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

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