drbd_receiver.c 128.7 KB
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/*
   drbd_receiver.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>.

   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 <asm/uaccess.h>
#include <net/sock.h>

#include <linux/drbd.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/in.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <linux/mm_inline.h>
#include <linux/slab.h>
#include <linux/pkt_sched.h>
#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include <linux/vmalloc.h>
#include <linux/random.h>
#include <linux/string.h>
#include <linux/scatterlist.h>
#include "drbd_int.h"
#include "drbd_req.h"

#include "drbd_vli.h"

enum finish_epoch {
	FE_STILL_LIVE,
	FE_DESTROYED,
	FE_RECYCLED,
};

static int drbd_do_handshake(struct drbd_conf *mdev);
static int drbd_do_auth(struct drbd_conf *mdev);

static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *, struct drbd_epoch *, enum epoch_event);
static int e_end_block(struct drbd_conf *, struct drbd_work *, int);


#define GFP_TRY	(__GFP_HIGHMEM | __GFP_NOWARN)

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/*
 * some helper functions to deal with single linked page lists,
 * page->private being our "next" pointer.
 */

/* If at least n pages are linked at head, get n pages off.
 * Otherwise, don't modify head, and return NULL.
 * Locking is the responsibility of the caller.
 */
static struct page *page_chain_del(struct page **head, int n)
{
	struct page *page;
	struct page *tmp;

	BUG_ON(!n);
	BUG_ON(!head);

	page = *head;
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	if (!page)
		return NULL;

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	while (page) {
		tmp = page_chain_next(page);
		if (--n == 0)
			break; /* found sufficient pages */
		if (tmp == NULL)
			/* insufficient pages, don't use any of them. */
			return NULL;
		page = tmp;
	}

	/* add end of list marker for the returned list */
	set_page_private(page, 0);
	/* actual return value, and adjustment of head */
	page = *head;
	*head = tmp;
	return page;
}

/* may be used outside of locks to find the tail of a (usually short)
 * "private" page chain, before adding it back to a global chain head
 * with page_chain_add() under a spinlock. */
static struct page *page_chain_tail(struct page *page, int *len)
{
	struct page *tmp;
	int i = 1;
	while ((tmp = page_chain_next(page)))
		++i, page = tmp;
	if (len)
		*len = i;
	return page;
}

static int page_chain_free(struct page *page)
{
	struct page *tmp;
	int i = 0;
	page_chain_for_each_safe(page, tmp) {
		put_page(page);
		++i;
	}
	return i;
}

static void page_chain_add(struct page **head,
		struct page *chain_first, struct page *chain_last)
{
#if 1
	struct page *tmp;
	tmp = page_chain_tail(chain_first, NULL);
	BUG_ON(tmp != chain_last);
#endif

	/* add chain to head */
	set_page_private(chain_last, (unsigned long)*head);
	*head = chain_first;
}

static struct page *drbd_pp_first_pages_or_try_alloc(struct drbd_conf *mdev, int number)
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{
	struct page *page = NULL;
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	struct page *tmp = NULL;
	int i = 0;
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	/* Yes, testing drbd_pp_vacant outside the lock is racy.
	 * So what. It saves a spin_lock. */
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	if (drbd_pp_vacant >= number) {
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		spin_lock(&drbd_pp_lock);
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		page = page_chain_del(&drbd_pp_pool, number);
		if (page)
			drbd_pp_vacant -= number;
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		spin_unlock(&drbd_pp_lock);
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		if (page)
			return page;
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	}
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	/* GFP_TRY, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
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	for (i = 0; i < number; i++) {
		tmp = alloc_page(GFP_TRY);
		if (!tmp)
			break;
		set_page_private(tmp, (unsigned long)page);
		page = tmp;
	}

	if (i == number)
		return page;

	/* Not enough pages immediately available this time.
	 * No need to jump around here, drbd_pp_alloc will retry this
	 * function "soon". */
	if (page) {
		tmp = page_chain_tail(page, NULL);
		spin_lock(&drbd_pp_lock);
		page_chain_add(&drbd_pp_pool, page, tmp);
		drbd_pp_vacant += i;
		spin_unlock(&drbd_pp_lock);
	}
	return NULL;
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}

static void reclaim_net_ee(struct drbd_conf *mdev, struct list_head *to_be_freed)
{
	struct drbd_epoch_entry *e;
	struct list_head *le, *tle;

	/* The EEs are always appended to the end of the list. Since
	   they are sent in order over the wire, they have to finish
	   in order. As soon as we see the first not finished we can
	   stop to examine the list... */

	list_for_each_safe(le, tle, &mdev->net_ee) {
		e = list_entry(le, struct drbd_epoch_entry, w.list);
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		if (drbd_ee_has_active_page(e))
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			break;
		list_move(le, to_be_freed);
	}
}

static void drbd_kick_lo_and_reclaim_net(struct drbd_conf *mdev)
{
	LIST_HEAD(reclaimed);
	struct drbd_epoch_entry *e, *t;

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	spin_lock_irq(&mdev->tconn->req_lock);
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	reclaim_net_ee(mdev, &reclaimed);
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	spin_unlock_irq(&mdev->tconn->req_lock);
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	list_for_each_entry_safe(e, t, &reclaimed, w.list)
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		drbd_free_net_ee(mdev, e);
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}

/**
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 * drbd_pp_alloc() - Returns @number pages, retries forever (or until signalled)
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 * @mdev:	DRBD device.
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 * @number:	number of pages requested
 * @retry:	whether to retry, if not enough pages are available right now
 *
 * Tries to allocate number pages, first from our own page pool, then from
 * the kernel, unless this allocation would exceed the max_buffers setting.
 * Possibly retry until DRBD frees sufficient pages somewhere else.
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 *
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 * Returns a page chain linked via page->private.
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 */
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static struct page *drbd_pp_alloc(struct drbd_conf *mdev, unsigned number, bool retry)
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{
	struct page *page = NULL;
	DEFINE_WAIT(wait);

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	/* Yes, we may run up to @number over max_buffers. If we
	 * follow it strictly, the admin will get it wrong anyways. */
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	if (atomic_read(&mdev->pp_in_use) < mdev->tconn->net_conf->max_buffers)
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		page = drbd_pp_first_pages_or_try_alloc(mdev, number);
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	while (page == NULL) {
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		prepare_to_wait(&drbd_pp_wait, &wait, TASK_INTERRUPTIBLE);

		drbd_kick_lo_and_reclaim_net(mdev);

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		if (atomic_read(&mdev->pp_in_use) < mdev->tconn->net_conf->max_buffers) {
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			page = drbd_pp_first_pages_or_try_alloc(mdev, number);
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			if (page)
				break;
		}

		if (!retry)
			break;

		if (signal_pending(current)) {
			dev_warn(DEV, "drbd_pp_alloc interrupted!\n");
			break;
		}

		schedule();
	}
	finish_wait(&drbd_pp_wait, &wait);

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	if (page)
		atomic_add(number, &mdev->pp_in_use);
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	return page;
}

/* Must not be used from irq, as that may deadlock: see drbd_pp_alloc.
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 * Is also used from inside an other spin_lock_irq(&mdev->tconn->req_lock);
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 * Either links the page chain back to the global pool,
 * or returns all pages to the system. */
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static void drbd_pp_free(struct drbd_conf *mdev, struct page *page, int is_net)
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{
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	atomic_t *a = is_net ? &mdev->pp_in_use_by_net : &mdev->pp_in_use;
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	int i;
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	if (drbd_pp_vacant > (DRBD_MAX_BIO_SIZE/PAGE_SIZE)*minor_count)
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		i = page_chain_free(page);
	else {
		struct page *tmp;
		tmp = page_chain_tail(page, &i);
		spin_lock(&drbd_pp_lock);
		page_chain_add(&drbd_pp_pool, page, tmp);
		drbd_pp_vacant += i;
		spin_unlock(&drbd_pp_lock);
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	}
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	i = atomic_sub_return(i, a);
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	if (i < 0)
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		dev_warn(DEV, "ASSERTION FAILED: %s: %d < 0\n",
			is_net ? "pp_in_use_by_net" : "pp_in_use", i);
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	wake_up(&drbd_pp_wait);
}

/*
You need to hold the req_lock:
 _drbd_wait_ee_list_empty()

You must not have the req_lock:
 drbd_free_ee()
 drbd_alloc_ee()
 drbd_init_ee()
 drbd_release_ee()
 drbd_ee_fix_bhs()
 drbd_process_done_ee()
 drbd_clear_done_ee()
 drbd_wait_ee_list_empty()
*/

struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev,
				     u64 id,
				     sector_t sector,
				     unsigned int data_size,
				     gfp_t gfp_mask) __must_hold(local)
{
	struct drbd_epoch_entry *e;
	struct page *page;
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	unsigned nr_pages = (data_size + PAGE_SIZE -1) >> PAGE_SHIFT;
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	if (drbd_insert_fault(mdev, DRBD_FAULT_AL_EE))
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		return NULL;

	e = mempool_alloc(drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM);
	if (!e) {
		if (!(gfp_mask & __GFP_NOWARN))
			dev_err(DEV, "alloc_ee: Allocation of an EE failed\n");
		return NULL;
	}

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	page = drbd_pp_alloc(mdev, nr_pages, (gfp_mask & __GFP_WAIT));
	if (!page)
		goto fail;
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	drbd_clear_interval(&e->i);
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	e->epoch = NULL;
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	e->mdev = mdev;
	e->pages = page;
	atomic_set(&e->pending_bios, 0);
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	e->i.size = data_size;
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	e->flags = 0;
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	e->i.sector = sector;
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	/*
	 * The block_id is opaque to the receiver.  It is not endianness
	 * converted, and sent back to the sender unchanged.
	 */
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	e->block_id = id;
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	return e;

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 fail:
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	mempool_free(e, drbd_ee_mempool);
	return NULL;
}

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void drbd_free_some_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e, int is_net)
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{
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	if (e->flags & EE_HAS_DIGEST)
		kfree(e->digest);
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	drbd_pp_free(mdev, e->pages, is_net);
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	D_ASSERT(atomic_read(&e->pending_bios) == 0);
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	D_ASSERT(drbd_interval_empty(&e->i));
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	mempool_free(e, drbd_ee_mempool);
}

int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list)
{
	LIST_HEAD(work_list);
	struct drbd_epoch_entry *e, *t;
	int count = 0;
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	int is_net = list == &mdev->net_ee;
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	spin_lock_irq(&mdev->tconn->req_lock);
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	list_splice_init(list, &work_list);
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	spin_unlock_irq(&mdev->tconn->req_lock);
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	list_for_each_entry_safe(e, t, &work_list, w.list) {
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		drbd_free_some_ee(mdev, e, is_net);
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		count++;
	}
	return count;
}


/*
 * This function is called from _asender only_
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 * but see also comments in _req_mod(,BARRIER_ACKED)
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 * and receive_Barrier.
 *
 * Move entries from net_ee to done_ee, if ready.
 * Grab done_ee, call all callbacks, free the entries.
 * The callbacks typically send out ACKs.
 */
static int drbd_process_done_ee(struct drbd_conf *mdev)
{
	LIST_HEAD(work_list);
	LIST_HEAD(reclaimed);
	struct drbd_epoch_entry *e, *t;
	int ok = (mdev->state.conn >= C_WF_REPORT_PARAMS);

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	spin_lock_irq(&mdev->tconn->req_lock);
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	reclaim_net_ee(mdev, &reclaimed);
	list_splice_init(&mdev->done_ee, &work_list);
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	spin_unlock_irq(&mdev->tconn->req_lock);
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	list_for_each_entry_safe(e, t, &reclaimed, w.list)
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		drbd_free_net_ee(mdev, e);
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	/* possible callbacks here:
	 * e_end_block, and e_end_resync_block, e_send_discard_ack.
	 * all ignore the last argument.
	 */
	list_for_each_entry_safe(e, t, &work_list, w.list) {
		/* list_del not necessary, next/prev members not touched */
		ok = e->w.cb(mdev, &e->w, !ok) && ok;
		drbd_free_ee(mdev, e);
	}
	wake_up(&mdev->ee_wait);

	return ok;
}

void _drbd_wait_ee_list_empty(struct drbd_conf *mdev, struct list_head *head)
{
	DEFINE_WAIT(wait);

	/* avoids spin_lock/unlock
	 * and calling prepare_to_wait in the fast path */
	while (!list_empty(head)) {
		prepare_to_wait(&mdev->ee_wait, &wait, TASK_UNINTERRUPTIBLE);
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		spin_unlock_irq(&mdev->tconn->req_lock);
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		io_schedule();
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		finish_wait(&mdev->ee_wait, &wait);
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		spin_lock_irq(&mdev->tconn->req_lock);
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	}
}

void drbd_wait_ee_list_empty(struct drbd_conf *mdev, struct list_head *head)
{
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	spin_lock_irq(&mdev->tconn->req_lock);
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	_drbd_wait_ee_list_empty(mdev, head);
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	spin_unlock_irq(&mdev->tconn->req_lock);
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}

/* see also kernel_accept; which is only present since 2.6.18.
 * also we want to log which part of it failed, exactly */
static int drbd_accept(struct drbd_conf *mdev, const char **what,
		struct socket *sock, struct socket **newsock)
{
	struct sock *sk = sock->sk;
	int err = 0;

	*what = "listen";
	err = sock->ops->listen(sock, 5);
	if (err < 0)
		goto out;

	*what = "sock_create_lite";
	err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
			       newsock);
	if (err < 0)
		goto out;

	*what = "accept";
	err = sock->ops->accept(sock, *newsock, 0);
	if (err < 0) {
		sock_release(*newsock);
		*newsock = NULL;
		goto out;
	}
	(*newsock)->ops  = sock->ops;

out:
	return err;
}

static int drbd_recv_short(struct drbd_conf *mdev, struct socket *sock,
		    void *buf, size_t size, int flags)
{
	mm_segment_t oldfs;
	struct kvec iov = {
		.iov_base = buf,
		.iov_len = size,
	};
	struct msghdr msg = {
		.msg_iovlen = 1,
		.msg_iov = (struct iovec *)&iov,
		.msg_flags = (flags ? flags : MSG_WAITALL | MSG_NOSIGNAL)
	};
	int rv;

	oldfs = get_fs();
	set_fs(KERNEL_DS);
	rv = sock_recvmsg(sock, &msg, size, msg.msg_flags);
	set_fs(oldfs);

	return rv;
}

static int drbd_recv(struct drbd_conf *mdev, void *buf, size_t size)
{
	mm_segment_t oldfs;
	struct kvec iov = {
		.iov_base = buf,
		.iov_len = size,
	};
	struct msghdr msg = {
		.msg_iovlen = 1,
		.msg_iov = (struct iovec *)&iov,
		.msg_flags = MSG_WAITALL | MSG_NOSIGNAL
	};
	int rv;

	oldfs = get_fs();
	set_fs(KERNEL_DS);

	for (;;) {
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		rv = sock_recvmsg(mdev->tconn->data.socket, &msg, size, msg.msg_flags);
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		if (rv == size)
			break;

		/* Note:
		 * ECONNRESET	other side closed the connection
		 * ERESTARTSYS	(on  sock) we got a signal
		 */

		if (rv < 0) {
			if (rv == -ECONNRESET)
				dev_info(DEV, "sock was reset by peer\n");
			else if (rv != -ERESTARTSYS)
				dev_err(DEV, "sock_recvmsg returned %d\n", rv);
			break;
		} else if (rv == 0) {
			dev_info(DEV, "sock was shut down by peer\n");
			break;
		} else	{
			/* signal came in, or peer/link went down,
			 * after we read a partial message
			 */
			/* D_ASSERT(signal_pending(current)); */
			break;
		}
	};

	set_fs(oldfs);

	if (rv != size)
		drbd_force_state(mdev, NS(conn, C_BROKEN_PIPE));

	return rv;
}

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/* quoting tcp(7):
 *   On individual connections, the socket buffer size must be set prior to the
 *   listen(2) or connect(2) calls in order to have it take effect.
 * This is our wrapper to do so.
 */
static void drbd_setbufsize(struct socket *sock, unsigned int snd,
		unsigned int rcv)
{
	/* open coded SO_SNDBUF, SO_RCVBUF */
	if (snd) {
		sock->sk->sk_sndbuf = snd;
		sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
	}
	if (rcv) {
		sock->sk->sk_rcvbuf = rcv;
		sock->sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
	}
}

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static struct socket *drbd_try_connect(struct drbd_conf *mdev)
{
	const char *what;
	struct socket *sock;
	struct sockaddr_in6 src_in6;
	int err;
	int disconnect_on_error = 1;

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	if (!get_net_conf(mdev->tconn))
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		return NULL;

	what = "sock_create_kern";
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	err = sock_create_kern(((struct sockaddr *)mdev->tconn->net_conf->my_addr)->sa_family,
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		SOCK_STREAM, IPPROTO_TCP, &sock);
	if (err < 0) {
		sock = NULL;
		goto out;
	}

	sock->sk->sk_rcvtimeo =
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	sock->sk->sk_sndtimeo =  mdev->tconn->net_conf->try_connect_int*HZ;
	drbd_setbufsize(sock, mdev->tconn->net_conf->sndbuf_size,
			mdev->tconn->net_conf->rcvbuf_size);
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       /* explicitly bind to the configured IP as source IP
	*  for the outgoing connections.
	*  This is needed for multihomed hosts and to be
	*  able to use lo: interfaces for drbd.
	* Make sure to use 0 as port number, so linux selects
	*  a free one dynamically.
	*/
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	memcpy(&src_in6, mdev->tconn->net_conf->my_addr,
	       min_t(int, mdev->tconn->net_conf->my_addr_len, sizeof(src_in6)));
	if (((struct sockaddr *)mdev->tconn->net_conf->my_addr)->sa_family == AF_INET6)
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		src_in6.sin6_port = 0;
	else
		((struct sockaddr_in *)&src_in6)->sin_port = 0; /* AF_INET & AF_SCI */

	what = "bind before connect";
	err = sock->ops->bind(sock,
			      (struct sockaddr *) &src_in6,
614
			      mdev->tconn->net_conf->my_addr_len);
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	if (err < 0)
		goto out;

	/* connect may fail, peer not yet available.
	 * stay C_WF_CONNECTION, don't go Disconnecting! */
	disconnect_on_error = 0;
	what = "connect";
	err = sock->ops->connect(sock,
623 624
				 (struct sockaddr *)mdev->tconn->net_conf->peer_addr,
				 mdev->tconn->net_conf->peer_addr_len, 0);
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out:
	if (err < 0) {
		if (sock) {
			sock_release(sock);
			sock = NULL;
		}
		switch (-err) {
			/* timeout, busy, signal pending */
		case ETIMEDOUT: case EAGAIN: case EINPROGRESS:
		case EINTR: case ERESTARTSYS:
			/* peer not (yet) available, network problem */
		case ECONNREFUSED: case ENETUNREACH:
		case EHOSTDOWN:    case EHOSTUNREACH:
			disconnect_on_error = 0;
			break;
		default:
			dev_err(DEV, "%s failed, err = %d\n", what, err);
		}
		if (disconnect_on_error)
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
	}
647
	put_net_conf(mdev->tconn);
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	return sock;
}

static struct socket *drbd_wait_for_connect(struct drbd_conf *mdev)
{
	int timeo, err;
	struct socket *s_estab = NULL, *s_listen;
	const char *what;

657
	if (!get_net_conf(mdev->tconn))
P
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		return NULL;

	what = "sock_create_kern";
661
	err = sock_create_kern(((struct sockaddr *)mdev->tconn->net_conf->my_addr)->sa_family,
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		SOCK_STREAM, IPPROTO_TCP, &s_listen);
	if (err) {
		s_listen = NULL;
		goto out;
	}

668
	timeo = mdev->tconn->net_conf->try_connect_int * HZ;
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669 670 671 672 673
	timeo += (random32() & 1) ? timeo / 7 : -timeo / 7; /* 28.5% random jitter */

	s_listen->sk->sk_reuse    = 1; /* SO_REUSEADDR */
	s_listen->sk->sk_rcvtimeo = timeo;
	s_listen->sk->sk_sndtimeo = timeo;
674 675
	drbd_setbufsize(s_listen, mdev->tconn->net_conf->sndbuf_size,
			mdev->tconn->net_conf->rcvbuf_size);
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	what = "bind before listen";
	err = s_listen->ops->bind(s_listen,
679 680
			      (struct sockaddr *) mdev->tconn->net_conf->my_addr,
			      mdev->tconn->net_conf->my_addr_len);
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681 682 683 684 685 686 687 688 689 690 691 692 693 694
	if (err < 0)
		goto out;

	err = drbd_accept(mdev, &what, s_listen, &s_estab);

out:
	if (s_listen)
		sock_release(s_listen);
	if (err < 0) {
		if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
			dev_err(DEV, "%s failed, err = %d\n", what, err);
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
		}
	}
695
	put_net_conf(mdev->tconn);
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	return s_estab;
}

static int drbd_send_fp(struct drbd_conf *mdev,
	struct socket *sock, enum drbd_packets cmd)
{
703
	struct p_header *h = &mdev->tconn->data.sbuf.header;
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	return _drbd_send_cmd(mdev, sock, cmd, h, sizeof(*h), 0);
}

static enum drbd_packets drbd_recv_fp(struct drbd_conf *mdev, struct socket *sock)
{
710
	struct p_header80 *h = &mdev->tconn->data.rbuf.header.h80;
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	int rr;

	rr = drbd_recv_short(mdev, sock, h, sizeof(*h), 0);

715
	if (rr == sizeof(*h) && h->magic == cpu_to_be32(DRBD_MAGIC))
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716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731
		return be16_to_cpu(h->command);

	return 0xffff;
}

/**
 * drbd_socket_okay() - Free the socket if its connection is not okay
 * @mdev:	DRBD device.
 * @sock:	pointer to the pointer to the socket.
 */
static int drbd_socket_okay(struct drbd_conf *mdev, struct socket **sock)
{
	int rr;
	char tb[4];

	if (!*sock)
732
		return false;
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	rr = drbd_recv_short(mdev, *sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);

	if (rr > 0 || rr == -EAGAIN) {
737
		return true;
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738 739 740
	} else {
		sock_release(*sock);
		*sock = NULL;
741
		return false;
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	}
}

/*
 * return values:
 *   1 yes, we have a valid connection
 *   0 oops, did not work out, please try again
 *  -1 peer talks different language,
 *     no point in trying again, please go standalone.
 *  -2 We do not have a network config...
 */
static int drbd_connect(struct drbd_conf *mdev)
{
	struct socket *s, *sock, *msock;
	int try, h, ok;

758
	D_ASSERT(!mdev->tconn->data.socket);
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	if (drbd_request_state(mdev, NS(conn, C_WF_CONNECTION)) < SS_SUCCESS)
		return -2;

	clear_bit(DISCARD_CONCURRENT, &mdev->flags);
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	mdev->tconn->agreed_pro_version = 99;
	/* agreed_pro_version must be smaller than 100 so we send the old
	   header (h80) in the first packet and in the handshake packet. */
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	sock  = NULL;
	msock = NULL;

	do {
		for (try = 0;;) {
			/* 3 tries, this should take less than a second! */
			s = drbd_try_connect(mdev);
			if (s || ++try >= 3)
				break;
			/* give the other side time to call bind() & listen() */
778
			schedule_timeout_interruptible(HZ / 10);
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		}

		if (s) {
			if (!sock) {
				drbd_send_fp(mdev, s, P_HAND_SHAKE_S);
				sock = s;
				s = NULL;
			} else if (!msock) {
				drbd_send_fp(mdev, s, P_HAND_SHAKE_M);
				msock = s;
				s = NULL;
			} else {
				dev_err(DEV, "Logic error in drbd_connect()\n");
				goto out_release_sockets;
			}
		}

		if (sock && msock) {
797
			schedule_timeout_interruptible(mdev->tconn->net_conf->ping_timeo*HZ/10);
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798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
			ok = drbd_socket_okay(mdev, &sock);
			ok = drbd_socket_okay(mdev, &msock) && ok;
			if (ok)
				break;
		}

retry:
		s = drbd_wait_for_connect(mdev);
		if (s) {
			try = drbd_recv_fp(mdev, s);
			drbd_socket_okay(mdev, &sock);
			drbd_socket_okay(mdev, &msock);
			switch (try) {
			case P_HAND_SHAKE_S:
				if (sock) {
					dev_warn(DEV, "initial packet S crossed\n");
					sock_release(sock);
				}
				sock = s;
				break;
			case P_HAND_SHAKE_M:
				if (msock) {
					dev_warn(DEV, "initial packet M crossed\n");
					sock_release(msock);
				}
				msock = s;
				set_bit(DISCARD_CONCURRENT, &mdev->flags);
				break;
			default:
				dev_warn(DEV, "Error receiving initial packet\n");
				sock_release(s);
				if (random32() & 1)
					goto retry;
			}
		}

		if (mdev->state.conn <= C_DISCONNECTING)
			goto out_release_sockets;
		if (signal_pending(current)) {
			flush_signals(current);
			smp_rmb();
839
			if (get_t_state(&mdev->tconn->receiver) == EXITING)
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840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860
				goto out_release_sockets;
		}

		if (sock && msock) {
			ok = drbd_socket_okay(mdev, &sock);
			ok = drbd_socket_okay(mdev, &msock) && ok;
			if (ok)
				break;
		}
	} while (1);

	msock->sk->sk_reuse = 1; /* SO_REUSEADDR */
	sock->sk->sk_reuse = 1; /* SO_REUSEADDR */

	sock->sk->sk_allocation = GFP_NOIO;
	msock->sk->sk_allocation = GFP_NOIO;

	sock->sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
	msock->sk->sk_priority = TC_PRIO_INTERACTIVE;

	/* NOT YET ...
861
	 * sock->sk->sk_sndtimeo = mdev->tconn->net_conf->timeout*HZ/10;
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	 * sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
	 * first set it to the P_HAND_SHAKE timeout,
	 * which we set to 4x the configured ping_timeout. */
	sock->sk->sk_sndtimeo =
866
	sock->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_timeo*4*HZ/10;
P
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867

868 869
	msock->sk->sk_sndtimeo = mdev->tconn->net_conf->timeout*HZ/10;
	msock->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_int*HZ;
P
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870 871

	/* we don't want delays.
L
Lucas De Marchi 已提交
872
	 * we use TCP_CORK where appropriate, though */
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873 874 875
	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

876 877
	mdev->tconn->data.socket = sock;
	mdev->tconn->meta.socket = msock;
878
	mdev->tconn->last_received = jiffies;
P
Philipp Reisner 已提交
879

880
	D_ASSERT(mdev->tconn->asender.task == NULL);
P
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881 882 883 884 885

	h = drbd_do_handshake(mdev);
	if (h <= 0)
		return h;

886
	if (mdev->tconn->cram_hmac_tfm) {
P
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887
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
888 889
		switch (drbd_do_auth(mdev)) {
		case -1:
P
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890 891
			dev_err(DEV, "Authentication of peer failed\n");
			return -1;
892 893 894
		case 0:
			dev_err(DEV, "Authentication of peer failed, trying again.\n");
			return 0;
P
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895 896 897 898 899 900
		}
	}

	if (drbd_request_state(mdev, NS(conn, C_WF_REPORT_PARAMS)) < SS_SUCCESS)
		return 0;

901
	sock->sk->sk_sndtimeo = mdev->tconn->net_conf->timeout*HZ/10;
P
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902 903 904 905 906
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

	atomic_set(&mdev->packet_seq, 0);
	mdev->peer_seq = 0;

907
	drbd_thread_start(&mdev->tconn->asender);
P
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908

909
	if (drbd_send_protocol(mdev) == -1)
910
		return -1;
P
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911
	drbd_send_sync_param(mdev, &mdev->sync_conf);
912
	drbd_send_sizes(mdev, 0, 0);
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913 914 915 916
	drbd_send_uuids(mdev);
	drbd_send_state(mdev);
	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
	clear_bit(RESIZE_PENDING, &mdev->flags);
917
	mod_timer(&mdev->request_timer, jiffies + HZ); /* just start it here. */
P
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918 919 920 921 922 923 924 925 926 927 928

	return 1;

out_release_sockets:
	if (sock)
		sock_release(sock);
	if (msock)
		sock_release(msock);
	return -1;
}

929 930
static bool decode_header(struct drbd_conf *mdev, struct p_header *h, enum drbd_packets *cmd,
			  unsigned int *packet_size)
P
Philipp Reisner 已提交
931
{
P
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932
	if (h->h80.magic == cpu_to_be32(DRBD_MAGIC)) {
933 934
		*cmd = be16_to_cpu(h->h80.command);
		*packet_size = be16_to_cpu(h->h80.length);
935
	} else if (h->h95.magic == cpu_to_be16(DRBD_MAGIC_BIG)) {
936
		*cmd = be16_to_cpu(h->h95.command);
P
Philipp Reisner 已提交
937
		*packet_size = be32_to_cpu(h->h95.length) & 0x00ffffff;
938
	} else {
939 940 941 942
		dev_err(DEV, "magic?? on data m: 0x%08x c: %d l: %d\n",
		    be32_to_cpu(h->h80.magic),
		    be16_to_cpu(h->h80.command),
		    be16_to_cpu(h->h80.length));
943
		return false;
P
Philipp Reisner 已提交
944
	}
945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960
	return true;
}

static int drbd_recv_header(struct drbd_conf *mdev, enum drbd_packets *cmd, unsigned int *packet_size)
{
	struct p_header *h = &mdev->tconn->data.rbuf.header;
	int r;

	r = drbd_recv(mdev, h, sizeof(*h));
	if (unlikely(r != sizeof(*h))) {
		if (!signal_pending(current))
			dev_warn(DEV, "short read expecting header on sock: r=%d\n", r);
		return false;
	}

	r = decode_header(mdev, h, cmd, packet_size);
961
	mdev->tconn->last_received = jiffies;
P
Philipp Reisner 已提交
962

963
	return r;
P
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964 965
}

966
static void drbd_flush(struct drbd_conf *mdev)
P
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967 968 969 970
{
	int rv;

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
971
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
972
					NULL);
P
Philipp Reisner 已提交
973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993
		if (rv) {
			dev_err(DEV, "local disk flush failed with status %d\n", rv);
			/* would rather check on EOPNOTSUPP, but that is not reliable.
			 * don't try again for ANY return value != 0
			 * if (rv == -EOPNOTSUPP) */
			drbd_bump_write_ordering(mdev, WO_drain_io);
		}
		put_ldev(mdev);
	}
}

/**
 * drbd_may_finish_epoch() - Applies an epoch_event to the epoch's state, eventually finishes it.
 * @mdev:	DRBD device.
 * @epoch:	Epoch object.
 * @ev:		Epoch event.
 */
static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *mdev,
					       struct drbd_epoch *epoch,
					       enum epoch_event ev)
{
994
	int epoch_size;
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995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017
	struct drbd_epoch *next_epoch;
	enum finish_epoch rv = FE_STILL_LIVE;

	spin_lock(&mdev->epoch_lock);
	do {
		next_epoch = NULL;

		epoch_size = atomic_read(&epoch->epoch_size);

		switch (ev & ~EV_CLEANUP) {
		case EV_PUT:
			atomic_dec(&epoch->active);
			break;
		case EV_GOT_BARRIER_NR:
			set_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags);
			break;
		case EV_BECAME_LAST:
			/* nothing to do*/
			break;
		}

		if (epoch_size != 0 &&
		    atomic_read(&epoch->active) == 0 &&
1018
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
P
Philipp Reisner 已提交
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037
			if (!(ev & EV_CLEANUP)) {
				spin_unlock(&mdev->epoch_lock);
				drbd_send_b_ack(mdev, epoch->barrier_nr, epoch_size);
				spin_lock(&mdev->epoch_lock);
			}
			dec_unacked(mdev);

			if (mdev->current_epoch != epoch) {
				next_epoch = list_entry(epoch->list.next, struct drbd_epoch, list);
				list_del(&epoch->list);
				ev = EV_BECAME_LAST | (ev & EV_CLEANUP);
				mdev->epochs--;
				kfree(epoch);

				if (rv == FE_STILL_LIVE)
					rv = FE_DESTROYED;
			} else {
				epoch->flags = 0;
				atomic_set(&epoch->epoch_size, 0);
1038
				/* atomic_set(&epoch->active, 0); is already zero */
P
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1039 1040
				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1041
				wake_up(&mdev->ee_wait);
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1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
			}
		}

		if (!next_epoch)
			break;

		epoch = next_epoch;
	} while (1);

	spin_unlock(&mdev->epoch_lock);

	return rv;
}

/**
 * drbd_bump_write_ordering() - Fall back to an other write ordering method
 * @mdev:	DRBD device.
 * @wo:		Write ordering method to try.
 */
void drbd_bump_write_ordering(struct drbd_conf *mdev, enum write_ordering_e wo) __must_hold(local)
{
	enum write_ordering_e pwo;
	static char *write_ordering_str[] = {
		[WO_none] = "none",
		[WO_drain_io] = "drain",
		[WO_bdev_flush] = "flush",
	};

	pwo = mdev->write_ordering;
	wo = min(pwo, wo);
	if (wo == WO_bdev_flush && mdev->ldev->dc.no_disk_flush)
		wo = WO_drain_io;
	if (wo == WO_drain_io && mdev->ldev->dc.no_disk_drain)
		wo = WO_none;
	mdev->write_ordering = wo;
1077
	if (pwo != mdev->write_ordering || wo == WO_bdev_flush)
P
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1078 1079 1080
		dev_info(DEV, "Method to ensure write ordering: %s\n", write_ordering_str[mdev->write_ordering]);
}

1081 1082 1083 1084 1085
/**
 * drbd_submit_ee()
 * @mdev:	DRBD device.
 * @e:		epoch entry
 * @rw:		flag field, see bio->bi_rw
1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
 *
 * May spread the pages to multiple bios,
 * depending on bio_add_page restrictions.
 *
 * Returns 0 if all bios have been submitted,
 * -ENOMEM if we could not allocate enough bios,
 * -ENOSPC (any better suggestion?) if we have not been able to bio_add_page a
 *  single page to an empty bio (which should never happen and likely indicates
 *  that the lower level IO stack is in some way broken). This has been observed
 *  on certain Xen deployments.
1096 1097 1098 1099 1100 1101 1102 1103
 */
/* TODO allocate from our own bio_set. */
int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e,
		const unsigned rw, const int fault_type)
{
	struct bio *bios = NULL;
	struct bio *bio;
	struct page *page = e->pages;
1104 1105
	sector_t sector = e->i.sector;
	unsigned ds = e->i.size;
1106 1107
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1108
	int err = -ENOMEM;
1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119

	/* In most cases, we will only need one bio.  But in case the lower
	 * level restrictions happen to be different at this offset on this
	 * side than those of the sending peer, we may need to submit the
	 * request in more than one bio. */
next_bio:
	bio = bio_alloc(GFP_NOIO, nr_pages);
	if (!bio) {
		dev_err(DEV, "submit_ee: Allocation of a bio failed\n");
		goto fail;
	}
1120
	/* > e->i.sector, unless this is the first bio */
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133
	bio->bi_sector = sector;
	bio->bi_bdev = mdev->ldev->backing_bdev;
	bio->bi_rw = rw;
	bio->bi_private = e;
	bio->bi_end_io = drbd_endio_sec;

	bio->bi_next = bios;
	bios = bio;
	++n_bios;

	page_chain_for_each(page) {
		unsigned len = min_t(unsigned, ds, PAGE_SIZE);
		if (!bio_add_page(bio, page, len, 0)) {
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144
			/* A single page must always be possible!
			 * But in case it fails anyways,
			 * we deal with it, and complain (below). */
			if (bio->bi_vcnt == 0) {
				dev_err(DEV,
					"bio_add_page failed for len=%u, "
					"bi_vcnt=0 (bi_sector=%llu)\n",
					len, (unsigned long long)bio->bi_sector);
				err = -ENOSPC;
				goto fail;
			}
1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
			goto next_bio;
		}
		ds -= len;
		sector += len >> 9;
		--nr_pages;
	}
	D_ASSERT(page == NULL);
	D_ASSERT(ds == 0);

	atomic_set(&e->pending_bios, n_bios);
	do {
		bio = bios;
		bios = bios->bi_next;
		bio->bi_next = NULL;

		drbd_generic_make_request(mdev, fault_type, bio);
	} while (bios);
	return 0;

fail:
	while (bios) {
		bio = bios;
		bios = bios->bi_next;
		bio_put(bio);
	}
1170
	return err;
1171 1172
}

1173
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
1174
{
1175
	int rv;
1176
	struct p_barrier *p = &mdev->tconn->data.rbuf.barrier;
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1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191
	struct drbd_epoch *epoch;

	inc_unacked(mdev);

	mdev->current_epoch->barrier_nr = p->barrier;
	rv = drbd_may_finish_epoch(mdev, mdev->current_epoch, EV_GOT_BARRIER_NR);

	/* P_BARRIER_ACK may imply that the corresponding extent is dropped from
	 * the activity log, which means it would not be resynced in case the
	 * R_PRIMARY crashes now.
	 * Therefore we must send the barrier_ack after the barrier request was
	 * completed. */
	switch (mdev->write_ordering) {
	case WO_none:
		if (rv == FE_RECYCLED)
1192
			return true;
1193 1194 1195 1196 1197 1198 1199 1200 1201

		/* receiver context, in the writeout path of the other node.
		 * avoid potential distributed deadlock */
		epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
		if (epoch)
			break;
		else
			dev_warn(DEV, "Allocation of an epoch failed, slowing down\n");
			/* Fall through */
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1202 1203 1204 1205

	case WO_bdev_flush:
	case WO_drain_io:
		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
1206 1207 1208 1209 1210 1211
		drbd_flush(mdev);

		if (atomic_read(&mdev->current_epoch->epoch_size)) {
			epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
			if (epoch)
				break;
P
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1212 1213
		}

1214 1215 1216 1217 1218
		epoch = mdev->current_epoch;
		wait_event(mdev->ee_wait, atomic_read(&epoch->epoch_size) == 0);

		D_ASSERT(atomic_read(&epoch->active) == 0);
		D_ASSERT(epoch->flags == 0);
P
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1219

1220
		return true;
1221 1222
	default:
		dev_err(DEV, "Strangeness in mdev->write_ordering %d\n", mdev->write_ordering);
1223
		return false;
P
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1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240
	}

	epoch->flags = 0;
	atomic_set(&epoch->epoch_size, 0);
	atomic_set(&epoch->active, 0);

	spin_lock(&mdev->epoch_lock);
	if (atomic_read(&mdev->current_epoch->epoch_size)) {
		list_add(&epoch->list, &mdev->current_epoch->list);
		mdev->current_epoch = epoch;
		mdev->epochs++;
	} else {
		/* The current_epoch got recycled while we allocated this one... */
		kfree(epoch);
	}
	spin_unlock(&mdev->epoch_lock);

1241
	return true;
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1242 1243 1244 1245 1246 1247 1248
}

/* used from receive_RSDataReply (recv_resync_read)
 * and from receive_Data */
static struct drbd_epoch_entry *
read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector, int data_size) __must_hold(local)
{
1249
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
P
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1250 1251
	struct drbd_epoch_entry *e;
	struct page *page;
1252
	int dgs, ds, rr;
1253 1254
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
1255
	unsigned long *data;
P
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1256

1257 1258
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
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	if (dgs) {
		rr = drbd_recv(mdev, dig_in, dgs);
		if (rr != dgs) {
1263 1264 1265 1266
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data digest: read %d expected %d\n",
					rr, dgs);
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1267 1268 1269 1270 1271 1272
			return NULL;
		}
	}

	data_size -= dgs;

1273 1274 1275 1276 1277 1278
	if (!expect(data_size != 0))
		return NULL;
	if (!expect(IS_ALIGNED(data_size, 512)))
		return NULL;
	if (!expect(data_size <= DRBD_MAX_BIO_SIZE))
		return NULL;
P
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1279

1280 1281 1282
	/* even though we trust out peer,
	 * we sometimes have to double check. */
	if (sector + (data_size>>9) > capacity) {
1283 1284
		dev_err(DEV, "request from peer beyond end of local disk: "
			"capacity: %llus < sector: %llus + size: %u\n",
1285 1286 1287 1288 1289
			(unsigned long long)capacity,
			(unsigned long long)sector, data_size);
		return NULL;
	}

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1290 1291 1292 1293 1294 1295
	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
	e = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
	if (!e)
		return NULL;
1296

P
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1297
	ds = data_size;
1298 1299 1300
	page = e->pages;
	page_chain_for_each(page) {
		unsigned len = min_t(int, ds, PAGE_SIZE);
1301
		data = kmap(page);
1302
		rr = drbd_recv(mdev, data, len);
1303
		if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
1304 1305 1306
			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
			data[0] = data[0] ^ (unsigned long)-1;
		}
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1307
		kunmap(page);
1308
		if (rr != len) {
P
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1309
			drbd_free_ee(mdev, e);
1310 1311 1312
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data: read %d expected %d\n",
				rr, len);
P
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1313 1314 1315 1316 1317 1318
			return NULL;
		}
		ds -= rr;
	}

	if (dgs) {
1319
		drbd_csum_ee(mdev, mdev->tconn->integrity_r_tfm, e, dig_vv);
P
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1320
		if (memcmp(dig_in, dig_vv, dgs)) {
1321 1322
			dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
				(unsigned long long)sector, data_size);
P
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1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341
			drbd_bcast_ee(mdev, "digest failed",
					dgs, dig_in, dig_vv, e);
			drbd_free_ee(mdev, e);
			return NULL;
		}
	}
	mdev->recv_cnt += data_size>>9;
	return e;
}

/* drbd_drain_block() just takes a data block
 * out of the socket input buffer, and discards it.
 */
static int drbd_drain_block(struct drbd_conf *mdev, int data_size)
{
	struct page *page;
	int rr, rv = 1;
	void *data;

1342
	if (!data_size)
1343
		return true;
1344

1345
	page = drbd_pp_alloc(mdev, 1, 1);
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1346 1347 1348 1349 1350 1351

	data = kmap(page);
	while (data_size) {
		rr = drbd_recv(mdev, data, min_t(int, data_size, PAGE_SIZE));
		if (rr != min_t(int, data_size, PAGE_SIZE)) {
			rv = 0;
1352 1353 1354 1355
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data: read %d expected %d\n",
					rr, min_t(int, data_size, PAGE_SIZE));
P
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1356 1357 1358 1359 1360
			break;
		}
		data_size -= rr;
	}
	kunmap(page);
1361
	drbd_pp_free(mdev, page, 0);
P
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1362 1363 1364 1365 1366 1367 1368 1369 1370
	return rv;
}

static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
			   sector_t sector, int data_size)
{
	struct bio_vec *bvec;
	struct bio *bio;
	int dgs, rr, i, expect;
1371 1372
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
P
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1373

1374 1375
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
P
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1376 1377 1378 1379

	if (dgs) {
		rr = drbd_recv(mdev, dig_in, dgs);
		if (rr != dgs) {
1380 1381 1382 1383
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data reply digest: read %d expected %d\n",
					rr, dgs);
P
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1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
			return 0;
		}
	}

	data_size -= dgs;

	/* optimistically update recv_cnt.  if receiving fails below,
	 * we disconnect anyways, and counters will be reset. */
	mdev->recv_cnt += data_size>>9;

	bio = req->master_bio;
	D_ASSERT(sector == bio->bi_sector);

	bio_for_each_segment(bvec, bio, i) {
		expect = min_t(int, data_size, bvec->bv_len);
		rr = drbd_recv(mdev,
			     kmap(bvec->bv_page)+bvec->bv_offset,
			     expect);
		kunmap(bvec->bv_page);
		if (rr != expect) {
1404 1405 1406 1407
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data reply: "
					"read %d expected %d\n",
					rr, expect);
P
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1408 1409 1410 1411 1412 1413
			return 0;
		}
		data_size -= rr;
	}

	if (dgs) {
1414
		drbd_csum_bio(mdev, mdev->tconn->integrity_r_tfm, bio, dig_vv);
P
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1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429
		if (memcmp(dig_in, dig_vv, dgs)) {
			dev_err(DEV, "Digest integrity check FAILED. Broken NICs?\n");
			return 0;
		}
	}

	D_ASSERT(data_size == 0);
	return 1;
}

/* e_end_resync_block() is called via
 * drbd_process_done_ee() by asender only */
static int e_end_resync_block(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
	struct drbd_epoch_entry *e = (struct drbd_epoch_entry *)w;
1430
	sector_t sector = e->i.sector;
P
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1431 1432
	int ok;

1433
	D_ASSERT(drbd_interval_empty(&e->i));
P
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1434

1435
	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
1436
		drbd_set_in_sync(mdev, sector, e->i.size);
P
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1437 1438 1439
		ok = drbd_send_ack(mdev, P_RS_WRITE_ACK, e);
	} else {
		/* Record failure to sync */
1440
		drbd_rs_failed_io(mdev, sector, e->i.size);
P
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1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453

		ok  = drbd_send_ack(mdev, P_NEG_ACK, e);
	}
	dec_unacked(mdev);

	return ok;
}

static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_size) __releases(local)
{
	struct drbd_epoch_entry *e;

	e = read_in_block(mdev, ID_SYNCER, sector, data_size);
1454 1455
	if (!e)
		goto fail;
P
Philipp Reisner 已提交
1456 1457 1458 1459 1460 1461 1462

	dec_rs_pending(mdev);

	inc_unacked(mdev);
	/* corresponding dec_unacked() in e_end_resync_block()
	 * respective _drbd_clear_done_ee */

1463 1464
	e->w.cb = e_end_resync_block;

1465
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1466
	list_add(&e->w.list, &mdev->sync_ee);
1467
	spin_unlock_irq(&mdev->tconn->req_lock);
P
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1468

1469
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1470
	if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)
1471
		return true;
P
Philipp Reisner 已提交
1472

1473 1474
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1475
	spin_lock_irq(&mdev->tconn->req_lock);
1476
	list_del(&e->w.list);
1477
	spin_unlock_irq(&mdev->tconn->req_lock);
1478

1479 1480 1481
	drbd_free_ee(mdev, e);
fail:
	put_ldev(mdev);
1482
	return false;
P
Philipp Reisner 已提交
1483 1484
}

1485
static struct drbd_request *
1486 1487
find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
	     sector_t sector, bool missing_ok, const char *func)
1488 1489 1490
{
	struct drbd_request *req;

1491 1492 1493
	/* Request object according to our peer */
	req = (struct drbd_request *)(unsigned long)id;
	if (drbd_contains_interval(root, sector, &req->i))
1494
		return req;
1495 1496 1497 1498
	if (!missing_ok) {
		dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
			(unsigned long)id, (unsigned long long)sector);
	}
1499 1500 1501
	return NULL;
}

1502
static int receive_DataReply(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
1503 1504 1505 1506
{
	struct drbd_request *req;
	sector_t sector;
	int ok;
1507
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1508 1509 1510

	sector = be64_to_cpu(p->sector);

1511
	spin_lock_irq(&mdev->tconn->req_lock);
1512
	req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
1513
	spin_unlock_irq(&mdev->tconn->req_lock);
1514
	if (unlikely(!req))
1515
		return false;
P
Philipp Reisner 已提交
1516

B
Bart Van Assche 已提交
1517
	/* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
P
Philipp Reisner 已提交
1518 1519 1520 1521 1522
	 * special casing it there for the various failure cases.
	 * still no race with drbd_fail_pending_reads */
	ok = recv_dless_read(mdev, req, sector, data_size);

	if (ok)
1523
		req_mod(req, DATA_RECEIVED);
P
Philipp Reisner 已提交
1524 1525 1526 1527 1528 1529 1530
	/* else: nothing. handled from drbd_disconnect...
	 * I don't think we may complete this just yet
	 * in case we are "on-disconnect: freeze" */

	return ok;
}

1531
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
1532 1533 1534
{
	sector_t sector;
	int ok;
1535
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1536 1537 1538 1539 1540 1541 1542

	sector = be64_to_cpu(p->sector);
	D_ASSERT(p->block_id == ID_SYNCER);

	if (get_ldev(mdev)) {
		/* data is submitted to disk within recv_resync_read.
		 * corresponding put_ldev done below on error,
1543
		 * or in drbd_endio_sec. */
P
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1544 1545 1546 1547 1548 1549 1550
		ok = recv_resync_read(mdev, sector, data_size);
	} else {
		if (__ratelimit(&drbd_ratelimit_state))
			dev_err(DEV, "Can not write resync data to local disk.\n");

		ok = drbd_drain_block(mdev, data_size);

1551
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1552 1553
	}

1554 1555
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

P
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1556 1557 1558 1559 1560 1561 1562 1563 1564
	return ok;
}

/* e_end_block() is called via drbd_process_done_ee().
 * this means this function only runs in the asender thread
 */
static int e_end_block(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
	struct drbd_epoch_entry *e = (struct drbd_epoch_entry *)w;
1565
	sector_t sector = e->i.sector;
P
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1566 1567
	int ok = 1, pcmd;

1568
	if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
1569
		if (likely((e->flags & EE_WAS_ERROR) == 0)) {
P
Philipp Reisner 已提交
1570 1571 1572 1573 1574 1575
			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
				mdev->state.conn <= C_PAUSED_SYNC_T &&
				e->flags & EE_MAY_SET_IN_SYNC) ?
				P_RS_WRITE_ACK : P_WRITE_ACK;
			ok &= drbd_send_ack(mdev, pcmd, e);
			if (pcmd == P_RS_WRITE_ACK)
1576
				drbd_set_in_sync(mdev, sector, e->i.size);
P
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1577 1578 1579 1580 1581 1582 1583 1584 1585
		} else {
			ok  = drbd_send_ack(mdev, P_NEG_ACK, e);
			/* we expect it to be marked out of sync anyways...
			 * maybe assert this?  */
		}
		dec_unacked(mdev);
	}
	/* we delete from the conflict detection hash _after_ we sent out the
	 * P_WRITE_ACK / P_NEG_ACK, to get the sequence number right.  */
1586
	if (mdev->tconn->net_conf->two_primaries) {
1587
		spin_lock_irq(&mdev->tconn->req_lock);
1588 1589 1590
		D_ASSERT(!drbd_interval_empty(&e->i));
		drbd_remove_interval(&mdev->epoch_entries, &e->i);
		drbd_clear_interval(&e->i);
1591
		spin_unlock_irq(&mdev->tconn->req_lock);
1592
	} else
1593
		D_ASSERT(drbd_interval_empty(&e->i));
P
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1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604

	drbd_may_finish_epoch(mdev, e->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));

	return ok;
}

static int e_send_discard_ack(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
	struct drbd_epoch_entry *e = (struct drbd_epoch_entry *)w;
	int ok = 1;

1605
	D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
P
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1606 1607
	ok = drbd_send_ack(mdev, P_DISCARD_ACK, e);

1608
	spin_lock_irq(&mdev->tconn->req_lock);
1609 1610 1611
	D_ASSERT(!drbd_interval_empty(&e->i));
	drbd_remove_interval(&mdev->epoch_entries, &e->i);
	drbd_clear_interval(&e->i);
1612
	spin_unlock_irq(&mdev->tconn->req_lock);
P
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1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671

	dec_unacked(mdev);

	return ok;
}

/* Called from receive_Data.
 * Synchronize packets on sock with packets on msock.
 *
 * This is here so even when a P_DATA packet traveling via sock overtook an Ack
 * packet traveling on msock, they are still processed in the order they have
 * been sent.
 *
 * Note: we don't care for Ack packets overtaking P_DATA packets.
 *
 * In case packet_seq is larger than mdev->peer_seq number, there are
 * outstanding packets on the msock. We wait for them to arrive.
 * In case we are the logically next packet, we update mdev->peer_seq
 * ourselves. Correctly handles 32bit wrap around.
 *
 * Assume we have a 10 GBit connection, that is about 1<<30 byte per second,
 * about 1<<21 sectors per second. So "worst" case, we have 1<<3 == 8 seconds
 * for the 24bit wrap (historical atomic_t guarantee on some archs), and we have
 * 1<<9 == 512 seconds aka ages for the 32bit wrap around...
 *
 * returns 0 if we may process the packet,
 * -ERESTARTSYS if we were interrupted (by disconnect signal). */
static int drbd_wait_peer_seq(struct drbd_conf *mdev, const u32 packet_seq)
{
	DEFINE_WAIT(wait);
	unsigned int p_seq;
	long timeout;
	int ret = 0;
	spin_lock(&mdev->peer_seq_lock);
	for (;;) {
		prepare_to_wait(&mdev->seq_wait, &wait, TASK_INTERRUPTIBLE);
		if (seq_le(packet_seq, mdev->peer_seq+1))
			break;
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
		p_seq = mdev->peer_seq;
		spin_unlock(&mdev->peer_seq_lock);
		timeout = schedule_timeout(30*HZ);
		spin_lock(&mdev->peer_seq_lock);
		if (timeout == 0 && p_seq == mdev->peer_seq) {
			ret = -ETIMEDOUT;
			dev_err(DEV, "ASSERT FAILED waited 30 seconds for sequence update, forcing reconnect\n");
			break;
		}
	}
	finish_wait(&mdev->seq_wait, &wait);
	if (mdev->peer_seq+1 == packet_seq)
		mdev->peer_seq++;
	spin_unlock(&mdev->peer_seq_lock);
	return ret;
}

1672 1673 1674 1675
/* see also bio_flags_to_wire()
 * DRBD_REQ_*, because we need to semantically map the flags to data packet
 * flags and back. We may replicate to other kernel versions. */
static unsigned long wire_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
1676
{
1677 1678 1679 1680
	return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
		(dpf & DP_FUA ? REQ_FUA : 0) |
		(dpf & DP_FLUSH ? REQ_FLUSH : 0) |
		(dpf & DP_DISCARD ? REQ_DISCARD : 0);
1681 1682
}

P
Philipp Reisner 已提交
1683
/* mirrored write */
1684
static int receive_Data(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
1685 1686 1687
{
	sector_t sector;
	struct drbd_epoch_entry *e;
1688
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1689 1690 1691 1692 1693 1694 1695 1696 1697
	int rw = WRITE;
	u32 dp_flags;

	if (!get_ldev(mdev)) {
		spin_lock(&mdev->peer_seq_lock);
		if (mdev->peer_seq+1 == be32_to_cpu(p->seq_num))
			mdev->peer_seq++;
		spin_unlock(&mdev->peer_seq_lock);

1698
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1699 1700 1701 1702 1703 1704
		atomic_inc(&mdev->current_epoch->epoch_size);
		return drbd_drain_block(mdev, data_size);
	}

	/* get_ldev(mdev) successful.
	 * Corresponding put_ldev done either below (on various errors),
1705
	 * or in drbd_endio_sec, if we successfully submit the data at
P
Philipp Reisner 已提交
1706 1707 1708 1709 1710 1711
	 * the end of this function. */

	sector = be64_to_cpu(p->sector);
	e = read_in_block(mdev, p->block_id, sector, data_size);
	if (!e) {
		put_ldev(mdev);
1712
		return false;
P
Philipp Reisner 已提交
1713 1714 1715 1716
	}

	e->w.cb = e_end_block;

1717 1718 1719 1720 1721 1722
	dp_flags = be32_to_cpu(p->dp_flags);
	rw |= wire_flags_to_bio(mdev, dp_flags);

	if (dp_flags & DP_MAY_SET_IN_SYNC)
		e->flags |= EE_MAY_SET_IN_SYNC;

P
Philipp Reisner 已提交
1723 1724 1725 1726 1727 1728 1729
	spin_lock(&mdev->epoch_lock);
	e->epoch = mdev->current_epoch;
	atomic_inc(&e->epoch->epoch_size);
	atomic_inc(&e->epoch->active);
	spin_unlock(&mdev->epoch_lock);

	/* I'm the receiver, I do hold a net_cnt reference. */
1730
	if (!mdev->tconn->net_conf->two_primaries) {
1731
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1732 1733 1734
	} else {
		/* don't get the req_lock yet,
		 * we may sleep in drbd_wait_peer_seq */
1735
		const int size = e->i.size;
P
Philipp Reisner 已提交
1736 1737 1738 1739
		const int discard = test_bit(DISCARD_CONCURRENT, &mdev->flags);
		DEFINE_WAIT(wait);
		int first;

1740
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
P
Philipp Reisner 已提交
1741 1742 1743 1744

		/* conflict detection and handling:
		 * 1. wait on the sequence number,
		 *    in case this data packet overtook ACK packets.
1745 1746 1747 1748
		 * 2. check our interval trees for conflicting requests:
		 *    we only need to check the write_requests tree; the
		 *    epoch_entries tree cannot contain any overlaps because
		 *    they were already eliminated on the submitting node.
P
Philipp Reisner 已提交
1749 1750 1751 1752 1753
		 *
		 * Note: for two_primaries, we are protocol C,
		 * so there cannot be any request that is DONE
		 * but still on the transfer log.
		 *
1754
		 * unconditionally add to the epoch_entries tree.
P
Philipp Reisner 已提交
1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777
		 *
		 * if no conflicting request is found:
		 *    submit.
		 *
		 * if any conflicting request is found
		 * that has not yet been acked,
		 * AND I have the "discard concurrent writes" flag:
		 *	 queue (via done_ee) the P_DISCARD_ACK; OUT.
		 *
		 * if any conflicting request is found:
		 *	 block the receiver, waiting on misc_wait
		 *	 until no more conflicting requests are there,
		 *	 or we get interrupted (disconnect).
		 *
		 *	 we do not just write after local io completion of those
		 *	 requests, but only after req is done completely, i.e.
		 *	 we wait for the P_DISCARD_ACK to arrive!
		 *
		 *	 then proceed normally, i.e. submit.
		 */
		if (drbd_wait_peer_seq(mdev, be32_to_cpu(p->seq_num)))
			goto out_interrupted;

1778
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1779

1780
		drbd_insert_interval(&mdev->epoch_entries, &e->i);
P
Philipp Reisner 已提交
1781 1782 1783

		first = 1;
		for (;;) {
1784
			struct drbd_interval *i;
P
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1785 1786 1787 1788
			int have_unacked = 0;
			int have_conflict = 0;
			prepare_to_wait(&mdev->misc_wait, &wait,
				TASK_INTERRUPTIBLE);
1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805

			i = drbd_find_overlap(&mdev->write_requests, sector, size);
			if (i) {
				struct drbd_request *req2 =
					container_of(i, struct drbd_request, i);

				/* only ALERT on first iteration,
				 * we may be woken up early... */
				if (first)
					dev_alert(DEV, "%s[%u] Concurrent local write detected!"
					      "	new: %llus +%u; pending: %llus +%u\n",
					      current->comm, current->pid,
					      (unsigned long long)sector, size,
					      (unsigned long long)req2->i.sector, req2->i.size);
				if (req2->rq_state & RQ_NET_PENDING)
					++have_unacked;
				++have_conflict;
P
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1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817
			}
			if (!have_conflict)
				break;

			/* Discard Ack only for the _first_ iteration */
			if (first && discard && have_unacked) {
				dev_alert(DEV, "Concurrent write! [DISCARD BY FLAG] sec=%llus\n",
				     (unsigned long long)sector);
				inc_unacked(mdev);
				e->w.cb = e_send_discard_ack;
				list_add_tail(&e->w.list, &mdev->done_ee);

1818
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1819 1820 1821 1822 1823 1824 1825

				/* we could probably send that P_DISCARD_ACK ourselves,
				 * but I don't like the receiver using the msock */

				put_ldev(mdev);
				wake_asender(mdev);
				finish_wait(&mdev->misc_wait, &wait);
1826
				return true;
P
Philipp Reisner 已提交
1827 1828 1829
			}

			if (signal_pending(current)) {
1830 1831
				drbd_remove_interval(&mdev->epoch_entries, &e->i);
				drbd_clear_interval(&e->i);
P
Philipp Reisner 已提交
1832

1833
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1834 1835 1836 1837 1838

				finish_wait(&mdev->misc_wait, &wait);
				goto out_interrupted;
			}

1839
			spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1840 1841 1842 1843 1844 1845 1846 1847 1848 1849
			if (first) {
				first = 0;
				dev_alert(DEV, "Concurrent write! [W AFTERWARDS] "
				     "sec=%llus\n", (unsigned long long)sector);
			} else if (discard) {
				/* we had none on the first iteration.
				 * there must be none now. */
				D_ASSERT(have_unacked == 0);
			}
			schedule();
1850
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1851 1852 1853 1854 1855
		}
		finish_wait(&mdev->misc_wait, &wait);
	}

	list_add(&e->w.list, &mdev->active_ee);
1856
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1857

1858
	switch (mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873
	case DRBD_PROT_C:
		inc_unacked(mdev);
		/* corresponding dec_unacked() in e_end_block()
		 * respective _drbd_clear_done_ee */
		break;
	case DRBD_PROT_B:
		/* I really don't like it that the receiver thread
		 * sends on the msock, but anyways */
		drbd_send_ack(mdev, P_RECV_ACK, e);
		break;
	case DRBD_PROT_A:
		/* nothing to do */
		break;
	}

1874
	if (mdev->state.pdsk < D_INCONSISTENT) {
P
Philipp Reisner 已提交
1875
		/* In case we have the only disk of the cluster, */
1876
		drbd_set_out_of_sync(mdev, e->i.sector, e->i.size);
P
Philipp Reisner 已提交
1877
		e->flags |= EE_CALL_AL_COMPLETE_IO;
1878
		e->flags &= ~EE_MAY_SET_IN_SYNC;
1879
		drbd_al_begin_io(mdev, e->i.sector);
P
Philipp Reisner 已提交
1880 1881
	}

1882
	if (drbd_submit_ee(mdev, e, rw, DRBD_FAULT_DT_WR) == 0)
1883
		return true;
P
Philipp Reisner 已提交
1884

1885 1886
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1887
	spin_lock_irq(&mdev->tconn->req_lock);
1888
	list_del(&e->w.list);
1889 1890
	drbd_remove_interval(&mdev->epoch_entries, &e->i);
	drbd_clear_interval(&e->i);
1891
	spin_unlock_irq(&mdev->tconn->req_lock);
1892
	if (e->flags & EE_CALL_AL_COMPLETE_IO)
1893
		drbd_al_complete_io(mdev, e->i.sector);
1894

P
Philipp Reisner 已提交
1895
out_interrupted:
1896
	drbd_may_finish_epoch(mdev, e->epoch, EV_PUT + EV_CLEANUP);
P
Philipp Reisner 已提交
1897 1898
	put_ldev(mdev);
	drbd_free_ee(mdev, e);
1899
	return false;
P
Philipp Reisner 已提交
1900 1901
}

1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
/* We may throttle resync, if the lower device seems to be busy,
 * and current sync rate is above c_min_rate.
 *
 * To decide whether or not the lower device is busy, we use a scheme similar
 * to MD RAID is_mddev_idle(): if the partition stats reveal "significant"
 * (more than 64 sectors) of activity we cannot account for with our own resync
 * activity, it obviously is "busy".
 *
 * The current sync rate used here uses only the most recent two step marks,
 * to have a short time average so we can react faster.
 */
1913
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
1914 1915 1916
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
1917
	struct lc_element *tmp;
1918 1919 1920 1921 1922 1923 1924
	int curr_events;
	int throttle = 0;

	/* feature disabled? */
	if (mdev->sync_conf.c_min_rate == 0)
		return 0;

1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936
	spin_lock_irq(&mdev->al_lock);
	tmp = lc_find(mdev->resync, BM_SECT_TO_EXT(sector));
	if (tmp) {
		struct bm_extent *bm_ext = lc_entry(tmp, struct bm_extent, lce);
		if (test_bit(BME_PRIORITY, &bm_ext->flags)) {
			spin_unlock_irq(&mdev->al_lock);
			return 0;
		}
		/* Do not slow down if app IO is already waiting for this extent */
	}
	spin_unlock_irq(&mdev->al_lock);

1937 1938 1939
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
1940

1941 1942 1943 1944 1945 1946 1947 1948
	if (!mdev->rs_last_events || curr_events - mdev->rs_last_events > 64) {
		unsigned long rs_left;
		int i;

		mdev->rs_last_events = curr_events;

		/* sync speed average over the last 2*DRBD_SYNC_MARK_STEP,
		 * approx. */
1949 1950 1951 1952 1953 1954
		i = (mdev->rs_last_mark + DRBD_SYNC_MARKS-1) % DRBD_SYNC_MARKS;

		if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T)
			rs_left = mdev->ov_left;
		else
			rs_left = drbd_bm_total_weight(mdev) - mdev->rs_failed;
1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968

		dt = ((long)jiffies - (long)mdev->rs_mark_time[i]) / HZ;
		if (!dt)
			dt++;
		db = mdev->rs_mark_left[i] - rs_left;
		dbdt = Bit2KB(db/dt);

		if (dbdt > mdev->sync_conf.c_min_rate)
			throttle = 1;
	}
	return throttle;
}


1969
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int digest_size)
P
Philipp Reisner 已提交
1970 1971 1972 1973 1974
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
	struct drbd_epoch_entry *e;
	struct digest_info *di = NULL;
1975
	int size, verb;
P
Philipp Reisner 已提交
1976
	unsigned int fault_type;
1977
	struct p_block_req *p =	&mdev->tconn->data.rbuf.block_req;
P
Philipp Reisner 已提交
1978 1979 1980 1981

	sector = be64_to_cpu(p->sector);
	size   = be32_to_cpu(p->blksize);

1982
	if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
P
Philipp Reisner 已提交
1983 1984
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
1985
		return false;
P
Philipp Reisner 已提交
1986 1987 1988 1989
	}
	if (sector + (size>>9) > capacity) {
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
1990
		return false;
P
Philipp Reisner 已提交
1991 1992 1993
	}

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
		verb = 1;
		switch (cmd) {
		case P_DATA_REQUEST:
			drbd_send_ack_rp(mdev, P_NEG_DREPLY, p);
			break;
		case P_RS_DATA_REQUEST:
		case P_CSUM_RS_REQUEST:
		case P_OV_REQUEST:
			drbd_send_ack_rp(mdev, P_NEG_RS_DREPLY , p);
			break;
		case P_OV_REPLY:
			verb = 0;
			dec_rs_pending(mdev);
			drbd_send_ack_ex(mdev, P_OV_RESULT, sector, size, ID_IN_SYNC);
			break;
		default:
			dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
				cmdname(cmd));
		}
		if (verb && __ratelimit(&drbd_ratelimit_state))
P
Philipp Reisner 已提交
2014 2015
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
2016

L
Lars Ellenberg 已提交
2017 2018
		/* drain possibly payload */
		return drbd_drain_block(mdev, digest_size);
P
Philipp Reisner 已提交
2019 2020 2021 2022 2023 2024 2025 2026
	}

	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
	e = drbd_alloc_ee(mdev, p->block_id, sector, size, GFP_NOIO);
	if (!e) {
		put_ldev(mdev);
2027
		return false;
P
Philipp Reisner 已提交
2028 2029
	}

2030
	switch (cmd) {
P
Philipp Reisner 已提交
2031 2032 2033
	case P_DATA_REQUEST:
		e->w.cb = w_e_end_data_req;
		fault_type = DRBD_FAULT_DT_RD;
2034 2035 2036
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
Philipp Reisner 已提交
2037 2038 2039
	case P_RS_DATA_REQUEST:
		e->w.cb = w_e_end_rsdata_req;
		fault_type = DRBD_FAULT_RS_RD;
2040 2041
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
P
Philipp Reisner 已提交
2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053
		break;

	case P_OV_REPLY:
	case P_CSUM_RS_REQUEST:
		fault_type = DRBD_FAULT_RS_RD;
		di = kmalloc(sizeof(*di) + digest_size, GFP_NOIO);
		if (!di)
			goto out_free_e;

		di->digest_size = digest_size;
		di->digest = (((char *)di)+sizeof(struct digest_info));

2054 2055 2056
		e->digest = di;
		e->flags |= EE_HAS_DIGEST;

P
Philipp Reisner 已提交
2057 2058 2059
		if (drbd_recv(mdev, di->digest, digest_size) != digest_size)
			goto out_free_e;

2060
		if (cmd == P_CSUM_RS_REQUEST) {
2061
			D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
2062
			e->w.cb = w_e_end_csum_rs_req;
2063 2064
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2065
		} else if (cmd == P_OV_REPLY) {
2066 2067
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
2068 2069
			e->w.cb = w_e_end_ov_reply;
			dec_rs_pending(mdev);
2070 2071 2072
			/* drbd_rs_begin_io done when we sent this request,
			 * but accounting still needs to be done. */
			goto submit_for_resync;
P
Philipp Reisner 已提交
2073 2074 2075 2076 2077
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
2078
		    mdev->tconn->agreed_pro_version >= 90) {
2079 2080
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2081 2082
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2083 2084
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2085 2086 2087 2088
			for (i = 0; i < DRBD_SYNC_MARKS; i++) {
				mdev->rs_mark_left[i] = mdev->ov_left;
				mdev->rs_mark_time[i] = now;
			}
P
Philipp Reisner 已提交
2089 2090 2091 2092 2093 2094 2095 2096 2097
			dev_info(DEV, "Online Verify start sector: %llu\n",
					(unsigned long long)sector);
		}
		e->w.cb = w_e_end_ov_req;
		fault_type = DRBD_FAULT_RS_RD;
		break;

	default:
		dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
2098
		    cmdname(cmd));
P
Philipp Reisner 已提交
2099
		fault_type = DRBD_FAULT_MAX;
2100
		goto out_free_e;
P
Philipp Reisner 已提交
2101 2102
	}

2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124
	/* Throttle, drbd_rs_begin_io and submit should become asynchronous
	 * wrt the receiver, but it is not as straightforward as it may seem.
	 * Various places in the resync start and stop logic assume resync
	 * requests are processed in order, requeuing this on the worker thread
	 * introduces a bunch of new code for synchronization between threads.
	 *
	 * Unlimited throttling before drbd_rs_begin_io may stall the resync
	 * "forever", throttling after drbd_rs_begin_io will lock that extent
	 * for application writes for the same time.  For now, just throttle
	 * here, where the rest of the code expects the receiver to sleep for
	 * a while, anyways.
	 */

	/* Throttle before drbd_rs_begin_io, as that locks out application IO;
	 * this defers syncer requests for some time, before letting at least
	 * on request through.  The resync controller on the receiving side
	 * will adapt to the incoming rate accordingly.
	 *
	 * We cannot throttle here if remote is Primary/SyncTarget:
	 * we would also throttle its application reads.
	 * In that case, throttling is done on the SyncTarget only.
	 */
2125 2126 2127
	if (mdev->state.peer != R_PRIMARY && drbd_rs_should_slow_down(mdev, sector))
		schedule_timeout_uninterruptible(HZ/10);
	if (drbd_rs_begin_io(mdev, sector))
2128
		goto out_free_e;
P
Philipp Reisner 已提交
2129

2130 2131 2132
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2133
submit:
P
Philipp Reisner 已提交
2134
	inc_unacked(mdev);
2135
	spin_lock_irq(&mdev->tconn->req_lock);
2136
	list_add_tail(&e->w.list, &mdev->read_ee);
2137
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2138

2139
	if (drbd_submit_ee(mdev, e, READ, fault_type) == 0)
2140
		return true;
P
Philipp Reisner 已提交
2141

2142 2143
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2144
	spin_lock_irq(&mdev->tconn->req_lock);
2145
	list_del(&e->w.list);
2146
	spin_unlock_irq(&mdev->tconn->req_lock);
2147 2148
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
Philipp Reisner 已提交
2149 2150 2151
out_free_e:
	put_ldev(mdev);
	drbd_free_ee(mdev, e);
2152
	return false;
P
Philipp Reisner 已提交
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165
}

static int drbd_asb_recover_0p(struct drbd_conf *mdev) __must_hold(local)
{
	int self, peer, rv = -100;
	unsigned long ch_self, ch_peer;

	self = mdev->ldev->md.uuid[UI_BITMAP] & 1;
	peer = mdev->p_uuid[UI_BITMAP] & 1;

	ch_peer = mdev->p_uuid[UI_SIZE];
	ch_self = mdev->comm_bm_set;

2166
	switch (mdev->tconn->net_conf->after_sb_0p) {
P
Philipp Reisner 已提交
2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193
	case ASB_CONSENSUS:
	case ASB_DISCARD_SECONDARY:
	case ASB_CALL_HELPER:
		dev_err(DEV, "Configuration error.\n");
		break;
	case ASB_DISCONNECT:
		break;
	case ASB_DISCARD_YOUNGER_PRI:
		if (self == 0 && peer == 1) {
			rv = -1;
			break;
		}
		if (self == 1 && peer == 0) {
			rv =  1;
			break;
		}
		/* Else fall through to one of the other strategies... */
	case ASB_DISCARD_OLDER_PRI:
		if (self == 0 && peer == 1) {
			rv = 1;
			break;
		}
		if (self == 1 && peer == 0) {
			rv = -1;
			break;
		}
		/* Else fall through to one of the other strategies... */
L
Lars Ellenberg 已提交
2194
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
P
Philipp Reisner 已提交
2195 2196 2197 2198 2199 2200 2201 2202 2203 2204
		     "Using discard-least-changes instead\n");
	case ASB_DISCARD_ZERO_CHG:
		if (ch_peer == 0 && ch_self == 0) {
			rv = test_bit(DISCARD_CONCURRENT, &mdev->flags)
				? -1 : 1;
			break;
		} else {
			if (ch_peer == 0) { rv =  1; break; }
			if (ch_self == 0) { rv = -1; break; }
		}
2205
		if (mdev->tconn->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
P
Philipp Reisner 已提交
2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228
			break;
	case ASB_DISCARD_LEAST_CHG:
		if	(ch_self < ch_peer)
			rv = -1;
		else if (ch_self > ch_peer)
			rv =  1;
		else /* ( ch_self == ch_peer ) */
		     /* Well, then use something else. */
			rv = test_bit(DISCARD_CONCURRENT, &mdev->flags)
				? -1 : 1;
		break;
	case ASB_DISCARD_LOCAL:
		rv = -1;
		break;
	case ASB_DISCARD_REMOTE:
		rv =  1;
	}

	return rv;
}

static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
{
2229
	int hg, rv = -100;
P
Philipp Reisner 已提交
2230

2231
	switch (mdev->tconn->net_conf->after_sb_1p) {
P
Philipp Reisner 已提交
2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255
	case ASB_DISCARD_YOUNGER_PRI:
	case ASB_DISCARD_OLDER_PRI:
	case ASB_DISCARD_LEAST_CHG:
	case ASB_DISCARD_LOCAL:
	case ASB_DISCARD_REMOTE:
		dev_err(DEV, "Configuration error.\n");
		break;
	case ASB_DISCONNECT:
		break;
	case ASB_CONSENSUS:
		hg = drbd_asb_recover_0p(mdev);
		if (hg == -1 && mdev->state.role == R_SECONDARY)
			rv = hg;
		if (hg == 1  && mdev->state.role == R_PRIMARY)
			rv = hg;
		break;
	case ASB_VIOLENTLY:
		rv = drbd_asb_recover_0p(mdev);
		break;
	case ASB_DISCARD_SECONDARY:
		return mdev->state.role == R_PRIMARY ? 1 : -1;
	case ASB_CALL_HELPER:
		hg = drbd_asb_recover_0p(mdev);
		if (hg == -1 && mdev->state.role == R_PRIMARY) {
2256 2257 2258
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
P
Philipp Reisner 已提交
2259 2260 2261
			 /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
			  * we might be here in C_WF_REPORT_PARAMS which is transient.
			  * we do not need to wait for the after state change work either. */
2262 2263
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277
				drbd_khelper(mdev, "pri-lost-after-sb");
			} else {
				dev_warn(DEV, "Successfully gave up primary role.\n");
				rv = hg;
			}
		} else
			rv = hg;
	}

	return rv;
}

static int drbd_asb_recover_2p(struct drbd_conf *mdev) __must_hold(local)
{
2278
	int hg, rv = -100;
P
Philipp Reisner 已提交
2279

2280
	switch (mdev->tconn->net_conf->after_sb_2p) {
P
Philipp Reisner 已提交
2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297
	case ASB_DISCARD_YOUNGER_PRI:
	case ASB_DISCARD_OLDER_PRI:
	case ASB_DISCARD_LEAST_CHG:
	case ASB_DISCARD_LOCAL:
	case ASB_DISCARD_REMOTE:
	case ASB_CONSENSUS:
	case ASB_DISCARD_SECONDARY:
		dev_err(DEV, "Configuration error.\n");
		break;
	case ASB_VIOLENTLY:
		rv = drbd_asb_recover_0p(mdev);
		break;
	case ASB_DISCONNECT:
		break;
	case ASB_CALL_HELPER:
		hg = drbd_asb_recover_0p(mdev);
		if (hg == -1) {
2298 2299
			enum drbd_state_rv rv2;

P
Philipp Reisner 已提交
2300 2301 2302
			 /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE,
			  * we might be here in C_WF_REPORT_PARAMS which is transient.
			  * we do not need to wait for the after state change work either. */
2303 2304
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342
				drbd_khelper(mdev, "pri-lost-after-sb");
			} else {
				dev_warn(DEV, "Successfully gave up primary role.\n");
				rv = hg;
			}
		} else
			rv = hg;
	}

	return rv;
}

static void drbd_uuid_dump(struct drbd_conf *mdev, char *text, u64 *uuid,
			   u64 bits, u64 flags)
{
	if (!uuid) {
		dev_info(DEV, "%s uuid info vanished while I was looking!\n", text);
		return;
	}
	dev_info(DEV, "%s %016llX:%016llX:%016llX:%016llX bits:%llu flags:%llX\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],
	     (unsigned long long)bits,
	     (unsigned long long)flags);
}

/*
  100	after split brain try auto recover
    2	C_SYNC_SOURCE set BitMap
    1	C_SYNC_SOURCE use BitMap
    0	no Sync
   -1	C_SYNC_TARGET use BitMap
   -2	C_SYNC_TARGET set BitMap
 -100	after split brain, disconnect
-1000	unrelated data
2343 2344
-1091   requires proto 91
-1096   requires proto 96
P
Philipp Reisner 已提交
2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372
 */
static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(local)
{
	u64 self, peer;
	int i, j;

	self = mdev->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);

	*rule_nr = 10;
	if (self == UUID_JUST_CREATED && peer == UUID_JUST_CREATED)
		return 0;

	*rule_nr = 20;
	if ((self == UUID_JUST_CREATED || self == (u64)0) &&
	     peer != UUID_JUST_CREATED)
		return -2;

	*rule_nr = 30;
	if (self != UUID_JUST_CREATED &&
	    (peer == UUID_JUST_CREATED || peer == (u64)0))
		return 2;

	if (self == peer) {
		int rct, dc; /* roles at crash time */

		if (mdev->p_uuid[UI_BITMAP] == (u64)0 && mdev->ldev->md.uuid[UI_BITMAP] != (u64)0) {

2373
			if (mdev->tconn->agreed_pro_version < 91)
2374
				return -1091;
P
Philipp Reisner 已提交
2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393

			if ((mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) &&
			    (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) {
				dev_info(DEV, "was SyncSource, missed the resync finished event, corrected myself:\n");
				drbd_uuid_set_bm(mdev, 0UL);

				drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
					       mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);
				*rule_nr = 34;
			} else {
				dev_info(DEV, "was SyncSource (peer failed to write sync_uuid)\n");
				*rule_nr = 36;
			}

			return 1;
		}

		if (mdev->ldev->md.uuid[UI_BITMAP] == (u64)0 && mdev->p_uuid[UI_BITMAP] != (u64)0) {

2394
			if (mdev->tconn->agreed_pro_version < 91)
2395
				return -1091;
P
Philipp Reisner 已提交
2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439

			if ((mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_BITMAP] & ~((u64)1)) &&
			    (mdev->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1))) {
				dev_info(DEV, "was SyncTarget, peer missed the resync finished event, corrected peer:\n");

				mdev->p_uuid[UI_HISTORY_START + 1] = mdev->p_uuid[UI_HISTORY_START];
				mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_BITMAP];
				mdev->p_uuid[UI_BITMAP] = 0UL;

				drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);
				*rule_nr = 35;
			} else {
				dev_info(DEV, "was SyncTarget (failed to write sync_uuid)\n");
				*rule_nr = 37;
			}

			return -1;
		}

		/* Common power [off|failure] */
		rct = (test_bit(CRASHED_PRIMARY, &mdev->flags) ? 1 : 0) +
			(mdev->p_uuid[UI_FLAGS] & 2);
		/* lowest bit is set when we were primary,
		 * next bit (weight 2) is set when peer was primary */
		*rule_nr = 40;

		switch (rct) {
		case 0: /* !self_pri && !peer_pri */ return 0;
		case 1: /*  self_pri && !peer_pri */ return 1;
		case 2: /* !self_pri &&  peer_pri */ return -1;
		case 3: /*  self_pri &&  peer_pri */
			dc = test_bit(DISCARD_CONCURRENT, &mdev->flags);
			return dc ? -1 : 1;
		}
	}

	*rule_nr = 50;
	peer = mdev->p_uuid[UI_BITMAP] & ~((u64)1);
	if (self == peer)
		return -1;

	*rule_nr = 51;
	peer = mdev->p_uuid[UI_HISTORY_START] & ~((u64)1);
	if (self == peer) {
2440
		if (mdev->tconn->agreed_pro_version < 96 ?
2441 2442 2443
		    (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) ==
		    (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1)) :
		    peer + UUID_NEW_BM_OFFSET == (mdev->p_uuid[UI_BITMAP] & ~((u64)1))) {
P
Philipp Reisner 已提交
2444 2445 2446
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

2447
			if (mdev->tconn->agreed_pro_version < 91)
2448
				return -1091;
P
Philipp Reisner 已提交
2449 2450 2451

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2452 2453 2454 2455

			dev_info(DEV, "Did not got last syncUUID packet, corrected:\n");
			drbd_uuid_dump(mdev, "peer", mdev->p_uuid, mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);

P
Philipp Reisner 已提交
2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476
			return -1;
		}
	}

	*rule_nr = 60;
	self = mdev->ldev->md.uuid[UI_CURRENT] & ~((u64)1);
	for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
		peer = mdev->p_uuid[i] & ~((u64)1);
		if (self == peer)
			return -2;
	}

	*rule_nr = 70;
	self = mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
	if (self == peer)
		return 1;

	*rule_nr = 71;
	self = mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1);
	if (self == peer) {
2477
		if (mdev->tconn->agreed_pro_version < 96 ?
2478 2479 2480
		    (mdev->ldev->md.uuid[UI_HISTORY_START + 1] & ~((u64)1)) ==
		    (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) :
		    self + UUID_NEW_BM_OFFSET == (mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1))) {
P
Philipp Reisner 已提交
2481 2482 2483
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

2484
			if (mdev->tconn->agreed_pro_version < 91)
2485
				return -1091;
P
Philipp Reisner 已提交
2486 2487 2488 2489

			_drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]);
			_drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]);

2490
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
Philipp Reisner 已提交
2491 2492 2493 2494 2495 2496 2497 2498 2499
			drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
				       mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);

			return 1;
		}
	}


	*rule_nr = 80;
2500
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
Philipp Reisner 已提交
2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 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 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552
	for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
		self = mdev->ldev->md.uuid[i] & ~((u64)1);
		if (self == peer)
			return 2;
	}

	*rule_nr = 90;
	self = mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1);
	peer = mdev->p_uuid[UI_BITMAP] & ~((u64)1);
	if (self == peer && self != ((u64)0))
		return 100;

	*rule_nr = 100;
	for (i = UI_HISTORY_START; i <= UI_HISTORY_END; i++) {
		self = mdev->ldev->md.uuid[i] & ~((u64)1);
		for (j = UI_HISTORY_START; j <= UI_HISTORY_END; j++) {
			peer = mdev->p_uuid[j] & ~((u64)1);
			if (self == peer)
				return -100;
		}
	}

	return -1000;
}

/* drbd_sync_handshake() returns the new conn state on success, or
   CONN_MASK (-1) on failure.
 */
static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_role peer_role,
					   enum drbd_disk_state peer_disk) __must_hold(local)
{
	int hg, rule_nr;
	enum drbd_conns rv = C_MASK;
	enum drbd_disk_state mydisk;

	mydisk = mdev->state.disk;
	if (mydisk == D_NEGOTIATING)
		mydisk = mdev->new_state_tmp.disk;

	dev_info(DEV, "drbd_sync_handshake:\n");
	drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, mdev->comm_bm_set, 0);
	drbd_uuid_dump(mdev, "peer", mdev->p_uuid,
		       mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);

	hg = drbd_uuid_compare(mdev, &rule_nr);

	dev_info(DEV, "uuid_compare()=%d by rule %d\n", hg, rule_nr);

	if (hg == -1000) {
		dev_alert(DEV, "Unrelated data, aborting!\n");
		return C_MASK;
	}
2553 2554
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
Philipp Reisner 已提交
2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567
		return C_MASK;
	}

	if    ((mydisk == D_INCONSISTENT && peer_disk > D_INCONSISTENT) ||
	    (peer_disk == D_INCONSISTENT && mydisk    > D_INCONSISTENT)) {
		int f = (hg == -100) || abs(hg) == 2;
		hg = mydisk > D_INCONSISTENT ? 1 : -1;
		if (f)
			hg = hg*2;
		dev_info(DEV, "Becoming sync %s due to disk states.\n",
		     hg > 0 ? "source" : "target");
	}

2568 2569 2570
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

2571
	if (hg == 100 || (hg == -100 && mdev->tconn->net_conf->always_asbp)) {
P
Philipp Reisner 已提交
2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599
		int pcount = (mdev->state.role == R_PRIMARY)
			   + (peer_role == R_PRIMARY);
		int forced = (hg == -100);

		switch (pcount) {
		case 0:
			hg = drbd_asb_recover_0p(mdev);
			break;
		case 1:
			hg = drbd_asb_recover_1p(mdev);
			break;
		case 2:
			hg = drbd_asb_recover_2p(mdev);
			break;
		}
		if (abs(hg) < 100) {
			dev_warn(DEV, "Split-Brain detected, %d primaries, "
			     "automatically solved. Sync from %s node\n",
			     pcount, (hg < 0) ? "peer" : "this");
			if (forced) {
				dev_warn(DEV, "Doing a full sync, since"
				     " UUIDs where ambiguous.\n");
				hg = hg*2;
			}
		}
	}

	if (hg == -100) {
2600
		if (mdev->tconn->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2601
			hg = -1;
2602
		if (!mdev->tconn->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2603 2604 2605 2606 2607 2608 2609 2610 2611
			hg = 1;

		if (abs(hg) < 100)
			dev_warn(DEV, "Split-Brain detected, manually solved. "
			     "Sync from %s node\n",
			     (hg < 0) ? "peer" : "this");
	}

	if (hg == -100) {
2612 2613 2614 2615
		/* FIXME this log message is not correct if we end up here
		 * after an attempted attach on a diskless node.
		 * We just refuse to attach -- well, we drop the "connection"
		 * to that disk, in a way... */
2616
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627
		drbd_khelper(mdev, "split-brain");
		return C_MASK;
	}

	if (hg > 0 && mydisk <= D_INCONSISTENT) {
		dev_err(DEV, "I shall become SyncSource, but I am inconsistent!\n");
		return C_MASK;
	}

	if (hg < 0 && /* by intention we do not use mydisk here. */
	    mdev->state.role == R_PRIMARY && mdev->state.disk >= D_CONSISTENT) {
2628
		switch (mdev->tconn->net_conf->rr_conflict) {
P
Philipp Reisner 已提交
2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640
		case ASB_CALL_HELPER:
			drbd_khelper(mdev, "pri-lost");
			/* fall through */
		case ASB_DISCONNECT:
			dev_err(DEV, "I shall become SyncTarget, but I am primary!\n");
			return C_MASK;
		case ASB_VIOLENTLY:
			dev_warn(DEV, "Becoming SyncTarget, violating the stable-data"
			     "assumption\n");
		}
	}

2641
	if (mdev->tconn->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
2642 2643 2644 2645 2646 2647 2648 2649 2650
		if (hg == 0)
			dev_info(DEV, "dry-run connect: No resync, would become Connected immediately.\n");
		else
			dev_info(DEV, "dry-run connect: Would become %s, doing a %s resync.",
				 drbd_conn_str(hg > 0 ? C_SYNC_SOURCE : C_SYNC_TARGET),
				 abs(hg) >= 2 ? "full" : "bit-map based");
		return C_MASK;
	}

P
Philipp Reisner 已提交
2651 2652
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2653 2654
		if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write, "set_n_write from sync_handshake",
					BM_LOCKED_SET_ALLOWED))
P
Philipp Reisner 已提交
2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693
			return C_MASK;
	}

	if (hg > 0) { /* become sync source. */
		rv = C_WF_BITMAP_S;
	} else if (hg < 0) { /* become sync target */
		rv = C_WF_BITMAP_T;
	} else {
		rv = C_CONNECTED;
		if (drbd_bm_total_weight(mdev)) {
			dev_info(DEV, "No resync, but %lu bits in bitmap!\n",
			     drbd_bm_total_weight(mdev));
		}
	}

	return rv;
}

/* returns 1 if invalid */
static int cmp_after_sb(enum drbd_after_sb_p peer, enum drbd_after_sb_p self)
{
	/* ASB_DISCARD_REMOTE - ASB_DISCARD_LOCAL is valid */
	if ((peer == ASB_DISCARD_REMOTE && self == ASB_DISCARD_LOCAL) ||
	    (self == ASB_DISCARD_REMOTE && peer == ASB_DISCARD_LOCAL))
		return 0;

	/* any other things with ASB_DISCARD_REMOTE or ASB_DISCARD_LOCAL are invalid */
	if (peer == ASB_DISCARD_REMOTE || peer == ASB_DISCARD_LOCAL ||
	    self == ASB_DISCARD_REMOTE || self == ASB_DISCARD_LOCAL)
		return 1;

	/* everything else is valid if they are equal on both sides. */
	if (peer == self)
		return 0;

	/* everything es is invalid. */
	return 1;
}

2694
static int receive_protocol(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
2695
{
2696
	struct p_protocol *p = &mdev->tconn->data.rbuf.protocol;
P
Philipp Reisner 已提交
2697
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2698
	int p_want_lose, p_two_primaries, cf;
P
Philipp Reisner 已提交
2699 2700 2701 2702 2703 2704 2705
	char p_integrity_alg[SHARED_SECRET_MAX] = "";

	p_proto		= be32_to_cpu(p->protocol);
	p_after_sb_0p	= be32_to_cpu(p->after_sb_0p);
	p_after_sb_1p	= be32_to_cpu(p->after_sb_1p);
	p_after_sb_2p	= be32_to_cpu(p->after_sb_2p);
	p_two_primaries = be32_to_cpu(p->two_primaries);
2706 2707 2708 2709 2710 2711 2712
	cf		= be32_to_cpu(p->conn_flags);
	p_want_lose = cf & CF_WANT_LOSE;

	clear_bit(CONN_DRY_RUN, &mdev->flags);

	if (cf & CF_DRY_RUN)
		set_bit(CONN_DRY_RUN, &mdev->flags);
P
Philipp Reisner 已提交
2713

2714
	if (p_proto != mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
2715 2716 2717 2718
		dev_err(DEV, "incompatible communication protocols\n");
		goto disconnect;
	}

2719
	if (cmp_after_sb(p_after_sb_0p, mdev->tconn->net_conf->after_sb_0p)) {
P
Philipp Reisner 已提交
2720 2721 2722 2723
		dev_err(DEV, "incompatible after-sb-0pri settings\n");
		goto disconnect;
	}

2724
	if (cmp_after_sb(p_after_sb_1p, mdev->tconn->net_conf->after_sb_1p)) {
P
Philipp Reisner 已提交
2725 2726 2727 2728
		dev_err(DEV, "incompatible after-sb-1pri settings\n");
		goto disconnect;
	}

2729
	if (cmp_after_sb(p_after_sb_2p, mdev->tconn->net_conf->after_sb_2p)) {
P
Philipp Reisner 已提交
2730 2731 2732 2733
		dev_err(DEV, "incompatible after-sb-2pri settings\n");
		goto disconnect;
	}

2734
	if (p_want_lose && mdev->tconn->net_conf->want_lose) {
P
Philipp Reisner 已提交
2735 2736 2737 2738
		dev_err(DEV, "both sides have the 'want_lose' flag set\n");
		goto disconnect;
	}

2739
	if (p_two_primaries != mdev->tconn->net_conf->two_primaries) {
P
Philipp Reisner 已提交
2740 2741 2742 2743
		dev_err(DEV, "incompatible setting of the two-primaries options\n");
		goto disconnect;
	}

2744
	if (mdev->tconn->agreed_pro_version >= 87) {
2745
		unsigned char *my_alg = mdev->tconn->net_conf->integrity_alg;
P
Philipp Reisner 已提交
2746 2747

		if (drbd_recv(mdev, p_integrity_alg, data_size) != data_size)
2748
			return false;
P
Philipp Reisner 已提交
2749 2750 2751 2752 2753 2754 2755 2756 2757 2758

		p_integrity_alg[SHARED_SECRET_MAX-1] = 0;
		if (strcmp(p_integrity_alg, my_alg)) {
			dev_err(DEV, "incompatible setting of the data-integrity-alg\n");
			goto disconnect;
		}
		dev_info(DEV, "data-integrity-alg: %s\n",
		     my_alg[0] ? my_alg : (unsigned char *)"<not-used>");
	}

2759
	return true;
P
Philipp Reisner 已提交
2760 2761 2762

disconnect:
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2763
	return false;
P
Philipp Reisner 已提交
2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792
}

/* helper function
 * input: alg name, feature name
 * return: NULL (alg name was "")
 *         ERR_PTR(error) if something goes wrong
 *         or the crypto hash ptr, if it worked out ok. */
struct crypto_hash *drbd_crypto_alloc_digest_safe(const struct drbd_conf *mdev,
		const char *alg, const char *name)
{
	struct crypto_hash *tfm;

	if (!alg[0])
		return NULL;

	tfm = crypto_alloc_hash(alg, 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm)) {
		dev_err(DEV, "Can not allocate \"%s\" as %s (reason: %ld)\n",
			alg, name, PTR_ERR(tfm));
		return tfm;
	}
	if (!drbd_crypto_is_hash(crypto_hash_tfm(tfm))) {
		crypto_free_hash(tfm);
		dev_err(DEV, "\"%s\" is not a digest (%s)\n", alg, name);
		return ERR_PTR(-EINVAL);
	}
	return tfm;
}

2793
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int packet_size)
P
Philipp Reisner 已提交
2794
{
2795
	int ok = true;
2796
	struct p_rs_param_95 *p = &mdev->tconn->data.rbuf.rs_param_95;
P
Philipp Reisner 已提交
2797 2798 2799
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
2800
	const int apv = mdev->tconn->agreed_pro_version;
2801 2802
	int *rs_plan_s = NULL;
	int fifo_size = 0;
P
Philipp Reisner 已提交
2803 2804 2805 2806

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2807 2808
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2809

2810
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2811
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2812
		    packet_size, exp_max_sz);
2813
		return false;
P
Philipp Reisner 已提交
2814 2815 2816
	}

	if (apv <= 88) {
2817
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header);
2818
		data_size   = packet_size  - header_size;
2819
	} else if (apv <= 94) {
2820
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header);
2821
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2822
		D_ASSERT(data_size == 0);
2823
	} else {
2824
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header);
2825
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2826 2827 2828 2829 2830 2831
		D_ASSERT(data_size == 0);
	}

	/* initialize verify_alg and csums_alg */
	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);

2832
	if (drbd_recv(mdev, &p->head.payload, header_size) != header_size)
2833
		return false;
P
Philipp Reisner 已提交
2834 2835 2836 2837 2838 2839 2840 2841 2842

	mdev->sync_conf.rate	  = be32_to_cpu(p->rate);

	if (apv >= 88) {
		if (apv == 88) {
			if (data_size > SHARED_SECRET_MAX) {
				dev_err(DEV, "verify-alg too long, "
				    "peer wants %u, accepting only %u byte\n",
						data_size, SHARED_SECRET_MAX);
2843
				return false;
P
Philipp Reisner 已提交
2844 2845 2846
			}

			if (drbd_recv(mdev, p->verify_alg, data_size) != data_size)
2847
				return false;
P
Philipp Reisner 已提交
2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890

			/* we expect NUL terminated string */
			/* but just in case someone tries to be evil */
			D_ASSERT(p->verify_alg[data_size-1] == 0);
			p->verify_alg[data_size-1] = 0;

		} else /* apv >= 89 */ {
			/* we still expect NUL terminated strings */
			/* but just in case someone tries to be evil */
			D_ASSERT(p->verify_alg[SHARED_SECRET_MAX-1] == 0);
			D_ASSERT(p->csums_alg[SHARED_SECRET_MAX-1] == 0);
			p->verify_alg[SHARED_SECRET_MAX-1] = 0;
			p->csums_alg[SHARED_SECRET_MAX-1] = 0;
		}

		if (strcmp(mdev->sync_conf.verify_alg, p->verify_alg)) {
			if (mdev->state.conn == C_WF_REPORT_PARAMS) {
				dev_err(DEV, "Different verify-alg settings. me=\"%s\" peer=\"%s\"\n",
				    mdev->sync_conf.verify_alg, p->verify_alg);
				goto disconnect;
			}
			verify_tfm = drbd_crypto_alloc_digest_safe(mdev,
					p->verify_alg, "verify-alg");
			if (IS_ERR(verify_tfm)) {
				verify_tfm = NULL;
				goto disconnect;
			}
		}

		if (apv >= 89 && strcmp(mdev->sync_conf.csums_alg, p->csums_alg)) {
			if (mdev->state.conn == C_WF_REPORT_PARAMS) {
				dev_err(DEV, "Different csums-alg settings. me=\"%s\" peer=\"%s\"\n",
				    mdev->sync_conf.csums_alg, p->csums_alg);
				goto disconnect;
			}
			csums_tfm = drbd_crypto_alloc_digest_safe(mdev,
					p->csums_alg, "csums-alg");
			if (IS_ERR(csums_tfm)) {
				csums_tfm = NULL;
				goto disconnect;
			}
		}

2891 2892 2893 2894 2895 2896
		if (apv > 94) {
			mdev->sync_conf.rate	  = be32_to_cpu(p->rate);
			mdev->sync_conf.c_plan_ahead = be32_to_cpu(p->c_plan_ahead);
			mdev->sync_conf.c_delay_target = be32_to_cpu(p->c_delay_target);
			mdev->sync_conf.c_fill_target = be32_to_cpu(p->c_fill_target);
			mdev->sync_conf.c_max_rate = be32_to_cpu(p->c_max_rate);
2897 2898 2899 2900 2901 2902 2903 2904 2905

			fifo_size = (mdev->sync_conf.c_plan_ahead * 10 * SLEEP_TIME) / HZ;
			if (fifo_size != mdev->rs_plan_s.size && fifo_size > 0) {
				rs_plan_s   = kzalloc(sizeof(int) * fifo_size, GFP_KERNEL);
				if (!rs_plan_s) {
					dev_err(DEV, "kmalloc of fifo_buffer failed");
					goto disconnect;
				}
			}
2906
		}
P
Philipp Reisner 已提交
2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923

		spin_lock(&mdev->peer_seq_lock);
		/* lock against drbd_nl_syncer_conf() */
		if (verify_tfm) {
			strcpy(mdev->sync_conf.verify_alg, p->verify_alg);
			mdev->sync_conf.verify_alg_len = strlen(p->verify_alg) + 1;
			crypto_free_hash(mdev->verify_tfm);
			mdev->verify_tfm = verify_tfm;
			dev_info(DEV, "using verify-alg: \"%s\"\n", p->verify_alg);
		}
		if (csums_tfm) {
			strcpy(mdev->sync_conf.csums_alg, p->csums_alg);
			mdev->sync_conf.csums_alg_len = strlen(p->csums_alg) + 1;
			crypto_free_hash(mdev->csums_tfm);
			mdev->csums_tfm = csums_tfm;
			dev_info(DEV, "using csums-alg: \"%s\"\n", p->csums_alg);
		}
2924 2925 2926 2927 2928 2929
		if (fifo_size != mdev->rs_plan_s.size) {
			kfree(mdev->rs_plan_s.values);
			mdev->rs_plan_s.values = rs_plan_s;
			mdev->rs_plan_s.size   = fifo_size;
			mdev->rs_planed = 0;
		}
P
Philipp Reisner 已提交
2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940
		spin_unlock(&mdev->peer_seq_lock);
	}

	return ok;
disconnect:
	/* just for completeness: actually not needed,
	 * as this is not reached if csums_tfm was ok. */
	crypto_free_hash(csums_tfm);
	/* but free the verify_tfm again, if csums_tfm did not work out */
	crypto_free_hash(verify_tfm);
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2941
	return false;
P
Philipp Reisner 已提交
2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956
}

/* warn if the arguments differ by more than 12.5% */
static void warn_if_differ_considerably(struct drbd_conf *mdev,
	const char *s, sector_t a, sector_t b)
{
	sector_t d;
	if (a == 0 || b == 0)
		return;
	d = (a > b) ? (a - b) : (b - a);
	if (d > (a>>3) || d > (b>>3))
		dev_warn(DEV, "Considerable difference in %s: %llus vs. %llus\n", s,
		     (unsigned long long)a, (unsigned long long)b);
}

2957
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
2958
{
2959
	struct p_sizes *p = &mdev->tconn->data.rbuf.sizes;
P
Philipp Reisner 已提交
2960 2961 2962
	enum determine_dev_size dd = unchanged;
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
2963
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
2964 2965 2966 2967 2968 2969 2970

	p_size = be64_to_cpu(p->d_size);
	p_usize = be64_to_cpu(p->u_size);

	if (p_size == 0 && mdev->state.disk == D_DISKLESS) {
		dev_err(DEV, "some backing storage is needed\n");
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2971
		return false;
P
Philipp Reisner 已提交
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
	}

	/* just store the peer's disk size for now.
	 * we still need to figure out whether we accept that. */
	mdev->p_size = p_size;

	if (get_ldev(mdev)) {
		warn_if_differ_considerably(mdev, "lower level device sizes",
			   p_size, drbd_get_max_capacity(mdev->ldev));
		warn_if_differ_considerably(mdev, "user requested size",
					    p_usize, mdev->ldev->dc.disk_size);

		/* if this is the first connect, or an otherwise expected
		 * param exchange, choose the minimum */
		if (mdev->state.conn == C_WF_REPORT_PARAMS)
			p_usize = min_not_zero((sector_t)mdev->ldev->dc.disk_size,
					     p_usize);

		my_usize = mdev->ldev->dc.disk_size;

		if (mdev->ldev->dc.disk_size != p_usize) {
			mdev->ldev->dc.disk_size = p_usize;
			dev_info(DEV, "Peer sets u_size to %lu sectors\n",
			     (unsigned long)mdev->ldev->dc.disk_size);
		}

		/* Never shrink a device with usable data during connect.
		   But allow online shrinking if we are connected. */
3000
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
3001 3002 3003 3004 3005 3006 3007
		   drbd_get_capacity(mdev->this_bdev) &&
		   mdev->state.disk >= D_OUTDATED &&
		   mdev->state.conn < C_CONNECTED) {
			dev_err(DEV, "The peer's disk size is too small!\n");
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
			mdev->ldev->dc.disk_size = my_usize;
			put_ldev(mdev);
3008
			return false;
P
Philipp Reisner 已提交
3009 3010 3011 3012
		}
		put_ldev(mdev);
	}

3013
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
3014
	if (get_ldev(mdev)) {
B
Bart Van Assche 已提交
3015
		dd = drbd_determine_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
3016 3017
		put_ldev(mdev);
		if (dd == dev_size_error)
3018
			return false;
P
Philipp Reisner 已提交
3019 3020 3021 3022 3023 3024
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

3025 3026 3027
	mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
	drbd_reconsider_max_bio_size(mdev);

P
Philipp Reisner 已提交
3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041
	if (get_ldev(mdev)) {
		if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev)) {
			mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
			ldsc = 1;
		}

		put_ldev(mdev);
	}

	if (mdev->state.conn > C_WF_REPORT_PARAMS) {
		if (be64_to_cpu(p->c_size) !=
		    drbd_get_capacity(mdev->this_bdev) || ldsc) {
			/* we have different sizes, probably peer
			 * needs to know my new size... */
3042
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3043 3044 3045 3046
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3047 3048 3049 3050 3051 3052
			    mdev->state.disk >= D_INCONSISTENT) {
				if (ddsf & DDSF_NO_RESYNC)
					dev_info(DEV, "Resync of new storage suppressed with --assume-clean\n");
				else
					resync_after_online_grow(mdev);
			} else
P
Philipp Reisner 已提交
3053 3054 3055 3056
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3057
	return true;
P
Philipp Reisner 已提交
3058 3059
}

3060
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3061
{
3062
	struct p_uuids *p = &mdev->tconn->data.rbuf.uuids;
P
Philipp Reisner 已提交
3063
	u64 *p_uuid;
3064
	int i, updated_uuids = 0;
P
Philipp Reisner 已提交
3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080

	p_uuid = kmalloc(sizeof(u64)*UI_EXTENDED_SIZE, GFP_NOIO);

	for (i = UI_CURRENT; i < UI_EXTENDED_SIZE; i++)
		p_uuid[i] = be64_to_cpu(p->uuid[i]);

	kfree(mdev->p_uuid);
	mdev->p_uuid = p_uuid;

	if (mdev->state.conn < C_CONNECTED &&
	    mdev->state.disk < D_INCONSISTENT &&
	    mdev->state.role == R_PRIMARY &&
	    (mdev->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {
		dev_err(DEV, "Can only connect to data with current UUID=%016llX\n",
		    (unsigned long long)mdev->ed_uuid);
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3081
		return false;
P
Philipp Reisner 已提交
3082 3083 3084 3085 3086
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
3087
			mdev->tconn->agreed_pro_version >= 90 &&
P
Philipp Reisner 已提交
3088 3089 3090 3091 3092
			mdev->ldev->md.uuid[UI_CURRENT] == UUID_JUST_CREATED &&
			(p_uuid[UI_FLAGS] & 8);
		if (skip_initial_sync) {
			dev_info(DEV, "Accepted new current UUID, preparing to skip initial sync\n");
			drbd_bitmap_io(mdev, &drbd_bmio_clear_n_write,
3093 3094
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3095 3096 3097 3098 3099
			_drbd_uuid_set(mdev, UI_CURRENT, p_uuid[UI_CURRENT]);
			_drbd_uuid_set(mdev, UI_BITMAP, 0);
			_drbd_set_state(_NS2(mdev, disk, D_UP_TO_DATE, pdsk, D_UP_TO_DATE),
					CS_VERBOSE, NULL);
			drbd_md_sync(mdev);
3100
			updated_uuids = 1;
P
Philipp Reisner 已提交
3101 3102
		}
		put_ldev(mdev);
3103 3104 3105 3106
	} else if (mdev->state.disk < D_INCONSISTENT &&
		   mdev->state.role == R_PRIMARY) {
		/* I am a diskless primary, the peer just created a new current UUID
		   for me. */
3107
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3108 3109 3110 3111 3112 3113 3114 3115
	}

	/* Before we test for the disk state, we should wait until an eventually
	   ongoing cluster wide state change is finished. That is important if
	   we are primary and are detaching from our disk. We need to see the
	   new disk state... */
	wait_event(mdev->misc_wait, !test_bit(CLUSTER_ST_CHANGE, &mdev->flags));
	if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
3116 3117 3118 3119
		updated_uuids |= drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);

	if (updated_uuids)
		drbd_print_uuids(mdev, "receiver updated UUIDs to");
P
Philipp Reisner 已提交
3120

3121
	return true;
P
Philipp Reisner 已提交
3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153
}

/**
 * convert_state() - Converts the peer's view of the cluster state to our point of view
 * @ps:		The state as seen by the peer.
 */
static union drbd_state convert_state(union drbd_state ps)
{
	union drbd_state ms;

	static enum drbd_conns c_tab[] = {
		[C_CONNECTED] = C_CONNECTED,

		[C_STARTING_SYNC_S] = C_STARTING_SYNC_T,
		[C_STARTING_SYNC_T] = C_STARTING_SYNC_S,
		[C_DISCONNECTING] = C_TEAR_DOWN, /* C_NETWORK_FAILURE, */
		[C_VERIFY_S]       = C_VERIFY_T,
		[C_MASK]   = C_MASK,
	};

	ms.i = ps.i;

	ms.conn = c_tab[ps.conn];
	ms.peer = ps.role;
	ms.role = ps.peer;
	ms.pdsk = ps.disk;
	ms.disk = ps.pdsk;
	ms.peer_isp = (ps.aftr_isp | ps.user_isp);

	return ms;
}

3154
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3155
{
3156
	struct p_req_state *p = &mdev->tconn->data.rbuf.req_state;
P
Philipp Reisner 已提交
3157
	union drbd_state mask, val;
3158
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3159 3160 3161 3162 3163 3164 3165

	mask.i = be32_to_cpu(p->mask);
	val.i = be32_to_cpu(p->val);

	if (test_bit(DISCARD_CONCURRENT, &mdev->flags) &&
	    test_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
		drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
3166
		return true;
P
Philipp Reisner 已提交
3167 3168 3169 3170 3171 3172 3173 3174 3175 3176
	}

	mask = convert_state(mask);
	val = convert_state(val);

	rv = drbd_change_state(mdev, CS_VERBOSE, mask, val);

	drbd_send_sr_reply(mdev, rv);
	drbd_md_sync(mdev);

3177
	return true;
P
Philipp Reisner 已提交
3178 3179
}

3180
static int receive_state(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3181
{
3182
	struct p_state *p = &mdev->tconn->data.rbuf.state;
3183
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3184
	enum drbd_disk_state real_peer_disk;
3185
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3186 3187 3188 3189 3190 3191 3192 3193 3194 3195
	int rv;

	peer_state.i = be32_to_cpu(p->state);

	real_peer_disk = peer_state.disk;
	if (peer_state.disk == D_NEGOTIATING) {
		real_peer_disk = mdev->p_uuid[UI_FLAGS] & 4 ? D_INCONSISTENT : D_CONSISTENT;
		dev_info(DEV, "real peer disk state = %s\n", drbd_disk_str(real_peer_disk));
	}

3196
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3197
 retry:
3198
	os = ns = mdev->state;
3199
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3200

3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221
	/* peer says his disk is uptodate, while we think it is inconsistent,
	 * and this happens while we think we have a sync going on. */
	if (os.pdsk == D_INCONSISTENT && real_peer_disk == D_UP_TO_DATE &&
	    os.conn > C_CONNECTED && os.disk == D_UP_TO_DATE) {
		/* If we are (becoming) SyncSource, but peer is still in sync
		 * preparation, ignore its uptodate-ness to avoid flapping, it
		 * will change to inconsistent once the peer reaches active
		 * syncing states.
		 * It may have changed syncer-paused flags, however, so we
		 * cannot ignore this completely. */
		if (peer_state.conn > C_CONNECTED &&
		    peer_state.conn < C_SYNC_SOURCE)
			real_peer_disk = D_INCONSISTENT;

		/* if peer_state changes to connected at the same time,
		 * it explicitly notifies us that it finished resync.
		 * Maybe we should finish it up, too? */
		else if (os.conn >= C_SYNC_SOURCE &&
			 peer_state.conn == C_CONNECTED) {
			if (drbd_bm_total_weight(mdev) <= mdev->rs_failed)
				drbd_resync_finished(mdev);
3222
			return true;
3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234
		}
	}

	/* peer says his disk is inconsistent, while we think it is uptodate,
	 * and this happens while the peer still thinks we have a sync going on,
	 * but we think we are already done with the sync.
	 * We ignore this to avoid flapping pdsk.
	 * This should not happen, if the peer is a recent version of drbd. */
	if (os.pdsk == D_UP_TO_DATE && real_peer_disk == D_INCONSISTENT &&
	    os.conn == C_CONNECTED && peer_state.conn > C_SYNC_SOURCE)
		real_peer_disk = D_UP_TO_DATE;

3235 3236
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3237

3238 3239 3240
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3241 3242 3243 3244 3245
	if (mdev->p_uuid && peer_state.disk >= D_NEGOTIATING &&
	    get_ldev_if_state(mdev, D_NEGOTIATING)) {
		int cr; /* consider resync */

		/* if we established a new connection */
3246
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3247 3248
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3249
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3250
		       (peer_state.disk == D_NEGOTIATING ||
3251
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3252 3253 3254 3255 3256
		/* if we have both been inconsistent, and the peer has been
		 * forced to be UpToDate with --overwrite-data */
		cr |= test_bit(CONSIDER_RESYNC, &mdev->flags);
		/* if we had been plain connected, and the admin requested to
		 * start a sync by "invalidate" or "invalidate-remote" */
3257
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3258 3259 3260 3261
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3262
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3263 3264

		put_ldev(mdev);
3265 3266
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3267
			if (mdev->state.disk == D_NEGOTIATING) {
3268
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3269 3270 3271
			} else if (peer_state.disk == D_NEGOTIATING) {
				dev_err(DEV, "Disk attach process on the peer node was aborted.\n");
				peer_state.disk = D_DISKLESS;
3272
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3273
			} else {
3274
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
3275
					return false;
3276
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
P
Philipp Reisner 已提交
3277
				drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3278
				return false;
P
Philipp Reisner 已提交
3279 3280 3281 3282
			}
		}
	}

3283
	spin_lock_irq(&mdev->tconn->req_lock);
3284
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3285 3286 3287 3288 3289
		goto retry;
	clear_bit(CONSIDER_RESYNC, &mdev->flags);
	ns.peer = peer_state.role;
	ns.pdsk = real_peer_disk;
	ns.peer_isp = (peer_state.aftr_isp | peer_state.user_isp);
3290
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3291
		ns.disk = mdev->new_state_tmp.disk;
3292 3293
	cs_flags = CS_VERBOSE + (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED ? 0 : CS_HARD);
	if (ns.pdsk == D_CONSISTENT && is_susp(ns) && ns.conn == C_CONNECTED && os.conn < C_CONNECTED &&
3294
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
3295
		/* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
3296
		   for temporal network outages! */
3297
		spin_unlock_irq(&mdev->tconn->req_lock);
3298 3299 3300 3301 3302
		dev_err(DEV, "Aborting Connect, can not thaw IO with an only Consistent peer\n");
		tl_clear(mdev);
		drbd_uuid_new_current(mdev);
		clear_bit(NEW_CUR_UUID, &mdev->flags);
		drbd_force_state(mdev, NS2(conn, C_PROTOCOL_ERROR, susp, 0));
3303
		return false;
3304
	}
3305
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3306
	ns = mdev->state;
3307
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3308 3309 3310

	if (rv < SS_SUCCESS) {
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3311
		return false;
P
Philipp Reisner 已提交
3312 3313
	}

3314 3315
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3316 3317 3318 3319 3320 3321 3322 3323 3324
		    peer_state.disk != D_NEGOTIATING ) {
			/* we want resync, peer has not yet decided to sync... */
			/* Nowadays only used when forcing a node into primary role and
			   setting its disk to UpToDate with that */
			drbd_send_uuids(mdev);
			drbd_send_state(mdev);
		}
	}

3325
	mdev->tconn->net_conf->want_lose = 0;
P
Philipp Reisner 已提交
3326 3327 3328

	drbd_md_sync(mdev); /* update connected indicator, la_size, ... */

3329
	return true;
P
Philipp Reisner 已提交
3330 3331
}

3332
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3333
{
3334
	struct p_rs_uuid *p = &mdev->tconn->data.rbuf.rs_uuid;
P
Philipp Reisner 已提交
3335 3336 3337

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3338
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349
		   mdev->state.conn < C_CONNECTED ||
		   mdev->state.disk < D_NEGOTIATING);

	/* D_ASSERT( mdev->state.conn == C_WF_SYNC_UUID ); */

	/* Here the _drbd_uuid_ functions are right, current should
	   _not_ be rotated into the history */
	if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
		_drbd_uuid_set(mdev, UI_CURRENT, be64_to_cpu(p->uuid));
		_drbd_uuid_set(mdev, UI_BITMAP, 0UL);

3350
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3351 3352 3353 3354 3355 3356
		drbd_start_resync(mdev, C_SYNC_TARGET);

		put_ldev(mdev);
	} else
		dev_err(DEV, "Ignoring SyncUUID packet!\n");

3357
	return true;
P
Philipp Reisner 已提交
3358 3359
}

3360 3361 3362 3363 3364 3365 3366
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3367 3368
receive_bitmap_plain(struct drbd_conf *mdev, unsigned int data_size,
		     unsigned long *buffer, struct bm_xfer_ctx *c)
P
Philipp Reisner 已提交
3369 3370 3371
{
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3372
	int err;
P
Philipp Reisner 已提交
3373

3374 3375
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3376
		return -EIO;
P
Philipp Reisner 已提交
3377 3378
	}
	if (want == 0)
3379 3380 3381 3382 3383 3384 3385
		return 0;
	err = drbd_recv(mdev, buffer, want);
	if (err != want) {
		if (err >= 0)
			err = -EIO;
		return err;
	}
P
Philipp Reisner 已提交
3386 3387 3388 3389 3390 3391 3392 3393

	drbd_bm_merge_lel(mdev, c->word_offset, num_words, buffer);

	c->word_offset += num_words;
	c->bit_offset = c->word_offset * BITS_PER_LONG;
	if (c->bit_offset > c->bm_bits)
		c->bit_offset = c->bm_bits;

3394
	return 1;
P
Philipp Reisner 已提交
3395 3396
}

3397 3398 3399 3400 3401 3402 3403
/**
 * recv_bm_rle_bits
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
P
Philipp Reisner 已提交
3404 3405
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3406 3407
		 struct bm_xfer_ctx *c,
		 unsigned int len)
P
Philipp Reisner 已提交
3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422
{
	struct bitstream bs;
	u64 look_ahead;
	u64 rl;
	u64 tmp;
	unsigned long s = c->bit_offset;
	unsigned long e;
	int toggle = DCBP_get_start(p);
	int have;
	int bits;

	bitstream_init(&bs, p->code, len, DCBP_get_pad_bits(p));

	bits = bitstream_get_bits(&bs, &look_ahead, 64);
	if (bits < 0)
3423
		return -EIO;
P
Philipp Reisner 已提交
3424 3425 3426 3427

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3428
			return -EIO;
P
Philipp Reisner 已提交
3429 3430 3431 3432 3433

		if (toggle) {
			e = s + rl -1;
			if (e >= c->bm_bits) {
				dev_err(DEV, "bitmap overflow (e:%lu) while decoding bm RLE packet\n", e);
3434
				return -EIO;
P
Philipp Reisner 已提交
3435 3436 3437 3438 3439 3440 3441 3442 3443
			}
			_drbd_bm_set_bits(mdev, s, e);
		}

		if (have < bits) {
			dev_err(DEV, "bitmap decoding error: h:%d b:%d la:0x%08llx l:%u/%u\n",
				have, bits, look_ahead,
				(unsigned int)(bs.cur.b - p->code),
				(unsigned int)bs.buf_len);
3444
			return -EIO;
P
Philipp Reisner 已提交
3445 3446 3447 3448 3449 3450
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3451
			return -EIO;
P
Philipp Reisner 已提交
3452 3453 3454 3455 3456 3457 3458
		look_ahead |= tmp << have;
		have += bits;
	}

	c->bit_offset = s;
	bm_xfer_ctx_bit_to_word_offset(c);

3459
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3460 3461
}

3462 3463 3464 3465 3466 3467 3468
/**
 * decode_bitmap_c
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
P
Philipp Reisner 已提交
3469 3470
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3471 3472
		struct bm_xfer_ctx *c,
		unsigned int len)
P
Philipp Reisner 已提交
3473 3474
{
	if (DCBP_get_code(p) == RLE_VLI_Bits)
3475
		return recv_bm_rle_bits(mdev, p, c, len);
P
Philipp Reisner 已提交
3476 3477 3478 3479 3480 3481 3482

	/* other variants had been implemented for evaluation,
	 * but have been dropped as this one turned out to be "best"
	 * during all our tests. */

	dev_err(DEV, "receive_bitmap_c: unknown encoding %u\n", p->encoding);
	drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR));
3483
	return -EIO;
P
Philipp Reisner 已提交
3484 3485 3486 3487 3488 3489
}

void INFO_bm_xfer_stats(struct drbd_conf *mdev,
		const char *direction, struct bm_xfer_ctx *c)
{
	/* what would it take to transfer it "plaintext" */
3490
	unsigned plain = sizeof(struct p_header) *
P
Philipp Reisner 已提交
3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527
		((c->bm_words+BM_PACKET_WORDS-1)/BM_PACKET_WORDS+1)
		+ c->bm_words * sizeof(long);
	unsigned total = c->bytes[0] + c->bytes[1];
	unsigned r;

	/* total can not be zero. but just in case: */
	if (total == 0)
		return;

	/* don't report if not compressed */
	if (total >= plain)
		return;

	/* total < plain. check for overflow, still */
	r = (total > UINT_MAX/1000) ? (total / (plain/1000))
		                    : (1000 * total / plain);

	if (r > 1000)
		r = 1000;

	r = 1000 - r;
	dev_info(DEV, "%s bitmap stats [Bytes(packets)]: plain %u(%u), RLE %u(%u), "
	     "total %u; compression: %u.%u%%\n",
			direction,
			c->bytes[1], c->packets[1],
			c->bytes[0], c->packets[0],
			total, r/10, r % 10);
}

/* Since we are processing the bitfield from lower addresses to higher,
   it does not matter if the process it in 32 bit chunks or 64 bit
   chunks as long as it is little endian. (Understand it as byte stream,
   beginning with the lowest byte...) If we would use big endian
   we would need to process it from the highest address to the lowest,
   in order to be agnostic to the 32 vs 64 bits issue.

   returns 0 on failure, 1 if we successfully received it. */
3528
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3529 3530 3531
{
	struct bm_xfer_ctx c;
	void *buffer;
3532
	int err;
3533
	int ok = false;
3534
	struct p_header *h = &mdev->tconn->data.rbuf.header;
P
Philipp Reisner 已提交
3535

3536 3537 3538
	drbd_bm_lock(mdev, "receive bitmap", BM_LOCKED_SET_ALLOWED);
	/* you are supposed to send additional out-of-sync information
	 * if you actually set bits during this phase */
P
Philipp Reisner 已提交
3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552

	/* maybe we should use some per thread scratch page,
	 * and allocate that during initial device creation? */
	buffer	 = (unsigned long *) __get_free_page(GFP_NOIO);
	if (!buffer) {
		dev_err(DEV, "failed to allocate one page buffer in %s\n", __func__);
		goto out;
	}

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

3553
	for(;;) {
3554
		if (cmd == P_BITMAP) {
3555
			err = receive_bitmap_plain(mdev, data_size, buffer, &c);
3556
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3557 3558 3559 3560
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3561
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3562 3563 3564 3565 3566 3567
				dev_err(DEV, "ReportCBitmap packet too large\n");
				goto out;
			}
			/* use the page buff */
			p = buffer;
			memcpy(p, h, sizeof(*h));
3568
			if (drbd_recv(mdev, p->head.payload, data_size) != data_size)
P
Philipp Reisner 已提交
3569
				goto out;
3570 3571
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3572
				goto out;
P
Philipp Reisner 已提交
3573
			}
3574
			err = decode_bitmap_c(mdev, p, &c, data_size);
P
Philipp Reisner 已提交
3575
		} else {
3576
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
P
Philipp Reisner 已提交
3577 3578 3579
			goto out;
		}

3580
		c.packets[cmd == P_BITMAP]++;
3581
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header) + data_size;
P
Philipp Reisner 已提交
3582

3583 3584 3585
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3586
			break;
3587
		}
3588
		if (!drbd_recv_header(mdev, &cmd, &data_size))
P
Philipp Reisner 已提交
3589
			goto out;
3590
	}
P
Philipp Reisner 已提交
3591 3592 3593 3594

	INFO_bm_xfer_stats(mdev, "receive", &c);

	if (mdev->state.conn == C_WF_BITMAP_T) {
3595 3596
		enum drbd_state_rv rv;

P
Philipp Reisner 已提交
3597 3598 3599 3600
		ok = !drbd_send_bitmap(mdev);
		if (!ok)
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3601 3602
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3603 3604 3605 3606 3607 3608 3609
	} else if (mdev->state.conn != C_WF_BITMAP_S) {
		/* admin may have requested C_DISCONNECTING,
		 * other threads may have noticed network errors */
		dev_info(DEV, "unexpected cstate (%s) in receive_bitmap\n",
		    drbd_conn_str(mdev->state.conn));
	}

3610
	ok = true;
P
Philipp Reisner 已提交
3611
 out:
3612
	drbd_bm_unlock(mdev);
P
Philipp Reisner 已提交
3613 3614 3615 3616 3617 3618
	if (ok && mdev->state.conn == C_WF_BITMAP_S)
		drbd_start_resync(mdev, C_SYNC_SOURCE);
	free_page((unsigned long) buffer);
	return ok;
}

3619
static int receive_skip(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3620 3621 3622 3623 3624
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3625 3626
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);
P
Philipp Reisner 已提交
3627

3628
	size = data_size;
P
Philipp Reisner 已提交
3629 3630 3631
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
		r = drbd_recv(mdev, sink, want);
3632 3633
		if (!expect(r > 0))
			break;
P
Philipp Reisner 已提交
3634 3635 3636 3637 3638
		size -= r;
	}
	return size == 0;
}

3639
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
3640
{
3641 3642
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
3643
	drbd_tcp_quickack(mdev->tconn->data.socket);
3644

3645
	return true;
3646 3647
}

3648 3649
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
{
3650
	struct p_block_desc *p = &mdev->tconn->data.rbuf.block_desc;
3651

3652 3653 3654 3655 3656 3657 3658 3659 3660 3661
	switch (mdev->state.conn) {
	case C_WF_SYNC_UUID:
	case C_WF_BITMAP_T:
	case C_BEHIND:
			break;
	default:
		dev_err(DEV, "ASSERT FAILED cstate = %s, expected: WFSyncUUID|WFBitMapT|Behind\n",
				drbd_conn_str(mdev->state.conn));
	}

3662 3663
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3664
	return true;
3665 3666
}

3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packets cmd, unsigned int to_receive);

struct data_cmd {
	int expect_payload;
	size_t pkt_size;
	drbd_cmd_handler_f function;
};

static struct data_cmd drbd_cmd_handler[] = {
	[P_DATA]	    = { 1, sizeof(struct p_data), receive_Data },
	[P_DATA_REPLY]	    = { 1, sizeof(struct p_data), receive_DataReply },
	[P_RS_DATA_REPLY]   = { 1, sizeof(struct p_data), receive_RSDataReply } ,
	[P_BARRIER]	    = { 0, sizeof(struct p_barrier), receive_Barrier } ,
3680 3681 3682
	[P_BITMAP]	    = { 1, sizeof(struct p_header), receive_bitmap } ,
	[P_COMPRESSED_BITMAP] = { 1, sizeof(struct p_header), receive_bitmap } ,
	[P_UNPLUG_REMOTE]   = { 0, sizeof(struct p_header), receive_UnplugRemote },
3683 3684
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
3685 3686
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header), receive_SyncParam },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header), receive_SyncParam },
3687 3688 3689 3690 3691 3692 3693 3694 3695 3696
	[P_PROTOCOL]        = { 1, sizeof(struct p_protocol), receive_protocol },
	[P_UUIDS]	    = { 0, sizeof(struct p_uuids), receive_uuids },
	[P_SIZES]	    = { 0, sizeof(struct p_sizes), receive_sizes },
	[P_STATE]	    = { 0, sizeof(struct p_state), receive_state },
	[P_STATE_CHG_REQ]   = { 0, sizeof(struct p_req_state), receive_req_state },
	[P_SYNC_UUID]       = { 0, sizeof(struct p_rs_uuid), receive_sync_uuid },
	[P_OV_REQUEST]      = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_OV_REPLY]        = { 1, sizeof(struct p_block_req), receive_DataRequest },
	[P_CSUM_RS_REQUEST] = { 1, sizeof(struct p_block_req), receive_DataRequest },
	[P_DELAY_PROBE]     = { 0, sizeof(struct p_delay_probe93), receive_skip },
3697
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
P
Philipp Reisner 已提交
3698 3699
	/* anything missing from this table is in
	 * the asender_tbl, see get_asender_cmd */
3700
	[P_MAX_CMD]	    = { 0, 0, NULL },
P
Philipp Reisner 已提交
3701 3702
};

3703
/* All handler functions that expect a sub-header get that sub-heder in
3704
   mdev->tconn->data.rbuf.header.head.payload.
3705

3706
   Usually in mdev->tconn->data.rbuf.header.head the callback can find the usual
3707 3708
   p_header, but they may not rely on that. Since there is also p_header95 !
 */
P
Philipp Reisner 已提交
3709 3710 3711

static void drbdd(struct drbd_conf *mdev)
{
3712
	struct p_header *header = &mdev->tconn->data.rbuf.header;
3713 3714 3715 3716
	unsigned int packet_size;
	enum drbd_packets cmd;
	size_t shs; /* sub header size */
	int rv;
P
Philipp Reisner 已提交
3717

3718
	while (get_t_state(&mdev->tconn->receiver) == RUNNING) {
P
Philipp Reisner 已提交
3719
		drbd_thread_current_set_cpu(mdev);
3720 3721
		if (!drbd_recv_header(mdev, &cmd, &packet_size))
			goto err_out;
P
Philipp Reisner 已提交
3722

3723 3724 3725
		if (unlikely(cmd >= P_MAX_CMD || !drbd_cmd_handler[cmd].function)) {
			dev_err(DEV, "unknown packet type %d, l: %d!\n", cmd, packet_size);
			goto err_out;
3726
		}
P
Philipp Reisner 已提交
3727

3728
		shs = drbd_cmd_handler[cmd].pkt_size - sizeof(struct p_header);
3729 3730 3731
		if (packet_size - shs > 0 && !drbd_cmd_handler[cmd].expect_payload) {
			dev_err(DEV, "No payload expected %s l:%d\n", cmdname(cmd), packet_size);
			goto err_out;
P
Philipp Reisner 已提交
3732 3733
		}

3734
		if (shs) {
3735
			rv = drbd_recv(mdev, &header->payload, shs);
3736
			if (unlikely(rv != shs)) {
3737 3738
				if (!signal_pending(current))
					dev_warn(DEV, "short read while reading sub header: rv=%d\n", rv);
3739 3740 3741 3742
				goto err_out;
			}
		}

3743
		rv = drbd_cmd_handler[cmd].function(mdev, cmd, packet_size - shs);
P
Philipp Reisner 已提交
3744

3745
		if (unlikely(!rv)) {
P
Philipp Reisner 已提交
3746
			dev_err(DEV, "error receiving %s, l: %d!\n",
3747 3748
			    cmdname(cmd), packet_size);
			goto err_out;
P
Philipp Reisner 已提交
3749 3750 3751
		}
	}

3752 3753 3754 3755
	if (0) {
	err_out:
		drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR));
	}
3756 3757 3758
	/* If we leave here, we probably want to update at least the
	 * "Connected" indicator on stable storage. Do so explicitly here. */
	drbd_md_sync(mdev);
P
Philipp Reisner 已提交
3759 3760
}

3761
void drbd_flush_workqueue(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3762 3763 3764 3765 3766
{
	struct drbd_wq_barrier barr;

	barr.w.cb = w_prev_work_done;
	init_completion(&barr.done);
3767
	drbd_queue_work(&tconn->data.work, &barr.w);
P
Philipp Reisner 已提交
3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781
	wait_for_completion(&barr.done);
}

static void drbd_disconnect(struct drbd_conf *mdev)
{
	enum drbd_fencing_p fp;
	union drbd_state os, ns;
	int rv = SS_UNKNOWN_ERROR;
	unsigned int i;

	if (mdev->state.conn == C_STANDALONE)
		return;

	/* asender does not clean up anything. it must not interfere, either */
3782
	drbd_thread_stop(&mdev->tconn->asender);
P
Philipp Reisner 已提交
3783 3784
	drbd_free_sock(mdev);

3785
	/* wait for current activity to cease. */
3786
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3787 3788 3789
	_drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
	_drbd_wait_ee_list_empty(mdev, &mdev->sync_ee);
	_drbd_wait_ee_list_empty(mdev, &mdev->read_ee);
3790
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807

	/* We do not have data structures that would allow us to
	 * get the rs_pending_cnt down to 0 again.
	 *  * On C_SYNC_TARGET we do not have any data structures describing
	 *    the pending RSDataRequest's we have sent.
	 *  * On C_SYNC_SOURCE there is no data structure that tracks
	 *    the P_RS_DATA_REPLY blocks that we sent to the SyncTarget.
	 *  And no, it is not the sum of the reference counts in the
	 *  resync_LRU. The resync_LRU tracks the whole operation including
	 *  the disk-IO, while the rs_pending_cnt only tracks the blocks
	 *  on the fly. */
	drbd_rs_cancel_all(mdev);
	mdev->rs_total = 0;
	mdev->rs_failed = 0;
	atomic_set(&mdev->rs_pending_cnt, 0);
	wake_up(&mdev->misc_wait);

3808 3809
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
3810 3811 3812 3813 3814 3815 3816
	/* make sure syncer is stopped and w_resume_next_sg queued */
	del_timer_sync(&mdev->resync_timer);
	resync_timer_fn((unsigned long)mdev);

	/* wait for all w_e_end_data_req, w_e_end_rsdata_req, w_send_barrier,
	 * w_make_resync_request etc. which may still be on the worker queue
	 * to be "canceled" */
3817
	drbd_flush_workqueue(mdev->tconn);
P
Philipp Reisner 已提交
3818 3819 3820 3821 3822 3823 3824 3825

	/* This also does reclaim_net_ee().  If we do this too early, we might
	 * miss some resync ee and pages.*/
	drbd_process_done_ee(mdev);

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

3826
	if (!is_susp(mdev->state))
P
Philipp Reisner 已提交
3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838
		tl_clear(mdev);

	dev_info(DEV, "Connection closed\n");

	drbd_md_sync(mdev);

	fp = FP_DONT_CARE;
	if (get_ldev(mdev)) {
		fp = mdev->ldev->dc.fencing;
		put_ldev(mdev);
	}

3839 3840
	if (mdev->state.role == R_PRIMARY && fp >= FP_RESOURCE && mdev->state.pdsk >= D_UNKNOWN)
		drbd_try_outdate_peer_async(mdev);
P
Philipp Reisner 已提交
3841

3842
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3843 3844 3845 3846 3847 3848 3849
	os = mdev->state;
	if (os.conn >= C_UNCONNECTED) {
		/* Do not restart in case we are C_DISCONNECTING */
		ns = os;
		ns.conn = C_UNCONNECTED;
		rv = _drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
	}
3850
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3851 3852

	if (os.conn == C_DISCONNECTING) {
3853
		wait_event(mdev->tconn->net_cnt_wait, atomic_read(&mdev->tconn->net_cnt) == 0);
P
Philipp Reisner 已提交
3854

3855 3856
		crypto_free_hash(mdev->tconn->cram_hmac_tfm);
		mdev->tconn->cram_hmac_tfm = NULL;
P
Philipp Reisner 已提交
3857

3858 3859
		kfree(mdev->tconn->net_conf);
		mdev->tconn->net_conf = NULL;
P
Philipp Reisner 已提交
3860 3861 3862
		drbd_request_state(mdev, NS(conn, C_STANDALONE));
	}

3863 3864 3865 3866
	/* serialize with bitmap writeout triggered by the state change,
	 * if any. */
	wait_event(mdev->misc_wait, !test_bit(BITMAP_IO, &mdev->flags));

P
Philipp Reisner 已提交
3867 3868 3869 3870 3871 3872 3873 3874 3875 3876
	/* tcp_close and release of sendpage pages can be deferred.  I don't
	 * want to use SO_LINGER, because apparently it can be deferred for
	 * more than 20 seconds (longest time I checked).
	 *
	 * Actually we don't care for exactly when the network stack does its
	 * put_page(), but release our reference on these pages right here.
	 */
	i = drbd_release_ee(mdev, &mdev->net_ee);
	if (i)
		dev_info(DEV, "net_ee not empty, killed %u entries\n", i);
3877 3878 3879
	i = atomic_read(&mdev->pp_in_use_by_net);
	if (i)
		dev_info(DEV, "pp_in_use_by_net = %d, expected 0\n", i);
P
Philipp Reisner 已提交
3880 3881
	i = atomic_read(&mdev->pp_in_use);
	if (i)
3882
		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
P
Philipp Reisner 已提交
3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904

	D_ASSERT(list_empty(&mdev->read_ee));
	D_ASSERT(list_empty(&mdev->active_ee));
	D_ASSERT(list_empty(&mdev->sync_ee));
	D_ASSERT(list_empty(&mdev->done_ee));

	/* ok, no more ee's on the fly, it is safe to reset the epoch_size */
	atomic_set(&mdev->current_epoch->epoch_size, 0);
	D_ASSERT(list_empty(&mdev->current_epoch->list));
}

/*
 * We support PRO_VERSION_MIN to PRO_VERSION_MAX. The protocol version
 * we can agree on is stored in agreed_pro_version.
 *
 * feature flags and the reserved array should be enough room for future
 * enhancements of the handshake protocol, and possible plugins...
 *
 * for now, they are expected to be zero, but ignored.
 */
static int drbd_send_handshake(struct drbd_conf *mdev)
{
3905
	/* ASSERT current == mdev->tconn->receiver ... */
3906
	struct p_handshake *p = &mdev->tconn->data.sbuf.handshake;
P
Philipp Reisner 已提交
3907 3908
	int ok;

3909
	if (mutex_lock_interruptible(&mdev->tconn->data.mutex)) {
P
Philipp Reisner 已提交
3910 3911 3912 3913
		dev_err(DEV, "interrupted during initial handshake\n");
		return 0; /* interrupted. not ok. */
	}

3914 3915
	if (mdev->tconn->data.socket == NULL) {
		mutex_unlock(&mdev->tconn->data.mutex);
P
Philipp Reisner 已提交
3916 3917 3918 3919 3920 3921
		return 0;
	}

	memset(p, 0, sizeof(*p));
	p->protocol_min = cpu_to_be32(PRO_VERSION_MIN);
	p->protocol_max = cpu_to_be32(PRO_VERSION_MAX);
3922 3923
	ok = _drbd_send_cmd(mdev, mdev->tconn->data.socket, P_HAND_SHAKE,
			    &p->head, sizeof(*p), 0 );
3924
	mutex_unlock(&mdev->tconn->data.mutex);
P
Philipp Reisner 已提交
3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936
	return ok;
}

/*
 * return values:
 *   1 yes, we have a valid connection
 *   0 oops, did not work out, please try again
 *  -1 peer talks different language,
 *     no point in trying again, please go standalone.
 */
static int drbd_do_handshake(struct drbd_conf *mdev)
{
3937
	/* ASSERT current == mdev->tconn->receiver ... */
3938
	struct p_handshake *p = &mdev->tconn->data.rbuf.handshake;
3939 3940 3941
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
	unsigned int length;
	enum drbd_packets cmd;
P
Philipp Reisner 已提交
3942 3943 3944 3945 3946 3947
	int rv;

	rv = drbd_send_handshake(mdev);
	if (!rv)
		return 0;

3948
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
3949 3950 3951
	if (!rv)
		return 0;

3952
	if (cmd != P_HAND_SHAKE) {
P
Philipp Reisner 已提交
3953
		dev_err(DEV, "expected HandShake packet, received: %s (0x%04x)\n",
3954
		     cmdname(cmd), cmd);
P
Philipp Reisner 已提交
3955 3956 3957
		return -1;
	}

3958
	if (length != expect) {
P
Philipp Reisner 已提交
3959
		dev_err(DEV, "expected HandShake length: %u, received: %u\n",
3960
		     expect, length);
P
Philipp Reisner 已提交
3961 3962 3963 3964 3965 3966
		return -1;
	}

	rv = drbd_recv(mdev, &p->head.payload, expect);

	if (rv != expect) {
3967 3968
		if (!signal_pending(current))
			dev_warn(DEV, "short read receiving handshake packet: l=%u\n", rv);
P
Philipp Reisner 已提交
3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980
		return 0;
	}

	p->protocol_min = be32_to_cpu(p->protocol_min);
	p->protocol_max = be32_to_cpu(p->protocol_max);
	if (p->protocol_max == 0)
		p->protocol_max = p->protocol_min;

	if (PRO_VERSION_MAX < p->protocol_min ||
	    PRO_VERSION_MIN > p->protocol_max)
		goto incompat;

3981
	mdev->tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
P
Philipp Reisner 已提交
3982 3983

	dev_info(DEV, "Handshake successful: "
3984
	     "Agreed network protocol version %d\n", mdev->tconn->agreed_pro_version);
P
Philipp Reisner 已提交
3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000

	return 1;

 incompat:
	dev_err(DEV, "incompatible DRBD dialects: "
	    "I support %d-%d, peer supports %d-%d\n",
	    PRO_VERSION_MIN, PRO_VERSION_MAX,
	    p->protocol_min, p->protocol_max);
	return -1;
}

#if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE)
static int drbd_do_auth(struct drbd_conf *mdev)
{
	dev_err(DEV, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
	dev_err(DEV, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
4001
	return -1;
P
Philipp Reisner 已提交
4002 4003 4004
}
#else
#define CHALLENGE_LEN 64
4005 4006 4007 4008 4009 4010 4011

/* Return value:
	1 - auth succeeded,
	0 - failed, try again (network error),
	-1 - auth failed, don't try again.
*/

P
Philipp Reisner 已提交
4012 4013 4014 4015 4016 4017 4018
static int drbd_do_auth(struct drbd_conf *mdev)
{
	char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
	struct scatterlist sg;
	char *response = NULL;
	char *right_response = NULL;
	char *peers_ch = NULL;
4019
	unsigned int key_len = strlen(mdev->tconn->net_conf->shared_secret);
P
Philipp Reisner 已提交
4020 4021
	unsigned int resp_size;
	struct hash_desc desc;
4022 4023
	enum drbd_packets cmd;
	unsigned int length;
P
Philipp Reisner 已提交
4024 4025
	int rv;

4026
	desc.tfm = mdev->tconn->cram_hmac_tfm;
P
Philipp Reisner 已提交
4027 4028
	desc.flags = 0;

4029
	rv = crypto_hash_setkey(mdev->tconn->cram_hmac_tfm,
4030
				(u8 *)mdev->tconn->net_conf->shared_secret, key_len);
P
Philipp Reisner 已提交
4031 4032
	if (rv) {
		dev_err(DEV, "crypto_hash_setkey() failed with %d\n", rv);
4033
		rv = -1;
P
Philipp Reisner 已提交
4034 4035 4036 4037 4038 4039 4040 4041 4042
		goto fail;
	}

	get_random_bytes(my_challenge, CHALLENGE_LEN);

	rv = drbd_send_cmd2(mdev, P_AUTH_CHALLENGE, my_challenge, CHALLENGE_LEN);
	if (!rv)
		goto fail;

4043
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4044 4045 4046
	if (!rv)
		goto fail;

4047
	if (cmd != P_AUTH_CHALLENGE) {
P
Philipp Reisner 已提交
4048
		dev_err(DEV, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4049
		    cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4050 4051 4052 4053
		rv = 0;
		goto fail;
	}

4054
	if (length > CHALLENGE_LEN * 2) {
P
Philipp Reisner 已提交
4055
		dev_err(DEV, "expected AuthChallenge payload too big.\n");
4056
		rv = -1;
P
Philipp Reisner 已提交
4057 4058 4059
		goto fail;
	}

4060
	peers_ch = kmalloc(length, GFP_NOIO);
P
Philipp Reisner 已提交
4061 4062
	if (peers_ch == NULL) {
		dev_err(DEV, "kmalloc of peers_ch failed\n");
4063
		rv = -1;
P
Philipp Reisner 已提交
4064 4065 4066
		goto fail;
	}

4067
	rv = drbd_recv(mdev, peers_ch, length);
P
Philipp Reisner 已提交
4068

4069
	if (rv != length) {
4070 4071
		if (!signal_pending(current))
			dev_warn(DEV, "short read AuthChallenge: l=%u\n", rv);
P
Philipp Reisner 已提交
4072 4073 4074 4075
		rv = 0;
		goto fail;
	}

4076
	resp_size = crypto_hash_digestsize(mdev->tconn->cram_hmac_tfm);
P
Philipp Reisner 已提交
4077 4078 4079
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
		dev_err(DEV, "kmalloc of response failed\n");
4080
		rv = -1;
P
Philipp Reisner 已提交
4081 4082 4083 4084
		goto fail;
	}

	sg_init_table(&sg, 1);
4085
	sg_set_buf(&sg, peers_ch, length);
P
Philipp Reisner 已提交
4086 4087 4088 4089

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
		dev_err(DEV, "crypto_hash_digest() failed with %d\n", rv);
4090
		rv = -1;
P
Philipp Reisner 已提交
4091 4092 4093 4094 4095 4096 4097
		goto fail;
	}

	rv = drbd_send_cmd2(mdev, P_AUTH_RESPONSE, response, resp_size);
	if (!rv)
		goto fail;

4098
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4099 4100 4101
	if (!rv)
		goto fail;

4102
	if (cmd != P_AUTH_RESPONSE) {
P
Philipp Reisner 已提交
4103
		dev_err(DEV, "expected AuthResponse packet, received: %s (0x%04x)\n",
4104
			cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4105 4106 4107 4108
		rv = 0;
		goto fail;
	}

4109
	if (length != resp_size) {
P
Philipp Reisner 已提交
4110 4111 4112 4113 4114 4115 4116 4117
		dev_err(DEV, "expected AuthResponse payload of wrong size\n");
		rv = 0;
		goto fail;
	}

	rv = drbd_recv(mdev, response , resp_size);

	if (rv != resp_size) {
4118 4119
		if (!signal_pending(current))
			dev_warn(DEV, "short read receiving AuthResponse: l=%u\n", rv);
P
Philipp Reisner 已提交
4120 4121 4122 4123 4124
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4125
	if (right_response == NULL) {
P
Philipp Reisner 已提交
4126
		dev_err(DEV, "kmalloc of right_response failed\n");
4127
		rv = -1;
P
Philipp Reisner 已提交
4128 4129 4130 4131 4132 4133 4134 4135
		goto fail;
	}

	sg_set_buf(&sg, my_challenge, CHALLENGE_LEN);

	rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
	if (rv) {
		dev_err(DEV, "crypto_hash_digest() failed with %d\n", rv);
4136
		rv = -1;
P
Philipp Reisner 已提交
4137 4138 4139 4140 4141 4142 4143
		goto fail;
	}

	rv = !memcmp(response, right_response, resp_size);

	if (rv)
		dev_info(DEV, "Peer authenticated using %d bytes of '%s' HMAC\n",
4144
		     resp_size, mdev->tconn->net_conf->cram_hmac_alg);
4145 4146
	else
		rv = -1;
P
Philipp Reisner 已提交
4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170

 fail:
	kfree(peers_ch);
	kfree(response);
	kfree(right_response);

	return rv;
}
#endif

int drbdd_init(struct drbd_thread *thi)
{
	struct drbd_conf *mdev = thi->mdev;
	unsigned int minor = mdev_to_minor(mdev);
	int h;

	sprintf(current->comm, "drbd%d_receiver", minor);

	dev_info(DEV, "receiver (re)started\n");

	do {
		h = drbd_connect(mdev);
		if (h == 0) {
			drbd_disconnect(mdev);
4171
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4172 4173 4174 4175 4176 4177 4178 4179
		}
		if (h == -1) {
			dev_warn(DEV, "Discarding network configuration.\n");
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
		}
	} while (h == 0);

	if (h > 0) {
4180
		if (get_net_conf(mdev->tconn)) {
P
Philipp Reisner 已提交
4181
			drbdd(mdev);
4182
			put_net_conf(mdev->tconn);
P
Philipp Reisner 已提交
4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193
		}
	}

	drbd_disconnect(mdev);

	dev_info(DEV, "receiver terminated\n");
	return 0;
}

/* ********* acknowledge sender ******** */

4194
static int got_RqSReply(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4195
{
4196
	struct p_req_state_reply *p = &mdev->tconn->meta.rbuf.req_state_reply;
P
Philipp Reisner 已提交
4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208

	int retcode = be32_to_cpu(p->retcode);

	if (retcode >= SS_SUCCESS) {
		set_bit(CL_ST_CHG_SUCCESS, &mdev->flags);
	} else {
		set_bit(CL_ST_CHG_FAIL, &mdev->flags);
		dev_err(DEV, "Requested state change failed by peer: %s (%d)\n",
		    drbd_set_st_err_str(retcode), retcode);
	}
	wake_up(&mdev->state_wait);

4209
	return true;
P
Philipp Reisner 已提交
4210 4211
}

4212
static int got_Ping(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4213 4214 4215 4216 4217
{
	return drbd_send_ping_ack(mdev);

}

4218
static int got_PingAck(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4219 4220
{
	/* restore idle timeout */
4221
	mdev->tconn->meta.socket->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_int*HZ;
4222 4223
	if (!test_and_set_bit(GOT_PING_ACK, &mdev->flags))
		wake_up(&mdev->misc_wait);
P
Philipp Reisner 已提交
4224

4225
	return true;
P
Philipp Reisner 已提交
4226 4227
}

4228
static int got_IsInSync(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4229
{
4230
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4231 4232 4233
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

4234
	D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
4235 4236 4237

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

4238 4239 4240 4241 4242 4243 4244
	if (get_ldev(mdev)) {
		drbd_rs_complete_io(mdev, sector);
		drbd_set_in_sync(mdev, sector, blksize);
		/* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */
		mdev->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
		put_ldev(mdev);
	}
P
Philipp Reisner 已提交
4245
	dec_rs_pending(mdev);
4246
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4247

4248
	return true;
P
Philipp Reisner 已提交
4249 4250
}

4251 4252 4253 4254
static int
validate_req_change_req_state(struct drbd_conf *mdev, u64 id, sector_t sector,
			      struct rb_root *root, const char *func,
			      enum drbd_req_event what, bool missing_ok)
P
Philipp Reisner 已提交
4255 4256 4257 4258
{
	struct drbd_request *req;
	struct bio_and_error m;

4259
	spin_lock_irq(&mdev->tconn->req_lock);
4260
	req = find_request(mdev, root, id, sector, missing_ok, func);
P
Philipp Reisner 已提交
4261
	if (unlikely(!req)) {
4262
		spin_unlock_irq(&mdev->tconn->req_lock);
4263
		return false;
P
Philipp Reisner 已提交
4264 4265
	}
	__req_mod(req, what, &m);
4266
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4267 4268 4269

	if (m.bio)
		complete_master_bio(mdev, &m);
4270
	return true;
P
Philipp Reisner 已提交
4271 4272
}

4273
static int got_BlockAck(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4274
{
4275
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4276 4277 4278 4279 4280 4281
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);
	enum drbd_req_event what;

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

4282
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4283 4284
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4285
		return true;
P
Philipp Reisner 已提交
4286
	}
4287
	switch (cmd) {
P
Philipp Reisner 已提交
4288
	case P_RS_WRITE_ACK:
4289
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4290
		what = WRITE_ACKED_BY_PEER_AND_SIS;
P
Philipp Reisner 已提交
4291 4292
		break;
	case P_WRITE_ACK:
4293
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4294
		what = WRITE_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4295 4296
		break;
	case P_RECV_ACK:
4297
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
4298
		what = RECV_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4299 4300
		break;
	case P_DISCARD_ACK:
4301
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4302
		what = CONFLICT_DISCARDED_BY_PEER;
P
Philipp Reisner 已提交
4303 4304 4305
		break;
	default:
		D_ASSERT(0);
4306
		return false;
P
Philipp Reisner 已提交
4307 4308 4309
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
4310 4311
					     &mdev->write_requests, __func__,
					     what, false);
P
Philipp Reisner 已提交
4312 4313
}

4314
static int got_NegAck(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4315
{
4316
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4317
	sector_t sector = be64_to_cpu(p->sector);
4318
	int size = be32_to_cpu(p->blksize);
4319 4320
	bool missing_ok = mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A ||
			  mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B;
4321
	bool found;
P
Philipp Reisner 已提交
4322 4323 4324

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

4325
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4326 4327
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4328
		return true;
P
Philipp Reisner 已提交
4329
	}
4330

4331
	found = validate_req_change_req_state(mdev, p->block_id, sector,
4332
					      &mdev->write_requests, __func__,
4333
					      NEG_ACKED, missing_ok);
4334 4335 4336 4337 4338 4339 4340
	if (!found) {
		/* Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs.
		   The master bio might already be completed, therefore the
		   request is no longer in the collision hash. */
		/* In Protocol B we might already have got a P_RECV_ACK
		   but then get a P_NEG_ACK afterwards. */
		if (!missing_ok)
4341
			return false;
4342
		drbd_set_out_of_sync(mdev, sector, size);
4343 4344
	}
	return true;
P
Philipp Reisner 已提交
4345 4346
}

4347
static int got_NegDReply(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4348
{
4349
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4350 4351 4352 4353 4354 4355 4356
	sector_t sector = be64_to_cpu(p->sector);

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));
	dev_err(DEV, "Got NegDReply; Sector %llus, len %u; Fail original request.\n",
	    (unsigned long long)sector, be32_to_cpu(p->blksize));

	return validate_req_change_req_state(mdev, p->block_id, sector,
4357
					     &mdev->read_requests, __func__,
4358
					     NEG_ACKED, false);
P
Philipp Reisner 已提交
4359 4360
}

4361
static int got_NegRSDReply(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4362 4363 4364
{
	sector_t sector;
	int size;
4365
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4366 4367 4368 4369 4370 4371 4372 4373 4374 4375

	sector = be64_to_cpu(p->sector);
	size = be32_to_cpu(p->blksize);

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

	dec_rs_pending(mdev);

	if (get_ldev_if_state(mdev, D_FAILED)) {
		drbd_rs_complete_io(mdev, sector);
4376
		switch (cmd) {
4377 4378 4379 4380 4381 4382 4383 4384 4385
		case P_NEG_RS_DREPLY:
			drbd_rs_failed_io(mdev, sector, size);
		case P_RS_CANCEL:
			break;
		default:
			D_ASSERT(0);
			put_ldev(mdev);
			return false;
		}
P
Philipp Reisner 已提交
4386 4387 4388
		put_ldev(mdev);
	}

4389
	return true;
P
Philipp Reisner 已提交
4390 4391
}

4392
static int got_BarrierAck(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4393
{
4394
	struct p_barrier_ack *p = &mdev->tconn->meta.rbuf.barrier_ack;
P
Philipp Reisner 已提交
4395 4396 4397

	tl_release(mdev, p->barrier, be32_to_cpu(p->set_size));

4398 4399
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4400 4401 4402
	    !test_and_set_bit(AHEAD_TO_SYNC_SOURCE, &mdev->current_epoch->flags)) {
		mdev->start_resync_timer.expires = jiffies + HZ;
		add_timer(&mdev->start_resync_timer);
4403 4404
	}

4405
	return true;
P
Philipp Reisner 已提交
4406 4407
}

4408
static int got_OVResult(struct drbd_conf *mdev, enum drbd_packets cmd)
P
Philipp Reisner 已提交
4409
{
4410
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424
	struct drbd_work *w;
	sector_t sector;
	int size;

	sector = be64_to_cpu(p->sector);
	size = be32_to_cpu(p->blksize);

	update_peer_seq(mdev, be32_to_cpu(p->seq_num));

	if (be64_to_cpu(p->block_id) == ID_OUT_OF_SYNC)
		drbd_ov_oos_found(mdev, sector, size);
	else
		ov_oos_print(mdev);

4425
	if (!get_ldev(mdev))
4426
		return true;
4427

P
Philipp Reisner 已提交
4428 4429 4430
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4431 4432 4433 4434 4435 4436 4437
	--mdev->ov_left;

	/* let's advance progress step marks only for every other megabyte */
	if ((mdev->ov_left & 0x200) == 0x200)
		drbd_advance_rs_marks(mdev, mdev->ov_left);

	if (mdev->ov_left == 0) {
P
Philipp Reisner 已提交
4438 4439 4440
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
4441
			drbd_queue_work_front(&mdev->tconn->data.work, w);
P
Philipp Reisner 已提交
4442 4443 4444 4445 4446 4447
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
			ov_oos_print(mdev);
			drbd_resync_finished(mdev);
		}
	}
4448
	put_ldev(mdev);
4449
	return true;
P
Philipp Reisner 已提交
4450 4451
}

4452
static int got_skip(struct drbd_conf *mdev, enum drbd_packets cmd)
4453
{
4454
	return true;
4455 4456
}

P
Philipp Reisner 已提交
4457 4458
struct asender_cmd {
	size_t pkt_size;
4459
	int (*process)(struct drbd_conf *mdev, enum drbd_packets cmd);
P
Philipp Reisner 已提交
4460 4461 4462 4463 4464 4465 4466 4467
};

static struct asender_cmd *get_asender_cmd(int cmd)
{
	static struct asender_cmd asender_tbl[] = {
		/* anything missing from this table is in
		 * the drbd_cmd_handler (drbd_default_handler) table,
		 * see the beginning of drbdd() */
4468 4469
	[P_PING]	    = { sizeof(struct p_header), got_Ping },
	[P_PING_ACK]	    = { sizeof(struct p_header), got_PingAck },
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	[P_RECV_ACK]	    = { sizeof(struct p_block_ack), got_BlockAck },
	[P_WRITE_ACK]	    = { sizeof(struct p_block_ack), got_BlockAck },
	[P_RS_WRITE_ACK]    = { sizeof(struct p_block_ack), got_BlockAck },
	[P_DISCARD_ACK]	    = { sizeof(struct p_block_ack), got_BlockAck },
	[P_NEG_ACK]	    = { sizeof(struct p_block_ack), got_NegAck },
	[P_NEG_DREPLY]	    = { sizeof(struct p_block_ack), got_NegDReply },
	[P_NEG_RS_DREPLY]   = { sizeof(struct p_block_ack), got_NegRSDReply},
	[P_OV_RESULT]	    = { sizeof(struct p_block_ack), got_OVResult },
	[P_BARRIER_ACK]	    = { sizeof(struct p_barrier_ack), got_BarrierAck },
	[P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), got_RqSReply },
	[P_RS_IS_IN_SYNC]   = { sizeof(struct p_block_ack), got_IsInSync },
4481
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
4482
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply},
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	[P_MAX_CMD]	    = { 0, NULL },
	};
	if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)
		return NULL;
	return &asender_tbl[cmd];
}

int drbd_asender(struct drbd_thread *thi)
{
	struct drbd_conf *mdev = thi->mdev;
4493
	struct p_header *h = &mdev->tconn->meta.rbuf.header;
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4494 4495
	struct asender_cmd *cmd = NULL;

4496
	int rv;
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	void *buf    = h;
	int received = 0;
4499
	int expect   = sizeof(struct p_header);
4500
	int ping_timeout_active = 0;
4501 4502
	int empty, pkt_size;
	enum drbd_packets cmd_nr;
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4503 4504 4505 4506 4507 4508

	sprintf(current->comm, "drbd%d_asender", mdev_to_minor(mdev));

	current->policy = SCHED_RR;  /* Make this a realtime task! */
	current->rt_priority = 2;    /* more important than all other tasks */

4509
	while (get_t_state(thi) == RUNNING) {
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4510 4511
		drbd_thread_current_set_cpu(mdev);
		if (test_and_clear_bit(SEND_PING, &mdev->flags)) {
4512 4513 4514 4515
			if (!drbd_send_ping(mdev)) {
				dev_err(DEV, "drbd_send_ping has failed\n");
				goto reconnect;
			}
4516
			mdev->tconn->meta.socket->sk->sk_rcvtimeo =
4517
				mdev->tconn->net_conf->ping_timeo*HZ/10;
4518
			ping_timeout_active = 1;
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		}

		/* conditionally cork;
		 * it may hurt latency if we cork without much to send */
4523
		if (!mdev->tconn->net_conf->no_cork &&
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4524
			3 < atomic_read(&mdev->unacked_cnt))
4525
			drbd_tcp_cork(mdev->tconn->meta.socket);
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4526 4527 4528
		while (1) {
			clear_bit(SIGNAL_ASENDER, &mdev->flags);
			flush_signals(current);
4529
			if (!drbd_process_done_ee(mdev))
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				goto reconnect;
			/* to avoid race with newly queued ACKs */
			set_bit(SIGNAL_ASENDER, &mdev->flags);
4533
			spin_lock_irq(&mdev->tconn->req_lock);
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4534
			empty = list_empty(&mdev->done_ee);
4535
			spin_unlock_irq(&mdev->tconn->req_lock);
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			/* new ack may have been queued right here,
			 * but then there is also a signal pending,
			 * and we start over... */
			if (empty)
				break;
		}
		/* but unconditionally uncork unless disabled */
4543
		if (!mdev->tconn->net_conf->no_cork)
4544
			drbd_tcp_uncork(mdev->tconn->meta.socket);
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4545 4546 4547 4548 4549

		/* short circuit, recv_msg would return EINTR anyways. */
		if (signal_pending(current))
			continue;

4550
		rv = drbd_recv_short(mdev, mdev->tconn->meta.socket,
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4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572
				     buf, expect-received, 0);
		clear_bit(SIGNAL_ASENDER, &mdev->flags);

		flush_signals(current);

		/* Note:
		 * -EINTR	 (on meta) we got a signal
		 * -EAGAIN	 (on meta) rcvtimeo expired
		 * -ECONNRESET	 other side closed the connection
		 * -ERESTARTSYS  (on data) we got a signal
		 * rv <  0	 other than above: unexpected error!
		 * rv == expected: full header or command
		 * rv <  expected: "woken" by signal during receive
		 * rv == 0	 : "connection shut down by peer"
		 */
		if (likely(rv > 0)) {
			received += rv;
			buf	 += rv;
		} else if (rv == 0) {
			dev_err(DEV, "meta connection shut down by peer.\n");
			goto reconnect;
		} else if (rv == -EAGAIN) {
4573 4574
			/* If the data socket received something meanwhile,
			 * that is good enough: peer is still alive. */
4575
			if (time_after(mdev->tconn->last_received,
4576
				jiffies - mdev->tconn->meta.socket->sk->sk_rcvtimeo))
4577
				continue;
4578
			if (ping_timeout_active) {
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				dev_err(DEV, "PingAck did not arrive in time.\n");
				goto reconnect;
			}
			set_bit(SEND_PING, &mdev->flags);
			continue;
		} else if (rv == -EINTR) {
			continue;
		} else {
			dev_err(DEV, "sock_recvmsg returned %d\n", rv);
			goto reconnect;
		}

		if (received == expect && cmd == NULL) {
4592
			if (!decode_header(mdev, h, &cmd_nr, &pkt_size))
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4593
				goto reconnect;
4594
			cmd = get_asender_cmd(cmd_nr);
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4595
			if (unlikely(cmd == NULL)) {
4596 4597
				dev_err(DEV, "unknown command %d on meta (l: %d)\n",
					cmd_nr, pkt_size);
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				goto disconnect;
			}
			expect = cmd->pkt_size;
4601 4602 4603
			if (pkt_size != expect - sizeof(struct p_header)) {
				dev_err(DEV, "Wrong packet size on meta (c: %d, l: %d)\n",
					cmd_nr, pkt_size);
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4604
				goto reconnect;
4605
			}
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4606 4607
		}
		if (received == expect) {
4608
			mdev->tconn->last_received = jiffies;
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4609
			D_ASSERT(cmd != NULL);
4610
			if (!cmd->process(mdev, cmd_nr))
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4611 4612
				goto reconnect;

4613 4614 4615 4616 4617
			/* the idle_timeout (ping-int)
			 * has been restored in got_PingAck() */
			if (cmd == get_asender_cmd(P_PING_ACK))
				ping_timeout_active = 0;

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4618 4619
			buf	 = h;
			received = 0;
4620
			expect	 = sizeof(struct p_header);
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			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
		drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE));
4628
		drbd_md_sync(mdev);
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	}
	if (0) {
disconnect:
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
4633
		drbd_md_sync(mdev);
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	}
	clear_bit(SIGNAL_ASENDER, &mdev->flags);

	D_ASSERT(mdev->state.conn < C_CONNECTED);
	dev_info(DEV, "asender terminated\n");

	return 0;
}