/*
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>
#include <linux/mutex.h>
#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>
#include <linux/workqueue.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"
static DEFINE_MUTEX(drbd_main_mutex);
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 void drbd_release(struct gendisk *gd, fmode_t mode);
static int w_md_sync(struct drbd_work *w, int unused);
static void md_sync_timer_fn(unsigned long data);
static int w_bitmap_io(struct drbd_work *w, int unused);
static int w_go_diskless(struct drbd_work *w, int unused);
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");
MODULE_PARM_DESC(minor_count, "Approximate number of drbd devices ("
__stringify(DRBD_MINOR_COUNT_MIN) "-" __stringify(DRBD_MINOR_COUNT_MAX) ")");
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 */
unsigned int minor_count = DRBD_MINOR_COUNT_DEF;
bool disable_sendpage;
bool 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;"
*/
struct idr minors;
struct list_head drbd_tconns; /* list of struct drbd_tconn */
struct kmem_cache *drbd_request_cache;
struct kmem_cache *drbd_ee_cache; /* peer requests */
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;
mempool_t *drbd_md_io_page_pool;
struct bio_set *drbd_md_io_bio_set;
/* 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);
static const struct block_device_operations drbd_ops = {
.owner = THIS_MODULE,
.open = drbd_open,
.release = drbd_release,
};
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;
return bio;
}
#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
/**
* tl_release() - mark as BARRIER_ACKED all requests in the corresponding transfer log epoch
* @tconn: DRBD connection.
* @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
* epoch of not yet barrier-acked requests, this function will cause a
* termination of the connection.
*/
void tl_release(struct drbd_tconn *tconn, unsigned int barrier_nr,
unsigned int set_size)
{
struct drbd_request *r;
struct drbd_request *req = NULL;
int expect_epoch = 0;
int expect_size = 0;
spin_lock_irq(&tconn->req_lock);
/* find oldest not yet barrier-acked write request,
* count writes in its epoch. */
list_for_each_entry(r, &tconn->transfer_log, tl_requests) {
const unsigned s = r->rq_state;
if (!req) {
if (!(s & RQ_WRITE))
continue;
if (!(s & RQ_NET_MASK))
continue;
if (s & RQ_NET_DONE)
continue;
req = r;
expect_epoch = req->epoch;
expect_size ++;
} else {
if (r->epoch != expect_epoch)
break;
if (!(s & RQ_WRITE))
continue;
/* if (s & RQ_DONE): not expected */
/* if (!(s & RQ_NET_MASK)): not expected */
expect_size++;
}
}
/* first some paranoia code */
if (req == NULL) {
conn_err(tconn, "BAD! BarrierAck #%u received, but no epoch in tl!?\n",
barrier_nr);
goto bail;
}
if (expect_epoch != barrier_nr) {
conn_err(tconn, "BAD! BarrierAck #%u received, expected #%u!\n",
barrier_nr, expect_epoch);
goto bail;
}
if (expect_size != set_size) {
conn_err(tconn, "BAD! BarrierAck #%u received with n_writes=%u, expected n_writes=%u!\n",
barrier_nr, set_size, expect_size);
goto bail;
}
/* Clean up list of requests processed during current epoch. */
/* this extra list walk restart is paranoia,
* to catch requests being barrier-acked "unexpectedly".
* It usually should find the same req again, or some READ preceding it. */
list_for_each_entry(req, &tconn->transfer_log, tl_requests)
if (req->epoch == expect_epoch)
break;
list_for_each_entry_safe_from(req, r, &tconn->transfer_log, tl_requests) {
if (req->epoch != expect_epoch)
break;
_req_mod(req, BARRIER_ACKED);
}
spin_unlock_irq(&tconn->req_lock);
return;
bail:
spin_unlock_irq(&tconn->req_lock);
conn_request_state(tconn, NS(conn, C_PROTOCOL_ERROR), CS_HARD);
}
/**
* _tl_restart() - Walks the transfer log, and applies an action to all requests
* @mdev: DRBD device.
* @what: The action/event to perform with all request objects
*
* @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
* RESTART_FROZEN_DISK_IO.
*/
/* must hold resource->req_lock */
void _tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
{
struct drbd_request *req, *r;
list_for_each_entry_safe(req, r, &tconn->transfer_log, tl_requests)
_req_mod(req, what);
}
void tl_restart(struct drbd_tconn *tconn, enum drbd_req_event what)
{
spin_lock_irq(&tconn->req_lock);
_tl_restart(tconn, what);
spin_unlock_irq(&tconn->req_lock);
}
/**
* 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.
*/
void tl_clear(struct drbd_tconn *tconn)
{
tl_restart(tconn, CONNECTION_LOST_WHILE_PENDING);
}
/**
* tl_abort_disk_io() - Abort disk I/O for all requests for a certain mdev in the TL
* @mdev: DRBD device.
*/
void tl_abort_disk_io(struct drbd_conf *mdev)
{
struct drbd_tconn *tconn = mdev->tconn;
struct drbd_request *req, *r;
spin_lock_irq(&tconn->req_lock);
list_for_each_entry_safe(req, r, &tconn->transfer_log, tl_requests) {
if (!(req->rq_state & RQ_LOCAL_PENDING))
continue;
if (req->w.mdev != mdev)
continue;
_req_mod(req, ABORT_DISK_IO);
}
spin_unlock_irq(&tconn->req_lock);
}
static int drbd_thread_setup(void *arg)
{
struct drbd_thread *thi = (struct drbd_thread *) arg;
struct drbd_tconn *tconn = thi->tconn;
unsigned long flags;
int retval;
snprintf(current->comm, sizeof(current->comm), "drbd_%c_%s",
thi->name[0], thi->tconn->name);
restart:
retval = thi->function(thi);
spin_lock_irqsave(&thi->t_lock, flags);
/* if the receiver has been "EXITING", the last thing it did
* 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".
* drbd_thread_start needs to set "RESTARTING" in that case.
* t_state check and assignment needs to be within the same spinlock,
* so either thread_start sees EXITING, and can remap to RESTARTING,
* or thread_start see NONE, and can proceed as normal.
*/
if (thi->t_state == RESTARTING) {
conn_info(tconn, "Restarting %s thread\n", thi->name);
thi->t_state = RUNNING;
spin_unlock_irqrestore(&thi->t_lock, flags);
goto restart;
}
thi->task = NULL;
thi->t_state = NONE;
smp_mb();
complete_all(&thi->stop);
spin_unlock_irqrestore(&thi->t_lock, flags);
conn_info(tconn, "Terminating %s\n", current->comm);
/* Release mod reference taken when thread was started */
kref_put(&tconn->kref, &conn_destroy);
module_put(THIS_MODULE);
return retval;
}
static void drbd_thread_init(struct drbd_tconn *tconn, struct drbd_thread *thi,
int (*func) (struct drbd_thread *), char *name)
{
spin_lock_init(&thi->t_lock);
thi->task = NULL;
thi->t_state = NONE;
thi->function = func;
thi->tconn = tconn;
strncpy(thi->name, name, ARRAY_SIZE(thi->name));
}
int drbd_thread_start(struct drbd_thread *thi)
{
struct drbd_tconn *tconn = thi->tconn;
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) {
case NONE:
conn_info(tconn, "Starting %s thread (from %s [%d])\n",
thi->name, current->comm, current->pid);
/* Get ref on module for thread - this is released when thread exits */
if (!try_module_get(THIS_MODULE)) {
conn_err(tconn, "Failed to get module reference in drbd_thread_start\n");
spin_unlock_irqrestore(&thi->t_lock, flags);
return false;
}
kref_get(&thi->tconn->kref);
init_completion(&thi->stop);
thi->reset_cpu_mask = 1;
thi->t_state = RUNNING;
spin_unlock_irqrestore(&thi->t_lock, flags);
flush_signals(current); /* otherw. may get -ERESTARTNOINTR */
nt = kthread_create(drbd_thread_setup, (void *) thi,
"drbd_%c_%s", thi->name[0], thi->tconn->name);
if (IS_ERR(nt)) {
conn_err(tconn, "Couldn't start thread\n");
kref_put(&tconn->kref, &conn_destroy);
module_put(THIS_MODULE);
return false;
}
spin_lock_irqsave(&thi->t_lock, flags);
thi->task = nt;
thi->t_state = RUNNING;
spin_unlock_irqrestore(&thi->t_lock, flags);
wake_up_process(nt);
break;
case EXITING:
thi->t_state = RESTARTING;
conn_info(tconn, "Restarting %s thread (from %s [%d])\n",
thi->name, current->comm, current->pid);
/* fall through */
case RUNNING:
case RESTARTING:
default:
spin_unlock_irqrestore(&thi->t_lock, flags);
break;
}
return true;
}
void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
{
unsigned long flags;
enum drbd_thread_state ns = restart ? RESTARTING : EXITING;
/* may be called from state engine, holding the req lock irqsave */
spin_lock_irqsave(&thi->t_lock, flags);
if (thi->t_state == NONE) {
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);
}
static struct drbd_thread *drbd_task_to_thread(struct drbd_tconn *tconn, struct task_struct *task)
{
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;
}
char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *task)
{
struct drbd_thread *thi = drbd_task_to_thread(tconn, task);
return thi ? thi->name : task->comm;
}
int conn_lowest_minor(struct drbd_tconn *tconn)
{
struct drbd_conf *mdev;
int vnr = 0, m;
rcu_read_lock();
mdev = idr_get_next(&tconn->volumes, &vnr);
m = mdev ? mdev_to_minor(mdev) : -1;
rcu_read_unlock();
return m;
}
#ifdef CONFIG_SMP
/**
* 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.
*/
void drbd_calc_cpu_mask(struct drbd_tconn *tconn)
{
int ord, cpu;
/* user override. */
if (cpumask_weight(tconn->cpu_mask))
return;
ord = conn_lowest_minor(tconn) % cpumask_weight(cpu_online_mask);
for_each_online_cpu(cpu) {
if (ord-- == 0) {
cpumask_set_cpu(cpu, tconn->cpu_mask);
return;
}
}
/* should not be reached */
cpumask_setall(tconn->cpu_mask);
}
/**
* drbd_thread_current_set_cpu() - modifies the cpu mask of the _current_ thread
* @mdev: DRBD device.
* @thi: drbd_thread object
*
* call in the "main loop" of _all_ threads, no need for any mutex, current won't die
* prematurely.
*/
void drbd_thread_current_set_cpu(struct drbd_thread *thi)
{
struct task_struct *p = current;
if (!thi->reset_cpu_mask)
return;
thi->reset_cpu_mask = 0;
set_cpus_allowed_ptr(p, thi->tconn->cpu_mask);
}
#endif
/**
* 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)
{
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);
}
}
static unsigned int prepare_header80(struct p_header80 *h, enum drbd_packet cmd, int size)
{
h->magic = cpu_to_be32(DRBD_MAGIC);
h->command = cpu_to_be16(cmd);
h->length = cpu_to_be16(size);
return sizeof(struct p_header80);
}
static unsigned int prepare_header95(struct p_header95 *h, enum drbd_packet cmd, int size)
{
h->magic = cpu_to_be16(DRBD_MAGIC_BIG);
h->command = cpu_to_be16(cmd);
h->length = cpu_to_be32(size);
return sizeof(struct p_header95);
}
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)
{
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)
return prepare_header95(buffer, cmd, size);
else
return prepare_header80(buffer, cmd, size);
}
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);
}
void *conn_prepare_command(struct drbd_tconn *tconn, struct drbd_socket *sock)
{
void *p;
mutex_lock(&sock->mutex);
p = __conn_prepare_command(tconn, sock);
if (!p)
mutex_unlock(&sock->mutex);
return p;
}
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;
header_size += prepare_header(tconn, vnr, sock->sbuf, cmd,
header_size + size);
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;
}
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);
}
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;
err = __conn_send_command(tconn, sock, cmd, header_size, data, size);
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;
}
int drbd_send_ping(struct drbd_tconn *tconn)
{
struct drbd_socket *sock;
sock = &tconn->meta;
if (!conn_prepare_command(tconn, sock))
return -EIO;
return conn_send_command(tconn, sock, P_PING, 0, NULL, 0);
}
int drbd_send_ping_ack(struct drbd_tconn *tconn)
{
struct drbd_socket *sock;
sock = &tconn->meta;
if (!conn_prepare_command(tconn, sock))
return -EIO;
return conn_send_command(tconn, sock, P_PING_ACK, 0, NULL, 0);
}
int drbd_send_sync_param(struct drbd_conf *mdev)
{
struct drbd_socket *sock;
struct p_rs_param_95 *p;
int size;
const int apv = mdev->tconn->agreed_pro_version;
enum drbd_packet cmd;
struct net_conf *nc;
struct disk_conf *dc;
sock = &mdev->tconn->data;
p = drbd_prepare_command(mdev, sock);
if (!p)
return -EIO;
rcu_read_lock();
nc = rcu_dereference(mdev->tconn->net_conf);
size = apv <= 87 ? sizeof(struct p_rs_param)
: apv == 88 ? sizeof(struct p_rs_param)
+ strlen(nc->verify_alg) + 1
: apv <= 94 ? sizeof(struct p_rs_param_89)
: /* apv >= 95 */ sizeof(struct p_rs_param_95);
cmd = apv >= 89 ? P_SYNC_PARAM89 : P_SYNC_PARAM;
/* initialize verify_alg and csums_alg */
memset(p->verify_alg, 0, 2 * SHARED_SECRET_MAX);
if (get_ldev(mdev)) {
dc = rcu_dereference(mdev->ldev->disk_conf);
p->resync_rate = cpu_to_be32(dc->resync_rate);
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);
put_ldev(mdev);
} else {
p->resync_rate = cpu_to_be32(DRBD_RESYNC_RATE_DEF);
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);
}
if (apv >= 88)
strcpy(p->verify_alg, nc->verify_alg);
if (apv >= 89)
strcpy(p->csums_alg, nc->csums_alg);
rcu_read_unlock();
return drbd_send_command(mdev, sock, cmd, size, NULL, 0);
}
int __drbd_send_protocol(struct drbd_tconn *tconn, enum drbd_packet cmd)
{
struct drbd_socket *sock;
struct p_protocol *p;
struct net_conf *nc;
int size, cf;
sock = &tconn->data;
p = __conn_prepare_command(tconn, sock);
if (!p)
return -EIO;
rcu_read_lock();
nc = rcu_dereference(tconn->net_conf);
if (nc->tentative && tconn->agreed_pro_version < 92) {
rcu_read_unlock();
mutex_unlock(&sock->mutex);
conn_err(tconn, "--dry-run is not supported by peer");
return -EOPNOTSUPP;
}
size = sizeof(*p);
if (tconn->agreed_pro_version >= 87)
size += strlen(nc->integrity_alg) + 1;
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);
cf = 0;
if (nc->discard_my_data)
cf |= CF_DISCARD_MY_DATA;
if (nc->tentative)
cf |= CF_DRY_RUN;
p->conn_flags = cpu_to_be32(cf);
if (tconn->agreed_pro_version >= 87)
strcpy(p->integrity_alg, nc->integrity_alg);
rcu_read_unlock();
return __conn_send_command(tconn, sock, cmd, size, NULL, 0);
}
int drbd_send_protocol(struct drbd_tconn *tconn)
{
int err;
mutex_lock(&tconn->data.mutex);
err = __drbd_send_protocol(tconn, P_PROTOCOL);
mutex_unlock(&tconn->data.mutex);
return err;
}
int _drbd_send_uuids(struct drbd_conf *mdev, u64 uuid_flags)
{
struct drbd_socket *sock;
struct p_uuids *p;
int i;
if (!get_ldev_if_state(mdev, D_NEGOTIATING))
return 0;
sock = &mdev->tconn->data;
p = drbd_prepare_command(mdev, sock);
if (!p) {
put_ldev(mdev);
return -EIO;
}
spin_lock_irq(&mdev->ldev->md.uuid_lock);
for (i = UI_CURRENT; i < UI_SIZE; i++)
p->uuid[i] = cpu_to_be64(mdev->ldev->md.uuid[i]);
spin_unlock_irq(&mdev->ldev->md.uuid_lock);
mdev->comm_bm_set = drbd_bm_total_weight(mdev);
p->uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set);
rcu_read_lock();
uuid_flags |= rcu_dereference(mdev->tconn->net_conf)->discard_my_data ? 1 : 0;
rcu_read_unlock();
uuid_flags |= test_bit(CRASHED_PRIMARY, &mdev->flags) ? 2 : 0;
uuid_flags |= mdev->new_state_tmp.disk == D_INCONSISTENT ? 4 : 0;
p->uuid[UI_FLAGS] = cpu_to_be64(uuid_flags);
put_ldev(mdev);
return drbd_send_command(mdev, sock, P_UUIDS, sizeof(*p), NULL, 0);
}
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);
}
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);
}
}
void drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev)
{
struct drbd_socket *sock;
struct p_rs_uuid *p;
u64 uuid;
D_ASSERT(mdev->state.disk == D_UP_TO_DATE);
uuid = mdev->ldev->md.uuid[UI_BITMAP];
if (uuid && uuid != UUID_JUST_CREATED)
uuid = uuid + UUID_NEW_BM_OFFSET;
else
get_random_bytes(&uuid, sizeof(u64));
drbd_uuid_set(mdev, UI_BITMAP, uuid);
drbd_print_uuids(mdev, "updated sync UUID");
drbd_md_sync(mdev);
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);
}
}
int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags)
{
struct drbd_socket *sock;
struct p_sizes *p;
sector_t d_size, u_size;
int q_order_type;
unsigned int max_bio_size;
if (get_ldev_if_state(mdev, D_NEGOTIATING)) {
D_ASSERT(mdev->ldev->backing_bdev);
d_size = drbd_get_max_capacity(mdev->ldev);
rcu_read_lock();
u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
rcu_read_unlock();
q_order_type = drbd_queue_order_type(mdev);
max_bio_size = queue_max_hw_sectors(mdev->ldev->backing_bdev->bd_disk->queue) << 9;
max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE);
put_ldev(mdev);
} else {
d_size = 0;
u_size = 0;
q_order_type = QUEUE_ORDERED_NONE;
max_bio_size = DRBD_MAX_BIO_SIZE; /* ... multiple BIOs per peer_request */
}
sock = &mdev->tconn->data;
p = drbd_prepare_command(mdev, sock);
if (!p)
return -EIO;
if (mdev->tconn->agreed_pro_version <= 94)
max_bio_size = min(max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
else if (mdev->tconn->agreed_pro_version < 100)
max_bio_size = min(max_bio_size, DRBD_MAX_BIO_SIZE_P95);
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);
}
/**
* drbd_send_current_state() - Sends the drbd state to the peer
* @mdev: DRBD device.
*/
int drbd_send_current_state(struct drbd_conf *mdev)
{
struct drbd_socket *sock;
struct p_state *p;
sock = &mdev->tconn->data;
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);
}
/**
* drbd_send_state() - After a state change, sends the new state to the peer
* @mdev: DRBD device.
* @state: the state to send, not necessarily the current state.
*
* Each state change queues an "after_state_ch" work, which will eventually
* send the resulting new state to the peer. If more state changes happen
* between queuing and processing of the after_state_ch work, we still
* want to send each intermediary state in the order it occurred.
*/
int drbd_send_state(struct drbd_conf *mdev, union drbd_state state)
{
struct drbd_socket *sock;
struct p_state *p;
sock = &mdev->tconn->data;
p = drbd_prepare_command(mdev, sock);
if (!p)
return -EIO;
p->state = cpu_to_be32(state.i); /* Within the send mutex */
return drbd_send_command(mdev, sock, P_STATE, sizeof(*p), NULL, 0);
}
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;
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);
}
int conn_send_state_req(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val)
{
enum drbd_packet cmd;
struct drbd_socket *sock;
struct p_req_state *p;
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);
}
void drbd_send_sr_reply(struct drbd_conf *mdev, enum drbd_state_rv retcode)
{
struct drbd_socket *sock;
struct p_req_state_reply *p;
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);
}
}
void conn_send_sr_reply(struct drbd_tconn *tconn, enum drbd_state_rv retcode)
{
struct drbd_socket *sock;
struct p_req_state_reply *p;
enum drbd_packet cmd = tconn->agreed_pro_version < 100 ? P_STATE_CHG_REPLY : P_CONN_ST_CHG_REPLY;
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);
}
}
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);
}
int fill_bitmap_rle_bits(struct drbd_conf *mdev,
struct p_compressed_bm *p,
unsigned int size,
struct bm_xfer_ctx *c)
{
struct bitstream bs;
unsigned long plain_bits;
unsigned long tmp;
unsigned long rl;
unsigned len;
unsigned toggle;
int bits, use_rle;
/* may we use this feature? */
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;
if (c->bit_offset >= c->bm_bits)
return 0; /* nothing to do. */
/* use at most thus many bytes */
bitstream_init(&bs, p->code, size, 0);
memset(p->code, 0, size);
/* 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, */
dcbp_set_start(p, 1);
/* but skip encoding of zero run length */
toggle = !toggle;
continue;
}
dcbp_set_start(p, 0);
}
/* 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 */
dcbp_set_pad_bits(p, (8 - bs.cur.bit) & 0x7);
return len;
}
/**
* send_bitmap_rle_or_plain
*
* Return 0 when done, 1 when another iteration is needed, and a negative error
* code upon failure.
*/
static int
send_bitmap_rle_or_plain(struct drbd_conf *mdev, struct bm_xfer_ctx *c)
{
struct drbd_socket *sock = &mdev->tconn->data;
unsigned int header_size = drbd_header_size(mdev->tconn);
struct p_compressed_bm *p = sock->sbuf + header_size;
int len, err;
len = fill_bitmap_rle_bits(mdev, p,
DRBD_SOCKET_BUFFER_SIZE - header_size - sizeof(*p), c);
if (len < 0)
return -EIO;
if (len) {
dcbp_set_code(p, RLE_VLI_Bits);
err = __send_command(mdev->tconn, mdev->vnr, sock,
P_COMPRESSED_BITMAP, sizeof(*p) + len,
NULL, 0);
c->packets[0]++;
c->bytes[0] += header_size + sizeof(*p) + len;
if (c->bit_offset >= c->bm_bits)
len = 0; /* DONE */
} else {
/* was not compressible.
* send a buffer full of plain text bits instead. */
unsigned int data_size;
unsigned long num_words;
unsigned long *p = sock->sbuf + header_size;
data_size = DRBD_SOCKET_BUFFER_SIZE - header_size;
num_words = min_t(size_t, data_size / sizeof(*p),
c->bm_words - c->word_offset);
len = num_words * sizeof(*p);
if (len)
drbd_bm_get_lel(mdev, c->word_offset, num_words, p);
err = __send_command(mdev->tconn, mdev->vnr, sock, P_BITMAP, len, NULL, 0);
c->word_offset += num_words;
c->bit_offset = c->word_offset * BITS_PER_LONG;
c->packets[1]++;
c->bytes[1] += header_size + len;
if (c->bit_offset > c->bm_bits)
c->bit_offset = c->bm_bits;
}
if (!err) {
if (len == 0) {
INFO_bm_xfer_stats(mdev, "send", c);
return 0;
} else
return 1;
}
return -EIO;
}
/* See the comment at receive_bitmap() */
static int _drbd_send_bitmap(struct drbd_conf *mdev)
{
struct bm_xfer_ctx c;
int err;
if (!expect(mdev->bitmap))
return false;
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 {
err = send_bitmap_rle_or_plain(mdev, &c);
} while (err > 0);
return err == 0;
}
int drbd_send_bitmap(struct drbd_conf *mdev)
{
struct drbd_socket *sock = &mdev->tconn->data;
int err = -1;
mutex_lock(&sock->mutex);
if (sock->socket)
err = !_drbd_send_bitmap(mdev);
mutex_unlock(&sock->mutex);
return err;
}
void drbd_send_b_ack(struct drbd_tconn *tconn, u32 barrier_nr, u32 set_size)
{
struct drbd_socket *sock;
struct p_barrier_ack *p;
if (tconn->cstate < C_WF_REPORT_PARAMS)
return;
sock = &tconn->meta;
p = conn_prepare_command(tconn, sock);
if (!p)
return;
p->barrier = barrier_nr;
p->set_size = cpu_to_be32(set_size);
conn_send_command(tconn, sock, P_BARRIER_ACK, sizeof(*p), NULL, 0);
}
/**
* _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
*/
static int _drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
u64 sector, u32 blksize, u64 block_id)
{
struct drbd_socket *sock;
struct p_block_ack *p;
if (mdev->state.conn < C_CONNECTED)
return -EIO;
sock = &mdev->tconn->meta;
p = drbd_prepare_command(mdev, sock);
if (!p)
return -EIO;
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);
}
/* 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. */
void drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packet cmd,
struct p_data *dp, int data_size)
{
if (mdev->tconn->peer_integrity_tfm)
data_size -= crypto_hash_digestsize(mdev->tconn->peer_integrity_tfm);
_drbd_send_ack(mdev, cmd, dp->sector, cpu_to_be32(data_size),
dp->block_id);
}
void drbd_send_ack_rp(struct drbd_conf *mdev, enum drbd_packet cmd,
struct p_block_req *rp)
{
_drbd_send_ack(mdev, cmd, rp->sector, rp->blksize, rp->block_id);
}
/**
* drbd_send_ack() - Sends an ack packet
* @mdev: DRBD device
* @cmd: packet command code
* @peer_req: peer request
*/
int drbd_send_ack(struct drbd_conf *mdev, enum drbd_packet cmd,
struct drbd_peer_request *peer_req)
{
return _drbd_send_ack(mdev, cmd,
cpu_to_be64(peer_req->i.sector),
cpu_to_be32(peer_req->i.size),
peer_req->block_id);
}
/* This function misuses the block_id field to signal if the blocks
* are is sync or not. */
int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packet cmd,
sector_t sector, int blksize, u64 block_id)
{
return _drbd_send_ack(mdev, cmd,
cpu_to_be64(sector),
cpu_to_be32(blksize),
cpu_to_be64(block_id));
}
int drbd_send_drequest(struct drbd_conf *mdev, int cmd,
sector_t sector, int size, u64 block_id)
{
struct drbd_socket *sock;
struct p_block_req *p;
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);
}
int drbd_send_drequest_csum(struct drbd_conf *mdev, sector_t sector, int size,
void *digest, int digest_size, enum drbd_packet cmd)
{
struct drbd_socket *sock;
struct p_block_req *p;
/* FIXME: Put the digest into the preallocated socket buffer. */
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);
}
int drbd_send_ov_request(struct drbd_conf *mdev, sector_t sector, int size)
{
struct drbd_socket *sock;
struct p_block_req *p;
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);
}
/* called on sndtimeo
* returns false if we should retry,
* true if we think connection is dead
*/
static int we_should_drop_the_connection(struct drbd_tconn *tconn, struct socket *sock)
{
int drop_it;
/* long elapsed = (long)(jiffies - mdev->last_received); */
drop_it = tconn->meta.socket == sock
|| !tconn->asender.task
|| get_t_state(&tconn->asender) != RUNNING
|| tconn->cstate < C_WF_REPORT_PARAMS;
if (drop_it)
return true;
drop_it = !--tconn->ko_count;
if (!drop_it) {
conn_err(tconn, "[%s/%d] sock_sendmsg time expired, ko = %u\n",
current->comm, current->pid, tconn->ko_count);
request_ping(tconn);
}
return drop_it; /* && (mdev->state == R_PRIMARY) */;
}
static void drbd_update_congested(struct drbd_tconn *tconn)
{
struct sock *sk = tconn->data.socket->sk;
if (sk->sk_wmem_queued > sk->sk_sndbuf * 4 / 5)
set_bit(NET_CONGESTED, &tconn->flags);
}
/* 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,
int offset, size_t size, unsigned msg_flags)
{
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);
kunmap(page);
if (!err)
mdev->send_cnt += size >> 9;
return err;
}
static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
int offset, size_t size, unsigned msg_flags)
{
struct socket *socket = mdev->tconn->data.socket;
mm_segment_t oldfs = get_fs();
int len = size;
int err = -EIO;
/* 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))
return _drbd_no_send_page(mdev, page, offset, size, msg_flags);
msg_flags |= MSG_NOSIGNAL;
drbd_update_congested(mdev->tconn);
set_fs(KERNEL_DS);
do {
int sent;
sent = socket->ops->sendpage(socket, page, offset, len, msg_flags);
if (sent <= 0) {
if (sent == -EAGAIN) {
if (we_should_drop_the_connection(mdev->tconn, socket))
break;
continue;
}
dev_warn(DEV, "%s: size=%d len=%d sent=%d\n",
__func__, (int)size, len, sent);
if (sent < 0)
err = sent;
break;
}
len -= sent;
offset += sent;
} while (len > 0 /* THINK && mdev->cstate >= C_CONNECTED*/);
set_fs(oldfs);
clear_bit(NET_CONGESTED, &mdev->tconn->flags);
if (len == 0) {
err = 0;
mdev->send_cnt += size >> 9;
}
return err;
}
static int _drbd_send_bio(struct drbd_conf *mdev, struct bio *bio)
{
struct bio_vec *bvec;
int i;
/* hint all but last page with MSG_MORE */
bio_for_each_segment(bvec, bio, i) {
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;
}
return 0;
}
static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio)
{
struct bio_vec *bvec;
int i;
/* hint all but last page with MSG_MORE */
bio_for_each_segment(bvec, bio, i) {
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;
}
return 0;
}
static int _drbd_send_zc_ee(struct drbd_conf *mdev,
struct drbd_peer_request *peer_req)
{
struct page *page = peer_req->pages;
unsigned len = peer_req->i.size;
int err;
/* hint all but last page with MSG_MORE */
page_chain_for_each(page) {
unsigned l = min_t(unsigned, len, PAGE_SIZE);
err = _drbd_send_page(mdev, page, 0, l,
page_chain_next(page) ? MSG_MORE : 0);
if (err)
return err;
len -= l;
}
return 0;
}
static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
{
if (mdev->tconn->agreed_pro_version >= 95)
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
return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
}
/* Used to send write requests
* R_PRIMARY -> Peer (P_DATA)
*/
int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
{
struct drbd_socket *sock;
struct p_data *p;
unsigned int dp_flags = 0;
int dgs;
int err;
sock = &mdev->tconn->data;
p = drbd_prepare_command(mdev, sock);
dgs = mdev->tconn->integrity_tfm ? crypto_hash_digestsize(mdev->tconn->integrity_tfm) : 0;
if (!p)
return -EIO;
p->sector = cpu_to_be64(req->i.sector);
p->block_id = (unsigned long)req;
p->seq_num = cpu_to_be32(atomic_inc_return(&mdev->packet_seq));
dp_flags = bio_flags_to_wire(mdev, req->master_bio->bi_rw);
if (mdev->state.conn >= C_SYNC_SOURCE &&
mdev->state.conn <= C_PAUSED_SYNC_T)
dp_flags |= DP_MAY_SET_IN_SYNC;
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;
}
p->dp_flags = cpu_to_be32(dp_flags);
if (dgs)
drbd_csum_bio(mdev, mdev->tconn->integrity_tfm, req->master_bio, p + 1);
err = __send_command(mdev->tconn, mdev->vnr, sock, P_DATA, sizeof(*p) + dgs, NULL, req->i.size);
if (!err) {
/* 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.
*/
if (!(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK)) || dgs)
err = _drbd_send_bio(mdev, req->master_bio);
else
err = _drbd_send_zc_bio(mdev, req->master_bio);
/* double check digest, sometimes buffers have been modified in flight. */
if (dgs > 0 && dgs <= 64) {
/* 64 byte, 512 bit, is the largest digest size
* currently supported in kernel crypto. */
unsigned char digest[64];
drbd_csum_bio(mdev, mdev->tconn->integrity_tfm, req->master_bio, digest);
if (memcmp(p + 1, digest, dgs)) {
dev_warn(DEV,
"Digest mismatch, buffer modified by upper layers during write: %llus +%u\n",
(unsigned long long)req->i.sector, req->i.size);
}
} /* else if (dgs > 64) {
... Be noisy about digest too large ...
} */
}
mutex_unlock(&sock->mutex); /* locked by drbd_prepare_command() */
return err;
}
/* 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)
*/
int drbd_send_block(struct drbd_conf *mdev, enum drbd_packet cmd,
struct drbd_peer_request *peer_req)
{
struct drbd_socket *sock;
struct p_data *p;
int err;
int dgs;
sock = &mdev->tconn->data;
p = drbd_prepare_command(mdev, sock);
dgs = mdev->tconn->integrity_tfm ? crypto_hash_digestsize(mdev->tconn->integrity_tfm) : 0;
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 */
p->dp_flags = 0;
if (dgs)
drbd_csum_ee(mdev, mdev->tconn->integrity_tfm, peer_req, p + 1);
err = __send_command(mdev->tconn, mdev->vnr, sock, cmd, sizeof(*p) + dgs, NULL, peer_req->i.size);
if (!err)
err = _drbd_send_zc_ee(mdev, peer_req);
mutex_unlock(&sock->mutex); /* locked by drbd_prepare_command() */
return err;
}
int drbd_send_out_of_sync(struct drbd_conf *mdev, struct drbd_request *req)
{
struct drbd_socket *sock;
struct p_block_desc *p;
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);
}
/*
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!
*/
int drbd_send(struct drbd_tconn *tconn, struct socket *sock,
void *buf, size_t size, unsigned msg_flags)
{
struct kvec iov;
struct msghdr msg;
int rv, sent = 0;
if (!sock)
return -EBADR;
/* 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;
if (sock == tconn->data.socket) {
rcu_read_lock();
tconn->ko_count = rcu_dereference(tconn->net_conf)->ko_count;
rcu_read_unlock();
drbd_update_congested(tconn);
}
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) {
if (we_should_drop_the_connection(tconn, sock))
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);
if (sock == tconn->data.socket)
clear_bit(NET_CONGESTED, &tconn->flags);
if (rv <= 0) {
if (rv != -EAGAIN) {
conn_err(tconn, "%s_sendmsg returned %d\n",
sock == tconn->meta.socket ? "msock" : "sock",
rv);
conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
} else
conn_request_state(tconn, NS(conn, C_TIMEOUT), CS_HARD);
}
return sent;
}
/**
* 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;
}
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;
mutex_lock(&drbd_main_mutex);
spin_lock_irqsave(&mdev->tconn->req_lock, flags);
/* 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++;
spin_unlock_irqrestore(&mdev->tconn->req_lock, flags);
mutex_unlock(&drbd_main_mutex);
return rv;
}
static void drbd_release(struct gendisk *gd, fmode_t mode)
{
struct drbd_conf *mdev = gd->private_data;
mutex_lock(&drbd_main_mutex);
mdev->open_cnt--;
mutex_unlock(&drbd_main_mutex);
}
static void drbd_set_defaults(struct drbd_conf *mdev)
{
/* Beware! The actual layout differs
* between big endian and little endian */
mdev->state = (union drbd_dev_state) {
{ .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);
atomic_set(&mdev->pp_in_use_by_net, 0);
atomic_set(&mdev->rs_sect_in, 0);
atomic_set(&mdev->rs_sect_ev, 0);
atomic_set(&mdev->ap_in_flight, 0);
atomic_set(&mdev->md_io_in_use, 0);
mutex_init(&mdev->own_state_mutex);
mdev->state_mutex = &mdev->own_state_mutex;
spin_lock_init(&mdev->al_lock);
spin_lock_init(&mdev->peer_seq_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);
INIT_LIST_HEAD(&mdev->go_diskless.list);
INIT_LIST_HEAD(&mdev->md_sync_work.list);
INIT_LIST_HEAD(&mdev->start_resync_work.list);
INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
mdev->resync_work.cb = w_resync_timer;
mdev->unplug_work.cb = w_send_write_hint;
mdev->go_diskless.cb = w_go_diskless;
mdev->md_sync_work.cb = w_md_sync;
mdev->bm_io_work.w.cb = w_bitmap_io;
mdev->start_resync_work.cb = w_start_resync;
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;
init_timer(&mdev->resync_timer);
init_timer(&mdev->md_sync_timer);
init_timer(&mdev->start_resync_timer);
init_timer(&mdev->request_timer);
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;
mdev->start_resync_timer.function = start_resync_timer_fn;
mdev->start_resync_timer.data = (unsigned long) mdev;
mdev->request_timer.function = request_timer_fn;
mdev->request_timer.data = (unsigned long) mdev;
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);
mdev->resync_wenr = LC_FREE;
mdev->peer_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
mdev->local_max_bio_size = DRBD_MAX_BIO_SIZE_SAFE;
}
void drbd_mdev_cleanup(struct drbd_conf *mdev)
{
int i;
if (mdev->tconn->receiver.t_state != NONE)
dev_err(DEV, "ASSERT FAILED: receiver t_state == %d expected 0.\n",
mdev->tconn->receiver.t_state);
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 =
mdev->rs_failed = 0;
mdev->rs_last_events = 0;
mdev->rs_last_sect_ev = 0;
for (i = 0; i < DRBD_SYNC_MARKS; i++) {
mdev->rs_mark_left[i] = 0;
mdev->rs_mark_time[i] = 0;
}
D_ASSERT(mdev->tconn->net_conf == NULL);
drbd_set_my_capacity(mdev, 0);
if (mdev->bitmap) {
/* maybe never allocated. */
drbd_bm_resize(mdev, 0, 1);
drbd_bm_cleanup(mdev);
}
drbd_free_bc(mdev->ldev);
mdev->ldev = NULL;
clear_bit(AL_SUSPENDED, &mdev->flags);
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));
D_ASSERT(list_empty(&mdev->tconn->sender_work.q));
D_ASSERT(list_empty(&mdev->resync_work.list));
D_ASSERT(list_empty(&mdev->unplug_work.list));
D_ASSERT(list_empty(&mdev->go_diskless.list));
drbd_set_defaults(mdev);
}
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); */
if (drbd_md_io_bio_set)
bioset_free(drbd_md_io_bio_set);
if (drbd_md_io_page_pool)
mempool_destroy(drbd_md_io_page_pool);
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);
drbd_md_io_bio_set = NULL;
drbd_md_io_page_pool = NULL;
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;
const int number = (DRBD_MAX_BIO_SIZE/PAGE_SIZE) * minor_count;
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;
drbd_md_io_page_pool = NULL;
drbd_md_io_bio_set = NULL;
/* 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(
"drbd_ee", sizeof(struct drbd_peer_request), 0, 0, NULL);
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 */
drbd_md_io_bio_set = bioset_create(DRBD_MIN_POOL_PAGES, 0);
if (drbd_md_io_bio_set == NULL)
goto Enomem;
drbd_md_io_page_pool = mempool_create_page_pool(DRBD_MIN_POOL_PAGES, 0);
if (drbd_md_io_page_pool == NULL)
goto Enomem;
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);
if (drbd_ee_mempool == NULL)
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,
};
static void drbd_release_all_peer_reqs(struct drbd_conf *mdev)
{
int rr;
rr = drbd_free_peer_reqs(mdev, &mdev->active_ee);
if (rr)
dev_err(DEV, "%d EEs in active list found!\n", rr);
rr = drbd_free_peer_reqs(mdev, &mdev->sync_ee);
if (rr)
dev_err(DEV, "%d EEs in sync list found!\n", rr);
rr = drbd_free_peer_reqs(mdev, &mdev->read_ee);
if (rr)
dev_err(DEV, "%d EEs in read list found!\n", rr);
rr = drbd_free_peer_reqs(mdev, &mdev->done_ee);
if (rr)
dev_err(DEV, "%d EEs in done list found!\n", rr);
rr = drbd_free_peer_reqs(mdev, &mdev->net_ee);
if (rr)
dev_err(DEV, "%d EEs in net list found!\n", rr);
}
/* caution. no locking. */
void drbd_minor_destroy(struct kref *kref)
{
struct drbd_conf *mdev = container_of(kref, struct drbd_conf, kref);
struct drbd_tconn *tconn = mdev->tconn;
del_timer_sync(&mdev->request_timer);
/* paranoia asserts */
D_ASSERT(mdev->open_cnt == 0);
/* 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);
drbd_free_bc(mdev->ldev);
mdev->ldev = NULL;
drbd_release_all_peer_reqs(mdev);
lc_destroy(mdev->act_log);
lc_destroy(mdev->resync);
kfree(mdev->p_uuid);
/* mdev->p_uuid = NULL; */
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);
kfree(mdev->rs_plan_s);
kfree(mdev);
kref_put(&tconn->kref, &conn_destroy);
}
/* One global retry thread, if we need to push back some bio and have it
* reinserted through our make request function.
*/
static struct retry_worker {
struct workqueue_struct *wq;
struct work_struct worker;
spinlock_t lock;
struct list_head writes;
} retry;
static void do_retry(struct work_struct *ws)
{
struct retry_worker *retry = container_of(ws, struct retry_worker, worker);
LIST_HEAD(writes);
struct drbd_request *req, *tmp;
spin_lock_irq(&retry->lock);
list_splice_init(&retry->writes, &writes);
spin_unlock_irq(&retry->lock);
list_for_each_entry_safe(req, tmp, &writes, tl_requests) {
struct drbd_conf *mdev = req->w.mdev;
struct bio *bio = req->master_bio;
unsigned long start_time = req->start_time;
bool expected;
expected =
expect(atomic_read(&req->completion_ref) == 0) &&
expect(req->rq_state & RQ_POSTPONED) &&
expect((req->rq_state & RQ_LOCAL_PENDING) == 0 ||
(req->rq_state & RQ_LOCAL_ABORTED) != 0);
if (!expected)
dev_err(DEV, "req=%p completion_ref=%d rq_state=%x\n",
req, atomic_read(&req->completion_ref),
req->rq_state);
/* We still need to put one kref associated with the
* "completion_ref" going zero in the code path that queued it
* here. The request object may still be referenced by a
* frozen local req->private_bio, in case we force-detached.
*/
kref_put(&req->kref, drbd_req_destroy);
/* A single suspended or otherwise blocking device may stall
* all others as well. Fortunately, this code path is to
* recover from a situation that "should not happen":
* concurrent writes in multi-primary setup.
* In a "normal" lifecycle, this workqueue is supposed to be
* destroyed without ever doing anything.
* If it turns out to be an issue anyways, we can do per
* resource (replication group) or per device (minor) retry
* workqueues instead.
*/
/* We are not just doing generic_make_request(),
* as we want to keep the start_time information. */
inc_ap_bio(mdev);
__drbd_make_request(mdev, bio, start_time);
}
}
void drbd_restart_request(struct drbd_request *req)
{
unsigned long flags;
spin_lock_irqsave(&retry.lock, flags);
list_move_tail(&req->tl_requests, &retry.writes);
spin_unlock_irqrestore(&retry.lock, flags);
/* Drop the extra reference that would otherwise
* have been dropped by complete_master_bio.
* do_retry() needs to grab a new one. */
dec_ap_bio(req->w.mdev);
queue_work(retry.wq, &retry.worker);
}
static void drbd_cleanup(void)
{
unsigned int i;
struct drbd_conf *mdev;
struct drbd_tconn *tconn, *tmp;
unregister_reboot_notifier(&drbd_notifier);
/* 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);
if (retry.wq)
destroy_workqueue(retry.wq);
drbd_genl_unregister();
idr_for_each_entry(&minors, mdev, i) {
idr_remove(&minors, mdev_to_minor(mdev));
idr_remove(&mdev->tconn->volumes, mdev->vnr);
destroy_workqueue(mdev->submit.wq);
del_gendisk(mdev->vdisk);
/* synchronize_rcu(); No other threads running at this point */
kref_put(&mdev->kref, &drbd_minor_destroy);
}
/* not _rcu since, no other updater anymore. Genl already unregistered */
list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
list_del(&tconn->all_tconn); /* not _rcu no proc, not other threads */
/* synchronize_rcu(); */
kref_put(&tconn->kref, &conn_destroy);
}
drbd_destroy_mempools();
unregister_blkdev(DRBD_MAJOR, "drbd");
idr_destroy(&minors);
printk(KERN_INFO "drbd: module cleanup done.\n");
}
/**
* drbd_congested() - Callback for the flusher thread
* @congested_data: User data
* @bdi_bits: Bits the BDI flusher thread 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;
if (!may_inc_ap_bio(mdev)) {
/* DRBD has frozen IO */
r = bdi_bits;
reason = 'd';
goto out;
}
if (test_bit(CALLBACK_PENDING, &mdev->tconn->flags)) {
r |= (1 << BDI_async_congested);
/* Without good local data, we would need to read from remote,
* and that would need the worker thread as well, which is
* currently blocked waiting for that usermode helper to
* finish.
*/
if (!get_ldev_if_state(mdev, D_UP_TO_DATE))
r |= (1 << BDI_sync_congested);
else
put_ldev(mdev);
r &= bdi_bits;
reason = 'c';
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';
}
if (bdi_bits & (1 << BDI_async_congested) && test_bit(NET_CONGESTED, &mdev->tconn->flags)) {
r |= (1 << BDI_async_congested);
reason = reason == 'b' ? 'a' : 'n';
}
out:
mdev->congestion_reason = reason;
return r;
}
static void drbd_init_workqueue(struct drbd_work_queue* wq)
{
spin_lock_init(&wq->q_lock);
INIT_LIST_HEAD(&wq->q);
init_waitqueue_head(&wq->q_wait);
}
struct drbd_tconn *conn_get_by_name(const char *name)
{
struct drbd_tconn *tconn;
if (!name || !name[0])
return NULL;
rcu_read_lock();
list_for_each_entry_rcu(tconn, &drbd_tconns, all_tconn) {
if (!strcmp(tconn->name, name)) {
kref_get(&tconn->kref);
goto found;
}
}
tconn = NULL;
found:
rcu_read_unlock();
return tconn;
}
struct drbd_tconn *conn_get_by_addrs(void *my_addr, int my_addr_len,
void *peer_addr, int peer_addr_len)
{
struct drbd_tconn *tconn;
rcu_read_lock();
list_for_each_entry_rcu(tconn, &drbd_tconns, all_tconn) {
if (tconn->my_addr_len == my_addr_len &&
tconn->peer_addr_len == peer_addr_len &&
!memcmp(&tconn->my_addr, my_addr, my_addr_len) &&
!memcmp(&tconn->peer_addr, peer_addr, peer_addr_len)) {
kref_get(&tconn->kref);
goto found;
}
}
tconn = NULL;
found:
rcu_read_unlock();
return tconn;
}
static int drbd_alloc_socket(struct drbd_socket *socket)
{
socket->rbuf = (void *) __get_free_page(GFP_KERNEL);
if (!socket->rbuf)
return -ENOMEM;
socket->sbuf = (void *) __get_free_page(GFP_KERNEL);
if (!socket->sbuf)
return -ENOMEM;
return 0;
}
static void drbd_free_socket(struct drbd_socket *socket)
{
free_page((unsigned long) socket->sbuf);
free_page((unsigned long) socket->rbuf);
}
void conn_free_crypto(struct drbd_tconn *tconn)
{
drbd_free_sock(tconn);
crypto_free_hash(tconn->csums_tfm);
crypto_free_hash(tconn->verify_tfm);
crypto_free_hash(tconn->cram_hmac_tfm);
crypto_free_hash(tconn->integrity_tfm);
crypto_free_hash(tconn->peer_integrity_tfm);
kfree(tconn->int_dig_in);
kfree(tconn->int_dig_vv);
tconn->csums_tfm = NULL;
tconn->verify_tfm = NULL;
tconn->cram_hmac_tfm = NULL;
tconn->integrity_tfm = NULL;
tconn->peer_integrity_tfm = NULL;
tconn->int_dig_in = NULL;
tconn->int_dig_vv = NULL;
}
int set_resource_options(struct drbd_tconn *tconn, struct res_opts *res_opts)
{
cpumask_var_t new_cpu_mask;
int err;
if (!zalloc_cpumask_var(&new_cpu_mask, GFP_KERNEL))
return -ENOMEM;
/*
retcode = ERR_NOMEM;
drbd_msg_put_info("unable to allocate cpumask");
*/
/* silently ignore cpu mask on UP kernel */
if (nr_cpu_ids > 1 && res_opts->cpu_mask[0] != 0) {
/* FIXME: Get rid of constant 32 here */
err = bitmap_parse(res_opts->cpu_mask, 32,
cpumask_bits(new_cpu_mask), nr_cpu_ids);
if (err) {
conn_warn(tconn, "bitmap_parse() failed with %d\n", err);
/* retcode = ERR_CPU_MASK_PARSE; */
goto fail;
}
}
tconn->res_opts = *res_opts;
if (!cpumask_equal(tconn->cpu_mask, new_cpu_mask)) {
cpumask_copy(tconn->cpu_mask, new_cpu_mask);
drbd_calc_cpu_mask(tconn);
tconn->receiver.reset_cpu_mask = 1;
tconn->asender.reset_cpu_mask = 1;
tconn->worker.reset_cpu_mask = 1;
}
err = 0;
fail:
free_cpumask_var(new_cpu_mask);
return err;
}
/* caller must be under genl_lock() */
struct drbd_tconn *conn_create(const char *name, struct res_opts *res_opts)
{
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;
if (drbd_alloc_socket(&tconn->data))
goto fail;
if (drbd_alloc_socket(&tconn->meta))
goto fail;
if (!zalloc_cpumask_var(&tconn->cpu_mask, GFP_KERNEL))
goto fail;
if (set_resource_options(tconn, res_opts))
goto fail;
tconn->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
if (!tconn->current_epoch)
goto fail;
INIT_LIST_HEAD(&tconn->transfer_log);
INIT_LIST_HEAD(&tconn->current_epoch->list);
tconn->epochs = 1;
spin_lock_init(&tconn->epoch_lock);
tconn->write_ordering = WO_bdev_flush;
tconn->send.seen_any_write_yet = false;
tconn->send.current_epoch_nr = 0;
tconn->send.current_epoch_writes = 0;
tconn->cstate = C_STANDALONE;
mutex_init(&tconn->cstate_mutex);
spin_lock_init(&tconn->req_lock);
mutex_init(&tconn->conf_update);
init_waitqueue_head(&tconn->ping_wait);
idr_init(&tconn->volumes);
drbd_init_workqueue(&tconn->sender_work);
mutex_init(&tconn->data.mutex);
mutex_init(&tconn->meta.mutex);
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");
kref_init(&tconn->kref);
list_add_tail_rcu(&tconn->all_tconn, &drbd_tconns);
return tconn;
fail:
kfree(tconn->current_epoch);
free_cpumask_var(tconn->cpu_mask);
drbd_free_socket(&tconn->meta);
drbd_free_socket(&tconn->data);
kfree(tconn->name);
kfree(tconn);
return NULL;
}
void conn_destroy(struct kref *kref)
{
struct drbd_tconn *tconn = container_of(kref, struct drbd_tconn, kref);
if (atomic_read(&tconn->current_epoch->epoch_size) != 0)
conn_err(tconn, "epoch_size:%d\n", atomic_read(&tconn->current_epoch->epoch_size));
kfree(tconn->current_epoch);
idr_destroy(&tconn->volumes);
free_cpumask_var(tconn->cpu_mask);
drbd_free_socket(&tconn->meta);
drbd_free_socket(&tconn->data);
kfree(tconn->name);
kfree(tconn->int_dig_in);
kfree(tconn->int_dig_vv);
kfree(tconn);
}
int init_submitter(struct drbd_conf *mdev)
{
/* opencoded create_singlethread_workqueue(),
* to be able to say "drbd%d", ..., minor */
mdev->submit.wq = alloc_workqueue("drbd%u_submit",
WQ_UNBOUND | WQ_MEM_RECLAIM, 1, mdev->minor);
if (!mdev->submit.wq)
return -ENOMEM;
INIT_WORK(&mdev->submit.worker, do_submit);
spin_lock_init(&mdev->submit.lock);
INIT_LIST_HEAD(&mdev->submit.writes);
return 0;
}
enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr)
{
struct drbd_conf *mdev;
struct gendisk *disk;
struct request_queue *q;
int vnr_got = vnr;
int minor_got = minor;
enum drbd_ret_code err = ERR_NOMEM;
mdev = minor_to_mdev(minor);
if (mdev)
return ERR_MINOR_EXISTS;
/* GFP_KERNEL, we are outside of all write-out paths */
mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
if (!mdev)
return ERR_NOMEM;
kref_get(&tconn->kref);
mdev->tconn = tconn;
mdev->minor = minor;
mdev->vnr = vnr;
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;
set_disk_ro(disk, true);
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;
blk_queue_make_request(q, drbd_make_request);
blk_queue_flush(q, REQ_FLUSH | REQ_FUA);
/* 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);
blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
blk_queue_merge_bvec(q, drbd_merge_bvec);
q->queue_lock = &mdev->tconn->req_lock; /* needed since we use */
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;
mdev->read_requests = RB_ROOT;
mdev->write_requests = RB_ROOT;
minor_got = idr_alloc(&minors, mdev, minor, minor + 1, GFP_KERNEL);
if (minor_got < 0) {
if (minor_got == -ENOSPC) {
err = ERR_MINOR_EXISTS;
drbd_msg_put_info("requested minor exists already");
}
goto out_no_minor_idr;
}
vnr_got = idr_alloc(&tconn->volumes, mdev, vnr, vnr + 1, GFP_KERNEL);
if (vnr_got < 0) {
if (vnr_got == -ENOSPC) {
err = ERR_INVALID_REQUEST;
drbd_msg_put_info("requested volume exists already");
}
goto out_idr_remove_minor;
}
if (init_submitter(mdev)) {
err = ERR_NOMEM;
drbd_msg_put_info("unable to create submit workqueue");
goto out_idr_remove_vol;
}
add_disk(disk);
kref_init(&mdev->kref); /* one ref for both idrs and the the add_disk */
/* inherit the connection state */
mdev->state.conn = tconn->cstate;
if (mdev->state.conn == C_WF_REPORT_PARAMS)
drbd_connected(mdev);
return NO_ERROR;
out_idr_remove_vol:
idr_remove(&tconn->volumes, vnr_got);
out_idr_remove_minor:
idr_remove(&minors, minor_got);
synchronize_rcu();
out_no_minor_idr:
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);
kref_put(&tconn->kref, &conn_destroy);
return err;
}
int __init drbd_init(void)
{
int err;
if (minor_count < DRBD_MINOR_COUNT_MIN || minor_count > DRBD_MINOR_COUNT_MAX) {
printk(KERN_ERR
"drbd: invalid minor_count (%d)\n", minor_count);
#ifdef MODULE
return -EINVAL;
#else
minor_count = DRBD_MINOR_COUNT_DEF;
#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;
}
err = drbd_genl_register();
if (err) {
printk(KERN_ERR "drbd: unable to register generic netlink family\n");
goto fail;
}
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 */
idr_init(&minors);
err = drbd_create_mempools();
if (err)
goto fail;
drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
if (!drbd_proc) {
printk(KERN_ERR "drbd: unable to register proc file\n");
goto fail;
}
rwlock_init(&global_state_lock);
INIT_LIST_HEAD(&drbd_tconns);
retry.wq = create_singlethread_workqueue("drbd-reissue");
if (!retry.wq) {
printk(KERN_ERR "drbd: unable to create retry workqueue\n");
goto fail;
}
INIT_WORK(&retry.worker, do_retry);
spin_lock_init(&retry.lock);
INIT_LIST_HEAD(&retry.writes);
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! */
fail:
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;
blkdev_put(ldev->backing_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
blkdev_put(ldev->md_bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
kfree(ldev->disk_conf);
kfree(ldev);
}
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);
}
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);
}
}
/* meta data management */
void conn_md_sync(struct drbd_tconn *tconn)
{
struct drbd_conf *mdev;
int vnr;
rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
kref_get(&mdev->kref);
rcu_read_unlock();
drbd_md_sync(mdev);
kref_put(&mdev->kref, &drbd_minor_destroy);
rcu_read_lock();
}
rcu_read_unlock();
}
/* aligned 4kByte */
struct meta_data_on_disk {
u64 la_size_sect; /* 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 (userspace) */
/* `-- act_log->nr_elements <-- ldev->dc.al_extents */
u32 bm_offset; /* offset to the bitmap, from here */
u32 bm_bytes_per_bit; /* BM_BLOCK_SIZE */
u32 la_peer_max_bio_size; /* last peer max_bio_size */
/* see al_tr_number_to_on_disk_sector() */
u32 al_stripes;
u32 al_stripe_size_4k;
u8 reserved_u8[4096 - (7*8 + 10*4)];
} __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;
/* Don't accidentally change the DRBD meta data layout. */
BUILD_BUG_ON(UI_SIZE != 4);
BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
del_timer(&mdev->md_sync_timer);
/* timer may be rearmed by drbd_md_mark_dirty() now. */
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;
buffer = drbd_md_get_buffer(mdev);
if (!buffer)
goto out;
memset(buffer, 0, sizeof(*buffer));
buffer->la_size_sect = 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_84_UNCLEAN);
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);
buffer->la_peer_max_bio_size = cpu_to_be32(mdev->peer_max_bio_size);
buffer->al_stripes = cpu_to_be32(mdev->ldev->md.al_stripes);
buffer->al_stripe_size_4k = cpu_to_be32(mdev->ldev->md.al_stripe_size_4k);
D_ASSERT(drbd_md_ss(mdev->ldev) == mdev->ldev->md.md_offset);
sector = mdev->ldev->md.md_offset;
if (drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE)) {
/* this was a try anyways ... */
dev_err(DEV, "meta data update failed!\n");
drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
}
/* 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);
drbd_md_put_buffer(mdev);
out:
put_ldev(mdev);
}
static int check_activity_log_stripe_size(struct drbd_conf *mdev,
struct meta_data_on_disk *on_disk,
struct drbd_md *in_core)
{
u32 al_stripes = be32_to_cpu(on_disk->al_stripes);
u32 al_stripe_size_4k = be32_to_cpu(on_disk->al_stripe_size_4k);
u64 al_size_4k;
/* both not set: default to old fixed size activity log */
if (al_stripes == 0 && al_stripe_size_4k == 0) {
al_stripes = 1;
al_stripe_size_4k = MD_32kB_SECT/8;
}
/* some paranoia plausibility checks */
/* we need both values to be set */
if (al_stripes == 0 || al_stripe_size_4k == 0)
goto err;
al_size_4k = (u64)al_stripes * al_stripe_size_4k;
/* Upper limit of activity log area, to avoid potential overflow
* problems in al_tr_number_to_on_disk_sector(). As right now, more
* than 72 * 4k blocks total only increases the amount of history,
* limiting this arbitrarily to 16 GB is not a real limitation ;-) */
if (al_size_4k > (16 * 1024 * 1024/4))
goto err;
/* Lower limit: we need at least 8 transaction slots (32kB)
* to not break existing setups */
if (al_size_4k < MD_32kB_SECT/8)
goto err;
in_core->al_stripe_size_4k = al_stripe_size_4k;
in_core->al_stripes = al_stripes;
in_core->al_size_4k = al_size_4k;
return 0;
err:
dev_err(DEV, "invalid activity log striping: al_stripes=%u, al_stripe_size_4k=%u\n",
al_stripes, al_stripe_size_4k);
return -EINVAL;
}
static int check_offsets_and_sizes(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
{
sector_t capacity = drbd_get_capacity(bdev->md_bdev);
struct drbd_md *in_core = &bdev->md;
s32 on_disk_al_sect;
s32 on_disk_bm_sect;
/* The on-disk size of the activity log, calculated from offsets, and
* the size of the activity log calculated from the stripe settings,
* should match.
* Though we could relax this a bit: it is ok, if the striped activity log
* fits in the available on-disk activity log size.
* Right now, that would break how resize is implemented.
* TODO: make drbd_determine_dev_size() (and the drbdmeta tool) aware
* of possible unused padding space in the on disk layout. */
if (in_core->al_offset < 0) {
if (in_core->bm_offset > in_core->al_offset)
goto err;
on_disk_al_sect = -in_core->al_offset;
on_disk_bm_sect = in_core->al_offset - in_core->bm_offset;
} else {
if (in_core->al_offset != MD_4kB_SECT)
goto err;
if (in_core->bm_offset < in_core->al_offset + in_core->al_size_4k * MD_4kB_SECT)
goto err;
on_disk_al_sect = in_core->bm_offset - MD_4kB_SECT;
on_disk_bm_sect = in_core->md_size_sect - in_core->bm_offset;
}
/* old fixed size meta data is exactly that: fixed. */
if (in_core->meta_dev_idx >= 0) {
if (in_core->md_size_sect != MD_128MB_SECT
|| in_core->al_offset != MD_4kB_SECT
|| in_core->bm_offset != MD_4kB_SECT + MD_32kB_SECT
|| in_core->al_stripes != 1
|| in_core->al_stripe_size_4k != MD_32kB_SECT/8)
goto err;
}
if (capacity < in_core->md_size_sect)
goto err;
if (capacity - in_core->md_size_sect < drbd_md_first_sector(bdev))
goto err;
/* should be aligned, and at least 32k */
if ((on_disk_al_sect & 7) || (on_disk_al_sect < MD_32kB_SECT))
goto err;
/* should fit (for now: exactly) into the available on-disk space;
* overflow prevention is in check_activity_log_stripe_size() above. */
if (on_disk_al_sect != in_core->al_size_4k * MD_4kB_SECT)
goto err;
/* again, should be aligned */
if (in_core->bm_offset & 7)
goto err;
/* FIXME check for device grow with flex external meta data? */
/* can the available bitmap space cover the last agreed device size? */
if (on_disk_bm_sect < (in_core->la_size_sect+7)/MD_4kB_SECT/8/512)
goto err;
return 0;
err:
dev_err(DEV, "meta data offsets don't make sense: idx=%d "
"al_s=%u, al_sz4k=%u, al_offset=%d, bm_offset=%d, "
"md_size_sect=%u, la_size=%llu, md_capacity=%llu\n",
in_core->meta_dev_idx,
in_core->al_stripes, in_core->al_stripe_size_4k,
in_core->al_offset, in_core->bm_offset, in_core->md_size_sect,
(unsigned long long)in_core->la_size_sect,
(unsigned long long)capacity);
return -EINVAL;
}
/**
* drbd_md_read() - Reads in the meta data super block
* @mdev: DRBD device.
* @bdev: Device from which the meta data should be read in.
*
* Return NO_ERROR on success, and an enum drbd_ret_code in case
* something goes wrong.
*
* Called exactly once during drbd_adm_attach(), while still being D_DISKLESS,
* even before @bdev is assigned to @mdev->ldev.
*/
int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
{
struct meta_data_on_disk *buffer;
u32 magic, flags;
int i, rv = NO_ERROR;
if (mdev->state.disk != D_DISKLESS)
return ERR_DISK_CONFIGURED;
buffer = drbd_md_get_buffer(mdev);
if (!buffer)
return ERR_NOMEM;
/* First, figure out where our meta data superblock is located,
* and read it. */
bdev->md.meta_dev_idx = bdev->disk_conf->meta_dev_idx;
bdev->md.md_offset = drbd_md_ss(bdev);
if (drbd_md_sync_page_io(mdev, bdev, bdev->md.md_offset, READ)) {
/* NOTE: can't do normal error processing here as this is
called BEFORE disk is attached */
dev_err(DEV, "Error while reading metadata.\n");
rv = ERR_IO_MD_DISK;
goto err;
}
magic = be32_to_cpu(buffer->magic);
flags = be32_to_cpu(buffer->flags);
if (magic == DRBD_MD_MAGIC_84_UNCLEAN ||
(magic == DRBD_MD_MAGIC_08 && !(flags & MDF_AL_CLEAN))) {
/* btw: that's Activity Log clean, not "all" clean. */
dev_err(DEV, "Found unclean meta data. Did you \"drbdadm apply-al\"?\n");
rv = ERR_MD_UNCLEAN;
goto err;
}
rv = ERR_MD_INVALID;
if (magic != DRBD_MD_MAGIC_08) {
if (magic == DRBD_MD_MAGIC_07)
dev_err(DEV, "Found old (0.7) meta data magic. Did you \"drbdadm create-md\"?\n");
else
dev_err(DEV, "Meta data magic not found. Did you \"drbdadm create-md\"?\n");
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);
goto err;
}
/* convert to in_core endian */
bdev->md.la_size_sect = be64_to_cpu(buffer->la_size_sect);
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);
bdev->md.md_size_sect = be32_to_cpu(buffer->md_size_sect);
bdev->md.al_offset = be32_to_cpu(buffer->al_offset);
bdev->md.bm_offset = be32_to_cpu(buffer->bm_offset);
if (check_activity_log_stripe_size(mdev, buffer, &bdev->md))
goto err;
if (check_offsets_and_sizes(mdev, bdev))
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);
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);
goto err;
}
rv = NO_ERROR;
spin_lock_irq(&mdev->tconn->req_lock);
if (mdev->state.conn < C_CONNECTED) {
unsigned int peer;
peer = be32_to_cpu(buffer->la_peer_max_bio_size);
peer = max(peer, DRBD_MAX_BIO_SIZE_SAFE);
mdev->peer_max_bio_size = peer;
}
spin_unlock_irq(&mdev->tconn->req_lock);
err:
drbd_md_put_buffer(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().
*/
#ifdef DEBUG
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
void drbd_md_mark_dirty(struct drbd_conf *mdev)
{
if (!test_and_set_bit(MD_DIRTY, &mdev->flags))
mod_timer(&mdev->md_sync_timer, jiffies + 5*HZ);
}
#endif
void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)
{
int i;
for (i = UI_HISTORY_START; i < UI_HISTORY_END; i++)
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)
{
unsigned long flags;
spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);
__drbd_uuid_set(mdev, idx, val);
spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);
}
void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)
{
unsigned long flags;
spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);
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);
spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);
}
/**
* 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;
unsigned long long bm_uuid;
get_random_bytes(&val, sizeof(u64));
spin_lock_irq(&mdev->ldev->md.uuid_lock);
bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];
if (bm_uuid)
dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);
mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT];
__drbd_uuid_set(mdev, UI_CURRENT, val);
spin_unlock_irq(&mdev->ldev->md.uuid_lock);
drbd_print_uuids(mdev, "new current UUID");
/* get it to stable storage _now_ */
drbd_md_sync(mdev);
}
void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)
{
unsigned long flags;
if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)
return;
spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);
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 {
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);
mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);
}
spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);
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;
drbd_resume_al(mdev);
if (get_ldev_if_state(mdev, D_ATTACHING)) {
drbd_bm_clear_all(mdev);
rv = drbd_bm_write(mdev);
put_ldev(mdev);
}
return rv;
}
static int w_bitmap_io(struct drbd_work *w, int unused)
{
struct bm_io_work *work = container_of(w, struct bm_io_work, w);
struct drbd_conf *mdev = w->mdev;
int rv = -EIO;
D_ASSERT(atomic_read(&mdev->ap_bio_cnt) == 0);
if (get_ldev(mdev)) {
drbd_bm_lock(mdev, work->why, work->flags);
rv = work->io_fn(mdev);
drbd_bm_unlock(mdev);
put_ldev(mdev);
}
clear_bit_unlock(BITMAP_IO, &mdev->flags);
wake_up(&mdev->misc_wait);
if (work->done)
work->done(mdev, rv);
clear_bit(BITMAP_IO_QUEUED, &mdev->flags);
work->why = NULL;
work->flags = 0;
return 0;
}
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);
}
static int w_go_diskless(struct drbd_work *w, int unused)
{
struct drbd_conf *mdev = w->mdev;
D_ASSERT(mdev->state.disk == D_FAILED);
/* 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
* the protected members anymore, though, so once put_ldev reaches zero
* again, it will be safe to free them. */
/* Try to write changed bitmap pages, read errors may have just
* set some bits outside the area covered by the activity log.
*
* If we have an IO error during the bitmap writeout,
* we will want a full sync next time, just in case.
* (Do we want a specific meta data flag for this?)
*
* If that does not make it to stable storage either,
* we cannot do anything about that anymore.
*
* We still need to check if both bitmap and ldev are present, we may
* end up here after a failed attach, before ldev was even assigned.
*/
if (mdev->bitmap && mdev->ldev) {
/* An interrupted resync or similar is allowed to recounts bits
* while we detach.
* Any modifications would not be expected anymore, though.
*/
if (drbd_bitmap_io_from_worker(mdev, drbd_bm_write,
"detach", BM_LOCKED_TEST_ALLOWED)) {
if (test_bit(WAS_READ_ERROR, &mdev->flags)) {
drbd_md_set_flag(mdev, MDF_FULL_SYNC);
drbd_md_sync(mdev);
}
}
}
drbd_force_state(mdev, NS(disk, D_DISKLESS));
return 0;
}
/**
* 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),
char *why, enum bm_flag flags)
{
D_ASSERT(current == mdev->tconn->worker.task);
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;
mdev->bm_io_work.flags = flags;
spin_lock_irq(&mdev->tconn->req_lock);
set_bit(BITMAP_IO, &mdev->flags);
if (atomic_read(&mdev->ap_bio_cnt) == 0) {
if (!test_and_set_bit(BITMAP_IO_QUEUED, &mdev->flags))
drbd_queue_work(&mdev->tconn->sender_work, &mdev->bm_io_work.w);
}
spin_unlock_irq(&mdev->tconn->req_lock);
}
/**
* 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.
*/
int drbd_bitmap_io(struct drbd_conf *mdev, int (*io_fn)(struct drbd_conf *),
char *why, enum bm_flag flags)
{
int rv;
D_ASSERT(current != mdev->tconn->worker.task);
if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
drbd_suspend_io(mdev);
drbd_bm_lock(mdev, why, flags);
rv = io_fn(mdev);
drbd_bm_unlock(mdev);
if ((flags & BM_LOCKED_SET_ALLOWED) == 0)
drbd_resume_io(mdev);
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;
/* must not double-queue! */
if (list_empty(&mdev->md_sync_work.list))
drbd_queue_work_front(&mdev->tconn->sender_work, &mdev->md_sync_work);
}
static int w_md_sync(struct drbd_work *w, int unused)
{
struct drbd_conf *mdev = w->mdev;
dev_warn(DEV, "md_sync_timer expired! Worker calls drbd_md_sync().\n");
#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
drbd_md_sync(mdev);
return 0;
}
const char *cmdname(enum drbd_packet cmd)
{
/* 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",
[P_SUPERSEDED] = "Superseded",
[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",
[P_RETRY_WRITE] = "RetryWrite",
[P_RS_CANCEL] = "RSCancel",
[P_CONN_ST_CHG_REQ] = "conn_st_chg_req",
[P_CONN_ST_CHG_REPLY] = "conn_st_chg_reply",
[P_RETRY_WRITE] = "retry_write",
[P_PROTOCOL_UPDATE] = "protocol_update",
/* enum drbd_packet, but not commands - obsoleted flags:
* P_MAY_IGNORE
* P_MAX_OPT_CMD
*/
};
/* too big for the array: 0xfffX */
if (cmd == P_INITIAL_META)
return "InitialMeta";
if (cmd == P_INITIAL_DATA)
return "InitialData";
if (cmd == P_CONNECTION_FEATURES)
return "ConnectionFeatures";
if (cmd >= ARRAY_SIZE(cmdnames))
return "Unknown";
return cmdnames[cmd];
}
/**
* 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)
{
struct net_conf *nc;
DEFINE_WAIT(wait);
long timeout;
rcu_read_lock();
nc = rcu_dereference(mdev->tconn->net_conf);
if (!nc) {
rcu_read_unlock();
return -ETIMEDOUT;
}
timeout = nc->ko_count ? nc->timeout * HZ / 10 * nc->ko_count : MAX_SCHEDULE_TIMEOUT;
rcu_read_unlock();
/* 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;
}
#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;
if (!rsp->count--) {
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",
[DRBD_FAULT_AL_EE] = "EE allocation",
[DRBD_FAULT_RECEIVE] = "receive data corruption",
};
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++;
if (__ratelimit(&drbd_ratelimit_state))
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 MODULE
sprintf(buildtag, "srcversion: %-24s", THIS_MODULE->srcversion);
#else
buildtag[0] = 'b';
#endif
}
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);