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author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2014-10-29 18:51:31 -0500 |
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committer | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2015-02-23 09:59:07 -0600 |
commit | 1aee41f637694d4bbf91c24195f2b63e3f6badd2 (patch) | |
tree | b6f532e5a4265193dd5ebc547a0ab9f772143762 /drivers/md/md-cluster.c | |
parent | 7d49ffcfa3cc08aa2301bf3fdb1e423a3fd33ee7 (diff) | |
download | op-kernel-dev-1aee41f637694d4bbf91c24195f2b63e3f6badd2.zip op-kernel-dev-1aee41f637694d4bbf91c24195f2b63e3f6badd2.tar.gz |
Add new disk to clustered array
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>
Diffstat (limited to 'drivers/md/md-cluster.c')
-rw-r--r-- | drivers/md/md-cluster.c | 104 |
1 files changed, 103 insertions, 1 deletions
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c index d85a6ca..03e521a 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -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) |