drbd_receiver.c 130.4 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,
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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,
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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);
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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
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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
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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
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738 739

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

748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765
static int drbd_connected(int vnr, void *p, void *data)
{
	struct drbd_conf *mdev = (struct drbd_conf *)p;
	int ok = 1;

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

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

	return !ok;
}

P
Philipp Reisner 已提交
766 767 768 769 770 771 772 773
/*
 * 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...
 */
774
static int drbd_connect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
775 776 777 778
{
	struct socket *s, *sock, *msock;
	int try, h, ok;

779
	if (conn_request_state(tconn, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
P
Philipp Reisner 已提交
780 781
		return -2;

782 783
	clear_bit(DISCARD_CONCURRENT, &tconn->flags);
	tconn->agreed_pro_version = 99;
P
Philipp Reisner 已提交
784 785
	/* 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
786 787 788 789 790 791 792

	sock  = NULL;
	msock = NULL;

	do {
		for (try = 0;;) {
			/* 3 tries, this should take less than a second! */
793
			s = drbd_try_connect(tconn);
P
Philipp Reisner 已提交
794 795 796
			if (s || ++try >= 3)
				break;
			/* give the other side time to call bind() & listen() */
797
			schedule_timeout_interruptible(HZ / 10);
P
Philipp Reisner 已提交
798 799 800 801
		}

		if (s) {
			if (!sock) {
802
				drbd_send_fp(tconn, s, P_HAND_SHAKE_S);
P
Philipp Reisner 已提交
803 804 805
				sock = s;
				s = NULL;
			} else if (!msock) {
806
				drbd_send_fp(tconn, s, P_HAND_SHAKE_M);
P
Philipp Reisner 已提交
807 808 809
				msock = s;
				s = NULL;
			} else {
810
				conn_err(tconn, "Logic error in drbd_connect()\n");
P
Philipp Reisner 已提交
811 812 813 814 815
				goto out_release_sockets;
			}
		}

		if (sock && msock) {
816
			schedule_timeout_interruptible(tconn->net_conf->ping_timeo*HZ/10);
817 818
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
819 820 821 822 823
			if (ok)
				break;
		}

retry:
824
		s = drbd_wait_for_connect(tconn);
P
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825
		if (s) {
826
			try = drbd_recv_fp(tconn, s);
827 828
			drbd_socket_okay(&sock);
			drbd_socket_okay(&msock);
P
Philipp Reisner 已提交
829 830 831
			switch (try) {
			case P_HAND_SHAKE_S:
				if (sock) {
832
					conn_warn(tconn, "initial packet S crossed\n");
P
Philipp Reisner 已提交
833 834 835 836 837 838
					sock_release(sock);
				}
				sock = s;
				break;
			case P_HAND_SHAKE_M:
				if (msock) {
839
					conn_warn(tconn, "initial packet M crossed\n");
P
Philipp Reisner 已提交
840 841 842
					sock_release(msock);
				}
				msock = s;
843
				set_bit(DISCARD_CONCURRENT, &tconn->flags);
P
Philipp Reisner 已提交
844 845
				break;
			default:
846
				conn_warn(tconn, "Error receiving initial packet\n");
P
Philipp Reisner 已提交
847 848 849 850 851 852
				sock_release(s);
				if (random32() & 1)
					goto retry;
			}
		}

853
		if (tconn->cstate <= C_DISCONNECTING)
P
Philipp Reisner 已提交
854 855 856 857
			goto out_release_sockets;
		if (signal_pending(current)) {
			flush_signals(current);
			smp_rmb();
858
			if (get_t_state(&tconn->receiver) == EXITING)
P
Philipp Reisner 已提交
859 860 861 862
				goto out_release_sockets;
		}

		if (sock && msock) {
863 864
			ok = drbd_socket_okay(&sock);
			ok = drbd_socket_okay(&msock) && ok;
P
Philipp Reisner 已提交
865 866 867 868 869 870 871 872 873 874 875 876 877 878 879
			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 ...
880
	 * sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
881 882 883 884
	 * 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 =
885
	sock->sk->sk_rcvtimeo = tconn->net_conf->ping_timeo*4*HZ/10;
P
Philipp Reisner 已提交
886

887 888
	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
889 890

	/* we don't want delays.
L
Lucas De Marchi 已提交
891
	 * we use TCP_CORK where appropriate, though */
P
Philipp Reisner 已提交
892 893 894
	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

895 896 897
	tconn->data.socket = sock;
	tconn->meta.socket = msock;
	tconn->last_received = jiffies;
P
Philipp Reisner 已提交
898

899
	h = drbd_do_handshake(tconn);
P
Philipp Reisner 已提交
900 901 902
	if (h <= 0)
		return h;

903
	if (tconn->cram_hmac_tfm) {
P
Philipp Reisner 已提交
904
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
905
		switch (drbd_do_auth(tconn)) {
906
		case -1:
907
			conn_err(tconn, "Authentication of peer failed\n");
P
Philipp Reisner 已提交
908
			return -1;
909
		case 0:
910
			conn_err(tconn, "Authentication of peer failed, trying again.\n");
911
			return 0;
P
Philipp Reisner 已提交
912 913 914
		}
	}

915
	if (conn_request_state(tconn, NS(conn, C_WF_REPORT_PARAMS), CS_VERBOSE) < SS_SUCCESS)
P
Philipp Reisner 已提交
916 917
		return 0;

918
	sock->sk->sk_sndtimeo = tconn->net_conf->timeout*HZ/10;
P
Philipp Reisner 已提交
919 920
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

921
	drbd_thread_start(&tconn->asender);
P
Philipp Reisner 已提交
922

923
	if (drbd_send_protocol(tconn) == -1)
924
		return -1;
P
Philipp Reisner 已提交
925

926
	return !idr_for_each(&tconn->volumes, drbd_connected, tconn);
P
Philipp Reisner 已提交
927 928 929 930 931 932 933 934 935

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

936
static bool decode_header(struct drbd_tconn *tconn, struct p_header *h, struct packet_info *pi)
P
Philipp Reisner 已提交
937
{
P
Philipp Reisner 已提交
938
	if (h->h80.magic == cpu_to_be32(DRBD_MAGIC)) {
939 940
		pi->cmd = be16_to_cpu(h->h80.command);
		pi->size = be16_to_cpu(h->h80.length);
941
		pi->vnr = 0;
942
	} else if (h->h95.magic == cpu_to_be16(DRBD_MAGIC_BIG)) {
943 944 945
		pi->cmd = be16_to_cpu(h->h95.command);
		pi->size = be32_to_cpu(h->h95.length) & 0x00ffffff;
		pi->vnr = 0;
946
	} else {
947
		conn_err(tconn, "magic?? on data m: 0x%08x c: %d l: %d\n",
948 949 950
		    be32_to_cpu(h->h80.magic),
		    be16_to_cpu(h->h80.command),
		    be16_to_cpu(h->h80.length));
951
		return false;
P
Philipp Reisner 已提交
952
	}
953 954 955
	return true;
}

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

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

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

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

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

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
979
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
980
					NULL);
P
Philipp Reisner 已提交
981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001
		if (rv) {
			dev_err(DEV, "local disk flush failed with status %d\n", rv);
			/* would rather check on EOPNOTSUPP, but that is not reliable.
			 * don't try again for ANY return value != 0
			 * if (rv == -EOPNOTSUPP) */
			drbd_bump_write_ordering(mdev, WO_drain_io);
		}
		put_ldev(mdev);
	}
}

/**
 * drbd_may_finish_epoch() - Applies an epoch_event to the epoch's state, eventually finishes it.
 * @mdev:	DRBD device.
 * @epoch:	Epoch object.
 * @ev:		Epoch event.
 */
static enum finish_epoch drbd_may_finish_epoch(struct drbd_conf *mdev,
					       struct drbd_epoch *epoch,
					       enum epoch_event ev)
{
1002
	int epoch_size;
P
Philipp Reisner 已提交
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
	struct drbd_epoch *next_epoch;
	enum finish_epoch rv = FE_STILL_LIVE;

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

		epoch_size = atomic_read(&epoch->epoch_size);

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

		if (epoch_size != 0 &&
		    atomic_read(&epoch->active) == 0 &&
1026
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
P
Philipp Reisner 已提交
1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
			if (!(ev & EV_CLEANUP)) {
				spin_unlock(&mdev->epoch_lock);
				drbd_send_b_ack(mdev, epoch->barrier_nr, epoch_size);
				spin_lock(&mdev->epoch_lock);
			}
			dec_unacked(mdev);

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

				if (rv == FE_STILL_LIVE)
					rv = FE_DESTROYED;
			} else {
				epoch->flags = 0;
				atomic_set(&epoch->epoch_size, 0);
1046
				/* atomic_set(&epoch->active, 0); is already zero */
P
Philipp Reisner 已提交
1047 1048
				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1049
				wake_up(&mdev->ee_wait);
P
Philipp Reisner 已提交
1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
			}
		}

		if (!next_epoch)
			break;

		epoch = next_epoch;
	} while (1);

	spin_unlock(&mdev->epoch_lock);

	return rv;
}

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

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

1089 1090 1091
/**
 * drbd_submit_ee()
 * @mdev:	DRBD device.
1092
 * @peer_req:	peer request
1093
 * @rw:		flag field, see bio->bi_rw
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
 *
 * May spread the pages to multiple bios,
 * depending on bio_add_page restrictions.
 *
 * Returns 0 if all bios have been submitted,
 * -ENOMEM if we could not allocate enough bios,
 * -ENOSPC (any better suggestion?) if we have not been able to bio_add_page a
 *  single page to an empty bio (which should never happen and likely indicates
 *  that the lower level IO stack is in some way broken). This has been observed
 *  on certain Xen deployments.
1104 1105
 */
/* TODO allocate from our own bio_set. */
1106
int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_peer_request *peer_req,
1107
		   const unsigned rw, const int fault_type)
1108 1109 1110
{
	struct bio *bios = NULL;
	struct bio *bio;
1111 1112 1113
	struct page *page = peer_req->pages;
	sector_t sector = peer_req->i.sector;
	unsigned ds = peer_req->i.size;
1114 1115
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1116
	int err = -ENOMEM;
1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127

	/* In most cases, we will only need one bio.  But in case the lower
	 * level restrictions happen to be different at this offset on this
	 * side than those of the sending peer, we may need to submit the
	 * request in more than one bio. */
next_bio:
	bio = bio_alloc(GFP_NOIO, nr_pages);
	if (!bio) {
		dev_err(DEV, "submit_ee: Allocation of a bio failed\n");
		goto fail;
	}
1128
	/* > peer_req->i.sector, unless this is the first bio */
1129 1130 1131
	bio->bi_sector = sector;
	bio->bi_bdev = mdev->ldev->backing_bdev;
	bio->bi_rw = rw;
1132
	bio->bi_private = peer_req;
1133 1134 1135 1136 1137 1138 1139 1140 1141
	bio->bi_end_io = drbd_endio_sec;

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

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

1162
	atomic_set(&peer_req->pending_bios, n_bios);
1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
	do {
		bio = bios;
		bios = bios->bi_next;
		bio->bi_next = NULL;

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

fail:
	while (bios) {
		bio = bios;
		bios = bios->bi_next;
		bio_put(bio);
	}
1178
	return err;
1179 1180
}

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

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

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

1194 1195
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packet cmd,
			   unsigned int data_size)
P
Philipp Reisner 已提交
1196
{
1197
	int rv;
1198
	struct p_barrier *p = &mdev->tconn->data.rbuf.barrier;
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1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
	struct drbd_epoch *epoch;

	inc_unacked(mdev);

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

	/* P_BARRIER_ACK may imply that the corresponding extent is dropped from
	 * the activity log, which means it would not be resynced in case the
	 * R_PRIMARY crashes now.
	 * Therefore we must send the barrier_ack after the barrier request was
	 * completed. */
	switch (mdev->write_ordering) {
	case WO_none:
		if (rv == FE_RECYCLED)
1214
			return true;
1215 1216 1217 1218 1219 1220 1221 1222 1223

		/* receiver context, in the writeout path of the other node.
		 * avoid potential distributed deadlock */
		epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
		if (epoch)
			break;
		else
			dev_warn(DEV, "Allocation of an epoch failed, slowing down\n");
			/* Fall through */
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Philipp Reisner 已提交
1224 1225 1226 1227

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

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

1236 1237 1238 1239 1240
		epoch = mdev->current_epoch;
		wait_event(mdev->ee_wait, atomic_read(&epoch->epoch_size) == 0);

		D_ASSERT(atomic_read(&epoch->active) == 0);
		D_ASSERT(epoch->flags == 0);
P
Philipp Reisner 已提交
1241

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

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

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

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

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

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

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

	data_size -= dgs;

1296 1297 1298 1299 1300 1301
	if (!expect(data_size != 0))
		return NULL;
	if (!expect(IS_ALIGNED(data_size, 512)))
		return NULL;
	if (!expect(data_size <= DRBD_MAX_BIO_SIZE))
		return NULL;
P
Philipp Reisner 已提交
1302

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

P
Philipp Reisner 已提交
1313 1314 1315
	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
1316 1317
	peer_req = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
	if (!peer_req)
P
Philipp Reisner 已提交
1318
		return NULL;
1319

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

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

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

1365
	if (!data_size)
1366
		return true;
1367

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

	data = kmap(page);
	while (data_size) {
1372
		rr = drbd_recv(mdev->tconn, data, min_t(int, data_size, PAGE_SIZE));
P
Philipp Reisner 已提交
1373 1374
		if (rr != min_t(int, data_size, PAGE_SIZE)) {
			rv = 0;
1375 1376 1377 1378
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data: read %d expected %d\n",
					rr, min_t(int, data_size, PAGE_SIZE));
P
Philipp Reisner 已提交
1379 1380 1381 1382 1383
			break;
		}
		data_size -= rr;
	}
	kunmap(page);
1384
	drbd_pp_free(mdev, page, 0);
P
Philipp Reisner 已提交
1385 1386 1387 1388 1389 1390 1391 1392 1393
	return rv;
}

static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
			   sector_t sector, int data_size)
{
	struct bio_vec *bvec;
	struct bio *bio;
	int dgs, rr, i, expect;
1394 1395
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
P
Philipp Reisner 已提交
1396

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

	if (dgs) {
1401
		rr = drbd_recv(mdev->tconn, dig_in, dgs);
P
Philipp Reisner 已提交
1402
		if (rr != dgs) {
1403 1404 1405 1406
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data reply digest: read %d expected %d\n",
					rr, dgs);
P
Philipp Reisner 已提交
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
			return 0;
		}
	}

	data_size -= dgs;

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

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

	bio_for_each_segment(bvec, bio, i) {
		expect = min_t(int, data_size, bvec->bv_len);
1422
		rr = drbd_recv(mdev->tconn,
P
Philipp Reisner 已提交
1423 1424 1425 1426
			     kmap(bvec->bv_page)+bvec->bv_offset,
			     expect);
		kunmap(bvec->bv_page);
		if (rr != expect) {
1427 1428 1429 1430
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data reply: "
					"read %d expected %d\n",
					rr, expect);
P
Philipp Reisner 已提交
1431 1432 1433 1434 1435 1436
			return 0;
		}
		data_size -= rr;
	}

	if (dgs) {
1437
		drbd_csum_bio(mdev, mdev->tconn->integrity_r_tfm, bio, dig_vv);
P
Philipp Reisner 已提交
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449
		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 */
1450
static int e_end_resync_block(struct drbd_work *w, int unused)
P
Philipp Reisner 已提交
1451
{
1452
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
1453
	struct drbd_conf *mdev = w->mdev;
1454
	sector_t sector = peer_req->i.sector;
P
Philipp Reisner 已提交
1455 1456
	int ok;

1457
	D_ASSERT(drbd_interval_empty(&peer_req->i));
P
Philipp Reisner 已提交
1458

1459 1460 1461
	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
1462 1463
	} else {
		/* Record failure to sync */
1464
		drbd_rs_failed_io(mdev, sector, peer_req->i.size);
P
Philipp Reisner 已提交
1465

1466
		ok  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
P
Philipp Reisner 已提交
1467 1468 1469 1470 1471 1472 1473 1474
	}
	dec_unacked(mdev);

	return ok;
}

static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_size) __releases(local)
{
1475
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
1476

1477 1478
	peer_req = read_in_block(mdev, ID_SYNCER, sector, data_size);
	if (!peer_req)
1479
		goto fail;
P
Philipp Reisner 已提交
1480 1481 1482 1483 1484 1485 1486

	dec_rs_pending(mdev);

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

1487
	peer_req->w.cb = e_end_resync_block;
1488

1489
	spin_lock_irq(&mdev->tconn->req_lock);
1490
	list_add(&peer_req->w.list, &mdev->sync_ee);
1491
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1492

1493
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1494
	if (drbd_submit_ee(mdev, peer_req, WRITE, DRBD_FAULT_RS_WR) == 0)
1495
		return true;
P
Philipp Reisner 已提交
1496

1497 1498
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1499
	spin_lock_irq(&mdev->tconn->req_lock);
1500
	list_del(&peer_req->w.list);
1501
	spin_unlock_irq(&mdev->tconn->req_lock);
1502

1503
	drbd_free_ee(mdev, peer_req);
1504 1505
fail:
	put_ldev(mdev);
1506
	return false;
P
Philipp Reisner 已提交
1507 1508
}

1509
static struct drbd_request *
1510 1511
find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
	     sector_t sector, bool missing_ok, const char *func)
1512 1513 1514
{
	struct drbd_request *req;

1515 1516
	/* Request object according to our peer */
	req = (struct drbd_request *)(unsigned long)id;
1517
	if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
1518
		return req;
1519 1520 1521 1522
	if (!missing_ok) {
		dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
			(unsigned long)id, (unsigned long long)sector);
	}
1523 1524 1525
	return NULL;
}

1526 1527
static int receive_DataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
1528 1529 1530 1531
{
	struct drbd_request *req;
	sector_t sector;
	int ok;
1532
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1533 1534 1535

	sector = be64_to_cpu(p->sector);

1536
	spin_lock_irq(&mdev->tconn->req_lock);
1537
	req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
1538
	spin_unlock_irq(&mdev->tconn->req_lock);
1539
	if (unlikely(!req))
1540
		return false;
P
Philipp Reisner 已提交
1541

B
Bart Van Assche 已提交
1542
	/* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
P
Philipp Reisner 已提交
1543 1544 1545 1546 1547
	 * 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)
1548
		req_mod(req, DATA_RECEIVED);
P
Philipp Reisner 已提交
1549 1550 1551 1552 1553 1554 1555
	/* 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;
}

1556 1557
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
P
Philipp Reisner 已提交
1558 1559 1560
{
	sector_t sector;
	int ok;
1561
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
Philipp Reisner 已提交
1562 1563 1564 1565 1566 1567 1568

	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,
1569
		 * or in drbd_endio_sec. */
P
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1570 1571 1572 1573 1574 1575 1576
		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);

1577
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1578 1579
	}

1580 1581
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

P
Philipp Reisner 已提交
1582 1583 1584 1585 1586 1587
	return ok;
}

/* e_end_block() is called via drbd_process_done_ee().
 * this means this function only runs in the asender thread
 */
1588
static int e_end_block(struct drbd_work *w, int cancel)
P
Philipp Reisner 已提交
1589
{
1590
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
1591
	struct drbd_conf *mdev = w->mdev;
1592
	sector_t sector = peer_req->i.sector;
P
Philipp Reisner 已提交
1593 1594
	int ok = 1, pcmd;

1595
	if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
1596
		if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
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1597 1598
			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
				mdev->state.conn <= C_PAUSED_SYNC_T &&
1599
				peer_req->flags & EE_MAY_SET_IN_SYNC) ?
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1600
				P_RS_WRITE_ACK : P_WRITE_ACK;
1601
			ok &= drbd_send_ack(mdev, pcmd, peer_req);
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1602
			if (pcmd == P_RS_WRITE_ACK)
1603
				drbd_set_in_sync(mdev, sector, peer_req->i.size);
P
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1604
		} else {
1605
			ok  = drbd_send_ack(mdev, P_NEG_ACK, peer_req);
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1606 1607 1608 1609 1610 1611 1612
			/* 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.  */
1613
	if (mdev->tconn->net_conf->two_primaries) {
1614
		spin_lock_irq(&mdev->tconn->req_lock);
1615 1616
		D_ASSERT(!drbd_interval_empty(&peer_req->i));
		drbd_remove_epoch_entry_interval(mdev, peer_req);
1617
		spin_unlock_irq(&mdev->tconn->req_lock);
1618
	} else
1619
		D_ASSERT(drbd_interval_empty(&peer_req->i));
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1620

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

	return ok;
}

1626
static int e_send_discard_ack(struct drbd_work *w, int unused)
P
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1627
{
1628
	struct drbd_peer_request *peer_req = (struct drbd_peer_request *)w;
1629
	struct drbd_conf *mdev = w->mdev;
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1630 1631
	int ok = 1;

1632
	D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
1633
	ok = drbd_send_ack(mdev, P_DISCARD_ACK, peer_req);
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1634

1635
	spin_lock_irq(&mdev->tconn->req_lock);
1636 1637
	D_ASSERT(!drbd_interval_empty(&peer_req->i));
	drbd_remove_epoch_entry_interval(mdev, peer_req);
1638
	spin_unlock_irq(&mdev->tconn->req_lock);
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1639 1640 1641 1642 1643 1644

	dec_unacked(mdev);

	return ok;
}

1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
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;
}

1660
static void update_peer_seq(struct drbd_conf *mdev, unsigned int peer_seq)
1661
{
1662
	unsigned int old_peer_seq;
1663 1664

	spin_lock(&mdev->peer_seq_lock);
1665 1666
	old_peer_seq = mdev->peer_seq;
	mdev->peer_seq = seq_max(mdev->peer_seq, peer_seq);
1667
	spin_unlock(&mdev->peer_seq_lock);
1668
	if (old_peer_seq != peer_seq)
1669 1670 1671
		wake_up(&mdev->seq_wait);
}

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1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701
/* 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);
1702
		if (!seq_greater(packet_seq, mdev->peer_seq + 1))
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1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724
			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;
}

1725 1726 1727 1728
/* 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)
1729
{
1730 1731 1732 1733
	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);
1734 1735
}

P
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1736
/* mirrored write */
1737 1738
static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
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1739 1740
{
	sector_t sector;
1741
	struct drbd_peer_request *peer_req;
1742
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1743 1744 1745 1746 1747 1748 1749 1750 1751
	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);

1752
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
Philipp Reisner 已提交
1753 1754 1755 1756 1757 1758
		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),
1759
	 * or in drbd_endio_sec, if we successfully submit the data at
P
Philipp Reisner 已提交
1760 1761 1762
	 * the end of this function. */

	sector = be64_to_cpu(p->sector);
1763 1764
	peer_req = read_in_block(mdev, p->block_id, sector, data_size);
	if (!peer_req) {
P
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1765
		put_ldev(mdev);
1766
		return false;
P
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1767 1768
	}

1769
	peer_req->w.cb = e_end_block;
P
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1770

1771 1772 1773 1774
	dp_flags = be32_to_cpu(p->dp_flags);
	rw |= wire_flags_to_bio(mdev, dp_flags);

	if (dp_flags & DP_MAY_SET_IN_SYNC)
1775
		peer_req->flags |= EE_MAY_SET_IN_SYNC;
1776

P
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1777
	spin_lock(&mdev->epoch_lock);
1778 1779 1780
	peer_req->epoch = mdev->current_epoch;
	atomic_inc(&peer_req->epoch->epoch_size);
	atomic_inc(&peer_req->epoch->active);
P
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1781 1782 1783
	spin_unlock(&mdev->epoch_lock);

	/* I'm the receiver, I do hold a net_cnt reference. */
1784
	if (!mdev->tconn->net_conf->two_primaries) {
1785
		spin_lock_irq(&mdev->tconn->req_lock);
P
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1786 1787 1788
	} else {
		/* don't get the req_lock yet,
		 * we may sleep in drbd_wait_peer_seq */
1789
		const int size = peer_req->i.size;
1790
		const int discard = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
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1791 1792 1793
		DEFINE_WAIT(wait);
		int first;

1794
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
P
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1795 1796 1797 1798

		/* conflict detection and handling:
		 * 1. wait on the sequence number,
		 *    in case this data packet overtook ACK packets.
1799
		 * 2. check for conflicting write requests.
P
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1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826
		 *
		 * 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;

1827
		spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1828 1829 1830

		first = 1;
		for (;;) {
1831
			struct drbd_interval *i;
P
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1832 1833 1834 1835
			int have_unacked = 0;
			int have_conflict = 0;
			prepare_to_wait(&mdev->misc_wait, &wait,
				TASK_INTERRUPTIBLE);
1836 1837 1838 1839 1840 1841

			i = drbd_find_overlap(&mdev->write_requests, sector, size);
			if (i) {
				/* only ALERT on first iteration,
				 * we may be woken up early... */
				if (first)
1842
					dev_alert(DEV, "%s[%u] Concurrent %s write detected!"
1843 1844
					      "	new: %llus +%u; pending: %llus +%u\n",
					      current->comm, current->pid,
1845
					      i->local ? "local" : "remote",
1846
					      (unsigned long long)sector, size,
1847 1848 1849 1850 1851 1852 1853 1854 1855
					      (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;
				}
1856
				++have_conflict;
P
Philipp Reisner 已提交
1857 1858 1859 1860 1861 1862 1863 1864 1865
			}
			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);
1866 1867
				peer_req->w.cb = e_send_discard_ack;
				list_add_tail(&peer_req->w.list, &mdev->done_ee);
P
Philipp Reisner 已提交
1868

1869
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1870 1871 1872 1873 1874

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

				put_ldev(mdev);
1875
				wake_asender(mdev->tconn);
P
Philipp Reisner 已提交
1876
				finish_wait(&mdev->misc_wait, &wait);
1877
				return true;
P
Philipp Reisner 已提交
1878 1879 1880
			}

			if (signal_pending(current)) {
1881
				spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1882 1883 1884 1885
				finish_wait(&mdev->misc_wait, &wait);
				goto out_interrupted;
			}

1886
			/* Indicate to wake up mdev->misc_wait upon completion.  */
1887
			i->waiting = true;
1888

1889
			spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1890 1891 1892 1893 1894 1895 1896 1897 1898 1899
			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();
1900
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1901 1902
		}
		finish_wait(&mdev->misc_wait, &wait);
1903

1904
		drbd_insert_interval(&mdev->write_requests, &peer_req->i);
P
Philipp Reisner 已提交
1905 1906
	}

1907
	list_add(&peer_req->w.list, &mdev->active_ee);
1908
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1909

1910
	switch (mdev->tconn->net_conf->wire_protocol) {
P
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1911 1912 1913 1914 1915 1916 1917 1918
	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 */
1919
		drbd_send_ack(mdev, P_RECV_ACK, peer_req);
P
Philipp Reisner 已提交
1920 1921 1922 1923 1924 1925
		break;
	case DRBD_PROT_A:
		/* nothing to do */
		break;
	}

1926
	if (mdev->state.pdsk < D_INCONSISTENT) {
P
Philipp Reisner 已提交
1927
		/* In case we have the only disk of the cluster, */
1928 1929 1930 1931
		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
1932 1933
	}

1934
	if (drbd_submit_ee(mdev, peer_req, rw, DRBD_FAULT_DT_WR) == 0)
1935
		return true;
P
Philipp Reisner 已提交
1936

1937 1938
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1939
	spin_lock_irq(&mdev->tconn->req_lock);
1940 1941
	list_del(&peer_req->w.list);
	drbd_remove_epoch_entry_interval(mdev, peer_req);
1942
	spin_unlock_irq(&mdev->tconn->req_lock);
1943 1944
	if (peer_req->flags & EE_CALL_AL_COMPLETE_IO)
		drbd_al_complete_io(mdev, peer_req->i.sector);
1945

P
Philipp Reisner 已提交
1946
out_interrupted:
1947
	drbd_may_finish_epoch(mdev, peer_req->epoch, EV_PUT + EV_CLEANUP);
P
Philipp Reisner 已提交
1948
	put_ldev(mdev);
1949
	drbd_free_ee(mdev, peer_req);
1950
	return false;
P
Philipp Reisner 已提交
1951 1952
}

1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963
/* 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.
 */
1964
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
1965 1966 1967
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
1968
	struct lc_element *tmp;
1969 1970 1971 1972 1973 1974 1975
	int curr_events;
	int throttle = 0;

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

1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
	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);

1988 1989 1990
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
1991

1992 1993 1994 1995 1996 1997 1998 1999
	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. */
2000 2001 2002 2003 2004 2005
		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;
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

		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;
}


2020 2021
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int digest_size)
P
Philipp Reisner 已提交
2022 2023 2024
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
2025
	struct drbd_peer_request *peer_req;
P
Philipp Reisner 已提交
2026
	struct digest_info *di = NULL;
2027
	int size, verb;
P
Philipp Reisner 已提交
2028
	unsigned int fault_type;
2029
	struct p_block_req *p =	&mdev->tconn->data.rbuf.block_req;
P
Philipp Reisner 已提交
2030 2031 2032 2033

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

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

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065
		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
2066 2067
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
2068

L
Lars Ellenberg 已提交
2069 2070
		/* drain possibly payload */
		return drbd_drain_block(mdev, digest_size);
P
Philipp Reisner 已提交
2071 2072 2073 2074 2075
	}

	/* 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.  */
2076 2077
	peer_req = drbd_alloc_ee(mdev, p->block_id, sector, size, GFP_NOIO);
	if (!peer_req) {
P
Philipp Reisner 已提交
2078
		put_ldev(mdev);
2079
		return false;
P
Philipp Reisner 已提交
2080 2081
	}

2082
	switch (cmd) {
P
Philipp Reisner 已提交
2083
	case P_DATA_REQUEST:
2084
		peer_req->w.cb = w_e_end_data_req;
P
Philipp Reisner 已提交
2085
		fault_type = DRBD_FAULT_DT_RD;
2086 2087 2088
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
Philipp Reisner 已提交
2089
	case P_RS_DATA_REQUEST:
2090
		peer_req->w.cb = w_e_end_rsdata_req;
P
Philipp Reisner 已提交
2091
		fault_type = DRBD_FAULT_RS_RD;
2092 2093
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
P
Philipp Reisner 已提交
2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
		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));

2106 2107
		peer_req->digest = di;
		peer_req->flags |= EE_HAS_DIGEST;
2108

2109
		if (drbd_recv(mdev->tconn, di->digest, digest_size) != digest_size)
P
Philipp Reisner 已提交
2110 2111
			goto out_free_e;

2112
		if (cmd == P_CSUM_RS_REQUEST) {
2113
			D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
2114
			peer_req->w.cb = w_e_end_csum_rs_req;
2115 2116
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2117
		} else if (cmd == P_OV_REPLY) {
2118 2119
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
2120
			peer_req->w.cb = w_e_end_ov_reply;
P
Philipp Reisner 已提交
2121
			dec_rs_pending(mdev);
2122 2123 2124
			/* 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
2125 2126 2127 2128 2129
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
2130
		    mdev->tconn->agreed_pro_version >= 90) {
2131 2132
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2133 2134
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2135 2136
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2137 2138 2139 2140
			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
2141 2142 2143
			dev_info(DEV, "Online Verify start sector: %llu\n",
					(unsigned long long)sector);
		}
2144
		peer_req->w.cb = w_e_end_ov_req;
P
Philipp Reisner 已提交
2145 2146 2147 2148 2149
		fault_type = DRBD_FAULT_RS_RD;
		break;

	default:
		dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
2150
		    cmdname(cmd));
P
Philipp Reisner 已提交
2151
		fault_type = DRBD_FAULT_MAX;
2152
		goto out_free_e;
P
Philipp Reisner 已提交
2153 2154
	}

2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176
	/* 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.
	 */
2177 2178 2179
	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))
2180
		goto out_free_e;
P
Philipp Reisner 已提交
2181

2182 2183 2184
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2185
submit:
P
Philipp Reisner 已提交
2186
	inc_unacked(mdev);
2187
	spin_lock_irq(&mdev->tconn->req_lock);
2188
	list_add_tail(&peer_req->w.list, &mdev->read_ee);
2189
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2190

2191
	if (drbd_submit_ee(mdev, peer_req, READ, fault_type) == 0)
2192
		return true;
P
Philipp Reisner 已提交
2193

2194 2195
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2196
	spin_lock_irq(&mdev->tconn->req_lock);
2197
	list_del(&peer_req->w.list);
2198
	spin_unlock_irq(&mdev->tconn->req_lock);
2199 2200
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
Philipp Reisner 已提交
2201 2202
out_free_e:
	put_ldev(mdev);
2203
	drbd_free_ee(mdev, peer_req);
2204
	return false;
P
Philipp Reisner 已提交
2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217
}

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;

2218
	switch (mdev->tconn->net_conf->after_sb_0p) {
P
Philipp Reisner 已提交
2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245
	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
2246
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
P
Philipp Reisner 已提交
2247 2248 2249
		     "Using discard-least-changes instead\n");
	case ASB_DISCARD_ZERO_CHG:
		if (ch_peer == 0 && ch_self == 0) {
2250
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2251 2252 2253 2254 2255 2256
				? -1 : 1;
			break;
		} else {
			if (ch_peer == 0) { rv =  1; break; }
			if (ch_self == 0) { rv = -1; break; }
		}
2257
		if (mdev->tconn->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
P
Philipp Reisner 已提交
2258 2259 2260 2261 2262 2263 2264 2265
			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. */
2266
			rv = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags)
P
Philipp Reisner 已提交
2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280
				? -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)
{
2281
	int hg, rv = -100;
P
Philipp Reisner 已提交
2282

2283
	switch (mdev->tconn->net_conf->after_sb_1p) {
P
Philipp Reisner 已提交
2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307
	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) {
2308 2309 2310
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
P
Philipp Reisner 已提交
2311 2312 2313
			 /* 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. */
2314 2315
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329
				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)
{
2330
	int hg, rv = -100;
P
Philipp Reisner 已提交
2331

2332
	switch (mdev->tconn->net_conf->after_sb_2p) {
P
Philipp Reisner 已提交
2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349
	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) {
2350 2351
			enum drbd_state_rv rv2;

P
Philipp Reisner 已提交
2352 2353 2354
			 /* 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. */
2355 2356
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394
				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
2395 2396
-1091   requires proto 91
-1096   requires proto 96
P
Philipp Reisner 已提交
2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424
 */
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) {

2425
			if (mdev->tconn->agreed_pro_version < 91)
2426
				return -1091;
P
Philipp Reisner 已提交
2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445

			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) {

2446
			if (mdev->tconn->agreed_pro_version < 91)
2447
				return -1091;
P
Philipp Reisner 已提交
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478

			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 */
2479
			dc = test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags);
P
Philipp Reisner 已提交
2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491
			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) {
2492
		if (mdev->tconn->agreed_pro_version < 96 ?
2493 2494 2495
		    (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
2496 2497 2498
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

2499
			if (mdev->tconn->agreed_pro_version < 91)
2500
				return -1091;
P
Philipp Reisner 已提交
2501 2502 2503

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2504 2505 2506 2507

			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
2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528
			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) {
2529
		if (mdev->tconn->agreed_pro_version < 96 ?
2530 2531 2532
		    (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
2533 2534 2535
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

2536
			if (mdev->tconn->agreed_pro_version < 91)
2537
				return -1091;
P
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2538 2539 2540 2541

			_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]);

2542
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
Philipp Reisner 已提交
2543 2544 2545 2546 2547 2548 2549 2550 2551
			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;
2552
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
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2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604
	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;
	}
2605 2606
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
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2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619
		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");
	}

2620 2621 2622
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

2623
	if (hg == 100 || (hg == -100 && mdev->tconn->net_conf->always_asbp)) {
P
Philipp Reisner 已提交
2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651
		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) {
2652
		if (mdev->tconn->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2653
			hg = -1;
2654
		if (!mdev->tconn->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2655 2656 2657 2658 2659 2660 2661 2662 2663
			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) {
2664 2665 2666 2667
		/* 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... */
2668
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679
		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) {
2680
		switch (mdev->tconn->net_conf->rr_conflict) {
P
Philipp Reisner 已提交
2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692
		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");
		}
	}

2693
	if (mdev->tconn->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
2694 2695 2696 2697 2698 2699 2700 2701 2702
		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
2703 2704
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2705 2706
		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
2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745
			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;
}

2746 2747
static int receive_protocol(struct drbd_conf *mdev, enum drbd_packet cmd,
			    unsigned int data_size)
P
Philipp Reisner 已提交
2748
{
2749
	struct p_protocol *p = &mdev->tconn->data.rbuf.protocol;
P
Philipp Reisner 已提交
2750
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2751
	int p_want_lose, p_two_primaries, cf;
P
Philipp Reisner 已提交
2752 2753 2754 2755 2756 2757 2758
	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);
2759 2760 2761 2762 2763 2764 2765
	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
2766

2767
	if (p_proto != mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
2768 2769 2770 2771
		dev_err(DEV, "incompatible communication protocols\n");
		goto disconnect;
	}

2772
	if (cmp_after_sb(p_after_sb_0p, mdev->tconn->net_conf->after_sb_0p)) {
P
Philipp Reisner 已提交
2773 2774 2775 2776
		dev_err(DEV, "incompatible after-sb-0pri settings\n");
		goto disconnect;
	}

2777
	if (cmp_after_sb(p_after_sb_1p, mdev->tconn->net_conf->after_sb_1p)) {
P
Philipp Reisner 已提交
2778 2779 2780 2781
		dev_err(DEV, "incompatible after-sb-1pri settings\n");
		goto disconnect;
	}

2782
	if (cmp_after_sb(p_after_sb_2p, mdev->tconn->net_conf->after_sb_2p)) {
P
Philipp Reisner 已提交
2783 2784 2785 2786
		dev_err(DEV, "incompatible after-sb-2pri settings\n");
		goto disconnect;
	}

2787
	if (p_want_lose && mdev->tconn->net_conf->want_lose) {
P
Philipp Reisner 已提交
2788 2789 2790 2791
		dev_err(DEV, "both sides have the 'want_lose' flag set\n");
		goto disconnect;
	}

2792
	if (p_two_primaries != mdev->tconn->net_conf->two_primaries) {
P
Philipp Reisner 已提交
2793 2794 2795 2796
		dev_err(DEV, "incompatible setting of the two-primaries options\n");
		goto disconnect;
	}

2797
	if (mdev->tconn->agreed_pro_version >= 87) {
2798
		unsigned char *my_alg = mdev->tconn->net_conf->integrity_alg;
P
Philipp Reisner 已提交
2799

2800
		if (drbd_recv(mdev->tconn, p_integrity_alg, data_size) != data_size)
2801
			return false;
P
Philipp Reisner 已提交
2802 2803 2804 2805 2806 2807 2808 2809 2810 2811

		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>");
	}

2812
	return true;
P
Philipp Reisner 已提交
2813 2814 2815

disconnect:
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2816
	return false;
P
Philipp Reisner 已提交
2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845
}

/* 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;
}

2846 2847
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int packet_size)
P
Philipp Reisner 已提交
2848
{
2849
	int ok = true;
2850
	struct p_rs_param_95 *p = &mdev->tconn->data.rbuf.rs_param_95;
P
Philipp Reisner 已提交
2851 2852 2853
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
2854
	const int apv = mdev->tconn->agreed_pro_version;
2855 2856
	int *rs_plan_s = NULL;
	int fifo_size = 0;
P
Philipp Reisner 已提交
2857 2858 2859 2860

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2861 2862
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2863

2864
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2865
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2866
		    packet_size, exp_max_sz);
2867
		return false;
P
Philipp Reisner 已提交
2868 2869 2870
	}

	if (apv <= 88) {
2871
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header);
2872
		data_size   = packet_size  - header_size;
2873
	} else if (apv <= 94) {
2874
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header);
2875
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2876
		D_ASSERT(data_size == 0);
2877
	} else {
2878
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header);
2879
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2880 2881 2882 2883 2884 2885
		D_ASSERT(data_size == 0);
	}

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

2886
	if (drbd_recv(mdev->tconn, &p->head.payload, header_size) != header_size)
2887
		return false;
P
Philipp Reisner 已提交
2888 2889 2890 2891 2892 2893 2894 2895 2896

	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);
2897
				return false;
P
Philipp Reisner 已提交
2898 2899
			}

2900
			if (drbd_recv(mdev->tconn, p->verify_alg, data_size) != data_size)
2901
				return false;
P
Philipp Reisner 已提交
2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944

			/* 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;
			}
		}

2945 2946 2947 2948 2949 2950
		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);
2951 2952 2953 2954 2955 2956 2957 2958 2959

			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;
				}
			}
2960
		}
P
Philipp Reisner 已提交
2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977

		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);
		}
2978 2979 2980 2981 2982 2983
		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
2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994
		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));
2995
	return false;
P
Philipp Reisner 已提交
2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010
}

/* 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);
}

3011 3012
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3013
{
3014
	struct p_sizes *p = &mdev->tconn->data.rbuf.sizes;
P
Philipp Reisner 已提交
3015 3016 3017
	enum determine_dev_size dd = unchanged;
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
3018
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
3019 3020 3021 3022 3023 3024 3025

	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));
3026
		return false;
P
Philipp Reisner 已提交
3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054
	}

	/* 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. */
3055
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
3056 3057 3058 3059 3060 3061 3062
		   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);
3063
			return false;
P
Philipp Reisner 已提交
3064 3065 3066 3067
		}
		put_ldev(mdev);
	}

3068
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
3069
	if (get_ldev(mdev)) {
B
Bart Van Assche 已提交
3070
		dd = drbd_determine_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
3071 3072
		put_ldev(mdev);
		if (dd == dev_size_error)
3073
			return false;
P
Philipp Reisner 已提交
3074 3075 3076 3077 3078 3079
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

3080 3081 3082
	mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
	drbd_reconsider_max_bio_size(mdev);

P
Philipp Reisner 已提交
3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096
	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... */
3097
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3098 3099 3100 3101
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3102 3103 3104 3105 3106 3107
			    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
3108 3109 3110 3111
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3112
	return true;
P
Philipp Reisner 已提交
3113 3114
}

3115 3116
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3117
{
3118
	struct p_uuids *p = &mdev->tconn->data.rbuf.uuids;
P
Philipp Reisner 已提交
3119
	u64 *p_uuid;
3120
	int i, updated_uuids = 0;
P
Philipp Reisner 已提交
3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136

	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));
3137
		return false;
P
Philipp Reisner 已提交
3138 3139 3140 3141 3142
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
3143
			mdev->tconn->agreed_pro_version >= 90 &&
P
Philipp Reisner 已提交
3144 3145 3146 3147 3148
			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,
3149 3150
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3151 3152 3153 3154 3155
			_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);
3156
			updated_uuids = 1;
P
Philipp Reisner 已提交
3157 3158
		}
		put_ldev(mdev);
3159 3160 3161 3162
	} 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. */
3163
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3164 3165 3166 3167 3168 3169 3170 3171
	}

	/* Before we test for the disk state, we should wait until an eventually
	   ongoing cluster wide state change is finished. That is important if
	   we are primary and are detaching from our disk. We need to see the
	   new disk state... */
	wait_event(mdev->misc_wait, !test_bit(CLUSTER_ST_CHANGE, &mdev->flags));
	if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
3172 3173 3174 3175
		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
3176

3177
	return true;
P
Philipp Reisner 已提交
3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209
}

/**
 * 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;
}

3210 3211
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3212
{
3213
	struct p_req_state *p = &mdev->tconn->data.rbuf.req_state;
P
Philipp Reisner 已提交
3214
	union drbd_state mask, val;
3215
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3216 3217 3218 3219

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

3220
	if (test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags) &&
P
Philipp Reisner 已提交
3221 3222
	    test_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
		drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
3223
		return true;
P
Philipp Reisner 已提交
3224 3225 3226 3227 3228 3229 3230 3231 3232 3233
	}

	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);

3234
	return true;
P
Philipp Reisner 已提交
3235 3236
}

3237 3238
static int receive_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3239
{
3240
	struct p_state *p = &mdev->tconn->data.rbuf.state;
3241
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3242
	enum drbd_disk_state real_peer_disk;
3243
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3244 3245 3246 3247 3248 3249 3250 3251 3252 3253
	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));
	}

3254
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3255
 retry:
3256
	os = ns = mdev->state;
3257
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3258

3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279
	/* 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);
3280
			return true;
3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292
		}
	}

	/* 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;

3293 3294
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3295

3296 3297 3298
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3299 3300 3301 3302 3303
	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 */
3304
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3305 3306
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3307
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3308
		       (peer_state.disk == D_NEGOTIATING ||
3309
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3310 3311 3312 3313 3314
		/* 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" */
3315
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3316 3317 3318 3319
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3320
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3321 3322

		put_ldev(mdev);
3323 3324
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3325
			if (mdev->state.disk == D_NEGOTIATING) {
3326
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3327 3328 3329
			} 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;
3330
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3331
			} else {
3332
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
3333
					return false;
3334
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
P
Philipp Reisner 已提交
3335
				drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3336
				return false;
P
Philipp Reisner 已提交
3337 3338 3339 3340
			}
		}
	}

3341
	spin_lock_irq(&mdev->tconn->req_lock);
3342
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3343 3344 3345 3346 3347
		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);
3348
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3349
		ns.disk = mdev->new_state_tmp.disk;
3350 3351
	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 &&
3352
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
3353
		/* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
3354
		   for temporal network outages! */
3355
		spin_unlock_irq(&mdev->tconn->req_lock);
3356 3357 3358 3359 3360
		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));
3361
		return false;
3362
	}
3363
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3364
	ns = mdev->state;
3365
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3366 3367 3368

	if (rv < SS_SUCCESS) {
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3369
		return false;
P
Philipp Reisner 已提交
3370 3371
	}

3372 3373
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3374 3375 3376 3377 3378 3379 3380 3381 3382
		    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);
		}
	}

3383
	mdev->tconn->net_conf->want_lose = 0;
P
Philipp Reisner 已提交
3384 3385 3386

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

3387
	return true;
P
Philipp Reisner 已提交
3388 3389
}

3390 3391
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3392
{
3393
	struct p_rs_uuid *p = &mdev->tconn->data.rbuf.rs_uuid;
P
Philipp Reisner 已提交
3394 3395 3396

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3397
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408
		   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);

3409
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3410 3411 3412 3413 3414 3415
		drbd_start_resync(mdev, C_SYNC_TARGET);

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

3416
	return true;
P
Philipp Reisner 已提交
3417 3418
}

3419 3420 3421 3422 3423 3424 3425
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3426 3427
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
3428 3429 3430
{
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3431
	int err;
P
Philipp Reisner 已提交
3432

3433 3434
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3435
		return -EIO;
P
Philipp Reisner 已提交
3436 3437
	}
	if (want == 0)
3438
		return 0;
3439
	err = drbd_recv(mdev->tconn, buffer, want);
3440 3441 3442 3443 3444
	if (err != want) {
		if (err >= 0)
			err = -EIO;
		return err;
	}
P
Philipp Reisner 已提交
3445 3446 3447 3448 3449 3450 3451 3452

	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;

3453
	return 1;
P
Philipp Reisner 已提交
3454 3455
}

3456 3457 3458 3459 3460 3461 3462
/**
 * 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
3463 3464
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3465 3466
		 struct bm_xfer_ctx *c,
		 unsigned int len)
P
Philipp Reisner 已提交
3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481
{
	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)
3482
		return -EIO;
P
Philipp Reisner 已提交
3483 3484 3485 3486

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3487
			return -EIO;
P
Philipp Reisner 已提交
3488 3489 3490 3491 3492

		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);
3493
				return -EIO;
P
Philipp Reisner 已提交
3494 3495 3496 3497 3498 3499 3500 3501 3502
			}
			_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);
3503
			return -EIO;
P
Philipp Reisner 已提交
3504 3505 3506 3507 3508 3509
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3510
			return -EIO;
P
Philipp Reisner 已提交
3511 3512 3513 3514 3515 3516 3517
		look_ahead |= tmp << have;
		have += bits;
	}

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

3518
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3519 3520
}

3521 3522 3523 3524 3525 3526 3527
/**
 * 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
3528 3529
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3530 3531
		struct bm_xfer_ctx *c,
		unsigned int len)
P
Philipp Reisner 已提交
3532 3533
{
	if (DCBP_get_code(p) == RLE_VLI_Bits)
3534
		return recv_bm_rle_bits(mdev, p, c, len);
P
Philipp Reisner 已提交
3535 3536 3537 3538 3539 3540 3541

	/* 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));
3542
	return -EIO;
P
Philipp Reisner 已提交
3543 3544 3545 3546 3547 3548
}

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" */
3549
	unsigned plain = sizeof(struct p_header) *
P
Philipp Reisner 已提交
3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586
		((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. */
3587 3588
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
			  unsigned int data_size)
P
Philipp Reisner 已提交
3589 3590 3591
{
	struct bm_xfer_ctx c;
	void *buffer;
3592
	int err;
3593
	int ok = false;
3594
	struct p_header *h = &mdev->tconn->data.rbuf.header;
3595
	struct packet_info pi;
P
Philipp Reisner 已提交
3596

3597 3598 3599
	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
3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613

	/* 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),
	};

3614
	for(;;) {
3615
		if (cmd == P_BITMAP) {
3616
			err = receive_bitmap_plain(mdev, data_size, buffer, &c);
3617
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3618 3619 3620 3621
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3622
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3623 3624 3625 3626 3627 3628
				dev_err(DEV, "ReportCBitmap packet too large\n");
				goto out;
			}
			/* use the page buff */
			p = buffer;
			memcpy(p, h, sizeof(*h));
3629
			if (drbd_recv(mdev->tconn, p->head.payload, data_size) != data_size)
P
Philipp Reisner 已提交
3630
				goto out;
3631 3632
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3633
				goto out;
P
Philipp Reisner 已提交
3634
			}
3635
			err = decode_bitmap_c(mdev, p, &c, data_size);
P
Philipp Reisner 已提交
3636
		} else {
3637
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
P
Philipp Reisner 已提交
3638 3639 3640
			goto out;
		}

3641
		c.packets[cmd == P_BITMAP]++;
3642
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header) + data_size;
P
Philipp Reisner 已提交
3643

3644 3645 3646
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3647
			break;
3648
		}
3649
		if (!drbd_recv_header(mdev->tconn, &pi))
P
Philipp Reisner 已提交
3650
			goto out;
3651 3652
		cmd = pi.cmd;
		data_size = pi.size;
3653
	}
P
Philipp Reisner 已提交
3654 3655 3656 3657

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

	if (mdev->state.conn == C_WF_BITMAP_T) {
3658 3659
		enum drbd_state_rv rv;

P
Philipp Reisner 已提交
3660 3661 3662 3663
		ok = !drbd_send_bitmap(mdev);
		if (!ok)
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3664 3665
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3666 3667 3668 3669 3670 3671 3672
	} 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));
	}

3673
	ok = true;
P
Philipp Reisner 已提交
3674
 out:
3675
	drbd_bm_unlock(mdev);
P
Philipp Reisner 已提交
3676 3677 3678 3679 3680 3681
	if (ok && mdev->state.conn == C_WF_BITMAP_S)
		drbd_start_resync(mdev, C_SYNC_SOURCE);
	free_page((unsigned long) buffer);
	return ok;
}

3682 3683
static int receive_skip(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
Philipp Reisner 已提交
3684 3685 3686 3687 3688
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3689 3690
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);
P
Philipp Reisner 已提交
3691

3692
	size = data_size;
P
Philipp Reisner 已提交
3693 3694
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
3695
		r = drbd_recv(mdev->tconn, sink, want);
3696 3697
		if (!expect(r > 0))
			break;
P
Philipp Reisner 已提交
3698 3699 3700 3701 3702
		size -= r;
	}
	return size == 0;
}

3703 3704
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packet cmd,
				unsigned int data_size)
3705
{
3706 3707
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
3708
	drbd_tcp_quickack(mdev->tconn->data.socket);
3709

3710
	return true;
3711 3712
}

3713 3714
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
3715
{
3716
	struct p_block_desc *p = &mdev->tconn->data.rbuf.block_desc;
3717

3718 3719 3720 3721 3722 3723 3724 3725 3726 3727
	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));
	}

3728 3729
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3730
	return true;
3731 3732
}

3733 3734
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packet cmd,
				  unsigned int to_receive);
3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746

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 } ,
3747 3748 3749
	[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 },
3750 3751
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
3752 3753
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header), receive_SyncParam },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header), receive_SyncParam },
3754 3755 3756 3757 3758 3759 3760 3761 3762 3763
	[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 },
3764
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
P
Philipp Reisner 已提交
3765 3766
	/* anything missing from this table is in
	 * the asender_tbl, see get_asender_cmd */
3767
	[P_MAX_CMD]	    = { 0, 0, NULL },
P
Philipp Reisner 已提交
3768 3769
};

3770
/* All handler functions that expect a sub-header get that sub-heder in
3771
   mdev->tconn->data.rbuf.header.head.payload.
3772

3773
   Usually in mdev->tconn->data.rbuf.header.head the callback can find the usual
3774 3775
   p_header, but they may not rely on that. Since there is also p_header95 !
 */
P
Philipp Reisner 已提交
3776

3777
static void drbdd(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3778
{
3779
	struct p_header *header = &tconn->data.rbuf.header;
3780
	struct packet_info pi;
3781 3782
	size_t shs; /* sub header size */
	int rv;
P
Philipp Reisner 已提交
3783

3784 3785 3786
	while (get_t_state(&tconn->receiver) == RUNNING) {
		drbd_thread_current_set_cpu(&tconn->receiver);
		if (!drbd_recv_header(tconn, &pi))
3787
			goto err_out;
P
Philipp Reisner 已提交
3788

3789
		if (unlikely(pi.cmd >= P_MAX_CMD || !drbd_cmd_handler[pi.cmd].function)) {
3790
			conn_err(tconn, "unknown packet type %d, l: %d!\n", pi.cmd, pi.size);
3791
			goto err_out;
3792
		}
P
Philipp Reisner 已提交
3793

3794 3795
		shs = drbd_cmd_handler[pi.cmd].pkt_size - sizeof(struct p_header);
		if (pi.size - shs > 0 && !drbd_cmd_handler[pi.cmd].expect_payload) {
3796
			conn_err(tconn, "No payload expected %s l:%d\n", cmdname(pi.cmd), pi.size);
3797
			goto err_out;
P
Philipp Reisner 已提交
3798 3799
		}

3800
		if (shs) {
3801
			rv = drbd_recv(tconn, &header->payload, shs);
3802
			if (unlikely(rv != shs)) {
3803
				if (!signal_pending(current))
3804
					conn_warn(tconn, "short read while reading sub header: rv=%d\n", rv);
3805 3806 3807 3808
				goto err_out;
			}
		}

3809
		rv = drbd_cmd_handler[pi.cmd].function(vnr_to_mdev(tconn, pi.vnr), pi.cmd, pi.size - shs);
P
Philipp Reisner 已提交
3810

3811
		if (unlikely(!rv)) {
3812
			conn_err(tconn, "error receiving %s, l: %d!\n",
3813
			    cmdname(pi.cmd), pi.size);
3814
			goto err_out;
P
Philipp Reisner 已提交
3815 3816 3817
		}
	}

3818 3819
	if (0) {
	err_out:
3820
		conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
3821
	}
P
Philipp Reisner 已提交
3822 3823
}

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

	barr.w.cb = w_prev_work_done;
3829
	barr.w.mdev = mdev;
P
Philipp Reisner 已提交
3830
	init_completion(&barr.done);
3831
	drbd_queue_work(&mdev->tconn->data.work, &barr.w);
P
Philipp Reisner 已提交
3832 3833 3834
	wait_for_completion(&barr.done);
}

3835
static void drbd_disconnect(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3836
{
3837
	enum drbd_conns oc;
P
Philipp Reisner 已提交
3838 3839
	int rv = SS_UNKNOWN_ERROR;

3840
	if (tconn->cstate == C_STANDALONE)
P
Philipp Reisner 已提交
3841 3842 3843
		return;

	/* asender does not clean up anything. it must not interfere, either */
3844 3845 3846 3847 3848 3849 3850 3851
	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);
3852 3853 3854 3855
	oc = tconn->cstate;
	if (oc >= C_UNCONNECTED)
		rv = _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);

3856 3857
	spin_unlock_irq(&tconn->req_lock);

3858
	if (oc == C_DISCONNECTING) {
3859 3860 3861 3862 3863 3864 3865
		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;
3866
		conn_request_state(tconn, NS(conn, C_STANDALONE), CS_VERBOSE);
3867 3868 3869 3870 3871 3872 3873 3874
	}
}

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
3875

3876
	/* wait for current activity to cease. */
3877
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3878 3879 3880
	_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);
3881
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898

	/* 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);

3899 3900
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
3901 3902 3903 3904 3905 3906 3907
	/* 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" */
3908
	drbd_flush_workqueue(mdev);
P
Philipp Reisner 已提交
3909 3910 3911 3912 3913 3914 3915 3916

	/* 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;

3917
	if (!is_susp(mdev->state))
P
Philipp Reisner 已提交
3918 3919 3920 3921 3922 3923 3924 3925 3926 3927
		tl_clear(mdev);

	drbd_md_sync(mdev);

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

3928 3929
	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
3930

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

	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));
3960 3961

	return 0;
P
Philipp Reisner 已提交
3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972
}

/*
 * 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.
 */
3973
static int drbd_send_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3974
{
3975
	/* ASSERT current == mdev->tconn->receiver ... */
3976
	struct p_handshake *p = &tconn->data.sbuf.handshake;
P
Philipp Reisner 已提交
3977 3978
	int ok;

3979 3980
	if (mutex_lock_interruptible(&tconn->data.mutex)) {
		conn_err(tconn, "interrupted during initial handshake\n");
P
Philipp Reisner 已提交
3981 3982 3983
		return 0; /* interrupted. not ok. */
	}

3984 3985
	if (tconn->data.socket == NULL) {
		mutex_unlock(&tconn->data.mutex);
P
Philipp Reisner 已提交
3986 3987 3988 3989 3990 3991
		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);
3992 3993 3994
	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
3995 3996 3997 3998 3999 4000 4001 4002 4003 4004
	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.
 */
4005
static int drbd_do_handshake(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4006
{
4007 4008
	/* ASSERT current == tconn->receiver ... */
	struct p_handshake *p = &tconn->data.rbuf.handshake;
4009
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
4010
	struct packet_info pi;
P
Philipp Reisner 已提交
4011 4012
	int rv;

4013
	rv = drbd_send_handshake(tconn);
P
Philipp Reisner 已提交
4014 4015 4016
	if (!rv)
		return 0;

4017
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4018 4019 4020
	if (!rv)
		return 0;

4021
	if (pi.cmd != P_HAND_SHAKE) {
4022
		conn_err(tconn, "expected HandShake packet, received: %s (0x%04x)\n",
4023
		     cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4024 4025 4026
		return -1;
	}

4027
	if (pi.size != expect) {
4028
		conn_err(tconn, "expected HandShake length: %u, received: %u\n",
4029
		     expect, pi.size);
P
Philipp Reisner 已提交
4030 4031 4032
		return -1;
	}

4033
	rv = drbd_recv(tconn, &p->head.payload, expect);
P
Philipp Reisner 已提交
4034 4035

	if (rv != expect) {
4036
		if (!signal_pending(current))
4037
			conn_warn(tconn, "short read receiving handshake packet: l=%u\n", rv);
P
Philipp Reisner 已提交
4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049
		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;

4050
	tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
P
Philipp Reisner 已提交
4051

4052 4053
	conn_info(tconn, "Handshake successful: "
	     "Agreed network protocol version %d\n", tconn->agreed_pro_version);
P
Philipp Reisner 已提交
4054 4055 4056 4057

	return 1;

 incompat:
4058
	conn_err(tconn, "incompatible DRBD dialects: "
P
Philipp Reisner 已提交
4059 4060 4061 4062 4063 4064 4065
	    "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)
4066
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4067 4068 4069
{
	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");
4070
	return -1;
P
Philipp Reisner 已提交
4071 4072 4073
}
#else
#define CHALLENGE_LEN 64
4074 4075 4076 4077 4078 4079 4080

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

4081
static int drbd_do_auth(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
4082 4083 4084 4085 4086 4087
{
	char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
	struct scatterlist sg;
	char *response = NULL;
	char *right_response = NULL;
	char *peers_ch = NULL;
4088
	unsigned int key_len = strlen(tconn->net_conf->shared_secret);
P
Philipp Reisner 已提交
4089 4090
	unsigned int resp_size;
	struct hash_desc desc;
4091
	struct packet_info pi;
P
Philipp Reisner 已提交
4092 4093
	int rv;

4094
	desc.tfm = tconn->cram_hmac_tfm;
P
Philipp Reisner 已提交
4095 4096
	desc.flags = 0;

4097 4098
	rv = crypto_hash_setkey(tconn->cram_hmac_tfm,
				(u8 *)tconn->net_conf->shared_secret, key_len);
P
Philipp Reisner 已提交
4099
	if (rv) {
4100
		conn_err(tconn, "crypto_hash_setkey() failed with %d\n", rv);
4101
		rv = -1;
P
Philipp Reisner 已提交
4102 4103 4104 4105 4106
		goto fail;
	}

	get_random_bytes(my_challenge, CHALLENGE_LEN);

4107
	rv = conn_send_cmd2(tconn, P_AUTH_CHALLENGE, my_challenge, CHALLENGE_LEN);
P
Philipp Reisner 已提交
4108 4109 4110
	if (!rv)
		goto fail;

4111
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4112 4113 4114
	if (!rv)
		goto fail;

4115
	if (pi.cmd != P_AUTH_CHALLENGE) {
4116
		conn_err(tconn, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4117
		    cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4118 4119 4120 4121
		rv = 0;
		goto fail;
	}

4122
	if (pi.size > CHALLENGE_LEN * 2) {
4123
		conn_err(tconn, "expected AuthChallenge payload too big.\n");
4124
		rv = -1;
P
Philipp Reisner 已提交
4125 4126 4127
		goto fail;
	}

4128
	peers_ch = kmalloc(pi.size, GFP_NOIO);
P
Philipp Reisner 已提交
4129
	if (peers_ch == NULL) {
4130
		conn_err(tconn, "kmalloc of peers_ch failed\n");
4131
		rv = -1;
P
Philipp Reisner 已提交
4132 4133 4134
		goto fail;
	}

4135
	rv = drbd_recv(tconn, peers_ch, pi.size);
P
Philipp Reisner 已提交
4136

4137
	if (rv != pi.size) {
4138
		if (!signal_pending(current))
4139
			conn_warn(tconn, "short read AuthChallenge: l=%u\n", rv);
P
Philipp Reisner 已提交
4140 4141 4142 4143
		rv = 0;
		goto fail;
	}

4144
	resp_size = crypto_hash_digestsize(tconn->cram_hmac_tfm);
P
Philipp Reisner 已提交
4145 4146
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
4147
		conn_err(tconn, "kmalloc of response failed\n");
4148
		rv = -1;
P
Philipp Reisner 已提交
4149 4150 4151 4152
		goto fail;
	}

	sg_init_table(&sg, 1);
4153
	sg_set_buf(&sg, peers_ch, pi.size);
P
Philipp Reisner 已提交
4154 4155 4156

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
4157
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4158
		rv = -1;
P
Philipp Reisner 已提交
4159 4160 4161
		goto fail;
	}

4162
	rv = conn_send_cmd2(tconn, P_AUTH_RESPONSE, response, resp_size);
P
Philipp Reisner 已提交
4163 4164 4165
	if (!rv)
		goto fail;

4166
	rv = drbd_recv_header(tconn, &pi);
P
Philipp Reisner 已提交
4167 4168 4169
	if (!rv)
		goto fail;

4170
	if (pi.cmd != P_AUTH_RESPONSE) {
4171
		conn_err(tconn, "expected AuthResponse packet, received: %s (0x%04x)\n",
4172
			cmdname(pi.cmd), pi.cmd);
P
Philipp Reisner 已提交
4173 4174 4175 4176
		rv = 0;
		goto fail;
	}

4177
	if (pi.size != resp_size) {
4178
		conn_err(tconn, "expected AuthResponse payload of wrong size\n");
P
Philipp Reisner 已提交
4179 4180 4181 4182
		rv = 0;
		goto fail;
	}

4183
	rv = drbd_recv(tconn, response , resp_size);
P
Philipp Reisner 已提交
4184 4185

	if (rv != resp_size) {
4186
		if (!signal_pending(current))
4187
			conn_warn(tconn, "short read receiving AuthResponse: l=%u\n", rv);
P
Philipp Reisner 已提交
4188 4189 4190 4191 4192
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4193
	if (right_response == NULL) {
4194
		conn_err(tconn, "kmalloc of right_response failed\n");
4195
		rv = -1;
P
Philipp Reisner 已提交
4196 4197 4198 4199 4200 4201 4202
		goto fail;
	}

	sg_set_buf(&sg, my_challenge, CHALLENGE_LEN);

	rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
	if (rv) {
4203
		conn_err(tconn, "crypto_hash_digest() failed with %d\n", rv);
4204
		rv = -1;
P
Philipp Reisner 已提交
4205 4206 4207 4208 4209 4210
		goto fail;
	}

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

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

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

	return rv;
}
#endif

int drbdd_init(struct drbd_thread *thi)
{
4227
	struct drbd_tconn *tconn = thi->tconn;
P
Philipp Reisner 已提交
4228 4229
	int h;

4230
	conn_info(tconn, "receiver (re)started\n");
P
Philipp Reisner 已提交
4231 4232

	do {
4233
		h = drbd_connect(tconn);
P
Philipp Reisner 已提交
4234
		if (h == 0) {
4235
			drbd_disconnect(tconn);
4236
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4237 4238
		}
		if (h == -1) {
4239
			conn_warn(tconn, "Discarding network configuration.\n");
4240
			conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
4241 4242 4243 4244
		}
	} while (h == 0);

	if (h > 0) {
4245 4246 4247
		if (get_net_conf(tconn)) {
			drbdd(tconn);
			put_net_conf(tconn);
P
Philipp Reisner 已提交
4248 4249 4250
		}
	}

4251
	drbd_disconnect(tconn);
P
Philipp Reisner 已提交
4252

4253
	conn_info(tconn, "receiver terminated\n");
P
Philipp Reisner 已提交
4254 4255 4256 4257 4258
	return 0;
}

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

4259
static int got_RqSReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4260
{
4261
	struct p_req_state_reply *p = &mdev->tconn->meta.rbuf.req_state_reply;
P
Philipp Reisner 已提交
4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273

	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);

4274
	return true;
P
Philipp Reisner 已提交
4275 4276
}

4277
static int got_Ping(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4278
{
4279
	return drbd_send_ping_ack(mdev->tconn);
P
Philipp Reisner 已提交
4280 4281 4282

}

4283
static int got_PingAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4284
{
4285
	struct drbd_tconn *tconn = mdev->tconn;
P
Philipp Reisner 已提交
4286
	/* restore idle timeout */
4287 4288 4289
	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
4290

4291
	return true;
P
Philipp Reisner 已提交
4292 4293
}

4294
static int got_IsInSync(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4295
{
4296
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4297 4298 4299
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

4300
	D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
4301 4302 4303

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

4304 4305 4306 4307 4308 4309 4310
	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
4311
	dec_rs_pending(mdev);
4312
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4313

4314
	return true;
P
Philipp Reisner 已提交
4315 4316
}

4317 4318 4319 4320
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
4321 4322 4323 4324
{
	struct drbd_request *req;
	struct bio_and_error m;

4325
	spin_lock_irq(&mdev->tconn->req_lock);
4326
	req = find_request(mdev, root, id, sector, missing_ok, func);
P
Philipp Reisner 已提交
4327
	if (unlikely(!req)) {
4328
		spin_unlock_irq(&mdev->tconn->req_lock);
4329
		return false;
P
Philipp Reisner 已提交
4330 4331
	}
	__req_mod(req, what, &m);
4332
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4333 4334 4335

	if (m.bio)
		complete_master_bio(mdev, &m);
4336
	return true;
P
Philipp Reisner 已提交
4337 4338
}

4339
static int got_BlockAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4340
{
4341
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4342 4343 4344 4345 4346 4347
	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));

4348
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4349 4350
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4351
		return true;
P
Philipp Reisner 已提交
4352
	}
4353
	switch (cmd) {
P
Philipp Reisner 已提交
4354
	case P_RS_WRITE_ACK:
4355
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4356
		what = WRITE_ACKED_BY_PEER_AND_SIS;
P
Philipp Reisner 已提交
4357 4358
		break;
	case P_WRITE_ACK:
4359
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4360
		what = WRITE_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4361 4362
		break;
	case P_RECV_ACK:
4363
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
4364
		what = RECV_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4365 4366
		break;
	case P_DISCARD_ACK:
4367
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4368
		what = CONFLICT_DISCARDED_BY_PEER;
P
Philipp Reisner 已提交
4369 4370 4371
		break;
	default:
		D_ASSERT(0);
4372
		return false;
P
Philipp Reisner 已提交
4373 4374 4375
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
4376 4377
					     &mdev->write_requests, __func__,
					     what, false);
P
Philipp Reisner 已提交
4378 4379
}

4380
static int got_NegAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4381
{
4382
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4383
	sector_t sector = be64_to_cpu(p->sector);
4384
	int size = be32_to_cpu(p->blksize);
4385 4386
	bool missing_ok = mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A ||
			  mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B;
4387
	bool found;
P
Philipp Reisner 已提交
4388 4389 4390

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

4391
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4392 4393
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4394
		return true;
P
Philipp Reisner 已提交
4395
	}
4396

4397
	found = validate_req_change_req_state(mdev, p->block_id, sector,
4398
					      &mdev->write_requests, __func__,
4399
					      NEG_ACKED, missing_ok);
4400 4401 4402 4403 4404 4405 4406
	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)
4407
			return false;
4408
		drbd_set_out_of_sync(mdev, sector, size);
4409 4410
	}
	return true;
P
Philipp Reisner 已提交
4411 4412
}

4413
static int got_NegDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4414
{
4415
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4416 4417 4418 4419 4420 4421 4422
	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,
4423
					     &mdev->read_requests, __func__,
4424
					     NEG_ACKED, false);
P
Philipp Reisner 已提交
4425 4426
}

4427
static int got_NegRSDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4428 4429 4430
{
	sector_t sector;
	int size;
4431
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4432 4433 4434 4435 4436 4437 4438 4439 4440 4441

	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);
4442
		switch (cmd) {
4443 4444 4445 4446 4447 4448 4449 4450 4451
		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
4452 4453 4454
		put_ldev(mdev);
	}

4455
	return true;
P
Philipp Reisner 已提交
4456 4457
}

4458
static int got_BarrierAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4459
{
4460
	struct p_barrier_ack *p = &mdev->tconn->meta.rbuf.barrier_ack;
P
Philipp Reisner 已提交
4461 4462 4463

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

4464 4465
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4466 4467 4468
	    !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);
4469 4470
	}

4471
	return true;
P
Philipp Reisner 已提交
4472 4473
}

4474
static int got_OVResult(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4475
{
4476
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490
	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);

4491
	if (!get_ldev(mdev))
4492
		return true;
4493

P
Philipp Reisner 已提交
4494 4495 4496
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4497 4498 4499 4500 4501 4502 4503
	--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
4504 4505 4506
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
4507
			w->mdev = mdev;
4508
			drbd_queue_work_front(&mdev->tconn->data.work, w);
P
Philipp Reisner 已提交
4509 4510 4511 4512 4513 4514
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
			ov_oos_print(mdev);
			drbd_resync_finished(mdev);
		}
	}
4515
	put_ldev(mdev);
4516
	return true;
P
Philipp Reisner 已提交
4517 4518
}

4519
static int got_skip(struct drbd_conf *mdev, enum drbd_packet cmd)
4520
{
4521
	return true;
4522 4523
}

P
Philipp Reisner 已提交
4524 4525
struct asender_cmd {
	size_t pkt_size;
4526
	int (*process)(struct drbd_conf *mdev, enum drbd_packet cmd);
P
Philipp Reisner 已提交
4527 4528 4529 4530 4531 4532 4533 4534
};

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() */
4535 4536
	[P_PING]	    = { sizeof(struct p_header), got_Ping },
	[P_PING_ACK]	    = { sizeof(struct p_header), got_PingAck },
P
Philipp Reisner 已提交
4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547
	[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 },
4548
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
4549
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply},
P
Philipp Reisner 已提交
4550 4551 4552 4553 4554 4555 4556
	[P_MAX_CMD]	    = { 0, NULL },
	};
	if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)
		return NULL;
	return &asender_tbl[cmd];
}

4557 4558 4559 4560 4561 4562 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
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
4593 4594
int drbd_asender(struct drbd_thread *thi)
{
4595
	struct drbd_tconn *tconn = thi->tconn;
4596
	struct p_header *h = &tconn->meta.rbuf.header;
P
Philipp Reisner 已提交
4597
	struct asender_cmd *cmd = NULL;
4598
	struct packet_info pi;
4599
	int rv;
P
Philipp Reisner 已提交
4600 4601
	void *buf    = h;
	int received = 0;
4602
	int expect   = sizeof(struct p_header);
4603
	int ping_timeout_active = 0;
P
Philipp Reisner 已提交
4604 4605 4606 4607

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

4608
	while (get_t_state(thi) == RUNNING) {
4609
		drbd_thread_current_set_cpu(thi);
4610
		if (test_and_clear_bit(SEND_PING, &tconn->flags)) {
4611
			if (!drbd_send_ping(tconn)) {
4612
				conn_err(tconn, "drbd_send_ping has failed\n");
4613 4614
				goto reconnect;
			}
4615 4616
			tconn->meta.socket->sk->sk_rcvtimeo =
				tconn->net_conf->ping_timeo*HZ/10;
4617
			ping_timeout_active = 1;
P
Philipp Reisner 已提交
4618 4619
		}

4620 4621 4622 4623 4624 4625
		/* 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
4626
		/* but unconditionally uncork unless disabled */
4627 4628
		if (!tconn->net_conf->no_cork)
			drbd_tcp_uncork(tconn->meta.socket);
P
Philipp Reisner 已提交
4629 4630 4631 4632 4633

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

4634 4635
		rv = drbd_recv_short(tconn->meta.socket, buf, expect-received, 0);
		clear_bit(SIGNAL_ASENDER, &tconn->flags);
P
Philipp Reisner 已提交
4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652

		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) {
4653
			conn_err(tconn, "meta connection shut down by peer.\n");
P
Philipp Reisner 已提交
4654 4655
			goto reconnect;
		} else if (rv == -EAGAIN) {
4656 4657
			/* If the data socket received something meanwhile,
			 * that is good enough: peer is still alive. */
4658 4659
			if (time_after(tconn->last_received,
				jiffies - tconn->meta.socket->sk->sk_rcvtimeo))
4660
				continue;
4661
			if (ping_timeout_active) {
4662
				conn_err(tconn, "PingAck did not arrive in time.\n");
P
Philipp Reisner 已提交
4663 4664
				goto reconnect;
			}
4665
			set_bit(SEND_PING, &tconn->flags);
P
Philipp Reisner 已提交
4666 4667 4668 4669
			continue;
		} else if (rv == -EINTR) {
			continue;
		} else {
4670
			conn_err(tconn, "sock_recvmsg returned %d\n", rv);
P
Philipp Reisner 已提交
4671 4672 4673 4674
			goto reconnect;
		}

		if (received == expect && cmd == NULL) {
4675
			if (!decode_header(tconn, h, &pi))
P
Philipp Reisner 已提交
4676
				goto reconnect;
4677
			cmd = get_asender_cmd(pi.cmd);
P
Philipp Reisner 已提交
4678
			if (unlikely(cmd == NULL)) {
4679
				conn_err(tconn, "unknown command %d on meta (l: %d)\n",
4680
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4681 4682 4683
				goto disconnect;
			}
			expect = cmd->pkt_size;
4684
			if (pi.size != expect - sizeof(struct p_header)) {
4685
				conn_err(tconn, "Wrong packet size on meta (c: %d, l: %d)\n",
4686
					pi.cmd, pi.size);
P
Philipp Reisner 已提交
4687
				goto reconnect;
4688
			}
P
Philipp Reisner 已提交
4689 4690
		}
		if (received == expect) {
4691 4692
			tconn->last_received = jiffies;
			if (!cmd->process(vnr_to_mdev(tconn, pi.vnr), pi.cmd))
P
Philipp Reisner 已提交
4693 4694
				goto reconnect;

4695 4696 4697 4698 4699
			/* 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
4700 4701
			buf	 = h;
			received = 0;
4702
			expect	 = sizeof(struct p_header);
P
Philipp Reisner 已提交
4703 4704 4705 4706 4707 4708
			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
4709
		conn_request_state(tconn, NS(conn, C_NETWORK_FAILURE), CS_HARD);
P
Philipp Reisner 已提交
4710 4711 4712
	}
	if (0) {
disconnect:
4713
		conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
P
Philipp Reisner 已提交
4714
	}
4715
	clear_bit(SIGNAL_ASENDER, &tconn->flags);
P
Philipp Reisner 已提交
4716

4717
	conn_info(tconn, "asender terminated\n");
P
Philipp Reisner 已提交
4718 4719 4720

	return 0;
}