1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3   drbd_int.h
4 
5   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
6 
7   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
8   Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
9   Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
10 
11 
12 */
13 
14 #ifndef _DRBD_INT_H
15 #define _DRBD_INT_H
16 
17 #include <crypto/hash.h>
18 #include <linux/compiler.h>
19 #include <linux/types.h>
20 #include <linux/list.h>
21 #include <linux/sched/signal.h>
22 #include <linux/bitops.h>
23 #include <linux/slab.h>
24 #include <linux/ratelimit.h>
25 #include <linux/tcp.h>
26 #include <linux/mutex.h>
27 #include <linux/major.h>
28 #include <linux/blkdev.h>
29 #include <linux/backing-dev.h>
30 #include <linux/idr.h>
31 #include <linux/dynamic_debug.h>
32 #include <net/tcp.h>
33 #include <linux/lru_cache.h>
34 #include <linux/prefetch.h>
35 #include <linux/drbd_genl_api.h>
36 #include <linux/drbd.h>
37 #include "drbd_strings.h"
38 #include "drbd_state.h"
39 #include "drbd_protocol.h"
40 
41 #ifdef __CHECKER__
42 # define __protected_by(x)       __attribute__((require_context(x,1,999,"rdwr")))
43 # define __protected_read_by(x)  __attribute__((require_context(x,1,999,"read")))
44 # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write")))
45 #else
46 # define __protected_by(x)
47 # define __protected_read_by(x)
48 # define __protected_write_by(x)
49 #endif
50 
51 /* shared module parameters, defined in drbd_main.c */
52 #ifdef CONFIG_DRBD_FAULT_INJECTION
53 extern int drbd_enable_faults;
54 extern int drbd_fault_rate;
55 #endif
56 
57 extern unsigned int drbd_minor_count;
58 extern char drbd_usermode_helper[];
59 extern int drbd_proc_details;
60 
61 
62 /* This is used to stop/restart our threads.
63  * Cannot use SIGTERM nor SIGKILL, since these
64  * are sent out by init on runlevel changes
65  * I choose SIGHUP for now.
66  */
67 #define DRBD_SIGKILL SIGHUP
68 
69 #define ID_IN_SYNC      (4711ULL)
70 #define ID_OUT_OF_SYNC  (4712ULL)
71 #define ID_SYNCER (-1ULL)
72 
73 #define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL)
74 
75 struct drbd_device;
76 struct drbd_connection;
77 
78 #define __drbd_printk_device(level, device, fmt, args...) \
79 	dev_printk(level, disk_to_dev((device)->vdisk), fmt, ## args)
80 #define __drbd_printk_peer_device(level, peer_device, fmt, args...) \
81 	dev_printk(level, disk_to_dev((peer_device)->device->vdisk), fmt, ## args)
82 #define __drbd_printk_resource(level, resource, fmt, args...) \
83 	printk(level "drbd %s: " fmt, (resource)->name, ## args)
84 #define __drbd_printk_connection(level, connection, fmt, args...) \
85 	printk(level "drbd %s: " fmt, (connection)->resource->name, ## args)
86 
87 void drbd_printk_with_wrong_object_type(void);
88 
89 #define __drbd_printk_if_same_type(obj, type, func, level, fmt, args...) \
90 	(__builtin_types_compatible_p(typeof(obj), type) || \
91 	 __builtin_types_compatible_p(typeof(obj), const type)), \
92 	func(level, (const type)(obj), fmt, ## args)
93 
94 #define drbd_printk(level, obj, fmt, args...) \
95 	__builtin_choose_expr( \
96 	  __drbd_printk_if_same_type(obj, struct drbd_device *, \
97 			     __drbd_printk_device, level, fmt, ## args), \
98 	  __builtin_choose_expr( \
99 	    __drbd_printk_if_same_type(obj, struct drbd_resource *, \
100 			       __drbd_printk_resource, level, fmt, ## args), \
101 	    __builtin_choose_expr( \
102 	      __drbd_printk_if_same_type(obj, struct drbd_connection *, \
103 				 __drbd_printk_connection, level, fmt, ## args), \
104 	      __builtin_choose_expr( \
105 		__drbd_printk_if_same_type(obj, struct drbd_peer_device *, \
106 				 __drbd_printk_peer_device, level, fmt, ## args), \
107 		drbd_printk_with_wrong_object_type()))))
108 
109 #define drbd_dbg(obj, fmt, args...) \
110 	drbd_printk(KERN_DEBUG, obj, fmt, ## args)
111 #define drbd_alert(obj, fmt, args...) \
112 	drbd_printk(KERN_ALERT, obj, fmt, ## args)
113 #define drbd_err(obj, fmt, args...) \
114 	drbd_printk(KERN_ERR, obj, fmt, ## args)
115 #define drbd_warn(obj, fmt, args...) \
116 	drbd_printk(KERN_WARNING, obj, fmt, ## args)
117 #define drbd_info(obj, fmt, args...) \
118 	drbd_printk(KERN_INFO, obj, fmt, ## args)
119 #define drbd_emerg(obj, fmt, args...) \
120 	drbd_printk(KERN_EMERG, obj, fmt, ## args)
121 
122 #define dynamic_drbd_dbg(device, fmt, args...) \
123 	dynamic_dev_dbg(disk_to_dev(device->vdisk), fmt, ## args)
124 
125 #define D_ASSERT(device, exp)	do { \
126 	if (!(exp)) \
127 		drbd_err(device, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__); \
128 	} while (0)
129 
130 /**
131  * expect  -  Make an assertion
132  *
133  * Unlike the assert macro, this macro returns a boolean result.
134  */
135 #define expect(exp) ({								\
136 		bool _bool = (exp);						\
137 		if (!_bool)							\
138 			drbd_err(device, "ASSERTION %s FAILED in %s\n",		\
139 			        #exp, __func__);				\
140 		_bool;								\
141 		})
142 
143 /* Defines to control fault insertion */
144 enum {
145 	DRBD_FAULT_MD_WR = 0,	/* meta data write */
146 	DRBD_FAULT_MD_RD = 1,	/*           read  */
147 	DRBD_FAULT_RS_WR = 2,	/* resync          */
148 	DRBD_FAULT_RS_RD = 3,
149 	DRBD_FAULT_DT_WR = 4,	/* data            */
150 	DRBD_FAULT_DT_RD = 5,
151 	DRBD_FAULT_DT_RA = 6,	/* data read ahead */
152 	DRBD_FAULT_BM_ALLOC = 7,	/* bitmap allocation */
153 	DRBD_FAULT_AL_EE = 8,	/* alloc ee */
154 	DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */
155 
156 	DRBD_FAULT_MAX,
157 };
158 
159 extern unsigned int
160 _drbd_insert_fault(struct drbd_device *device, unsigned int type);
161 
162 static inline int
drbd_insert_fault(struct drbd_device * device,unsigned int type)163 drbd_insert_fault(struct drbd_device *device, unsigned int type) {
164 #ifdef CONFIG_DRBD_FAULT_INJECTION
165 	return drbd_fault_rate &&
166 		(drbd_enable_faults & (1<<type)) &&
167 		_drbd_insert_fault(device, type);
168 #else
169 	return 0;
170 #endif
171 }
172 
173 /* integer division, round _UP_ to the next integer */
174 #define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0))
175 /* usual integer division */
176 #define div_floor(A, B) ((A)/(B))
177 
178 extern struct ratelimit_state drbd_ratelimit_state;
179 extern struct idr drbd_devices; /* RCU, updates: genl_lock() */
180 extern struct list_head drbd_resources; /* RCU, updates: genl_lock() */
181 
182 extern const char *cmdname(enum drbd_packet cmd);
183 
184 /* for sending/receiving the bitmap,
185  * possibly in some encoding scheme */
186 struct bm_xfer_ctx {
187 	/* "const"
188 	 * stores total bits and long words
189 	 * of the bitmap, so we don't need to
190 	 * call the accessor functions over and again. */
191 	unsigned long bm_bits;
192 	unsigned long bm_words;
193 	/* during xfer, current position within the bitmap */
194 	unsigned long bit_offset;
195 	unsigned long word_offset;
196 
197 	/* statistics; index: (h->command == P_BITMAP) */
198 	unsigned packets[2];
199 	unsigned bytes[2];
200 };
201 
202 extern void INFO_bm_xfer_stats(struct drbd_device *device,
203 		const char *direction, struct bm_xfer_ctx *c);
204 
bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx * c)205 static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c)
206 {
207 	/* word_offset counts "native long words" (32 or 64 bit),
208 	 * aligned at 64 bit.
209 	 * Encoded packet may end at an unaligned bit offset.
210 	 * In case a fallback clear text packet is transmitted in
211 	 * between, we adjust this offset back to the last 64bit
212 	 * aligned "native long word", which makes coding and decoding
213 	 * the plain text bitmap much more convenient.  */
214 #if BITS_PER_LONG == 64
215 	c->word_offset = c->bit_offset >> 6;
216 #elif BITS_PER_LONG == 32
217 	c->word_offset = c->bit_offset >> 5;
218 	c->word_offset &= ~(1UL);
219 #else
220 # error "unsupported BITS_PER_LONG"
221 #endif
222 }
223 
224 extern unsigned int drbd_header_size(struct drbd_connection *connection);
225 
226 /**********************************************************************/
227 enum drbd_thread_state {
228 	NONE,
229 	RUNNING,
230 	EXITING,
231 	RESTARTING
232 };
233 
234 struct drbd_thread {
235 	spinlock_t t_lock;
236 	struct task_struct *task;
237 	struct completion stop;
238 	enum drbd_thread_state t_state;
239 	int (*function) (struct drbd_thread *);
240 	struct drbd_resource *resource;
241 	struct drbd_connection *connection;
242 	int reset_cpu_mask;
243 	const char *name;
244 };
245 
get_t_state(struct drbd_thread * thi)246 static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi)
247 {
248 	/* THINK testing the t_state seems to be uncritical in all cases
249 	 * (but thread_{start,stop}), so we can read it *without* the lock.
250 	 *	--lge */
251 
252 	smp_rmb();
253 	return thi->t_state;
254 }
255 
256 struct drbd_work {
257 	struct list_head list;
258 	int (*cb)(struct drbd_work *, int cancel);
259 };
260 
261 struct drbd_device_work {
262 	struct drbd_work w;
263 	struct drbd_device *device;
264 };
265 
266 #include "drbd_interval.h"
267 
268 extern int drbd_wait_misc(struct drbd_device *, struct drbd_interval *);
269 
270 extern void lock_all_resources(void);
271 extern void unlock_all_resources(void);
272 
273 struct drbd_request {
274 	struct drbd_work w;
275 	struct drbd_device *device;
276 
277 	/* if local IO is not allowed, will be NULL.
278 	 * if local IO _is_ allowed, holds the locally submitted bio clone,
279 	 * or, after local IO completion, the ERR_PTR(error).
280 	 * see drbd_request_endio(). */
281 	struct bio *private_bio;
282 
283 	struct drbd_interval i;
284 
285 	/* epoch: used to check on "completion" whether this req was in
286 	 * the current epoch, and we therefore have to close it,
287 	 * causing a p_barrier packet to be send, starting a new epoch.
288 	 *
289 	 * This corresponds to "barrier" in struct p_barrier[_ack],
290 	 * and to "barrier_nr" in struct drbd_epoch (and various
291 	 * comments/function parameters/local variable names).
292 	 */
293 	unsigned int epoch;
294 
295 	struct list_head tl_requests; /* ring list in the transfer log */
296 	struct bio *master_bio;       /* master bio pointer */
297 
298 	/* see struct drbd_device */
299 	struct list_head req_pending_master_completion;
300 	struct list_head req_pending_local;
301 
302 	/* for generic IO accounting */
303 	unsigned long start_jif;
304 
305 	/* for DRBD internal statistics */
306 
307 	/* Minimal set of time stamps to determine if we wait for activity log
308 	 * transactions, local disk or peer.  32 bit "jiffies" are good enough,
309 	 * we don't expect a DRBD request to be stalled for several month.
310 	 */
311 
312 	/* before actual request processing */
313 	unsigned long in_actlog_jif;
314 
315 	/* local disk */
316 	unsigned long pre_submit_jif;
317 
318 	/* per connection */
319 	unsigned long pre_send_jif;
320 	unsigned long acked_jif;
321 	unsigned long net_done_jif;
322 
323 	/* Possibly even more detail to track each phase:
324 	 *  master_completion_jif
325 	 *      how long did it take to complete the master bio
326 	 *      (application visible latency)
327 	 *  allocated_jif
328 	 *      how long the master bio was blocked until we finally allocated
329 	 *      a tracking struct
330 	 *  in_actlog_jif
331 	 *      how long did we wait for activity log transactions
332 	 *
333 	 *  net_queued_jif
334 	 *      when did we finally queue it for sending
335 	 *  pre_send_jif
336 	 *      when did we start sending it
337 	 *  post_send_jif
338 	 *      how long did we block in the network stack trying to send it
339 	 *  acked_jif
340 	 *      when did we receive (or fake, in protocol A) a remote ACK
341 	 *  net_done_jif
342 	 *      when did we receive final acknowledgement (P_BARRIER_ACK),
343 	 *      or decide, e.g. on connection loss, that we do no longer expect
344 	 *      anything from this peer for this request.
345 	 *
346 	 *  pre_submit_jif
347 	 *  post_sub_jif
348 	 *      when did we start submiting to the lower level device,
349 	 *      and how long did we block in that submit function
350 	 *  local_completion_jif
351 	 *      how long did it take the lower level device to complete this request
352 	 */
353 
354 
355 	/* once it hits 0, we may complete the master_bio */
356 	atomic_t completion_ref;
357 	/* once it hits 0, we may destroy this drbd_request object */
358 	struct kref kref;
359 
360 	unsigned rq_state; /* see comments above _req_mod() */
361 };
362 
363 struct drbd_epoch {
364 	struct drbd_connection *connection;
365 	struct list_head list;
366 	unsigned int barrier_nr;
367 	atomic_t epoch_size; /* increased on every request added. */
368 	atomic_t active;     /* increased on every req. added, and dec on every finished. */
369 	unsigned long flags;
370 };
371 
372 /* Prototype declaration of function defined in drbd_receiver.c */
373 int drbdd_init(struct drbd_thread *);
374 int drbd_asender(struct drbd_thread *);
375 
376 /* drbd_epoch flag bits */
377 enum {
378 	DE_HAVE_BARRIER_NUMBER,
379 };
380 
381 enum epoch_event {
382 	EV_PUT,
383 	EV_GOT_BARRIER_NR,
384 	EV_BECAME_LAST,
385 	EV_CLEANUP = 32, /* used as flag */
386 };
387 
388 struct digest_info {
389 	int digest_size;
390 	void *digest;
391 };
392 
393 struct drbd_peer_request {
394 	struct drbd_work w;
395 	struct drbd_peer_device *peer_device;
396 	struct drbd_epoch *epoch; /* for writes */
397 	struct page *pages;
398 	atomic_t pending_bios;
399 	struct drbd_interval i;
400 	/* see comments on ee flag bits below */
401 	unsigned long flags;
402 	unsigned long submit_jif;
403 	union {
404 		u64 block_id;
405 		struct digest_info *digest;
406 	};
407 };
408 
409 /* ee flag bits.
410  * While corresponding bios are in flight, the only modification will be
411  * set_bit WAS_ERROR, which has to be atomic.
412  * If no bios are in flight yet, or all have been completed,
413  * non-atomic modification to ee->flags is ok.
414  */
415 enum {
416 	__EE_CALL_AL_COMPLETE_IO,
417 	__EE_MAY_SET_IN_SYNC,
418 
419 	/* is this a TRIM aka REQ_OP_DISCARD? */
420 	__EE_TRIM,
421 	/* explicit zero-out requested, or
422 	 * our lower level cannot handle trim,
423 	 * and we want to fall back to zeroout instead */
424 	__EE_ZEROOUT,
425 
426 	/* In case a barrier failed,
427 	 * we need to resubmit without the barrier flag. */
428 	__EE_RESUBMITTED,
429 
430 	/* we may have several bios per peer request.
431 	 * if any of those fail, we set this flag atomically
432 	 * from the endio callback */
433 	__EE_WAS_ERROR,
434 
435 	/* This ee has a pointer to a digest instead of a block id */
436 	__EE_HAS_DIGEST,
437 
438 	/* Conflicting local requests need to be restarted after this request */
439 	__EE_RESTART_REQUESTS,
440 
441 	/* The peer wants a write ACK for this (wire proto C) */
442 	__EE_SEND_WRITE_ACK,
443 
444 	/* Is set when net_conf had two_primaries set while creating this peer_req */
445 	__EE_IN_INTERVAL_TREE,
446 
447 	/* for debugfs: */
448 	/* has this been submitted, or does it still wait for something else? */
449 	__EE_SUBMITTED,
450 
451 	/* this is/was a write request */
452 	__EE_WRITE,
453 
454 	/* this is/was a write same request */
455 	__EE_WRITE_SAME,
456 
457 	/* this originates from application on peer
458 	 * (not some resync or verify or other DRBD internal request) */
459 	__EE_APPLICATION,
460 
461 	/* If it contains only 0 bytes, send back P_RS_DEALLOCATED */
462 	__EE_RS_THIN_REQ,
463 };
464 #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
465 #define EE_MAY_SET_IN_SYNC     (1<<__EE_MAY_SET_IN_SYNC)
466 #define EE_TRIM                (1<<__EE_TRIM)
467 #define EE_ZEROOUT             (1<<__EE_ZEROOUT)
468 #define EE_RESUBMITTED         (1<<__EE_RESUBMITTED)
469 #define EE_WAS_ERROR           (1<<__EE_WAS_ERROR)
470 #define EE_HAS_DIGEST          (1<<__EE_HAS_DIGEST)
471 #define EE_RESTART_REQUESTS	(1<<__EE_RESTART_REQUESTS)
472 #define EE_SEND_WRITE_ACK	(1<<__EE_SEND_WRITE_ACK)
473 #define EE_IN_INTERVAL_TREE	(1<<__EE_IN_INTERVAL_TREE)
474 #define EE_SUBMITTED		(1<<__EE_SUBMITTED)
475 #define EE_WRITE		(1<<__EE_WRITE)
476 #define EE_WRITE_SAME		(1<<__EE_WRITE_SAME)
477 #define EE_APPLICATION		(1<<__EE_APPLICATION)
478 #define EE_RS_THIN_REQ		(1<<__EE_RS_THIN_REQ)
479 
480 /* flag bits per device */
481 enum {
482 	UNPLUG_REMOTE,		/* sending a "UnplugRemote" could help */
483 	MD_DIRTY,		/* current uuids and flags not yet on disk */
484 	USE_DEGR_WFC_T,		/* degr-wfc-timeout instead of wfc-timeout. */
485 	CL_ST_CHG_SUCCESS,
486 	CL_ST_CHG_FAIL,
487 	CRASHED_PRIMARY,	/* This node was a crashed primary.
488 				 * Gets cleared when the state.conn
489 				 * goes into C_CONNECTED state. */
490 	CONSIDER_RESYNC,
491 
492 	MD_NO_FUA,		/* Users wants us to not use FUA/FLUSH on meta data dev */
493 
494 	BITMAP_IO,		/* suspend application io;
495 				   once no more io in flight, start bitmap io */
496 	BITMAP_IO_QUEUED,       /* Started bitmap IO */
497 	WAS_IO_ERROR,		/* Local disk failed, returned IO error */
498 	WAS_READ_ERROR,		/* Local disk READ failed (set additionally to the above) */
499 	FORCE_DETACH,		/* Force-detach from local disk, aborting any pending local IO */
500 	RESYNC_AFTER_NEG,       /* Resync after online grow after the attach&negotiate finished. */
501 	RESIZE_PENDING,		/* Size change detected locally, waiting for the response from
502 				 * the peer, if it changed there as well. */
503 	NEW_CUR_UUID,		/* Create new current UUID when thawing IO */
504 	AL_SUSPENDED,		/* Activity logging is currently suspended. */
505 	AHEAD_TO_SYNC_SOURCE,   /* Ahead -> SyncSource queued */
506 	B_RS_H_DONE,		/* Before resync handler done (already executed) */
507 	DISCARD_MY_DATA,	/* discard_my_data flag per volume */
508 	READ_BALANCE_RR,
509 
510 	FLUSH_PENDING,		/* if set, device->flush_jif is when we submitted that flush
511 				 * from drbd_flush_after_epoch() */
512 
513 	/* cleared only after backing device related structures have been destroyed. */
514 	GOING_DISKLESS,		/* Disk is being detached, because of io-error, or admin request. */
515 
516 	/* to be used in drbd_device_post_work() */
517 	GO_DISKLESS,		/* tell worker to schedule cleanup before detach */
518 	DESTROY_DISK,		/* tell worker to close backing devices and destroy related structures. */
519 	MD_SYNC,		/* tell worker to call drbd_md_sync() */
520 	RS_START,		/* tell worker to start resync/OV */
521 	RS_PROGRESS,		/* tell worker that resync made significant progress */
522 	RS_DONE,		/* tell worker that resync is done */
523 };
524 
525 struct drbd_bitmap; /* opaque for drbd_device */
526 
527 /* definition of bits in bm_flags to be used in drbd_bm_lock
528  * and drbd_bitmap_io and friends. */
529 enum bm_flag {
530 	/* currently locked for bulk operation */
531 	BM_LOCKED_MASK = 0xf,
532 
533 	/* in detail, that is: */
534 	BM_DONT_CLEAR = 0x1,
535 	BM_DONT_SET   = 0x2,
536 	BM_DONT_TEST  = 0x4,
537 
538 	/* so we can mark it locked for bulk operation,
539 	 * and still allow all non-bulk operations */
540 	BM_IS_LOCKED  = 0x8,
541 
542 	/* (test bit, count bit) allowed (common case) */
543 	BM_LOCKED_TEST_ALLOWED = BM_DONT_CLEAR | BM_DONT_SET | BM_IS_LOCKED,
544 
545 	/* testing bits, as well as setting new bits allowed, but clearing bits
546 	 * would be unexpected.  Used during bitmap receive.  Setting new bits
547 	 * requires sending of "out-of-sync" information, though. */
548 	BM_LOCKED_SET_ALLOWED = BM_DONT_CLEAR | BM_IS_LOCKED,
549 
550 	/* for drbd_bm_write_copy_pages, everything is allowed,
551 	 * only concurrent bulk operations are locked out. */
552 	BM_LOCKED_CHANGE_ALLOWED = BM_IS_LOCKED,
553 };
554 
555 struct drbd_work_queue {
556 	struct list_head q;
557 	spinlock_t q_lock;  /* to protect the list. */
558 	wait_queue_head_t q_wait;
559 };
560 
561 struct drbd_socket {
562 	struct mutex mutex;
563 	struct socket    *socket;
564 	/* this way we get our
565 	 * send/receive buffers off the stack */
566 	void *sbuf;
567 	void *rbuf;
568 };
569 
570 struct drbd_md {
571 	u64 md_offset;		/* sector offset to 'super' block */
572 
573 	u64 la_size_sect;	/* last agreed size, unit sectors */
574 	spinlock_t uuid_lock;
575 	u64 uuid[UI_SIZE];
576 	u64 device_uuid;
577 	u32 flags;
578 	u32 md_size_sect;
579 
580 	s32 al_offset;	/* signed relative sector offset to activity log */
581 	s32 bm_offset;	/* signed relative sector offset to bitmap */
582 
583 	/* cached value of bdev->disk_conf->meta_dev_idx (see below) */
584 	s32 meta_dev_idx;
585 
586 	/* see al_tr_number_to_on_disk_sector() */
587 	u32 al_stripes;
588 	u32 al_stripe_size_4k;
589 	u32 al_size_4k; /* cached product of the above */
590 };
591 
592 struct drbd_backing_dev {
593 	struct block_device *backing_bdev;
594 	struct block_device *md_bdev;
595 	struct drbd_md md;
596 	struct disk_conf *disk_conf; /* RCU, for updates: resource->conf_update */
597 	sector_t known_size; /* last known size of that backing device */
598 };
599 
600 struct drbd_md_io {
601 	struct page *page;
602 	unsigned long start_jif;	/* last call to drbd_md_get_buffer */
603 	unsigned long submit_jif;	/* last _drbd_md_sync_page_io() submit */
604 	const char *current_use;
605 	atomic_t in_use;
606 	unsigned int done;
607 	int error;
608 };
609 
610 struct bm_io_work {
611 	struct drbd_work w;
612 	char *why;
613 	enum bm_flag flags;
614 	int (*io_fn)(struct drbd_device *device);
615 	void (*done)(struct drbd_device *device, int rv);
616 };
617 
618 struct fifo_buffer {
619 	unsigned int head_index;
620 	unsigned int size;
621 	int total; /* sum of all values */
622 	int values[];
623 };
624 extern struct fifo_buffer *fifo_alloc(unsigned int fifo_size);
625 
626 /* flag bits per connection */
627 enum {
628 	NET_CONGESTED,		/* The data socket is congested */
629 	RESOLVE_CONFLICTS,	/* Set on one node, cleared on the peer! */
630 	SEND_PING,
631 	GOT_PING_ACK,		/* set when we receive a ping_ack packet, ping_wait gets woken */
632 	CONN_WD_ST_CHG_REQ,	/* A cluster wide state change on the connection is active */
633 	CONN_WD_ST_CHG_OKAY,
634 	CONN_WD_ST_CHG_FAIL,
635 	CONN_DRY_RUN,		/* Expect disconnect after resync handshake. */
636 	CREATE_BARRIER,		/* next P_DATA is preceded by a P_BARRIER */
637 	STATE_SENT,		/* Do not change state/UUIDs while this is set */
638 	CALLBACK_PENDING,	/* Whether we have a call_usermodehelper(, UMH_WAIT_PROC)
639 				 * pending, from drbd worker context.
640 				 */
641 	DISCONNECT_SENT,
642 
643 	DEVICE_WORK_PENDING,	/* tell worker that some device has pending work */
644 };
645 
646 enum which_state { NOW, OLD = NOW, NEW };
647 
648 struct drbd_resource {
649 	char *name;
650 #ifdef CONFIG_DEBUG_FS
651 	struct dentry *debugfs_res;
652 	struct dentry *debugfs_res_volumes;
653 	struct dentry *debugfs_res_connections;
654 	struct dentry *debugfs_res_in_flight_summary;
655 #endif
656 	struct kref kref;
657 	struct idr devices;		/* volume number to device mapping */
658 	struct list_head connections;
659 	struct list_head resources;
660 	struct res_opts res_opts;
661 	struct mutex conf_update;	/* mutex for ready-copy-update of net_conf and disk_conf */
662 	struct mutex adm_mutex;		/* mutex to serialize administrative requests */
663 	spinlock_t req_lock;
664 
665 	unsigned susp:1;		/* IO suspended by user */
666 	unsigned susp_nod:1;		/* IO suspended because no data */
667 	unsigned susp_fen:1;		/* IO suspended because fence peer handler runs */
668 
669 	enum write_ordering_e write_ordering;
670 
671 	cpumask_var_t cpu_mask;
672 };
673 
674 struct drbd_thread_timing_details
675 {
676 	unsigned long start_jif;
677 	void *cb_addr;
678 	const char *caller_fn;
679 	unsigned int line;
680 	unsigned int cb_nr;
681 };
682 
683 struct drbd_connection {
684 	struct list_head connections;
685 	struct drbd_resource *resource;
686 #ifdef CONFIG_DEBUG_FS
687 	struct dentry *debugfs_conn;
688 	struct dentry *debugfs_conn_callback_history;
689 	struct dentry *debugfs_conn_oldest_requests;
690 #endif
691 	struct kref kref;
692 	struct idr peer_devices;	/* volume number to peer device mapping */
693 	enum drbd_conns cstate;		/* Only C_STANDALONE to C_WF_REPORT_PARAMS */
694 	struct mutex cstate_mutex;	/* Protects graceful disconnects */
695 	unsigned int connect_cnt;	/* Inc each time a connection is established */
696 
697 	unsigned long flags;
698 	struct net_conf *net_conf;	/* content protected by rcu */
699 	wait_queue_head_t ping_wait;	/* Woken upon reception of a ping, and a state change */
700 
701 	struct sockaddr_storage my_addr;
702 	int my_addr_len;
703 	struct sockaddr_storage peer_addr;
704 	int peer_addr_len;
705 
706 	struct drbd_socket data;	/* data/barrier/cstate/parameter packets */
707 	struct drbd_socket meta;	/* ping/ack (metadata) packets */
708 	int agreed_pro_version;		/* actually used protocol version */
709 	u32 agreed_features;
710 	unsigned long last_received;	/* in jiffies, either socket */
711 	unsigned int ko_count;
712 
713 	struct list_head transfer_log;	/* all requests not yet fully processed */
714 
715 	struct crypto_shash *cram_hmac_tfm;
716 	struct crypto_shash *integrity_tfm;  /* checksums we compute, updates protected by connection->data->mutex */
717 	struct crypto_shash *peer_integrity_tfm;  /* checksums we verify, only accessed from receiver thread  */
718 	struct crypto_shash *csums_tfm;
719 	struct crypto_shash *verify_tfm;
720 	void *int_dig_in;
721 	void *int_dig_vv;
722 
723 	/* receiver side */
724 	struct drbd_epoch *current_epoch;
725 	spinlock_t epoch_lock;
726 	unsigned int epochs;
727 	atomic_t current_tle_nr;	/* transfer log epoch number */
728 	unsigned current_tle_writes;	/* writes seen within this tl epoch */
729 
730 	unsigned long last_reconnect_jif;
731 	/* empty member on older kernels without blk_start_plug() */
732 	struct blk_plug receiver_plug;
733 	struct drbd_thread receiver;
734 	struct drbd_thread worker;
735 	struct drbd_thread ack_receiver;
736 	struct workqueue_struct *ack_sender;
737 
738 	/* cached pointers,
739 	 * so we can look up the oldest pending requests more quickly.
740 	 * protected by resource->req_lock */
741 	struct drbd_request *req_next; /* DRBD 9: todo.req_next */
742 	struct drbd_request *req_ack_pending;
743 	struct drbd_request *req_not_net_done;
744 
745 	/* sender side */
746 	struct drbd_work_queue sender_work;
747 
748 #define DRBD_THREAD_DETAILS_HIST	16
749 	unsigned int w_cb_nr; /* keeps counting up */
750 	unsigned int r_cb_nr; /* keeps counting up */
751 	struct drbd_thread_timing_details w_timing_details[DRBD_THREAD_DETAILS_HIST];
752 	struct drbd_thread_timing_details r_timing_details[DRBD_THREAD_DETAILS_HIST];
753 
754 	struct {
755 		unsigned long last_sent_barrier_jif;
756 
757 		/* whether this sender thread
758 		 * has processed a single write yet. */
759 		bool seen_any_write_yet;
760 
761 		/* Which barrier number to send with the next P_BARRIER */
762 		int current_epoch_nr;
763 
764 		/* how many write requests have been sent
765 		 * with req->epoch == current_epoch_nr.
766 		 * If none, no P_BARRIER will be sent. */
767 		unsigned current_epoch_writes;
768 	} send;
769 };
770 
has_net_conf(struct drbd_connection * connection)771 static inline bool has_net_conf(struct drbd_connection *connection)
772 {
773 	bool has_net_conf;
774 
775 	rcu_read_lock();
776 	has_net_conf = rcu_dereference(connection->net_conf);
777 	rcu_read_unlock();
778 
779 	return has_net_conf;
780 }
781 
782 void __update_timing_details(
783 		struct drbd_thread_timing_details *tdp,
784 		unsigned int *cb_nr,
785 		void *cb,
786 		const char *fn, const unsigned int line);
787 
788 #define update_worker_timing_details(c, cb) \
789 	__update_timing_details(c->w_timing_details, &c->w_cb_nr, cb, __func__ , __LINE__ )
790 #define update_receiver_timing_details(c, cb) \
791 	__update_timing_details(c->r_timing_details, &c->r_cb_nr, cb, __func__ , __LINE__ )
792 
793 struct submit_worker {
794 	struct workqueue_struct *wq;
795 	struct work_struct worker;
796 
797 	/* protected by ..->resource->req_lock */
798 	struct list_head writes;
799 };
800 
801 struct drbd_peer_device {
802 	struct list_head peer_devices;
803 	struct drbd_device *device;
804 	struct drbd_connection *connection;
805 	struct work_struct send_acks_work;
806 #ifdef CONFIG_DEBUG_FS
807 	struct dentry *debugfs_peer_dev;
808 #endif
809 };
810 
811 struct drbd_device {
812 	struct drbd_resource *resource;
813 	struct list_head peer_devices;
814 	struct list_head pending_bitmap_io;
815 
816 	unsigned long flush_jif;
817 #ifdef CONFIG_DEBUG_FS
818 	struct dentry *debugfs_minor;
819 	struct dentry *debugfs_vol;
820 	struct dentry *debugfs_vol_oldest_requests;
821 	struct dentry *debugfs_vol_act_log_extents;
822 	struct dentry *debugfs_vol_resync_extents;
823 	struct dentry *debugfs_vol_data_gen_id;
824 	struct dentry *debugfs_vol_ed_gen_id;
825 #endif
826 
827 	unsigned int vnr;	/* volume number within the connection */
828 	unsigned int minor;	/* device minor number */
829 
830 	struct kref kref;
831 
832 	/* things that are stored as / read from meta data on disk */
833 	unsigned long flags;
834 
835 	/* configured by drbdsetup */
836 	struct drbd_backing_dev *ldev __protected_by(local);
837 
838 	sector_t p_size;     /* partner's disk size */
839 	struct request_queue *rq_queue;
840 	struct gendisk	    *vdisk;
841 
842 	unsigned long last_reattach_jif;
843 	struct drbd_work resync_work;
844 	struct drbd_work unplug_work;
845 	struct timer_list resync_timer;
846 	struct timer_list md_sync_timer;
847 	struct timer_list start_resync_timer;
848 	struct timer_list request_timer;
849 
850 	/* Used after attach while negotiating new disk state. */
851 	union drbd_state new_state_tmp;
852 
853 	union drbd_dev_state state;
854 	wait_queue_head_t misc_wait;
855 	wait_queue_head_t state_wait;  /* upon each state change. */
856 	unsigned int send_cnt;
857 	unsigned int recv_cnt;
858 	unsigned int read_cnt;
859 	unsigned int writ_cnt;
860 	unsigned int al_writ_cnt;
861 	unsigned int bm_writ_cnt;
862 	atomic_t ap_bio_cnt;	 /* Requests we need to complete */
863 	atomic_t ap_actlog_cnt;  /* Requests waiting for activity log */
864 	atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */
865 	atomic_t rs_pending_cnt; /* RS request/data packets on the wire */
866 	atomic_t unacked_cnt;	 /* Need to send replies for */
867 	atomic_t local_cnt;	 /* Waiting for local completion */
868 	atomic_t suspend_cnt;
869 
870 	/* Interval tree of pending local requests */
871 	struct rb_root read_requests;
872 	struct rb_root write_requests;
873 
874 	/* for statistics and timeouts */
875 	/* [0] read, [1] write */
876 	struct list_head pending_master_completion[2];
877 	struct list_head pending_completion[2];
878 
879 	/* use checksums for *this* resync */
880 	bool use_csums;
881 	/* blocks to resync in this run [unit BM_BLOCK_SIZE] */
882 	unsigned long rs_total;
883 	/* number of resync blocks that failed in this run */
884 	unsigned long rs_failed;
885 	/* Syncer's start time [unit jiffies] */
886 	unsigned long rs_start;
887 	/* cumulated time in PausedSyncX state [unit jiffies] */
888 	unsigned long rs_paused;
889 	/* skipped because csum was equal [unit BM_BLOCK_SIZE] */
890 	unsigned long rs_same_csum;
891 #define DRBD_SYNC_MARKS 8
892 #define DRBD_SYNC_MARK_STEP (3*HZ)
893 	/* block not up-to-date at mark [unit BM_BLOCK_SIZE] */
894 	unsigned long rs_mark_left[DRBD_SYNC_MARKS];
895 	/* marks's time [unit jiffies] */
896 	unsigned long rs_mark_time[DRBD_SYNC_MARKS];
897 	/* current index into rs_mark_{left,time} */
898 	int rs_last_mark;
899 	unsigned long rs_last_bcast; /* [unit jiffies] */
900 
901 	/* where does the admin want us to start? (sector) */
902 	sector_t ov_start_sector;
903 	sector_t ov_stop_sector;
904 	/* where are we now? (sector) */
905 	sector_t ov_position;
906 	/* Start sector of out of sync range (to merge printk reporting). */
907 	sector_t ov_last_oos_start;
908 	/* size of out-of-sync range in sectors. */
909 	sector_t ov_last_oos_size;
910 	unsigned long ov_left; /* in bits */
911 
912 	struct drbd_bitmap *bitmap;
913 	unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */
914 
915 	/* Used to track operations of resync... */
916 	struct lru_cache *resync;
917 	/* Number of locked elements in resync LRU */
918 	unsigned int resync_locked;
919 	/* resync extent number waiting for application requests */
920 	unsigned int resync_wenr;
921 
922 	int open_cnt;
923 	u64 *p_uuid;
924 
925 	struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */
926 	struct list_head sync_ee;   /* IO in progress (P_RS_DATA_REPLY gets written to disk) */
927 	struct list_head done_ee;   /* need to send P_WRITE_ACK */
928 	struct list_head read_ee;   /* [RS]P_DATA_REQUEST being read */
929 	struct list_head net_ee;    /* zero-copy network send in progress */
930 
931 	int next_barrier_nr;
932 	struct list_head resync_reads;
933 	atomic_t pp_in_use;		/* allocated from page pool */
934 	atomic_t pp_in_use_by_net;	/* sendpage()d, still referenced by tcp */
935 	wait_queue_head_t ee_wait;
936 	struct drbd_md_io md_io;
937 	spinlock_t al_lock;
938 	wait_queue_head_t al_wait;
939 	struct lru_cache *act_log;	/* activity log */
940 	unsigned int al_tr_number;
941 	int al_tr_cycle;
942 	wait_queue_head_t seq_wait;
943 	atomic_t packet_seq;
944 	unsigned int peer_seq;
945 	spinlock_t peer_seq_lock;
946 	unsigned long comm_bm_set; /* communicated number of set bits. */
947 	struct bm_io_work bm_io_work;
948 	u64 ed_uuid; /* UUID of the exposed data */
949 	struct mutex own_state_mutex;
950 	struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */
951 	char congestion_reason;  /* Why we where congested... */
952 	atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
953 	atomic_t rs_sect_ev; /* for submitted resync data rate, both */
954 	int rs_last_sect_ev; /* counter to compare with */
955 	int rs_last_events;  /* counter of read or write "events" (unit sectors)
956 			      * on the lower level device when we last looked. */
957 	int c_sync_rate; /* current resync rate after syncer throttle magic */
958 	struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, connection->conn_update) */
959 	int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */
960 	atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */
961 	unsigned int peer_max_bio_size;
962 	unsigned int local_max_bio_size;
963 
964 	/* any requests that would block in drbd_make_request()
965 	 * are deferred to this single-threaded work queue */
966 	struct submit_worker submit;
967 };
968 
969 struct drbd_bm_aio_ctx {
970 	struct drbd_device *device;
971 	struct list_head list; /* on device->pending_bitmap_io */;
972 	unsigned long start_jif;
973 	atomic_t in_flight;
974 	unsigned int done;
975 	unsigned flags;
976 #define BM_AIO_COPY_PAGES	1
977 #define BM_AIO_WRITE_HINTED	2
978 #define BM_AIO_WRITE_ALL_PAGES	4
979 #define BM_AIO_READ		8
980 	int error;
981 	struct kref kref;
982 };
983 
984 struct drbd_config_context {
985 	/* assigned from drbd_genlmsghdr */
986 	unsigned int minor;
987 	/* assigned from request attributes, if present */
988 	unsigned int volume;
989 #define VOLUME_UNSPECIFIED		(-1U)
990 	/* pointer into the request skb,
991 	 * limited lifetime! */
992 	char *resource_name;
993 	struct nlattr *my_addr;
994 	struct nlattr *peer_addr;
995 
996 	/* reply buffer */
997 	struct sk_buff *reply_skb;
998 	/* pointer into reply buffer */
999 	struct drbd_genlmsghdr *reply_dh;
1000 	/* resolved from attributes, if possible */
1001 	struct drbd_device *device;
1002 	struct drbd_resource *resource;
1003 	struct drbd_connection *connection;
1004 };
1005 
minor_to_device(unsigned int minor)1006 static inline struct drbd_device *minor_to_device(unsigned int minor)
1007 {
1008 	return (struct drbd_device *)idr_find(&drbd_devices, minor);
1009 }
1010 
first_peer_device(struct drbd_device * device)1011 static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device)
1012 {
1013 	return list_first_entry_or_null(&device->peer_devices, struct drbd_peer_device, peer_devices);
1014 }
1015 
1016 static inline struct drbd_peer_device *
conn_peer_device(struct drbd_connection * connection,int volume_number)1017 conn_peer_device(struct drbd_connection *connection, int volume_number)
1018 {
1019 	return idr_find(&connection->peer_devices, volume_number);
1020 }
1021 
1022 #define for_each_resource(resource, _resources) \
1023 	list_for_each_entry(resource, _resources, resources)
1024 
1025 #define for_each_resource_rcu(resource, _resources) \
1026 	list_for_each_entry_rcu(resource, _resources, resources)
1027 
1028 #define for_each_resource_safe(resource, tmp, _resources) \
1029 	list_for_each_entry_safe(resource, tmp, _resources, resources)
1030 
1031 #define for_each_connection(connection, resource) \
1032 	list_for_each_entry(connection, &resource->connections, connections)
1033 
1034 #define for_each_connection_rcu(connection, resource) \
1035 	list_for_each_entry_rcu(connection, &resource->connections, connections)
1036 
1037 #define for_each_connection_safe(connection, tmp, resource) \
1038 	list_for_each_entry_safe(connection, tmp, &resource->connections, connections)
1039 
1040 #define for_each_peer_device(peer_device, device) \
1041 	list_for_each_entry(peer_device, &device->peer_devices, peer_devices)
1042 
1043 #define for_each_peer_device_rcu(peer_device, device) \
1044 	list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices)
1045 
1046 #define for_each_peer_device_safe(peer_device, tmp, device) \
1047 	list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices)
1048 
device_to_minor(struct drbd_device * device)1049 static inline unsigned int device_to_minor(struct drbd_device *device)
1050 {
1051 	return device->minor;
1052 }
1053 
1054 /*
1055  * function declarations
1056  *************************/
1057 
1058 /* drbd_main.c */
1059 
1060 enum dds_flags {
1061 	DDSF_FORCED    = 1,
1062 	DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */
1063 };
1064 
1065 extern void drbd_init_set_defaults(struct drbd_device *device);
1066 extern int  drbd_thread_start(struct drbd_thread *thi);
1067 extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait);
1068 #ifdef CONFIG_SMP
1069 extern void drbd_thread_current_set_cpu(struct drbd_thread *thi);
1070 #else
1071 #define drbd_thread_current_set_cpu(A) ({})
1072 #endif
1073 extern void tl_release(struct drbd_connection *, unsigned int barrier_nr,
1074 		       unsigned int set_size);
1075 extern void tl_clear(struct drbd_connection *);
1076 extern void drbd_free_sock(struct drbd_connection *connection);
1077 extern int drbd_send(struct drbd_connection *connection, struct socket *sock,
1078 		     void *buf, size_t size, unsigned msg_flags);
1079 extern int drbd_send_all(struct drbd_connection *, struct socket *, void *, size_t,
1080 			 unsigned);
1081 
1082 extern int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd);
1083 extern int drbd_send_protocol(struct drbd_connection *connection);
1084 extern int drbd_send_uuids(struct drbd_peer_device *);
1085 extern int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *);
1086 extern void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *);
1087 extern int drbd_send_sizes(struct drbd_peer_device *, int trigger_reply, enum dds_flags flags);
1088 extern int drbd_send_state(struct drbd_peer_device *, union drbd_state s);
1089 extern int drbd_send_current_state(struct drbd_peer_device *);
1090 extern int drbd_send_sync_param(struct drbd_peer_device *);
1091 extern void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr,
1092 			    u32 set_size);
1093 extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet,
1094 			 struct drbd_peer_request *);
1095 extern void drbd_send_ack_rp(struct drbd_peer_device *, enum drbd_packet,
1096 			     struct p_block_req *rp);
1097 extern void drbd_send_ack_dp(struct drbd_peer_device *, enum drbd_packet,
1098 			     struct p_data *dp, int data_size);
1099 extern int drbd_send_ack_ex(struct drbd_peer_device *, enum drbd_packet,
1100 			    sector_t sector, int blksize, u64 block_id);
1101 extern int drbd_send_out_of_sync(struct drbd_peer_device *, struct drbd_request *);
1102 extern int drbd_send_block(struct drbd_peer_device *, enum drbd_packet,
1103 			   struct drbd_peer_request *);
1104 extern int drbd_send_dblock(struct drbd_peer_device *, struct drbd_request *req);
1105 extern int drbd_send_drequest(struct drbd_peer_device *, int cmd,
1106 			      sector_t sector, int size, u64 block_id);
1107 extern int drbd_send_drequest_csum(struct drbd_peer_device *, sector_t sector,
1108 				   int size, void *digest, int digest_size,
1109 				   enum drbd_packet cmd);
1110 extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int size);
1111 
1112 extern int drbd_send_bitmap(struct drbd_device *device);
1113 extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode);
1114 extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode);
1115 extern int drbd_send_rs_deallocated(struct drbd_peer_device *, struct drbd_peer_request *);
1116 extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev);
1117 extern void drbd_device_cleanup(struct drbd_device *device);
1118 extern void drbd_print_uuids(struct drbd_device *device, const char *text);
1119 extern void drbd_queue_unplug(struct drbd_device *device);
1120 
1121 extern void conn_md_sync(struct drbd_connection *connection);
1122 extern void drbd_md_write(struct drbd_device *device, void *buffer);
1123 extern void drbd_md_sync(struct drbd_device *device);
1124 extern int  drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev);
1125 extern void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
1126 extern void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
1127 extern void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local);
1128 extern void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local);
1129 extern void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local);
1130 extern void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
1131 extern void drbd_md_set_flag(struct drbd_device *device, int flags) __must_hold(local);
1132 extern void drbd_md_clear_flag(struct drbd_device *device, int flags)__must_hold(local);
1133 extern int drbd_md_test_flag(struct drbd_backing_dev *, int);
1134 extern void drbd_md_mark_dirty(struct drbd_device *device);
1135 extern void drbd_queue_bitmap_io(struct drbd_device *device,
1136 				 int (*io_fn)(struct drbd_device *),
1137 				 void (*done)(struct drbd_device *, int),
1138 				 char *why, enum bm_flag flags);
1139 extern int drbd_bitmap_io(struct drbd_device *device,
1140 		int (*io_fn)(struct drbd_device *),
1141 		char *why, enum bm_flag flags);
1142 extern int drbd_bitmap_io_from_worker(struct drbd_device *device,
1143 		int (*io_fn)(struct drbd_device *),
1144 		char *why, enum bm_flag flags);
1145 extern int drbd_bmio_set_n_write(struct drbd_device *device) __must_hold(local);
1146 extern int drbd_bmio_clear_n_write(struct drbd_device *device) __must_hold(local);
1147 
1148 /* Meta data layout
1149  *
1150  * We currently have two possible layouts.
1151  * Offsets in (512 byte) sectors.
1152  * external:
1153  *   |----------- md_size_sect ------------------|
1154  *   [ 4k superblock ][ activity log ][  Bitmap  ]
1155  *   | al_offset == 8 |
1156  *   | bm_offset = al_offset + X      |
1157  *  ==> bitmap sectors = md_size_sect - bm_offset
1158  *
1159  *  Variants:
1160  *     old, indexed fixed size meta data:
1161  *
1162  * internal:
1163  *            |----------- md_size_sect ------------------|
1164  * [data.....][  Bitmap  ][ activity log ][ 4k superblock ][padding*]
1165  *                        | al_offset < 0 |
1166  *            | bm_offset = al_offset - Y |
1167  *  ==> bitmap sectors = Y = al_offset - bm_offset
1168  *
1169  *  [padding*] are zero or up to 7 unused 512 Byte sectors to the
1170  *  end of the device, so that the [4k superblock] will be 4k aligned.
1171  *
1172  *  The activity log consists of 4k transaction blocks,
1173  *  which are written in a ring-buffer, or striped ring-buffer like fashion,
1174  *  which are writtensize used to be fixed 32kB,
1175  *  but is about to become configurable.
1176  */
1177 
1178 /* Our old fixed size meta data layout
1179  * allows up to about 3.8TB, so if you want more,
1180  * you need to use the "flexible" meta data format. */
1181 #define MD_128MB_SECT (128LLU << 11)  /* 128 MB, unit sectors */
1182 #define MD_4kB_SECT	 8
1183 #define MD_32kB_SECT	64
1184 
1185 /* One activity log extent represents 4M of storage */
1186 #define AL_EXTENT_SHIFT 22
1187 #define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT)
1188 
1189 /* We could make these currently hardcoded constants configurable
1190  * variables at create-md time (or even re-configurable at runtime?).
1191  * Which will require some more changes to the DRBD "super block"
1192  * and attach code.
1193  *
1194  * updates per transaction:
1195  *   This many changes to the active set can be logged with one transaction.
1196  *   This number is arbitrary.
1197  * context per transaction:
1198  *   This many context extent numbers are logged with each transaction.
1199  *   This number is resulting from the transaction block size (4k), the layout
1200  *   of the transaction header, and the number of updates per transaction.
1201  *   See drbd_actlog.c:struct al_transaction_on_disk
1202  * */
1203 #define AL_UPDATES_PER_TRANSACTION	 64	// arbitrary
1204 #define AL_CONTEXT_PER_TRANSACTION	919	// (4096 - 36 - 6*64)/4
1205 
1206 #if BITS_PER_LONG == 32
1207 #define LN2_BPL 5
1208 #define cpu_to_lel(A) cpu_to_le32(A)
1209 #define lel_to_cpu(A) le32_to_cpu(A)
1210 #elif BITS_PER_LONG == 64
1211 #define LN2_BPL 6
1212 #define cpu_to_lel(A) cpu_to_le64(A)
1213 #define lel_to_cpu(A) le64_to_cpu(A)
1214 #else
1215 #error "LN2 of BITS_PER_LONG unknown!"
1216 #endif
1217 
1218 /* resync bitmap */
1219 /* 16MB sized 'bitmap extent' to track syncer usage */
1220 struct bm_extent {
1221 	int rs_left; /* number of bits set (out of sync) in this extent. */
1222 	int rs_failed; /* number of failed resync requests in this extent. */
1223 	unsigned long flags;
1224 	struct lc_element lce;
1225 };
1226 
1227 #define BME_NO_WRITES  0  /* bm_extent.flags: no more requests on this one! */
1228 #define BME_LOCKED     1  /* bm_extent.flags: syncer active on this one. */
1229 #define BME_PRIORITY   2  /* finish resync IO on this extent ASAP! App IO waiting! */
1230 
1231 /* drbd_bitmap.c */
1232 /*
1233  * We need to store one bit for a block.
1234  * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap.
1235  * Bit 0 ==> local node thinks this block is binary identical on both nodes
1236  * Bit 1 ==> local node thinks this block needs to be synced.
1237  */
1238 
1239 #define SLEEP_TIME (HZ/10)
1240 
1241 /* We do bitmap IO in units of 4k blocks.
1242  * We also still have a hardcoded 4k per bit relation. */
1243 #define BM_BLOCK_SHIFT	12			 /* 4k per bit */
1244 #define BM_BLOCK_SIZE	 (1<<BM_BLOCK_SHIFT)
1245 /* mostly arbitrarily set the represented size of one bitmap extent,
1246  * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap
1247  * at 4k per bit resolution) */
1248 #define BM_EXT_SHIFT	 24	/* 16 MiB per resync extent */
1249 #define BM_EXT_SIZE	 (1<<BM_EXT_SHIFT)
1250 
1251 #if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12)
1252 #error "HAVE YOU FIXED drbdmeta AS WELL??"
1253 #endif
1254 
1255 /* thus many _storage_ sectors are described by one bit */
1256 #define BM_SECT_TO_BIT(x)   ((x)>>(BM_BLOCK_SHIFT-9))
1257 #define BM_BIT_TO_SECT(x)   ((sector_t)(x)<<(BM_BLOCK_SHIFT-9))
1258 #define BM_SECT_PER_BIT     BM_BIT_TO_SECT(1)
1259 
1260 /* bit to represented kilo byte conversion */
1261 #define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10))
1262 
1263 /* in which _bitmap_ extent (resp. sector) the bit for a certain
1264  * _storage_ sector is located in */
1265 #define BM_SECT_TO_EXT(x)   ((x)>>(BM_EXT_SHIFT-9))
1266 #define BM_BIT_TO_EXT(x)    ((x) >> (BM_EXT_SHIFT - BM_BLOCK_SHIFT))
1267 
1268 /* first storage sector a bitmap extent corresponds to */
1269 #define BM_EXT_TO_SECT(x)   ((sector_t)(x) << (BM_EXT_SHIFT-9))
1270 /* how much _storage_ sectors we have per bitmap extent */
1271 #define BM_SECT_PER_EXT     BM_EXT_TO_SECT(1)
1272 /* how many bits are covered by one bitmap extent (resync extent) */
1273 #define BM_BITS_PER_EXT     (1UL << (BM_EXT_SHIFT - BM_BLOCK_SHIFT))
1274 
1275 #define BM_BLOCKS_PER_BM_EXT_MASK  (BM_BITS_PER_EXT - 1)
1276 
1277 
1278 /* in one sector of the bitmap, we have this many activity_log extents. */
1279 #define AL_EXT_PER_BM_SECT  (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT))
1280 
1281 /* the extent in "PER_EXTENT" below is an activity log extent
1282  * we need that many (long words/bytes) to store the bitmap
1283  *		     of one AL_EXTENT_SIZE chunk of storage.
1284  * we can store the bitmap for that many AL_EXTENTS within
1285  * one sector of the _on_disk_ bitmap:
1286  * bit	 0	  bit 37   bit 38	     bit (512*8)-1
1287  *	     ...|........|........|.. // ..|........|
1288  * sect. 0	 `296	  `304			   ^(512*8*8)-1
1289  *
1290 #define BM_WORDS_PER_EXT    ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG )
1291 #define BM_BYTES_PER_EXT    ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 )  // 128
1292 #define BM_EXT_PER_SECT	    ( 512 / BM_BYTES_PER_EXTENT )	 //   4
1293  */
1294 
1295 #define DRBD_MAX_SECTORS_32 (0xffffffffLU)
1296 /* we have a certain meta data variant that has a fixed on-disk size of 128
1297  * MiB, of which 4k are our "superblock", and 32k are the fixed size activity
1298  * log, leaving this many sectors for the bitmap.
1299  */
1300 
1301 #define DRBD_MAX_SECTORS_FIXED_BM \
1302 	  ((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9)))
1303 #define DRBD_MAX_SECTORS      DRBD_MAX_SECTORS_FIXED_BM
1304 /* 16 TB in units of sectors */
1305 #if BITS_PER_LONG == 32
1306 /* adjust by one page worth of bitmap,
1307  * so we won't wrap around in drbd_bm_find_next_bit.
1308  * you should use 64bit OS for that much storage, anyways. */
1309 #define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff)
1310 #else
1311 /* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */
1312 #define DRBD_MAX_SECTORS_FLEX (1UL << 51)
1313 /* corresponds to (1UL << 38) bits right now. */
1314 #endif
1315 
1316 /* Estimate max bio size as 256 * PAGE_SIZE,
1317  * so for typical PAGE_SIZE of 4k, that is (1<<20) Byte.
1318  * Since we may live in a mixed-platform cluster,
1319  * we limit us to a platform agnostic constant here for now.
1320  * A followup commit may allow even bigger BIO sizes,
1321  * once we thought that through. */
1322 #define DRBD_MAX_BIO_SIZE (1U << 20)
1323 #if DRBD_MAX_BIO_SIZE > (BIO_MAX_VECS << PAGE_SHIFT)
1324 #error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE
1325 #endif
1326 #define DRBD_MAX_BIO_SIZE_SAFE (1U << 12)       /* Works always = 4k */
1327 
1328 #define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */
1329 #define DRBD_MAX_BIO_SIZE_P95    (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */
1330 
1331 /* For now, don't allow more than half of what we can "activate" in one
1332  * activity log transaction to be discarded in one go. We may need to rework
1333  * drbd_al_begin_io() to allow for even larger discard ranges */
1334 #define DRBD_MAX_BATCH_BIO_SIZE	 (AL_UPDATES_PER_TRANSACTION/2*AL_EXTENT_SIZE)
1335 #define DRBD_MAX_BBIO_SECTORS    (DRBD_MAX_BATCH_BIO_SIZE >> 9)
1336 
1337 extern int  drbd_bm_init(struct drbd_device *device);
1338 extern int  drbd_bm_resize(struct drbd_device *device, sector_t sectors, int set_new_bits);
1339 extern void drbd_bm_cleanup(struct drbd_device *device);
1340 extern void drbd_bm_set_all(struct drbd_device *device);
1341 extern void drbd_bm_clear_all(struct drbd_device *device);
1342 /* set/clear/test only a few bits at a time */
1343 extern int  drbd_bm_set_bits(
1344 		struct drbd_device *device, unsigned long s, unsigned long e);
1345 extern int  drbd_bm_clear_bits(
1346 		struct drbd_device *device, unsigned long s, unsigned long e);
1347 extern int drbd_bm_count_bits(
1348 	struct drbd_device *device, const unsigned long s, const unsigned long e);
1349 /* bm_set_bits variant for use while holding drbd_bm_lock,
1350  * may process the whole bitmap in one go */
1351 extern void _drbd_bm_set_bits(struct drbd_device *device,
1352 		const unsigned long s, const unsigned long e);
1353 extern int  drbd_bm_test_bit(struct drbd_device *device, unsigned long bitnr);
1354 extern int  drbd_bm_e_weight(struct drbd_device *device, unsigned long enr);
1355 extern int  drbd_bm_read(struct drbd_device *device) __must_hold(local);
1356 extern void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr);
1357 extern int  drbd_bm_write(struct drbd_device *device) __must_hold(local);
1358 extern void drbd_bm_reset_al_hints(struct drbd_device *device) __must_hold(local);
1359 extern int  drbd_bm_write_hinted(struct drbd_device *device) __must_hold(local);
1360 extern int  drbd_bm_write_lazy(struct drbd_device *device, unsigned upper_idx) __must_hold(local);
1361 extern int drbd_bm_write_all(struct drbd_device *device) __must_hold(local);
1362 extern int  drbd_bm_write_copy_pages(struct drbd_device *device) __must_hold(local);
1363 extern size_t	     drbd_bm_words(struct drbd_device *device);
1364 extern unsigned long drbd_bm_bits(struct drbd_device *device);
1365 extern sector_t      drbd_bm_capacity(struct drbd_device *device);
1366 
1367 #define DRBD_END_OF_BITMAP	(~(unsigned long)0)
1368 extern unsigned long drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo);
1369 /* bm_find_next variants for use while you hold drbd_bm_lock() */
1370 extern unsigned long _drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo);
1371 extern unsigned long _drbd_bm_find_next_zero(struct drbd_device *device, unsigned long bm_fo);
1372 extern unsigned long _drbd_bm_total_weight(struct drbd_device *device);
1373 extern unsigned long drbd_bm_total_weight(struct drbd_device *device);
1374 /* for receive_bitmap */
1375 extern void drbd_bm_merge_lel(struct drbd_device *device, size_t offset,
1376 		size_t number, unsigned long *buffer);
1377 /* for _drbd_send_bitmap */
1378 extern void drbd_bm_get_lel(struct drbd_device *device, size_t offset,
1379 		size_t number, unsigned long *buffer);
1380 
1381 extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags);
1382 extern void drbd_bm_unlock(struct drbd_device *device);
1383 /* drbd_main.c */
1384 
1385 extern struct kmem_cache *drbd_request_cache;
1386 extern struct kmem_cache *drbd_ee_cache;	/* peer requests */
1387 extern struct kmem_cache *drbd_bm_ext_cache;	/* bitmap extents */
1388 extern struct kmem_cache *drbd_al_ext_cache;	/* activity log extents */
1389 extern mempool_t drbd_request_mempool;
1390 extern mempool_t drbd_ee_mempool;
1391 
1392 /* drbd's page pool, used to buffer data received from the peer,
1393  * or data requested by the peer.
1394  *
1395  * This does not have an emergency reserve.
1396  *
1397  * When allocating from this pool, it first takes pages from the pool.
1398  * Only if the pool is depleted will try to allocate from the system.
1399  *
1400  * The assumption is that pages taken from this pool will be processed,
1401  * and given back, "quickly", and then can be recycled, so we can avoid
1402  * frequent calls to alloc_page(), and still will be able to make progress even
1403  * under memory pressure.
1404  */
1405 extern struct page *drbd_pp_pool;
1406 extern spinlock_t   drbd_pp_lock;
1407 extern int	    drbd_pp_vacant;
1408 extern wait_queue_head_t drbd_pp_wait;
1409 
1410 /* We also need a standard (emergency-reserve backed) page pool
1411  * for meta data IO (activity log, bitmap).
1412  * We can keep it global, as long as it is used as "N pages at a time".
1413  * 128 should be plenty, currently we probably can get away with as few as 1.
1414  */
1415 #define DRBD_MIN_POOL_PAGES	128
1416 extern mempool_t drbd_md_io_page_pool;
1417 
1418 /* We also need to make sure we get a bio
1419  * when we need it for housekeeping purposes */
1420 extern struct bio_set drbd_md_io_bio_set;
1421 
1422 /* And a bio_set for cloning */
1423 extern struct bio_set drbd_io_bio_set;
1424 
1425 extern struct mutex resources_mutex;
1426 
1427 extern int conn_lowest_minor(struct drbd_connection *connection);
1428 extern enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor);
1429 extern void drbd_destroy_device(struct kref *kref);
1430 extern void drbd_delete_device(struct drbd_device *device);
1431 
1432 extern struct drbd_resource *drbd_create_resource(const char *name);
1433 extern void drbd_free_resource(struct drbd_resource *resource);
1434 
1435 extern int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts);
1436 extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts);
1437 extern void drbd_destroy_connection(struct kref *kref);
1438 extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
1439 					    void *peer_addr, int peer_addr_len);
1440 extern struct drbd_resource *drbd_find_resource(const char *name);
1441 extern void drbd_destroy_resource(struct kref *kref);
1442 extern void conn_free_crypto(struct drbd_connection *connection);
1443 
1444 /* drbd_req */
1445 extern void do_submit(struct work_struct *ws);
1446 extern void __drbd_make_request(struct drbd_device *, struct bio *);
1447 void drbd_submit_bio(struct bio *bio);
1448 extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req);
1449 extern int is_valid_ar_handle(struct drbd_request *, sector_t);
1450 
1451 
1452 /* drbd_nl.c */
1453 
1454 extern struct mutex notification_mutex;
1455 
1456 extern void drbd_suspend_io(struct drbd_device *device);
1457 extern void drbd_resume_io(struct drbd_device *device);
1458 extern char *ppsize(char *buf, unsigned long long size);
1459 extern sector_t drbd_new_dev_size(struct drbd_device *, struct drbd_backing_dev *, sector_t, int);
1460 enum determine_dev_size {
1461 	DS_ERROR_SHRINK = -3,
1462 	DS_ERROR_SPACE_MD = -2,
1463 	DS_ERROR = -1,
1464 	DS_UNCHANGED = 0,
1465 	DS_SHRUNK = 1,
1466 	DS_GREW = 2,
1467 	DS_GREW_FROM_ZERO = 3,
1468 };
1469 extern enum determine_dev_size
1470 drbd_determine_dev_size(struct drbd_device *, enum dds_flags, struct resize_parms *) __must_hold(local);
1471 extern void resync_after_online_grow(struct drbd_device *);
1472 extern void drbd_reconsider_queue_parameters(struct drbd_device *device,
1473 			struct drbd_backing_dev *bdev, struct o_qlim *o);
1474 extern enum drbd_state_rv drbd_set_role(struct drbd_device *device,
1475 					enum drbd_role new_role,
1476 					int force);
1477 extern bool conn_try_outdate_peer(struct drbd_connection *connection);
1478 extern void conn_try_outdate_peer_async(struct drbd_connection *connection);
1479 extern enum drbd_peer_state conn_khelper(struct drbd_connection *connection, char *cmd);
1480 extern int drbd_khelper(struct drbd_device *device, char *cmd);
1481 
1482 /* drbd_worker.c */
1483 /* bi_end_io handlers */
1484 extern void drbd_md_endio(struct bio *bio);
1485 extern void drbd_peer_request_endio(struct bio *bio);
1486 extern void drbd_request_endio(struct bio *bio);
1487 extern int drbd_worker(struct drbd_thread *thi);
1488 enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor);
1489 void drbd_resync_after_changed(struct drbd_device *device);
1490 extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side);
1491 extern void resume_next_sg(struct drbd_device *device);
1492 extern void suspend_other_sg(struct drbd_device *device);
1493 extern int drbd_resync_finished(struct drbd_device *device);
1494 /* maybe rather drbd_main.c ? */
1495 extern void *drbd_md_get_buffer(struct drbd_device *device, const char *intent);
1496 extern void drbd_md_put_buffer(struct drbd_device *device);
1497 extern int drbd_md_sync_page_io(struct drbd_device *device,
1498 		struct drbd_backing_dev *bdev, sector_t sector, enum req_op op);
1499 extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int);
1500 extern void wait_until_done_or_force_detached(struct drbd_device *device,
1501 		struct drbd_backing_dev *bdev, unsigned int *done);
1502 extern void drbd_rs_controller_reset(struct drbd_device *device);
1503 
ov_out_of_sync_print(struct drbd_device * device)1504 static inline void ov_out_of_sync_print(struct drbd_device *device)
1505 {
1506 	if (device->ov_last_oos_size) {
1507 		drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n",
1508 		     (unsigned long long)device->ov_last_oos_start,
1509 		     (unsigned long)device->ov_last_oos_size);
1510 	}
1511 	device->ov_last_oos_size = 0;
1512 }
1513 
1514 
1515 extern void drbd_csum_bio(struct crypto_shash *, struct bio *, void *);
1516 extern void drbd_csum_ee(struct crypto_shash *, struct drbd_peer_request *,
1517 			 void *);
1518 /* worker callbacks */
1519 extern int w_e_end_data_req(struct drbd_work *, int);
1520 extern int w_e_end_rsdata_req(struct drbd_work *, int);
1521 extern int w_e_end_csum_rs_req(struct drbd_work *, int);
1522 extern int w_e_end_ov_reply(struct drbd_work *, int);
1523 extern int w_e_end_ov_req(struct drbd_work *, int);
1524 extern int w_ov_finished(struct drbd_work *, int);
1525 extern int w_resync_timer(struct drbd_work *, int);
1526 extern int w_send_write_hint(struct drbd_work *, int);
1527 extern int w_send_dblock(struct drbd_work *, int);
1528 extern int w_send_read_req(struct drbd_work *, int);
1529 extern int w_e_reissue(struct drbd_work *, int);
1530 extern int w_restart_disk_io(struct drbd_work *, int);
1531 extern int w_send_out_of_sync(struct drbd_work *, int);
1532 
1533 extern void resync_timer_fn(struct timer_list *t);
1534 extern void start_resync_timer_fn(struct timer_list *t);
1535 
1536 extern void drbd_endio_write_sec_final(struct drbd_peer_request *peer_req);
1537 
1538 /* drbd_receiver.c */
1539 extern int drbd_issue_discard_or_zero_out(struct drbd_device *device,
1540 		sector_t start, unsigned int nr_sectors, int flags);
1541 extern int drbd_receiver(struct drbd_thread *thi);
1542 extern int drbd_ack_receiver(struct drbd_thread *thi);
1543 extern void drbd_send_ping_wf(struct work_struct *ws);
1544 extern void drbd_send_acks_wf(struct work_struct *ws);
1545 extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device);
1546 extern bool drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector,
1547 		bool throttle_if_app_is_waiting);
1548 extern int drbd_submit_peer_request(struct drbd_device *,
1549 				    struct drbd_peer_request *, blk_opf_t, int);
1550 extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *);
1551 extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_peer_device *, u64,
1552 						     sector_t, unsigned int,
1553 						     unsigned int,
1554 						     gfp_t) __must_hold(local);
1555 extern void __drbd_free_peer_req(struct drbd_device *, struct drbd_peer_request *,
1556 				 int);
1557 #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0)
1558 #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1)
1559 extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool);
1560 extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled);
1561 extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed);
1562 extern int drbd_connected(struct drbd_peer_device *);
1563 
1564 /* sets the number of 512 byte sectors of our virtual device */
1565 void drbd_set_my_capacity(struct drbd_device *device, sector_t size);
1566 
1567 /*
1568  * used to submit our private bio
1569  */
drbd_submit_bio_noacct(struct drbd_device * device,int fault_type,struct bio * bio)1570 static inline void drbd_submit_bio_noacct(struct drbd_device *device,
1571 					     int fault_type, struct bio *bio)
1572 {
1573 	__release(local);
1574 	if (!bio->bi_bdev) {
1575 		drbd_err(device, "drbd_submit_bio_noacct: bio->bi_bdev == NULL\n");
1576 		bio->bi_status = BLK_STS_IOERR;
1577 		bio_endio(bio);
1578 		return;
1579 	}
1580 
1581 	if (drbd_insert_fault(device, fault_type))
1582 		bio_io_error(bio);
1583 	else
1584 		submit_bio_noacct(bio);
1585 }
1586 
1587 void drbd_bump_write_ordering(struct drbd_resource *resource, struct drbd_backing_dev *bdev,
1588 			      enum write_ordering_e wo);
1589 
1590 /* drbd_proc.c */
1591 extern struct proc_dir_entry *drbd_proc;
1592 int drbd_seq_show(struct seq_file *seq, void *v);
1593 
1594 /* drbd_actlog.c */
1595 extern bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *i);
1596 extern int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i);
1597 extern void drbd_al_begin_io_commit(struct drbd_device *device);
1598 extern bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i);
1599 extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i);
1600 extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i);
1601 extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector);
1602 extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector);
1603 extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector);
1604 extern void drbd_rs_cancel_all(struct drbd_device *device);
1605 extern int drbd_rs_del_all(struct drbd_device *device);
1606 extern void drbd_rs_failed_io(struct drbd_device *device,
1607 		sector_t sector, int size);
1608 extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go);
1609 
1610 enum update_sync_bits_mode { RECORD_RS_FAILED, SET_OUT_OF_SYNC, SET_IN_SYNC };
1611 extern int __drbd_change_sync(struct drbd_device *device, sector_t sector, int size,
1612 		enum update_sync_bits_mode mode);
1613 #define drbd_set_in_sync(device, sector, size) \
1614 	__drbd_change_sync(device, sector, size, SET_IN_SYNC)
1615 #define drbd_set_out_of_sync(device, sector, size) \
1616 	__drbd_change_sync(device, sector, size, SET_OUT_OF_SYNC)
1617 #define drbd_rs_failed_io(device, sector, size) \
1618 	__drbd_change_sync(device, sector, size, RECORD_RS_FAILED)
1619 extern void drbd_al_shrink(struct drbd_device *device);
1620 extern int drbd_al_initialize(struct drbd_device *, void *);
1621 
1622 /* drbd_nl.c */
1623 /* state info broadcast */
1624 struct sib_info {
1625 	enum drbd_state_info_bcast_reason sib_reason;
1626 	union {
1627 		struct {
1628 			char *helper_name;
1629 			unsigned helper_exit_code;
1630 		};
1631 		struct {
1632 			union drbd_state os;
1633 			union drbd_state ns;
1634 		};
1635 	};
1636 };
1637 void drbd_bcast_event(struct drbd_device *device, const struct sib_info *sib);
1638 
1639 extern int notify_resource_state(struct sk_buff *,
1640 				  unsigned int,
1641 				  struct drbd_resource *,
1642 				  struct resource_info *,
1643 				  enum drbd_notification_type);
1644 extern int notify_device_state(struct sk_buff *,
1645 				unsigned int,
1646 				struct drbd_device *,
1647 				struct device_info *,
1648 				enum drbd_notification_type);
1649 extern int notify_connection_state(struct sk_buff *,
1650 				    unsigned int,
1651 				    struct drbd_connection *,
1652 				    struct connection_info *,
1653 				    enum drbd_notification_type);
1654 extern int notify_peer_device_state(struct sk_buff *,
1655 				     unsigned int,
1656 				     struct drbd_peer_device *,
1657 				     struct peer_device_info *,
1658 				     enum drbd_notification_type);
1659 extern void notify_helper(enum drbd_notification_type, struct drbd_device *,
1660 			  struct drbd_connection *, const char *, int);
1661 
1662 /*
1663  * inline helper functions
1664  *************************/
1665 
1666 /* see also page_chain_add and friends in drbd_receiver.c */
page_chain_next(struct page * page)1667 static inline struct page *page_chain_next(struct page *page)
1668 {
1669 	return (struct page *)page_private(page);
1670 }
1671 #define page_chain_for_each(page) \
1672 	for (; page && ({ prefetch(page_chain_next(page)); 1; }); \
1673 			page = page_chain_next(page))
1674 #define page_chain_for_each_safe(page, n) \
1675 	for (; page && ({ n = page_chain_next(page); 1; }); page = n)
1676 
1677 
drbd_peer_req_has_active_page(struct drbd_peer_request * peer_req)1678 static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req)
1679 {
1680 	struct page *page = peer_req->pages;
1681 	page_chain_for_each(page) {
1682 		if (page_count(page) > 1)
1683 			return 1;
1684 	}
1685 	return 0;
1686 }
1687 
drbd_read_state(struct drbd_device * device)1688 static inline union drbd_state drbd_read_state(struct drbd_device *device)
1689 {
1690 	struct drbd_resource *resource = device->resource;
1691 	union drbd_state rv;
1692 
1693 	rv.i = device->state.i;
1694 	rv.susp = resource->susp;
1695 	rv.susp_nod = resource->susp_nod;
1696 	rv.susp_fen = resource->susp_fen;
1697 
1698 	return rv;
1699 }
1700 
1701 enum drbd_force_detach_flags {
1702 	DRBD_READ_ERROR,
1703 	DRBD_WRITE_ERROR,
1704 	DRBD_META_IO_ERROR,
1705 	DRBD_FORCE_DETACH,
1706 };
1707 
1708 #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)1709 static inline void __drbd_chk_io_error_(struct drbd_device *device,
1710 		enum drbd_force_detach_flags df,
1711 		const char *where)
1712 {
1713 	enum drbd_io_error_p ep;
1714 
1715 	rcu_read_lock();
1716 	ep = rcu_dereference(device->ldev->disk_conf)->on_io_error;
1717 	rcu_read_unlock();
1718 	switch (ep) {
1719 	case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */
1720 		if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) {
1721 			if (__ratelimit(&drbd_ratelimit_state))
1722 				drbd_err(device, "Local IO failed in %s.\n", where);
1723 			if (device->state.disk > D_INCONSISTENT)
1724 				_drbd_set_state(_NS(device, disk, D_INCONSISTENT), CS_HARD, NULL);
1725 			break;
1726 		}
1727 		fallthrough;	/* for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */
1728 	case EP_DETACH:
1729 	case EP_CALL_HELPER:
1730 		/* Remember whether we saw a READ or WRITE error.
1731 		 *
1732 		 * Recovery of the affected area for WRITE failure is covered
1733 		 * by the activity log.
1734 		 * READ errors may fall outside that area though. Certain READ
1735 		 * errors can be "healed" by writing good data to the affected
1736 		 * blocks, which triggers block re-allocation in lower layers.
1737 		 *
1738 		 * If we can not write the bitmap after a READ error,
1739 		 * we may need to trigger a full sync (see w_go_diskless()).
1740 		 *
1741 		 * Force-detach is not really an IO error, but rather a
1742 		 * desperate measure to try to deal with a completely
1743 		 * unresponsive lower level IO stack.
1744 		 * Still it should be treated as a WRITE error.
1745 		 *
1746 		 * Meta IO error is always WRITE error:
1747 		 * we read meta data only once during attach,
1748 		 * which will fail in case of errors.
1749 		 */
1750 		set_bit(WAS_IO_ERROR, &device->flags);
1751 		if (df == DRBD_READ_ERROR)
1752 			set_bit(WAS_READ_ERROR, &device->flags);
1753 		if (df == DRBD_FORCE_DETACH)
1754 			set_bit(FORCE_DETACH, &device->flags);
1755 		if (device->state.disk > D_FAILED) {
1756 			_drbd_set_state(_NS(device, disk, D_FAILED), CS_HARD, NULL);
1757 			drbd_err(device,
1758 				"Local IO failed in %s. Detaching...\n", where);
1759 		}
1760 		break;
1761 	}
1762 }
1763 
1764 /**
1765  * drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers
1766  * @device:	 DRBD device.
1767  * @error:	 Error code passed to the IO completion callback
1768  * @forcedetach: Force detach. I.e. the error happened while accessing the meta data
1769  *
1770  * See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED)
1771  */
1772 #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)1773 static inline void drbd_chk_io_error_(struct drbd_device *device,
1774 	int error, enum drbd_force_detach_flags forcedetach, const char *where)
1775 {
1776 	if (error) {
1777 		unsigned long flags;
1778 		spin_lock_irqsave(&device->resource->req_lock, flags);
1779 		__drbd_chk_io_error_(device, forcedetach, where);
1780 		spin_unlock_irqrestore(&device->resource->req_lock, flags);
1781 	}
1782 }
1783 
1784 
1785 /**
1786  * drbd_md_first_sector() - Returns the first sector number of the meta data area
1787  * @bdev:	Meta data block device.
1788  *
1789  * BTW, for internal meta data, this happens to be the maximum capacity
1790  * we could agree upon with our peer node.
1791  */
drbd_md_first_sector(struct drbd_backing_dev * bdev)1792 static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev)
1793 {
1794 	switch (bdev->md.meta_dev_idx) {
1795 	case DRBD_MD_INDEX_INTERNAL:
1796 	case DRBD_MD_INDEX_FLEX_INT:
1797 		return bdev->md.md_offset + bdev->md.bm_offset;
1798 	case DRBD_MD_INDEX_FLEX_EXT:
1799 	default:
1800 		return bdev->md.md_offset;
1801 	}
1802 }
1803 
1804 /**
1805  * drbd_md_last_sector() - Return the last sector number of the meta data area
1806  * @bdev:	Meta data block device.
1807  */
drbd_md_last_sector(struct drbd_backing_dev * bdev)1808 static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
1809 {
1810 	switch (bdev->md.meta_dev_idx) {
1811 	case DRBD_MD_INDEX_INTERNAL:
1812 	case DRBD_MD_INDEX_FLEX_INT:
1813 		return bdev->md.md_offset + MD_4kB_SECT -1;
1814 	case DRBD_MD_INDEX_FLEX_EXT:
1815 	default:
1816 		return bdev->md.md_offset + bdev->md.md_size_sect -1;
1817 	}
1818 }
1819 
1820 /* Returns the number of 512 byte sectors of the device */
drbd_get_capacity(struct block_device * bdev)1821 static inline sector_t drbd_get_capacity(struct block_device *bdev)
1822 {
1823 	return bdev ? bdev_nr_sectors(bdev) : 0;
1824 }
1825 
1826 /**
1827  * drbd_get_max_capacity() - Returns the capacity we announce to out peer
1828  * @bdev:	Meta data block device.
1829  *
1830  * returns the capacity we announce to out peer.  we clip ourselves at the
1831  * various MAX_SECTORS, because if we don't, current implementation will
1832  * oops sooner or later
1833  */
drbd_get_max_capacity(struct drbd_backing_dev * bdev)1834 static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev)
1835 {
1836 	sector_t s;
1837 
1838 	switch (bdev->md.meta_dev_idx) {
1839 	case DRBD_MD_INDEX_INTERNAL:
1840 	case DRBD_MD_INDEX_FLEX_INT:
1841 		s = drbd_get_capacity(bdev->backing_bdev)
1842 			? min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
1843 				drbd_md_first_sector(bdev))
1844 			: 0;
1845 		break;
1846 	case DRBD_MD_INDEX_FLEX_EXT:
1847 		s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
1848 				drbd_get_capacity(bdev->backing_bdev));
1849 		/* clip at maximum size the meta device can support */
1850 		s = min_t(sector_t, s,
1851 			BM_EXT_TO_SECT(bdev->md.md_size_sect
1852 				     - bdev->md.bm_offset));
1853 		break;
1854 	default:
1855 		s = min_t(sector_t, DRBD_MAX_SECTORS,
1856 				drbd_get_capacity(bdev->backing_bdev));
1857 	}
1858 	return s;
1859 }
1860 
1861 /**
1862  * drbd_md_ss() - Return the sector number of our meta data super block
1863  * @bdev:	Meta data block device.
1864  */
drbd_md_ss(struct drbd_backing_dev * bdev)1865 static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev)
1866 {
1867 	const int meta_dev_idx = bdev->md.meta_dev_idx;
1868 
1869 	if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT)
1870 		return 0;
1871 
1872 	/* Since drbd08, internal meta data is always "flexible".
1873 	 * position: last 4k aligned block of 4k size */
1874 	if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
1875 	    meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)
1876 		return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8;
1877 
1878 	/* external, some index; this is the old fixed size layout */
1879 	return MD_128MB_SECT * bdev->md.meta_dev_idx;
1880 }
1881 
1882 static inline void
drbd_queue_work(struct drbd_work_queue * q,struct drbd_work * w)1883 drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w)
1884 {
1885 	unsigned long flags;
1886 	spin_lock_irqsave(&q->q_lock, flags);
1887 	list_add_tail(&w->list, &q->q);
1888 	spin_unlock_irqrestore(&q->q_lock, flags);
1889 	wake_up(&q->q_wait);
1890 }
1891 
1892 static inline void
drbd_queue_work_if_unqueued(struct drbd_work_queue * q,struct drbd_work * w)1893 drbd_queue_work_if_unqueued(struct drbd_work_queue *q, struct drbd_work *w)
1894 {
1895 	unsigned long flags;
1896 	spin_lock_irqsave(&q->q_lock, flags);
1897 	if (list_empty_careful(&w->list))
1898 		list_add_tail(&w->list, &q->q);
1899 	spin_unlock_irqrestore(&q->q_lock, flags);
1900 	wake_up(&q->q_wait);
1901 }
1902 
1903 static inline void
drbd_device_post_work(struct drbd_device * device,int work_bit)1904 drbd_device_post_work(struct drbd_device *device, int work_bit)
1905 {
1906 	if (!test_and_set_bit(work_bit, &device->flags)) {
1907 		struct drbd_connection *connection =
1908 			first_peer_device(device)->connection;
1909 		struct drbd_work_queue *q = &connection->sender_work;
1910 		if (!test_and_set_bit(DEVICE_WORK_PENDING, &connection->flags))
1911 			wake_up(&q->q_wait);
1912 	}
1913 }
1914 
1915 extern void drbd_flush_workqueue(struct drbd_work_queue *work_queue);
1916 
1917 /* To get the ack_receiver out of the blocking network stack,
1918  * so it can change its sk_rcvtimeo from idle- to ping-timeout,
1919  * and send a ping, we need to send a signal.
1920  * Which signal we send is irrelevant. */
wake_ack_receiver(struct drbd_connection * connection)1921 static inline void wake_ack_receiver(struct drbd_connection *connection)
1922 {
1923 	struct task_struct *task = connection->ack_receiver.task;
1924 	if (task && get_t_state(&connection->ack_receiver) == RUNNING)
1925 		send_sig(SIGXCPU, task, 1);
1926 }
1927 
request_ping(struct drbd_connection * connection)1928 static inline void request_ping(struct drbd_connection *connection)
1929 {
1930 	set_bit(SEND_PING, &connection->flags);
1931 	wake_ack_receiver(connection);
1932 }
1933 
1934 extern void *conn_prepare_command(struct drbd_connection *, struct drbd_socket *);
1935 extern void *drbd_prepare_command(struct drbd_peer_device *, struct drbd_socket *);
1936 extern int conn_send_command(struct drbd_connection *, struct drbd_socket *,
1937 			     enum drbd_packet, unsigned int, void *,
1938 			     unsigned int);
1939 extern int drbd_send_command(struct drbd_peer_device *, struct drbd_socket *,
1940 			     enum drbd_packet, unsigned int, void *,
1941 			     unsigned int);
1942 
1943 extern int drbd_send_ping(struct drbd_connection *connection);
1944 extern int drbd_send_ping_ack(struct drbd_connection *connection);
1945 extern int drbd_send_state_req(struct drbd_peer_device *, union drbd_state, union drbd_state);
1946 extern int conn_send_state_req(struct drbd_connection *, union drbd_state, union drbd_state);
1947 
drbd_thread_stop(struct drbd_thread * thi)1948 static inline void drbd_thread_stop(struct drbd_thread *thi)
1949 {
1950 	_drbd_thread_stop(thi, false, true);
1951 }
1952 
drbd_thread_stop_nowait(struct drbd_thread * thi)1953 static inline void drbd_thread_stop_nowait(struct drbd_thread *thi)
1954 {
1955 	_drbd_thread_stop(thi, false, false);
1956 }
1957 
drbd_thread_restart_nowait(struct drbd_thread * thi)1958 static inline void drbd_thread_restart_nowait(struct drbd_thread *thi)
1959 {
1960 	_drbd_thread_stop(thi, true, false);
1961 }
1962 
1963 /* counts how many answer packets packets we expect from our peer,
1964  * for either explicit application requests,
1965  * or implicit barrier packets as necessary.
1966  * increased:
1967  *  w_send_barrier
1968  *  _req_mod(req, QUEUE_FOR_NET_WRITE or QUEUE_FOR_NET_READ);
1969  *    it is much easier and equally valid to count what we queue for the
1970  *    worker, even before it actually was queued or send.
1971  *    (drbd_make_request_common; recovery path on read io-error)
1972  * decreased:
1973  *  got_BarrierAck (respective tl_clear, tl_clear_barrier)
1974  *  _req_mod(req, DATA_RECEIVED)
1975  *     [from receive_DataReply]
1976  *  _req_mod(req, WRITE_ACKED_BY_PEER or RECV_ACKED_BY_PEER or NEG_ACKED)
1977  *     [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)]
1978  *     for some reason it is NOT decreased in got_NegAck,
1979  *     but in the resulting cleanup code from report_params.
1980  *     we should try to remember the reason for that...
1981  *  _req_mod(req, SEND_FAILED or SEND_CANCELED)
1982  *  _req_mod(req, CONNECTION_LOST_WHILE_PENDING)
1983  *     [from tl_clear_barrier]
1984  */
inc_ap_pending(struct drbd_device * device)1985 static inline void inc_ap_pending(struct drbd_device *device)
1986 {
1987 	atomic_inc(&device->ap_pending_cnt);
1988 }
1989 
1990 #define ERR_IF_CNT_IS_NEGATIVE(which, func, line)			\
1991 	if (atomic_read(&device->which) < 0)				\
1992 		drbd_err(device, "in %s:%d: " #which " = %d < 0 !\n",	\
1993 			func, line,					\
1994 			atomic_read(&device->which))
1995 
1996 #define dec_ap_pending(device) _dec_ap_pending(device, __func__, __LINE__)
_dec_ap_pending(struct drbd_device * device,const char * func,int line)1997 static inline void _dec_ap_pending(struct drbd_device *device, const char *func, int line)
1998 {
1999 	if (atomic_dec_and_test(&device->ap_pending_cnt))
2000 		wake_up(&device->misc_wait);
2001 	ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line);
2002 }
2003 
2004 /* counts how many resync-related answers we still expect from the peer
2005  *		     increase			decrease
2006  * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY)
2007  * C_SYNC_SOURCE sends P_RS_DATA_REPLY   (and expects P_WRITE_ACK with ID_SYNCER)
2008  *					   (or P_NEG_ACK with ID_SYNCER)
2009  */
inc_rs_pending(struct drbd_device * device)2010 static inline void inc_rs_pending(struct drbd_device *device)
2011 {
2012 	atomic_inc(&device->rs_pending_cnt);
2013 }
2014 
2015 #define dec_rs_pending(device) _dec_rs_pending(device, __func__, __LINE__)
_dec_rs_pending(struct drbd_device * device,const char * func,int line)2016 static inline void _dec_rs_pending(struct drbd_device *device, const char *func, int line)
2017 {
2018 	atomic_dec(&device->rs_pending_cnt);
2019 	ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line);
2020 }
2021 
2022 /* counts how many answers we still need to send to the peer.
2023  * increased on
2024  *  receive_Data	unless protocol A;
2025  *			we need to send a P_RECV_ACK (proto B)
2026  *			or P_WRITE_ACK (proto C)
2027  *  receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK
2028  *  receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA
2029  *  receive_Barrier_*	we need to send a P_BARRIER_ACK
2030  */
inc_unacked(struct drbd_device * device)2031 static inline void inc_unacked(struct drbd_device *device)
2032 {
2033 	atomic_inc(&device->unacked_cnt);
2034 }
2035 
2036 #define dec_unacked(device) _dec_unacked(device, __func__, __LINE__)
_dec_unacked(struct drbd_device * device,const char * func,int line)2037 static inline void _dec_unacked(struct drbd_device *device, const char *func, int line)
2038 {
2039 	atomic_dec(&device->unacked_cnt);
2040 	ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
2041 }
2042 
2043 #define sub_unacked(device, n) _sub_unacked(device, n, __func__, __LINE__)
_sub_unacked(struct drbd_device * device,int n,const char * func,int line)2044 static inline void _sub_unacked(struct drbd_device *device, int n, const char *func, int line)
2045 {
2046 	atomic_sub(n, &device->unacked_cnt);
2047 	ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
2048 }
2049 
is_sync_target_state(enum drbd_conns connection_state)2050 static inline bool is_sync_target_state(enum drbd_conns connection_state)
2051 {
2052 	return	connection_state == C_SYNC_TARGET ||
2053 		connection_state == C_PAUSED_SYNC_T;
2054 }
2055 
is_sync_source_state(enum drbd_conns connection_state)2056 static inline bool is_sync_source_state(enum drbd_conns connection_state)
2057 {
2058 	return	connection_state == C_SYNC_SOURCE ||
2059 		connection_state == C_PAUSED_SYNC_S;
2060 }
2061 
is_sync_state(enum drbd_conns connection_state)2062 static inline bool is_sync_state(enum drbd_conns connection_state)
2063 {
2064 	return	is_sync_source_state(connection_state) ||
2065 		is_sync_target_state(connection_state);
2066 }
2067 
2068 /**
2069  * get_ldev() - Increase the ref count on device->ldev. Returns 0 if there is no ldev
2070  * @_device:		DRBD device.
2071  * @_min_state:		Minimum device state required for success.
2072  *
2073  * You have to call put_ldev() when finished working with device->ldev.
2074  */
2075 #define get_ldev_if_state(_device, _min_state)				\
2076 	(_get_ldev_if_state((_device), (_min_state)) ?			\
2077 	 ({ __acquire(x); true; }) : false)
2078 #define get_ldev(_device) get_ldev_if_state(_device, D_INCONSISTENT)
2079 
put_ldev(struct drbd_device * device)2080 static inline void put_ldev(struct drbd_device *device)
2081 {
2082 	enum drbd_disk_state disk_state = device->state.disk;
2083 	/* We must check the state *before* the atomic_dec becomes visible,
2084 	 * or we have a theoretical race where someone hitting zero,
2085 	 * while state still D_FAILED, will then see D_DISKLESS in the
2086 	 * condition below and calling into destroy, where he must not, yet. */
2087 	int i = atomic_dec_return(&device->local_cnt);
2088 
2089 	/* This may be called from some endio handler,
2090 	 * so we must not sleep here. */
2091 
2092 	__release(local);
2093 	D_ASSERT(device, i >= 0);
2094 	if (i == 0) {
2095 		if (disk_state == D_DISKLESS)
2096 			/* even internal references gone, safe to destroy */
2097 			drbd_device_post_work(device, DESTROY_DISK);
2098 		if (disk_state == D_FAILED)
2099 			/* all application IO references gone. */
2100 			if (!test_and_set_bit(GOING_DISKLESS, &device->flags))
2101 				drbd_device_post_work(device, GO_DISKLESS);
2102 		wake_up(&device->misc_wait);
2103 	}
2104 }
2105 
2106 #ifndef __CHECKER__
_get_ldev_if_state(struct drbd_device * device,enum drbd_disk_state mins)2107 static inline int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins)
2108 {
2109 	int io_allowed;
2110 
2111 	/* never get a reference while D_DISKLESS */
2112 	if (device->state.disk == D_DISKLESS)
2113 		return 0;
2114 
2115 	atomic_inc(&device->local_cnt);
2116 	io_allowed = (device->state.disk >= mins);
2117 	if (!io_allowed)
2118 		put_ldev(device);
2119 	return io_allowed;
2120 }
2121 #else
2122 extern int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins);
2123 #endif
2124 
2125 /* this throttles on-the-fly application requests
2126  * according to max_buffers settings;
2127  * maybe re-implement using semaphores? */
drbd_get_max_buffers(struct drbd_device * device)2128 static inline int drbd_get_max_buffers(struct drbd_device *device)
2129 {
2130 	struct net_conf *nc;
2131 	int mxb;
2132 
2133 	rcu_read_lock();
2134 	nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
2135 	mxb = nc ? nc->max_buffers : 1000000;  /* arbitrary limit on open requests */
2136 	rcu_read_unlock();
2137 
2138 	return mxb;
2139 }
2140 
drbd_state_is_stable(struct drbd_device * device)2141 static inline int drbd_state_is_stable(struct drbd_device *device)
2142 {
2143 	union drbd_dev_state s = device->state;
2144 
2145 	/* DO NOT add a default clause, we want the compiler to warn us
2146 	 * for any newly introduced state we may have forgotten to add here */
2147 
2148 	switch ((enum drbd_conns)s.conn) {
2149 	/* new io only accepted when there is no connection, ... */
2150 	case C_STANDALONE:
2151 	case C_WF_CONNECTION:
2152 	/* ... or there is a well established connection. */
2153 	case C_CONNECTED:
2154 	case C_SYNC_SOURCE:
2155 	case C_SYNC_TARGET:
2156 	case C_VERIFY_S:
2157 	case C_VERIFY_T:
2158 	case C_PAUSED_SYNC_S:
2159 	case C_PAUSED_SYNC_T:
2160 	case C_AHEAD:
2161 	case C_BEHIND:
2162 		/* transitional states, IO allowed */
2163 	case C_DISCONNECTING:
2164 	case C_UNCONNECTED:
2165 	case C_TIMEOUT:
2166 	case C_BROKEN_PIPE:
2167 	case C_NETWORK_FAILURE:
2168 	case C_PROTOCOL_ERROR:
2169 	case C_TEAR_DOWN:
2170 	case C_WF_REPORT_PARAMS:
2171 	case C_STARTING_SYNC_S:
2172 	case C_STARTING_SYNC_T:
2173 		break;
2174 
2175 		/* Allow IO in BM exchange states with new protocols */
2176 	case C_WF_BITMAP_S:
2177 		if (first_peer_device(device)->connection->agreed_pro_version < 96)
2178 			return 0;
2179 		break;
2180 
2181 		/* no new io accepted in these states */
2182 	case C_WF_BITMAP_T:
2183 	case C_WF_SYNC_UUID:
2184 	case C_MASK:
2185 		/* not "stable" */
2186 		return 0;
2187 	}
2188 
2189 	switch ((enum drbd_disk_state)s.disk) {
2190 	case D_DISKLESS:
2191 	case D_INCONSISTENT:
2192 	case D_OUTDATED:
2193 	case D_CONSISTENT:
2194 	case D_UP_TO_DATE:
2195 	case D_FAILED:
2196 		/* disk state is stable as well. */
2197 		break;
2198 
2199 	/* no new io accepted during transitional states */
2200 	case D_ATTACHING:
2201 	case D_NEGOTIATING:
2202 	case D_UNKNOWN:
2203 	case D_MASK:
2204 		/* not "stable" */
2205 		return 0;
2206 	}
2207 
2208 	return 1;
2209 }
2210 
drbd_suspended(struct drbd_device * device)2211 static inline int drbd_suspended(struct drbd_device *device)
2212 {
2213 	struct drbd_resource *resource = device->resource;
2214 
2215 	return resource->susp || resource->susp_fen || resource->susp_nod;
2216 }
2217 
may_inc_ap_bio(struct drbd_device * device)2218 static inline bool may_inc_ap_bio(struct drbd_device *device)
2219 {
2220 	int mxb = drbd_get_max_buffers(device);
2221 
2222 	if (drbd_suspended(device))
2223 		return false;
2224 	if (atomic_read(&device->suspend_cnt))
2225 		return false;
2226 
2227 	/* to avoid potential deadlock or bitmap corruption,
2228 	 * in various places, we only allow new application io
2229 	 * to start during "stable" states. */
2230 
2231 	/* no new io accepted when attaching or detaching the disk */
2232 	if (!drbd_state_is_stable(device))
2233 		return false;
2234 
2235 	/* since some older kernels don't have atomic_add_unless,
2236 	 * and we are within the spinlock anyways, we have this workaround.  */
2237 	if (atomic_read(&device->ap_bio_cnt) > mxb)
2238 		return false;
2239 	if (test_bit(BITMAP_IO, &device->flags))
2240 		return false;
2241 	return true;
2242 }
2243 
inc_ap_bio_cond(struct drbd_device * device)2244 static inline bool inc_ap_bio_cond(struct drbd_device *device)
2245 {
2246 	bool rv = false;
2247 
2248 	spin_lock_irq(&device->resource->req_lock);
2249 	rv = may_inc_ap_bio(device);
2250 	if (rv)
2251 		atomic_inc(&device->ap_bio_cnt);
2252 	spin_unlock_irq(&device->resource->req_lock);
2253 
2254 	return rv;
2255 }
2256 
inc_ap_bio(struct drbd_device * device)2257 static inline void inc_ap_bio(struct drbd_device *device)
2258 {
2259 	/* we wait here
2260 	 *    as long as the device is suspended
2261 	 *    until the bitmap is no longer on the fly during connection
2262 	 *    handshake as long as we would exceed the max_buffer limit.
2263 	 *
2264 	 * to avoid races with the reconnect code,
2265 	 * we need to atomic_inc within the spinlock. */
2266 
2267 	wait_event(device->misc_wait, inc_ap_bio_cond(device));
2268 }
2269 
dec_ap_bio(struct drbd_device * device)2270 static inline void dec_ap_bio(struct drbd_device *device)
2271 {
2272 	int mxb = drbd_get_max_buffers(device);
2273 	int ap_bio = atomic_dec_return(&device->ap_bio_cnt);
2274 
2275 	D_ASSERT(device, ap_bio >= 0);
2276 
2277 	if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) {
2278 		if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
2279 			drbd_queue_work(&first_peer_device(device)->
2280 				connection->sender_work,
2281 				&device->bm_io_work.w);
2282 	}
2283 
2284 	/* this currently does wake_up for every dec_ap_bio!
2285 	 * maybe rather introduce some type of hysteresis?
2286 	 * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */
2287 	if (ap_bio < mxb)
2288 		wake_up(&device->misc_wait);
2289 }
2290 
verify_can_do_stop_sector(struct drbd_device * device)2291 static inline bool verify_can_do_stop_sector(struct drbd_device *device)
2292 {
2293 	return first_peer_device(device)->connection->agreed_pro_version >= 97 &&
2294 		first_peer_device(device)->connection->agreed_pro_version != 100;
2295 }
2296 
drbd_set_ed_uuid(struct drbd_device * device,u64 val)2297 static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val)
2298 {
2299 	int changed = device->ed_uuid != val;
2300 	device->ed_uuid = val;
2301 	return changed;
2302 }
2303 
drbd_queue_order_type(struct drbd_device * device)2304 static inline int drbd_queue_order_type(struct drbd_device *device)
2305 {
2306 	/* sorry, we currently have no working implementation
2307 	 * of distributed TCQ stuff */
2308 #ifndef QUEUE_ORDERED_NONE
2309 #define QUEUE_ORDERED_NONE 0
2310 #endif
2311 	return QUEUE_ORDERED_NONE;
2312 }
2313 
first_connection(struct drbd_resource * resource)2314 static inline struct drbd_connection *first_connection(struct drbd_resource *resource)
2315 {
2316 	return list_first_entry_or_null(&resource->connections,
2317 				struct drbd_connection, connections);
2318 }
2319 
2320 #endif
2321