Update flex_bg free blocks and free inodes counters when resizing.

This fixes a bug which prevented the newly created inodes after a
resize from being used on filesystems with flex_bg.

Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

2 files changed, 14 insertions, 2 deletions

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 4392e3fd0f0f..b60afbcd7e46 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -929,6 +929,15 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
         percpu_counter_add(&sbi->s_freeinodes_counter,
                            EXT4_INODES_PER_GROUP(sb));
 
+        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
+                ext4_group_t flex_group;
+                flex_group = ext4_flex_group(sbi, input->group);
+                sbi->s_flex_groups[flex_group].free_blocks +=
+                        input->free_blocks_count;
+                sbi->s_flex_groups[flex_group].free_inodes +=
+                        EXT4_INODES_PER_GROUP(sb);
+        }
+
         ext4_journal_dirty_metadata(handle, sbi->s_sbh);
         sb->s_dirt = 1;
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index efa40d9d3792..f58cc0309dc9 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1507,8 +1507,11 @@ static int ext4_fill_flex_info(struct super_block *sb)
         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
 
-        flex_group_count = (sbi->s_groups_count + groups_per_flex - 1) /
-                groups_per_flex;
+        /* We allocate both existing and potentially added groups */
+        flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
+                            ((sbi->s_es->s_reserved_gdt_blocks +1 ) <<
+                              EXT4_DESC_PER_BLOCK_BITS(sb))) /
+                           groups_per_flex;
         sbi->s_flex_groups = kzalloc(flex_group_count *
                                      sizeof(struct flex_groups), GFP_KERNEL);
         if (sbi->s_flex_groups == NULL) {