ext4: Use bitops to read/modify EXT4_I(inode)->i_state

ext4: Use bitops to read/modify EXT4_I(inode)->i_state

commit 19f5fb7ad679bb361222c7916086435020c37cce upstream (as of v2.6.33-git11)

At several places we modify EXT4_I(inode)->i_state without holding
i_mutex (ext4_release_file, ext4_bmap, ext4_journalled_writepage,
ext4_do_update_inode, ...). These modifications are racy and we can
lose updates to i_state. So convert handling of i_state to use bitops
which are atomic.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>