Re: [PATCH 3/4] fs: Lock the inode LRU list separately

From: Christoph Hellwig
Date: Thu Oct 28 2010 - 06:25:36 EST


> That doesn't happen because the counter is only modified when
> the inode is moved on/off the list and there are checks to avoid
> removing an inode that is not on the list. Also, the inode is not
> removed from the LRU in dispose_one_inode - it is always done when
> the inode is marked I_FREEING while the i_lock is held before
> calling dispose_one_inode().
>
> Basically I wanted to remove the strange "inode is not on the LRU if
> it is dirty or under writeback" accounting checks and make the
> accounting symmetric with adding/removing the inodes from the LRU.
> These are protected by list_empty() checks, so should always end up
> with the correct accounting.
>
> hence the only special case now is prune_icache() which already
> holds the inode_lru_lock() so can't call the helper. Besides, we
> don't need any checks there because we know the inode is on the LRU
> already....

Indeed. What about adding a

BUG_ON(!list_empty(&inode->i_lru));

to evict to ensure this invariant?

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/