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Add new disk to clustered array

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Algorithm:
1. Node 1 issues mdadm --manage /dev/mdX --add /dev/sdYY which issues
   ioctl(ADD_NEW_DISC with disc.state set to MD_DISK_CLUSTER_ADD)
2. Node 1 sends NEWDISK with uuid and slot number
3. Other nodes issue kobject_uevent_env with uuid and slot number
(Steps 4,5 could be a udev rule)
4. In userspace, the node searches for the disk, perhaps
   using blkid -t SUB_UUID=""
5. Other nodes issue either of the following depending on whether the disk
   was found:
   ioctl(ADD_NEW_DISK with disc.state set to MD_DISK_CANDIDATE and
	 disc.number set to slot number)
   ioctl(CLUSTERED_DISK_NACK)
6. Other nodes drop lock on no-new-devs (CR) if device is found
7. Node 1 attempts EX lock on no-new-devs
8. If node 1 gets the lock, it sends METADATA_UPDATED after unmarking the disk
   as SpareLocal
9. If not (get no-new-dev lock), it fails the operation and sends METADATA_UPDATED
10. Other nodes understand if the device is added or not by reading the superblock again after receiving the METADATA_UPDATED message.

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
This commit is contained in:
Goldwyn Rodrigues 2014-10-29 18:51:31 -05:00
parent 7d49ffcfa3
commit 1aee41f637
7 changed files with 169 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

104
drivers/md/md-cluster.c
View File

@ -12,11 +12,13 @@
#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;
@ -56,19 +58,25 @@ struct md_cluster_info {
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;
};
enum msg_type {
METADATA_UPDATED = 0,
RESYNCING,
NEWDISK,
};
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)
@ -358,13 +366,41 @@ static void process_suspend_info(struct md_cluster_info *cinfo,
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);
kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
wait_for_completion_timeout(&cinfo->newdisk_completion,
NEW_DEV_TIMEOUT);
}
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_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);
md_reload_sb(mddev);
process_metadata_update(mddev, msg);
break;
case RESYNCING:
pr_info("%s: %d Received message: RESYNCING from %d\n",
@ -372,6 +408,10 @@ static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
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);
};
}
@ -593,10 +633,18 @@ static int join(struct mddev *mddev, int nodes)
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);
@ -621,6 +669,7 @@ 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)
@ -642,6 +691,7 @@ static int leave(struct mddev *mddev)
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);
@ -742,6 +792,55 @@ out:
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 void new_disk_ack(struct mddev *mddev, bool ack)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
if (ack)
dlm_unlock_sync(cinfo->no_new_dev_lockres);
complete(&cinfo->newdisk_completion);
}
static struct md_cluster_operations cluster_ops = {
.join = join,
.leave = leave,
@ -753,6 +852,9 @@ static struct md_cluster_operations cluster_ops = {
.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,
};
static int __init cluster_init(void)

4
drivers/md/md-cluster.h
View File

@ -6,6 +6,7 @@
#include "md.h"
struct mddev;
struct md_rdev;
struct md_cluster_operations {
int (*join)(struct mddev *mddev, int nodes);
@ -18,6 +19,9 @@ struct md_cluster_operations {
int (*metadata_update_finish)(struct mddev *mddev);
int (*metadata_update_cancel)(struct mddev *mddev);
int (*area_resyncing)(struct mddev *mddev, sector_t lo, sector_t hi);
int (*add_new_disk_start)(struct mddev *mddev, struct md_rdev *rdev);
int (*add_new_disk_finish)(struct mddev *mddev);
void (*new_disk_ack)(struct mddev *mddev, bool ack);
};
#endif /* _MD_CLUSTER_H */

52
drivers/md/md.c
View File

@ -2210,7 +2210,7 @@ static void sync_sbs(struct mddev *mddev, int nospares)
}
}
static void md_update_sb(struct mddev *mddev, int force_change)
void md_update_sb(struct mddev *mddev, int force_change)
{
struct md_rdev *rdev;
int sync_req;
@ -2371,6 +2371,7 @@ repeat:
wake_up(&rdev->blocked_wait);
}
}
EXPORT_SYMBOL(md_update_sb);
/* words written to sysfs files may, or may not, be \n terminated.
* We want to accept with case. For this we use cmd_match.
@ -3151,7 +3152,7 @@ static void analyze_sbs(struct mddev *mddev)
kick_rdev_from_array(rdev);
continue;
}
if (rdev != freshest)
if (rdev != freshest) {
if (super_types[mddev->major_version].
validate_super(mddev, rdev)) {
printk(KERN_WARNING "md: kicking non-fresh %s"
@ -3160,6 +3161,15 @@ static void analyze_sbs(struct mddev *mddev)
kick_rdev_from_array(rdev);
continue;
}
/* No device should have a Candidate flag
* when reading devices
*/
if (test_bit(Candidate, &rdev->flags)) {
pr_info("md: kicking Cluster Candidate %s from array!\n",
bdevname(rdev->bdev, b));
kick_rdev_from_array(rdev);
}
}
if (mddev->level == LEVEL_MULTIPATH) {
rdev->desc_nr = i++;
rdev->raid_disk = rdev->desc_nr;
@ -5655,7 +5665,6 @@ static int get_array_info(struct mddev *mddev, void __user *arg)
info.state |= (1<<MD_SB_BITMAP_PRESENT);
if (mddev_is_clustered(mddev))
info.state |= (1<<MD_SB_CLUSTERED);
info.active_disks = insync;
info.working_disks = working;
info.failed_disks = failed;
@ -5744,6 +5753,13 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
struct md_rdev *rdev;
dev_t dev = MKDEV(info->major,info->minor);
if (mddev_is_clustered(mddev) &&
!(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
pr_err("%s: Cannot add to clustered mddev. Try --cluster-add\n",
mdname(mddev));
return -EINVAL;
}
if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
return -EOVERFLOW;
@ -5830,6 +5846,25 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
else
clear_bit(WriteMostly, &rdev->flags);
/*
* check whether the device shows up in other nodes
*/
if (mddev_is_clustered(mddev)) {
if (info->state & (1 << MD_DISK_CANDIDATE)) {
/* Through --cluster-confirm */
set_bit(Candidate, &rdev->flags);
md_cluster_ops->new_disk_ack(mddev, true);
} else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
/* --add initiated by this node */
err = md_cluster_ops->add_new_disk_start(mddev, rdev);
if (err) {
md_cluster_ops->add_new_disk_finish(mddev);
export_rdev(rdev);
return err;
}
}
}
rdev->raid_disk = -1;
err = bind_rdev_to_array(rdev, mddev);
if (!err && !mddev->pers->hot_remove_disk) {
@ -5855,6 +5890,9 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
if (!err)
md_new_event(mddev);
md_wakeup_thread(mddev->thread);
if (mddev_is_clustered(mddev) &&
(info->state & (1 << MD_DISK_CLUSTER_ADD)))
md_cluster_ops->add_new_disk_finish(mddev);
return err;
}
@ -6456,6 +6494,7 @@ static inline bool md_ioctl_valid(unsigned int cmd)
case SET_DISK_FAULTY:
case STOP_ARRAY:
case STOP_ARRAY_RO:
case CLUSTERED_DISK_NACK:
return true;
default:
return false;
@ -6728,6 +6767,13 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
goto unlock;
}
case CLUSTERED_DISK_NACK:
if (mddev_is_clustered(mddev))
md_cluster_ops->new_disk_ack(mddev, false);
else
err = -EINVAL;
goto unlock;
case HOT_ADD_DISK:
err = hot_add_disk(mddev, new_decode_dev(arg));
goto unlock;

5
drivers/md/md.h
View File

@ -171,6 +171,10 @@ enum flag_bits {
* a want_replacement device with same
* raid_disk number.
*/
Candidate, /* For clustered environments only:
* This device is seen locally but not
* by the whole cluster
*/
};
#define BB_LEN_MASK (0x00000000000001FFULL)
@ -666,6 +670,7 @@ extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
extern void md_reload_sb(struct mddev *mddev);
extern void md_update_sb(struct mddev *mddev, int force);
static inline int mddev_check_plugged(struct mddev *mddev)
{
return !!blk_check_plugged(md_unplug, mddev,

1
drivers/md/raid1.c
View File

@ -1571,6 +1571,7 @@ static int raid1_spare_active(struct mddev *mddev)
struct md_rdev *rdev = conf->mirrors[i].rdev;
struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
if (repl
&& !test_bit(Candidate, &repl->flags)
&& repl->recovery_offset == MaxSector
&& !test_bit(Faulty, &repl->flags)
&& !test_and_set_bit(In_sync, &repl->flags)) {

6
include/uapi/linux/raid/md_p.h
View File

@ -78,6 +78,12 @@
#define MD_DISK_ACTIVE 1 /* disk is running or spare disk */
#define MD_DISK_SYNC 2 /* disk is in sync with the raid set */
#define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */
#define MD_DISK_CLUSTER_ADD 4 /* Initiate a disk add across the cluster
* For clustered enviroments only.
*/
#define MD_DISK_CANDIDATE 5 /* disk is added as spare (local) until confirmed
* For clustered enviroments only.
*/
#define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config.
* read requests will only be sent here in

1
include/uapi/linux/raid/md_u.h
View File

@ -62,6 +62,7 @@
#define STOP_ARRAY _IO (MD_MAJOR, 0x32)
#define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
#define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
#define CLUSTERED_DISK_NACK _IO (MD_MAJOR, 0x35)
/* 63 partitions with the alternate major number (mdp) */
#define MdpMinorShift 6