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linux/drivers/md/md-cluster.h

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Introduce md_cluster_operations to handle cluster functions This allows dynamic registering of cluster hooks. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-03-29 15:01:53 +00:00
#ifndef _MD_CLUSTER_H
#define _MD_CLUSTER_H
#include "md.h"
struct mddev;
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>
2014-10-29 23:51:31 +00:00
struct md_rdev;
Introduce md_cluster_operations to handle cluster functions This allows dynamic registering of cluster hooks. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-03-29 15:01:53 +00:00
struct md_cluster_operations {
Add node recovery callbacks DLM offers callbacks when a node fails and the lock remastery is performed: 1. recover_prep: called when DLM discovers a node is down 2. recover_slot: called when DLM identifies the node and recovery can start 3. recover_done: called when all nodes have completed recover_slot recover_slot() and recover_done() are also called when the node joins initially in order to inform the node with its slot number. These slot numbers start from one, so we deduct one to make it start with zero which the cluster-md code uses. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-03-30 05:42:49 +00:00
int (*join)(struct mddev *mddev, int nodes);
Introduce md_cluster_operations to handle cluster functions This allows dynamic registering of cluster hooks. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-03-29 15:01:53 +00:00
int (*leave)(struct mddev *mddev);
Add node recovery callbacks DLM offers callbacks when a node fails and the lock remastery is performed: 1. recover_prep: called when DLM discovers a node is down 2. recover_slot: called when DLM identifies the node and recovery can start 3. recover_done: called when all nodes have completed recover_slot recover_slot() and recover_done() are also called when the node joins initially in order to inform the node with its slot number. These slot numbers start from one, so we deduct one to make it start with zero which the cluster-md code uses. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-03-30 05:42:49 +00:00
int (*slot_number)(struct mddev *mddev);
Gather on-going resync information of other nodes When a node joins, it does not know of other nodes performing resync. So, each node keeps the resync information in it's LVB. When a new node joins, it reads the LVB of each "online" bitmap. [TODO] The new node attempts to get the PW lock on other bitmap, if it is successful, it reads the bitmap and performs the resync (if required) on it's behalf. If the node does not get the PW, it requests CR and reads the LVB for the resync information. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-06-06 17:35:34 +00:00
void (*resync_info_update)(struct mddev *mddev, sector_t lo, sector_t hi);
Send RESYNCING while performing resync start/stop When a resync is initiated, RESYNCING message is sent to all active nodes with the range (lo,hi). When the resync is over, a RESYNCING message is sent with (0,0). A high sector value of zero indicates that the resync is over. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-06-07 07:16:58 +00:00
int (*resync_start)(struct mddev *mddev, sector_t lo, sector_t hi);
void (*resync_finish)(struct mddev *mddev);
metadata_update sends message to other nodes - request to send a message - make changes to superblock - send messages telling everyone that the superblock has changed - other nodes all read the superblock - other nodes all ack the messages - updating node release the "I'm sending a message" resource. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-06-07 06:44:51 +00:00
int (*metadata_update_start)(struct mddev *mddev);
int (*metadata_update_finish)(struct mddev *mddev);
int (*metadata_update_cancel)(struct mddev *mddev);
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>
2015-06-24 14:30:32 +00:00
int (*area_resyncing)(struct mddev *mddev, int direction, sector_t lo, sector_t hi);
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>
2014-10-29 23:51:31 +00:00
int (*add_new_disk_start)(struct mddev *mddev, struct md_rdev *rdev);
int (*add_new_disk_finish)(struct mddev *mddev);
md: Fix stray --cluster-confirm crash A --cluster-confirm without an --add (by another node) can crash the kernel. Fix it by guarding it using a state. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-02 16:55:49 +00:00
int (*new_disk_ack)(struct mddev *mddev, bool ack);
md-cluster: remove capabilities This adds "remove" capabilities for the clustered environment. When a user initiates removal of a device from the array, a REMOVE message with disk number in the array is sent to all the nodes which kick the respective device in their own array. This facilitates the removal of failed devices. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-14 15:44:44 +00:00
int (*remove_disk)(struct mddev *mddev, struct md_rdev *rdev);
md-cluster: re-add capabilities When "re-add" is writted to /sys/block/mdXX/md/dev-YYY/state, the clustered md: 1. Sends RE_ADD message with the desc_nr. Nodes receiving the message clear the Faulty bit in their respective rdev->flags. 2. The node initiating re-add, gathers the bitmaps of all nodes and copies them into the local bitmap. It does not clear the bitmap from which it is copying. 3. Initiating node schedules a md recovery to sync the devices. Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-14 15:45:42 +00:00
int (*gather_bitmaps)(struct md_rdev *rdev);
Introduce md_cluster_operations to handle cluster functions This allows dynamic registering of cluster hooks. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
2014-03-29 15:01:53 +00:00
};
#endif /* _MD_CLUSTER_H */
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