diff mbox series

[1/3] ext4: fix overhead calculation to account for the reserved gdt blocks

Message ID 20220415025440.2342107-1-tytso@mit.edu
State Awaiting Upstream
Headers show
Series [1/3] ext4: fix overhead calculation to account for the reserved gdt blocks | expand

Commit Message

Theodore Ts'o April 15, 2022, 2:54 a.m. UTC 
The kernel calculation was underestimating the overhead by not taking
into account the reserved gdt blocks.  With this change, the overhead
calculated by the kernel matches the overhead calculation in mke2fs.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
---
 fs/ext4/super.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f2a5e78f93a9..23a9b2c086ed 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4177,9 +4177,11 @@  static int count_overhead(struct super_block *sb, ext4_group_t grp,
 	ext4_fsblk_t		first_block, last_block, b;
 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
 	int			s, j, count = 0;
+	int			has_super = ext4_bg_has_super(sb, grp);
 
 	if (!ext4_has_feature_bigalloc(sb))
-		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
+		return (has_super + ext4_bg_num_gdb(sb, grp) +
+			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
 			sbi->s_itb_per_group + 2);
 
 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +