Commit a5c0e2fd authored by Ritesh Harjani's avatar Ritesh Harjani Committed by Theodore Ts'o
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ext4: correct cluster len and clusters changed accounting in ext4_mb_mark_bb 



ext4_mb_mark_bb() currently wrongly calculates cluster len (clen) and
flex_group->free_clusters. This patch fixes that.

Identified based on code review of ext4_mb_mark_bb() function.

Signed-off-by: default avatarRitesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/a0b035d536bafa88110b74456853774b64c8ac40.1644992609.git.riteshh@linux.ibm.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 2d442920

fs/ext4/mballoc.c

+12 −7
Original line number Diff line number Diff line
@@ -3899,10 +3899,11 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, 
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	ext4_group_t group;

	ext4_grpblk_t blkoff;

	int i, clen, err;

	int i, err;

	int already;

	unsigned int clen, clen_changed;



	clen = EXT4_B2C(sbi, len);

	clen = EXT4_NUM_B2C(sbi, len);



	ext4_get_group_no_and_offset(sb, block, &group, &blkoff);

	bitmap_bh = ext4_read_block_bitmap(sb, group);
@@ -3923,6 +3924,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, 
		if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state)

			already++;



	clen_changed = clen - already;

	if (state)

		ext4_set_bits(bitmap_bh->b_data, blkoff, clen);

	else
@@ -3935,9 +3937,9 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, 
						group, gdp));

	}

	if (state)

		clen = ext4_free_group_clusters(sb, gdp) - clen + already;

		clen = ext4_free_group_clusters(sb, gdp) - clen_changed;

	else

		clen = ext4_free_group_clusters(sb, gdp) + clen - already;

		clen = ext4_free_group_clusters(sb, gdp) + clen_changed;



	ext4_free_group_clusters_set(sb, gdp, clen);

	ext4_block_bitmap_csum_set(sb, group, gdp, bitmap_bh);
@@ -3947,10 +3949,13 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, 


	if (sbi->s_log_groups_per_flex) {

		ext4_group_t flex_group = ext4_flex_group(sbi, group);

		struct flex_groups *fg = sbi_array_rcu_deref(sbi,

					   s_flex_groups, flex_group);



		atomic64_sub(len,

			     &sbi_array_rcu_deref(sbi, s_flex_groups,

						  flex_group)->free_clusters);

		if (state)

			atomic64_sub(clen_changed, &fg->free_clusters);

		else

			atomic64_add(clen_changed, &fg->free_clusters);

	}



	err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);