On Sat 05-02-22 19:39:50, Ritesh Harjani wrote:
> 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: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/mballoc.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index c781974df9d0..2f117ce3bb73 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -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);
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
