Hi Jan,
On Thu, Jun 11, 2020 at 10:12 AM Jan Kara <jack@xxxxxxx> wrote:
>
> Currently, operations on inode->i_io_list are protected by
> wb->list_lock. In the following patches we'll need to maintain
> consistency between inode->i_state and inode->i_io_list so change the
> code so that inode->i_lock protects also all inode's i_io_list handling.
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
LGTM.
Reviewed-by: Martijn Coenen <maco@xxxxxxxxxxx>
> ---
> fs/fs-writeback.c | 22 +++++++++++++++++-----
> 1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index a605c3dddabc..ff0b18331590 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -144,6 +144,7 @@ static void inode_io_list_del_locked(struct inode *inode,
> struct bdi_writeback *wb)
> {
> assert_spin_locked(&wb->list_lock);
> + assert_spin_locked(&inode->i_lock);
>
> list_del_init(&inode->i_io_list);
> wb_io_lists_depopulated(wb);
> @@ -1122,7 +1123,9 @@ void inode_io_list_del(struct inode *inode)
> struct bdi_writeback *wb;
>
> wb = inode_to_wb_and_lock_list(inode);
> + spin_lock(&inode->i_lock);
> inode_io_list_del_locked(inode, wb);
> + spin_unlock(&inode->i_lock);
> spin_unlock(&wb->list_lock);
> }
> EXPORT_SYMBOL(inode_io_list_del);
> @@ -1172,8 +1175,10 @@ void sb_clear_inode_writeback(struct inode *inode)
> * the case then the inode must have been redirtied while it was being written
> * out and we don't reset its dirtied_when.
> */
> -static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
> +static void redirty_tail_locked(struct inode *inode, struct bdi_writeback *wb)
> {
> + assert_spin_locked(&inode->i_lock);
> +
> if (!list_empty(&wb->b_dirty)) {
> struct inode *tail;
>
> @@ -1184,6 +1189,13 @@ static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
> inode_io_list_move_locked(inode, wb, &wb->b_dirty);
> }
>
> +static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
> +{
> + spin_lock(&inode->i_lock);
> + redirty_tail_locked(inode, wb);
> + spin_unlock(&inode->i_lock);
> +}
> +
> /*
> * requeue inode for re-scanning after bdi->b_io list is exhausted.
> */
> @@ -1394,7 +1406,7 @@ static void requeue_inode(struct inode *inode, struct bdi_writeback *wb,
> * writeback is not making progress due to locked
> * buffers. Skip this inode for now.
> */
> - redirty_tail(inode, wb);
> + redirty_tail_locked(inode, wb);
> return;
> }
>
> @@ -1414,7 +1426,7 @@ static void requeue_inode(struct inode *inode, struct bdi_writeback *wb,
> * retrying writeback of the dirty page/inode
> * that cannot be performed immediately.
> */
> - redirty_tail(inode, wb);
> + redirty_tail_locked(inode, wb);
> }
> } else if (inode->i_state & I_DIRTY) {
> /*
> @@ -1422,7 +1434,7 @@ static void requeue_inode(struct inode *inode, struct bdi_writeback *wb,
> * such as delayed allocation during submission or metadata
> * updates after data IO completion.
> */
> - redirty_tail(inode, wb);
> + redirty_tail_locked(inode, wb);
> } else if (inode->i_state & I_DIRTY_TIME) {
> inode->dirtied_when = jiffies;
> inode_io_list_move_locked(inode, wb, &wb->b_dirty_time);
> @@ -1669,8 +1681,8 @@ static long writeback_sb_inodes(struct super_block *sb,
> */
> spin_lock(&inode->i_lock);
> if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
> + redirty_tail_locked(inode, wb);
> spin_unlock(&inode->i_lock);
> - redirty_tail(inode, wb);
> continue;
> }
> if ((inode->i_state & I_SYNC) && wbc.sync_mode != WB_SYNC_ALL) {
> --
> 2.16.4
>
