ext2: fix missing percpu_counter_inc

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@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index fda7d3f5b4be53161b725a0b6b8a5660027242a7..432c3febea6df969c53ac7ec5b1b76578b93baa0 100644 (file)
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -80,6 +80,7 @@ static void ext2_release_inode(struct super_block *sb, int group, int dir)
        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);
@@ -528,7 +529,7 @@ 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);