Merge branch 'cleanup/blocksize-diet-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus

13 files changed, 84 insertions, 73 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index f64471e..6b2ec90 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1371,8 +1371,7 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
 
 	if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
 		BUG_ON(tm->slot != 0);
-		eb_rewin = alloc_dummy_extent_buffer(eb->start,
-						fs_info->tree_root->nodesize);
+		eb_rewin = alloc_dummy_extent_buffer(fs_info, eb->start);
 		if (!eb_rewin) {
 			btrfs_tree_read_unlock_blocking(eb);
 			free_extent_buffer(eb);
@@ -1452,7 +1451,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 	} else if (old_root) {
 		btrfs_tree_read_unlock(eb_root);
 		free_extent_buffer(eb_root);
-		eb = alloc_dummy_extent_buffer(logical, root->nodesize);
+		eb = alloc_dummy_extent_buffer(root->fs_info, logical);
 	} else {
 		btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK);
 		eb = btrfs_clone_extent_buffer(eb_root);
@@ -2290,7 +2289,7 @@ static void reada_for_search(struct btrfs_root *root,
 		if ((search <= target && target - search <= 65536) ||
 		    (search > target && search - target <= 65536)) {
 			gen = btrfs_node_ptr_generation(node, nr);
-			readahead_tree_block(root, search, blocksize);
+			readahead_tree_block(root, search);
 			nread += blocksize;
 		}
 		nscan++;
@@ -2309,7 +2308,6 @@ static noinline void reada_for_balance(struct btrfs_root *root,
 	u64 gen;
 	u64 block1 = 0;
 	u64 block2 = 0;
-	int blocksize;
 
 	parent = path->nodes[level + 1];
 	if (!parent)
@@ -2317,7 +2315,6 @@ static noinline void reada_for_balance(struct btrfs_root *root,
 
 	nritems = btrfs_header_nritems(parent);
 	slot = path->slots[level + 1];
-	blocksize = root->nodesize;
 
 	if (slot > 0) {
 		block1 = btrfs_node_blockptr(parent, slot - 1);
@@ -2342,9 +2339,9 @@ static noinline void reada_for_balance(struct btrfs_root *root,
 	}
 
 	if (block1)
-		readahead_tree_block(root, block1, blocksize);
+		readahead_tree_block(root, block1);
 	if (block2)
-		readahead_tree_block(root, block2, blocksize);
+		readahead_tree_block(root, block2);
 }
 
 
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8d48660..65384de 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1073,12 +1073,12 @@ static const struct address_space_operations btree_aops = {
 	.set_page_dirty = btree_set_page_dirty,
 };
 
-void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
+void readahead_tree_block(struct btrfs_root *root, u64 bytenr)
 {
 	struct extent_buffer *buf = NULL;
 	struct inode *btree_inode = root->fs_info->btree_inode;
 
-	buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
+	buf = btrfs_find_create_tree_block(root, bytenr);
 	if (!buf)
 		return;
 	read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
@@ -1086,7 +1086,7 @@ void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 	free_extent_buffer(buf);
 }
 
-int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
 			 int mirror_num, struct extent_buffer **eb)
 {
 	struct extent_buffer *buf = NULL;
@@ -1094,7 +1094,7 @@ int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 	struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
 	int ret;
 
-	buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
+	buf = btrfs_find_create_tree_block(root, bytenr);
 	if (!buf)
 		return 0;
 
@@ -1125,12 +1125,11 @@ struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 }
 
 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
-						 u64 bytenr, u32 blocksize)
+						 u64 bytenr)
 {
 	if (btrfs_test_is_dummy_root(root))
-		return alloc_test_extent_buffer(root->fs_info, bytenr,
-						blocksize);
-	return alloc_extent_buffer(root->fs_info, bytenr, blocksize);
+		return alloc_test_extent_buffer(root->fs_info, bytenr);
+	return alloc_extent_buffer(root->fs_info, bytenr);
 }
 
 
@@ -1152,7 +1151,7 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 	struct extent_buffer *buf = NULL;
 	int ret;
 
-	buf = btrfs_find_create_tree_block(root, bytenr, root->nodesize);
+	buf = btrfs_find_create_tree_block(root, bytenr);
 	if (!buf)
 		return NULL;
 
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 4146518..27d44c0 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -46,11 +46,11 @@ struct btrfs_fs_devices;
 
 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 				      u64 parent_transid);
-void readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize);
-int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+void readahead_tree_block(struct btrfs_root *root, u64 bytenr);
+int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr,
 			 int mirror_num, struct extent_buffer **eb);
 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
-						   u64 bytenr, u32 blocksize);
+						   u64 bytenr);
 void clean_tree_block(struct btrfs_trans_handle *trans,
 		      struct btrfs_root *root, struct extent_buffer *buf);
 int open_ctree(struct super_block *sb,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 21c373f..1c591d6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -7149,11 +7149,11 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
 
 static struct extent_buffer *
 btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		      u64 bytenr, u32 blocksize, int level)
+		      u64 bytenr, int level)
 {
 	struct extent_buffer *buf;
 
-	buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
+	buf = btrfs_find_create_tree_block(root, bytenr);
 	if (!buf)
 		return ERR_PTR(-ENOMEM);
 	btrfs_set_header_generation(buf, trans->transid);
@@ -7272,7 +7272,7 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 
 	if (btrfs_test_is_dummy_root(root)) {
 		buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
-					    blocksize, level);
+					    level);
 		if (!IS_ERR(buf))
 			root->alloc_bytenr += blocksize;
 		return buf;
@@ -7289,8 +7289,7 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 		return ERR_PTR(ret);
 	}
 
-	buf = btrfs_init_new_buffer(trans, root, ins.objectid,
-				    blocksize, level);
+	buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
 	BUG_ON(IS_ERR(buf)); /* -ENOMEM */
 
 	if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
@@ -7419,7 +7418,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
 				continue;
 		}
 reada:
-		readahead_tree_block(root, bytenr, blocksize);
+		readahead_tree_block(root, bytenr);
 		nread++;
 	}
 	wc->reada_slot = slot;
@@ -7760,7 +7759,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 
 	next = btrfs_find_tree_block(root, bytenr);
 	if (!next) {
-		next = btrfs_find_create_tree_block(root, bytenr, blocksize);
+		next = btrfs_find_create_tree_block(root, bytenr);
 		if (!next)
 			return -ENOMEM;
 		btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 4ebabd2..c4ca90a 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4598,11 +4598,11 @@ static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
 
 static struct extent_buffer *
 __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
-		      unsigned long len, gfp_t mask)
+		      unsigned long len)
 {
 	struct extent_buffer *eb = NULL;
 
-	eb = kmem_cache_zalloc(extent_buffer_cache, mask);
+	eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS);
 	if (eb == NULL)
 		return NULL;
 	eb->start = start;
@@ -4643,7 +4643,7 @@ struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
 	struct extent_buffer *new;
 	unsigned long num_pages = num_extent_pages(src->start, src->len);
 
-	new = __alloc_extent_buffer(NULL, src->start, src->len, GFP_NOFS);
+	new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
 	if (new == NULL)
 		return NULL;
 
@@ -4666,13 +4666,26 @@ struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
 	return new;
 }
 
-struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len)
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+						u64 start)
 {
 	struct extent_buffer *eb;
-	unsigned long num_pages = num_extent_pages(0, len);
+	unsigned long len;
+	unsigned long num_pages;
 	unsigned long i;
 
-	eb = __alloc_extent_buffer(NULL, start, len, GFP_NOFS);
+	if (!fs_info) {
+		/*
+		 * Called only from tests that don't always have a fs_info
+		 * available, but we know that nodesize is 4096
+		 */
+		len = 4096;
+	} else {
+		len = fs_info->tree_root->nodesize;
+	}
+	num_pages = num_extent_pages(0, len);
+
+	eb = __alloc_extent_buffer(fs_info, start, len);
 	if (!eb)
 		return NULL;
 
@@ -4762,7 +4775,7 @@ struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
-					       u64 start, unsigned long len)
+					       u64 start)
 {
 	struct extent_buffer *eb, *exists = NULL;
 	int ret;
@@ -4770,7 +4783,7 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 	eb = find_extent_buffer(fs_info, start);
 	if (eb)
 		return eb;
-	eb = alloc_dummy_extent_buffer(start, len);
+	eb = alloc_dummy_extent_buffer(fs_info, start);
 	if (!eb)
 		return NULL;
 	eb->fs_info = fs_info;
@@ -4808,8 +4821,9 @@ free_eb:
 #endif
 
 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
-					  u64 start, unsigned long len)
+					  u64 start)
 {
+	unsigned long len = fs_info->tree_root->nodesize;
 	unsigned long num_pages = num_extent_pages(start, len);
 	unsigned long i;
 	unsigned long index = start >> PAGE_CACHE_SHIFT;
@@ -4824,7 +4838,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 	if (eb)
 		return eb;
 
-	eb = __alloc_extent_buffer(fs_info, start, len, GFP_NOFS);
+	eb = __alloc_extent_buffer(fs_info, start, len);
 	if (!eb)
 		return NULL;
 
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index ece9ce8..71268e5 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -262,8 +262,9 @@ int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private);
 void set_page_extent_mapped(struct page *page);
 
 struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
-					  u64 start, unsigned long len);
-struct extent_buffer *alloc_dummy_extent_buffer(u64 start, unsigned long len);
+					  u64 start);
+struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
+		u64 start);
 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 					 u64 start);
@@ -377,5 +378,5 @@ noinline u64 find_lock_delalloc_range(struct inode *inode,
 				      u64 *end, u64 max_bytes);
 #endif
 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
-					       u64 start, unsigned long len);
+					       u64 start);
 #endif
diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index b63ae20..4d3d4e5 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -66,7 +66,6 @@ struct reada_extctl {
 struct reada_extent {
 	u64			logical;
 	struct btrfs_key	top;
-	u32			blocksize;
 	int			err;
 	struct list_head	extctl;
 	int 			refcnt;
@@ -349,7 +348,6 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
 
 	blocksize = root->nodesize;
 	re->logical = logical;
-	re->blocksize = blocksize;
 	re->top = *top;
 	INIT_LIST_HEAD(&re->extctl);
 	spin_lock_init(&re->lock);
@@ -660,7 +658,6 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
 	int mirror_num = 0;
 	struct extent_buffer *eb = NULL;
 	u64 logical;
-	u32 blocksize;
 	int ret;
 	int i;
 	int need_kick = 0;
@@ -694,7 +691,7 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
 		spin_unlock(&fs_info->reada_lock);
 		return 0;
 	}
-	dev->reada_next = re->logical + re->blocksize;
+	dev->reada_next = re->logical + fs_info->tree_root->nodesize;
 	re->refcnt++;
 
 	spin_unlock(&fs_info->reada_lock);
@@ -709,7 +706,6 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
 		}
 	}
 	logical = re->logical;
-	blocksize = re->blocksize;
 
 	spin_lock(&re->lock);
 	if (re->scheduled_for == NULL) {
@@ -724,8 +720,8 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
 		return 0;
 
 	atomic_inc(&dev->reada_in_flight);
-	ret = reada_tree_block_flagged(fs_info->extent_root, logical, blocksize,
-			 mirror_num, &eb);
+	ret = reada_tree_block_flagged(fs_info->extent_root, logical,
+			mirror_num, &eb);
 	if (ret)
 		__readahead_hook(fs_info->extent_root, NULL, logical, ret);
 	else if (eb)
@@ -851,7 +847,7 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
 				break;
 			printk(KERN_DEBUG
 				"  re: logical %llu size %u empty %d for %lld",
-				re->logical, re->blocksize,
+				re->logical, fs_info->tree_root->nodesize,
 				list_empty(&re->extctl), re->scheduled_for ?
 				re->scheduled_for->devid : -1);
 
@@ -886,7 +882,8 @@ static void dump_devs(struct btrfs_fs_info *fs_info, int all)
 		}
 		printk(KERN_DEBUG
 			"re: logical %llu size %u list empty %d for %lld",
-			re->logical, re->blocksize, list_empty(&re->extctl),
+			re->logical, fs_info->tree_root->nodesize,
+			list_empty(&re->extctl),
 			re->scheduled_for ? re->scheduled_for->devid : -1);
 		for (i = 0; i < re->nzones; ++i) {
 			printk(KERN_CONT " zone %llu-%llu devs",
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 74257d6..d830853 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2855,9 +2855,10 @@ static void update_processed_blocks(struct reloc_control *rc,
 	}
 }
 
-static int tree_block_processed(u64 bytenr, u32 blocksize,
-				struct reloc_control *rc)
+static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
 {
+	u32 blocksize = rc->extent_root->nodesize;
+
 	if (test_range_bit(&rc->processed_blocks, bytenr,
 			   bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
 		return 1;
@@ -2965,8 +2966,7 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
 	while (rb_node) {
 		block = rb_entry(rb_node, struct tree_block, rb_node);
 		if (!block->key_ready)
-			readahead_tree_block(rc->extent_root, block->bytenr,
-					block->key.objectid);
+			readahead_tree_block(rc->extent_root, block->bytenr);
 		rb_node = rb_next(rb_node);
 	}
 
@@ -3353,7 +3353,7 @@ static int __add_tree_block(struct reloc_control *rc,
 	bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
 					SKINNY_METADATA);
 
-	if (tree_block_processed(bytenr, blocksize, rc))
+	if (tree_block_processed(bytenr, rc))
 		return 0;
 
 	if (tree_search(blocks, bytenr))
@@ -3611,7 +3611,7 @@ static int find_data_references(struct reloc_control *rc,
 		if (added)
 			goto next;
 
-		if (!tree_block_processed(leaf->start, leaf->len, rc)) {
+		if (!tree_block_processed(leaf->start, rc)) {
 			block = kmalloc(sizeof(*block), GFP_NOFS);
 			if (!block) {
 				err = -ENOMEM;
diff --git a/fs/btrfs/tests/extent-buffer-tests.c b/fs/btrfs/tests/extent-buffer-tests.c
index cc286ce..f51963a 100644
--- a/fs/btrfs/tests/extent-buffer-tests.c
+++ b/fs/btrfs/tests/extent-buffer-tests.c
@@ -53,7 +53,7 @@ static int test_btrfs_split_item(void)
 		return -ENOMEM;
 	}
 
-	path->nodes[0] = eb = alloc_dummy_extent_buffer(0, 4096);
+	path->nodes[0] = eb = alloc_dummy_extent_buffer(NULL, 4096);
 	if (!eb) {
 		test_msg("Could not allocate dummy buffer\n");
 		ret = -ENOMEM;
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
index 3ae0f5b..a116b55 100644
--- a/fs/btrfs/tests/inode-tests.c
+++ b/fs/btrfs/tests/inode-tests.c
@@ -255,7 +255,7 @@ static noinline int test_btrfs_get_extent(void)
 		goto out;
 	}
 
-	root->node = alloc_dummy_extent_buffer(0, 4096);
+	root->node = alloc_dummy_extent_buffer(NULL, 4096);
 	if (!root->node) {
 		test_msg("Couldn't allocate dummy buffer\n");
 		goto out;
@@ -843,7 +843,7 @@ static int test_hole_first(void)
 		goto out;
 	}
 
-	root->node = alloc_dummy_extent_buffer(0, 4096);
+	root->node = alloc_dummy_extent_buffer(NULL, 4096);
 	if (!root->node) {
 		test_msg("Couldn't allocate dummy buffer\n");
 		goto out;
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index ec3dcb2..73f299e 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -404,12 +404,22 @@ int btrfs_test_qgroups(void)
 		ret = -ENOMEM;
 		goto out;
 	}
+	/* We are using this root as our extent root */
+	root->fs_info->extent_root = root;
+
+	/*
+	 * Some of the paths we test assume we have a filled out fs_info, so we
+	 * just need to add the root in there so we don't panic.
+	 */
+	root->fs_info->tree_root = root;
+	root->fs_info->quota_root = root;
+	root->fs_info->quota_enabled = 1;
 
 	/*
 	 * Can't use bytenr 0, some things freak out
 	 * *cough*backref walking code*cough*
 	 */
-	root->node = alloc_test_extent_buffer(root->fs_info, 4096, 4096);
+	root->node = alloc_test_extent_buffer(root->fs_info, 4096);
 	if (!root->node) {
 		test_msg("Couldn't allocate dummy buffer\n");
 		ret = -ENOMEM;
@@ -448,17 +458,6 @@ int btrfs_test_qgroups(void)
 		goto out;
 	}
 
-	/* We are using this root as our extent root */
-	root->fs_info->extent_root = root;
-
-	/*
-	 * Some of the paths we test assume we have a filled out fs_info, so we
-	 * just need to addt he root in there so we don't panic.
-	 */
-	root->fs_info->tree_root = root;
-	root->fs_info->quota_root = root;
-	root->fs_info->quota_enabled = 1;
-
 	test_msg("Running qgroup tests\n");
 	ret = test_no_shared_qgroup(root);
 	if (ret)
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 25a1c36..67e5bf7 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2165,7 +2165,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 		parent = path->nodes[*level];
 		root_owner = btrfs_header_owner(parent);
 
-		next = btrfs_find_create_tree_block(root, bytenr, blocksize);
+		next = btrfs_find_create_tree_block(root, bytenr);
 		if (!next)
 			return -ENOMEM;
 
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 50c5a87..0d9bfeb 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6247,8 +6247,13 @@ int btrfs_read_sys_array(struct btrfs_root *root)
 	u32 cur;
 	struct btrfs_key key;
 
-	sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
-					  BTRFS_SUPER_INFO_SIZE);
+	ASSERT(BTRFS_SUPER_INFO_SIZE <= root->nodesize);
+	/*
+	 * This will create extent buffer of nodesize, superblock size is
+	 * fixed to BTRFS_SUPER_INFO_SIZE. If nodesize > sb size, this will
+	 * overallocate but we can keep it as-is, only the first page is used.
+	 */
+	sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET);
 	if (!sb)
 		return -ENOMEM;
 	btrfs_set_buffer_uptodate(sb);