From mboxrd@z Thu Jan  1 00:00:00 1970
From: Fengguang Wu <fengguang.wu@intel.com>
Subject: Re: [PATCH 7/7] writeback: Avoid iput() from flusher thread
Date: Thu, 22 Mar 2012 11:01:06 +0800
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Cc: Christoph Hellwig <hch@infradead.org>,
	linux-fsdevel@vger.kernel.org
To: Jan Kara <jack@suse.cz>
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> +/*
> + * Sleep until I_SYNC is cleared. This function must be called with i_lock
> + * held and drops it. It is aimed for callers not holding any inode reference
> + * so once i_lock is dropped, inode can go away.
> + */
> +static void inode_sleep_on_writeback(struct inode *inode)
> +	__releases(inode->i_lock)
> +{
> +	DEFINE_WAIT(wait);
> +	wait_queue_head_t *wqh = bit_waitqueue(&inode->i_state, __I_SYNC);
> +	int sleep;

i_state is "unsigned long", it's better to use the same type.

> +
> +	prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
> +	sleep = inode->i_state & I_SYNC;
> +	spin_unlock(&inode->i_lock);
> +	if (sleep)
> +		schedule();
> +	finish_wait(wqh, &wait);
> +}
> +