drbd_main.c 92.0 KB
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/*
   drbd.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>.

   Thanks to Carter Burden, Bart Grantham and Gennadiy Nerubayev
   from Logicworks, Inc. for making SDP replication support possible.

   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 <linux/drbd.h>
#include <asm/uaccess.h>
#include <asm/types.h>
#include <net/sock.h>
#include <linux/ctype.h>
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#include <linux/mutex.h>
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#include <linux/fs.h>
#include <linux/file.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memcontrol.h>
#include <linux/mm_inline.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/reboot.h>
#include <linux/notifier.h>
#include <linux/kthread.h>

#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include <linux/vmalloc.h>

#include <linux/drbd_limits.h>
#include "drbd_int.h"
#include "drbd_req.h" /* only for _req_mod in tl_release and tl_clear */

#include "drbd_vli.h"

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static DEFINE_MUTEX(drbd_main_mutex);
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int drbdd_init(struct drbd_thread *);
int drbd_worker(struct drbd_thread *);
int drbd_asender(struct drbd_thread *);

int drbd_init(void);
static int drbd_open(struct block_device *bdev, fmode_t mode);
static int drbd_release(struct gendisk *gd, fmode_t mode);
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static int w_md_sync(struct drbd_work *w, int unused);
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static void md_sync_timer_fn(unsigned long data);
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static int w_bitmap_io(struct drbd_work *w, int unused);
static int w_go_diskless(struct drbd_work *w, int unused);
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MODULE_AUTHOR("Philipp Reisner <phil@linbit.com>, "
	      "Lars Ellenberg <lars@linbit.com>");
MODULE_DESCRIPTION("drbd - Distributed Replicated Block Device v" REL_VERSION);
MODULE_VERSION(REL_VERSION);
MODULE_LICENSE("GPL");
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MODULE_PARM_DESC(minor_count, "Approximate number of drbd devices ("
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		 __stringify(DRBD_MINOR_COUNT_MIN) "-" __stringify(DRBD_MINOR_COUNT_MAX) ")");
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MODULE_ALIAS_BLOCKDEV_MAJOR(DRBD_MAJOR);

#include <linux/moduleparam.h>
/* allow_open_on_secondary */
MODULE_PARM_DESC(allow_oos, "DONT USE!");
/* thanks to these macros, if compiled into the kernel (not-module),
 * this becomes the boot parameter drbd.minor_count */
module_param(minor_count, uint, 0444);
module_param(disable_sendpage, bool, 0644);
module_param(allow_oos, bool, 0);
module_param(proc_details, int, 0644);

#ifdef CONFIG_DRBD_FAULT_INJECTION
int enable_faults;
int fault_rate;
static int fault_count;
int fault_devs;
/* bitmap of enabled faults */
module_param(enable_faults, int, 0664);
/* fault rate % value - applies to all enabled faults */
module_param(fault_rate, int, 0664);
/* count of faults inserted */
module_param(fault_count, int, 0664);
/* bitmap of devices to insert faults on */
module_param(fault_devs, int, 0644);
#endif

/* module parameter, defined */
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unsigned int minor_count = DRBD_MINOR_COUNT_DEF;
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int disable_sendpage;
int allow_oos;
int proc_details;       /* Detail level in proc drbd*/

/* Module parameter for setting the user mode helper program
 * to run. Default is /sbin/drbdadm */
char usermode_helper[80] = "/sbin/drbdadm";

module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0644);

/* in 2.6.x, our device mapping and config info contains our virtual gendisks
 * as member "struct gendisk *vdisk;"
 */
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struct idr minors;
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struct list_head drbd_tconns;  /* list of struct drbd_tconn */
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struct kmem_cache *drbd_request_cache;
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struct kmem_cache *drbd_ee_cache;	/* peer requests */
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struct kmem_cache *drbd_bm_ext_cache;	/* bitmap extents */
struct kmem_cache *drbd_al_ext_cache;	/* activity log extents */
mempool_t *drbd_request_mempool;
mempool_t *drbd_ee_mempool;
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mempool_t *drbd_md_io_page_pool;
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struct bio_set *drbd_md_io_bio_set;
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/* I do not use a standard mempool, because:
   1) I want to hand out the pre-allocated objects first.
   2) I want to be able to interrupt sleeping allocation with a signal.
   Note: This is a single linked list, the next pointer is the private
	 member of struct page.
 */
struct page *drbd_pp_pool;
spinlock_t   drbd_pp_lock;
int          drbd_pp_vacant;
wait_queue_head_t drbd_pp_wait;

DEFINE_RATELIMIT_STATE(drbd_ratelimit_state, 5 * HZ, 5);

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static const struct block_device_operations drbd_ops = {
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	.owner =   THIS_MODULE,
	.open =    drbd_open,
	.release = drbd_release,
};

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static void bio_destructor_drbd(struct bio *bio)
{
	bio_free(bio, drbd_md_io_bio_set);
}

struct bio *bio_alloc_drbd(gfp_t gfp_mask)
{
	struct bio *bio;

	if (!drbd_md_io_bio_set)
		return bio_alloc(gfp_mask, 1);

	bio = bio_alloc_bioset(gfp_mask, 1, drbd_md_io_bio_set);
	if (!bio)
		return NULL;
	bio->bi_destructor = bio_destructor_drbd;
	return bio;
}

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#ifdef __CHECKER__
/* When checking with sparse, and this is an inline function, sparse will
   give tons of false positives. When this is a real functions sparse works.
 */
int _get_ldev_if_state(struct drbd_conf *mdev, enum drbd_disk_state mins)
{
	int io_allowed;

	atomic_inc(&mdev->local_cnt);
	io_allowed = (mdev->state.disk >= mins);
	if (!io_allowed) {
		if (atomic_dec_and_test(&mdev->local_cnt))
			wake_up(&mdev->misc_wait);
	}
	return io_allowed;
}

#endif

/**
 * DOC: The transfer log
 *
 * The transfer log is a single linked list of &struct drbd_tl_epoch objects.
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 * mdev->tconn->newest_tle points to the head, mdev->tconn->oldest_tle points to the tail
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 * of the list. There is always at least one &struct drbd_tl_epoch object.
 *
 * Each &struct drbd_tl_epoch has a circular double linked list of requests
 * attached.
 */
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static int tl_init(struct drbd_tconn *tconn)
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{
	struct drbd_tl_epoch *b;

	/* during device minor initialization, we may well use GFP_KERNEL */
	b = kmalloc(sizeof(struct drbd_tl_epoch), GFP_KERNEL);
	if (!b)
		return 0;
	INIT_LIST_HEAD(&b->requests);
	INIT_LIST_HEAD(&b->w.list);
	b->next = NULL;
	b->br_number = 4711;
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	b->n_writes = 0;
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	b->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */

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	tconn->oldest_tle = b;
	tconn->newest_tle = b;
	INIT_LIST_HEAD(&tconn->out_of_sequence_requests);
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	return 1;
}

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static void tl_cleanup(struct drbd_tconn *tconn)
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{
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	if (tconn->oldest_tle != tconn->newest_tle)
		conn_err(tconn, "ASSERT FAILED: oldest_tle == newest_tle\n");
	if (!list_empty(&tconn->out_of_sequence_requests))
		conn_err(tconn, "ASSERT FAILED: list_empty(out_of_sequence_requests)\n");
	kfree(tconn->oldest_tle);
	tconn->oldest_tle = NULL;
	kfree(tconn->unused_spare_tle);
	tconn->unused_spare_tle = NULL;
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}

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/**
 * _tl_add_barrier() - Adds a barrier to the transfer log
 * @mdev:	DRBD device.
 * @new:	Barrier to be added before the current head of the TL.
 *
 * The caller must hold the req_lock.
 */
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void _tl_add_barrier(struct drbd_tconn *tconn, struct drbd_tl_epoch *new)
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{
	struct drbd_tl_epoch *newest_before;

	INIT_LIST_HEAD(&new->requests);
	INIT_LIST_HEAD(&new->w.list);
	new->w.cb = NULL; /* if this is != NULL, we need to dec_ap_pending in tl_clear */
	new->next = NULL;
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	new->n_writes = 0;
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	newest_before = tconn->newest_tle;
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	/* never send a barrier number == 0, because that is special-cased
	 * when using TCQ for our write ordering code */
	new->br_number = (newest_before->br_number+1) ?: 1;
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	if (tconn->newest_tle != new) {
		tconn->newest_tle->next = new;
		tconn->newest_tle = new;
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	}
}

/**
 * tl_release() - Free or recycle the oldest &struct drbd_tl_epoch object of the TL
 * @mdev:	DRBD device.
 * @barrier_nr:	Expected identifier of the DRBD write barrier packet.
 * @set_size:	Expected number of requests before that barrier.
 *
 * In case the passed barrier_nr or set_size does not match the oldest
 * &struct drbd_tl_epoch objects this function will cause a termination
 * of the connection.
 */
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void tl_release(struct drbd_tconn *tconn, unsigned int barrier_nr,
		unsigned int set_size)
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{
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	struct drbd_conf *mdev;
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	struct drbd_tl_epoch *b, *nob; /* next old barrier */
	struct list_head *le, *tle;
	struct drbd_request *r;

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	spin_lock_irq(&tconn->req_lock);
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	b = tconn->oldest_tle;
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	/* first some paranoia code */
	if (b == NULL) {
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		conn_err(tconn, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
			 barrier_nr);
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		goto bail;
	}
	if (b->br_number != barrier_nr) {
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		conn_err(tconn, "BAD! BarrierAck #%u received, expected #%u!\n",
			 barrier_nr, b->br_number);
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		goto bail;
	}
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	if (b->n_writes != set_size) {
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		conn_err(tconn, "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n",
			 barrier_nr, set_size, b->n_writes);
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		goto bail;
	}

	/* Clean up list of requests processed during current epoch */
	list_for_each_safe(le, tle, &b->requests) {
		r = list_entry(le, struct drbd_request, tl_requests);
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		_req_mod(r, BARRIER_ACKED);
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	}
	/* There could be requests on the list waiting for completion
	   of the write to the local disk. To avoid corruptions of
	   slab's data structures we have to remove the lists head.

	   Also there could have been a barrier ack out of sequence, overtaking
	   the write acks - which would be a bug and violating write ordering.
	   To not deadlock in case we lose connection while such requests are
	   still pending, we need some way to find them for the
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	   _req_mode(CONNECTION_LOST_WHILE_PENDING).
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	   These have been list_move'd to the out_of_sequence_requests list in
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	   _req_mod(, BARRIER_ACKED) above.
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	   */
	list_del_init(&b->requests);
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	mdev = b->w.mdev;
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	nob = b->next;
	if (test_and_clear_bit(CREATE_BARRIER, &mdev->flags)) {
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		_tl_add_barrier(tconn, b);
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		if (nob)
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			tconn->oldest_tle = nob;
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		/* if nob == NULL b was the only barrier, and becomes the new
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		   barrier. Therefore tconn->oldest_tle points already to b */
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	} else {
		D_ASSERT(nob != NULL);
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		tconn->oldest_tle = nob;
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		kfree(b);
	}

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	spin_unlock_irq(&tconn->req_lock);
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	dec_ap_pending(mdev);

	return;

bail:
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	spin_unlock_irq(&tconn->req_lock);
	conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
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}

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/**
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 * _tl_restart() - Walks the transfer log, and applies an action to all requests
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 * @mdev:	DRBD device.
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 * @what:       The action/event to perform with all request objects
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 *
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 * @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
 * RESTART_FROZEN_DISK_IO.
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 */
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void _tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
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{
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	struct drbd_tl_epoch *b, *tmp, **pn;
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	struct list_head *le, *tle, carry_reads;
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	struct drbd_request *req;
	int rv, n_writes, n_reads;
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	b = tconn->oldest_tle;
	pn = &tconn->oldest_tle;
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	while (b) {
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		n_writes = 0;
		n_reads = 0;
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		INIT_LIST_HEAD(&carry_reads);
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		list_for_each_safe(le, tle, &b->requests) {
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			req = list_entry(le, struct drbd_request, tl_requests);
			rv = _req_mod(req, what);

			n_writes += (rv & MR_WRITE) >> MR_WRITE_SHIFT;
			n_reads  += (rv & MR_READ) >> MR_READ_SHIFT;
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		}
		tmp = b->next;

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		if (n_writes) {
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			if (what == RESEND) {
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				b->n_writes = n_writes;
				if (b->w.cb == NULL) {
					b->w.cb = w_send_barrier;
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					inc_ap_pending(b->w.mdev);
					set_bit(CREATE_BARRIER, &b->w.mdev->flags);
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				}

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				drbd_queue_work(&tconn->data.work, &b->w);
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			}
			pn = &b->next;
		} else {
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			if (n_reads)
				list_add(&carry_reads, &b->requests);
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			/* there could still be requests on that ring list,
			 * in case local io is still pending */
			list_del(&b->requests);

			/* dec_ap_pending corresponding to queue_barrier.
			 * the newest barrier may not have been queued yet,
			 * in which case w.cb is still NULL. */
			if (b->w.cb != NULL)
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				dec_ap_pending(b->w.mdev);
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			if (b == tconn->newest_tle) {
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				/* recycle, but reinit! */
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				if (tmp != NULL)
					conn_err(tconn, "ASSERT FAILED tmp == NULL");
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				INIT_LIST_HEAD(&b->requests);
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				list_splice(&carry_reads, &b->requests);
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				INIT_LIST_HEAD(&b->w.list);
				b->w.cb = NULL;
				b->br_number = net_random();
				b->n_writes = 0;

				*pn = b;
				break;
			}
			*pn = tmp;
			kfree(b);
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		}
		b = tmp;
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		list_splice(&carry_reads, &b->requests);
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	}
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}

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/**
 * tl_clear() - Clears all requests and &struct drbd_tl_epoch objects out of the TL
 * @mdev:	DRBD device.
 *
 * This is called after the connection to the peer was lost. The storage covered
 * by the requests on the transfer gets marked as our of sync. Called from the
 * receiver thread and the worker thread.
 */
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void tl_clear(struct drbd_tconn *tconn)
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{
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	struct drbd_conf *mdev;
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	struct list_head *le, *tle;
	struct drbd_request *r;
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	int vnr;
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	spin_lock_irq(&tconn->req_lock);
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	_tl_restart(tconn, CONNECTION_LOST_WHILE_PENDING);
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	/* we expect this list to be empty. */
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	if (!list_empty(&tconn->out_of_sequence_requests))
		conn_err(tconn, "ASSERT FAILED list_empty(&out_of_sequence_requests)\n");
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	/* but just in case, clean it up anyways! */
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	list_for_each_safe(le, tle, &tconn->out_of_sequence_requests) {
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		r = list_entry(le, struct drbd_request, tl_requests);
		/* It would be nice to complete outside of spinlock.
		 * But this is easier for now. */
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		_req_mod(r, CONNECTION_LOST_WHILE_PENDING);
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	}

	/* ensure bit indicating barrier is required is clear */
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	rcu_read_lock();
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	idr_for_each_entry(&tconn->volumes, mdev, vnr)
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		clear_bit(CREATE_BARRIER, &mdev->flags);
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	rcu_read_unlock();
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	spin_unlock_irq(&tconn->req_lock);
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}

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void tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
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{
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	spin_lock_irq(&tconn->req_lock);
	_tl_restart(tconn, what);
	spin_unlock_irq(&tconn->req_lock);
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}

static int drbd_thread_setup(void *arg)
{
	struct drbd_thread *thi = (struct drbd_thread *) arg;
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	struct drbd_tconn *tconn = thi->tconn;
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	unsigned long flags;
	int retval;

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	snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
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		 thi->name[0], thi->tconn->name);
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restart:
	retval = thi->function(thi);

	spin_lock_irqsave(&thi->t_lock, flags);

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	/* if the receiver has been "EXITING", the last thing it did
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	 * was set the conn state to "StandAlone",
	 * if now a re-connect request comes in, conn state goes C_UNCONNECTED,
	 * and receiver thread will be "started".
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	 * drbd_thread_start needs to set "RESTARTING" in that case.
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	 * t_state check and assignment needs to be within the same spinlock,
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	 * so either thread_start sees EXITING, and can remap to RESTARTING,
	 * or thread_start see NONE, and can proceed as normal.
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	 */

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	if (thi->t_state == RESTARTING) {
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		conn_info(tconn, "Restarting %s thread\n", thi->name);
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		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		goto restart;
	}

	thi->task = NULL;
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	thi->t_state = NONE;
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	smp_mb();
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	complete_all(&thi->stop);
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	spin_unlock_irqrestore(&thi->t_lock, flags);

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	conn_info(tconn, "Terminating %s\n", current->comm);
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	/* Release mod reference taken when thread was started */
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	kref_put(&tconn->kref, &conn_destroy);
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	module_put(THIS_MODULE);
	return retval;
}

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static void drbd_thread_init(struct drbd_tconn *tconn, struct drbd_thread *thi,
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			     int (*func) (struct drbd_thread *), char *name)
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{
	spin_lock_init(&thi->t_lock);
	thi->task    = NULL;
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	thi->t_state = NONE;
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	thi->function = func;
524
	thi->tconn = tconn;
525
	strncpy(thi->name, name, ARRAY_SIZE(thi->name));
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}

int drbd_thread_start(struct drbd_thread *thi)
{
530
	struct drbd_tconn *tconn = thi->tconn;
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	struct task_struct *nt;
	unsigned long flags;

	/* is used from state engine doing drbd_thread_stop_nowait,
	 * while holding the req lock irqsave */
	spin_lock_irqsave(&thi->t_lock, flags);

	switch (thi->t_state) {
539
	case NONE:
540
		conn_info(tconn, "Starting %s thread (from %s [%d])\n",
541
			 thi->name, current->comm, current->pid);
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		/* Get ref on module for thread - this is released when thread exits */
		if (!try_module_get(THIS_MODULE)) {
545
			conn_err(tconn, "Failed to get module reference in drbd_thread_start\n");
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			spin_unlock_irqrestore(&thi->t_lock, flags);
547
			return false;
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		}

550 551
		kref_get(&thi->tconn->kref);

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		init_completion(&thi->stop);
		thi->reset_cpu_mask = 1;
554
		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		flush_signals(current); /* otherw. may get -ERESTARTNOINTR */

		nt = kthread_create(drbd_thread_setup, (void *) thi,
559
				    "drbd_%c_%s", thi->name[0], thi->tconn->name);
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		if (IS_ERR(nt)) {
562
			conn_err(tconn, "Couldn't start thread\n");
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564
			kref_put(&tconn->kref, &conn_destroy);
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			module_put(THIS_MODULE);
566
			return false;
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		}
		spin_lock_irqsave(&thi->t_lock, flags);
		thi->task = nt;
570
		thi->t_state = RUNNING;
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		wake_up_process(nt);
		break;
574 575
	case EXITING:
		thi->t_state = RESTARTING;
576
		conn_info(tconn, "Restarting %s thread (from %s [%d])\n",
577
				thi->name, current->comm, current->pid);
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		/* fall through */
579 580
	case RUNNING:
	case RESTARTING:
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	default:
		spin_unlock_irqrestore(&thi->t_lock, flags);
		break;
	}

586
	return true;
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}


void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
{
	unsigned long flags;

594
	enum drbd_thread_state ns = restart ? RESTARTING : EXITING;
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	/* may be called from state engine, holding the req lock irqsave */
	spin_lock_irqsave(&thi->t_lock, flags);

599
	if (thi->t_state == NONE) {
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		spin_unlock_irqrestore(&thi->t_lock, flags);
		if (restart)
			drbd_thread_start(thi);
		return;
	}

	if (thi->t_state != ns) {
		if (thi->task == NULL) {
			spin_unlock_irqrestore(&thi->t_lock, flags);
			return;
		}

		thi->t_state = ns;
		smp_mb();
		init_completion(&thi->stop);
		if (thi->task != current)
			force_sig(DRBD_SIGKILL, thi->task);
	}

	spin_unlock_irqrestore(&thi->t_lock, flags);

	if (wait)
		wait_for_completion(&thi->stop);
}

625
static struct drbd_thread *drbd_task_to_thread(struct drbd_tconn *tconn, struct task_struct *task)
626 627 628 629 630 631 632 633 634
{
	struct drbd_thread *thi =
		task == tconn->receiver.task ? &tconn->receiver :
		task == tconn->asender.task  ? &tconn->asender :
		task == tconn->worker.task   ? &tconn->worker : NULL;

	return thi;
}

635
char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *task)
636
{
637
	struct drbd_thread *thi = drbd_task_to_thread(tconn, task);
638 639 640
	return thi ? thi->name : task->comm;
}

641
int conn_lowest_minor(struct drbd_tconn *tconn)
642
{
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	struct drbd_conf *mdev;
644
	int vnr = 0, m;
645

646
	rcu_read_lock();
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	mdev = idr_get_next(&tconn->volumes, &vnr);
648 649 650 651
	m = mdev ? mdev_to_minor(mdev) : -1;
	rcu_read_unlock();

	return m;
652
}
653 654

#ifdef CONFIG_SMP
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/**
 * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
 * @mdev:	DRBD device.
 *
 * Forces all threads of a device onto the same CPU. This is beneficial for
 * DRBD's performance. May be overwritten by user's configuration.
 */
662
void drbd_calc_cpu_mask(struct drbd_tconn *tconn)
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{
	int ord, cpu;

	/* user override. */
667
	if (cpumask_weight(tconn->cpu_mask))
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		return;

670
	ord = conn_lowest_minor(tconn) % cpumask_weight(cpu_online_mask);
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	for_each_online_cpu(cpu) {
		if (ord-- == 0) {
673
			cpumask_set_cpu(cpu, tconn->cpu_mask);
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			return;
		}
	}
	/* should not be reached */
678
	cpumask_setall(tconn->cpu_mask);
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}

/**
 * drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread
 * @mdev:	DRBD device.
684
 * @thi:	drbd_thread object
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 *
 * call in the "main loop" of _all_ threads, no need for any mutex, current won't die
 * prematurely.
 */
689
void drbd_thread_current_set_cpu(struct drbd_thread *thi)
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{
	struct task_struct *p = current;
692

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	if (!thi->reset_cpu_mask)
		return;
	thi->reset_cpu_mask = 0;
696
	set_cpus_allowed_ptr(p, thi->tconn->cpu_mask);
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}
#endif

700 701 702 703 704 705 706 707 708
/**
 * drbd_header_size  -  size of a packet header
 *
 * The header size is a multiple of 8, so any payload following the header is
 * word aligned on 64-bit architectures.  (The bitmap send and receive code
 * relies on this.)
 */
unsigned int drbd_header_size(struct drbd_tconn *tconn)
{
709 710 711 712 713 714 715 716 717
	if (tconn->agreed_pro_version >= 100) {
		BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header100), 8));
		return sizeof(struct p_header100);
	} else {
		BUILD_BUG_ON(sizeof(struct p_header80) !=
			     sizeof(struct p_header95));
		BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct p_header80), 8));
		return sizeof(struct p_header80);
	}
718 719
}

720
static unsigned int prepare_header80(struct p_header80 *h, enum drbd_packet cmd, int size)
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{
	h->magic   = cpu_to_be32(DRBD_MAGIC);
	h->command = cpu_to_be16(cmd);
	h->length  = cpu_to_be16(size);
725
	return sizeof(struct p_header80);
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}

728
static unsigned int prepare_header95(struct p_header95 *h, enum drbd_packet cmd, int size)
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{
	h->magic   = cpu_to_be16(DRBD_MAGIC_BIG);
	h->command = cpu_to_be16(cmd);
732
	h->length = cpu_to_be32(size);
733
	return sizeof(struct p_header95);
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}

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static unsigned int prepare_header100(struct p_header100 *h, enum drbd_packet cmd,
				      int size, int vnr)
{
	h->magic = cpu_to_be32(DRBD_MAGIC_100);
	h->volume = cpu_to_be16(vnr);
	h->command = cpu_to_be16(cmd);
	h->length = cpu_to_be32(size);
	h->pad = 0;
	return sizeof(struct p_header100);
}

static unsigned int prepare_header(struct drbd_tconn *tconn, int vnr,
				   void *buffer, enum drbd_packet cmd, int size)
749
{
750 751 752 753
	if (tconn->agreed_pro_version >= 100)
		return prepare_header100(buffer, cmd, size, vnr);
	else if (tconn->agreed_pro_version >= 95 &&
		 size > DRBD_MAX_SIZE_H80_PACKET)
754
		return prepare_header95(buffer, cmd, size);
755
	else
756
		return prepare_header80(buffer, cmd, size);
757 758
}

759 760 761 762 763 764 765 766
static void *__conn_prepare_command(struct drbd_tconn *tconn,
				    struct drbd_socket *sock)
{
	if (!sock->socket)
		return NULL;
	return sock->sbuf + drbd_header_size(tconn);
}

767 768
void *conn_prepare_command(struct drbd_tconn *tconn, struct drbd_socket *sock)
{
769 770
	void *p;

771
	mutex_lock(&sock->mutex);
772 773
	p = __conn_prepare_command(tconn, sock);
	if (!p)
774
		mutex_unlock(&sock->mutex);
775 776

	return p;
777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800
}

void *drbd_prepare_command(struct drbd_conf *mdev, struct drbd_socket *sock)
{
	return conn_prepare_command(mdev->tconn, sock);
}

static int __send_command(struct drbd_tconn *tconn, int vnr,
			  struct drbd_socket *sock, enum drbd_packet cmd,
			  unsigned int header_size, void *data,
			  unsigned int size)
{
	int msg_flags;
	int err;

	/*
	 * Called with @data == NULL and the size of the data blocks in @size
	 * for commands that send data blocks.  For those commands, omit the
	 * MSG_MORE flag: this will increase the likelihood that data blocks
	 * which are page aligned on the sender will end up page aligned on the
	 * receiver.
	 */
	msg_flags = data ? MSG_MORE : 0;

801 802
	header_size += prepare_header(tconn, vnr, sock->sbuf, cmd,
				      header_size + size);
803 804 805 806 807 808 809
	err = drbd_send_all(tconn, sock->socket, sock->sbuf, header_size,
			    msg_flags);
	if (data && !err)
		err = drbd_send_all(tconn, sock->socket, data, size, 0);
	return err;
}

810 811 812 813 814 815 816
static int __conn_send_command(struct drbd_tconn *tconn, struct drbd_socket *sock,
			       enum drbd_packet cmd, unsigned int header_size,
			       void *data, unsigned int size)
{
	return __send_command(tconn, 0, sock, cmd, header_size, data, size);
}

817 818 819 820 821 822
int conn_send_command(struct drbd_tconn *tconn, struct drbd_socket *sock,
		      enum drbd_packet cmd, unsigned int header_size,
		      void *data, unsigned int size)
{
	int err;

823
	err = __conn_send_command(tconn, sock, cmd, header_size, data, size);
824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839
	mutex_unlock(&sock->mutex);
	return err;
}

int drbd_send_command(struct drbd_conf *mdev, struct drbd_socket *sock,
		      enum drbd_packet cmd, unsigned int header_size,
		      void *data, unsigned int size)
{
	int err;

	err = __send_command(mdev->tconn, mdev->vnr, sock, cmd, header_size,
			     data, size);
	mutex_unlock(&sock->mutex);
	return err;
}

840 841
int drbd_send_ping(struct drbd_tconn *tconn)
{
842 843 844 845 846
	struct drbd_socket *sock;

	sock = &tconn->meta;
	if (!conn_prepare_command(tconn, sock))
		return -EIO;
847
	return conn_send_command(tconn, sock, P_PING, 0, NULL, 0);
848 849 850 851
}

int drbd_send_ping_ack(struct drbd_tconn *tconn)
{
852 853 854 855 856
	struct drbd_socket *sock;

	sock = &tconn->meta;
	if (!conn_prepare_command(tconn, sock))
		return -EIO;
857
	return conn_send_command(tconn, sock, P_PING_ACK, 0, NULL, 0);
858 859
}

860
int drbd_send_sync_param(struct drbd_conf *mdev)
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{
862
	struct drbd_socket *sock;
863 864
	struct p_rs_param_95 *p;
	int size;
865
	const int apv = mdev->tconn->agreed_pro_version;
866
	enum drbd_packet cmd;
867
	struct net_conf *nc;
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	struct disk_conf *dc;
869 870 871 872 873

	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
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875 876 877
	rcu_read_lock();
	nc = rcu_dereference(mdev->tconn->net_conf);

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	size = apv <= 87 ? sizeof(struct p_rs_param)
		: apv == 88 ? sizeof(struct p_rs_param)
880
			+ strlen(nc->verify_alg) + 1
881 882
		: apv <= 94 ? sizeof(struct p_rs_param_89)
		: /* apv >= 95 */ sizeof(struct p_rs_param_95);
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884
	cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
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886 887
	/* initialize verify_alg and csums_alg */
	memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
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889
	if (get_ldev(mdev)) {
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		dc = rcu_dereference(mdev->ldev->disk_conf);
891
		p->resync_rate = cpu_to_be32(dc->resync_rate);
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		p->c_plan_ahead = cpu_to_be32(dc->c_plan_ahead);
		p->c_delay_target = cpu_to_be32(dc->c_delay_target);
		p->c_fill_target = cpu_to_be32(dc->c_fill_target);
		p->c_max_rate = cpu_to_be32(dc->c_max_rate);
896 897
		put_ldev(mdev);
	} else {
898
		p->resync_rate = cpu_to_be32(DRBD_RESYNC_RATE_DEF);
899 900 901 902 903
		p->c_plan_ahead = cpu_to_be32(DRBD_C_PLAN_AHEAD_DEF);
		p->c_delay_target = cpu_to_be32(DRBD_C_DELAY_TARGET_DEF);
		p->c_fill_target = cpu_to_be32(DRBD_C_FILL_TARGET_DEF);
		p->c_max_rate = cpu_to_be32(DRBD_C_MAX_RATE_DEF);
	}
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905
	if (apv >= 88)
906
		strcpy(p->verify_alg, nc->verify_alg);
907
	if (apv >= 89)
908 909
		strcpy(p->csums_alg, nc->csums_alg);
	rcu_read_unlock();
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911
	return drbd_send_command(mdev, sock, cmd, size, NULL, 0);
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}

914
int __drbd_send_protocol(struct drbd_tconn *tconn)
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{
916
	struct drbd_socket *sock;
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	struct p_protocol *p;
918
	struct net_conf *nc;
919
	int size, cf;
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921
	sock = &tconn->data;
922
	p = __conn_prepare_command(tconn, sock);
923 924 925
	if (!p)
		return -EIO;

926 927 928 929 930 931 932 933 934 935
	rcu_read_lock();
	nc = rcu_dereference(tconn->net_conf);

	if (nc->dry_run && tconn->agreed_pro_version < 92) {
		rcu_read_unlock();
		mutex_unlock(&sock->mutex);
		conn_err(tconn, "--dry-run is not supported by peer");
		return -EOPNOTSUPP;
	}

936
	size = sizeof(*p);
937
	if (tconn->agreed_pro_version >= 87)
938
		size += strlen(nc->integrity_alg) + 1;
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940 941 942 943 944
	p->protocol      = cpu_to_be32(nc->wire_protocol);
	p->after_sb_0p   = cpu_to_be32(nc->after_sb_0p);
	p->after_sb_1p   = cpu_to_be32(nc->after_sb_1p);
	p->after_sb_2p   = cpu_to_be32(nc->after_sb_2p);
	p->two_primaries = cpu_to_be32(nc->two_primaries);
945
	cf = 0;
946 947
	if (nc->discard_my_data)
		cf |= CF_DISCARD_MY_DATA;
948
	if (nc->dry_run)
949
		cf |= CF_DRY_RUN;
950 951
	p->conn_flags    = cpu_to_be32(cf);

952
	if (tconn->agreed_pro_version >= 87)
953 954 955
		strcpy(p->integrity_alg, nc->integrity_alg);
	rcu_read_unlock();

956 957 958 959 960 961 962 963 964 965 966 967
	return __conn_send_command(tconn, sock, P_PROTOCOL, size, NULL, 0);
}

int drbd_send_protocol(struct drbd_tconn *tconn)
{
	int err;

	mutex_lock(&tconn->data.mutex);
	err = __drbd_send_protocol(tconn);
	mutex_unlock(&tconn->data.mutex);

	return err;
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}

int _drbd_send_uuids(struct drbd_conf *mdev, u64 uuid_flags)
{
972 973
	struct drbd_socket *sock;
	struct p_uuids *p;
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	int i;

	if (!get_ldev_if_state(mdev, D_NEGOTIATING))
977
		return 0;
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979 980 981 982 983 984
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p) {
		put_ldev(mdev);
		return -EIO;
	}
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	for (i = UI_CURRENT; i < UI_SIZE; i++)
986
		p->uuid[i] = mdev->ldev ? cpu_to_be64(mdev->ldev->md.uuid[i]) : 0;
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	mdev->comm_bm_set = drbd_bm_total_weight(mdev);
989
	p->uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set);
990
	rcu_read_lock();
991
	uuid_flags |= rcu_dereference(mdev->tconn->net_conf)->discard_my_data ? 1 : 0;
992
	rcu_read_unlock();
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	uuid_flags |= test_bit(CRASHED_PRIMARY, &mdev->flags) ? 2 : 0;
	uuid_flags |= mdev->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0;
995
	p->uuid[UI_FLAGS] = cpu_to_be64(uuid_flags);
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	put_ldev(mdev);
998
	return drbd_send_command(mdev, sock, P_UUIDS, sizeof(*p), NULL, 0);
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}

int drbd_send_uuids(struct drbd_conf *mdev)
{
	return _drbd_send_uuids(mdev, 0);
}

int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev)
{
	return _drbd_send_uuids(mdev, 8);
}

1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
void drbd_print_uuids(struct drbd_conf *mdev, const char *text)
{
	if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
		u64 *uuid = mdev->ldev->md.uuid;
		dev_info(DEV, "%s %016llX:%016llX:%016llX:%016llX\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]);
		put_ldev(mdev);
	} else {
		dev_info(DEV, "%s effective data uuid: %016llX\n",
				text,
				(unsigned long long)mdev->ed_uuid);
	}
}

1029
void drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev)
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{
1031 1032
	struct drbd_socket *sock;
	struct p_rs_uuid *p;
1033 1034 1035
	u64 uuid;

	D_ASSERT(mdev->state.disk == D_UP_TO_DATE);
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1037
	uuid = mdev->ldev->md.uuid[UI_BITMAP] + UUID_NEW_BM_OFFSET;
1038
	drbd_uuid_set(mdev, UI_BITMAP, uuid);
1039
	drbd_print_uuids(mdev, "updated sync UUID");
1040
	drbd_md_sync(mdev);
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1042 1043 1044 1045 1046 1047
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (p) {
		p->uuid = cpu_to_be64(uuid);
		drbd_send_command(mdev, sock, P_SYNC_UUID, sizeof(*p), NULL, 0);
	}
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}

1050
int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags)
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{
1052 1053
	struct drbd_socket *sock;
	struct p_sizes *p;
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	sector_t d_size, u_size;
1055
	int q_order_type, max_bio_size;
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	if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
		D_ASSERT(mdev->ldev->backing_bdev);
		d_size = drbd_get_max_capacity(mdev->ldev);
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		rcu_read_lock();
		u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
		rcu_read_unlock();
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		q_order_type = drbd_queue_order_type(mdev);
1064 1065
		max_bio_size = queue_max_hw_sectors(mdev->ldev->backing_bdev->bd_disk->queue) << 9;
		max_bio_size = min_t(int, max_bio_size, DRBD_MAX_BIO_SIZE);
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		put_ldev(mdev);
	} else {
		d_size = 0;
		u_size = 0;
		q_order_type = QUEUE_ORDERED_NONE;
1071
		max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
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	}

1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->d_size = cpu_to_be64(d_size);
	p->u_size = cpu_to_be64(u_size);
	p->c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(mdev->this_bdev));
	p->max_bio_size = cpu_to_be32(max_bio_size);
	p->queue_order_type = cpu_to_be16(q_order_type);
	p->dds_flags = cpu_to_be16(flags);
	return drbd_send_command(mdev, sock, P_SIZES, sizeof(*p), NULL, 0);
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}

/**
 * drbd_send_state() - Sends the drbd state to the peer
 * @mdev:	DRBD device.
 */
int drbd_send_state(struct drbd_conf *mdev)
{
1093
	struct drbd_socket *sock;
1094
	struct p_state *p;
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1096
	sock = &mdev->tconn->data;
1097 1098 1099 1100 1101 1102
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->state = cpu_to_be32(mdev->state.i); /* Within the send mutex */
	return drbd_send_command(mdev, sock, P_STATE, sizeof(*p), NULL, 0);
}
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1104 1105 1106 1107
int drbd_send_state_req(struct drbd_conf *mdev, union drbd_state mask, union drbd_state val)
{
	struct drbd_socket *sock;
	struct p_req_state *p;
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1109 1110 1111 1112 1113 1114 1115
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->mask = cpu_to_be32(mask.i);
	p->val = cpu_to_be32(val.i);
	return drbd_send_command(mdev, sock, P_STATE_CHG_REQ, sizeof(*p), NULL, 0);
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}

1119
int conn_send_state_req(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val)
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{
1121 1122 1123
	enum drbd_packet cmd;
	struct drbd_socket *sock;
	struct p_req_state *p;
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1125 1126 1127 1128 1129 1130 1131 1132
	cmd = tconn->agreed_pro_version < 100 ? P_STATE_CHG_REQ : P_CONN_ST_CHG_REQ;
	sock = &tconn->data;
	p = conn_prepare_command(tconn, sock);
	if (!p)
		return -EIO;
	p->mask = cpu_to_be32(mask.i);
	p->val = cpu_to_be32(val.i);
	return conn_send_command(tconn, sock, cmd, sizeof(*p), NULL, 0);
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}

1135
void drbd_send_sr_reply(struct drbd_conf *mdev, enum drbd_state_rv retcode)
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{
1137 1138
	struct drbd_socket *sock;
	struct p_req_state_reply *p;
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	sock = &mdev->tconn->meta;
	p = drbd_prepare_command(mdev, sock);
	if (p) {
		p->retcode = cpu_to_be32(retcode);
		drbd_send_command(mdev, sock, P_STATE_CHG_REPLY, sizeof(*p), NULL, 0);
	}
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}

1148
void conn_send_sr_reply(struct drbd_tconn *tconn, enum drbd_state_rv retcode)
1149
{
1150 1151
	struct drbd_socket *sock;
	struct p_req_state_reply *p;
1152 1153
	enum drbd_packet cmd = tconn->agreed_pro_version < 100 ? P_STATE_CHG_REPLY : P_CONN_ST_CHG_REPLY;

1154 1155 1156 1157 1158 1159
	sock = &tconn->meta;
	p = conn_prepare_command(tconn, sock);
	if (p) {
		p->retcode = cpu_to_be32(retcode);
		conn_send_command(tconn, sock, cmd, sizeof(*p), NULL, 0);
	}
1160 1161
}

1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178
static void dcbp_set_code(struct p_compressed_bm *p, enum drbd_bitmap_code code)
{
	BUG_ON(code & ~0xf);
	p->encoding = (p->encoding & ~0xf) | code;
}

static void dcbp_set_start(struct p_compressed_bm *p, int set)
{
	p->encoding = (p->encoding & ~0x80) | (set ? 0x80 : 0);
}

static void dcbp_set_pad_bits(struct p_compressed_bm *p, int n)
{
	BUG_ON(n & ~0x7);
	p->encoding = (p->encoding & (~0x7 << 4)) | (n << 4);
}

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int fill_bitmap_rle_bits(struct drbd_conf *mdev,
1180 1181 1182
			 struct p_compressed_bm *p,
			 unsigned int size,
			 struct bm_xfer_ctx *c)
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{
	struct bitstream bs;
	unsigned long plain_bits;
	unsigned long tmp;
	unsigned long rl;
	unsigned len;
	unsigned toggle;
1190
	int bits, use_rle;
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	/* may we use this feature? */
1193 1194 1195 1196 1197
	rcu_read_lock();
	use_rle = rcu_dereference(mdev->tconn->net_conf)->use_rle;
	rcu_read_unlock();
	if (!use_rle || mdev->tconn->agreed_pro_version < 90)
		return 0;
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	if (c->bit_offset >= c->bm_bits)
		return 0; /* nothing to do. */

	/* use at most thus many bytes */
1203 1204
	bitstream_init(&bs, p->code, size, 0);
	memset(p->code, 0, size);
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	/* plain bits covered in this code string */
	plain_bits = 0;

	/* p->encoding & 0x80 stores whether the first run length is set.
	 * bit offset is implicit.
	 * start with toggle == 2 to be able to tell the first iteration */
	toggle = 2;

	/* see how much plain bits we can stuff into one packet
	 * using RLE and VLI. */
	do {
		tmp = (toggle == 0) ? _drbd_bm_find_next_zero(mdev, c->bit_offset)
				    : _drbd_bm_find_next(mdev, c->bit_offset);
		if (tmp == -1UL)
			tmp = c->bm_bits;
		rl = tmp - c->bit_offset;

		if (toggle == 2) { /* first iteration */
			if (rl == 0) {
				/* the first checked bit was set,
				 * store start value, */
1226
				dcbp_set_start(p, 1);
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				/* but skip encoding of zero run length */
				toggle = !toggle;
				continue;
			}
1231
			dcbp_set_start(p, 0);
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		}

		/* paranoia: catch zero runlength.
		 * can only happen if bitmap is modified while we scan it. */
		if (rl == 0) {
			dev_err(DEV, "unexpected zero runlength while encoding bitmap "
			    "t:%u bo:%lu\n", toggle, c->bit_offset);
			return -1;
		}

		bits = vli_encode_bits(&bs, rl);
		if (bits == -ENOBUFS) /* buffer full */
			break;
		if (bits <= 0) {
			dev_err(DEV, "error while encoding bitmap: %d\n", bits);
			return 0;
		}

		toggle = !toggle;
		plain_bits += rl;
		c->bit_offset = tmp;
	} while (c->bit_offset < c->bm_bits);

	len = bs.cur.b - p->code + !!bs.cur.bit;

	if (plain_bits < (len << 3)) {
		/* incompressible with this method.
		 * we need to rewind both word and bit position. */
		c->bit_offset -= plain_bits;
		bm_xfer_ctx_bit_to_word_offset(c);
		c->bit_offset = c->word_offset * BITS_PER_LONG;
		return 0;
	}

	/* RLE + VLI was able to compress it just fine.
	 * update c->word_offset. */
	bm_xfer_ctx_bit_to_word_offset(c);

	/* store pad_bits */
1271
	dcbp_set_pad_bits(p, (8 - bs.cur.bit) & 0x7);
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	return len;
}

1276 1277 1278 1279 1280 1281 1282
/**
 * send_bitmap_rle_or_plain
 *
 * Return 0 when done, 1 when another iteration is needed, and a negative error
 * code upon failure.
 */
static int
1283
send_bitmap_rle_or_plain(struct drbd_conf *mdev, struct bm_xfer_ctx *c)
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{
1285
	struct drbd_socket *sock = &mdev->tconn->data;
1286
	unsigned int header_size = drbd_header_size(mdev->tconn);
1287
	struct p_compressed_bm *p = sock->sbuf + header_size;
1288
	int len, err;
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	len = fill_bitmap_rle_bits(mdev, p,
			DRBD_SOCKET_BUFFER_SIZE - header_size - sizeof(*p), c);
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	if (len < 0)
1293
		return -EIO;
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	if (len) {
1296
		dcbp_set_code(p, RLE_VLI_Bits);
1297 1298 1299
		err = __send_command(mdev->tconn, mdev->vnr, sock,
				     P_COMPRESSED_BITMAP, sizeof(*p) + len,
				     NULL, 0);
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		c->packets[0]++;
1301
		c->bytes[0] += header_size + sizeof(*p) + len;
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		if (c->bit_offset >= c->bm_bits)
			len = 0; /* DONE */
	} else {
		/* was not compressible.
		 * send a buffer full of plain text bits instead. */
1308 1309
		unsigned int data_size;
		unsigned long num_words;
1310
		unsigned long *p = sock->sbuf + header_size;
1311 1312

		data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
1313
		num_words = min_t(size_t, data_size / sizeof(*p),
1314
				  c->bm_words - c->word_offset);
1315
		len = num_words * sizeof(*p);
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		if (len)
1317 1318
			drbd_bm_get_lel(mdev, c->word_offset, num_words, p);
		err = __send_command(mdev->tconn, mdev->vnr, sock, P_BITMAP, len, NULL, 0);
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		c->word_offset += num_words;
		c->bit_offset = c->word_offset * BITS_PER_LONG;

		c->packets[1]++;
1323
		c->bytes[1] += header_size + len;
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		if (c->bit_offset > c->bm_bits)
			c->bit_offset = c->bm_bits;
	}
1328
	if (!err) {
1329 1330 1331 1332 1333 1334 1335
		if (len == 0) {
			INFO_bm_xfer_stats(mdev, "send", c);
			return 0;
		} else
			return 1;
	}
	return -EIO;
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}

/* See the comment at receive_bitmap() */
1339
static int _drbd_send_bitmap(struct drbd_conf *mdev)
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{
	struct bm_xfer_ctx c;
1342
	int err;
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1344 1345
	if (!expect(mdev->bitmap))
		return false;
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	if (get_ldev(mdev)) {
		if (drbd_md_test_flag(mdev->ldev, MDF_FULL_SYNC)) {
			dev_info(DEV, "Writing the whole bitmap, MDF_FullSync was set.\n");
			drbd_bm_set_all(mdev);
			if (drbd_bm_write(mdev)) {
				/* write_bm did fail! Leave full sync flag set in Meta P_DATA
				 * but otherwise process as per normal - need to tell other
				 * side that a full resync is required! */
				dev_err(DEV, "Failed to write bitmap to disk!\n");
			} else {
				drbd_md_clear_flag(mdev, MDF_FULL_SYNC);
				drbd_md_sync(mdev);
			}
		}
		put_ldev(mdev);
	}

	c = (struct bm_xfer_ctx) {
		.bm_bits = drbd_bm_bits(mdev),
		.bm_words = drbd_bm_words(mdev),
	};

	do {
1370
		err = send_bitmap_rle_or_plain(mdev, &c);
1371
	} while (err > 0);
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1373
	return err == 0;
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}

int drbd_send_bitmap(struct drbd_conf *mdev)
{
1378 1379
	struct drbd_socket *sock = &mdev->tconn->data;
	int err = -1;
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1381 1382 1383 1384
	mutex_lock(&sock->mutex);
	if (sock->socket)
		err = !_drbd_send_bitmap(mdev);
	mutex_unlock(&sock->mutex);
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	return err;
}
1387

1388
void drbd_send_b_ack(struct drbd_conf *mdev, u32 barrier_nr, u32 set_size)
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{
1390 1391
	struct drbd_socket *sock;
	struct p_barrier_ack *p;
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1393 1394
	if (mdev->state.conn < C_CONNECTED)
		return;
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1396 1397 1398 1399 1400 1401 1402
	sock = &mdev->tconn->meta;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return;
	p->barrier = barrier_nr;
	p->set_size = cpu_to_be32(set_size);
	drbd_send_command(mdev, sock, P_BARRIER_ACK, sizeof(*p), NULL, 0);
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}

/**
 * _drbd_send_ack() - Sends an ack packet
 * @mdev:	DRBD device.
 * @cmd:	Packet command code.
 * @sector:	sector, needs to be in big endian byte order
 * @blksize:	size in byte, needs to be in big endian byte order
 * @block_id:	Id, big endian byte order
 */
1413 1414
static int _drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
			  u64 sector, u32 blksize, u64 block_id)
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{
1416 1417
	struct drbd_socket *sock;
	struct p_block_ack *p;
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1419 1420
	if (mdev->state.conn < C_CONNECTED)
		return -EIO;
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1422 1423 1424
	sock = &mdev->tconn->meta;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
1425
		return -EIO;
1426 1427 1428 1429 1430
	p->sector = sector;
	p->block_id = block_id;
	p->blksize = blksize;
	p->seq_num = cpu_to_be32(atomic_inc_return(&mdev->packet_seq));
	return drbd_send_command(mdev, sock, cmd, sizeof(*p), NULL, 0);
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}

1433 1434 1435
/* dp->sector and dp->block_id already/still in network byte order,
 * data_size is payload size according to dp->head,
 * and may need to be corrected for digest size. */
1436 1437
void drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd,
		      struct p_data *dp, int data_size)
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{
1439 1440
	if (mdev->tconn->peer_integrity_tfm)
		data_size -= crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
1441 1442
	_drbd_send_ack(mdev, cmd, dp->sector, cpu_to_be32(data_size),
		       dp->block_id);
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}

1445 1446
void drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packet cmd,
		      struct p_block_req *rp)
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{
1448
	_drbd_send_ack(mdev, cmd, rp->sector, rp->blksize, rp->block_id);
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}

/**
 * drbd_send_ack() - Sends an ack packet
1453 1454 1455
 * @mdev:	DRBD device
 * @cmd:	packet command code
 * @peer_req:	peer request
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 */
1457
int drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
1458
		  struct drbd_peer_request *peer_req)
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{
1460 1461 1462 1463
	return _drbd_send_ack(mdev, cmd,
			      cpu_to_be64(peer_req->i.sector),
			      cpu_to_be32(peer_req->i.size),
			      peer_req->block_id);
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}

/* This function misuses the block_id field to signal if the blocks
 * are is sync or not. */
1468
int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packet cmd,
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		     sector_t sector, int blksize, u64 block_id)
{
1471 1472 1473 1474
	return _drbd_send_ack(mdev, cmd,
			      cpu_to_be64(sector),
			      cpu_to_be32(blksize),
			      cpu_to_be64(block_id));
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}

int drbd_send_drequest(struct drbd_conf *mdev, int cmd,
		       sector_t sector, int size, u64 block_id)
{
1480 1481
	struct drbd_socket *sock;
	struct p_block_req *p;
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1483 1484 1485 1486 1487 1488 1489 1490
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->sector = cpu_to_be64(sector);
	p->block_id = block_id;
	p->blksize = cpu_to_be32(size);
	return drbd_send_command(mdev, sock, cmd, sizeof(*p), NULL, 0);
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}

1493 1494
int drbd_send_drequest_csum(struct drbd_conf *mdev, sector_t sector, int size,
			    void *digest, int digest_size, enum drbd_packet cmd)
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{
1496 1497
	struct drbd_socket *sock;
	struct p_block_req *p;
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1499
	/* FIXME: Put the digest into the preallocated socket buffer.  */
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1501 1502 1503 1504 1505 1506 1507 1508 1509
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->sector = cpu_to_be64(sector);
	p->block_id = ID_SYNCER /* unused */;
	p->blksize = cpu_to_be32(size);
	return drbd_send_command(mdev, sock, cmd, sizeof(*p),
				 digest, digest_size);
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}

int drbd_send_ov_request(struct drbd_conf *mdev, sector_t sector, int size)
{
1514 1515
	struct drbd_socket *sock;
	struct p_block_req *p;
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	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->sector = cpu_to_be64(sector);
	p->block_id = ID_SYNCER /* unused */;
	p->blksize = cpu_to_be32(size);
	return drbd_send_command(mdev, sock, P_OV_REQUEST, sizeof(*p), NULL, 0);
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}

/* called on sndtimeo
1528 1529
 * returns false if we should retry,
 * true if we think connection is dead
P
Philipp Reisner 已提交
1530
 */
1531
static int we_should_drop_the_connection(struct drbd_tconn *tconn, struct socket *sock)
P
Philipp Reisner 已提交
1532 1533 1534 1535
{
	int drop_it;
	/* long elapsed = (long)(jiffies - mdev->last_received); */

1536 1537 1538
	drop_it =   tconn->meta.socket == sock
		|| !tconn->asender.task
		|| get_t_state(&tconn->asender) != RUNNING
1539
		|| tconn->cstate < C_WF_REPORT_PARAMS;
P
Philipp Reisner 已提交
1540 1541

	if (drop_it)
1542
		return true;
P
Philipp Reisner 已提交
1543

1544
	drop_it = !--tconn->ko_count;
P
Philipp Reisner 已提交
1545
	if (!drop_it) {
1546 1547 1548
		conn_err(tconn, "[%s/%d] sock_sendmsg time expired, ko = %u\n",
			 current->comm, current->pid, tconn->ko_count);
		request_ping(tconn);
P
Philipp Reisner 已提交
1549 1550 1551 1552 1553
	}

	return drop_it; /* && (mdev->state == R_PRIMARY) */;
}

1554
static void drbd_update_congested(struct drbd_tconn *tconn)
1555
{
1556
	struct sock *sk = tconn->data.socket->sk;
1557
	if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
1558
		set_bit(NET_CONGESTED, &tconn->flags);
1559 1560
}

P
Philipp Reisner 已提交
1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582
/* The idea of sendpage seems to be to put some kind of reference
 * to the page into the skb, and to hand it over to the NIC. In
 * this process get_page() gets called.
 *
 * As soon as the page was really sent over the network put_page()
 * gets called by some part of the network layer. [ NIC driver? ]
 *
 * [ get_page() / put_page() increment/decrement the count. If count
 *   reaches 0 the page will be freed. ]
 *
 * This works nicely with pages from FSs.
 * But this means that in protocol A we might signal IO completion too early!
 *
 * In order not to corrupt data during a resync we must make sure
 * that we do not reuse our own buffer pages (EEs) to early, therefore
 * we have the net_ee list.
 *
 * XFS seems to have problems, still, it submits pages with page_count == 0!
 * As a workaround, we disable sendpage on pages
 * with page_count == 0 or PageSlab.
 */
static int _drbd_no_send_page(struct drbd_conf *mdev, struct page *page,
1583
			      int offset, size_t size, unsigned msg_flags)
P
Philipp Reisner 已提交
1584
{
1585 1586 1587 1588 1589 1590 1591
	struct socket *socket;
	void *addr;
	int err;

	socket = mdev->tconn->data.socket;
	addr = kmap(page) + offset;
	err = drbd_send_all(mdev->tconn, socket, addr, size, msg_flags);
P
Philipp Reisner 已提交
1592
	kunmap(page);
1593 1594 1595
	if (!err)
		mdev->send_cnt += size >> 9;
	return err;
P
Philipp Reisner 已提交
1596 1597 1598
}

static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
L
Lars Ellenberg 已提交
1599
		    int offset, size_t size, unsigned msg_flags)
P
Philipp Reisner 已提交
1600
{
1601
	struct socket *socket = mdev->tconn->data.socket;
P
Philipp Reisner 已提交
1602 1603
	mm_segment_t oldfs = get_fs();
	int len = size;
1604
	int err = -EIO;
P
Philipp Reisner 已提交
1605 1606 1607 1608 1609 1610 1611 1612

	/* e.g. XFS meta- & log-data is in slab pages, which have a
	 * page_count of 0 and/or have PageSlab() set.
	 * we cannot use send_page for those, as that does get_page();
	 * put_page(); and would cause either a VM_BUG directly, or
	 * __page_cache_release a page that would actually still be referenced
	 * by someone, leading to some obscure delayed Oops somewhere else. */
	if (disable_sendpage || (page_count(page) < 1) || PageSlab(page))
1613
		return _drbd_no_send_page(mdev, page, offset, size, msg_flags);
P
Philipp Reisner 已提交
1614

L
Lars Ellenberg 已提交
1615
	msg_flags |= MSG_NOSIGNAL;
1616
	drbd_update_congested(mdev->tconn);
P
Philipp Reisner 已提交
1617 1618
	set_fs(KERNEL_DS);
	do {
1619 1620 1621
		int sent;

		sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
P
Philipp Reisner 已提交
1622
		if (sent <= 0) {
1623 1624 1625 1626 1627
			if (sent == -EAGAIN) {
				if (we_should_drop_the_connection(mdev->tconn, socket))
					break;
				continue;
			}
P
Philipp Reisner 已提交
1628 1629
			dev_warn(DEV, "%s: size=%d len=%d sent=%d\n",
			     __func__, (int)size, len, sent);
1630 1631
			if (sent < 0)
				err = sent;
P
Philipp Reisner 已提交
1632 1633 1634 1635 1636 1637
			break;
		}
		len    -= sent;
		offset += sent;
	} while (len > 0 /* THINK && mdev->cstate >= C_CONNECTED*/);
	set_fs(oldfs);
1638
	clear_bit(NET_CONGESTED, &mdev->tconn->flags);
P
Philipp Reisner 已提交
1639

1640 1641 1642 1643 1644
	if (len == 0) {
		err = 0;
		mdev->send_cnt += size >> 9;
	}
	return err;
P
Philipp Reisner 已提交
1645 1646 1647 1648 1649 1650
}

static int _drbd_send_bio(struct drbd_conf *mdev, struct bio *bio)
{
	struct bio_vec *bvec;
	int i;
L
Lars Ellenberg 已提交
1651
	/* hint all but last page with MSG_MORE */
P
Philipp Reisner 已提交
1652
	__bio_for_each_segment(bvec, bio, i, 0) {
1653 1654 1655 1656 1657 1658 1659
		int err;

		err = _drbd_no_send_page(mdev, bvec->bv_page,
					 bvec->bv_offset, bvec->bv_len,
					 i == bio->bi_vcnt - 1 ? 0 : MSG_MORE);
		if (err)
			return err;
P
Philipp Reisner 已提交
1660
	}
1661
	return 0;
P
Philipp Reisner 已提交
1662 1663 1664 1665 1666 1667
}

static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio)
{
	struct bio_vec *bvec;
	int i;
L
Lars Ellenberg 已提交
1668
	/* hint all but last page with MSG_MORE */
P
Philipp Reisner 已提交
1669
	__bio_for_each_segment(bvec, bio, i, 0) {
1670 1671 1672 1673 1674 1675 1676
		int err;

		err = _drbd_send_page(mdev, bvec->bv_page,
				      bvec->bv_offset, bvec->bv_len,
				      i == bio->bi_vcnt - 1 ? 0 : MSG_MORE);
		if (err)
			return err;
P
Philipp Reisner 已提交
1677
	}
1678
	return 0;
P
Philipp Reisner 已提交
1679 1680
}

1681 1682
static int _drbd_send_zc_ee(struct drbd_conf *mdev,
			    struct drbd_peer_request *peer_req)
1683
{
1684 1685
	struct page *page = peer_req->pages;
	unsigned len = peer_req->i.size;
1686
	int err;
1687

L
Lars Ellenberg 已提交
1688
	/* hint all but last page with MSG_MORE */
1689 1690
	page_chain_for_each(page) {
		unsigned l = min_t(unsigned, len, PAGE_SIZE);
1691 1692 1693 1694 1695

		err = _drbd_send_page(mdev, page, 0, l,
				      page_chain_next(page) ? MSG_MORE : 0);
		if (err)
			return err;
1696 1697
		len -= l;
	}
1698
	return 0;
1699 1700
}

1701 1702
static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
{
1703
	if (mdev->tconn->agreed_pro_version >= 95)
1704 1705 1706 1707 1708
		return  (bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
			(bi_rw & REQ_FUA ? DP_FUA : 0) |
			(bi_rw & REQ_FLUSH ? DP_FLUSH : 0) |
			(bi_rw & REQ_DISCARD ? DP_DISCARD : 0);
	else
J
Jens Axboe 已提交
1709
		return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
1710 1711
}

P
Philipp Reisner 已提交
1712 1713 1714 1715 1716
/* Used to send write requests
 * R_PRIMARY -> Peer	(P_DATA)
 */
int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
{
1717 1718
	struct drbd_socket *sock;
	struct p_data *p;
P
Philipp Reisner 已提交
1719 1720
	unsigned int dp_flags = 0;
	int dgs;
1721
	int err;
P
Philipp Reisner 已提交
1722

1723 1724
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
1725 1726
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_tfm) : 0;
P
Philipp Reisner 已提交
1727

1728 1729 1730 1731 1732
	if (!p)
		return -EIO;
	p->sector = cpu_to_be64(req->i.sector);
	p->block_id = (unsigned long)req;
	p->seq_num = cpu_to_be32(req->seq_num = atomic_inc_return(&mdev->packet_seq));
1733
	dp_flags = bio_flags_to_wire(mdev, req->master_bio->bi_rw);
P
Philipp Reisner 已提交
1734 1735 1736
	if (mdev->state.conn >= C_SYNC_SOURCE &&
	    mdev->state.conn <= C_PAUSED_SYNC_T)
		dp_flags |= DP_MAY_SET_IN_SYNC;
1737 1738 1739 1740 1741 1742
	if (mdev->tconn->agreed_pro_version >= 100) {
		if (req->rq_state & RQ_EXP_RECEIVE_ACK)
			dp_flags |= DP_SEND_RECEIVE_ACK;
		if (req->rq_state & RQ_EXP_WRITE_ACK)
			dp_flags |= DP_SEND_WRITE_ACK;
	}
1743 1744
	p->dp_flags = cpu_to_be32(dp_flags);
	if (dgs)
1745
		drbd_csum_bio(mdev, mdev->tconn->integrity_tfm, req->master_bio, p + 1);
1746
	err = __send_command(mdev->tconn, mdev->vnr, sock, P_DATA, sizeof(*p) + dgs, NULL, req->i.size);
1747
	if (!err) {
1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758
		/* For protocol A, we have to memcpy the payload into
		 * socket buffers, as we may complete right away
		 * as soon as we handed it over to tcp, at which point the data
		 * pages may become invalid.
		 *
		 * For data-integrity enabled, we copy it as well, so we can be
		 * sure that even if the bio pages may still be modified, it
		 * won't change the data on the wire, thus if the digest checks
		 * out ok after sending on this side, but does not fit on the
		 * receiving side, we sure have detected corruption elsewhere.
		 */
1759
		if (!(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK)) || dgs)
1760
			err = _drbd_send_bio(mdev, req->master_bio);
P
Philipp Reisner 已提交
1761
		else
1762
			err = _drbd_send_zc_bio(mdev, req->master_bio);
1763 1764 1765

		/* double check digest, sometimes buffers have been modified in flight. */
		if (dgs > 0 && dgs <= 64) {
B
Bart Van Assche 已提交
1766
			/* 64 byte, 512 bit, is the largest digest size
1767 1768
			 * currently supported in kernel crypto. */
			unsigned char digest[64];
1769
			drbd_csum_bio(mdev, mdev->tconn->integrity_tfm, req->master_bio, digest);
1770
			if (memcmp(p + 1, digest, dgs)) {
1771 1772
				dev_warn(DEV,
					"Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
1773
					(unsigned long long)req->i.sector, req->i.size);
1774 1775 1776 1777
			}
		} /* else if (dgs > 64) {
		     ... Be noisy about digest too large ...
		} */
P
Philipp Reisner 已提交
1778
	}
1779
	mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1780

1781
	return err;
P
Philipp Reisner 已提交
1782 1783 1784 1785 1786 1787
}

/* answer packet, used to send data back for read requests:
 *  Peer       -> (diskless) R_PRIMARY   (P_DATA_REPLY)
 *  C_SYNC_SOURCE -> C_SYNC_TARGET         (P_RS_DATA_REPLY)
 */
1788
int drbd_send_block(struct drbd_conf *mdev, enum drbd_packet cmd,
1789
		    struct drbd_peer_request *peer_req)
P
Philipp Reisner 已提交
1790
{
1791 1792
	struct drbd_socket *sock;
	struct p_data *p;
1793
	int err;
P
Philipp Reisner 已提交
1794 1795
	int dgs;

1796 1797 1798
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);

1799 1800
	dgs = (mdev->tconn->agreed_pro_version >= 87 && mdev->tconn->integrity_tfm) ?
		crypto_hash_digestsize(mdev->tconn->integrity_tfm) : 0;
P
Philipp Reisner 已提交
1801

1802 1803 1804 1805 1806 1807
	if (!p)
		return -EIO;
	p->sector = cpu_to_be64(peer_req->i.sector);
	p->block_id = peer_req->block_id;
	p->seq_num = 0;  /* unused */
	if (dgs)
1808
		drbd_csum_ee(mdev, mdev->tconn->integrity_tfm, peer_req, p + 1);
1809
	err = __send_command(mdev->tconn, mdev->vnr, sock, cmd, sizeof(*p) + dgs, NULL, peer_req->i.size);
1810 1811
	if (!err)
		err = _drbd_send_zc_ee(mdev, peer_req);
1812
	mutex_unlock(&sock->mutex);  /* locked by drbd_prepare_command() */
1813

1814
	return err;
P
Philipp Reisner 已提交
1815 1816
}

1817
int drbd_send_out_of_sync(struct drbd_conf *mdev, struct drbd_request *req)
1818
{
1819 1820
	struct drbd_socket *sock;
	struct p_block_desc *p;
1821

1822 1823 1824 1825 1826 1827 1828
	sock = &mdev->tconn->data;
	p = drbd_prepare_command(mdev, sock);
	if (!p)
		return -EIO;
	p->sector = cpu_to_be64(req->i.sector);
	p->blksize = cpu_to_be32(req->i.size);
	return drbd_send_command(mdev, sock, P_OUT_OF_SYNC, sizeof(*p), NULL, 0);
1829 1830
}

P
Philipp Reisner 已提交
1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846
/*
  drbd_send distinguishes two cases:

  Packets sent via the data socket "sock"
  and packets sent via the meta data socket "msock"

		    sock                      msock
  -----------------+-------------------------+------------------------------
  timeout           conf.timeout / 2          conf.timeout / 2
  timeout action    send a ping via msock     Abort communication
					      and close all sockets
*/

/*
 * you must have down()ed the appropriate [m]sock_mutex elsewhere!
 */
1847
int drbd_send(struct drbd_tconn *tconn, struct socket *sock,
P
Philipp Reisner 已提交
1848 1849 1850 1851 1852 1853 1854
	      void *buf, size_t size, unsigned msg_flags)
{
	struct kvec iov;
	struct msghdr msg;
	int rv, sent = 0;

	if (!sock)
1855
		return -EBADR;
P
Philipp Reisner 已提交
1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867

	/* THINK  if (signal_pending) return ... ? */

	iov.iov_base = buf;
	iov.iov_len  = size;

	msg.msg_name       = NULL;
	msg.msg_namelen    = 0;
	msg.msg_control    = NULL;
	msg.msg_controllen = 0;
	msg.msg_flags      = msg_flags | MSG_NOSIGNAL;

1868
	if (sock == tconn->data.socket) {
1869 1870 1871
		rcu_read_lock();
		tconn->ko_count = rcu_dereference(tconn->net_conf)->ko_count;
		rcu_read_unlock();
1872
		drbd_update_congested(tconn);
P
Philipp Reisner 已提交
1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
	}
	do {
		/* STRANGE
		 * tcp_sendmsg does _not_ use its size parameter at all ?
		 *
		 * -EAGAIN on timeout, -EINTR on signal.
		 */
/* THINK
 * do we need to block DRBD_SIG if sock == &meta.socket ??
 * otherwise wake_asender() might interrupt some send_*Ack !
 */
		rv = kernel_sendmsg(sock, &msg, &iov, 1, size);
		if (rv == -EAGAIN) {
1886
			if (we_should_drop_the_connection(tconn, sock))
P
Philipp Reisner 已提交
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901
				break;
			else
				continue;
		}
		if (rv == -EINTR) {
			flush_signals(current);
			rv = 0;
		}
		if (rv < 0)
			break;
		sent += rv;
		iov.iov_base += rv;
		iov.iov_len  -= rv;
	} while (sent < size);

1902 1903
	if (sock == tconn->data.socket)
		clear_bit(NET_CONGESTED, &tconn->flags);
P
Philipp Reisner 已提交
1904 1905 1906

	if (rv <= 0) {
		if (rv != -EAGAIN) {
1907 1908 1909
			conn_err(tconn, "%s_sendmsg returned %d\n",
				 sock == tconn->meta.socket ? "msock" : "sock",
				 rv);
1910
			conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
P
Philipp Reisner 已提交
1911
		} else
1912
			conn_request_state(tconn, NS(conn, C_TIMEOUT), CS_HARD);
P
Philipp Reisner 已提交
1913 1914 1915 1916 1917
	}

	return sent;
}

1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
/**
 * drbd_send_all  -  Send an entire buffer
 *
 * Returns 0 upon success and a negative error value otherwise.
 */
int drbd_send_all(struct drbd_tconn *tconn, struct socket *sock, void *buffer,
		  size_t size, unsigned msg_flags)
{
	int err;

	err = drbd_send(tconn, sock, buffer, size, msg_flags);
	if (err < 0)
		return err;
	if (err != size)
		return -EIO;
	return 0;
}

P
Philipp Reisner 已提交
1936 1937 1938 1939 1940 1941
static int drbd_open(struct block_device *bdev, fmode_t mode)
{
	struct drbd_conf *mdev = bdev->bd_disk->private_data;
	unsigned long flags;
	int rv = 0;

1942
	mutex_lock(&drbd_main_mutex);
1943
	spin_lock_irqsave(&mdev->tconn->req_lock, flags);
P
Philipp Reisner 已提交
1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
	/* to have a stable mdev->state.role
	 * and no race with updating open_cnt */

	if (mdev->state.role != R_PRIMARY) {
		if (mode & FMODE_WRITE)
			rv = -EROFS;
		else if (!allow_oos)
			rv = -EMEDIUMTYPE;
	}

	if (!rv)
		mdev->open_cnt++;
1956
	spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
1957
	mutex_unlock(&drbd_main_mutex);
P
Philipp Reisner 已提交
1958 1959 1960 1961 1962 1963 1964

	return rv;
}

static int drbd_release(struct gendisk *gd, fmode_t mode)
{
	struct drbd_conf *mdev = gd->private_data;
1965
	mutex_lock(&drbd_main_mutex);
P
Philipp Reisner 已提交
1966
	mdev->open_cnt--;
1967
	mutex_unlock(&drbd_main_mutex);
P
Philipp Reisner 已提交
1968 1969 1970 1971 1972
	return 0;
}

static void drbd_set_defaults(struct drbd_conf *mdev)
{
1973 1974
	/* Beware! The actual layout differs
	 * between big endian and little endian */
1975
	mdev->state = (union drbd_dev_state) {
P
Philipp Reisner 已提交
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995
		{ .role = R_SECONDARY,
		  .peer = R_UNKNOWN,
		  .conn = C_STANDALONE,
		  .disk = D_DISKLESS,
		  .pdsk = D_UNKNOWN,
		} };
}

void drbd_init_set_defaults(struct drbd_conf *mdev)
{
	/* the memset(,0,) did most of this.
	 * note: only assignments, no allocation in here */

	drbd_set_defaults(mdev);

	atomic_set(&mdev->ap_bio_cnt, 0);
	atomic_set(&mdev->ap_pending_cnt, 0);
	atomic_set(&mdev->rs_pending_cnt, 0);
	atomic_set(&mdev->unacked_cnt, 0);
	atomic_set(&mdev->local_cnt, 0);
1996
	atomic_set(&mdev->pp_in_use_by_net, 0);
1997
	atomic_set(&mdev->rs_sect_in, 0);
1998
	atomic_set(&mdev->rs_sect_ev, 0);
1999
	atomic_set(&mdev->ap_in_flight, 0);
P
Philipp Reisner 已提交
2000 2001

	mutex_init(&mdev->md_io_mutex);
2002 2003
	mutex_init(&mdev->own_state_mutex);
	mdev->state_mutex = &mdev->own_state_mutex;
P
Philipp Reisner 已提交
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

	spin_lock_init(&mdev->al_lock);
	spin_lock_init(&mdev->peer_seq_lock);
	spin_lock_init(&mdev->epoch_lock);

	INIT_LIST_HEAD(&mdev->active_ee);
	INIT_LIST_HEAD(&mdev->sync_ee);
	INIT_LIST_HEAD(&mdev->done_ee);
	INIT_LIST_HEAD(&mdev->read_ee);
	INIT_LIST_HEAD(&mdev->net_ee);
	INIT_LIST_HEAD(&mdev->resync_reads);
	INIT_LIST_HEAD(&mdev->resync_work.list);
	INIT_LIST_HEAD(&mdev->unplug_work.list);
2017
	INIT_LIST_HEAD(&mdev->go_diskless.list);
P
Philipp Reisner 已提交
2018
	INIT_LIST_HEAD(&mdev->md_sync_work.list);
2019
	INIT_LIST_HEAD(&mdev->start_resync_work.list);
P
Philipp Reisner 已提交
2020
	INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
2021

2022
	mdev->resync_work.cb  = w_resync_timer;
P
Philipp Reisner 已提交
2023
	mdev->unplug_work.cb  = w_send_write_hint;
2024
	mdev->go_diskless.cb  = w_go_diskless;
P
Philipp Reisner 已提交
2025 2026
	mdev->md_sync_work.cb = w_md_sync;
	mdev->bm_io_work.w.cb = w_bitmap_io;
2027
	mdev->start_resync_work.cb = w_start_resync;
2028 2029 2030 2031 2032 2033 2034 2035

	mdev->resync_work.mdev  = mdev;
	mdev->unplug_work.mdev  = mdev;
	mdev->go_diskless.mdev  = mdev;
	mdev->md_sync_work.mdev = mdev;
	mdev->bm_io_work.w.mdev = mdev;
	mdev->start_resync_work.mdev = mdev;

P
Philipp Reisner 已提交
2036 2037
	init_timer(&mdev->resync_timer);
	init_timer(&mdev->md_sync_timer);
2038
	init_timer(&mdev->start_resync_timer);
2039
	init_timer(&mdev->request_timer);
P
Philipp Reisner 已提交
2040 2041 2042 2043
	mdev->resync_timer.function = resync_timer_fn;
	mdev->resync_timer.data = (unsigned long) mdev;
	mdev->md_sync_timer.function = md_sync_timer_fn;
	mdev->md_sync_timer.data = (unsigned long) mdev;
2044 2045
	mdev->start_resync_timer.function = start_resync_timer_fn;
	mdev->start_resync_timer.data = (unsigned long) mdev;
2046 2047
	mdev->request_timer.function = request_timer_fn;
	mdev->request_timer.data = (unsigned long) mdev;
P
Philipp Reisner 已提交
2048 2049 2050 2051 2052 2053 2054

	init_waitqueue_head(&mdev->misc_wait);
	init_waitqueue_head(&mdev->state_wait);
	init_waitqueue_head(&mdev->ee_wait);
	init_waitqueue_head(&mdev->al_wait);
	init_waitqueue_head(&mdev->seq_wait);

2055
	mdev->write_ordering = WO_bdev_flush;
P
Philipp Reisner 已提交
2056
	mdev->resync_wenr = LC_FREE;
2057 2058
	mdev->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
	mdev->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
P
Philipp Reisner 已提交
2059 2060 2061 2062
}

void drbd_mdev_cleanup(struct drbd_conf *mdev)
{
2063
	int i;
2064
	if (mdev->tconn->receiver.t_state != NONE)
P
Philipp Reisner 已提交
2065
		dev_err(DEV, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
2066
				mdev->tconn->receiver.t_state);
P
Philipp Reisner 已提交
2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079

	/* no need to lock it, I'm the only thread alive */
	if (atomic_read(&mdev->current_epoch->epoch_size) !=  0)
		dev_err(DEV, "epoch_size:%d\n", atomic_read(&mdev->current_epoch->epoch_size));
	mdev->al_writ_cnt  =
	mdev->bm_writ_cnt  =
	mdev->read_cnt     =
	mdev->recv_cnt     =
	mdev->send_cnt     =
	mdev->writ_cnt     =
	mdev->p_size       =
	mdev->rs_start     =
	mdev->rs_total     =
2080 2081
	mdev->rs_failed    = 0;
	mdev->rs_last_events = 0;
2082
	mdev->rs_last_sect_ev = 0;
2083 2084 2085 2086
	for (i = 0; i < DRBD_SYNC_MARKS; i++) {
		mdev->rs_mark_left[i] = 0;
		mdev->rs_mark_time[i] = 0;
	}
2087
	D_ASSERT(mdev->tconn->net_conf == NULL);
P
Philipp Reisner 已提交
2088 2089 2090 2091

	drbd_set_my_capacity(mdev, 0);
	if (mdev->bitmap) {
		/* maybe never allocated. */
2092
		drbd_bm_resize(mdev, 0, 1);
P
Philipp Reisner 已提交
2093 2094 2095
		drbd_bm_cleanup(mdev);
	}

2096 2097 2098
	drbd_free_bc(mdev->ldev);
	mdev->ldev = NULL;

2099
	clear_bit(AL_SUSPENDED, &mdev->flags);
P
Philipp Reisner 已提交
2100 2101 2102 2103 2104 2105 2106

	D_ASSERT(list_empty(&mdev->active_ee));
	D_ASSERT(list_empty(&mdev->sync_ee));
	D_ASSERT(list_empty(&mdev->done_ee));
	D_ASSERT(list_empty(&mdev->read_ee));
	D_ASSERT(list_empty(&mdev->net_ee));
	D_ASSERT(list_empty(&mdev->resync_reads));
2107 2108
	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
	D_ASSERT(list_empty(&mdev->tconn->meta.work.q));
P
Philipp Reisner 已提交
2109 2110
	D_ASSERT(list_empty(&mdev->resync_work.list));
	D_ASSERT(list_empty(&mdev->unplug_work.list));
2111
	D_ASSERT(list_empty(&mdev->go_diskless.list));
2112 2113

	drbd_set_defaults(mdev);
P
Philipp Reisner 已提交
2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
}


static void drbd_destroy_mempools(void)
{
	struct page *page;

	while (drbd_pp_pool) {
		page = drbd_pp_pool;
		drbd_pp_pool = (struct page *)page_private(page);
		__free_page(page);
		drbd_pp_vacant--;
	}

	/* D_ASSERT(atomic_read(&drbd_pp_vacant)==0); */

2130 2131
	if (drbd_md_io_bio_set)
		bioset_free(drbd_md_io_bio_set);
2132 2133
	if (drbd_md_io_page_pool)
		mempool_destroy(drbd_md_io_page_pool);
P
Philipp Reisner 已提交
2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146
	if (drbd_ee_mempool)
		mempool_destroy(drbd_ee_mempool);
	if (drbd_request_mempool)
		mempool_destroy(drbd_request_mempool);
	if (drbd_ee_cache)
		kmem_cache_destroy(drbd_ee_cache);
	if (drbd_request_cache)
		kmem_cache_destroy(drbd_request_cache);
	if (drbd_bm_ext_cache)
		kmem_cache_destroy(drbd_bm_ext_cache);
	if (drbd_al_ext_cache)
		kmem_cache_destroy(drbd_al_ext_cache);

2147
	drbd_md_io_bio_set   = NULL;
2148
	drbd_md_io_page_pool = NULL;
P
Philipp Reisner 已提交
2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161
	drbd_ee_mempool      = NULL;
	drbd_request_mempool = NULL;
	drbd_ee_cache        = NULL;
	drbd_request_cache   = NULL;
	drbd_bm_ext_cache    = NULL;
	drbd_al_ext_cache    = NULL;

	return;
}

static int drbd_create_mempools(void)
{
	struct page *page;
2162
	const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count;
P
Philipp Reisner 已提交
2163 2164 2165 2166 2167 2168 2169 2170 2171
	int i;

	/* prepare our caches and mempools */
	drbd_request_mempool = NULL;
	drbd_ee_cache        = NULL;
	drbd_request_cache   = NULL;
	drbd_bm_ext_cache    = NULL;
	drbd_al_ext_cache    = NULL;
	drbd_pp_pool         = NULL;
2172
	drbd_md_io_page_pool = NULL;
2173
	drbd_md_io_bio_set   = NULL;
P
Philipp Reisner 已提交
2174 2175 2176 2177 2178 2179 2180 2181

	/* caches */
	drbd_request_cache = kmem_cache_create(
		"drbd_req", sizeof(struct drbd_request), 0, 0, NULL);
	if (drbd_request_cache == NULL)
		goto Enomem;

	drbd_ee_cache = kmem_cache_create(
2182
		"drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
P
Philipp Reisner 已提交
2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196
	if (drbd_ee_cache == NULL)
		goto Enomem;

	drbd_bm_ext_cache = kmem_cache_create(
		"drbd_bm", sizeof(struct bm_extent), 0, 0, NULL);
	if (drbd_bm_ext_cache == NULL)
		goto Enomem;

	drbd_al_ext_cache = kmem_cache_create(
		"drbd_al", sizeof(struct lc_element), 0, 0, NULL);
	if (drbd_al_ext_cache == NULL)
		goto Enomem;

	/* mempools */
2197 2198 2199 2200
	drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0);
	if (drbd_md_io_bio_set == NULL)
		goto Enomem;

2201 2202 2203 2204
	drbd_md_io_page_pool = mempool_create_page_pool(DRBD_MIN_POOL_PAGES, 0);
	if (drbd_md_io_page_pool == NULL)
		goto Enomem;

P
Philipp Reisner 已提交
2205 2206 2207 2208 2209 2210 2211
	drbd_request_mempool = mempool_create(number,
		mempool_alloc_slab, mempool_free_slab, drbd_request_cache);
	if (drbd_request_mempool == NULL)
		goto Enomem;

	drbd_ee_mempool = mempool_create(number,
		mempool_alloc_slab, mempool_free_slab, drbd_ee_cache);
2212
	if (drbd_ee_mempool == NULL)
P
Philipp Reisner 已提交
2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247
		goto Enomem;

	/* drbd's page pool */
	spin_lock_init(&drbd_pp_lock);

	for (i = 0; i < number; i++) {
		page = alloc_page(GFP_HIGHUSER);
		if (!page)
			goto Enomem;
		set_page_private(page, (unsigned long)drbd_pp_pool);
		drbd_pp_pool = page;
	}
	drbd_pp_vacant = number;

	return 0;

Enomem:
	drbd_destroy_mempools(); /* in case we allocated some */
	return -ENOMEM;
}

static int drbd_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	/* just so we have it.  you never know what interesting things we
	 * might want to do here some day...
	 */

	return NOTIFY_DONE;
}

static struct notifier_block drbd_notifier = {
	.notifier_call = drbd_notify_sys,
};

2248
static void drbd_release_all_peer_reqs(struct drbd_conf *mdev)
P
Philipp Reisner 已提交
2249 2250 2251
{
	int rr;

2252
	rr = drbd_free_peer_reqs(mdev, &mdev->active_ee);
P
Philipp Reisner 已提交
2253 2254 2255
	if (rr)
		dev_err(DEV, "%d EEs in active list found!\n", rr);

2256
	rr = drbd_free_peer_reqs(mdev, &mdev->sync_ee);
P
Philipp Reisner 已提交
2257 2258 2259
	if (rr)
		dev_err(DEV, "%d EEs in sync list found!\n", rr);

2260
	rr = drbd_free_peer_reqs(mdev, &mdev->read_ee);
P
Philipp Reisner 已提交
2261 2262 2263
	if (rr)
		dev_err(DEV, "%d EEs in read list found!\n", rr);

2264
	rr = drbd_free_peer_reqs(mdev, &mdev->done_ee);
P
Philipp Reisner 已提交
2265 2266 2267
	if (rr)
		dev_err(DEV, "%d EEs in done list found!\n", rr);

2268
	rr = drbd_free_peer_reqs(mdev, &mdev->net_ee);
P
Philipp Reisner 已提交
2269 2270 2271 2272
	if (rr)
		dev_err(DEV, "%d EEs in net list found!\n", rr);
}

2273
/* caution. no locking. */
2274
void drbd_minor_destroy(struct kref *kref)
P
Philipp Reisner 已提交
2275
{
2276
	struct drbd_conf *mdev = container_of(kref, struct drbd_conf, kref);
2277 2278
	struct drbd_tconn *tconn = mdev->tconn;

P
Philipp Reisner 已提交
2279
	/* paranoia asserts */
2280
	D_ASSERT(mdev->open_cnt == 0);
2281
	D_ASSERT(list_empty(&mdev->tconn->data.work.q));
P
Philipp Reisner 已提交
2282 2283 2284 2285 2286 2287 2288 2289
	/* end paranoia asserts */

	/* cleanup stuff that may have been allocated during
	 * device (re-)configuration or state changes */

	if (mdev->this_bdev)
		bdput(mdev->this_bdev);

2290 2291
	drbd_free_bc(mdev->ldev);
	mdev->ldev = NULL;
P
Philipp Reisner 已提交
2292

2293
	drbd_release_all_peer_reqs(mdev);
P
Philipp Reisner 已提交
2294 2295 2296 2297 2298 2299 2300

	lc_destroy(mdev->act_log);
	lc_destroy(mdev->resync);

	kfree(mdev->p_uuid);
	/* mdev->p_uuid = NULL; */

2301 2302 2303 2304 2305 2306
	kfree(mdev->current_epoch);
	if (mdev->bitmap) /* should no longer be there. */
		drbd_bm_cleanup(mdev);
	__free_page(mdev->md_io_page);
	put_disk(mdev->vdisk);
	blk_cleanup_queue(mdev->rq_queue);
2307
	kfree(mdev->rs_plan_s);
2308
	kfree(mdev);
2309 2310

	kref_put(&tconn->kref, &conn_destroy);
P
Philipp Reisner 已提交
2311 2312 2313 2314 2315
}

static void drbd_cleanup(void)
{
	unsigned int i;
2316
	struct drbd_conf *mdev;
2317
	struct drbd_tconn *tconn, *tmp;
P
Philipp Reisner 已提交
2318 2319 2320

	unregister_reboot_notifier(&drbd_notifier);

2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331
	/* first remove proc,
	 * drbdsetup uses it's presence to detect
	 * whether DRBD is loaded.
	 * If we would get stuck in proc removal,
	 * but have netlink already deregistered,
	 * some drbdsetup commands may wait forever
	 * for an answer.
	 */
	if (drbd_proc)
		remove_proc_entry("drbd", NULL);

2332
	drbd_genl_unregister();
P
Philipp Reisner 已提交
2333

2334 2335 2336 2337
	idr_for_each_entry(&minors, mdev, i) {
		idr_remove(&minors, mdev_to_minor(mdev));
		idr_remove(&mdev->tconn->volumes, mdev->vnr);
		del_gendisk(mdev->vdisk);
P
Philipp Reisner 已提交
2338
		/* synchronize_rcu(); No other threads running at this point */
2339 2340 2341
		kref_put(&mdev->kref, &drbd_minor_destroy);
	}

P
Philipp Reisner 已提交
2342
	/* not _rcu since, no other updater anymore. Genl already unregistered */
2343
	list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
P
Philipp Reisner 已提交
2344 2345
		list_del(&tconn->all_tconn); /* not _rcu no proc, not other threads */
		/* synchronize_rcu(); */
2346 2347
		kref_put(&tconn->kref, &conn_destroy);
	}
2348

2349
	drbd_destroy_mempools();
P
Philipp Reisner 已提交
2350 2351
	unregister_blkdev(DRBD_MAJOR, "drbd");

2352 2353
	idr_destroy(&minors);

P
Philipp Reisner 已提交
2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370
	printk(KERN_INFO "drbd: module cleanup done.\n");
}

/**
 * drbd_congested() - Callback for pdflush
 * @congested_data:	User data
 * @bdi_bits:		Bits pdflush is currently interested in
 *
 * Returns 1<<BDI_async_congested and/or 1<<BDI_sync_congested if we are congested.
 */
static int drbd_congested(void *congested_data, int bdi_bits)
{
	struct drbd_conf *mdev = congested_data;
	struct request_queue *q;
	char reason = '-';
	int r = 0;

2371
	if (!may_inc_ap_bio(mdev)) {
P
Philipp Reisner 已提交
2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385
		/* DRBD has frozen IO */
		r = bdi_bits;
		reason = 'd';
		goto out;
	}

	if (get_ldev(mdev)) {
		q = bdev_get_queue(mdev->ldev->backing_bdev);
		r = bdi_congested(&q->backing_dev_info, bdi_bits);
		put_ldev(mdev);
		if (r)
			reason = 'b';
	}

2386
	if (bdi_bits & (1 << BDI_async_congested) && test_bit(NET_CONGESTED, &mdev->tconn->flags)) {
P
Philipp Reisner 已提交
2387 2388 2389 2390 2391 2392 2393 2394 2395
		r |= (1 << BDI_async_congested);
		reason = reason == 'b' ? 'a' : 'n';
	}

out:
	mdev->congestion_reason = reason;
	return r;
}

2396 2397 2398 2399 2400 2401 2402
static void drbd_init_workqueue(struct drbd_work_queue* wq)
{
	sema_init(&wq->s, 0);
	spin_lock_init(&wq->q_lock);
	INIT_LIST_HEAD(&wq->q);
}

2403
struct drbd_tconn *conn_get_by_name(const char *name)
2404 2405 2406
{
	struct drbd_tconn *tconn;

2407 2408 2409
	if (!name || !name[0])
		return NULL;

P
Philipp Reisner 已提交
2410
	rcu_read_lock();
2411
	list_for_each_entry_rcu(tconn, &drbd_tconns, all_tconn) {
2412 2413
		if (!strcmp(tconn->name, name)) {
			kref_get(&tconn->kref);
2414
			goto found;
2415
		}
2416 2417 2418
	}
	tconn = NULL;
found:
P
Philipp Reisner 已提交
2419
	rcu_read_unlock();
2420 2421 2422
	return tconn;
}

2423 2424 2425 2426 2427
static int drbd_alloc_socket(struct drbd_socket *socket)
{
	socket->rbuf = (void *) __get_free_page(GFP_KERNEL);
	if (!socket->rbuf)
		return -ENOMEM;
2428 2429 2430
	socket->sbuf = (void *) __get_free_page(GFP_KERNEL);
	if (!socket->sbuf)
		return -ENOMEM;
2431 2432 2433 2434 2435
	return 0;
}

static void drbd_free_socket(struct drbd_socket *socket)
{
2436
	free_page((unsigned long) socket->sbuf);
2437 2438 2439
	free_page((unsigned long) socket->rbuf);
}

2440 2441
void conn_free_crypto(struct drbd_tconn *tconn)
{
2442 2443 2444 2445
	drbd_free_sock(tconn);

	crypto_free_hash(tconn->csums_tfm);
	crypto_free_hash(tconn->verify_tfm);
2446
	crypto_free_hash(tconn->cram_hmac_tfm);
2447
	crypto_free_hash(tconn->integrity_tfm);
2448
	crypto_free_hash(tconn->peer_integrity_tfm);
2449 2450
	kfree(tconn->int_dig_in);
	kfree(tconn->int_dig_vv);
2451 2452 2453

	tconn->csums_tfm = NULL;
	tconn->verify_tfm = NULL;
2454
	tconn->cram_hmac_tfm = NULL;
2455
	tconn->integrity_tfm = NULL;
2456
	tconn->peer_integrity_tfm = NULL;
2457 2458 2459 2460
	tconn->int_dig_in = NULL;
	tconn->int_dig_vv = NULL;
}

2461
/* caller must be under genl_lock() */
2462
struct drbd_tconn *conn_create(const char *name)
2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
{
	struct drbd_tconn *tconn;

	tconn = kzalloc(sizeof(struct drbd_tconn), GFP_KERNEL);
	if (!tconn)
		return NULL;

	tconn->name = kstrdup(name, GFP_KERNEL);
	if (!tconn->name)
		goto fail;

2474 2475 2476 2477 2478
	if (drbd_alloc_socket(&tconn->data))
		goto fail;
	if (drbd_alloc_socket(&tconn->meta))
		goto fail;

2479 2480 2481
	if (!zalloc_cpumask_var(&tconn->cpu_mask, GFP_KERNEL))
		goto fail;

2482 2483 2484
	if (!tl_init(tconn))
		goto fail;

2485
	tconn->cstate = C_STANDALONE;
2486
	mutex_init(&tconn->cstate_mutex);
2487
	spin_lock_init(&tconn->req_lock);
2488
	mutex_init(&tconn->conf_update);
2489
	init_waitqueue_head(&tconn->ping_wait);
2490
	idr_init(&tconn->volumes);
2491

2492 2493 2494 2495 2496 2497
	drbd_init_workqueue(&tconn->data.work);
	mutex_init(&tconn->data.mutex);

	drbd_init_workqueue(&tconn->meta.work);
	mutex_init(&tconn->meta.mutex);

2498 2499 2500 2501
	drbd_thread_init(tconn, &tconn->receiver, drbdd_init, "receiver");
	drbd_thread_init(tconn, &tconn->worker, drbd_worker, "worker");
	drbd_thread_init(tconn, &tconn->asender, drbd_asender, "asender");

2502
	drbd_set_res_opts_defaults(&tconn->res_opts);
2503

2504
	kref_init(&tconn->kref);
2505
	list_add_tail_rcu(&tconn->all_tconn, &drbd_tconns);
2506 2507 2508 2509

	return tconn;

fail:
2510
	tl_cleanup(tconn);
2511
	free_cpumask_var(tconn->cpu_mask);
2512 2513
	drbd_free_socket(&tconn->meta);
	drbd_free_socket(&tconn->data);
2514 2515 2516 2517 2518 2519
	kfree(tconn->name);
	kfree(tconn);

	return NULL;
}

2520
void conn_destroy(struct kref *kref)
2521
{
2522 2523
	struct drbd_tconn *tconn = container_of(kref, struct drbd_tconn, kref);

2524
	idr_destroy(&tconn->volumes);
2525

2526
	free_cpumask_var(tconn->cpu_mask);
2527 2528
	drbd_free_socket(&tconn->meta);
	drbd_free_socket(&tconn->data);
2529
	kfree(tconn->name);
2530 2531
	kfree(tconn->int_dig_in);
	kfree(tconn->int_dig_vv);
2532 2533 2534
	kfree(tconn);
}

2535
enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr)
P
Philipp Reisner 已提交
2536 2537 2538 2539
{
	struct drbd_conf *mdev;
	struct gendisk *disk;
	struct request_queue *q;
2540
	int vnr_got = vnr;
2541
	int minor_got = minor;
2542
	enum drbd_ret_code err = ERR_NOMEM;
2543 2544 2545 2546

	mdev = minor_to_mdev(minor);
	if (mdev)
		return ERR_MINOR_EXISTS;
P
Philipp Reisner 已提交
2547 2548 2549 2550

	/* GFP_KERNEL, we are outside of all write-out paths */
	mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
	if (!mdev)
2551 2552
		return ERR_NOMEM;

2553
	kref_get(&tconn->kref);
2554
	mdev->tconn = tconn;
2555

P
Philipp Reisner 已提交
2556
	mdev->minor = minor;
2557
	mdev->vnr = vnr;
P
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2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571

	drbd_init_set_defaults(mdev);

	q = blk_alloc_queue(GFP_KERNEL);
	if (!q)
		goto out_no_q;
	mdev->rq_queue = q;
	q->queuedata   = mdev;

	disk = alloc_disk(1);
	if (!disk)
		goto out_no_disk;
	mdev->vdisk = disk;

2572
	set_disk_ro(disk, true);
P
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2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587

	disk->queue = q;
	disk->major = DRBD_MAJOR;
	disk->first_minor = minor;
	disk->fops = &drbd_ops;
	sprintf(disk->disk_name, "drbd%d", minor);
	disk->private_data = mdev;

	mdev->this_bdev = bdget(MKDEV(DRBD_MAJOR, minor));
	/* we have no partitions. we contain only ourselves. */
	mdev->this_bdev->bd_contains = mdev->this_bdev;

	q->backing_dev_info.congested_fn = drbd_congested;
	q->backing_dev_info.congested_data = mdev;

2588
	blk_queue_make_request(q, drbd_make_request);
2589 2590 2591
	/* Setting the max_hw_sectors to an odd value of 8kibyte here
	   This triggers a max_bio_size message upon first attach or connect */
	blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);
P
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2592 2593
	blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
	blk_queue_merge_bvec(q, drbd_merge_bvec);
2594
	q->queue_lock = &mdev->tconn->req_lock; /* needed since we use */
P
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2595 2596 2597 2598 2599 2600 2601

	mdev->md_io_page = alloc_page(GFP_KERNEL);
	if (!mdev->md_io_page)
		goto out_no_io_page;

	if (drbd_bm_init(mdev))
		goto out_no_bitmap;
2602
	mdev->read_requests = RB_ROOT;
2603
	mdev->write_requests = RB_ROOT;
P
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2604 2605 2606 2607 2608 2609 2610 2611

	mdev->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
	if (!mdev->current_epoch)
		goto out_no_epoch;

	INIT_LIST_HEAD(&mdev->current_epoch->list);
	mdev->epochs = 1;

2612
	if (!idr_pre_get(&minors, GFP_KERNEL))
2613 2614 2615
		goto out_no_minor_idr;
	if (idr_get_new_above(&minors, mdev, minor, &minor_got))
		goto out_no_minor_idr;
2616
	if (minor_got != minor) {
2617 2618
		err = ERR_MINOR_EXISTS;
		drbd_msg_put_info("requested minor exists already");
2619
		goto out_idr_remove_minor;
2620
	}
2621 2622 2623 2624 2625 2626 2627 2628 2629 2630

	if (!idr_pre_get(&tconn->volumes, GFP_KERNEL))
		goto out_idr_remove_minor;
	if (idr_get_new_above(&tconn->volumes, mdev, vnr, &vnr_got))
		goto out_idr_remove_minor;
	if (vnr_got != vnr) {
		err = ERR_INVALID_REQUEST;
		drbd_msg_put_info("requested volume exists already");
		goto out_idr_remove_vol;
	}
2631
	add_disk(disk);
2632
	kref_init(&mdev->kref); /* one ref for both idrs and the the add_disk */
2633

2634 2635 2636
	/* inherit the connection state */
	mdev->state.conn = tconn->cstate;
	if (mdev->state.conn == C_WF_REPORT_PARAMS)
P
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2637
		drbd_connected(mdev);
2638

2639
	return NO_ERROR;
P
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2640

2641 2642
out_idr_remove_vol:
	idr_remove(&tconn->volumes, vnr_got);
2643 2644
out_idr_remove_minor:
	idr_remove(&minors, minor_got);
2645
	synchronize_rcu();
2646
out_no_minor_idr:
2647
	kfree(mdev->current_epoch);
P
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2648 2649 2650 2651 2652 2653 2654 2655 2656 2657
out_no_epoch:
	drbd_bm_cleanup(mdev);
out_no_bitmap:
	__free_page(mdev->md_io_page);
out_no_io_page:
	put_disk(disk);
out_no_disk:
	blk_cleanup_queue(q);
out_no_q:
	kfree(mdev);
2658
	kref_put(&tconn->kref, &conn_destroy);
2659
	return err;
P
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2660 2661 2662 2663 2664 2665
}

int __init drbd_init(void)
{
	int err;

2666
	if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {
P
Philipp Reisner 已提交
2667
		printk(KERN_ERR
2668
		       "drbd: invalid minor_count (%d)\n", minor_count);
P
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2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683
#ifdef MODULE
		return -EINVAL;
#else
		minor_count = 8;
#endif
	}

	err = register_blkdev(DRBD_MAJOR, "drbd");
	if (err) {
		printk(KERN_ERR
		       "drbd: unable to register block device major %d\n",
		       DRBD_MAJOR);
		return err;
	}

2684 2685 2686 2687 2688 2689 2690
	err = drbd_genl_register();
	if (err) {
		printk(KERN_ERR "drbd: unable to register generic netlink family\n");
		goto fail;
	}


P
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2691 2692 2693 2694 2695 2696 2697 2698 2699 2700
	register_reboot_notifier(&drbd_notifier);

	/*
	 * allocate all necessary structs
	 */
	err = -ENOMEM;

	init_waitqueue_head(&drbd_pp_wait);

	drbd_proc = NULL; /* play safe for drbd_cleanup */
2701
	idr_init(&minors);
P
Philipp Reisner 已提交
2702 2703 2704

	err = drbd_create_mempools();
	if (err)
2705
		goto fail;
P
Philipp Reisner 已提交
2706

2707
	drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
P
Philipp Reisner 已提交
2708 2709
	if (!drbd_proc)	{
		printk(KERN_ERR "drbd: unable to register proc file\n");
2710
		goto fail;
P
Philipp Reisner 已提交
2711 2712 2713
	}

	rwlock_init(&global_state_lock);
2714
	INIT_LIST_HEAD(&drbd_tconns);
P
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2715 2716 2717 2718 2719 2720 2721 2722 2723 2724

	printk(KERN_INFO "drbd: initialized. "
	       "Version: " REL_VERSION " (api:%d/proto:%d-%d)\n",
	       API_VERSION, PRO_VERSION_MIN, PRO_VERSION_MAX);
	printk(KERN_INFO "drbd: %s\n", drbd_buildtag());
	printk(KERN_INFO "drbd: registered as block device major %d\n",
		DRBD_MAJOR);

	return 0; /* Success! */

2725
fail:
P
Philipp Reisner 已提交
2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739
	drbd_cleanup();
	if (err == -ENOMEM)
		/* currently always the case */
		printk(KERN_ERR "drbd: ran out of memory\n");
	else
		printk(KERN_ERR "drbd: initialization failure\n");
	return err;
}

void drbd_free_bc(struct drbd_backing_dev *ldev)
{
	if (ldev == NULL)
		return;

2740 2741
	blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
	blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
P
Philipp Reisner 已提交
2742 2743 2744 2745

	kfree(ldev);
}

2746 2747 2748 2749 2750 2751 2752 2753
void drbd_free_sock(struct drbd_tconn *tconn)
{
	if (tconn->data.socket) {
		mutex_lock(&tconn->data.mutex);
		kernel_sock_shutdown(tconn->data.socket, SHUT_RDWR);
		sock_release(tconn->data.socket);
		tconn->data.socket = NULL;
		mutex_unlock(&tconn->data.mutex);
P
Philipp Reisner 已提交
2754
	}
2755 2756 2757 2758 2759 2760
	if (tconn->meta.socket) {
		mutex_lock(&tconn->meta.mutex);
		kernel_sock_shutdown(tconn->meta.socket, SHUT_RDWR);
		sock_release(tconn->meta.socket);
		tconn->meta.socket = NULL;
		mutex_unlock(&tconn->meta.mutex);
P
Philipp Reisner 已提交
2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775
	}
}

/* meta data management */

struct meta_data_on_disk {
	u64 la_size;           /* last agreed size. */
	u64 uuid[UI_SIZE];   /* UUIDs. */
	u64 device_uuid;
	u64 reserved_u64_1;
	u32 flags;             /* MDF */
	u32 magic;
	u32 md_size_sect;
	u32 al_offset;         /* offset to this block */
	u32 al_nr_extents;     /* important for restoring the AL */
2776
	      /* `-- act_log->nr_elements <-- ldev->dc.al_extents */
P
Philipp Reisner 已提交
2777 2778
	u32 bm_offset;         /* offset to the bitmap, from here */
	u32 bm_bytes_per_bit;  /* BM_BLOCK_SIZE */
2779 2780
	u32 la_peer_max_bio_size;   /* last peer max_bio_size */
	u32 reserved_u32[3];
P
Philipp Reisner 已提交
2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793

} __packed;

/**
 * drbd_md_sync() - Writes the meta data super block if the MD_DIRTY flag bit is set
 * @mdev:	DRBD device.
 */
void drbd_md_sync(struct drbd_conf *mdev)
{
	struct meta_data_on_disk *buffer;
	sector_t sector;
	int i;

2794 2795
	del_timer(&mdev->md_sync_timer);
	/* timer may be rearmed by drbd_md_mark_dirty() now. */
P
Philipp Reisner 已提交
2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820
	if (!test_and_clear_bit(MD_DIRTY, &mdev->flags))
		return;

	/* We use here D_FAILED and not D_ATTACHING because we try to write
	 * metadata even if we detach due to a disk failure! */
	if (!get_ldev_if_state(mdev, D_FAILED))
		return;

	mutex_lock(&mdev->md_io_mutex);
	buffer = (struct meta_data_on_disk *)page_address(mdev->md_io_page);
	memset(buffer, 0, 512);

	buffer->la_size = cpu_to_be64(drbd_get_capacity(mdev->this_bdev));
	for (i = UI_CURRENT; i < UI_SIZE; i++)
		buffer->uuid[i] = cpu_to_be64(mdev->ldev->md.uuid[i]);
	buffer->flags = cpu_to_be32(mdev->ldev->md.flags);
	buffer->magic = cpu_to_be32(DRBD_MD_MAGIC);

	buffer->md_size_sect  = cpu_to_be32(mdev->ldev->md.md_size_sect);
	buffer->al_offset     = cpu_to_be32(mdev->ldev->md.al_offset);
	buffer->al_nr_extents = cpu_to_be32(mdev->act_log->nr_elements);
	buffer->bm_bytes_per_bit = cpu_to_be32(BM_BLOCK_SIZE);
	buffer->device_uuid = cpu_to_be64(mdev->ldev->md.device_uuid);

	buffer->bm_offset = cpu_to_be32(mdev->ldev->md.bm_offset);
2821
	buffer->la_peer_max_bio_size = cpu_to_be32(mdev->peer_max_bio_size);
P
Philipp Reisner 已提交
2822 2823 2824 2825

	D_ASSERT(drbd_md_ss__(mdev, mdev->ldev) == mdev->ldev->md.md_offset);
	sector = mdev->ldev->md.md_offset;

2826
	if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
P
Philipp Reisner 已提交
2827 2828
		/* this was a try anyways ... */
		dev_err(DEV, "meta data update failed!\n");
2829
		drbd_chk_io_error(mdev, 1, true);
P
Philipp Reisner 已提交
2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844
	}

	/* Update mdev->ldev->md.la_size_sect,
	 * since we updated it on metadata. */
	mdev->ldev->md.la_size_sect = drbd_get_capacity(mdev->this_bdev);

	mutex_unlock(&mdev->md_io_mutex);
	put_ldev(mdev);
}

/**
 * drbd_md_read() - Reads in the meta data super block
 * @mdev:	DRBD device.
 * @bdev:	Device from which the meta data should be read in.
 *
2845
 * Return 0 (NO_ERROR) on success, and an enum drbd_ret_code in case
P
Philipp Reisner 已提交
2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858
 * something goes wrong.  Currently only: ERR_IO_MD_DISK, ERR_MD_INVALID.
 */
int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
{
	struct meta_data_on_disk *buffer;
	int i, rv = NO_ERROR;

	if (!get_ldev_if_state(mdev, D_ATTACHING))
		return ERR_IO_MD_DISK;

	mutex_lock(&mdev->md_io_mutex);
	buffer = (struct meta_data_on_disk *)page_address(mdev->md_io_page);

2859
	if (drbd_md_sync_page_io(mdev, bdev, bdev->md.md_offset, READ)) {
L
Lucas De Marchi 已提交
2860
		/* NOTE: can't do normal error processing here as this is
P
Philipp Reisner 已提交
2861 2862 2863 2864 2865 2866
		   called BEFORE disk is attached */
		dev_err(DEV, "Error while reading metadata.\n");
		rv = ERR_IO_MD_DISK;
		goto err;
	}

2867
	if (buffer->magic != cpu_to_be32(DRBD_MD_MAGIC)) {
P
Philipp Reisner 已提交
2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903
		dev_err(DEV, "Error while reading metadata, magic not found.\n");
		rv = ERR_MD_INVALID;
		goto err;
	}
	if (be32_to_cpu(buffer->al_offset) != bdev->md.al_offset) {
		dev_err(DEV, "unexpected al_offset: %d (expected %d)\n",
		    be32_to_cpu(buffer->al_offset), bdev->md.al_offset);
		rv = ERR_MD_INVALID;
		goto err;
	}
	if (be32_to_cpu(buffer->bm_offset) != bdev->md.bm_offset) {
		dev_err(DEV, "unexpected bm_offset: %d (expected %d)\n",
		    be32_to_cpu(buffer->bm_offset), bdev->md.bm_offset);
		rv = ERR_MD_INVALID;
		goto err;
	}
	if (be32_to_cpu(buffer->md_size_sect) != bdev->md.md_size_sect) {
		dev_err(DEV, "unexpected md_size: %u (expected %u)\n",
		    be32_to_cpu(buffer->md_size_sect), bdev->md.md_size_sect);
		rv = ERR_MD_INVALID;
		goto err;
	}

	if (be32_to_cpu(buffer->bm_bytes_per_bit) != BM_BLOCK_SIZE) {
		dev_err(DEV, "unexpected bm_bytes_per_bit: %u (expected %u)\n",
		    be32_to_cpu(buffer->bm_bytes_per_bit), BM_BLOCK_SIZE);
		rv = ERR_MD_INVALID;
		goto err;
	}

	bdev->md.la_size_sect = be64_to_cpu(buffer->la_size);
	for (i = UI_CURRENT; i < UI_SIZE; i++)
		bdev->md.uuid[i] = be64_to_cpu(buffer->uuid[i]);
	bdev->md.flags = be32_to_cpu(buffer->flags);
	bdev->md.device_uuid = be64_to_cpu(buffer->device_uuid);

2904
	spin_lock_irq(&mdev->tconn->req_lock);
2905 2906 2907 2908 2909 2910
	if (mdev->state.conn < C_CONNECTED) {
		int peer;
		peer = be32_to_cpu(buffer->la_peer_max_bio_size);
		peer = max_t(int, peer, DRBD_MAX_BIO_SIZE_SAFE);
		mdev->peer_max_bio_size = peer;
	}
2911
	spin_unlock_irq(&mdev->tconn->req_lock);
2912

P
Philipp Reisner 已提交
2913 2914 2915 2916
	/* This blocks wants to be get removed... */
	bdev->disk_conf->al_extents = be32_to_cpu(buffer->al_nr_extents);
	if (bdev->disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
		bdev->disk_conf->al_extents = DRBD_AL_EXTENTS_DEF;
P
Philipp Reisner 已提交
2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932

 err:
	mutex_unlock(&mdev->md_io_mutex);
	put_ldev(mdev);

	return rv;
}

/**
 * drbd_md_mark_dirty() - Mark meta data super block as dirty
 * @mdev:	DRBD device.
 *
 * Call this function if you change anything that should be written to
 * the meta-data super block. This function sets MD_DIRTY, and starts a
 * timer that ensures that within five seconds you have to call drbd_md_sync().
 */
2933
#ifdef DEBUG
2934 2935 2936 2937 2938 2939 2940 2941 2942
void drbd_md_mark_dirty_(struct drbd_conf *mdev, unsigned int line, const char *func)
{
	if (!test_and_set_bit(MD_DIRTY, &mdev->flags)) {
		mod_timer(&mdev->md_sync_timer, jiffies + HZ);
		mdev->last_md_mark_dirty.line = line;
		mdev->last_md_mark_dirty.func = func;
	}
}
#else
P
Philipp Reisner 已提交
2943 2944
void drbd_md_mark_dirty(struct drbd_conf *mdev)
{
2945
	if (!test_and_set_bit(MD_DIRTY, &mdev->flags))
2946
		mod_timer(&mdev->md_sync_timer, jiffies + 5*HZ);
P
Philipp Reisner 已提交
2947
}
2948
#endif
P
Philipp Reisner 已提交
2949 2950 2951 2952 2953

static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
{
	int i;

2954
	for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
P
Philipp Reisner 已提交
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 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992
		mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i];
}

void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
	if (idx == UI_CURRENT) {
		if (mdev->state.role == R_PRIMARY)
			val |= 1;
		else
			val &= ~((u64)1);

		drbd_set_ed_uuid(mdev, val);
	}

	mdev->ldev->md.uuid[idx] = val;
	drbd_md_mark_dirty(mdev);
}


void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
	if (mdev->ldev->md.uuid[idx]) {
		drbd_uuid_move_history(mdev);
		mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx];
	}
	_drbd_uuid_set(mdev, idx, val);
}

/**
 * drbd_uuid_new_current() - Creates a new current UUID
 * @mdev:	DRBD device.
 *
 * Creates a new current UUID, and rotates the old current UUID into
 * the bitmap slot. Causes an incremental resync upon next connect.
 */
void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local)
{
	u64 val;
2993 2994 2995 2996
	unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];

	if (bm_uuid)
		dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);
P
Philipp Reisner 已提交
2997 2998 2999 3000 3001

	mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT];

	get_random_bytes(&val, sizeof(u64));
	_drbd_uuid_set(mdev, UI_CURRENT, val);
3002
	drbd_print_uuids(mdev, "new current UUID");
3003 3004
	/* get it to stable storage _now_ */
	drbd_md_sync(mdev);
P
Philipp Reisner 已提交
3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016
}

void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)
{
	if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
		return;

	if (val == 0) {
		drbd_uuid_move_history(mdev);
		mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];
		mdev->ldev->md.uuid[UI_BITMAP] = 0;
	} else {
3017 3018 3019
		unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];
		if (bm_uuid)
			dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);
P
Philipp Reisner 已提交
3020

3021
		mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
P
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3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063
	}
	drbd_md_mark_dirty(mdev);
}

/**
 * drbd_bmio_set_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
 * @mdev:	DRBD device.
 *
 * Sets all bits in the bitmap and writes the whole bitmap to stable storage.
 */
int drbd_bmio_set_n_write(struct drbd_conf *mdev)
{
	int rv = -EIO;

	if (get_ldev_if_state(mdev, D_ATTACHING)) {
		drbd_md_set_flag(mdev, MDF_FULL_SYNC);
		drbd_md_sync(mdev);
		drbd_bm_set_all(mdev);

		rv = drbd_bm_write(mdev);

		if (!rv) {
			drbd_md_clear_flag(mdev, MDF_FULL_SYNC);
			drbd_md_sync(mdev);
		}

		put_ldev(mdev);
	}

	return rv;
}

/**
 * drbd_bmio_clear_n_write() - io_fn for drbd_queue_bitmap_io() or drbd_bitmap_io()
 * @mdev:	DRBD device.
 *
 * Clears all bits in the bitmap and writes the whole bitmap to stable storage.
 */
int drbd_bmio_clear_n_write(struct drbd_conf *mdev)
{
	int rv = -EIO;

3064
	drbd_resume_al(mdev);
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Philipp Reisner 已提交
3065 3066 3067 3068 3069 3070 3071 3072 3073
	if (get_ldev_if_state(mdev, D_ATTACHING)) {
		drbd_bm_clear_all(mdev);
		rv = drbd_bm_write(mdev);
		put_ldev(mdev);
	}

	return rv;
}

3074
static int w_bitmap_io(struct drbd_work *w, int unused)
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3075 3076
{
	struct bm_io_work *work = container_of(w, struct bm_io_work, w);
3077
	struct drbd_conf *mdev = w->mdev;
3078
	int rv = -EIO;
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3079 3080 3081

	D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0);

3082
	if (get_ldev(mdev)) {
3083
		drbd_bm_lock(mdev, work->why, work->flags);
3084 3085 3086 3087
		rv = work->io_fn(mdev);
		drbd_bm_unlock(mdev);
		put_ldev(mdev);
	}
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3088

3089
	clear_bit_unlock(BITMAP_IO, &mdev->flags);
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3090 3091 3092 3093 3094 3095 3096
	wake_up(&mdev->misc_wait);

	if (work->done)
		work->done(mdev, rv);

	clear_bit(BITMAP_IO_QUEUED, &mdev->flags);
	work->why = NULL;
3097
	work->flags = 0;
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3098

3099
	return 0;
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}

3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114
void drbd_ldev_destroy(struct drbd_conf *mdev)
{
	lc_destroy(mdev->resync);
	mdev->resync = NULL;
	lc_destroy(mdev->act_log);
	mdev->act_log = NULL;
	__no_warn(local,
		drbd_free_bc(mdev->ldev);
		mdev->ldev = NULL;);

	clear_bit(GO_DISKLESS, &mdev->flags);
}

3115
static int w_go_diskless(struct drbd_work *w, int unused)
3116
{
3117 3118
	struct drbd_conf *mdev = w->mdev;

3119
	D_ASSERT(mdev->state.disk == D_FAILED);
3120 3121
	/* we cannot assert local_cnt == 0 here, as get_ldev_if_state will
	 * inc/dec it frequently. Once we are D_DISKLESS, no one will touch
3122 3123
	 * the protected members anymore, though, so once put_ldev reaches zero
	 * again, it will be safe to free them. */
3124
	drbd_force_state(mdev, NS(disk, D_DISKLESS));
3125
	return 0;
3126 3127 3128 3129 3130 3131
}

void drbd_go_diskless(struct drbd_conf *mdev)
{
	D_ASSERT(mdev->state.disk == D_FAILED);
	if (!test_and_set_bit(GO_DISKLESS, &mdev->flags))
3132
		drbd_queue_work(&mdev->tconn->data.work, &mdev->go_diskless);
3133 3134
}

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/**
 * drbd_queue_bitmap_io() - Queues an IO operation on the whole bitmap
 * @mdev:	DRBD device.
 * @io_fn:	IO callback to be called when bitmap IO is possible
 * @done:	callback to be called after the bitmap IO was performed
 * @why:	Descriptive text of the reason for doing the IO
 *
 * While IO on the bitmap happens we freeze application IO thus we ensure
 * that drbd_set_out_of_sync() can not be called. This function MAY ONLY be
 * called from worker context. It MUST NOT be used while a previous such
 * work is still pending!
 */
void drbd_queue_bitmap_io(struct drbd_conf *mdev,
			  int (*io_fn)(struct drbd_conf *),
			  void (*done)(struct drbd_conf *, int),
3150
			  char *why, enum bm_flag flags)
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{
3152
	D_ASSERT(current == mdev->tconn->worker.task);
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	D_ASSERT(!test_bit(BITMAP_IO_QUEUED, &mdev->flags));
	D_ASSERT(!test_bit(BITMAP_IO, &mdev->flags));
	D_ASSERT(list_empty(&mdev->bm_io_work.w.list));
	if (mdev->bm_io_work.why)
		dev_err(DEV, "FIXME going to queue '%s' but '%s' still pending?\n",
			why, mdev->bm_io_work.why);

	mdev->bm_io_work.io_fn = io_fn;
	mdev->bm_io_work.done = done;
	mdev->bm_io_work.why = why;
3164
	mdev->bm_io_work.flags = flags;
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3165

3166
	spin_lock_irq(&mdev->tconn->req_lock);
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3167 3168
	set_bit(BITMAP_IO, &mdev->flags);
	if (atomic_read(&mdev->ap_bio_cnt) == 0) {
3169
		if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags))
3170
			drbd_queue_work(&mdev->tconn->data.work, &mdev->bm_io_work.w);
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3171
	}
3172
	spin_unlock_irq(&mdev->tconn->req_lock);
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}

/**
 * drbd_bitmap_io() -  Does an IO operation on the whole bitmap
 * @mdev:	DRBD device.
 * @io_fn:	IO callback to be called when bitmap IO is possible
 * @why:	Descriptive text of the reason for doing the IO
 *
 * freezes application IO while that the actual IO operations runs. This
 * functions MAY NOT be called from worker context.
 */
3184 3185
int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *),
		char *why, enum bm_flag flags)
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3186 3187 3188
{
	int rv;

3189
	D_ASSERT(current != mdev->tconn->worker.task);
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3190

3191 3192
	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
		drbd_suspend_io(mdev);
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3193

3194
	drbd_bm_lock(mdev, why, flags);
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3195 3196 3197
	rv = io_fn(mdev);
	drbd_bm_unlock(mdev);

3198 3199
	if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
		drbd_resume_io(mdev);
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3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227

	return rv;
}

void drbd_md_set_flag(struct drbd_conf *mdev, int flag) __must_hold(local)
{
	if ((mdev->ldev->md.flags & flag) != flag) {
		drbd_md_mark_dirty(mdev);
		mdev->ldev->md.flags |= flag;
	}
}

void drbd_md_clear_flag(struct drbd_conf *mdev, int flag) __must_hold(local)
{
	if ((mdev->ldev->md.flags & flag) != 0) {
		drbd_md_mark_dirty(mdev);
		mdev->ldev->md.flags &= ~flag;
	}
}
int drbd_md_test_flag(struct drbd_backing_dev *bdev, int flag)
{
	return (bdev->md.flags & flag) != 0;
}

static void md_sync_timer_fn(unsigned long data)
{
	struct drbd_conf *mdev = (struct drbd_conf *) data;

3228
	drbd_queue_work_front(&mdev->tconn->data.work, &mdev->md_sync_work);
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3229 3230
}

3231
static int w_md_sync(struct drbd_work *w, int unused)
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3232
{
3233 3234
	struct drbd_conf *mdev = w->mdev;

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3235
	dev_warn(DEV, "md_sync_timer expired! Worker calls drbd_md_sync().\n");
3236 3237 3238 3239
#ifdef DEBUG
	dev_warn(DEV, "last md_mark_dirty: %s:%u\n",
		mdev->last_md_mark_dirty.func, mdev->last_md_mark_dirty.line);
#endif
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3240
	drbd_md_sync(mdev);
3241
	return 0;
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}

3244
const char *cmdname(enum drbd_packet cmd)
3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273
{
	/* THINK may need to become several global tables
	 * when we want to support more than
	 * one PRO_VERSION */
	static const char *cmdnames[] = {
		[P_DATA]	        = "Data",
		[P_DATA_REPLY]	        = "DataReply",
		[P_RS_DATA_REPLY]	= "RSDataReply",
		[P_BARRIER]	        = "Barrier",
		[P_BITMAP]	        = "ReportBitMap",
		[P_BECOME_SYNC_TARGET]  = "BecomeSyncTarget",
		[P_BECOME_SYNC_SOURCE]  = "BecomeSyncSource",
		[P_UNPLUG_REMOTE]	= "UnplugRemote",
		[P_DATA_REQUEST]	= "DataRequest",
		[P_RS_DATA_REQUEST]     = "RSDataRequest",
		[P_SYNC_PARAM]	        = "SyncParam",
		[P_SYNC_PARAM89]	= "SyncParam89",
		[P_PROTOCOL]            = "ReportProtocol",
		[P_UUIDS]	        = "ReportUUIDs",
		[P_SIZES]	        = "ReportSizes",
		[P_STATE]	        = "ReportState",
		[P_SYNC_UUID]           = "ReportSyncUUID",
		[P_AUTH_CHALLENGE]      = "AuthChallenge",
		[P_AUTH_RESPONSE]	= "AuthResponse",
		[P_PING]		= "Ping",
		[P_PING_ACK]	        = "PingAck",
		[P_RECV_ACK]	        = "RecvAck",
		[P_WRITE_ACK]	        = "WriteAck",
		[P_RS_WRITE_ACK]	= "RSWriteAck",
3274
		[P_DISCARD_WRITE]        = "DiscardWrite",
3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288
		[P_NEG_ACK]	        = "NegAck",
		[P_NEG_DREPLY]	        = "NegDReply",
		[P_NEG_RS_DREPLY]	= "NegRSDReply",
		[P_BARRIER_ACK]	        = "BarrierAck",
		[P_STATE_CHG_REQ]       = "StateChgRequest",
		[P_STATE_CHG_REPLY]     = "StateChgReply",
		[P_OV_REQUEST]          = "OVRequest",
		[P_OV_REPLY]            = "OVReply",
		[P_OV_RESULT]           = "OVResult",
		[P_CSUM_RS_REQUEST]     = "CsumRSRequest",
		[P_RS_IS_IN_SYNC]	= "CsumRSIsInSync",
		[P_COMPRESSED_BITMAP]   = "CBitmap",
		[P_DELAY_PROBE]         = "DelayProbe",
		[P_OUT_OF_SYNC]		= "OutOfSync",
3289
		[P_RETRY_WRITE]		= "RetryWrite",
3290 3291 3292 3293 3294 3295 3296 3297
		[P_RS_CANCEL]		= "RSCancel",
		[P_CONN_ST_CHG_REQ]	= "conn_st_chg_req",
		[P_CONN_ST_CHG_REPLY]	= "conn_st_chg_reply",

		/* enum drbd_packet, but not commands - obsoleted flags:
		 *	P_MAY_IGNORE
		 *	P_MAX_OPT_CMD
		 */
3298 3299
	};

3300
	/* too big for the array: 0xfffX */
3301 3302 3303 3304
	if (cmd == P_INITIAL_META)
		return "InitialMeta";
	if (cmd == P_INITIAL_DATA)
		return "InitialData";
3305 3306
	if (cmd == P_CONNECTION_FEATURES)
		return "ConnectionFeatures";
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Andreas Gruenbacher 已提交
3307
	if (cmd >= ARRAY_SIZE(cmdnames))
3308 3309 3310 3311
		return "Unknown";
	return cmdnames[cmd];
}

3312 3313 3314 3315 3316 3317 3318 3319
/**
 * drbd_wait_misc  -  wait for a request to make progress
 * @mdev:	device associated with the request
 * @i:		the struct drbd_interval embedded in struct drbd_request or
 *		struct drbd_peer_request
 */
int drbd_wait_misc(struct drbd_conf *mdev, struct drbd_interval *i)
{
3320
	struct net_conf *nc;
3321 3322 3323
	DEFINE_WAIT(wait);
	long timeout;

3324 3325 3326 3327
	rcu_read_lock();
	nc = rcu_dereference(mdev->tconn->net_conf);
	if (!nc) {
		rcu_read_unlock();
3328
		return -ETIMEDOUT;
3329 3330 3331
	}
	timeout = nc->ko_count ? nc->timeout * HZ / 10 * nc->ko_count : MAX_SCHEDULE_TIMEOUT;
	rcu_read_unlock();
3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346

	/* Indicate to wake up mdev->misc_wait on progress.  */
	i->waiting = true;
	prepare_to_wait(&mdev->misc_wait, &wait, TASK_INTERRUPTIBLE);
	spin_unlock_irq(&mdev->tconn->req_lock);
	timeout = schedule_timeout(timeout);
	finish_wait(&mdev->misc_wait, &wait);
	spin_lock_irq(&mdev->tconn->req_lock);
	if (!timeout || mdev->state.conn < C_CONNECTED)
		return -ETIMEDOUT;
	if (signal_pending(current))
		return -ERESTARTSYS;
	return 0;
}

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3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367
#ifdef CONFIG_DRBD_FAULT_INJECTION
/* Fault insertion support including random number generator shamelessly
 * stolen from kernel/rcutorture.c */
struct fault_random_state {
	unsigned long state;
	unsigned long count;
};

#define FAULT_RANDOM_MULT 39916801  /* prime */
#define FAULT_RANDOM_ADD	479001701 /* prime */
#define FAULT_RANDOM_REFRESH 10000

/*
 * Crude but fast random-number generator.  Uses a linear congruential
 * generator, with occasional help from get_random_bytes().
 */
static unsigned long
_drbd_fault_random(struct fault_random_state *rsp)
{
	long refresh;

3368
	if (!rsp->count--) {
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Philipp Reisner 已提交
3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387
		get_random_bytes(&refresh, sizeof(refresh));
		rsp->state += refresh;
		rsp->count = FAULT_RANDOM_REFRESH;
	}
	rsp->state = rsp->state * FAULT_RANDOM_MULT + FAULT_RANDOM_ADD;
	return swahw32(rsp->state);
}

static char *
_drbd_fault_str(unsigned int type) {
	static char *_faults[] = {
		[DRBD_FAULT_MD_WR] = "Meta-data write",
		[DRBD_FAULT_MD_RD] = "Meta-data read",
		[DRBD_FAULT_RS_WR] = "Resync write",
		[DRBD_FAULT_RS_RD] = "Resync read",
		[DRBD_FAULT_DT_WR] = "Data write",
		[DRBD_FAULT_DT_RD] = "Data read",
		[DRBD_FAULT_DT_RA] = "Data read ahead",
		[DRBD_FAULT_BM_ALLOC] = "BM allocation",
3388 3389
		[DRBD_FAULT_AL_EE] = "EE allocation",
		[DRBD_FAULT_RECEIVE] = "receive data corruption",
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Philipp Reisner 已提交
3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407
	};

	return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**";
}

unsigned int
_drbd_insert_fault(struct drbd_conf *mdev, unsigned int type)
{
	static struct fault_random_state rrs = {0, 0};

	unsigned int ret = (
		(fault_devs == 0 ||
			((1 << mdev_to_minor(mdev)) & fault_devs) != 0) &&
		(((_drbd_fault_random(&rrs) % 100) + 1) <= fault_rate));

	if (ret) {
		fault_count++;

3408
		if (__ratelimit(&drbd_ratelimit_state))
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3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442
			dev_warn(DEV, "***Simulating %s failure\n",
				_drbd_fault_str(type));
	}

	return ret;
}
#endif

const char *drbd_buildtag(void)
{
	/* DRBD built from external sources has here a reference to the
	   git hash of the source code. */

	static char buildtag[38] = "\0uilt-in";

	if (buildtag[0] == 0) {
#ifdef CONFIG_MODULES
		if (THIS_MODULE != NULL)
			sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
		else
#endif
			buildtag[0] = 'b';
	}

	return buildtag;
}

module_init(drbd_init)
module_exit(drbd_cleanup)

EXPORT_SYMBOL(drbd_conn_str);
EXPORT_SYMBOL(drbd_role_str);
EXPORT_SYMBOL(drbd_disk_str);
EXPORT_SYMBOL(drbd_set_st_err_str);