Commit e94987db authored by Goldwyn Rodrigues's avatar Goldwyn Rodrigues
Browse files

Initiate recovery on node failure 



The DLM informs us in case of node failure with the DLM slot number.
cluster_info->recovery_map sets the bit corresponding to the slot number
and wakes up the recovery thread.

The recovery thread:
1. Derives the slot number from the recovery_map
2. Locks the bitmap corresponding to the slot
3. Copies the set bits to the node-local bitmap

Signed-off-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
parent 11dd35da

drivers/md/md-cluster.c

+58 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/dlm.h>

#include <linux/sched.h>

#include "md.h"

#include "bitmap.h"

#include "md-cluster.h"



#define LVB_SIZE	64
@@ -49,6 +50,8 @@ struct md_cluster_info { 
	struct dlm_lock_resource *bitmap_lockres;

	struct list_head suspend_list;

	spinlock_t suspend_lock;

	struct md_thread *recovery_thread;

	unsigned long recovery_map;

};



static void sync_ast(void *arg)
@@ -184,6 +187,50 @@ static struct suspend_info *read_resync_info(struct mddev *mddev, struct dlm_loc 
	return s;

}



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);

		if (ret)

			pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);

		dlm_unlock_sync(bm_lockres);

clear_bit:

		clear_bit(slot, &cinfo->recovery_map);

	}

}



static void recover_prep(void *arg)

{

}
@@ -197,6 +244,16 @@ static void recover_slot(void *arg, struct dlm_slot *slot) 
			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,
@@ -338,6 +395,7 @@ static int leave(struct mddev *mddev) 


	if (!cinfo)

		return 0;

	md_unregister_thread(&cinfo->recovery_thread);

	lockres_free(cinfo->sb_lock);

	lockres_free(cinfo->bitmap_lockres);

	dlm_release_lockspace(cinfo->lockspace, 2);