linux/drivers/md/md-cluster.c
Goldwyn Rodrigues 90382ed9af Fix read-balancing during node failure
During a node failure, We need to suspend read balancing so that the
reads are directed to the first device and stale data is not read.
Suspending writes is not required because these would be recorded and
synced eventually.

A new flag MD_CLUSTER_SUSPEND_READ_BALANCING is set in recover_prep().
area_resyncing() will respond true for the entire devices if this
flag is set and the request type is READ. The flag is cleared
in recover_done().

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reported-By: David Teigland <teigland@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
2015-07-24 13:37:59 +10:00

976 lines
25 KiB
C

/*
* 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/dlm.h>
#include <linux/sched.h>
#include <linux/raid/md_p.h>
#include "md.h"
#include "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() */
struct completion completion; /* completion for synchronized locking */
void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
struct mddev *mddev; /* pointing back to mddev. */
};
struct suspend_info {
int slot;
sector_t lo;
sector_t hi;
struct list_head list;
};
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
struct md_cluster_info {
/* dlm lock space and resources for clustered raid. */
dlm_lockspace_t *lockspace;
int slot_number;
struct completion completion;
struct dlm_lock_resource *sb_lock;
struct mutex sb_mutex;
struct dlm_lock_resource *bitmap_lockres;
struct list_head suspend_list;
spinlock_t suspend_lock;
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;
unsigned long state;
};
enum msg_type {
METADATA_UPDATED = 0,
RESYNCING,
NEWDISK,
REMOVE,
RE_ADD,
};
struct cluster_msg {
int type;
int slot;
/* TODO: Unionize this for smaller footprint */
sector_t low;
sector_t high;
char uuid[16];
int raid_slot;
};
static void sync_ast(void *arg)
{
struct dlm_lock_resource *res;
res = (struct dlm_lock_resource *) arg;
complete(&res->completion);
}
static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
{
int ret = 0;
init_completion(&res->completion);
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_for_completion(&res->completion);
return res->lksb.sb_status;
}
static int dlm_unlock_sync(struct dlm_lock_resource *res)
{
return dlm_lock_sync(res, DLM_LOCK_NL);
}
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;
res->ls = cinfo->lockspace;
res->mddev = mddev;
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)
{
if (!res)
return;
init_completion(&res->completion);
dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res);
wait_for_completion(&res->completion);
kfree(res->name);
kfree(res->lksb.sb_lvbptr);
kfree(res);
}
static char *pretty_uuid(char *dest, char *src)
{
int i, len = 0;
for (i = 0; i < 16; i++) {
if (i == 4 || i == 6 || i == 8 || i == 10)
len += sprintf(dest + len, "-");
len += sprintf(dest + len, "%02x", (__u8)src[i]);
}
return dest;
}
static void add_resync_info(struct mddev *mddev, 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 struct suspend_info *read_resync_info(struct mddev *mddev, struct dlm_lock_resource *lockres)
{
struct resync_info ri;
struct suspend_info *s = NULL;
sector_t hi = 0;
dlm_lock_sync(lockres, DLM_LOCK_CR);
memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
hi = le64_to_cpu(ri.hi);
if (ri.hi > 0) {
s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
if (!s)
goto out;
s->hi = hi;
s->lo = le64_to_cpu(ri.lo);
}
dlm_unlock_sync(lockres);
out:
return s;
}
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;
struct suspend_info *s, *tmp;
sector_t lo, hi;
while (cinfo->recovery_map) {
slot = fls64((u64)cinfo->recovery_map) - 1;
/* Clear suspend_area associated with the bitmap */
spin_lock_irq(&cinfo->suspend_lock);
list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
if (slot == s->slot) {
list_del(&s->list);
kfree(s);
}
spin_unlock_irq(&cinfo->suspend_lock);
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(bm_lockres, DLM_LOCK_PW);
if (ret) {
pr_err("md-cluster: Could not DLM lock %s: %d\n",
str, ret);
goto clear_bit;
}
ret = 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 dlm_unlock;
}
if (hi > 0) {
/* TODO:Wait for current resync to get over */
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
if (lo < mddev->recovery_cp)
mddev->recovery_cp = lo;
md_check_recovery(mddev);
}
dlm_unlock:
dlm_unlock_sync(bm_lockres);
clear_bit:
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(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);
set_bit(slot->slot - 1, &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_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;
complete(&cinfo->completion);
clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
}
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 = (struct dlm_lock_resource *)arg;
struct md_cluster_info *cinfo = res->mddev->cluster_info;
if (mode == DLM_LOCK_EX)
md_wakeup_thread(cinfo->recv_thread);
}
static void __remove_suspend_info(struct md_cluster_info *cinfo, int slot)
{
struct suspend_info *s, *tmp;
list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
if (slot == s->slot) {
pr_info("%s:%d Deleting suspend_info: %d\n",
__func__, __LINE__, slot);
list_del(&s->list);
kfree(s);
break;
}
}
static void remove_suspend_info(struct md_cluster_info *cinfo, int slot)
{
spin_lock_irq(&cinfo->suspend_lock);
__remove_suspend_info(cinfo, slot);
spin_unlock_irq(&cinfo->suspend_lock);
}
static void process_suspend_info(struct md_cluster_info *cinfo,
int slot, sector_t lo, sector_t hi)
{
struct suspend_info *s;
if (!hi) {
remove_suspend_info(cinfo, slot);
return;
}
s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
if (!s)
return;
s->slot = slot;
s->lo = lo;
s->hi = hi;
spin_lock_irq(&cinfo->suspend_lock);
/* Remove existing entry (if exists) before adding */
__remove_suspend_info(cinfo, slot);
list_add(&s->list, &cinfo->suspend_list);
spin_unlock_irq(&cinfo->suspend_lock);
}
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=");
pretty_uuid(disk_uuid + len, cmsg->uuid);
snprintf(raid_slot, 16, "RAID_DISK=%d", 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)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
md_reload_sb(mddev);
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
}
static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
{
struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev, msg->raid_slot);
if (rdev)
md_kick_rdev_from_array(rdev);
else
pr_warn("%s: %d Could not find disk(%d) to REMOVE\n", __func__, __LINE__, msg->raid_slot);
}
static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
{
struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev, 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__, msg->raid_slot);
}
static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
{
switch (msg->type) {
case METADATA_UPDATED:
pr_info("%s: %d Received message: METADATA_UPDATE from %d\n",
__func__, __LINE__, msg->slot);
process_metadata_update(mddev, msg);
break;
case RESYNCING:
pr_info("%s: %d Received message: RESYNCING from %d\n",
__func__, __LINE__, msg->slot);
process_suspend_info(mddev->cluster_info, msg->slot,
msg->low, msg->high);
break;
case NEWDISK:
pr_info("%s: %d Received message: NEWDISK from %d\n",
__func__, __LINE__, msg->slot);
process_add_new_disk(mddev, msg);
break;
case REMOVE:
pr_info("%s: %d Received REMOVE from %d\n",
__func__, __LINE__, msg->slot);
process_remove_disk(mddev, msg);
break;
case RE_ADD:
pr_info("%s: %d Received RE_ADD from %d\n",
__func__, __LINE__, msg->slot);
process_readd_disk(mddev, msg);
break;
default:
pr_warn("%s:%d Received unknown message from %d\n",
__func__, __LINE__, msg->slot);
}
}
/*
* 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;
/*get CR on Message*/
if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
pr_err("md/raid1:failed to get CR on MESSAGE\n");
return;
}
/* read lvb and wake up thread to process this message_lockres */
memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
process_recvd_msg(thread->mddev, &msg);
/*release CR on ack_lockres*/
dlm_unlock_sync(ack_lockres);
/*up-convert to EX on message_lockres*/
dlm_lock_sync(message_lockres, DLM_LOCK_EX);
/*get CR on ack_lockres again*/
dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
/*release CR on message_lockres*/
dlm_unlock_sync(message_lockres);
}
/* lock_comm()
* Takes the lock on the TOKEN lock resource so no other
* node can communicate while the operation is underway.
*/
static int lock_comm(struct md_cluster_info *cinfo)
{
int error;
error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
if (error)
pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
__func__, __LINE__, error);
return error;
}
static void unlock_comm(struct md_cluster_info *cinfo)
{
dlm_unlock_sync(cinfo->token_lockres);
}
/* __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 CR
* 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 CR on Message*/
error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CR);
if (error) {
pr_err("md-cluster: failed to convert EX to CR on MESSAGE(%d)\n",
error);
goto failed_message;
}
/*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:
dlm_unlock_sync(cinfo->message_lockres);
failed_message:
return error;
}
static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
{
int ret;
lock_comm(cinfo);
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;
struct suspend_info *s;
char str[64];
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))
continue;
bm_lockres->flags |= DLM_LKF_NOQUEUE;
ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
if (ret == -EAGAIN) {
memset(bm_lockres->lksb.sb_lvbptr, '\0', LVB_SIZE);
s = read_resync_info(mddev, bm_lockres);
if (s) {
pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
__func__, __LINE__,
(unsigned long long) s->lo,
(unsigned long long) s->hi, i);
spin_lock_irq(&cinfo->suspend_lock);
s->slot = i;
list_add(&s->list, &cinfo->suspend_list);
spin_unlock_irq(&cinfo->suspend_lock);
}
ret = 0;
lockres_free(bm_lockres);
continue;
}
if (ret)
goto out;
/* TODO: Read the disk bitmap sb and check if it needs recovery */
dlm_unlock_sync(bm_lockres);
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];
if (!try_module_get(THIS_MODULE))
return -ENOENT;
cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
init_completion(&cinfo->completion);
mutex_init(&cinfo->sb_mutex);
mddev->cluster_info = cinfo;
memset(str, 0, 64);
pretty_uuid(str, 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;
}
cinfo->sb_lock = lockres_init(mddev, "cmd-super",
NULL, 0);
if (!cinfo->sb_lock) {
ret = -ENOMEM;
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->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
if (!cinfo->ack_lockres)
goto err;
cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
if (!cinfo->no_new_dev_lockres)
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);
/* 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)
goto err;
if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
pr_err("Failed to get bitmap lock\n");
ret = -EINVAL;
goto err;
}
INIT_LIST_HEAD(&cinfo->suspend_list);
spin_lock_init(&cinfo->suspend_lock);
ret = gather_all_resync_info(mddev, nodes);
if (ret)
goto err;
return 0;
err:
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->bitmap_lockres);
lockres_free(cinfo->sb_lock);
if (cinfo->lockspace)
dlm_release_lockspace(cinfo->lockspace, 2);
mddev->cluster_info = NULL;
kfree(cinfo);
module_put(THIS_MODULE);
return ret;
}
static int leave(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
if (!cinfo)
return 0;
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->sb_lock);
lockres_free(cinfo->bitmap_lockres);
dlm_release_lockspace(cinfo->lockspace, 2);
return 0;
}
/* slot_number(): Returns the MD slot number to use
* DLM starts the slot numbers from 1, wheras cluster-md
* wants the number to be from zero, so we deduct one
*/
static int slot_number(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
return cinfo->slot_number - 1;
}
static void resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
add_resync_info(mddev, cinfo->bitmap_lockres, lo, hi);
/* Re-acquire the lock to refresh LVB */
dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
}
static int metadata_update_start(struct mddev *mddev)
{
return lock_comm(mddev->cluster_info);
}
static int metadata_update_finish(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
int ret;
memset(&cmsg, 0, sizeof(cmsg));
cmsg.type = cpu_to_le32(METADATA_UPDATED);
ret = __sendmsg(cinfo, &cmsg);
unlock_comm(cinfo);
return ret;
}
static int metadata_update_cancel(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
return dlm_unlock_sync(cinfo->token_lockres);
}
static int resync_send(struct mddev *mddev, enum msg_type type,
sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
int slot = cinfo->slot_number - 1;
pr_info("%s:%d lo: %llu hi: %llu\n", __func__, __LINE__,
(unsigned long long)lo,
(unsigned long long)hi);
resync_info_update(mddev, lo, hi);
cmsg.type = cpu_to_le32(type);
cmsg.slot = cpu_to_le32(slot);
cmsg.low = cpu_to_le64(lo);
cmsg.high = cpu_to_le64(hi);
return sendmsg(cinfo, &cmsg);
}
static int resync_start(struct mddev *mddev, sector_t lo, sector_t hi)
{
pr_info("%s:%d\n", __func__, __LINE__);
return resync_send(mddev, RESYNCING, lo, hi);
}
static void resync_finish(struct mddev *mddev)
{
pr_info("%s:%d\n", __func__, __LINE__);
resync_send(mddev, RESYNCING, 0, 0);
}
static int area_resyncing(struct mddev *mddev, int direction,
sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret = 0;
struct suspend_info *s;
if ((direction == READ) &&
test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
return 1;
spin_lock_irq(&cinfo->suspend_lock);
if (list_empty(&cinfo->suspend_list))
goto out;
list_for_each_entry(s, &cinfo->suspend_list, list)
if (hi > s->lo && lo < s->hi) {
ret = 1;
break;
}
out:
spin_unlock_irq(&cinfo->suspend_lock);
return ret;
}
static int add_new_disk_start(struct mddev *mddev, struct md_rdev *rdev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
int ret = 0;
struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
char *uuid = sb->device_uuid;
memset(&cmsg, 0, sizeof(cmsg));
cmsg.type = cpu_to_le32(NEWDISK);
memcpy(cmsg.uuid, uuid, 16);
cmsg.raid_slot = rdev->desc_nr;
lock_comm(cinfo);
ret = __sendmsg(cinfo, &cmsg);
if (ret)
return ret;
cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
/* Some node does not "see" the device */
if (ret == -EAGAIN)
ret = -ENOENT;
else
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
return ret;
}
static int add_new_disk_finish(struct mddev *mddev)
{
struct cluster_msg cmsg;
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret;
/* Write sb and inform others */
md_update_sb(mddev, 1);
cmsg.type = METADATA_UPDATED;
ret = __sendmsg(cinfo, &cmsg);
unlock_comm(cinfo);
return ret;
}
static int new_disk_ack(struct mddev *mddev, bool ack)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
return -EINVAL;
}
if (ack)
dlm_unlock_sync(cinfo->no_new_dev_lockres);
complete(&cinfo->newdisk_completion);
return 0;
}
static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct cluster_msg cmsg;
struct md_cluster_info *cinfo = mddev->cluster_info;
cmsg.type = REMOVE;
cmsg.raid_slot = rdev->desc_nr;
return __sendmsg(cinfo, &cmsg);
}
static int gather_bitmaps(struct md_rdev *rdev)
{
int sn, err;
sector_t lo, hi;
struct cluster_msg cmsg;
struct mddev *mddev = rdev->mddev;
struct md_cluster_info *cinfo = mddev->cluster_info;
cmsg.type = RE_ADD;
cmsg.raid_slot = rdev->desc_nr;
err = sendmsg(cinfo, &cmsg);
if (err)
goto out;
for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
if (sn == (cinfo->slot_number - 1))
continue;
err = bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
if (err) {
pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
goto out;
}
if ((hi > 0) && (lo < mddev->recovery_cp))
mddev->recovery_cp = lo;
}
out:
return err;
}
static struct md_cluster_operations cluster_ops = {
.join = join,
.leave = leave,
.slot_number = slot_number,
.resync_info_update = resync_info_update,
.resync_start = resync_start,
.resync_finish = resync_finish,
.metadata_update_start = metadata_update_start,
.metadata_update_finish = metadata_update_finish,
.metadata_update_cancel = metadata_update_cancel,
.area_resyncing = area_resyncing,
.add_new_disk_start = add_new_disk_start,
.add_new_disk_finish = add_new_disk_finish,
.new_disk_ack = new_disk_ack,
.remove_disk = remove_disk,
.gather_bitmaps = gather_bitmaps,
};
static int __init cluster_init(void)
{
pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n");
pr_info("Registering Cluster MD functions\n");
register_md_cluster_operations(&cluster_ops, THIS_MODULE);
return 0;
}
static void cluster_exit(void)
{
unregister_md_cluster_operations();
}
module_init(cluster_init);
module_exit(cluster_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Clustering support for MD");