xref: /openbmc/linux/fs/dlm/dlm_internal.h (revision a1bc86e6bddd34362ca08a3a4d898eb4b5c15215)
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
6 **
7 **  This copyrighted material is made available to anyone wishing to use,
8 **  modify, copy, or redistribute it subject to the terms and conditions
9 **  of the GNU General Public License v.2.
10 **
11 *******************************************************************************
12 ******************************************************************************/
13 
14 #ifndef __DLM_INTERNAL_DOT_H__
15 #define __DLM_INTERNAL_DOT_H__
16 
17 /*
18  * This is the main header file to be included in each DLM source file.
19  */
20 
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/types.h>
25 #include <linux/ctype.h>
26 #include <linux/spinlock.h>
27 #include <linux/vmalloc.h>
28 #include <linux/list.h>
29 #include <linux/errno.h>
30 #include <linux/random.h>
31 #include <linux/delay.h>
32 #include <linux/socket.h>
33 #include <linux/kthread.h>
34 #include <linux/kobject.h>
35 #include <linux/kref.h>
36 #include <linux/kernel.h>
37 #include <linux/jhash.h>
38 #include <linux/miscdevice.h>
39 #include <linux/mutex.h>
40 #include <asm/semaphore.h>
41 #include <asm/uaccess.h>
42 
43 #include <linux/dlm.h>
44 #include "config.h"
45 
46 #define DLM_LOCKSPACE_LEN	64
47 
48 /* Size of the temp buffer midcomms allocates on the stack.
49    We try to make this large enough so most messages fit.
50    FIXME: should sctp make this unnecessary? */
51 
52 #define DLM_INBUF_LEN		148
53 
54 struct dlm_ls;
55 struct dlm_lkb;
56 struct dlm_rsb;
57 struct dlm_member;
58 struct dlm_lkbtable;
59 struct dlm_rsbtable;
60 struct dlm_dirtable;
61 struct dlm_direntry;
62 struct dlm_recover;
63 struct dlm_header;
64 struct dlm_message;
65 struct dlm_rcom;
66 struct dlm_mhandle;
67 
68 #define log_print(fmt, args...) \
69 	printk(KERN_ERR "dlm: "fmt"\n" , ##args)
70 #define log_error(ls, fmt, args...) \
71 	printk(KERN_ERR "dlm: %s: " fmt "\n", (ls)->ls_name , ##args)
72 
73 #define log_debug(ls, fmt, args...) \
74 do { \
75 	if (dlm_config.ci_log_debug) \
76 		printk(KERN_DEBUG "dlm: %s: " fmt "\n", \
77 		       (ls)->ls_name , ##args); \
78 } while (0)
79 
80 #define DLM_ASSERT(x, do) \
81 { \
82   if (!(x)) \
83   { \
84     printk(KERN_ERR "\nDLM:  Assertion failed on line %d of file %s\n" \
85                "DLM:  assertion:  \"%s\"\n" \
86                "DLM:  time = %lu\n", \
87                __LINE__, __FILE__, #x, jiffies); \
88     {do} \
89     printk("\n"); \
90     BUG(); \
91     panic("DLM:  Record message above and reboot.\n"); \
92   } \
93 }
94 
95 #define DLM_FAKE_USER_AST ERR_PTR(-EINVAL)
96 
97 
98 struct dlm_direntry {
99 	struct list_head	list;
100 	uint32_t		master_nodeid;
101 	uint16_t		length;
102 	char			name[1];
103 };
104 
105 struct dlm_dirtable {
106 	struct list_head	list;
107 	rwlock_t		lock;
108 };
109 
110 struct dlm_rsbtable {
111 	struct list_head	list;
112 	struct list_head	toss;
113 	rwlock_t		lock;
114 };
115 
116 struct dlm_lkbtable {
117 	struct list_head	list;
118 	rwlock_t		lock;
119 	uint16_t		counter;
120 };
121 
122 /*
123  * Lockspace member (per node in a ls)
124  */
125 
126 struct dlm_member {
127 	struct list_head	list;
128 	int			nodeid;
129 	int			weight;
130 };
131 
132 /*
133  * Save and manage recovery state for a lockspace.
134  */
135 
136 struct dlm_recover {
137 	struct list_head	list;
138 	int			*nodeids;
139 	int			node_count;
140 	uint64_t		seq;
141 };
142 
143 /*
144  * Pass input args to second stage locking function.
145  */
146 
147 struct dlm_args {
148 	uint32_t		flags;
149 	void			*astaddr;
150 	long			astparam;
151 	void			*bastaddr;
152 	int			mode;
153 	struct dlm_lksb		*lksb;
154 };
155 
156 
157 /*
158  * Lock block
159  *
160  * A lock can be one of three types:
161  *
162  * local copy      lock is mastered locally
163  *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
164  * process copy    lock is mastered on a remote node
165  *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
166  * master copy     master node's copy of a lock owned by remote node
167  *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
168  *
169  * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
170  * dlm_unlock.  The dlm does not modify these or use any private flags in
171  * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
172  * are sent as-is to the remote master when the lock is remote.
173  *
174  * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
175  * Some internal flags are shared between the master and process nodes;
176  * these shared flags are kept in the lower two bytes.  One of these
177  * flags set on the master copy will be propagated to the process copy
178  * and v.v.  Other internal flags are private to the master or process
179  * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
180  *
181  * lkb_sbflags: status block flags.  These flags are copied directly into
182  * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
183  * ast.  All defined in dlm.h with DLM_SBF_ prefix.
184  *
185  * lkb_status: the lock status indicates which rsb queue the lock is
186  * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
187  *
188  * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
189  * reply is needed.  Only set when the lkb is on the lockspace waiters
190  * list awaiting a reply from a remote node.
191  *
192  * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
193  * is a master copy, nodeid specifies the remote lock holder, when the
194  * lkb is a process copy, the nodeid specifies the lock master.
195  */
196 
197 /* lkb_ast_type */
198 
199 #define AST_COMP		1
200 #define AST_BAST		2
201 
202 /* lkb_status */
203 
204 #define DLM_LKSTS_WAITING	1
205 #define DLM_LKSTS_GRANTED	2
206 #define DLM_LKSTS_CONVERT	3
207 
208 /* lkb_flags */
209 
210 #define DLM_IFL_MSTCPY		0x00010000
211 #define DLM_IFL_RESEND		0x00020000
212 #define DLM_IFL_DEAD		0x00040000
213 #define DLM_IFL_USER		0x00000001
214 #define DLM_IFL_ORPHAN		0x00000002
215 
216 struct dlm_lkb {
217 	struct dlm_rsb		*lkb_resource;	/* the rsb */
218 	struct kref		lkb_ref;
219 	int			lkb_nodeid;	/* copied from rsb */
220 	int			lkb_ownpid;	/* pid of lock owner */
221 	uint32_t		lkb_id;		/* our lock ID */
222 	uint32_t		lkb_remid;	/* lock ID on remote partner */
223 	uint32_t		lkb_exflags;	/* external flags from caller */
224 	uint32_t		lkb_sbflags;	/* lksb flags */
225 	uint32_t		lkb_flags;	/* internal flags */
226 	uint32_t		lkb_lvbseq;	/* lvb sequence number */
227 
228 	int8_t			lkb_status;     /* granted, waiting, convert */
229 	int8_t			lkb_rqmode;	/* requested lock mode */
230 	int8_t			lkb_grmode;	/* granted lock mode */
231 	int8_t			lkb_bastmode;	/* requested mode */
232 	int8_t			lkb_highbast;	/* highest mode bast sent for */
233 
234 	int8_t			lkb_wait_type;	/* type of reply waiting for */
235 	int8_t			lkb_ast_type;	/* type of ast queued for */
236 
237 	struct list_head	lkb_idtbl_list;	/* lockspace lkbtbl */
238 	struct list_head	lkb_statequeue;	/* rsb g/c/w list */
239 	struct list_head	lkb_rsb_lookup;	/* waiting for rsb lookup */
240 	struct list_head	lkb_wait_reply;	/* waiting for remote reply */
241 	struct list_head	lkb_astqueue;	/* need ast to be sent */
242 	struct list_head	lkb_ownqueue;	/* list of locks for a process */
243 
244 	char			*lkb_lvbptr;
245 	struct dlm_lksb		*lkb_lksb;      /* caller's status block */
246 	void			*lkb_astaddr;	/* caller's ast function */
247 	void			*lkb_bastaddr;	/* caller's bast function */
248 	long			lkb_astparam;	/* caller's ast arg */
249 };
250 
251 
252 struct dlm_rsb {
253 	struct dlm_ls		*res_ls;	/* the lockspace */
254 	struct kref		res_ref;
255 	struct mutex		res_mutex;
256 	unsigned long		res_flags;
257 	int			res_length;	/* length of rsb name */
258 	int			res_nodeid;
259 	uint32_t                res_lvbseq;
260 	uint32_t		res_hash;
261 	uint32_t		res_bucket;	/* rsbtbl */
262 	unsigned long		res_toss_time;
263 	uint32_t		res_first_lkid;
264 	struct list_head	res_lookup;	/* lkbs waiting on first */
265 	struct list_head	res_hashchain;	/* rsbtbl */
266 	struct list_head	res_grantqueue;
267 	struct list_head	res_convertqueue;
268 	struct list_head	res_waitqueue;
269 
270 	struct list_head	res_root_list;	    /* used for recovery */
271 	struct list_head	res_recover_list;   /* used for recovery */
272 	int			res_recover_locks_count;
273 
274 	char			*res_lvbptr;
275 	char			res_name[1];
276 };
277 
278 /* find_rsb() flags */
279 
280 #define R_MASTER		1	/* only return rsb if it's a master */
281 #define R_CREATE		2	/* create/add rsb if not found */
282 
283 /* rsb_flags */
284 
285 enum rsb_flags {
286 	RSB_MASTER_UNCERTAIN,
287 	RSB_VALNOTVALID,
288 	RSB_VALNOTVALID_PREV,
289 	RSB_NEW_MASTER,
290 	RSB_NEW_MASTER2,
291 	RSB_RECOVER_CONVERT,
292 	RSB_LOCKS_PURGED,
293 };
294 
295 static inline void rsb_set_flag(struct dlm_rsb *r, enum rsb_flags flag)
296 {
297 	__set_bit(flag, &r->res_flags);
298 }
299 
300 static inline void rsb_clear_flag(struct dlm_rsb *r, enum rsb_flags flag)
301 {
302 	__clear_bit(flag, &r->res_flags);
303 }
304 
305 static inline int rsb_flag(struct dlm_rsb *r, enum rsb_flags flag)
306 {
307 	return test_bit(flag, &r->res_flags);
308 }
309 
310 
311 /* dlm_header is first element of all structs sent between nodes */
312 
313 #define DLM_HEADER_MAJOR	0x00030000
314 #define DLM_HEADER_MINOR	0x00000000
315 
316 #define DLM_MSG			1
317 #define DLM_RCOM		2
318 
319 struct dlm_header {
320 	uint32_t		h_version;
321 	uint32_t		h_lockspace;
322 	uint32_t		h_nodeid;	/* nodeid of sender */
323 	uint16_t		h_length;
324 	uint8_t			h_cmd;		/* DLM_MSG, DLM_RCOM */
325 	uint8_t			h_pad;
326 };
327 
328 
329 #define DLM_MSG_REQUEST		1
330 #define DLM_MSG_CONVERT		2
331 #define DLM_MSG_UNLOCK		3
332 #define DLM_MSG_CANCEL		4
333 #define DLM_MSG_REQUEST_REPLY	5
334 #define DLM_MSG_CONVERT_REPLY	6
335 #define DLM_MSG_UNLOCK_REPLY	7
336 #define DLM_MSG_CANCEL_REPLY	8
337 #define DLM_MSG_GRANT		9
338 #define DLM_MSG_BAST		10
339 #define DLM_MSG_LOOKUP		11
340 #define DLM_MSG_REMOVE		12
341 #define DLM_MSG_LOOKUP_REPLY	13
342 
343 struct dlm_message {
344 	struct dlm_header	m_header;
345 	uint32_t		m_type;		/* DLM_MSG_ */
346 	uint32_t		m_nodeid;
347 	uint32_t		m_pid;
348 	uint32_t		m_lkid;		/* lkid on sender */
349 	uint32_t		m_remid;	/* lkid on receiver */
350 	uint32_t		m_parent_lkid;
351 	uint32_t		m_parent_remid;
352 	uint32_t		m_exflags;
353 	uint32_t		m_sbflags;
354 	uint32_t		m_flags;
355 	uint32_t		m_lvbseq;
356 	uint32_t		m_hash;
357 	int			m_status;
358 	int			m_grmode;
359 	int			m_rqmode;
360 	int			m_bastmode;
361 	int			m_asts;
362 	int			m_result;	/* 0 or -EXXX */
363 	char			m_extra[0];	/* name or lvb */
364 };
365 
366 
367 #define DLM_RS_NODES		0x00000001
368 #define DLM_RS_NODES_ALL	0x00000002
369 #define DLM_RS_DIR		0x00000004
370 #define DLM_RS_DIR_ALL		0x00000008
371 #define DLM_RS_LOCKS		0x00000010
372 #define DLM_RS_LOCKS_ALL	0x00000020
373 #define DLM_RS_DONE		0x00000040
374 #define DLM_RS_DONE_ALL		0x00000080
375 
376 #define DLM_RCOM_STATUS		1
377 #define DLM_RCOM_NAMES		2
378 #define DLM_RCOM_LOOKUP		3
379 #define DLM_RCOM_LOCK		4
380 #define DLM_RCOM_STATUS_REPLY	5
381 #define DLM_RCOM_NAMES_REPLY	6
382 #define DLM_RCOM_LOOKUP_REPLY	7
383 #define DLM_RCOM_LOCK_REPLY	8
384 
385 struct dlm_rcom {
386 	struct dlm_header	rc_header;
387 	uint32_t		rc_type;	/* DLM_RCOM_ */
388 	int			rc_result;	/* multi-purpose */
389 	uint64_t		rc_id;		/* match reply with request */
390 	uint64_t		rc_seq;		/* sender's ls_recover_seq */
391 	uint64_t		rc_seq_reply;	/* remote ls_recover_seq */
392 	char			rc_buf[0];
393 };
394 
395 struct rcom_config {
396 	uint32_t		rf_lvblen;
397 	uint32_t		rf_lsflags;
398 	uint64_t		rf_unused;
399 };
400 
401 struct rcom_lock {
402 	uint32_t		rl_ownpid;
403 	uint32_t		rl_lkid;
404 	uint32_t		rl_remid;
405 	uint32_t		rl_parent_lkid;
406 	uint32_t		rl_parent_remid;
407 	uint32_t		rl_exflags;
408 	uint32_t		rl_flags;
409 	uint32_t		rl_lvbseq;
410 	int			rl_result;
411 	int8_t			rl_rqmode;
412 	int8_t			rl_grmode;
413 	int8_t			rl_status;
414 	int8_t			rl_asts;
415 	uint16_t		rl_wait_type;
416 	uint16_t		rl_namelen;
417 	char			rl_name[DLM_RESNAME_MAXLEN];
418 	char			rl_lvb[0];
419 };
420 
421 struct dlm_ls {
422 	struct list_head	ls_list;	/* list of lockspaces */
423 	dlm_lockspace_t		*ls_local_handle;
424 	uint32_t		ls_global_id;	/* global unique lockspace ID */
425 	uint32_t		ls_exflags;
426 	int			ls_lvblen;
427 	int			ls_count;	/* reference count */
428 	unsigned long		ls_flags;	/* LSFL_ */
429 	struct kobject		ls_kobj;
430 
431 	struct dlm_rsbtable	*ls_rsbtbl;
432 	uint32_t		ls_rsbtbl_size;
433 
434 	struct dlm_lkbtable	*ls_lkbtbl;
435 	uint32_t		ls_lkbtbl_size;
436 
437 	struct dlm_dirtable	*ls_dirtbl;
438 	uint32_t		ls_dirtbl_size;
439 
440 	struct mutex		ls_waiters_mutex;
441 	struct list_head	ls_waiters;	/* lkbs needing a reply */
442 
443 	struct list_head	ls_nodes;	/* current nodes in ls */
444 	struct list_head	ls_nodes_gone;	/* dead node list, recovery */
445 	int			ls_num_nodes;	/* number of nodes in ls */
446 	int			ls_low_nodeid;
447 	int			ls_total_weight;
448 	int			*ls_node_array;
449 
450 	struct dlm_rsb		ls_stub_rsb;	/* for returning errors */
451 	struct dlm_lkb		ls_stub_lkb;	/* for returning errors */
452 	struct dlm_message	ls_stub_ms;	/* for faking a reply */
453 
454 	struct dentry		*ls_debug_rsb_dentry; /* debugfs */
455 	struct dentry		*ls_debug_waiters_dentry; /* debugfs */
456 
457 	wait_queue_head_t	ls_uevent_wait;	/* user part of join/leave */
458 	int			ls_uevent_result;
459 
460 	struct miscdevice       ls_device;
461 
462 	/* recovery related */
463 
464 	struct timer_list	ls_timer;
465 	struct task_struct	*ls_recoverd_task;
466 	struct mutex		ls_recoverd_active;
467 	spinlock_t		ls_recover_lock;
468 	uint32_t		ls_recover_status; /* DLM_RS_ */
469 	uint64_t		ls_recover_seq;
470 	struct dlm_recover	*ls_recover_args;
471 	struct rw_semaphore	ls_in_recovery;	/* block local requests */
472 	struct list_head	ls_requestqueue;/* queue remote requests */
473 	struct mutex		ls_requestqueue_mutex;
474 	char			*ls_recover_buf;
475 	int			ls_recover_nodeid; /* for debugging */
476 	uint64_t		ls_rcom_seq;
477 	spinlock_t		ls_rcom_spin;
478 	struct list_head	ls_recover_list;
479 	spinlock_t		ls_recover_list_lock;
480 	int			ls_recover_list_count;
481 	wait_queue_head_t	ls_wait_general;
482 	struct mutex		ls_clear_proc_locks;
483 
484 	struct list_head	ls_root_list;	/* root resources */
485 	struct rw_semaphore	ls_root_sem;	/* protect root_list */
486 
487 	int			ls_namelen;
488 	char			ls_name[1];
489 };
490 
491 #define LSFL_WORK		0
492 #define LSFL_RUNNING		1
493 #define LSFL_RECOVERY_STOP	2
494 #define LSFL_RCOM_READY		3
495 #define LSFL_RCOM_WAIT		4
496 #define LSFL_UEVENT_WAIT	5
497 
498 /* much of this is just saving user space pointers associated with the
499    lock that we pass back to the user lib with an ast */
500 
501 struct dlm_user_args {
502 	struct dlm_user_proc	*proc; /* each process that opens the lockspace
503 					  device has private data
504 					  (dlm_user_proc) on the struct file,
505 					  the process's locks point back to it*/
506 	struct dlm_lksb		lksb;
507 	int			old_mode;
508 	int			update_user_lvb;
509 	struct dlm_lksb __user	*user_lksb;
510 	void __user		*castparam;
511 	void __user		*castaddr;
512 	void __user		*bastparam;
513 	void __user		*bastaddr;
514 };
515 
516 #define DLM_PROC_FLAGS_CLOSING 1
517 #define DLM_PROC_FLAGS_COMPAT  2
518 
519 /* locks list is kept so we can remove all a process's locks when it
520    exits (or orphan those that are persistent) */
521 
522 struct dlm_user_proc {
523 	dlm_lockspace_t		*lockspace;
524 	unsigned long		flags; /* DLM_PROC_FLAGS */
525 	struct list_head	asts;
526 	spinlock_t		asts_spin;
527 	struct list_head	locks;
528 	spinlock_t		locks_spin;
529 	struct list_head	unlocking;
530 	wait_queue_head_t	wait;
531 };
532 
533 static inline int dlm_locking_stopped(struct dlm_ls *ls)
534 {
535 	return !test_bit(LSFL_RUNNING, &ls->ls_flags);
536 }
537 
538 static inline int dlm_recovery_stopped(struct dlm_ls *ls)
539 {
540 	return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
541 }
542 
543 static inline int dlm_no_directory(struct dlm_ls *ls)
544 {
545 	return (ls->ls_exflags & DLM_LSFL_NODIR) ? 1 : 0;
546 }
547 
548 #endif				/* __DLM_INTERNAL_DOT_H__ */
549 
550