drbd_receiver.c 129.4 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"

enum finish_epoch {
	FE_STILL_LIVE,
	FE_DESTROYED,
	FE_RECYCLED,
};

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

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


#define GFP_TRY	(__GFP_HIGHMEM | __GFP_NOWARN)

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

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

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

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

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

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

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

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

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

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

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

	if (i == number)
		return page;

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

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

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

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

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

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

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

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

		drbd_kick_lo_and_reclaim_net(mdev);

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

		if (!retry)
			break;

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

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

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

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

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

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

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

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

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	page = drbd_pp_alloc(mdev, nr_pages, (gfp_mask & __GFP_WAIT));
	if (!page)
		goto fail;
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	drbd_clear_interval(&e->i);
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	e->i.size = data_size;
	e->i.sector = sector;
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	e->i.local = false;
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	e->i.waiting = false;

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	e->epoch = NULL;
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	e->mdev = mdev;
	e->pages = page;
	atomic_set(&e->pending_bios, 0);
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	e->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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	e->block_id = id;
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	return e;

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

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

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


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

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

	return ok;
}

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

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

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

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

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

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

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

out:
	return err;
}

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

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

	return rv;
}

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

	oldfs = get_fs();
	set_fs(KERNEL_DS);

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

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

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

	set_fs(oldfs);

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

	return rv;
}

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

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

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

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

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

	what = "bind before connect";
	err = sock->ops->bind(sock,
			      (struct sockaddr *) &src_in6,
617
			      mdev->tconn->net_conf->my_addr_len);
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	if (err < 0)
		goto out;

	/* connect may fail, peer not yet available.
	 * stay C_WF_CONNECTION, don't go Disconnecting! */
	disconnect_on_error = 0;
	what = "connect";
	err = sock->ops->connect(sock,
626 627
				 (struct sockaddr *)mdev->tconn->net_conf->peer_addr,
				 mdev->tconn->net_conf->peer_addr_len, 0);
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out:
	if (err < 0) {
		if (sock) {
			sock_release(sock);
			sock = NULL;
		}
		switch (-err) {
			/* timeout, busy, signal pending */
		case ETIMEDOUT: case EAGAIN: case EINPROGRESS:
		case EINTR: case ERESTARTSYS:
			/* peer not (yet) available, network problem */
		case ECONNREFUSED: case ENETUNREACH:
		case EHOSTDOWN:    case EHOSTUNREACH:
			disconnect_on_error = 0;
			break;
		default:
			dev_err(DEV, "%s failed, err = %d\n", what, err);
		}
		if (disconnect_on_error)
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
	}
650
	put_net_conf(mdev->tconn);
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	return sock;
}

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

660
	if (!get_net_conf(mdev->tconn))
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661 662 663
		return NULL;

	what = "sock_create_kern";
664
	err = sock_create_kern(((struct sockaddr *)mdev->tconn->net_conf->my_addr)->sa_family,
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		SOCK_STREAM, IPPROTO_TCP, &s_listen);
	if (err) {
		s_listen = NULL;
		goto out;
	}

671
	timeo = mdev->tconn->net_conf->try_connect_int * HZ;
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	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;
677 678
	drbd_setbufsize(s_listen, mdev->tconn->net_conf->sndbuf_size,
			mdev->tconn->net_conf->rcvbuf_size);
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	what = "bind before listen";
	err = s_listen->ops->bind(s_listen,
682 683
			      (struct sockaddr *) mdev->tconn->net_conf->my_addr,
			      mdev->tconn->net_conf->my_addr_len);
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684 685 686 687 688 689 690 691 692 693 694 695 696 697
	if (err < 0)
		goto out;

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

out:
	if (s_listen)
		sock_release(s_listen);
	if (err < 0) {
		if (err != -EAGAIN && err != -EINTR && err != -ERESTARTSYS) {
			dev_err(DEV, "%s failed, err = %d\n", what, err);
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
		}
	}
698
	put_net_conf(mdev->tconn);
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	return s_estab;
}

703 704
static int drbd_send_fp(struct drbd_conf *mdev, struct socket *sock,
			enum drbd_packet cmd)
P
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705
{
706
	struct p_header *h = &mdev->tconn->data.sbuf.header;
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	return _drbd_send_cmd(mdev, sock, cmd, h, sizeof(*h), 0);
}

711 712
static enum drbd_packet drbd_recv_fp(struct drbd_conf *mdev,
				     struct socket *sock)
P
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713
{
714
	struct p_header80 *h = &mdev->tconn->data.rbuf.header.h80;
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715 716 717 718
	int rr;

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

719
	if (rr == sizeof(*h) && h->magic == cpu_to_be32(DRBD_MAGIC))
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720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735
		return be16_to_cpu(h->command);

	return 0xffff;
}

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

	if (!*sock)
736
		return false;
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	rr = drbd_recv_short(mdev, *sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);

	if (rr > 0 || rr == -EAGAIN) {
741
		return true;
P
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742 743 744
	} else {
		sock_release(*sock);
		*sock = NULL;
745
		return false;
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746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761
	}
}

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

762
	D_ASSERT(!mdev->tconn->data.socket);
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	if (drbd_request_state(mdev, NS(conn, C_WF_CONNECTION)) < SS_SUCCESS)
		return -2;

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

	do {
		for (try = 0;;) {
			/* 3 tries, this should take less than a second! */
			s = drbd_try_connect(mdev);
			if (s || ++try >= 3)
				break;
			/* give the other side time to call bind() & listen() */
782
			schedule_timeout_interruptible(HZ / 10);
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		}

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

		if (sock && msock) {
801
			schedule_timeout_interruptible(mdev->tconn->net_conf->ping_timeo*HZ/10);
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			ok = drbd_socket_okay(mdev, &sock);
			ok = drbd_socket_okay(mdev, &msock) && ok;
			if (ok)
				break;
		}

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

		if (mdev->state.conn <= C_DISCONNECTING)
			goto out_release_sockets;
		if (signal_pending(current)) {
			flush_signals(current);
			smp_rmb();
843
			if (get_t_state(&mdev->tconn->receiver) == EXITING)
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844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864
				goto out_release_sockets;
		}

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

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

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

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

	/* NOT YET ...
865
	 * sock->sk->sk_sndtimeo = mdev->tconn->net_conf->timeout*HZ/10;
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	 * sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
	 * first set it to the P_HAND_SHAKE timeout,
	 * which we set to 4x the configured ping_timeout. */
	sock->sk->sk_sndtimeo =
870
	sock->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_timeo*4*HZ/10;
P
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871

872 873
	msock->sk->sk_sndtimeo = mdev->tconn->net_conf->timeout*HZ/10;
	msock->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_int*HZ;
P
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874 875

	/* we don't want delays.
L
Lucas De Marchi 已提交
876
	 * we use TCP_CORK where appropriate, though */
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877 878 879
	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

880 881
	mdev->tconn->data.socket = sock;
	mdev->tconn->meta.socket = msock;
882
	mdev->tconn->last_received = jiffies;
P
Philipp Reisner 已提交
883

884
	D_ASSERT(mdev->tconn->asender.task == NULL);
P
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885 886 887 888 889

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

890
	if (mdev->tconn->cram_hmac_tfm) {
P
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891
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
892 893
		switch (drbd_do_auth(mdev)) {
		case -1:
P
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894 895
			dev_err(DEV, "Authentication of peer failed\n");
			return -1;
896 897 898
		case 0:
			dev_err(DEV, "Authentication of peer failed, trying again.\n");
			return 0;
P
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899 900 901 902 903 904
		}
	}

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

905
	sock->sk->sk_sndtimeo = mdev->tconn->net_conf->timeout*HZ/10;
P
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906 907 908 909 910
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

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

911
	drbd_thread_start(&mdev->tconn->asender);
P
Philipp Reisner 已提交
912

913
	if (drbd_send_protocol(mdev) == -1)
914
		return -1;
P
Philipp Reisner 已提交
915
	drbd_send_sync_param(mdev, &mdev->sync_conf);
916
	drbd_send_sizes(mdev, 0, 0);
P
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917 918 919 920
	drbd_send_uuids(mdev);
	drbd_send_state(mdev);
	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
	clear_bit(RESIZE_PENDING, &mdev->flags);
921
	mod_timer(&mdev->request_timer, jiffies + HZ); /* just start it here. */
P
Philipp Reisner 已提交
922 923 924 925 926 927 928 929 930 931 932

	return 1;

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

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

952 953
static int drbd_recv_header(struct drbd_conf *mdev, enum drbd_packet *cmd,
			    unsigned int *packet_size)
954 955 956 957 958 959 960 961 962 963 964 965
{
	struct p_header *h = &mdev->tconn->data.rbuf.header;
	int r;

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

	r = decode_header(mdev, h, cmd, packet_size);
966
	mdev->tconn->last_received = jiffies;
P
Philipp Reisner 已提交
967

968
	return r;
P
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969 970
}

971
static void drbd_flush(struct drbd_conf *mdev)
P
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972 973 974 975
{
	int rv;

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
976
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
977
					NULL);
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978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998
		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)
{
999
	int epoch_size;
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1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022
	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 &&
1023
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
P
Philipp Reisner 已提交
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
			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);
1043
				/* atomic_set(&epoch->active, 0); is already zero */
P
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1044 1045
				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1046
				wake_up(&mdev->ee_wait);
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1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081
			}
		}

		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;
1082
	if (pwo != mdev->write_ordering || wo == WO_bdev_flush)
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1083 1084 1085
		dev_info(DEV, "Method to ensure write ordering: %s\n", write_ordering_str[mdev->write_ordering]);
}

1086 1087 1088 1089 1090
/**
 * drbd_submit_ee()
 * @mdev:	DRBD device.
 * @e:		epoch entry
 * @rw:		flag field, see bio->bi_rw
1091 1092 1093 1094 1095 1096 1097 1098 1099 1100
 *
 * 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.
1101 1102 1103 1104 1105 1106 1107 1108
 */
/* TODO allocate from our own bio_set. */
int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e,
		const unsigned rw, const int fault_type)
{
	struct bio *bios = NULL;
	struct bio *bio;
	struct page *page = e->pages;
1109 1110
	sector_t sector = e->i.sector;
	unsigned ds = e->i.size;
1111 1112
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1113
	int err = -ENOMEM;
1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124

	/* 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;
	}
1125
	/* > e->i.sector, unless this is the first bio */
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138
	bio->bi_sector = sector;
	bio->bi_bdev = mdev->ldev->backing_bdev;
	bio->bi_rw = rw;
	bio->bi_private = e;
	bio->bi_end_io = drbd_endio_sec;

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

	page_chain_for_each(page) {
		unsigned len = min_t(unsigned, ds, PAGE_SIZE);
		if (!bio_add_page(bio, page, len, 0)) {
1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149
			/* 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;
			}
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174
			goto next_bio;
		}
		ds -= len;
		sector += len >> 9;
		--nr_pages;
	}
	D_ASSERT(page == NULL);
	D_ASSERT(ds == 0);

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

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

fail:
	while (bios) {
		bio = bios;
		bios = bios->bi_next;
		bio_put(bio);
	}
1175
	return err;
1176 1177
}

1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190
static void drbd_remove_epoch_entry_interval(struct drbd_conf *mdev,
					     struct drbd_epoch_entry *e)
{
	struct drbd_interval *i = &e->i;

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

	/* Wake up any processes waiting for this epoch entry to complete.  */
	if (i->waiting)
		wake_up(&mdev->misc_wait);
}

1191 1192
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packet cmd,
			   unsigned int data_size)
P
Philipp Reisner 已提交
1193
{
1194
	int rv;
1195
	struct p_barrier *p = &mdev->tconn->data.rbuf.barrier;
P
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1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
	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)
1211
			return true;
1212 1213 1214 1215 1216 1217 1218 1219 1220

		/* 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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1221 1222 1223 1224

	case WO_bdev_flush:
	case WO_drain_io:
		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
1225 1226 1227 1228 1229 1230
		drbd_flush(mdev);

		if (atomic_read(&mdev->current_epoch->epoch_size)) {
			epoch = kmalloc(sizeof(struct drbd_epoch), GFP_NOIO);
			if (epoch)
				break;
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1231 1232
		}

1233 1234 1235 1236 1237
		epoch = mdev->current_epoch;
		wait_event(mdev->ee_wait, atomic_read(&epoch->epoch_size) == 0);

		D_ASSERT(atomic_read(&epoch->active) == 0);
		D_ASSERT(epoch->flags == 0);
P
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1238

1239
		return true;
1240 1241
	default:
		dev_err(DEV, "Strangeness in mdev->write_ordering %d\n", mdev->write_ordering);
1242
		return false;
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1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
	}

	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);

1260
	return true;
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1261 1262 1263 1264 1265 1266 1267
}

/* used from receive_RSDataReply (recv_resync_read)
 * and from receive_Data */
static struct drbd_epoch_entry *
read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector, int data_size) __must_hold(local)
{
1268
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
P
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1269 1270
	struct drbd_epoch_entry *e;
	struct page *page;
1271
	int dgs, ds, rr;
1272 1273
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
1274
	unsigned long *data;
P
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1276 1277
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
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1278 1279 1280 1281

	if (dgs) {
		rr = drbd_recv(mdev, dig_in, dgs);
		if (rr != dgs) {
1282 1283 1284 1285
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data digest: read %d expected %d\n",
					rr, dgs);
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1286 1287 1288 1289 1290 1291
			return NULL;
		}
	}

	data_size -= dgs;

1292 1293 1294 1295 1296 1297
	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;
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1299 1300 1301
	/* even though we trust out peer,
	 * we sometimes have to double check. */
	if (sector + (data_size>>9) > capacity) {
1302 1303
		dev_err(DEV, "request from peer beyond end of local disk: "
			"capacity: %llus < sector: %llus + size: %u\n",
1304 1305 1306 1307 1308
			(unsigned long long)capacity,
			(unsigned long long)sector, data_size);
		return NULL;
	}

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1309 1310 1311 1312 1313 1314
	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
	e = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
	if (!e)
		return NULL;
1315

P
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1316
	ds = data_size;
1317 1318 1319
	page = e->pages;
	page_chain_for_each(page) {
		unsigned len = min_t(int, ds, PAGE_SIZE);
1320
		data = kmap(page);
1321
		rr = drbd_recv(mdev, data, len);
1322
		if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
1323 1324 1325
			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
			data[0] = data[0] ^ (unsigned long)-1;
		}
P
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1326
		kunmap(page);
1327
		if (rr != len) {
P
Philipp Reisner 已提交
1328
			drbd_free_ee(mdev, e);
1329 1330 1331
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data: read %d expected %d\n",
				rr, len);
P
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1332 1333 1334 1335 1336 1337
			return NULL;
		}
		ds -= rr;
	}

	if (dgs) {
1338
		drbd_csum_ee(mdev, mdev->tconn->integrity_r_tfm, e, dig_vv);
P
Philipp Reisner 已提交
1339
		if (memcmp(dig_in, dig_vv, dgs)) {
1340 1341
			dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
				(unsigned long long)sector, data_size);
P
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1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360
			drbd_bcast_ee(mdev, "digest failed",
					dgs, dig_in, dig_vv, e);
			drbd_free_ee(mdev, e);
			return NULL;
		}
	}
	mdev->recv_cnt += data_size>>9;
	return e;
}

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

1361
	if (!data_size)
1362
		return true;
1363

1364
	page = drbd_pp_alloc(mdev, 1, 1);
P
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1365 1366 1367 1368 1369 1370

	data = kmap(page);
	while (data_size) {
		rr = drbd_recv(mdev, data, min_t(int, data_size, PAGE_SIZE));
		if (rr != min_t(int, data_size, PAGE_SIZE)) {
			rv = 0;
1371 1372 1373 1374
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data: read %d expected %d\n",
					rr, min_t(int, data_size, PAGE_SIZE));
P
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1375 1376 1377 1378 1379
			break;
		}
		data_size -= rr;
	}
	kunmap(page);
1380
	drbd_pp_free(mdev, page, 0);
P
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1381 1382 1383 1384 1385 1386 1387 1388 1389
	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;
1390 1391
	void *dig_in = mdev->tconn->int_dig_in;
	void *dig_vv = mdev->tconn->int_dig_vv;
P
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1392

1393 1394
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_r_tfm) : 0;
P
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1395 1396 1397 1398

	if (dgs) {
		rr = drbd_recv(mdev, dig_in, dgs);
		if (rr != dgs) {
1399 1400 1401 1402
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data reply digest: read %d expected %d\n",
					rr, dgs);
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1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
			return 0;
		}
	}

	data_size -= dgs;

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

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

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

	if (dgs) {
1433
		drbd_csum_bio(mdev, mdev->tconn->integrity_r_tfm, bio, dig_vv);
P
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1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448
		if (memcmp(dig_in, dig_vv, dgs)) {
			dev_err(DEV, "Digest integrity check FAILED. Broken NICs?\n");
			return 0;
		}
	}

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

/* e_end_resync_block() is called via
 * drbd_process_done_ee() by asender only */
static int e_end_resync_block(struct drbd_conf *mdev, struct drbd_work *w, int unused)
{
	struct drbd_epoch_entry *e = (struct drbd_epoch_entry *)w;
1449
	sector_t sector = e->i.sector;
P
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1450 1451
	int ok;

1452
	D_ASSERT(drbd_interval_empty(&e->i));
P
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1453

1454
	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
1455
		drbd_set_in_sync(mdev, sector, e->i.size);
P
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1456 1457 1458
		ok = drbd_send_ack(mdev, P_RS_WRITE_ACK, e);
	} else {
		/* Record failure to sync */
1459
		drbd_rs_failed_io(mdev, sector, e->i.size);
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1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472

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

	return ok;
}

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

	e = read_in_block(mdev, ID_SYNCER, sector, data_size);
1473 1474
	if (!e)
		goto fail;
P
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1475 1476 1477 1478 1479 1480 1481

	dec_rs_pending(mdev);

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

1482 1483
	e->w.cb = e_end_resync_block;

1484
	spin_lock_irq(&mdev->tconn->req_lock);
P
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1485
	list_add(&e->w.list, &mdev->sync_ee);
1486
	spin_unlock_irq(&mdev->tconn->req_lock);
P
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1487

1488
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1489
	if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)
1490
		return true;
P
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1491

1492 1493
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1494
	spin_lock_irq(&mdev->tconn->req_lock);
1495
	list_del(&e->w.list);
1496
	spin_unlock_irq(&mdev->tconn->req_lock);
1497

1498 1499 1500
	drbd_free_ee(mdev, e);
fail:
	put_ldev(mdev);
1501
	return false;
P
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1502 1503
}

1504
static struct drbd_request *
1505 1506
find_request(struct drbd_conf *mdev, struct rb_root *root, u64 id,
	     sector_t sector, bool missing_ok, const char *func)
1507 1508 1509
{
	struct drbd_request *req;

1510 1511
	/* Request object according to our peer */
	req = (struct drbd_request *)(unsigned long)id;
1512
	if (drbd_contains_interval(root, sector, &req->i) && req->i.local)
1513
		return req;
1514 1515 1516 1517
	if (!missing_ok) {
		dev_err(DEV, "%s: failed to find request %lu, sector %llus\n", func,
			(unsigned long)id, (unsigned long long)sector);
	}
1518 1519 1520
	return NULL;
}

1521 1522
static int receive_DataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
1523 1524 1525 1526
{
	struct drbd_request *req;
	sector_t sector;
	int ok;
1527
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1528 1529 1530

	sector = be64_to_cpu(p->sector);

1531
	spin_lock_irq(&mdev->tconn->req_lock);
1532
	req = find_request(mdev, &mdev->read_requests, p->block_id, sector, false, __func__);
1533
	spin_unlock_irq(&mdev->tconn->req_lock);
1534
	if (unlikely(!req))
1535
		return false;
P
Philipp Reisner 已提交
1536

B
Bart Van Assche 已提交
1537
	/* hlist_del(&req->collision) is done in _req_may_be_done, to avoid
P
Philipp Reisner 已提交
1538 1539 1540 1541 1542
	 * 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)
1543
		req_mod(req, DATA_RECEIVED);
P
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1544 1545 1546 1547 1548 1549 1550
	/* 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;
}

1551 1552
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
P
Philipp Reisner 已提交
1553 1554 1555
{
	sector_t sector;
	int ok;
1556
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1557 1558 1559 1560 1561 1562 1563

	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,
1564
		 * or in drbd_endio_sec. */
P
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1565 1566 1567 1568 1569 1570 1571
		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);

1572
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
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1573 1574
	}

1575 1576
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

P
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1577 1578 1579 1580 1581 1582 1583 1584 1585
	return ok;
}

/* e_end_block() is called via drbd_process_done_ee().
 * this means this function only runs in the asender thread
 */
static int e_end_block(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
{
	struct drbd_epoch_entry *e = (struct drbd_epoch_entry *)w;
1586
	sector_t sector = e->i.sector;
P
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1587 1588
	int ok = 1, pcmd;

1589
	if (mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C) {
1590
		if (likely((e->flags & EE_WAS_ERROR) == 0)) {
P
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1591 1592 1593 1594 1595 1596
			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
				mdev->state.conn <= C_PAUSED_SYNC_T &&
				e->flags & EE_MAY_SET_IN_SYNC) ?
				P_RS_WRITE_ACK : P_WRITE_ACK;
			ok &= drbd_send_ack(mdev, pcmd, e);
			if (pcmd == P_RS_WRITE_ACK)
1597
				drbd_set_in_sync(mdev, sector, e->i.size);
P
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1598 1599 1600 1601 1602 1603 1604 1605 1606
		} else {
			ok  = drbd_send_ack(mdev, P_NEG_ACK, e);
			/* we expect it to be marked out of sync anyways...
			 * maybe assert this?  */
		}
		dec_unacked(mdev);
	}
	/* we delete from the conflict detection hash _after_ we sent out the
	 * P_WRITE_ACK / P_NEG_ACK, to get the sequence number right.  */
1607
	if (mdev->tconn->net_conf->two_primaries) {
1608
		spin_lock_irq(&mdev->tconn->req_lock);
1609
		D_ASSERT(!drbd_interval_empty(&e->i));
1610
		drbd_remove_epoch_entry_interval(mdev, e);
1611
		spin_unlock_irq(&mdev->tconn->req_lock);
1612
	} else
1613
		D_ASSERT(drbd_interval_empty(&e->i));
P
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1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624

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

	return ok;
}

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

1625
	D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
P
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1626 1627
	ok = drbd_send_ack(mdev, P_DISCARD_ACK, e);

1628
	spin_lock_irq(&mdev->tconn->req_lock);
1629
	D_ASSERT(!drbd_interval_empty(&e->i));
1630
	drbd_remove_epoch_entry_interval(mdev, e);
1631
	spin_unlock_irq(&mdev->tconn->req_lock);
P
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1632 1633 1634 1635 1636 1637

	dec_unacked(mdev);

	return ok;
}

1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664
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;
}

static void update_peer_seq(struct drbd_conf *mdev, unsigned int new_seq)
{
	unsigned int m;

	spin_lock(&mdev->peer_seq_lock);
	m = seq_max(mdev->peer_seq, new_seq);
	mdev->peer_seq = m;
	spin_unlock(&mdev->peer_seq_lock);
	if (m == new_seq)
		wake_up(&mdev->seq_wait);
}

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1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694
/* 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);
1695
		if (!seq_greater(packet_seq, mdev->peer_seq + 1))
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1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717
			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;
}

1718 1719 1720 1721
/* 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)
1722
{
1723 1724 1725 1726
	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);
1727 1728
}

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1729
/* mirrored write */
1730 1731
static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
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1732 1733 1734
{
	sector_t sector;
	struct drbd_epoch_entry *e;
1735
	struct p_data *p = &mdev->tconn->data.rbuf.data;
P
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1736 1737 1738 1739 1740 1741 1742 1743 1744
	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);

1745
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
P
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1746 1747 1748 1749 1750 1751
		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),
1752
	 * or in drbd_endio_sec, if we successfully submit the data at
P
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1753 1754 1755 1756 1757 1758
	 * the end of this function. */

	sector = be64_to_cpu(p->sector);
	e = read_in_block(mdev, p->block_id, sector, data_size);
	if (!e) {
		put_ldev(mdev);
1759
		return false;
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1760 1761 1762 1763
	}

	e->w.cb = e_end_block;

1764 1765 1766 1767 1768 1769
	dp_flags = be32_to_cpu(p->dp_flags);
	rw |= wire_flags_to_bio(mdev, dp_flags);

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

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1770 1771 1772 1773 1774 1775 1776
	spin_lock(&mdev->epoch_lock);
	e->epoch = mdev->current_epoch;
	atomic_inc(&e->epoch->epoch_size);
	atomic_inc(&e->epoch->active);
	spin_unlock(&mdev->epoch_lock);

	/* I'm the receiver, I do hold a net_cnt reference. */
1777
	if (!mdev->tconn->net_conf->two_primaries) {
1778
		spin_lock_irq(&mdev->tconn->req_lock);
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1779 1780 1781
	} else {
		/* don't get the req_lock yet,
		 * we may sleep in drbd_wait_peer_seq */
1782
		const int size = e->i.size;
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1783 1784 1785 1786
		const int discard = test_bit(DISCARD_CONCURRENT, &mdev->flags);
		DEFINE_WAIT(wait);
		int first;

1787
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
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1788 1789 1790 1791

		/* conflict detection and handling:
		 * 1. wait on the sequence number,
		 *    in case this data packet overtook ACK packets.
1792
		 * 2. check for conflicting write requests.
P
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1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
		 *
		 * 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;

1820
		spin_lock_irq(&mdev->tconn->req_lock);
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1821 1822 1823

		first = 1;
		for (;;) {
1824
			struct drbd_interval *i;
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1825 1826 1827 1828
			int have_unacked = 0;
			int have_conflict = 0;
			prepare_to_wait(&mdev->misc_wait, &wait,
				TASK_INTERRUPTIBLE);
1829 1830 1831 1832 1833 1834

			i = drbd_find_overlap(&mdev->write_requests, sector, size);
			if (i) {
				/* only ALERT on first iteration,
				 * we may be woken up early... */
				if (first)
1835
					dev_alert(DEV, "%s[%u] Concurrent %s write detected!"
1836 1837
					      "	new: %llus +%u; pending: %llus +%u\n",
					      current->comm, current->pid,
1838
					      i->local ? "local" : "remote",
1839
					      (unsigned long long)sector, size,
1840 1841 1842 1843 1844 1845 1846 1847 1848
					      (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;
				}
1849
				++have_conflict;
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1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861
			}
			if (!have_conflict)
				break;

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

1862
				spin_unlock_irq(&mdev->tconn->req_lock);
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1863 1864 1865 1866 1867 1868 1869

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

				put_ldev(mdev);
				wake_asender(mdev);
				finish_wait(&mdev->misc_wait, &wait);
1870
				return true;
P
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1871 1872 1873
			}

			if (signal_pending(current)) {
1874
				spin_unlock_irq(&mdev->tconn->req_lock);
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1875 1876 1877 1878
				finish_wait(&mdev->misc_wait, &wait);
				goto out_interrupted;
			}

1879
			/* Indicate to wake up mdev->misc_wait upon completion.  */
1880
			i->waiting = true;
1881

1882
			spin_unlock_irq(&mdev->tconn->req_lock);
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1883 1884 1885 1886 1887 1888 1889 1890 1891 1892
			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();
1893
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
1894 1895
		}
		finish_wait(&mdev->misc_wait, &wait);
1896 1897

		drbd_insert_interval(&mdev->write_requests, &e->i);
P
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1898 1899 1900
	}

	list_add(&e->w.list, &mdev->active_ee);
1901
	spin_unlock_irq(&mdev->tconn->req_lock);
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1902

1903
	switch (mdev->tconn->net_conf->wire_protocol) {
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1904 1905 1906 1907 1908 1909 1910 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 */
		drbd_send_ack(mdev, P_RECV_ACK, e);
		break;
	case DRBD_PROT_A:
		/* nothing to do */
		break;
	}

1919
	if (mdev->state.pdsk < D_INCONSISTENT) {
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1920
		/* In case we have the only disk of the cluster, */
1921
		drbd_set_out_of_sync(mdev, e->i.sector, e->i.size);
P
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1922
		e->flags |= EE_CALL_AL_COMPLETE_IO;
1923
		e->flags &= ~EE_MAY_SET_IN_SYNC;
1924
		drbd_al_begin_io(mdev, e->i.sector);
P
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1925 1926
	}

1927
	if (drbd_submit_ee(mdev, e, rw, DRBD_FAULT_DT_WR) == 0)
1928
		return true;
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Philipp Reisner 已提交
1929

1930 1931
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1932
	spin_lock_irq(&mdev->tconn->req_lock);
1933
	list_del(&e->w.list);
1934
	drbd_remove_epoch_entry_interval(mdev, e);
1935
	spin_unlock_irq(&mdev->tconn->req_lock);
1936
	if (e->flags & EE_CALL_AL_COMPLETE_IO)
1937
		drbd_al_complete_io(mdev, e->i.sector);
1938

P
Philipp Reisner 已提交
1939
out_interrupted:
1940
	drbd_may_finish_epoch(mdev, e->epoch, EV_PUT + EV_CLEANUP);
P
Philipp Reisner 已提交
1941 1942
	put_ldev(mdev);
	drbd_free_ee(mdev, e);
1943
	return false;
P
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1944 1945
}

1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
/* 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.
 */
1957
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
1958 1959 1960
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
1961
	struct lc_element *tmp;
1962 1963 1964 1965 1966 1967 1968
	int curr_events;
	int throttle = 0;

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

1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980
	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);

1981 1982 1983
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
1984

1985 1986 1987 1988 1989 1990 1991 1992
	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. */
1993 1994 1995 1996 1997 1998
		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;
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

		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;
}


2013 2014
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int digest_size)
P
Philipp Reisner 已提交
2015 2016 2017 2018 2019
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
	struct drbd_epoch_entry *e;
	struct digest_info *di = NULL;
2020
	int size, verb;
P
Philipp Reisner 已提交
2021
	unsigned int fault_type;
2022
	struct p_block_req *p =	&mdev->tconn->data.rbuf.block_req;
P
Philipp Reisner 已提交
2023 2024 2025 2026

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

2027
	if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
P
Philipp Reisner 已提交
2028 2029
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2030
		return false;
P
Philipp Reisner 已提交
2031 2032 2033 2034
	}
	if (sector + (size>>9) > capacity) {
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
2035
		return false;
P
Philipp Reisner 已提交
2036 2037 2038
	}

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
		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
2059 2060
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
2061

L
Lars Ellenberg 已提交
2062 2063
		/* drain possibly payload */
		return drbd_drain_block(mdev, digest_size);
P
Philipp Reisner 已提交
2064 2065 2066 2067 2068 2069 2070 2071
	}

	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
	 * "criss-cross" setup, that might cause write-out on some other DRBD,
	 * which in turn might block on the other node at this very place.  */
	e = drbd_alloc_ee(mdev, p->block_id, sector, size, GFP_NOIO);
	if (!e) {
		put_ldev(mdev);
2072
		return false;
P
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2073 2074
	}

2075
	switch (cmd) {
P
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2076 2077 2078
	case P_DATA_REQUEST:
		e->w.cb = w_e_end_data_req;
		fault_type = DRBD_FAULT_DT_RD;
2079 2080 2081
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
Philipp Reisner 已提交
2082 2083 2084
	case P_RS_DATA_REQUEST:
		e->w.cb = w_e_end_rsdata_req;
		fault_type = DRBD_FAULT_RS_RD;
2085 2086
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
P
Philipp Reisner 已提交
2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098
		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));

2099 2100 2101
		e->digest = di;
		e->flags |= EE_HAS_DIGEST;

P
Philipp Reisner 已提交
2102 2103 2104
		if (drbd_recv(mdev, di->digest, digest_size) != digest_size)
			goto out_free_e;

2105
		if (cmd == P_CSUM_RS_REQUEST) {
2106
			D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
2107
			e->w.cb = w_e_end_csum_rs_req;
2108 2109
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2110
		} else if (cmd == P_OV_REPLY) {
2111 2112
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
2113 2114
			e->w.cb = w_e_end_ov_reply;
			dec_rs_pending(mdev);
2115 2116 2117
			/* 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
2118 2119 2120 2121 2122
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
2123
		    mdev->tconn->agreed_pro_version >= 90) {
2124 2125
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2126 2127
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2128 2129
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2130 2131 2132 2133
			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
2134 2135 2136 2137 2138 2139 2140 2141 2142
			dev_info(DEV, "Online Verify start sector: %llu\n",
					(unsigned long long)sector);
		}
		e->w.cb = w_e_end_ov_req;
		fault_type = DRBD_FAULT_RS_RD;
		break;

	default:
		dev_err(DEV, "unexpected command (%s) in receive_DataRequest\n",
2143
		    cmdname(cmd));
P
Philipp Reisner 已提交
2144
		fault_type = DRBD_FAULT_MAX;
2145
		goto out_free_e;
P
Philipp Reisner 已提交
2146 2147
	}

2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169
	/* 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.
	 */
2170 2171 2172
	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))
2173
		goto out_free_e;
P
Philipp Reisner 已提交
2174

2175 2176 2177
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2178
submit:
P
Philipp Reisner 已提交
2179
	inc_unacked(mdev);
2180
	spin_lock_irq(&mdev->tconn->req_lock);
2181
	list_add_tail(&e->w.list, &mdev->read_ee);
2182
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
2183

2184
	if (drbd_submit_ee(mdev, e, READ, fault_type) == 0)
2185
		return true;
P
Philipp Reisner 已提交
2186

2187 2188
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2189
	spin_lock_irq(&mdev->tconn->req_lock);
2190
	list_del(&e->w.list);
2191
	spin_unlock_irq(&mdev->tconn->req_lock);
2192 2193
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
Philipp Reisner 已提交
2194 2195 2196
out_free_e:
	put_ldev(mdev);
	drbd_free_ee(mdev, e);
2197
	return false;
P
Philipp Reisner 已提交
2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210
}

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;

2211
	switch (mdev->tconn->net_conf->after_sb_0p) {
P
Philipp Reisner 已提交
2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238
	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
2239
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
P
Philipp Reisner 已提交
2240 2241 2242 2243 2244 2245 2246 2247 2248 2249
		     "Using discard-least-changes instead\n");
	case ASB_DISCARD_ZERO_CHG:
		if (ch_peer == 0 && ch_self == 0) {
			rv = test_bit(DISCARD_CONCURRENT, &mdev->flags)
				? -1 : 1;
			break;
		} else {
			if (ch_peer == 0) { rv =  1; break; }
			if (ch_self == 0) { rv = -1; break; }
		}
2250
		if (mdev->tconn->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
P
Philipp Reisner 已提交
2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273
			break;
	case ASB_DISCARD_LEAST_CHG:
		if	(ch_self < ch_peer)
			rv = -1;
		else if (ch_self > ch_peer)
			rv =  1;
		else /* ( ch_self == ch_peer ) */
		     /* Well, then use something else. */
			rv = test_bit(DISCARD_CONCURRENT, &mdev->flags)
				? -1 : 1;
		break;
	case ASB_DISCARD_LOCAL:
		rv = -1;
		break;
	case ASB_DISCARD_REMOTE:
		rv =  1;
	}

	return rv;
}

static int drbd_asb_recover_1p(struct drbd_conf *mdev) __must_hold(local)
{
2274
	int hg, rv = -100;
P
Philipp Reisner 已提交
2275

2276
	switch (mdev->tconn->net_conf->after_sb_1p) {
P
Philipp Reisner 已提交
2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300
	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) {
2301 2302 2303
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
P
Philipp Reisner 已提交
2304 2305 2306
			 /* 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. */
2307 2308
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322
				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)
{
2323
	int hg, rv = -100;
P
Philipp Reisner 已提交
2324

2325
	switch (mdev->tconn->net_conf->after_sb_2p) {
P
Philipp Reisner 已提交
2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342
	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) {
2343 2344
			enum drbd_state_rv rv2;

P
Philipp Reisner 已提交
2345 2346 2347
			 /* 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. */
2348 2349
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
P
Philipp Reisner 已提交
2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387
				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
2388 2389
-1091   requires proto 91
-1096   requires proto 96
P
Philipp Reisner 已提交
2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417
 */
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) {

2418
			if (mdev->tconn->agreed_pro_version < 91)
2419
				return -1091;
P
Philipp Reisner 已提交
2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438

			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) {

2439
			if (mdev->tconn->agreed_pro_version < 91)
2440
				return -1091;
P
Philipp Reisner 已提交
2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484

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

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

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

			return -1;
		}

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

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

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

	*rule_nr = 51;
	peer = mdev->p_uuid[UI_HISTORY_START] & ~((u64)1);
	if (self == peer) {
2485
		if (mdev->tconn->agreed_pro_version < 96 ?
2486 2487 2488
		    (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
2489 2490 2491
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

2492
			if (mdev->tconn->agreed_pro_version < 91)
2493
				return -1091;
P
Philipp Reisner 已提交
2494 2495 2496

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2497 2498 2499 2500

			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
2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521
			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) {
2522
		if (mdev->tconn->agreed_pro_version < 96 ?
2523 2524 2525
		    (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
2526 2527 2528
			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

2529
			if (mdev->tconn->agreed_pro_version < 91)
2530
				return -1091;
P
Philipp Reisner 已提交
2531 2532 2533 2534

			_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]);

2535
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
Philipp Reisner 已提交
2536 2537 2538 2539 2540 2541 2542 2543 2544
			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;
2545
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
Philipp Reisner 已提交
2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597
	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;
	}
2598 2599
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
Philipp Reisner 已提交
2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612
		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");
	}

2613 2614 2615
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

2616
	if (hg == 100 || (hg == -100 && mdev->tconn->net_conf->always_asbp)) {
P
Philipp Reisner 已提交
2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644
		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) {
2645
		if (mdev->tconn->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2646
			hg = -1;
2647
		if (!mdev->tconn->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
P
Philipp Reisner 已提交
2648 2649 2650 2651 2652 2653 2654 2655 2656
			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) {
2657 2658 2659 2660
		/* 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... */
2661
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672
		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) {
2673
		switch (mdev->tconn->net_conf->rr_conflict) {
P
Philipp Reisner 已提交
2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685
		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");
		}
	}

2686
	if (mdev->tconn->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
2687 2688 2689 2690 2691 2692 2693 2694 2695
		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
2696 2697
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2698 2699
		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
2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738
			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;
}

2739 2740
static int receive_protocol(struct drbd_conf *mdev, enum drbd_packet cmd,
			    unsigned int data_size)
P
Philipp Reisner 已提交
2741
{
2742
	struct p_protocol *p = &mdev->tconn->data.rbuf.protocol;
P
Philipp Reisner 已提交
2743
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2744
	int p_want_lose, p_two_primaries, cf;
P
Philipp Reisner 已提交
2745 2746 2747 2748 2749 2750 2751
	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);
2752 2753 2754 2755 2756 2757 2758
	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
2759

2760
	if (p_proto != mdev->tconn->net_conf->wire_protocol) {
P
Philipp Reisner 已提交
2761 2762 2763 2764
		dev_err(DEV, "incompatible communication protocols\n");
		goto disconnect;
	}

2765
	if (cmp_after_sb(p_after_sb_0p, mdev->tconn->net_conf->after_sb_0p)) {
P
Philipp Reisner 已提交
2766 2767 2768 2769
		dev_err(DEV, "incompatible after-sb-0pri settings\n");
		goto disconnect;
	}

2770
	if (cmp_after_sb(p_after_sb_1p, mdev->tconn->net_conf->after_sb_1p)) {
P
Philipp Reisner 已提交
2771 2772 2773 2774
		dev_err(DEV, "incompatible after-sb-1pri settings\n");
		goto disconnect;
	}

2775
	if (cmp_after_sb(p_after_sb_2p, mdev->tconn->net_conf->after_sb_2p)) {
P
Philipp Reisner 已提交
2776 2777 2778 2779
		dev_err(DEV, "incompatible after-sb-2pri settings\n");
		goto disconnect;
	}

2780
	if (p_want_lose && mdev->tconn->net_conf->want_lose) {
P
Philipp Reisner 已提交
2781 2782 2783 2784
		dev_err(DEV, "both sides have the 'want_lose' flag set\n");
		goto disconnect;
	}

2785
	if (p_two_primaries != mdev->tconn->net_conf->two_primaries) {
P
Philipp Reisner 已提交
2786 2787 2788 2789
		dev_err(DEV, "incompatible setting of the two-primaries options\n");
		goto disconnect;
	}

2790
	if (mdev->tconn->agreed_pro_version >= 87) {
2791
		unsigned char *my_alg = mdev->tconn->net_conf->integrity_alg;
P
Philipp Reisner 已提交
2792 2793

		if (drbd_recv(mdev, p_integrity_alg, data_size) != data_size)
2794
			return false;
P
Philipp Reisner 已提交
2795 2796 2797 2798 2799 2800 2801 2802 2803 2804

		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>");
	}

2805
	return true;
P
Philipp Reisner 已提交
2806 2807 2808

disconnect:
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2809
	return false;
P
Philipp Reisner 已提交
2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838
}

/* 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;
}

2839 2840
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int packet_size)
P
Philipp Reisner 已提交
2841
{
2842
	int ok = true;
2843
	struct p_rs_param_95 *p = &mdev->tconn->data.rbuf.rs_param_95;
P
Philipp Reisner 已提交
2844 2845 2846
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
2847
	const int apv = mdev->tconn->agreed_pro_version;
2848 2849
	int *rs_plan_s = NULL;
	int fifo_size = 0;
P
Philipp Reisner 已提交
2850 2851 2852 2853

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2854 2855
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2856

2857
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2858
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2859
		    packet_size, exp_max_sz);
2860
		return false;
P
Philipp Reisner 已提交
2861 2862 2863
	}

	if (apv <= 88) {
2864
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header);
2865
		data_size   = packet_size  - header_size;
2866
	} else if (apv <= 94) {
2867
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header);
2868
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2869
		D_ASSERT(data_size == 0);
2870
	} else {
2871
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header);
2872
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2873 2874 2875 2876 2877 2878
		D_ASSERT(data_size == 0);
	}

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

2879
	if (drbd_recv(mdev, &p->head.payload, header_size) != header_size)
2880
		return false;
P
Philipp Reisner 已提交
2881 2882 2883 2884 2885 2886 2887 2888 2889

	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);
2890
				return false;
P
Philipp Reisner 已提交
2891 2892 2893
			}

			if (drbd_recv(mdev, p->verify_alg, data_size) != data_size)
2894
				return false;
P
Philipp Reisner 已提交
2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937

			/* 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;
			}
		}

2938 2939 2940 2941 2942 2943
		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);
2944 2945 2946 2947 2948 2949 2950 2951 2952

			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;
				}
			}
2953
		}
P
Philipp Reisner 已提交
2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970

		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);
		}
2971 2972 2973 2974 2975 2976
		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
2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987
		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));
2988
	return false;
P
Philipp Reisner 已提交
2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003
}

/* 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);
}

3004 3005
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3006
{
3007
	struct p_sizes *p = &mdev->tconn->data.rbuf.sizes;
P
Philipp Reisner 已提交
3008 3009 3010
	enum determine_dev_size dd = unchanged;
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
3011
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
3012 3013 3014 3015 3016 3017 3018

	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));
3019
		return false;
P
Philipp Reisner 已提交
3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047
	}

	/* 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. */
3048
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
3049 3050 3051 3052 3053 3054 3055
		   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);
3056
			return false;
P
Philipp Reisner 已提交
3057 3058 3059 3060
		}
		put_ldev(mdev);
	}

3061
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
3062
	if (get_ldev(mdev)) {
B
Bart Van Assche 已提交
3063
		dd = drbd_determine_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
3064 3065
		put_ldev(mdev);
		if (dd == dev_size_error)
3066
			return false;
P
Philipp Reisner 已提交
3067 3068 3069 3070 3071 3072
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

3073 3074 3075
	mdev->peer_max_bio_size = be32_to_cpu(p->max_bio_size);
	drbd_reconsider_max_bio_size(mdev);

P
Philipp Reisner 已提交
3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089
	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... */
3090
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3091 3092 3093 3094
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3095 3096 3097 3098 3099 3100
			    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
3101 3102 3103 3104
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3105
	return true;
P
Philipp Reisner 已提交
3106 3107
}

3108 3109
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3110
{
3111
	struct p_uuids *p = &mdev->tconn->data.rbuf.uuids;
P
Philipp Reisner 已提交
3112
	u64 *p_uuid;
3113
	int i, updated_uuids = 0;
P
Philipp Reisner 已提交
3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129

	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));
3130
		return false;
P
Philipp Reisner 已提交
3131 3132 3133 3134 3135
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
3136
			mdev->tconn->agreed_pro_version >= 90 &&
P
Philipp Reisner 已提交
3137 3138 3139 3140 3141
			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,
3142 3143
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3144 3145 3146 3147 3148
			_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);
3149
			updated_uuids = 1;
P
Philipp Reisner 已提交
3150 3151
		}
		put_ldev(mdev);
3152 3153 3154 3155
	} 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. */
3156
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3157 3158 3159 3160 3161 3162 3163 3164
	}

	/* 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)
3165 3166 3167 3168
		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
3169

3170
	return true;
P
Philipp Reisner 已提交
3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202
}

/**
 * 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;
}

3203 3204
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3205
{
3206
	struct p_req_state *p = &mdev->tconn->data.rbuf.req_state;
P
Philipp Reisner 已提交
3207
	union drbd_state mask, val;
3208
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3209 3210 3211 3212 3213 3214 3215

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

	if (test_bit(DISCARD_CONCURRENT, &mdev->flags) &&
	    test_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
		drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
3216
		return true;
P
Philipp Reisner 已提交
3217 3218 3219 3220 3221 3222 3223 3224 3225 3226
	}

	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);

3227
	return true;
P
Philipp Reisner 已提交
3228 3229
}

3230 3231
static int receive_state(struct drbd_conf *mdev, enum drbd_packet cmd,
			 unsigned int data_size)
P
Philipp Reisner 已提交
3232
{
3233
	struct p_state *p = &mdev->tconn->data.rbuf.state;
3234
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3235
	enum drbd_disk_state real_peer_disk;
3236
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3237 3238 3239 3240 3241 3242 3243 3244 3245 3246
	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));
	}

3247
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3248
 retry:
3249
	os = ns = mdev->state;
3250
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3251

3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272
	/* 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);
3273
			return true;
3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285
		}
	}

	/* 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;

3286 3287
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3288

3289 3290 3291
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3292 3293 3294 3295 3296
	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 */
3297
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3298 3299
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3300
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3301
		       (peer_state.disk == D_NEGOTIATING ||
3302
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3303 3304 3305 3306 3307
		/* 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" */
3308
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3309 3310 3311 3312
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3313
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3314 3315

		put_ldev(mdev);
3316 3317
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3318
			if (mdev->state.disk == D_NEGOTIATING) {
3319
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3320 3321 3322
			} 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;
3323
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3324
			} else {
3325
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
3326
					return false;
3327
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
P
Philipp Reisner 已提交
3328
				drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3329
				return false;
P
Philipp Reisner 已提交
3330 3331 3332 3333
			}
		}
	}

3334
	spin_lock_irq(&mdev->tconn->req_lock);
3335
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3336 3337 3338 3339 3340
		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);
3341
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3342
		ns.disk = mdev->new_state_tmp.disk;
3343 3344
	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 &&
3345
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
3346
		/* Do not allow tl_restart(RESEND) for a rebooted peer. We can only allow this
3347
		   for temporal network outages! */
3348
		spin_unlock_irq(&mdev->tconn->req_lock);
3349 3350 3351 3352 3353
		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));
3354
		return false;
3355
	}
3356
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3357
	ns = mdev->state;
3358
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3359 3360 3361

	if (rv < SS_SUCCESS) {
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3362
		return false;
P
Philipp Reisner 已提交
3363 3364
	}

3365 3366
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3367 3368 3369 3370 3371 3372 3373 3374 3375
		    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);
		}
	}

3376
	mdev->tconn->net_conf->want_lose = 0;
P
Philipp Reisner 已提交
3377 3378 3379

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

3380
	return true;
P
Philipp Reisner 已提交
3381 3382
}

3383 3384
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packet cmd,
			     unsigned int data_size)
P
Philipp Reisner 已提交
3385
{
3386
	struct p_rs_uuid *p = &mdev->tconn->data.rbuf.rs_uuid;
P
Philipp Reisner 已提交
3387 3388 3389

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3390
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401
		   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);

3402
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3403 3404 3405 3406 3407 3408
		drbd_start_resync(mdev, C_SYNC_TARGET);

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

3409
	return true;
P
Philipp Reisner 已提交
3410 3411
}

3412 3413 3414 3415 3416 3417 3418
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3419 3420
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
3421 3422 3423
{
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3424
	int err;
P
Philipp Reisner 已提交
3425

3426 3427
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3428
		return -EIO;
P
Philipp Reisner 已提交
3429 3430
	}
	if (want == 0)
3431 3432 3433 3434 3435 3436 3437
		return 0;
	err = drbd_recv(mdev, buffer, want);
	if (err != want) {
		if (err >= 0)
			err = -EIO;
		return err;
	}
P
Philipp Reisner 已提交
3438 3439 3440 3441 3442 3443 3444 3445

	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;

3446
	return 1;
P
Philipp Reisner 已提交
3447 3448
}

3449 3450 3451 3452 3453 3454 3455
/**
 * 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
3456 3457
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3458 3459
		 struct bm_xfer_ctx *c,
		 unsigned int len)
P
Philipp Reisner 已提交
3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474
{
	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)
3475
		return -EIO;
P
Philipp Reisner 已提交
3476 3477 3478 3479

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3480
			return -EIO;
P
Philipp Reisner 已提交
3481 3482 3483 3484 3485

		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);
3486
				return -EIO;
P
Philipp Reisner 已提交
3487 3488 3489 3490 3491 3492 3493 3494 3495
			}
			_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);
3496
			return -EIO;
P
Philipp Reisner 已提交
3497 3498 3499 3500 3501 3502
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3503
			return -EIO;
P
Philipp Reisner 已提交
3504 3505 3506 3507 3508 3509 3510
		look_ahead |= tmp << have;
		have += bits;
	}

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

3511
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3512 3513
}

3514 3515 3516 3517 3518 3519 3520
/**
 * 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
3521 3522
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
3523 3524
		struct bm_xfer_ctx *c,
		unsigned int len)
P
Philipp Reisner 已提交
3525 3526
{
	if (DCBP_get_code(p) == RLE_VLI_Bits)
3527
		return recv_bm_rle_bits(mdev, p, c, len);
P
Philipp Reisner 已提交
3528 3529 3530 3531 3532 3533 3534

	/* 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));
3535
	return -EIO;
P
Philipp Reisner 已提交
3536 3537 3538 3539 3540 3541
}

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" */
3542
	unsigned plain = sizeof(struct p_header) *
P
Philipp Reisner 已提交
3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579
		((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. */
3580 3581
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packet cmd,
			  unsigned int data_size)
P
Philipp Reisner 已提交
3582 3583 3584
{
	struct bm_xfer_ctx c;
	void *buffer;
3585
	int err;
3586
	int ok = false;
3587
	struct p_header *h = &mdev->tconn->data.rbuf.header;
P
Philipp Reisner 已提交
3588

3589 3590 3591
	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
3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605

	/* 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),
	};

3606
	for(;;) {
3607
		if (cmd == P_BITMAP) {
3608
			err = receive_bitmap_plain(mdev, data_size, buffer, &c);
3609
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3610 3611 3612 3613
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3614
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3615 3616 3617 3618 3619 3620
				dev_err(DEV, "ReportCBitmap packet too large\n");
				goto out;
			}
			/* use the page buff */
			p = buffer;
			memcpy(p, h, sizeof(*h));
3621
			if (drbd_recv(mdev, p->head.payload, data_size) != data_size)
P
Philipp Reisner 已提交
3622
				goto out;
3623 3624
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3625
				goto out;
P
Philipp Reisner 已提交
3626
			}
3627
			err = decode_bitmap_c(mdev, p, &c, data_size);
P
Philipp Reisner 已提交
3628
		} else {
3629
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
P
Philipp Reisner 已提交
3630 3631 3632
			goto out;
		}

3633
		c.packets[cmd == P_BITMAP]++;
3634
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header) + data_size;
P
Philipp Reisner 已提交
3635

3636 3637 3638
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3639
			break;
3640
		}
3641
		if (!drbd_recv_header(mdev, &cmd, &data_size))
P
Philipp Reisner 已提交
3642
			goto out;
3643
	}
P
Philipp Reisner 已提交
3644 3645 3646 3647

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

	if (mdev->state.conn == C_WF_BITMAP_T) {
3648 3649
		enum drbd_state_rv rv;

P
Philipp Reisner 已提交
3650 3651 3652 3653
		ok = !drbd_send_bitmap(mdev);
		if (!ok)
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3654 3655
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3656 3657 3658 3659 3660 3661 3662
	} 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));
	}

3663
	ok = true;
P
Philipp Reisner 已提交
3664
 out:
3665
	drbd_bm_unlock(mdev);
P
Philipp Reisner 已提交
3666 3667 3668 3669 3670 3671
	if (ok && mdev->state.conn == C_WF_BITMAP_S)
		drbd_start_resync(mdev, C_SYNC_SOURCE);
	free_page((unsigned long) buffer);
	return ok;
}

3672 3673
static int receive_skip(struct drbd_conf *mdev, enum drbd_packet cmd,
			unsigned int data_size)
P
Philipp Reisner 已提交
3674 3675 3676 3677 3678
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3679 3680
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);
P
Philipp Reisner 已提交
3681

3682
	size = data_size;
P
Philipp Reisner 已提交
3683 3684 3685
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
		r = drbd_recv(mdev, sink, want);
3686 3687
		if (!expect(r > 0))
			break;
P
Philipp Reisner 已提交
3688 3689 3690 3691 3692
		size -= r;
	}
	return size == 0;
}

3693 3694
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packet cmd,
				unsigned int data_size)
3695
{
3696 3697
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
3698
	drbd_tcp_quickack(mdev->tconn->data.socket);
3699

3700
	return true;
3701 3702
}

3703 3704
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packet cmd,
			       unsigned int data_size)
3705
{
3706
	struct p_block_desc *p = &mdev->tconn->data.rbuf.block_desc;
3707

3708 3709 3710 3711 3712 3713 3714 3715 3716 3717
	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));
	}

3718 3719
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3720
	return true;
3721 3722
}

3723 3724
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packet cmd,
				  unsigned int to_receive);
3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736

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 } ,
3737 3738 3739
	[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 },
3740 3741
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
3742 3743
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header), receive_SyncParam },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header), receive_SyncParam },
3744 3745 3746 3747 3748 3749 3750 3751 3752 3753
	[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 },
3754
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
P
Philipp Reisner 已提交
3755 3756
	/* anything missing from this table is in
	 * the asender_tbl, see get_asender_cmd */
3757
	[P_MAX_CMD]	    = { 0, 0, NULL },
P
Philipp Reisner 已提交
3758 3759
};

3760
/* All handler functions that expect a sub-header get that sub-heder in
3761
   mdev->tconn->data.rbuf.header.head.payload.
3762

3763
   Usually in mdev->tconn->data.rbuf.header.head the callback can find the usual
3764 3765
   p_header, but they may not rely on that. Since there is also p_header95 !
 */
P
Philipp Reisner 已提交
3766 3767 3768

static void drbdd(struct drbd_conf *mdev)
{
3769
	struct p_header *header = &mdev->tconn->data.rbuf.header;
3770
	unsigned int packet_size;
3771
	enum drbd_packet cmd;
3772 3773
	size_t shs; /* sub header size */
	int rv;
P
Philipp Reisner 已提交
3774

3775
	while (get_t_state(&mdev->tconn->receiver) == RUNNING) {
P
Philipp Reisner 已提交
3776
		drbd_thread_current_set_cpu(mdev);
3777 3778
		if (!drbd_recv_header(mdev, &cmd, &packet_size))
			goto err_out;
P
Philipp Reisner 已提交
3779

3780 3781 3782
		if (unlikely(cmd >= P_MAX_CMD || !drbd_cmd_handler[cmd].function)) {
			dev_err(DEV, "unknown packet type %d, l: %d!\n", cmd, packet_size);
			goto err_out;
3783
		}
P
Philipp Reisner 已提交
3784

3785
		shs = drbd_cmd_handler[cmd].pkt_size - sizeof(struct p_header);
3786 3787 3788
		if (packet_size - shs > 0 && !drbd_cmd_handler[cmd].expect_payload) {
			dev_err(DEV, "No payload expected %s l:%d\n", cmdname(cmd), packet_size);
			goto err_out;
P
Philipp Reisner 已提交
3789 3790
		}

3791
		if (shs) {
3792
			rv = drbd_recv(mdev, &header->payload, shs);
3793
			if (unlikely(rv != shs)) {
3794 3795
				if (!signal_pending(current))
					dev_warn(DEV, "short read while reading sub header: rv=%d\n", rv);
3796 3797 3798 3799
				goto err_out;
			}
		}

3800
		rv = drbd_cmd_handler[cmd].function(mdev, cmd, packet_size - shs);
P
Philipp Reisner 已提交
3801

3802
		if (unlikely(!rv)) {
P
Philipp Reisner 已提交
3803
			dev_err(DEV, "error receiving %s, l: %d!\n",
3804 3805
			    cmdname(cmd), packet_size);
			goto err_out;
P
Philipp Reisner 已提交
3806 3807 3808
		}
	}

3809 3810 3811 3812
	if (0) {
	err_out:
		drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR));
	}
3813 3814 3815
	/* If we leave here, we probably want to update at least the
	 * "Connected" indicator on stable storage. Do so explicitly here. */
	drbd_md_sync(mdev);
P
Philipp Reisner 已提交
3816 3817
}

3818
void drbd_flush_workqueue(struct drbd_tconn *tconn)
P
Philipp Reisner 已提交
3819 3820 3821 3822 3823
{
	struct drbd_wq_barrier barr;

	barr.w.cb = w_prev_work_done;
	init_completion(&barr.done);
3824
	drbd_queue_work(&tconn->data.work, &barr.w);
P
Philipp Reisner 已提交
3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838
	wait_for_completion(&barr.done);
}

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

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

	/* asender does not clean up anything. it must not interfere, either */
3839
	drbd_thread_stop(&mdev->tconn->asender);
P
Philipp Reisner 已提交
3840 3841
	drbd_free_sock(mdev);

3842
	/* wait for current activity to cease. */
3843
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3844 3845 3846
	_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);
3847
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864

	/* 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);

3865 3866
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
3867 3868 3869 3870 3871 3872 3873
	/* 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" */
3874
	drbd_flush_workqueue(mdev->tconn);
P
Philipp Reisner 已提交
3875 3876 3877 3878 3879 3880 3881 3882

	/* 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;

3883
	if (!is_susp(mdev->state))
P
Philipp Reisner 已提交
3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895
		tl_clear(mdev);

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

	drbd_md_sync(mdev);

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

3896 3897
	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
3898

3899
	spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3900 3901 3902 3903 3904 3905 3906
	os = mdev->state;
	if (os.conn >= C_UNCONNECTED) {
		/* Do not restart in case we are C_DISCONNECTING */
		ns = os;
		ns.conn = C_UNCONNECTED;
		rv = _drbd_set_state(mdev, ns, CS_VERBOSE, NULL);
	}
3907
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
3908 3909

	if (os.conn == C_DISCONNECTING) {
3910
		wait_event(mdev->tconn->net_cnt_wait, atomic_read(&mdev->tconn->net_cnt) == 0);
P
Philipp Reisner 已提交
3911

3912 3913
		crypto_free_hash(mdev->tconn->cram_hmac_tfm);
		mdev->tconn->cram_hmac_tfm = NULL;
P
Philipp Reisner 已提交
3914

3915 3916
		kfree(mdev->tconn->net_conf);
		mdev->tconn->net_conf = NULL;
P
Philipp Reisner 已提交
3917 3918 3919
		drbd_request_state(mdev, NS(conn, C_STANDALONE));
	}

3920 3921 3922 3923
	/* 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
3924 3925 3926 3927 3928 3929 3930 3931 3932 3933
	/* 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);
3934 3935 3936
	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
3937 3938
	i = atomic_read(&mdev->pp_in_use);
	if (i)
3939
		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
P
Philipp Reisner 已提交
3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961

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

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

/*
 * We support PRO_VERSION_MIN to PRO_VERSION_MAX. The protocol version
 * we can agree on is stored in agreed_pro_version.
 *
 * feature flags and the reserved array should be enough room for future
 * enhancements of the handshake protocol, and possible plugins...
 *
 * for now, they are expected to be zero, but ignored.
 */
static int drbd_send_handshake(struct drbd_conf *mdev)
{
3962
	/* ASSERT current == mdev->tconn->receiver ... */
3963
	struct p_handshake *p = &mdev->tconn->data.sbuf.handshake;
P
Philipp Reisner 已提交
3964 3965
	int ok;

3966
	if (mutex_lock_interruptible(&mdev->tconn->data.mutex)) {
P
Philipp Reisner 已提交
3967 3968 3969 3970
		dev_err(DEV, "interrupted during initial handshake\n");
		return 0; /* interrupted. not ok. */
	}

3971 3972
	if (mdev->tconn->data.socket == NULL) {
		mutex_unlock(&mdev->tconn->data.mutex);
P
Philipp Reisner 已提交
3973 3974 3975 3976 3977 3978
		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);
3979 3980
	ok = _drbd_send_cmd(mdev, mdev->tconn->data.socket, P_HAND_SHAKE,
			    &p->head, sizeof(*p), 0 );
3981
	mutex_unlock(&mdev->tconn->data.mutex);
P
Philipp Reisner 已提交
3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993
	return ok;
}

/*
 * return values:
 *   1 yes, we have a valid connection
 *   0 oops, did not work out, please try again
 *  -1 peer talks different language,
 *     no point in trying again, please go standalone.
 */
static int drbd_do_handshake(struct drbd_conf *mdev)
{
3994
	/* ASSERT current == mdev->tconn->receiver ... */
3995
	struct p_handshake *p = &mdev->tconn->data.rbuf.handshake;
3996 3997
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
	unsigned int length;
3998
	enum drbd_packet cmd;
P
Philipp Reisner 已提交
3999 4000 4001 4002 4003 4004
	int rv;

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

4005
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4006 4007 4008
	if (!rv)
		return 0;

4009
	if (cmd != P_HAND_SHAKE) {
P
Philipp Reisner 已提交
4010
		dev_err(DEV, "expected HandShake packet, received: %s (0x%04x)\n",
4011
		     cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4012 4013 4014
		return -1;
	}

4015
	if (length != expect) {
P
Philipp Reisner 已提交
4016
		dev_err(DEV, "expected HandShake length: %u, received: %u\n",
4017
		     expect, length);
P
Philipp Reisner 已提交
4018 4019 4020 4021 4022 4023
		return -1;
	}

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

	if (rv != expect) {
4024 4025
		if (!signal_pending(current))
			dev_warn(DEV, "short read receiving handshake packet: l=%u\n", rv);
P
Philipp Reisner 已提交
4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037
		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;

4038
	mdev->tconn->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);
P
Philipp Reisner 已提交
4039 4040

	dev_info(DEV, "Handshake successful: "
4041
	     "Agreed network protocol version %d\n", mdev->tconn->agreed_pro_version);
P
Philipp Reisner 已提交
4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057

	return 1;

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

#if !defined(CONFIG_CRYPTO_HMAC) && !defined(CONFIG_CRYPTO_HMAC_MODULE)
static int drbd_do_auth(struct drbd_conf *mdev)
{
	dev_err(DEV, "This kernel was build without CONFIG_CRYPTO_HMAC.\n");
	dev_err(DEV, "You need to disable 'cram-hmac-alg' in drbd.conf.\n");
4058
	return -1;
P
Philipp Reisner 已提交
4059 4060 4061
}
#else
#define CHALLENGE_LEN 64
4062 4063 4064 4065 4066 4067 4068

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

P
Philipp Reisner 已提交
4069 4070 4071 4072 4073 4074 4075
static int drbd_do_auth(struct drbd_conf *mdev)
{
	char my_challenge[CHALLENGE_LEN];  /* 64 Bytes... */
	struct scatterlist sg;
	char *response = NULL;
	char *right_response = NULL;
	char *peers_ch = NULL;
4076
	unsigned int key_len = strlen(mdev->tconn->net_conf->shared_secret);
P
Philipp Reisner 已提交
4077 4078
	unsigned int resp_size;
	struct hash_desc desc;
4079
	enum drbd_packet cmd;
4080
	unsigned int length;
P
Philipp Reisner 已提交
4081 4082
	int rv;

4083
	desc.tfm = mdev->tconn->cram_hmac_tfm;
P
Philipp Reisner 已提交
4084 4085
	desc.flags = 0;

4086
	rv = crypto_hash_setkey(mdev->tconn->cram_hmac_tfm,
4087
				(u8 *)mdev->tconn->net_conf->shared_secret, key_len);
P
Philipp Reisner 已提交
4088 4089
	if (rv) {
		dev_err(DEV, "crypto_hash_setkey() failed with %d\n", rv);
4090
		rv = -1;
P
Philipp Reisner 已提交
4091 4092 4093 4094 4095 4096 4097 4098 4099
		goto fail;
	}

	get_random_bytes(my_challenge, CHALLENGE_LEN);

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

4100
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4101 4102 4103
	if (!rv)
		goto fail;

4104
	if (cmd != P_AUTH_CHALLENGE) {
P
Philipp Reisner 已提交
4105
		dev_err(DEV, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4106
		    cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4107 4108 4109 4110
		rv = 0;
		goto fail;
	}

4111
	if (length > CHALLENGE_LEN * 2) {
P
Philipp Reisner 已提交
4112
		dev_err(DEV, "expected AuthChallenge payload too big.\n");
4113
		rv = -1;
P
Philipp Reisner 已提交
4114 4115 4116
		goto fail;
	}

4117
	peers_ch = kmalloc(length, GFP_NOIO);
P
Philipp Reisner 已提交
4118 4119
	if (peers_ch == NULL) {
		dev_err(DEV, "kmalloc of peers_ch failed\n");
4120
		rv = -1;
P
Philipp Reisner 已提交
4121 4122 4123
		goto fail;
	}

4124
	rv = drbd_recv(mdev, peers_ch, length);
P
Philipp Reisner 已提交
4125

4126
	if (rv != length) {
4127 4128
		if (!signal_pending(current))
			dev_warn(DEV, "short read AuthChallenge: l=%u\n", rv);
P
Philipp Reisner 已提交
4129 4130 4131 4132
		rv = 0;
		goto fail;
	}

4133
	resp_size = crypto_hash_digestsize(mdev->tconn->cram_hmac_tfm);
P
Philipp Reisner 已提交
4134 4135 4136
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
		dev_err(DEV, "kmalloc of response failed\n");
4137
		rv = -1;
P
Philipp Reisner 已提交
4138 4139 4140 4141
		goto fail;
	}

	sg_init_table(&sg, 1);
4142
	sg_set_buf(&sg, peers_ch, length);
P
Philipp Reisner 已提交
4143 4144 4145 4146

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
		dev_err(DEV, "crypto_hash_digest() failed with %d\n", rv);
4147
		rv = -1;
P
Philipp Reisner 已提交
4148 4149 4150 4151 4152 4153 4154
		goto fail;
	}

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

4155
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4156 4157 4158
	if (!rv)
		goto fail;

4159
	if (cmd != P_AUTH_RESPONSE) {
P
Philipp Reisner 已提交
4160
		dev_err(DEV, "expected AuthResponse packet, received: %s (0x%04x)\n",
4161
			cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4162 4163 4164 4165
		rv = 0;
		goto fail;
	}

4166
	if (length != resp_size) {
P
Philipp Reisner 已提交
4167 4168 4169 4170 4171 4172 4173 4174
		dev_err(DEV, "expected AuthResponse payload of wrong size\n");
		rv = 0;
		goto fail;
	}

	rv = drbd_recv(mdev, response , resp_size);

	if (rv != resp_size) {
4175 4176
		if (!signal_pending(current))
			dev_warn(DEV, "short read receiving AuthResponse: l=%u\n", rv);
P
Philipp Reisner 已提交
4177 4178 4179 4180 4181
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4182
	if (right_response == NULL) {
P
Philipp Reisner 已提交
4183
		dev_err(DEV, "kmalloc of right_response failed\n");
4184
		rv = -1;
P
Philipp Reisner 已提交
4185 4186 4187 4188 4189 4190 4191 4192
		goto fail;
	}

	sg_set_buf(&sg, my_challenge, CHALLENGE_LEN);

	rv = crypto_hash_digest(&desc, &sg, sg.length, right_response);
	if (rv) {
		dev_err(DEV, "crypto_hash_digest() failed with %d\n", rv);
4193
		rv = -1;
P
Philipp Reisner 已提交
4194 4195 4196 4197 4198 4199 4200
		goto fail;
	}

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

	if (rv)
		dev_info(DEV, "Peer authenticated using %d bytes of '%s' HMAC\n",
4201
		     resp_size, mdev->tconn->net_conf->cram_hmac_alg);
4202 4203
	else
		rv = -1;
P
Philipp Reisner 已提交
4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227

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

	return rv;
}
#endif

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

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

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

	do {
		h = drbd_connect(mdev);
		if (h == 0) {
			drbd_disconnect(mdev);
4228
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4229 4230 4231 4232 4233 4234 4235 4236
		}
		if (h == -1) {
			dev_warn(DEV, "Discarding network configuration.\n");
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
		}
	} while (h == 0);

	if (h > 0) {
4237
		if (get_net_conf(mdev->tconn)) {
P
Philipp Reisner 已提交
4238
			drbdd(mdev);
4239
			put_net_conf(mdev->tconn);
P
Philipp Reisner 已提交
4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250
		}
	}

	drbd_disconnect(mdev);

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

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

4251
static int got_RqSReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4252
{
4253
	struct p_req_state_reply *p = &mdev->tconn->meta.rbuf.req_state_reply;
P
Philipp Reisner 已提交
4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265

	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);

4266
	return true;
P
Philipp Reisner 已提交
4267 4268
}

4269
static int got_Ping(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4270 4271 4272 4273 4274
{
	return drbd_send_ping_ack(mdev);

}

4275
static int got_PingAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4276 4277
{
	/* restore idle timeout */
4278
	mdev->tconn->meta.socket->sk->sk_rcvtimeo = mdev->tconn->net_conf->ping_int*HZ;
4279 4280
	if (!test_and_set_bit(GOT_PING_ACK, &mdev->flags))
		wake_up(&mdev->misc_wait);
P
Philipp Reisner 已提交
4281

4282
	return true;
P
Philipp Reisner 已提交
4283 4284
}

4285
static int got_IsInSync(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4286
{
4287
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4288 4289 4290
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

4291
	D_ASSERT(mdev->tconn->agreed_pro_version >= 89);
P
Philipp Reisner 已提交
4292 4293 4294

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

4295 4296 4297 4298 4299 4300 4301
	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
4302
	dec_rs_pending(mdev);
4303
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4304

4305
	return true;
P
Philipp Reisner 已提交
4306 4307
}

4308 4309 4310 4311
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
4312 4313 4314 4315
{
	struct drbd_request *req;
	struct bio_and_error m;

4316
	spin_lock_irq(&mdev->tconn->req_lock);
4317
	req = find_request(mdev, root, id, sector, missing_ok, func);
P
Philipp Reisner 已提交
4318
	if (unlikely(!req)) {
4319
		spin_unlock_irq(&mdev->tconn->req_lock);
4320
		return false;
P
Philipp Reisner 已提交
4321 4322
	}
	__req_mod(req, what, &m);
4323
	spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4324 4325 4326

	if (m.bio)
		complete_master_bio(mdev, &m);
4327
	return true;
P
Philipp Reisner 已提交
4328 4329
}

4330
static int got_BlockAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4331
{
4332
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4333 4334 4335 4336 4337 4338
	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));

4339
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4340 4341
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4342
		return true;
P
Philipp Reisner 已提交
4343
	}
4344
	switch (cmd) {
P
Philipp Reisner 已提交
4345
	case P_RS_WRITE_ACK:
4346
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4347
		what = WRITE_ACKED_BY_PEER_AND_SIS;
P
Philipp Reisner 已提交
4348 4349
		break;
	case P_WRITE_ACK:
4350
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4351
		what = WRITE_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4352 4353
		break;
	case P_RECV_ACK:
4354
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B);
4355
		what = RECV_ACKED_BY_PEER;
P
Philipp Reisner 已提交
4356 4357
		break;
	case P_DISCARD_ACK:
4358
		D_ASSERT(mdev->tconn->net_conf->wire_protocol == DRBD_PROT_C);
4359
		what = CONFLICT_DISCARDED_BY_PEER;
P
Philipp Reisner 已提交
4360 4361 4362
		break;
	default:
		D_ASSERT(0);
4363
		return false;
P
Philipp Reisner 已提交
4364 4365 4366
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
4367 4368
					     &mdev->write_requests, __func__,
					     what, false);
P
Philipp Reisner 已提交
4369 4370
}

4371
static int got_NegAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4372
{
4373
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4374
	sector_t sector = be64_to_cpu(p->sector);
4375
	int size = be32_to_cpu(p->blksize);
4376 4377
	bool missing_ok = mdev->tconn->net_conf->wire_protocol == DRBD_PROT_A ||
			  mdev->tconn->net_conf->wire_protocol == DRBD_PROT_B;
4378
	bool found;
P
Philipp Reisner 已提交
4379 4380 4381

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

4382
	if (p->block_id == ID_SYNCER) {
P
Philipp Reisner 已提交
4383 4384
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4385
		return true;
P
Philipp Reisner 已提交
4386
	}
4387

4388
	found = validate_req_change_req_state(mdev, p->block_id, sector,
4389
					      &mdev->write_requests, __func__,
4390
					      NEG_ACKED, missing_ok);
4391 4392 4393 4394 4395 4396 4397
	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)
4398
			return false;
4399
		drbd_set_out_of_sync(mdev, sector, size);
4400 4401
	}
	return true;
P
Philipp Reisner 已提交
4402 4403
}

4404
static int got_NegDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4405
{
4406
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4407 4408 4409 4410 4411 4412 4413
	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,
4414
					     &mdev->read_requests, __func__,
4415
					     NEG_ACKED, false);
P
Philipp Reisner 已提交
4416 4417
}

4418
static int got_NegRSDReply(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4419 4420 4421
{
	sector_t sector;
	int size;
4422
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4423 4424 4425 4426 4427 4428 4429 4430 4431 4432

	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);
4433
		switch (cmd) {
4434 4435 4436 4437 4438 4439 4440 4441 4442
		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
4443 4444 4445
		put_ldev(mdev);
	}

4446
	return true;
P
Philipp Reisner 已提交
4447 4448
}

4449
static int got_BarrierAck(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4450
{
4451
	struct p_barrier_ack *p = &mdev->tconn->meta.rbuf.barrier_ack;
P
Philipp Reisner 已提交
4452 4453 4454

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

4455 4456
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4457 4458 4459
	    !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);
4460 4461
	}

4462
	return true;
P
Philipp Reisner 已提交
4463 4464
}

4465
static int got_OVResult(struct drbd_conf *mdev, enum drbd_packet cmd)
P
Philipp Reisner 已提交
4466
{
4467
	struct p_block_ack *p = &mdev->tconn->meta.rbuf.block_ack;
P
Philipp Reisner 已提交
4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481
	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);

4482
	if (!get_ldev(mdev))
4483
		return true;
4484

P
Philipp Reisner 已提交
4485 4486 4487
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4488 4489 4490 4491 4492 4493 4494
	--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
4495 4496 4497
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
4498
			drbd_queue_work_front(&mdev->tconn->data.work, w);
P
Philipp Reisner 已提交
4499 4500 4501 4502 4503 4504
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
			ov_oos_print(mdev);
			drbd_resync_finished(mdev);
		}
	}
4505
	put_ldev(mdev);
4506
	return true;
P
Philipp Reisner 已提交
4507 4508
}

4509
static int got_skip(struct drbd_conf *mdev, enum drbd_packet cmd)
4510
{
4511
	return true;
4512 4513
}

P
Philipp Reisner 已提交
4514 4515
struct asender_cmd {
	size_t pkt_size;
4516
	int (*process)(struct drbd_conf *mdev, enum drbd_packet cmd);
P
Philipp Reisner 已提交
4517 4518 4519 4520 4521 4522 4523 4524
};

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() */
4525 4526
	[P_PING]	    = { sizeof(struct p_header), got_Ping },
	[P_PING_ACK]	    = { sizeof(struct p_header), got_PingAck },
P
Philipp Reisner 已提交
4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537
	[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 },
4538
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
4539
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply},
P
Philipp Reisner 已提交
4540 4541 4542 4543 4544 4545 4546 4547 4548 4549
	[P_MAX_CMD]	    = { 0, NULL },
	};
	if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)
		return NULL;
	return &asender_tbl[cmd];
}

int drbd_asender(struct drbd_thread *thi)
{
	struct drbd_conf *mdev = thi->mdev;
4550
	struct p_header *h = &mdev->tconn->meta.rbuf.header;
P
Philipp Reisner 已提交
4551 4552
	struct asender_cmd *cmd = NULL;

4553
	int rv;
P
Philipp Reisner 已提交
4554 4555
	void *buf    = h;
	int received = 0;
4556
	int expect   = sizeof(struct p_header);
4557
	int ping_timeout_active = 0;
4558
	int empty, pkt_size;
4559
	enum drbd_packet cmd_nr;
P
Philipp Reisner 已提交
4560 4561 4562 4563 4564 4565

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

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

4566
	while (get_t_state(thi) == RUNNING) {
P
Philipp Reisner 已提交
4567 4568
		drbd_thread_current_set_cpu(mdev);
		if (test_and_clear_bit(SEND_PING, &mdev->flags)) {
4569 4570 4571 4572
			if (!drbd_send_ping(mdev)) {
				dev_err(DEV, "drbd_send_ping has failed\n");
				goto reconnect;
			}
4573
			mdev->tconn->meta.socket->sk->sk_rcvtimeo =
4574
				mdev->tconn->net_conf->ping_timeo*HZ/10;
4575
			ping_timeout_active = 1;
P
Philipp Reisner 已提交
4576 4577 4578 4579
		}

		/* conditionally cork;
		 * it may hurt latency if we cork without much to send */
4580
		if (!mdev->tconn->net_conf->no_cork &&
P
Philipp Reisner 已提交
4581
			3 < atomic_read(&mdev->unacked_cnt))
4582
			drbd_tcp_cork(mdev->tconn->meta.socket);
P
Philipp Reisner 已提交
4583 4584 4585
		while (1) {
			clear_bit(SIGNAL_ASENDER, &mdev->flags);
			flush_signals(current);
4586
			if (!drbd_process_done_ee(mdev))
P
Philipp Reisner 已提交
4587 4588 4589
				goto reconnect;
			/* to avoid race with newly queued ACKs */
			set_bit(SIGNAL_ASENDER, &mdev->flags);
4590
			spin_lock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4591
			empty = list_empty(&mdev->done_ee);
4592
			spin_unlock_irq(&mdev->tconn->req_lock);
P
Philipp Reisner 已提交
4593 4594 4595 4596 4597 4598 4599
			/* new ack may have been queued right here,
			 * but then there is also a signal pending,
			 * and we start over... */
			if (empty)
				break;
		}
		/* but unconditionally uncork unless disabled */
4600
		if (!mdev->tconn->net_conf->no_cork)
4601
			drbd_tcp_uncork(mdev->tconn->meta.socket);
P
Philipp Reisner 已提交
4602 4603 4604 4605 4606

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

4607
		rv = drbd_recv_short(mdev, mdev->tconn->meta.socket,
P
Philipp Reisner 已提交
4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629
				     buf, expect-received, 0);
		clear_bit(SIGNAL_ASENDER, &mdev->flags);

		flush_signals(current);

		/* Note:
		 * -EINTR	 (on meta) we got a signal
		 * -EAGAIN	 (on meta) rcvtimeo expired
		 * -ECONNRESET	 other side closed the connection
		 * -ERESTARTSYS  (on data) we got a signal
		 * rv <  0	 other than above: unexpected error!
		 * rv == expected: full header or command
		 * rv <  expected: "woken" by signal during receive
		 * rv == 0	 : "connection shut down by peer"
		 */
		if (likely(rv > 0)) {
			received += rv;
			buf	 += rv;
		} else if (rv == 0) {
			dev_err(DEV, "meta connection shut down by peer.\n");
			goto reconnect;
		} else if (rv == -EAGAIN) {
4630 4631
			/* If the data socket received something meanwhile,
			 * that is good enough: peer is still alive. */
4632
			if (time_after(mdev->tconn->last_received,
4633
				jiffies - mdev->tconn->meta.socket->sk->sk_rcvtimeo))
4634
				continue;
4635
			if (ping_timeout_active) {
P
Philipp Reisner 已提交
4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648
				dev_err(DEV, "PingAck did not arrive in time.\n");
				goto reconnect;
			}
			set_bit(SEND_PING, &mdev->flags);
			continue;
		} else if (rv == -EINTR) {
			continue;
		} else {
			dev_err(DEV, "sock_recvmsg returned %d\n", rv);
			goto reconnect;
		}

		if (received == expect && cmd == NULL) {
4649
			if (!decode_header(mdev, h, &cmd_nr, &pkt_size))
P
Philipp Reisner 已提交
4650
				goto reconnect;
4651
			cmd = get_asender_cmd(cmd_nr);
P
Philipp Reisner 已提交
4652
			if (unlikely(cmd == NULL)) {
4653 4654
				dev_err(DEV, "unknown command %d on meta (l: %d)\n",
					cmd_nr, pkt_size);
P
Philipp Reisner 已提交
4655 4656 4657
				goto disconnect;
			}
			expect = cmd->pkt_size;
4658 4659 4660
			if (pkt_size != expect - sizeof(struct p_header)) {
				dev_err(DEV, "Wrong packet size on meta (c: %d, l: %d)\n",
					cmd_nr, pkt_size);
P
Philipp Reisner 已提交
4661
				goto reconnect;
4662
			}
P
Philipp Reisner 已提交
4663 4664
		}
		if (received == expect) {
4665
			mdev->tconn->last_received = jiffies;
P
Philipp Reisner 已提交
4666
			D_ASSERT(cmd != NULL);
4667
			if (!cmd->process(mdev, cmd_nr))
P
Philipp Reisner 已提交
4668 4669
				goto reconnect;

4670 4671 4672 4673 4674
			/* 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
4675 4676
			buf	 = h;
			received = 0;
4677
			expect	 = sizeof(struct p_header);
P
Philipp Reisner 已提交
4678 4679 4680 4681 4682 4683 4684
			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
		drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE));
4685
		drbd_md_sync(mdev);
P
Philipp Reisner 已提交
4686 4687 4688 4689
	}
	if (0) {
disconnect:
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
4690
		drbd_md_sync(mdev);
P
Philipp Reisner 已提交
4691 4692 4693 4694 4695 4696 4697 4698
	}
	clear_bit(SIGNAL_ASENDER, &mdev->flags);

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

	return 0;
}