4 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
6 Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
7 Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
8 Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
10 drbd is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
15 drbd is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with drbd; see the file COPYING. If not, write to
22 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
29 #include <linux/compiler.h>
30 #include <linux/types.h>
31 #include <linux/list.h>
32 #include <linux/sched.h>
33 #include <linux/bitops.h>
34 #include <linux/slab.h>
35 #include <linux/crypto.h>
36 #include <linux/ratelimit.h>
37 #include <linux/tcp.h>
38 #include <linux/mutex.h>
39 #include <linux/major.h>
40 #include <linux/blkdev.h>
41 #include <linux/genhd.h>
42 #include <linux/idr.h>
44 #include <linux/lru_cache.h>
45 #include <linux/prefetch.h>
46 #include <linux/drbd_genl_api.h>
47 #include <linux/drbd.h>
48 #include "drbd_strings.h"
49 #include "drbd_state.h"
50 #include "drbd_protocol.h"
53 # define __protected_by(x) __attribute__((require_context(x,1,999,"rdwr")))
54 # define __protected_read_by(x) __attribute__((require_context(x,1,999,"read")))
55 # define __protected_write_by(x) __attribute__((require_context(x,1,999,"write")))
56 # define __must_hold(x) __attribute__((context(x,1,1), require_context(x,1,999,"call")))
58 # define __protected_by(x)
59 # define __protected_read_by(x)
60 # define __protected_write_by(x)
61 # define __must_hold(x)
64 #define __no_warn(lock, stmt) do { __acquire(lock); stmt; __release(lock); } while (0)
66 /* module parameter, defined in drbd_main.c */
67 extern unsigned int minor_count;
68 extern bool disable_sendpage;
69 extern bool allow_oos;
70 void tl_abort_disk_io(struct drbd_device *device);
72 #ifdef CONFIG_DRBD_FAULT_INJECTION
73 extern int enable_faults;
74 extern int fault_rate;
75 extern int fault_devs;
78 extern char usermode_helper[];
81 /* I don't remember why XCPU ...
82 * This is used to wake the asender,
83 * and to interrupt sending the sending task
86 #define DRBD_SIG SIGXCPU
88 /* This is used to stop/restart our threads.
89 * Cannot use SIGTERM nor SIGKILL, since these
90 * are sent out by init on runlevel changes
91 * I choose SIGHUP for now.
93 #define DRBD_SIGKILL SIGHUP
95 #define ID_IN_SYNC (4711ULL)
96 #define ID_OUT_OF_SYNC (4712ULL)
97 #define ID_SYNCER (-1ULL)
99 #define UUID_NEW_BM_OFFSET ((u64)0x0001000000000000ULL)
102 struct drbd_connection;
104 #define __drbd_printk_device(level, device, fmt, args...) \
105 dev_printk(level, disk_to_dev((device)->vdisk), fmt, ## args)
106 #define __drbd_printk_peer_device(level, peer_device, fmt, args...) \
107 dev_printk(level, disk_to_dev((peer_device)->device->vdisk), fmt, ## args)
108 #define __drbd_printk_resource(level, resource, fmt, args...) \
109 printk(level "drbd %s: " fmt, (resource)->name, ## args)
110 #define __drbd_printk_connection(level, connection, fmt, args...) \
111 printk(level "drbd %s: " fmt, (connection)->resource->name, ## args)
113 void drbd_printk_with_wrong_object_type(void);
115 #define __drbd_printk_if_same_type(obj, type, func, level, fmt, args...) \
116 (__builtin_types_compatible_p(typeof(obj), type) || \
117 __builtin_types_compatible_p(typeof(obj), const type)), \
118 func(level, (const type)(obj), fmt, ## args)
120 #define drbd_printk(level, obj, fmt, args...) \
121 __builtin_choose_expr( \
122 __drbd_printk_if_same_type(obj, struct drbd_device *, \
123 __drbd_printk_device, level, fmt, ## args), \
124 __builtin_choose_expr( \
125 __drbd_printk_if_same_type(obj, struct drbd_resource *, \
126 __drbd_printk_resource, level, fmt, ## args), \
127 __builtin_choose_expr( \
128 __drbd_printk_if_same_type(obj, struct drbd_connection *, \
129 __drbd_printk_connection, level, fmt, ## args), \
130 __builtin_choose_expr( \
131 __drbd_printk_if_same_type(obj, struct drbd_peer_device *, \
132 __drbd_printk_peer_device, level, fmt, ## args), \
133 drbd_printk_with_wrong_object_type()))))
135 #define drbd_dbg(obj, fmt, args...) \
136 drbd_printk(KERN_DEBUG, obj, fmt, ## args)
137 #define drbd_alert(obj, fmt, args...) \
138 drbd_printk(KERN_ALERT, obj, fmt, ## args)
139 #define drbd_err(obj, fmt, args...) \
140 drbd_printk(KERN_ERR, obj, fmt, ## args)
141 #define drbd_warn(obj, fmt, args...) \
142 drbd_printk(KERN_WARNING, obj, fmt, ## args)
143 #define drbd_info(obj, fmt, args...) \
144 drbd_printk(KERN_INFO, obj, fmt, ## args)
145 #define drbd_emerg(obj, fmt, args...) \
146 drbd_printk(KERN_EMERG, obj, fmt, ## args)
148 #define dynamic_drbd_dbg(device, fmt, args...) \
149 dynamic_dev_dbg(disk_to_dev(device->vdisk), fmt, ## args)
151 #define D_ASSERT(device, exp) do { \
153 drbd_err(device, "ASSERT( " #exp " ) in %s:%d\n", __FILE__, __LINE__); \
157 * expect - Make an assertion
159 * Unlike the assert macro, this macro returns a boolean result.
161 #define expect(exp) ({ \
162 bool _bool = (exp); \
164 drbd_err(device, "ASSERTION %s FAILED in %s\n", \
169 /* Defines to control fault insertion */
171 DRBD_FAULT_MD_WR = 0, /* meta data write */
172 DRBD_FAULT_MD_RD = 1, /* read */
173 DRBD_FAULT_RS_WR = 2, /* resync */
174 DRBD_FAULT_RS_RD = 3,
175 DRBD_FAULT_DT_WR = 4, /* data */
176 DRBD_FAULT_DT_RD = 5,
177 DRBD_FAULT_DT_RA = 6, /* data read ahead */
178 DRBD_FAULT_BM_ALLOC = 7, /* bitmap allocation */
179 DRBD_FAULT_AL_EE = 8, /* alloc ee */
180 DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */
186 _drbd_insert_fault(struct drbd_device *device, unsigned int type);
189 drbd_insert_fault(struct drbd_device *device, unsigned int type) {
190 #ifdef CONFIG_DRBD_FAULT_INJECTION
192 (enable_faults & (1<<type)) &&
193 _drbd_insert_fault(device, type);
199 /* integer division, round _UP_ to the next integer */
200 #define div_ceil(A, B) ((A)/(B) + ((A)%(B) ? 1 : 0))
201 /* usual integer division */
202 #define div_floor(A, B) ((A)/(B))
204 extern struct ratelimit_state drbd_ratelimit_state;
205 extern struct idr drbd_devices; /* RCU, updates: genl_lock() */
206 extern struct list_head drbd_resources; /* RCU, updates: genl_lock() */
208 extern const char *cmdname(enum drbd_packet cmd);
210 /* for sending/receiving the bitmap,
211 * possibly in some encoding scheme */
214 * stores total bits and long words
215 * of the bitmap, so we don't need to
216 * call the accessor functions over and again. */
217 unsigned long bm_bits;
218 unsigned long bm_words;
219 /* during xfer, current position within the bitmap */
220 unsigned long bit_offset;
221 unsigned long word_offset;
223 /* statistics; index: (h->command == P_BITMAP) */
228 extern void INFO_bm_xfer_stats(struct drbd_device *device,
229 const char *direction, struct bm_xfer_ctx *c);
231 static inline void bm_xfer_ctx_bit_to_word_offset(struct bm_xfer_ctx *c)
233 /* word_offset counts "native long words" (32 or 64 bit),
235 * Encoded packet may end at an unaligned bit offset.
236 * In case a fallback clear text packet is transmitted in
237 * between, we adjust this offset back to the last 64bit
238 * aligned "native long word", which makes coding and decoding
239 * the plain text bitmap much more convenient. */
240 #if BITS_PER_LONG == 64
241 c->word_offset = c->bit_offset >> 6;
242 #elif BITS_PER_LONG == 32
243 c->word_offset = c->bit_offset >> 5;
244 c->word_offset &= ~(1UL);
246 # error "unsupported BITS_PER_LONG"
250 extern unsigned int drbd_header_size(struct drbd_connection *connection);
252 /**********************************************************************/
253 enum drbd_thread_state {
262 struct task_struct *task;
263 struct completion stop;
264 enum drbd_thread_state t_state;
265 int (*function) (struct drbd_thread *);
266 struct drbd_connection *connection;
271 static inline enum drbd_thread_state get_t_state(struct drbd_thread *thi)
273 /* THINK testing the t_state seems to be uncritical in all cases
274 * (but thread_{start,stop}), so we can read it *without* the lock.
282 struct list_head list;
283 int (*cb)(struct drbd_work *, int cancel);
285 struct drbd_device *device;
286 struct drbd_connection *connection;
290 #include "drbd_interval.h"
292 extern int drbd_wait_misc(struct drbd_device *, struct drbd_interval *);
294 struct drbd_request {
297 /* if local IO is not allowed, will be NULL.
298 * if local IO _is_ allowed, holds the locally submitted bio clone,
299 * or, after local IO completion, the ERR_PTR(error).
300 * see drbd_request_endio(). */
301 struct bio *private_bio;
303 struct drbd_interval i;
305 /* epoch: used to check on "completion" whether this req was in
306 * the current epoch, and we therefore have to close it,
307 * causing a p_barrier packet to be send, starting a new epoch.
309 * This corresponds to "barrier" in struct p_barrier[_ack],
310 * and to "barrier_nr" in struct drbd_epoch (and various
311 * comments/function parameters/local variable names).
315 struct list_head tl_requests; /* ring list in the transfer log */
316 struct bio *master_bio; /* master bio pointer */
317 unsigned long start_time;
319 /* once it hits 0, we may complete the master_bio */
320 atomic_t completion_ref;
321 /* once it hits 0, we may destroy this drbd_request object */
324 unsigned rq_state; /* see comments above _req_mod() */
328 struct drbd_connection *connection;
329 struct list_head list;
330 unsigned int barrier_nr;
331 atomic_t epoch_size; /* increased on every request added. */
332 atomic_t active; /* increased on every req. added, and dec on every finished. */
336 /* Prototype declaration of function defined in drbd_receiver.c */
337 int drbdd_init(struct drbd_thread *);
338 int drbd_asender(struct drbd_thread *);
340 /* drbd_epoch flag bits */
342 DE_HAVE_BARRIER_NUMBER,
349 EV_CLEANUP = 32, /* used as flag */
352 struct drbd_wq_barrier {
354 struct completion done;
362 struct drbd_peer_request {
364 struct drbd_epoch *epoch; /* for writes */
366 atomic_t pending_bios;
367 struct drbd_interval i;
368 /* see comments on ee flag bits below */
372 struct digest_info *digest;
377 * While corresponding bios are in flight, the only modification will be
378 * set_bit WAS_ERROR, which has to be atomic.
379 * If no bios are in flight yet, or all have been completed,
380 * non-atomic modification to ee->flags is ok.
383 __EE_CALL_AL_COMPLETE_IO,
384 __EE_MAY_SET_IN_SYNC,
386 /* In case a barrier failed,
387 * we need to resubmit without the barrier flag. */
390 /* we may have several bios per peer request.
391 * if any of those fail, we set this flag atomically
392 * from the endio callback */
395 /* This ee has a pointer to a digest instead of a block id */
398 /* Conflicting local requests need to be restarted after this request */
399 __EE_RESTART_REQUESTS,
401 /* The peer wants a write ACK for this (wire proto C) */
404 /* Is set when net_conf had two_primaries set while creating this peer_req */
405 __EE_IN_INTERVAL_TREE,
407 #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
408 #define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC)
409 #define EE_RESUBMITTED (1<<__EE_RESUBMITTED)
410 #define EE_WAS_ERROR (1<<__EE_WAS_ERROR)
411 #define EE_HAS_DIGEST (1<<__EE_HAS_DIGEST)
412 #define EE_RESTART_REQUESTS (1<<__EE_RESTART_REQUESTS)
413 #define EE_SEND_WRITE_ACK (1<<__EE_SEND_WRITE_ACK)
414 #define EE_IN_INTERVAL_TREE (1<<__EE_IN_INTERVAL_TREE)
416 /* flag bits per device */
418 UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */
419 MD_DIRTY, /* current uuids and flags not yet on disk */
420 USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */
423 CRASHED_PRIMARY, /* This node was a crashed primary.
424 * Gets cleared when the state.conn
425 * goes into C_CONNECTED state. */
428 MD_NO_FUA, /* Users wants us to not use FUA/FLUSH on meta data dev */
429 SUSPEND_IO, /* suspend application io */
430 BITMAP_IO, /* suspend application io;
431 once no more io in flight, start bitmap io */
432 BITMAP_IO_QUEUED, /* Started bitmap IO */
433 GO_DISKLESS, /* Disk is being detached, on io-error or admin request. */
434 WAS_IO_ERROR, /* Local disk failed, returned IO error */
435 WAS_READ_ERROR, /* Local disk READ failed (set additionally to the above) */
436 FORCE_DETACH, /* Force-detach from local disk, aborting any pending local IO */
437 RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */
438 RESIZE_PENDING, /* Size change detected locally, waiting for the response from
439 * the peer, if it changed there as well. */
440 NEW_CUR_UUID, /* Create new current UUID when thawing IO */
441 AL_SUSPENDED, /* Activity logging is currently suspended. */
442 AHEAD_TO_SYNC_SOURCE, /* Ahead -> SyncSource queued */
443 B_RS_H_DONE, /* Before resync handler done (already executed) */
444 DISCARD_MY_DATA, /* discard_my_data flag per volume */
448 struct drbd_bitmap; /* opaque for drbd_device */
450 /* definition of bits in bm_flags to be used in drbd_bm_lock
451 * and drbd_bitmap_io and friends. */
453 /* do we need to kfree, or vfree bm_pages? */
454 BM_P_VMALLOCED = 0x10000, /* internal use only, will be masked out */
456 /* currently locked for bulk operation */
457 BM_LOCKED_MASK = 0xf,
459 /* in detail, that is: */
464 /* so we can mark it locked for bulk operation,
465 * and still allow all non-bulk operations */
468 /* (test bit, count bit) allowed (common case) */
469 BM_LOCKED_TEST_ALLOWED = BM_DONT_CLEAR | BM_DONT_SET | BM_IS_LOCKED,
471 /* testing bits, as well as setting new bits allowed, but clearing bits
472 * would be unexpected. Used during bitmap receive. Setting new bits
473 * requires sending of "out-of-sync" information, though. */
474 BM_LOCKED_SET_ALLOWED = BM_DONT_CLEAR | BM_IS_LOCKED,
476 /* for drbd_bm_write_copy_pages, everything is allowed,
477 * only concurrent bulk operations are locked out. */
478 BM_LOCKED_CHANGE_ALLOWED = BM_IS_LOCKED,
481 struct drbd_work_queue {
483 spinlock_t q_lock; /* to protect the list. */
484 wait_queue_head_t q_wait;
489 struct socket *socket;
490 /* this way we get our
491 * send/receive buffers off the stack */
497 u64 md_offset; /* sector offset to 'super' block */
499 u64 la_size_sect; /* last agreed size, unit sectors */
500 spinlock_t uuid_lock;
506 s32 al_offset; /* signed relative sector offset to activity log */
507 s32 bm_offset; /* signed relative sector offset to bitmap */
509 /* cached value of bdev->disk_conf->meta_dev_idx (see below) */
512 /* see al_tr_number_to_on_disk_sector() */
514 u32 al_stripe_size_4k;
515 u32 al_size_4k; /* cached product of the above */
518 struct drbd_backing_dev {
519 struct block_device *backing_bdev;
520 struct block_device *md_bdev;
522 struct disk_conf *disk_conf; /* RCU, for updates: resource->conf_update */
523 sector_t known_size; /* last known size of that backing device */
535 int (*io_fn)(struct drbd_device *device);
536 void (*done)(struct drbd_device *device, int rv);
539 enum write_ordering_e {
546 unsigned int head_index;
548 int total; /* sum of all values */
551 extern struct fifo_buffer *fifo_alloc(int fifo_size);
553 /* flag bits per connection */
555 NET_CONGESTED, /* The data socket is congested */
556 RESOLVE_CONFLICTS, /* Set on one node, cleared on the peer! */
557 SEND_PING, /* whether asender should send a ping asap */
558 SIGNAL_ASENDER, /* whether asender wants to be interrupted */
559 GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */
560 CONN_WD_ST_CHG_REQ, /* A cluster wide state change on the connection is active */
563 CONN_DRY_RUN, /* Expect disconnect after resync handshake. */
564 CREATE_BARRIER, /* next P_DATA is preceded by a P_BARRIER */
565 STATE_SENT, /* Do not change state/UUIDs while this is set */
566 CALLBACK_PENDING, /* Whether we have a call_usermodehelper(, UMH_WAIT_PROC)
567 * pending, from drbd worker context.
568 * If set, bdi_write_congested() returns true,
569 * so shrink_page_list() would not recurse into,
570 * and potentially deadlock on, this drbd worker.
575 struct drbd_resource {
578 struct idr devices; /* volume number to device mapping */
579 struct list_head connections;
580 struct list_head resources;
581 struct res_opts res_opts;
582 struct mutex conf_update; /* mutex for ready-copy-update of net_conf and disk_conf */
585 unsigned susp:1; /* IO suspended by user */
586 unsigned susp_nod:1; /* IO suspended because no data */
587 unsigned susp_fen:1; /* IO suspended because fence peer handler runs */
589 cpumask_var_t cpu_mask;
592 struct drbd_connection {
593 struct list_head connections;
594 struct drbd_resource *resource;
596 struct idr peer_devices; /* volume number to peer device mapping */
597 enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */
598 struct mutex cstate_mutex; /* Protects graceful disconnects */
599 unsigned int connect_cnt; /* Inc each time a connection is established */
602 struct net_conf *net_conf; /* content protected by rcu */
603 wait_queue_head_t ping_wait; /* Woken upon reception of a ping, and a state change */
605 struct sockaddr_storage my_addr;
607 struct sockaddr_storage peer_addr;
610 struct drbd_socket data; /* data/barrier/cstate/parameter packets */
611 struct drbd_socket meta; /* ping/ack (metadata) packets */
612 int agreed_pro_version; /* actually used protocol version */
613 unsigned long last_received; /* in jiffies, either socket */
614 unsigned int ko_count;
616 struct list_head transfer_log; /* all requests not yet fully processed */
618 struct crypto_hash *cram_hmac_tfm;
619 struct crypto_hash *integrity_tfm; /* checksums we compute, updates protected by connection->data->mutex */
620 struct crypto_hash *peer_integrity_tfm; /* checksums we verify, only accessed from receiver thread */
621 struct crypto_hash *csums_tfm;
622 struct crypto_hash *verify_tfm;
627 struct drbd_epoch *current_epoch;
628 spinlock_t epoch_lock;
630 enum write_ordering_e write_ordering;
631 atomic_t current_tle_nr; /* transfer log epoch number */
632 unsigned current_tle_writes; /* writes seen within this tl epoch */
634 unsigned long last_reconnect_jif;
635 struct drbd_thread receiver;
636 struct drbd_thread worker;
637 struct drbd_thread asender;
640 struct drbd_work_queue sender_work;
643 /* whether this sender thread
644 * has processed a single write yet. */
645 bool seen_any_write_yet;
647 /* Which barrier number to send with the next P_BARRIER */
648 int current_epoch_nr;
650 /* how many write requests have been sent
651 * with req->epoch == current_epoch_nr.
652 * If none, no P_BARRIER will be sent. */
653 unsigned current_epoch_writes;
657 struct submit_worker {
658 struct workqueue_struct *wq;
659 struct work_struct worker;
662 struct list_head writes;
665 struct drbd_peer_device {
666 struct list_head peer_devices;
667 struct drbd_device *device;
668 struct drbd_connection *connection;
672 struct drbd_resource *resource;
673 struct list_head peer_devices;
674 int vnr; /* volume number within the connection */
677 /* things that are stored as / read from meta data on disk */
680 /* configured by drbdsetup */
681 struct drbd_backing_dev *ldev __protected_by(local);
683 sector_t p_size; /* partner's disk size */
684 struct request_queue *rq_queue;
685 struct block_device *this_bdev;
686 struct gendisk *vdisk;
688 unsigned long last_reattach_jif;
689 struct drbd_work resync_work,
694 struct timer_list resync_timer;
695 struct timer_list md_sync_timer;
696 struct timer_list start_resync_timer;
697 struct timer_list request_timer;
698 #ifdef DRBD_DEBUG_MD_SYNC
702 } last_md_mark_dirty;
705 /* Used after attach while negotiating new disk state. */
706 union drbd_state new_state_tmp;
708 union drbd_dev_state state;
709 wait_queue_head_t misc_wait;
710 wait_queue_head_t state_wait; /* upon each state change. */
711 unsigned int send_cnt;
712 unsigned int recv_cnt;
713 unsigned int read_cnt;
714 unsigned int writ_cnt;
715 unsigned int al_writ_cnt;
716 unsigned int bm_writ_cnt;
717 atomic_t ap_bio_cnt; /* Requests we need to complete */
718 atomic_t ap_pending_cnt; /* AP data packets on the wire, ack expected */
719 atomic_t rs_pending_cnt; /* RS request/data packets on the wire */
720 atomic_t unacked_cnt; /* Need to send replies for */
721 atomic_t local_cnt; /* Waiting for local completion */
723 /* Interval tree of pending local requests */
724 struct rb_root read_requests;
725 struct rb_root write_requests;
727 /* blocks to resync in this run [unit BM_BLOCK_SIZE] */
728 unsigned long rs_total;
729 /* number of resync blocks that failed in this run */
730 unsigned long rs_failed;
731 /* Syncer's start time [unit jiffies] */
732 unsigned long rs_start;
733 /* cumulated time in PausedSyncX state [unit jiffies] */
734 unsigned long rs_paused;
735 /* skipped because csum was equal [unit BM_BLOCK_SIZE] */
736 unsigned long rs_same_csum;
737 #define DRBD_SYNC_MARKS 8
738 #define DRBD_SYNC_MARK_STEP (3*HZ)
739 /* block not up-to-date at mark [unit BM_BLOCK_SIZE] */
740 unsigned long rs_mark_left[DRBD_SYNC_MARKS];
741 /* marks's time [unit jiffies] */
742 unsigned long rs_mark_time[DRBD_SYNC_MARKS];
743 /* current index into rs_mark_{left,time} */
745 unsigned long rs_last_bcast; /* [unit jiffies] */
747 /* where does the admin want us to start? (sector) */
748 sector_t ov_start_sector;
749 sector_t ov_stop_sector;
750 /* where are we now? (sector) */
751 sector_t ov_position;
752 /* Start sector of out of sync range (to merge printk reporting). */
753 sector_t ov_last_oos_start;
754 /* size of out-of-sync range in sectors. */
755 sector_t ov_last_oos_size;
756 unsigned long ov_left; /* in bits */
758 struct drbd_bitmap *bitmap;
759 unsigned long bm_resync_fo; /* bit offset for drbd_bm_find_next */
761 /* Used to track operations of resync... */
762 struct lru_cache *resync;
763 /* Number of locked elements in resync LRU */
764 unsigned int resync_locked;
765 /* resync extent number waiting for application requests */
766 unsigned int resync_wenr;
771 struct list_head active_ee; /* IO in progress (P_DATA gets written to disk) */
772 struct list_head sync_ee; /* IO in progress (P_RS_DATA_REPLY gets written to disk) */
773 struct list_head done_ee; /* need to send P_WRITE_ACK */
774 struct list_head read_ee; /* [RS]P_DATA_REQUEST being read */
775 struct list_head net_ee; /* zero-copy network send in progress */
778 struct list_head resync_reads;
779 atomic_t pp_in_use; /* allocated from page pool */
780 atomic_t pp_in_use_by_net; /* sendpage()d, still referenced by tcp */
781 wait_queue_head_t ee_wait;
782 struct page *md_io_page; /* one page buffer for md_io */
783 struct drbd_md_io md_io;
784 atomic_t md_io_in_use; /* protects the md_io, md_io_page and md_io_tmpp */
786 wait_queue_head_t al_wait;
787 struct lru_cache *act_log; /* activity log */
788 unsigned int al_tr_number;
790 wait_queue_head_t seq_wait;
792 unsigned int peer_seq;
793 spinlock_t peer_seq_lock;
795 unsigned long comm_bm_set; /* communicated number of set bits. */
796 struct bm_io_work bm_io_work;
797 u64 ed_uuid; /* UUID of the exposed data */
798 struct mutex own_state_mutex;
799 struct mutex *state_mutex; /* either own_state_mutex or first_peer_device(device)->connection->cstate_mutex */
800 char congestion_reason; /* Why we where congested... */
801 atomic_t rs_sect_in; /* for incoming resync data rate, SyncTarget */
802 atomic_t rs_sect_ev; /* for submitted resync data rate, both */
803 int rs_last_sect_ev; /* counter to compare with */
804 int rs_last_events; /* counter of read or write "events" (unit sectors)
805 * on the lower level device when we last looked. */
806 int c_sync_rate; /* current resync rate after syncer throttle magic */
807 struct fifo_buffer *rs_plan_s; /* correction values of resync planer (RCU, connection->conn_update) */
808 int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */
809 atomic_t ap_in_flight; /* App sectors in flight (waiting for ack) */
810 unsigned int peer_max_bio_size;
811 unsigned int local_max_bio_size;
813 /* any requests that would block in drbd_make_request()
814 * are deferred to this single-threaded work queue */
815 struct submit_worker submit;
818 static inline struct drbd_device *minor_to_device(unsigned int minor)
820 return (struct drbd_device *)idr_find(&drbd_devices, minor);
823 static inline struct drbd_peer_device *first_peer_device(struct drbd_device *device)
825 return list_first_entry(&device->peer_devices, struct drbd_peer_device, peer_devices);
828 #define for_each_resource(resource, _resources) \
829 list_for_each_entry(resource, _resources, resources)
831 #define for_each_resource_rcu(resource, _resources) \
832 list_for_each_entry_rcu(resource, _resources, resources)
834 #define for_each_resource_safe(resource, tmp, _resources) \
835 list_for_each_entry_safe(resource, tmp, _resources, resources)
837 #define for_each_connection(connection, resource) \
838 list_for_each_entry(connection, &resource->connections, connections)
840 #define for_each_connection_rcu(connection, resource) \
841 list_for_each_entry_rcu(connection, &resource->connections, connections)
843 #define for_each_connection_safe(connection, tmp, resource) \
844 list_for_each_entry_safe(connection, tmp, &resource->connections, connections)
846 #define for_each_peer_device(peer_device, device) \
847 list_for_each_entry(peer_device, &device->peer_devices, peer_devices)
849 #define for_each_peer_device_rcu(peer_device, device) \
850 list_for_each_entry_rcu(peer_device, &device->peer_devices, peer_devices)
852 #define for_each_peer_device_safe(peer_device, tmp, device) \
853 list_for_each_entry_safe(peer_device, tmp, &device->peer_devices, peer_devices)
855 static inline unsigned int device_to_minor(struct drbd_device *device)
857 return device->minor;
861 * function declarations
862 *************************/
868 DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */
871 extern void drbd_init_set_defaults(struct drbd_device *device);
872 extern int drbd_thread_start(struct drbd_thread *thi);
873 extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait);
875 extern void drbd_thread_current_set_cpu(struct drbd_thread *thi);
877 #define drbd_thread_current_set_cpu(A) ({})
879 extern void tl_release(struct drbd_connection *, unsigned int barrier_nr,
880 unsigned int set_size);
881 extern void tl_clear(struct drbd_connection *);
882 extern void drbd_free_sock(struct drbd_connection *connection);
883 extern int drbd_send(struct drbd_connection *connection, struct socket *sock,
884 void *buf, size_t size, unsigned msg_flags);
885 extern int drbd_send_all(struct drbd_connection *, struct socket *, void *, size_t,
888 extern int __drbd_send_protocol(struct drbd_connection *connection, enum drbd_packet cmd);
889 extern int drbd_send_protocol(struct drbd_connection *connection);
890 extern int drbd_send_uuids(struct drbd_peer_device *);
891 extern int drbd_send_uuids_skip_initial_sync(struct drbd_peer_device *);
892 extern void drbd_gen_and_send_sync_uuid(struct drbd_peer_device *);
893 extern int drbd_send_sizes(struct drbd_peer_device *, int trigger_reply, enum dds_flags flags);
894 extern int drbd_send_state(struct drbd_peer_device *, union drbd_state s);
895 extern int drbd_send_current_state(struct drbd_peer_device *);
896 extern int drbd_send_sync_param(struct drbd_peer_device *);
897 extern void drbd_send_b_ack(struct drbd_connection *connection, u32 barrier_nr,
899 extern int drbd_send_ack(struct drbd_peer_device *, enum drbd_packet,
900 struct drbd_peer_request *);
901 extern void drbd_send_ack_rp(struct drbd_peer_device *, enum drbd_packet,
902 struct p_block_req *rp);
903 extern void drbd_send_ack_dp(struct drbd_peer_device *, enum drbd_packet,
904 struct p_data *dp, int data_size);
905 extern int drbd_send_ack_ex(struct drbd_peer_device *, enum drbd_packet,
906 sector_t sector, int blksize, u64 block_id);
907 extern int drbd_send_out_of_sync(struct drbd_peer_device *, struct drbd_request *);
908 extern int drbd_send_block(struct drbd_peer_device *, enum drbd_packet,
909 struct drbd_peer_request *);
910 extern int drbd_send_dblock(struct drbd_peer_device *, struct drbd_request *req);
911 extern int drbd_send_drequest(struct drbd_peer_device *, int cmd,
912 sector_t sector, int size, u64 block_id);
913 extern int drbd_send_drequest_csum(struct drbd_peer_device *, sector_t sector,
914 int size, void *digest, int digest_size,
915 enum drbd_packet cmd);
916 extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int size);
918 extern int drbd_send_bitmap(struct drbd_device *device);
919 extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode);
920 extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode);
921 extern void drbd_free_bc(struct drbd_backing_dev *ldev);
922 extern void drbd_device_cleanup(struct drbd_device *device);
923 void drbd_print_uuids(struct drbd_device *device, const char *text);
925 extern void conn_md_sync(struct drbd_connection *connection);
926 extern void drbd_md_write(struct drbd_device *device, void *buffer);
927 extern void drbd_md_sync(struct drbd_device *device);
928 extern int drbd_md_read(struct drbd_device *device, struct drbd_backing_dev *bdev);
929 extern void drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
930 extern void _drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
931 extern void drbd_uuid_new_current(struct drbd_device *device) __must_hold(local);
932 extern void drbd_uuid_set_bm(struct drbd_device *device, u64 val) __must_hold(local);
933 extern void drbd_uuid_move_history(struct drbd_device *device) __must_hold(local);
934 extern void __drbd_uuid_set(struct drbd_device *device, int idx, u64 val) __must_hold(local);
935 extern void drbd_md_set_flag(struct drbd_device *device, int flags) __must_hold(local);
936 extern void drbd_md_clear_flag(struct drbd_device *device, int flags)__must_hold(local);
937 extern int drbd_md_test_flag(struct drbd_backing_dev *, int);
938 #ifndef DRBD_DEBUG_MD_SYNC
939 extern void drbd_md_mark_dirty(struct drbd_device *device);
941 #define drbd_md_mark_dirty(m) drbd_md_mark_dirty_(m, __LINE__ , __func__ )
942 extern void drbd_md_mark_dirty_(struct drbd_device *device,
943 unsigned int line, const char *func);
945 extern void drbd_queue_bitmap_io(struct drbd_device *device,
946 int (*io_fn)(struct drbd_device *),
947 void (*done)(struct drbd_device *, int),
948 char *why, enum bm_flag flags);
949 extern int drbd_bitmap_io(struct drbd_device *device,
950 int (*io_fn)(struct drbd_device *),
951 char *why, enum bm_flag flags);
952 extern int drbd_bitmap_io_from_worker(struct drbd_device *device,
953 int (*io_fn)(struct drbd_device *),
954 char *why, enum bm_flag flags);
955 extern int drbd_bmio_set_n_write(struct drbd_device *device);
956 extern int drbd_bmio_clear_n_write(struct drbd_device *device);
957 extern void drbd_ldev_destroy(struct drbd_device *device);
961 * We currently have two possible layouts.
962 * Offsets in (512 byte) sectors.
964 * |----------- md_size_sect ------------------|
965 * [ 4k superblock ][ activity log ][ Bitmap ]
967 * | bm_offset = al_offset + X |
968 * ==> bitmap sectors = md_size_sect - bm_offset
971 * old, indexed fixed size meta data:
974 * |----------- md_size_sect ------------------|
975 * [data.....][ Bitmap ][ activity log ][ 4k superblock ][padding*]
977 * | bm_offset = al_offset - Y |
978 * ==> bitmap sectors = Y = al_offset - bm_offset
980 * [padding*] are zero or up to 7 unused 512 Byte sectors to the
981 * end of the device, so that the [4k superblock] will be 4k aligned.
983 * The activity log consists of 4k transaction blocks,
984 * which are written in a ring-buffer, or striped ring-buffer like fashion,
985 * which are writtensize used to be fixed 32kB,
986 * but is about to become configurable.
989 /* Our old fixed size meta data layout
990 * allows up to about 3.8TB, so if you want more,
991 * you need to use the "flexible" meta data format. */
992 #define MD_128MB_SECT (128LLU << 11) /* 128 MB, unit sectors */
993 #define MD_4kB_SECT 8
994 #define MD_32kB_SECT 64
996 /* One activity log extent represents 4M of storage */
997 #define AL_EXTENT_SHIFT 22
998 #define AL_EXTENT_SIZE (1<<AL_EXTENT_SHIFT)
1000 /* We could make these currently hardcoded constants configurable
1001 * variables at create-md time (or even re-configurable at runtime?).
1002 * Which will require some more changes to the DRBD "super block"
1005 * updates per transaction:
1006 * This many changes to the active set can be logged with one transaction.
1007 * This number is arbitrary.
1008 * context per transaction:
1009 * This many context extent numbers are logged with each transaction.
1010 * This number is resulting from the transaction block size (4k), the layout
1011 * of the transaction header, and the number of updates per transaction.
1012 * See drbd_actlog.c:struct al_transaction_on_disk
1014 #define AL_UPDATES_PER_TRANSACTION 64 // arbitrary
1015 #define AL_CONTEXT_PER_TRANSACTION 919 // (4096 - 36 - 6*64)/4
1017 #if BITS_PER_LONG == 32
1019 #define cpu_to_lel(A) cpu_to_le32(A)
1020 #define lel_to_cpu(A) le32_to_cpu(A)
1021 #elif BITS_PER_LONG == 64
1023 #define cpu_to_lel(A) cpu_to_le64(A)
1024 #define lel_to_cpu(A) le64_to_cpu(A)
1026 #error "LN2 of BITS_PER_LONG unknown!"
1030 /* 16MB sized 'bitmap extent' to track syncer usage */
1032 int rs_left; /* number of bits set (out of sync) in this extent. */
1033 int rs_failed; /* number of failed resync requests in this extent. */
1034 unsigned long flags;
1035 struct lc_element lce;
1038 #define BME_NO_WRITES 0 /* bm_extent.flags: no more requests on this one! */
1039 #define BME_LOCKED 1 /* bm_extent.flags: syncer active on this one. */
1040 #define BME_PRIORITY 2 /* finish resync IO on this extent ASAP! App IO waiting! */
1044 * We need to store one bit for a block.
1045 * Example: 1GB disk @ 4096 byte blocks ==> we need 32 KB bitmap.
1046 * Bit 0 ==> local node thinks this block is binary identical on both nodes
1047 * Bit 1 ==> local node thinks this block needs to be synced.
1050 #define SLEEP_TIME (HZ/10)
1052 /* We do bitmap IO in units of 4k blocks.
1053 * We also still have a hardcoded 4k per bit relation. */
1054 #define BM_BLOCK_SHIFT 12 /* 4k per bit */
1055 #define BM_BLOCK_SIZE (1<<BM_BLOCK_SHIFT)
1056 /* mostly arbitrarily set the represented size of one bitmap extent,
1057 * aka resync extent, to 16 MiB (which is also 512 Byte worth of bitmap
1058 * at 4k per bit resolution) */
1059 #define BM_EXT_SHIFT 24 /* 16 MiB per resync extent */
1060 #define BM_EXT_SIZE (1<<BM_EXT_SHIFT)
1062 #if (BM_EXT_SHIFT != 24) || (BM_BLOCK_SHIFT != 12)
1063 #error "HAVE YOU FIXED drbdmeta AS WELL??"
1066 /* thus many _storage_ sectors are described by one bit */
1067 #define BM_SECT_TO_BIT(x) ((x)>>(BM_BLOCK_SHIFT-9))
1068 #define BM_BIT_TO_SECT(x) ((sector_t)(x)<<(BM_BLOCK_SHIFT-9))
1069 #define BM_SECT_PER_BIT BM_BIT_TO_SECT(1)
1071 /* bit to represented kilo byte conversion */
1072 #define Bit2KB(bits) ((bits)<<(BM_BLOCK_SHIFT-10))
1074 /* in which _bitmap_ extent (resp. sector) the bit for a certain
1075 * _storage_ sector is located in */
1076 #define BM_SECT_TO_EXT(x) ((x)>>(BM_EXT_SHIFT-9))
1078 /* how much _storage_ sectors we have per bitmap sector */
1079 #define BM_EXT_TO_SECT(x) ((sector_t)(x) << (BM_EXT_SHIFT-9))
1080 #define BM_SECT_PER_EXT BM_EXT_TO_SECT(1)
1082 /* in one sector of the bitmap, we have this many activity_log extents. */
1083 #define AL_EXT_PER_BM_SECT (1 << (BM_EXT_SHIFT - AL_EXTENT_SHIFT))
1085 #define BM_BLOCKS_PER_BM_EXT_B (BM_EXT_SHIFT - BM_BLOCK_SHIFT)
1086 #define BM_BLOCKS_PER_BM_EXT_MASK ((1<<BM_BLOCKS_PER_BM_EXT_B) - 1)
1088 /* the extent in "PER_EXTENT" below is an activity log extent
1089 * we need that many (long words/bytes) to store the bitmap
1090 * of one AL_EXTENT_SIZE chunk of storage.
1091 * we can store the bitmap for that many AL_EXTENTS within
1092 * one sector of the _on_disk_ bitmap:
1093 * bit 0 bit 37 bit 38 bit (512*8)-1
1094 * ...|........|........|.. // ..|........|
1095 * sect. 0 `296 `304 ^(512*8*8)-1
1097 #define BM_WORDS_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / BITS_PER_LONG )
1098 #define BM_BYTES_PER_EXT ( (AL_EXT_SIZE/BM_BLOCK_SIZE) / 8 ) // 128
1099 #define BM_EXT_PER_SECT ( 512 / BM_BYTES_PER_EXTENT ) // 4
1102 #define DRBD_MAX_SECTORS_32 (0xffffffffLU)
1103 /* we have a certain meta data variant that has a fixed on-disk size of 128
1104 * MiB, of which 4k are our "superblock", and 32k are the fixed size activity
1105 * log, leaving this many sectors for the bitmap.
1108 #define DRBD_MAX_SECTORS_FIXED_BM \
1109 ((MD_128MB_SECT - MD_32kB_SECT - MD_4kB_SECT) * (1LL<<(BM_EXT_SHIFT-9)))
1110 #if !defined(CONFIG_LBDAF) && BITS_PER_LONG == 32
1111 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_32
1112 #define DRBD_MAX_SECTORS_FLEX DRBD_MAX_SECTORS_32
1114 #define DRBD_MAX_SECTORS DRBD_MAX_SECTORS_FIXED_BM
1115 /* 16 TB in units of sectors */
1116 #if BITS_PER_LONG == 32
1117 /* adjust by one page worth of bitmap,
1118 * so we won't wrap around in drbd_bm_find_next_bit.
1119 * you should use 64bit OS for that much storage, anyways. */
1120 #define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff)
1122 /* we allow up to 1 PiB now on 64bit architecture with "flexible" meta data */
1123 #define DRBD_MAX_SECTORS_FLEX (1UL << 51)
1124 /* corresponds to (1UL << 38) bits right now. */
1128 /* BIO_MAX_SIZE is 256 * PAGE_CACHE_SIZE,
1129 * so for typical PAGE_CACHE_SIZE of 4k, that is (1<<20) Byte.
1130 * Since we may live in a mixed-platform cluster,
1131 * we limit us to a platform agnostic constant here for now.
1132 * A followup commit may allow even bigger BIO sizes,
1133 * once we thought that through. */
1134 #define DRBD_MAX_BIO_SIZE (1U << 20)
1135 #if DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE
1136 #error Architecture not supported: DRBD_MAX_BIO_SIZE > BIO_MAX_SIZE
1138 #define DRBD_MAX_BIO_SIZE_SAFE (1U << 12) /* Works always = 4k */
1140 #define DRBD_MAX_SIZE_H80_PACKET (1U << 15) /* Header 80 only allows packets up to 32KiB data */
1141 #define DRBD_MAX_BIO_SIZE_P95 (1U << 17) /* Protocol 95 to 99 allows bios up to 128KiB */
1143 extern int drbd_bm_init(struct drbd_device *device);
1144 extern int drbd_bm_resize(struct drbd_device *device, sector_t sectors, int set_new_bits);
1145 extern void drbd_bm_cleanup(struct drbd_device *device);
1146 extern void drbd_bm_set_all(struct drbd_device *device);
1147 extern void drbd_bm_clear_all(struct drbd_device *device);
1148 /* set/clear/test only a few bits at a time */
1149 extern int drbd_bm_set_bits(
1150 struct drbd_device *device, unsigned long s, unsigned long e);
1151 extern int drbd_bm_clear_bits(
1152 struct drbd_device *device, unsigned long s, unsigned long e);
1153 extern int drbd_bm_count_bits(
1154 struct drbd_device *device, const unsigned long s, const unsigned long e);
1155 /* bm_set_bits variant for use while holding drbd_bm_lock,
1156 * may process the whole bitmap in one go */
1157 extern void _drbd_bm_set_bits(struct drbd_device *device,
1158 const unsigned long s, const unsigned long e);
1159 extern int drbd_bm_test_bit(struct drbd_device *device, unsigned long bitnr);
1160 extern int drbd_bm_e_weight(struct drbd_device *device, unsigned long enr);
1161 extern int drbd_bm_write_page(struct drbd_device *device, unsigned int idx) __must_hold(local);
1162 extern int drbd_bm_read(struct drbd_device *device) __must_hold(local);
1163 extern void drbd_bm_mark_for_writeout(struct drbd_device *device, int page_nr);
1164 extern int drbd_bm_write(struct drbd_device *device) __must_hold(local);
1165 extern int drbd_bm_write_hinted(struct drbd_device *device) __must_hold(local);
1166 extern int drbd_bm_write_all(struct drbd_device *device) __must_hold(local);
1167 extern int drbd_bm_write_copy_pages(struct drbd_device *device) __must_hold(local);
1168 extern size_t drbd_bm_words(struct drbd_device *device);
1169 extern unsigned long drbd_bm_bits(struct drbd_device *device);
1170 extern sector_t drbd_bm_capacity(struct drbd_device *device);
1172 #define DRBD_END_OF_BITMAP (~(unsigned long)0)
1173 extern unsigned long drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo);
1174 /* bm_find_next variants for use while you hold drbd_bm_lock() */
1175 extern unsigned long _drbd_bm_find_next(struct drbd_device *device, unsigned long bm_fo);
1176 extern unsigned long _drbd_bm_find_next_zero(struct drbd_device *device, unsigned long bm_fo);
1177 extern unsigned long _drbd_bm_total_weight(struct drbd_device *device);
1178 extern unsigned long drbd_bm_total_weight(struct drbd_device *device);
1179 extern int drbd_bm_rs_done(struct drbd_device *device);
1180 /* for receive_bitmap */
1181 extern void drbd_bm_merge_lel(struct drbd_device *device, size_t offset,
1182 size_t number, unsigned long *buffer);
1183 /* for _drbd_send_bitmap */
1184 extern void drbd_bm_get_lel(struct drbd_device *device, size_t offset,
1185 size_t number, unsigned long *buffer);
1187 extern void drbd_bm_lock(struct drbd_device *device, char *why, enum bm_flag flags);
1188 extern void drbd_bm_unlock(struct drbd_device *device);
1191 extern struct kmem_cache *drbd_request_cache;
1192 extern struct kmem_cache *drbd_ee_cache; /* peer requests */
1193 extern struct kmem_cache *drbd_bm_ext_cache; /* bitmap extents */
1194 extern struct kmem_cache *drbd_al_ext_cache; /* activity log extents */
1195 extern mempool_t *drbd_request_mempool;
1196 extern mempool_t *drbd_ee_mempool;
1198 /* drbd's page pool, used to buffer data received from the peer,
1199 * or data requested by the peer.
1201 * This does not have an emergency reserve.
1203 * When allocating from this pool, it first takes pages from the pool.
1204 * Only if the pool is depleted will try to allocate from the system.
1206 * The assumption is that pages taken from this pool will be processed,
1207 * and given back, "quickly", and then can be recycled, so we can avoid
1208 * frequent calls to alloc_page(), and still will be able to make progress even
1209 * under memory pressure.
1211 extern struct page *drbd_pp_pool;
1212 extern spinlock_t drbd_pp_lock;
1213 extern int drbd_pp_vacant;
1214 extern wait_queue_head_t drbd_pp_wait;
1216 /* We also need a standard (emergency-reserve backed) page pool
1217 * for meta data IO (activity log, bitmap).
1218 * We can keep it global, as long as it is used as "N pages at a time".
1219 * 128 should be plenty, currently we probably can get away with as few as 1.
1221 #define DRBD_MIN_POOL_PAGES 128
1222 extern mempool_t *drbd_md_io_page_pool;
1224 /* We also need to make sure we get a bio
1225 * when we need it for housekeeping purposes */
1226 extern struct bio_set *drbd_md_io_bio_set;
1227 /* to allocate from that set */
1228 extern struct bio *bio_alloc_drbd(gfp_t gfp_mask);
1230 extern rwlock_t global_state_lock;
1232 extern int conn_lowest_minor(struct drbd_connection *connection);
1233 enum drbd_ret_code drbd_create_device(struct drbd_resource *resource, unsigned int minor, int vnr);
1234 extern void drbd_destroy_device(struct kref *kref);
1235 extern void drbd_delete_device(struct drbd_device *mdev);
1237 extern struct drbd_resource *drbd_create_resource(const char *name);
1238 extern void drbd_free_resource(struct drbd_resource *resource);
1240 extern int set_resource_options(struct drbd_resource *resource, struct res_opts *res_opts);
1241 extern struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts);
1242 extern void drbd_destroy_connection(struct kref *kref);
1243 extern struct drbd_connection *conn_get_by_addrs(void *my_addr, int my_addr_len,
1244 void *peer_addr, int peer_addr_len);
1245 extern struct drbd_resource *drbd_find_resource(const char *name);
1246 extern void drbd_destroy_resource(struct kref *kref);
1247 extern void conn_free_crypto(struct drbd_connection *connection);
1249 extern int proc_details;
1252 extern void do_submit(struct work_struct *ws);
1253 extern void __drbd_make_request(struct drbd_device *, struct bio *, unsigned long);
1254 extern void drbd_make_request(struct request_queue *q, struct bio *bio);
1255 extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req);
1256 extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec);
1257 extern int is_valid_ar_handle(struct drbd_request *, sector_t);
1261 extern int drbd_msg_put_info(const char *info);
1262 extern void drbd_suspend_io(struct drbd_device *device);
1263 extern void drbd_resume_io(struct drbd_device *device);
1264 extern char *ppsize(char *buf, unsigned long long size);
1265 extern sector_t drbd_new_dev_size(struct drbd_device *, struct drbd_backing_dev *, sector_t, int);
1266 enum determine_dev_size {
1267 DS_ERROR_SHRINK = -3,
1268 DS_ERROR_SPACE_MD = -2,
1273 DS_GREW_FROM_ZERO = 3,
1275 extern enum determine_dev_size
1276 drbd_determine_dev_size(struct drbd_device *, enum dds_flags, struct resize_parms *) __must_hold(local);
1277 extern void resync_after_online_grow(struct drbd_device *);
1278 extern void drbd_reconsider_max_bio_size(struct drbd_device *device);
1279 extern enum drbd_state_rv drbd_set_role(struct drbd_device *device,
1280 enum drbd_role new_role,
1282 extern bool conn_try_outdate_peer(struct drbd_connection *connection);
1283 extern void conn_try_outdate_peer_async(struct drbd_connection *connection);
1284 extern int drbd_khelper(struct drbd_device *device, char *cmd);
1287 extern int drbd_worker(struct drbd_thread *thi);
1288 enum drbd_ret_code drbd_resync_after_valid(struct drbd_device *device, int o_minor);
1289 void drbd_resync_after_changed(struct drbd_device *device);
1290 extern void drbd_start_resync(struct drbd_device *device, enum drbd_conns side);
1291 extern void resume_next_sg(struct drbd_device *device);
1292 extern void suspend_other_sg(struct drbd_device *device);
1293 extern int drbd_resync_finished(struct drbd_device *device);
1294 /* maybe rather drbd_main.c ? */
1295 extern void *drbd_md_get_buffer(struct drbd_device *device);
1296 extern void drbd_md_put_buffer(struct drbd_device *device);
1297 extern int drbd_md_sync_page_io(struct drbd_device *device,
1298 struct drbd_backing_dev *bdev, sector_t sector, int rw);
1299 extern void drbd_ov_out_of_sync_found(struct drbd_device *, sector_t, int);
1300 extern void wait_until_done_or_force_detached(struct drbd_device *device,
1301 struct drbd_backing_dev *bdev, unsigned int *done);
1302 extern void drbd_rs_controller_reset(struct drbd_device *device);
1304 static inline void ov_out_of_sync_print(struct drbd_device *device)
1306 if (device->ov_last_oos_size) {
1307 drbd_err(device, "Out of sync: start=%llu, size=%lu (sectors)\n",
1308 (unsigned long long)device->ov_last_oos_start,
1309 (unsigned long)device->ov_last_oos_size);
1311 device->ov_last_oos_size = 0;
1315 extern void drbd_csum_bio(struct crypto_hash *, struct bio *, void *);
1316 extern void drbd_csum_ee(struct crypto_hash *, struct drbd_peer_request *, void *);
1317 /* worker callbacks */
1318 extern int w_e_end_data_req(struct drbd_work *, int);
1319 extern int w_e_end_rsdata_req(struct drbd_work *, int);
1320 extern int w_e_end_csum_rs_req(struct drbd_work *, int);
1321 extern int w_e_end_ov_reply(struct drbd_work *, int);
1322 extern int w_e_end_ov_req(struct drbd_work *, int);
1323 extern int w_ov_finished(struct drbd_work *, int);
1324 extern int w_resync_timer(struct drbd_work *, int);
1325 extern int w_send_write_hint(struct drbd_work *, int);
1326 extern int w_make_resync_request(struct drbd_work *, int);
1327 extern int w_send_dblock(struct drbd_work *, int);
1328 extern int w_send_read_req(struct drbd_work *, int);
1329 extern int w_prev_work_done(struct drbd_work *, int);
1330 extern int w_e_reissue(struct drbd_work *, int);
1331 extern int w_restart_disk_io(struct drbd_work *, int);
1332 extern int w_send_out_of_sync(struct drbd_work *, int);
1333 extern int w_start_resync(struct drbd_work *, int);
1335 extern void resync_timer_fn(unsigned long data);
1336 extern void start_resync_timer_fn(unsigned long data);
1338 /* drbd_receiver.c */
1339 extern int drbd_receiver(struct drbd_thread *thi);
1340 extern int drbd_asender(struct drbd_thread *thi);
1341 extern int drbd_rs_should_slow_down(struct drbd_device *device, sector_t sector);
1342 extern int drbd_submit_peer_request(struct drbd_device *,
1343 struct drbd_peer_request *, const unsigned,
1345 extern int drbd_free_peer_reqs(struct drbd_device *, struct list_head *);
1346 extern struct drbd_peer_request *drbd_alloc_peer_req(struct drbd_peer_device *, u64,
1347 sector_t, unsigned int,
1348 gfp_t) __must_hold(local);
1349 extern void __drbd_free_peer_req(struct drbd_device *, struct drbd_peer_request *,
1351 #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0)
1352 #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1)
1353 extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool);
1354 extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled);
1355 extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed);
1356 extern void conn_flush_workqueue(struct drbd_connection *connection);
1357 extern int drbd_connected(struct drbd_peer_device *);
1358 static inline void drbd_flush_workqueue(struct drbd_device *device)
1360 conn_flush_workqueue(first_peer_device(device)->connection);
1363 /* Yes, there is kernel_setsockopt, but only since 2.6.18.
1364 * So we have our own copy of it here. */
1365 static inline int drbd_setsockopt(struct socket *sock, int level, int optname,
1366 char *optval, int optlen)
1368 mm_segment_t oldfs = get_fs();
1369 char __user *uoptval;
1372 uoptval = (char __user __force *)optval;
1375 if (level == SOL_SOCKET)
1376 err = sock_setsockopt(sock, level, optname, uoptval, optlen);
1378 err = sock->ops->setsockopt(sock, level, optname, uoptval,
1384 static inline void drbd_tcp_cork(struct socket *sock)
1387 (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK,
1388 (char*)&val, sizeof(val));
1391 static inline void drbd_tcp_uncork(struct socket *sock)
1394 (void) drbd_setsockopt(sock, SOL_TCP, TCP_CORK,
1395 (char*)&val, sizeof(val));
1398 static inline void drbd_tcp_nodelay(struct socket *sock)
1401 (void) drbd_setsockopt(sock, SOL_TCP, TCP_NODELAY,
1402 (char*)&val, sizeof(val));
1405 static inline void drbd_tcp_quickack(struct socket *sock)
1408 (void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK,
1409 (char*)&val, sizeof(val));
1412 void drbd_bump_write_ordering(struct drbd_connection *connection, enum write_ordering_e wo);
1415 extern struct proc_dir_entry *drbd_proc;
1416 extern const struct file_operations drbd_proc_fops;
1417 extern const char *drbd_conn_str(enum drbd_conns s);
1418 extern const char *drbd_role_str(enum drbd_role s);
1421 extern int drbd_al_begin_io_nonblock(struct drbd_device *device, struct drbd_interval *i);
1422 extern void drbd_al_begin_io_commit(struct drbd_device *device, bool delegate);
1423 extern bool drbd_al_begin_io_fastpath(struct drbd_device *device, struct drbd_interval *i);
1424 extern void drbd_al_begin_io(struct drbd_device *device, struct drbd_interval *i, bool delegate);
1425 extern void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i);
1426 extern void drbd_rs_complete_io(struct drbd_device *device, sector_t sector);
1427 extern int drbd_rs_begin_io(struct drbd_device *device, sector_t sector);
1428 extern int drbd_try_rs_begin_io(struct drbd_device *device, sector_t sector);
1429 extern void drbd_rs_cancel_all(struct drbd_device *device);
1430 extern int drbd_rs_del_all(struct drbd_device *device);
1431 extern void drbd_rs_failed_io(struct drbd_device *device,
1432 sector_t sector, int size);
1433 extern void drbd_advance_rs_marks(struct drbd_device *device, unsigned long still_to_go);
1434 extern void __drbd_set_in_sync(struct drbd_device *device, sector_t sector,
1435 int size, const char *file, const unsigned int line);
1436 #define drbd_set_in_sync(device, sector, size) \
1437 __drbd_set_in_sync(device, sector, size, __FILE__, __LINE__)
1438 extern int __drbd_set_out_of_sync(struct drbd_device *device, sector_t sector,
1439 int size, const char *file, const unsigned int line);
1440 #define drbd_set_out_of_sync(device, sector, size) \
1441 __drbd_set_out_of_sync(device, sector, size, __FILE__, __LINE__)
1442 extern void drbd_al_shrink(struct drbd_device *device);
1443 extern int drbd_initialize_al(struct drbd_device *, void *);
1446 /* state info broadcast */
1448 enum drbd_state_info_bcast_reason sib_reason;
1452 unsigned helper_exit_code;
1455 union drbd_state os;
1456 union drbd_state ns;
1460 void drbd_bcast_event(struct drbd_device *device, const struct sib_info *sib);
1463 * inline helper functions
1464 *************************/
1466 /* see also page_chain_add and friends in drbd_receiver.c */
1467 static inline struct page *page_chain_next(struct page *page)
1469 return (struct page *)page_private(page);
1471 #define page_chain_for_each(page) \
1472 for (; page && ({ prefetch(page_chain_next(page)); 1; }); \
1473 page = page_chain_next(page))
1474 #define page_chain_for_each_safe(page, n) \
1475 for (; page && ({ n = page_chain_next(page); 1; }); page = n)
1478 static inline int drbd_peer_req_has_active_page(struct drbd_peer_request *peer_req)
1480 struct page *page = peer_req->pages;
1481 page_chain_for_each(page) {
1482 if (page_count(page) > 1)
1488 static inline enum drbd_state_rv
1489 _drbd_set_state(struct drbd_device *device, union drbd_state ns,
1490 enum chg_state_flags flags, struct completion *done)
1492 enum drbd_state_rv rv;
1494 read_lock(&global_state_lock);
1495 rv = __drbd_set_state(device, ns, flags, done);
1496 read_unlock(&global_state_lock);
1501 static inline union drbd_state drbd_read_state(struct drbd_device *device)
1503 struct drbd_resource *resource = device->resource;
1504 union drbd_state rv;
1506 rv.i = device->state.i;
1507 rv.susp = resource->susp;
1508 rv.susp_nod = resource->susp_nod;
1509 rv.susp_fen = resource->susp_fen;
1514 enum drbd_force_detach_flags {
1521 #define __drbd_chk_io_error(m,f) __drbd_chk_io_error_(m,f, __func__)
1522 static inline void __drbd_chk_io_error_(struct drbd_device *device,
1523 enum drbd_force_detach_flags df,
1526 enum drbd_io_error_p ep;
1529 ep = rcu_dereference(device->ldev->disk_conf)->on_io_error;
1532 case EP_PASS_ON: /* FIXME would this be better named "Ignore"? */
1533 if (df == DRBD_READ_ERROR || df == DRBD_WRITE_ERROR) {
1534 if (__ratelimit(&drbd_ratelimit_state))
1535 drbd_err(device, "Local IO failed in %s.\n", where);
1536 if (device->state.disk > D_INCONSISTENT)
1537 _drbd_set_state(_NS(device, disk, D_INCONSISTENT), CS_HARD, NULL);
1540 /* NOTE fall through for DRBD_META_IO_ERROR or DRBD_FORCE_DETACH */
1542 case EP_CALL_HELPER:
1543 /* Remember whether we saw a READ or WRITE error.
1545 * Recovery of the affected area for WRITE failure is covered
1546 * by the activity log.
1547 * READ errors may fall outside that area though. Certain READ
1548 * errors can be "healed" by writing good data to the affected
1549 * blocks, which triggers block re-allocation in lower layers.
1551 * If we can not write the bitmap after a READ error,
1552 * we may need to trigger a full sync (see w_go_diskless()).
1554 * Force-detach is not really an IO error, but rather a
1555 * desperate measure to try to deal with a completely
1556 * unresponsive lower level IO stack.
1557 * Still it should be treated as a WRITE error.
1559 * Meta IO error is always WRITE error:
1560 * we read meta data only once during attach,
1561 * which will fail in case of errors.
1563 set_bit(WAS_IO_ERROR, &device->flags);
1564 if (df == DRBD_READ_ERROR)
1565 set_bit(WAS_READ_ERROR, &device->flags);
1566 if (df == DRBD_FORCE_DETACH)
1567 set_bit(FORCE_DETACH, &device->flags);
1568 if (device->state.disk > D_FAILED) {
1569 _drbd_set_state(_NS(device, disk, D_FAILED), CS_HARD, NULL);
1571 "Local IO failed in %s. Detaching...\n", where);
1578 * drbd_chk_io_error: Handle the on_io_error setting, should be called from all io completion handlers
1579 * @device: DRBD device.
1580 * @error: Error code passed to the IO completion callback
1581 * @forcedetach: Force detach. I.e. the error happened while accessing the meta data
1583 * See also drbd_main.c:after_state_ch() if (os.disk > D_FAILED && ns.disk == D_FAILED)
1585 #define drbd_chk_io_error(m,e,f) drbd_chk_io_error_(m,e,f, __func__)
1586 static inline void drbd_chk_io_error_(struct drbd_device *device,
1587 int error, enum drbd_force_detach_flags forcedetach, const char *where)
1590 unsigned long flags;
1591 spin_lock_irqsave(&device->resource->req_lock, flags);
1592 __drbd_chk_io_error_(device, forcedetach, where);
1593 spin_unlock_irqrestore(&device->resource->req_lock, flags);
1599 * drbd_md_first_sector() - Returns the first sector number of the meta data area
1600 * @bdev: Meta data block device.
1602 * BTW, for internal meta data, this happens to be the maximum capacity
1603 * we could agree upon with our peer node.
1605 static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev)
1607 switch (bdev->md.meta_dev_idx) {
1608 case DRBD_MD_INDEX_INTERNAL:
1609 case DRBD_MD_INDEX_FLEX_INT:
1610 return bdev->md.md_offset + bdev->md.bm_offset;
1611 case DRBD_MD_INDEX_FLEX_EXT:
1613 return bdev->md.md_offset;
1618 * drbd_md_last_sector() - Return the last sector number of the meta data area
1619 * @bdev: Meta data block device.
1621 static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
1623 switch (bdev->md.meta_dev_idx) {
1624 case DRBD_MD_INDEX_INTERNAL:
1625 case DRBD_MD_INDEX_FLEX_INT:
1626 return bdev->md.md_offset + MD_4kB_SECT -1;
1627 case DRBD_MD_INDEX_FLEX_EXT:
1629 return bdev->md.md_offset + bdev->md.md_size_sect -1;
1633 /* Returns the number of 512 byte sectors of the device */
1634 static inline sector_t drbd_get_capacity(struct block_device *bdev)
1636 /* return bdev ? get_capacity(bdev->bd_disk) : 0; */
1637 return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0;
1641 * drbd_get_max_capacity() - Returns the capacity we announce to out peer
1642 * @bdev: Meta data block device.
1644 * returns the capacity we announce to out peer. we clip ourselves at the
1645 * various MAX_SECTORS, because if we don't, current implementation will
1646 * oops sooner or later
1648 static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev)
1652 switch (bdev->md.meta_dev_idx) {
1653 case DRBD_MD_INDEX_INTERNAL:
1654 case DRBD_MD_INDEX_FLEX_INT:
1655 s = drbd_get_capacity(bdev->backing_bdev)
1656 ? min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
1657 drbd_md_first_sector(bdev))
1660 case DRBD_MD_INDEX_FLEX_EXT:
1661 s = min_t(sector_t, DRBD_MAX_SECTORS_FLEX,
1662 drbd_get_capacity(bdev->backing_bdev));
1663 /* clip at maximum size the meta device can support */
1664 s = min_t(sector_t, s,
1665 BM_EXT_TO_SECT(bdev->md.md_size_sect
1666 - bdev->md.bm_offset));
1669 s = min_t(sector_t, DRBD_MAX_SECTORS,
1670 drbd_get_capacity(bdev->backing_bdev));
1676 * drbd_md_ss() - Return the sector number of our meta data super block
1677 * @bdev: Meta data block device.
1679 static inline sector_t drbd_md_ss(struct drbd_backing_dev *bdev)
1681 const int meta_dev_idx = bdev->md.meta_dev_idx;
1683 if (meta_dev_idx == DRBD_MD_INDEX_FLEX_EXT)
1686 /* Since drbd08, internal meta data is always "flexible".
1687 * position: last 4k aligned block of 4k size */
1688 if (meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
1689 meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)
1690 return (drbd_get_capacity(bdev->backing_bdev) & ~7ULL) - 8;
1692 /* external, some index; this is the old fixed size layout */
1693 return MD_128MB_SECT * bdev->md.meta_dev_idx;
1697 drbd_queue_work_front(struct drbd_work_queue *q, struct drbd_work *w)
1699 unsigned long flags;
1700 spin_lock_irqsave(&q->q_lock, flags);
1701 list_add(&w->list, &q->q);
1702 spin_unlock_irqrestore(&q->q_lock, flags);
1703 wake_up(&q->q_wait);
1707 drbd_queue_work(struct drbd_work_queue *q, struct drbd_work *w)
1709 unsigned long flags;
1710 spin_lock_irqsave(&q->q_lock, flags);
1711 list_add_tail(&w->list, &q->q);
1712 spin_unlock_irqrestore(&q->q_lock, flags);
1713 wake_up(&q->q_wait);
1716 static inline void wake_asender(struct drbd_connection *connection)
1718 if (test_bit(SIGNAL_ASENDER, &connection->flags))
1719 force_sig(DRBD_SIG, connection->asender.task);
1722 static inline void request_ping(struct drbd_connection *connection)
1724 set_bit(SEND_PING, &connection->flags);
1725 wake_asender(connection);
1728 extern void *conn_prepare_command(struct drbd_connection *, struct drbd_socket *);
1729 extern void *drbd_prepare_command(struct drbd_peer_device *, struct drbd_socket *);
1730 extern int conn_send_command(struct drbd_connection *, struct drbd_socket *,
1731 enum drbd_packet, unsigned int, void *,
1733 extern int drbd_send_command(struct drbd_peer_device *, struct drbd_socket *,
1734 enum drbd_packet, unsigned int, void *,
1737 extern int drbd_send_ping(struct drbd_connection *connection);
1738 extern int drbd_send_ping_ack(struct drbd_connection *connection);
1739 extern int drbd_send_state_req(struct drbd_peer_device *, union drbd_state, union drbd_state);
1740 extern int conn_send_state_req(struct drbd_connection *, union drbd_state, union drbd_state);
1742 static inline void drbd_thread_stop(struct drbd_thread *thi)
1744 _drbd_thread_stop(thi, false, true);
1747 static inline void drbd_thread_stop_nowait(struct drbd_thread *thi)
1749 _drbd_thread_stop(thi, false, false);
1752 static inline void drbd_thread_restart_nowait(struct drbd_thread *thi)
1754 _drbd_thread_stop(thi, true, false);
1757 /* counts how many answer packets packets we expect from our peer,
1758 * for either explicit application requests,
1759 * or implicit barrier packets as necessary.
1762 * _req_mod(req, QUEUE_FOR_NET_WRITE or QUEUE_FOR_NET_READ);
1763 * it is much easier and equally valid to count what we queue for the
1764 * worker, even before it actually was queued or send.
1765 * (drbd_make_request_common; recovery path on read io-error)
1767 * got_BarrierAck (respective tl_clear, tl_clear_barrier)
1768 * _req_mod(req, DATA_RECEIVED)
1769 * [from receive_DataReply]
1770 * _req_mod(req, WRITE_ACKED_BY_PEER or RECV_ACKED_BY_PEER or NEG_ACKED)
1771 * [from got_BlockAck (P_WRITE_ACK, P_RECV_ACK)]
1772 * for some reason it is NOT decreased in got_NegAck,
1773 * but in the resulting cleanup code from report_params.
1774 * we should try to remember the reason for that...
1775 * _req_mod(req, SEND_FAILED or SEND_CANCELED)
1776 * _req_mod(req, CONNECTION_LOST_WHILE_PENDING)
1777 * [from tl_clear_barrier]
1779 static inline void inc_ap_pending(struct drbd_device *device)
1781 atomic_inc(&device->ap_pending_cnt);
1784 #define ERR_IF_CNT_IS_NEGATIVE(which, func, line) \
1785 if (atomic_read(&device->which) < 0) \
1786 drbd_err(device, "in %s:%d: " #which " = %d < 0 !\n", \
1788 atomic_read(&device->which))
1790 #define dec_ap_pending(device) _dec_ap_pending(device, __FUNCTION__, __LINE__)
1791 static inline void _dec_ap_pending(struct drbd_device *device, const char *func, int line)
1793 if (atomic_dec_and_test(&device->ap_pending_cnt))
1794 wake_up(&device->misc_wait);
1795 ERR_IF_CNT_IS_NEGATIVE(ap_pending_cnt, func, line);
1798 /* counts how many resync-related answers we still expect from the peer
1800 * C_SYNC_TARGET sends P_RS_DATA_REQUEST (and expects P_RS_DATA_REPLY)
1801 * C_SYNC_SOURCE sends P_RS_DATA_REPLY (and expects P_WRITE_ACK with ID_SYNCER)
1802 * (or P_NEG_ACK with ID_SYNCER)
1804 static inline void inc_rs_pending(struct drbd_device *device)
1806 atomic_inc(&device->rs_pending_cnt);
1809 #define dec_rs_pending(device) _dec_rs_pending(device, __FUNCTION__, __LINE__)
1810 static inline void _dec_rs_pending(struct drbd_device *device, const char *func, int line)
1812 atomic_dec(&device->rs_pending_cnt);
1813 ERR_IF_CNT_IS_NEGATIVE(rs_pending_cnt, func, line);
1816 /* counts how many answers we still need to send to the peer.
1818 * receive_Data unless protocol A;
1819 * we need to send a P_RECV_ACK (proto B)
1820 * or P_WRITE_ACK (proto C)
1821 * receive_RSDataReply (recv_resync_read) we need to send a P_WRITE_ACK
1822 * receive_DataRequest (receive_RSDataRequest) we need to send back P_DATA
1823 * receive_Barrier_* we need to send a P_BARRIER_ACK
1825 static inline void inc_unacked(struct drbd_device *device)
1827 atomic_inc(&device->unacked_cnt);
1830 #define dec_unacked(device) _dec_unacked(device, __FUNCTION__, __LINE__)
1831 static inline void _dec_unacked(struct drbd_device *device, const char *func, int line)
1833 atomic_dec(&device->unacked_cnt);
1834 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
1837 #define sub_unacked(device, n) _sub_unacked(device, n, __FUNCTION__, __LINE__)
1838 static inline void _sub_unacked(struct drbd_device *device, int n, const char *func, int line)
1840 atomic_sub(n, &device->unacked_cnt);
1841 ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line);
1845 * get_ldev() - Increase the ref count on device->ldev. Returns 0 if there is no ldev
1848 * You have to call put_ldev() when finished working with device->ldev.
1850 #define get_ldev(M) __cond_lock(local, _get_ldev_if_state(M,D_INCONSISTENT))
1851 #define get_ldev_if_state(M,MINS) __cond_lock(local, _get_ldev_if_state(M,MINS))
1853 static inline void put_ldev(struct drbd_device *device)
1855 int i = atomic_dec_return(&device->local_cnt);
1857 /* This may be called from some endio handler,
1858 * so we must not sleep here. */
1861 D_ASSERT(device, i >= 0);
1863 if (device->state.disk == D_DISKLESS)
1864 /* even internal references gone, safe to destroy */
1865 drbd_ldev_destroy(device);
1866 if (device->state.disk == D_FAILED) {
1867 /* all application IO references gone. */
1868 if (!test_and_set_bit(GO_DISKLESS, &device->flags))
1869 drbd_queue_work(&first_peer_device(device)->connection->sender_work, &device->go_diskless);
1871 wake_up(&device->misc_wait);
1876 static inline int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins)
1880 /* never get a reference while D_DISKLESS */
1881 if (device->state.disk == D_DISKLESS)
1884 atomic_inc(&device->local_cnt);
1885 io_allowed = (device->state.disk >= mins);
1891 extern int _get_ldev_if_state(struct drbd_device *device, enum drbd_disk_state mins);
1894 /* you must have an "get_ldev" reference */
1895 static inline void drbd_get_syncer_progress(struct drbd_device *device,
1896 unsigned long *bits_left, unsigned int *per_mil_done)
1898 /* this is to break it at compile time when we change that, in case we
1899 * want to support more than (1<<32) bits on a 32bit arch. */
1900 typecheck(unsigned long, device->rs_total);
1902 /* note: both rs_total and rs_left are in bits, i.e. in
1903 * units of BM_BLOCK_SIZE.
1904 * for the percentage, we don't care. */
1906 if (device->state.conn == C_VERIFY_S || device->state.conn == C_VERIFY_T)
1907 *bits_left = device->ov_left;
1909 *bits_left = drbd_bm_total_weight(device) - device->rs_failed;
1910 /* >> 10 to prevent overflow,
1911 * +1 to prevent division by zero */
1912 if (*bits_left > device->rs_total) {
1913 /* doh. maybe a logic bug somewhere.
1914 * may also be just a race condition
1915 * between this and a disconnect during sync.
1916 * for now, just prevent in-kernel buffer overflow.
1919 drbd_warn(device, "cs:%s rs_left=%lu > rs_total=%lu (rs_failed %lu)\n",
1920 drbd_conn_str(device->state.conn),
1921 *bits_left, device->rs_total, device->rs_failed);
1924 /* Make sure the division happens in long context.
1925 * We allow up to one petabyte storage right now,
1926 * at a granularity of 4k per bit that is 2**38 bits.
1927 * After shift right and multiplication by 1000,
1928 * this should still fit easily into a 32bit long,
1929 * so we don't need a 64bit division on 32bit arch.
1930 * Note: currently we don't support such large bitmaps on 32bit
1931 * arch anyways, but no harm done to be prepared for it here.
1933 unsigned int shift = device->rs_total > UINT_MAX ? 16 : 10;
1934 unsigned long left = *bits_left >> shift;
1935 unsigned long total = 1UL + (device->rs_total >> shift);
1936 unsigned long tmp = 1000UL - left * 1000UL/total;
1937 *per_mil_done = tmp;
1942 /* this throttles on-the-fly application requests
1943 * according to max_buffers settings;
1944 * maybe re-implement using semaphores? */
1945 static inline int drbd_get_max_buffers(struct drbd_device *device)
1947 struct net_conf *nc;
1951 nc = rcu_dereference(first_peer_device(device)->connection->net_conf);
1952 mxb = nc ? nc->max_buffers : 1000000; /* arbitrary limit on open requests */
1958 static inline int drbd_state_is_stable(struct drbd_device *device)
1960 union drbd_dev_state s = device->state;
1962 /* DO NOT add a default clause, we want the compiler to warn us
1963 * for any newly introduced state we may have forgotten to add here */
1965 switch ((enum drbd_conns)s.conn) {
1966 /* new io only accepted when there is no connection, ... */
1968 case C_WF_CONNECTION:
1969 /* ... or there is a well established connection. */
1975 case C_PAUSED_SYNC_S:
1976 case C_PAUSED_SYNC_T:
1979 /* transitional states, IO allowed */
1980 case C_DISCONNECTING:
1984 case C_NETWORK_FAILURE:
1985 case C_PROTOCOL_ERROR:
1987 case C_WF_REPORT_PARAMS:
1988 case C_STARTING_SYNC_S:
1989 case C_STARTING_SYNC_T:
1992 /* Allow IO in BM exchange states with new protocols */
1994 if (first_peer_device(device)->connection->agreed_pro_version < 96)
1998 /* no new io accepted in these states */
2000 case C_WF_SYNC_UUID:
2006 switch ((enum drbd_disk_state)s.disk) {
2008 case D_INCONSISTENT:
2013 /* disk state is stable as well. */
2016 /* no new io accepted during transitional states */
2028 static inline int drbd_suspended(struct drbd_device *device)
2030 struct drbd_resource *resource = device->resource;
2032 return resource->susp || resource->susp_fen || resource->susp_nod;
2035 static inline bool may_inc_ap_bio(struct drbd_device *device)
2037 int mxb = drbd_get_max_buffers(device);
2039 if (drbd_suspended(device))
2041 if (test_bit(SUSPEND_IO, &device->flags))
2044 /* to avoid potential deadlock or bitmap corruption,
2045 * in various places, we only allow new application io
2046 * to start during "stable" states. */
2048 /* no new io accepted when attaching or detaching the disk */
2049 if (!drbd_state_is_stable(device))
2052 /* since some older kernels don't have atomic_add_unless,
2053 * and we are within the spinlock anyways, we have this workaround. */
2054 if (atomic_read(&device->ap_bio_cnt) > mxb)
2056 if (test_bit(BITMAP_IO, &device->flags))
2061 static inline bool inc_ap_bio_cond(struct drbd_device *device)
2065 spin_lock_irq(&device->resource->req_lock);
2066 rv = may_inc_ap_bio(device);
2068 atomic_inc(&device->ap_bio_cnt);
2069 spin_unlock_irq(&device->resource->req_lock);
2074 static inline void inc_ap_bio(struct drbd_device *device)
2077 * as long as the device is suspended
2078 * until the bitmap is no longer on the fly during connection
2079 * handshake as long as we would exceed the max_buffer limit.
2081 * to avoid races with the reconnect code,
2082 * we need to atomic_inc within the spinlock. */
2084 wait_event(device->misc_wait, inc_ap_bio_cond(device));
2087 static inline void dec_ap_bio(struct drbd_device *device)
2089 int mxb = drbd_get_max_buffers(device);
2090 int ap_bio = atomic_dec_return(&device->ap_bio_cnt);
2092 D_ASSERT(device, ap_bio >= 0);
2094 if (ap_bio == 0 && test_bit(BITMAP_IO, &device->flags)) {
2095 if (!test_and_set_bit(BITMAP_IO_QUEUED, &device->flags))
2096 drbd_queue_work(&first_peer_device(device)->connection->sender_work, &device->bm_io_work.w);
2099 /* this currently does wake_up for every dec_ap_bio!
2100 * maybe rather introduce some type of hysteresis?
2101 * e.g. (ap_bio == mxb/2 || ap_bio == 0) ? */
2103 wake_up(&device->misc_wait);
2106 static inline bool verify_can_do_stop_sector(struct drbd_device *device)
2108 return first_peer_device(device)->connection->agreed_pro_version >= 97 &&
2109 first_peer_device(device)->connection->agreed_pro_version != 100;
2112 static inline int drbd_set_ed_uuid(struct drbd_device *device, u64 val)
2114 int changed = device->ed_uuid != val;
2115 device->ed_uuid = val;
2119 static inline int drbd_queue_order_type(struct drbd_device *device)
2121 /* sorry, we currently have no working implementation
2122 * of distributed TCQ stuff */
2123 #ifndef QUEUE_ORDERED_NONE
2124 #define QUEUE_ORDERED_NONE 0
2126 return QUEUE_ORDERED_NONE;
2129 static inline void drbd_md_flush(struct drbd_device *device)
2133 if (device->ldev == NULL) {
2134 drbd_warn(device, "device->ldev == NULL in drbd_md_flush\n");
2138 if (test_bit(MD_NO_FUA, &device->flags))
2141 r = blkdev_issue_flush(device->ldev->md_bdev, GFP_NOIO, NULL);
2143 set_bit(MD_NO_FUA, &device->flags);
2144 drbd_err(device, "meta data flush failed with status %d, disabling md-flushes\n", r);
2148 static inline struct drbd_connection *first_connection(struct drbd_resource *resource)
2150 return list_first_entry(&resource->connections,
2151 struct drbd_connection, connections);