xfs_fs_nr_cached_objects() touches sb->s_fs_info, and this patch makes it to be destructed later. After this patch xfs_fs_nr_cached_objects() is safe for splitting unregister_shrinker(): mp->m_perag_tree is stable till destroy_super_work(), while iteration over it is already RCU-protected by internal XFS business. Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> --- fs/xfs/xfs_super.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 9e2ce4cd98e1..c1e00dd06893 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1774,11 +1774,20 @@ xfs_fs_put_super( xfs_destroy_mount_workqueues(mp); xfs_close_devices(mp); - sb->s_fs_info = NULL; xfs_free_fsname(mp); - kfree(mp); } +STATIC void +xfs_fs_destroy_super( + struct super_block *sb) +{ + if (sb->s_fs_info) { + kfree(sb->s_fs_info); + sb->s_fs_info = NULL; + } +} + + STATIC struct dentry * xfs_fs_mount( struct file_system_type *fs_type, @@ -1816,6 +1825,7 @@ static const struct super_operations xfs_super_operations = { .dirty_inode = xfs_fs_dirty_inode, .drop_inode = xfs_fs_drop_inode, .put_super = xfs_fs_put_super, + .destroy_super = xfs_fs_destroy_super, .sync_fs = xfs_fs_sync_fs, .freeze_fs = xfs_fs_freeze, .unfreeze_fs = xfs_fs_unfreeze,