Re: The bug of iput() removal from flusher thread?

From: Dave Chinner
Date: Tue Nov 20 2012 - 21:43:58 EST


On Wed, Nov 21, 2012 at 02:48:51AM +0100, Jan Kara wrote:
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index 51ea267..3e3422f 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -228,6 +228,8 @@ static void requeue_io(struct inode *inode, struct bdi_writeback *wb)
> static void inode_sync_complete(struct inode *inode)
> {
> inode->i_state &= ~I_SYNC;
> + /* If inode is clean an unused, put it into LRU now... */
> + inode_add_lru(inode);
> /* Waiters must see I_SYNC cleared before being woken up */
> smp_mb();
> wake_up_bit(&inode->i_state, __I_SYNC);
> diff --git a/fs/inode.c b/fs/inode.c
> index b03c719..8f6396f 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -408,6 +408,19 @@ static void inode_lru_list_add(struct inode *inode)
> spin_unlock(&inode->i_sb->s_inode_lru_lock);
> }
>
> +/*
> + * Add inode to LRU if needed (inode is unused and clean).
> + *
> + * Needs inode->i_lock held.
> + */
> +void inode_add_lru(struct inode *inode)
> +{
> + if (!(inode->i_state & (I_DIRTY | I_FREEING | I_SYNC)) &&
> + !atomic_read(&inode->i_count) && inode->i_sb->s_flags & MS_ACTIVE)
> + inode_lru_list_add(inode);

Needs to avoid I_WILL_FREE as well. There's no point putting it on
the LRU if we are writing from iput_final()....

Otherwise looks OK.

Cheers,

Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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