diff mbox series

[4.9,22/24] ext4: fix overhead calculation to account for the reserved gdt blocks

Message ID 20220426081732.028630377@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH April 26, 2022, 8:21 a.m. UTC 
From: Theodore Ts'o <tytso@mit.edu>

commit 10b01ee92df52c8d7200afead4d5e5f55a5c58b1 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/ext4/super.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3241,9 +3241,11 @@  static int count_overhead(struct super_b
 	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) +