[deliverable/linux.git] / drivers / block / drbd / drbd_req.h

/*
   drbd_req.h

   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.

   Copyright (C) 2006-2008, LINBIT Information Technologies GmbH.
   Copyright (C) 2006-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
   Copyright (C) 2006-2008, Philipp Reisner <philipp.reisner@linbit.com>.

   DRBD is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   DRBD is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with drbd; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef _DRBD_REQ_H
#define _DRBD_REQ_H

#include <linux/module.h>

#include <linux/slab.h>
#include <linux/drbd.h>
#include "drbd_int.h"
#include "drbd_wrappers.h"

/* The request callbacks will be called in irq context by the IDE drivers,
   and in Softirqs/Tasklets/BH context by the SCSI drivers,
   and by the receiver and worker in kernel-thread context.
   Try to get the locking right :) */

/*
 * Objects of type struct drbd_request do only exist on a R_PRIMARY node, and are
 * associated with IO requests originating from the block layer above us.
 *
 * There are quite a few things that may happen to a drbd request
 * during its lifetime.
 *
 *  It will be created.
 *  It will be marked with the intention to be
 *    submitted to local disk and/or
 *    send via the network.
 *
 *  It has to be placed on the transfer log and other housekeeping lists,
 *  In case we have a network connection.
 *
 *  It may be identified as a concurrent (write) request
 *    and be handled accordingly.
 *
 *  It may me handed over to the local disk subsystem.
 *  It may be completed by the local disk subsystem,
 *    either successfully or with io-error.
 *  In case it is a READ request, and it failed locally,
 *    it may be retried remotely.
 *
 *  It may be queued for sending.
 *  It may be handed over to the network stack,
 *    which may fail.
 *  It may be acknowledged by the "peer" according to the wire_protocol in use.
 *    this may be a negative ack.
 *  It may receive a faked ack when the network connection is lost and the
 *  transfer log is cleaned up.
 *  Sending may be canceled due to network connection loss.
 *  When it finally has outlived its time,
 *    corresponding dirty bits in the resync-bitmap may be cleared or set,
 *    it will be destroyed,
 *    and completion will be signalled to the originator,
 *      with or without "success".
 */

enum drbd_req_event {
	CREATED,
	TO_BE_SENT,
	TO_BE_SUBMITTED,

	/* XXX yes, now I am inconsistent...
	 * these are not "events" but "actions"
	 * oh, well... */
	QUEUE_FOR_NET_WRITE,
	QUEUE_FOR_NET_READ,
	QUEUE_FOR_SEND_OOS,

	/* An empty flush is queued as P_BARRIER,
	 * which will cause it to complete "successfully",
	 * even if the local disk flush failed.
	 *
	 * Just like "real" requests, empty flushes (blkdev_issue_flush()) will
	 * only see an error if neither local nor remote data is reachable. */
	QUEUE_AS_DRBD_BARRIER,

	SEND_CANCELED,
	SEND_FAILED,
	HANDED_OVER_TO_NETWORK,
	OOS_HANDED_TO_NETWORK,
	CONNECTION_LOST_WHILE_PENDING,
	READ_RETRY_REMOTE_CANCELED,
	RECV_ACKED_BY_PEER,
	WRITE_ACKED_BY_PEER,
	WRITE_ACKED_BY_PEER_AND_SIS, /* and set_in_sync */
	CONFLICT_RESOLVED,
	POSTPONE_WRITE,
	NEG_ACKED,
	BARRIER_ACKED, /* in protocol A and B */
	DATA_RECEIVED, /* (remote read) */

	READ_COMPLETED_WITH_ERROR,
	READ_AHEAD_COMPLETED_WITH_ERROR,
	WRITE_COMPLETED_WITH_ERROR,
	ABORT_DISK_IO,
	COMPLETED_OK,
	RESEND,
	FAIL_FROZEN_DISK_IO,
	RESTART_FROZEN_DISK_IO,
	NOTHING,
};

/* encoding of request states for now.  we don't actually need that many bits.
 * we don't need to do atomic bit operations either, since most of the time we
 * need to look at the connection state and/or manipulate some lists at the
 * same time, so we should hold the request lock anyways.
 */
enum drbd_req_state_bits {
	/* 3210
	 * 0000: no local possible
	 * 0001: to be submitted
	 *    UNUSED, we could map: 011: submitted, completion still pending
	 * 0110: completed ok
	 * 0010: completed with error
	 * 1001: Aborted (before completion)
	 * 1x10: Aborted and completed -> free
	 */
	__RQ_LOCAL_PENDING,
	__RQ_LOCAL_COMPLETED,
	__RQ_LOCAL_OK,
	__RQ_LOCAL_ABORTED,

	/* 87654
	 * 00000: no network possible
	 * 00001: to be send
	 * 00011: to be send, on worker queue
	 * 00101: sent, expecting recv_ack (B) or write_ack (C)
	 * 11101: sent,
	 *        recv_ack (B) or implicit "ack" (A),
	 *        still waiting for the barrier ack.
	 *        master_bio may already be completed and invalidated.
	 * 11100: write acked (C),
	 *        data received (for remote read, any protocol)
	 *        or finally the barrier ack has arrived (B,A)...
	 *        request can be freed
	 * 01100: neg-acked (write, protocol C)
	 *        or neg-d-acked (read, any protocol)
	 *        or killed from the transfer log
	 *        during cleanup after connection loss
	 *        request can be freed
	 * 01000: canceled or send failed...
	 *        request can be freed
	 */

	/* if "SENT" is not set, yet, this can still fail or be canceled.
	 * if "SENT" is set already, we still wait for an Ack packet.
	 * when cleared, the master_bio may be completed.
	 * in (B,A) the request object may still linger on the transaction log
	 * until the corresponding barrier ack comes in */
	__RQ_NET_PENDING,

	/* If it is QUEUED, and it is a WRITE, it is also registered in the
	 * transfer log. Currently we need this flag to avoid conflicts between
	 * worker canceling the request and tl_clear_barrier killing it from
	 * transfer log.  We should restructure the code so this conflict does
	 * no longer occur. */
	__RQ_NET_QUEUED,

	/* well, actually only "handed over to the network stack".
	 *
	 * TODO can potentially be dropped because of the similar meaning
	 * of RQ_NET_SENT and ~RQ_NET_QUEUED.
	 * however it is not exactly the same. before we drop it
	 * we must ensure that we can tell a request with network part
	 * from a request without, regardless of what happens to it. */
	__RQ_NET_SENT,

	/* when set, the request may be freed (if RQ_NET_QUEUED is clear).
	 * basically this means the corresponding P_BARRIER_ACK was received */
	__RQ_NET_DONE,

	/* whether or not we know (C) or pretend (B,A) that the write
	 * was successfully written on the peer.
	 */
	__RQ_NET_OK,

	/* peer called drbd_set_in_sync() for this write */
	__RQ_NET_SIS,

	/* keep this last, its for the RQ_NET_MASK */
	__RQ_NET_MAX,

	/* Set when this is a write, clear for a read */
	__RQ_WRITE,

	/* Should call drbd_al_complete_io() for this request... */
	__RQ_IN_ACT_LOG,

	/* The peer has sent a retry ACK */
	__RQ_POSTPONED,

	/* would have been completed,
	 * but was not, because of drbd_suspended() */
	__RQ_COMPLETION_SUSP,

	/* We expect a receive ACK (wire proto B) */
	__RQ_EXP_RECEIVE_ACK,

	/* We expect a write ACK (wite proto C) */
	__RQ_EXP_WRITE_ACK,

	/* waiting for a barrier ack, did an extra kref_get */
	__RQ_EXP_BARR_ACK,
};

#define RQ_LOCAL_PENDING   (1UL << __RQ_LOCAL_PENDING)
#define RQ_LOCAL_COMPLETED (1UL << __RQ_LOCAL_COMPLETED)
#define RQ_LOCAL_OK        (1UL << __RQ_LOCAL_OK)
#define RQ_LOCAL_ABORTED   (1UL << __RQ_LOCAL_ABORTED)

#define RQ_LOCAL_MASK      ((RQ_LOCAL_ABORTED << 1)-1)

#define RQ_NET_PENDING     (1UL << __RQ_NET_PENDING)
#define RQ_NET_QUEUED      (1UL << __RQ_NET_QUEUED)
#define RQ_NET_SENT        (1UL << __RQ_NET_SENT)
#define RQ_NET_DONE        (1UL << __RQ_NET_DONE)
#define RQ_NET_OK          (1UL << __RQ_NET_OK)
#define RQ_NET_SIS         (1UL << __RQ_NET_SIS)

/* 0x1f8 */
#define RQ_NET_MASK        (((1UL << __RQ_NET_MAX)-1) & ~RQ_LOCAL_MASK)

#define RQ_WRITE           (1UL << __RQ_WRITE)
#define RQ_IN_ACT_LOG      (1UL << __RQ_IN_ACT_LOG)
#define RQ_POSTPONED	   (1UL << __RQ_POSTPONED)
#define RQ_COMPLETION_SUSP (1UL << __RQ_COMPLETION_SUSP)
#define RQ_EXP_RECEIVE_ACK (1UL << __RQ_EXP_RECEIVE_ACK)
#define RQ_EXP_WRITE_ACK   (1UL << __RQ_EXP_WRITE_ACK)
#define RQ_EXP_BARR_ACK    (1UL << __RQ_EXP_BARR_ACK)

/* For waking up the frozen transfer log mod_req() has to return if the request
   should be counted in the epoch object*/
#define MR_WRITE       1
#define MR_READ        2

static inline void drbd_req_make_private_bio(struct drbd_request *req, struct bio *bio_src)
{
	struct bio *bio;
	bio = bio_clone(bio_src, GFP_NOIO); /* XXX cannot fail?? */

	req->private_bio = bio;

	bio->bi_private  = req;
	bio->bi_end_io   = drbd_request_endio;
	bio->bi_next     = NULL;
}

/* Short lived temporary struct on the stack.
 * We could squirrel the error to be returned into
 * bio->bi_iter.bi_size, or similar. But that would be too ugly. */
struct bio_and_error {
	struct bio *bio;
	int error;
};

extern void start_new_tl_epoch(struct drbd_connection *connection);
extern void drbd_req_destroy(struct kref *kref);
extern void _req_may_be_done(struct drbd_request *req,
		struct bio_and_error *m);
extern int __req_mod(struct drbd_request *req, enum drbd_req_event what,
		struct bio_and_error *m);
extern void complete_master_bio(struct drbd_device *device,
		struct bio_and_error *m);
extern void request_timer_fn(unsigned long data);
extern void tl_restart(struct drbd_connection *connection, enum drbd_req_event what);
extern void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what);

/* this is in drbd_main.c */
extern void drbd_restart_request(struct drbd_request *req);

/* use this if you don't want to deal with calling complete_master_bio()
 * outside the spinlock, e.g. when walking some list on cleanup. */
static inline int _req_mod(struct drbd_request *req, enum drbd_req_event what)
{
	struct drbd_device *device = req->device;
	struct bio_and_error m;
	int rv;

	/* __req_mod possibly frees req, do not touch req after that! */
	rv = __req_mod(req, what, &m);
	if (m.bio)
		complete_master_bio(device, &m);

	return rv;
}

/* completion of master bio is outside of our spinlock.
 * We still may or may not be inside some irqs disabled section
 * of the lower level driver completion callback, so we need to
 * spin_lock_irqsave here. */
static inline int req_mod(struct drbd_request *req,
		enum drbd_req_event what)
{
	unsigned long flags;
	struct drbd_device *device = req->device;
	struct bio_and_error m;
	int rv;

	spin_lock_irqsave(&device->resource->req_lock, flags);
	rv = __req_mod(req, what, &m);
	spin_unlock_irqrestore(&device->resource->req_lock, flags);

	if (m.bio)
		complete_master_bio(device, &m);

	return rv;
}

static inline bool drbd_should_do_remote(union drbd_dev_state s)
{
	return s.pdsk == D_UP_TO_DATE ||
		(s.pdsk >= D_INCONSISTENT &&
		 s.conn >= C_WF_BITMAP_T &&
		 s.conn < C_AHEAD);
	/* Before proto 96 that was >= CONNECTED instead of >= C_WF_BITMAP_T.
	   That is equivalent since before 96 IO was frozen in the C_WF_BITMAP*
	   states. */
}
static inline bool drbd_should_send_out_of_sync(union drbd_dev_state s)
{
	return s.conn == C_AHEAD || s.conn == C_WF_BITMAP_S;
	/* pdsk = D_INCONSISTENT as a consequence. Protocol 96 check not necessary
	   since we enter state C_AHEAD only if proto >= 96 */
}

#endif
Commit	Line	Data
b411b363 PR	1	/*
	2	drbd_req.h
	3
	4	This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
	5
	6	Copyright (C) 2006-2008, LINBIT Information Technologies GmbH.
	7	Copyright (C) 2006-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
	8	Copyright (C) 2006-2008, Philipp Reisner <philipp.reisner@linbit.com>.
	9
	10	DRBD is free software; you can redistribute it and/or modify
	11	it under the terms of the GNU General Public License as published by
	12	the Free Software Foundation; either version 2, or (at your option)
	13	any later version.
	14
	15	DRBD is distributed in the hope that it will be useful,
	16	but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	GNU General Public License for more details.
	19
	20	You should have received a copy of the GNU General Public License
	21	along with drbd; see the file COPYING. If not, write to
	22	the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
	23	*/
	24
	25	#ifndef _DRBD_REQ_H
	26	#define _DRBD_REQ_H
	27
b411b363 PR	28	#include <linux/module.h>
	29
	30	#include <linux/slab.h>
	31	#include <linux/drbd.h>
	32	#include "drbd_int.h"
	33	#include "drbd_wrappers.h"
	34
	35	/* The request callbacks will be called in irq context by the IDE drivers,
	36	and in Softirqs/Tasklets/BH context by the SCSI drivers,
	37	and by the receiver and worker in kernel-thread context.
	38	Try to get the locking right :) */
	39
	40	/*
	41	* Objects of type struct drbd_request do only exist on a R_PRIMARY node, and are
	42	* associated with IO requests originating from the block layer above us.
	43	*
	44	* There are quite a few things that may happen to a drbd request
	45	* during its lifetime.
	46	*
	47	* It will be created.
	48	* It will be marked with the intention to be
	49	* submitted to local disk and/or
	50	* send via the network.
	51	*
	52	* It has to be placed on the transfer log and other housekeeping lists,
	53	* In case we have a network connection.
	54	*
	55	* It may be identified as a concurrent (write) request
	56	* and be handled accordingly.
	57	*
	58	* It may me handed over to the local disk subsystem.
	59	* It may be completed by the local disk subsystem,
3ad2f3fb	60	* either successfully or with io-error.
b411b363 PR	61	* In case it is a READ request, and it failed locally,
	62	* it may be retried remotely.
	63	*
	64	* It may be queued for sending.
	65	* It may be handed over to the network stack,
	66	* which may fail.
	67	* It may be acknowledged by the "peer" according to the wire_protocol in use.
	68	* this may be a negative ack.
	69	* It may receive a faked ack when the network connection is lost and the
	70	* transfer log is cleaned up.
	71	* Sending may be canceled due to network connection loss.
	72	* When it finally has outlived its time,
	73	* corresponding dirty bits in the resync-bitmap may be cleared or set,
	74	* it will be destroyed,
	75	* and completion will be signalled to the originator,
	76	* with or without "success".
	77	*/
	78
	79	enum drbd_req_event {
8554df1c AG	80	CREATED,
	81	TO_BE_SENT,
	82	TO_BE_SUBMITTED,
b411b363 PR	83
b411b363 PR	84	/* XXX yes, now I am inconsistent...
73a01a18	85	* these are not "events" but "actions"
b411b363	86	* oh, well... */
8554df1c AG	87	QUEUE_FOR_NET_WRITE,
	88	QUEUE_FOR_NET_READ,
	89	QUEUE_FOR_SEND_OOS,
	90
7074e4a7 LE	91	/* An empty flush is queued as P_BARRIER,
	92	* which will cause it to complete "successfully",
	93	* even if the local disk flush failed.
	94	*
	95	* Just like "real" requests, empty flushes (blkdev_issue_flush()) will
	96	* only see an error if neither local nor remote data is reachable. */
	97	QUEUE_AS_DRBD_BARRIER,
	98
8554df1c AG	99	SEND_CANCELED,
	100	SEND_FAILED,
	101	HANDED_OVER_TO_NETWORK,
	102	OOS_HANDED_TO_NETWORK,
	103	CONNECTION_LOST_WHILE_PENDING,
	104	READ_RETRY_REMOTE_CANCELED,
	105	RECV_ACKED_BY_PEER,
	106	WRITE_ACKED_BY_PEER,
	107	WRITE_ACKED_BY_PEER_AND_SIS, /* and set_in_sync */
d4dabbe2	108	CONFLICT_RESOLVED,
7be8da07	109	POSTPONE_WRITE,
8554df1c AG	110	NEG_ACKED,
	111	BARRIER_ACKED, /* in protocol A and B */
	112	DATA_RECEIVED, /* (remote read) */
	113
	114	READ_COMPLETED_WITH_ERROR,
	115	READ_AHEAD_COMPLETED_WITH_ERROR,
	116	WRITE_COMPLETED_WITH_ERROR,
cdfda633	117	ABORT_DISK_IO,
8554df1c AG	118	COMPLETED_OK,
	119	RESEND,
	120	FAIL_FROZEN_DISK_IO,
	121	RESTART_FROZEN_DISK_IO,
	122	NOTHING,
b411b363 PR	123	};
	124
	125	/* encoding of request states for now. we don't actually need that many bits.
	126	* we don't need to do atomic bit operations either, since most of the time we
	127	* need to look at the connection state and/or manipulate some lists at the
	128	* same time, so we should hold the request lock anyways.
	129	*/
	130	enum drbd_req_state_bits {
cdfda633 PR	131	/* 3210
	132	* 0000: no local possible
	133	* 0001: to be submitted
b411b363	134	* UNUSED, we could map: 011: submitted, completion still pending
cdfda633 PR	135	* 0110: completed ok
	136	* 0010: completed with error
	137	* 1001: Aborted (before completion)
	138	* 1x10: Aborted and completed -> free
b411b363 PR	139	*/
	140	__RQ_LOCAL_PENDING,
	141	__RQ_LOCAL_COMPLETED,
	142	__RQ_LOCAL_OK,
cdfda633	143	__RQ_LOCAL_ABORTED,
b411b363	144
cdfda633	145	/* 87654
b411b363 PR	146	* 00000: no network possible
	147	* 00001: to be send
	148	* 00011: to be send, on worker queue
	149	* 00101: sent, expecting recv_ack (B) or write_ack (C)
	150	* 11101: sent,
	151	* recv_ack (B) or implicit "ack" (A),
	152	* still waiting for the barrier ack.
	153	* master_bio may already be completed and invalidated.
8554df1c AG	154	* 11100: write acked (C),
8554df1c AG	155	* data received (for remote read, any protocol)
b411b363 PR	156	* or finally the barrier ack has arrived (B,A)...
	157	* request can be freed
	158	* 01100: neg-acked (write, protocol C)
	159	* or neg-d-acked (read, any protocol)
	160	* or killed from the transfer log
	161	* during cleanup after connection loss
	162	* request can be freed
	163	* 01000: canceled or send failed...
	164	* request can be freed
	165	*/
	166
	167	/* if "SENT" is not set, yet, this can still fail or be canceled.
	168	* if "SENT" is set already, we still wait for an Ack packet.
	169	* when cleared, the master_bio may be completed.
	170	* in (B,A) the request object may still linger on the transaction log
	171	* until the corresponding barrier ack comes in */
	172	__RQ_NET_PENDING,
	173
	174	/* If it is QUEUED, and it is a WRITE, it is also registered in the
	175	* transfer log. Currently we need this flag to avoid conflicts between
	176	* worker canceling the request and tl_clear_barrier killing it from
	177	* transfer log. We should restructure the code so this conflict does
	178	* no longer occur. */
	179	__RQ_NET_QUEUED,
	180
	181	/* well, actually only "handed over to the network stack".
	182	*
	183	* TODO can potentially be dropped because of the similar meaning
	184	* of RQ_NET_SENT and ~RQ_NET_QUEUED.
	185	* however it is not exactly the same. before we drop it
	186	* we must ensure that we can tell a request with network part
	187	* from a request without, regardless of what happens to it. */
	188	__RQ_NET_SENT,
	189
	190	/* when set, the request may be freed (if RQ_NET_QUEUED is clear).
	191	* basically this means the corresponding P_BARRIER_ACK was received */
	192	__RQ_NET_DONE,
	193
	194	/* whether or not we know (C) or pretend (B,A) that the write
	195	* was successfully written on the peer.
	196	*/
	197	__RQ_NET_OK,
	198
	199	/* peer called drbd_set_in_sync() for this write */
	200	__RQ_NET_SIS,
	201
	202	/* keep this last, its for the RQ_NET_MASK */
	203	__RQ_NET_MAX,
288f422e PR	204
	205	/* Set when this is a write, clear for a read */
	206	__RQ_WRITE,
0778286a PR	207
	208	/* Should call drbd_al_complete_io() for this request... */
	209	__RQ_IN_ACT_LOG,
7be8da07 AG	210
	211	/* The peer has sent a retry ACK */
	212	__RQ_POSTPONED,
303d1448	213
a0d856df LE	214	/* would have been completed,
	215	* but was not, because of drbd_suspended() */
	216	__RQ_COMPLETION_SUSP,
	217
303d1448 PR	218	/* We expect a receive ACK (wire proto B) */
	219	__RQ_EXP_RECEIVE_ACK,
	220
	221	/* We expect a write ACK (wite proto C) */
	222	__RQ_EXP_WRITE_ACK,
a0d856df LE	223
	224	/* waiting for a barrier ack, did an extra kref_get */
	225	__RQ_EXP_BARR_ACK,
b411b363 PR	226	};
	227
	228	#define RQ_LOCAL_PENDING (1UL << __RQ_LOCAL_PENDING)
	229	#define RQ_LOCAL_COMPLETED (1UL << __RQ_LOCAL_COMPLETED)
	230	#define RQ_LOCAL_OK (1UL << __RQ_LOCAL_OK)
cdfda633	231	#define RQ_LOCAL_ABORTED (1UL << __RQ_LOCAL_ABORTED)
b411b363	232
cdfda633	233	#define RQ_LOCAL_MASK ((RQ_LOCAL_ABORTED << 1)-1)
b411b363 PR	234
	235	#define RQ_NET_PENDING (1UL << __RQ_NET_PENDING)
	236	#define RQ_NET_QUEUED (1UL << __RQ_NET_QUEUED)
	237	#define RQ_NET_SENT (1UL << __RQ_NET_SENT)
	238	#define RQ_NET_DONE (1UL << __RQ_NET_DONE)
	239	#define RQ_NET_OK (1UL << __RQ_NET_OK)
	240	#define RQ_NET_SIS (1UL << __RQ_NET_SIS)
	241
	242	/* 0x1f8 */
	243	#define RQ_NET_MASK (((1UL << __RQ_NET_MAX)-1) & ~RQ_LOCAL_MASK)
	244
288f422e	245	#define RQ_WRITE (1UL << __RQ_WRITE)
0778286a	246	#define RQ_IN_ACT_LOG (1UL << __RQ_IN_ACT_LOG)
7be8da07	247	#define RQ_POSTPONED (1UL << __RQ_POSTPONED)
a0d856df	248	#define RQ_COMPLETION_SUSP (1UL << __RQ_COMPLETION_SUSP)
303d1448 PR	249	#define RQ_EXP_RECEIVE_ACK (1UL << __RQ_EXP_RECEIVE_ACK)
303d1448 PR	250	#define RQ_EXP_WRITE_ACK (1UL << __RQ_EXP_WRITE_ACK)
a0d856df	251	#define RQ_EXP_BARR_ACK (1UL << __RQ_EXP_BARR_ACK)
288f422e	252
11b58e73 PR	253	/* For waking up the frozen transfer log mod_req() has to return if the request
11b58e73 PR	254	should be counted in the epoch object*/
f497609e AG	255	#define MR_WRITE 1
f497609e AG	256	#define MR_READ 2
11b58e73	257
5ba82308 PR	258	static inline void drbd_req_make_private_bio(struct drbd_request req, struct bio bio_src)
	259	{
	260	struct bio *bio;
	261	bio = bio_clone(bio_src, GFP_NOIO); /* XXX cannot fail?? */
	262
	263	req->private_bio = bio;
	264
	265	bio->bi_private = req;
fcefa62e	266	bio->bi_end_io = drbd_request_endio;
5ba82308 PR	267	bio->bi_next = NULL;
	268	}
	269
b411b363 PR	270	/* Short lived temporary struct on the stack.
b411b363 PR	271	* We could squirrel the error to be returned into
4f024f37	272	* bio->bi_iter.bi_size, or similar. But that would be too ugly. */
b411b363 PR	273	struct bio_and_error {
	274	struct bio *bio;
	275	int error;
	276	};
	277
bde89a9e	278	extern void start_new_tl_epoch(struct drbd_connection *connection);
9a278a79	279	extern void drbd_req_destroy(struct kref *kref);
b411b363 PR	280	extern void _req_may_be_done(struct drbd_request *req,
b411b363 PR	281	struct bio_and_error *m);
2a80699f	282	extern int __req_mod(struct drbd_request *req, enum drbd_req_event what,
b411b363	283	struct bio_and_error *m);
b30ab791	284	extern void complete_master_bio(struct drbd_device *device,
b411b363	285	struct bio_and_error *m);
7fde2be9	286	extern void request_timer_fn(unsigned long data);
bde89a9e AG	287	extern void tl_restart(struct drbd_connection *connection, enum drbd_req_event what);
bde89a9e AG	288	extern void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what);
b411b363	289
2312f0b3	290	/* this is in drbd_main.c */
9d05e7c4	291	extern void drbd_restart_request(struct drbd_request *req);
2312f0b3	292
b411b363 PR	293	/* use this if you don't want to deal with calling complete_master_bio()
b411b363 PR	294	* outside the spinlock, e.g. when walking some list on cleanup. */
2a80699f	295	static inline int _req_mod(struct drbd_request *req, enum drbd_req_event what)
b411b363	296	{
84b8c06b	297	struct drbd_device *device = req->device;
b411b363	298	struct bio_and_error m;
2a80699f	299	int rv;
b411b363 PR	300
b411b363 PR	301	/* __req_mod possibly frees req, do not touch req after that! */
2a80699f	302	rv = __req_mod(req, what, &m);
b411b363	303	if (m.bio)
b30ab791	304	complete_master_bio(device, &m);
2a80699f PR	305
2a80699f PR	306	return rv;
b411b363 PR	307	}
b411b363 PR	308
759fbdfb PR	309	/* completion of master bio is outside of our spinlock.
	310	* We still may or may not be inside some irqs disabled section
	311	* of the lower level driver completion callback, so we need to
	312	* spin_lock_irqsave here. */
2a80699f	313	static inline int req_mod(struct drbd_request *req,
b411b363 PR	314	enum drbd_req_event what)
b411b363 PR	315	{
759fbdfb	316	unsigned long flags;
84b8c06b	317	struct drbd_device *device = req->device;
b411b363	318	struct bio_and_error m;
2a80699f PR	319	int rv;
2a80699f PR	320
0500813f	321	spin_lock_irqsave(&device->resource->req_lock, flags);
2a80699f	322	rv = __req_mod(req, what, &m);
0500813f	323	spin_unlock_irqrestore(&device->resource->req_lock, flags);
b411b363 PR	324
b411b363 PR	325	if (m.bio)
b30ab791	326	complete_master_bio(device, &m);
2a80699f PR	327
2a80699f PR	328	return rv;
b411b363	329	}
6a35c45f	330
da9fbc27	331	static inline bool drbd_should_do_remote(union drbd_dev_state s)
6a35c45f PR	332	{
	333	return s.pdsk == D_UP_TO_DATE \|\|
	334	(s.pdsk >= D_INCONSISTENT &&
	335	s.conn >= C_WF_BITMAP_T &&
	336	s.conn < C_AHEAD);
	337	/* Before proto 96 that was >= CONNECTED instead of >= C_WF_BITMAP_T.
	338	That is equivalent since before 96 IO was frozen in the C_WF_BITMAP*
	339	states. */
	340	}
da9fbc27	341	static inline bool drbd_should_send_out_of_sync(union drbd_dev_state s)
6a35c45f PR	342	{
	343	return s.conn == C_AHEAD \|\| s.conn == C_WF_BITMAP_S;
	344	/* pdsk = D_INCONSISTENT as a consequence. Protocol 96 check not necessary
	345	since we enter state C_AHEAD only if proto >= 96 */
	346	}
	347
b411b363	348	#endif