xref: /openbmc/linux/fs/dlm/dlm_internal.h (revision a1e58bbd)
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2004-2007 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 
96 struct dlm_direntry {
97 	struct list_head	list;
98 	uint32_t		master_nodeid;
99 	uint16_t		length;
100 	char			name[1];
101 };
102 
103 struct dlm_dirtable {
104 	struct list_head	list;
105 	rwlock_t		lock;
106 };
107 
108 struct dlm_rsbtable {
109 	struct list_head	list;
110 	struct list_head	toss;
111 	rwlock_t		lock;
112 };
113 
114 struct dlm_lkbtable {
115 	struct list_head	list;
116 	rwlock_t		lock;
117 	uint16_t		counter;
118 };
119 
120 /*
121  * Lockspace member (per node in a ls)
122  */
123 
124 struct dlm_member {
125 	struct list_head	list;
126 	int			nodeid;
127 	int			weight;
128 };
129 
130 /*
131  * Save and manage recovery state for a lockspace.
132  */
133 
134 struct dlm_recover {
135 	struct list_head	list;
136 	int			*nodeids;
137 	int			node_count;
138 	uint64_t		seq;
139 };
140 
141 /*
142  * Pass input args to second stage locking function.
143  */
144 
145 struct dlm_args {
146 	uint32_t		flags;
147 	void			(*astfn) (void *astparam);
148 	void			*astparam;
149 	void			(*bastfn) (void *astparam, int mode);
150 	int			mode;
151 	struct dlm_lksb		*lksb;
152 	unsigned long		timeout;
153 };
154 
155 
156 /*
157  * Lock block
158  *
159  * A lock can be one of three types:
160  *
161  * local copy      lock is mastered locally
162  *                 (lkb_nodeid is zero and DLM_LKF_MSTCPY is not set)
163  * process copy    lock is mastered on a remote node
164  *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is not set)
165  * master copy     master node's copy of a lock owned by remote node
166  *                 (lkb_nodeid is non-zero and DLM_LKF_MSTCPY is set)
167  *
168  * lkb_exflags: a copy of the most recent flags arg provided to dlm_lock or
169  * dlm_unlock.  The dlm does not modify these or use any private flags in
170  * this field; it only contains DLM_LKF_ flags from dlm.h.  These flags
171  * are sent as-is to the remote master when the lock is remote.
172  *
173  * lkb_flags: internal dlm flags (DLM_IFL_ prefix) from dlm_internal.h.
174  * Some internal flags are shared between the master and process nodes;
175  * these shared flags are kept in the lower two bytes.  One of these
176  * flags set on the master copy will be propagated to the process copy
177  * and v.v.  Other internal flags are private to the master or process
178  * node (e.g. DLM_IFL_MSTCPY).  These are kept in the high two bytes.
179  *
180  * lkb_sbflags: status block flags.  These flags are copied directly into
181  * the caller's lksb.sb_flags prior to the dlm_lock/dlm_unlock completion
182  * ast.  All defined in dlm.h with DLM_SBF_ prefix.
183  *
184  * lkb_status: the lock status indicates which rsb queue the lock is
185  * on, grant, convert, or wait.  DLM_LKSTS_ WAITING/GRANTED/CONVERT
186  *
187  * lkb_wait_type: the dlm message type (DLM_MSG_ prefix) for which a
188  * reply is needed.  Only set when the lkb is on the lockspace waiters
189  * list awaiting a reply from a remote node.
190  *
191  * lkb_nodeid: when the lkb is a local copy, nodeid is 0; when the lkb
192  * is a master copy, nodeid specifies the remote lock holder, when the
193  * lkb is a process copy, the nodeid specifies the lock master.
194  */
195 
196 /* lkb_ast_type */
197 
198 #define AST_COMP		1
199 #define AST_BAST		2
200 
201 /* lkb_status */
202 
203 #define DLM_LKSTS_WAITING	1
204 #define DLM_LKSTS_GRANTED	2
205 #define DLM_LKSTS_CONVERT	3
206 
207 /* lkb_flags */
208 
209 #define DLM_IFL_MSTCPY		0x00010000
210 #define DLM_IFL_RESEND		0x00020000
211 #define DLM_IFL_DEAD		0x00040000
212 #define DLM_IFL_OVERLAP_UNLOCK  0x00080000
213 #define DLM_IFL_OVERLAP_CANCEL  0x00100000
214 #define DLM_IFL_ENDOFLIFE	0x00200000
215 #define DLM_IFL_WATCH_TIMEWARN	0x00400000
216 #define DLM_IFL_TIMEOUT_CANCEL	0x00800000
217 #define DLM_IFL_DEADLOCK_CANCEL	0x01000000
218 #define DLM_IFL_USER		0x00000001
219 #define DLM_IFL_ORPHAN		0x00000002
220 
221 struct dlm_lkb {
222 	struct dlm_rsb		*lkb_resource;	/* the rsb */
223 	struct kref		lkb_ref;
224 	int			lkb_nodeid;	/* copied from rsb */
225 	int			lkb_ownpid;	/* pid of lock owner */
226 	uint32_t		lkb_id;		/* our lock ID */
227 	uint32_t		lkb_remid;	/* lock ID on remote partner */
228 	uint32_t		lkb_exflags;	/* external flags from caller */
229 	uint32_t		lkb_sbflags;	/* lksb flags */
230 	uint32_t		lkb_flags;	/* internal flags */
231 	uint32_t		lkb_lvbseq;	/* lvb sequence number */
232 
233 	int8_t			lkb_status;     /* granted, waiting, convert */
234 	int8_t			lkb_rqmode;	/* requested lock mode */
235 	int8_t			lkb_grmode;	/* granted lock mode */
236 	int8_t			lkb_bastmode;	/* requested mode */
237 	int8_t			lkb_highbast;	/* highest mode bast sent for */
238 	int8_t			lkb_wait_type;	/* type of reply waiting for */
239 	int8_t			lkb_wait_count;
240 	int8_t			lkb_ast_type;	/* type of ast queued for */
241 
242 	struct list_head	lkb_idtbl_list;	/* lockspace lkbtbl */
243 	struct list_head	lkb_statequeue;	/* rsb g/c/w list */
244 	struct list_head	lkb_rsb_lookup;	/* waiting for rsb lookup */
245 	struct list_head	lkb_wait_reply;	/* waiting for remote reply */
246 	struct list_head	lkb_astqueue;	/* need ast to be sent */
247 	struct list_head	lkb_ownqueue;	/* list of locks for a process */
248 	struct list_head	lkb_time_list;
249 	unsigned long		lkb_timestamp;
250 	unsigned long		lkb_timeout_cs;
251 
252 	char			*lkb_lvbptr;
253 	struct dlm_lksb		*lkb_lksb;      /* caller's status block */
254 	void			(*lkb_astfn) (void *astparam);
255 	void			(*lkb_bastfn) (void *astparam, int mode);
256 	union {
257 		void			*lkb_astparam;	/* caller's ast arg */
258 		struct dlm_user_args	*lkb_ua;
259 	};
260 };
261 
262 
263 struct dlm_rsb {
264 	struct dlm_ls		*res_ls;	/* the lockspace */
265 	struct kref		res_ref;
266 	struct mutex		res_mutex;
267 	unsigned long		res_flags;
268 	int			res_length;	/* length of rsb name */
269 	int			res_nodeid;
270 	uint32_t                res_lvbseq;
271 	uint32_t		res_hash;
272 	uint32_t		res_bucket;	/* rsbtbl */
273 	unsigned long		res_toss_time;
274 	uint32_t		res_first_lkid;
275 	struct list_head	res_lookup;	/* lkbs waiting on first */
276 	struct list_head	res_hashchain;	/* rsbtbl */
277 	struct list_head	res_grantqueue;
278 	struct list_head	res_convertqueue;
279 	struct list_head	res_waitqueue;
280 
281 	struct list_head	res_root_list;	    /* used for recovery */
282 	struct list_head	res_recover_list;   /* used for recovery */
283 	int			res_recover_locks_count;
284 
285 	char			*res_lvbptr;
286 	char			res_name[1];
287 };
288 
289 /* find_rsb() flags */
290 
291 #define R_MASTER		1	/* only return rsb if it's a master */
292 #define R_CREATE		2	/* create/add rsb if not found */
293 
294 /* rsb_flags */
295 
296 enum rsb_flags {
297 	RSB_MASTER_UNCERTAIN,
298 	RSB_VALNOTVALID,
299 	RSB_VALNOTVALID_PREV,
300 	RSB_NEW_MASTER,
301 	RSB_NEW_MASTER2,
302 	RSB_RECOVER_CONVERT,
303 	RSB_LOCKS_PURGED,
304 };
305 
306 static inline void rsb_set_flag(struct dlm_rsb *r, enum rsb_flags flag)
307 {
308 	__set_bit(flag, &r->res_flags);
309 }
310 
311 static inline void rsb_clear_flag(struct dlm_rsb *r, enum rsb_flags flag)
312 {
313 	__clear_bit(flag, &r->res_flags);
314 }
315 
316 static inline int rsb_flag(struct dlm_rsb *r, enum rsb_flags flag)
317 {
318 	return test_bit(flag, &r->res_flags);
319 }
320 
321 
322 /* dlm_header is first element of all structs sent between nodes */
323 
324 #define DLM_HEADER_MAJOR	0x00030000
325 #define DLM_HEADER_MINOR	0x00000000
326 
327 #define DLM_MSG			1
328 #define DLM_RCOM		2
329 
330 struct dlm_header {
331 	uint32_t		h_version;
332 	uint32_t		h_lockspace;
333 	uint32_t		h_nodeid;	/* nodeid of sender */
334 	uint16_t		h_length;
335 	uint8_t			h_cmd;		/* DLM_MSG, DLM_RCOM */
336 	uint8_t			h_pad;
337 };
338 
339 
340 #define DLM_MSG_REQUEST		1
341 #define DLM_MSG_CONVERT		2
342 #define DLM_MSG_UNLOCK		3
343 #define DLM_MSG_CANCEL		4
344 #define DLM_MSG_REQUEST_REPLY	5
345 #define DLM_MSG_CONVERT_REPLY	6
346 #define DLM_MSG_UNLOCK_REPLY	7
347 #define DLM_MSG_CANCEL_REPLY	8
348 #define DLM_MSG_GRANT		9
349 #define DLM_MSG_BAST		10
350 #define DLM_MSG_LOOKUP		11
351 #define DLM_MSG_REMOVE		12
352 #define DLM_MSG_LOOKUP_REPLY	13
353 #define DLM_MSG_PURGE		14
354 
355 struct dlm_message {
356 	struct dlm_header	m_header;
357 	uint32_t		m_type;		/* DLM_MSG_ */
358 	uint32_t		m_nodeid;
359 	uint32_t		m_pid;
360 	uint32_t		m_lkid;		/* lkid on sender */
361 	uint32_t		m_remid;	/* lkid on receiver */
362 	uint32_t		m_parent_lkid;
363 	uint32_t		m_parent_remid;
364 	uint32_t		m_exflags;
365 	uint32_t		m_sbflags;
366 	uint32_t		m_flags;
367 	uint32_t		m_lvbseq;
368 	uint32_t		m_hash;
369 	int			m_status;
370 	int			m_grmode;
371 	int			m_rqmode;
372 	int			m_bastmode;
373 	int			m_asts;
374 	int			m_result;	/* 0 or -EXXX */
375 	char			m_extra[0];	/* name or lvb */
376 };
377 
378 
379 #define DLM_RS_NODES		0x00000001
380 #define DLM_RS_NODES_ALL	0x00000002
381 #define DLM_RS_DIR		0x00000004
382 #define DLM_RS_DIR_ALL		0x00000008
383 #define DLM_RS_LOCKS		0x00000010
384 #define DLM_RS_LOCKS_ALL	0x00000020
385 #define DLM_RS_DONE		0x00000040
386 #define DLM_RS_DONE_ALL		0x00000080
387 
388 #define DLM_RCOM_STATUS		1
389 #define DLM_RCOM_NAMES		2
390 #define DLM_RCOM_LOOKUP		3
391 #define DLM_RCOM_LOCK		4
392 #define DLM_RCOM_STATUS_REPLY	5
393 #define DLM_RCOM_NAMES_REPLY	6
394 #define DLM_RCOM_LOOKUP_REPLY	7
395 #define DLM_RCOM_LOCK_REPLY	8
396 
397 struct dlm_rcom {
398 	struct dlm_header	rc_header;
399 	uint32_t		rc_type;	/* DLM_RCOM_ */
400 	int			rc_result;	/* multi-purpose */
401 	uint64_t		rc_id;		/* match reply with request */
402 	uint64_t		rc_seq;		/* sender's ls_recover_seq */
403 	uint64_t		rc_seq_reply;	/* remote ls_recover_seq */
404 	char			rc_buf[0];
405 };
406 
407 union dlm_packet {
408 	struct dlm_header	header;		/* common to other two */
409 	struct dlm_message	message;
410 	struct dlm_rcom		rcom;
411 };
412 
413 struct rcom_config {
414 	__le32			rf_lvblen;
415 	__le32			rf_lsflags;
416 	__le64			rf_unused;
417 };
418 
419 struct rcom_lock {
420 	__le32			rl_ownpid;
421 	__le32			rl_lkid;
422 	__le32			rl_remid;
423 	__le32			rl_parent_lkid;
424 	__le32			rl_parent_remid;
425 	__le32			rl_exflags;
426 	__le32			rl_flags;
427 	__le32			rl_lvbseq;
428 	__le32			rl_result;
429 	int8_t			rl_rqmode;
430 	int8_t			rl_grmode;
431 	int8_t			rl_status;
432 	int8_t			rl_asts;
433 	__le16			rl_wait_type;
434 	__le16			rl_namelen;
435 	char			rl_name[DLM_RESNAME_MAXLEN];
436 	char			rl_lvb[0];
437 };
438 
439 struct dlm_ls {
440 	struct list_head	ls_list;	/* list of lockspaces */
441 	dlm_lockspace_t		*ls_local_handle;
442 	uint32_t		ls_global_id;	/* global unique lockspace ID */
443 	uint32_t		ls_exflags;
444 	int			ls_lvblen;
445 	int			ls_count;	/* reference count */
446 	unsigned long		ls_flags;	/* LSFL_ */
447 	struct kobject		ls_kobj;
448 
449 	struct dlm_rsbtable	*ls_rsbtbl;
450 	uint32_t		ls_rsbtbl_size;
451 
452 	struct dlm_lkbtable	*ls_lkbtbl;
453 	uint32_t		ls_lkbtbl_size;
454 
455 	struct dlm_dirtable	*ls_dirtbl;
456 	uint32_t		ls_dirtbl_size;
457 
458 	struct mutex		ls_waiters_mutex;
459 	struct list_head	ls_waiters;	/* lkbs needing a reply */
460 
461 	struct mutex		ls_orphans_mutex;
462 	struct list_head	ls_orphans;
463 
464 	struct mutex		ls_timeout_mutex;
465 	struct list_head	ls_timeout;
466 
467 	struct list_head	ls_nodes;	/* current nodes in ls */
468 	struct list_head	ls_nodes_gone;	/* dead node list, recovery */
469 	int			ls_num_nodes;	/* number of nodes in ls */
470 	int			ls_low_nodeid;
471 	int			ls_total_weight;
472 	int			*ls_node_array;
473 	gfp_t			ls_allocation;
474 
475 	struct dlm_rsb		ls_stub_rsb;	/* for returning errors */
476 	struct dlm_lkb		ls_stub_lkb;	/* for returning errors */
477 	struct dlm_message	ls_stub_ms;	/* for faking a reply */
478 
479 	struct dentry		*ls_debug_rsb_dentry; /* debugfs */
480 	struct dentry		*ls_debug_waiters_dentry; /* debugfs */
481 	struct dentry		*ls_debug_locks_dentry; /* debugfs */
482 
483 	wait_queue_head_t	ls_uevent_wait;	/* user part of join/leave */
484 	int			ls_uevent_result;
485 	struct completion	ls_members_done;
486 	int			ls_members_result;
487 
488 	struct miscdevice       ls_device;
489 
490 	/* recovery related */
491 
492 	struct timer_list	ls_timer;
493 	struct task_struct	*ls_recoverd_task;
494 	struct mutex		ls_recoverd_active;
495 	spinlock_t		ls_recover_lock;
496 	unsigned long		ls_recover_begin; /* jiffies timestamp */
497 	uint32_t		ls_recover_status; /* DLM_RS_ */
498 	uint64_t		ls_recover_seq;
499 	struct dlm_recover	*ls_recover_args;
500 	struct rw_semaphore	ls_in_recovery;	/* block local requests */
501 	struct rw_semaphore	ls_recv_active;	/* block dlm_recv */
502 	struct list_head	ls_requestqueue;/* queue remote requests */
503 	struct mutex		ls_requestqueue_mutex;
504 	struct dlm_rcom		*ls_recover_buf;
505 	int			ls_recover_nodeid; /* for debugging */
506 	uint64_t		ls_rcom_seq;
507 	spinlock_t		ls_rcom_spin;
508 	struct list_head	ls_recover_list;
509 	spinlock_t		ls_recover_list_lock;
510 	int			ls_recover_list_count;
511 	wait_queue_head_t	ls_wait_general;
512 	struct mutex		ls_clear_proc_locks;
513 
514 	struct list_head	ls_root_list;	/* root resources */
515 	struct rw_semaphore	ls_root_sem;	/* protect root_list */
516 
517 	int			ls_namelen;
518 	char			ls_name[1];
519 };
520 
521 #define LSFL_WORK		0
522 #define LSFL_RUNNING		1
523 #define LSFL_RECOVERY_STOP	2
524 #define LSFL_RCOM_READY		3
525 #define LSFL_RCOM_WAIT		4
526 #define LSFL_UEVENT_WAIT	5
527 #define LSFL_TIMEWARN		6
528 
529 /* much of this is just saving user space pointers associated with the
530    lock that we pass back to the user lib with an ast */
531 
532 struct dlm_user_args {
533 	struct dlm_user_proc	*proc; /* each process that opens the lockspace
534 					  device has private data
535 					  (dlm_user_proc) on the struct file,
536 					  the process's locks point back to it*/
537 	struct dlm_lksb		lksb;
538 	int			old_mode;
539 	int			update_user_lvb;
540 	struct dlm_lksb __user	*user_lksb;
541 	void __user		*castparam;
542 	void __user		*castaddr;
543 	void __user		*bastparam;
544 	void __user		*bastaddr;
545 	uint64_t		xid;
546 };
547 
548 #define DLM_PROC_FLAGS_CLOSING 1
549 #define DLM_PROC_FLAGS_COMPAT  2
550 
551 /* locks list is kept so we can remove all a process's locks when it
552    exits (or orphan those that are persistent) */
553 
554 struct dlm_user_proc {
555 	dlm_lockspace_t		*lockspace;
556 	unsigned long		flags; /* DLM_PROC_FLAGS */
557 	struct list_head	asts;
558 	spinlock_t		asts_spin;
559 	struct list_head	locks;
560 	spinlock_t		locks_spin;
561 	struct list_head	unlocking;
562 	wait_queue_head_t	wait;
563 };
564 
565 static inline int dlm_locking_stopped(struct dlm_ls *ls)
566 {
567 	return !test_bit(LSFL_RUNNING, &ls->ls_flags);
568 }
569 
570 static inline int dlm_recovery_stopped(struct dlm_ls *ls)
571 {
572 	return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
573 }
574 
575 static inline int dlm_no_directory(struct dlm_ls *ls)
576 {
577 	return (ls->ls_exflags & DLM_LSFL_NODIR) ? 1 : 0;
578 }
579 
580 int dlm_netlink_init(void);
581 void dlm_netlink_exit(void);
582 void dlm_timeout_warn(struct dlm_lkb *lkb);
583 
584 #ifdef CONFIG_DLM_DEBUG
585 int dlm_register_debugfs(void);
586 void dlm_unregister_debugfs(void);
587 int dlm_create_debug_file(struct dlm_ls *ls);
588 void dlm_delete_debug_file(struct dlm_ls *ls);
589 #else
590 static inline int dlm_register_debugfs(void) { return 0; }
591 static inline void dlm_unregister_debugfs(void) { }
592 static inline int dlm_create_debug_file(struct dlm_ls *ls) { return 0; }
593 static inline void dlm_delete_debug_file(struct dlm_ls *ls) { }
594 #endif
595 
596 #endif				/* __DLM_INTERNAL_DOT_H__ */
597 
598