Commit b98938d1 authored by Guoqing Jiang's avatar Guoqing Jiang Committed by Shaohua Li
Browse files

md-cluster: introduce cluster_check_sync_size 



Support resize is a little complex for clustered
raid, since we need to ensure all the nodes share
the same knowledge about the size of raid.

We achieve the goal by check the sync_size which
is in each node's bitmap, we can only change the
capacity after cluster_check_sync_size returns 0.

Also, get_bitmap_from_slot is added to get a slot's
bitmap. And we exported some funcs since they are
used in cluster_check_sync_size().

We can also reuse get_bitmap_from_slot to remove
redundant code existed in bitmap_copy_from_slot.

Reviewed-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarGuoqing Jiang <gqjiang@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 7da3d203

drivers/md/bitmap.c

+31 −10
Original line number Diff line number Diff line
@@ -471,6 +471,7 @@ void bitmap_update_sb(struct bitmap *bitmap) 
	kunmap_atomic(sb);

	write_page(bitmap, bitmap->storage.sb_page, 1);

}

EXPORT_SYMBOL(bitmap_update_sb);



/* print out the bitmap file superblock */

void bitmap_print_sb(struct bitmap *bitmap)
@@ -1727,7 +1728,7 @@ void bitmap_flush(struct mddev *mddev) 
/*

 * free memory that was allocated

 */

static void bitmap_free(struct bitmap *bitmap)

void bitmap_free(struct bitmap *bitmap)

{

	unsigned long k, pages;

	struct bitmap_page *bp;
@@ -1761,6 +1762,7 @@ static void bitmap_free(struct bitmap *bitmap) 
	kfree(bp);

	kfree(bitmap);

}

EXPORT_SYMBOL(bitmap_free);



void bitmap_destroy(struct mddev *mddev)

{
@@ -1920,6 +1922,27 @@ out: 
}

EXPORT_SYMBOL_GPL(bitmap_load);



struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)

{

	int rv = 0;

	struct bitmap *bitmap;



	bitmap = bitmap_create(mddev, slot);

	if (IS_ERR(bitmap)) {

		rv = PTR_ERR(bitmap);

		return ERR_PTR(rv);

	}



	rv = bitmap_init_from_disk(bitmap, 0);

	if (rv) {

		bitmap_free(bitmap);

		return ERR_PTR(rv);

	}



	return bitmap;

}

EXPORT_SYMBOL(get_bitmap_from_slot);



/* Loads the bitmap associated with slot and copies the resync information

 * to our bitmap

 */
@@ -1929,14 +1952,13 @@ int bitmap_copy_from_slot(struct mddev *mddev, int slot, 
	int rv = 0, i, j;

	sector_t block, lo = 0, hi = 0;

	struct bitmap_counts *counts;

	struct bitmap *bitmap = bitmap_create(mddev, slot);



	if (IS_ERR(bitmap))

		return PTR_ERR(bitmap);

	struct bitmap *bitmap;



	rv = bitmap_init_from_disk(bitmap, 0);

	if (rv)

		goto err;

	bitmap = get_bitmap_from_slot(mddev, slot);

	if (IS_ERR(bitmap)) {

		pr_err("%s can't get bitmap from slot %d\n", __func__, slot);

		return -1;

	}



	counts = &bitmap->counts;

	for (j = 0; j < counts->chunks; j++) {
@@ -1963,8 +1985,7 @@ int bitmap_copy_from_slot(struct mddev *mddev, int slot, 
	bitmap_unplug(mddev->bitmap);

	*low = lo;

	*high = hi;

err:

	bitmap_free(bitmap);



	return rv;

}

EXPORT_SYMBOL_GPL(bitmap_copy_from_slot);

drivers/md/bitmap.h

+2 −0
Original line number Diff line number Diff line
@@ -267,8 +267,10 @@ void bitmap_daemon_work(struct mddev *mddev); 


int bitmap_resize(struct bitmap *bitmap, sector_t blocks,

		  int chunksize, int init);

struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot);

int bitmap_copy_from_slot(struct mddev *mddev, int slot,

				sector_t *lo, sector_t *hi, bool clear_bits);

void bitmap_free(struct bitmap *bitmap);

#endif



#endif

drivers/md/md-cluster.c

+60 −0
Original line number Diff line number Diff line
@@ -1091,6 +1091,66 @@ static void metadata_update_cancel(struct mddev *mddev) 
	unlock_comm(cinfo);

}



/*

 * return 0 if all the bitmaps have the same sync_size

 */

int cluster_check_sync_size(struct mddev *mddev)

{

	int i, rv;

	bitmap_super_t *sb;

	unsigned long my_sync_size, sync_size = 0;

	int node_num = mddev->bitmap_info.nodes;

	int current_slot = md_cluster_ops->slot_number(mddev);

	struct bitmap *bitmap = mddev->bitmap;

	char str[64];

	struct dlm_lock_resource *bm_lockres;



	sb = kmap_atomic(bitmap->storage.sb_page);

	my_sync_size = sb->sync_size;

	kunmap_atomic(sb);



	for (i = 0; i < node_num; i++) {

		if (i == current_slot)

			continue;



		bitmap = get_bitmap_from_slot(mddev, i);

		if (IS_ERR(bitmap)) {

			pr_err("can't get bitmap from slot %d\n", i);

			return -1;

		}



		/*

		 * If we can hold the bitmap lock of one node then

		 * the slot is not occupied, update the sb.

		 */

		snprintf(str, 64, "bitmap%04d", i);

		bm_lockres = lockres_init(mddev, str, NULL, 1);

		if (!bm_lockres) {

			pr_err("md-cluster: Cannot initialize %s\n", str);

			lockres_free(bm_lockres);

			return -1;

		}

		bm_lockres->flags |= DLM_LKF_NOQUEUE;

		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);

		if (!rv)

			bitmap_update_sb(bitmap);

		lockres_free(bm_lockres);



		sb = kmap_atomic(bitmap->storage.sb_page);

		if (sync_size == 0)

			sync_size = sb->sync_size;

		else if (sync_size != sb->sync_size) {

			kunmap_atomic(sb);

			bitmap_free(bitmap);

			return -1;

		}

		kunmap_atomic(sb);

		bitmap_free(bitmap);

	}



	return (my_sync_size == sync_size) ? 0 : -1;

}



static int resync_start(struct mddev *mddev)

{

	struct md_cluster_info *cinfo = mddev->cluster_info;

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