On Thu 03-06-21 18:31:54, Roman Gushchin wrote:
> If an inode's state has I_WILL_FREE flag set, the inode will be
> freed soon, so there is no point in trying to switch the inode
> to a different cgwb.
>
> I_WILL_FREE was ignored since the introduction of the inode switching,
> so it looks like it doesn't lead to any noticeable issues for a user.
> This is why the patch is not intended for a stable backport.
>
> Suggested-by: Jan Kara <jack@xxxxxxx>
> Signed-off-by: Roman Gushchin <guro@xxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/fs-writeback.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index e91980f49388..bd99890599e0 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -389,10 +389,10 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
> xa_lock_irq(&mapping->i_pages);
>
> /*
> - * Once I_FREEING is visible under i_lock, the eviction path owns
> - * the inode and we shouldn't modify ->i_io_list.
> + * Once I_FREEING or I_WILL_FREE are visible under i_lock, the eviction
> + * path owns the inode and we shouldn't modify ->i_io_list.
> */
> - if (unlikely(inode->i_state & I_FREEING))
> + if (unlikely(inode->i_state & (I_FREEING | I_WILL_FREE)))
> goto skip_switch;
>
> trace_inode_switch_wbs(inode, old_wb, new_wb);
> @@ -517,7 +517,7 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
> /* while holding I_WB_SWITCH, no one else can update the association */
> spin_lock(&inode->i_lock);
> if (!(inode->i_sb->s_flags & SB_ACTIVE) ||
> - inode->i_state & (I_WB_SWITCH | I_FREEING) ||
> + inode->i_state & (I_WB_SWITCH | I_FREEING | I_WILL_FREE) ||
> inode_to_wb(inode) == isw->new_wb) {
> spin_unlock(&inode->i_lock);
> goto out_free;
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
