drbd_main.c 84.1 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);
static int w_md_sync(struct drbd_conf *mdev, struct drbd_work *w, int unused);
static void md_sync_timer_fn(unsigned long data);
static int w_bitmap_io(struct drbd_conf *mdev, struct drbd_work *w, int unused);
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static int w_go_diskless(struct drbd_conf *mdev, 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, "Maximum number of drbd devices ("
		 __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(cn_idx, uint, 0444);
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;
unsigned int cn_idx = CN_IDX_DRBD;
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;"
 */
struct drbd_conf **minor_table;
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struct list_head drbd_tconns;  /* list of struct drbd_tconn */
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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;

/* 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,
};

#define ARRY_SIZE(A) (sizeof(A)/sizeof(A[0]))

#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.
 */
static int tl_init(struct drbd_conf *mdev)
{
	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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	mdev->tconn->oldest_tle = b;
	mdev->tconn->newest_tle = b;
	INIT_LIST_HEAD(&mdev->tconn->out_of_sequence_requests);
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	return 1;
}

static void tl_cleanup(struct drbd_conf *mdev)
{
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	D_ASSERT(mdev->tconn->oldest_tle == mdev->tconn->newest_tle);
	D_ASSERT(list_empty(&mdev->tconn->out_of_sequence_requests));
	kfree(mdev->tconn->oldest_tle);
	mdev->tconn->oldest_tle = NULL;
	kfree(mdev->tconn->unused_spare_tle);
	mdev->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.
 */
void _tl_add_barrier(struct drbd_conf *mdev, struct drbd_tl_epoch *new)
{
	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 = mdev->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 (mdev->tconn->newest_tle != new) {
		mdev->tconn->newest_tle->next = new;
		mdev->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.
 */
void tl_release(struct drbd_conf *mdev, unsigned int barrier_nr,
		       unsigned int set_size)
{
	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(&mdev->tconn->req_lock);
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	b = mdev->tconn->oldest_tle;
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	/* first some paranoia code */
	if (b == NULL) {
		dev_err(DEV, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
			barrier_nr);
		goto bail;
	}
	if (b->br_number != barrier_nr) {
		dev_err(DEV, "BAD! BarrierAck #%u received, expected #%u!\n",
			barrier_nr, b->br_number);
		goto bail;
	}
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	if (b->n_writes != set_size) {
		dev_err(DEV, "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);

	nob = b->next;
	if (test_and_clear_bit(CREATE_BARRIER, &mdev->flags)) {
		_tl_add_barrier(mdev, b);
		if (nob)
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			mdev->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 mdev->tconn->oldest_tle points already to b */
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	} else {
		D_ASSERT(nob != NULL);
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		mdev->tconn->oldest_tle = nob;
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		kfree(b);
	}

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

	return;

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

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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_conf *mdev, 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 = mdev->tconn->oldest_tle;
	pn = &mdev->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;
					inc_ap_pending(mdev);
					set_bit(CREATE_BARRIER, &mdev->flags);
				}

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				drbd_queue_work(&mdev->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)
				dec_ap_pending(mdev);

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			if (b == mdev->tconn->newest_tle) {
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				/* recycle, but reinit! */
				D_ASSERT(tmp == NULL);
				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.
 */
void tl_clear(struct drbd_conf *mdev)
{
	struct list_head *le, *tle;
	struct drbd_request *r;

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	spin_lock_irq(&mdev->tconn->req_lock);
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	_tl_restart(mdev, CONNECTION_LOST_WHILE_PENDING);
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	/* we expect this list to be empty. */
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	D_ASSERT(list_empty(&mdev->tconn->out_of_sequence_requests));
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	/* but just in case, clean it up anyways! */
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	list_for_each_safe(le, tle, &mdev->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 */
	clear_bit(CREATE_BARRIER, &mdev->flags);

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

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

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

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	snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
		 thi->name[0], thi->mdev->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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		dev_info(DEV, "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);

	dev_info(DEV, "Terminating %s\n", current->comm);

	/* Release mod reference taken when thread was started */
	module_put(THIS_MODULE);
	return retval;
}

static void drbd_thread_init(struct drbd_conf *mdev, 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;
	thi->mdev = mdev;
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	strncpy(thi->name, name, ARRAY_SIZE(thi->name));
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}

int drbd_thread_start(struct drbd_thread *thi)
{
	struct drbd_conf *mdev = thi->mdev;
	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) {
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	case NONE:
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		dev_info(DEV, "Starting %s thread (from %s [%d])\n",
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			 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)) {
			dev_err(DEV, "Failed to get module reference in drbd_thread_start\n");
			spin_unlock_irqrestore(&thi->t_lock, flags);
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			return false;
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		}

		init_completion(&thi->stop);
		D_ASSERT(thi->task == NULL);
		thi->reset_cpu_mask = 1;
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		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,
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				    "drbd%d_%s", mdev_to_minor(mdev), thi->name);
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		if (IS_ERR(nt)) {
			dev_err(DEV, "Couldn't start thread\n");

			module_put(THIS_MODULE);
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			return false;
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		}
		spin_lock_irqsave(&thi->t_lock, flags);
		thi->task = nt;
538
		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		wake_up_process(nt);
		break;
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	case EXITING:
		thi->t_state = RESTARTING;
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		dev_info(DEV, "Restarting %s thread (from %s [%d])\n",
545
				thi->name, current->comm, current->pid);
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		/* fall through */
547 548
	case RUNNING:
	case RESTARTING:
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	default:
		spin_unlock_irqrestore(&thi->t_lock, flags);
		break;
	}

554
	return true;
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}


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

562
	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);

567
	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);
}

594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610
static struct drbd_thread *drbd_task_to_thread(struct drbd_conf *mdev, struct task_struct *task)
{
	struct drbd_tconn *tconn = mdev->tconn;
	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;
}

char *drbd_task_to_thread_name(struct drbd_conf *mdev, struct task_struct *task)
{
	struct drbd_thread *thi = drbd_task_to_thread(mdev, task);
	return thi ? thi->name : task->comm;
}

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#ifdef CONFIG_SMP
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static int conn_lowest_minor(struct drbd_tconn *tconn)
{
	int minor = 0;
	idr_get_next(&tconn->volumes, &minor);
	return minor;
}
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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.
 */
625
void drbd_calc_cpu_mask(struct drbd_tconn *tconn)
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{
	int ord, cpu;

	/* user override. */
630
	if (cpumask_weight(tconn->cpu_mask))
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		return;

633
	ord = conn_lowest_minor(tconn) % cpumask_weight(cpu_online_mask);
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	for_each_online_cpu(cpu) {
		if (ord-- == 0) {
636
			cpumask_set_cpu(cpu, tconn->cpu_mask);
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			return;
		}
	}
	/* should not be reached */
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	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.
647
 * @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.
 */
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void drbd_thread_current_set_cpu(struct drbd_thread *thi)
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{
	struct task_struct *p = current;
655

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	if (!thi->reset_cpu_mask)
		return;
	thi->reset_cpu_mask = 0;
659
	set_cpus_allowed_ptr(p, thi->mdev->tconn->cpu_mask);
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}
#endif

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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);
}

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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);
}

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static void _prepare_header(struct drbd_tconn *tconn, int vnr, struct p_header *h,
			    enum drbd_packet cmd, int size)
{
	if (tconn->agreed_pro_version >= 100 || size > DRBD_MAX_SIZE_H80_PACKET)
		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,
687
			   enum drbd_packet cmd, int size)
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{
689
	_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,
694 695
		   enum drbd_packet cmd, struct p_header *h, size_t size,
		   unsigned msg_flags)
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{
	int sent, ok;

699
	_prepare_header(tconn, vnr, h, cmd, size - sizeof(struct p_header));
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701
	sent = drbd_send(tconn, sock, h, size, msg_flags);
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	ok = (sent == size);
704
	if (!ok && !signal_pending(current))
705 706
		conn_warn(tconn, "short sent %s size=%d sent=%d\n",
			  cmdname(cmd), (int)size, sent);
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	return ok;
}

/* don't pass the socket. we may only look at it
 * when we hold the appropriate socket mutex.
 */
int drbd_send_cmd(struct drbd_conf *mdev, int use_data_socket,
714
		  enum drbd_packet cmd, struct p_header *h, size_t size)
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{
	int ok = 0;
	struct socket *sock;

	if (use_data_socket) {
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		mutex_lock(&mdev->tconn->data.mutex);
		sock = mdev->tconn->data.socket;
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	} else {
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		mutex_lock(&mdev->tconn->meta.mutex);
		sock = mdev->tconn->meta.socket;
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	}

	/* drbd_disconnect() could have called drbd_free_sock()
	 * while we were waiting in down()... */
	if (likely(sock != NULL))
		ok = _drbd_send_cmd(mdev, sock, cmd, h, size, 0);

	if (use_data_socket)
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		mutex_unlock(&mdev->tconn->data.mutex);
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	else
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		mutex_unlock(&mdev->tconn->meta.mutex);
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	return ok;
}

739
int conn_send_cmd2(struct drbd_tconn *tconn, enum drbd_packet cmd, char *data,
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		   size_t size)
{
742
	struct p_header80 h;
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	int ok;

745
	prepare_header80(&h, cmd, size);
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747
	if (!drbd_get_data_sock(tconn))
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		return 0;

	ok = (sizeof(h) ==
751
		drbd_send(tconn, tconn->data.socket, &h, sizeof(h), 0));
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	ok = ok && (size ==
753
		drbd_send(tconn, tconn->data.socket, data, size, 0));
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755
	drbd_put_data_sock(tconn);
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	return ok;
}

int drbd_send_sync_param(struct drbd_conf *mdev, struct syncer_conf *sc)
{
762
	struct p_rs_param_95 *p;
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	struct socket *sock;
	int size, rv;
765
	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)
			+ strlen(mdev->sync_conf.verify_alg) + 1
770 771
		: 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 */
776 777
	mutex_lock(&mdev->tconn->data.mutex);
	sock = mdev->tconn->data.socket;
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	if (likely(sock != NULL)) {
780 781
		enum drbd_packet cmd =
			apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
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783
		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);

		p->rate = cpu_to_be32(sc->rate);
789 790 791 792
		p->c_plan_ahead = cpu_to_be32(sc->c_plan_ahead);
		p->c_delay_target = cpu_to_be32(sc->c_delay_target);
		p->c_fill_target = cpu_to_be32(sc->c_fill_target);
		p->c_max_rate = cpu_to_be32(sc->c_max_rate);
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		if (apv >= 88)
			strcpy(p->verify_alg, mdev->sync_conf.verify_alg);
		if (apv >= 89)
			strcpy(p->csums_alg, mdev->sync_conf.csums_alg);

		rv = _drbd_send_cmd(mdev, sock, cmd, &p->head, size, 0);
	} else
		rv = 0; /* not ok */

803
	mutex_unlock(&mdev->tconn->data.mutex);
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	return rv;
}

808
int drbd_send_protocol(struct drbd_tconn *tconn)
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{
	struct p_protocol *p;
811
	int size, cf, rv;
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	size = sizeof(struct p_protocol);

815 816
	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)
		return 0;

824 825 826 827 828
	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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830
	cf = 0;
831
	if (tconn->net_conf->want_lose)
832
		cf |= CF_WANT_LOSE;
833 834
	if (tconn->net_conf->dry_run) {
		if (tconn->agreed_pro_version >= 92)
835 836
			cf |= CF_DRY_RUN;
		else {
837
			conn_err(tconn, "--dry-run is not supported by peer");
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			kfree(p);
839
			return -1;
840 841 842 843
		}
	}
	p->conn_flags    = cpu_to_be32(cf);

844 845
	if (tconn->agreed_pro_version >= 87)
		strcpy(p->integrity_alg, tconn->net_conf->integrity_alg);
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847
	rv = conn_send_cmd2(tconn, P_PROTOCOL, p->head.payload, size - sizeof(struct p_header));
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	kfree(p);
	return rv;
}

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))
		return 1;

	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);
865
	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);

872
	return drbd_send_cmd(mdev, USE_DATA_SOCKET, 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);
}

885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902
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);
	}
}

903
int drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev)
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{
	struct p_rs_uuid p;
906 907 908
	u64 uuid;

	D_ASSERT(mdev->state.disk == D_UP_TO_DATE);
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910
	uuid = mdev->ldev->md.uuid[UI_BITMAP] + UUID_NEW_BM_OFFSET;
911
	drbd_uuid_set(mdev, UI_BITMAP, uuid);
912
	drbd_print_uuids(mdev, "updated sync UUID");
913 914
	drbd_md_sync(mdev);
	p.uuid = cpu_to_be64(uuid);
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916
	return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_SYNC_UUID, &p.head, sizeof(p));
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}

919
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;
923
	int q_order_type, max_bio_size;
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	int ok;

	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);
931 932
		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;
938
		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));
944
	p.max_bio_size = cpu_to_be32(max_bio_size);
945 946
	p.queue_order_type = cpu_to_be16(q_order_type);
	p.dds_flags = cpu_to_be16(flags);
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948
	ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, P_SIZES, &p.head, sizeof(p));
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	return ok;
}

/**
 * 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;
	int ok = 0;

962
	mutex_lock(&mdev->tconn->data.mutex);
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	p.state = cpu_to_be32(mdev->state.i); /* Within the send mutex */
965
	sock = mdev->tconn->data.socket;
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	if (likely(sock != NULL)) {
968
		ok = _drbd_send_cmd(mdev, sock, P_STATE, &p.head, sizeof(p), 0);
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	}

971
	mutex_unlock(&mdev->tconn->data.mutex);
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	return ok;
}

int drbd_send_state_req(struct drbd_conf *mdev,
	union drbd_state mask, union drbd_state val)
{
	struct p_req_state p;

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

984
	return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_STATE_CHG_REQ, &p.head, sizeof(p));
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}

987
int 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);

993
	return drbd_send_cmd(mdev, USE_META_SOCKET, P_STATE_CHG_REPLY, &p.head, sizeof(p));
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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? */
	if ((mdev->sync_conf.use_rle == 0) ||
1010
		(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;
}

1090 1091 1092 1093 1094 1095 1096
/**
 * 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,
1098
			 struct p_header *h, struct bm_xfer_ctx *c)
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{
	struct p_compressed_bm *p = (void*)h;
	unsigned long num_words;
	int len;
	int ok;

	len = fill_bitmap_rle_bits(mdev, p, c);

	if (len < 0)
1108
		return -EIO;
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	if (len) {
		DCBP_set_code(p, RLE_VLI_Bits);
1112
		ok = _drbd_send_cmd(mdev, mdev->tconn->data.socket, P_COMPRESSED_BITMAP, h,
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			sizeof(*p) + len, 0);

		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);
1127
		ok = _drbd_send_cmd(mdev, mdev->tconn->data.socket, P_BITMAP,
1128
				   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]++;
1133
		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;
	}
1138 1139 1140 1141 1142 1143 1144 1145
	if (ok) {
		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;
1152
	struct p_header *p;
1153
	int err;
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1155 1156
	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? */
1160
	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__);
1163
		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 {
1189 1190
		err = send_bitmap_rle_or_plain(mdev, p, &c);
	} while (err > 0);
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	free_page((unsigned long) p);
1193
	return err == 0;
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}

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

1200
	if (!drbd_get_data_sock(mdev->tconn))
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		return -1;
	err = !_drbd_send_bitmap(mdev);
1203
	drbd_put_data_sock(mdev->tconn);
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	return err;
}

int drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, u32 set_size)
{
	int ok;
	struct p_barrier_ack p;

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

	if (mdev->state.conn < C_CONNECTED)
1216
		return false;
1217
	ok = drbd_send_cmd(mdev, USE_META_SOCKET, P_BARRIER_ACK, &p.head, sizeof(p));
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	return ok;
}

/**
 * _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
 */
1229 1230
static int _drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
			  u64 sector, u32 blksize, u64 block_id)
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{
	int ok;
	struct p_block_ack p;

	p.sector   = sector;
	p.block_id = block_id;
	p.blksize  = blksize;
	p.seq_num  = cpu_to_be32(atomic_add_return(1, &mdev->packet_seq));

1240
	if (!mdev->tconn->meta.socket || mdev->state.conn < C_CONNECTED)
1241
		return false;
1242
	ok = drbd_send_cmd(mdev, USE_META_SOCKET, cmd, &p.head, sizeof(p));
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	return ok;
}

1246 1247 1248
/* 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. */
1249
int drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd,
1250
		     struct p_data *dp, int data_size)
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{
1252 1253
	data_size -= (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
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	return _drbd_send_ack(mdev, cmd, dp->sector, cpu_to_be32(data_size),
			      dp->block_id);
}

1258
int drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packet cmd,
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		     struct p_block_req *rp)
{
	return _drbd_send_ack(mdev, cmd, rp->sector, rp->blksize, rp->block_id);
}

/**
 * drbd_send_ack() - Sends an ack packet
1266 1267 1268
 * @mdev:	DRBD device
 * @cmd:	packet command code
 * @peer_req:	peer request
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 */
1270
int drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
1271
		  struct drbd_peer_request *peer_req)
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{
	return _drbd_send_ack(mdev, cmd,
1274 1275 1276
			      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. */
1281
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)
{
	return _drbd_send_ack(mdev, cmd,
			      cpu_to_be64(sector),
			      cpu_to_be32(blksize),
			      cpu_to_be64(block_id));
}

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

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

1300
	ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, cmd, &p.head, sizeof(p));
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	return ok;
}

1304 1305
int drbd_send_drequest_csum(struct drbd_conf *mdev, sector_t sector, int size,
			    void *digest, int digest_size, enum drbd_packet cmd)
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{
	int ok;
	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);
1312
	p.block_id = ID_SYNCER /* unused */;
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	p.blksize  = cpu_to_be32(size);

1315
	mutex_lock(&mdev->tconn->data.mutex);
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1317 1318
	ok = (sizeof(p) == drbd_send(mdev->tconn, mdev->tconn->data.socket, &p, sizeof(p), 0));
	ok = ok && (digest_size == drbd_send(mdev->tconn, mdev->tconn->data.socket, digest, digest_size, 0));
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1320
	mutex_unlock(&mdev->tconn->data.mutex);
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	return ok;
}

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

	p.sector   = cpu_to_be64(sector);
1331
	p.block_id = ID_SYNCER /* unused */;
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	p.blksize  = cpu_to_be32(size);

1334
	ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, P_OV_REQUEST, &p.head, sizeof(p));
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	return ok;
}

/* called on sndtimeo
1339 1340
 * returns false if we should retry,
 * true if we think connection is dead
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 */
1342
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); */

1347 1348 1349 1350
	drop_it =   tconn->meta.socket == sock
		|| !tconn->asender.task
		|| get_t_state(&tconn->asender) != RUNNING
		|| tconn->volume0->state.conn < C_CONNECTED;
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	if (drop_it)
1353
		return true;
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1355
	drop_it = !--tconn->ko_count;
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	if (!drop_it) {
1357 1358 1359
		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) */;
}

1365
static void drbd_update_congested(struct drbd_tconn *tconn)
1366
{
1367
	struct sock *sk = tconn->data.socket->sk;
1368
	if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
1369
		set_bit(NET_CONGESTED, &tconn->flags);
1370 1371
}

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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,
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		   int offset, size_t size, unsigned msg_flags)
P
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{
1396
	int sent = drbd_send(mdev->tconn, mdev->tconn->data.socket, kmap(page) + offset, size, msg_flags);
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	kunmap(page);
	if (sent == size)
		mdev->send_cnt += size>>9;
	return sent == size;
}

static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
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		    int offset, size_t size, unsigned msg_flags)
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{
	mm_segment_t oldfs = get_fs();
	int sent, ok;
	int len = size;

	/* 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))
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		return _drbd_no_send_page(mdev, page, offset, size, msg_flags);
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L
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	msg_flags |= MSG_NOSIGNAL;
1420
	drbd_update_congested(mdev->tconn);
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	set_fs(KERNEL_DS);
	do {
1423
		sent = mdev->tconn->data.socket->ops->sendpage(mdev->tconn->data.socket, page,
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							offset, len,
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							msg_flags);
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		if (sent == -EAGAIN) {
1427
			if (we_should_drop_the_connection(mdev->tconn,
1428
							  mdev->tconn->data.socket))
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				break;
			else
				continue;
		}
		if (sent <= 0) {
			dev_warn(DEV, "%s: size=%d len=%d sent=%d\n",
			     __func__, (int)size, len, sent);
			break;
		}
		len    -= sent;
		offset += sent;
	} while (len > 0 /* THINK && mdev->cstate >= C_CONNECTED*/);
	set_fs(oldfs);
1442
	clear_bit(NET_CONGESTED, &mdev->tconn->flags);
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	ok = (len == 0);
	if (likely(ok))
		mdev->send_cnt += size>>9;
	return ok;
}

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

static int _drbd_send_zc_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) {
		if (!_drbd_send_page(mdev, bvec->bv_page,
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				     bvec->bv_offset, bvec->bv_len,
				     i == bio->bi_vcnt -1 ? 0 : MSG_MORE))
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			return 0;
	}
	return 1;
}

1478 1479
static int _drbd_send_zc_ee(struct drbd_conf *mdev,
			    struct drbd_peer_request *peer_req)
1480
{
1481 1482 1483
	struct page *page = peer_req->pages;
	unsigned len = peer_req->i.size;

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	/* hint all but last page with MSG_MORE */
1485 1486
	page_chain_for_each(page) {
		unsigned l = min_t(unsigned, len, PAGE_SIZE);
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		if (!_drbd_send_page(mdev, page, 0, l,
				page_chain_next(page) ? MSG_MORE : 0))
1489 1490 1491 1492 1493 1494
			return 0;
		len -= l;
	}
	return 1;
}

1495 1496
static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
{
1497
	if (mdev->tconn->agreed_pro_version >= 95)
1498 1499 1500 1501 1502
		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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		return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
1504 1505
}

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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)
{
	int ok = 1;
	struct p_data p;
	unsigned int dp_flags = 0;
	void *dgb;
	int dgs;

1517
	if (!drbd_get_data_sock(mdev->tconn))
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		return 0;

1520 1521
	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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	prepare_header(mdev, &p.head, P_DATA, sizeof(p) - sizeof(struct p_header) + dgs + req->i.size);
1524
	p.sector   = cpu_to_be64(req->i.sector);
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1525
	p.block_id = (unsigned long)req;
P
Philipp Reisner 已提交
1526
	p.seq_num  = cpu_to_be32(req->seq_num = atomic_add_return(1, &mdev->packet_seq));
P
Philipp Reisner 已提交
1527

1528 1529
	dp_flags = bio_flags_to_wire(mdev, req->master_bio->bi_rw);

P
Philipp Reisner 已提交
1530 1531 1532 1533 1534 1535 1536
	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);
	ok = (sizeof(p) ==
1537
		drbd_send(mdev->tconn, mdev->tconn->data.socket, &p, sizeof(p), dgs ? MSG_MORE : 0));
P
Philipp Reisner 已提交
1538
	if (ok && dgs) {
1539 1540
		dgb = mdev->tconn->int_dig_out;
		drbd_csum_bio(mdev, mdev->tconn->integrity_w_tfm, req->master_bio, dgb);
1541
		ok = dgs == drbd_send(mdev->tconn, mdev->tconn->data.socket, dgb, dgs, 0);
P
Philipp Reisner 已提交
1542 1543
	}
	if (ok) {
1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554
		/* 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.
		 */
1555
		if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A || dgs)
P
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1556 1557 1558
			ok = _drbd_send_bio(mdev, req->master_bio);
		else
			ok = _drbd_send_zc_bio(mdev, req->master_bio);
1559 1560 1561

		/* double check digest, sometimes buffers have been modified in flight. */
		if (dgs > 0 && dgs <= 64) {
B
Bart Van Assche 已提交
1562
			/* 64 byte, 512 bit, is the largest digest size
1563 1564
			 * currently supported in kernel crypto. */
			unsigned char digest[64];
1565 1566
			drbd_csum_bio(mdev, mdev->tconn->integrity_w_tfm, req->master_bio, digest);
			if (memcmp(mdev->tconn->int_dig_out, digest, dgs)) {
1567 1568
				dev_warn(DEV,
					"Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
1569
					(unsigned long long)req->i.sector, req->i.size);
1570 1571 1572 1573
			}
		} /* else if (dgs > 64) {
		     ... Be noisy about digest too large ...
		} */
P
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1574 1575
	}

1576
	drbd_put_data_sock(mdev->tconn);
1577

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1578 1579 1580 1581 1582 1583 1584
	return ok;
}

/* 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)
 */
1585
int drbd_send_block(struct drbd_conf *mdev, enum drbd_packet cmd,
1586
		    struct drbd_peer_request *peer_req)
P
Philipp Reisner 已提交
1587 1588 1589 1590 1591 1592
{
	int ok;
	struct p_data p;
	void *dgb;
	int dgs;

1593 1594
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_w_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_w_tfm) : 0;
P
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1595

1596 1597 1598 1599 1600
	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;
1601
	p.seq_num = 0;  /* unused */
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1602 1603 1604 1605 1606

	/* 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.
	 */
1607
	if (!drbd_get_data_sock(mdev->tconn))
P
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1608 1609
		return 0;

1610
	ok = sizeof(p) == drbd_send(mdev->tconn, mdev->tconn->data.socket, &p, sizeof(p), dgs ? MSG_MORE : 0);
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1611
	if (ok && dgs) {
1612
		dgb = mdev->tconn->int_dig_out;
1613
		drbd_csum_ee(mdev, mdev->tconn->integrity_w_tfm, peer_req, dgb);
1614
		ok = dgs == drbd_send(mdev->tconn, mdev->tconn->data.socket, dgb, dgs, 0);
P
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1615 1616
	}
	if (ok)
1617
		ok = _drbd_send_zc_ee(mdev, peer_req);
P
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1618

1619
	drbd_put_data_sock(mdev->tconn);
1620

P
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1621 1622 1623
	return ok;
}

1624 1625 1626 1627
int drbd_send_oos(struct drbd_conf *mdev, struct drbd_request *req)
{
	struct p_block_desc p;

1628 1629
	p.sector  = cpu_to_be64(req->i.sector);
	p.blksize = cpu_to_be32(req->i.size);
1630 1631 1632 1633

	return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_OUT_OF_SYNC, &p.head, sizeof(p));
}

P
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1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
/*
  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!
 */
1650
int drbd_send(struct drbd_tconn *tconn, struct socket *sock,
P
Philipp Reisner 已提交
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670
	      void *buf, size_t size, unsigned msg_flags)
{
	struct kvec iov;
	struct msghdr msg;
	int rv, sent = 0;

	if (!sock)
		return -1000;

	/* 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;

1671 1672 1673
	if (sock == tconn->data.socket) {
		tconn->ko_count = tconn->net_conf->ko_count;
		drbd_update_congested(tconn);
P
Philipp Reisner 已提交
1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686
	}
	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) {
1687
			if (we_should_drop_the_connection(tconn, sock))
P
Philipp Reisner 已提交
1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702
				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);

1703 1704
	if (sock == tconn->data.socket)
		clear_bit(NET_CONGESTED, &tconn->flags);
P
Philipp Reisner 已提交
1705 1706 1707

	if (rv <= 0) {
		if (rv != -EAGAIN) {
1708 1709 1710 1711
			conn_err(tconn, "%s_sendmsg returned %d\n",
				 sock == tconn->meta.socket ? "msock" : "sock",
				 rv);
			drbd_force_state(tconn->volume0, NS(conn, C_BROKEN_PIPE));
P
Philipp Reisner 已提交
1712
		} else
1713
			drbd_force_state(tconn->volume0, NS(conn, C_TIMEOUT));
P
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1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724
	}

	return sent;
}

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;

1725
	mutex_lock(&drbd_main_mutex);
1726
	spin_lock_irqsave(&mdev->tconn->req_lock, flags);
P
Philipp Reisner 已提交
1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738
	/* 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++;
1739
	spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
1740
	mutex_unlock(&drbd_main_mutex);
P
Philipp Reisner 已提交
1741 1742 1743 1744 1745 1746 1747

	return rv;
}

static int drbd_release(struct gendisk *gd, fmode_t mode)
{
	struct drbd_conf *mdev = gd->private_data;
1748
	mutex_lock(&drbd_main_mutex);
P
Philipp Reisner 已提交
1749
	mdev->open_cnt--;
1750
	mutex_unlock(&drbd_main_mutex);
P
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1751 1752 1753 1754 1755
	return 0;
}

static void drbd_set_defaults(struct drbd_conf *mdev)
{
1756 1757 1758 1759 1760 1761 1762 1763 1764
	/* This way we get a compile error when sync_conf grows,
	   and we forgot to initialize it here */
	mdev->sync_conf = (struct syncer_conf) {
		/* .rate = */		DRBD_RATE_DEF,
		/* .after = */		DRBD_AFTER_DEF,
		/* .al_extents = */	DRBD_AL_EXTENTS_DEF,
		/* .verify_alg = */	{}, 0,
		/* .cpu_mask = */	{}, 0,
		/* .csums_alg = */	{}, 0,
1765
		/* .use_rle = */	0,
1766 1767 1768 1769
		/* .on_no_data = */	DRBD_ON_NO_DATA_DEF,
		/* .c_plan_ahead = */	DRBD_C_PLAN_AHEAD_DEF,
		/* .c_delay_target = */	DRBD_C_DELAY_TARGET_DEF,
		/* .c_fill_target = */	DRBD_C_FILL_TARGET_DEF,
1770 1771
		/* .c_max_rate = */	DRBD_C_MAX_RATE_DEF,
		/* .c_min_rate = */	DRBD_C_MIN_RATE_DEF
1772 1773 1774 1775
	};

	/* Have to use that way, because the layout differs between
	   big endian and little endian */
P
Philipp Reisner 已提交
1776 1777 1778 1779 1780 1781
	mdev->state = (union drbd_state) {
		{ .role = R_SECONDARY,
		  .peer = R_UNKNOWN,
		  .conn = C_STANDALONE,
		  .disk = D_DISKLESS,
		  .pdsk = D_UNKNOWN,
1782 1783 1784
		  .susp = 0,
		  .susp_nod = 0,
		  .susp_fen = 0
P
Philipp Reisner 已提交
1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800
		} };
}

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);
	atomic_set(&mdev->pp_in_use, 0);
1801
	atomic_set(&mdev->pp_in_use_by_net, 0);
1802
	atomic_set(&mdev->rs_sect_in, 0);
1803
	atomic_set(&mdev->rs_sect_ev, 0);
1804
	atomic_set(&mdev->ap_in_flight, 0);
P
Philipp Reisner 已提交
1805 1806

	mutex_init(&mdev->md_io_mutex);
1807 1808 1809 1810
	mutex_init(&mdev->tconn->data.mutex);
	mutex_init(&mdev->tconn->meta.mutex);
	sema_init(&mdev->tconn->data.work.s, 0);
	sema_init(&mdev->tconn->meta.work.s, 0);
P
Philipp Reisner 已提交
1811 1812
	mutex_init(&mdev->state_mutex);

1813 1814
	spin_lock_init(&mdev->tconn->data.work.q_lock);
	spin_lock_init(&mdev->tconn->meta.work.q_lock);
P
Philipp Reisner 已提交
1815 1816

	spin_lock_init(&mdev->al_lock);
1817
	spin_lock_init(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1818 1819 1820 1821 1822 1823 1824 1825 1826
	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);
1827 1828
	INIT_LIST_HEAD(&mdev->tconn->data.work.q);
	INIT_LIST_HEAD(&mdev->tconn->meta.work.q);
P
Philipp Reisner 已提交
1829 1830
	INIT_LIST_HEAD(&mdev->resync_work.list);
	INIT_LIST_HEAD(&mdev->unplug_work.list);
1831
	INIT_LIST_HEAD(&mdev->go_diskless.list);
P
Philipp Reisner 已提交
1832
	INIT_LIST_HEAD(&mdev->md_sync_work.list);
1833
	INIT_LIST_HEAD(&mdev->start_resync_work.list);
P
Philipp Reisner 已提交
1834
	INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
1835

1836
	mdev->resync_work.cb  = w_resync_timer;
P
Philipp Reisner 已提交
1837
	mdev->unplug_work.cb  = w_send_write_hint;
1838
	mdev->go_diskless.cb  = w_go_diskless;
P
Philipp Reisner 已提交
1839 1840
	mdev->md_sync_work.cb = w_md_sync;
	mdev->bm_io_work.w.cb = w_bitmap_io;
1841
	mdev->start_resync_work.cb = w_start_resync;
1842 1843 1844 1845 1846 1847 1848 1849

	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;

P
Philipp Reisner 已提交
1850 1851
	init_timer(&mdev->resync_timer);
	init_timer(&mdev->md_sync_timer);
1852
	init_timer(&mdev->start_resync_timer);
1853
	init_timer(&mdev->request_timer);
P
Philipp Reisner 已提交
1854 1855 1856 1857
	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;
1858 1859
	mdev->start_resync_timer.function = start_resync_timer_fn;
	mdev->start_resync_timer.data = (unsigned long) mdev;
1860 1861
	mdev->request_timer.function = request_timer_fn;
	mdev->request_timer.data = (unsigned long) mdev;
P
Philipp Reisner 已提交
1862 1863 1864 1865 1866 1867 1868

	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);

1869 1870 1871
	drbd_thread_init(mdev, &mdev->tconn->receiver, drbdd_init, "receiver");
	drbd_thread_init(mdev, &mdev->tconn->worker, drbd_worker, "worker");
	drbd_thread_init(mdev, &mdev->tconn->asender, drbd_asender, "asender");
P
Philipp Reisner 已提交
1872

P
Philipp Reisner 已提交
1873
	/* mdev->tconn->agreed_pro_version gets initialized in drbd_connect() */
1874
	mdev->write_ordering = WO_bdev_flush;
P
Philipp Reisner 已提交
1875
	mdev->resync_wenr = LC_FREE;
1876 1877
	mdev->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
	mdev->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
P
Philipp Reisner 已提交
1878 1879 1880 1881
}

void drbd_mdev_cleanup(struct drbd_conf *mdev)
{
1882
	int i;
1883
	if (mdev->tconn->receiver.t_state != NONE)
P
Philipp Reisner 已提交
1884
		dev_err(DEV, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
1885
				mdev->tconn->receiver.t_state);
P
Philipp Reisner 已提交
1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898

	/* 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     =
1899 1900
	mdev->rs_failed    = 0;
	mdev->rs_last_events = 0;
1901
	mdev->rs_last_sect_ev = 0;
1902 1903 1904 1905
	for (i = 0; i < DRBD_SYNC_MARKS; i++) {
		mdev->rs_mark_left[i] = 0;
		mdev->rs_mark_time[i] = 0;
	}
1906
	D_ASSERT(mdev->tconn->net_conf == NULL);
P
Philipp Reisner 已提交
1907 1908 1909 1910

	drbd_set_my_capacity(mdev, 0);
	if (mdev->bitmap) {
		/* maybe never allocated. */
1911
		drbd_bm_resize(mdev, 0, 1);
P
Philipp Reisner 已提交
1912 1913 1914 1915
		drbd_bm_cleanup(mdev);
	}

	drbd_free_resources(mdev);
1916
	clear_bit(AL_SUSPENDED, &mdev->flags);
P
Philipp Reisner 已提交
1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927

	/*
	 * 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));
1928 1929
	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
	D_ASSERT(list_empty(&mdev->tconn->meta.work.q));
P
Philipp Reisner 已提交
1930 1931
	D_ASSERT(list_empty(&mdev->resync_work.list));
	D_ASSERT(list_empty(&mdev->unplug_work.list));
1932
	D_ASSERT(list_empty(&mdev->go_diskless.list));
1933 1934

	drbd_set_defaults(mdev);
P
Philipp Reisner 已提交
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976
}


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); */

	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);

	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;
1977
	const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count;
P
Philipp Reisner 已提交
1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994
	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;

	/* 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(
1995
		"drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
P
Philipp Reisner 已提交
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
	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 */
	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);
2017
	if (drbd_ee_mempool == NULL)
P
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2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 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
		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);
}

/* caution. no locking.
 * currently only used from module cleanup code. */
static void drbd_delete_device(unsigned int minor)
{
	struct drbd_conf *mdev = minor_to_mdev(minor);

	if (!mdev)
		return;

	/* paranoia asserts */
2088
	D_ASSERT(mdev->open_cnt == 0);
2089
	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
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2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100
	/* 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);
2101
	drbd_free_tconn(mdev->tconn);
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2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122

	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;

	unregister_reboot_notifier(&drbd_notifier);

2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
	/* 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);

P
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2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163
	drbd_nl_cleanup();

	if (minor_table) {
		i = minor_count;
		while (i--)
			drbd_delete_device(i);
		drbd_destroy_mempools();
	}

	kfree(minor_table);

	unregister_blkdev(DRBD_MAJOR, "drbd");

	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;

2164
	if (!may_inc_ap_bio(mdev)) {
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		/* 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';
	}

2179
	if (bdi_bits & (1 << BDI_async_congested) && test_bit(NET_CONGESTED, &mdev->tconn->flags)) {
P
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2180 2181 2182 2183 2184 2185 2186 2187 2188
		r |= (1 << BDI_async_congested);
		reason = reason == 'b' ? 'a' : 'n';
	}

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

2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200
struct drbd_tconn *drbd_new_tconn(char *name)
{
	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;

2201 2202
	atomic_set(&tconn->net_cnt, 0);
	init_waitqueue_head(&tconn->net_cnt_wait);
2203
	idr_init(&tconn->volumes);
2204

2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222
	write_lock_irq(&global_state_lock);
	list_add(&tconn->all_tconn, &drbd_tconns);
	write_unlock_irq(&global_state_lock);

	return tconn;

fail:
	kfree(tconn->name);
	kfree(tconn);

	return NULL;
}

void drbd_free_tconn(struct drbd_tconn *tconn)
{
	write_lock_irq(&global_state_lock);
	list_del(&tconn->all_tconn);
	write_unlock_irq(&global_state_lock);
2223
	idr_destroy(&tconn->volumes);
2224 2225

	kfree(tconn->name);
2226 2227 2228
	kfree(tconn->int_dig_out);
	kfree(tconn->int_dig_in);
	kfree(tconn->int_dig_vv);
2229 2230 2231
	kfree(tconn);
}

P
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2232 2233 2234 2235 2236
struct drbd_conf *drbd_new_device(unsigned int minor)
{
	struct drbd_conf *mdev;
	struct gendisk *disk;
	struct request_queue *q;
2237
	char conn_name[9]; /* drbd1234N */
2238
	int vnr;
P
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2239 2240 2241 2242 2243

	/* GFP_KERNEL, we are outside of all write-out paths */
	mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
	if (!mdev)
		return NULL;
2244 2245
	sprintf(conn_name, "drbd%d", minor);
	mdev->tconn = drbd_new_tconn(conn_name);
2246 2247
	if (!mdev->tconn)
		goto out_no_tconn;
2248 2249 2250 2251 2252 2253 2254 2255
	if (!idr_pre_get(&mdev->tconn->volumes, GFP_KERNEL))
		goto out_no_cpumask;
	if (idr_get_new(&mdev->tconn->volumes, mdev, &vnr))
		goto out_no_cpumask;
	if (vnr != 0) {
		dev_err(DEV, "vnr = %d\n", vnr);
		goto out_no_cpumask;
	}
2256
	if (!zalloc_cpumask_var(&mdev->tconn->cpu_mask, GFP_KERNEL))
P
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		goto out_no_cpumask;

2259
	mdev->tconn->volume0 = mdev;
P
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	mdev->minor = minor;

	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;

2275
	set_disk_ro(disk, true);
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	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;

2291
	blk_queue_make_request(q, drbd_make_request);
2292 2293 2294
	/* 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
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	blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
	blk_queue_merge_bvec(q, drbd_merge_bvec);
2297
	q->queue_lock = &mdev->tconn->req_lock; /* needed since we use */
P
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	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;
	/* no need to lock access, we are still initializing this minor device. */
	if (!tl_init(mdev))
		goto out_no_tl;
2308
	mdev->read_requests = RB_ROOT;
2309
	mdev->write_requests = RB_ROOT;
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	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;

	return mdev;

/* out_whatever_else:
	kfree(mdev->current_epoch); */
out_no_epoch:
	tl_cleanup(mdev);
out_no_tl:
	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:
2333
	free_cpumask_var(mdev->tconn->cpu_mask);
P
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out_no_cpumask:
2335 2336
	drbd_free_tconn(mdev->tconn);
out_no_tconn:
P
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	kfree(mdev);
	return NULL;
}

/* counterpart of drbd_new_device.
 * last part of drbd_delete_device. */
void drbd_free_mdev(struct drbd_conf *mdev)
{
	kfree(mdev->current_epoch);
	tl_cleanup(mdev);
	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
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	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
2362

2363
	if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {
P
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		printk(KERN_ERR
			"drbd: invalid minor_count (%d)\n", minor_count);
#ifdef MODULE
		return -EINVAL;
#else
		minor_count = 8;
#endif
	}

	err = drbd_nl_init();
	if (err)
		return err;

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

	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 */
	minor_table = kzalloc(sizeof(struct drbd_conf *)*minor_count,
				GFP_KERNEL);
	if (!minor_table)
		goto Enomem;

	err = drbd_create_mempools();
	if (err)
		goto Enomem;

2404
	drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
P
Philipp Reisner 已提交
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	if (!drbd_proc)	{
		printk(KERN_ERR "drbd: unable to register proc file\n");
		goto Enomem;
	}

	rwlock_init(&global_state_lock);
2411
	INIT_LIST_HEAD(&drbd_tconns);
P
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	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);
	printk(KERN_INFO "drbd: minor_table @ 0x%p\n", minor_table);

	return 0; /* Success! */

Enomem:
	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;

2438 2439
	blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
	blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
P
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2440 2441 2442 2443

	kfree(ldev);
}

2444 2445 2446 2447 2448 2449 2450 2451
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
Philipp Reisner 已提交
2452
	}
2453 2454 2455 2456 2457 2458
	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);
P
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	}
}


void drbd_free_resources(struct drbd_conf *mdev)
{
	crypto_free_hash(mdev->csums_tfm);
	mdev->csums_tfm = NULL;
	crypto_free_hash(mdev->verify_tfm);
	mdev->verify_tfm = NULL;
2469 2470 2471 2472 2473 2474
	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;
P
Philipp Reisner 已提交
2475

2476
	drbd_free_sock(mdev->tconn);
P
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2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497

	__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 */
	      /* `-- act_log->nr_elements <-- sync_conf.al_extents */
	u32 bm_offset;         /* offset to the bitmap, from here */
	u32 bm_bytes_per_bit;  /* BM_BLOCK_SIZE */
2498 2499
	u32 la_peer_max_bio_size;   /* last peer max_bio_size */
	u32 reserved_u32[3];
P
Philipp Reisner 已提交
2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512

} __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;

2513 2514
	del_timer(&mdev->md_sync_timer);
	/* timer may be rearmed by drbd_md_mark_dirty() now. */
P
Philipp Reisner 已提交
2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539
	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);
2540
	buffer->la_peer_max_bio_size = cpu_to_be32(mdev->peer_max_bio_size);
P
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2541 2542 2543 2544

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

2545
	if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
P
Philipp Reisner 已提交
2546 2547
		/* this was a try anyways ... */
		dev_err(DEV, "meta data update failed!\n");
2548
		drbd_chk_io_error(mdev, 1, true);
P
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2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563
	}

	/* 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.
 *
2564
 * Return 0 (NO_ERROR) on success, and an enum drbd_ret_code in case
P
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2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578
 * 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);

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

2586
	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);
	mdev->sync_conf.al_extents = be32_to_cpu(buffer->al_nr_extents);
	bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);

2624
	spin_lock_irq(&mdev->tconn->req_lock);
2625 2626 2627 2628 2629 2630
	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;
	}
2631
	spin_unlock_irq(&mdev->tconn->req_lock);
2632

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	if (mdev->sync_conf.al_extents < 7)
		mdev->sync_conf.al_extents = 127;

 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().
 */
2651
#ifdef DEBUG
2652 2653 2654 2655 2656 2657 2658 2659 2660
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)
{
2663
	if (!test_and_set_bit(MD_DIRTY, &mdev->flags))
2664
		mod_timer(&mdev->md_sync_timer, jiffies + 5*HZ);
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}
2666
#endif
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static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
{
	int i;

2672
	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;
2711 2712 2713 2714
	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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	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);
2720
	drbd_print_uuids(mdev, "new current UUID");
2721 2722
	/* 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 {
2735 2736 2737
		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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2739
		mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
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	}
	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;

2782
	drbd_resume_al(mdev);
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	if (get_ldev_if_state(mdev, D_ATTACHING)) {
		drbd_bm_clear_all(mdev);
		rv = drbd_bm_write(mdev);
		put_ldev(mdev);
	}

	return rv;
}

static int w_bitmap_io(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
	struct bm_io_work *work = container_of(w, struct bm_io_work, w);
2795
	int rv = -EIO;
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	D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0);

2799
	if (get_ldev(mdev)) {
2800
		drbd_bm_lock(mdev, work->why, work->flags);
2801 2802 2803 2804
		rv = work->io_fn(mdev);
		drbd_bm_unlock(mdev);
		put_ldev(mdev);
	}
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	clear_bit(BITMAP_IO, &mdev->flags);
2807
	smp_mb__after_clear_bit();
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	wake_up(&mdev->misc_wait);

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

	clear_bit(BITMAP_IO_QUEUED, &mdev->flags);
	work->why = NULL;
2815
	work->flags = 0;
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	return 1;
}

2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836
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;);

	if (mdev->md_io_tmpp) {
		__free_page(mdev->md_io_tmpp);
		mdev->md_io_tmpp = NULL;
	}
	clear_bit(GO_DISKLESS, &mdev->flags);
}

2837 2838 2839
static int w_go_diskless(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
	D_ASSERT(mdev->state.disk == D_FAILED);
2840 2841
	/* 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
2842 2843
	 * the protected members anymore, though, so once put_ldev reaches zero
	 * again, it will be safe to free them. */
2844 2845 2846 2847 2848 2849 2850 2851
	drbd_force_state(mdev, NS(disk, D_DISKLESS));
	return 1;
}

void drbd_go_diskless(struct drbd_conf *mdev)
{
	D_ASSERT(mdev->state.disk == D_FAILED);
	if (!test_and_set_bit(GO_DISKLESS, &mdev->flags))
2852
		drbd_queue_work(&mdev->tconn->data.work, &mdev->go_diskless);
2853 2854
}

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/**
 * 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),
2870
			  char *why, enum bm_flag flags)
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{
2872
	D_ASSERT(current == mdev->tconn->worker.task);
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	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;
2884
	mdev->bm_io_work.flags = flags;
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2886
	spin_lock_irq(&mdev->tconn->req_lock);
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	set_bit(BITMAP_IO, &mdev->flags);
	if (atomic_read(&mdev->ap_bio_cnt) == 0) {
2889
		if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags))
2890
			drbd_queue_work(&mdev->tconn->data.work, &mdev->bm_io_work.w);
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	}
2892
	spin_unlock_irq(&mdev->tconn->req_lock);
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}

/**
 * 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.
 */
2904 2905
int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *),
		char *why, enum bm_flag flags)
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{
	int rv;

2909
	D_ASSERT(current != mdev->tconn->worker.task);
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2911 2912
	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
		drbd_suspend_io(mdev);
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2914
	drbd_bm_lock(mdev, why, flags);
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	rv = io_fn(mdev);
	drbd_bm_unlock(mdev);

2918 2919
	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
		drbd_resume_io(mdev);
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	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;

2948
	drbd_queue_work_front(&mdev->tconn->data.work, &mdev->md_sync_work);
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}

static int w_md_sync(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
	dev_warn(DEV, "md_sync_timer expired! Worker calls drbd_md_sync().\n");
2954 2955 2956 2957
#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);
	return 1;
}

2962
const char *cmdname(enum drbd_packet cmd)
2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020
{
	/* 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",
		[P_DISCARD_ACK]	        = "DiscardAck",
		[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",
		[P_MAX_CMD]	        = NULL,
	};

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

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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;

3042
	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",
3062 3063
		[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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Philipp Reisner 已提交
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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);