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md-cluster.c
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/*
* Copyright (C) 2015, SUSE
*
* This program 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.
*
*/
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/dlm.h>
#include <linux/sched.h>
#include <linux/raid/md_p.h>
#include "md.h"
#include "md-bitmap.h"
#include "md-cluster.h"
#define LVB_SIZE 64
#define NEW_DEV_TIMEOUT 5000
struct dlm_lock_resource {
dlm_lockspace_t *ls;
struct dlm_lksb lksb;
char *name; /* lock name. */
uint32_t flags; /* flags to pass to dlm_lock() */
wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
bool sync_locking_done;
void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
struct mddev *mddev; /* pointing back to mddev. */
int mode;
};
struct resync_info {
__le64 lo;
__le64 hi;
};
/* md_cluster_info flags */
#define MD_CLUSTER_WAITING_FOR_NEWDISK 1
#define MD_CLUSTER_SUSPEND_READ_BALANCING 2
#define MD_CLUSTER_BEGIN_JOIN_CLUSTER 3
/* Lock the send communication. This is done through
* bit manipulation as opposed to a mutex in order to
* accomodate lock and hold. See next comment.
*/
#define MD_CLUSTER_SEND_LOCK 4
/* If cluster operations (such as adding a disk) must lock the
* communication channel, so as to perform extra operations
* (update metadata) and no other operation is allowed on the
* MD. Token needs to be locked and held until the operation
* completes witha md_update_sb(), which would eventually release
* the lock.
*/
#define MD_CLUSTER_SEND_LOCKED_ALREADY 5
/* We should receive message after node joined cluster and
* set up all the related infos such as bitmap and personality */
#define MD_CLUSTER_ALREADY_IN_CLUSTER 6
#define MD_CLUSTER_PENDING_RECV_EVENT 7
#define MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD 8
struct md_cluster_info {
struct mddev *mddev; /* the md device which md_cluster_info belongs to */
/* dlm lock space and resources for clustered raid. */
dlm_lockspace_t *lockspace;
int slot_number;
struct completion completion;
struct mutex recv_mutex;
struct dlm_lock_resource *bitmap_lockres;
struct dlm_lock_resource **other_bitmap_lockres;
struct dlm_lock_resource *resync_lockres;
struct list_head suspend_list;
spinlock_t suspend_lock;
/* record the region which write should be suspended */
sector_t suspend_lo;
sector_t suspend_hi;
int suspend_from; /* the slot which broadcast suspend_lo/hi */
struct md_thread *recovery_thread;
unsigned long recovery_map;
/* communication loc resources */
struct dlm_lock_resource *ack_lockres;
struct dlm_lock_resource *message_lockres;
struct dlm_lock_resource *token_lockres;
struct dlm_lock_resource *no_new_dev_lockres;
struct md_thread *recv_thread;
struct completion newdisk_completion;
wait_queue_head_t wait;
unsigned long state;
/* record the region in RESYNCING message */
sector_t sync_low;
sector_t sync_hi;
};
enum msg_type {
METADATA_UPDATED = 0,
RESYNCING,
NEWDISK,
REMOVE,
RE_ADD,
BITMAP_NEEDS_SYNC,
CHANGE_CAPACITY,
BITMAP_RESIZE,
};
struct cluster_msg {
__le32 type;
__le32 slot;
/* TODO: Unionize this for smaller footprint */
__le64 low;
__le64 high;
char uuid[16];
__le32 raid_slot;
};
static void sync_ast(void *arg)
{
struct dlm_lock_resource *res;
res = arg;
res->sync_locking_done = true;
wake_up(&res->sync_locking);
}
static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
{
int ret = 0;
ret = dlm_lock(res->ls, mode, &res->lksb,
res->flags, res->name, strlen(res->name),
0, sync_ast, res, res->bast);
if (ret)
return ret;
wait_event(res->sync_locking, res->sync_locking_done);
res->sync_locking_done = false;
if (res->lksb.sb_status == 0)
res->mode = mode;
return res->lksb.sb_status;
}
static int dlm_unlock_sync(struct dlm_lock_resource *res)
{
return dlm_lock_sync(res, DLM_LOCK_NL);
}
/*
* An variation of dlm_lock_sync, which make lock request could
* be interrupted
*/
static int dlm_lock_sync_interruptible(struct dlm_lock_resource *res, int mode,
struct mddev *mddev)
{
int ret = 0;
ret = dlm_lock(res->ls, mode, &res->lksb,
res->flags, res->name, strlen(res->name),
0, sync_ast, res, res->bast);
if (ret)
return ret;
wait_event(res->sync_locking, res->sync_locking_done
|| kthread_should_stop()
|| test_bit(MD_CLOSING, &mddev->flags));
if (!res->sync_locking_done) {
/*
* the convert queue contains the lock request when request is
* interrupted, and sync_ast could still be run, so need to
* cancel the request and reset completion
*/
ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_CANCEL,
&res->lksb, res);
res->sync_locking_done = false;
if (unlikely(ret != 0))
pr_info("failed to cancel previous lock request "
"%s return %d\n", res->name, ret);
return -EPERM;
} else
res->sync_locking_done = false;
if (res->lksb.sb_status == 0)
res->mode = mode;
return res->lksb.sb_status;
}
static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
{
struct dlm_lock_resource *res = NULL;
int ret, namelen;
struct md_cluster_info *cinfo = mddev->cluster_info;
res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
if (!res)
return NULL;
init_waitqueue_head(&res->sync_locking);
res->sync_locking_done = false;
res->ls = cinfo->lockspace;
res->mddev = mddev;
res->mode = DLM_LOCK_IV;
namelen = strlen(name);
res->name = kzalloc(namelen + 1, GFP_KERNEL);
if (!res->name) {
pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
goto out_err;
}
strlcpy(res->name, name, namelen + 1);
if (with_lvb) {
res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
if (!res->lksb.sb_lvbptr) {
pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
goto out_err;
}
res->flags = DLM_LKF_VALBLK;
}
if (bastfn)
res->bast = bastfn;
res->flags |= DLM_LKF_EXPEDITE;
ret = dlm_lock_sync(res, DLM_LOCK_NL);
if (ret) {
pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
goto out_err;
}
res->flags &= ~DLM_LKF_EXPEDITE;
res->flags |= DLM_LKF_CONVERT;
return res;
out_err:
kfree(res->lksb.sb_lvbptr);
kfree(res->name);
kfree(res);
return NULL;
}
static void lockres_free(struct dlm_lock_resource *res)
{
int ret = 0;
if (!res)
return;
/*
* use FORCEUNLOCK flag, so we can unlock even the lock is on the
* waiting or convert queue
*/
ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_FORCEUNLOCK,
&res->lksb, res);
if (unlikely(ret != 0))
pr_err("failed to unlock %s return %d\n", res->name, ret);
else
wait_event(res->sync_locking, res->sync_locking_done);
kfree(res->name);
kfree(res->lksb.sb_lvbptr);
kfree(res);
}
static void add_resync_info(struct dlm_lock_resource *lockres,
sector_t lo, sector_t hi)
{
struct resync_info *ri;
ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
ri->lo = cpu_to_le64(lo);
ri->hi = cpu_to_le64(hi);
}
static int read_resync_info(struct mddev *mddev,
struct dlm_lock_resource *lockres)
{
struct resync_info ri;
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret = 0;
dlm_lock_sync(lockres, DLM_LOCK_CR);
memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
if (le64_to_cpu(ri.hi) > 0) {
cinfo->suspend_hi = le64_to_cpu(ri.hi);
cinfo->suspend_lo = le64_to_cpu(ri.lo);
ret = 1;
}
dlm_unlock_sync(lockres);
return ret;
}
static void recover_bitmaps(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct md_cluster_info *cinfo = mddev->cluster_info;
struct dlm_lock_resource *bm_lockres;
char str[64];
int slot, ret;
sector_t lo, hi;
while (cinfo->recovery_map) {
slot = fls64((u64)cinfo->recovery_map) - 1;
snprintf(str, 64, "bitmap%04d", slot);
bm_lockres = lockres_init(mddev, str, NULL, 1);
if (!bm_lockres) {
pr_err("md-cluster: Cannot initialize bitmaps\n");
goto clear_bit;
}
ret = dlm_lock_sync_interruptible(bm_lockres, DLM_LOCK_PW, mddev);
if (ret) {
pr_err("md-cluster: Could not DLM lock %s: %d\n",
str, ret);
goto clear_bit;
}
ret = md_bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
if (ret) {
pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
goto clear_bit;
}
/* Clear suspend_area associated with the bitmap */
spin_lock_irq(&cinfo->suspend_lock);
cinfo->suspend_hi = 0;
cinfo->suspend_lo = 0;
cinfo->suspend_from = -1;
spin_unlock_irq(&cinfo->suspend_lock);
/* Kick off a reshape if needed */
if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
mddev->reshape_position != MaxSector)
md_wakeup_thread(mddev->sync_thread);
if (hi > 0) {
if (lo < mddev->recovery_cp)
mddev->recovery_cp = lo;
/* wake up thread to continue resync in case resync
* is not finished */
if (mddev->recovery_cp != MaxSector) {
/*
* clear the REMOTE flag since we will launch
* resync thread in current node.
*/
clear_bit(MD_RESYNCING_REMOTE,
&mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
}
clear_bit:
lockres_free(bm_lockres);
clear_bit(slot, &cinfo->recovery_map);
}
}
static void recover_prep(void *arg)
{
struct mddev *mddev = arg;
struct md_cluster_info *cinfo = mddev->cluster_info;
set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
}
static void __recover_slot(struct mddev *mddev, int slot)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
set_bit(slot, &cinfo->recovery_map);
if (!cinfo->recovery_thread) {
cinfo->recovery_thread = md_register_thread(recover_bitmaps,
mddev, "recover");
if (!cinfo->recovery_thread) {
pr_warn("md-cluster: Could not create recovery thread\n");
return;
}
}
md_wakeup_thread(cinfo->recovery_thread);
}
static void recover_slot(void *arg, struct dlm_slot *slot)
{
struct mddev *mddev = arg;
struct md_cluster_info *cinfo = mddev->cluster_info;
pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
mddev->bitmap_info.cluster_name,
slot->nodeid, slot->slot,
cinfo->slot_number);
/* deduct one since dlm slot starts from one while the num of
* cluster-md begins with 0 */
__recover_slot(mddev, slot->slot - 1);
}
static void recover_done(void *arg, struct dlm_slot *slots,
int num_slots, int our_slot,
uint32_t generation)
{
struct mddev *mddev = arg;
struct md_cluster_info *cinfo = mddev->cluster_info;
cinfo->slot_number = our_slot;
/* completion is only need to be complete when node join cluster,
* it doesn't need to run during another node's failure */
if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
complete(&cinfo->completion);
clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
}
clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
}
/* the ops is called when node join the cluster, and do lock recovery
* if node failure occurs */
static const struct dlm_lockspace_ops md_ls_ops = {
.recover_prep = recover_prep,
.recover_slot = recover_slot,
.recover_done = recover_done,
};
/*
* The BAST function for the ack lock resource
* This function wakes up the receive thread in
* order to receive and process the message.
*/
static void ack_bast(void *arg, int mode)
{
struct dlm_lock_resource *res = arg;
struct md_cluster_info *cinfo = res->mddev->cluster_info;
if (mode == DLM_LOCK_EX) {
if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
md_wakeup_thread(cinfo->recv_thread);
else
set_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state);
}
}
static void remove_suspend_info(struct mddev *mddev, int slot)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
mddev->pers->quiesce(mddev, 1);
spin_lock_irq(&cinfo->suspend_lock);
cinfo->suspend_hi = 0;
cinfo->suspend_lo = 0;
spin_unlock_irq(&cinfo->suspend_lock);
mddev->pers->quiesce(mddev, 0);
}
static void process_suspend_info(struct mddev *mddev,
int slot, sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct mdp_superblock_1 *sb = NULL;
struct md_rdev *rdev;
if (!hi) {
/*
* clear the REMOTE flag since resync or recovery is finished
* in remote node.
*/
clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
remove_suspend_info(mddev, slot);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
return;
}
rdev_for_each(rdev, mddev)
if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
sb = page_address(rdev->sb_page);
break;
}
/*
* The bitmaps are not same for different nodes
* if RESYNCING is happening in one node, then
* the node which received the RESYNCING message
* probably will perform resync with the region
* [lo, hi] again, so we could reduce resync time
* a lot if we can ensure that the bitmaps among
* different nodes are match up well.
*
* sync_low/hi is used to record the region which
* arrived in the previous RESYNCING message,
*
* Call md_bitmap_sync_with_cluster to clear NEEDED_MASK
* and set RESYNC_MASK since resync thread is running
* in another node, so we don't need to do the resync
* again with the same section.
*
* Skip md_bitmap_sync_with_cluster in case reshape
* happening, because reshaping region is small and
* we don't want to trigger lots of WARN.
*/
if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
md_bitmap_sync_with_cluster(mddev, cinfo->sync_low,
cinfo->sync_hi, lo, hi);
cinfo->sync_low = lo;
cinfo->sync_hi = hi;
mddev->pers->quiesce(mddev, 1);
spin_lock_irq(&cinfo->suspend_lock);
cinfo->suspend_from = slot;
cinfo->suspend_lo = lo;
cinfo->suspend_hi = hi;
spin_unlock_irq(&cinfo->suspend_lock);
mddev->pers->quiesce(mddev, 0);
}
static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
{
char disk_uuid[64];
struct md_cluster_info *cinfo = mddev->cluster_info;
char event_name[] = "EVENT=ADD_DEVICE";
char raid_slot[16];
char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
int len;
len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
sprintf(disk_uuid + len, "%pU", cmsg->uuid);
snprintf(raid_slot, 16, "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
init_completion(&cinfo->newdisk_completion);
set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
wait_for_completion_timeout(&cinfo->newdisk_completion,
NEW_DEV_TIMEOUT);
clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
}
static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
{
int got_lock = 0;
struct md_cluster_info *cinfo = mddev->cluster_info;
mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
wait_event(mddev->thread->wqueue,
(got_lock = mddev_trylock(mddev)) ||
test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
md_reload_sb(mddev, mddev->good_device_nr);
if (got_lock)
mddev_unlock(mddev);
}
static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
{
struct md_rdev *rdev;
rcu_read_lock();
rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
if (rdev) {
set_bit(ClusterRemove, &rdev->flags);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
else
pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
__func__, __LINE__, le32_to_cpu(msg->raid_slot));
rcu_read_unlock();
}
static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
{
struct md_rdev *rdev;
rcu_read_lock();
rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
if (rdev && test_bit(Faulty, &rdev->flags))
clear_bit(Faulty, &rdev->flags);
else
pr_warn("%s: %d Could not find disk(%d) which is faulty",
__func__, __LINE__, le32_to_cpu(msg->raid_slot));
rcu_read_unlock();
}
static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
{
int ret = 0;
if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
"node %d received it's own msg\n", le32_to_cpu(msg->slot)))
return -1;
switch (le32_to_cpu(msg->type)) {
case METADATA_UPDATED:
process_metadata_update(mddev, msg);
break;
case CHANGE_CAPACITY:
set_capacity(mddev->gendisk, mddev->array_sectors);
revalidate_disk(mddev->gendisk);
break;
case RESYNCING:
set_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
process_suspend_info(mddev, le32_to_cpu(msg->slot),
le64_to_cpu(msg->low),
le64_to_cpu(msg->high));
break;
case NEWDISK:
process_add_new_disk(mddev, msg);
break;
case REMOVE:
process_remove_disk(mddev, msg);
break;
case RE_ADD:
process_readd_disk(mddev, msg);
break;
case BITMAP_NEEDS_SYNC:
__recover_slot(mddev, le32_to_cpu(msg->slot));
break;
case BITMAP_RESIZE:
if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
ret = md_bitmap_resize(mddev->bitmap,
le64_to_cpu(msg->high), 0, 0);
break;
default:
ret = -1;
pr_warn("%s:%d Received unknown message from %d\n",
__func__, __LINE__, msg->slot);
}
return ret;
}
/*
* thread for receiving message
*/
static void recv_daemon(struct md_thread *thread)
{
struct md_cluster_info *cinfo = thread->mddev->cluster_info;
struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
struct cluster_msg msg;
int ret;
mutex_lock(&cinfo->recv_mutex);
/*get CR on Message*/
if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
pr_err("md/raid1:failed to get CR on MESSAGE\n");
mutex_unlock(&cinfo->recv_mutex);
return;
}
/* read lvb and wake up thread to process this message_lockres */
memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
ret = process_recvd_msg(thread->mddev, &msg);
if (ret)
goto out;
/*release CR on ack_lockres*/
ret = dlm_unlock_sync(ack_lockres);
if (unlikely(ret != 0))
pr_info("unlock ack failed return %d\n", ret);
/*up-convert to PR on message_lockres*/
ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
if (unlikely(ret != 0))
pr_info("lock PR on msg failed return %d\n", ret);
/*get CR on ack_lockres again*/
ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
if (unlikely(ret != 0))
pr_info("lock CR on ack failed return %d\n", ret);
out:
/*release CR on message_lockres*/
ret = dlm_unlock_sync(message_lockres);
if (unlikely(ret != 0))
pr_info("unlock msg failed return %d\n", ret);
mutex_unlock(&cinfo->recv_mutex);
}
/* lock_token()
* Takes the lock on the TOKEN lock resource so no other
* node can communicate while the operation is underway.
*/
static int lock_token(struct md_cluster_info *cinfo, bool mddev_locked)
{
int error, set_bit = 0;
struct mddev *mddev = cinfo->mddev;
/*
* If resync thread run after raid1d thread, then process_metadata_update
* could not continue if raid1d held reconfig_mutex (and raid1d is blocked
* since another node already got EX on Token and waitting the EX of Ack),
* so let resync wake up thread in case flag is set.
*/
if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
&cinfo->state)) {
error = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
&cinfo->state);
WARN_ON_ONCE(error);
md_wakeup_thread(mddev->thread);
set_bit = 1;
}
error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
if (set_bit)
clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
if (error)
pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
__func__, __LINE__, error);
/* Lock the receive sequence */
mutex_lock(&cinfo->recv_mutex);
return error;
}
/* lock_comm()
* Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
*/
static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
{
wait_event(cinfo->wait,
!test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
return lock_token(cinfo, mddev_locked);
}
static void unlock_comm(struct md_cluster_info *cinfo)
{
WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
mutex_unlock(&cinfo->recv_mutex);
dlm_unlock_sync(cinfo->token_lockres);
clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
wake_up(&cinfo->wait);
}
/* __sendmsg()
* This function performs the actual sending of the message. This function is
* usually called after performing the encompassing operation
* The function:
* 1. Grabs the message lockresource in EX mode
* 2. Copies the message to the message LVB
* 3. Downconverts message lockresource to CW
* 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
* and the other nodes read the message. The thread will wait here until all other
* nodes have released ack lock resource.
* 5. Downconvert ack lockresource to CR
*/
static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
{
int error;
int slot = cinfo->slot_number - 1;
cmsg->slot = cpu_to_le32(slot);
/*get EX on Message*/
error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
if (error) {
pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
goto failed_message;
}
memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
sizeof(struct cluster_msg));
/*down-convert EX to CW on Message*/
error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
if (error) {
pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
error);
goto failed_ack;
}
/*up-convert CR to EX on Ack*/
error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
if (error) {
pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
error);
goto failed_ack;
}
/*down-convert EX to CR on Ack*/
error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
if (error) {
pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
error);
goto failed_ack;
}
failed_ack:
error = dlm_unlock_sync(cinfo->message_lockres);
if (unlikely(error != 0)) {
pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
error);
/* in case the message can't be released due to some reason */
goto failed_ack;
}
failed_message:
return error;
}
static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
bool mddev_locked)
{
int ret;
lock_comm(cinfo, mddev_locked);
ret = __sendmsg(cinfo, cmsg);
unlock_comm(cinfo);
return ret;
}
static int gather_all_resync_info(struct mddev *mddev, int total_slots)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int i, ret = 0;
struct dlm_lock_resource *bm_lockres;
char str[64];
sector_t lo, hi;
for (i = 0; i < total_slots; i++) {
memset(str, '\0', 64);
snprintf(str, 64, "bitmap%04d", i);
bm_lockres = lockres_init(mddev, str, NULL, 1);
if (!bm_lockres)
return -ENOMEM;
if (i == (cinfo->slot_number - 1)) {
lockres_free(bm_lockres);
continue;
}
bm_lockres->flags |= DLM_LKF_NOQUEUE;
ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
if (ret == -EAGAIN) {
if (read_resync_info(mddev, bm_lockres)) {
pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
__func__, __LINE__,
(unsigned long long) cinfo->suspend_lo,
(unsigned long long) cinfo->suspend_hi,
i);
cinfo->suspend_from = i;
}
ret = 0;
lockres_free(bm_lockres);
continue;
}
if (ret) {
lockres_free(bm_lockres);
goto out;
}
/* Read the disk bitmap sb and check if it needs recovery */
ret = md_bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
if (ret) {
pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
lockres_free(bm_lockres);
continue;
}
if ((hi > 0) && (lo < mddev->recovery_cp)) {
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
mddev->recovery_cp = lo;
md_check_recovery(mddev);
}
lockres_free(bm_lockres);
}
out:
return ret;
}
static int join(struct mddev *mddev, int nodes)
{
struct md_cluster_info *cinfo;
int ret, ops_rv;
char str[64];
cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
INIT_LIST_HEAD(&cinfo->suspend_list);
spin_lock_init(&cinfo->suspend_lock);
init_completion(&cinfo->completion);
set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
init_waitqueue_head(&cinfo->wait);
mutex_init(&cinfo->recv_mutex);
mddev->cluster_info = cinfo;
cinfo->mddev = mddev;
memset(str, 0, 64);
sprintf(str, "%pU", mddev->uuid);
ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
DLM_LSFL_FS, LVB_SIZE,
&md_ls_ops, mddev, &ops_rv, &cinfo->lockspace);
if (ret)
goto err;
wait_for_completion(&cinfo->completion);
if (nodes < cinfo->slot_number) {
pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
cinfo->slot_number, nodes);
ret = -ERANGE;
goto err;
}
/* Initiate the communication resources */
ret = -ENOMEM;
cinfo->recv_thread = md_register_thread(recv_daemon, mddev, "cluster_recv");
if (!cinfo->recv_thread) {
pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
goto err;
}
cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
if (!cinfo->message_lockres)
goto err;
cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
if (!cinfo->token_lockres)
goto err;
cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
if (!cinfo->no_new_dev_lockres)
goto err;
ret = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
if (ret) {
ret = -EAGAIN;
pr_err("md-cluster: can't join cluster to avoid lock issue\n");
goto err;
}
cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
if (!cinfo->ack_lockres) {
ret = -ENOMEM;
goto err;
}
/* get sync CR lock on ACK. */
if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
ret);
dlm_unlock_sync(cinfo->token_lockres);
/* get sync CR lock on no-new-dev. */
if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
if (!cinfo->bitmap_lockres) {
ret = -ENOMEM;
goto err;
}
if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
pr_err("Failed to get bitmap lock\n");
ret = -EINVAL;
goto err;
}
cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
if (!cinfo->resync_lockres) {
ret = -ENOMEM;
goto err;
}
return 0;
err:
set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
md_unregister_thread(&cinfo->recovery_thread);
md_unregister_thread(&cinfo->recv_thread);
lockres_free(cinfo->message_lockres);
lockres_free(cinfo->token_lockres);
lockres_free(cinfo->ack_lockres);
lockres_free(cinfo->no_new_dev_lockres);
lockres_free(cinfo->resync_lockres);
lockres_free(cinfo->bitmap_lockres);
if (cinfo->lockspace)
dlm_release_lockspace(cinfo->lockspace, 2);
mddev->cluster_info = NULL;
kfree(cinfo);
return ret;
}
static void load_bitmaps(struct mddev *mddev, int total_slots)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
/* load all the node's bitmap info for resync */
if (gather_all_resync_info(mddev, total_slots))
pr_err("md-cluster: failed to gather all resyn infos\n");
set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state);
/* wake up recv thread in case something need to be handled */
if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state))
md_wakeup_thread(cinfo->recv_thread);
}
static void resync_bitmap(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg = {0};
int err;
cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
err = sendmsg(cinfo, &cmsg, 1);
if (err)
pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
__func__, __LINE__, err);
}
static void unlock_all_bitmaps(struct mddev *mddev);
static int leave(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
if (!cinfo)
return 0;
/*