ext4: fix overhead calculation used by ext4_statfs()
Commit f975d6bcc7a introduced bug which caused ext4_statfs() to
miscalculate the number of file system overhead blocks. This causes
the f_blocks field in the statfs structure to be larger than it should
be. This would in turn cause the "df" output to show the number of
data blocks in the file system and the number of data blocks used to
be larger than they should be.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 293fa1c..01434f2 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1161,8 +1161,7 @@
unsigned long s_desc_per_block; /* Number of group descriptors per block */
ext4_group_t s_groups_count; /* Number of groups in the fs */
ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
- unsigned long s_overhead_last; /* Last calculated overhead */
- unsigned long s_blocks_last; /* Last seen block count */
+ unsigned long s_overhead; /* # of fs overhead clusters */
unsigned int s_cluster_ratio; /* Number of blocks per cluster */
unsigned int s_cluster_bits; /* log2 of s_cluster_ratio */
loff_t s_bitmap_maxbytes; /* max bytes for bitmap files */
@@ -2037,6 +2036,7 @@
extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
/* super.c */
+extern int ext4_calculate_overhead(struct super_block *sb);
extern int ext4_superblock_csum_verify(struct super_block *sb,
struct ext4_super_block *es);
extern void ext4_superblock_csum_set(struct super_block *sb,