drbd_main.c 87.0 KB
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/*
   drbd.c

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

   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.

   Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev
   from Logicworks, Inc. for making SDP replication support possible.

   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.

 */

#include <linux/module.h>
#include <linux/drbd.h>
#include <asm/uaccess.h>
#include <asm/types.h>
#include <net/sock.h>
#include <linux/ctype.h>
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#include <linux/mutex.h>
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#include <linux/fs.h>
#include <linux/file.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <linux/mm_inline.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/reboot.h>
#include <linux/notifier.h>
#include <linux/kthread.h>

#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include <linux/vmalloc.h>

#include <linux/drbd_limits.h>
#include "drbd_int.h"
#include "drbd_req.h" /* only for _req_mod in tl_release and tl_clear */

#include "drbd_vli.h"

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static DEFINE_MUTEX(drbd_main_mutex);
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int drbdd_init(struct drbd_thread *);
int drbd_worker(struct drbd_thread *);
int drbd_asender(struct drbd_thread *);

int drbd_init(void);
static int drbd_open(struct block_device *bdev, fmode_t mode);
static int drbd_release(struct gendisk *gd, fmode_t mode);
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static int w_md_sync(struct drbd_work *w, int unused);
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static void md_sync_timer_fn(unsigned long data);
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static int w_bitmap_io(struct drbd_work *w, int unused);
static int w_go_diskless(struct drbd_work *w, int unused);
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MODULE_AUTHOR("Philipp Reisner <phil@linbit.com>, "
	      "Lars Ellenberg <lars@linbit.com>");
MODULE_DESCRIPTION("drbd - Distributed Replicated Block Device v" REL_VERSION);
MODULE_VERSION(REL_VERSION);
MODULE_LICENSE("GPL");
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MODULE_PARM_DESC(minor_count, "Approximate number of drbd devices ("
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		 __stringify(DRBD_MINOR_COUNT_MIN) "-" __stringify(DRBD_MINOR_COUNT_MAX) ")");
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MODULE_ALIAS_BLOCKDEV_MAJOR(DRBD_MAJOR);

#include <linux/moduleparam.h>
/* allow_open_on_secondary */
MODULE_PARM_DESC(allow_oos, "DONT USE!");
/* thanks to these macros, if compiled into the kernel (not-module),
 * this becomes the boot parameter drbd.minor_count */
module_param(minor_count, uint, 0444);
module_param(disable_sendpage, bool, 0644);
module_param(allow_oos, bool, 0);
module_param(proc_details, int, 0644);

#ifdef CONFIG_DRBD_FAULT_INJECTION
int enable_faults;
int fault_rate;
static int fault_count;
int fault_devs;
/* bitmap of enabled faults */
module_param(enable_faults, int, 0664);
/* fault rate % value - applies to all enabled faults */
module_param(fault_rate, int, 0664);
/* count of faults inserted */
module_param(fault_count, int, 0664);
/* bitmap of devices to insert faults on */
module_param(fault_devs, int, 0644);
#endif

/* module parameter, defined */
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unsigned int minor_count = DRBD_MINOR_COUNT_DEF;
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int disable_sendpage;
int allow_oos;
int proc_details;       /* Detail level in proc drbd*/

/* Module parameter for setting the user mode helper program
 * to run. Default is /sbin/drbdadm */
char usermode_helper[80] = "/sbin/drbdadm";

module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0644);

/* in 2.6.x, our device mapping and config info contains our virtual gendisks
 * as member "struct gendisk *vdisk;"
 */
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struct idr minors;
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struct list_head drbd_tconns;  /* list of struct drbd_tconn */
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DEFINE_MUTEX(drbd_cfg_mutex);
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struct kmem_cache *drbd_request_cache;
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struct kmem_cache *drbd_ee_cache;	/* peer requests */
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struct kmem_cache *drbd_bm_ext_cache;	/* bitmap extents */
struct kmem_cache *drbd_al_ext_cache;	/* activity log extents */
mempool_t *drbd_request_mempool;
mempool_t *drbd_ee_mempool;
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mempool_t *drbd_md_io_page_pool;
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struct bio_set *drbd_md_io_bio_set;
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/* I do not use a standard mempool, because:
   1) I want to hand out the pre-allocated objects first.
   2) I want to be able to interrupt sleeping allocation with a signal.
   Note: This is a single linked list, the next pointer is the private
	 member of struct page.
 */
struct page *drbd_pp_pool;
spinlock_t   drbd_pp_lock;
int          drbd_pp_vacant;
wait_queue_head_t drbd_pp_wait;

DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5);

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static const struct block_device_operations drbd_ops = {
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	.owner =   THIS_MODULE,
	.open =    drbd_open,
	.release = drbd_release,
};

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static void bio_destructor_drbd(struct bio *bio)
{
	bio_free(bio, drbd_md_io_bio_set);
}

struct bio *bio_alloc_drbd(gfp_t gfp_mask)
{
	struct bio *bio;

	if (!drbd_md_io_bio_set)
		return bio_alloc(gfp_mask, 1);

	bio = bio_alloc_bioset(gfp_mask, 1, drbd_md_io_bio_set);
	if (!bio)
		return NULL;
	bio->bi_destructor = bio_destructor_drbd;
	return bio;
}

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#ifdef __CHECKER__
/* When checking with sparse, and this is an inline function, sparse will
   give tons of false positives. When this is a real functions sparse works.
 */
int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins)
{
	int io_allowed;

	atomic_inc(&mdev->local_cnt);
	io_allowed = (mdev->state.disk >= mins);
	if (!io_allowed) {
		if (atomic_dec_and_test(&mdev->local_cnt))
			wake_up(&mdev->misc_wait);
	}
	return io_allowed;
}

#endif

/**
 * DOC: The transfer log
 *
 * The transfer log is a single linked list of &struct drbd_tl_epoch objects.
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 * mdev->tconn->newest_tle points to the head, mdev->tconn->oldest_tle points to the tail
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 * of the list. There is always at least one &struct drbd_tl_epoch object.
 *
 * Each &struct drbd_tl_epoch has a circular double linked list of requests
 * attached.
 */
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static int tl_init(struct drbd_tconn *tconn)
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{
	struct drbd_tl_epoch *b;

	/* during device minor initialization, we may well use GFP_KERNEL */
	b = kmalloc(sizeof(struct drbd_tl_epoch), GFP_KERNEL);
	if (!b)
		return 0;
	INIT_LIST_HEAD(&b->requests);
	INIT_LIST_HEAD(&b->w.list);
	b->next = NULL;
	b->br_number = 4711;
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	b->n_writes = 0;
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	b->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */

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	tconn->oldest_tle = b;
	tconn->newest_tle = b;
	INIT_LIST_HEAD(&tconn->out_of_sequence_requests);
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	return 1;
}

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static void tl_cleanup(struct drbd_tconn *tconn)
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{
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	if (tconn->oldest_tle != tconn->newest_tle)
		conn_err(tconn, "ASSERT FAILED: oldest_tle == newest_tle\n");
	if (!list_empty(&tconn->out_of_sequence_requests))
		conn_err(tconn, "ASSERT FAILED: list_empty(out_of_sequence_requests)\n");
	kfree(tconn->oldest_tle);
	tconn->oldest_tle = NULL;
	kfree(tconn->unused_spare_tle);
	tconn->unused_spare_tle = NULL;
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}

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/**
 * _tl_add_barrier() - Adds a barrier to the transfer log
 * @mdev:	DRBD device.
 * @new:	Barrier to be added before the current head of the TL.
 *
 * The caller must hold the req_lock.
 */
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void _tl_add_barrier(struct drbd_tconn *tconn, struct drbd_tl_epoch *new)
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{
	struct drbd_tl_epoch *newest_before;

	INIT_LIST_HEAD(&new->requests);
	INIT_LIST_HEAD(&new->w.list);
	new->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */
	new->next = NULL;
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	new->n_writes = 0;
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	newest_before = tconn->newest_tle;
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	/* never send a barrier number == 0, because that is special-cased
	 * when using TCQ for our write ordering code */
	new->br_number = (newest_before->br_number+1) ?: 1;
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	if (tconn->newest_tle != new) {
		tconn->newest_tle->next = new;
		tconn->newest_tle = new;
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	}
}

/**
 * tl_release() - Free or recycle the oldest &struct drbd_tl_epoch object of the TL
 * @mdev:	DRBD device.
 * @barrier_nr:	Expected identifier of the DRBD write barrier packet.
 * @set_size:	Expected number of requests before that barrier.
 *
 * In case the passed barrier_nr or set_size does not match the oldest
 * &struct drbd_tl_epoch objects this function will cause a termination
 * of the connection.
 */
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void tl_release(struct drbd_tconn *tconn, unsigned int barrier_nr,
		unsigned int set_size)
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{
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	struct drbd_conf *mdev;
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	struct drbd_tl_epoch *b, *nob; /* next old barrier */
	struct list_head *le, *tle;
	struct drbd_request *r;

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	spin_lock_irq(&tconn->req_lock);
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	b = tconn->oldest_tle;
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	/* first some paranoia code */
	if (b == NULL) {
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		conn_err(tconn, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
			 barrier_nr);
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		goto bail;
	}
	if (b->br_number != barrier_nr) {
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		conn_err(tconn, "BAD! BarrierAck #%u received, expected #%u!\n",
			 barrier_nr, b->br_number);
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		goto bail;
	}
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	if (b->n_writes != set_size) {
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		conn_err(tconn, "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n",
			 barrier_nr, set_size, b->n_writes);
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		goto bail;
	}

	/* Clean up list of requests processed during current epoch */
	list_for_each_safe(le, tle, &b->requests) {
		r = list_entry(le, struct drbd_request, tl_requests);
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		_req_mod(r, BARRIER_ACKED);
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	}
	/* There could be requests on the list waiting for completion
	   of the write to the local disk. To avoid corruptions of
	   slab's data structures we have to remove the lists head.

	   Also there could have been a barrier ack out of sequence, overtaking
	   the write acks - which would be a bug and violating write ordering.
	   To not deadlock in case we lose connection while such requests are
	   still pending, we need some way to find them for the
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	   _req_mode(CONNECTION_LOST_WHILE_PENDING).
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	   These have been list_move'd to the out_of_sequence_requests list in
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	   _req_mod(, BARRIER_ACKED) above.
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	   */
	list_del_init(&b->requests);
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	mdev = b->w.mdev;
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	nob = b->next;
	if (test_and_clear_bit(CREATE_BARRIER, &mdev->flags)) {
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		_tl_add_barrier(tconn, b);
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		if (nob)
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			tconn->oldest_tle = nob;
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		/* if nob == NULL b was the only barrier, and becomes the new
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		   barrier. Therefore tconn->oldest_tle points already to b */
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	} else {
		D_ASSERT(nob != NULL);
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		tconn->oldest_tle = nob;
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		kfree(b);
	}

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	spin_unlock_irq(&tconn->req_lock);
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	dec_ap_pending(mdev);

	return;

bail:
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	spin_unlock_irq(&tconn->req_lock);
	conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
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}

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/**
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 * _tl_restart() - Walks the transfer log, and applies an action to all requests
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 * @mdev:	DRBD device.
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 * @what:       The action/event to perform with all request objects
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 *
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 * @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
 * RESTART_FROZEN_DISK_IO.
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 */
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void _tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
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{
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	struct drbd_tl_epoch *b, *tmp, **pn;
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	struct list_head *le, *tle, carry_reads;
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	struct drbd_request *req;
	int rv, n_writes, n_reads;
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	b = tconn->oldest_tle;
	pn = &tconn->oldest_tle;
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	while (b) {
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		n_writes = 0;
		n_reads = 0;
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		INIT_LIST_HEAD(&carry_reads);
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		list_for_each_safe(le, tle, &b->requests) {
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			req = list_entry(le, struct drbd_request, tl_requests);
			rv = _req_mod(req, what);

			n_writes += (rv & MR_WRITE) >> MR_WRITE_SHIFT;
			n_reads  += (rv & MR_READ) >> MR_READ_SHIFT;
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		}
		tmp = b->next;

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		if (n_writes) {
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			if (what == RESEND) {
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				b->n_writes = n_writes;
				if (b->w.cb == NULL) {
					b->w.cb = w_send_barrier;
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					inc_ap_pending(b->w.mdev);
					set_bit(CREATE_BARRIER, &b->w.mdev->flags);
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				}

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				drbd_queue_work(&tconn->data.work, &b->w);
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			}
			pn = &b->next;
		} else {
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			if (n_reads)
				list_add(&carry_reads, &b->requests);
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			/* there could still be requests on that ring list,
			 * in case local io is still pending */
			list_del(&b->requests);

			/* dec_ap_pending corresponding to queue_barrier.
			 * the newest barrier may not have been queued yet,
			 * in which case w.cb is still NULL. */
			if (b->w.cb != NULL)
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				dec_ap_pending(b->w.mdev);
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			if (b == tconn->newest_tle) {
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				/* recycle, but reinit! */
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				if (tmp != NULL)
					conn_err(tconn, "ASSERT FAILED tmp == NULL");
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				INIT_LIST_HEAD(&b->requests);
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				list_splice(&carry_reads, &b->requests);
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				INIT_LIST_HEAD(&b->w.list);
				b->w.cb = NULL;
				b->br_number = net_random();
				b->n_writes = 0;

				*pn = b;
				break;
			}
			*pn = tmp;
			kfree(b);
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		}
		b = tmp;
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		list_splice(&carry_reads, &b->requests);
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	}
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}

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/**
 * tl_clear() - Clears all requests and &struct drbd_tl_epoch objects out of the TL
 * @mdev:	DRBD device.
 *
 * This is called after the connection to the peer was lost. The storage covered
 * by the requests on the transfer gets marked as our of sync. Called from the
 * receiver thread and the worker thread.
 */
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void tl_clear(struct drbd_tconn *tconn)
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{
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	struct drbd_conf *mdev;
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	struct list_head *le, *tle;
	struct drbd_request *r;
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	int vnr;
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	spin_lock_irq(&tconn->req_lock);
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	_tl_restart(tconn, CONNECTION_LOST_WHILE_PENDING);
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	/* we expect this list to be empty. */
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	if (!list_empty(&tconn->out_of_sequence_requests))
		conn_err(tconn, "ASSERT FAILED list_empty(&out_of_sequence_requests)\n");
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	/* but just in case, clean it up anyways! */
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	list_for_each_safe(le, tle, &tconn->out_of_sequence_requests) {
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		r = list_entry(le, struct drbd_request, tl_requests);
		/* It would be nice to complete outside of spinlock.
		 * But this is easier for now. */
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		_req_mod(r, CONNECTION_LOST_WHILE_PENDING);
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	}

	/* ensure bit indicating barrier is required is clear */
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	idr_for_each_entry(&tconn->volumes, mdev, vnr)
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		clear_bit(CREATE_BARRIER, &mdev->flags);
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	spin_unlock_irq(&tconn->req_lock);
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}

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void tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
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{
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	spin_lock_irq(&tconn->req_lock);
	_tl_restart(tconn, what);
	spin_unlock_irq(&tconn->req_lock);
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}

static int drbd_thread_setup(void *arg)
{
	struct drbd_thread *thi = (struct drbd_thread *) arg;
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	struct drbd_tconn *tconn = thi->tconn;
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	unsigned long flags;
	int retval;

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	snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
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		 thi->name[0], thi->tconn->name);
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restart:
	retval = thi->function(thi);

	spin_lock_irqsave(&thi->t_lock, flags);

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	/* if the receiver has been "EXITING", the last thing it did
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	 * was set the conn state to "StandAlone",
	 * if now a re-connect request comes in, conn state goes C_UNCONNECTED,
	 * and receiver thread will be "started".
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	 * drbd_thread_start needs to set "RESTARTING" in that case.
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	 * t_state check and assignment needs to be within the same spinlock,
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	 * so either thread_start sees EXITING, and can remap to RESTARTING,
	 * or thread_start see NONE, and can proceed as normal.
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	 */

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	if (thi->t_state == RESTARTING) {
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		conn_info(tconn, "Restarting %s thread\n", thi->name);
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		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		goto restart;
	}

	thi->task = NULL;
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	thi->t_state = NONE;
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	smp_mb();
	complete(&thi->stop);
	spin_unlock_irqrestore(&thi->t_lock, flags);

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	conn_info(tconn, "Terminating %s\n", current->comm);
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	/* Release mod reference taken when thread was started */
	module_put(THIS_MODULE);
	return retval;
}

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static void drbd_thread_init(struct drbd_tconn *tconn, struct drbd_thread *thi,
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			     int (*func) (struct drbd_thread *), char *name)
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{
	spin_lock_init(&thi->t_lock);
	thi->task    = NULL;
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	thi->t_state = NONE;
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	thi->function = func;
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	thi->tconn = tconn;
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	strncpy(thi->name, name, ARRAY_SIZE(thi->name));
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}

int drbd_thread_start(struct drbd_thread *thi)
{
527
	struct drbd_tconn *tconn = thi->tconn;
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	struct task_struct *nt;
	unsigned long flags;

	/* is used from state engine doing drbd_thread_stop_nowait,
	 * while holding the req lock irqsave */
	spin_lock_irqsave(&thi->t_lock, flags);

	switch (thi->t_state) {
536
	case NONE:
537
		conn_info(tconn, "Starting %s thread (from %s [%d])\n",
538
			 thi->name, current->comm, current->pid);
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		/* Get ref on module for thread - this is released when thread exits */
		if (!try_module_get(THIS_MODULE)) {
542
			conn_err(tconn, "Failed to get module reference in drbd_thread_start\n");
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			spin_unlock_irqrestore(&thi->t_lock, flags);
544
			return false;
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		}

		init_completion(&thi->stop);
		thi->reset_cpu_mask = 1;
549
		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		flush_signals(current); /* otherw. may get -ERESTARTNOINTR */

		nt = kthread_create(drbd_thread_setup, (void *) thi,
554
				    "drbd_%c_%s", thi->name[0], thi->tconn->name);
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		if (IS_ERR(nt)) {
557
			conn_err(tconn, "Couldn't start thread\n");
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			module_put(THIS_MODULE);
560
			return false;
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		}
		spin_lock_irqsave(&thi->t_lock, flags);
		thi->task = nt;
564
		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		wake_up_process(nt);
		break;
568 569
	case EXITING:
		thi->t_state = RESTARTING;
570
		conn_info(tconn, "Restarting %s thread (from %s [%d])\n",
571
				thi->name, current->comm, current->pid);
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		/* fall through */
573 574
	case RUNNING:
	case RESTARTING:
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	default:
		spin_unlock_irqrestore(&thi->t_lock, flags);
		break;
	}

580
	return true;
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}


void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
{
	unsigned long flags;

588
	enum drbd_thread_state ns = restart ? RESTARTING : EXITING;
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	/* may be called from state engine, holding the req lock irqsave */
	spin_lock_irqsave(&thi->t_lock, flags);

593
	if (thi->t_state == NONE) {
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		if (restart)
			drbd_thread_start(thi);
		return;
	}

	if (thi->t_state != ns) {
		if (thi->task == NULL) {
			spin_unlock_irqrestore(&thi->t_lock, flags);
			return;
		}

		thi->t_state = ns;
		smp_mb();
		init_completion(&thi->stop);
		if (thi->task != current)
			force_sig(DRBD_SIGKILL, thi->task);
	}

	spin_unlock_irqrestore(&thi->t_lock, flags);

	if (wait)
		wait_for_completion(&thi->stop);
}

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static struct drbd_thread *drbd_task_to_thread(struct drbd_tconn *tconn, struct task_struct *task)
620 621 622 623 624 625 626 627 628
{
	struct drbd_thread *thi =
		task == tconn->receiver.task ? &tconn->receiver :
		task == tconn->asender.task  ? &tconn->asender :
		task == tconn->worker.task   ? &tconn->worker : NULL;

	return thi;
}

629
char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *task)
630
{
631
	struct drbd_thread *thi = drbd_task_to_thread(tconn, task);
632 633 634
	return thi ? thi->name : task->comm;
}

635
int conn_lowest_minor(struct drbd_tconn *tconn)
636
{
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	int vnr = 0;
	struct drbd_conf *mdev;
639

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	mdev = idr_get_next(&tconn->volumes, &vnr);
	if (!mdev)
642
		return -1;
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	return mdev_to_minor(mdev);
644
}
645 646

#ifdef CONFIG_SMP
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/**
 * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
 * @mdev:	DRBD device.
 *
 * Forces all threads of a device onto the same CPU. This is beneficial for
 * DRBD's performance. May be overwritten by user's configuration.
 */
654
void drbd_calc_cpu_mask(struct drbd_tconn *tconn)
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{
	int ord, cpu;

	/* user override. */
659
	if (cpumask_weight(tconn->cpu_mask))
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		return;

662
	ord = conn_lowest_minor(tconn) % cpumask_weight(cpu_online_mask);
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	for_each_online_cpu(cpu) {
		if (ord-- == 0) {
665
			cpumask_set_cpu(cpu, tconn->cpu_mask);
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			return;
		}
	}
	/* should not be reached */
670
	cpumask_setall(tconn->cpu_mask);
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}

/**
 * drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread
 * @mdev:	DRBD device.
676
 * @thi:	drbd_thread object
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 *
 * call in the "main loop" of _all_ threads, no need for any mutex, current won't die
 * prematurely.
 */
681
void drbd_thread_current_set_cpu(struct drbd_thread *thi)
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{
	struct task_struct *p = current;
684

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	if (!thi->reset_cpu_mask)
		return;
	thi->reset_cpu_mask = 0;
688
	set_cpus_allowed_ptr(p, thi->tconn->cpu_mask);
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}
#endif

692
static void prepare_header80(struct p_header80 *h, enum drbd_packet cmd, int size)
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{
	h->magic   = cpu_to_be32(DRBD_MAGIC);
	h->command = cpu_to_be16(cmd);
	h->length  = cpu_to_be16(size);
}

699
static void prepare_header95(struct p_header95 *h, enum drbd_packet cmd, int size)
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{
	h->magic   = cpu_to_be16(DRBD_MAGIC_BIG);
	h->command = cpu_to_be16(cmd);
	h->length  = cpu_to_be32(size);
}

706 707 708
static void _prepare_header(struct drbd_tconn *tconn, int vnr, struct p_header *h,
			    enum drbd_packet cmd, int size)
{
709
	if (tconn->agreed_pro_version >= 95)
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		prepare_header95(&h->h95, cmd, size);
	else
		prepare_header80(&h->h80, cmd, size);
}

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static void prepare_header(struct drbd_conf *mdev, struct p_header *h,
716
			   enum drbd_packet cmd, int size)
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{
718
	_prepare_header(mdev->tconn, mdev->vnr, h, cmd, size);
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}

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/* the appropriate socket mutex must be held already */
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int _conn_send_cmd(struct drbd_tconn *tconn, int vnr, struct socket *sock,
723 724
		   enum drbd_packet cmd, struct p_header *h, size_t size,
		   unsigned msg_flags)
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{
726
	int err;
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728
	_prepare_header(tconn, vnr, h, cmd, size - sizeof(struct p_header));
729 730 731 732 733
	err = drbd_send_all(tconn, sock, h, size, msg_flags);
	if (err && !signal_pending(current))
		conn_warn(tconn, "short send %s size=%d\n",
			  cmdname(cmd), (int)size);
	return err;
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}

/* don't pass the socket. we may only look at it
 * when we hold the appropriate socket mutex.
 */
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int conn_send_cmd(struct drbd_tconn *tconn, int vnr, struct drbd_socket *sock,
740
		  enum drbd_packet cmd, struct p_header *h, size_t size)
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{
742
	int err = -EIO;
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	mutex_lock(&sock->mutex);
	if (sock->socket)
		err = _conn_send_cmd(tconn, vnr, sock->socket, cmd, h, size, 0);
	mutex_unlock(&sock->mutex);
748
	return err;
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}

751
int conn_send_cmd2(struct drbd_tconn *tconn, enum drbd_packet cmd, char *data,
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		   size_t size)
{
754
	struct p_header80 h;
755
	int err;
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757
	prepare_header80(&h, cmd, size);
758 759 760 761 762 763 764 765
	err = drbd_get_data_sock(tconn);
	if (!err) {
		err = drbd_send_all(tconn, tconn->data.socket, &h, sizeof(h), 0);
		if (!err)
			err = drbd_send_all(tconn, tconn->data.socket, data, size, 0);
		drbd_put_data_sock(tconn);
	}
	return err;
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}

768
int drbd_send_sync_param(struct drbd_conf *mdev)
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{
770
	struct p_rs_param_95 *p;
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	struct socket *sock;
772
	int size, err;
773
	const int apv = mdev->tconn->agreed_pro_version;
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	size = apv <= 87 ? sizeof(struct p_rs_param)
		: apv == 88 ? sizeof(struct p_rs_param)
777
			+ strlen(mdev->tconn->net_conf->verify_alg) + 1
778 779
		: apv <= 94 ? sizeof(struct p_rs_param_89)
		: /* apv >= 95 */ sizeof(struct p_rs_param_95);
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	/* used from admin command context and receiver/worker context.
	 * to avoid kmalloc, grab the socket right here,
	 * then use the pre-allocated sbuf there */
784 785
	mutex_lock(&mdev->tconn->data.mutex);
	sock = mdev->tconn->data.socket;
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	if (likely(sock != NULL)) {
788 789
		enum drbd_packet cmd =
			apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
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791
		p = &mdev->tconn->data.sbuf.rs_param_95;
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		/* initialize verify_alg and csums_alg */
		memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);

796 797 798 799 800 801 802 803 804 805 806 807 808 809
		if (get_ldev(mdev)) {
			p->rate = cpu_to_be32(mdev->ldev->dc.resync_rate);
			p->c_plan_ahead = cpu_to_be32(mdev->ldev->dc.c_plan_ahead);
			p->c_delay_target = cpu_to_be32(mdev->ldev->dc.c_delay_target);
			p->c_fill_target = cpu_to_be32(mdev->ldev->dc.c_fill_target);
			p->c_max_rate = cpu_to_be32(mdev->ldev->dc.c_max_rate);
			put_ldev(mdev);
		} else {
			p->rate = cpu_to_be32(DRBD_RATE_DEF);
			p->c_plan_ahead = cpu_to_be32(DRBD_C_PLAN_AHEAD_DEF);
			p->c_delay_target = cpu_to_be32(DRBD_C_DELAY_TARGET_DEF);
			p->c_fill_target = cpu_to_be32(DRBD_C_FILL_TARGET_DEF);
			p->c_max_rate = cpu_to_be32(DRBD_C_MAX_RATE_DEF);
		}
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		if (apv >= 88)
812
			strcpy(p->verify_alg, mdev->tconn->net_conf->verify_alg);
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		if (apv >= 89)
814
			strcpy(p->csums_alg, mdev->tconn->net_conf->csums_alg);
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816
		err = _drbd_send_cmd(mdev, sock, cmd, &p->head, size, 0);
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	} else
818
		err = -EIO;
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820
	mutex_unlock(&mdev->tconn->data.mutex);
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822
	return err;
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}

825
int drbd_send_protocol(struct drbd_tconn *tconn)
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{
	struct p_protocol *p;
828
	int size, cf, err;
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	size = sizeof(struct p_protocol);

832 833
	if (tconn->agreed_pro_version >= 87)
		size += strlen(tconn->net_conf->integrity_alg) + 1;
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	/* we must not recurse into our own queue,
	 * as that is blocked during handshake */
	p = kmalloc(size, GFP_NOIO);
	if (p == NULL)
839
		return -ENOMEM;
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841 842 843 844 845
	p->protocol      = cpu_to_be32(tconn->net_conf->wire_protocol);
	p->after_sb_0p   = cpu_to_be32(tconn->net_conf->after_sb_0p);
	p->after_sb_1p   = cpu_to_be32(tconn->net_conf->after_sb_1p);
	p->after_sb_2p   = cpu_to_be32(tconn->net_conf->after_sb_2p);
	p->two_primaries = cpu_to_be32(tconn->net_conf->two_primaries);
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847
	cf = 0;
848
	if (tconn->net_conf->want_lose)
849
		cf |= CF_WANT_LOSE;
850 851
	if (tconn->net_conf->dry_run) {
		if (tconn->agreed_pro_version >= 92)
852 853
			cf |= CF_DRY_RUN;
		else {
854
			conn_err(tconn, "--dry-run is not supported by peer");
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			kfree(p);
856
			return -EOPNOTSUPP;
857 858 859 860
		}
	}
	p->conn_flags    = cpu_to_be32(cf);

861 862
	if (tconn->agreed_pro_version >= 87)
		strcpy(p->integrity_alg, tconn->net_conf->integrity_alg);
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864
	err = conn_send_cmd2(tconn, P_PROTOCOL, p->head.payload, size - sizeof(struct p_header));
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	kfree(p);
866
	return err;
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}

int _drbd_send_uuids(struct drbd_conf *mdev, u64 uuid_flags)
{
	struct p_uuids p;
	int i;

	if (!get_ldev_if_state(mdev, D_NEGOTIATING))
875
		return 0;
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	for (i = UI_CURRENT; i < UI_SIZE; i++)
		p.uuid[i] = mdev->ldev ? cpu_to_be64(mdev->ldev->md.uuid[i]) : 0;

	mdev->comm_bm_set = drbd_bm_total_weight(mdev);
	p.uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set);
882
	uuid_flags |= mdev->tconn->net_conf->want_lose ? 1 : 0;
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	uuid_flags |= test_bit(CRASHED_PRIMARY, &mdev->flags) ? 2 : 0;
	uuid_flags |= mdev->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0;
	p.uuid[UI_FLAGS] = cpu_to_be64(uuid_flags);

	put_ldev(mdev);

889
	return drbd_send_cmd(mdev, &mdev->tconn->data, P_UUIDS, &p.head, sizeof(p));
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}

int drbd_send_uuids(struct drbd_conf *mdev)
{
	return _drbd_send_uuids(mdev, 0);
}

int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev)
{
	return _drbd_send_uuids(mdev, 8);
}

902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919
void drbd_print_uuids(struct drbd_conf *mdev, const char *text)
{
	if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
		u64 *uuid = mdev->ldev->md.uuid;
		dev_info(DEV, "%s %016llX:%016llX:%016llX:%016llX\n",
		     text,
		     (unsigned long long)uuid[UI_CURRENT],
		     (unsigned long long)uuid[UI_BITMAP],
		     (unsigned long long)uuid[UI_HISTORY_START],
		     (unsigned long long)uuid[UI_HISTORY_END]);
		put_ldev(mdev);
	} else {
		dev_info(DEV, "%s effective data uuid: %016llX\n",
				text,
				(unsigned long long)mdev->ed_uuid);
	}
}

920
void drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev)
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{
	struct p_rs_uuid p;
923 924 925
	u64 uuid;

	D_ASSERT(mdev->state.disk == D_UP_TO_DATE);
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927
	uuid = mdev->ldev->md.uuid[UI_BITMAP] + UUID_NEW_BM_OFFSET;
928
	drbd_uuid_set(mdev, UI_BITMAP, uuid);
929
	drbd_print_uuids(mdev, "updated sync UUID");
930 931
	drbd_md_sync(mdev);
	p.uuid = cpu_to_be64(uuid);
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933
	drbd_send_cmd(mdev, &mdev->tconn->data, P_SYNC_UUID, &p.head, sizeof(p));
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}

936
int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags)
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{
	struct p_sizes p;
	sector_t d_size, u_size;
940
	int q_order_type, max_bio_size;
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	if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
		D_ASSERT(mdev->ldev->backing_bdev);
		d_size = drbd_get_max_capacity(mdev->ldev);
		u_size = mdev->ldev->dc.disk_size;
		q_order_type = drbd_queue_order_type(mdev);
947 948
		max_bio_size = queue_max_hw_sectors(mdev->ldev->backing_bdev->bd_disk->queue) << 9;
		max_bio_size = min_t(int, max_bio_size, DRBD_MAX_BIO_SIZE);
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		put_ldev(mdev);
	} else {
		d_size = 0;
		u_size = 0;
		q_order_type = QUEUE_ORDERED_NONE;
954
		max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
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	}

	p.d_size = cpu_to_be64(d_size);
	p.u_size = cpu_to_be64(u_size);
	p.c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(mdev->this_bdev));
960
	p.max_bio_size = cpu_to_be32(max_bio_size);
961 962
	p.queue_order_type = cpu_to_be16(q_order_type);
	p.dds_flags = cpu_to_be16(flags);
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964
	return drbd_send_cmd(mdev, &mdev->tconn->data, P_SIZES, &p.head, sizeof(p));
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}

/**
 * drbd_send_state() - Sends the drbd state to the peer
 * @mdev:	DRBD device.
 */
int drbd_send_state(struct drbd_conf *mdev)
{
	struct socket *sock;
	struct p_state p;
975
	int err = -EIO;
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977
	mutex_lock(&mdev->tconn->data.mutex);
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	p.state = cpu_to_be32(mdev->state.i); /* Within the send mutex */
980
	sock = mdev->tconn->data.socket;
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982
	if (likely(sock != NULL))
983
		err = _drbd_send_cmd(mdev, sock, P_STATE, &p.head, sizeof(p), 0);
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985
	mutex_unlock(&mdev->tconn->data.mutex);
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987
	return err;
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}

990 991
int _conn_send_state_req(struct drbd_tconn *tconn, int vnr, enum drbd_packet cmd,
			 union drbd_state mask, union drbd_state val)
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{
	struct p_req_state p;

	p.mask    = cpu_to_be32(mask.i);
	p.val     = cpu_to_be32(val.i);

998
	return conn_send_cmd(tconn, vnr, &tconn->data, cmd, &p.head, sizeof(p));
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}

1001
void drbd_send_sr_reply(struct drbd_conf *mdev, enum drbd_state_rv retcode)
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{
	struct p_req_state_reply p;

	p.retcode    = cpu_to_be32(retcode);

1007
	drbd_send_cmd(mdev, &mdev->tconn->meta, P_STATE_CHG_REPLY, &p.head, sizeof(p));
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}

1010 1011 1012 1013 1014 1015 1016
int conn_send_sr_reply(struct drbd_tconn *tconn, enum drbd_state_rv retcode)
{
	struct p_req_state_reply p;
	enum drbd_packet cmd = tconn->agreed_pro_version < 100 ? P_STATE_CHG_REPLY : P_CONN_ST_CHG_REPLY;

	p.retcode    = cpu_to_be32(retcode);

1017
	return !conn_send_cmd(tconn, 0, &tconn->meta, cmd, &p.head, sizeof(p));
1018 1019
}

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int fill_bitmap_rle_bits(struct drbd_conf *mdev,
	struct p_compressed_bm *p,
	struct bm_xfer_ctx *c)
{
	struct bitstream bs;
	unsigned long plain_bits;
	unsigned long tmp;
	unsigned long rl;
	unsigned len;
	unsigned toggle;
	int bits;

	/* may we use this feature? */
1033
	if ((mdev->tconn->net_conf->use_rle == 0) ||
1034
		(mdev->tconn->agreed_pro_version < 90))
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			return 0;

	if (c->bit_offset >= c->bm_bits)
		return 0; /* nothing to do. */

	/* use at most thus many bytes */
	bitstream_init(&bs, p->code, BM_PACKET_VLI_BYTES_MAX, 0);
	memset(p->code, 0, BM_PACKET_VLI_BYTES_MAX);
	/* plain bits covered in this code string */
	plain_bits = 0;

	/* p->encoding & 0x80 stores whether the first run length is set.
	 * bit offset is implicit.
	 * start with toggle == 2 to be able to tell the first iteration */
	toggle = 2;

	/* see how much plain bits we can stuff into one packet
	 * using RLE and VLI. */
	do {
		tmp = (toggle == 0) ? _drbd_bm_find_next_zero(mdev, c->bit_offset)
				    : _drbd_bm_find_next(mdev, c->bit_offset);
		if (tmp == -1UL)
			tmp = c->bm_bits;
		rl = tmp - c->bit_offset;

		if (toggle == 2) { /* first iteration */
			if (rl == 0) {
				/* the first checked bit was set,
				 * store start value, */
				DCBP_set_start(p, 1);
				/* but skip encoding of zero run length */
				toggle = !toggle;
				continue;
			}
			DCBP_set_start(p, 0);
		}

		/* paranoia: catch zero runlength.
		 * can only happen if bitmap is modified while we scan it. */
		if (rl == 0) {
			dev_err(DEV, "unexpected zero runlength while encoding bitmap "
			    "t:%u bo:%lu\n", toggle, c->bit_offset);
			return -1;
		}

		bits = vli_encode_bits(&bs, rl);
		if (bits == -ENOBUFS) /* buffer full */
			break;
		if (bits <= 0) {
			dev_err(DEV, "error while encoding bitmap: %d\n", bits);
			return 0;
		}

		toggle = !toggle;
		plain_bits += rl;
		c->bit_offset = tmp;
	} while (c->bit_offset < c->bm_bits);

	len = bs.cur.b - p->code + !!bs.cur.bit;

	if (plain_bits < (len << 3)) {
		/* incompressible with this method.
		 * we need to rewind both word and bit position. */
		c->bit_offset -= plain_bits;
		bm_xfer_ctx_bit_to_word_offset(c);
		c->bit_offset = c->word_offset * BITS_PER_LONG;
		return 0;
	}

	/* RLE + VLI was able to compress it just fine.
	 * update c->word_offset. */
	bm_xfer_ctx_bit_to_word_offset(c);

	/* store pad_bits */
	DCBP_set_pad_bits(p, (8 - bs.cur.bit) & 0x7);

	return len;
}

1114 1115 1116 1117 1118 1119 1120
/**
 * send_bitmap_rle_or_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
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send_bitmap_rle_or_plain(struct drbd_conf *mdev,
1122
			 struct p_header *h, struct bm_xfer_ctx *c)
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{
	struct p_compressed_bm *p = (void*)h;
	unsigned long num_words;
1126
	int len, err;
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	len = fill_bitmap_rle_bits(mdev, p, c);

	if (len < 0)
1131
		return -EIO;
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	if (len) {
		DCBP_set_code(p, RLE_VLI_Bits);
1135 1136
		err = _drbd_send_cmd(mdev, mdev->tconn->data.socket,
				     P_COMPRESSED_BITMAP, h,
1137
				     sizeof(*p) + len, 0);
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		c->packets[0]++;
		c->bytes[0] += sizeof(*p) + len;

		if (c->bit_offset >= c->bm_bits)
			len = 0; /* DONE */
	} else {
		/* was not compressible.
		 * send a buffer full of plain text bits instead. */
		num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
		len = num_words * sizeof(long);
		if (len)
			drbd_bm_get_lel(mdev, c->word_offset, num_words, (unsigned long*)h->payload);
1151
		err = _drbd_send_cmd(mdev, mdev->tconn->data.socket, P_BITMAP,
1152
				     h, sizeof(struct p_header80) + len, 0);
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		c->word_offset += num_words;
		c->bit_offset = c->word_offset * BITS_PER_LONG;

		c->packets[1]++;
1157
		c->bytes[1] += sizeof(struct p_header80) + len;
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		if (c->bit_offset > c->bm_bits)
			c->bit_offset = c->bm_bits;
	}
1162
	if (!err) {
1163 1164 1165 1166 1167 1168 1169
		if (len == 0) {
			INFO_bm_xfer_stats(mdev, "send", c);
			return 0;
		} else
			return 1;
	}
	return -EIO;
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}

/* See the comment at receive_bitmap() */
int _drbd_send_bitmap(struct drbd_conf *mdev)
{
	struct bm_xfer_ctx c;
1176
	struct p_header *p;
1177
	int err;
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1179 1180
	if (!expect(mdev->bitmap))
		return false;
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	/* maybe we should use some per thread scratch page,
	 * and allocate that during initial device creation? */
1184
	p = (struct p_header *) __get_free_page(GFP_NOIO);
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	if (!p) {
		dev_err(DEV, "failed to allocate one page buffer in %s\n", __func__);
1187
		return false;
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	}

	if (get_ldev(mdev)) {
		if (drbd_md_test_flag(mdev->ldev, MDF_FULL_SYNC)) {
			dev_info(DEV, "Writing the whole bitmap, MDF_FullSync was set.\n");
			drbd_bm_set_all(mdev);
			if (drbd_bm_write(mdev)) {
				/* write_bm did fail! Leave full sync flag set in Meta P_DATA
				 * but otherwise process as per normal - need to tell other
				 * side that a full resync is required! */
				dev_err(DEV, "Failed to write bitmap to disk!\n");
			} else {
				drbd_md_clear_flag(mdev, MDF_FULL_SYNC);
				drbd_md_sync(mdev);
			}
		}
		put_ldev(mdev);
	}

	c = (struct bm_xfer_ctx) {
		.bm_bits = drbd_bm_bits(mdev),
		.bm_words = drbd_bm_words(mdev),
	};

	do {
1213 1214
		err = send_bitmap_rle_or_plain(mdev, p, &c);
	} while (err > 0);
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	free_page((unsigned long) p);
1217
	return err == 0;
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}

int drbd_send_bitmap(struct drbd_conf *mdev)
{
	int err;

1224
	if (drbd_get_data_sock(mdev->tconn))
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		return -1;
	err = !_drbd_send_bitmap(mdev);
1227
	drbd_put_data_sock(mdev->tconn);
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	return err;
}
1230
void drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, u32 set_size)
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{
	struct p_barrier_ack p;

	p.barrier  = barrier_nr;
	p.set_size = cpu_to_be32(set_size);

1237 1238
	if (mdev->state.conn >= C_CONNECTED)
		drbd_send_cmd(mdev, &mdev->tconn->meta, P_BARRIER_ACK, &p.head, sizeof(p));
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}

/**
 * _drbd_send_ack() - Sends an ack packet
 * @mdev:	DRBD device.
 * @cmd:	Packet command code.
 * @sector:	sector, needs to be in big endian byte order
 * @blksize:	size in byte, needs to be in big endian byte order
 * @block_id:	Id, big endian byte order
 */
1249 1250
static int _drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
			  u64 sector, u32 blksize, u64 block_id)
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{
	struct p_block_ack p;

	p.sector   = sector;
	p.block_id = block_id;
	p.blksize  = blksize;
1257
	p.seq_num  = cpu_to_be32(atomic_inc_return(&mdev->packet_seq));
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1259
	if (!mdev->tconn->meta.socket || mdev->state.conn < C_CONNECTED)
1260 1261
		return -EIO;
	return drbd_send_cmd(mdev, &mdev->tconn->meta, cmd, &p.head, sizeof(p));
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}

1264 1265 1266
/* dp->sector and dp->block_id already/still in network byte order,
 * data_size is payload size according to dp->head,
 * and may need to be corrected for digest size. */
1267 1268
void drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd,
		      struct p_data *dp, int data_size)
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{
1270 1271
	data_size -= (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
1272 1273
	_drbd_send_ack(mdev, cmd, dp->sector, cpu_to_be32(data_size),
		       dp->block_id);
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}

1276 1277
void drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packet cmd,
		      struct p_block_req *rp)
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{
1279
	_drbd_send_ack(mdev, cmd, rp->sector, rp->blksize, rp->block_id);
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}

/**
 * drbd_send_ack() - Sends an ack packet
1284 1285 1286
 * @mdev:	DRBD device
 * @cmd:	packet command code
 * @peer_req:	peer request
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 */
1288
int drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
1289
		  struct drbd_peer_request *peer_req)
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{
1291 1292 1293 1294
	return _drbd_send_ack(mdev, cmd,
			      cpu_to_be64(peer_req->i.sector),
			      cpu_to_be32(peer_req->i.size),
			      peer_req->block_id);
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}

/* This function misuses the block_id field to signal if the blocks
 * are is sync or not. */
1299
int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packet cmd,
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		     sector_t sector, int blksize, u64 block_id)
{
1302 1303 1304 1305
	return _drbd_send_ack(mdev, cmd,
			      cpu_to_be64(sector),
			      cpu_to_be32(blksize),
			      cpu_to_be64(block_id));
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}

int drbd_send_drequest(struct drbd_conf *mdev, int cmd,
		       sector_t sector, int size, u64 block_id)
{
	struct p_block_req p;

	p.sector   = cpu_to_be64(sector);
	p.block_id = block_id;
	p.blksize  = cpu_to_be32(size);

1317
	return drbd_send_cmd(mdev, &mdev->tconn->data, cmd, &p.head, sizeof(p));
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}

1320 1321
int drbd_send_drequest_csum(struct drbd_conf *mdev, sector_t sector, int size,
			    void *digest, int digest_size, enum drbd_packet cmd)
P
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{
1323
	int err;
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	struct p_block_req p;

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	prepare_header(mdev, &p.head, cmd, sizeof(p) - sizeof(struct p_header) + digest_size);
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	p.sector   = cpu_to_be64(sector);
1328
	p.block_id = ID_SYNCER /* unused */;
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	p.blksize  = cpu_to_be32(size);

1331
	mutex_lock(&mdev->tconn->data.mutex);
1332 1333 1334
	err = drbd_send_all(mdev->tconn, mdev->tconn->data.socket, &p, sizeof(p), 0);
	if (!err)
		err = drbd_send_all(mdev->tconn, mdev->tconn->data.socket, digest, digest_size, 0);
1335
	mutex_unlock(&mdev->tconn->data.mutex);
1336
	return err;
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}

int drbd_send_ov_request(struct drbd_conf *mdev, sector_t sector, int size)
{
	struct p_block_req p;

	p.sector   = cpu_to_be64(sector);
1344
	p.block_id = ID_SYNCER /* unused */;
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	p.blksize  = cpu_to_be32(size);

1347
	return drbd_send_cmd(mdev, &mdev->tconn->data, P_OV_REQUEST, &p.head, sizeof(p));
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}

/* called on sndtimeo
1351 1352
 * returns false if we should retry,
 * true if we think connection is dead
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 */
1354
static int we_should_drop_the_connection(struct drbd_tconn *tconn, struct socket *sock)
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{
	int drop_it;
	/* long elapsed = (long)(jiffies - mdev->last_received); */

1359 1360 1361
	drop_it =   tconn->meta.socket == sock
		|| !tconn->asender.task
		|| get_t_state(&tconn->asender) != RUNNING
1362
		|| tconn->cstate < C_WF_REPORT_PARAMS;
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	if (drop_it)
1365
		return true;
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1366

1367
	drop_it = !--tconn->ko_count;
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	if (!drop_it) {
1369 1370 1371
		conn_err(tconn, "[%s/%d] sock_sendmsg time expired, ko = %u\n",
			 current->comm, current->pid, tconn->ko_count);
		request_ping(tconn);
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	}

	return drop_it; /* && (mdev->state == R_PRIMARY) */;
}

1377
static void drbd_update_congested(struct drbd_tconn *tconn)
1378
{
1379
	struct sock *sk = tconn->data.socket->sk;
1380
	if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
1381
		set_bit(NET_CONGESTED, &tconn->flags);
1382 1383
}

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/* The idea of sendpage seems to be to put some kind of reference
 * to the page into the skb, and to hand it over to the NIC. In
 * this process get_page() gets called.
 *
 * As soon as the page was really sent over the network put_page()
 * gets called by some part of the network layer. [ NIC driver? ]
 *
 * [ get_page() / put_page() increment/decrement the count. If count
 *   reaches 0 the page will be freed. ]
 *
 * This works nicely with pages from FSs.
 * But this means that in protocol A we might signal IO completion too early!
 *
 * In order not to corrupt data during a resync we must make sure
 * that we do not reuse our own buffer pages (EEs) to early, therefore
 * we have the net_ee list.
 *
 * XFS seems to have problems, still, it submits pages with page_count == 0!
 * As a workaround, we disable sendpage on pages
 * with page_count == 0 or PageSlab.
 */
static int _drbd_no_send_page(struct drbd_conf *mdev, struct page *page,
1406
			      int offset, size_t size, unsigned msg_flags)
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{
1408 1409 1410 1411 1412 1413 1414
	struct socket *socket;
	void *addr;
	int err;

	socket = mdev->tconn->data.socket;
	addr = kmap(page) + offset;
	err = drbd_send_all(mdev->tconn, socket, addr, size, msg_flags);
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	kunmap(page);
1416 1417 1418
	if (!err)
		mdev->send_cnt += size >> 9;
	return err;
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}

static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
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		    int offset, size_t size, unsigned msg_flags)
P
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{
1424
	struct socket *socket = mdev->tconn->data.socket;
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	mm_segment_t oldfs = get_fs();
	int len = size;
1427
	int err = -EIO;
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	/* e.g. XFS meta- & log-data is in slab pages, which have a
	 * page_count of 0 and/or have PageSlab() set.
	 * we cannot use send_page for those, as that does get_page();
	 * put_page(); and would cause either a VM_BUG directly, or
	 * __page_cache_release a page that would actually still be referenced
	 * by someone, leading to some obscure delayed Oops somewhere else. */
	if (disable_sendpage || (page_count(page) < 1) || PageSlab(page))
1436
		return _drbd_no_send_page(mdev, page, offset, size, msg_flags);
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	msg_flags |= MSG_NOSIGNAL;
1439
	drbd_update_congested(mdev->tconn);
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1440 1441
	set_fs(KERNEL_DS);
	do {
1442 1443 1444
		int sent;

		sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
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		if (sent <= 0) {
1446 1447 1448 1449 1450
			if (sent == -EAGAIN) {
				if (we_should_drop_the_connection(mdev->tconn, socket))
					break;
				continue;
			}
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			dev_warn(DEV, "%s: size=%d len=%d sent=%d\n",
			     __func__, (int)size, len, sent);
1453 1454
			if (sent < 0)
				err = sent;
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			break;
		}
		len    -= sent;
		offset += sent;
	} while (len > 0 /* THINK && mdev->cstate >= C_CONNECTED*/);
	set_fs(oldfs);
1461
	clear_bit(NET_CONGESTED, &mdev->tconn->flags);
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1463 1464 1465 1466 1467
	if (len == 0) {
		err = 0;
		mdev->send_cnt += size >> 9;
	}
	return err;
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}

static int _drbd_send_bio(struct drbd_conf *mdev, struct bio *bio)
{
	struct bio_vec *bvec;
	int i;
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	/* hint all but last page with MSG_MORE */
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	__bio_for_each_segment(bvec, bio, i, 0) {
1476 1477 1478 1479 1480 1481 1482
		int err;

		err = _drbd_no_send_page(mdev, bvec->bv_page,
					 bvec->bv_offset, bvec->bv_len,
					 i == bio->bi_vcnt - 1 ? 0 : MSG_MORE);
		if (err)
			return err;
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	}
1484
	return 0;
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}

static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio)
{
	struct bio_vec *bvec;
	int i;
L
Lars Ellenberg 已提交
1491
	/* hint all but last page with MSG_MORE */
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Philipp Reisner 已提交
1492
	__bio_for_each_segment(bvec, bio, i, 0) {
1493 1494 1495 1496 1497 1498 1499
		int err;

		err = _drbd_send_page(mdev, bvec->bv_page,
				      bvec->bv_offset, bvec->bv_len,
				      i == bio->bi_vcnt - 1 ? 0 : MSG_MORE);
		if (err)
			return err;
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	}
1501
	return 0;
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}

1504 1505
static int _drbd_send_zc_ee(struct drbd_conf *mdev,
			    struct drbd_peer_request *peer_req)
1506
{
1507 1508
	struct page *page = peer_req->pages;
	unsigned len = peer_req->i.size;
1509
	int err;
1510

L
Lars Ellenberg 已提交
1511
	/* hint all but last page with MSG_MORE */
1512 1513
	page_chain_for_each(page) {
		unsigned l = min_t(unsigned, len, PAGE_SIZE);
1514 1515 1516 1517 1518

		err = _drbd_send_page(mdev, page, 0, l,
				      page_chain_next(page) ? MSG_MORE : 0);
		if (err)
			return err;
1519 1520
		len -= l;
	}
1521
	return 0;
1522 1523
}

1524 1525
static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
{
1526
	if (mdev->tconn->agreed_pro_version >= 95)
1527 1528 1529 1530 1531
		return  (bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
			(bi_rw & REQ_FUA ? DP_FUA : 0) |
			(bi_rw & REQ_FLUSH ? DP_FLUSH : 0) |
			(bi_rw & REQ_DISCARD ? DP_DISCARD : 0);
	else
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1532
		return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
1533 1534
}

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/* Used to send write requests
 * R_PRIMARY -> Peer	(P_DATA)
 */
int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
{
1540
	int err;
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1541 1542 1543 1544 1545
	struct p_data p;
	unsigned int dp_flags = 0;
	void *dgb;
	int dgs;

1546 1547 1548
	err = drbd_get_data_sock(mdev->tconn);
	if (err)
		return err;
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1549

1550 1551
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_w_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_w_tfm) : 0;
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1552

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	prepare_header(mdev, &p.head, P_DATA, sizeof(p) - sizeof(struct p_header) + dgs + req->i.size);
1554
	p.sector   = cpu_to_be64(req->i.sector);
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1555
	p.block_id = (unsigned long)req;
1556
	p.seq_num  = cpu_to_be32(req->seq_num = atomic_inc_return(&mdev->packet_seq));
P
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1557

1558 1559
	dp_flags = bio_flags_to_wire(mdev, req->master_bio->bi_rw);

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1560 1561 1562 1563 1564 1565
	if (mdev->state.conn >= C_SYNC_SOURCE &&
	    mdev->state.conn <= C_PAUSED_SYNC_T)
		dp_flags |= DP_MAY_SET_IN_SYNC;

	p.dp_flags = cpu_to_be32(dp_flags);
	set_bit(UNPLUG_REMOTE, &mdev->flags);
1566 1567 1568
	err = drbd_send_all(mdev->tconn, mdev->tconn->data.socket, &p,
			    sizeof(p), dgs ? MSG_MORE : 0);
	if (!err && dgs) {
1569 1570
		dgb = mdev->tconn->int_dig_out;
		drbd_csum_bio(mdev, mdev->tconn->integrity_w_tfm, req->master_bio, dgb);
1571
		err = drbd_send_all(mdev->tconn, mdev->tconn->data.socket, dgb, dgs, 0);
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	}
1573
	if (!err) {
1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584
		/* For protocol A, we have to memcpy the payload into
		 * socket buffers, as we may complete right away
		 * as soon as we handed it over to tcp, at which point the data
		 * pages may become invalid.
		 *
		 * For data-integrity enabled, we copy it as well, so we can be
		 * sure that even if the bio pages may still be modified, it
		 * won't change the data on the wire, thus if the digest checks
		 * out ok after sending on this side, but does not fit on the
		 * receiving side, we sure have detected corruption elsewhere.
		 */
1585
		if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A || dgs)
1586
			err = _drbd_send_bio(mdev, req->master_bio);
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		else
1588
			err = _drbd_send_zc_bio(mdev, req->master_bio);
1589 1590 1591

		/* double check digest, sometimes buffers have been modified in flight. */
		if (dgs > 0 && dgs <= 64) {
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			/* 64 byte, 512 bit, is the largest digest size
1593 1594
			 * currently supported in kernel crypto. */
			unsigned char digest[64];
1595 1596
			drbd_csum_bio(mdev, mdev->tconn->integrity_w_tfm, req->master_bio, digest);
			if (memcmp(mdev->tconn->int_dig_out, digest, dgs)) {
1597 1598
				dev_warn(DEV,
					"Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
1599
					(unsigned long long)req->i.sector, req->i.size);
1600 1601 1602 1603
			}
		} /* else if (dgs > 64) {
		     ... Be noisy about digest too large ...
		} */
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	}

1606
	drbd_put_data_sock(mdev->tconn);
1607

1608
	return err;
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}

/* answer packet, used to send data back for read requests:
 *  Peer       -> (diskless) R_PRIMARY   (P_DATA_REPLY)
 *  C_SYNC_SOURCE -> C_SYNC_TARGET         (P_RS_DATA_REPLY)
 */
1615
int drbd_send_block(struct drbd_conf *mdev, enum drbd_packet cmd,
1616
		    struct drbd_peer_request *peer_req)
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1617
{
1618
	int err;
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	struct p_data p;
	void *dgb;
	int dgs;

1623 1624
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_w_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_w_tfm) : 0;
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1626 1627 1628 1629 1630
	prepare_header(mdev, &p.head, cmd, sizeof(p) -
					   sizeof(struct p_header80) +
					   dgs + peer_req->i.size);
	p.sector   = cpu_to_be64(peer_req->i.sector);
	p.block_id = peer_req->block_id;
1631
	p.seq_num = 0;  /* unused */
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	/* Only called by our kernel thread.
	 * This one may be interrupted by DRBD_SIG and/or DRBD_SIGKILL
	 * in response to admin command or module unload.
	 */
1637 1638 1639 1640 1641 1642
	err = drbd_get_data_sock(mdev->tconn);
	if (err)
		return err;
	err = drbd_send_all(mdev->tconn, mdev->tconn->data.socket, &p,
			    sizeof(p), dgs ? MSG_MORE : 0);
	if (!err && dgs) {
1643
		dgb = mdev->tconn->int_dig_out;
1644
		drbd_csum_ee(mdev, mdev->tconn->integrity_w_tfm, peer_req, dgb);
1645 1646
		err = drbd_send_all(mdev->tconn, mdev->tconn->data.socket, dgb,
				    dgs, 0);
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	}
1648 1649
	if (!err)
		err = _drbd_send_zc_ee(mdev, peer_req);
1650
	drbd_put_data_sock(mdev->tconn);
1651

1652
	return err;
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1653 1654
}

1655
int drbd_send_out_of_sync(struct drbd_conf *mdev, struct drbd_request *req)
1656 1657 1658
{
	struct p_block_desc p;

1659 1660
	p.sector  = cpu_to_be64(req->i.sector);
	p.blksize = cpu_to_be32(req->i.size);
1661

1662
	return drbd_send_cmd(mdev, &mdev->tconn->data, P_OUT_OF_SYNC, &p.head, sizeof(p));
1663 1664
}

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1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680
/*
  drbd_send distinguishes two cases:

  Packets sent via the data socket "sock"
  and packets sent via the meta data socket "msock"

		    sock                      msock
  -----------------+-------------------------+------------------------------
  timeout           conf.timeout / 2          conf.timeout / 2
  timeout action    send a ping via msock     Abort communication
					      and close all sockets
*/

/*
 * you must have down()ed the appropriate [m]sock_mutex elsewhere!
 */
1681
int drbd_send(struct drbd_tconn *tconn, struct socket *sock,
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1682 1683 1684 1685 1686 1687 1688
	      void *buf, size_t size, unsigned msg_flags)
{
	struct kvec iov;
	struct msghdr msg;
	int rv, sent = 0;

	if (!sock)
1689
		return -EBADR;
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1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701

	/* THINK  if (signal_pending) return ... ? */

	iov.iov_base = buf;
	iov.iov_len  = size;

	msg.msg_name       = NULL;
	msg.msg_namelen    = 0;
	msg.msg_control    = NULL;
	msg.msg_controllen = 0;
	msg.msg_flags      = msg_flags | MSG_NOSIGNAL;

1702 1703 1704
	if (sock == tconn->data.socket) {
		tconn->ko_count = tconn->net_conf->ko_count;
		drbd_update_congested(tconn);
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	}
	do {
		/* STRANGE
		 * tcp_sendmsg does _not_ use its size parameter at all ?
		 *
		 * -EAGAIN on timeout, -EINTR on signal.
		 */
/* THINK
 * do we need to block DRBD_SIG if sock == &meta.socket ??
 * otherwise wake_asender() might interrupt some send_*Ack !
 */
		rv = kernel_sendmsg(sock, &msg, &iov, 1, size);
		if (rv == -EAGAIN) {
1718
			if (we_should_drop_the_connection(tconn, sock))
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1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733
				break;
			else
				continue;
		}
		if (rv == -EINTR) {
			flush_signals(current);
			rv = 0;
		}
		if (rv < 0)
			break;
		sent += rv;
		iov.iov_base += rv;
		iov.iov_len  -= rv;
	} while (sent < size);

1734 1735
	if (sock == tconn->data.socket)
		clear_bit(NET_CONGESTED, &tconn->flags);
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1736 1737 1738

	if (rv <= 0) {
		if (rv != -EAGAIN) {
1739 1740 1741
			conn_err(tconn, "%s_sendmsg returned %d\n",
				 sock == tconn->meta.socket ? "msock" : "sock",
				 rv);
1742
			conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
P
Philipp Reisner 已提交
1743
		} else
1744
			conn_request_state(tconn, NS(conn, C_TIMEOUT), CS_HARD);
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1745 1746 1747 1748 1749
	}

	return sent;
}

1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767
/**
 * drbd_send_all  -  Send an entire buffer
 *
 * Returns 0 upon success and a negative error value otherwise.
 */
int drbd_send_all(struct drbd_tconn *tconn, struct socket *sock, void *buffer,
		  size_t size, unsigned msg_flags)
{
	int err;

	err = drbd_send(tconn, sock, buffer, size, msg_flags);
	if (err < 0)
		return err;
	if (err != size)
		return -EIO;
	return 0;
}

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1768 1769 1770 1771 1772 1773
static int drbd_open(struct block_device *bdev, fmode_t mode)
{
	struct drbd_conf *mdev = bdev->bd_disk->private_data;
	unsigned long flags;
	int rv = 0;

1774
	mutex_lock(&drbd_main_mutex);
1775
	spin_lock_irqsave(&mdev->tconn->req_lock, flags);
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1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787
	/* to have a stable mdev->state.role
	 * and no race with updating open_cnt */

	if (mdev->state.role != R_PRIMARY) {
		if (mode & FMODE_WRITE)
			rv = -EROFS;
		else if (!allow_oos)
			rv = -EMEDIUMTYPE;
	}

	if (!rv)
		mdev->open_cnt++;
1788
	spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
1789
	mutex_unlock(&drbd_main_mutex);
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1790 1791 1792 1793 1794 1795 1796

	return rv;
}

static int drbd_release(struct gendisk *gd, fmode_t mode)
{
	struct drbd_conf *mdev = gd->private_data;
1797
	mutex_lock(&drbd_main_mutex);
P
Philipp Reisner 已提交
1798
	mdev->open_cnt--;
1799
	mutex_unlock(&drbd_main_mutex);
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1800 1801 1802 1803 1804
	return 0;
}

static void drbd_set_defaults(struct drbd_conf *mdev)
{
1805 1806
	/* Beware! The actual layout differs
	 * between big endian and little endian */
P
Philipp Reisner 已提交
1807 1808 1809 1810 1811 1812
	mdev->state = (union drbd_state) {
		{ .role = R_SECONDARY,
		  .peer = R_UNKNOWN,
		  .conn = C_STANDALONE,
		  .disk = D_DISKLESS,
		  .pdsk = D_UNKNOWN,
1813 1814 1815
		  .susp = 0,
		  .susp_nod = 0,
		  .susp_fen = 0
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1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830
		} };
}

void drbd_init_set_defaults(struct drbd_conf *mdev)
{
	/* the memset(,0,) did most of this.
	 * note: only assignments, no allocation in here */

	drbd_set_defaults(mdev);

	atomic_set(&mdev->ap_bio_cnt, 0);
	atomic_set(&mdev->ap_pending_cnt, 0);
	atomic_set(&mdev->rs_pending_cnt, 0);
	atomic_set(&mdev->unacked_cnt, 0);
	atomic_set(&mdev->local_cnt, 0);
1831
	atomic_set(&mdev->pp_in_use_by_net, 0);
1832
	atomic_set(&mdev->rs_sect_in, 0);
1833
	atomic_set(&mdev->rs_sect_ev, 0);
1834
	atomic_set(&mdev->ap_in_flight, 0);
P
Philipp Reisner 已提交
1835 1836

	mutex_init(&mdev->md_io_mutex);
1837 1838
	mutex_init(&mdev->own_state_mutex);
	mdev->state_mutex = &mdev->own_state_mutex;
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1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851

	spin_lock_init(&mdev->al_lock);
	spin_lock_init(&mdev->peer_seq_lock);
	spin_lock_init(&mdev->epoch_lock);

	INIT_LIST_HEAD(&mdev->active_ee);
	INIT_LIST_HEAD(&mdev->sync_ee);
	INIT_LIST_HEAD(&mdev->done_ee);
	INIT_LIST_HEAD(&mdev->read_ee);
	INIT_LIST_HEAD(&mdev->net_ee);
	INIT_LIST_HEAD(&mdev->resync_reads);
	INIT_LIST_HEAD(&mdev->resync_work.list);
	INIT_LIST_HEAD(&mdev->unplug_work.list);
1852
	INIT_LIST_HEAD(&mdev->go_diskless.list);
P
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1853
	INIT_LIST_HEAD(&mdev->md_sync_work.list);
1854
	INIT_LIST_HEAD(&mdev->start_resync_work.list);
P
Philipp Reisner 已提交
1855
	INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
1856

1857
	mdev->resync_work.cb  = w_resync_timer;
P
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1858
	mdev->unplug_work.cb  = w_send_write_hint;
1859
	mdev->go_diskless.cb  = w_go_diskless;
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1860 1861
	mdev->md_sync_work.cb = w_md_sync;
	mdev->bm_io_work.w.cb = w_bitmap_io;
1862
	mdev->start_resync_work.cb = w_start_resync;
1863 1864 1865 1866 1867 1868 1869 1870

	mdev->resync_work.mdev  = mdev;
	mdev->unplug_work.mdev  = mdev;
	mdev->go_diskless.mdev  = mdev;
	mdev->md_sync_work.mdev = mdev;
	mdev->bm_io_work.w.mdev = mdev;
	mdev->start_resync_work.mdev = mdev;

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1871 1872
	init_timer(&mdev->resync_timer);
	init_timer(&mdev->md_sync_timer);
1873
	init_timer(&mdev->start_resync_timer);
1874
	init_timer(&mdev->request_timer);
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1875 1876 1877 1878
	mdev->resync_timer.function = resync_timer_fn;
	mdev->resync_timer.data = (unsigned long) mdev;
	mdev->md_sync_timer.function = md_sync_timer_fn;
	mdev->md_sync_timer.data = (unsigned long) mdev;
1879 1880
	mdev->start_resync_timer.function = start_resync_timer_fn;
	mdev->start_resync_timer.data = (unsigned long) mdev;
1881 1882
	mdev->request_timer.function = request_timer_fn;
	mdev->request_timer.data = (unsigned long) mdev;
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1883 1884 1885 1886 1887 1888 1889

	init_waitqueue_head(&mdev->misc_wait);
	init_waitqueue_head(&mdev->state_wait);
	init_waitqueue_head(&mdev->ee_wait);
	init_waitqueue_head(&mdev->al_wait);
	init_waitqueue_head(&mdev->seq_wait);

P
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1890
	/* mdev->tconn->agreed_pro_version gets initialized in drbd_connect() */
1891
	mdev->write_ordering = WO_bdev_flush;
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1892
	mdev->resync_wenr = LC_FREE;
1893 1894
	mdev->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
	mdev->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
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}

void drbd_mdev_cleanup(struct drbd_conf *mdev)
{
1899
	int i;
1900
	if (mdev->tconn->receiver.t_state != NONE)
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1901
		dev_err(DEV, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
1902
				mdev->tconn->receiver.t_state);
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1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915

	/* no need to lock it, I'm the only thread alive */
	if (atomic_read(&mdev->current_epoch->epoch_size) !=  0)
		dev_err(DEV, "epoch_size:%d\n", atomic_read(&mdev->current_epoch->epoch_size));
	mdev->al_writ_cnt  =
	mdev->bm_writ_cnt  =
	mdev->read_cnt     =
	mdev->recv_cnt     =
	mdev->send_cnt     =
	mdev->writ_cnt     =
	mdev->p_size       =
	mdev->rs_start     =
	mdev->rs_total     =
1916 1917
	mdev->rs_failed    = 0;
	mdev->rs_last_events = 0;
1918
	mdev->rs_last_sect_ev = 0;
1919 1920 1921 1922
	for (i = 0; i < DRBD_SYNC_MARKS; i++) {
		mdev->rs_mark_left[i] = 0;
		mdev->rs_mark_time[i] = 0;
	}
1923
	D_ASSERT(mdev->tconn->net_conf == NULL);
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1924 1925 1926 1927

	drbd_set_my_capacity(mdev, 0);
	if (mdev->bitmap) {
		/* maybe never allocated. */
1928
		drbd_bm_resize(mdev, 0, 1);
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1929 1930 1931 1932
		drbd_bm_cleanup(mdev);
	}

	drbd_free_resources(mdev);
1933
	clear_bit(AL_SUSPENDED, &mdev->flags);
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1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944

	/*
	 * currently we drbd_init_ee only on module load, so
	 * we may do drbd_release_ee only on module unload!
	 */
	D_ASSERT(list_empty(&mdev->active_ee));
	D_ASSERT(list_empty(&mdev->sync_ee));
	D_ASSERT(list_empty(&mdev->done_ee));
	D_ASSERT(list_empty(&mdev->read_ee));
	D_ASSERT(list_empty(&mdev->net_ee));
	D_ASSERT(list_empty(&mdev->resync_reads));
1945 1946
	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
	D_ASSERT(list_empty(&mdev->tconn->meta.work.q));
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1947 1948
	D_ASSERT(list_empty(&mdev->resync_work.list));
	D_ASSERT(list_empty(&mdev->unplug_work.list));
1949
	D_ASSERT(list_empty(&mdev->go_diskless.list));
1950 1951

	drbd_set_defaults(mdev);
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}


static void drbd_destroy_mempools(void)
{
	struct page *page;

	while (drbd_pp_pool) {
		page = drbd_pp_pool;
		drbd_pp_pool = (struct page *)page_private(page);
		__free_page(page);
		drbd_pp_vacant--;
	}

	/* D_ASSERT(atomic_read(&drbd_pp_vacant)==0); */

1968 1969
	if (drbd_md_io_bio_set)
		bioset_free(drbd_md_io_bio_set);
1970 1971
	if (drbd_md_io_page_pool)
		mempool_destroy(drbd_md_io_page_pool);
P
Philipp Reisner 已提交
1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
	if (drbd_ee_mempool)
		mempool_destroy(drbd_ee_mempool);
	if (drbd_request_mempool)
		mempool_destroy(drbd_request_mempool);
	if (drbd_ee_cache)
		kmem_cache_destroy(drbd_ee_cache);
	if (drbd_request_cache)
		kmem_cache_destroy(drbd_request_cache);
	if (drbd_bm_ext_cache)
		kmem_cache_destroy(drbd_bm_ext_cache);
	if (drbd_al_ext_cache)
		kmem_cache_destroy(drbd_al_ext_cache);

1985
	drbd_md_io_bio_set   = NULL;
1986
	drbd_md_io_page_pool = NULL;
P
Philipp Reisner 已提交
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
	drbd_ee_mempool      = NULL;
	drbd_request_mempool = NULL;
	drbd_ee_cache        = NULL;
	drbd_request_cache   = NULL;
	drbd_bm_ext_cache    = NULL;
	drbd_al_ext_cache    = NULL;

	return;
}

static int drbd_create_mempools(void)
{
	struct page *page;
2000
	const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count;
P
Philipp Reisner 已提交
2001 2002 2003 2004 2005 2006 2007 2008 2009
	int i;

	/* prepare our caches and mempools */
	drbd_request_mempool = NULL;
	drbd_ee_cache        = NULL;
	drbd_request_cache   = NULL;
	drbd_bm_ext_cache    = NULL;
	drbd_al_ext_cache    = NULL;
	drbd_pp_pool         = NULL;
2010
	drbd_md_io_page_pool = NULL;
2011
	drbd_md_io_bio_set   = NULL;
P
Philipp Reisner 已提交
2012 2013 2014 2015 2016 2017 2018 2019

	/* caches */
	drbd_request_cache = kmem_cache_create(
		"drbd_req", sizeof(struct drbd_request), 0, 0, NULL);
	if (drbd_request_cache == NULL)
		goto Enomem;

	drbd_ee_cache = kmem_cache_create(
2020
		"drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
P
Philipp Reisner 已提交
2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
	if (drbd_ee_cache == NULL)
		goto Enomem;

	drbd_bm_ext_cache = kmem_cache_create(
		"drbd_bm", sizeof(struct bm_extent), 0, 0, NULL);
	if (drbd_bm_ext_cache == NULL)
		goto Enomem;

	drbd_al_ext_cache = kmem_cache_create(
		"drbd_al", sizeof(struct lc_element), 0, 0, NULL);
	if (drbd_al_ext_cache == NULL)
		goto Enomem;

	/* mempools */
2035 2036 2037 2038
	drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0);
	if (drbd_md_io_bio_set == NULL)
		goto Enomem;

2039 2040 2041 2042
	drbd_md_io_page_pool = mempool_create_page_pool(DRBD_MIN_POOL_PAGES, 0);
	if (drbd_md_io_page_pool == NULL)
		goto Enomem;

P
Philipp Reisner 已提交
2043 2044 2045 2046 2047 2048 2049
	drbd_request_mempool = mempool_create(number,
		mempool_alloc_slab, mempool_free_slab, drbd_request_cache);
	if (drbd_request_mempool == NULL)
		goto Enomem;

	drbd_ee_mempool = mempool_create(number,
		mempool_alloc_slab, mempool_free_slab, drbd_ee_cache);
2050
	if (drbd_ee_mempool == NULL)
P
Philipp Reisner 已提交
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110
		goto Enomem;

	/* drbd's page pool */
	spin_lock_init(&drbd_pp_lock);

	for (i = 0; i < number; i++) {
		page = alloc_page(GFP_HIGHUSER);
		if (!page)
			goto Enomem;
		set_page_private(page, (unsigned long)drbd_pp_pool);
		drbd_pp_pool = page;
	}
	drbd_pp_vacant = number;

	return 0;

Enomem:
	drbd_destroy_mempools(); /* in case we allocated some */
	return -ENOMEM;
}

static int drbd_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	/* just so we have it.  you never know what interesting things we
	 * might want to do here some day...
	 */

	return NOTIFY_DONE;
}

static struct notifier_block drbd_notifier = {
	.notifier_call = drbd_notify_sys,
};

static void drbd_release_ee_lists(struct drbd_conf *mdev)
{
	int rr;

	rr = drbd_release_ee(mdev, &mdev->active_ee);
	if (rr)
		dev_err(DEV, "%d EEs in active list found!\n", rr);

	rr = drbd_release_ee(mdev, &mdev->sync_ee);
	if (rr)
		dev_err(DEV, "%d EEs in sync list found!\n", rr);

	rr = drbd_release_ee(mdev, &mdev->read_ee);
	if (rr)
		dev_err(DEV, "%d EEs in read list found!\n", rr);

	rr = drbd_release_ee(mdev, &mdev->done_ee);
	if (rr)
		dev_err(DEV, "%d EEs in done list found!\n", rr);

	rr = drbd_release_ee(mdev, &mdev->net_ee);
	if (rr)
		dev_err(DEV, "%d EEs in net list found!\n", rr);
}

2111 2112
/* caution. no locking. */
void drbd_delete_device(unsigned int minor)
P
Philipp Reisner 已提交
2113 2114 2115 2116 2117 2118
{
	struct drbd_conf *mdev = minor_to_mdev(minor);

	if (!mdev)
		return;

2119 2120 2121
	idr_remove(&mdev->tconn->volumes, mdev->vnr);
	idr_remove(&minors, minor);
	synchronize_rcu();
2122

P
Philipp Reisner 已提交
2123
	/* paranoia asserts */
2124
	D_ASSERT(mdev->open_cnt == 0);
2125
	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
P
Philipp Reisner 已提交
2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154
	/* end paranoia asserts */

	del_gendisk(mdev->vdisk);

	/* cleanup stuff that may have been allocated during
	 * device (re-)configuration or state changes */

	if (mdev->this_bdev)
		bdput(mdev->this_bdev);

	drbd_free_resources(mdev);

	drbd_release_ee_lists(mdev);

	lc_destroy(mdev->act_log);
	lc_destroy(mdev->resync);

	kfree(mdev->p_uuid);
	/* mdev->p_uuid = NULL; */

	/* cleanup the rest that has been
	 * allocated from drbd_new_device
	 * and actually free the mdev itself */
	drbd_free_mdev(mdev);
}

static void drbd_cleanup(void)
{
	unsigned int i;
2155
	struct drbd_conf *mdev;
P
Philipp Reisner 已提交
2156 2157 2158

	unregister_reboot_notifier(&drbd_notifier);

2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169
	/* first remove proc,
	 * drbdsetup uses it's presence to detect
	 * whether DRBD is loaded.
	 * If we would get stuck in proc removal,
	 * but have netlink already deregistered,
	 * some drbdsetup commands may wait forever
	 * for an answer.
	 */
	if (drbd_proc)
		remove_proc_entry("drbd", NULL);

2170
	drbd_genl_unregister();
P
Philipp Reisner 已提交
2171

2172 2173 2174
	idr_for_each_entry(&minors, mdev, i)
		drbd_delete_device(i);
	drbd_destroy_mempools();
P
Philipp Reisner 已提交
2175 2176
	unregister_blkdev(DRBD_MAJOR, "drbd");

2177 2178
	idr_destroy(&minors);

P
Philipp Reisner 已提交
2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195
	printk(KERN_INFO "drbd: module cleanup done.\n");
}

/**
 * drbd_congested() - Callback for pdflush
 * @congested_data:	User data
 * @bdi_bits:		Bits pdflush is currently interested in
 *
 * Returns 1<<BDI_async_congested and/or 1<<BDI_sync_congested if we are congested.
 */
static int drbd_congested(void *congested_data, int bdi_bits)
{
	struct drbd_conf *mdev = congested_data;
	struct request_queue *q;
	char reason = '-';
	int r = 0;

2196
	if (!may_inc_ap_bio(mdev)) {
P
Philipp Reisner 已提交
2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210
		/* DRBD has frozen IO */
		r = bdi_bits;
		reason = 'd';
		goto out;
	}

	if (get_ldev(mdev)) {
		q = bdev_get_queue(mdev->ldev->backing_bdev);
		r = bdi_congested(&q->backing_dev_info, bdi_bits);
		put_ldev(mdev);
		if (r)
			reason = 'b';
	}

2211
	if (bdi_bits & (1 << BDI_async_congested) && test_bit(NET_CONGESTED, &mdev->tconn->flags)) {
P
Philipp Reisner 已提交
2212 2213 2214 2215 2216 2217 2218 2219 2220
		r |= (1 << BDI_async_congested);
		reason = reason == 'b' ? 'a' : 'n';
	}

out:
	mdev->congestion_reason = reason;
	return r;
}

2221 2222 2223 2224 2225 2226 2227
static void drbd_init_workqueue(struct drbd_work_queue* wq)
{
	sema_init(&wq->s, 0);
	spin_lock_init(&wq->q_lock);
	INIT_LIST_HEAD(&wq->q);
}

2228 2229 2230 2231
struct drbd_tconn *conn_by_name(const char *name)
{
	struct drbd_tconn *tconn;

2232 2233 2234
	if (!name || !name[0])
		return NULL;

2235
	mutex_lock(&drbd_cfg_mutex);
2236 2237 2238 2239 2240 2241
	list_for_each_entry(tconn, &drbd_tconns, all_tconn) {
		if (!strcmp(tconn->name, name))
			goto found;
	}
	tconn = NULL;
found:
2242
	mutex_unlock(&drbd_cfg_mutex);
2243 2244 2245
	return tconn;
}

2246
struct drbd_tconn *drbd_new_tconn(const char *name)
2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257
{
	struct drbd_tconn *tconn;

	tconn = kzalloc(sizeof(struct drbd_tconn), GFP_KERNEL);
	if (!tconn)
		return NULL;

	tconn->name = kstrdup(name, GFP_KERNEL);
	if (!tconn->name)
		goto fail;

2258 2259 2260
	if (!zalloc_cpumask_var(&tconn->cpu_mask, GFP_KERNEL))
		goto fail;

2261 2262 2263
	if (!tl_init(tconn))
		goto fail;

2264
	tconn->cstate = C_STANDALONE;
2265
	mutex_init(&tconn->cstate_mutex);
2266
	spin_lock_init(&tconn->req_lock);
2267 2268
	atomic_set(&tconn->net_cnt, 0);
	init_waitqueue_head(&tconn->net_cnt_wait);
2269
	init_waitqueue_head(&tconn->ping_wait);
2270
	idr_init(&tconn->volumes);
2271

2272 2273 2274 2275 2276 2277
	drbd_init_workqueue(&tconn->data.work);
	mutex_init(&tconn->data.mutex);

	drbd_init_workqueue(&tconn->meta.work);
	mutex_init(&tconn->meta.mutex);

2278 2279 2280 2281
	drbd_thread_init(tconn, &tconn->receiver, drbdd_init, "receiver");
	drbd_thread_init(tconn, &tconn->worker, drbd_worker, "worker");
	drbd_thread_init(tconn, &tconn->asender, drbd_asender, "asender");

2282 2283 2284 2285 2286
	tconn->res_opts = (struct res_opts) {
		{}, 0, /* cpu_mask */
		DRBD_ON_NO_DATA_DEF, /* on_no_data */
	};

2287 2288 2289
	mutex_lock(&drbd_cfg_mutex);
	list_add_tail(&tconn->all_tconn, &drbd_tconns);
	mutex_unlock(&drbd_cfg_mutex);
2290 2291 2292 2293

	return tconn;

fail:
2294
	tl_cleanup(tconn);
2295
	free_cpumask_var(tconn->cpu_mask);
2296 2297 2298 2299 2300 2301 2302 2303 2304
	kfree(tconn->name);
	kfree(tconn);

	return NULL;
}

void drbd_free_tconn(struct drbd_tconn *tconn)
{
	list_del(&tconn->all_tconn);
2305
	idr_destroy(&tconn->volumes);
2306

2307
	free_cpumask_var(tconn->cpu_mask);
2308
	kfree(tconn->name);
2309 2310 2311
	kfree(tconn->int_dig_out);
	kfree(tconn->int_dig_in);
	kfree(tconn->int_dig_vv);
2312 2313 2314
	kfree(tconn);
}

2315
enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr)
P
Philipp Reisner 已提交
2316 2317 2318 2319
{
	struct drbd_conf *mdev;
	struct gendisk *disk;
	struct request_queue *q;
2320
	int vnr_got = vnr;
2321
	int minor_got = minor;
2322
	enum drbd_ret_code err = ERR_NOMEM;
2323 2324 2325 2326

	mdev = minor_to_mdev(minor);
	if (mdev)
		return ERR_MINOR_EXISTS;
P
Philipp Reisner 已提交
2327 2328 2329 2330

	/* GFP_KERNEL, we are outside of all write-out paths */
	mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
	if (!mdev)
2331 2332 2333
		return ERR_NOMEM;

	mdev->tconn = tconn;
P
Philipp Reisner 已提交
2334
	mdev->minor = minor;
2335
	mdev->vnr = vnr;
P
Philipp Reisner 已提交
2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349

	drbd_init_set_defaults(mdev);

	q = blk_alloc_queue(GFP_KERNEL);
	if (!q)
		goto out_no_q;
	mdev->rq_queue = q;
	q->queuedata   = mdev;

	disk = alloc_disk(1);
	if (!disk)
		goto out_no_disk;
	mdev->vdisk = disk;

2350
	set_disk_ro(disk, true);
P
Philipp Reisner 已提交
2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365

	disk->queue = q;
	disk->major = DRBD_MAJOR;
	disk->first_minor = minor;
	disk->fops = &drbd_ops;
	sprintf(disk->disk_name, "drbd%d", minor);
	disk->private_data = mdev;

	mdev->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor));
	/* we have no partitions. we contain only ourselves. */
	mdev->this_bdev->bd_contains = mdev->this_bdev;

	q->backing_dev_info.congested_fn = drbd_congested;
	q->backing_dev_info.congested_data = mdev;

2366
	blk_queue_make_request(q, drbd_make_request);
2367 2368 2369
	/* Setting the max_hw_sectors to an odd value of 8kibyte here
	   This triggers a max_bio_size message upon first attach or connect */
	blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);
P
Philipp Reisner 已提交
2370 2371
	blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
	blk_queue_merge_bvec(q, drbd_merge_bvec);
2372
	q->queue_lock = &mdev->tconn->req_lock; /* needed since we use */
P
Philipp Reisner 已提交
2373 2374 2375 2376 2377 2378 2379

	mdev->md_io_page = alloc_page(GFP_KERNEL);
	if (!mdev->md_io_page)
		goto out_no_io_page;

	if (drbd_bm_init(mdev))
		goto out_no_bitmap;
2380
	mdev->read_requests = RB_ROOT;
2381
	mdev->write_requests = RB_ROOT;
P
Philipp Reisner 已提交
2382 2383 2384 2385 2386 2387 2388 2389

	mdev->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
	if (!mdev->current_epoch)
		goto out_no_epoch;

	INIT_LIST_HEAD(&mdev->current_epoch->list);
	mdev->epochs = 1;

2390
	if (!idr_pre_get(&minors, GFP_KERNEL))
2391 2392 2393
		goto out_no_minor_idr;
	if (idr_get_new_above(&minors, mdev, minor, &minor_got))
		goto out_no_minor_idr;
2394
	if (minor_got != minor) {
2395 2396
		err = ERR_MINOR_EXISTS;
		drbd_msg_put_info("requested minor exists already");
2397
		goto out_idr_remove_minor;
2398
	}
2399 2400 2401 2402 2403 2404 2405 2406 2407 2408

	if (!idr_pre_get(&tconn->volumes, GFP_KERNEL))
		goto out_idr_remove_minor;
	if (idr_get_new_above(&tconn->volumes, mdev, vnr, &vnr_got))
		goto out_idr_remove_minor;
	if (vnr_got != vnr) {
		err = ERR_INVALID_REQUEST;
		drbd_msg_put_info("requested volume exists already");
		goto out_idr_remove_vol;
	}
2409 2410
	add_disk(disk);

2411 2412 2413 2414 2415
	/* inherit the connection state */
	mdev->state.conn = tconn->cstate;
	if (mdev->state.conn == C_WF_REPORT_PARAMS)
		drbd_connected(vnr, mdev, tconn);

2416
	return NO_ERROR;
P
Philipp Reisner 已提交
2417

2418 2419
out_idr_remove_vol:
	idr_remove(&tconn->volumes, vnr_got);
2420 2421
out_idr_remove_minor:
	idr_remove(&minors, minor_got);
2422
	synchronize_rcu();
2423
out_no_minor_idr:
2424
	kfree(mdev->current_epoch);
P
Philipp Reisner 已提交
2425 2426 2427 2428 2429 2430 2431 2432 2433 2434
out_no_epoch:
	drbd_bm_cleanup(mdev);
out_no_bitmap:
	__free_page(mdev->md_io_page);
out_no_io_page:
	put_disk(disk);
out_no_disk:
	blk_cleanup_queue(q);
out_no_q:
	kfree(mdev);
2435
	return err;
P
Philipp Reisner 已提交
2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455
}

/* counterpart of drbd_new_device.
 * last part of drbd_delete_device. */
void drbd_free_mdev(struct drbd_conf *mdev)
{
	kfree(mdev->current_epoch);
	if (mdev->bitmap) /* should no longer be there. */
		drbd_bm_cleanup(mdev);
	__free_page(mdev->md_io_page);
	put_disk(mdev->vdisk);
	blk_cleanup_queue(mdev->rq_queue);
	kfree(mdev);
}


int __init drbd_init(void)
{
	int err;

P
Philipp Reisner 已提交
2456 2457
	BUILD_BUG_ON(sizeof(struct p_header80) != sizeof(struct p_header95));
	BUILD_BUG_ON(sizeof(struct p_handshake) != 80);
P
Philipp Reisner 已提交
2458

2459
	if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {
P
Philipp Reisner 已提交
2460
		printk(KERN_ERR
2461
		       "drbd: invalid minor_count (%d)\n", minor_count);
P
Philipp Reisner 已提交
2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476
#ifdef MODULE
		return -EINVAL;
#else
		minor_count = 8;
#endif
	}

	err = register_blkdev(DRBD_MAJOR, "drbd");
	if (err) {
		printk(KERN_ERR
		       "drbd: unable to register block device major %d\n",
		       DRBD_MAJOR);
		return err;
	}

2477 2478 2479 2480 2481 2482 2483
	err = drbd_genl_register();
	if (err) {
		printk(KERN_ERR "drbd: unable to register generic netlink family\n");
		goto fail;
	}


P
Philipp Reisner 已提交
2484 2485 2486 2487 2488 2489 2490 2491 2492 2493
	register_reboot_notifier(&drbd_notifier);

	/*
	 * allocate all necessary structs
	 */
	err = -ENOMEM;

	init_waitqueue_head(&drbd_pp_wait);

	drbd_proc = NULL; /* play safe for drbd_cleanup */
2494
	idr_init(&minors);
P
Philipp Reisner 已提交
2495 2496 2497

	err = drbd_create_mempools();
	if (err)
2498
		goto fail;
P
Philipp Reisner 已提交
2499

2500
	drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
P
Philipp Reisner 已提交
2501 2502
	if (!drbd_proc)	{
		printk(KERN_ERR "drbd: unable to register proc file\n");
2503
		goto fail;
P
Philipp Reisner 已提交
2504 2505 2506
	}

	rwlock_init(&global_state_lock);
2507
	INIT_LIST_HEAD(&drbd_tconns);
P
Philipp Reisner 已提交
2508 2509 2510 2511 2512 2513 2514 2515 2516 2517

	printk(KERN_INFO "drbd: initialized. "
	       "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n",
	       API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
	printk(KERN_INFO "drbd: %s\n", drbd_buildtag());
	printk(KERN_INFO "drbd: registered as block device major %d\n",
		DRBD_MAJOR);

	return 0; /* Success! */

2518
fail:
P
Philipp Reisner 已提交
2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532
	drbd_cleanup();
	if (err == -ENOMEM)
		/* currently always the case */
		printk(KERN_ERR "drbd: ran out of memory\n");
	else
		printk(KERN_ERR "drbd: initialization failure\n");
	return err;
}

void drbd_free_bc(struct drbd_backing_dev *ldev)
{
	if (ldev == NULL)
		return;

2533 2534
	blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
	blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
P
Philipp Reisner 已提交
2535 2536 2537 2538

	kfree(ldev);
}

2539 2540 2541 2542 2543 2544 2545 2546
void drbd_free_sock(struct drbd_tconn *tconn)
{
	if (tconn->data.socket) {
		mutex_lock(&tconn->data.mutex);
		kernel_sock_shutdown(tconn->data.socket, SHUT_RDWR);
		sock_release(tconn->data.socket);
		tconn->data.socket = NULL;
		mutex_unlock(&tconn->data.mutex);
P
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2547
	}
2548 2549 2550 2551 2552 2553
	if (tconn->meta.socket) {
		mutex_lock(&tconn->meta.mutex);
		kernel_sock_shutdown(tconn->meta.socket, SHUT_RDWR);
		sock_release(tconn->meta.socket);
		tconn->meta.socket = NULL;
		mutex_unlock(&tconn->meta.mutex);
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2554 2555 2556 2557 2558 2559
	}
}


void drbd_free_resources(struct drbd_conf *mdev)
{
2560 2561 2562 2563
	crypto_free_hash(mdev->tconn->csums_tfm);
	mdev->tconn->csums_tfm = NULL;
	crypto_free_hash(mdev->tconn->verify_tfm);
	mdev->tconn->verify_tfm = NULL;
2564 2565 2566 2567 2568 2569
	crypto_free_hash(mdev->tconn->cram_hmac_tfm);
	mdev->tconn->cram_hmac_tfm = NULL;
	crypto_free_hash(mdev->tconn->integrity_w_tfm);
	mdev->tconn->integrity_w_tfm = NULL;
	crypto_free_hash(mdev->tconn->integrity_r_tfm);
	mdev->tconn->integrity_r_tfm = NULL;
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2570

2571
	drbd_free_sock(mdev->tconn);
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2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589

	__no_warn(local,
		  drbd_free_bc(mdev->ldev);
		  mdev->ldev = NULL;);
}

/* meta data management */

struct meta_data_on_disk {
	u64 la_size;           /* last agreed size. */
	u64 uuid[UI_SIZE];   /* UUIDs. */
	u64 device_uuid;
	u64 reserved_u64_1;
	u32 flags;             /* MDF */
	u32 magic;
	u32 md_size_sect;
	u32 al_offset;         /* offset to this block */
	u32 al_nr_extents;     /* important for restoring the AL */
2590
	      /* `-- act_log->nr_elements <-- ldev->dc.al_extents */
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2591 2592
	u32 bm_offset;         /* offset to the bitmap, from here */
	u32 bm_bytes_per_bit;  /* BM_BLOCK_SIZE */
2593 2594
	u32 la_peer_max_bio_size;   /* last peer max_bio_size */
	u32 reserved_u32[3];
P
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} __packed;

/**
 * drbd_md_sync() - Writes the meta data super block if the MD_DIRTY flag bit is set
 * @mdev:	DRBD device.
 */
void drbd_md_sync(struct drbd_conf *mdev)
{
	struct meta_data_on_disk *buffer;
	sector_t sector;
	int i;

2608 2609
	del_timer(&mdev->md_sync_timer);
	/* timer may be rearmed by drbd_md_mark_dirty() now. */
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2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634
	if (!test_and_clear_bit(MD_DIRTY, &mdev->flags))
		return;

	/* We use here D_FAILED and not D_ATTACHING because we try to write
	 * metadata even if we detach due to a disk failure! */
	if (!get_ldev_if_state(mdev, D_FAILED))
		return;

	mutex_lock(&mdev->md_io_mutex);
	buffer = (struct meta_data_on_disk *)page_address(mdev->md_io_page);
	memset(buffer, 0, 512);

	buffer->la_size = cpu_to_be64(drbd_get_capacity(mdev->this_bdev));
	for (i = UI_CURRENT; i < UI_SIZE; i++)
		buffer->uuid[i] = cpu_to_be64(mdev->ldev->md.uuid[i]);
	buffer->flags = cpu_to_be32(mdev->ldev->md.flags);
	buffer->magic = cpu_to_be32(DRBD_MD_MAGIC);

	buffer->md_size_sect  = cpu_to_be32(mdev->ldev->md.md_size_sect);
	buffer->al_offset     = cpu_to_be32(mdev->ldev->md.al_offset);
	buffer->al_nr_extents = cpu_to_be32(mdev->act_log->nr_elements);
	buffer->bm_bytes_per_bit = cpu_to_be32(BM_BLOCK_SIZE);
	buffer->device_uuid = cpu_to_be64(mdev->ldev->md.device_uuid);

	buffer->bm_offset = cpu_to_be32(mdev->ldev->md.bm_offset);
2635
	buffer->la_peer_max_bio_size = cpu_to_be32(mdev->peer_max_bio_size);
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2636 2637 2638 2639

	D_ASSERT(drbd_md_ss__(mdev, mdev->ldev) == mdev->ldev->md.md_offset);
	sector = mdev->ldev->md.md_offset;

2640
	if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
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2641 2642
		/* this was a try anyways ... */
		dev_err(DEV, "meta data update failed!\n");
2643
		drbd_chk_io_error(mdev, 1, true);
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	}

	/* Update mdev->ldev->md.la_size_sect,
	 * since we updated it on metadata. */
	mdev->ldev->md.la_size_sect = drbd_get_capacity(mdev->this_bdev);

	mutex_unlock(&mdev->md_io_mutex);
	put_ldev(mdev);
}

/**
 * drbd_md_read() - Reads in the meta data super block
 * @mdev:	DRBD device.
 * @bdev:	Device from which the meta data should be read in.
 *
2659
 * Return 0 (NO_ERROR) on success, and an enum drbd_ret_code in case
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 * something goes wrong.  Currently only: ERR_IO_MD_DISK, ERR_MD_INVALID.
 */
int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
{
	struct meta_data_on_disk *buffer;
	int i, rv = NO_ERROR;

	if (!get_ldev_if_state(mdev, D_ATTACHING))
		return ERR_IO_MD_DISK;

	mutex_lock(&mdev->md_io_mutex);
	buffer = (struct meta_data_on_disk *)page_address(mdev->md_io_page);

2673
	if (drbd_md_sync_page_io(mdev, bdev, bdev->md.md_offset, READ)) {
L
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2674
		/* NOTE: can't do normal error processing here as this is
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2675 2676 2677 2678 2679 2680
		   called BEFORE disk is attached */
		dev_err(DEV, "Error while reading metadata.\n");
		rv = ERR_IO_MD_DISK;
		goto err;
	}

2681
	if (buffer->magic != cpu_to_be32(DRBD_MD_MAGIC)) {
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		dev_err(DEV, "Error while reading metadata, magic not found.\n");
		rv = ERR_MD_INVALID;
		goto err;
	}
	if (be32_to_cpu(buffer->al_offset) != bdev->md.al_offset) {
		dev_err(DEV, "unexpected al_offset: %d (expected %d)\n",
		    be32_to_cpu(buffer->al_offset), bdev->md.al_offset);
		rv = ERR_MD_INVALID;
		goto err;
	}
	if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
		dev_err(DEV, "unexpected bm_offset: %d (expected %d)\n",
		    be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
		rv = ERR_MD_INVALID;
		goto err;
	}
	if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
		dev_err(DEV, "unexpected md_size: %u (expected %u)\n",
		    be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
		rv = ERR_MD_INVALID;
		goto err;
	}

	if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) {
		dev_err(DEV, "unexpected bm_bytes_per_bit: %u (expected %u)\n",
		    be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE);
		rv = ERR_MD_INVALID;
		goto err;
	}

	bdev->md.la_size_sect = be64_to_cpu(buffer->la_size);
	for (i = UI_CURRENT; i < UI_SIZE; i++)
		bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
	bdev->md.flags = be32_to_cpu(buffer->flags);
2716
	bdev->dc.al_extents = be32_to_cpu(buffer->al_nr_extents);
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2717 2718
	bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);

2719
	spin_lock_irq(&mdev->tconn->req_lock);
2720 2721 2722 2723 2724 2725
	if (mdev->state.conn < C_CONNECTED) {
		int peer;
		peer = be32_to_cpu(buffer->la_peer_max_bio_size);
		peer = max_t(int, peer, DRBD_MAX_BIO_SIZE_SAFE);
		mdev->peer_max_bio_size = peer;
	}
2726
	spin_unlock_irq(&mdev->tconn->req_lock);
2727

2728 2729
	if (bdev->dc.al_extents < 7)
		bdev->dc.al_extents = 127;
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2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745

 err:
	mutex_unlock(&mdev->md_io_mutex);
	put_ldev(mdev);

	return rv;
}

/**
 * drbd_md_mark_dirty() - Mark meta data super block as dirty
 * @mdev:	DRBD device.
 *
 * Call this function if you change anything that should be written to
 * the meta-data super block. This function sets MD_DIRTY, and starts a
 * timer that ensures that within five seconds you have to call drbd_md_sync().
 */
2746
#ifdef DEBUG
2747 2748 2749 2750 2751 2752 2753 2754 2755
void drbd_md_mark_dirty_(struct drbd_conf *mdev, unsigned int line, const char *func)
{
	if (!test_and_set_bit(MD_DIRTY, &mdev->flags)) {
		mod_timer(&mdev->md_sync_timer, jiffies + HZ);
		mdev->last_md_mark_dirty.line = line;
		mdev->last_md_mark_dirty.func = func;
	}
}
#else
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void drbd_md_mark_dirty(struct drbd_conf *mdev)
{
2758
	if (!test_and_set_bit(MD_DIRTY, &mdev->flags))
2759
		mod_timer(&mdev->md_sync_timer, jiffies + 5*HZ);
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2760
}
2761
#endif
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static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
{
	int i;

2767
	for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
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		mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i];
}

void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
	if (idx == UI_CURRENT) {
		if (mdev->state.role == R_PRIMARY)
			val |= 1;
		else
			val &= ~((u64)1);

		drbd_set_ed_uuid(mdev, val);
	}

	mdev->ldev->md.uuid[idx] = val;
	drbd_md_mark_dirty(mdev);
}


void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
	if (mdev->ldev->md.uuid[idx]) {
		drbd_uuid_move_history(mdev);
		mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx];
	}
	_drbd_uuid_set(mdev, idx, val);
}

/**
 * drbd_uuid_new_current() - Creates a new current UUID
 * @mdev:	DRBD device.
 *
 * Creates a new current UUID, and rotates the old current UUID into
 * the bitmap slot. Causes an incremental resync upon next connect.
 */
void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local)
{
	u64 val;
2806 2807 2808 2809
	unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];

	if (bm_uuid)
		dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);
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2810 2811 2812 2813 2814

	mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT];

	get_random_bytes(&val, sizeof(u64));
	_drbd_uuid_set(mdev, UI_CURRENT, val);
2815
	drbd_print_uuids(mdev, "new current UUID");
2816 2817
	/* get it to stable storage _now_ */
	drbd_md_sync(mdev);
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}

void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)
{
	if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
		return;

	if (val == 0) {
		drbd_uuid_move_history(mdev);
		mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];
		mdev->ldev->md.uuid[UI_BITMAP] = 0;
	} else {
2830 2831 2832
		unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];
		if (bm_uuid)
			dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);
P
Philipp Reisner 已提交
2833

2834
		mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
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2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876
	}
	drbd_md_mark_dirty(mdev);
}

/**
 * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
 * @mdev:	DRBD device.
 *
 * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
 */
int drbd_bmio_set_n_write(struct drbd_conf *mdev)
{
	int rv = -EIO;

	if (get_ldev_if_state(mdev, D_ATTACHING)) {
		drbd_md_set_flag(mdev, MDF_FULL_SYNC);
		drbd_md_sync(mdev);
		drbd_bm_set_all(mdev);

		rv = drbd_bm_write(mdev);

		if (!rv) {
			drbd_md_clear_flag(mdev, MDF_FULL_SYNC);
			drbd_md_sync(mdev);
		}

		put_ldev(mdev);
	}

	return rv;
}

/**
 * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
 * @mdev:	DRBD device.
 *
 * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
 */
int drbd_bmio_clear_n_write(struct drbd_conf *mdev)
{
	int rv = -EIO;

2877
	drbd_resume_al(mdev);
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2878 2879 2880 2881 2882 2883 2884 2885 2886
	if (get_ldev_if_state(mdev, D_ATTACHING)) {
		drbd_bm_clear_all(mdev);
		rv = drbd_bm_write(mdev);
		put_ldev(mdev);
	}

	return rv;
}

2887
static int w_bitmap_io(struct drbd_work *w, int unused)
P
Philipp Reisner 已提交
2888 2889
{
	struct bm_io_work *work = container_of(w, struct bm_io_work, w);
2890
	struct drbd_conf *mdev = w->mdev;
2891
	int rv = -EIO;
P
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2892 2893 2894

	D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0);

2895
	if (get_ldev(mdev)) {
2896
		drbd_bm_lock(mdev, work->why, work->flags);
2897 2898 2899 2900
		rv = work->io_fn(mdev);
		drbd_bm_unlock(mdev);
		put_ldev(mdev);
	}
P
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2901

2902
	clear_bit_unlock(BITMAP_IO, &mdev->flags);
P
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2903 2904 2905 2906 2907 2908 2909
	wake_up(&mdev->misc_wait);

	if (work->done)
		work->done(mdev, rv);

	clear_bit(BITMAP_IO_QUEUED, &mdev->flags);
	work->why = NULL;
2910
	work->flags = 0;
P
Philipp Reisner 已提交
2911

2912
	return 0;
P
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2913 2914
}

2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927
void drbd_ldev_destroy(struct drbd_conf *mdev)
{
	lc_destroy(mdev->resync);
	mdev->resync = NULL;
	lc_destroy(mdev->act_log);
	mdev->act_log = NULL;
	__no_warn(local,
		drbd_free_bc(mdev->ldev);
		mdev->ldev = NULL;);

	clear_bit(GO_DISKLESS, &mdev->flags);
}

2928
static int w_go_diskless(struct drbd_work *w, int unused)
2929
{
2930 2931
	struct drbd_conf *mdev = w->mdev;

2932
	D_ASSERT(mdev->state.disk == D_FAILED);
2933 2934
	/* we cannot assert local_cnt == 0 here, as get_ldev_if_state will
	 * inc/dec it frequently. Once we are D_DISKLESS, no one will touch
2935 2936
	 * the protected members anymore, though, so once put_ldev reaches zero
	 * again, it will be safe to free them. */
2937
	drbd_force_state(mdev, NS(disk, D_DISKLESS));
2938
	return 0;
2939 2940 2941 2942 2943 2944
}

void drbd_go_diskless(struct drbd_conf *mdev)
{
	D_ASSERT(mdev->state.disk == D_FAILED);
	if (!test_and_set_bit(GO_DISKLESS, &mdev->flags))
2945
		drbd_queue_work(&mdev->tconn->data.work, &mdev->go_diskless);
2946 2947
}

P
Philipp Reisner 已提交
2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962
/**
 * drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap
 * @mdev:	DRBD device.
 * @io_fn:	IO callback to be called when bitmap IO is possible
 * @done:	callback to be called after the bitmap IO was performed
 * @why:	Descriptive text of the reason for doing the IO
 *
 * While IO on the bitmap happens we freeze application IO thus we ensure
 * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
 * called from worker context. It MUST NOT be used while a previous such
 * work is still pending!
 */
void drbd_queue_bitmap_io(struct drbd_conf *mdev,
			  int (*io_fn)(struct drbd_conf *),
			  void (*done)(struct drbd_conf *, int),
2963
			  char *why, enum bm_flag flags)
P
Philipp Reisner 已提交
2964
{
2965
	D_ASSERT(current == mdev->tconn->worker.task);
P
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2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976

	D_ASSERT(!test_bit(BITMAP_IO_QUEUED, &mdev->flags));
	D_ASSERT(!test_bit(BITMAP_IO, &mdev->flags));
	D_ASSERT(list_empty(&mdev->bm_io_work.w.list));
	if (mdev->bm_io_work.why)
		dev_err(DEV, "FIXME going to queue '%s' but '%s' still pending?\n",
			why, mdev->bm_io_work.why);

	mdev->bm_io_work.io_fn = io_fn;
	mdev->bm_io_work.done = done;
	mdev->bm_io_work.why = why;
2977
	mdev->bm_io_work.flags = flags;
P
Philipp Reisner 已提交
2978

2979
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2980 2981
	set_bit(BITMAP_IO, &mdev->flags);
	if (atomic_read(&mdev->ap_bio_cnt) == 0) {
2982
		if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags))
2983
			drbd_queue_work(&mdev->tconn->data.work, &mdev->bm_io_work.w);
P
Philipp Reisner 已提交
2984
	}
2985
	spin_unlock_irq(&mdev->tconn->req_lock);
P
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2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996
}

/**
 * drbd_bitmap_io() -  Does an IO operation on the whole bitmap
 * @mdev:	DRBD device.
 * @io_fn:	IO callback to be called when bitmap IO is possible
 * @why:	Descriptive text of the reason for doing the IO
 *
 * freezes application IO while that the actual IO operations runs. This
 * functions MAY NOT be called from worker context.
 */
2997 2998
int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *),
		char *why, enum bm_flag flags)
P
Philipp Reisner 已提交
2999 3000 3001
{
	int rv;

3002
	D_ASSERT(current != mdev->tconn->worker.task);
P
Philipp Reisner 已提交
3003

3004 3005
	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
		drbd_suspend_io(mdev);
P
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3006

3007
	drbd_bm_lock(mdev, why, flags);
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3008 3009 3010
	rv = io_fn(mdev);
	drbd_bm_unlock(mdev);

3011 3012
	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
		drbd_resume_io(mdev);
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3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040

	return rv;
}

void drbd_md_set_flag(struct drbd_conf *mdev, int flag) __must_hold(local)
{
	if ((mdev->ldev->md.flags & flag) != flag) {
		drbd_md_mark_dirty(mdev);
		mdev->ldev->md.flags |= flag;
	}
}

void drbd_md_clear_flag(struct drbd_conf *mdev, int flag) __must_hold(local)
{
	if ((mdev->ldev->md.flags & flag) != 0) {
		drbd_md_mark_dirty(mdev);
		mdev->ldev->md.flags &= ~flag;
	}
}
int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag)
{
	return (bdev->md.flags & flag) != 0;
}

static void md_sync_timer_fn(unsigned long data)
{
	struct drbd_conf *mdev = (struct drbd_conf *) data;

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	drbd_queue_work_front(&mdev->tconn->data.work, &mdev->md_sync_work);
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}

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static int w_md_sync(struct drbd_work *w, int unused)
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{
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	struct drbd_conf *mdev = w->mdev;

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	dev_warn(DEV, "md_sync_timer expired! Worker calls drbd_md_sync().\n");
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#ifdef DEBUG
	dev_warn(DEV, "last md_mark_dirty: %s:%u\n",
		mdev->last_md_mark_dirty.func, mdev->last_md_mark_dirty.line);
#endif
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	drbd_md_sync(mdev);
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	return 0;
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}

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const char *cmdname(enum drbd_packet cmd)
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{
	/* THINK may need to become several global tables
	 * when we want to support more than
	 * one PRO_VERSION */
	static const char *cmdnames[] = {
		[P_DATA]	        = "Data",
		[P_DATA_REPLY]	        = "DataReply",
		[P_RS_DATA_REPLY]	= "RSDataReply",
		[P_BARRIER]	        = "Barrier",
		[P_BITMAP]	        = "ReportBitMap",
		[P_BECOME_SYNC_TARGET]  = "BecomeSyncTarget",
		[P_BECOME_SYNC_SOURCE]  = "BecomeSyncSource",
		[P_UNPLUG_REMOTE]	= "UnplugRemote",
		[P_DATA_REQUEST]	= "DataRequest",
		[P_RS_DATA_REQUEST]     = "RSDataRequest",
		[P_SYNC_PARAM]	        = "SyncParam",
		[P_SYNC_PARAM89]	= "SyncParam89",
		[P_PROTOCOL]            = "ReportProtocol",
		[P_UUIDS]	        = "ReportUUIDs",
		[P_SIZES]	        = "ReportSizes",
		[P_STATE]	        = "ReportState",
		[P_SYNC_UUID]           = "ReportSyncUUID",
		[P_AUTH_CHALLENGE]      = "AuthChallenge",
		[P_AUTH_RESPONSE]	= "AuthResponse",
		[P_PING]		= "Ping",
		[P_PING_ACK]	        = "PingAck",
		[P_RECV_ACK]	        = "RecvAck",
		[P_WRITE_ACK]	        = "WriteAck",
		[P_RS_WRITE_ACK]	= "RSWriteAck",
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		[P_DISCARD_WRITE]        = "DiscardWrite",
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		[P_NEG_ACK]	        = "NegAck",
		[P_NEG_DREPLY]	        = "NegDReply",
		[P_NEG_RS_DREPLY]	= "NegRSDReply",
		[P_BARRIER_ACK]	        = "BarrierAck",
		[P_STATE_CHG_REQ]       = "StateChgRequest",
		[P_STATE_CHG_REPLY]     = "StateChgReply",
		[P_OV_REQUEST]          = "OVRequest",
		[P_OV_REPLY]            = "OVReply",
		[P_OV_RESULT]           = "OVResult",
		[P_CSUM_RS_REQUEST]     = "CsumRSRequest",
		[P_RS_IS_IN_SYNC]	= "CsumRSIsInSync",
		[P_COMPRESSED_BITMAP]   = "CBitmap",
		[P_DELAY_PROBE]         = "DelayProbe",
		[P_OUT_OF_SYNC]		= "OutOfSync",
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		[P_RETRY_WRITE]		= "RetryWrite",
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	};

	if (cmd == P_HAND_SHAKE_M)
		return "HandShakeM";
	if (cmd == P_HAND_SHAKE_S)
		return "HandShakeS";
	if (cmd == P_HAND_SHAKE)
		return "HandShake";
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	if (cmd >= ARRAY_SIZE(cmdnames))
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		return "Unknown";
	return cmdnames[cmd];
}

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/**
 * drbd_wait_misc  -  wait for a request to make progress
 * @mdev:	device associated with the request
 * @i:		the struct drbd_interval embedded in struct drbd_request or
 *		struct drbd_peer_request
 */
int drbd_wait_misc(struct drbd_conf *mdev, struct drbd_interval *i)
{
	struct net_conf *net_conf = mdev->tconn->net_conf;
	DEFINE_WAIT(wait);
	long timeout;

	if (!net_conf)
		return -ETIMEDOUT;
	timeout = MAX_SCHEDULE_TIMEOUT;
	if (net_conf->ko_count)
		timeout = net_conf->timeout * HZ / 10 * net_conf->ko_count;

	/* Indicate to wake up mdev->misc_wait on progress.  */
	i->waiting = true;
	prepare_to_wait(&mdev->misc_wait, &wait, TASK_INTERRUPTIBLE);
	spin_unlock_irq(&mdev->tconn->req_lock);
	timeout = schedule_timeout(timeout);
	finish_wait(&mdev->misc_wait, &wait);
	spin_lock_irq(&mdev->tconn->req_lock);
	if (!timeout || mdev->state.conn < C_CONNECTED)
		return -ETIMEDOUT;
	if (signal_pending(current))
		return -ERESTARTSYS;
	return 0;
}

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#ifdef CONFIG_DRBD_FAULT_INJECTION
/* Fault insertion support including random number generator shamelessly
 * stolen from kernel/rcutorture.c */
struct fault_random_state {
	unsigned long state;
	unsigned long count;
};

#define FAULT_RANDOM_MULT 39916801  /* prime */
#define FAULT_RANDOM_ADD	479001701 /* prime */
#define FAULT_RANDOM_REFRESH 10000

/*
 * Crude but fast random-number generator.  Uses a linear congruential
 * generator, with occasional help from get_random_bytes().
 */
static unsigned long
_drbd_fault_random(struct fault_random_state *rsp)
{
	long refresh;

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	if (!rsp->count--) {
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		get_random_bytes(&refresh, sizeof(refresh));
		rsp->state += refresh;
		rsp->count = FAULT_RANDOM_REFRESH;
	}
	rsp->state = rsp->state * FAULT_RANDOM_MULT + FAULT_RANDOM_ADD;
	return swahw32(rsp->state);
}

static char *
_drbd_fault_str(unsigned int type) {
	static char *_faults[] = {
		[DRBD_FAULT_MD_WR] = "Meta-data write",
		[DRBD_FAULT_MD_RD] = "Meta-data read",
		[DRBD_FAULT_RS_WR] = "Resync write",
		[DRBD_FAULT_RS_RD] = "Resync read",
		[DRBD_FAULT_DT_WR] = "Data write",
		[DRBD_FAULT_DT_RD] = "Data read",
		[DRBD_FAULT_DT_RA] = "Data read ahead",
		[DRBD_FAULT_BM_ALLOC] = "BM allocation",
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		[DRBD_FAULT_AL_EE] = "EE allocation",
		[DRBD_FAULT_RECEIVE] = "receive data corruption",
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	};

	return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**";
}

unsigned int
_drbd_insert_fault(struct drbd_conf *mdev, unsigned int type)
{
	static struct fault_random_state rrs = {0, 0};

	unsigned int ret = (
		(fault_devs == 0 ||
			((1 << mdev_to_minor(mdev)) & fault_devs) != 0) &&
		(((_drbd_fault_random(&rrs) % 100) + 1) <= fault_rate));

	if (ret) {
		fault_count++;

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		if (__ratelimit(&drbd_ratelimit_state))
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			dev_warn(DEV, "***Simulating %s failure\n",
				_drbd_fault_str(type));
	}

	return ret;
}
#endif

const char *drbd_buildtag(void)
{
	/* DRBD built from external sources has here a reference to the
	   git hash of the source code. */

	static char buildtag[38] = "\0uilt-in";

	if (buildtag[0] == 0) {
#ifdef CONFIG_MODULES
		if (THIS_MODULE != NULL)
			sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
		else
#endif
			buildtag[0] = 'b';
	}

	return buildtag;
}

module_init(drbd_init)
module_exit(drbd_cleanup)

EXPORT_SYMBOL(drbd_conn_str);
EXPORT_SYMBOL(drbd_role_str);
EXPORT_SYMBOL(drbd_disk_str);
EXPORT_SYMBOL(drbd_set_st_err_str);