[mirror_ubuntu-bionic-kernel.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"

/* 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) */

	COMPLETED_OK,
	READ_COMPLETED_WITH_ERROR,
	READ_AHEAD_COMPLETED_WITH_ERROR,
	WRITE_COMPLETED_WITH_ERROR,
	DISCARD_COMPLETED_NOTSUPP,
	DISCARD_COMPLETED_WITH_ERROR,

	ABORT_DISK_IO,
	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);
extern void tl_abort_disk_io(struct drbd_device *device);

/* 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;
}

extern bool drbd_should_do_remote(union drbd_dev_state);

#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"
b411b363 PR	33
	34	/* The request callbacks will be called in irq context by the IDE drivers,
	35	and in Softirqs/Tasklets/BH context by the SCSI drivers,
	36	and by the receiver and worker in kernel-thread context.
	37	Try to get the locking right :) */
	38
	39	/*
	40	* Objects of type struct drbd_request do only exist on a R_PRIMARY node, and are
	41	* associated with IO requests originating from the block layer above us.
	42	*
	43	* There are quite a few things that may happen to a drbd request
	44	* during its lifetime.
	45	*
	46	* It will be created.
	47	* It will be marked with the intention to be
	48	* submitted to local disk and/or
	49	* send via the network.
	50	*
	51	* It has to be placed on the transfer log and other housekeeping lists,
	52	* In case we have a network connection.
	53	*
	54	* It may be identified as a concurrent (write) request
	55	* and be handled accordingly.
	56	*
	57	* It may me handed over to the local disk subsystem.
	58	* It may be completed by the local disk subsystem,
3ad2f3fb	59	* either successfully or with io-error.
b411b363 PR	60	* In case it is a READ request, and it failed locally,
	61	* it may be retried remotely.
	62	*
	63	* It may be queued for sending.
	64	* It may be handed over to the network stack,
	65	* which may fail.
	66	* It may be acknowledged by the "peer" according to the wire_protocol in use.
	67	* this may be a negative ack.
	68	* It may receive a faked ack when the network connection is lost and the
	69	* transfer log is cleaned up.
	70	* Sending may be canceled due to network connection loss.
	71	* When it finally has outlived its time,
	72	* corresponding dirty bits in the resync-bitmap may be cleared or set,
	73	* it will be destroyed,
	74	* and completion will be signalled to the originator,
	75	* with or without "success".
	76	*/
	77
	78	enum drbd_req_event {
8554df1c AG	79	CREATED,
	80	TO_BE_SENT,
	81	TO_BE_SUBMITTED,
b411b363 PR	82
b411b363 PR	83	/* XXX yes, now I am inconsistent...
73a01a18	84	* these are not "events" but "actions"
b411b363	85	* oh, well... */
8554df1c AG	86	QUEUE_FOR_NET_WRITE,
	87	QUEUE_FOR_NET_READ,
	88	QUEUE_FOR_SEND_OOS,
	89
7074e4a7 LE	90	/* An empty flush is queued as P_BARRIER,
	91	* which will cause it to complete "successfully",
	92	* even if the local disk flush failed.
	93	*
	94	* Just like "real" requests, empty flushes (blkdev_issue_flush()) will
	95	* only see an error if neither local nor remote data is reachable. */
	96	QUEUE_AS_DRBD_BARRIER,
	97
8554df1c AG	98	SEND_CANCELED,
	99	SEND_FAILED,
	100	HANDED_OVER_TO_NETWORK,
	101	OOS_HANDED_TO_NETWORK,
	102	CONNECTION_LOST_WHILE_PENDING,
	103	READ_RETRY_REMOTE_CANCELED,
	104	RECV_ACKED_BY_PEER,
	105	WRITE_ACKED_BY_PEER,
	106	WRITE_ACKED_BY_PEER_AND_SIS, /* and set_in_sync */
d4dabbe2	107	CONFLICT_RESOLVED,
7be8da07	108	POSTPONE_WRITE,
8554df1c AG	109	NEG_ACKED,
	110	BARRIER_ACKED, /* in protocol A and B */
	111	DATA_RECEIVED, /* (remote read) */
	112
2f632aeb	113	COMPLETED_OK,
8554df1c AG	114	READ_COMPLETED_WITH_ERROR,
	115	READ_AHEAD_COMPLETED_WITH_ERROR,
	116	WRITE_COMPLETED_WITH_ERROR,
2f632aeb LE	117	DISCARD_COMPLETED_NOTSUPP,
	118	DISCARD_COMPLETED_WITH_ERROR,
	119
cdfda633	120	ABORT_DISK_IO,
8554df1c AG	121	RESEND,
	122	FAIL_FROZEN_DISK_IO,
	123	RESTART_FROZEN_DISK_IO,
	124	NOTHING,
b411b363 PR	125	};
	126
	127	/* encoding of request states for now. we don't actually need that many bits.
	128	* we don't need to do atomic bit operations either, since most of the time we
	129	* need to look at the connection state and/or manipulate some lists at the
	130	* same time, so we should hold the request lock anyways.
	131	*/
	132	enum drbd_req_state_bits {
cdfda633 PR	133	/* 3210
	134	* 0000: no local possible
	135	* 0001: to be submitted
b411b363	136	* UNUSED, we could map: 011: submitted, completion still pending
cdfda633 PR	137	* 0110: completed ok
	138	* 0010: completed with error
	139	* 1001: Aborted (before completion)
	140	* 1x10: Aborted and completed -> free
b411b363 PR	141	*/
	142	__RQ_LOCAL_PENDING,
	143	__RQ_LOCAL_COMPLETED,
	144	__RQ_LOCAL_OK,
cdfda633	145	__RQ_LOCAL_ABORTED,
b411b363	146
cdfda633	147	/* 87654
b411b363 PR	148	* 00000: no network possible
	149	* 00001: to be send
	150	* 00011: to be send, on worker queue
	151	* 00101: sent, expecting recv_ack (B) or write_ack (C)
	152	* 11101: sent,
	153	* recv_ack (B) or implicit "ack" (A),
	154	* still waiting for the barrier ack.
	155	* master_bio may already be completed and invalidated.
8554df1c AG	156	* 11100: write acked (C),
8554df1c AG	157	* data received (for remote read, any protocol)
b411b363 PR	158	* or finally the barrier ack has arrived (B,A)...
	159	* request can be freed
	160	* 01100: neg-acked (write, protocol C)
	161	* or neg-d-acked (read, any protocol)
	162	* or killed from the transfer log
	163	* during cleanup after connection loss
	164	* request can be freed
	165	* 01000: canceled or send failed...
	166	* request can be freed
	167	*/
	168
	169	/* if "SENT" is not set, yet, this can still fail or be canceled.
	170	* if "SENT" is set already, we still wait for an Ack packet.
	171	* when cleared, the master_bio may be completed.
	172	* in (B,A) the request object may still linger on the transaction log
	173	* until the corresponding barrier ack comes in */
	174	__RQ_NET_PENDING,
	175
	176	/* If it is QUEUED, and it is a WRITE, it is also registered in the
	177	* transfer log. Currently we need this flag to avoid conflicts between
	178	* worker canceling the request and tl_clear_barrier killing it from
	179	* transfer log. We should restructure the code so this conflict does
	180	* no longer occur. */
	181	__RQ_NET_QUEUED,
	182
	183	/* well, actually only "handed over to the network stack".
	184	*
	185	* TODO can potentially be dropped because of the similar meaning
	186	* of RQ_NET_SENT and ~RQ_NET_QUEUED.
	187	* however it is not exactly the same. before we drop it
	188	* we must ensure that we can tell a request with network part
	189	* from a request without, regardless of what happens to it. */
	190	__RQ_NET_SENT,
	191
	192	/* when set, the request may be freed (if RQ_NET_QUEUED is clear).
	193	* basically this means the corresponding P_BARRIER_ACK was received */
	194	__RQ_NET_DONE,
	195
	196	/* whether or not we know (C) or pretend (B,A) that the write
	197	* was successfully written on the peer.
	198	*/
	199	__RQ_NET_OK,
	200
	201	/* peer called drbd_set_in_sync() for this write */
	202	__RQ_NET_SIS,
	203
	204	/* keep this last, its for the RQ_NET_MASK */
	205	__RQ_NET_MAX,
288f422e PR	206
	207	/* Set when this is a write, clear for a read */
	208	__RQ_WRITE,
0778286a PR	209
	210	/* Should call drbd_al_complete_io() for this request... */
	211	__RQ_IN_ACT_LOG,
7be8da07 AG	212
	213	/* The peer has sent a retry ACK */
	214	__RQ_POSTPONED,
303d1448	215
a0d856df LE	216	/* would have been completed,
	217	* but was not, because of drbd_suspended() */
	218	__RQ_COMPLETION_SUSP,
	219
303d1448 PR	220	/* We expect a receive ACK (wire proto B) */
	221	__RQ_EXP_RECEIVE_ACK,
	222
	223	/* We expect a write ACK (wite proto C) */
	224	__RQ_EXP_WRITE_ACK,
a0d856df LE	225
	226	/* waiting for a barrier ack, did an extra kref_get */
	227	__RQ_EXP_BARR_ACK,
b411b363 PR	228	};
	229
	230	#define RQ_LOCAL_PENDING (1UL << __RQ_LOCAL_PENDING)
	231	#define RQ_LOCAL_COMPLETED (1UL << __RQ_LOCAL_COMPLETED)
	232	#define RQ_LOCAL_OK (1UL << __RQ_LOCAL_OK)
cdfda633	233	#define RQ_LOCAL_ABORTED (1UL << __RQ_LOCAL_ABORTED)
b411b363	234
cdfda633	235	#define RQ_LOCAL_MASK ((RQ_LOCAL_ABORTED << 1)-1)
b411b363 PR	236
	237	#define RQ_NET_PENDING (1UL << __RQ_NET_PENDING)
	238	#define RQ_NET_QUEUED (1UL << __RQ_NET_QUEUED)
	239	#define RQ_NET_SENT (1UL << __RQ_NET_SENT)
	240	#define RQ_NET_DONE (1UL << __RQ_NET_DONE)
	241	#define RQ_NET_OK (1UL << __RQ_NET_OK)
	242	#define RQ_NET_SIS (1UL << __RQ_NET_SIS)
	243
	244	/* 0x1f8 */
	245	#define RQ_NET_MASK (((1UL << __RQ_NET_MAX)-1) & ~RQ_LOCAL_MASK)
	246
288f422e	247	#define RQ_WRITE (1UL << __RQ_WRITE)
0778286a	248	#define RQ_IN_ACT_LOG (1UL << __RQ_IN_ACT_LOG)
7be8da07	249	#define RQ_POSTPONED (1UL << __RQ_POSTPONED)
a0d856df	250	#define RQ_COMPLETION_SUSP (1UL << __RQ_COMPLETION_SUSP)
303d1448 PR	251	#define RQ_EXP_RECEIVE_ACK (1UL << __RQ_EXP_RECEIVE_ACK)
303d1448 PR	252	#define RQ_EXP_WRITE_ACK (1UL << __RQ_EXP_WRITE_ACK)
a0d856df	253	#define RQ_EXP_BARR_ACK (1UL << __RQ_EXP_BARR_ACK)
288f422e	254
11b58e73 PR	255	/* For waking up the frozen transfer log mod_req() has to return if the request
11b58e73 PR	256	should be counted in the epoch object*/
f497609e AG	257	#define MR_WRITE 1
f497609e AG	258	#define MR_READ 2
11b58e73	259
5ba82308 PR	260	static inline void drbd_req_make_private_bio(struct drbd_request req, struct bio bio_src)
	261	{
	262	struct bio *bio;
	263	bio = bio_clone(bio_src, GFP_NOIO); /* XXX cannot fail?? */
	264
	265	req->private_bio = bio;
	266
	267	bio->bi_private = req;
fcefa62e	268	bio->bi_end_io = drbd_request_endio;
5ba82308 PR	269	bio->bi_next = NULL;
	270	}
	271
b411b363 PR	272	/* Short lived temporary struct on the stack.
b411b363 PR	273	* We could squirrel the error to be returned into
4f024f37	274	* bio->bi_iter.bi_size, or similar. But that would be too ugly. */
b411b363 PR	275	struct bio_and_error {
	276	struct bio *bio;
	277	int error;
	278	};
	279
bde89a9e	280	extern void start_new_tl_epoch(struct drbd_connection *connection);
9a278a79	281	extern void drbd_req_destroy(struct kref *kref);
b411b363 PR	282	extern void _req_may_be_done(struct drbd_request *req,
b411b363 PR	283	struct bio_and_error *m);
2a80699f	284	extern int __req_mod(struct drbd_request *req, enum drbd_req_event what,
b411b363	285	struct bio_and_error *m);
b30ab791	286	extern void complete_master_bio(struct drbd_device *device,
b411b363	287	struct bio_and_error *m);
7fde2be9	288	extern void request_timer_fn(unsigned long data);
bde89a9e AG	289	extern void tl_restart(struct drbd_connection *connection, enum drbd_req_event what);
bde89a9e AG	290	extern void _tl_restart(struct drbd_connection *connection, enum drbd_req_event what);
8ce953aa	291	extern void tl_abort_disk_io(struct drbd_device *device);
b411b363	292
2312f0b3	293	/* this is in drbd_main.c */
9d05e7c4	294	extern void drbd_restart_request(struct drbd_request *req);
2312f0b3	295
b411b363 PR	296	/* use this if you don't want to deal with calling complete_master_bio()
b411b363 PR	297	* outside the spinlock, e.g. when walking some list on cleanup. */
2a80699f	298	static inline int _req_mod(struct drbd_request *req, enum drbd_req_event what)
b411b363	299	{
84b8c06b	300	struct drbd_device *device = req->device;
b411b363	301	struct bio_and_error m;
2a80699f	302	int rv;
b411b363 PR	303
b411b363 PR	304	/* __req_mod possibly frees req, do not touch req after that! */
2a80699f	305	rv = __req_mod(req, what, &m);
b411b363	306	if (m.bio)
b30ab791	307	complete_master_bio(device, &m);
2a80699f PR	308
2a80699f PR	309	return rv;
b411b363 PR	310	}
b411b363 PR	311
759fbdfb PR	312	/* completion of master bio is outside of our spinlock.
	313	* We still may or may not be inside some irqs disabled section
	314	* of the lower level driver completion callback, so we need to
	315	* spin_lock_irqsave here. */
2a80699f	316	static inline int req_mod(struct drbd_request *req,
b411b363 PR	317	enum drbd_req_event what)
b411b363 PR	318	{
759fbdfb	319	unsigned long flags;
84b8c06b	320	struct drbd_device *device = req->device;
b411b363	321	struct bio_and_error m;
2a80699f PR	322	int rv;
2a80699f PR	323
0500813f	324	spin_lock_irqsave(&device->resource->req_lock, flags);
2a80699f	325	rv = __req_mod(req, what, &m);
0500813f	326	spin_unlock_irqrestore(&device->resource->req_lock, flags);
b411b363 PR	327
b411b363 PR	328	if (m.bio)
b30ab791	329	complete_master_bio(device, &m);
2a80699f PR	330
2a80699f PR	331	return rv;
b411b363	332	}
6a35c45f	333
2e9ffde6	334	extern bool drbd_should_do_remote(union drbd_dev_state);
6a35c45f	335
b411b363	336	#endif