On Fri, Feb 24, 2017 at 11:15:21AM +0800, Guoqing Jiang wrote:
> 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().
>
> Reviewed-by: NeilBrown <neilb@xxxxxxxx>
> Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
> ---
> drivers/md/bitmap.c | 25 ++++++++++++++++++++-
> drivers/md/bitmap.h | 2 ++
> drivers/md/md-cluster.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 84 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
> index 9fb2ccac958a..67a7d399f501 100644
> --- a/drivers/md/bitmap.c
> +++ b/drivers/md/bitmap.c
> @@ -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 @@ int bitmap_load(struct mddev *mddev)
> }
> 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
> */
> diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
> index 5b6dd63dda91..9f761097aab2 100644
> --- a/drivers/md/bitmap.h
> +++ b/drivers/md/bitmap.h
> @@ -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
> diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
> index f1b9a7a3ddd2..d3c024e6bfcf 100644
> --- a/drivers/md/md-cluster.c
> +++ b/drivers/md/md-cluster.c
> @@ -1089,6 +1089,64 @@ static void metadata_update_cancel(struct mddev *mddev)
> unlock_comm(cinfo);
> }
>
> +/*
> + * retun 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);
> + }
just print error here?
> + bm_lockres->flags |= DLM_LKF_NOQUEUE;
> + rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
> + if (!rv)
> + bitmap_update_sb(bitmap);
always the sb even the sync_size is the same?
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