Re: [RFC] 2.4 truncate locking

[William Lee Irwin III]

On Wed, Apr 17, 2002 at 08:09:12AM -0700, William Lee Irwin III wrote:
> I did some research on how truncate_inode_pages()'s locking works.
> Please feel free to clarify and/or correct my notes on the subject,
> which I'd like to turn into a docpatch soon.
>
> (9) exclusion from simultaneous manipulation of page->mapping
> 	pagemap_lru_lock

This is incorrect. It appears to be a combination of PG_locked and
pagecache_lock, where both are required for writing, and only one of
the two for reading.

Cheers,
Bill