drbd_receiver.c 130.5 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 int drbd_disconnected(int vnr, void *p, void *data);
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static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *, struct drbd_epoch *, enum epoch_event);
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static int e_end_block(struct drbd_work *, int);
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#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;
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	peer_req->w.mdev = mdev;
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	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;
}


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/* 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(&peer_req->w, !ok) && ok;
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		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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		conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
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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;

586
	if (!get_net_conf(tconn))
P
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587 588 589
		return NULL;

	what = "sock_create_kern";
590
	err = sock_create_kern(((struct sockaddr *)tconn->net_conf->my_addr)->sa_family,
P
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591 592 593 594 595 596 597
		SOCK_STREAM, IPPROTO_TCP, &sock);
	if (err < 0) {
		sock = NULL;
		goto out;
	}

	sock->sk->sk_rcvtimeo =
598 599 600
	sock->sk->sk_sndtimeo =  tconn->net_conf->try_connect_int*HZ;
	drbd_setbufsize(sock, tconn->net_conf->sndbuf_size,
			tconn->net_conf->rcvbuf_size);
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601 602 603 604 605 606 607 608

       /* 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.
	*/
609 610 611
	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)
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		src_in6.sin6_port = 0;
	else
		((struct sockaddr_in *)&src_in6)->sin_port = 0; /* AF_INET & AF_SCI */

	what = "bind before connect";
	err = sock->ops->bind(sock,
			      (struct sockaddr *) &src_in6,
619
			      tconn->net_conf->my_addr_len);
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620 621 622 623 624 625 626 627
	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,
628 629
				 (struct sockaddr *)tconn->net_conf->peer_addr,
				 tconn->net_conf->peer_addr_len, 0);
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630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646

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:
647
			conn_err(tconn, "%s failed, err = %d\n", what, err);
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		}
		if (disconnect_on_error)
650
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
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651
	}
652
	put_net_conf(tconn);
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653 654 655
	return sock;
}

656
static struct socket *drbd_wait_for_connect(struct drbd_tconn *tconn)
P
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657 658 659 660 661
{
	int timeo, err;
	struct socket *s_estab = NULL, *s_listen;
	const char *what;

662
	if (!get_net_conf(tconn))
P
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663 664 665
		return NULL;

	what = "sock_create_kern";
666
	err = sock_create_kern(((struct sockaddr *)tconn->net_conf->my_addr)->sa_family,
P
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667 668 669 670 671 672
		SOCK_STREAM, IPPROTO_TCP, &s_listen);
	if (err) {
		s_listen = NULL;
		goto out;
	}

673
	timeo = tconn->net_conf->try_connect_int * HZ;
P
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674 675 676 677 678
	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;
679 680
	drbd_setbufsize(s_listen, tconn->net_conf->sndbuf_size,
			tconn->net_conf->rcvbuf_size);
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681 682 683

	what = "bind before listen";
	err = s_listen->ops->bind(s_listen,
684 685
			      (struct sockaddr *) tconn->net_conf->my_addr,
			      tconn->net_conf->my_addr_len);
P
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686 687 688
	if (err < 0)
		goto out;

689
	err = drbd_accept(&what, s_listen, &s_estab);
P
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690 691 692 693 694 695

out:
	if (s_listen)
		sock_release(s_listen);
	if (err < 0) {
		if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
696
			conn_err(tconn, "%s failed, err = %d\n", what, err);
697
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
698 699
		}
	}
700
	put_net_conf(tconn);
P
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701 702 703 704

	return s_estab;
}

705
static int drbd_send_fp(struct drbd_tconn *tconn, struct socket *sock, enum drbd_packet cmd)
P
Philipp Reisner 已提交
706
{
707
	struct p_header *h = &tconn->data.sbuf.header;
P
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708

709
	return _conn_send_cmd(tconn, 0, sock, cmd, h, sizeof(*h), 0);
P
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710 711
}

712
static enum drbd_packet drbd_recv_fp(struct drbd_tconn *tconn, struct socket *sock)
P
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713
{
714
	struct p_header80 *h = &tconn->data.rbuf.header.h80;
P
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715 716
	int rr;

717
	rr = drbd_recv_short(sock, h, sizeof(*h), 0);
P
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718

719
	if (rr == sizeof(*h) && h->magic == cpu_to_be32(DRBD_MAGIC))
P
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720 721 722 723 724 725 726 727 728
		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.
 */
729
static int drbd_socket_okay(struct socket **sock)
P
Philipp Reisner 已提交
730 731 732 733 734
{
	int rr;
	char tb[4];

	if (!*sock)
735
		return false;
P
Philipp Reisner 已提交
736

737
	rr = drbd_recv_short(*sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);
P
Philipp Reisner 已提交
738 739

	if (rr > 0 || rr == -EAGAIN) {
740
		return true;
P
Philipp Reisner 已提交
741 742 743
	} else {
		sock_release(*sock);
		*sock = NULL;
744
		return false;
P
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745 746 747
	}
}

748 749 750 751 752 753 754 755
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;

756 757 758 759
	mdev->state_mutex = mdev->tconn->agreed_pro_version < 100 ?
		&mdev->tconn->cstate_mutex :
		&mdev->own_state_mutex;

760 761 762 763 764 765 766
	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);

767

768 769 770
	return !ok;
}

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Philipp Reisner 已提交
771 772 773 774 775 776 777 778
/*
 * 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...
 */
779
static int drbd_connect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
780 781 782 783
{
	struct socket *s, *sock, *msock;
	int try, h, ok;

784
	if (conn_request_state(tconn, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
P
Philipp Reisner 已提交
785 786
		return -2;

787 788
	clear_bit(DISCARD_CONCURRENT, &tconn->flags);
	tconn->agreed_pro_version = 99;
P
Philipp Reisner 已提交
789 790
	/* 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
791 792 793 794 795 796 797

	sock  = NULL;
	msock = NULL;

	do {
		for (try = 0;;) {
			/* 3 tries, this should take less than a second! */
798
			s = drbd_try_connect(tconn);
P
Philipp Reisner 已提交
799 800 801
			if (s || ++try >= 3)
				break;
			/* give the other side time to call bind() & listen() */
802
			schedule_timeout_interruptible(HZ / 10);
P
Philipp Reisner 已提交
803 804 805 806
		}

		if (s) {
			if (!sock) {
807
				drbd_send_fp(tconn, s, P_HAND_SHAKE_S);
P
Philipp Reisner 已提交
808 809 810
				sock = s;
				s = NULL;
			} else if (!msock) {
811
				drbd_send_fp(tconn, s, P_HAND_SHAKE_M);
P
Philipp Reisner 已提交
812 813 814
				msock = s;
				s = NULL;
			} else {
815
				conn_err(tconn, "Logic error in drbd_connect()\n");
P
Philipp Reisner 已提交
816 817 818 819 820
				goto out_release_sockets;
			}
		}

		if (sock && msock) {
821
			schedule_timeout_interruptible(tconn->net_conf->ping_timeo*HZ/10);
822 823
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
824 825 826 827 828
			if (ok)
				break;
		}

retry:
829
		s = drbd_wait_for_connect(tconn);
P
Philipp Reisner 已提交
830
		if (s) {
831
			try = drbd_recv_fp(tconn, s);
832 833
			drbd_socket_okay(&sock);
			drbd_socket_okay(&msock);
P
Philipp Reisner 已提交
834 835 836
			switch (try) {
			case P_HAND_SHAKE_S:
				if (sock) {
837
					conn_warn(tconn, "initial packet S crossed\n");
P
Philipp Reisner 已提交
838 839 840 841 842 843
					sock_release(sock);
				}
				sock = s;
				break;
			case P_HAND_SHAKE_M:
				if (msock) {
844
					conn_warn(tconn, "initial packet M crossed\n");
P
Philipp Reisner 已提交
845 846 847
					sock_release(msock);
				}
				msock = s;
848
				set_bit(DISCARD_CONCURRENT, &tconn->flags);
P
Philipp Reisner 已提交
849 850
				break;
			default:
851
				conn_warn(tconn, "Error receiving initial packet\n");
P
Philipp Reisner 已提交
852 853 854 855 856 857
				sock_release(s);
				if (random32() & 1)
					goto retry;
			}
		}

858
		if (tconn->cstate <= C_DISCONNECTING)
P
Philipp Reisner 已提交
859 860 861 862
			goto out_release_sockets;
		if (signal_pending(current)) {
			flush_signals(current);
			smp_rmb();
863
			if (get_t_state(&tconn->receiver) == EXITING)
P
Philipp Reisner 已提交
864 865 866 867
				goto out_release_sockets;
		}

		if (sock && msock) {
868 869
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884
			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 ...
885
	 * sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
886 887 888 889
	 * 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 =
890
	sock->sk->sk_rcvtimeo = tconn->net_conf->ping_timeo*4*HZ/10;
P
Philipp Reisner 已提交
891

892 893
	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
894 895

	/* we don't want delays.
L
Lucas De Marchi 已提交
896
	 * we use TCP_CORK where appropriate, though */
P
Philipp Reisner 已提交
897 898 899
	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

900 901 902
	tconn->data.socket = sock;
	tconn->meta.socket = msock;
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
903

904
	h = drbd_do_handshake(tconn);
P
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905 906 907
	if (h <= 0)
		return h;

908
	if (tconn->cram_hmac_tfm) {
P
Philipp Reisner 已提交
909
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
910
		switch (drbd_do_auth(tconn)) {
911
		case -1:
912
			conn_err(tconn, "Authentication of peer failed\n");
P
Philipp Reisner 已提交
913
			return -1;
914
		case 0:
915
			conn_err(tconn, "Authentication of peer failed, trying again.\n");
916
			return 0;
P
Philipp Reisner 已提交
917 918 919
		}
	}

920
	if (conn_request_state(tconn, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE) < SS_SUCCESS)
P
Philipp Reisner 已提交
921 922
		return 0;

923
	sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
924 925
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

926
	drbd_thread_start(&tconn->asender);
P
Philipp Reisner 已提交
927

928
	if (drbd_send_protocol(tconn) == -1)
929
		return -1;
P
Philipp Reisner 已提交
930

931
	return !idr_for_each(&tconn->volumes, drbd_connected, tconn);
P
Philipp Reisner 已提交
932 933 934 935 936 937 938 939 940

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

941
static bool decode_header(struct drbd_tconn *tconn, struct p_header *h, struct packet_info *pi)
P
Philipp Reisner 已提交
942
{
P
Philipp Reisner 已提交
943
	if (h->h80.magic == cpu_to_be32(DRBD_MAGIC)) {
944 945
		pi->cmd = be16_to_cpu(h->h80.command);
		pi->size = be16_to_cpu(h->h80.length);
946
		pi->vnr = 0;
947
	} else if (h->h95.magic == cpu_to_be16(DRBD_MAGIC_BIG)) {
948 949 950
		pi->cmd = be16_to_cpu(h->h95.command);
		pi->size = be32_to_cpu(h->h95.length) & 0x00ffffff;
		pi->vnr = 0;
951
	} else {
952
		conn_err(tconn, "magic?? on data m: 0x%08x c: %d l: %d\n",
953 954 955
		    be32_to_cpu(h->h80.magic),
		    be16_to_cpu(h->h80.command),
		    be16_to_cpu(h->h80.length));
956
		return false;
P
Philipp Reisner 已提交
957
	}
958 959 960
	return true;
}

961
static int drbd_recv_header(struct drbd_tconn *tconn, struct packet_info *pi)
962
{
963
	struct p_header *h = &tconn->data.rbuf.header;
964 965
	int r;

966
	r = drbd_recv(tconn, h, sizeof(*h));
967 968
	if (unlikely(r != sizeof(*h))) {
		if (!signal_pending(current))
969
			conn_warn(tconn, "short read expecting header on sock: r=%d\n", r);
970 971 972
		return false;
	}

973 974
	r = decode_header(tconn, h, pi);
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
975

976
	return r;
P
Philipp Reisner 已提交
977 978
}

979
static void drbd_flush(struct drbd_conf *mdev)
P
Philipp Reisner 已提交
980 981 982 983
{
	int rv;

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
984
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
985
					NULL);
P
Philipp Reisner 已提交
986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006
		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)
{
1007
	int epoch_size;
P
Philipp Reisner 已提交
1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030
	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 &&
1031
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
P
Philipp Reisner 已提交
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
			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);
1051
				/* atomic_set(&epoch->active, 0); is already zero */
P
Philipp Reisner 已提交
1052 1053
				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1054
				wake_up(&mdev->ee_wait);
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Philipp Reisner 已提交
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 1085 1086 1087 1088 1089
			}
		}

		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;
1090
	if (pwo != mdev->write_ordering || wo == WO_bdev_flush)
P
Philipp Reisner 已提交
1091 1092 1093
		dev_info(DEV, "Method to ensure write ordering: %s\n", write_ordering_str[mdev->write_ordering]);
}

1094 1095 1096
/**
 * drbd_submit_ee()
 * @mdev:	DRBD device.
1097
 * @peer_req:	peer request
1098
 * @rw:		flag field, see bio->bi_rw
1099 1100 1101 1102 1103 1104 1105 1106 1107 1108
 *
 * 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.
1109 1110
 */
/* TODO allocate from our own bio_set. */
1111
int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_peer_request *peer_req,
1112
		   const unsigned rw, const int fault_type)
1113 1114 1115
{
	struct bio *bios = NULL;
	struct bio *bio;
1116 1117 1118
	struct page *page = peer_req->pages;
	sector_t sector = peer_req->i.sector;
	unsigned ds = peer_req->i.size;
1119 1120
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1121
	int err = -ENOMEM;
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132

	/* 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;
	}
1133
	/* > peer_req->i.sector, unless this is the first bio */
1134 1135 1136
	bio->bi_sector = sector;
	bio->bi_bdev = mdev->ldev->backing_bdev;
	bio->bi_rw = rw;
1137
	bio->bi_private = peer_req;
1138 1139 1140 1141 1142 1143 1144 1145 1146
	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)) {
1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157
			/* 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;
			}
1158 1159 1160 1161 1162 1163 1164 1165 1166
			goto next_bio;
		}
		ds -= len;
		sector += len >> 9;
		--nr_pages;
	}
	D_ASSERT(page == NULL);
	D_ASSERT(ds == 0);

1167
	atomic_set(&peer_req->pending_bios, n_bios);
1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
	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);
	}
1183
	return err;
1184 1185
}

1186
static void drbd_remove_epoch_entry_interval(struct drbd_conf *mdev,
1187
					     struct drbd_peer_request *peer_req)
1188
{
1189
	struct drbd_interval *i = &peer_req->i;
1190 1191 1192 1193

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

A
Andreas Gruenbacher 已提交
1194
	/* Wake up any processes waiting for this peer request to complete.  */
1195 1196 1197 1198
	if (i->waiting)
		wake_up(&mdev->misc_wait);
}

1199 1200
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packet cmd,
			   unsigned int data_size)
P
Philipp Reisner 已提交
1201
{
1202
	int rv;
1203
	struct p_barrier *p = &mdev->tconn->data.rbuf.barrier;
P
Philipp Reisner 已提交
1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218
	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)
1219
			return true;
1220 1221 1222 1223 1224 1225 1226 1227 1228

		/* 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
1229 1230 1231 1232

	case WO_bdev_flush:
	case WO_drain_io:
		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
1233 1234 1235 1236 1237 1238
		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
1239 1240
		}

1241 1242 1243 1244 1245
		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
1246

1247
		return true;
1248 1249
	default:
		dev_err(DEV, "Strangeness in mdev->write_ordering %d\n", mdev->write_ordering);
1250
		return false;
P
Philipp Reisner 已提交
1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267
	}

	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);

1268
	return true;
P
Philipp Reisner 已提交
1269 1270 1271 1272
}

/* used from receive_RSDataReply (recv_resync_read)
 * and from receive_Data */
1273 1274 1275
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
1276
{
1277
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
1278
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1279
	struct page *page;
1280
	int dgs, ds, rr;
1281 1282
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
1283
	unsigned long *data;
P
Philipp Reisner 已提交
1284

1285 1286
	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
1287 1288

	if (dgs) {
1289
		rr = drbd_recv(mdev->tconn, dig_in, dgs);
P
Philipp Reisner 已提交
1290
		if (rr != dgs) {
1291 1292 1293 1294
			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
1295 1296 1297 1298 1299 1300
			return NULL;
		}
	}

	data_size -= dgs;

1301 1302 1303 1304 1305 1306
	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
1307

1308 1309 1310
	/* even though we trust out peer,
	 * we sometimes have to double check. */
	if (sector + (data_size>>9) > capacity) {
1311 1312
		dev_err(DEV, "request from peer beyond end of local disk: "
			"capacity: %llus < sector: %llus + size: %u\n",
1313 1314 1315 1316 1317
			(unsigned long long)capacity,
			(unsigned long long)sector, data_size);
		return NULL;
	}

P
Philipp Reisner 已提交
1318 1319 1320
	/* 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.  */
1321 1322
	peer_req = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
	if (!peer_req)
P
Philipp Reisner 已提交
1323
		return NULL;
1324

P
Philipp Reisner 已提交
1325
	ds = data_size;
1326
	page = peer_req->pages;
1327 1328
	page_chain_for_each(page) {
		unsigned len = min_t(int, ds, PAGE_SIZE);
1329
		data = kmap(page);
1330
		rr = drbd_recv(mdev->tconn, data, len);
1331
		if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
1332 1333 1334
			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
			data[0] = data[0] ^ (unsigned long)-1;
		}
P
Philipp Reisner 已提交
1335
		kunmap(page);
1336
		if (rr != len) {
1337
			drbd_free_ee(mdev, peer_req);
1338 1339 1340
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data: read %d expected %d\n",
				rr, len);
P
Philipp Reisner 已提交
1341 1342 1343 1344 1345 1346
			return NULL;
		}
		ds -= rr;
	}

	if (dgs) {
1347
		drbd_csum_ee(mdev, mdev->tconn->integrity_r_tfm, peer_req, dig_vv);
P
Philipp Reisner 已提交
1348
		if (memcmp(dig_in, dig_vv, dgs)) {
1349 1350
			dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
				(unsigned long long)sector, data_size);
P
Philipp Reisner 已提交
1351
			drbd_bcast_ee(mdev, "digest failed",
1352 1353
					dgs, dig_in, dig_vv, peer_req);
			drbd_free_ee(mdev, peer_req);
P
Philipp Reisner 已提交
1354 1355 1356 1357
			return NULL;
		}
	}
	mdev->recv_cnt += data_size>>9;
1358
	return peer_req;
P
Philipp Reisner 已提交
1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369
}

/* 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;

1370
	if (!data_size)
1371
		return true;
1372

1373
	page = drbd_pp_alloc(mdev, 1, 1);
P
Philipp Reisner 已提交
1374 1375 1376

	data = kmap(page);
	while (data_size) {
1377
		rr = drbd_recv(mdev->tconn, data, min_t(int, data_size, PAGE_SIZE));
P
Philipp Reisner 已提交
1378 1379
		if (rr != min_t(int, data_size, PAGE_SIZE)) {
			rv = 0;
1380 1381 1382 1383
			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
1384 1385 1386 1387 1388
			break;
		}
		data_size -= rr;
	}
	kunmap(page);
1389
	drbd_pp_free(mdev, page, 0);
P
Philipp Reisner 已提交
1390 1391 1392 1393 1394 1395 1396 1397 1398
	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;
1399 1400
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
P
Philipp Reisner 已提交
1401

1402 1403
	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
1404 1405

	if (dgs) {
1406
		rr = drbd_recv(mdev->tconn, dig_in, dgs);
P
Philipp Reisner 已提交
1407
		if (rr != dgs) {
1408 1409 1410 1411
			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
1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426
			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);
1427
		rr = drbd_recv(mdev->tconn,
P
Philipp Reisner 已提交
1428 1429 1430 1431
			     kmap(bvec->bv_page)+bvec->bv_offset,
			     expect);
		kunmap(bvec->bv_page);
		if (rr != expect) {
1432 1433 1434 1435
			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
1436 1437 1438 1439 1440 1441
			return 0;
		}
		data_size -= rr;
	}

	if (dgs) {
1442
		drbd_csum_bio(mdev, mdev->tconn->integrity_r_tfm, bio, dig_vv);
P
Philipp Reisner 已提交
1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
		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 */
1455
static int e_end_resync_block(struct drbd_work *w, int unused)
P
Philipp Reisner 已提交
1456
{
1457
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
1458
	struct drbd_conf *mdev = w->mdev;
1459
	sector_t sector = peer_req->i.sector;
P
Philipp Reisner 已提交
1460 1461
	int ok;

1462
	D_ASSERT(drbd_interval_empty(&peer_req->i));
P
Philipp Reisner 已提交
1463

1464 1465 1466
	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
1467 1468
	} else {
		/* Record failure to sync */
1469
		drbd_rs_failed_io(mdev, sector, peer_req->i.size);
P
Philipp Reisner 已提交
1470

1471
		ok  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
P
Philipp Reisner 已提交
1472 1473 1474 1475 1476 1477 1478 1479
	}
	dec_unacked(mdev);

	return ok;
}

static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_size) __releases(local)
{
1480
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1481

1482 1483
	peer_req = read_in_block(mdev, ID_SYNCER, sector, data_size);
	if (!peer_req)
1484
		goto fail;
P
Philipp Reisner 已提交
1485 1486 1487 1488 1489 1490 1491

	dec_rs_pending(mdev);

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

1492
	peer_req->w.cb = e_end_resync_block;
1493

1494
	spin_lock_irq(&mdev->tconn->req_lock);
1495
	list_add(&peer_req->w.list, &mdev->sync_ee);
1496
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1497

1498
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1499
	if (drbd_submit_ee(mdev, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
1500
		return true;
P
Philipp Reisner 已提交
1501

1502 1503
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1504
	spin_lock_irq(&mdev->tconn->req_lock);
1505
	list_del(&peer_req->w.list);
1506
	spin_unlock_irq(&mdev->tconn->req_lock);
1507

1508
	drbd_free_ee(mdev, peer_req);
1509 1510
fail:
	put_ldev(mdev);
1511
	return false;
P
Philipp Reisner 已提交
1512 1513
}

1514
static struct drbd_request *
1515 1516
find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
	     sector_t sector, bool missing_ok, const char *func)
1517 1518 1519
{
	struct drbd_request *req;

1520 1521
	/* Request object according to our peer */
	req = (struct drbd_request *)(unsigned long)id;
1522
	if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
1523
		return req;
1524 1525 1526 1527
	if (!missing_ok) {
		dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
			(unsigned long)id, (unsigned long long)sector);
	}
1528 1529 1530
	return NULL;
}

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

	sector = be64_to_cpu(p->sector);

1541
	spin_lock_irq(&mdev->tconn->req_lock);
1542
	req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
1543
	spin_unlock_irq(&mdev->tconn->req_lock);
1544
	if (unlikely(!req))
1545
		return false;
P
Philipp Reisner 已提交
1546

B
Bart Van Assche 已提交
1547
	/* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
P
Philipp Reisner 已提交
1548 1549 1550 1551 1552
	 * 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)
1553
		req_mod(req, DATA_RECEIVED);
P
Philipp Reisner 已提交
1554 1555 1556 1557 1558 1559 1560
	/* 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;
}

1561 1562
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
P
Philipp Reisner 已提交
1563 1564 1565
{
	sector_t sector;
	int ok;
1566
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1567 1568 1569 1570 1571 1572 1573

	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,
1574
		 * or in drbd_endio_sec. */
P
Philipp Reisner 已提交
1575 1576 1577 1578 1579 1580 1581
		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);

1582
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1583 1584
	}

1585 1586
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

P
Philipp Reisner 已提交
1587 1588 1589 1590 1591 1592
	return ok;
}

/* e_end_block() is called via drbd_process_done_ee().
 * this means this function only runs in the asender thread
 */
1593
static int e_end_block(struct drbd_work *w, int cancel)
P
Philipp Reisner 已提交
1594
{
1595
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
1596
	struct drbd_conf *mdev = w->mdev;
1597
	sector_t sector = peer_req->i.sector;
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1598 1599
	int ok = 1, pcmd;

1600
	if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
1601
		if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
P
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1602 1603
			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
				mdev->state.conn <= C_PAUSED_SYNC_T &&
1604
				peer_req->flags & EE_MAY_SET_IN_SYNC) ?
P
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1605
				P_RS_WRITE_ACK : P_WRITE_ACK;
1606
			ok &= drbd_send_ack(mdev, pcmd, peer_req);
P
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1607
			if (pcmd == P_RS_WRITE_ACK)
1608
				drbd_set_in_sync(mdev, sector, peer_req->i.size);
P
Philipp Reisner 已提交
1609
		} else {
1610
			ok  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
P
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1611 1612 1613 1614 1615 1616 1617
			/* 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.  */
1618
	if (mdev->tconn->net_conf->two_primaries) {
1619
		spin_lock_irq(&mdev->tconn->req_lock);
1620 1621
		D_ASSERT(!drbd_interval_empty(&peer_req->i));
		drbd_remove_epoch_entry_interval(mdev, peer_req);
1622
		spin_unlock_irq(&mdev->tconn->req_lock);
1623
	} else
1624
		D_ASSERT(drbd_interval_empty(&peer_req->i));
P
Philipp Reisner 已提交
1625

1626
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + (cancel ? EV_CLEANUP : 0));
P
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1627 1628 1629 1630

	return ok;
}

1631
static int e_send_discard_ack(struct drbd_work *w, int unused)
P
Philipp Reisner 已提交
1632
{
1633
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
1634
	struct drbd_conf *mdev = w->mdev;
P
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1635 1636
	int ok = 1;

1637
	D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
1638
	ok = drbd_send_ack(mdev, P_DISCARD_ACK, peer_req);
P
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1639

1640
	spin_lock_irq(&mdev->tconn->req_lock);
1641 1642
	D_ASSERT(!drbd_interval_empty(&peer_req->i));
	drbd_remove_epoch_entry_interval(mdev, peer_req);
1643
	spin_unlock_irq(&mdev->tconn->req_lock);
P
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1644 1645 1646 1647 1648 1649

	dec_unacked(mdev);

	return ok;
}

1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664
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;
}

1665
static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
1666
{
1667
	unsigned int old_peer_seq;
1668 1669

	spin_lock(&mdev->peer_seq_lock);
1670 1671
	old_peer_seq = mdev->peer_seq;
	mdev->peer_seq = seq_max(mdev->peer_seq, peer_seq);
1672
	spin_unlock(&mdev->peer_seq_lock);
1673
	if (old_peer_seq != peer_seq)
1674 1675 1676
		wake_up(&mdev->seq_wait);
}

P
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1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706
/* 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);
1707
		if (!seq_greater(packet_seq, mdev->peer_seq + 1))
P
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1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729
			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;
}

1730 1731 1732 1733
/* 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)
1734
{
1735 1736 1737 1738
	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);
1739 1740
}

P
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1741
/* mirrored write */
1742 1743
static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
Philipp Reisner 已提交
1744 1745
{
	sector_t sector;
1746
	struct drbd_peer_request *peer_req;
1747
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1748 1749 1750 1751 1752 1753 1754 1755 1756
	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);

1757
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1758 1759 1760 1761 1762 1763
		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),
1764
	 * or in drbd_endio_sec, if we successfully submit the data at
P
Philipp Reisner 已提交
1765 1766 1767
	 * the end of this function. */

	sector = be64_to_cpu(p->sector);
1768 1769
	peer_req = read_in_block(mdev, p->block_id, sector, data_size);
	if (!peer_req) {
P
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1770
		put_ldev(mdev);
1771
		return false;
P
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1772 1773
	}

1774
	peer_req->w.cb = e_end_block;
P
Philipp Reisner 已提交
1775

1776 1777 1778 1779
	dp_flags = be32_to_cpu(p->dp_flags);
	rw |= wire_flags_to_bio(mdev, dp_flags);

	if (dp_flags & DP_MAY_SET_IN_SYNC)
1780
		peer_req->flags |= EE_MAY_SET_IN_SYNC;
1781

P
Philipp Reisner 已提交
1782
	spin_lock(&mdev->epoch_lock);
1783 1784 1785
	peer_req->epoch = mdev->current_epoch;
	atomic_inc(&peer_req->epoch->epoch_size);
	atomic_inc(&peer_req->epoch->active);
P
Philipp Reisner 已提交
1786 1787 1788
	spin_unlock(&mdev->epoch_lock);

	/* I'm the receiver, I do hold a net_cnt reference. */
1789
	if (!mdev->tconn->net_conf->two_primaries) {
1790
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1791 1792 1793
	} else {
		/* don't get the req_lock yet,
		 * we may sleep in drbd_wait_peer_seq */
1794
		const int size = peer_req->i.size;
1795
		const int discard = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
P
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1796 1797 1798
		DEFINE_WAIT(wait);
		int first;

1799
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
P
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1800 1801 1802 1803

		/* conflict detection and handling:
		 * 1. wait on the sequence number,
		 *    in case this data packet overtook ACK packets.
1804
		 * 2. check for conflicting write requests.
P
Philipp Reisner 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831
		 *
		 * 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;

1832
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1833 1834 1835

		first = 1;
		for (;;) {
1836
			struct drbd_interval *i;
P
Philipp Reisner 已提交
1837 1838 1839 1840
			int have_unacked = 0;
			int have_conflict = 0;
			prepare_to_wait(&mdev->misc_wait, &wait,
				TASK_INTERRUPTIBLE);
1841 1842 1843 1844 1845 1846

			i = drbd_find_overlap(&mdev->write_requests, sector, size);
			if (i) {
				/* only ALERT on first iteration,
				 * we may be woken up early... */
				if (first)
1847
					dev_alert(DEV, "%s[%u] Concurrent %s write detected!"
1848 1849
					      "	new: %llus +%u; pending: %llus +%u\n",
					      current->comm, current->pid,
1850
					      i->local ? "local" : "remote",
1851
					      (unsigned long long)sector, size,
1852 1853 1854 1855 1856 1857 1858 1859 1860
					      (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;
				}
1861
				++have_conflict;
P
Philipp Reisner 已提交
1862 1863 1864 1865 1866 1867 1868 1869 1870
			}
			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);
1871 1872
				peer_req->w.cb = e_send_discard_ack;
				list_add_tail(&peer_req->w.list, &mdev->done_ee);
P
Philipp Reisner 已提交
1873

1874
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1875 1876 1877 1878 1879

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

				put_ldev(mdev);
1880
				wake_asender(mdev->tconn);
P
Philipp Reisner 已提交
1881
				finish_wait(&mdev->misc_wait, &wait);
1882
				return true;
P
Philipp Reisner 已提交
1883 1884 1885
			}

			if (signal_pending(current)) {
1886
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1887 1888 1889 1890
				finish_wait(&mdev->misc_wait, &wait);
				goto out_interrupted;
			}

1891
			/* Indicate to wake up mdev->misc_wait upon completion.  */
1892
			i->waiting = true;
1893

1894
			spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1895 1896 1897 1898 1899 1900 1901 1902 1903 1904
			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();
1905
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1906 1907
		}
		finish_wait(&mdev->misc_wait, &wait);
1908

1909
		drbd_insert_interval(&mdev->write_requests, &peer_req->i);
P
Philipp Reisner 已提交
1910 1911
	}

1912
	list_add(&peer_req->w.list, &mdev->active_ee);
1913
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1914

1915
	switch (mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
1916 1917 1918 1919 1920 1921 1922 1923
	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 */
1924
		drbd_send_ack(mdev, P_RECV_ACK, peer_req);
P
Philipp Reisner 已提交
1925 1926 1927 1928 1929 1930
		break;
	case DRBD_PROT_A:
		/* nothing to do */
		break;
	}

1931
	if (mdev->state.pdsk < D_INCONSISTENT) {
P
Philipp Reisner 已提交
1932
		/* In case we have the only disk of the cluster, */
1933 1934 1935 1936
		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
1937 1938
	}

1939
	if (drbd_submit_ee(mdev, peer_req, rw, DRBD_FAULT_DT_WR) == 0)
1940
		return true;
P
Philipp Reisner 已提交
1941

1942 1943
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1944
	spin_lock_irq(&mdev->tconn->req_lock);
1945 1946
	list_del(&peer_req->w.list);
	drbd_remove_epoch_entry_interval(mdev, peer_req);
1947
	spin_unlock_irq(&mdev->tconn->req_lock);
1948 1949
	if (peer_req->flags & EE_CALL_AL_COMPLETE_IO)
		drbd_al_complete_io(mdev, peer_req->i.sector);
1950

P
Philipp Reisner 已提交
1951
out_interrupted:
1952
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + EV_CLEANUP);
P
Philipp Reisner 已提交
1953
	put_ldev(mdev);
1954
	drbd_free_ee(mdev, peer_req);
1955
	return false;
P
Philipp Reisner 已提交
1956 1957
}

1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968
/* 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.
 */
1969
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
1970 1971 1972
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
1973
	struct lc_element *tmp;
1974 1975 1976 1977 1978 1979 1980
	int curr_events;
	int throttle = 0;

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

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
	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);

1993 1994 1995
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
1996

1997 1998 1999 2000 2001 2002 2003 2004
	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. */
2005 2006 2007 2008 2009 2010
		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;
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

		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;
}


2025 2026
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int digest_size)
P
Philipp Reisner 已提交
2027 2028 2029
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
2030
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
2031
	struct digest_info *di = NULL;
2032
	int size, verb;
P
Philipp Reisner 已提交
2033
	unsigned int fault_type;
2034
	struct p_block_req *p =	&mdev->tconn->data.rbuf.block_req;
P
Philipp Reisner 已提交
2035 2036 2037 2038

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

2039
	if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
P
Philipp Reisner 已提交
2040 2041
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2042
		return false;
P
Philipp Reisner 已提交
2043 2044 2045 2046
	}
	if (sector + (size>>9) > capacity) {
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2047
		return false;
P
Philipp Reisner 已提交
2048 2049 2050
	}

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070
		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
2071 2072
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
2073

L
Lars Ellenberg 已提交
2074 2075
		/* drain possibly payload */
		return drbd_drain_block(mdev, digest_size);
P
Philipp Reisner 已提交
2076 2077 2078 2079 2080
	}

	/* 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.  */
2081 2082
	peer_req = drbd_alloc_ee(mdev, p->block_id, sector, size, GFP_NOIO);
	if (!peer_req) {
P
Philipp Reisner 已提交
2083
		put_ldev(mdev);
2084
		return false;
P
Philipp Reisner 已提交
2085 2086
	}

2087
	switch (cmd) {
P
Philipp Reisner 已提交
2088
	case P_DATA_REQUEST:
2089
		peer_req->w.cb = w_e_end_data_req;
P
Philipp Reisner 已提交
2090
		fault_type = DRBD_FAULT_DT_RD;
2091 2092 2093
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
Philipp Reisner 已提交
2094
	case P_RS_DATA_REQUEST:
2095
		peer_req->w.cb = w_e_end_rsdata_req;
P
Philipp Reisner 已提交
2096
		fault_type = DRBD_FAULT_RS_RD;
2097 2098
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
P
Philipp Reisner 已提交
2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110
		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));

2111 2112
		peer_req->digest = di;
		peer_req->flags |= EE_HAS_DIGEST;
2113

2114
		if (drbd_recv(mdev->tconn, di->digest, digest_size) != digest_size)
P
Philipp Reisner 已提交
2115 2116
			goto out_free_e;

2117
		if (cmd == P_CSUM_RS_REQUEST) {
2118
			D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
2119
			peer_req->w.cb = w_e_end_csum_rs_req;
2120 2121
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2122
		} else if (cmd == P_OV_REPLY) {
2123 2124
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
2125
			peer_req->w.cb = w_e_end_ov_reply;
P
Philipp Reisner 已提交
2126
			dec_rs_pending(mdev);
2127 2128 2129
			/* 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
2130 2131 2132 2133 2134
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
2135
		    mdev->tconn->agreed_pro_version >= 90) {
2136 2137
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2138 2139
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2140 2141
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2142 2143 2144 2145
			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
2146 2147 2148
			dev_info(DEV, "Online Verify start sector: %llu\n",
					(unsigned long long)sector);
		}
2149
		peer_req->w.cb = w_e_end_ov_req;
P
Philipp Reisner 已提交
2150 2151 2152 2153 2154
		fault_type = DRBD_FAULT_RS_RD;
		break;

	default:
		dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
2155
		    cmdname(cmd));
P
Philipp Reisner 已提交
2156
		fault_type = DRBD_FAULT_MAX;
2157
		goto out_free_e;
P
Philipp Reisner 已提交
2158 2159
	}

2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181
	/* 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.
	 */
2182 2183 2184
	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))
2185
		goto out_free_e;
P
Philipp Reisner 已提交
2186

2187 2188 2189
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2190
submit:
P
Philipp Reisner 已提交
2191
	inc_unacked(mdev);
2192
	spin_lock_irq(&mdev->tconn->req_lock);
2193
	list_add_tail(&peer_req->w.list, &mdev->read_ee);
2194
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2195

2196
	if (drbd_submit_ee(mdev, peer_req, READ, fault_type) == 0)
2197
		return true;
P
Philipp Reisner 已提交
2198

2199 2200
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2201
	spin_lock_irq(&mdev->tconn->req_lock);
2202
	list_del(&peer_req->w.list);
2203
	spin_unlock_irq(&mdev->tconn->req_lock);
2204 2205
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
Philipp Reisner 已提交
2206 2207
out_free_e:
	put_ldev(mdev);
2208
	drbd_free_ee(mdev, peer_req);
2209
	return false;
P
Philipp Reisner 已提交
2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222
}

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;

2223
	switch (mdev->tconn->net_conf->after_sb_0p) {
P
Philipp Reisner 已提交
2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250
	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
2251
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
P
Philipp Reisner 已提交
2252 2253 2254
		     "Using discard-least-changes instead\n");
	case ASB_DISCARD_ZERO_CHG:
		if (ch_peer == 0 && ch_self == 0) {
2255
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2256 2257 2258 2259 2260 2261
				? -1 : 1;
			break;
		} else {
			if (ch_peer == 0) { rv =  1; break; }
			if (ch_self == 0) { rv = -1; break; }
		}
2262
		if (mdev->tconn->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
P
Philipp Reisner 已提交
2263 2264 2265 2266 2267 2268 2269 2270
			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. */
2271
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285
				? -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)
{
2286
	int hg, rv = -100;
P
Philipp Reisner 已提交
2287

2288
	switch (mdev->tconn->net_conf->after_sb_1p) {
P
Philipp Reisner 已提交
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312
	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) {
2313 2314 2315
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
P
Philipp Reisner 已提交
2316 2317 2318
			 /* 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. */
2319 2320
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334
				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)
{
2335
	int hg, rv = -100;
P
Philipp Reisner 已提交
2336

2337
	switch (mdev->tconn->net_conf->after_sb_2p) {
P
Philipp Reisner 已提交
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354
	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) {
2355 2356
			enum drbd_state_rv rv2;

P
Philipp Reisner 已提交
2357 2358 2359
			 /* 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. */
2360 2361
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
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 2392 2393 2394 2395 2396 2397 2398 2399
				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
2400 2401
-1091   requires proto 91
-1096   requires proto 96
P
Philipp Reisner 已提交
2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429
 */
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) {

2430
			if (mdev->tconn->agreed_pro_version < 91)
2431
				return -1091;
P
Philipp Reisner 已提交
2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450

			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) {

2451
			if (mdev->tconn->agreed_pro_version < 91)
2452
				return -1091;
P
Philipp Reisner 已提交
2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483

			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 */
2484
			dc = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
P
Philipp Reisner 已提交
2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496
			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) {
2497
		if (mdev->tconn->agreed_pro_version < 96 ?
2498 2499 2500
		    (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
2501 2502 2503
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

2504
			if (mdev->tconn->agreed_pro_version < 91)
2505
				return -1091;
P
Philipp Reisner 已提交
2506 2507 2508

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2509 2510 2511 2512

			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
2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533
			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) {
2534
		if (mdev->tconn->agreed_pro_version < 96 ?
2535 2536 2537
		    (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
2538 2539 2540
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

2541
			if (mdev->tconn->agreed_pro_version < 91)
2542
				return -1091;
P
Philipp Reisner 已提交
2543 2544 2545 2546

			_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]);

2547
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
Philipp Reisner 已提交
2548 2549 2550 2551 2552 2553 2554 2555 2556
			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;
2557
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
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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 2602 2603 2604 2605 2606 2607 2608 2609
	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;
	}
2610 2611
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
Philipp Reisner 已提交
2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624
		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");
	}

2625 2626 2627
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

2628
	if (hg == 100 || (hg == -100 && mdev->tconn->net_conf->always_asbp)) {
P
Philipp Reisner 已提交
2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656
		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) {
2657
		if (mdev->tconn->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2658
			hg = -1;
2659
		if (!mdev->tconn->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2660 2661 2662 2663 2664 2665 2666 2667 2668
			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) {
2669 2670 2671 2672
		/* 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... */
2673
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684
		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) {
2685
		switch (mdev->tconn->net_conf->rr_conflict) {
P
Philipp Reisner 已提交
2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697
		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");
		}
	}

2698
	if (mdev->tconn->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
2699 2700 2701 2702 2703 2704 2705 2706 2707
		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
2708 2709
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2710 2711
		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
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 2743 2744 2745 2746 2747 2748 2749 2750
			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;
}

2751 2752
static int receive_protocol(struct drbd_conf *mdev, enum drbd_packet cmd,
			    unsigned int data_size)
P
Philipp Reisner 已提交
2753
{
2754
	struct p_protocol *p = &mdev->tconn->data.rbuf.protocol;
P
Philipp Reisner 已提交
2755
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2756
	int p_want_lose, p_two_primaries, cf;
P
Philipp Reisner 已提交
2757 2758 2759 2760 2761 2762 2763
	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);
2764 2765 2766 2767 2768 2769 2770
	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
2771

2772
	if (p_proto != mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
2773 2774 2775 2776
		dev_err(DEV, "incompatible communication protocols\n");
		goto disconnect;
	}

2777
	if (cmp_after_sb(p_after_sb_0p, mdev->tconn->net_conf->after_sb_0p)) {
P
Philipp Reisner 已提交
2778 2779 2780 2781
		dev_err(DEV, "incompatible after-sb-0pri settings\n");
		goto disconnect;
	}

2782
	if (cmp_after_sb(p_after_sb_1p, mdev->tconn->net_conf->after_sb_1p)) {
P
Philipp Reisner 已提交
2783 2784 2785 2786
		dev_err(DEV, "incompatible after-sb-1pri settings\n");
		goto disconnect;
	}

2787
	if (cmp_after_sb(p_after_sb_2p, mdev->tconn->net_conf->after_sb_2p)) {
P
Philipp Reisner 已提交
2788 2789 2790 2791
		dev_err(DEV, "incompatible after-sb-2pri settings\n");
		goto disconnect;
	}

2792
	if (p_want_lose && mdev->tconn->net_conf->want_lose) {
P
Philipp Reisner 已提交
2793 2794 2795 2796
		dev_err(DEV, "both sides have the 'want_lose' flag set\n");
		goto disconnect;
	}

2797
	if (p_two_primaries != mdev->tconn->net_conf->two_primaries) {
P
Philipp Reisner 已提交
2798 2799 2800 2801
		dev_err(DEV, "incompatible setting of the two-primaries options\n");
		goto disconnect;
	}

2802
	if (mdev->tconn->agreed_pro_version >= 87) {
2803
		unsigned char *my_alg = mdev->tconn->net_conf->integrity_alg;
P
Philipp Reisner 已提交
2804

2805
		if (drbd_recv(mdev->tconn, p_integrity_alg, data_size) != data_size)
2806
			return false;
P
Philipp Reisner 已提交
2807 2808 2809 2810 2811 2812 2813 2814 2815 2816

		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>");
	}

2817
	return true;
P
Philipp Reisner 已提交
2818 2819 2820

disconnect:
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2821
	return false;
P
Philipp Reisner 已提交
2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850
}

/* 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;
}

2851 2852
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int packet_size)
P
Philipp Reisner 已提交
2853
{
2854
	int ok = true;
2855
	struct p_rs_param_95 *p = &mdev->tconn->data.rbuf.rs_param_95;
P
Philipp Reisner 已提交
2856 2857 2858
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
2859
	const int apv = mdev->tconn->agreed_pro_version;
2860 2861
	int *rs_plan_s = NULL;
	int fifo_size = 0;
P
Philipp Reisner 已提交
2862 2863 2864 2865

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2866 2867
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2868

2869
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2870
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2871
		    packet_size, exp_max_sz);
2872
		return false;
P
Philipp Reisner 已提交
2873 2874 2875
	}

	if (apv <= 88) {
2876
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header);
2877
		data_size   = packet_size  - header_size;
2878
	} else if (apv <= 94) {
2879
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header);
2880
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2881
		D_ASSERT(data_size == 0);
2882
	} else {
2883
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header);
2884
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2885 2886 2887 2888 2889 2890
		D_ASSERT(data_size == 0);
	}

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

2891
	if (drbd_recv(mdev->tconn, &p->head.payload, header_size) != header_size)
2892
		return false;
P
Philipp Reisner 已提交
2893 2894 2895 2896 2897 2898 2899 2900 2901

	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);
2902
				return false;
P
Philipp Reisner 已提交
2903 2904
			}

2905
			if (drbd_recv(mdev->tconn, p->verify_alg, data_size) != data_size)
2906
				return false;
P
Philipp Reisner 已提交
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 2942 2943 2944 2945 2946 2947 2948 2949

			/* 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;
			}
		}

2950 2951 2952 2953 2954 2955
		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);
2956 2957 2958 2959 2960 2961 2962 2963 2964

			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;
				}
			}
2965
		}
P
Philipp Reisner 已提交
2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982

		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);
		}
2983 2984 2985 2986 2987 2988
		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
2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999
		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));
3000
	return false;
P
Philipp Reisner 已提交
3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015
}

/* 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);
}

3016 3017
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3018
{
3019
	struct p_sizes *p = &mdev->tconn->data.rbuf.sizes;
P
Philipp Reisner 已提交
3020 3021 3022
	enum determine_dev_size dd = unchanged;
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
3023
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
3024 3025 3026 3027 3028 3029 3030

	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));
3031
		return false;
P
Philipp Reisner 已提交
3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059
	}

	/* 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. */
3060
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
3061 3062 3063 3064 3065 3066 3067
		   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);
3068
			return false;
P
Philipp Reisner 已提交
3069 3070 3071 3072
		}
		put_ldev(mdev);
	}

3073
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
3074
	if (get_ldev(mdev)) {
B
Bart Van Assche 已提交
3075
		dd = drbd_determine_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
3076 3077
		put_ldev(mdev);
		if (dd == dev_size_error)
3078
			return false;
P
Philipp Reisner 已提交
3079 3080 3081 3082 3083 3084
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

3085 3086 3087
	mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
	drbd_reconsider_max_bio_size(mdev);

P
Philipp Reisner 已提交
3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101
	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... */
3102
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3103 3104 3105 3106
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3107 3108 3109 3110 3111 3112
			    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
3113 3114 3115 3116
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3117
	return true;
P
Philipp Reisner 已提交
3118 3119
}

3120 3121
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3122
{
3123
	struct p_uuids *p = &mdev->tconn->data.rbuf.uuids;
P
Philipp Reisner 已提交
3124
	u64 *p_uuid;
3125
	int i, updated_uuids = 0;
P
Philipp Reisner 已提交
3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141

	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));
3142
		return false;
P
Philipp Reisner 已提交
3143 3144 3145 3146 3147
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
3148
			mdev->tconn->agreed_pro_version >= 90 &&
P
Philipp Reisner 已提交
3149 3150 3151 3152 3153
			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,
3154 3155
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3156 3157 3158 3159 3160
			_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);
3161
			updated_uuids = 1;
P
Philipp Reisner 已提交
3162 3163
		}
		put_ldev(mdev);
3164 3165 3166 3167
	} 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. */
3168
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3169 3170 3171 3172 3173 3174
	}

	/* 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... */
3175 3176
	mutex_lock(mdev->state_mutex);
	mutex_unlock(mdev->state_mutex);
P
Philipp Reisner 已提交
3177
	if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
3178 3179 3180 3181
		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
3182

3183
	return true;
P
Philipp Reisner 已提交
3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215
}

/**
 * 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;
}

3216 3217
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3218
{
3219
	struct p_req_state *p = &mdev->tconn->data.rbuf.req_state;
P
Philipp Reisner 已提交
3220
	union drbd_state mask, val;
3221
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3222 3223 3224 3225

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

3226
	if (test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags) &&
3227
	    mutex_is_locked(mdev->state_mutex)) {
P
Philipp Reisner 已提交
3228
		drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
3229
		return true;
P
Philipp Reisner 已提交
3230 3231 3232 3233 3234 3235 3236 3237 3238 3239
	}

	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);

3240
	return true;
P
Philipp Reisner 已提交
3241 3242
}

3243 3244
static int receive_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3245
{
3246
	struct p_state *p = &mdev->tconn->data.rbuf.state;
3247
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3248
	enum drbd_disk_state real_peer_disk;
3249
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3250 3251 3252 3253 3254 3255 3256 3257 3258 3259
	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));
	}

3260
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3261
 retry:
3262
	os = ns = mdev->state;
3263
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3264

3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285
	/* 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);
3286
			return true;
3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298
		}
	}

	/* 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;

3299 3300
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3301

3302 3303 3304
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3305 3306 3307 3308 3309
	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 */
3310
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3311 3312
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3313
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3314
		       (peer_state.disk == D_NEGOTIATING ||
3315
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3316 3317 3318 3319 3320
		/* 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" */
3321
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3322 3323 3324 3325
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3326
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3327 3328

		put_ldev(mdev);
3329 3330
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3331
			if (mdev->state.disk == D_NEGOTIATING) {
3332
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3333 3334 3335
			} 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;
3336
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3337
			} else {
3338
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
3339
					return false;
3340
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
P
Philipp Reisner 已提交
3341
				drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3342
				return false;
P
Philipp Reisner 已提交
3343 3344 3345 3346
			}
		}
	}

3347
	spin_lock_irq(&mdev->tconn->req_lock);
3348
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3349 3350 3351 3352 3353
		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);
3354
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3355
		ns.disk = mdev->new_state_tmp.disk;
3356 3357
	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 &&
3358
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
3359
		/* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
3360
		   for temporal network outages! */
3361
		spin_unlock_irq(&mdev->tconn->req_lock);
3362 3363 3364 3365 3366
		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));
3367
		return false;
3368
	}
3369
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3370
	ns = mdev->state;
3371
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3372 3373 3374

	if (rv < SS_SUCCESS) {
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3375
		return false;
P
Philipp Reisner 已提交
3376 3377
	}

3378 3379
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3380 3381 3382 3383 3384 3385 3386 3387 3388
		    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);
		}
	}

3389
	mdev->tconn->net_conf->want_lose = 0;
P
Philipp Reisner 已提交
3390 3391 3392

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

3393
	return true;
P
Philipp Reisner 已提交
3394 3395
}

3396 3397
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3398
{
3399
	struct p_rs_uuid *p = &mdev->tconn->data.rbuf.rs_uuid;
P
Philipp Reisner 已提交
3400 3401 3402

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3403
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414
		   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);

3415
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3416 3417 3418 3419 3420 3421
		drbd_start_resync(mdev, C_SYNC_TARGET);

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

3422
	return true;
P
Philipp Reisner 已提交
3423 3424
}

3425 3426 3427 3428 3429 3430 3431
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3432 3433
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
3434 3435 3436
{
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3437
	int err;
P
Philipp Reisner 已提交
3438

3439 3440
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3441
		return -EIO;
P
Philipp Reisner 已提交
3442 3443
	}
	if (want == 0)
3444
		return 0;
3445
	err = drbd_recv(mdev->tconn, buffer, want);
3446 3447 3448 3449 3450
	if (err != want) {
		if (err >= 0)
			err = -EIO;
		return err;
	}
P
Philipp Reisner 已提交
3451 3452 3453 3454 3455 3456 3457 3458

	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;

3459
	return 1;
P
Philipp Reisner 已提交
3460 3461
}

3462 3463 3464 3465 3466 3467 3468
/**
 * 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
3469 3470
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3471 3472
		 struct bm_xfer_ctx *c,
		 unsigned int len)
P
Philipp Reisner 已提交
3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487
{
	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)
3488
		return -EIO;
P
Philipp Reisner 已提交
3489 3490 3491 3492

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3493
			return -EIO;
P
Philipp Reisner 已提交
3494 3495 3496 3497 3498

		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);
3499
				return -EIO;
P
Philipp Reisner 已提交
3500 3501 3502 3503 3504 3505 3506 3507 3508
			}
			_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);
3509
			return -EIO;
P
Philipp Reisner 已提交
3510 3511 3512 3513 3514 3515
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3516
			return -EIO;
P
Philipp Reisner 已提交
3517 3518 3519 3520 3521 3522 3523
		look_ahead |= tmp << have;
		have += bits;
	}

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

3524
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3525 3526
}

3527 3528 3529 3530 3531 3532 3533
/**
 * 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
3534 3535
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3536 3537
		struct bm_xfer_ctx *c,
		unsigned int len)
P
Philipp Reisner 已提交
3538 3539
{
	if (DCBP_get_code(p) == RLE_VLI_Bits)
3540
		return recv_bm_rle_bits(mdev, p, c, len);
P
Philipp Reisner 已提交
3541 3542 3543 3544 3545 3546 3547

	/* 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));
3548
	return -EIO;
P
Philipp Reisner 已提交
3549 3550 3551 3552 3553 3554
}

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" */
3555
	unsigned plain = sizeof(struct p_header) *
P
Philipp Reisner 已提交
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 3584 3585 3586 3587 3588 3589 3590 3591 3592
		((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. */
3593 3594
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
			  unsigned int data_size)
P
Philipp Reisner 已提交
3595 3596 3597
{
	struct bm_xfer_ctx c;
	void *buffer;
3598
	int err;
3599
	int ok = false;
3600
	struct p_header *h = &mdev->tconn->data.rbuf.header;
3601
	struct packet_info pi;
P
Philipp Reisner 已提交
3602

3603 3604 3605
	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
3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619

	/* 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),
	};

3620
	for(;;) {
3621
		if (cmd == P_BITMAP) {
3622
			err = receive_bitmap_plain(mdev, data_size, buffer, &c);
3623
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3624 3625 3626 3627
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3628
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3629 3630 3631 3632 3633 3634
				dev_err(DEV, "ReportCBitmap packet too large\n");
				goto out;
			}
			/* use the page buff */
			p = buffer;
			memcpy(p, h, sizeof(*h));
3635
			if (drbd_recv(mdev->tconn, p->head.payload, data_size) != data_size)
P
Philipp Reisner 已提交
3636
				goto out;
3637 3638
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3639
				goto out;
P
Philipp Reisner 已提交
3640
			}
3641
			err = decode_bitmap_c(mdev, p, &c, data_size);
P
Philipp Reisner 已提交
3642
		} else {
3643
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
P
Philipp Reisner 已提交
3644 3645 3646
			goto out;
		}

3647
		c.packets[cmd == P_BITMAP]++;
3648
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header) + data_size;
P
Philipp Reisner 已提交
3649

3650 3651 3652
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3653
			break;
3654
		}
3655
		if (!drbd_recv_header(mdev->tconn, &pi))
P
Philipp Reisner 已提交
3656
			goto out;
3657 3658
		cmd = pi.cmd;
		data_size = pi.size;
3659
	}
P
Philipp Reisner 已提交
3660 3661 3662 3663

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

	if (mdev->state.conn == C_WF_BITMAP_T) {
3664 3665
		enum drbd_state_rv rv;

P
Philipp Reisner 已提交
3666 3667 3668 3669
		ok = !drbd_send_bitmap(mdev);
		if (!ok)
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3670 3671
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3672 3673 3674 3675 3676 3677 3678
	} 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));
	}

3679
	ok = true;
P
Philipp Reisner 已提交
3680
 out:
3681
	drbd_bm_unlock(mdev);
P
Philipp Reisner 已提交
3682 3683 3684 3685 3686 3687
	if (ok && mdev->state.conn == C_WF_BITMAP_S)
		drbd_start_resync(mdev, C_SYNC_SOURCE);
	free_page((unsigned long) buffer);
	return ok;
}

3688 3689
static int receive_skip(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
Philipp Reisner 已提交
3690 3691 3692 3693 3694
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3695 3696
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);
P
Philipp Reisner 已提交
3697

3698
	size = data_size;
P
Philipp Reisner 已提交
3699 3700
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
3701
		r = drbd_recv(mdev->tconn, sink, want);
3702 3703
		if (!expect(r > 0))
			break;
P
Philipp Reisner 已提交
3704 3705 3706 3707 3708
		size -= r;
	}
	return size == 0;
}

3709 3710
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packet cmd,
				unsigned int data_size)
3711
{
3712 3713
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
3714
	drbd_tcp_quickack(mdev->tconn->data.socket);
3715

3716
	return true;
3717 3718
}

3719 3720
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
3721
{
3722
	struct p_block_desc *p = &mdev->tconn->data.rbuf.block_desc;
3723

3724 3725 3726 3727 3728 3729 3730 3731 3732 3733
	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));
	}

3734 3735
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3736
	return true;
3737 3738
}

3739 3740
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packet cmd,
				  unsigned int to_receive);
3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752

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 } ,
3753 3754 3755
	[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 },
3756 3757
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
3758 3759
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header), receive_SyncParam },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header), receive_SyncParam },
3760 3761 3762 3763 3764 3765 3766 3767 3768 3769
	[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 },
3770
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
P
Philipp Reisner 已提交
3771 3772
	/* anything missing from this table is in
	 * the asender_tbl, see get_asender_cmd */
3773
	[P_MAX_CMD]	    = { 0, 0, NULL },
P
Philipp Reisner 已提交
3774 3775
};

3776
/* All handler functions that expect a sub-header get that sub-heder in
3777
   mdev->tconn->data.rbuf.header.head.payload.
3778

3779
   Usually in mdev->tconn->data.rbuf.header.head the callback can find the usual
3780 3781
   p_header, but they may not rely on that. Since there is also p_header95 !
 */
P
Philipp Reisner 已提交
3782

3783
static void drbdd(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3784
{
3785
	struct p_header *header = &tconn->data.rbuf.header;
3786
	struct packet_info pi;
3787 3788
	size_t shs; /* sub header size */
	int rv;
P
Philipp Reisner 已提交
3789

3790 3791 3792
	while (get_t_state(&tconn->receiver) == RUNNING) {
		drbd_thread_current_set_cpu(&tconn->receiver);
		if (!drbd_recv_header(tconn, &pi))
3793
			goto err_out;
P
Philipp Reisner 已提交
3794

3795
		if (unlikely(pi.cmd >= P_MAX_CMD || !drbd_cmd_handler[pi.cmd].function)) {
3796
			conn_err(tconn, "unknown packet type %d, l: %d!\n", pi.cmd, pi.size);
3797
			goto err_out;
3798
		}
P
Philipp Reisner 已提交
3799

3800 3801
		shs = drbd_cmd_handler[pi.cmd].pkt_size - sizeof(struct p_header);
		if (pi.size - shs > 0 && !drbd_cmd_handler[pi.cmd].expect_payload) {
3802
			conn_err(tconn, "No payload expected %s l:%d\n", cmdname(pi.cmd), pi.size);
3803
			goto err_out;
P
Philipp Reisner 已提交
3804 3805
		}

3806
		if (shs) {
3807
			rv = drbd_recv(tconn, &header->payload, shs);
3808
			if (unlikely(rv != shs)) {
3809
				if (!signal_pending(current))
3810
					conn_warn(tconn, "short read while reading sub header: rv=%d\n", rv);
3811 3812 3813 3814
				goto err_out;
			}
		}

3815
		rv = drbd_cmd_handler[pi.cmd].function(vnr_to_mdev(tconn, pi.vnr), pi.cmd, pi.size - shs);
P
Philipp Reisner 已提交
3816

3817
		if (unlikely(!rv)) {
3818
			conn_err(tconn, "error receiving %s, l: %d!\n",
3819
			    cmdname(pi.cmd), pi.size);
3820
			goto err_out;
P
Philipp Reisner 已提交
3821 3822 3823
		}
	}

3824 3825
	if (0) {
	err_out:
3826
		conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
3827
	}
P
Philipp Reisner 已提交
3828 3829
}

3830
void drbd_flush_workqueue(struct drbd_conf *mdev)
P
Philipp Reisner 已提交
3831 3832 3833 3834
{
	struct drbd_wq_barrier barr;

	barr.w.cb = w_prev_work_done;
3835
	barr.w.mdev = mdev;
P
Philipp Reisner 已提交
3836
	init_completion(&barr.done);
3837
	drbd_queue_work(&mdev->tconn->data.work, &barr.w);
P
Philipp Reisner 已提交
3838 3839 3840
	wait_for_completion(&barr.done);
}

3841
static void drbd_disconnect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3842
{
3843
	enum drbd_conns oc;
P
Philipp Reisner 已提交
3844 3845
	int rv = SS_UNKNOWN_ERROR;

3846
	if (tconn->cstate == C_STANDALONE)
P
Philipp Reisner 已提交
3847 3848 3849
		return;

	/* asender does not clean up anything. it must not interfere, either */
3850 3851 3852 3853 3854 3855 3856 3857
	drbd_thread_stop(&tconn->asender);
	drbd_free_sock(tconn);

	idr_for_each(&tconn->volumes, drbd_disconnected, tconn);

	conn_info(tconn, "Connection closed\n");

	spin_lock_irq(&tconn->req_lock);
3858 3859 3860 3861
	oc = tconn->cstate;
	if (oc >= C_UNCONNECTED)
		rv = _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);

3862 3863
	spin_unlock_irq(&tconn->req_lock);

3864
	if (oc == C_DISCONNECTING) {
3865 3866 3867 3868 3869 3870 3871
		wait_event(tconn->net_cnt_wait, atomic_read(&tconn->net_cnt) == 0);

		crypto_free_hash(tconn->cram_hmac_tfm);
		tconn->cram_hmac_tfm = NULL;

		kfree(tconn->net_conf);
		tconn->net_conf = NULL;
3872
		conn_request_state(tconn, NS(conn, C_STANDALONE), CS_VERBOSE);
3873 3874 3875 3876 3877 3878 3879 3880
	}
}

static int drbd_disconnected(int vnr, void *p, void *data)
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
	enum drbd_fencing_p fp;
	unsigned int i;
P
Philipp Reisner 已提交
3881

3882
	/* wait for current activity to cease. */
3883
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3884 3885 3886
	_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);
3887
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904

	/* 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);

3905 3906
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
3907 3908 3909 3910 3911 3912 3913
	/* 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" */
3914
	drbd_flush_workqueue(mdev);
P
Philipp Reisner 已提交
3915 3916 3917 3918 3919 3920 3921 3922

	/* 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;

3923
	if (!is_susp(mdev->state))
P
Philipp Reisner 已提交
3924 3925 3926 3927 3928 3929 3930 3931 3932 3933
		tl_clear(mdev);

	drbd_md_sync(mdev);

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

3934 3935
	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
3936

3937 3938 3939 3940
	/* 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
3941 3942 3943 3944 3945 3946 3947 3948 3949 3950
	/* 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);
3951 3952 3953
	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
3954 3955
	i = atomic_read(&mdev->pp_in_use);
	if (i)
3956
		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
P
Philipp Reisner 已提交
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));
3966 3967

	return 0;
P
Philipp Reisner 已提交
3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978
}

/*
 * 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.
 */
3979
static int drbd_send_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3980
{
3981
	/* ASSERT current == mdev->tconn->receiver ... */
3982
	struct p_handshake *p = &tconn->data.sbuf.handshake;
P
Philipp Reisner 已提交
3983 3984
	int ok;

3985 3986
	if (mutex_lock_interruptible(&tconn->data.mutex)) {
		conn_err(tconn, "interrupted during initial handshake\n");
P
Philipp Reisner 已提交
3987 3988 3989
		return 0; /* interrupted. not ok. */
	}

3990 3991
	if (tconn->data.socket == NULL) {
		mutex_unlock(&tconn->data.mutex);
P
Philipp Reisner 已提交
3992 3993 3994 3995 3996 3997
		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);
3998 3999 4000
	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
4001 4002 4003 4004 4005 4006 4007 4008 4009 4010
	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.
 */
4011
static int drbd_do_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4012
{
4013 4014
	/* ASSERT current == tconn->receiver ... */
	struct p_handshake *p = &tconn->data.rbuf.handshake;
4015
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
4016
	struct packet_info pi;
P
Philipp Reisner 已提交
4017 4018
	int rv;

4019
	rv = drbd_send_handshake(tconn);
P
Philipp Reisner 已提交
4020 4021 4022
	if (!rv)
		return 0;

4023
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4024 4025 4026
	if (!rv)
		return 0;

4027
	if (pi.cmd != P_HAND_SHAKE) {
4028
		conn_err(tconn, "expected HandShake packet, received: %s (0x%04x)\n",
4029
		     cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4030 4031 4032
		return -1;
	}

4033
	if (pi.size != expect) {
4034
		conn_err(tconn, "expected HandShake length: %u, received: %u\n",
4035
		     expect, pi.size);
P
Philipp Reisner 已提交
4036 4037 4038
		return -1;
	}

4039
	rv = drbd_recv(tconn, &p->head.payload, expect);
P
Philipp Reisner 已提交
4040 4041

	if (rv != expect) {
4042
		if (!signal_pending(current))
4043
			conn_warn(tconn, "short read receiving handshake packet: l=%u\n", rv);
P
Philipp Reisner 已提交
4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055
		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;

4056
	tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
P
Philipp Reisner 已提交
4057

4058 4059
	conn_info(tconn, "Handshake successful: "
	     "Agreed network protocol version %d\n", tconn->agreed_pro_version);
P
Philipp Reisner 已提交
4060 4061 4062 4063

	return 1;

 incompat:
4064
	conn_err(tconn, "incompatible DRBD dialects: "
P
Philipp Reisner 已提交
4065 4066 4067 4068 4069 4070 4071
	    "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)
4072
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4073 4074 4075
{
	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");
4076
	return -1;
P
Philipp Reisner 已提交
4077 4078 4079
}
#else
#define CHALLENGE_LEN 64
4080 4081 4082 4083 4084 4085 4086

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

4087
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4088 4089 4090 4091 4092 4093
{
	char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
	struct scatterlist sg;
	char *response = NULL;
	char *right_response = NULL;
	char *peers_ch = NULL;
4094
	unsigned int key_len = strlen(tconn->net_conf->shared_secret);
P
Philipp Reisner 已提交
4095 4096
	unsigned int resp_size;
	struct hash_desc desc;
4097
	struct packet_info pi;
P
Philipp Reisner 已提交
4098 4099
	int rv;

4100
	desc.tfm = tconn->cram_hmac_tfm;
P
Philipp Reisner 已提交
4101 4102
	desc.flags = 0;

4103 4104
	rv = crypto_hash_setkey(tconn->cram_hmac_tfm,
				(u8 *)tconn->net_conf->shared_secret, key_len);
P
Philipp Reisner 已提交
4105
	if (rv) {
4106
		conn_err(tconn, "crypto_hash_setkey() failed with %d\n", rv);
4107
		rv = -1;
P
Philipp Reisner 已提交
4108 4109 4110 4111 4112
		goto fail;
	}

	get_random_bytes(my_challenge, CHALLENGE_LEN);

4113
	rv = conn_send_cmd2(tconn, P_AUTH_CHALLENGE, my_challenge, CHALLENGE_LEN);
P
Philipp Reisner 已提交
4114 4115 4116
	if (!rv)
		goto fail;

4117
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4118 4119 4120
	if (!rv)
		goto fail;

4121
	if (pi.cmd != P_AUTH_CHALLENGE) {
4122
		conn_err(tconn, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4123
		    cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4124 4125 4126 4127
		rv = 0;
		goto fail;
	}

4128
	if (pi.size > CHALLENGE_LEN * 2) {
4129
		conn_err(tconn, "expected AuthChallenge payload too big.\n");
4130
		rv = -1;
P
Philipp Reisner 已提交
4131 4132 4133
		goto fail;
	}

4134
	peers_ch = kmalloc(pi.size, GFP_NOIO);
P
Philipp Reisner 已提交
4135
	if (peers_ch == NULL) {
4136
		conn_err(tconn, "kmalloc of peers_ch failed\n");
4137
		rv = -1;
P
Philipp Reisner 已提交
4138 4139 4140
		goto fail;
	}

4141
	rv = drbd_recv(tconn, peers_ch, pi.size);
P
Philipp Reisner 已提交
4142

4143
	if (rv != pi.size) {
4144
		if (!signal_pending(current))
4145
			conn_warn(tconn, "short read AuthChallenge: l=%u\n", rv);
P
Philipp Reisner 已提交
4146 4147 4148 4149
		rv = 0;
		goto fail;
	}

4150
	resp_size = crypto_hash_digestsize(tconn->cram_hmac_tfm);
P
Philipp Reisner 已提交
4151 4152
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
4153
		conn_err(tconn, "kmalloc of response failed\n");
4154
		rv = -1;
P
Philipp Reisner 已提交
4155 4156 4157 4158
		goto fail;
	}

	sg_init_table(&sg, 1);
4159
	sg_set_buf(&sg, peers_ch, pi.size);
P
Philipp Reisner 已提交
4160 4161 4162

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
4163
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4164
		rv = -1;
P
Philipp Reisner 已提交
4165 4166 4167
		goto fail;
	}

4168
	rv = conn_send_cmd2(tconn, P_AUTH_RESPONSE, response, resp_size);
P
Philipp Reisner 已提交
4169 4170 4171
	if (!rv)
		goto fail;

4172
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4173 4174 4175
	if (!rv)
		goto fail;

4176
	if (pi.cmd != P_AUTH_RESPONSE) {
4177
		conn_err(tconn, "expected AuthResponse packet, received: %s (0x%04x)\n",
4178
			cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4179 4180 4181 4182
		rv = 0;
		goto fail;
	}

4183
	if (pi.size != resp_size) {
4184
		conn_err(tconn, "expected AuthResponse payload of wrong size\n");
P
Philipp Reisner 已提交
4185 4186 4187 4188
		rv = 0;
		goto fail;
	}

4189
	rv = drbd_recv(tconn, response , resp_size);
P
Philipp Reisner 已提交
4190 4191

	if (rv != resp_size) {
4192
		if (!signal_pending(current))
4193
			conn_warn(tconn, "short read receiving AuthResponse: l=%u\n", rv);
P
Philipp Reisner 已提交
4194 4195 4196 4197 4198
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4199
	if (right_response == NULL) {
4200
		conn_err(tconn, "kmalloc of right_response failed\n");
4201
		rv = -1;
P
Philipp Reisner 已提交
4202 4203 4204 4205 4206 4207 4208
		goto fail;
	}

	sg_set_buf(&sg, my_challenge, CHALLENGE_LEN);

	rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
	if (rv) {
4209
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4210
		rv = -1;
P
Philipp Reisner 已提交
4211 4212 4213 4214 4215 4216
		goto fail;
	}

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

	if (rv)
4217 4218
		conn_info(tconn, "Peer authenticated using %d bytes of '%s' HMAC\n",
		     resp_size, tconn->net_conf->cram_hmac_alg);
4219 4220
	else
		rv = -1;
P
Philipp Reisner 已提交
4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232

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

	return rv;
}
#endif

int drbdd_init(struct drbd_thread *thi)
{
4233
	struct drbd_tconn *tconn = thi->tconn;
P
Philipp Reisner 已提交
4234 4235
	int h;

4236
	conn_info(tconn, "receiver (re)started\n");
P
Philipp Reisner 已提交
4237 4238

	do {
4239
		h = drbd_connect(tconn);
P
Philipp Reisner 已提交
4240
		if (h == 0) {
4241
			drbd_disconnect(tconn);
4242
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4243 4244
		}
		if (h == -1) {
4245
			conn_warn(tconn, "Discarding network configuration.\n");
4246
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
4247 4248 4249 4250
		}
	} while (h == 0);

	if (h > 0) {
4251 4252 4253
		if (get_net_conf(tconn)) {
			drbdd(tconn);
			put_net_conf(tconn);
P
Philipp Reisner 已提交
4254 4255 4256
		}
	}

4257
	drbd_disconnect(tconn);
P
Philipp Reisner 已提交
4258

4259
	conn_info(tconn, "receiver terminated\n");
P
Philipp Reisner 已提交
4260 4261 4262 4263 4264
	return 0;
}

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

4265
static int got_RqSReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4266
{
4267
	struct p_req_state_reply *p = &mdev->tconn->meta.rbuf.req_state_reply;
P
Philipp Reisner 已提交
4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279

	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);

4280
	return true;
P
Philipp Reisner 已提交
4281 4282
}

4283
static int got_Ping(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4284
{
4285
	return drbd_send_ping_ack(mdev->tconn);
P
Philipp Reisner 已提交
4286 4287 4288

}

4289
static int got_PingAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4290
{
4291
	struct drbd_tconn *tconn = mdev->tconn;
P
Philipp Reisner 已提交
4292
	/* restore idle timeout */
4293 4294 4295
	tconn->meta.socket->sk->sk_rcvtimeo = tconn->net_conf->ping_int*HZ;
	if (!test_and_set_bit(GOT_PING_ACK, &tconn->flags))
		wake_up(&tconn->ping_wait);
P
Philipp Reisner 已提交
4296

4297
	return true;
P
Philipp Reisner 已提交
4298 4299
}

4300
static int got_IsInSync(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4301
{
4302
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4303 4304 4305
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

4306
	D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
4307 4308 4309

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

4310 4311 4312 4313 4314 4315 4316
	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
4317
	dec_rs_pending(mdev);
4318
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4319

4320
	return true;
P
Philipp Reisner 已提交
4321 4322
}

4323 4324 4325 4326
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
4327 4328 4329 4330
{
	struct drbd_request *req;
	struct bio_and_error m;

4331
	spin_lock_irq(&mdev->tconn->req_lock);
4332
	req = find_request(mdev, root, id, sector, missing_ok, func);
P
Philipp Reisner 已提交
4333
	if (unlikely(!req)) {
4334
		spin_unlock_irq(&mdev->tconn->req_lock);
4335
		return false;
P
Philipp Reisner 已提交
4336 4337
	}
	__req_mod(req, what, &m);
4338
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4339 4340 4341

	if (m.bio)
		complete_master_bio(mdev, &m);
4342
	return true;
P
Philipp Reisner 已提交
4343 4344
}

4345
static int got_BlockAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4346
{
4347
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4348 4349 4350 4351 4352 4353
	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));

4354
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4355 4356
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4357
		return true;
P
Philipp Reisner 已提交
4358
	}
4359
	switch (cmd) {
P
Philipp Reisner 已提交
4360
	case P_RS_WRITE_ACK:
4361
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4362
		what = WRITE_ACKED_BY_PEER_AND_SIS;
P
Philipp Reisner 已提交
4363 4364
		break;
	case P_WRITE_ACK:
4365
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4366
		what = WRITE_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4367 4368
		break;
	case P_RECV_ACK:
4369
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
4370
		what = RECV_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4371 4372
		break;
	case P_DISCARD_ACK:
4373
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4374
		what = CONFLICT_DISCARDED_BY_PEER;
P
Philipp Reisner 已提交
4375 4376 4377
		break;
	default:
		D_ASSERT(0);
4378
		return false;
P
Philipp Reisner 已提交
4379 4380 4381
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
4382 4383
					     &mdev->write_requests, __func__,
					     what, false);
P
Philipp Reisner 已提交
4384 4385
}

4386
static int got_NegAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4387
{
4388
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4389
	sector_t sector = be64_to_cpu(p->sector);
4390
	int size = be32_to_cpu(p->blksize);
4391 4392
	bool missing_ok = mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A ||
			  mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B;
4393
	bool found;
P
Philipp Reisner 已提交
4394 4395 4396

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

4397
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4398 4399
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4400
		return true;
P
Philipp Reisner 已提交
4401
	}
4402

4403
	found = validate_req_change_req_state(mdev, p->block_id, sector,
4404
					      &mdev->write_requests, __func__,
4405
					      NEG_ACKED, missing_ok);
4406 4407 4408 4409 4410 4411 4412
	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)
4413
			return false;
4414
		drbd_set_out_of_sync(mdev, sector, size);
4415 4416
	}
	return true;
P
Philipp Reisner 已提交
4417 4418
}

4419
static int got_NegDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4420
{
4421
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4422 4423 4424 4425 4426 4427 4428
	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,
4429
					     &mdev->read_requests, __func__,
4430
					     NEG_ACKED, false);
P
Philipp Reisner 已提交
4431 4432
}

4433
static int got_NegRSDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4434 4435 4436
{
	sector_t sector;
	int size;
4437
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4438 4439 4440 4441 4442 4443 4444 4445 4446 4447

	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);
4448
		switch (cmd) {
4449 4450 4451 4452 4453 4454 4455 4456 4457
		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
4458 4459 4460
		put_ldev(mdev);
	}

4461
	return true;
P
Philipp Reisner 已提交
4462 4463
}

4464
static int got_BarrierAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4465
{
4466
	struct p_barrier_ack *p = &mdev->tconn->meta.rbuf.barrier_ack;
P
Philipp Reisner 已提交
4467 4468 4469

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

4470 4471
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4472 4473 4474
	    !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);
4475 4476
	}

4477
	return true;
P
Philipp Reisner 已提交
4478 4479
}

4480
static int got_OVResult(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4481
{
4482
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496
	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);

4497
	if (!get_ldev(mdev))
4498
		return true;
4499

P
Philipp Reisner 已提交
4500 4501 4502
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4503 4504 4505 4506 4507 4508 4509
	--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
4510 4511 4512
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
4513
			w->mdev = mdev;
4514
			drbd_queue_work_front(&mdev->tconn->data.work, w);
P
Philipp Reisner 已提交
4515 4516 4517 4518 4519 4520
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
			ov_oos_print(mdev);
			drbd_resync_finished(mdev);
		}
	}
4521
	put_ldev(mdev);
4522
	return true;
P
Philipp Reisner 已提交
4523 4524
}

4525
static int got_skip(struct drbd_conf *mdev, enum drbd_packet cmd)
4526
{
4527
	return true;
4528 4529
}

P
Philipp Reisner 已提交
4530 4531
struct asender_cmd {
	size_t pkt_size;
4532
	int (*process)(struct drbd_conf *mdev, enum drbd_packet cmd);
P
Philipp Reisner 已提交
4533 4534 4535 4536 4537 4538 4539 4540
};

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() */
4541 4542
	[P_PING]	    = { sizeof(struct p_header), got_Ping },
	[P_PING_ACK]	    = { sizeof(struct p_header), got_PingAck },
P
Philipp Reisner 已提交
4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553
	[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 },
4554
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
4555
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply},
P
Philipp Reisner 已提交
4556 4557 4558 4559 4560 4561 4562
	[P_MAX_CMD]	    = { 0, NULL },
	};
	if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)
		return NULL;
	return &asender_tbl[cmd];
}

4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598
static int _drbd_process_done_ee(int vnr, void *p, void *data)
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
	return !drbd_process_done_ee(mdev);
}

static int _check_ee_empty(int vnr, void *p, void *data)
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
	struct drbd_tconn *tconn = mdev->tconn;
	int not_empty;

	spin_lock_irq(&tconn->req_lock);
	not_empty = !list_empty(&mdev->done_ee);
	spin_unlock_irq(&tconn->req_lock);

	return not_empty;
}

static int tconn_process_done_ee(struct drbd_tconn *tconn)
{
	int not_empty, err;

	do {
		clear_bit(SIGNAL_ASENDER, &tconn->flags);
		flush_signals(current);
		err = idr_for_each(&tconn->volumes, _drbd_process_done_ee, NULL);
		if (err)
			return err;
		set_bit(SIGNAL_ASENDER, &tconn->flags);
		not_empty = idr_for_each(&tconn->volumes, _check_ee_empty, NULL);
	} while (not_empty);

	return 0;
}

P
Philipp Reisner 已提交
4599 4600
int drbd_asender(struct drbd_thread *thi)
{
4601
	struct drbd_tconn *tconn = thi->tconn;
4602
	struct p_header *h = &tconn->meta.rbuf.header;
P
Philipp Reisner 已提交
4603
	struct asender_cmd *cmd = NULL;
4604
	struct packet_info pi;
4605
	int rv;
P
Philipp Reisner 已提交
4606 4607
	void *buf    = h;
	int received = 0;
4608
	int expect   = sizeof(struct p_header);
4609
	int ping_timeout_active = 0;
P
Philipp Reisner 已提交
4610 4611 4612 4613

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

4614
	while (get_t_state(thi) == RUNNING) {
4615
		drbd_thread_current_set_cpu(thi);
4616
		if (test_and_clear_bit(SEND_PING, &tconn->flags)) {
4617
			if (!drbd_send_ping(tconn)) {
4618
				conn_err(tconn, "drbd_send_ping has failed\n");
4619 4620
				goto reconnect;
			}
4621 4622
			tconn->meta.socket->sk->sk_rcvtimeo =
				tconn->net_conf->ping_timeo*HZ/10;
4623
			ping_timeout_active = 1;
P
Philipp Reisner 已提交
4624 4625
		}

4626 4627 4628 4629 4630 4631
		/* TODO: conditionally cork; it may hurt latency if we cork without
		   much to send */
		if (!tconn->net_conf->no_cork)
			drbd_tcp_cork(tconn->meta.socket);
		if (tconn_process_done_ee(tconn))
			goto reconnect;
P
Philipp Reisner 已提交
4632
		/* but unconditionally uncork unless disabled */
4633 4634
		if (!tconn->net_conf->no_cork)
			drbd_tcp_uncork(tconn->meta.socket);
P
Philipp Reisner 已提交
4635 4636 4637 4638 4639

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

4640 4641
		rv = drbd_recv_short(tconn->meta.socket, buf, expect-received, 0);
		clear_bit(SIGNAL_ASENDER, &tconn->flags);
P
Philipp Reisner 已提交
4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658

		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) {
4659
			conn_err(tconn, "meta connection shut down by peer.\n");
P
Philipp Reisner 已提交
4660 4661
			goto reconnect;
		} else if (rv == -EAGAIN) {
4662 4663
			/* If the data socket received something meanwhile,
			 * that is good enough: peer is still alive. */
4664 4665
			if (time_after(tconn->last_received,
				jiffies - tconn->meta.socket->sk->sk_rcvtimeo))
4666
				continue;
4667
			if (ping_timeout_active) {
4668
				conn_err(tconn, "PingAck did not arrive in time.\n");
P
Philipp Reisner 已提交
4669 4670
				goto reconnect;
			}
4671
			set_bit(SEND_PING, &tconn->flags);
P
Philipp Reisner 已提交
4672 4673 4674 4675
			continue;
		} else if (rv == -EINTR) {
			continue;
		} else {
4676
			conn_err(tconn, "sock_recvmsg returned %d\n", rv);
P
Philipp Reisner 已提交
4677 4678 4679 4680
			goto reconnect;
		}

		if (received == expect && cmd == NULL) {
4681
			if (!decode_header(tconn, h, &pi))
P
Philipp Reisner 已提交
4682
				goto reconnect;
4683
			cmd = get_asender_cmd(pi.cmd);
P
Philipp Reisner 已提交
4684
			if (unlikely(cmd == NULL)) {
4685
				conn_err(tconn, "unknown command %d on meta (l: %d)\n",
4686
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4687 4688 4689
				goto disconnect;
			}
			expect = cmd->pkt_size;
4690
			if (pi.size != expect - sizeof(struct p_header)) {
4691
				conn_err(tconn, "Wrong packet size on meta (c: %d, l: %d)\n",
4692
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4693
				goto reconnect;
4694
			}
P
Philipp Reisner 已提交
4695 4696
		}
		if (received == expect) {
4697 4698
			tconn->last_received = jiffies;
			if (!cmd->process(vnr_to_mdev(tconn, pi.vnr), pi.cmd))
P
Philipp Reisner 已提交
4699 4700
				goto reconnect;

4701 4702 4703 4704 4705
			/* 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
4706 4707
			buf	 = h;
			received = 0;
4708
			expect	 = sizeof(struct p_header);
P
Philipp Reisner 已提交
4709 4710 4711 4712 4713 4714
			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
4715
		conn_request_state(tconn, NS(conn, C_NETWORK_FAILURE), CS_HARD);
P
Philipp Reisner 已提交
4716 4717 4718
	}
	if (0) {
disconnect:
4719
		conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
4720
	}
4721
	clear_bit(SIGNAL_ASENDER, &tconn->flags);
P
Philipp Reisner 已提交
4722

4723
	conn_info(tconn, "asender terminated\n");
P
Philipp Reisner 已提交
4724 4725 4726

	return 0;
}