drbd_receiver.c 130.3 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"

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struct packet_info {
	enum drbd_packet cmd;
	int size;
	int vnr;
};

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enum finish_epoch {
	FE_STILL_LIVE,
	FE_DESTROYED,
	FE_RECYCLED,
};

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static int drbd_do_handshake(struct drbd_tconn *tconn);
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static int drbd_do_auth(struct drbd_tconn *tconn);
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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)
{
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	struct drbd_peer_request *peer_req;
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	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) {
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		peer_req = list_entry(le, struct drbd_peer_request, w.list);
		if (drbd_ee_has_active_page(peer_req))
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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);
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	struct drbd_peer_request *peer_req, *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(peer_req, t, &reclaimed, w.list)
		drbd_free_net_ee(mdev, peer_req);
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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()
*/

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struct drbd_peer_request *
drbd_alloc_ee(struct drbd_conf *mdev, u64 id, sector_t sector,
	      unsigned int data_size, gfp_t gfp_mask) __must_hold(local)
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{
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	struct drbd_peer_request *peer_req;
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	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;

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	peer_req = mempool_alloc(drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM);
	if (!peer_req) {
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		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(&peer_req->i);
	peer_req->i.size = data_size;
	peer_req->i.sector = sector;
	peer_req->i.local = false;
	peer_req->i.waiting = false;

	peer_req->epoch = NULL;
	peer_req->mdev = mdev;
	peer_req->pages = page;
	atomic_set(&peer_req->pending_bios, 0);
	peer_req->flags = 0;
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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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	peer_req->block_id = id;
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	return peer_req;
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 fail:
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	mempool_free(peer_req, drbd_ee_mempool);
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	return NULL;
}

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

int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list)
{
	LIST_HEAD(work_list);
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	struct drbd_peer_request *peer_req, *t;
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	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(peer_req, t, &work_list, w.list) {
		drbd_free_some_ee(mdev, peer_req, 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);
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	struct drbd_peer_request *peer_req, *t;
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	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(peer_req, t, &reclaimed, w.list)
		drbd_free_net_ee(mdev, peer_req);
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	/* possible callbacks here:
	 * e_end_block, and e_end_resync_block, e_send_discard_ack.
	 * all ignore the last argument.
	 */
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	list_for_each_entry_safe(peer_req, t, &work_list, w.list) {
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		/* list_del not necessary, next/prev members not touched */
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		ok = peer_req->w.cb(mdev, &peer_req->w, !ok) && ok;
		drbd_free_ee(mdev, peer_req);
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	}
	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 */
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static int drbd_accept(const char **what, struct socket *sock, struct socket **newsock)
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{
	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;
}

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static int drbd_recv_short(struct socket *sock, void *buf, size_t size, int flags)
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{
	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;
}

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static int drbd_recv(struct drbd_tconn *tconn, void *buf, size_t size)
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{
	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(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)
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				conn_info(tconn, "sock was reset by peer\n");
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			else if (rv != -ERESTARTSYS)
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				conn_err(tconn, "sock_recvmsg returned %d\n", rv);
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			break;
		} else if (rv == 0) {
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			conn_info(tconn, "sock was shut down by peer\n");
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			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)
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		drbd_force_state(tconn->volume0, NS(conn, C_BROKEN_PIPE));
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	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_tconn *tconn)
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{
	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(tconn))
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588 589 590
		return NULL;

	what = "sock_create_kern";
591
	err = sock_create_kern(((struct sockaddr *)tconn->net_conf->my_addr)->sa_family,
P
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592 593 594 595 596 597 598
		SOCK_STREAM, IPPROTO_TCP, &sock);
	if (err < 0) {
		sock = NULL;
		goto out;
	}

	sock->sk->sk_rcvtimeo =
599 600 601
	sock->sk->sk_sndtimeo =  tconn->net_conf->try_connect_int*HZ;
	drbd_setbufsize(sock, tconn->net_conf->sndbuf_size,
			tconn->net_conf->rcvbuf_size);
P
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602 603 604 605 606 607 608 609

       /* 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.
	*/
610 611 612
	memcpy(&src_in6, tconn->net_conf->my_addr,
	       min_t(int, tconn->net_conf->my_addr_len, sizeof(src_in6)));
	if (((struct sockaddr *)tconn->net_conf->my_addr)->sa_family == AF_INET6)
P
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613 614 615 616 617 618 619
		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,
620
			      tconn->net_conf->my_addr_len);
P
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621 622 623 624 625 626 627 628
	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,
629 630
				 (struct sockaddr *)tconn->net_conf->peer_addr,
				 tconn->net_conf->peer_addr_len, 0);
P
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631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647

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:
648
			conn_err(tconn, "%s failed, err = %d\n", what, err);
P
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649 650
		}
		if (disconnect_on_error)
651
			drbd_force_state(tconn->volume0, NS(conn, C_DISCONNECTING));
P
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652
	}
653
	put_net_conf(tconn);
P
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654 655 656
	return sock;
}

657
static struct socket *drbd_wait_for_connect(struct drbd_tconn *tconn)
P
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658 659 660 661 662
{
	int timeo, err;
	struct socket *s_estab = NULL, *s_listen;
	const char *what;

663
	if (!get_net_conf(tconn))
P
Philipp Reisner 已提交
664 665 666
		return NULL;

	what = "sock_create_kern";
667
	err = sock_create_kern(((struct sockaddr *)tconn->net_conf->my_addr)->sa_family,
P
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668 669 670 671 672 673
		SOCK_STREAM, IPPROTO_TCP, &s_listen);
	if (err) {
		s_listen = NULL;
		goto out;
	}

674
	timeo = tconn->net_conf->try_connect_int * HZ;
P
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675 676 677 678 679
	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;
680 681
	drbd_setbufsize(s_listen, tconn->net_conf->sndbuf_size,
			tconn->net_conf->rcvbuf_size);
P
Philipp Reisner 已提交
682 683 684

	what = "bind before listen";
	err = s_listen->ops->bind(s_listen,
685 686
			      (struct sockaddr *) tconn->net_conf->my_addr,
			      tconn->net_conf->my_addr_len);
P
Philipp Reisner 已提交
687 688 689
	if (err < 0)
		goto out;

690
	err = drbd_accept(&what, s_listen, &s_estab);
P
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691 692 693 694 695 696

out:
	if (s_listen)
		sock_release(s_listen);
	if (err < 0) {
		if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
697 698
			conn_err(tconn, "%s failed, err = %d\n", what, err);
			drbd_force_state(tconn->volume0, NS(conn, C_DISCONNECTING));
P
Philipp Reisner 已提交
699 700
		}
	}
701
	put_net_conf(tconn);
P
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702 703 704 705

	return s_estab;
}

706
static int drbd_send_fp(struct drbd_tconn *tconn, struct socket *sock, enum drbd_packet cmd)
P
Philipp Reisner 已提交
707
{
708
	struct p_header *h = &tconn->data.sbuf.header;
P
Philipp Reisner 已提交
709

710
	return _conn_send_cmd(tconn, 0, sock, cmd, h, sizeof(*h), 0);
P
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711 712
}

713
static enum drbd_packet drbd_recv_fp(struct drbd_tconn *tconn, struct socket *sock)
P
Philipp Reisner 已提交
714
{
715
	struct p_header80 *h = &tconn->data.rbuf.header.h80;
P
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716 717
	int rr;

718
	rr = drbd_recv_short(sock, h, sizeof(*h), 0);
P
Philipp Reisner 已提交
719

720
	if (rr == sizeof(*h) && h->magic == cpu_to_be32(DRBD_MAGIC))
P
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721 722 723 724 725 726 727 728 729
		return be16_to_cpu(h->command);

	return 0xffff;
}

/**
 * drbd_socket_okay() - Free the socket if its connection is not okay
 * @sock:	pointer to the pointer to the socket.
 */
730
static int drbd_socket_okay(struct socket **sock)
P
Philipp Reisner 已提交
731 732 733 734 735
{
	int rr;
	char tb[4];

	if (!*sock)
736
		return false;
P
Philipp Reisner 已提交
737

738
	rr = drbd_recv_short(*sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);
P
Philipp Reisner 已提交
739 740

	if (rr > 0 || rr == -EAGAIN) {
741
		return true;
P
Philipp Reisner 已提交
742 743 744
	} else {
		sock_release(*sock);
		*sock = NULL;
745
		return false;
P
Philipp Reisner 已提交
746 747 748
	}
}

749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
static int drbd_connected(int vnr, void *p, void *data)
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
	int ok = 1;

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

	ok &= drbd_send_sync_param(mdev, &mdev->sync_conf);
	ok &= drbd_send_sizes(mdev, 0, 0);
	ok &= drbd_send_uuids(mdev);
	ok &= drbd_send_state(mdev);
	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
	clear_bit(RESIZE_PENDING, &mdev->flags);

	return !ok;
}

P
Philipp Reisner 已提交
767 768 769 770 771 772 773 774
/*
 * 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...
 */
775
static int drbd_connect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
776 777 778 779
{
	struct socket *s, *sock, *msock;
	int try, h, ok;

780
	if (drbd_request_state(tconn->volume0, NS(conn, C_WF_CONNECTION)) < SS_SUCCESS)
P
Philipp Reisner 已提交
781 782
		return -2;

783 784
	clear_bit(DISCARD_CONCURRENT, &tconn->flags);
	tconn->agreed_pro_version = 99;
P
Philipp Reisner 已提交
785 786
	/* agreed_pro_version must be smaller than 100 so we send the old
	   header (h80) in the first packet and in the handshake packet. */
P
Philipp Reisner 已提交
787 788 789 790 791 792 793

	sock  = NULL;
	msock = NULL;

	do {
		for (try = 0;;) {
			/* 3 tries, this should take less than a second! */
794
			s = drbd_try_connect(tconn);
P
Philipp Reisner 已提交
795 796 797
			if (s || ++try >= 3)
				break;
			/* give the other side time to call bind() & listen() */
798
			schedule_timeout_interruptible(HZ / 10);
P
Philipp Reisner 已提交
799 800 801 802
		}

		if (s) {
			if (!sock) {
803
				drbd_send_fp(tconn, s, P_HAND_SHAKE_S);
P
Philipp Reisner 已提交
804 805 806
				sock = s;
				s = NULL;
			} else if (!msock) {
807
				drbd_send_fp(tconn, s, P_HAND_SHAKE_M);
P
Philipp Reisner 已提交
808 809 810
				msock = s;
				s = NULL;
			} else {
811
				conn_err(tconn, "Logic error in drbd_connect()\n");
P
Philipp Reisner 已提交
812 813 814 815 816
				goto out_release_sockets;
			}
		}

		if (sock && msock) {
817
			schedule_timeout_interruptible(tconn->net_conf->ping_timeo*HZ/10);
818 819
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
820 821 822 823 824
			if (ok)
				break;
		}

retry:
825
		s = drbd_wait_for_connect(tconn);
P
Philipp Reisner 已提交
826
		if (s) {
827
			try = drbd_recv_fp(tconn, s);
828 829
			drbd_socket_okay(&sock);
			drbd_socket_okay(&msock);
P
Philipp Reisner 已提交
830 831 832
			switch (try) {
			case P_HAND_SHAKE_S:
				if (sock) {
833
					conn_warn(tconn, "initial packet S crossed\n");
P
Philipp Reisner 已提交
834 835 836 837 838 839
					sock_release(sock);
				}
				sock = s;
				break;
			case P_HAND_SHAKE_M:
				if (msock) {
840
					conn_warn(tconn, "initial packet M crossed\n");
P
Philipp Reisner 已提交
841 842 843
					sock_release(msock);
				}
				msock = s;
844
				set_bit(DISCARD_CONCURRENT, &tconn->flags);
P
Philipp Reisner 已提交
845 846
				break;
			default:
847
				conn_warn(tconn, "Error receiving initial packet\n");
P
Philipp Reisner 已提交
848 849 850 851 852 853
				sock_release(s);
				if (random32() & 1)
					goto retry;
			}
		}

854
		if (tconn->volume0->state.conn <= C_DISCONNECTING)
P
Philipp Reisner 已提交
855 856 857 858
			goto out_release_sockets;
		if (signal_pending(current)) {
			flush_signals(current);
			smp_rmb();
859
			if (get_t_state(&tconn->receiver) == EXITING)
P
Philipp Reisner 已提交
860 861 862 863
				goto out_release_sockets;
		}

		if (sock && msock) {
864 865
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
866 867 868 869 870 871 872 873 874 875 876 877 878 879 880
			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 ...
881
	 * sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
882 883 884 885
	 * 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 =
886
	sock->sk->sk_rcvtimeo = tconn->net_conf->ping_timeo*4*HZ/10;
P
Philipp Reisner 已提交
887

888 889
	msock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
	msock->sk->sk_rcvtimeo = tconn->net_conf->ping_int*HZ;
P
Philipp Reisner 已提交
890 891

	/* we don't want delays.
L
Lucas De Marchi 已提交
892
	 * we use TCP_CORK where appropriate, though */
P
Philipp Reisner 已提交
893 894 895
	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

896 897 898
	tconn->data.socket = sock;
	tconn->meta.socket = msock;
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
899

900
	h = drbd_do_handshake(tconn);
P
Philipp Reisner 已提交
901 902 903
	if (h <= 0)
		return h;

904
	if (tconn->cram_hmac_tfm) {
P
Philipp Reisner 已提交
905
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
906
		switch (drbd_do_auth(tconn)) {
907
		case -1:
908
			conn_err(tconn, "Authentication of peer failed\n");
P
Philipp Reisner 已提交
909
			return -1;
910
		case 0:
911
			conn_err(tconn, "Authentication of peer failed, trying again.\n");
912
			return 0;
P
Philipp Reisner 已提交
913 914 915
		}
	}

916
	if (drbd_request_state(tconn->volume0, NS(conn, C_WF_REPORT_PARAMS)) < SS_SUCCESS)
P
Philipp Reisner 已提交
917 918
		return 0;

919
	sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
920 921
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

922
	drbd_thread_start(&tconn->asender);
P
Philipp Reisner 已提交
923

924
	if (drbd_send_protocol(tconn) == -1)
925
		return -1;
P
Philipp Reisner 已提交
926

927
	return !idr_for_each(&tconn->volumes, drbd_connected, tconn);
P
Philipp Reisner 已提交
928 929 930 931 932 933 934 935 936

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

937
static bool decode_header(struct drbd_tconn *tconn, struct p_header *h, struct packet_info *pi)
P
Philipp Reisner 已提交
938
{
P
Philipp Reisner 已提交
939
	if (h->h80.magic == cpu_to_be32(DRBD_MAGIC)) {
940 941
		pi->cmd = be16_to_cpu(h->h80.command);
		pi->size = be16_to_cpu(h->h80.length);
942
	} else if (h->h95.magic == cpu_to_be16(DRBD_MAGIC_BIG)) {
943 944 945
		pi->cmd = be16_to_cpu(h->h95.command);
		pi->size = be32_to_cpu(h->h95.length) & 0x00ffffff;
		pi->vnr = 0;
946
	} else {
947
		conn_err(tconn, "magic?? on data m: 0x%08x c: %d l: %d\n",
948 949 950
		    be32_to_cpu(h->h80.magic),
		    be16_to_cpu(h->h80.command),
		    be16_to_cpu(h->h80.length));
951
		return false;
P
Philipp Reisner 已提交
952
	}
953 954 955
	return true;
}

956
static int drbd_recv_header(struct drbd_tconn *tconn, struct packet_info *pi)
957
{
958
	struct p_header *h = &tconn->data.rbuf.header;
959 960
	int r;

961
	r = drbd_recv(tconn, h, sizeof(*h));
962 963
	if (unlikely(r != sizeof(*h))) {
		if (!signal_pending(current))
964
			conn_warn(tconn, "short read expecting header on sock: r=%d\n", r);
965 966 967
		return false;
	}

968 969
	r = decode_header(tconn, h, pi);
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
970

971
	return r;
P
Philipp Reisner 已提交
972 973
}

974
static void drbd_flush(struct drbd_conf *mdev)
P
Philipp Reisner 已提交
975 976 977 978
{
	int rv;

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
979
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
980
					NULL);
P
Philipp Reisner 已提交
981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001
		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)
{
1002
	int epoch_size;
P
Philipp Reisner 已提交
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
	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 &&
1026
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
P
Philipp Reisner 已提交
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
			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);
1046
				/* atomic_set(&epoch->active, 0); is already zero */
P
Philipp Reisner 已提交
1047 1048
				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1049
				wake_up(&mdev->ee_wait);
P
Philipp Reisner 已提交
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 1077 1078 1079 1080 1081 1082 1083 1084
			}
		}

		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;
1085
	if (pwo != mdev->write_ordering || wo == WO_bdev_flush)
P
Philipp Reisner 已提交
1086 1087 1088
		dev_info(DEV, "Method to ensure write ordering: %s\n", write_ordering_str[mdev->write_ordering]);
}

1089 1090 1091
/**
 * drbd_submit_ee()
 * @mdev:	DRBD device.
1092
 * @peer_req:	peer request
1093
 * @rw:		flag field, see bio->bi_rw
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
 *
 * 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.
1104 1105
 */
/* TODO allocate from our own bio_set. */
1106
int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_peer_request *peer_req,
1107
		   const unsigned rw, const int fault_type)
1108 1109 1110
{
	struct bio *bios = NULL;
	struct bio *bio;
1111 1112 1113
	struct page *page = peer_req->pages;
	sector_t sector = peer_req->i.sector;
	unsigned ds = peer_req->i.size;
1114 1115
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1116
	int err = -ENOMEM;
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127

	/* 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;
	}
1128
	/* > peer_req->i.sector, unless this is the first bio */
1129 1130 1131
	bio->bi_sector = sector;
	bio->bi_bdev = mdev->ldev->backing_bdev;
	bio->bi_rw = rw;
1132
	bio->bi_private = peer_req;
1133 1134 1135 1136 1137 1138 1139 1140 1141
	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)) {
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
			/* 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;
			}
1153 1154 1155 1156 1157 1158 1159 1160 1161
			goto next_bio;
		}
		ds -= len;
		sector += len >> 9;
		--nr_pages;
	}
	D_ASSERT(page == NULL);
	D_ASSERT(ds == 0);

1162
	atomic_set(&peer_req->pending_bios, n_bios);
1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
	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);
	}
1178
	return err;
1179 1180
}

1181
static void drbd_remove_epoch_entry_interval(struct drbd_conf *mdev,
1182
					     struct drbd_peer_request *peer_req)
1183
{
1184
	struct drbd_interval *i = &peer_req->i;
1185 1186 1187 1188

	drbd_remove_interval(&mdev->write_requests, i);
	drbd_clear_interval(i);

A
Andreas Gruenbacher 已提交
1189
	/* Wake up any processes waiting for this peer request to complete.  */
1190 1191 1192 1193
	if (i->waiting)
		wake_up(&mdev->misc_wait);
}

1194 1195
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packet cmd,
			   unsigned int data_size)
P
Philipp Reisner 已提交
1196
{
1197
	int rv;
1198
	struct p_barrier *p = &mdev->tconn->data.rbuf.barrier;
P
Philipp Reisner 已提交
1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
	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)
1214
			return true;
1215 1216 1217 1218 1219 1220 1221 1222 1223

		/* 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 */
P
Philipp Reisner 已提交
1224 1225 1226 1227

	case WO_bdev_flush:
	case WO_drain_io:
		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
1228 1229 1230 1231 1232 1233
		drbd_flush(mdev);

		if (atomic_read(&mdev->current_epoch->epoch_size)) {
			epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
			if (epoch)
				break;
P
Philipp Reisner 已提交
1234 1235
		}

1236 1237 1238 1239 1240
		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
Philipp Reisner 已提交
1241

1242
		return true;
1243 1244
	default:
		dev_err(DEV, "Strangeness in mdev->write_ordering %d\n", mdev->write_ordering);
1245
		return false;
P
Philipp Reisner 已提交
1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
	}

	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);

1263
	return true;
P
Philipp Reisner 已提交
1264 1265 1266 1267
}

/* used from receive_RSDataReply (recv_resync_read)
 * and from receive_Data */
1268 1269 1270
static struct drbd_peer_request *
read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector,
	      int data_size) __must_hold(local)
P
Philipp Reisner 已提交
1271
{
1272
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
1273
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1274
	struct page *page;
1275
	int dgs, ds, rr;
1276 1277
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
1278
	unsigned long *data;
P
Philipp Reisner 已提交
1279

1280 1281
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
P
Philipp Reisner 已提交
1282 1283

	if (dgs) {
1284
		rr = drbd_recv(mdev->tconn, dig_in, dgs);
P
Philipp Reisner 已提交
1285
		if (rr != dgs) {
1286 1287 1288 1289
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data digest: read %d expected %d\n",
					rr, dgs);
P
Philipp Reisner 已提交
1290 1291 1292 1293 1294 1295
			return NULL;
		}
	}

	data_size -= dgs;

1296 1297 1298 1299 1300 1301
	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
Philipp Reisner 已提交
1302

1303 1304 1305
	/* even though we trust out peer,
	 * we sometimes have to double check. */
	if (sector + (data_size>>9) > capacity) {
1306 1307
		dev_err(DEV, "request from peer beyond end of local disk: "
			"capacity: %llus < sector: %llus + size: %u\n",
1308 1309 1310 1311 1312
			(unsigned long long)capacity,
			(unsigned long long)sector, data_size);
		return NULL;
	}

P
Philipp Reisner 已提交
1313 1314 1315
	/* 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.  */
1316 1317
	peer_req = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
	if (!peer_req)
P
Philipp Reisner 已提交
1318
		return NULL;
1319

P
Philipp Reisner 已提交
1320
	ds = data_size;
1321
	page = peer_req->pages;
1322 1323
	page_chain_for_each(page) {
		unsigned len = min_t(int, ds, PAGE_SIZE);
1324
		data = kmap(page);
1325
		rr = drbd_recv(mdev->tconn, data, len);
1326
		if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
1327 1328 1329
			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
			data[0] = data[0] ^ (unsigned long)-1;
		}
P
Philipp Reisner 已提交
1330
		kunmap(page);
1331
		if (rr != len) {
1332
			drbd_free_ee(mdev, peer_req);
1333 1334 1335
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data: read %d expected %d\n",
				rr, len);
P
Philipp Reisner 已提交
1336 1337 1338 1339 1340 1341
			return NULL;
		}
		ds -= rr;
	}

	if (dgs) {
1342
		drbd_csum_ee(mdev, mdev->tconn->integrity_r_tfm, peer_req, dig_vv);
P
Philipp Reisner 已提交
1343
		if (memcmp(dig_in, dig_vv, dgs)) {
1344 1345
			dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
				(unsigned long long)sector, data_size);
P
Philipp Reisner 已提交
1346
			drbd_bcast_ee(mdev, "digest failed",
1347 1348
					dgs, dig_in, dig_vv, peer_req);
			drbd_free_ee(mdev, peer_req);
P
Philipp Reisner 已提交
1349 1350 1351 1352
			return NULL;
		}
	}
	mdev->recv_cnt += data_size>>9;
1353
	return peer_req;
P
Philipp Reisner 已提交
1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364
}

/* 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;

1365
	if (!data_size)
1366
		return true;
1367

1368
	page = drbd_pp_alloc(mdev, 1, 1);
P
Philipp Reisner 已提交
1369 1370 1371

	data = kmap(page);
	while (data_size) {
1372
		rr = drbd_recv(mdev->tconn, data, min_t(int, data_size, PAGE_SIZE));
P
Philipp Reisner 已提交
1373 1374
		if (rr != min_t(int, data_size, PAGE_SIZE)) {
			rv = 0;
1375 1376 1377 1378
			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
Philipp Reisner 已提交
1379 1380 1381 1382 1383
			break;
		}
		data_size -= rr;
	}
	kunmap(page);
1384
	drbd_pp_free(mdev, page, 0);
P
Philipp Reisner 已提交
1385 1386 1387 1388 1389 1390 1391 1392 1393
	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;
1394 1395
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
P
Philipp Reisner 已提交
1396

1397 1398
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
P
Philipp Reisner 已提交
1399 1400

	if (dgs) {
1401
		rr = drbd_recv(mdev->tconn, dig_in, dgs);
P
Philipp Reisner 已提交
1402
		if (rr != dgs) {
1403 1404 1405 1406
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data reply digest: read %d expected %d\n",
					rr, dgs);
P
Philipp Reisner 已提交
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
			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);
1422
		rr = drbd_recv(mdev->tconn,
P
Philipp Reisner 已提交
1423 1424 1425 1426
			     kmap(bvec->bv_page)+bvec->bv_offset,
			     expect);
		kunmap(bvec->bv_page);
		if (rr != expect) {
1427 1428 1429 1430
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data reply: "
					"read %d expected %d\n",
					rr, expect);
P
Philipp Reisner 已提交
1431 1432 1433 1434 1435 1436
			return 0;
		}
		data_size -= rr;
	}

	if (dgs) {
1437
		drbd_csum_bio(mdev, mdev->tconn->integrity_r_tfm, bio, dig_vv);
P
Philipp Reisner 已提交
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451
		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)
{
1452 1453
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
	sector_t sector = peer_req->i.sector;
P
Philipp Reisner 已提交
1454 1455
	int ok;

1456
	D_ASSERT(drbd_interval_empty(&peer_req->i));
P
Philipp Reisner 已提交
1457

1458 1459 1460
	if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
		drbd_set_in_sync(mdev, sector, peer_req->i.size);
		ok = drbd_send_ack(mdev, P_RS_WRITE_ACK, peer_req);
P
Philipp Reisner 已提交
1461 1462
	} else {
		/* Record failure to sync */
1463
		drbd_rs_failed_io(mdev, sector, peer_req->i.size);
P
Philipp Reisner 已提交
1464

1465
		ok  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
P
Philipp Reisner 已提交
1466 1467 1468 1469 1470 1471 1472 1473
	}
	dec_unacked(mdev);

	return ok;
}

static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_size) __releases(local)
{
1474
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1475

1476 1477
	peer_req = read_in_block(mdev, ID_SYNCER, sector, data_size);
	if (!peer_req)
1478
		goto fail;
P
Philipp Reisner 已提交
1479 1480 1481 1482 1483 1484 1485

	dec_rs_pending(mdev);

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

1486
	peer_req->w.cb = e_end_resync_block;
1487

1488
	spin_lock_irq(&mdev->tconn->req_lock);
1489
	list_add(&peer_req->w.list, &mdev->sync_ee);
1490
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1491

1492
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1493
	if (drbd_submit_ee(mdev, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
1494
		return true;
P
Philipp Reisner 已提交
1495

1496 1497
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1498
	spin_lock_irq(&mdev->tconn->req_lock);
1499
	list_del(&peer_req->w.list);
1500
	spin_unlock_irq(&mdev->tconn->req_lock);
1501

1502
	drbd_free_ee(mdev, peer_req);
1503 1504
fail:
	put_ldev(mdev);
1505
	return false;
P
Philipp Reisner 已提交
1506 1507
}

1508
static struct drbd_request *
1509 1510
find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
	     sector_t sector, bool missing_ok, const char *func)
1511 1512 1513
{
	struct drbd_request *req;

1514 1515
	/* Request object according to our peer */
	req = (struct drbd_request *)(unsigned long)id;
1516
	if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
1517
		return req;
1518 1519 1520 1521
	if (!missing_ok) {
		dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
			(unsigned long)id, (unsigned long long)sector);
	}
1522 1523 1524
	return NULL;
}

1525 1526
static int receive_DataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
1527 1528 1529 1530
{
	struct drbd_request *req;
	sector_t sector;
	int ok;
1531
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1532 1533 1534

	sector = be64_to_cpu(p->sector);

1535
	spin_lock_irq(&mdev->tconn->req_lock);
1536
	req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
1537
	spin_unlock_irq(&mdev->tconn->req_lock);
1538
	if (unlikely(!req))
1539
		return false;
P
Philipp Reisner 已提交
1540

B
Bart Van Assche 已提交
1541
	/* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
P
Philipp Reisner 已提交
1542 1543 1544 1545 1546
	 * 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)
1547
		req_mod(req, DATA_RECEIVED);
P
Philipp Reisner 已提交
1548 1549 1550 1551 1552 1553 1554
	/* 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;
}

1555 1556
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
P
Philipp Reisner 已提交
1557 1558 1559
{
	sector_t sector;
	int ok;
1560
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1561 1562 1563 1564 1565 1566 1567

	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,
1568
		 * or in drbd_endio_sec. */
P
Philipp Reisner 已提交
1569 1570 1571 1572 1573 1574 1575
		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);

1576
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1577 1578
	}

1579 1580
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

P
Philipp Reisner 已提交
1581 1582 1583 1584 1585 1586 1587 1588
	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)
{
1589 1590
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
	sector_t sector = peer_req->i.sector;
P
Philipp Reisner 已提交
1591 1592
	int ok = 1, pcmd;

1593
	if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
1594
		if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
P
Philipp Reisner 已提交
1595 1596
			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
				mdev->state.conn <= C_PAUSED_SYNC_T &&
1597
				peer_req->flags & EE_MAY_SET_IN_SYNC) ?
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1598
				P_RS_WRITE_ACK : P_WRITE_ACK;
1599
			ok &= drbd_send_ack(mdev, pcmd, peer_req);
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1600
			if (pcmd == P_RS_WRITE_ACK)
1601
				drbd_set_in_sync(mdev, sector, peer_req->i.size);
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1602
		} else {
1603
			ok  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
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1604 1605 1606 1607 1608 1609 1610
			/* 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.  */
1611
	if (mdev->tconn->net_conf->two_primaries) {
1612
		spin_lock_irq(&mdev->tconn->req_lock);
1613 1614
		D_ASSERT(!drbd_interval_empty(&peer_req->i));
		drbd_remove_epoch_entry_interval(mdev, peer_req);
1615
		spin_unlock_irq(&mdev->tconn->req_lock);
1616
	} else
1617
		D_ASSERT(drbd_interval_empty(&peer_req->i));
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1618

1619
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));
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1620 1621 1622 1623 1624 1625

	return ok;
}

static int e_send_discard_ack(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
1626
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
P
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1627 1628
	int ok = 1;

1629
	D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
1630
	ok = drbd_send_ack(mdev, P_DISCARD_ACK, peer_req);
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1631

1632
	spin_lock_irq(&mdev->tconn->req_lock);
1633 1634
	D_ASSERT(!drbd_interval_empty(&peer_req->i));
	drbd_remove_epoch_entry_interval(mdev, peer_req);
1635
	spin_unlock_irq(&mdev->tconn->req_lock);
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1636 1637 1638 1639 1640 1641

	dec_unacked(mdev);

	return ok;
}

1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656
static bool seq_greater(u32 a, u32 b)
{
	/*
	 * We assume 32-bit wrap-around here.
	 * For 24-bit wrap-around, we would have to shift:
	 *  a <<= 8; b <<= 8;
	 */
	return (s32)a - (s32)b > 0;
}

static u32 seq_max(u32 a, u32 b)
{
	return seq_greater(a, b) ? a : b;
}

1657
static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
1658
{
1659
	unsigned int old_peer_seq;
1660 1661

	spin_lock(&mdev->peer_seq_lock);
1662 1663
	old_peer_seq = mdev->peer_seq;
	mdev->peer_seq = seq_max(mdev->peer_seq, peer_seq);
1664
	spin_unlock(&mdev->peer_seq_lock);
1665
	if (old_peer_seq != peer_seq)
1666 1667 1668
		wake_up(&mdev->seq_wait);
}

P
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1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698
/* 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);
1699
		if (!seq_greater(packet_seq, mdev->peer_seq + 1))
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1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
			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;
}

1722 1723 1724 1725
/* 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)
1726
{
1727 1728 1729 1730
	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);
1731 1732
}

P
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1733
/* mirrored write */
1734 1735
static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
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1736 1737
{
	sector_t sector;
1738
	struct drbd_peer_request *peer_req;
1739
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1740 1741 1742 1743 1744 1745 1746 1747 1748
	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);

1749
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
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1750 1751 1752 1753 1754 1755
		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),
1756
	 * or in drbd_endio_sec, if we successfully submit the data at
P
Philipp Reisner 已提交
1757 1758 1759
	 * the end of this function. */

	sector = be64_to_cpu(p->sector);
1760 1761
	peer_req = read_in_block(mdev, p->block_id, sector, data_size);
	if (!peer_req) {
P
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1762
		put_ldev(mdev);
1763
		return false;
P
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1764 1765
	}

1766
	peer_req->w.cb = e_end_block;
P
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1767

1768 1769 1770 1771
	dp_flags = be32_to_cpu(p->dp_flags);
	rw |= wire_flags_to_bio(mdev, dp_flags);

	if (dp_flags & DP_MAY_SET_IN_SYNC)
1772
		peer_req->flags |= EE_MAY_SET_IN_SYNC;
1773

P
Philipp Reisner 已提交
1774
	spin_lock(&mdev->epoch_lock);
1775 1776 1777
	peer_req->epoch = mdev->current_epoch;
	atomic_inc(&peer_req->epoch->epoch_size);
	atomic_inc(&peer_req->epoch->active);
P
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1778 1779 1780
	spin_unlock(&mdev->epoch_lock);

	/* I'm the receiver, I do hold a net_cnt reference. */
1781
	if (!mdev->tconn->net_conf->two_primaries) {
1782
		spin_lock_irq(&mdev->tconn->req_lock);
P
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1783 1784 1785
	} else {
		/* don't get the req_lock yet,
		 * we may sleep in drbd_wait_peer_seq */
1786
		const int size = peer_req->i.size;
1787
		const int discard = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
P
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1788 1789 1790
		DEFINE_WAIT(wait);
		int first;

1791
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
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1792 1793 1794 1795

		/* conflict detection and handling:
		 * 1. wait on the sequence number,
		 *    in case this data packet overtook ACK packets.
1796
		 * 2. check for conflicting write requests.
P
Philipp Reisner 已提交
1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823
		 *
		 * Note: for two_primaries, we are protocol C,
		 * so there cannot be any request that is DONE
		 * but still on the transfer log.
		 *
		 * 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;

1824
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1825 1826 1827

		first = 1;
		for (;;) {
1828
			struct drbd_interval *i;
P
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1829 1830 1831 1832
			int have_unacked = 0;
			int have_conflict = 0;
			prepare_to_wait(&mdev->misc_wait, &wait,
				TASK_INTERRUPTIBLE);
1833 1834 1835 1836 1837 1838

			i = drbd_find_overlap(&mdev->write_requests, sector, size);
			if (i) {
				/* only ALERT on first iteration,
				 * we may be woken up early... */
				if (first)
1839
					dev_alert(DEV, "%s[%u] Concurrent %s write detected!"
1840 1841
					      "	new: %llus +%u; pending: %llus +%u\n",
					      current->comm, current->pid,
1842
					      i->local ? "local" : "remote",
1843
					      (unsigned long long)sector, size,
1844 1845 1846 1847 1848 1849 1850 1851 1852
					      (unsigned long long)i->sector, i->size);

				if (i->local) {
					struct drbd_request *req2;

					req2 = container_of(i, struct drbd_request, i);
					if (req2->rq_state & RQ_NET_PENDING)
						++have_unacked;
				}
1853
				++have_conflict;
P
Philipp Reisner 已提交
1854 1855 1856 1857 1858 1859 1860 1861 1862
			}
			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);
1863 1864
				peer_req->w.cb = e_send_discard_ack;
				list_add_tail(&peer_req->w.list, &mdev->done_ee);
P
Philipp Reisner 已提交
1865

1866
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1867 1868 1869 1870 1871

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

				put_ldev(mdev);
1872
				wake_asender(mdev->tconn);
P
Philipp Reisner 已提交
1873
				finish_wait(&mdev->misc_wait, &wait);
1874
				return true;
P
Philipp Reisner 已提交
1875 1876 1877
			}

			if (signal_pending(current)) {
1878
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1879 1880 1881 1882
				finish_wait(&mdev->misc_wait, &wait);
				goto out_interrupted;
			}

1883
			/* Indicate to wake up mdev->misc_wait upon completion.  */
1884
			i->waiting = true;
1885

1886
			spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896
			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();
1897
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1898 1899
		}
		finish_wait(&mdev->misc_wait, &wait);
1900

1901
		drbd_insert_interval(&mdev->write_requests, &peer_req->i);
P
Philipp Reisner 已提交
1902 1903
	}

1904
	list_add(&peer_req->w.list, &mdev->active_ee);
1905
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1906

1907
	switch (mdev->tconn->net_conf->wire_protocol) {
P
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1908 1909 1910 1911 1912 1913 1914 1915
	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 */
1916
		drbd_send_ack(mdev, P_RECV_ACK, peer_req);
P
Philipp Reisner 已提交
1917 1918 1919 1920 1921 1922
		break;
	case DRBD_PROT_A:
		/* nothing to do */
		break;
	}

1923
	if (mdev->state.pdsk < D_INCONSISTENT) {
P
Philipp Reisner 已提交
1924
		/* In case we have the only disk of the cluster, */
1925 1926 1927 1928
		drbd_set_out_of_sync(mdev, peer_req->i.sector, peer_req->i.size);
		peer_req->flags |= EE_CALL_AL_COMPLETE_IO;
		peer_req->flags &= ~EE_MAY_SET_IN_SYNC;
		drbd_al_begin_io(mdev, peer_req->i.sector);
P
Philipp Reisner 已提交
1929 1930
	}

1931
	if (drbd_submit_ee(mdev, peer_req, rw, DRBD_FAULT_DT_WR) == 0)
1932
		return true;
P
Philipp Reisner 已提交
1933

1934 1935
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1936
	spin_lock_irq(&mdev->tconn->req_lock);
1937 1938
	list_del(&peer_req->w.list);
	drbd_remove_epoch_entry_interval(mdev, peer_req);
1939
	spin_unlock_irq(&mdev->tconn->req_lock);
1940 1941
	if (peer_req->flags & EE_CALL_AL_COMPLETE_IO)
		drbd_al_complete_io(mdev, peer_req->i.sector);
1942

P
Philipp Reisner 已提交
1943
out_interrupted:
1944
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + EV_CLEANUP);
P
Philipp Reisner 已提交
1945
	put_ldev(mdev);
1946
	drbd_free_ee(mdev, peer_req);
1947
	return false;
P
Philipp Reisner 已提交
1948 1949
}

1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960
/* 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.
 */
1961
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
1962 1963 1964
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
1965
	struct lc_element *tmp;
1966 1967 1968 1969 1970 1971 1972
	int curr_events;
	int throttle = 0;

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

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
	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);

1985 1986 1987
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
1988

1989 1990 1991 1992 1993 1994 1995 1996
	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. */
1997 1998 1999 2000 2001 2002
		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;
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

		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;
}


2017 2018
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int digest_size)
P
Philipp Reisner 已提交
2019 2020 2021
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
2022
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
2023
	struct digest_info *di = NULL;
2024
	int size, verb;
P
Philipp Reisner 已提交
2025
	unsigned int fault_type;
2026
	struct p_block_req *p =	&mdev->tconn->data.rbuf.block_req;
P
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2027 2028 2029 2030

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

2031
	if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
P
Philipp Reisner 已提交
2032 2033
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2034
		return false;
P
Philipp Reisner 已提交
2035 2036 2037 2038
	}
	if (sector + (size>>9) > capacity) {
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2039
		return false;
P
Philipp Reisner 已提交
2040 2041 2042
	}

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062
		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
2063 2064
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
2065

L
Lars Ellenberg 已提交
2066 2067
		/* drain possibly payload */
		return drbd_drain_block(mdev, digest_size);
P
Philipp Reisner 已提交
2068 2069 2070 2071 2072
	}

	/* 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.  */
2073 2074
	peer_req = drbd_alloc_ee(mdev, p->block_id, sector, size, GFP_NOIO);
	if (!peer_req) {
P
Philipp Reisner 已提交
2075
		put_ldev(mdev);
2076
		return false;
P
Philipp Reisner 已提交
2077 2078
	}

2079
	switch (cmd) {
P
Philipp Reisner 已提交
2080
	case P_DATA_REQUEST:
2081
		peer_req->w.cb = w_e_end_data_req;
P
Philipp Reisner 已提交
2082
		fault_type = DRBD_FAULT_DT_RD;
2083 2084 2085
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
Philipp Reisner 已提交
2086
	case P_RS_DATA_REQUEST:
2087
		peer_req->w.cb = w_e_end_rsdata_req;
P
Philipp Reisner 已提交
2088
		fault_type = DRBD_FAULT_RS_RD;
2089 2090
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
P
Philipp Reisner 已提交
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102
		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));

2103 2104
		peer_req->digest = di;
		peer_req->flags |= EE_HAS_DIGEST;
2105

2106
		if (drbd_recv(mdev->tconn, di->digest, digest_size) != digest_size)
P
Philipp Reisner 已提交
2107 2108
			goto out_free_e;

2109
		if (cmd == P_CSUM_RS_REQUEST) {
2110
			D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
2111
			peer_req->w.cb = w_e_end_csum_rs_req;
2112 2113
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2114
		} else if (cmd == P_OV_REPLY) {
2115 2116
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
2117
			peer_req->w.cb = w_e_end_ov_reply;
P
Philipp Reisner 已提交
2118
			dec_rs_pending(mdev);
2119 2120 2121
			/* 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
2122 2123 2124 2125 2126
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
2127
		    mdev->tconn->agreed_pro_version >= 90) {
2128 2129
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2130 2131
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2132 2133
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2134 2135 2136 2137
			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
2138 2139 2140
			dev_info(DEV, "Online Verify start sector: %llu\n",
					(unsigned long long)sector);
		}
2141
		peer_req->w.cb = w_e_end_ov_req;
P
Philipp Reisner 已提交
2142 2143 2144 2145 2146
		fault_type = DRBD_FAULT_RS_RD;
		break;

	default:
		dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
2147
		    cmdname(cmd));
P
Philipp Reisner 已提交
2148
		fault_type = DRBD_FAULT_MAX;
2149
		goto out_free_e;
P
Philipp Reisner 已提交
2150 2151
	}

2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173
	/* 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.
	 */
2174 2175 2176
	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))
2177
		goto out_free_e;
P
Philipp Reisner 已提交
2178

2179 2180 2181
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2182
submit:
P
Philipp Reisner 已提交
2183
	inc_unacked(mdev);
2184
	spin_lock_irq(&mdev->tconn->req_lock);
2185
	list_add_tail(&peer_req->w.list, &mdev->read_ee);
2186
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2187

2188
	if (drbd_submit_ee(mdev, peer_req, READ, fault_type) == 0)
2189
		return true;
P
Philipp Reisner 已提交
2190

2191 2192
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2193
	spin_lock_irq(&mdev->tconn->req_lock);
2194
	list_del(&peer_req->w.list);
2195
	spin_unlock_irq(&mdev->tconn->req_lock);
2196 2197
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
Philipp Reisner 已提交
2198 2199
out_free_e:
	put_ldev(mdev);
2200
	drbd_free_ee(mdev, peer_req);
2201
	return false;
P
Philipp Reisner 已提交
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214
}

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;

2215
	switch (mdev->tconn->net_conf->after_sb_0p) {
P
Philipp Reisner 已提交
2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242
	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
2243
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
P
Philipp Reisner 已提交
2244 2245 2246
		     "Using discard-least-changes instead\n");
	case ASB_DISCARD_ZERO_CHG:
		if (ch_peer == 0 && ch_self == 0) {
2247
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2248 2249 2250 2251 2252 2253
				? -1 : 1;
			break;
		} else {
			if (ch_peer == 0) { rv =  1; break; }
			if (ch_self == 0) { rv = -1; break; }
		}
2254
		if (mdev->tconn->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
P
Philipp Reisner 已提交
2255 2256 2257 2258 2259 2260 2261 2262
			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. */
2263
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277
				? -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)
{
2278
	int hg, rv = -100;
P
Philipp Reisner 已提交
2279

2280
	switch (mdev->tconn->net_conf->after_sb_1p) {
P
Philipp Reisner 已提交
2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304
	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) {
2305 2306 2307
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
P
Philipp Reisner 已提交
2308 2309 2310
			 /* 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. */
2311 2312
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326
				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)
{
2327
	int hg, rv = -100;
P
Philipp Reisner 已提交
2328

2329
	switch (mdev->tconn->net_conf->after_sb_2p) {
P
Philipp Reisner 已提交
2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346
	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) {
2347 2348
			enum drbd_state_rv rv2;

P
Philipp Reisner 已提交
2349 2350 2351
			 /* 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. */
2352 2353
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391
				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
2392 2393
-1091   requires proto 91
-1096   requires proto 96
P
Philipp Reisner 已提交
2394 2395 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
 */
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) {

2422
			if (mdev->tconn->agreed_pro_version < 91)
2423
				return -1091;
P
Philipp Reisner 已提交
2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442

			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) {

2443
			if (mdev->tconn->agreed_pro_version < 91)
2444
				return -1091;
P
Philipp Reisner 已提交
2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475

			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 */
2476
			dc = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
P
Philipp Reisner 已提交
2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488
			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) {
2489
		if (mdev->tconn->agreed_pro_version < 96 ?
2490 2491 2492
		    (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
2493 2494 2495
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

2496
			if (mdev->tconn->agreed_pro_version < 91)
2497
				return -1091;
P
Philipp Reisner 已提交
2498 2499 2500

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2501 2502 2503 2504

			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
2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525
			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) {
2526
		if (mdev->tconn->agreed_pro_version < 96 ?
2527 2528 2529
		    (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
2530 2531 2532
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

2533
			if (mdev->tconn->agreed_pro_version < 91)
2534
				return -1091;
P
Philipp Reisner 已提交
2535 2536 2537 2538

			_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]);

2539
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
Philipp Reisner 已提交
2540 2541 2542 2543 2544 2545 2546 2547 2548
			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;
2549
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
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2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 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 2600 2601
	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;
	}
2602 2603
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
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2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616
		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");
	}

2617 2618 2619
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

2620
	if (hg == 100 || (hg == -100 && mdev->tconn->net_conf->always_asbp)) {
P
Philipp Reisner 已提交
2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648
		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) {
2649
		if (mdev->tconn->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2650
			hg = -1;
2651
		if (!mdev->tconn->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2652 2653 2654 2655 2656 2657 2658 2659 2660
			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) {
2661 2662 2663 2664
		/* 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... */
2665
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676
		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) {
2677
		switch (mdev->tconn->net_conf->rr_conflict) {
P
Philipp Reisner 已提交
2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689
		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");
		}
	}

2690
	if (mdev->tconn->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
2691 2692 2693 2694 2695 2696 2697 2698 2699
		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
2700 2701
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2702 2703
		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
2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742
			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;
}

2743 2744
static int receive_protocol(struct drbd_conf *mdev, enum drbd_packet cmd,
			    unsigned int data_size)
P
Philipp Reisner 已提交
2745
{
2746
	struct p_protocol *p = &mdev->tconn->data.rbuf.protocol;
P
Philipp Reisner 已提交
2747
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2748
	int p_want_lose, p_two_primaries, cf;
P
Philipp Reisner 已提交
2749 2750 2751 2752 2753 2754 2755
	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);
2756 2757 2758 2759 2760 2761 2762
	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
2763

2764
	if (p_proto != mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
2765 2766 2767 2768
		dev_err(DEV, "incompatible communication protocols\n");
		goto disconnect;
	}

2769
	if (cmp_after_sb(p_after_sb_0p, mdev->tconn->net_conf->after_sb_0p)) {
P
Philipp Reisner 已提交
2770 2771 2772 2773
		dev_err(DEV, "incompatible after-sb-0pri settings\n");
		goto disconnect;
	}

2774
	if (cmp_after_sb(p_after_sb_1p, mdev->tconn->net_conf->after_sb_1p)) {
P
Philipp Reisner 已提交
2775 2776 2777 2778
		dev_err(DEV, "incompatible after-sb-1pri settings\n");
		goto disconnect;
	}

2779
	if (cmp_after_sb(p_after_sb_2p, mdev->tconn->net_conf->after_sb_2p)) {
P
Philipp Reisner 已提交
2780 2781 2782 2783
		dev_err(DEV, "incompatible after-sb-2pri settings\n");
		goto disconnect;
	}

2784
	if (p_want_lose && mdev->tconn->net_conf->want_lose) {
P
Philipp Reisner 已提交
2785 2786 2787 2788
		dev_err(DEV, "both sides have the 'want_lose' flag set\n");
		goto disconnect;
	}

2789
	if (p_two_primaries != mdev->tconn->net_conf->two_primaries) {
P
Philipp Reisner 已提交
2790 2791 2792 2793
		dev_err(DEV, "incompatible setting of the two-primaries options\n");
		goto disconnect;
	}

2794
	if (mdev->tconn->agreed_pro_version >= 87) {
2795
		unsigned char *my_alg = mdev->tconn->net_conf->integrity_alg;
P
Philipp Reisner 已提交
2796

2797
		if (drbd_recv(mdev->tconn, p_integrity_alg, data_size) != data_size)
2798
			return false;
P
Philipp Reisner 已提交
2799 2800 2801 2802 2803 2804 2805 2806 2807 2808

		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>");
	}

2809
	return true;
P
Philipp Reisner 已提交
2810 2811 2812

disconnect:
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2813
	return false;
P
Philipp Reisner 已提交
2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842
}

/* 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;
}

2843 2844
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int packet_size)
P
Philipp Reisner 已提交
2845
{
2846
	int ok = true;
2847
	struct p_rs_param_95 *p = &mdev->tconn->data.rbuf.rs_param_95;
P
Philipp Reisner 已提交
2848 2849 2850
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
2851
	const int apv = mdev->tconn->agreed_pro_version;
2852 2853
	int *rs_plan_s = NULL;
	int fifo_size = 0;
P
Philipp Reisner 已提交
2854 2855 2856 2857

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2858 2859
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2860

2861
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2862
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2863
		    packet_size, exp_max_sz);
2864
		return false;
P
Philipp Reisner 已提交
2865 2866 2867
	}

	if (apv <= 88) {
2868
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header);
2869
		data_size   = packet_size  - header_size;
2870
	} else if (apv <= 94) {
2871
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header);
2872
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2873
		D_ASSERT(data_size == 0);
2874
	} else {
2875
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header);
2876
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2877 2878 2879 2880 2881 2882
		D_ASSERT(data_size == 0);
	}

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

2883
	if (drbd_recv(mdev->tconn, &p->head.payload, header_size) != header_size)
2884
		return false;
P
Philipp Reisner 已提交
2885 2886 2887 2888 2889 2890 2891 2892 2893

	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);
2894
				return false;
P
Philipp Reisner 已提交
2895 2896
			}

2897
			if (drbd_recv(mdev->tconn, p->verify_alg, data_size) != data_size)
2898
				return false;
P
Philipp Reisner 已提交
2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941

			/* 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;
			}
		}

2942 2943 2944 2945 2946 2947
		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);
2948 2949 2950 2951 2952 2953 2954 2955 2956

			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;
				}
			}
2957
		}
P
Philipp Reisner 已提交
2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974

		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);
		}
2975 2976 2977 2978 2979 2980
		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
2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991
		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));
2992
	return false;
P
Philipp Reisner 已提交
2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007
}

/* 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);
}

3008 3009
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3010
{
3011
	struct p_sizes *p = &mdev->tconn->data.rbuf.sizes;
P
Philipp Reisner 已提交
3012 3013 3014
	enum determine_dev_size dd = unchanged;
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
3015
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
3016 3017 3018 3019 3020 3021 3022

	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));
3023
		return false;
P
Philipp Reisner 已提交
3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051
	}

	/* 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. */
3052
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
3053 3054 3055 3056 3057 3058 3059
		   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);
3060
			return false;
P
Philipp Reisner 已提交
3061 3062 3063 3064
		}
		put_ldev(mdev);
	}

3065
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
3066
	if (get_ldev(mdev)) {
B
Bart Van Assche 已提交
3067
		dd = drbd_determine_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
3068 3069
		put_ldev(mdev);
		if (dd == dev_size_error)
3070
			return false;
P
Philipp Reisner 已提交
3071 3072 3073 3074 3075 3076
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

3077 3078 3079
	mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
	drbd_reconsider_max_bio_size(mdev);

P
Philipp Reisner 已提交
3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093
	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... */
3094
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3095 3096 3097 3098
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3099 3100 3101 3102 3103 3104
			    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
3105 3106 3107 3108
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3109
	return true;
P
Philipp Reisner 已提交
3110 3111
}

3112 3113
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3114
{
3115
	struct p_uuids *p = &mdev->tconn->data.rbuf.uuids;
P
Philipp Reisner 已提交
3116
	u64 *p_uuid;
3117
	int i, updated_uuids = 0;
P
Philipp Reisner 已提交
3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133

	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));
3134
		return false;
P
Philipp Reisner 已提交
3135 3136 3137 3138 3139
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
3140
			mdev->tconn->agreed_pro_version >= 90 &&
P
Philipp Reisner 已提交
3141 3142 3143 3144 3145
			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,
3146 3147
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3148 3149 3150 3151 3152
			_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);
3153
			updated_uuids = 1;
P
Philipp Reisner 已提交
3154 3155
		}
		put_ldev(mdev);
3156 3157 3158 3159
	} 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. */
3160
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3161 3162 3163 3164 3165 3166 3167 3168
	}

	/* 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)
3169 3170 3171 3172
		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
3173

3174
	return true;
P
Philipp Reisner 已提交
3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206
}

/**
 * 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;
}

3207 3208
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3209
{
3210
	struct p_req_state *p = &mdev->tconn->data.rbuf.req_state;
P
Philipp Reisner 已提交
3211
	union drbd_state mask, val;
3212
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3213 3214 3215 3216

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

3217
	if (test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags) &&
P
Philipp Reisner 已提交
3218 3219
	    test_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
		drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
3220
		return true;
P
Philipp Reisner 已提交
3221 3222 3223 3224 3225 3226 3227 3228 3229 3230
	}

	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);

3231
	return true;
P
Philipp Reisner 已提交
3232 3233
}

3234 3235
static int receive_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3236
{
3237
	struct p_state *p = &mdev->tconn->data.rbuf.state;
3238
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3239
	enum drbd_disk_state real_peer_disk;
3240
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3241 3242 3243 3244 3245 3246 3247 3248 3249 3250
	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));
	}

3251
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3252
 retry:
3253
	os = ns = mdev->state;
3254
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3255

3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276
	/* 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);
3277
			return true;
3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289
		}
	}

	/* 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;

3290 3291
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3292

3293 3294 3295
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3296 3297 3298 3299 3300
	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 */
3301
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3302 3303
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3304
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3305
		       (peer_state.disk == D_NEGOTIATING ||
3306
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3307 3308 3309 3310 3311
		/* 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" */
3312
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3313 3314 3315 3316
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3317
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3318 3319

		put_ldev(mdev);
3320 3321
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3322
			if (mdev->state.disk == D_NEGOTIATING) {
3323
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3324 3325 3326
			} 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;
3327
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3328
			} else {
3329
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
3330
					return false;
3331
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
P
Philipp Reisner 已提交
3332
				drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3333
				return false;
P
Philipp Reisner 已提交
3334 3335 3336 3337
			}
		}
	}

3338
	spin_lock_irq(&mdev->tconn->req_lock);
3339
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3340 3341 3342 3343 3344
		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);
3345
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3346
		ns.disk = mdev->new_state_tmp.disk;
3347 3348
	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 &&
3349
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
3350
		/* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
3351
		   for temporal network outages! */
3352
		spin_unlock_irq(&mdev->tconn->req_lock);
3353 3354 3355 3356 3357
		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));
3358
		return false;
3359
	}
3360
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3361
	ns = mdev->state;
3362
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3363 3364 3365

	if (rv < SS_SUCCESS) {
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3366
		return false;
P
Philipp Reisner 已提交
3367 3368
	}

3369 3370
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3371 3372 3373 3374 3375 3376 3377 3378 3379
		    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);
		}
	}

3380
	mdev->tconn->net_conf->want_lose = 0;
P
Philipp Reisner 已提交
3381 3382 3383

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

3384
	return true;
P
Philipp Reisner 已提交
3385 3386
}

3387 3388
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3389
{
3390
	struct p_rs_uuid *p = &mdev->tconn->data.rbuf.rs_uuid;
P
Philipp Reisner 已提交
3391 3392 3393

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3394
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405
		   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);

3406
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3407 3408 3409 3410 3411 3412
		drbd_start_resync(mdev, C_SYNC_TARGET);

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

3413
	return true;
P
Philipp Reisner 已提交
3414 3415
}

3416 3417 3418 3419 3420 3421 3422
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3423 3424
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
3425 3426 3427
{
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3428
	int err;
P
Philipp Reisner 已提交
3429

3430 3431
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3432
		return -EIO;
P
Philipp Reisner 已提交
3433 3434
	}
	if (want == 0)
3435
		return 0;
3436
	err = drbd_recv(mdev->tconn, buffer, want);
3437 3438 3439 3440 3441
	if (err != want) {
		if (err >= 0)
			err = -EIO;
		return err;
	}
P
Philipp Reisner 已提交
3442 3443 3444 3445 3446 3447 3448 3449

	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;

3450
	return 1;
P
Philipp Reisner 已提交
3451 3452
}

3453 3454 3455 3456 3457 3458 3459
/**
 * 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
3460 3461
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3462 3463
		 struct bm_xfer_ctx *c,
		 unsigned int len)
P
Philipp Reisner 已提交
3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478
{
	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)
3479
		return -EIO;
P
Philipp Reisner 已提交
3480 3481 3482 3483

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3484
			return -EIO;
P
Philipp Reisner 已提交
3485 3486 3487 3488 3489

		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);
3490
				return -EIO;
P
Philipp Reisner 已提交
3491 3492 3493 3494 3495 3496 3497 3498 3499
			}
			_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);
3500
			return -EIO;
P
Philipp Reisner 已提交
3501 3502 3503 3504 3505 3506
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3507
			return -EIO;
P
Philipp Reisner 已提交
3508 3509 3510 3511 3512 3513 3514
		look_ahead |= tmp << have;
		have += bits;
	}

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

3515
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3516 3517
}

3518 3519 3520 3521 3522 3523 3524
/**
 * 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
3525 3526
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3527 3528
		struct bm_xfer_ctx *c,
		unsigned int len)
P
Philipp Reisner 已提交
3529 3530
{
	if (DCBP_get_code(p) == RLE_VLI_Bits)
3531
		return recv_bm_rle_bits(mdev, p, c, len);
P
Philipp Reisner 已提交
3532 3533 3534 3535 3536 3537 3538

	/* 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));
3539
	return -EIO;
P
Philipp Reisner 已提交
3540 3541 3542 3543 3544 3545
}

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" */
3546
	unsigned plain = sizeof(struct p_header) *
P
Philipp Reisner 已提交
3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583
		((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. */
3584 3585
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
			  unsigned int data_size)
P
Philipp Reisner 已提交
3586 3587 3588
{
	struct bm_xfer_ctx c;
	void *buffer;
3589
	int err;
3590
	int ok = false;
3591
	struct p_header *h = &mdev->tconn->data.rbuf.header;
3592
	struct packet_info pi;
P
Philipp Reisner 已提交
3593

3594 3595 3596
	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
3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610

	/* 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),
	};

3611
	for(;;) {
3612
		if (cmd == P_BITMAP) {
3613
			err = receive_bitmap_plain(mdev, data_size, buffer, &c);
3614
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3615 3616 3617 3618
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3619
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3620 3621 3622 3623 3624 3625
				dev_err(DEV, "ReportCBitmap packet too large\n");
				goto out;
			}
			/* use the page buff */
			p = buffer;
			memcpy(p, h, sizeof(*h));
3626
			if (drbd_recv(mdev->tconn, p->head.payload, data_size) != data_size)
P
Philipp Reisner 已提交
3627
				goto out;
3628 3629
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3630
				goto out;
P
Philipp Reisner 已提交
3631
			}
3632
			err = decode_bitmap_c(mdev, p, &c, data_size);
P
Philipp Reisner 已提交
3633
		} else {
3634
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
P
Philipp Reisner 已提交
3635 3636 3637
			goto out;
		}

3638
		c.packets[cmd == P_BITMAP]++;
3639
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header) + data_size;
P
Philipp Reisner 已提交
3640

3641 3642 3643
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3644
			break;
3645
		}
3646
		if (!drbd_recv_header(mdev->tconn, &pi))
P
Philipp Reisner 已提交
3647
			goto out;
3648 3649
		cmd = pi.cmd;
		data_size = pi.size;
3650
	}
P
Philipp Reisner 已提交
3651 3652 3653 3654

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

	if (mdev->state.conn == C_WF_BITMAP_T) {
3655 3656
		enum drbd_state_rv rv;

P
Philipp Reisner 已提交
3657 3658 3659 3660
		ok = !drbd_send_bitmap(mdev);
		if (!ok)
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3661 3662
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3663 3664 3665 3666 3667 3668 3669
	} 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));
	}

3670
	ok = true;
P
Philipp Reisner 已提交
3671
 out:
3672
	drbd_bm_unlock(mdev);
P
Philipp Reisner 已提交
3673 3674 3675 3676 3677 3678
	if (ok && mdev->state.conn == C_WF_BITMAP_S)
		drbd_start_resync(mdev, C_SYNC_SOURCE);
	free_page((unsigned long) buffer);
	return ok;
}

3679 3680
static int receive_skip(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
Philipp Reisner 已提交
3681 3682 3683 3684 3685
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3686 3687
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);
P
Philipp Reisner 已提交
3688

3689
	size = data_size;
P
Philipp Reisner 已提交
3690 3691
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
3692
		r = drbd_recv(mdev->tconn, sink, want);
3693 3694
		if (!expect(r > 0))
			break;
P
Philipp Reisner 已提交
3695 3696 3697 3698 3699
		size -= r;
	}
	return size == 0;
}

3700 3701
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packet cmd,
				unsigned int data_size)
3702
{
3703 3704
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
3705
	drbd_tcp_quickack(mdev->tconn->data.socket);
3706

3707
	return true;
3708 3709
}

3710 3711
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
3712
{
3713
	struct p_block_desc *p = &mdev->tconn->data.rbuf.block_desc;
3714

3715 3716 3717 3718 3719 3720 3721 3722 3723 3724
	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));
	}

3725 3726
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3727
	return true;
3728 3729
}

3730 3731
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packet cmd,
				  unsigned int to_receive);
3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743

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 } ,
3744 3745 3746
	[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 },
3747 3748
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
3749 3750
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header), receive_SyncParam },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header), receive_SyncParam },
3751 3752 3753 3754 3755 3756 3757 3758 3759 3760
	[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 },
3761
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
P
Philipp Reisner 已提交
3762 3763
	/* anything missing from this table is in
	 * the asender_tbl, see get_asender_cmd */
3764
	[P_MAX_CMD]	    = { 0, 0, NULL },
P
Philipp Reisner 已提交
3765 3766
};

3767
/* All handler functions that expect a sub-header get that sub-heder in
3768
   mdev->tconn->data.rbuf.header.head.payload.
3769

3770
   Usually in mdev->tconn->data.rbuf.header.head the callback can find the usual
3771 3772
   p_header, but they may not rely on that. Since there is also p_header95 !
 */
P
Philipp Reisner 已提交
3773 3774 3775

static void drbdd(struct drbd_conf *mdev)
{
3776
	struct p_header *header = &mdev->tconn->data.rbuf.header;
3777
	struct packet_info pi;
3778 3779
	size_t shs; /* sub header size */
	int rv;
P
Philipp Reisner 已提交
3780

3781
	while (get_t_state(&mdev->tconn->receiver) == RUNNING) {
3782
		drbd_thread_current_set_cpu(&mdev->tconn->receiver);
3783
		if (!drbd_recv_header(mdev->tconn, &pi))
3784
			goto err_out;
P
Philipp Reisner 已提交
3785

3786 3787
		if (unlikely(pi.cmd >= P_MAX_CMD || !drbd_cmd_handler[pi.cmd].function)) {
			dev_err(DEV, "unknown packet type %d, l: %d!\n", pi.cmd, pi.size);
3788
			goto err_out;
3789
		}
P
Philipp Reisner 已提交
3790

3791 3792 3793
		shs = drbd_cmd_handler[pi.cmd].pkt_size - sizeof(struct p_header);
		if (pi.size - shs > 0 && !drbd_cmd_handler[pi.cmd].expect_payload) {
			dev_err(DEV, "No payload expected %s l:%d\n", cmdname(pi.cmd), pi.size);
3794
			goto err_out;
P
Philipp Reisner 已提交
3795 3796
		}

3797
		if (shs) {
3798
			rv = drbd_recv(mdev->tconn, &header->payload, shs);
3799
			if (unlikely(rv != shs)) {
3800 3801
				if (!signal_pending(current))
					dev_warn(DEV, "short read while reading sub header: rv=%d\n", rv);
3802 3803 3804 3805
				goto err_out;
			}
		}

3806
		rv = drbd_cmd_handler[pi.cmd].function(mdev, pi.cmd, pi.size - shs);
P
Philipp Reisner 已提交
3807

3808
		if (unlikely(!rv)) {
P
Philipp Reisner 已提交
3809
			dev_err(DEV, "error receiving %s, l: %d!\n",
3810
			    cmdname(pi.cmd), pi.size);
3811
			goto err_out;
P
Philipp Reisner 已提交
3812 3813 3814
		}
	}

3815 3816 3817 3818
	if (0) {
	err_out:
		drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR));
	}
3819 3820 3821
	/* 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
3822 3823
}

3824
void drbd_flush_workqueue(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3825 3826 3827 3828 3829
{
	struct drbd_wq_barrier barr;

	barr.w.cb = w_prev_work_done;
	init_completion(&barr.done);
3830
	drbd_queue_work(&tconn->data.work, &barr.w);
P
Philipp Reisner 已提交
3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844
	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 */
3845
	drbd_thread_stop(&mdev->tconn->asender);
P
Philipp Reisner 已提交
3846 3847
	drbd_free_sock(mdev);

3848
	/* wait for current activity to cease. */
3849
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3850 3851 3852
	_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);
3853
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870

	/* 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);

3871 3872
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
3873 3874 3875 3876 3877 3878 3879
	/* 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" */
3880
	drbd_flush_workqueue(mdev->tconn);
P
Philipp Reisner 已提交
3881 3882 3883 3884 3885 3886 3887 3888

	/* 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;

3889
	if (!is_susp(mdev->state))
P
Philipp Reisner 已提交
3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901
		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);
	}

3902 3903
	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
3904

3905
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3906 3907 3908 3909 3910 3911 3912
	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);
	}
3913
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3914 3915

	if (os.conn == C_DISCONNECTING) {
3916
		wait_event(mdev->tconn->net_cnt_wait, atomic_read(&mdev->tconn->net_cnt) == 0);
P
Philipp Reisner 已提交
3917

3918 3919
		crypto_free_hash(mdev->tconn->cram_hmac_tfm);
		mdev->tconn->cram_hmac_tfm = NULL;
P
Philipp Reisner 已提交
3920

3921 3922
		kfree(mdev->tconn->net_conf);
		mdev->tconn->net_conf = NULL;
P
Philipp Reisner 已提交
3923 3924 3925
		drbd_request_state(mdev, NS(conn, C_STANDALONE));
	}

3926 3927 3928 3929
	/* 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
3930 3931 3932 3933 3934 3935 3936 3937 3938 3939
	/* 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);
3940 3941 3942
	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
3943 3944
	i = atomic_read(&mdev->pp_in_use);
	if (i)
3945
		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
P
Philipp Reisner 已提交
3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965

	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.
 */
3966
static int drbd_send_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3967
{
3968
	/* ASSERT current == mdev->tconn->receiver ... */
3969
	struct p_handshake *p = &tconn->data.sbuf.handshake;
P
Philipp Reisner 已提交
3970 3971
	int ok;

3972 3973
	if (mutex_lock_interruptible(&tconn->data.mutex)) {
		conn_err(tconn, "interrupted during initial handshake\n");
P
Philipp Reisner 已提交
3974 3975 3976
		return 0; /* interrupted. not ok. */
	}

3977 3978
	if (tconn->data.socket == NULL) {
		mutex_unlock(&tconn->data.mutex);
P
Philipp Reisner 已提交
3979 3980 3981 3982 3983 3984
		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);
3985 3986 3987
	ok = _conn_send_cmd(tconn, 0, tconn->data.socket, P_HAND_SHAKE,
			    &p->head, sizeof(*p), 0);
	mutex_unlock(&tconn->data.mutex);
P
Philipp Reisner 已提交
3988 3989 3990 3991 3992 3993 3994 3995 3996 3997
	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.
 */
3998
static int drbd_do_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3999
{
4000 4001
	/* ASSERT current == tconn->receiver ... */
	struct p_handshake *p = &tconn->data.rbuf.handshake;
4002
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
4003
	struct packet_info pi;
P
Philipp Reisner 已提交
4004 4005
	int rv;

4006
	rv = drbd_send_handshake(tconn);
P
Philipp Reisner 已提交
4007 4008 4009
	if (!rv)
		return 0;

4010
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4011 4012 4013
	if (!rv)
		return 0;

4014
	if (pi.cmd != P_HAND_SHAKE) {
4015
		conn_err(tconn, "expected HandShake packet, received: %s (0x%04x)\n",
4016
		     cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4017 4018 4019
		return -1;
	}

4020
	if (pi.size != expect) {
4021
		conn_err(tconn, "expected HandShake length: %u, received: %u\n",
4022
		     expect, pi.size);
P
Philipp Reisner 已提交
4023 4024 4025
		return -1;
	}

4026
	rv = drbd_recv(tconn, &p->head.payload, expect);
P
Philipp Reisner 已提交
4027 4028

	if (rv != expect) {
4029
		if (!signal_pending(current))
4030
			conn_warn(tconn, "short read receiving handshake packet: l=%u\n", rv);
P
Philipp Reisner 已提交
4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042
		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;

4043
	tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
P
Philipp Reisner 已提交
4044

4045 4046
	conn_info(tconn, "Handshake successful: "
	     "Agreed network protocol version %d\n", tconn->agreed_pro_version);
P
Philipp Reisner 已提交
4047 4048 4049 4050

	return 1;

 incompat:
4051
	conn_err(tconn, "incompatible DRBD dialects: "
P
Philipp Reisner 已提交
4052 4053 4054 4055 4056 4057 4058
	    "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)
4059
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4060 4061 4062
{
	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");
4063
	return -1;
P
Philipp Reisner 已提交
4064 4065 4066
}
#else
#define CHALLENGE_LEN 64
4067 4068 4069 4070 4071 4072 4073

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

4074
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4075 4076 4077 4078 4079 4080
{
	char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
	struct scatterlist sg;
	char *response = NULL;
	char *right_response = NULL;
	char *peers_ch = NULL;
4081
	unsigned int key_len = strlen(tconn->net_conf->shared_secret);
P
Philipp Reisner 已提交
4082 4083
	unsigned int resp_size;
	struct hash_desc desc;
4084
	struct packet_info pi;
P
Philipp Reisner 已提交
4085 4086
	int rv;

4087
	desc.tfm = tconn->cram_hmac_tfm;
P
Philipp Reisner 已提交
4088 4089
	desc.flags = 0;

4090 4091
	rv = crypto_hash_setkey(tconn->cram_hmac_tfm,
				(u8 *)tconn->net_conf->shared_secret, key_len);
P
Philipp Reisner 已提交
4092
	if (rv) {
4093
		conn_err(tconn, "crypto_hash_setkey() failed with %d\n", rv);
4094
		rv = -1;
P
Philipp Reisner 已提交
4095 4096 4097 4098 4099
		goto fail;
	}

	get_random_bytes(my_challenge, CHALLENGE_LEN);

4100
	rv = conn_send_cmd2(tconn, P_AUTH_CHALLENGE, my_challenge, CHALLENGE_LEN);
P
Philipp Reisner 已提交
4101 4102 4103
	if (!rv)
		goto fail;

4104
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4105 4106 4107
	if (!rv)
		goto fail;

4108
	if (pi.cmd != P_AUTH_CHALLENGE) {
4109
		conn_err(tconn, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4110
		    cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4111 4112 4113 4114
		rv = 0;
		goto fail;
	}

4115
	if (pi.size > CHALLENGE_LEN * 2) {
4116
		conn_err(tconn, "expected AuthChallenge payload too big.\n");
4117
		rv = -1;
P
Philipp Reisner 已提交
4118 4119 4120
		goto fail;
	}

4121
	peers_ch = kmalloc(pi.size, GFP_NOIO);
P
Philipp Reisner 已提交
4122
	if (peers_ch == NULL) {
4123
		conn_err(tconn, "kmalloc of peers_ch failed\n");
4124
		rv = -1;
P
Philipp Reisner 已提交
4125 4126 4127
		goto fail;
	}

4128
	rv = drbd_recv(tconn, peers_ch, pi.size);
P
Philipp Reisner 已提交
4129

4130
	if (rv != pi.size) {
4131
		if (!signal_pending(current))
4132
			conn_warn(tconn, "short read AuthChallenge: l=%u\n", rv);
P
Philipp Reisner 已提交
4133 4134 4135 4136
		rv = 0;
		goto fail;
	}

4137
	resp_size = crypto_hash_digestsize(tconn->cram_hmac_tfm);
P
Philipp Reisner 已提交
4138 4139
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
4140
		conn_err(tconn, "kmalloc of response failed\n");
4141
		rv = -1;
P
Philipp Reisner 已提交
4142 4143 4144 4145
		goto fail;
	}

	sg_init_table(&sg, 1);
4146
	sg_set_buf(&sg, peers_ch, pi.size);
P
Philipp Reisner 已提交
4147 4148 4149

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
4150
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4151
		rv = -1;
P
Philipp Reisner 已提交
4152 4153 4154
		goto fail;
	}

4155
	rv = conn_send_cmd2(tconn, P_AUTH_RESPONSE, response, resp_size);
P
Philipp Reisner 已提交
4156 4157 4158
	if (!rv)
		goto fail;

4159
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4160 4161 4162
	if (!rv)
		goto fail;

4163
	if (pi.cmd != P_AUTH_RESPONSE) {
4164
		conn_err(tconn, "expected AuthResponse packet, received: %s (0x%04x)\n",
4165
			cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4166 4167 4168 4169
		rv = 0;
		goto fail;
	}

4170
	if (pi.size != resp_size) {
4171
		conn_err(tconn, "expected AuthResponse payload of wrong size\n");
P
Philipp Reisner 已提交
4172 4173 4174 4175
		rv = 0;
		goto fail;
	}

4176
	rv = drbd_recv(tconn, response , resp_size);
P
Philipp Reisner 已提交
4177 4178

	if (rv != resp_size) {
4179
		if (!signal_pending(current))
4180
			conn_warn(tconn, "short read receiving AuthResponse: l=%u\n", rv);
P
Philipp Reisner 已提交
4181 4182 4183 4184 4185
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4186
	if (right_response == NULL) {
4187
		conn_err(tconn, "kmalloc of right_response failed\n");
4188
		rv = -1;
P
Philipp Reisner 已提交
4189 4190 4191 4192 4193 4194 4195
		goto fail;
	}

	sg_set_buf(&sg, my_challenge, CHALLENGE_LEN);

	rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
	if (rv) {
4196
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4197
		rv = -1;
P
Philipp Reisner 已提交
4198 4199 4200 4201 4202 4203
		goto fail;
	}

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

	if (rv)
4204 4205
		conn_info(tconn, "Peer authenticated using %d bytes of '%s' HMAC\n",
		     resp_size, tconn->net_conf->cram_hmac_alg);
4206 4207
	else
		rv = -1;
P
Philipp Reisner 已提交
4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228

 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 {
4229
		h = drbd_connect(mdev->tconn);
P
Philipp Reisner 已提交
4230 4231
		if (h == 0) {
			drbd_disconnect(mdev);
4232
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4233 4234 4235 4236 4237 4238 4239 4240
		}
		if (h == -1) {
			dev_warn(DEV, "Discarding network configuration.\n");
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
		}
	} while (h == 0);

	if (h > 0) {
4241
		if (get_net_conf(mdev->tconn)) {
P
Philipp Reisner 已提交
4242
			drbdd(mdev);
4243
			put_net_conf(mdev->tconn);
P
Philipp Reisner 已提交
4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254
		}
	}

	drbd_disconnect(mdev);

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

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

4255
static int got_RqSReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4256
{
4257
	struct p_req_state_reply *p = &mdev->tconn->meta.rbuf.req_state_reply;
P
Philipp Reisner 已提交
4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269

	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);

4270
	return true;
P
Philipp Reisner 已提交
4271 4272
}

4273
static int got_Ping(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4274 4275 4276 4277 4278
{
	return drbd_send_ping_ack(mdev);

}

4279
static int got_PingAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4280 4281
{
	/* restore idle timeout */
4282
	mdev->tconn->meta.socket->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_int*HZ;
4283 4284
	if (!test_and_set_bit(GOT_PING_ACK, &mdev->flags))
		wake_up(&mdev->misc_wait);
P
Philipp Reisner 已提交
4285

4286
	return true;
P
Philipp Reisner 已提交
4287 4288
}

4289
static int got_IsInSync(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4290
{
4291
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4292 4293 4294
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

4295
	D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
4296 4297 4298

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

4299 4300 4301 4302 4303 4304 4305
	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
4306
	dec_rs_pending(mdev);
4307
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4308

4309
	return true;
P
Philipp Reisner 已提交
4310 4311
}

4312 4313 4314 4315
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
4316 4317 4318 4319
{
	struct drbd_request *req;
	struct bio_and_error m;

4320
	spin_lock_irq(&mdev->tconn->req_lock);
4321
	req = find_request(mdev, root, id, sector, missing_ok, func);
P
Philipp Reisner 已提交
4322
	if (unlikely(!req)) {
4323
		spin_unlock_irq(&mdev->tconn->req_lock);
4324
		return false;
P
Philipp Reisner 已提交
4325 4326
	}
	__req_mod(req, what, &m);
4327
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4328 4329 4330

	if (m.bio)
		complete_master_bio(mdev, &m);
4331
	return true;
P
Philipp Reisner 已提交
4332 4333
}

4334
static int got_BlockAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4335
{
4336
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4337 4338 4339 4340 4341 4342
	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));

4343
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4344 4345
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4346
		return true;
P
Philipp Reisner 已提交
4347
	}
4348
	switch (cmd) {
P
Philipp Reisner 已提交
4349
	case P_RS_WRITE_ACK:
4350
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4351
		what = WRITE_ACKED_BY_PEER_AND_SIS;
P
Philipp Reisner 已提交
4352 4353
		break;
	case P_WRITE_ACK:
4354
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4355
		what = WRITE_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4356 4357
		break;
	case P_RECV_ACK:
4358
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
4359
		what = RECV_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4360 4361
		break;
	case P_DISCARD_ACK:
4362
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4363
		what = CONFLICT_DISCARDED_BY_PEER;
P
Philipp Reisner 已提交
4364 4365 4366
		break;
	default:
		D_ASSERT(0);
4367
		return false;
P
Philipp Reisner 已提交
4368 4369 4370
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
4371 4372
					     &mdev->write_requests, __func__,
					     what, false);
P
Philipp Reisner 已提交
4373 4374
}

4375
static int got_NegAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4376
{
4377
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4378
	sector_t sector = be64_to_cpu(p->sector);
4379
	int size = be32_to_cpu(p->blksize);
4380 4381
	bool missing_ok = mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A ||
			  mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B;
4382
	bool found;
P
Philipp Reisner 已提交
4383 4384 4385

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

4386
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4387 4388
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4389
		return true;
P
Philipp Reisner 已提交
4390
	}
4391

4392
	found = validate_req_change_req_state(mdev, p->block_id, sector,
4393
					      &mdev->write_requests, __func__,
4394
					      NEG_ACKED, missing_ok);
4395 4396 4397 4398 4399 4400 4401
	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)
4402
			return false;
4403
		drbd_set_out_of_sync(mdev, sector, size);
4404 4405
	}
	return true;
P
Philipp Reisner 已提交
4406 4407
}

4408
static int got_NegDReply(struct drbd_conf *mdev, enum drbd_packet 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
	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,
4418
					     &mdev->read_requests, __func__,
4419
					     NEG_ACKED, false);
P
Philipp Reisner 已提交
4420 4421
}

4422
static int got_NegRSDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4423 4424 4425
{
	sector_t sector;
	int size;
4426
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4427 4428 4429 4430 4431 4432 4433 4434 4435 4436

	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);
4437
		switch (cmd) {
4438 4439 4440 4441 4442 4443 4444 4445 4446
		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
4447 4448 4449
		put_ldev(mdev);
	}

4450
	return true;
P
Philipp Reisner 已提交
4451 4452
}

4453
static int got_BarrierAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4454
{
4455
	struct p_barrier_ack *p = &mdev->tconn->meta.rbuf.barrier_ack;
P
Philipp Reisner 已提交
4456 4457 4458

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

4459 4460
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4461 4462 4463
	    !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);
4464 4465
	}

4466
	return true;
P
Philipp Reisner 已提交
4467 4468
}

4469
static int got_OVResult(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4470
{
4471
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485
	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);

4486
	if (!get_ldev(mdev))
4487
		return true;
4488

P
Philipp Reisner 已提交
4489 4490 4491
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4492 4493 4494 4495 4496 4497 4498
	--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
4499 4500 4501
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
4502
			drbd_queue_work_front(&mdev->tconn->data.work, w);
P
Philipp Reisner 已提交
4503 4504 4505 4506 4507 4508
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
			ov_oos_print(mdev);
			drbd_resync_finished(mdev);
		}
	}
4509
	put_ldev(mdev);
4510
	return true;
P
Philipp Reisner 已提交
4511 4512
}

4513
static int got_skip(struct drbd_conf *mdev, enum drbd_packet cmd)
4514
{
4515
	return true;
4516 4517
}

P
Philipp Reisner 已提交
4518 4519
struct asender_cmd {
	size_t pkt_size;
4520
	int (*process)(struct drbd_conf *mdev, enum drbd_packet cmd);
P
Philipp Reisner 已提交
4521 4522 4523 4524 4525 4526 4527 4528
};

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() */
4529 4530
	[P_PING]	    = { sizeof(struct p_header), got_Ping },
	[P_PING_ACK]	    = { sizeof(struct p_header), got_PingAck },
P
Philipp Reisner 已提交
4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541
	[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 },
4542
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
4543
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply},
P
Philipp Reisner 已提交
4544 4545 4546 4547 4548 4549 4550 4551 4552 4553
	[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;
4554
	struct p_header *h = &mdev->tconn->meta.rbuf.header;
P
Philipp Reisner 已提交
4555
	struct asender_cmd *cmd = NULL;
4556
	struct packet_info pi;
P
Philipp Reisner 已提交
4557

4558
	int rv;
P
Philipp Reisner 已提交
4559 4560
	void *buf    = h;
	int received = 0;
4561
	int expect   = sizeof(struct p_header);
4562
	int ping_timeout_active = 0;
4563
	int empty;
P
Philipp Reisner 已提交
4564 4565 4566 4567 4568 4569

	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 */

4570
	while (get_t_state(thi) == RUNNING) {
4571
		drbd_thread_current_set_cpu(thi);
4572
		if (test_and_clear_bit(SEND_PING, &mdev->tconn->flags)) {
4573 4574 4575 4576
			if (!drbd_send_ping(mdev)) {
				dev_err(DEV, "drbd_send_ping has failed\n");
				goto reconnect;
			}
4577
			mdev->tconn->meta.socket->sk->sk_rcvtimeo =
4578
				mdev->tconn->net_conf->ping_timeo*HZ/10;
4579
			ping_timeout_active = 1;
P
Philipp Reisner 已提交
4580 4581 4582 4583
		}

		/* conditionally cork;
		 * it may hurt latency if we cork without much to send */
4584
		if (!mdev->tconn->net_conf->no_cork &&
P
Philipp Reisner 已提交
4585
			3 < atomic_read(&mdev->unacked_cnt))
4586
			drbd_tcp_cork(mdev->tconn->meta.socket);
P
Philipp Reisner 已提交
4587
		while (1) {
4588
			clear_bit(SIGNAL_ASENDER, &mdev->tconn->flags);
P
Philipp Reisner 已提交
4589
			flush_signals(current);
4590
			if (!drbd_process_done_ee(mdev))
P
Philipp Reisner 已提交
4591 4592
				goto reconnect;
			/* to avoid race with newly queued ACKs */
4593
			set_bit(SIGNAL_ASENDER, &mdev->tconn->flags);
4594
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4595
			empty = list_empty(&mdev->done_ee);
4596
			spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4597 4598 4599 4600 4601 4602 4603
			/* 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 */
4604
		if (!mdev->tconn->net_conf->no_cork)
4605
			drbd_tcp_uncork(mdev->tconn->meta.socket);
P
Philipp Reisner 已提交
4606 4607 4608 4609 4610

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

4611
		rv = drbd_recv_short(mdev->tconn->meta.socket, buf, expect-received, 0);
4612
		clear_bit(SIGNAL_ASENDER, &mdev->tconn->flags);
P
Philipp Reisner 已提交
4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632

		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) {
4633 4634
			/* If the data socket received something meanwhile,
			 * that is good enough: peer is still alive. */
4635
			if (time_after(mdev->tconn->last_received,
4636
				jiffies - mdev->tconn->meta.socket->sk->sk_rcvtimeo))
4637
				continue;
4638
			if (ping_timeout_active) {
P
Philipp Reisner 已提交
4639 4640 4641
				dev_err(DEV, "PingAck did not arrive in time.\n");
				goto reconnect;
			}
4642
			set_bit(SEND_PING, &mdev->tconn->flags);
P
Philipp Reisner 已提交
4643 4644 4645 4646 4647 4648 4649 4650 4651
			continue;
		} else if (rv == -EINTR) {
			continue;
		} else {
			dev_err(DEV, "sock_recvmsg returned %d\n", rv);
			goto reconnect;
		}

		if (received == expect && cmd == NULL) {
4652
			if (!decode_header(mdev->tconn, h, &pi))
P
Philipp Reisner 已提交
4653
				goto reconnect;
4654
			cmd = get_asender_cmd(pi.cmd);
P
Philipp Reisner 已提交
4655
			if (unlikely(cmd == NULL)) {
4656
				dev_err(DEV, "unknown command %d on meta (l: %d)\n",
4657
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4658 4659 4660
				goto disconnect;
			}
			expect = cmd->pkt_size;
4661
			if (pi.size != expect - sizeof(struct p_header)) {
4662
				dev_err(DEV, "Wrong packet size on meta (c: %d, l: %d)\n",
4663
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4664
				goto reconnect;
4665
			}
P
Philipp Reisner 已提交
4666 4667
		}
		if (received == expect) {
4668
			mdev->tconn->last_received = jiffies;
P
Philipp Reisner 已提交
4669
			D_ASSERT(cmd != NULL);
4670
			if (!cmd->process(mdev, pi.cmd))
P
Philipp Reisner 已提交
4671 4672
				goto reconnect;

4673 4674 4675 4676 4677
			/* the idle_timeout (ping-int)
			 * has been restored in got_PingAck() */
			if (cmd == get_asender_cmd(P_PING_ACK))
				ping_timeout_active = 0;

P
Philipp Reisner 已提交
4678 4679
			buf	 = h;
			received = 0;
4680
			expect	 = sizeof(struct p_header);
P
Philipp Reisner 已提交
4681 4682 4683 4684 4685 4686 4687
			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
		drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE));
4688
		drbd_md_sync(mdev);
P
Philipp Reisner 已提交
4689 4690 4691 4692
	}
	if (0) {
disconnect:
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
4693
		drbd_md_sync(mdev);
P
Philipp Reisner 已提交
4694
	}
4695
	clear_bit(SIGNAL_ASENDER, &mdev->tconn->flags);
P
Philipp Reisner 已提交
4696 4697 4698 4699 4700 4701

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

	return 0;
}