drbd_receiver.c 128.5 KB
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/*
   drbd_receiver.c

   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.

   Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
   Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
   Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.

   drbd is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   drbd is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with drbd; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/module.h>

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

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

#include "drbd_vli.h"

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;

	spin_lock_irq(&mdev->req_lock);
	reclaim_net_ee(mdev, &reclaimed);
	spin_unlock_irq(&mdev->req_lock);

	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. */
	if (atomic_read(&mdev->pp_in_use) < mdev->net_conf->max_buffers)
		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);

		if (atomic_read(&mdev->pp_in_use) < mdev->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->req_lock);
 * 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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	INIT_HLIST_NODE(&e->colision);
	e->epoch = NULL;
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	e->mdev = mdev;
	e->pages = page;
	atomic_set(&e->pending_bios, 0);
	e->size = data_size;
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	e->flags = 0;
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	e->sector = sector;
	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(hlist_unhashed(&e->colision));
	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->req_lock);
	list_splice_init(list, &work_list);
	spin_unlock_irq(&mdev->req_lock);

	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_
 * but see also comments in _req_mod(,barrier_acked)
 * 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);

	spin_lock_irq(&mdev->req_lock);
	reclaim_net_ee(mdev, &reclaimed);
	list_splice_init(&mdev->done_ee, &work_list);
	spin_unlock_irq(&mdev->req_lock);

	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);
		spin_unlock_irq(&mdev->req_lock);
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		io_schedule();
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		finish_wait(&mdev->ee_wait, &wait);
		spin_lock_irq(&mdev->req_lock);
	}
}

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

/* 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 (;;) {
		rv = sock_recvmsg(mdev->data.socket, &msg, size, msg.msg_flags);
		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;

	if (!get_net_conf(mdev))
		return NULL;

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

	sock->sk->sk_rcvtimeo =
	sock->sk->sk_sndtimeo =  mdev->net_conf->try_connect_int*HZ;
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	drbd_setbufsize(sock, mdev->net_conf->sndbuf_size,
			mdev->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.
	*/
	memcpy(&src_in6, mdev->net_conf->my_addr,
	       min_t(int, mdev->net_conf->my_addr_len, sizeof(src_in6)));
	if (((struct sockaddr *)mdev->net_conf->my_addr)->sa_family == AF_INET6)
		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,
			      mdev->net_conf->my_addr_len);
	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,
				 (struct sockaddr *)mdev->net_conf->peer_addr,
				 mdev->net_conf->peer_addr_len, 0);

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));
	}
	put_net_conf(mdev);
	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;

	if (!get_net_conf(mdev))
		return NULL;

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

	timeo = mdev->net_conf->try_connect_int * HZ;
	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;
670 671
	drbd_setbufsize(s_listen, mdev->net_conf->sndbuf_size,
			mdev->net_conf->rcvbuf_size);
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	what = "bind before listen";
	err = s_listen->ops->bind(s_listen,
			      (struct sockaddr *) mdev->net_conf->my_addr,
			      mdev->net_conf->my_addr_len);
	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));
		}
	}
	put_net_conf(mdev);

	return s_estab;
}

static int drbd_send_fp(struct drbd_conf *mdev,
	struct socket *sock, enum drbd_packets cmd)
{
699
	struct p_header80 *h = &mdev->data.sbuf.header.h80;
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	return _drbd_send_cmd(mdev, sock, cmd, h, sizeof(*h), 0);
}

static enum drbd_packets drbd_recv_fp(struct drbd_conf *mdev, struct socket *sock)
{
706
	struct p_header80 *h = &mdev->data.rbuf.header.h80;
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	int rr;

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

	if (rr == sizeof(*h) && h->magic == BE_DRBD_MAGIC)
		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)
728
		return false;
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	rr = drbd_recv_short(mdev, *sock, tb, 4, MSG_DONTWAIT | MSG_PEEK);

	if (rr > 0 || rr == -EAGAIN) {
733
		return true;
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	} else {
		sock_release(*sock);
		*sock = NULL;
737
		return false;
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	}
}

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

	D_ASSERT(!mdev->data.socket);

	if (drbd_request_state(mdev, NS(conn, C_WF_CONNECTION)) < SS_SUCCESS)
		return -2;

	clear_bit(DISCARD_CONCURRENT, &mdev->flags);

	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() */
771
			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) {
790
			schedule_timeout_interruptible(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();
			if (get_t_state(&mdev->receiver) == Exiting)
				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 ...
	 * sock->sk->sk_sndtimeo = mdev->net_conf->timeout*HZ/10;
	 * 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 =
	sock->sk->sk_rcvtimeo = mdev->net_conf->ping_timeo*4*HZ/10;

	msock->sk->sk_sndtimeo = mdev->net_conf->timeout*HZ/10;
	msock->sk->sk_rcvtimeo = mdev->net_conf->ping_int*HZ;

	/* we don't want delays.
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	 * we use TCP_CORK where appropriate, though */
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	drbd_tcp_nodelay(sock);
	drbd_tcp_nodelay(msock);

	mdev->data.socket = sock;
	mdev->meta.socket = msock;
	mdev->last_received = jiffies;

	D_ASSERT(mdev->asender.task == NULL);

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

	if (mdev->cram_hmac_tfm) {
		/* drbd_request_state(mdev, NS(conn, WFAuth)); */
881 882
		switch (drbd_do_auth(mdev)) {
		case -1:
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			dev_err(DEV, "Authentication of peer failed\n");
			return -1;
885 886 887
		case 0:
			dev_err(DEV, "Authentication of peer failed, trying again.\n");
			return 0;
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		}
	}

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

	sock->sk->sk_sndtimeo = mdev->net_conf->timeout*HZ/10;
	sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;

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

	drbd_thread_start(&mdev->asender);

902 903 904 905 906
	if (mdev->agreed_pro_version < 95 && get_ldev(mdev)) {
		drbd_setup_queue_param(mdev, DRBD_MAX_SIZE_H80_PACKET);
		put_ldev(mdev);
	}

907
	if (drbd_send_protocol(mdev) == -1)
908
		return -1;
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	drbd_send_sync_param(mdev, &mdev->sync_conf);
910
	drbd_send_sizes(mdev, 0, 0);
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	drbd_send_uuids(mdev);
	drbd_send_state(mdev);
	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
	clear_bit(RESIZE_PENDING, &mdev->flags);
915
	mod_timer(&mdev->request_timer, jiffies + HZ); /* just start it here. */
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	return 1;

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

927
static int drbd_recv_header(struct drbd_conf *mdev, enum drbd_packets *cmd, unsigned int *packet_size)
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{
929
	union p_header *h = &mdev->data.rbuf.header;
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	int r;

	r = drbd_recv(mdev, h, sizeof(*h));
	if (unlikely(r != sizeof(*h))) {
934 935
		if (!signal_pending(current))
			dev_warn(DEV, "short read expecting header on sock: r=%d\n", r);
936
		return false;
937 938 939 940 941 942 943 944 945
	}

	if (likely(h->h80.magic == BE_DRBD_MAGIC)) {
		*cmd = be16_to_cpu(h->h80.command);
		*packet_size = be16_to_cpu(h->h80.length);
	} else if (h->h95.magic == BE_DRBD_MAGIC_BIG) {
		*cmd = be16_to_cpu(h->h95.command);
		*packet_size = be32_to_cpu(h->h95.length);
	} else {
946 947 948 949
		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));
950
		return false;
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	}
	mdev->last_received = jiffies;

954
	return true;
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}

957
static void drbd_flush(struct drbd_conf *mdev)
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{
	int rv;

	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
962
		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
963
					NULL);
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		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)
{
985
	int epoch_size;
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	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 &&
1009
		    test_bit(DE_HAVE_BARRIER_NUMBER, &epoch->flags)) {
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			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);
1029
				/* atomic_set(&epoch->active, 0); is already zero */
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				if (rv == FE_STILL_LIVE)
					rv = FE_RECYCLED;
1032
				wake_up(&mdev->ee_wait);
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			}
		}

		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;
1068
	if (pwo != mdev->write_ordering || wo == WO_bdev_flush)
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		dev_info(DEV, "Method to ensure write ordering: %s\n", write_ordering_str[mdev->write_ordering]);
}

1072 1073 1074 1075 1076
/**
 * drbd_submit_ee()
 * @mdev:	DRBD device.
 * @e:		epoch entry
 * @rw:		flag field, see bio->bi_rw
1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
 *
 * 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.
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098
 */
/* 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;
	sector_t sector = e->sector;
	unsigned ds = e->size;
	unsigned n_bios = 0;
	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
1099
	int err = -ENOMEM;
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 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;
	}
	/* > e->sector, unless this is the first bio */
	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)) {
1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135
			/* 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;
			}
1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160
			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);
	}
1161
	return err;
1162 1163
}

1164
static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
1165
{
1166
	int rv;
1167
	struct p_barrier *p = &mdev->data.rbuf.barrier;
P
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1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
	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)
1183
			return true;
1184 1185 1186 1187 1188 1189 1190 1191 1192

		/* 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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	case WO_bdev_flush:
	case WO_drain_io:
		drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
1197 1198 1199 1200 1201 1202
		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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		}

1205 1206 1207 1208 1209
		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);
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1211
		return true;
1212 1213
	default:
		dev_err(DEV, "Strangeness in mdev->write_ordering %d\n", mdev->write_ordering);
1214
		return false;
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	}

	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);

1232
	return true;
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}

/* 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)
{
1240
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
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	struct drbd_epoch_entry *e;
	struct page *page;
1243
	int dgs, ds, rr;
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	void *dig_in = mdev->int_dig_in;
	void *dig_vv = mdev->int_dig_vv;
1246
	unsigned long *data;
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	dgs = (mdev->agreed_pro_version >= 87 && mdev->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->integrity_r_tfm) : 0;

	if (dgs) {
		rr = drbd_recv(mdev, dig_in, dgs);
		if (rr != dgs) {
1254 1255 1256 1257
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data digest: read %d expected %d\n",
					rr, dgs);
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			return NULL;
		}
	}

	data_size -= dgs;

1264
	ERR_IF(data_size == 0) return NULL;
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	ERR_IF(data_size &  0x1ff) return NULL;
1266
	ERR_IF(data_size >  DRBD_MAX_BIO_SIZE) return NULL;
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1268 1269 1270
	/* even though we trust out peer,
	 * we sometimes have to double check. */
	if (sector + (data_size>>9) > capacity) {
1271 1272
		dev_err(DEV, "request from peer beyond end of local disk: "
			"capacity: %llus < sector: %llus + size: %u\n",
1273 1274 1275 1276 1277
			(unsigned long long)capacity,
			(unsigned long long)sector, data_size);
		return NULL;
	}

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	/* 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;
1284

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	ds = data_size;
1286 1287 1288
	page = e->pages;
	page_chain_for_each(page) {
		unsigned len = min_t(int, ds, PAGE_SIZE);
1289
		data = kmap(page);
1290
		rr = drbd_recv(mdev, data, len);
1291
		if (drbd_insert_fault(mdev, DRBD_FAULT_RECEIVE)) {
1292 1293 1294
			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
			data[0] = data[0] ^ (unsigned long)-1;
		}
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		kunmap(page);
1296
		if (rr != len) {
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			drbd_free_ee(mdev, e);
1298 1299 1300
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data: read %d expected %d\n",
				rr, len);
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			return NULL;
		}
		ds -= rr;
	}

	if (dgs) {
1307
		drbd_csum_ee(mdev, mdev->integrity_r_tfm, e, dig_vv);
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		if (memcmp(dig_in, dig_vv, dgs)) {
1309 1310
			dev_err(DEV, "Digest integrity check FAILED: %llus +%u\n",
				(unsigned long long)sector, data_size);
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			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;

1330
	if (!data_size)
1331
		return true;
1332

1333
	page = drbd_pp_alloc(mdev, 1, 1);
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	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;
1340 1341 1342 1343
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data: read %d expected %d\n",
					rr, min_t(int, data_size, PAGE_SIZE));
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			break;
		}
		data_size -= rr;
	}
	kunmap(page);
1349
	drbd_pp_free(mdev, page, 0);
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	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;
	void *dig_in = mdev->int_dig_in;
	void *dig_vv = mdev->int_dig_vv;

	dgs = (mdev->agreed_pro_version >= 87 && mdev->integrity_r_tfm) ?
		crypto_hash_digestsize(mdev->integrity_r_tfm) : 0;

	if (dgs) {
		rr = drbd_recv(mdev, dig_in, dgs);
		if (rr != dgs) {
1368 1369 1370 1371
			if (!signal_pending(current))
				dev_warn(DEV,
					"short read receiving data reply digest: read %d expected %d\n",
					rr, dgs);
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			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) {
1392 1393 1394 1395
			if (!signal_pending(current))
				dev_warn(DEV, "short read receiving data reply: "
					"read %d expected %d\n",
					rr, expect);
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			return 0;
		}
		data_size -= rr;
	}

	if (dgs) {
1402
		drbd_csum_bio(mdev, mdev->integrity_r_tfm, bio, dig_vv);
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		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;
	sector_t sector = e->sector;
	int ok;

	D_ASSERT(hlist_unhashed(&e->colision));

1423
	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
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		drbd_set_in_sync(mdev, sector, e->size);
		ok = drbd_send_ack(mdev, P_RS_WRITE_ACK, e);
	} else {
		/* Record failure to sync */
		drbd_rs_failed_io(mdev, sector, e->size);

		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);
1442 1443
	if (!e)
		goto fail;
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	dec_rs_pending(mdev);

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

1451 1452
	e->w.cb = e_end_resync_block;

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	spin_lock_irq(&mdev->req_lock);
	list_add(&e->w.list, &mdev->sync_ee);
	spin_unlock_irq(&mdev->req_lock);

1457
	atomic_add(data_size >> 9, &mdev->rs_sect_ev);
1458
	if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)
1459
		return true;
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1461 1462
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1463 1464 1465 1466
	spin_lock_irq(&mdev->req_lock);
	list_del(&e->w.list);
	spin_unlock_irq(&mdev->req_lock);

1467 1468 1469
	drbd_free_ee(mdev, e);
fail:
	put_ldev(mdev);
1470
	return false;
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}

1473
static int receive_DataReply(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
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{
	struct drbd_request *req;
	sector_t sector;
	int ok;
1478
	struct p_data *p = &mdev->data.rbuf.data;
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	sector = be64_to_cpu(p->sector);

	spin_lock_irq(&mdev->req_lock);
	req = _ar_id_to_req(mdev, p->block_id, sector);
	spin_unlock_irq(&mdev->req_lock);
	if (unlikely(!req)) {
		dev_err(DEV, "Got a corrupt block_id/sector pair(1).\n");
1487
		return false;
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	}

	/* hlist_del(&req->colision) is done in _req_may_be_done, to avoid
	 * 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)
		req_mod(req, data_received);
	/* 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;
}

1504
static int receive_RSDataReply(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
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{
	sector_t sector;
	int ok;
1508
	struct p_data *p = &mdev->data.rbuf.data;
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	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,
		 * or in drbd_endio_write_sec. */
		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);

1524
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
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	}

1527 1528
	atomic_add(data_size >> 9, &mdev->rs_sect_in);

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	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;
	sector_t sector = e->sector;
	int ok = 1, pcmd;

	if (mdev->net_conf->wire_protocol == DRBD_PROT_C) {
1542
		if (likely((e->flags & EE_WAS_ERROR) == 0)) {
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			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)
				drbd_set_in_sync(mdev, sector, e->size);
		} 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.  */
	if (mdev->net_conf->two_primaries) {
		spin_lock_irq(&mdev->req_lock);
		D_ASSERT(!hlist_unhashed(&e->colision));
		hlist_del_init(&e->colision);
		spin_unlock_irq(&mdev->req_lock);
	} else {
		D_ASSERT(hlist_unhashed(&e->colision));
	}

	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;

	D_ASSERT(mdev->net_conf->wire_protocol == DRBD_PROT_C);
	ok = drbd_send_ack(mdev, P_DISCARD_ACK, e);

	spin_lock_irq(&mdev->req_lock);
	D_ASSERT(!hlist_unhashed(&e->colision));
	hlist_del_init(&e->colision);
	spin_unlock_irq(&mdev->req_lock);

	dec_unacked(mdev);

	return ok;
}

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

1644 1645 1646 1647
/* 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)
1648
{
1649 1650 1651 1652
	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);
1653 1654
}

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/* mirrored write */
1656
static int receive_Data(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
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{
	sector_t sector;
	struct drbd_epoch_entry *e;
1660
	struct p_data *p = &mdev->data.rbuf.data;
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	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);

1670
		drbd_send_ack_dp(mdev, P_NEG_ACK, p, data_size);
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		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),
	 * or in drbd_endio_write_sec, if we successfully submit the data at
	 * 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);
1684
		return false;
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	}

	e->w.cb = e_end_block;

1689 1690 1691 1692 1693 1694
	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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	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. */
	if (!mdev->net_conf->two_primaries) {
		spin_lock_irq(&mdev->req_lock);
	} else {
		/* don't get the req_lock yet,
		 * we may sleep in drbd_wait_peer_seq */
		const int size = e->size;
		const int discard = test_bit(DISCARD_CONCURRENT, &mdev->flags);
		DEFINE_WAIT(wait);
		struct drbd_request *i;
		struct hlist_node *n;
		struct hlist_head *slot;
		int first;

		D_ASSERT(mdev->net_conf->wire_protocol == DRBD_PROT_C);
		BUG_ON(mdev->ee_hash == NULL);
		BUG_ON(mdev->tl_hash == NULL);

		/* conflict detection and handling:
		 * 1. wait on the sequence number,
		 *    in case this data packet overtook ACK packets.
		 * 2. check our hash tables for conflicting requests.
		 *    we only need to walk the tl_hash, since an ee can not
		 *    have a conflict with an other ee: on the submitting
		 *    node, the corresponding req had already been conflicting,
		 *    and a conflicting req is never sent.
		 *
		 * Note: for two_primaries, we are protocol C,
		 * so there cannot be any request that is DONE
		 * but still on the transfer log.
		 *
		 * unconditionally add to the ee_hash.
		 *
		 * 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;

		spin_lock_irq(&mdev->req_lock);

		hlist_add_head(&e->colision, ee_hash_slot(mdev, sector));

#define OVERLAPS overlaps(i->sector, i->size, sector, size)
		slot = tl_hash_slot(mdev, sector);
		first = 1;
		for (;;) {
			int have_unacked = 0;
			int have_conflict = 0;
			prepare_to_wait(&mdev->misc_wait, &wait,
				TASK_INTERRUPTIBLE);
			hlist_for_each_entry(i, n, slot, colision) {
				if (OVERLAPS) {
					/* only ALERT on first iteration,
					 * we may be woken up early... */
					if (first)
						dev_alert(DEV, "%s[%u] Concurrent local write detected!"
						      "	new: %llus +%u; pending: %llus +%u\n",
						      current->comm, current->pid,
						      (unsigned long long)sector, size,
						      (unsigned long long)i->sector, i->size);
					if (i->rq_state & RQ_NET_PENDING)
						++have_unacked;
					++have_conflict;
				}
			}
#undef OVERLAPS
			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);

				spin_unlock_irq(&mdev->req_lock);

				/* 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);
1803
				return true;
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1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849
			}

			if (signal_pending(current)) {
				hlist_del_init(&e->colision);

				spin_unlock_irq(&mdev->req_lock);

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

			spin_unlock_irq(&mdev->req_lock);
			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();
			spin_lock_irq(&mdev->req_lock);
		}
		finish_wait(&mdev->misc_wait, &wait);
	}

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

	switch (mdev->net_conf->wire_protocol) {
	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;
	}

1850
	if (mdev->state.pdsk < D_INCONSISTENT) {
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1851 1852 1853
		/* In case we have the only disk of the cluster, */
		drbd_set_out_of_sync(mdev, e->sector, e->size);
		e->flags |= EE_CALL_AL_COMPLETE_IO;
1854
		e->flags &= ~EE_MAY_SET_IN_SYNC;
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1855 1856 1857
		drbd_al_begin_io(mdev, e->sector);
	}

1858
	if (drbd_submit_ee(mdev, e, rw, DRBD_FAULT_DT_WR) == 0)
1859
		return true;
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1860

1861 1862
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
1863 1864 1865 1866 1867 1868 1869
	spin_lock_irq(&mdev->req_lock);
	list_del(&e->w.list);
	hlist_del_init(&e->colision);
	spin_unlock_irq(&mdev->req_lock);
	if (e->flags & EE_CALL_AL_COMPLETE_IO)
		drbd_al_complete_io(mdev, e->sector);

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1870
out_interrupted:
1871
	drbd_may_finish_epoch(mdev, e->epoch, EV_PUT + EV_CLEANUP);
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1872 1873
	put_ldev(mdev);
	drbd_free_ee(mdev, e);
1874
	return false;
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1875 1876
}

1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
/* 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.
 */
1888
int drbd_rs_should_slow_down(struct drbd_conf *mdev, sector_t sector)
1889 1890 1891
{
	struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
	unsigned long db, dt, dbdt;
1892
	struct lc_element *tmp;
1893 1894 1895 1896 1897 1898 1899
	int curr_events;
	int throttle = 0;

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

1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911
	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);

1912 1913 1914
	curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
		      (int)part_stat_read(&disk->part0, sectors[1]) -
			atomic_read(&mdev->rs_sect_ev);
1915

1916 1917 1918 1919 1920 1921 1922 1923
	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. */
1924 1925 1926 1927 1928 1929
		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;
1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943

		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;
}


1944
static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int digest_size)
P
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1945 1946 1947 1948 1949
{
	sector_t sector;
	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
	struct drbd_epoch_entry *e;
	struct digest_info *di = NULL;
1950
	int size, verb;
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1951
	unsigned int fault_type;
1952
	struct p_block_req *p =	&mdev->data.rbuf.block_req;
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1953 1954 1955 1956

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

1957
	if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
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1958 1959
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
1960
		return false;
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1961 1962 1963 1964
	}
	if (sector + (size>>9) > capacity) {
		dev_err(DEV, "%s:%d: sector: %llus, size: %u\n", __FILE__, __LINE__,
				(unsigned long long)sector, size);
1965
		return false;
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1966 1967 1968
	}

	if (!get_ldev_if_state(mdev, D_UP_TO_DATE)) {
1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988
		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
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1989 1990
			dev_err(DEV, "Can not satisfy peer's read request, "
			    "no local data.\n");
1991

L
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1992 1993
		/* drain possibly payload */
		return drbd_drain_block(mdev, digest_size);
P
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1994 1995 1996 1997 1998 1999 2000 2001
	}

	/* 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);
2002
		return false;
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2003 2004
	}

2005
	switch (cmd) {
P
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	case P_DATA_REQUEST:
		e->w.cb = w_e_end_data_req;
		fault_type = DRBD_FAULT_DT_RD;
2009 2010 2011
		/* application IO, don't drbd_rs_begin_io */
		goto submit;

P
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	case P_RS_DATA_REQUEST:
		e->w.cb = w_e_end_rsdata_req;
		fault_type = DRBD_FAULT_RS_RD;
2015 2016
		/* used in the sector offset progress display */
		mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
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2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
		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));

2029 2030 2031
		e->digest = di;
		e->flags |= EE_HAS_DIGEST;

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2032 2033 2034
		if (drbd_recv(mdev, di->digest, digest_size) != digest_size)
			goto out_free_e;

2035
		if (cmd == P_CSUM_RS_REQUEST) {
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2036 2037
			D_ASSERT(mdev->agreed_pro_version >= 89);
			e->w.cb = w_e_end_csum_rs_req;
2038 2039
			/* used in the sector offset progress display */
			mdev->bm_resync_fo = BM_SECT_TO_BIT(sector);
2040
		} else if (cmd == P_OV_REPLY) {
2041 2042
			/* track progress, we may need to throttle */
			atomic_add(size >> 9, &mdev->rs_sect_in);
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2043 2044
			e->w.cb = w_e_end_ov_reply;
			dec_rs_pending(mdev);
2045 2046 2047
			/* 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
2048 2049 2050 2051 2052 2053
		}
		break;

	case P_OV_REQUEST:
		if (mdev->ov_start_sector == ~(sector_t)0 &&
		    mdev->agreed_pro_version >= 90) {
2054 2055
			unsigned long now = jiffies;
			int i;
P
Philipp Reisner 已提交
2056 2057
			mdev->ov_start_sector = sector;
			mdev->ov_position = sector;
2058 2059
			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
			mdev->rs_total = mdev->ov_left;
2060 2061 2062 2063
			for (i = 0; i < DRBD_SYNC_MARKS; i++) {
				mdev->rs_mark_left[i] = mdev->ov_left;
				mdev->rs_mark_time[i] = now;
			}
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2064 2065 2066 2067 2068 2069 2070 2071 2072
			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",
2073
		    cmdname(cmd));
P
Philipp Reisner 已提交
2074
		fault_type = DRBD_FAULT_MAX;
2075
		goto out_free_e;
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2076 2077
	}

2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099
	/* 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.
	 */
2100 2101 2102
	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))
2103
		goto out_free_e;
P
Philipp Reisner 已提交
2104

2105 2106 2107
submit_for_resync:
	atomic_add(size >> 9, &mdev->rs_sect_ev);

2108
submit:
P
Philipp Reisner 已提交
2109
	inc_unacked(mdev);
2110 2111 2112
	spin_lock_irq(&mdev->req_lock);
	list_add_tail(&e->w.list, &mdev->read_ee);
	spin_unlock_irq(&mdev->req_lock);
P
Philipp Reisner 已提交
2113

2114
	if (drbd_submit_ee(mdev, e, READ, fault_type) == 0)
2115
		return true;
P
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2116

2117 2118
	/* don't care for the reason here */
	dev_err(DEV, "submit failed, triggering re-connect\n");
2119 2120 2121 2122 2123
	spin_lock_irq(&mdev->req_lock);
	list_del(&e->w.list);
	spin_unlock_irq(&mdev->req_lock);
	/* no drbd_rs_complete_io(), we are dropping the connection anyways */

P
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2124 2125 2126
out_free_e:
	put_ldev(mdev);
	drbd_free_ee(mdev, e);
2127
	return false;
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2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168
}

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;

	switch (mdev->net_conf->after_sb_0p) {
	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
2169
		dev_warn(DEV, "Discard younger/older primary did not find a decision\n"
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2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203
		     "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; }
		}
		if (mdev->net_conf->after_sb_0p == ASB_DISCARD_ZERO_CHG)
			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)
{
2204
	int hg, rv = -100;
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2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230

	switch (mdev->net_conf->after_sb_1p) {
	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) {
2231 2232 2233
			enum drbd_state_rv rv2;

			drbd_set_role(mdev, R_SECONDARY, 0);
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			 /* 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. */
2237 2238
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
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				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)
{
2253
	int hg, rv = -100;
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	switch (mdev->net_conf->after_sb_2p) {
	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) {
2273 2274
			enum drbd_state_rv rv2;

P
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			 /* 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. */
2278 2279
			rv2 = drbd_change_state(mdev, CS_VERBOSE, NS(role, R_SECONDARY));
			if (rv2 != SS_SUCCESS) {
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				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
2318 2319
-1091   requires proto 91
-1096   requires proto 96
P
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 */
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) {

			if (mdev->agreed_pro_version < 91)
2349
				return -1091;
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			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) {

			if (mdev->agreed_pro_version < 91)
2370
				return -1091;
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			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) {
2415 2416 2417 2418
		if (mdev->agreed_pro_version < 96 ?
		    (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))) {
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			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of the peer's UUIDs. */

			if (mdev->agreed_pro_version < 91)
2423
				return -1091;
P
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2424 2425 2426

			mdev->p_uuid[UI_BITMAP] = mdev->p_uuid[UI_HISTORY_START];
			mdev->p_uuid[UI_HISTORY_START] = mdev->p_uuid[UI_HISTORY_START + 1];
2427 2428 2429 2430

			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
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			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) {
2452 2453 2454 2455
		if (mdev->agreed_pro_version < 96 ?
		    (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
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			/* The last P_SYNC_UUID did not get though. Undo the last start of
			   resync as sync source modifications of our UUIDs. */

			if (mdev->agreed_pro_version < 91)
2460
				return -1091;
P
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			_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]);

2465
			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");
P
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			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;
2475
	peer = mdev->p_uuid[UI_CURRENT] & ~((u64)1);
P
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	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;
	}
2528 2529
	if (hg < -1000) {
		dev_alert(DEV, "To resolve this both sides have to support at least protocol %d\n", -hg - 1000);
P
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		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");
	}

2543 2544 2545
	if (abs(hg) == 100)
		drbd_khelper(mdev, "initial-split-brain");

P
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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
	if (hg == 100 || (hg == -100 && mdev->net_conf->always_asbp)) {
		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) {
		if (mdev->net_conf->want_lose && !(mdev->p_uuid[UI_FLAGS]&1))
			hg = -1;
		if (!mdev->net_conf->want_lose && (mdev->p_uuid[UI_FLAGS]&1))
			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) {
2587 2588 2589 2590
		/* 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... */
2591
		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
P
Philipp Reisner 已提交
2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615
		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) {
		switch (mdev->net_conf->rr_conflict) {
		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");
		}
	}

2616 2617 2618 2619 2620 2621 2622 2623 2624 2625
	if (mdev->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
		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
2626 2627
	if (abs(hg) >= 2) {
		dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
2628 2629
		if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write, "set_n_write from sync_handshake",
					BM_LOCKED_SET_ALLOWED))
P
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2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668
			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;
}

2669
static int receive_protocol(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
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2670
{
2671
	struct p_protocol *p = &mdev->data.rbuf.protocol;
P
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2672
	int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
2673
	int p_want_lose, p_two_primaries, cf;
P
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2674 2675 2676 2677 2678 2679 2680
	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);
2681 2682 2683 2684 2685 2686 2687
	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
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	if (p_proto != mdev->net_conf->wire_protocol) {
		dev_err(DEV, "incompatible communication protocols\n");
		goto disconnect;
	}

	if (cmp_after_sb(p_after_sb_0p, mdev->net_conf->after_sb_0p)) {
		dev_err(DEV, "incompatible after-sb-0pri settings\n");
		goto disconnect;
	}

	if (cmp_after_sb(p_after_sb_1p, mdev->net_conf->after_sb_1p)) {
		dev_err(DEV, "incompatible after-sb-1pri settings\n");
		goto disconnect;
	}

	if (cmp_after_sb(p_after_sb_2p, mdev->net_conf->after_sb_2p)) {
		dev_err(DEV, "incompatible after-sb-2pri settings\n");
		goto disconnect;
	}

	if (p_want_lose && mdev->net_conf->want_lose) {
		dev_err(DEV, "both sides have the 'want_lose' flag set\n");
		goto disconnect;
	}

	if (p_two_primaries != mdev->net_conf->two_primaries) {
		dev_err(DEV, "incompatible setting of the two-primaries options\n");
		goto disconnect;
	}

	if (mdev->agreed_pro_version >= 87) {
		unsigned char *my_alg = mdev->net_conf->integrity_alg;

		if (drbd_recv(mdev, p_integrity_alg, data_size) != data_size)
2723
			return false;
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2724 2725 2726 2727 2728 2729 2730 2731 2732 2733

		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>");
	}

2734
	return true;
P
Philipp Reisner 已提交
2735 2736 2737

disconnect:
	drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
2738
	return false;
P
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2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767
}

/* 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;
}

2768
static int receive_SyncParam(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int packet_size)
P
Philipp Reisner 已提交
2769
{
2770
	int ok = true;
2771
	struct p_rs_param_95 *p = &mdev->data.rbuf.rs_param_95;
P
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2772 2773 2774 2775
	unsigned int header_size, data_size, exp_max_sz;
	struct crypto_hash *verify_tfm = NULL;
	struct crypto_hash *csums_tfm = NULL;
	const int apv = mdev->agreed_pro_version;
2776 2777
	int *rs_plan_s = NULL;
	int fifo_size = 0;
P
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2778 2779 2780 2781

	exp_max_sz  = apv <= 87 ? sizeof(struct p_rs_param)
		    : apv == 88 ? sizeof(struct p_rs_param)
					+ SHARED_SECRET_MAX
2782 2783
		    : apv <= 94 ? sizeof(struct p_rs_param_89)
		    : /* apv >= 95 */ sizeof(struct p_rs_param_95);
P
Philipp Reisner 已提交
2784

2785
	if (packet_size > exp_max_sz) {
P
Philipp Reisner 已提交
2786
		dev_err(DEV, "SyncParam packet too long: received %u, expected <= %u bytes\n",
2787
		    packet_size, exp_max_sz);
2788
		return false;
P
Philipp Reisner 已提交
2789 2790 2791
	}

	if (apv <= 88) {
2792 2793
		header_size = sizeof(struct p_rs_param) - sizeof(struct p_header80);
		data_size   = packet_size  - header_size;
2794
	} else if (apv <= 94) {
2795 2796
		header_size = sizeof(struct p_rs_param_89) - sizeof(struct p_header80);
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2797
		D_ASSERT(data_size == 0);
2798
	} else {
2799 2800
		header_size = sizeof(struct p_rs_param_95) - sizeof(struct p_header80);
		data_size   = packet_size  - header_size;
P
Philipp Reisner 已提交
2801 2802 2803 2804 2805 2806
		D_ASSERT(data_size == 0);
	}

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

2807
	if (drbd_recv(mdev, &p->head.payload, header_size) != header_size)
2808
		return false;
P
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2809 2810 2811 2812 2813 2814 2815 2816 2817

	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);
2818
				return false;
P
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2819 2820 2821
			}

			if (drbd_recv(mdev, p->verify_alg, data_size) != data_size)
2822
				return false;
P
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2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865

			/* 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;
			}
		}

2866 2867 2868 2869 2870 2871
		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);
2872 2873 2874 2875 2876 2877 2878 2879 2880

			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;
				}
			}
2881
		}
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2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898

		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);
		}
2899 2900 2901 2902 2903 2904
		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;
		}
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2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915
		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));
2916
	return false;
P
Philipp Reisner 已提交
2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937
}

static void drbd_setup_order_type(struct drbd_conf *mdev, int peer)
{
	/* sorry, we currently have no working implementation
	 * of distributed TCQ */
}

/* 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);
}

2938
static int receive_sizes(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
2939
{
2940
	struct p_sizes *p = &mdev->data.rbuf.sizes;
P
Philipp Reisner 已提交
2941
	enum determine_dev_size dd = unchanged;
2942
	unsigned int max_bio_size;
P
Philipp Reisner 已提交
2943 2944
	sector_t p_size, p_usize, my_usize;
	int ldsc = 0; /* local disk size changed */
2945
	enum dds_flags ddsf;
P
Philipp Reisner 已提交
2946 2947 2948 2949 2950 2951 2952

	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));
2953
		return false;
P
Philipp Reisner 已提交
2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981
	}

	/* 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. */
2982
		if (drbd_new_dev_size(mdev, mdev->ldev, 0) <
P
Philipp Reisner 已提交
2983 2984 2985 2986 2987 2988 2989
		   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);
2990
			return false;
P
Philipp Reisner 已提交
2991 2992 2993 2994
		}
		put_ldev(mdev);
	}

2995
	ddsf = be16_to_cpu(p->dds_flags);
P
Philipp Reisner 已提交
2996
	if (get_ldev(mdev)) {
2997
		dd = drbd_determin_dev_size(mdev, ddsf);
P
Philipp Reisner 已提交
2998 2999
		put_ldev(mdev);
		if (dd == dev_size_error)
3000
			return false;
P
Philipp Reisner 已提交
3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012
		drbd_md_sync(mdev);
	} else {
		/* I am diskless, need to accept the peer's size. */
		drbd_set_my_capacity(mdev, p_size);
	}

	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;
		}

3013
		if (mdev->agreed_pro_version < 94)
3014
			max_bio_size = be32_to_cpu(p->max_bio_size);
3015
		else if (mdev->agreed_pro_version == 94)
3016
			max_bio_size = DRBD_MAX_SIZE_H80_PACKET;
3017
		else /* drbd 8.3.8 onwards */
3018
			max_bio_size = DRBD_MAX_BIO_SIZE;
3019

3020 3021
		if (max_bio_size != queue_max_hw_sectors(mdev->rq_queue) << 9)
			drbd_setup_queue_param(mdev, max_bio_size);
P
Philipp Reisner 已提交
3022

3023
		drbd_setup_order_type(mdev, be16_to_cpu(p->queue_order_type));
P
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3024 3025 3026 3027 3028 3029 3030 3031
		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... */
3032
			drbd_send_sizes(mdev, 0, ddsf);
P
Philipp Reisner 已提交
3033 3034 3035 3036
		}
		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
			if (mdev->state.pdsk >= D_INCONSISTENT &&
3037 3038 3039 3040 3041 3042
			    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
3043 3044 3045 3046
				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
		}
	}

3047
	return true;
P
Philipp Reisner 已提交
3048 3049
}

3050
static int receive_uuids(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3051
{
3052
	struct p_uuids *p = &mdev->data.rbuf.uuids;
P
Philipp Reisner 已提交
3053
	u64 *p_uuid;
3054
	int i, updated_uuids = 0;
P
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3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070

	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));
3071
		return false;
P
Philipp Reisner 已提交
3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082
	}

	if (get_ldev(mdev)) {
		int skip_initial_sync =
			mdev->state.conn == C_CONNECTED &&
			mdev->agreed_pro_version >= 90 &&
			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,
3083 3084
					"clear_n_write from receive_uuids",
					BM_LOCKED_TEST_ALLOWED);
P
Philipp Reisner 已提交
3085 3086 3087 3088 3089
			_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);
3090
			updated_uuids = 1;
P
Philipp Reisner 已提交
3091 3092
		}
		put_ldev(mdev);
3093 3094 3095 3096
	} 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. */
3097
		updated_uuids = drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
P
Philipp Reisner 已提交
3098 3099 3100 3101 3102 3103 3104 3105
	}

	/* 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)
3106 3107 3108 3109
		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
3110

3111
	return true;
P
Philipp Reisner 已提交
3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143
}

/**
 * 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;
}

3144
static int receive_req_state(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3145
{
3146
	struct p_req_state *p = &mdev->data.rbuf.req_state;
P
Philipp Reisner 已提交
3147
	union drbd_state mask, val;
3148
	enum drbd_state_rv rv;
P
Philipp Reisner 已提交
3149 3150 3151 3152 3153 3154 3155

	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);
3156
		return true;
P
Philipp Reisner 已提交
3157 3158 3159 3160 3161 3162 3163 3164 3165 3166
	}

	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);

3167
	return true;
P
Philipp Reisner 已提交
3168 3169
}

3170
static int receive_state(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3171
{
3172
	struct p_state *p = &mdev->data.rbuf.state;
3173
	union drbd_state os, ns, peer_state;
P
Philipp Reisner 已提交
3174
	enum drbd_disk_state real_peer_disk;
3175
	enum chg_state_flags cs_flags;
P
Philipp Reisner 已提交
3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187
	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));
	}

	spin_lock_irq(&mdev->req_lock);
 retry:
3188
	os = ns = mdev->state;
P
Philipp Reisner 已提交
3189 3190
	spin_unlock_irq(&mdev->req_lock);

3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211
	/* 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);
3212
			return true;
3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224
		}
	}

	/* 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;

3225 3226
	if (ns.conn == C_WF_REPORT_PARAMS)
		ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3227

3228 3229 3230
	if (peer_state.conn == C_AHEAD)
		ns.conn = C_BEHIND;

P
Philipp Reisner 已提交
3231 3232 3233 3234 3235
	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 */
3236
		cr  = (os.conn < C_CONNECTED);
P
Philipp Reisner 已提交
3237 3238
		/* if we had an established connection
		 * and one of the nodes newly attaches a disk */
3239
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3240
		       (peer_state.disk == D_NEGOTIATING ||
3241
			os.disk == D_NEGOTIATING));
P
Philipp Reisner 已提交
3242 3243 3244 3245 3246
		/* 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" */
3247
		cr |= (os.conn == C_CONNECTED &&
P
Philipp Reisner 已提交
3248 3249 3250 3251
				(peer_state.conn >= C_STARTING_SYNC_S &&
				 peer_state.conn <= C_WF_BITMAP_T));

		if (cr)
3252
			ns.conn = drbd_sync_handshake(mdev, peer_state.role, real_peer_disk);
P
Philipp Reisner 已提交
3253 3254

		put_ldev(mdev);
3255 3256
		if (ns.conn == C_MASK) {
			ns.conn = C_CONNECTED;
P
Philipp Reisner 已提交
3257
			if (mdev->state.disk == D_NEGOTIATING) {
3258
				drbd_force_state(mdev, NS(disk, D_FAILED));
P
Philipp Reisner 已提交
3259 3260 3261
			} 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;
3262
				real_peer_disk = D_DISKLESS;
P
Philipp Reisner 已提交
3263
			} else {
3264
				if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
3265
					return false;
3266
				D_ASSERT(os.conn == C_WF_REPORT_PARAMS);
P
Philipp Reisner 已提交
3267
				drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3268
				return false;
P
Philipp Reisner 已提交
3269 3270 3271 3272 3273
			}
		}
	}

	spin_lock_irq(&mdev->req_lock);
3274
	if (mdev->state.i != os.i)
P
Philipp Reisner 已提交
3275 3276 3277 3278 3279
		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);
3280
	if ((ns.conn == C_CONNECTED || ns.conn == C_WF_BITMAP_S) && ns.disk == D_NEGOTIATING)
P
Philipp Reisner 已提交
3281
		ns.disk = mdev->new_state_tmp.disk;
3282 3283
	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 &&
3284 3285 3286 3287 3288 3289 3290 3291 3292
	    test_bit(NEW_CUR_UUID, &mdev->flags)) {
		/* Do not allow tl_restart(resend) for a rebooted peer. We can only allow this
		   for temporal network outages! */
		spin_unlock_irq(&mdev->req_lock);
		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));
3293
		return false;
3294
	}
3295
	rv = _drbd_set_state(mdev, ns, cs_flags, NULL);
P
Philipp Reisner 已提交
3296 3297 3298 3299 3300
	ns = mdev->state;
	spin_unlock_irq(&mdev->req_lock);

	if (rv < SS_SUCCESS) {
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
3301
		return false;
P
Philipp Reisner 已提交
3302 3303
	}

3304 3305
	if (os.conn > C_WF_REPORT_PARAMS) {
		if (ns.conn > C_CONNECTED && peer_state.conn <= C_CONNECTED &&
P
Philipp Reisner 已提交
3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318
		    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);
		}
	}

	mdev->net_conf->want_lose = 0;

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

3319
	return true;
P
Philipp Reisner 已提交
3320 3321
}

3322
static int receive_sync_uuid(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3323
{
3324
	struct p_rs_uuid *p = &mdev->data.rbuf.rs_uuid;
P
Philipp Reisner 已提交
3325 3326 3327

	wait_event(mdev->misc_wait,
		   mdev->state.conn == C_WF_SYNC_UUID ||
3328
		   mdev->state.conn == C_BEHIND ||
P
Philipp Reisner 已提交
3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339
		   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);

3340
		drbd_print_uuids(mdev, "updated sync uuid");
P
Philipp Reisner 已提交
3341 3342 3343 3344 3345 3346
		drbd_start_resync(mdev, C_SYNC_TARGET);

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

3347
	return true;
P
Philipp Reisner 已提交
3348 3349
}

3350 3351 3352 3353 3354 3355 3356
/**
 * receive_bitmap_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
3357 3358
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
3359 3360 3361
{
	unsigned num_words = min_t(size_t, BM_PACKET_WORDS, c->bm_words - c->word_offset);
	unsigned want = num_words * sizeof(long);
3362
	int err;
P
Philipp Reisner 已提交
3363

3364 3365
	if (want != data_size) {
		dev_err(DEV, "%s:want (%u) != data_size (%u)\n", __func__, want, data_size);
3366
		return -EIO;
P
Philipp Reisner 已提交
3367 3368
	}
	if (want == 0)
3369 3370 3371 3372 3373 3374 3375
		return 0;
	err = drbd_recv(mdev, buffer, want);
	if (err != want) {
		if (err >= 0)
			err = -EIO;
		return err;
	}
P
Philipp Reisner 已提交
3376 3377 3378 3379 3380 3381 3382 3383

	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;

3384
	return 1;
P
Philipp Reisner 已提交
3385 3386
}

3387 3388 3389 3390 3391 3392 3393
/**
 * 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
3394 3395 3396 3397 3398 3399 3400 3401 3402 3403
recv_bm_rle_bits(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
		struct bm_xfer_ctx *c)
{
	struct bitstream bs;
	u64 look_ahead;
	u64 rl;
	u64 tmp;
	unsigned long s = c->bit_offset;
	unsigned long e;
3404
	int len = be16_to_cpu(p->head.length) - (sizeof(*p) - sizeof(p->head));
P
Philipp Reisner 已提交
3405 3406 3407 3408 3409 3410 3411 3412
	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)
3413
		return -EIO;
P
Philipp Reisner 已提交
3414 3415 3416 3417

	for (have = bits; have > 0; s += rl, toggle = !toggle) {
		bits = vli_decode_bits(&rl, look_ahead);
		if (bits <= 0)
3418
			return -EIO;
P
Philipp Reisner 已提交
3419 3420 3421 3422 3423

		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);
3424
				return -EIO;
P
Philipp Reisner 已提交
3425 3426 3427 3428 3429 3430 3431 3432 3433
			}
			_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);
3434
			return -EIO;
P
Philipp Reisner 已提交
3435 3436 3437 3438 3439 3440
		}
		look_ahead >>= bits;
		have -= bits;

		bits = bitstream_get_bits(&bs, &tmp, 64 - have);
		if (bits < 0)
3441
			return -EIO;
P
Philipp Reisner 已提交
3442 3443 3444 3445 3446 3447 3448
		look_ahead |= tmp << have;
		have += bits;
	}

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

3449
	return (s != c->bm_bits);
P
Philipp Reisner 已提交
3450 3451
}

3452 3453 3454 3455 3456 3457 3458
/**
 * 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
3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471
decode_bitmap_c(struct drbd_conf *mdev,
		struct p_compressed_bm *p,
		struct bm_xfer_ctx *c)
{
	if (DCBP_get_code(p) == RLE_VLI_Bits)
		return recv_bm_rle_bits(mdev, p, c);

	/* 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));
3472
	return -EIO;
P
Philipp Reisner 已提交
3473 3474 3475 3476 3477 3478
}

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" */
3479
	unsigned plain = sizeof(struct p_header80) *
P
Philipp Reisner 已提交
3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516
		((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. */
3517
static int receive_bitmap(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3518 3519 3520
{
	struct bm_xfer_ctx c;
	void *buffer;
3521
	int err;
3522
	int ok = false;
3523
	struct p_header80 *h = &mdev->data.rbuf.header.h80;
P
Philipp Reisner 已提交
3524

3525 3526 3527
	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
3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541

	/* 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),
	};

3542
	for(;;) {
3543
		if (cmd == P_BITMAP) {
3544
			err = receive_bitmap_plain(mdev, data_size, buffer, &c);
3545
		} else if (cmd == P_COMPRESSED_BITMAP) {
P
Philipp Reisner 已提交
3546 3547 3548 3549
			/* MAYBE: sanity check that we speak proto >= 90,
			 * and the feature is enabled! */
			struct p_compressed_bm *p;

3550
			if (data_size > BM_PACKET_PAYLOAD_BYTES) {
P
Philipp Reisner 已提交
3551 3552 3553 3554 3555 3556
				dev_err(DEV, "ReportCBitmap packet too large\n");
				goto out;
			}
			/* use the page buff */
			p = buffer;
			memcpy(p, h, sizeof(*h));
3557
			if (drbd_recv(mdev, p->head.payload, data_size) != data_size)
P
Philipp Reisner 已提交
3558
				goto out;
3559 3560
			if (data_size <= (sizeof(*p) - sizeof(p->head))) {
				dev_err(DEV, "ReportCBitmap packet too small (l:%u)\n", data_size);
3561
				goto out;
P
Philipp Reisner 已提交
3562
			}
3563
			err = decode_bitmap_c(mdev, p, &c);
P
Philipp Reisner 已提交
3564
		} else {
3565
			dev_warn(DEV, "receive_bitmap: cmd neither ReportBitMap nor ReportCBitMap (is 0x%x)", cmd);
P
Philipp Reisner 已提交
3566 3567 3568
			goto out;
		}

3569 3570
		c.packets[cmd == P_BITMAP]++;
		c.bytes[cmd == P_BITMAP] += sizeof(struct p_header80) + data_size;
P
Philipp Reisner 已提交
3571

3572 3573 3574
		if (err <= 0) {
			if (err < 0)
				goto out;
P
Philipp Reisner 已提交
3575
			break;
3576
		}
3577
		if (!drbd_recv_header(mdev, &cmd, &data_size))
P
Philipp Reisner 已提交
3578
			goto out;
3579
	}
P
Philipp Reisner 已提交
3580 3581 3582 3583

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

	if (mdev->state.conn == C_WF_BITMAP_T) {
3584 3585
		enum drbd_state_rv rv;

P
Philipp Reisner 已提交
3586 3587 3588 3589
		ok = !drbd_send_bitmap(mdev);
		if (!ok)
			goto out;
		/* Omit CS_ORDERED with this state transition to avoid deadlocks. */
3590 3591
		rv = _drbd_request_state(mdev, NS(conn, C_WF_SYNC_UUID), CS_VERBOSE);
		D_ASSERT(rv == SS_SUCCESS);
P
Philipp Reisner 已提交
3592 3593 3594 3595 3596 3597 3598
	} 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));
	}

3599
	ok = true;
P
Philipp Reisner 已提交
3600
 out:
3601
	drbd_bm_unlock(mdev);
P
Philipp Reisner 已提交
3602 3603 3604 3605 3606 3607
	if (ok && mdev->state.conn == C_WF_BITMAP_S)
		drbd_start_resync(mdev, C_SYNC_SOURCE);
	free_page((unsigned long) buffer);
	return ok;
}

3608
static int receive_skip(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
P
Philipp Reisner 已提交
3609 3610 3611 3612 3613
{
	/* TODO zero copy sink :) */
	static char sink[128];
	int size, want, r;

3614 3615
	dev_warn(DEV, "skipping unknown optional packet type %d, l: %d!\n",
		 cmd, data_size);
P
Philipp Reisner 已提交
3616

3617
	size = data_size;
P
Philipp Reisner 已提交
3618 3619 3620 3621 3622 3623 3624 3625 3626
	while (size > 0) {
		want = min_t(int, size, sizeof(sink));
		r = drbd_recv(mdev, sink, want);
		ERR_IF(r <= 0) break;
		size -= r;
	}
	return size == 0;
}

3627
static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
3628
{
3629 3630 3631
	/* Make sure we've acked all the TCP data associated
	 * with the data requests being unplugged */
	drbd_tcp_quickack(mdev->data.socket);
3632

3633
	return true;
3634 3635
}

3636 3637 3638 3639
static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
{
	struct p_block_desc *p = &mdev->data.rbuf.block_desc;

3640 3641 3642 3643 3644 3645 3646 3647 3648 3649
	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));
	}

3650 3651
	drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));

3652
	return true;
3653 3654
}

3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packets cmd, unsigned int to_receive);

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

static struct data_cmd drbd_cmd_handler[] = {
	[P_DATA]	    = { 1, sizeof(struct p_data), receive_Data },
	[P_DATA_REPLY]	    = { 1, sizeof(struct p_data), receive_DataReply },
	[P_RS_DATA_REPLY]   = { 1, sizeof(struct p_data), receive_RSDataReply } ,
	[P_BARRIER]	    = { 0, sizeof(struct p_barrier), receive_Barrier } ,
	[P_BITMAP]	    = { 1, sizeof(struct p_header80), receive_bitmap } ,
	[P_COMPRESSED_BITMAP] = { 1, sizeof(struct p_header80), receive_bitmap } ,
	[P_UNPLUG_REMOTE]   = { 0, sizeof(struct p_header80), receive_UnplugRemote },
	[P_DATA_REQUEST]    = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_RS_DATA_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
	[P_SYNC_PARAM]	    = { 1, sizeof(struct p_header80), receive_SyncParam },
	[P_SYNC_PARAM89]    = { 1, sizeof(struct p_header80), receive_SyncParam },
	[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 },
3685
	[P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
P
Philipp Reisner 已提交
3686 3687
	/* anything missing from this table is in
	 * the asender_tbl, see get_asender_cmd */
3688
	[P_MAX_CMD]	    = { 0, 0, NULL },
P
Philipp Reisner 已提交
3689 3690
};

3691 3692 3693 3694 3695 3696
/* All handler functions that expect a sub-header get that sub-heder in
   mdev->data.rbuf.header.head.payload.

   Usually in mdev->data.rbuf.header.head the callback can find the usual
   p_header, but they may not rely on that. Since there is also p_header95 !
 */
P
Philipp Reisner 已提交
3697 3698 3699

static void drbdd(struct drbd_conf *mdev)
{
3700 3701 3702 3703 3704
	union p_header *header = &mdev->data.rbuf.header;
	unsigned int packet_size;
	enum drbd_packets cmd;
	size_t shs; /* sub header size */
	int rv;
P
Philipp Reisner 已提交
3705 3706 3707

	while (get_t_state(&mdev->receiver) == Running) {
		drbd_thread_current_set_cpu(mdev);
3708 3709
		if (!drbd_recv_header(mdev, &cmd, &packet_size))
			goto err_out;
P
Philipp Reisner 已提交
3710

3711 3712 3713
		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;
3714
		}
P
Philipp Reisner 已提交
3715

3716 3717 3718 3719
		shs = drbd_cmd_handler[cmd].pkt_size - sizeof(union p_header);
		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
3720 3721
		}

3722 3723 3724
		if (shs) {
			rv = drbd_recv(mdev, &header->h80.payload, shs);
			if (unlikely(rv != shs)) {
3725 3726
				if (!signal_pending(current))
					dev_warn(DEV, "short read while reading sub header: rv=%d\n", rv);
3727 3728 3729 3730
				goto err_out;
			}
		}

3731
		rv = drbd_cmd_handler[cmd].function(mdev, cmd, packet_size - shs);
P
Philipp Reisner 已提交
3732

3733
		if (unlikely(!rv)) {
P
Philipp Reisner 已提交
3734
			dev_err(DEV, "error receiving %s, l: %d!\n",
3735 3736
			    cmdname(cmd), packet_size);
			goto err_out;
P
Philipp Reisner 已提交
3737 3738 3739
		}
	}

3740 3741 3742 3743
	if (0) {
	err_out:
		drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR));
	}
3744 3745 3746
	/* 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
3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758
}

void drbd_flush_workqueue(struct drbd_conf *mdev)
{
	struct drbd_wq_barrier barr;

	barr.w.cb = w_prev_work_done;
	init_completion(&barr.done);
	drbd_queue_work(&mdev->data.work, &barr.w);
	wait_for_completion(&barr.done);
}

3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788
void drbd_free_tl_hash(struct drbd_conf *mdev)
{
	struct hlist_head *h;

	spin_lock_irq(&mdev->req_lock);

	if (!mdev->tl_hash || mdev->state.conn != C_STANDALONE) {
		spin_unlock_irq(&mdev->req_lock);
		return;
	}
	/* paranoia code */
	for (h = mdev->ee_hash; h < mdev->ee_hash + mdev->ee_hash_s; h++)
		if (h->first)
			dev_err(DEV, "ASSERT FAILED ee_hash[%u].first == %p, expected NULL\n",
				(int)(h - mdev->ee_hash), h->first);
	kfree(mdev->ee_hash);
	mdev->ee_hash = NULL;
	mdev->ee_hash_s = 0;

	/* paranoia code */
	for (h = mdev->tl_hash; h < mdev->tl_hash + mdev->tl_hash_s; h++)
		if (h->first)
			dev_err(DEV, "ASSERT FAILED tl_hash[%u] == %p, expected NULL\n",
				(int)(h - mdev->tl_hash), h->first);
	kfree(mdev->tl_hash);
	mdev->tl_hash = NULL;
	mdev->tl_hash_s = 0;
	spin_unlock_irq(&mdev->req_lock);
}

P
Philipp Reisner 已提交
3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802
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 */
	drbd_thread_stop(&mdev->asender);
	drbd_free_sock(mdev);

3803
	/* wait for current activity to cease. */
P
Philipp Reisner 已提交
3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825
	spin_lock_irq(&mdev->req_lock);
	_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);
	spin_unlock_irq(&mdev->req_lock);

	/* 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);

3826 3827
	del_timer(&mdev->request_timer);

P
Philipp Reisner 已提交
3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843
	/* 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" */
	drbd_flush_workqueue(mdev);

	/* 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;

3844
	if (!is_susp(mdev->state))
P
Philipp Reisner 已提交
3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856
		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);
	}

3857 3858
	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
3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870

	spin_lock_irq(&mdev->req_lock);
	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);
	}
	spin_unlock_irq(&mdev->req_lock);

	if (os.conn == C_DISCONNECTING) {
3871
		wait_event(mdev->net_cnt_wait, atomic_read(&mdev->net_cnt) == 0);
P
Philipp Reisner 已提交
3872 3873 3874 3875 3876 3877 3878 3879 3880

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

		kfree(mdev->net_conf);
		mdev->net_conf = NULL;
		drbd_request_state(mdev, NS(conn, C_STANDALONE));
	}

3881 3882 3883 3884
	/* 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
3885 3886 3887 3888 3889 3890 3891 3892 3893 3894
	/* 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);
3895 3896 3897
	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
3898 3899
	i = atomic_read(&mdev->pp_in_use);
	if (i)
3900
		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
P
Philipp Reisner 已提交
3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940

	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)
{
	/* ASSERT current == mdev->receiver ... */
	struct p_handshake *p = &mdev->data.sbuf.handshake;
	int ok;

	if (mutex_lock_interruptible(&mdev->data.mutex)) {
		dev_err(DEV, "interrupted during initial handshake\n");
		return 0; /* interrupted. not ok. */
	}

	if (mdev->data.socket == NULL) {
		mutex_unlock(&mdev->data.mutex);
		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);
	ok = _drbd_send_cmd( mdev, mdev->data.socket, P_HAND_SHAKE,
3941
			     (struct p_header80 *)p, sizeof(*p), 0 );
P
Philipp Reisner 已提交
3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956
	mutex_unlock(&mdev->data.mutex);
	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)
{
	/* ASSERT current == mdev->receiver ... */
	struct p_handshake *p = &mdev->data.rbuf.handshake;
3957 3958 3959
	const int expect = sizeof(struct p_handshake) - sizeof(struct p_header80);
	unsigned int length;
	enum drbd_packets cmd;
P
Philipp Reisner 已提交
3960 3961 3962 3963 3964 3965
	int rv;

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

3966
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
3967 3968 3969
	if (!rv)
		return 0;

3970
	if (cmd != P_HAND_SHAKE) {
P
Philipp Reisner 已提交
3971
		dev_err(DEV, "expected HandShake packet, received: %s (0x%04x)\n",
3972
		     cmdname(cmd), cmd);
P
Philipp Reisner 已提交
3973 3974 3975
		return -1;
	}

3976
	if (length != expect) {
P
Philipp Reisner 已提交
3977
		dev_err(DEV, "expected HandShake length: %u, received: %u\n",
3978
		     expect, length);
P
Philipp Reisner 已提交
3979 3980 3981 3982 3983 3984
		return -1;
	}

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

	if (rv != expect) {
3985 3986
		if (!signal_pending(current))
			dev_warn(DEV, "short read receiving handshake packet: l=%u\n", rv);
P
Philipp Reisner 已提交
3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018
		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;

	mdev->agreed_pro_version = min_t(int, PRO_VERSION_MAX, p->protocol_max);

	dev_info(DEV, "Handshake successful: "
	     "Agreed network protocol version %d\n", mdev->agreed_pro_version);

	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");
4019
	return -1;
P
Philipp Reisner 已提交
4020 4021 4022
}
#else
#define CHALLENGE_LEN 64
4023 4024 4025 4026 4027 4028 4029

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

P
Philipp Reisner 已提交
4030 4031 4032 4033 4034 4035 4036 4037 4038 4039
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;
	unsigned int key_len = strlen(mdev->net_conf->shared_secret);
	unsigned int resp_size;
	struct hash_desc desc;
4040 4041
	enum drbd_packets cmd;
	unsigned int length;
P
Philipp Reisner 已提交
4042 4043 4044 4045 4046 4047 4048 4049 4050
	int rv;

	desc.tfm = mdev->cram_hmac_tfm;
	desc.flags = 0;

	rv = crypto_hash_setkey(mdev->cram_hmac_tfm,
				(u8 *)mdev->net_conf->shared_secret, key_len);
	if (rv) {
		dev_err(DEV, "crypto_hash_setkey() failed with %d\n", rv);
4051
		rv = -1;
P
Philipp Reisner 已提交
4052 4053 4054 4055 4056 4057 4058 4059 4060
		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;

4061
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4062 4063 4064
	if (!rv)
		goto fail;

4065
	if (cmd != P_AUTH_CHALLENGE) {
P
Philipp Reisner 已提交
4066
		dev_err(DEV, "expected AuthChallenge packet, received: %s (0x%04x)\n",
4067
		    cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4068 4069 4070 4071
		rv = 0;
		goto fail;
	}

4072
	if (length > CHALLENGE_LEN * 2) {
P
Philipp Reisner 已提交
4073
		dev_err(DEV, "expected AuthChallenge payload too big.\n");
4074
		rv = -1;
P
Philipp Reisner 已提交
4075 4076 4077
		goto fail;
	}

4078
	peers_ch = kmalloc(length, GFP_NOIO);
P
Philipp Reisner 已提交
4079 4080
	if (peers_ch == NULL) {
		dev_err(DEV, "kmalloc of peers_ch failed\n");
4081
		rv = -1;
P
Philipp Reisner 已提交
4082 4083 4084
		goto fail;
	}

4085
	rv = drbd_recv(mdev, peers_ch, length);
P
Philipp Reisner 已提交
4086

4087
	if (rv != length) {
4088 4089
		if (!signal_pending(current))
			dev_warn(DEV, "short read AuthChallenge: l=%u\n", rv);
P
Philipp Reisner 已提交
4090 4091 4092 4093 4094 4095 4096 4097
		rv = 0;
		goto fail;
	}

	resp_size = crypto_hash_digestsize(mdev->cram_hmac_tfm);
	response = kmalloc(resp_size, GFP_NOIO);
	if (response == NULL) {
		dev_err(DEV, "kmalloc of response failed\n");
4098
		rv = -1;
P
Philipp Reisner 已提交
4099 4100 4101 4102
		goto fail;
	}

	sg_init_table(&sg, 1);
4103
	sg_set_buf(&sg, peers_ch, length);
P
Philipp Reisner 已提交
4104 4105 4106 4107

	rv = crypto_hash_digest(&desc, &sg, sg.length, response);
	if (rv) {
		dev_err(DEV, "crypto_hash_digest() failed with %d\n", rv);
4108
		rv = -1;
P
Philipp Reisner 已提交
4109 4110 4111 4112 4113 4114 4115
		goto fail;
	}

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

4116
	rv = drbd_recv_header(mdev, &cmd, &length);
P
Philipp Reisner 已提交
4117 4118 4119
	if (!rv)
		goto fail;

4120
	if (cmd != P_AUTH_RESPONSE) {
P
Philipp Reisner 已提交
4121
		dev_err(DEV, "expected AuthResponse packet, received: %s (0x%04x)\n",
4122
			cmdname(cmd), cmd);
P
Philipp Reisner 已提交
4123 4124 4125 4126
		rv = 0;
		goto fail;
	}

4127
	if (length != resp_size) {
P
Philipp Reisner 已提交
4128 4129 4130 4131 4132 4133 4134 4135
		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) {
4136 4137
		if (!signal_pending(current))
			dev_warn(DEV, "short read receiving AuthResponse: l=%u\n", rv);
P
Philipp Reisner 已提交
4138 4139 4140 4141 4142
		rv = 0;
		goto fail;
	}

	right_response = kmalloc(resp_size, GFP_NOIO);
4143
	if (right_response == NULL) {
P
Philipp Reisner 已提交
4144
		dev_err(DEV, "kmalloc of right_response failed\n");
4145
		rv = -1;
P
Philipp Reisner 已提交
4146 4147 4148 4149 4150 4151 4152 4153
		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);
4154
		rv = -1;
P
Philipp Reisner 已提交
4155 4156 4157 4158 4159 4160 4161 4162
		goto fail;
	}

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

	if (rv)
		dev_info(DEV, "Peer authenticated using %d bytes of '%s' HMAC\n",
		     resp_size, mdev->net_conf->cram_hmac_alg);
4163 4164
	else
		rv = -1;
P
Philipp Reisner 已提交
4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188

 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);
4189
			schedule_timeout_interruptible(HZ);
P
Philipp Reisner 已提交
4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211
		}
		if (h == -1) {
			dev_warn(DEV, "Discarding network configuration.\n");
			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
		}
	} while (h == 0);

	if (h > 0) {
		if (get_net_conf(mdev)) {
			drbdd(mdev);
			put_net_conf(mdev);
		}
	}

	drbd_disconnect(mdev);

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

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

4212
static int got_RqSReply(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226
{
	struct p_req_state_reply *p = (struct p_req_state_reply *)h;

	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);

4227
	return true;
P
Philipp Reisner 已提交
4228 4229
}

4230
static int got_Ping(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4231 4232 4233 4234 4235
{
	return drbd_send_ping_ack(mdev);

}

4236
static int got_PingAck(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4237 4238 4239
{
	/* restore idle timeout */
	mdev->meta.socket->sk->sk_rcvtimeo = mdev->net_conf->ping_int*HZ;
4240 4241
	if (!test_and_set_bit(GOT_PING_ACK, &mdev->flags))
		wake_up(&mdev->misc_wait);
P
Philipp Reisner 已提交
4242

4243
	return true;
P
Philipp Reisner 已提交
4244 4245
}

4246
static int got_IsInSync(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4247 4248 4249 4250 4251 4252 4253 4254 4255
{
	struct p_block_ack *p = (struct p_block_ack *)h;
	sector_t sector = be64_to_cpu(p->sector);
	int blksize = be32_to_cpu(p->blksize);

	D_ASSERT(mdev->agreed_pro_version >= 89);

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

4256 4257 4258 4259 4260 4261 4262
	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
4263
	dec_rs_pending(mdev);
4264
	atomic_add(blksize >> 9, &mdev->rs_sect_in);
P
Philipp Reisner 已提交
4265

4266
	return true;
P
Philipp Reisner 已提交
4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306
}

/* when we receive the ACK for a write request,
 * verify that we actually know about it */
static struct drbd_request *_ack_id_to_req(struct drbd_conf *mdev,
	u64 id, sector_t sector)
{
	struct hlist_head *slot = tl_hash_slot(mdev, sector);
	struct hlist_node *n;
	struct drbd_request *req;

	hlist_for_each_entry(req, n, slot, colision) {
		if ((unsigned long)req == (unsigned long)id) {
			if (req->sector != sector) {
				dev_err(DEV, "_ack_id_to_req: found req %p but it has "
				    "wrong sector (%llus versus %llus)\n", req,
				    (unsigned long long)req->sector,
				    (unsigned long long)sector);
				break;
			}
			return req;
		}
	}
	return NULL;
}

typedef struct drbd_request *(req_validator_fn)
	(struct drbd_conf *mdev, u64 id, sector_t sector);

static int validate_req_change_req_state(struct drbd_conf *mdev,
	u64 id, sector_t sector, req_validator_fn validator,
	const char *func, enum drbd_req_event what)
{
	struct drbd_request *req;
	struct bio_and_error m;

	spin_lock_irq(&mdev->req_lock);
	req = validator(mdev, id, sector);
	if (unlikely(!req)) {
		spin_unlock_irq(&mdev->req_lock);
4307 4308 4309

		dev_err(DEV, "%s: failed to find req %p, sector %llus\n", func,
			(void *)(unsigned long)id, (unsigned long long)sector);
4310
		return false;
P
Philipp Reisner 已提交
4311 4312 4313 4314 4315 4316
	}
	__req_mod(req, what, &m);
	spin_unlock_irq(&mdev->req_lock);

	if (m.bio)
		complete_master_bio(mdev, &m);
4317
	return true;
P
Philipp Reisner 已提交
4318 4319
}

4320
static int got_BlockAck(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331
{
	struct p_block_ack *p = (struct p_block_ack *)h;
	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));

	if (is_syncer_block_id(p->block_id)) {
		drbd_set_in_sync(mdev, sector, blksize);
		dec_rs_pending(mdev);
4332
		return true;
P
Philipp Reisner 已提交
4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352
	}
	switch (be16_to_cpu(h->command)) {
	case P_RS_WRITE_ACK:
		D_ASSERT(mdev->net_conf->wire_protocol == DRBD_PROT_C);
		what = write_acked_by_peer_and_sis;
		break;
	case P_WRITE_ACK:
		D_ASSERT(mdev->net_conf->wire_protocol == DRBD_PROT_C);
		what = write_acked_by_peer;
		break;
	case P_RECV_ACK:
		D_ASSERT(mdev->net_conf->wire_protocol == DRBD_PROT_B);
		what = recv_acked_by_peer;
		break;
	case P_DISCARD_ACK:
		D_ASSERT(mdev->net_conf->wire_protocol == DRBD_PROT_C);
		what = conflict_discarded_by_peer;
		break;
	default:
		D_ASSERT(0);
4353
		return false;
P
Philipp Reisner 已提交
4354 4355 4356 4357 4358 4359
	}

	return validate_req_change_req_state(mdev, p->block_id, sector,
		_ack_id_to_req, __func__ , what);
}

4360
static int got_NegAck(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4361 4362 4363
{
	struct p_block_ack *p = (struct p_block_ack *)h;
	sector_t sector = be64_to_cpu(p->sector);
4364 4365 4366
	int size = be32_to_cpu(p->blksize);
	struct drbd_request *req;
	struct bio_and_error m;
P
Philipp Reisner 已提交
4367 4368 4369 4370 4371 4372

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

	if (is_syncer_block_id(p->block_id)) {
		dec_rs_pending(mdev);
		drbd_rs_failed_io(mdev, sector, size);
4373
		return true;
P
Philipp Reisner 已提交
4374
	}
4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401

	spin_lock_irq(&mdev->req_lock);
	req = _ack_id_to_req(mdev, p->block_id, sector);
	if (!req) {
		spin_unlock_irq(&mdev->req_lock);
		if (mdev->net_conf->wire_protocol == DRBD_PROT_A ||
		    mdev->net_conf->wire_protocol == DRBD_PROT_B) {
			/* 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.
			   => Do not try to validate block_id as request. */
			/* In Protocol B we might already have got a P_RECV_ACK
			   but then get a P_NEG_ACK after wards. */
			drbd_set_out_of_sync(mdev, sector, size);
			return true;
		} else {
			dev_err(DEV, "%s: failed to find req %p, sector %llus\n", __func__,
				(void *)(unsigned long)p->block_id, (unsigned long long)sector);
			return false;
		}
	}
	__req_mod(req, neg_acked, &m);
	spin_unlock_irq(&mdev->req_lock);

	if (m.bio)
		complete_master_bio(mdev, &m);
	return true;
P
Philipp Reisner 已提交
4402 4403
}

4404
static int got_NegDReply(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416
{
	struct p_block_ack *p = (struct p_block_ack *)h;
	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,
		_ar_id_to_req, __func__ , neg_acked);
}

4417
static int got_NegRSDReply(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431
{
	sector_t sector;
	int size;
	struct p_block_ack *p = (struct p_block_ack *)h;

	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);
4432 4433 4434 4435 4436 4437 4438 4439 4440 4441
		switch (be16_to_cpu(h->command)) {
		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
4442 4443 4444
		put_ldev(mdev);
	}

4445
	return true;
P
Philipp Reisner 已提交
4446 4447
}

4448
static int got_BarrierAck(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4449 4450 4451 4452 4453
{
	struct p_barrier_ack *p = (struct p_barrier_ack *)h;

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

4454 4455
	if (mdev->state.conn == C_AHEAD &&
	    atomic_read(&mdev->ap_in_flight) == 0 &&
4456 4457 4458
	    !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);
4459 4460
	}

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

4464
static int got_OVResult(struct drbd_conf *mdev, struct p_header80 *h)
P
Philipp Reisner 已提交
4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480
{
	struct p_block_ack *p = (struct p_block_ack *)h;
	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);

4481
	if (!get_ldev(mdev))
4482
		return true;
4483

P
Philipp Reisner 已提交
4484 4485 4486
	drbd_rs_complete_io(mdev, sector);
	dec_rs_pending(mdev);

4487 4488 4489 4490 4491 4492 4493
	--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
4494 4495 4496 4497 4498 4499 4500 4501 4502 4503
		w = kmalloc(sizeof(*w), GFP_NOIO);
		if (w) {
			w->cb = w_ov_finished;
			drbd_queue_work_front(&mdev->data.work, w);
		} else {
			dev_err(DEV, "kmalloc(w) failed.");
			ov_oos_print(mdev);
			drbd_resync_finished(mdev);
		}
	}
4504
	put_ldev(mdev);
4505
	return true;
P
Philipp Reisner 已提交
4506 4507
}

4508
static int got_skip(struct drbd_conf *mdev, struct p_header80 *h)
4509
{
4510
	return true;
4511 4512
}

P
Philipp Reisner 已提交
4513 4514
struct asender_cmd {
	size_t pkt_size;
4515
	int (*process)(struct drbd_conf *mdev, struct p_header80 *h);
P
Philipp Reisner 已提交
4516 4517 4518 4519 4520 4521 4522 4523
};

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() */
4524 4525
	[P_PING]	    = { sizeof(struct p_header80), got_Ping },
	[P_PING_ACK]	    = { sizeof(struct p_header80), got_PingAck },
P
Philipp Reisner 已提交
4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536
	[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 },
4537
	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe93), got_skip },
4538
	[P_RS_CANCEL]       = { sizeof(struct p_block_ack), got_NegRSDReply},
P
Philipp Reisner 已提交
4539 4540 4541 4542 4543 4544 4545 4546 4547 4548
	[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;
4549
	struct p_header80 *h = &mdev->meta.rbuf.header.h80;
P
Philipp Reisner 已提交
4550 4551 4552 4553 4554
	struct asender_cmd *cmd = NULL;

	int rv, len;
	void *buf    = h;
	int received = 0;
4555
	int expect   = sizeof(struct p_header80);
P
Philipp Reisner 已提交
4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578
	int empty;

	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 */

	while (get_t_state(thi) == Running) {
		drbd_thread_current_set_cpu(mdev);
		if (test_and_clear_bit(SEND_PING, &mdev->flags)) {
			ERR_IF(!drbd_send_ping(mdev)) goto reconnect;
			mdev->meta.socket->sk->sk_rcvtimeo =
				mdev->net_conf->ping_timeo*HZ/10;
		}

		/* conditionally cork;
		 * it may hurt latency if we cork without much to send */
		if (!mdev->net_conf->no_cork &&
			3 < atomic_read(&mdev->unacked_cnt))
			drbd_tcp_cork(mdev->meta.socket);
		while (1) {
			clear_bit(SIGNAL_ASENDER, &mdev->flags);
			flush_signals(current);
4579
			if (!drbd_process_done_ee(mdev))
P
Philipp Reisner 已提交
4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638
				goto reconnect;
			/* to avoid race with newly queued ACKs */
			set_bit(SIGNAL_ASENDER, &mdev->flags);
			spin_lock_irq(&mdev->req_lock);
			empty = list_empty(&mdev->done_ee);
			spin_unlock_irq(&mdev->req_lock);
			/* 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 */
		if (!mdev->net_conf->no_cork)
			drbd_tcp_uncork(mdev->meta.socket);

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

		rv = drbd_recv_short(mdev, mdev->meta.socket,
				     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) {
			if (mdev->meta.socket->sk->sk_rcvtimeo ==
			    mdev->net_conf->ping_timeo*HZ/10) {
				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) {
			if (unlikely(h->magic != BE_DRBD_MAGIC)) {
4639 4640 4641 4642
				dev_err(DEV, "magic?? on meta m: 0x%08x c: %d l: %d\n",
				    be32_to_cpu(h->magic),
				    be16_to_cpu(h->command),
				    be16_to_cpu(h->length));
P
Philipp Reisner 已提交
4643 4644 4645 4646 4647
				goto reconnect;
			}
			cmd = get_asender_cmd(be16_to_cpu(h->command));
			len = be16_to_cpu(h->length);
			if (unlikely(cmd == NULL)) {
4648 4649 4650 4651
				dev_err(DEV, "unknown command?? on meta m: 0x%08x c: %d l: %d\n",
				    be32_to_cpu(h->magic),
				    be16_to_cpu(h->command),
				    be16_to_cpu(h->length));
P
Philipp Reisner 已提交
4652 4653 4654
				goto disconnect;
			}
			expect = cmd->pkt_size;
4655
			ERR_IF(len != expect-sizeof(struct p_header80))
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Philipp Reisner 已提交
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				goto reconnect;
		}
		if (received == expect) {
			D_ASSERT(cmd != NULL);
			if (!cmd->process(mdev, h))
				goto reconnect;

			buf	 = h;
			received = 0;
4665
			expect	 = sizeof(struct p_header80);
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Philipp Reisner 已提交
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			cmd	 = NULL;
		}
	}

	if (0) {
reconnect:
		drbd_force_state(mdev, NS(conn, C_NETWORK_FAILURE));
4673
		drbd_md_sync(mdev);
P
Philipp Reisner 已提交
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	}
	if (0) {
disconnect:
		drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
4678
		drbd_md_sync(mdev);
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	}
	clear_bit(SIGNAL_ASENDER, &mdev->flags);

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

	return 0;
}