Re: [PATCH v2] vfs: __read_cache_page should use gfp argument rather than GFP_KERNEL

[Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>]

On Wed, 21 Dec 2011 11:05:48 -0600
Dave Kleikamp <dave.kleikamp@xxxxxxxxxx> wrote:

> [ updated to remove now-obsolete comment in read_cache_page_gfp()]
> 
> lockdep reports a deadlock in jfs because a special inode's rw semaphore
> is taken recursively. The mapping's gfp mask is GFP_NOFS, but is not used
> when __read_cache_page() calls add_to_page_cache_lru().

Well hang on, it's not just a lockdep splat.  The kernel actually will
deadlock if we reenter JFS via this GFP_KERNEL allocation attempt, yes?

Was that GFP_NOFS allocation recently added to JFS?  If not then we
should backport this deadlock fix into -stable, no?


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