ext4: remove call to ext4_group_desc() in ext4_group_used_meta_blocks() (e187c658) · Commits · 戴 / test

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>

fs/ext4/balloc.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -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);
		}

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