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[linux-2.6] / 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 static void *o2cb_dlm_lvb(union ocfs2_dlm_lksb *lksb)
240 {
241         return (void *)(lksb->lksb_o2dlm.lvb);
242 }
243
244 static void o2cb_dump_lksb(union ocfs2_dlm_lksb *lksb)
245 {
246         dlm_print_one_lock(lksb->lksb_o2dlm.lockid);
247 }
248
249 /*
250  * Called from the dlm when it's about to evict a node. This is how the
251  * classic stack signals node death.
252  */
253 static void o2dlm_eviction_cb(int node_num, void *data)
254 {
255         struct ocfs2_cluster_connection *conn = data;
256
257         mlog(ML_NOTICE, "o2dlm has evicted node %d from group %.*s\n",
258              node_num, conn->cc_namelen, conn->cc_name);
259
260         conn->cc_recovery_handler(node_num, conn->cc_recovery_data);
261 }
262
263 static int o2cb_cluster_connect(struct ocfs2_cluster_connection *conn)
264 {
265         int rc = 0;
266         u32 dlm_key;
267         struct dlm_ctxt *dlm;
268         struct o2dlm_private *priv;
269         struct dlm_protocol_version dlm_version;
270
271         BUG_ON(conn == NULL);
272         BUG_ON(o2cb_stack.sp_proto == NULL);
273
274         /* for now we only have one cluster/node, make sure we see it
275          * in the heartbeat universe */
276         if (!o2hb_check_local_node_heartbeating()) {
277                 rc = -EINVAL;
278                 goto out;
279         }
280
281         priv = kzalloc(sizeof(struct o2dlm_private), GFP_KERNEL);
282         if (!priv) {
283                 rc = -ENOMEM;
284                 goto out_free;
285         }
286
287         /* This just fills the structure in.  It is safe to pass conn. */
288         dlm_setup_eviction_cb(&priv->op_eviction_cb, o2dlm_eviction_cb,
289                               conn);
290
291         conn->cc_private = priv;
292
293         /* used by the dlm code to make message headers unique, each
294          * node in this domain must agree on this. */
295         dlm_key = crc32_le(0, conn->cc_name, conn->cc_namelen);
296         dlm_version.pv_major = conn->cc_version.pv_major;
297         dlm_version.pv_minor = conn->cc_version.pv_minor;
298
299         dlm = dlm_register_domain(conn->cc_name, dlm_key, &dlm_version);
300         if (IS_ERR(dlm)) {
301                 rc = PTR_ERR(dlm);
302                 mlog_errno(rc);
303                 goto out_free;
304         }
305
306         conn->cc_version.pv_major = dlm_version.pv_major;
307         conn->cc_version.pv_minor = dlm_version.pv_minor;
308         conn->cc_lockspace = dlm;
309
310         dlm_register_eviction_cb(dlm, &priv->op_eviction_cb);
311
312 out_free:
313         if (rc && conn->cc_private)
314                 kfree(conn->cc_private);
315
316 out:
317         return rc;
318 }
319
320 static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn,
321                                    int hangup_pending)
322 {
323         struct dlm_ctxt *dlm = conn->cc_lockspace;
324         struct o2dlm_private *priv = conn->cc_private;
325
326         dlm_unregister_eviction_cb(&priv->op_eviction_cb);
327         conn->cc_private = NULL;
328         kfree(priv);
329
330         dlm_unregister_domain(dlm);
331         conn->cc_lockspace = NULL;
332
333         return 0;
334 }
335
336 static void o2hb_stop(const char *group)
337 {
338         int ret;
339         char *argv[5], *envp[3];
340
341         argv[0] = (char *)o2nm_get_hb_ctl_path();
342         argv[1] = "-K";
343         argv[2] = "-u";
344         argv[3] = (char *)group;
345         argv[4] = NULL;
346
347         mlog(0, "Run: %s %s %s %s\n", argv[0], argv[1], argv[2], argv[3]);
348
349         /* minimal command environment taken from cpu_run_sbin_hotplug */
350         envp[0] = "HOME=/";
351         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
352         envp[2] = NULL;
353
354         ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
355         if (ret < 0)
356                 mlog_errno(ret);
357 }
358
359 /*
360  * Hangup is a hack for tools compatibility.  Older ocfs2-tools software
361  * expects the filesystem to call "ocfs2_hb_ctl" during unmount.  This
362  * happens regardless of whether the DLM got started, so we can't do it
363  * in ocfs2_cluster_disconnect().  We bring the o2hb_stop() function into
364  * the glue and provide a "hangup" API for super.c to call.
365  *
366  * Other stacks will eventually provide a NULL ->hangup() pointer.
367  */
368 static void o2cb_cluster_hangup(const char *group, int grouplen)
369 {
370         o2hb_stop(group);
371 }
372
373 static int o2cb_cluster_this_node(unsigned int *node)
374 {
375         int node_num;
376
377         node_num = o2nm_this_node();
378         if (node_num == O2NM_INVALID_NODE_NUM)
379                 return -ENOENT;
380
381         if (node_num >= O2NM_MAX_NODES)
382                 return -EOVERFLOW;
383
384         *node = node_num;
385         return 0;
386 }
387
388 static struct ocfs2_stack_operations o2cb_stack_ops = {
389         .connect        = o2cb_cluster_connect,
390         .disconnect     = o2cb_cluster_disconnect,
391         .hangup         = o2cb_cluster_hangup,
392         .this_node      = o2cb_cluster_this_node,
393         .dlm_lock       = o2cb_dlm_lock,
394         .dlm_unlock     = o2cb_dlm_unlock,
395         .lock_status    = o2cb_dlm_lock_status,
396         .lock_lvb       = o2cb_dlm_lvb,
397         .dump_lksb      = o2cb_dump_lksb,
398 };
399
400 static struct ocfs2_stack_plugin o2cb_stack = {
401         .sp_name        = "o2cb",
402         .sp_ops         = &o2cb_stack_ops,
403         .sp_owner       = THIS_MODULE,
404 };
405
406 static int __init o2cb_stack_init(void)
407 {
408         return ocfs2_stack_glue_register(&o2cb_stack);
409 }
410
411 static void __exit o2cb_stack_exit(void)
412 {
413         ocfs2_stack_glue_unregister(&o2cb_stack);
414 }
415
416 MODULE_AUTHOR("Oracle");
417 MODULE_DESCRIPTION("ocfs2 driver for the classic o2cb stack");
418 MODULE_LICENSE("GPL");
419 module_init(o2cb_stack_init);
420 module_exit(o2cb_stack_exit);