Re: [PATCH] fix inode state corruption (2.6.8-rc1-bk1)

[Andrew Morton <akpm@osdl.org>]

Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> This patch fixes a hard-to-trigger condition, where the inode is on
>  the inode_in_use list while it's state is dirty.  In this state dirty
>  pages are not written back in sync() or from kupdate, only from direct
>  page reclaim.  And this causes a livelock in balance_dirty_pages after
>  a while.

How ghastly.

Why did you make the list movement conditional on non-zero `wait'?

It would be equivalent to remove these lines from __mark_inode_dirty():

		/*
		 * If the inode is locked, just update its dirty state. 
		 * The unlocker will place the inode on the appropriate
		 * superblock list, based upon its state.
		 */
		if (inode->i_state & I_LOCK)
			goto out;

but probably not so good, because that could cause other tasks to come
around and wait on this inode while it is under writeout instead of writing
back different inodes.