1 /*
2   drbd_int.h
3 
4   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
5 
6   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
7   Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
8   Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
9 
10   drbd is free software; you can redistribute it and/or modify
11   it under the terms of the GNU General Public License as published by
12   the Free Software Foundation; either version 2, or (at your option)
13   any later version.
14 
15   drbd is distributed in the hope that it will be useful,
16   but WITHOUT ANY WARRANTY; without even the implied warranty of
17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
18   GNU General Public License for more details.
19 
20   You should have received a copy of the GNU General Public License
21   along with drbd; see the file COPYING.  If not, write to
22   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
23 
24 */
25 
26 #ifndef _DRBD_INT_H
27 #define _DRBD_INT_H
28 
29 #include <crypto/hash.h>
30 #include <linux/compiler.h>
31 #include <linux/types.h>
32 #include <linux/list.h>
33 #include <linux/sched/signal.h>
34 #include <linux/bitops.h>
35 #include <linux/slab.h>
36 #include <linux/ratelimit.h>
37 #include <linux/tcp.h>
38 #include <linux/mutex.h>
39 #include <linux/major.h>
40 #include <linux/blkdev.h>
41 #include <linux/backing-dev.h>
42 #include <linux/genhd.h>
43 #include <linux/idr.h>
44 #include <linux/dynamic_debug.h>
45 #include <net/tcp.h>
46 #include <linux/lru_cache.h>
47 #include <linux/prefetch.h>
48 #include <linux/drbd_genl_api.h>
49 #include <linux/drbd.h>
50 #include "drbd_strings.h"
51 #include "drbd_state.h"
52 #include "drbd_protocol.h"
53 
54 #ifdef __CHECKER__
55 # define __protected_by(x)       __attribute__((require_context(x,1,999,"rdwr")))
56 # define __protected_read_by(x)  __attribute__((require_context(x,1,999,"read")))
57 # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write")))
58 #else
59 # define __protected_by(x)
60 # define __protected_read_by(x)
61 # define __protected_write_by(x)
62 #endif
63 
64 /* shared module parameters, defined in drbd_main.c */
65 #ifdef CONFIG_DRBD_FAULT_INJECTION
66 extern int drbd_enable_faults;
67 extern int drbd_fault_rate;
68 #endif
69 
70 extern unsigned int drbd_minor_count;
71 extern char drbd_usermode_helper[];
72 extern int drbd_proc_details;
73 
74 
75 /* This is used to stop/restart our threads.
76  * Cannot use SIGTERM nor SIGKILL, since these
77  * are sent out by init on runlevel changes
78  * I choose SIGHUP for now.
79  */
80 #define DRBD_SIGKILL SIGHUP
81 
82 #define ID_IN_SYNC      (4711ULL)
83 #define ID_OUT_OF_SYNC  (4712ULL)
84 #define ID_SYNCER (-1ULL)
85 
86 #define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL)
87 
88 struct drbd_device;
89 struct drbd_connection;
90 
91 #define __drbd_printk_device(level, device, fmt, args...) \
92 	dev_printk(level, disk_to_dev((device)->vdisk), fmt, ## args)
93 #define __drbd_printk_peer_device(level, peer_device, fmt, args...) \
94 	dev_printk(level, disk_to_dev((peer_device)->device->vdisk), fmt, ## args)
95 #define __drbd_printk_resource(level, resource, fmt, args...) \
96 	printk(level "drbd %s: " fmt, (resource)->name, ## args)
97 #define __drbd_printk_connection(level, connection, fmt, args...) \
98 	printk(level "drbd %s: " fmt, (connection)->resource->name, ## args)
99 
100 void drbd_printk_with_wrong_object_type(void);
101 
102 #define __drbd_printk_if_same_type(obj, type, func, level, fmt, args...) \
103 	(__builtin_types_compatible_p(typeof(obj), type) || \
104 	 __builtin_types_compatible_p(typeof(obj), const type)), \
105 	func(level, (const type)(obj), fmt, ## args)
106 
107 #define drbd_printk(level, obj, fmt, args...) \
108 	__builtin_choose_expr( \
109 	  __drbd_printk_if_same_type(obj, struct drbd_device *, \
110 			     __drbd_printk_device, level, fmt, ## args), \
111 	  __builtin_choose_expr( \
112 	    __drbd_printk_if_same_type(obj, struct drbd_resource *, \
113 			       __drbd_printk_resource, level, fmt, ## args), \
114 	    __builtin_choose_expr( \
115 	      __drbd_printk_if_same_type(obj, struct drbd_connection *, \
116 				 __drbd_printk_connection, level, fmt, ## args), \
117 	      __builtin_choose_expr( \
118 		__drbd_printk_if_same_type(obj, struct drbd_peer_device *, \
119 				 __drbd_printk_peer_device, level, fmt, ## args), \
120 		drbd_printk_with_wrong_object_type()))))
121 
122 #define drbd_dbg(obj, fmt, args...) \
123 	drbd_printk(KERN_DEBUG, obj, fmt, ## args)
124 #define drbd_alert(obj, fmt, args...) \
125 	drbd_printk(KERN_ALERT, obj, fmt, ## args)
126 #define drbd_err(obj, fmt, args...) \
127 	drbd_printk(KERN_ERR, obj, fmt, ## args)
128 #define drbd_warn(obj, fmt, args...) \
129 	drbd_printk(KERN_WARNING, obj, fmt, ## args)
130 #define drbd_info(obj, fmt, args...) \
131 	drbd_printk(KERN_INFO, obj, fmt, ## args)
132 #define drbd_emerg(obj, fmt, args...) \
133 	drbd_printk(KERN_EMERG, obj, fmt, ## args)
134 
135 #define dynamic_drbd_dbg(device, fmt, args...) \
136 	dynamic_dev_dbg(disk_to_dev(device->vdisk), fmt, ## args)
137 
138 #define D_ASSERT(device, exp)	do { \
139 	if (!(exp)) \
140 		drbd_err(device, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__); \
141 	} while (0)
142 
143 /**
144  * expect  -  Make an assertion
145  *
146  * Unlike the assert macro, this macro returns a boolean result.
147  */
148 #define expect(exp) ({								\
149 		bool _bool = (exp);						\
150 		if (!_bool)							\
151 			drbd_err(device, "ASSERTION %s FAILED in %s\n",		\
152 			        #exp, __func__);				\
153 		_bool;								\
154 		})
155 
156 /* Defines to control fault insertion */
157 enum {
158 	DRBD_FAULT_MD_WR = 0,	/* meta data write */
159 	DRBD_FAULT_MD_RD = 1,	/*           read  */
160 	DRBD_FAULT_RS_WR = 2,	/* resync          */
161 	DRBD_FAULT_RS_RD = 3,
162 	DRBD_FAULT_DT_WR = 4,	/* data            */
163 	DRBD_FAULT_DT_RD = 5,
164 	DRBD_FAULT_DT_RA = 6,	/* data read ahead */
165 	DRBD_FAULT_BM_ALLOC = 7,	/* bitmap allocation */
166 	DRBD_FAULT_AL_EE = 8,	/* alloc ee */
167 	DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */
168 
169 	DRBD_FAULT_MAX,
170 };
171 
172 extern unsigned int
173 _drbd_insert_fault(struct drbd_device *device, unsigned int type);
174 
175 static inline int
drbd_insert_fault(struct drbd_device * device,unsigned int type)176 drbd_insert_fault(struct drbd_device *device, unsigned int type) {
177 #ifdef CONFIG_DRBD_FAULT_INJECTION
178 	return drbd_fault_rate &&
179 		(drbd_enable_faults & (1<<type)) &&
180 		_drbd_insert_fault(device, type);
181 #else
182 	return 0;
183 #endif
184 }
185 
186 /* integer division, round _UP_ to the next integer */
187 #define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0))
188 /* usual integer division */
189 #define div_floor(A, B) ((A)/(B))
190 
191 extern struct ratelimit_state drbd_ratelimit_state;
192 extern struct idr drbd_devices; /* RCU, updates: genl_lock() */
193 extern struct list_head drbd_resources; /* RCU, updates: genl_lock() */
194 
195 extern const char *cmdname(enum drbd_packet cmd);
196 
197 /* for sending/receiving the bitmap,
198  * possibly in some encoding scheme */
199 struct bm_xfer_ctx {
200 	/* "const"
201 	 * stores total bits and long words
202 	 * of the bitmap, so we don't need to
203 	 * call the accessor functions over and again. */
204 	unsigned long bm_bits;
205 	unsigned long bm_words;
206 	/* during xfer, current position within the bitmap */
207 	unsigned long bit_offset;
208 	unsigned long word_offset;
209 
210 	/* statistics; index: (h->command == P_BITMAP) */
211 	unsigned packets[2];
212 	unsigned bytes[2];
213 };
214 
215 extern void INFO_bm_xfer_stats(struct drbd_device *device,
216 		const char *direction, struct bm_xfer_ctx *c);
217 
bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx * c)218 static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c)
219 {
220 	/* word_offset counts "native long words" (32 or 64 bit),
221 	 * aligned at 64 bit.
222 	 * Encoded packet may end at an unaligned bit offset.
223 	 * In case a fallback clear text packet is transmitted in
224 	 * between, we adjust this offset back to the last 64bit
225 	 * aligned "native long word", which makes coding and decoding
226 	 * the plain text bitmap much more convenient.  */
227 #if BITS_PER_LONG == 64
228 	c->word_offset = c->bit_offset >> 6;
229 #elif BITS_PER_LONG == 32
230 	c->word_offset = c->bit_offset >> 5;
231 	c->word_offset &= ~(1UL);
232 #else
233 # error "unsupported BITS_PER_LONG"
234 #endif
235 }
236 
237 extern unsigned int drbd_header_size(struct drbd_connection *connection);
238 
239 /**********************************************************************/
240 enum drbd_thread_state {
241 	NONE,
242 	RUNNING,
243 	EXITING,
244 	RESTARTING
245 };
246 
247 struct drbd_thread {
248 	spinlock_t t_lock;
249 	struct task_struct *task;
250 	struct completion stop;
251 	enum drbd_thread_state t_state;
252 	int (*function) (struct drbd_thread *);
253 	struct drbd_resource *resource;
254 	struct drbd_connection *connection;
255 	int reset_cpu_mask;
256 	const char *name;
257 };
258 
get_t_state(struct drbd_thread * thi)259 static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi)
260 {
261 	/* THINK testing the t_state seems to be uncritical in all cases
262 	 * (but thread_{start,stop}), so we can read it *without* the lock.
263 	 *	--lge */
264 
265 	smp_rmb();
266 	return thi->t_state;
267 }
268 
269 struct drbd_work {
270 	struct list_head list;
271 	int (*cb)(struct drbd_work *, int cancel);
272 };
273 
274 struct drbd_device_work {
275 	struct drbd_work w;
276 	struct drbd_device *device;
277 };
278 
279 #include "drbd_interval.h"
280 
281 extern int drbd_wait_misc(struct drbd_device *, struct drbd_interval *);
282 
283 extern void lock_all_resources(void);
284 extern void unlock_all_resources(void);
285 
286 struct drbd_request {
287 	struct drbd_work w;
288 	struct drbd_device *device;
289 
290 	/* if local IO is not allowed, will be NULL.
291 	 * if local IO _is_ allowed, holds the locally submitted bio clone,
292 	 * or, after local IO completion, the ERR_PTR(error).
293 	 * see drbd_request_endio(). */
294 	struct bio *private_bio;
295 
296 	struct drbd_interval i;
297 
298 	/* epoch: used to check on "completion" whether this req was in
299 	 * the current epoch, and we therefore have to close it,
300 	 * causing a p_barrier packet to be send, starting a new epoch.
301 	 *
302 	 * This corresponds to "barrier" in struct p_barrier[_ack],
303 	 * and to "barrier_nr" in struct drbd_epoch (and various
304 	 * comments/function parameters/local variable names).
305 	 */
306 	unsigned int epoch;
307 
308 	struct list_head tl_requests; /* ring list in the transfer log */
309 	struct bio *master_bio;       /* master bio pointer */
310 
311 	/* see struct drbd_device */
312 	struct list_head req_pending_master_completion;
313 	struct list_head req_pending_local;
314 
315 	/* for generic IO accounting */
316 	unsigned long start_jif;
317 
318 	/* for DRBD internal statistics */
319 
320 	/* Minimal set of time stamps to determine if we wait for activity log
321 	 * transactions, local disk or peer.  32 bit "jiffies" are good enough,
322 	 * we don't expect a DRBD request to be stalled for several month.
323 	 */
324 
325 	/* before actual request processing */
326 	unsigned long in_actlog_jif;
327 
328 	/* local disk */
329 	unsigned long pre_submit_jif;
330 
331 	/* per connection */
332 	unsigned long pre_send_jif;
333 	unsigned long acked_jif;
334 	unsigned long net_done_jif;
335 
336 	/* Possibly even more detail to track each phase:
337 	 *  master_completion_jif
338 	 *      how long did it take to complete the master bio
339 	 *      (application visible latency)
340 	 *  allocated_jif
341 	 *      how long the master bio was blocked until we finally allocated
342 	 *      a tracking struct
343 	 *  in_actlog_jif
344 	 *      how long did we wait for activity log transactions
345 	 *
346 	 *  net_queued_jif
347 	 *      when did we finally queue it for sending
348 	 *  pre_send_jif
349 	 *      when did we start sending it
350 	 *  post_send_jif
351 	 *      how long did we block in the network stack trying to send it
352 	 *  acked_jif
353 	 *      when did we receive (or fake, in protocol A) a remote ACK
354 	 *  net_done_jif
355 	 *      when did we receive final acknowledgement (P_BARRIER_ACK),
356 	 *      or decide, e.g. on connection loss, that we do no longer expect
357 	 *      anything from this peer for this request.
358 	 *
359 	 *  pre_submit_jif
360 	 *  post_sub_jif
361 	 *      when did we start submiting to the lower level device,
362 	 *      and how long did we block in that submit function
363 	 *  local_completion_jif
364 	 *      how long did it take the lower level device to complete this request
365 	 */
366 
367 
368 	/* once it hits 0, we may complete the master_bio */
369 	atomic_t completion_ref;
370 	/* once it hits 0, we may destroy this drbd_request object */
371 	struct kref kref;
372 
373 	unsigned rq_state; /* see comments above _req_mod() */
374 };
375 
376 struct drbd_epoch {
377 	struct drbd_connection *connection;
378 	struct list_head list;
379 	unsigned int barrier_nr;
380 	atomic_t epoch_size; /* increased on every request added. */
381 	atomic_t active;     /* increased on every req. added, and dec on every finished. */
382 	unsigned long flags;
383 };
384 
385 /* Prototype declaration of function defined in drbd_receiver.c */
386 int drbdd_init(struct drbd_thread *);
387 int drbd_asender(struct drbd_thread *);
388 
389 /* drbd_epoch flag bits */
390 enum {
391 	DE_HAVE_BARRIER_NUMBER,
392 };
393 
394 enum epoch_event {
395 	EV_PUT,
396 	EV_GOT_BARRIER_NR,
397 	EV_BECAME_LAST,
398 	EV_CLEANUP = 32, /* used as flag */
399 };
400 
401 struct digest_info {
402 	int digest_size;
403 	void *digest;
404 };
405 
406 struct drbd_peer_request {
407 	struct drbd_work w;
408 	struct drbd_peer_device *peer_device;
409 	struct drbd_epoch *epoch; /* for writes */
410 	struct page *pages;
411 	atomic_t pending_bios;
412 	struct drbd_interval i;
413 	/* see comments on ee flag bits below */
414 	unsigned long flags;
415 	unsigned long submit_jif;
416 	union {
417 		u64 block_id;
418 		struct digest_info *digest;
419 	};
420 };
421 
422 /* ee flag bits.
423  * While corresponding bios are in flight, the only modification will be
424  * set_bit WAS_ERROR, which has to be atomic.
425  * If no bios are in flight yet, or all have been completed,
426  * non-atomic modification to ee->flags is ok.
427  */
428 enum {
429 	__EE_CALL_AL_COMPLETE_IO,
430 	__EE_MAY_SET_IN_SYNC,
431 
432 	/* is this a TRIM aka REQ_DISCARD? */
433 	__EE_IS_TRIM,
434 
435 	/* In case a barrier failed,
436 	 * we need to resubmit without the barrier flag. */
437 	__EE_RESUBMITTED,
438 
439 	/* we may have several bios per peer request.
440 	 * if any of those fail, we set this flag atomically
441 	 * from the endio callback */
442 	__EE_WAS_ERROR,
443 
444 	/* This ee has a pointer to a digest instead of a block id */
445 	__EE_HAS_DIGEST,
446 
447 	/* Conflicting local requests need to be restarted after this request */
448 	__EE_RESTART_REQUESTS,
449 
450 	/* The peer wants a write ACK for this (wire proto C) */
451 	__EE_SEND_WRITE_ACK,
452 
453 	/* Is set when net_conf had two_primaries set while creating this peer_req */
454 	__EE_IN_INTERVAL_TREE,
455 
456 	/* for debugfs: */
457 	/* has this been submitted, or does it still wait for something else? */
458 	__EE_SUBMITTED,
459 
460 	/* this is/was a write request */
461 	__EE_WRITE,
462 
463 	/* this is/was a write same request */
464 	__EE_WRITE_SAME,
465 
466 	/* this originates from application on peer
467 	 * (not some resync or verify or other DRBD internal request) */
468 	__EE_APPLICATION,
469 
470 	/* If it contains only 0 bytes, send back P_RS_DEALLOCATED */
471 	__EE_RS_THIN_REQ,
472 };
473 #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
474 #define EE_MAY_SET_IN_SYNC     (1<<__EE_MAY_SET_IN_SYNC)
475 #define EE_IS_TRIM             (1<<__EE_IS_TRIM)
476 #define EE_RESUBMITTED         (1<<__EE_RESUBMITTED)
477 #define EE_WAS_ERROR           (1<<__EE_WAS_ERROR)
478 #define EE_HAS_DIGEST          (1<<__EE_HAS_DIGEST)
479 #define EE_RESTART_REQUESTS	(1<<__EE_RESTART_REQUESTS)
480 #define EE_SEND_WRITE_ACK	(1<<__EE_SEND_WRITE_ACK)
481 #define EE_IN_INTERVAL_TREE	(1<<__EE_IN_INTERVAL_TREE)
482 #define EE_SUBMITTED		(1<<__EE_SUBMITTED)
483 #define EE_WRITE		(1<<__EE_WRITE)
484 #define EE_WRITE_SAME		(1<<__EE_WRITE_SAME)
485 #define EE_APPLICATION		(1<<__EE_APPLICATION)
486 #define EE_RS_THIN_REQ		(1<<__EE_RS_THIN_REQ)
487 
488 /* flag bits per device */
489 enum {
490 	UNPLUG_REMOTE,		/* sending a "UnplugRemote" could help */
491 	MD_DIRTY,		/* current uuids and flags not yet on disk */
492 	USE_DEGR_WFC_T,		/* degr-wfc-timeout instead of wfc-timeout. */
493 	CL_ST_CHG_SUCCESS,
494 	CL_ST_CHG_FAIL,
495 	CRASHED_PRIMARY,	/* This node was a crashed primary.
496 				 * Gets cleared when the state.conn
497 				 * goes into C_CONNECTED state. */
498 	CONSIDER_RESYNC,
499 
500 	MD_NO_FUA,		/* Users wants us to not use FUA/FLUSH on meta data dev */
501 
502 	BITMAP_IO,		/* suspend application io;
503 				   once no more io in flight, start bitmap io */
504 	BITMAP_IO_QUEUED,       /* Started bitmap IO */
505 	WAS_IO_ERROR,		/* Local disk failed, returned IO error */
506 	WAS_READ_ERROR,		/* Local disk READ failed (set additionally to the above) */
507 	FORCE_DETACH,		/* Force-detach from local disk, aborting any pending local IO */
508 	RESYNC_AFTER_NEG,       /* Resync after online grow after the attach&negotiate finished. */
509 	RESIZE_PENDING,		/* Size change detected locally, waiting for the response from
510 				 * the peer, if it changed there as well. */
511 	NEW_CUR_UUID,		/* Create new current UUID when thawing IO */
512 	AL_SUSPENDED,		/* Activity logging is currently suspended. */
513 	AHEAD_TO_SYNC_SOURCE,   /* Ahead -> SyncSource queued */
514 	B_RS_H_DONE,		/* Before resync handler done (already executed) */
515 	DISCARD_MY_DATA,	/* discard_my_data flag per volume */
516 	READ_BALANCE_RR,
517 
518 	FLUSH_PENDING,		/* if set, device->flush_jif is when we submitted that flush
519 				 * from drbd_flush_after_epoch() */
520 
521 	/* cleared only after backing device related structures have been destroyed. */
522 	GOING_DISKLESS,		/* Disk is being detached, because of io-error, or admin request. */
523 
524 	/* to be used in drbd_device_post_work() */
525 	GO_DISKLESS,		/* tell worker to schedule cleanup before detach */
526 	DESTROY_DISK,		/* tell worker to close backing devices and destroy related structures. */
527 	MD_SYNC,		/* tell worker to call drbd_md_sync() */
528 	RS_START,		/* tell worker to start resync/OV */
529 	RS_PROGRESS,		/* tell worker that resync made significant progress */
530 	RS_DONE,		/* tell worker that resync is done */
531 };
532 
533 struct drbd_bitmap; /* opaque for drbd_device */
534 
535 /* definition of bits in bm_flags to be used in drbd_bm_lock
536  * and drbd_bitmap_io and friends. */
537 enum bm_flag {
538 	/* currently locked for bulk operation */
539 	BM_LOCKED_MASK = 0xf,
540 
541 	/* in detail, that is: */
542 	BM_DONT_CLEAR = 0x1,
543 	BM_DONT_SET   = 0x2,
544 	BM_DONT_TEST  = 0x4,
545 
546 	/* so we can mark it locked for bulk operation,
547 	 * and still allow all non-bulk operations */
548 	BM_IS_LOCKED  = 0x8,
549 
550 	/* (test bit, count bit) allowed (common case) */
551 	BM_LOCKED_TEST_ALLOWED = BM_DONT_CLEAR | BM_DONT_SET | BM_IS_LOCKED,
552 
553 	/* testing bits, as well as setting new bits allowed, but clearing bits
554 	 * would be unexpected.  Used during bitmap receive.  Setting new bits
555 	 * requires sending of "out-of-sync" information, though. */
556 	BM_LOCKED_SET_ALLOWED = BM_DONT_CLEAR | BM_IS_LOCKED,
557 
558 	/* for drbd_bm_write_copy_pages, everything is allowed,
559 	 * only concurrent bulk operations are locked out. */
560 	BM_LOCKED_CHANGE_ALLOWED = BM_IS_LOCKED,
561 };
562 
563 struct drbd_work_queue {
564 	struct list_head q;
565 	spinlock_t q_lock;  /* to protect the list. */
566 	wait_queue_head_t q_wait;
567 };
568 
569 struct drbd_socket {
570 	struct mutex mutex;
571 	struct socket    *socket;
572 	/* this way we get our
573 	 * send/receive buffers off the stack */
574 	void *sbuf;
575 	void *rbuf;
576 };
577 
578 struct drbd_md {
579 	u64 md_offset;		/* sector offset to 'super' block */
580 
581 	u64 la_size_sect;	/* last agreed size, unit sectors */
582 	spinlock_t uuid_lock;
583 	u64 uuid[UI_SIZE];
584 	u64 device_uuid;
585 	u32 flags;
586 	u32 md_size_sect;
587 
588 	s32 al_offset;	/* signed relative sector offset to activity log */
589 	s32 bm_offset;	/* signed relative sector offset to bitmap */
590 
591 	/* cached value of bdev->disk_conf->meta_dev_idx (see below) */
592 	s32 meta_dev_idx;
593 
594 	/* see al_tr_number_to_on_disk_sector() */
595 	u32 al_stripes;
596 	u32 al_stripe_size_4k;
597 	u32 al_size_4k; /* cached product of the above */
598 };
599 
600 struct drbd_backing_dev {
601 	struct block_device *backing_bdev;
602 	struct block_device *md_bdev;
603 	struct drbd_md md;
604 	struct disk_conf *disk_conf; /* RCU, for updates: resource->conf_update */
605 	sector_t known_size; /* last known size of that backing device */
606 };
607 
608 struct drbd_md_io {
609 	struct page *page;
610 	unsigned long start_jif;	/* last call to drbd_md_get_buffer */
611 	unsigned long submit_jif;	/* last _drbd_md_sync_page_io() submit */
612 	const char *current_use;
613 	atomic_t in_use;
614 	unsigned int done;
615 	int error;
616 };
617 
618 struct bm_io_work {
619 	struct drbd_work w;
620 	char *why;
621 	enum bm_flag flags;
622 	int (*io_fn)(struct drbd_device *device);
623 	void (*done)(struct drbd_device *device, int rv);
624 };
625 
626 struct fifo_buffer {
627 	unsigned int head_index;
628 	unsigned int size;
629 	int total; /* sum of all values */
630 	int values[0];
631 };
632 extern struct fifo_buffer *fifo_alloc(int fifo_size);
633 
634 /* flag bits per connection */
635 enum {
636 	NET_CONGESTED,		/* The data socket is congested */
637 	RESOLVE_CONFLICTS,	/* Set on one node, cleared on the peer! */
638 	SEND_PING,
639 	GOT_PING_ACK,		/* set when we receive a ping_ack packet, ping_wait gets woken */
640 	CONN_WD_ST_CHG_REQ,	/* A cluster wide state change on the connection is active */
641 	CONN_WD_ST_CHG_OKAY,
642 	CONN_WD_ST_CHG_FAIL,
643 	CONN_DRY_RUN,		/* Expect disconnect after resync handshake. */
644 	CREATE_BARRIER,		/* next P_DATA is preceded by a P_BARRIER */
645 	STATE_SENT,		/* Do not change state/UUIDs while this is set */
646 	CALLBACK_PENDING,	/* Whether we have a call_usermodehelper(, UMH_WAIT_PROC)
647 				 * pending, from drbd worker context.
648 				 * If set, bdi_write_congested() returns true,
649 				 * so shrink_page_list() would not recurse into,
650 				 * and potentially deadlock on, this drbd worker.
651 				 */
652 	DISCONNECT_SENT,
653 
654 	DEVICE_WORK_PENDING,	/* tell worker that some device has pending work */
655 };
656 
657 enum which_state { NOW, OLD = NOW, NEW };
658 
659 struct drbd_resource {
660 	char *name;
661 #ifdef CONFIG_DEBUG_FS
662 	struct dentry *debugfs_res;
663 	struct dentry *debugfs_res_volumes;
664 	struct dentry *debugfs_res_connections;
665 	struct dentry *debugfs_res_in_flight_summary;
666 #endif
667 	struct kref kref;
668 	struct idr devices;		/* volume number to device mapping */
669 	struct list_head connections;
670 	struct list_head resources;
671 	struct res_opts res_opts;
672 	struct mutex conf_update;	/* mutex for ready-copy-update of net_conf and disk_conf */
673 	struct mutex adm_mutex;		/* mutex to serialize administrative requests */
674 	spinlock_t req_lock;
675 
676 	unsigned susp:1;		/* IO suspended by user */
677 	unsigned susp_nod:1;		/* IO suspended because no data */
678 	unsigned susp_fen:1;		/* IO suspended because fence peer handler runs */
679 
680 	enum write_ordering_e write_ordering;
681 
682 	cpumask_var_t cpu_mask;
683 };
684 
685 struct drbd_thread_timing_details
686 {
687 	unsigned long start_jif;
688 	void *cb_addr;
689 	const char *caller_fn;
690 	unsigned int line;
691 	unsigned int cb_nr;
692 };
693 
694 struct drbd_connection {
695 	struct list_head connections;
696 	struct drbd_resource *resource;
697 #ifdef CONFIG_DEBUG_FS
698 	struct dentry *debugfs_conn;
699 	struct dentry *debugfs_conn_callback_history;
700 	struct dentry *debugfs_conn_oldest_requests;
701 #endif
702 	struct kref kref;
703 	struct idr peer_devices;	/* volume number to peer device mapping */
704 	enum drbd_conns cstate;		/* Only C_STANDALONE to C_WF_REPORT_PARAMS */
705 	struct mutex cstate_mutex;	/* Protects graceful disconnects */
706 	unsigned int connect_cnt;	/* Inc each time a connection is established */
707 
708 	unsigned long flags;
709 	struct net_conf *net_conf;	/* content protected by rcu */
710 	wait_queue_head_t ping_wait;	/* Woken upon reception of a ping, and a state change */
711 
712 	struct sockaddr_storage my_addr;
713 	int my_addr_len;
714 	struct sockaddr_storage peer_addr;
715 	int peer_addr_len;
716 
717 	struct drbd_socket data;	/* data/barrier/cstate/parameter packets */
718 	struct drbd_socket meta;	/* ping/ack (metadata) packets */
719 	int agreed_pro_version;		/* actually used protocol version */
720 	u32 agreed_features;
721 	unsigned long last_received;	/* in jiffies, either socket */
722 	unsigned int ko_count;
723 
724 	struct list_head transfer_log;	/* all requests not yet fully processed */
725 
726 	struct crypto_shash *cram_hmac_tfm;
727 	struct crypto_ahash *integrity_tfm;  /* checksums we compute, updates protected by connection->data->mutex */
728 	struct crypto_ahash *peer_integrity_tfm;  /* checksums we verify, only accessed from receiver thread  */
729 	struct crypto_ahash *csums_tfm;
730 	struct crypto_ahash *verify_tfm;
731 	void *int_dig_in;
732 	void *int_dig_vv;
733 
734 	/* receiver side */
735 	struct drbd_epoch *current_epoch;
736 	spinlock_t epoch_lock;
737 	unsigned int epochs;
738 	atomic_t current_tle_nr;	/* transfer log epoch number */
739 	unsigned current_tle_writes;	/* writes seen within this tl epoch */
740 
741 	unsigned long last_reconnect_jif;
742 	/* empty member on older kernels without blk_start_plug() */
743 	struct blk_plug receiver_plug;
744 	struct drbd_thread receiver;
745 	struct drbd_thread worker;
746 	struct drbd_thread ack_receiver;
747 	struct workqueue_struct *ack_sender;
748 
749 	/* cached pointers,
750 	 * so we can look up the oldest pending requests more quickly.
751 	 * protected by resource->req_lock */
752 	struct drbd_request *req_next; /* DRBD 9: todo.req_next */
753 	struct drbd_request *req_ack_pending;
754 	struct drbd_request *req_not_net_done;
755 
756 	/* sender side */
757 	struct drbd_work_queue sender_work;
758 
759 #define DRBD_THREAD_DETAILS_HIST	16
760 	unsigned int w_cb_nr; /* keeps counting up */
761 	unsigned int r_cb_nr; /* keeps counting up */
762 	struct drbd_thread_timing_details w_timing_details[DRBD_THREAD_DETAILS_HIST];
763 	struct drbd_thread_timing_details r_timing_details[DRBD_THREAD_DETAILS_HIST];
764 
765 	struct {
766 		unsigned long last_sent_barrier_jif;
767 
768 		/* whether this sender thread
769 		 * has processed a single write yet. */
770 		bool seen_any_write_yet;
771 
772 		/* Which barrier number to send with the next P_BARRIER */
773 		int current_epoch_nr;
774 
775 		/* how many write requests have been sent
776 		 * with req->epoch == current_epoch_nr.
777 		 * If none, no P_BARRIER will be sent. */
778 		unsigned current_epoch_writes;
779 	} send;
780 };
781 
has_net_conf(struct drbd_connection * connection)782 static inline bool has_net_conf(struct drbd_connection *connection)
783 {
784 	bool has_net_conf;
785 
786 	rcu_read_lock();
787 	has_net_conf = rcu_dereference(connection->net_conf);
788 	rcu_read_unlock();
789 
790 	return has_net_conf;
791 }
792 
793 void __update_timing_details(
794 		struct drbd_thread_timing_details *tdp,
795 		unsigned int *cb_nr,
796 		void *cb,
797 		const char *fn, const unsigned int line);
798 
799 #define update_worker_timing_details(c, cb) \
800 	__update_timing_details(c->w_timing_details, &c->w_cb_nr, cb, __func__ , __LINE__ )
801 #define update_receiver_timing_details(c, cb) \
802 	__update_timing_details(c->r_timing_details, &c->r_cb_nr, cb, __func__ , __LINE__ )
803 
804 struct submit_worker {
805 	struct workqueue_struct *wq;
806 	struct work_struct worker;
807 
808 	/* protected by ..->resource->req_lock */
809 	struct list_head writes;
810 };
811 
812 struct drbd_peer_device {
813 	struct list_head peer_devices;
814 	struct drbd_device *device;
815 	struct drbd_connection *connection;
816 	struct work_struct send_acks_work;
817 #ifdef CONFIG_DEBUG_FS
818 	struct dentry *debugfs_peer_dev;
819 #endif
820 };
821 
822 struct drbd_device {
823 	struct drbd_resource *resource;
824 	struct list_head peer_devices;
825 	struct list_head pending_bitmap_io;
826 
827 	unsigned long flush_jif;
828 #ifdef CONFIG_DEBUG_FS
829 	struct dentry *debugfs_minor;
830 	struct dentry *debugfs_vol;
831 	struct dentry *debugfs_vol_oldest_requests;
832 	struct dentry *debugfs_vol_act_log_extents;
833 	struct dentry *debugfs_vol_resync_extents;
834 	struct dentry *debugfs_vol_data_gen_id;
835 	struct dentry *debugfs_vol_ed_gen_id;
836 #endif
837 
838 	unsigned int vnr;	/* volume number within the connection */
839 	unsigned int minor;	/* device minor number */
840 
841 	struct kref kref;
842 
843 	/* things that are stored as / read from meta data on disk */
844 	unsigned long flags;
845 
846 	/* configured by drbdsetup */
847 	struct drbd_backing_dev *ldev __protected_by(local);
848 
849 	sector_t p_size;     /* partner's disk size */
850 	struct request_queue *rq_queue;
851 	struct block_device *this_bdev;
852 	struct gendisk	    *vdisk;
853 
854 	unsigned long last_reattach_jif;
855 	struct drbd_work resync_work;
856 	struct drbd_work unplug_work;
857 	struct timer_list resync_timer;
858 	struct timer_list md_sync_timer;
859 	struct timer_list start_resync_timer;
860 	struct timer_list request_timer;
861 
862 	/* Used after attach while negotiating new disk state. */
863 	union drbd_state new_state_tmp;
864 
865 	union drbd_dev_state state;
866 	wait_queue_head_t misc_wait;
867 	wait_queue_head_t state_wait;  /* upon each state change. */
868 	unsigned int send_cnt;
869 	unsigned int recv_cnt;
870 	unsigned int read_cnt;
871 	unsigned int writ_cnt;
872 	unsigned int al_writ_cnt;
873 	unsigned int bm_writ_cnt;
874 	atomic_t ap_bio_cnt;	 /* Requests we need to complete */
875 	atomic_t ap_actlog_cnt;  /* Requests waiting for activity log */
876 	atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */
877 	atomic_t rs_pending_cnt; /* RS request/data packets on the wire */
878 	atomic_t unacked_cnt;	 /* Need to send replies for */
879 	atomic_t local_cnt;	 /* Waiting for local completion */
880 	atomic_t suspend_cnt;
881 
882 	/* Interval tree of pending local requests */
883 	struct rb_root read_requests;
884 	struct rb_root write_requests;
885 
886 	/* for statistics and timeouts */
887 	/* [0] read, [1] write */
888 	struct list_head pending_master_completion[2];
889 	struct list_head pending_completion[2];
890 
891 	/* use checksums for *this* resync */
892 	bool use_csums;
893 	/* blocks to resync in this run [unit BM_BLOCK_SIZE] */
894 	unsigned long rs_total;
895 	/* number of resync blocks that failed in this run */
896 	unsigned long rs_failed;
897 	/* Syncer's start time [unit jiffies] */
898 	unsigned long rs_start;
899 	/* cumulated time in PausedSyncX state [unit jiffies] */
900 	unsigned long rs_paused;
901 	/* skipped because csum was equal [unit BM_BLOCK_SIZE] */
902 	unsigned long rs_same_csum;
903 #define DRBD_SYNC_MARKS 8
904 #define DRBD_SYNC_MARK_STEP (3*HZ)
905 	/* block not up-to-date at mark [unit BM_BLOCK_SIZE] */
906 	unsigned long rs_mark_left[DRBD_SYNC_MARKS];
907 	/* marks's time [unit jiffies] */
908 	unsigned long rs_mark_time[DRBD_SYNC_MARKS];
909 	/* current index into rs_mark_{left,time} */
910 	int rs_last_mark;
911 	unsigned long rs_last_bcast; /* [unit jiffies] */
912 
913 	/* where does the admin want us to start? (sector) */
914 	sector_t ov_start_sector;
915 	sector_t ov_stop_sector;
916 	/* where are we now? (sector) */
917 	sector_t ov_position;
918 	/* Start sector of out of sync range (to merge printk reporting). */
919 	sector_t ov_last_oos_start;
920 	/* size of out-of-sync range in sectors. */
921 	sector_t ov_last_oos_size;
922 	unsigned long ov_left; /* in bits */
923 
924 	struct drbd_bitmap *bitmap;
925 	unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */
926 
927 	/* Used to track operations of resync... */
928 	struct lru_cache *resync;
929 	/* Number of locked elements in resync LRU */
930 	unsigned int resync_locked;
931 	/* resync extent number waiting for application requests */
932 	unsigned int resync_wenr;
933 
934 	int open_cnt;
935 	u64 *p_uuid;
936 
937 	struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */
938 	struct list_head sync_ee;   /* IO in progress (P_RS_DATA_REPLY gets written to disk) */
939 	struct list_head done_ee;   /* need to send P_WRITE_ACK */
940 	struct list_head read_ee;   /* [RS]P_DATA_REQUEST being read */
941 	struct list_head net_ee;    /* zero-copy network send in progress */
942 
943 	int next_barrier_nr;
944 	struct list_head resync_reads;
945 	atomic_t pp_in_use;		/* allocated from page pool */
946 	atomic_t pp_in_use_by_net;	/* sendpage()d, still referenced by tcp */
947 	wait_queue_head_t ee_wait;
948 	struct drbd_md_io md_io;
949 	spinlock_t al_lock;
950 	wait_queue_head_t al_wait;
951 	struct lru_cache *act_log;	/* activity log */
952 	unsigned int al_tr_number;
953 	int al_tr_cycle;
954 	wait_queue_head_t seq_wait;
955 	atomic_t packet_seq;
956 	unsigned int peer_seq;
957 	spinlock_t peer_seq_lock;
958 	unsigned long comm_bm_set; /* communicated number of set bits. */
959 	struct bm_io_work bm_io_work;
960 	u64 ed_uuid; /* UUID of the exposed data */
961 	struct mutex own_state_mutex;
962 	struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */
963 	char congestion_reason;  /* Why we where congested... */
964 	atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
965 	atomic_t rs_sect_ev; /* for submitted resync data rate, both */
966 	int rs_last_sect_ev; /* counter to compare with */
967 	int rs_last_events;  /* counter of read or write "events" (unit sectors)
968 			      * on the lower level device when we last looked. */
969 	int c_sync_rate; /* current resync rate after syncer throttle magic */
970 	struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, connection->conn_update) */
971 	int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */
972 	atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */
973 	unsigned int peer_max_bio_size;
974 	unsigned int local_max_bio_size;
975 
976 	/* any requests that would block in drbd_make_request()
977 	 * are deferred to this single-threaded work queue */
978 	struct submit_worker submit;
979 };
980 
981 struct drbd_bm_aio_ctx {
982 	struct drbd_device *device;
983 	struct list_head list; /* on device->pending_bitmap_io */;
984 	unsigned long start_jif;
985 	atomic_t in_flight;
986 	unsigned int done;
987 	unsigned flags;
988 #define BM_AIO_COPY_PAGES	1
989 #define BM_AIO_WRITE_HINTED	2
990 #define BM_AIO_WRITE_ALL_PAGES	4
991 #define BM_AIO_READ		8
992 	int error;
993 	struct kref kref;
994 };
995 
996 struct drbd_config_context {
997 	/* assigned from drbd_genlmsghdr */
998 	unsigned int minor;
999 	/* assigned from request attributes, if present */
1000 	unsigned int volume;
1001 #define VOLUME_UNSPECIFIED		(-1U)
1002 	/* pointer into the request skb,
1003 	 * limited lifetime! */
1004 	char *resource_name;
1005 	struct nlattr *my_addr;
1006 	struct nlattr *peer_addr;
1007 
1008 	/* reply buffer */
1009 	struct sk_buff *reply_skb;
1010 	/* pointer into reply buffer */
1011 	struct drbd_genlmsghdr *reply_dh;
1012 	/* resolved from attributes, if possible */
1013 	struct drbd_device *device;
1014 	struct drbd_resource *resource;
1015 	struct drbd_connection *connection;
1016 };
1017 
minor_to_device(unsigned int minor)1018 static inline struct drbd_device *minor_to_device(unsigned int minor)
1019 {
1020 	return (struct drbd_device *)idr_find(&drbd_devices, minor);
1021 }
1022 
first_peer_device(struct drbd_device * device)1023 static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device)
1024 {
1025 	return list_first_entry_or_null(&device->peer_devices, struct drbd_peer_device, peer_devices);
1026 }
1027 
1028 static inline struct drbd_peer_device *
conn_peer_device(struct drbd_connection * connection,int volume_number)1029 conn_peer_device(struct drbd_connection *connection, int volume_number)
1030 {
1031 	return idr_find(&connection->peer_devices, volume_number);
1032 }
1033 
1034 #define for_each_resource(resource, _resources) \
1035 	list_for_each_entry(resource, _resources, resources)
1036 
1037 #define for_each_resource_rcu(resource, _resources) \
1038 	list_for_each_entry_rcu(resource, _resources, resources)
1039 
1040 #define for_each_resource_safe(resource, tmp, _resources) \
1041 	list_for_each_entry_safe(resource, tmp, _resources, resources)
1042 
1043 #define for_each_connection(connection, resource) \
1044 	list_for_each_entry(connection, &resource->connections, connections)
1045 
1046 #define for_each_connection_rcu(connection, resource) \
1047 	list_for_each_entry_rcu(connection, &resource->connections, connections)
1048 
1049 #define for_each_connection_safe(connection, tmp, resource) \
1050 	list_for_each_entry_safe(connection, tmp, &resource->connections, connections)
1051 
1052 #define for_each_peer_device(peer_device, device) \
1053 	list_for_each_entry(peer_device, &device->peer_devices, peer_devices)
1054 
1055 #define for_each_peer_device_rcu(peer_device, device) \
1056 	list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices)
1057 
1058 #define for_each_peer_device_safe(peer_device, tmp, device) \
1059 	list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices)
1060 
device_to_minor(struct drbd_device * device)1061 static inline unsigned int device_to_minor(struct drbd_device *device)
1062 {
1063 	return device->minor;
1064 }
1065 
1066 /*
1067  * function declarations
1068  *************************/
1069 
1070 /* drbd_main.c */
1071 
1072 enum dds_flags {
1073 	DDSF_FORCED    = 1,
1074 	DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */
1075 };
1076 
1077 extern void drbd_init_set_defaults(struct drbd_device *device);
1078 extern int  drbd_thread_start(struct drbd_thread *thi);
1079 extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait);
1080 #ifdef CONFIG_SMP
1081 extern void drbd_thread_current_set_cpu(struct drbd_thread *thi);
1082 #else
1083 #define drbd_thread_current_set_cpu(A) ({})
1084 #endif
1085 extern void tl_release(struct drbd_connection *, unsigned int barrier_nr,
1086 		       unsigned int set_size);
1087 extern void tl_clear(struct drbd_connection *);
1088 extern void drbd_free_sock(struct drbd_connection *connection);
1089 extern int drbd_send(struct drbd_connection *connection, struct socket *sock,
1090 		     void *buf, size_t size, unsigned msg_flags);
1091 extern int drbd_send_all(struct drbd_connection *, struct socket *, void *, size_t,
1092 			 unsigned);
1093 
1094 extern int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd);
1095 extern int drbd_send_protocol(struct drbd_connection *connection);
1096 extern int drbd_send_uuids(struct drbd_peer_device *);
1097 extern int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *);
1098 extern void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *);
1099 extern int drbd_send_sizes(struct drbd_peer_device *, int trigger_reply, enum dds_flags flags);
1100 extern int drbd_send_state(struct drbd_peer_device *, union drbd_state s);
1101 extern int drbd_send_current_state(struct drbd_peer_device *);
1102 extern int drbd_send_sync_param(struct drbd_peer_device *);
1103 extern void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr,
1104 			    u32 set_size);
1105 extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet,
1106 			 struct drbd_peer_request *);
1107 extern void drbd_send_ack_rp(struct drbd_peer_device *, enum drbd_packet,
1108 			     struct p_block_req *rp);
1109 extern void drbd_send_ack_dp(struct drbd_peer_device *, enum drbd_packet,
1110 			     struct p_data *dp, int data_size);
1111 extern int drbd_send_ack_ex(struct drbd_peer_device *, enum drbd_packet,
1112 			    sector_t sector, int blksize, u64 block_id);
1113 extern int drbd_send_out_of_sync(struct drbd_peer_device *, struct drbd_request *);
1114 extern int drbd_send_block(struct drbd_peer_device *, enum drbd_packet,
1115 			   struct drbd_peer_request *);
1116 extern int drbd_send_dblock(struct drbd_peer_device *, struct drbd_request *req);
1117 extern int drbd_send_drequest(struct drbd_peer_device *, int cmd,
1118 			      sector_t sector, int size, u64 block_id);
1119 extern int drbd_send_drequest_csum(struct drbd_peer_device *, sector_t sector,
1120 				   int size, void *digest, int digest_size,
1121 				   enum drbd_packet cmd);
1122 extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int size);
1123 
1124 extern int drbd_send_bitmap(struct drbd_device *device);
1125 extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode);
1126 extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode);
1127 extern int drbd_send_rs_deallocated(struct drbd_peer_device *, struct drbd_peer_request *);
1128 extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev);
1129 extern void drbd_device_cleanup(struct drbd_device *device);
1130 extern void drbd_print_uuids(struct drbd_device *device, const char *text);
1131 extern void drbd_queue_unplug(struct drbd_device *device);
1132 
1133 extern void conn_md_sync(struct drbd_connection *connection);
1134 extern void drbd_md_write(struct drbd_device *device, void *buffer);
1135 extern void drbd_md_sync(struct drbd_device *device);
1136 extern int  drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev);
1137 extern void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
1138 extern void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
1139 extern void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local);
1140 extern void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local);
1141 extern void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local);
1142 extern void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
1143 extern void drbd_md_set_flag(struct drbd_device *device, int flags) __must_hold(local);
1144 extern void drbd_md_clear_flag(struct drbd_device *device, int flags)__must_hold(local);
1145 extern int drbd_md_test_flag(struct drbd_backing_dev *, int);
1146 extern void drbd_md_mark_dirty(struct drbd_device *device);
1147 extern void drbd_queue_bitmap_io(struct drbd_device *device,
1148 				 int (*io_fn)(struct drbd_device *),
1149 				 void (*done)(struct drbd_device *, int),
1150 				 char *why, enum bm_flag flags);
1151 extern int drbd_bitmap_io(struct drbd_device *device,
1152 		int (*io_fn)(struct drbd_device *),
1153 		char *why, enum bm_flag flags);
1154 extern int drbd_bitmap_io_from_worker(struct drbd_device *device,
1155 		int (*io_fn)(struct drbd_device *),
1156 		char *why, enum bm_flag flags);
1157 extern int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local);
1158 extern int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local);
1159 
1160 /* Meta data layout
1161  *
1162  * We currently have two possible layouts.
1163  * Offsets in (512 byte) sectors.
1164  * external:
1165  *   |----------- md_size_sect ------------------|
1166  *   [ 4k superblock ][ activity log ][  Bitmap  ]
1167  *   | al_offset == 8 |
1168  *   | bm_offset = al_offset + X      |
1169  *  ==> bitmap sectors = md_size_sect - bm_offset
1170  *
1171  *  Variants:
1172  *     old, indexed fixed size meta data:
1173  *
1174  * internal:
1175  *            |----------- md_size_sect ------------------|
1176  * [data.....][  Bitmap  ][ activity log ][ 4k superblock ][padding*]
1177  *                        | al_offset < 0 |
1178  *            | bm_offset = al_offset - Y |
1179  *  ==> bitmap sectors = Y = al_offset - bm_offset
1180  *
1181  *  [padding*] are zero or up to 7 unused 512 Byte sectors to the
1182  *  end of the device, so that the [4k superblock] will be 4k aligned.
1183  *
1184  *  The activity log consists of 4k transaction blocks,
1185  *  which are written in a ring-buffer, or striped ring-buffer like fashion,
1186  *  which are writtensize used to be fixed 32kB,
1187  *  but is about to become configurable.
1188  */
1189 
1190 /* Our old fixed size meta data layout
1191  * allows up to about 3.8TB, so if you want more,
1192  * you need to use the "flexible" meta data format. */
1193 #define MD_128MB_SECT (128LLU << 11)  /* 128 MB, unit sectors */
1194 #define MD_4kB_SECT	 8
1195 #define MD_32kB_SECT	64
1196 
1197 /* One activity log extent represents 4M of storage */
1198 #define AL_EXTENT_SHIFT 22
1199 #define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT)
1200 
1201 /* We could make these currently hardcoded constants configurable
1202  * variables at create-md time (or even re-configurable at runtime?).
1203  * Which will require some more changes to the DRBD "super block"
1204  * and attach code.
1205  *
1206  * updates per transaction:
1207  *   This many changes to the active set can be logged with one transaction.
1208  *   This number is arbitrary.
1209  * context per transaction:
1210  *   This many context extent numbers are logged with each transaction.
1211  *   This number is resulting from the transaction block size (4k), the layout
1212  *   of the transaction header, and the number of updates per transaction.
1213  *   See drbd_actlog.c:struct al_transaction_on_disk
1214  * */
1215 #define AL_UPDATES_PER_TRANSACTION	 64	// arbitrary
1216 #define AL_CONTEXT_PER_TRANSACTION	919	// (4096 - 36 - 6*64)/4
1217 
1218 #if BITS_PER_LONG == 32
1219 #define LN2_BPL 5
1220 #define cpu_to_lel(A) cpu_to_le32(A)
1221 #define lel_to_cpu(A) le32_to_cpu(A)
1222 #elif BITS_PER_LONG == 64
1223 #define LN2_BPL 6
1224 #define cpu_to_lel(A) cpu_to_le64(A)
1225 #define lel_to_cpu(A) le64_to_cpu(A)
1226 #else
1227 #error "LN2 of BITS_PER_LONG unknown!"
1228 #endif
1229 
1230 /* resync bitmap */
1231 /* 16MB sized 'bitmap extent' to track syncer usage */
1232 struct bm_extent {
1233 	int rs_left; /* number of bits set (out of sync) in this extent. */
1234 	int rs_failed; /* number of failed resync requests in this extent. */
1235 	unsigned long flags;
1236 	struct lc_element lce;
1237 };
1238 
1239 #define BME_NO_WRITES  0  /* bm_extent.flags: no more requests on this one! */
1240 #define BME_LOCKED     1  /* bm_extent.flags: syncer active on this one. */
1241 #define BME_PRIORITY   2  /* finish resync IO on this extent ASAP! App IO waiting! */
1242 
1243 /* drbd_bitmap.c */
1244 /*
1245  * We need to store one bit for a block.
1246  * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap.
1247  * Bit 0 ==> local node thinks this block is binary identical on both nodes
1248  * Bit 1 ==> local node thinks this block needs to be synced.
1249  */
1250 
1251 #define SLEEP_TIME (HZ/10)
1252 
1253 /* We do bitmap IO in units of 4k blocks.
1254  * We also still have a hardcoded 4k per bit relation. */
1255 #define BM_BLOCK_SHIFT	12			 /* 4k per bit */
1256 #define BM_BLOCK_SIZE	 (1<<BM_BLOCK_SHIFT)
1257 /* mostly arbitrarily set the represented size of one bitmap extent,
1258  * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap
1259  * at 4k per bit resolution) */
1260 #define BM_EXT_SHIFT	 24	/* 16 MiB per resync extent */
1261 #define BM_EXT_SIZE	 (1<<BM_EXT_SHIFT)
1262 
1263 #if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12)
1264 #error "HAVE YOU FIXED drbdmeta AS WELL??"
1265 #endif
1266 
1267 /* thus many _storage_ sectors are described by one bit */
1268 #define BM_SECT_TO_BIT(x)   ((x)>>(BM_BLOCK_SHIFT-9))
1269 #define BM_BIT_TO_SECT(x)   ((sector_t)(x)<<(BM_BLOCK_SHIFT-9))
1270 #define BM_SECT_PER_BIT     BM_BIT_TO_SECT(1)
1271 
1272 /* bit to represented kilo byte conversion */
1273 #define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10))
1274 
1275 /* in which _bitmap_ extent (resp. sector) the bit for a certain
1276  * _storage_ sector is located in */
1277 #define BM_SECT_TO_EXT(x)   ((x)>>(BM_EXT_SHIFT-9))
1278 #define BM_BIT_TO_EXT(x)    ((x) >> (BM_EXT_SHIFT - BM_BLOCK_SHIFT))
1279 
1280 /* first storage sector a bitmap extent corresponds to */
1281 #define BM_EXT_TO_SECT(x)   ((sector_t)(x) << (BM_EXT_SHIFT-9))
1282 /* how much _storage_ sectors we have per bitmap extent */
1283 #define BM_SECT_PER_EXT     BM_EXT_TO_SECT(1)
1284 /* how many bits are covered by one bitmap extent (resync extent) */
1285 #define BM_BITS_PER_EXT     (1UL << (BM_EXT_SHIFT - BM_BLOCK_SHIFT))
1286 
1287 #define BM_BLOCKS_PER_BM_EXT_MASK  (BM_BITS_PER_EXT - 1)
1288 
1289 
1290 /* in one sector of the bitmap, we have this many activity_log extents. */
1291 #define AL_EXT_PER_BM_SECT  (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT))
1292 
1293 /* the extent in "PER_EXTENT" below is an activity log extent
1294  * we need that many (long words/bytes) to store the bitmap
1295  *		     of one AL_EXTENT_SIZE chunk of storage.
1296  * we can store the bitmap for that many AL_EXTENTS within
1297  * one sector of the _on_disk_ bitmap:
1298  * bit	 0	  bit 37   bit 38	     bit (512*8)-1
1299  *	     ...|........|........|.. // ..|........|
1300  * sect. 0	 `296	  `304			   ^(512*8*8)-1
1301  *
1302 #define BM_WORDS_PER_EXT    ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG )
1303 #define BM_BYTES_PER_EXT    ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 )  // 128
1304 #define BM_EXT_PER_SECT	    ( 512 / BM_BYTES_PER_EXTENT )	 //   4
1305  */
1306 
1307 #define DRBD_MAX_SECTORS_32 (0xffffffffLU)
1308 /* we have a certain meta data variant that has a fixed on-disk size of 128
1309  * MiB, of which 4k are our "superblock", and 32k are the fixed size activity
1310  * log, leaving this many sectors for the bitmap.
1311  */
1312 
1313 #define DRBD_MAX_SECTORS_FIXED_BM \
1314 	  ((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9)))
1315 #if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
1316 #define DRBD_MAX_SECTORS      DRBD_MAX_SECTORS_32
1317 #define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32
1318 #else
1319 #define DRBD_MAX_SECTORS      DRBD_MAX_SECTORS_FIXED_BM
1320 /* 16 TB in units of sectors */
1321 #if BITS_PER_LONG == 32
1322 /* adjust by one page worth of bitmap,
1323  * so we won't wrap around in drbd_bm_find_next_bit.
1324  * you should use 64bit OS for that much storage, anyways. */
1325 #define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff)
1326 #else
1327 /* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */
1328 #define DRBD_MAX_SECTORS_FLEX (1UL << 51)
1329 /* corresponds to (1UL << 38) bits right now. */
1330 #endif
1331 #endif
1332 
1333 /* Estimate max bio size as 256 * PAGE_SIZE,
1334  * so for typical PAGE_SIZE of 4k, that is (1<<20) Byte.
1335  * Since we may live in a mixed-platform cluster,
1336  * we limit us to a platform agnostic constant here for now.
1337  * A followup commit may allow even bigger BIO sizes,
1338  * once we thought that through. */
1339 #define DRBD_MAX_BIO_SIZE (1U << 20)
1340 #if DRBD_MAX_BIO_SIZE > (BIO_MAX_PAGES << PAGE_SHIFT)
1341 #error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE
1342 #endif
1343 #define DRBD_MAX_BIO_SIZE_SAFE (1U << 12)       /* Works always = 4k */
1344 
1345 #define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */
1346 #define DRBD_MAX_BIO_SIZE_P95    (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */
1347 
1348 /* For now, don't allow more than half of what we can "activate" in one
1349  * activity log transaction to be discarded in one go. We may need to rework
1350  * drbd_al_begin_io() to allow for even larger discard ranges */
1351 #define DRBD_MAX_BATCH_BIO_SIZE	 (AL_UPDATES_PER_TRANSACTION/2*AL_EXTENT_SIZE)
1352 #define DRBD_MAX_BBIO_SECTORS    (DRBD_MAX_BATCH_BIO_SIZE >> 9)
1353 
1354 extern int  drbd_bm_init(struct drbd_device *device);
1355 extern int  drbd_bm_resize(struct drbd_device *device, sector_t sectors, int set_new_bits);
1356 extern void drbd_bm_cleanup(struct drbd_device *device);
1357 extern void drbd_bm_set_all(struct drbd_device *device);
1358 extern void drbd_bm_clear_all(struct drbd_device *device);
1359 /* set/clear/test only a few bits at a time */
1360 extern int  drbd_bm_set_bits(
1361 		struct drbd_device *device, unsigned long s, unsigned long e);
1362 extern int  drbd_bm_clear_bits(
1363 		struct drbd_device *device, unsigned long s, unsigned long e);
1364 extern int drbd_bm_count_bits(
1365 	struct drbd_device *device, const unsigned long s, const unsigned long e);
1366 /* bm_set_bits variant for use while holding drbd_bm_lock,
1367  * may process the whole bitmap in one go */
1368 extern void _drbd_bm_set_bits(struct drbd_device *device,
1369 		const unsigned long s, const unsigned long e);
1370 extern int  drbd_bm_test_bit(struct drbd_device *device, unsigned long bitnr);
1371 extern int  drbd_bm_e_weight(struct drbd_device *device, unsigned long enr);
1372 extern int  drbd_bm_read(struct drbd_device *device) __must_hold(local);
1373 extern void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr);
1374 extern int  drbd_bm_write(struct drbd_device *device) __must_hold(local);
1375 extern void drbd_bm_reset_al_hints(struct drbd_device *device) __must_hold(local);
1376 extern int  drbd_bm_write_hinted(struct drbd_device *device) __must_hold(local);
1377 extern int  drbd_bm_write_lazy(struct drbd_device *device, unsigned upper_idx) __must_hold(local);
1378 extern int drbd_bm_write_all(struct drbd_device *device) __must_hold(local);
1379 extern int  drbd_bm_write_copy_pages(struct drbd_device *device) __must_hold(local);
1380 extern size_t	     drbd_bm_words(struct drbd_device *device);
1381 extern unsigned long drbd_bm_bits(struct drbd_device *device);
1382 extern sector_t      drbd_bm_capacity(struct drbd_device *device);
1383 
1384 #define DRBD_END_OF_BITMAP	(~(unsigned long)0)
1385 extern unsigned long drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo);
1386 /* bm_find_next variants for use while you hold drbd_bm_lock() */
1387 extern unsigned long _drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo);
1388 extern unsigned long _drbd_bm_find_next_zero(struct drbd_device *device, unsigned long bm_fo);
1389 extern unsigned long _drbd_bm_total_weight(struct drbd_device *device);
1390 extern unsigned long drbd_bm_total_weight(struct drbd_device *device);
1391 /* for receive_bitmap */
1392 extern void drbd_bm_merge_lel(struct drbd_device *device, size_t offset,
1393 		size_t number, unsigned long *buffer);
1394 /* for _drbd_send_bitmap */
1395 extern void drbd_bm_get_lel(struct drbd_device *device, size_t offset,
1396 		size_t number, unsigned long *buffer);
1397 
1398 extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags);
1399 extern void drbd_bm_unlock(struct drbd_device *device);
1400 /* drbd_main.c */
1401 
1402 extern struct kmem_cache *drbd_request_cache;
1403 extern struct kmem_cache *drbd_ee_cache;	/* peer requests */
1404 extern struct kmem_cache *drbd_bm_ext_cache;	/* bitmap extents */
1405 extern struct kmem_cache *drbd_al_ext_cache;	/* activity log extents */
1406 extern mempool_t drbd_request_mempool;
1407 extern mempool_t drbd_ee_mempool;
1408 
1409 /* drbd's page pool, used to buffer data received from the peer,
1410  * or data requested by the peer.
1411  *
1412  * This does not have an emergency reserve.
1413  *
1414  * When allocating from this pool, it first takes pages from the pool.
1415  * Only if the pool is depleted will try to allocate from the system.
1416  *
1417  * The assumption is that pages taken from this pool will be processed,
1418  * and given back, "quickly", and then can be recycled, so we can avoid
1419  * frequent calls to alloc_page(), and still will be able to make progress even
1420  * under memory pressure.
1421  */
1422 extern struct page *drbd_pp_pool;
1423 extern spinlock_t   drbd_pp_lock;
1424 extern int	    drbd_pp_vacant;
1425 extern wait_queue_head_t drbd_pp_wait;
1426 
1427 /* We also need a standard (emergency-reserve backed) page pool
1428  * for meta data IO (activity log, bitmap).
1429  * We can keep it global, as long as it is used as "N pages at a time".
1430  * 128 should be plenty, currently we probably can get away with as few as 1.
1431  */
1432 #define DRBD_MIN_POOL_PAGES	128
1433 extern mempool_t drbd_md_io_page_pool;
1434 
1435 /* We also need to make sure we get a bio
1436  * when we need it for housekeeping purposes */
1437 extern struct bio_set drbd_md_io_bio_set;
1438 /* to allocate from that set */
1439 extern struct bio *bio_alloc_drbd(gfp_t gfp_mask);
1440 
1441 /* And a bio_set for cloning */
1442 extern struct bio_set drbd_io_bio_set;
1443 
1444 extern struct mutex resources_mutex;
1445 
1446 extern int conn_lowest_minor(struct drbd_connection *connection);
1447 extern enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor);
1448 extern void drbd_destroy_device(struct kref *kref);
1449 extern void drbd_delete_device(struct drbd_device *device);
1450 
1451 extern struct drbd_resource *drbd_create_resource(const char *name);
1452 extern void drbd_free_resource(struct drbd_resource *resource);
1453 
1454 extern int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts);
1455 extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts);
1456 extern void drbd_destroy_connection(struct kref *kref);
1457 extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
1458 					    void *peer_addr, int peer_addr_len);
1459 extern struct drbd_resource *drbd_find_resource(const char *name);
1460 extern void drbd_destroy_resource(struct kref *kref);
1461 extern void conn_free_crypto(struct drbd_connection *connection);
1462 
1463 /* drbd_req */
1464 extern void do_submit(struct work_struct *ws);
1465 extern void __drbd_make_request(struct drbd_device *, struct bio *, unsigned long);
1466 extern blk_qc_t drbd_make_request(struct request_queue *q, struct bio *bio);
1467 extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req);
1468 extern int is_valid_ar_handle(struct drbd_request *, sector_t);
1469 
1470 
1471 /* drbd_nl.c */
1472 
1473 extern struct mutex notification_mutex;
1474 
1475 extern void drbd_suspend_io(struct drbd_device *device);
1476 extern void drbd_resume_io(struct drbd_device *device);
1477 extern char *ppsize(char *buf, unsigned long long size);
1478 extern sector_t drbd_new_dev_size(struct drbd_device *, struct drbd_backing_dev *, sector_t, int);
1479 enum determine_dev_size {
1480 	DS_ERROR_SHRINK = -3,
1481 	DS_ERROR_SPACE_MD = -2,
1482 	DS_ERROR = -1,
1483 	DS_UNCHANGED = 0,
1484 	DS_SHRUNK = 1,
1485 	DS_GREW = 2,
1486 	DS_GREW_FROM_ZERO = 3,
1487 };
1488 extern enum determine_dev_size
1489 drbd_determine_dev_size(struct drbd_device *, enum dds_flags, struct resize_parms *) __must_hold(local);
1490 extern void resync_after_online_grow(struct drbd_device *);
1491 extern void drbd_reconsider_queue_parameters(struct drbd_device *device,
1492 			struct drbd_backing_dev *bdev, struct o_qlim *o);
1493 extern enum drbd_state_rv drbd_set_role(struct drbd_device *device,
1494 					enum drbd_role new_role,
1495 					int force);
1496 extern bool conn_try_outdate_peer(struct drbd_connection *connection);
1497 extern void conn_try_outdate_peer_async(struct drbd_connection *connection);
1498 extern enum drbd_peer_state conn_khelper(struct drbd_connection *connection, char *cmd);
1499 extern int drbd_khelper(struct drbd_device *device, char *cmd);
1500 
1501 /* drbd_worker.c */
1502 /* bi_end_io handlers */
1503 extern void drbd_md_endio(struct bio *bio);
1504 extern void drbd_peer_request_endio(struct bio *bio);
1505 extern void drbd_request_endio(struct bio *bio);
1506 extern int drbd_worker(struct drbd_thread *thi);
1507 enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor);
1508 void drbd_resync_after_changed(struct drbd_device *device);
1509 extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side);
1510 extern void resume_next_sg(struct drbd_device *device);
1511 extern void suspend_other_sg(struct drbd_device *device);
1512 extern int drbd_resync_finished(struct drbd_device *device);
1513 /* maybe rather drbd_main.c ? */
1514 extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent);
1515 extern void drbd_md_put_buffer(struct drbd_device *device);
1516 extern int drbd_md_sync_page_io(struct drbd_device *device,
1517 		struct drbd_backing_dev *bdev, sector_t sector, int op);
1518 extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int);
1519 extern void wait_until_done_or_force_detached(struct drbd_device *device,
1520 		struct drbd_backing_dev *bdev, unsigned int *done);
1521 extern void drbd_rs_controller_reset(struct drbd_device *device);
1522 
ov_out_of_sync_print(struct drbd_device * device)1523 static inline void ov_out_of_sync_print(struct drbd_device *device)
1524 {
1525 	if (device->ov_last_oos_size) {
1526 		drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n",
1527 		     (unsigned long long)device->ov_last_oos_start,
1528 		     (unsigned long)device->ov_last_oos_size);
1529 	}
1530 	device->ov_last_oos_size = 0;
1531 }
1532 
1533 
1534 extern void drbd_csum_bio(struct crypto_ahash *, struct bio *, void *);
1535 extern void drbd_csum_ee(struct crypto_ahash *, struct drbd_peer_request *, void *);
1536 /* worker callbacks */
1537 extern int w_e_end_data_req(struct drbd_work *, int);
1538 extern int w_e_end_rsdata_req(struct drbd_work *, int);
1539 extern int w_e_end_csum_rs_req(struct drbd_work *, int);
1540 extern int w_e_end_ov_reply(struct drbd_work *, int);
1541 extern int w_e_end_ov_req(struct drbd_work *, int);
1542 extern int w_ov_finished(struct drbd_work *, int);
1543 extern int w_resync_timer(struct drbd_work *, int);
1544 extern int w_send_write_hint(struct drbd_work *, int);
1545 extern int w_send_dblock(struct drbd_work *, int);
1546 extern int w_send_read_req(struct drbd_work *, int);
1547 extern int w_e_reissue(struct drbd_work *, int);
1548 extern int w_restart_disk_io(struct drbd_work *, int);
1549 extern int w_send_out_of_sync(struct drbd_work *, int);
1550 extern int w_start_resync(struct drbd_work *, int);
1551 
1552 extern void resync_timer_fn(struct timer_list *t);
1553 extern void start_resync_timer_fn(struct timer_list *t);
1554 
1555 extern void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req);
1556 
1557 /* drbd_receiver.c */
1558 extern int drbd_receiver(struct drbd_thread *thi);
1559 extern int drbd_ack_receiver(struct drbd_thread *thi);
1560 extern void drbd_send_ping_wf(struct work_struct *ws);
1561 extern void drbd_send_acks_wf(struct work_struct *ws);
1562 extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device);
1563 extern bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector,
1564 		bool throttle_if_app_is_waiting);
1565 extern int drbd_submit_peer_request(struct drbd_device *,
1566 				    struct drbd_peer_request *, const unsigned,
1567 				    const unsigned, const int);
1568 extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *);
1569 extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_peer_device *, u64,
1570 						     sector_t, unsigned int,
1571 						     unsigned int,
1572 						     gfp_t) __must_hold(local);
1573 extern void __drbd_free_peer_req(struct drbd_device *, struct drbd_peer_request *,
1574 				 int);
1575 #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0)
1576 #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1)
1577 extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool);
1578 extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled);
1579 extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed);
1580 extern int drbd_connected(struct drbd_peer_device *);
1581 
drbd_tcp_cork(struct socket * sock)1582 static inline void drbd_tcp_cork(struct socket *sock)
1583 {
1584 	int val = 1;
1585 	(void) kernel_setsockopt(sock, SOL_TCP, TCP_CORK,
1586 			(char*)&val, sizeof(val));
1587 }
1588 
drbd_tcp_uncork(struct socket * sock)1589 static inline void drbd_tcp_uncork(struct socket *sock)
1590 {
1591 	int val = 0;
1592 	(void) kernel_setsockopt(sock, SOL_TCP, TCP_CORK,
1593 			(char*)&val, sizeof(val));
1594 }
1595 
drbd_tcp_nodelay(struct socket * sock)1596 static inline void drbd_tcp_nodelay(struct socket *sock)
1597 {
1598 	int val = 1;
1599 	(void) kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
1600 			(char*)&val, sizeof(val));
1601 }
1602 
drbd_tcp_quickack(struct socket * sock)1603 static inline void drbd_tcp_quickack(struct socket *sock)
1604 {
1605 	int val = 2;
1606 	(void) kernel_setsockopt(sock, SOL_TCP, TCP_QUICKACK,
1607 			(char*)&val, sizeof(val));
1608 }
1609 
1610 /* sets the number of 512 byte sectors of our virtual device */
drbd_set_my_capacity(struct drbd_device * device,sector_t size)1611 static inline void drbd_set_my_capacity(struct drbd_device *device,
1612 					sector_t size)
1613 {
1614 	/* set_capacity(device->this_bdev->bd_disk, size); */
1615 	set_capacity(device->vdisk, size);
1616 	device->this_bdev->bd_inode->i_size = (loff_t)size << 9;
1617 }
1618 
1619 /*
1620  * used to submit our private bio
1621  */
drbd_generic_make_request(struct drbd_device * device,int fault_type,struct bio * bio)1622 static inline void drbd_generic_make_request(struct drbd_device *device,
1623 					     int fault_type, struct bio *bio)
1624 {
1625 	__release(local);
1626 	if (!bio->bi_disk) {
1627 		drbd_err(device, "drbd_generic_make_request: bio->bi_disk == NULL\n");
1628 		bio->bi_status = BLK_STS_IOERR;
1629 		bio_endio(bio);
1630 		return;
1631 	}
1632 
1633 	if (drbd_insert_fault(device, fault_type))
1634 		bio_io_error(bio);
1635 	else
1636 		generic_make_request(bio);
1637 }
1638 
1639 void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev,
1640 			      enum write_ordering_e wo);
1641 
1642 /* drbd_proc.c */
1643 extern struct proc_dir_entry *drbd_proc;
1644 int drbd_seq_show(struct seq_file *seq, void *v);
1645 
1646 /* drbd_actlog.c */
1647 extern bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i);
1648 extern int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i);
1649 extern void drbd_al_begin_io_commit(struct drbd_device *device);
1650 extern bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i);
1651 extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i);
1652 extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i);
1653 extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector);
1654 extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector);
1655 extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector);
1656 extern void drbd_rs_cancel_all(struct drbd_device *device);
1657 extern int drbd_rs_del_all(struct drbd_device *device);
1658 extern void drbd_rs_failed_io(struct drbd_device *device,
1659 		sector_t sector, int size);
1660 extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go);
1661 
1662 enum update_sync_bits_mode { RECORD_RS_FAILED, SET_OUT_OF_SYNC, SET_IN_SYNC };
1663 extern int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size,
1664 		enum update_sync_bits_mode mode);
1665 #define drbd_set_in_sync(device, sector, size) \
1666 	__drbd_change_sync(device, sector, size, SET_IN_SYNC)
1667 #define drbd_set_out_of_sync(device, sector, size) \
1668 	__drbd_change_sync(device, sector, size, SET_OUT_OF_SYNC)
1669 #define drbd_rs_failed_io(device, sector, size) \
1670 	__drbd_change_sync(device, sector, size, RECORD_RS_FAILED)
1671 extern void drbd_al_shrink(struct drbd_device *device);
1672 extern int drbd_al_initialize(struct drbd_device *, void *);
1673 
1674 /* drbd_nl.c */
1675 /* state info broadcast */
1676 struct sib_info {
1677 	enum drbd_state_info_bcast_reason sib_reason;
1678 	union {
1679 		struct {
1680 			char *helper_name;
1681 			unsigned helper_exit_code;
1682 		};
1683 		struct {
1684 			union drbd_state os;
1685 			union drbd_state ns;
1686 		};
1687 	};
1688 };
1689 void drbd_bcast_event(struct drbd_device *device, const struct sib_info *sib);
1690 
1691 extern void notify_resource_state(struct sk_buff *,
1692 				  unsigned int,
1693 				  struct drbd_resource *,
1694 				  struct resource_info *,
1695 				  enum drbd_notification_type);
1696 extern void notify_device_state(struct sk_buff *,
1697 				unsigned int,
1698 				struct drbd_device *,
1699 				struct device_info *,
1700 				enum drbd_notification_type);
1701 extern void notify_connection_state(struct sk_buff *,
1702 				    unsigned int,
1703 				    struct drbd_connection *,
1704 				    struct connection_info *,
1705 				    enum drbd_notification_type);
1706 extern void notify_peer_device_state(struct sk_buff *,
1707 				     unsigned int,
1708 				     struct drbd_peer_device *,
1709 				     struct peer_device_info *,
1710 				     enum drbd_notification_type);
1711 extern void notify_helper(enum drbd_notification_type, struct drbd_device *,
1712 			  struct drbd_connection *, const char *, int);
1713 
1714 /*
1715  * inline helper functions
1716  *************************/
1717 
1718 /* see also page_chain_add and friends in drbd_receiver.c */
page_chain_next(struct page * page)1719 static inline struct page *page_chain_next(struct page *page)
1720 {
1721 	return (struct page *)page_private(page);
1722 }
1723 #define page_chain_for_each(page) \
1724 	for (; page && ({ prefetch(page_chain_next(page)); 1; }); \
1725 			page = page_chain_next(page))
1726 #define page_chain_for_each_safe(page, n) \
1727 	for (; page && ({ n = page_chain_next(page); 1; }); page = n)
1728 
1729 
drbd_peer_req_has_active_page(struct drbd_peer_request * peer_req)1730 static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req)
1731 {
1732 	struct page *page = peer_req->pages;
1733 	page_chain_for_each(page) {
1734 		if (page_count(page) > 1)
1735 			return 1;
1736 	}
1737 	return 0;
1738 }
1739 
drbd_read_state(struct drbd_device * device)1740 static inline union drbd_state drbd_read_state(struct drbd_device *device)
1741 {
1742 	struct drbd_resource *resource = device->resource;
1743 	union drbd_state rv;
1744 
1745 	rv.i = device->state.i;
1746 	rv.susp = resource->susp;
1747 	rv.susp_nod = resource->susp_nod;
1748 	rv.susp_fen = resource->susp_fen;
1749 
1750 	return rv;
1751 }
1752 
1753 enum drbd_force_detach_flags {
1754 	DRBD_READ_ERROR,
1755 	DRBD_WRITE_ERROR,
1756 	DRBD_META_IO_ERROR,
1757 	DRBD_FORCE_DETACH,
1758 };
1759 
1760 #define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__)
__drbd_chk_io_error_(struct drbd_device * device,enum drbd_force_detach_flags df,const char * where)1761 static inline void __drbd_chk_io_error_(struct drbd_device *device,
1762 		enum drbd_force_detach_flags df,
1763 		const char *where)
1764 {
1765 	enum drbd_io_error_p ep;
1766 
1767 	rcu_read_lock();
1768 	ep = rcu_dereference(device->ldev->disk_conf)->on_io_error;
1769 	rcu_read_unlock();
1770 	switch (ep) {
1771 	case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */
1772 		if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) {
1773 			if (__ratelimit(&drbd_ratelimit_state))
1774 				drbd_err(device, "Local IO failed in %s.\n", where);
1775 			if (device->state.disk > D_INCONSISTENT)
1776 				_drbd_set_state(_NS(device, disk, D_INCONSISTENT), CS_HARD, NULL);
1777 			break;
1778 		}
1779 		/* NOTE fall through for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */
1780 	case EP_DETACH:
1781 	case EP_CALL_HELPER:
1782 		/* Remember whether we saw a READ or WRITE error.
1783 		 *
1784 		 * Recovery of the affected area for WRITE failure is covered
1785 		 * by the activity log.
1786 		 * READ errors may fall outside that area though. Certain READ
1787 		 * errors can be "healed" by writing good data to the affected
1788 		 * blocks, which triggers block re-allocation in lower layers.
1789 		 *
1790 		 * If we can not write the bitmap after a READ error,
1791 		 * we may need to trigger a full sync (see w_go_diskless()).
1792 		 *
1793 		 * Force-detach is not really an IO error, but rather a
1794 		 * desperate measure to try to deal with a completely
1795 		 * unresponsive lower level IO stack.
1796 		 * Still it should be treated as a WRITE error.
1797 		 *
1798 		 * Meta IO error is always WRITE error:
1799 		 * we read meta data only once during attach,
1800 		 * which will fail in case of errors.
1801 		 */
1802 		set_bit(WAS_IO_ERROR, &device->flags);
1803 		if (df == DRBD_READ_ERROR)
1804 			set_bit(WAS_READ_ERROR, &device->flags);
1805 		if (df == DRBD_FORCE_DETACH)
1806 			set_bit(FORCE_DETACH, &device->flags);
1807 		if (device->state.disk > D_FAILED) {
1808 			_drbd_set_state(_NS(device, disk, D_FAILED), CS_HARD, NULL);
1809 			drbd_err(device,
1810 				"Local IO failed in %s. Detaching...\n", where);
1811 		}
1812 		break;
1813 	}
1814 }
1815 
1816 /**
1817  * drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers
1818  * @device:	 DRBD device.
1819  * @error:	 Error code passed to the IO completion callback
1820  * @forcedetach: Force detach. I.e. the error happened while accessing the meta data
1821  *
1822  * See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED)
1823  */
1824 #define drbd_chk_io_error(m,e,f) drbd_chk_io_error_(m,e,f, __func__)
drbd_chk_io_error_(struct drbd_device * device,int error,enum drbd_force_detach_flags forcedetach,const char * where)1825 static inline void drbd_chk_io_error_(struct drbd_device *device,
1826 	int error, enum drbd_force_detach_flags forcedetach, const char *where)
1827 {
1828 	if (error) {
1829 		unsigned long flags;
1830 		spin_lock_irqsave(&device->resource->req_lock, flags);
1831 		__drbd_chk_io_error_(device, forcedetach, where);
1832 		spin_unlock_irqrestore(&device->resource->req_lock, flags);
1833 	}
1834 }
1835 
1836 
1837 /**
1838  * drbd_md_first_sector() - Returns the first sector number of the meta data area
1839  * @bdev:	Meta data block device.
1840  *
1841  * BTW, for internal meta data, this happens to be the maximum capacity
1842  * we could agree upon with our peer node.
1843  */
drbd_md_first_sector(struct drbd_backing_dev * bdev)1844 static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev)
1845 {
1846 	switch (bdev->md.meta_dev_idx) {
1847 	case DRBD_MD_INDEX_INTERNAL:
1848 	case DRBD_MD_INDEX_FLEX_INT:
1849 		return bdev->md.md_offset + bdev->md.bm_offset;
1850 	case DRBD_MD_INDEX_FLEX_EXT:
1851 	default:
1852 		return bdev->md.md_offset;
1853 	}
1854 }
1855 
1856 /**
1857  * drbd_md_last_sector() - Return the last sector number of the meta data area
1858  * @bdev:	Meta data block device.
1859  */
drbd_md_last_sector(struct drbd_backing_dev * bdev)1860 static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
1861 {
1862 	switch (bdev->md.meta_dev_idx) {
1863 	case DRBD_MD_INDEX_INTERNAL:
1864 	case DRBD_MD_INDEX_FLEX_INT:
1865 		return bdev->md.md_offset + MD_4kB_SECT -1;
1866 	case DRBD_MD_INDEX_FLEX_EXT:
1867 	default:
1868 		return bdev->md.md_offset + bdev->md.md_size_sect -1;
1869 	}
1870 }
1871 
1872 /* Returns the number of 512 byte sectors of the device */
drbd_get_capacity(struct block_device * bdev)1873 static inline sector_t drbd_get_capacity(struct block_device *bdev)
1874 {
1875 	/* return bdev ? get_capacity(bdev->bd_disk) : 0; */
1876 	return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0;
1877 }
1878 
1879 /**
1880  * drbd_get_max_capacity() - Returns the capacity we announce to out peer
1881  * @bdev:	Meta data block device.
1882  *
1883  * returns the capacity we announce to out peer.  we clip ourselves at the
1884  * various MAX_SECTORS, because if we don't, current implementation will
1885  * oops sooner or later
1886  */
drbd_get_max_capacity(struct drbd_backing_dev * bdev)1887 static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev)
1888 {
1889 	sector_t s;
1890 
1891 	switch (bdev->md.meta_dev_idx) {
1892 	case DRBD_MD_INDEX_INTERNAL:
1893 	case DRBD_MD_INDEX_FLEX_INT:
1894 		s = drbd_get_capacity(bdev->backing_bdev)
1895 			? min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
1896 				drbd_md_first_sector(bdev))
1897 			: 0;
1898 		break;
1899 	case DRBD_MD_INDEX_FLEX_EXT:
1900 		s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
1901 				drbd_get_capacity(bdev->backing_bdev));
1902 		/* clip at maximum size the meta device can support */
1903 		s = min_t(sector_t, s,
1904 			BM_EXT_TO_SECT(bdev->md.md_size_sect
1905 				     - bdev->md.bm_offset));
1906 		break;
1907 	default:
1908 		s = min_t(sector_t, DRBD_MAX_SECTORS,
1909 				drbd_get_capacity(bdev->backing_bdev));
1910 	}
1911 	return s;
1912 }
1913 
1914 /**
1915  * drbd_md_ss() - Return the sector number of our meta data super block
1916  * @bdev:	Meta data block device.
1917  */
drbd_md_ss(struct drbd_backing_dev * bdev)1918 static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev)
1919 {
1920 	const int meta_dev_idx = bdev->md.meta_dev_idx;
1921 
1922 	if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT)
1923 		return 0;
1924 
1925 	/* Since drbd08, internal meta data is always "flexible".
1926 	 * position: last 4k aligned block of 4k size */
1927 	if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
1928 	    meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)
1929 		return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8;
1930 
1931 	/* external, some index; this is the old fixed size layout */
1932 	return MD_128MB_SECT * bdev->md.meta_dev_idx;
1933 }
1934 
1935 static inline void
drbd_queue_work(struct drbd_work_queue * q,struct drbd_work * w)1936 drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w)
1937 {
1938 	unsigned long flags;
1939 	spin_lock_irqsave(&q->q_lock, flags);
1940 	list_add_tail(&w->list, &q->q);
1941 	spin_unlock_irqrestore(&q->q_lock, flags);
1942 	wake_up(&q->q_wait);
1943 }
1944 
1945 static inline void
drbd_queue_work_if_unqueued(struct drbd_work_queue * q,struct drbd_work * w)1946 drbd_queue_work_if_unqueued(struct drbd_work_queue *q, struct drbd_work *w)
1947 {
1948 	unsigned long flags;
1949 	spin_lock_irqsave(&q->q_lock, flags);
1950 	if (list_empty_careful(&w->list))
1951 		list_add_tail(&w->list, &q->q);
1952 	spin_unlock_irqrestore(&q->q_lock, flags);
1953 	wake_up(&q->q_wait);
1954 }
1955 
1956 static inline void
drbd_device_post_work(struct drbd_device * device,int work_bit)1957 drbd_device_post_work(struct drbd_device *device, int work_bit)
1958 {
1959 	if (!test_and_set_bit(work_bit, &device->flags)) {
1960 		struct drbd_connection *connection =
1961 			first_peer_device(device)->connection;
1962 		struct drbd_work_queue *q = &connection->sender_work;
1963 		if (!test_and_set_bit(DEVICE_WORK_PENDING, &connection->flags))
1964 			wake_up(&q->q_wait);
1965 	}
1966 }
1967 
1968 extern void drbd_flush_workqueue(struct drbd_work_queue *work_queue);
1969 
1970 /* To get the ack_receiver out of the blocking network stack,
1971  * so it can change its sk_rcvtimeo from idle- to ping-timeout,
1972  * and send a ping, we need to send a signal.
1973  * Which signal we send is irrelevant. */
wake_ack_receiver(struct drbd_connection * connection)1974 static inline void wake_ack_receiver(struct drbd_connection *connection)
1975 {
1976 	struct task_struct *task = connection->ack_receiver.task;
1977 	if (task && get_t_state(&connection->ack_receiver) == RUNNING)
1978 		force_sig(SIGXCPU, task);
1979 }
1980 
request_ping(struct drbd_connection * connection)1981 static inline void request_ping(struct drbd_connection *connection)
1982 {
1983 	set_bit(SEND_PING, &connection->flags);
1984 	wake_ack_receiver(connection);
1985 }
1986 
1987 extern void *conn_prepare_command(struct drbd_connection *, struct drbd_socket *);
1988 extern void *drbd_prepare_command(struct drbd_peer_device *, struct drbd_socket *);
1989 extern int conn_send_command(struct drbd_connection *, struct drbd_socket *,
1990 			     enum drbd_packet, unsigned int, void *,
1991 			     unsigned int);
1992 extern int drbd_send_command(struct drbd_peer_device *, struct drbd_socket *,
1993 			     enum drbd_packet, unsigned int, void *,
1994 			     unsigned int);
1995 
1996 extern int drbd_send_ping(struct drbd_connection *connection);
1997 extern int drbd_send_ping_ack(struct drbd_connection *connection);
1998 extern int drbd_send_state_req(struct drbd_peer_device *, union drbd_state, union drbd_state);
1999 extern int conn_send_state_req(struct drbd_connection *, union drbd_state, union drbd_state);
2000 
drbd_thread_stop(struct drbd_thread * thi)2001 static inline void drbd_thread_stop(struct drbd_thread *thi)
2002 {
2003 	_drbd_thread_stop(thi, false, true);
2004 }
2005 
drbd_thread_stop_nowait(struct drbd_thread * thi)2006 static inline void drbd_thread_stop_nowait(struct drbd_thread *thi)
2007 {
2008 	_drbd_thread_stop(thi, false, false);
2009 }
2010 
drbd_thread_restart_nowait(struct drbd_thread * thi)2011 static inline void drbd_thread_restart_nowait(struct drbd_thread *thi)
2012 {
2013 	_drbd_thread_stop(thi, true, false);
2014 }
2015 
2016 /* counts how many answer packets packets we expect from our peer,
2017  * for either explicit application requests,
2018  * or implicit barrier packets as necessary.
2019  * increased:
2020  *  w_send_barrier
2021  *  _req_mod(req, QUEUE_FOR_NET_WRITE or QUEUE_FOR_NET_READ);
2022  *    it is much easier and equally valid to count what we queue for the
2023  *    worker, even before it actually was queued or send.
2024  *    (drbd_make_request_common; recovery path on read io-error)
2025  * decreased:
2026  *  got_BarrierAck (respective tl_clear, tl_clear_barrier)
2027  *  _req_mod(req, DATA_RECEIVED)
2028  *     [from receive_DataReply]
2029  *  _req_mod(req, WRITE_ACKED_BY_PEER or RECV_ACKED_BY_PEER or NEG_ACKED)
2030  *     [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)]
2031  *     for some reason it is NOT decreased in got_NegAck,
2032  *     but in the resulting cleanup code from report_params.
2033  *     we should try to remember the reason for that...
2034  *  _req_mod(req, SEND_FAILED or SEND_CANCELED)
2035  *  _req_mod(req, CONNECTION_LOST_WHILE_PENDING)
2036  *     [from tl_clear_barrier]
2037  */
inc_ap_pending(struct drbd_device * device)2038 static inline void inc_ap_pending(struct drbd_device *device)
2039 {
2040 	atomic_inc(&device->ap_pending_cnt);
2041 }
2042 
2043 #define ERR_IF_CNT_IS_NEGATIVE(which, func, line)			\
2044 	if (atomic_read(&device->which) < 0)				\
2045 		drbd_err(device, "in %s:%d: " #which " = %d < 0 !\n",	\
2046 			func, line,					\
2047 			atomic_read(&device->which))
2048 
2049 #define dec_ap_pending(device) _dec_ap_pending(device, __func__, __LINE__)
_dec_ap_pending(struct drbd_device * device,const char * func,int line)2050 static inline void _dec_ap_pending(struct drbd_device *device, const char *func, int line)
2051 {
2052 	if (atomic_dec_and_test(&device->ap_pending_cnt))
2053 		wake_up(&device->misc_wait);
2054 	ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line);
2055 }
2056 
2057 /* counts how many resync-related answers we still expect from the peer
2058  *		     increase			decrease
2059  * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY)
2060  * C_SYNC_SOURCE sends P_RS_DATA_REPLY   (and expects P_WRITE_ACK with ID_SYNCER)
2061  *					   (or P_NEG_ACK with ID_SYNCER)
2062  */
inc_rs_pending(struct drbd_device * device)2063 static inline void inc_rs_pending(struct drbd_device *device)
2064 {
2065 	atomic_inc(&device->rs_pending_cnt);
2066 }
2067 
2068 #define dec_rs_pending(device) _dec_rs_pending(device, __func__, __LINE__)
_dec_rs_pending(struct drbd_device * device,const char * func,int line)2069 static inline void _dec_rs_pending(struct drbd_device *device, const char *func, int line)
2070 {
2071 	atomic_dec(&device->rs_pending_cnt);
2072 	ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line);
2073 }
2074 
2075 /* counts how many answers we still need to send to the peer.
2076  * increased on
2077  *  receive_Data	unless protocol A;
2078  *			we need to send a P_RECV_ACK (proto B)
2079  *			or P_WRITE_ACK (proto C)
2080  *  receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK
2081  *  receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA
2082  *  receive_Barrier_*	we need to send a P_BARRIER_ACK
2083  */
inc_unacked(struct drbd_device * device)2084 static inline void inc_unacked(struct drbd_device *device)
2085 {
2086 	atomic_inc(&device->unacked_cnt);
2087 }
2088 
2089 #define dec_unacked(device) _dec_unacked(device, __func__, __LINE__)
_dec_unacked(struct drbd_device * device,const char * func,int line)2090 static inline void _dec_unacked(struct drbd_device *device, const char *func, int line)
2091 {
2092 	atomic_dec(&device->unacked_cnt);
2093 	ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
2094 }
2095 
2096 #define sub_unacked(device, n) _sub_unacked(device, n, __func__, __LINE__)
_sub_unacked(struct drbd_device * device,int n,const char * func,int line)2097 static inline void _sub_unacked(struct drbd_device *device, int n, const char *func, int line)
2098 {
2099 	atomic_sub(n, &device->unacked_cnt);
2100 	ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
2101 }
2102 
is_sync_target_state(enum drbd_conns connection_state)2103 static inline bool is_sync_target_state(enum drbd_conns connection_state)
2104 {
2105 	return	connection_state == C_SYNC_TARGET ||
2106 		connection_state == C_PAUSED_SYNC_T;
2107 }
2108 
is_sync_source_state(enum drbd_conns connection_state)2109 static inline bool is_sync_source_state(enum drbd_conns connection_state)
2110 {
2111 	return	connection_state == C_SYNC_SOURCE ||
2112 		connection_state == C_PAUSED_SYNC_S;
2113 }
2114 
is_sync_state(enum drbd_conns connection_state)2115 static inline bool is_sync_state(enum drbd_conns connection_state)
2116 {
2117 	return	is_sync_source_state(connection_state) ||
2118 		is_sync_target_state(connection_state);
2119 }
2120 
2121 /**
2122  * get_ldev() - Increase the ref count on device->ldev. Returns 0 if there is no ldev
2123  * @_device:		DRBD device.
2124  * @_min_state:		Minimum device state required for success.
2125  *
2126  * You have to call put_ldev() when finished working with device->ldev.
2127  */
2128 #define get_ldev_if_state(_device, _min_state)				\
2129 	(_get_ldev_if_state((_device), (_min_state)) ?			\
2130 	 ({ __acquire(x); true; }) : false)
2131 #define get_ldev(_device) get_ldev_if_state(_device, D_INCONSISTENT)
2132 
put_ldev(struct drbd_device * device)2133 static inline void put_ldev(struct drbd_device *device)
2134 {
2135 	enum drbd_disk_state disk_state = device->state.disk;
2136 	/* We must check the state *before* the atomic_dec becomes visible,
2137 	 * or we have a theoretical race where someone hitting zero,
2138 	 * while state still D_FAILED, will then see D_DISKLESS in the
2139 	 * condition below and calling into destroy, where he must not, yet. */
2140 	int i = atomic_dec_return(&device->local_cnt);
2141 
2142 	/* This may be called from some endio handler,
2143 	 * so we must not sleep here. */
2144 
2145 	__release(local);
2146 	D_ASSERT(device, i >= 0);
2147 	if (i == 0) {
2148 		if (disk_state == D_DISKLESS)
2149 			/* even internal references gone, safe to destroy */
2150 			drbd_device_post_work(device, DESTROY_DISK);
2151 		if (disk_state == D_FAILED)
2152 			/* all application IO references gone. */
2153 			if (!test_and_set_bit(GOING_DISKLESS, &device->flags))
2154 				drbd_device_post_work(device, GO_DISKLESS);
2155 		wake_up(&device->misc_wait);
2156 	}
2157 }
2158 
2159 #ifndef __CHECKER__
_get_ldev_if_state(struct drbd_device * device,enum drbd_disk_state mins)2160 static inline int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins)
2161 {
2162 	int io_allowed;
2163 
2164 	/* never get a reference while D_DISKLESS */
2165 	if (device->state.disk == D_DISKLESS)
2166 		return 0;
2167 
2168 	atomic_inc(&device->local_cnt);
2169 	io_allowed = (device->state.disk >= mins);
2170 	if (!io_allowed)
2171 		put_ldev(device);
2172 	return io_allowed;
2173 }
2174 #else
2175 extern int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins);
2176 #endif
2177 
2178 /* this throttles on-the-fly application requests
2179  * according to max_buffers settings;
2180  * maybe re-implement using semaphores? */
drbd_get_max_buffers(struct drbd_device * device)2181 static inline int drbd_get_max_buffers(struct drbd_device *device)
2182 {
2183 	struct net_conf *nc;
2184 	int mxb;
2185 
2186 	rcu_read_lock();
2187 	nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
2188 	mxb = nc ? nc->max_buffers : 1000000;  /* arbitrary limit on open requests */
2189 	rcu_read_unlock();
2190 
2191 	return mxb;
2192 }
2193 
drbd_state_is_stable(struct drbd_device * device)2194 static inline int drbd_state_is_stable(struct drbd_device *device)
2195 {
2196 	union drbd_dev_state s = device->state;
2197 
2198 	/* DO NOT add a default clause, we want the compiler to warn us
2199 	 * for any newly introduced state we may have forgotten to add here */
2200 
2201 	switch ((enum drbd_conns)s.conn) {
2202 	/* new io only accepted when there is no connection, ... */
2203 	case C_STANDALONE:
2204 	case C_WF_CONNECTION:
2205 	/* ... or there is a well established connection. */
2206 	case C_CONNECTED:
2207 	case C_SYNC_SOURCE:
2208 	case C_SYNC_TARGET:
2209 	case C_VERIFY_S:
2210 	case C_VERIFY_T:
2211 	case C_PAUSED_SYNC_S:
2212 	case C_PAUSED_SYNC_T:
2213 	case C_AHEAD:
2214 	case C_BEHIND:
2215 		/* transitional states, IO allowed */
2216 	case C_DISCONNECTING:
2217 	case C_UNCONNECTED:
2218 	case C_TIMEOUT:
2219 	case C_BROKEN_PIPE:
2220 	case C_NETWORK_FAILURE:
2221 	case C_PROTOCOL_ERROR:
2222 	case C_TEAR_DOWN:
2223 	case C_WF_REPORT_PARAMS:
2224 	case C_STARTING_SYNC_S:
2225 	case C_STARTING_SYNC_T:
2226 		break;
2227 
2228 		/* Allow IO in BM exchange states with new protocols */
2229 	case C_WF_BITMAP_S:
2230 		if (first_peer_device(device)->connection->agreed_pro_version < 96)
2231 			return 0;
2232 		break;
2233 
2234 		/* no new io accepted in these states */
2235 	case C_WF_BITMAP_T:
2236 	case C_WF_SYNC_UUID:
2237 	case C_MASK:
2238 		/* not "stable" */
2239 		return 0;
2240 	}
2241 
2242 	switch ((enum drbd_disk_state)s.disk) {
2243 	case D_DISKLESS:
2244 	case D_INCONSISTENT:
2245 	case D_OUTDATED:
2246 	case D_CONSISTENT:
2247 	case D_UP_TO_DATE:
2248 	case D_FAILED:
2249 		/* disk state is stable as well. */
2250 		break;
2251 
2252 	/* no new io accepted during transitional states */
2253 	case D_ATTACHING:
2254 	case D_NEGOTIATING:
2255 	case D_UNKNOWN:
2256 	case D_MASK:
2257 		/* not "stable" */
2258 		return 0;
2259 	}
2260 
2261 	return 1;
2262 }
2263 
drbd_suspended(struct drbd_device * device)2264 static inline int drbd_suspended(struct drbd_device *device)
2265 {
2266 	struct drbd_resource *resource = device->resource;
2267 
2268 	return resource->susp || resource->susp_fen || resource->susp_nod;
2269 }
2270 
may_inc_ap_bio(struct drbd_device * device)2271 static inline bool may_inc_ap_bio(struct drbd_device *device)
2272 {
2273 	int mxb = drbd_get_max_buffers(device);
2274 
2275 	if (drbd_suspended(device))
2276 		return false;
2277 	if (atomic_read(&device->suspend_cnt))
2278 		return false;
2279 
2280 	/* to avoid potential deadlock or bitmap corruption,
2281 	 * in various places, we only allow new application io
2282 	 * to start during "stable" states. */
2283 
2284 	/* no new io accepted when attaching or detaching the disk */
2285 	if (!drbd_state_is_stable(device))
2286 		return false;
2287 
2288 	/* since some older kernels don't have atomic_add_unless,
2289 	 * and we are within the spinlock anyways, we have this workaround.  */
2290 	if (atomic_read(&device->ap_bio_cnt) > mxb)
2291 		return false;
2292 	if (test_bit(BITMAP_IO, &device->flags))
2293 		return false;
2294 	return true;
2295 }
2296 
inc_ap_bio_cond(struct drbd_device * device)2297 static inline bool inc_ap_bio_cond(struct drbd_device *device)
2298 {
2299 	bool rv = false;
2300 
2301 	spin_lock_irq(&device->resource->req_lock);
2302 	rv = may_inc_ap_bio(device);
2303 	if (rv)
2304 		atomic_inc(&device->ap_bio_cnt);
2305 	spin_unlock_irq(&device->resource->req_lock);
2306 
2307 	return rv;
2308 }
2309 
inc_ap_bio(struct drbd_device * device)2310 static inline void inc_ap_bio(struct drbd_device *device)
2311 {
2312 	/* we wait here
2313 	 *    as long as the device is suspended
2314 	 *    until the bitmap is no longer on the fly during connection
2315 	 *    handshake as long as we would exceed the max_buffer limit.
2316 	 *
2317 	 * to avoid races with the reconnect code,
2318 	 * we need to atomic_inc within the spinlock. */
2319 
2320 	wait_event(device->misc_wait, inc_ap_bio_cond(device));
2321 }
2322 
dec_ap_bio(struct drbd_device * device)2323 static inline void dec_ap_bio(struct drbd_device *device)
2324 {
2325 	int mxb = drbd_get_max_buffers(device);
2326 	int ap_bio = atomic_dec_return(&device->ap_bio_cnt);
2327 
2328 	D_ASSERT(device, ap_bio >= 0);
2329 
2330 	if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) {
2331 		if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
2332 			drbd_queue_work(&first_peer_device(device)->
2333 				connection->sender_work,
2334 				&device->bm_io_work.w);
2335 	}
2336 
2337 	/* this currently does wake_up for every dec_ap_bio!
2338 	 * maybe rather introduce some type of hysteresis?
2339 	 * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */
2340 	if (ap_bio < mxb)
2341 		wake_up(&device->misc_wait);
2342 }
2343 
verify_can_do_stop_sector(struct drbd_device * device)2344 static inline bool verify_can_do_stop_sector(struct drbd_device *device)
2345 {
2346 	return first_peer_device(device)->connection->agreed_pro_version >= 97 &&
2347 		first_peer_device(device)->connection->agreed_pro_version != 100;
2348 }
2349 
drbd_set_ed_uuid(struct drbd_device * device,u64 val)2350 static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val)
2351 {
2352 	int changed = device->ed_uuid != val;
2353 	device->ed_uuid = val;
2354 	return changed;
2355 }
2356 
drbd_queue_order_type(struct drbd_device * device)2357 static inline int drbd_queue_order_type(struct drbd_device *device)
2358 {
2359 	/* sorry, we currently have no working implementation
2360 	 * of distributed TCQ stuff */
2361 #ifndef QUEUE_ORDERED_NONE
2362 #define QUEUE_ORDERED_NONE 0
2363 #endif
2364 	return QUEUE_ORDERED_NONE;
2365 }
2366 
first_connection(struct drbd_resource * resource)2367 static inline struct drbd_connection *first_connection(struct drbd_resource *resource)
2368 {
2369 	return list_first_entry_or_null(&resource->connections,
2370 				struct drbd_connection, connections);
2371 }
2372 
2373 #endif
2374