[PATCH 4.14 183/228] ext2: fix missing percpu_counter_inc

[Greg Kroah-Hartman]

From: Mikulas Patocka <mpatocka@xxxxxxxxxx>

commit bc2fbaa4d3808aef82dd1064a8e61c16549fe956 upstream.

sbi->s_freeinodes_counter is only decreased by the ext2 code, it is never
increased. This patch fixes it.

Note that sbi->s_freeinodes_counter is only used in the algorithm that
tries to find the group for new allocations, so this bug is not easily
visible (the only visibility is that the group finding algorithm selects
inoptinal result).

Link: https://lore.kernel.org/r/alpine.LRH.2.02.2004201538300.19436@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/ext2/ialloc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -80,6 +80,7 @@ static void ext2_release_inode(struct su
 	if (dir)
 		le16_add_cpu(&desc->bg_used_dirs_count, -1);
 	spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
+	percpu_counter_inc(&EXT2_SB(sb)->s_freeinodes_counter);
 	if (dir)
 		percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
 	mark_buffer_dirty(bh);
@@ -531,7 +532,7 @@ got:
 		goto fail;
 	}
 
-	percpu_counter_add(&sbi->s_freeinodes_counter, -1);
+	percpu_counter_dec(&sbi->s_freeinodes_counter);
 	if (S_ISDIR(mode))
 		percpu_counter_inc(&sbi->s_dirs_counter);