 263 static void o2dlm_eviction_cb(int node_num, void *data)
 264 {
 265         struct ocfs2_cluster_connection *conn = data;
 266
 267         mlog(ML_NOTICE, "o2dlm has evicted node %d from group %.*s\n",
 268              node_num, conn->cc_namelen, conn->cc_name);
 269
 270         conn->cc_recovery_handler(node_num, conn->cc_recovery_data);
 271 }
 272
 273 static int o2cb_cluster_connect(struct ocfs2_cluster_connection *conn)
 274 {
 275         int rc = 0;
 276         u32 dlm_key;
 277         struct dlm_ctxt *dlm;
 278         struct o2dlm_private *priv;
 279         struct dlm_protocol_version dlm_version;
 280
 281         BUG_ON(conn == NULL);
 282         BUG_ON(o2cb_stack.sp_proto == NULL);
 283
 284         /* for now we only have one cluster/node, make sure we see it
 285          * in the heartbeat universe */
 286         if (!o2hb_check_local_node_heartbeating()) {
 287                 rc = -EINVAL;
 288                 goto out;
 289         }
 290
 291         priv = kzalloc(sizeof(struct o2dlm_private), GFP_KERNEL);
 292         if (!priv) {
 293                 rc = -ENOMEM;
 294                 goto out_free;
 295         }
 296
 297         /* This just fills the structure in.  It is safe to pass conn. */
 298         dlm_setup_eviction_cb(&priv->op_eviction_cb, o2dlm_eviction_cb,
 299                               conn);
 300
 301         conn->cc_private = priv;
 302
 303         /* used by the dlm code to make message headers unique, each
 304          * node in this domain must agree on this. */
 305         dlm_key = crc32_le(0, conn->cc_name, conn->cc_namelen);
 306         dlm_version.pv_major = conn->cc_version.pv_major;
 307         dlm_version.pv_minor = conn->cc_version.pv_minor;
 308
 309         dlm = dlm_register_domain(conn->cc_name, dlm_key, &dlm_version);
 310         if (IS_ERR(dlm)) {
 311                 rc = PTR_ERR(dlm);
 312                 mlog_errno(rc);
 313                 goto out_free;
 314         }
 315
 316         conn->cc_version.pv_major = dlm_version.pv_major;
 317         conn->cc_version.pv_minor = dlm_version.pv_minor;
 318         conn->cc_lockspace = dlm;
 319
 320         dlm_register_eviction_cb(dlm, &priv->op_eviction_cb);
 321
 322 out_free:
 323         if (rc && conn->cc_private)
 324                 kfree(conn->cc_private);
 325
 326 out:
 327         return rc;
 328 }
 329
 330 static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn)
 331 {
 332         struct dlm_ctxt *dlm = conn->cc_lockspace;
 333         struct o2dlm_private *priv = conn->cc_private;
 334
 335         dlm_unregister_eviction_cb(&priv->op_eviction_cb);
 336         conn->cc_private = NULL;
 337         kfree(priv);
 338
 339         dlm_unregister_domain(dlm);
 340         conn->cc_lockspace = NULL;
 341
 342         return 0;
 343 }
 344
 345 static int o2cb_cluster_this_node(unsigned int *node)
 346 {
 347         int node_num;
 348
 349         node_num = o2nm_this_node();
 350         if (node_num == O2NM_INVALID_NODE_NUM)
 351                 return -ENOENT;
 352
 353         if (node_num >= O2NM_MAX_NODES)
 354                 return -EOVERFLOW;
 355
 356         *node = node_num;
 357         return 0;
 358 }
 359
 360 static struct ocfs2_stack_operations o2cb_stack_ops = {
 361         .connect        = o2cb_cluster_connect,
 362         .disconnect     = o2cb_cluster_disconnect,
 363         .this_node      = o2cb_cluster_this_node,
 364         .dlm_lock       = o2cb_dlm_lock,
 365         .dlm_unlock     = o2cb_dlm_unlock,
 366         .lock_status    = o2cb_dlm_lock_status,
 367         .lvb_valid      = o2cb_dlm_lvb_valid,
 368         .lock_lvb       = o2cb_dlm_lvb,
 369         .dump_lksb      = o2cb_dump_lksb,
 370 };
 371
 372 static struct ocfs2_stack_plugin o2cb_stack = {
 373         .sp_name        = "o2cb",
 374         .sp_ops         = &o2cb_stack_ops,
 375         .sp_owner       = THIS_MODULE,
 376 };
 377
 378 static int __init o2cb_stack_init(void)
 379 {
 380         return ocfs2_stack_glue_register(&o2cb_stack);
 381 }
 382
 383 static void __exit o2cb_stack_exit(void)
 384 {
 385         ocfs2_stack_glue_unregister(&o2cb_stack);
 386 }
 387
 388 MODULE_AUTHOR("Oracle");
 389 MODULE_DESCRIPTION("ocfs2 driver for the classic o2cb stack");
 390 MODULE_LICENSE("GPL");
 391 module_init(o2cb_stack_init);
 392 module_exit(o2cb_stack_exit);