[PATCH v4 14/24] ext4: prepare buddy cache inode for BS > PS with large folios

[libaokun@huaweicloud.com]

From: Baokun Li <libaokun1@huawei.com>

We use EXT4_BAD_INO for the buddy cache inode number. This inode is not
accessed via __ext4_new_inode() or __ext4_iget(), meaning
ext4_set_inode_mapping_order() is not called to set its folio order range.

However, future block size greater than page size support requires this
inode to support large folios, and the buddy cache code already handles
BS > PS. Therefore, ext4_set_inode_mapping_order() is now explicitly
called for this specific inode to set its folio order range.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/mballoc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 3f10c64ab2b1..102c6439eb11 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3493,6 +3493,8 @@ static int ext4_mb_init_backend(struct super_block *sb)
 	 * this will avoid confusion if it ever shows up during debugging. */
 	sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
 	EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
+	ext4_set_inode_mapping_order(sbi->s_buddy_cache);
+
 	for (i = 0; i < ngroups; i++) {
 		cond_resched();
 		desc = ext4_get_group_desc(sb, i, NULL);
-- 
2.46.1