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ext4: correct cluster len and clusters changed accounting in ext4_mb_mark_bb

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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@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/a0b035d536bafa88110b74456853774b64c8ac40.1644992609.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Ritesh Harjani 2022-02-16 12:32:43 +05:30 committed by Theodore Ts'o
parent 2d44292058
commit a5c0e2fdf7
1 changed files with 12 additions and 7 deletions
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19
fs/ext4/mballoc.c
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@ -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);