ext4: remove call to ext4_group_desc() in ext4_group_used_meta_blocks()

The static function ext4_group_used_meta_blocks() only has one caller,
who already has access to the block group's group descriptor.  So it's
better to have ext4_init_block_bitmap() pass the group descriptor to
ext4_group_used_meta_blocks(), so it doesn't need to call
ext4_group_desc().  Previously this function did not check if
ext4_group_desc() returned NULL due to an error, potentially causing a
kernel OOPS report.  This avoids the issue entirely.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 38f40d5..b37b128 100644 (file)
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -55,7 +55,8 @@ static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block,
 }
 
 static int ext4_group_used_meta_blocks(struct super_block *sb,
-                               ext4_group_t block_group)
+                                      ext4_group_t block_group,
+                                      struct ext4_group_desc *gdp)
 {
        ext4_fsblk_t tmp;
        struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -63,10 +64,6 @@ static int ext4_group_used_meta_blocks(struct super_block *sb,
        int used_blocks = sbi->s_itb_per_group + 2;
 
        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
-               struct ext4_group_desc *gdp;
-               struct buffer_head *bh;
-
-               gdp = ext4_get_group_desc(sb, block_group, &bh);
                if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp),
                                        block_group))
                        used_blocks--;
@@ -177,7 +174,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
                 */
                mark_bitmap_end(group_blocks, sb->s_blocksize * 8, bh->b_data);
        }
-       return free_blocks - ext4_group_used_meta_blocks(sb, block_group);
+       return free_blocks - ext4_group_used_meta_blocks(sb, block_group, gdp);
 }