From b98938d16a108d0201d54b8db1337dac71aebfdd Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Wed, 1 Mar 2017 16:42:39 +0800 Subject: [PATCH] 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: NeilBrown Signed-off-by: Guoqing Jiang Signed-off-by: Shaohua Li --- drivers/md/bitmap.c | 41 +++++++++++++++++++++------- drivers/md/bitmap.h | 2 ++ drivers/md/md-cluster.c | 60 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+), 10 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 9fb2ccac958a..b6fa55a3cff8 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 @@ 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); 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 8b7d55bf5aa2..92c3c51ede4d 100644 --- a/drivers/md/md-cluster.c +++ b/drivers/md/md-cluster.c @@ -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; -- 2.20.1