[dm-devel] [RFC PATCH] block: all callers should check blkdev_issue_flush's return

[Joel Becker]

On Tue, Jun 26, 2012 at 11:57:50AM -0400, Mike Snitzer wrote:
> On Tue, Jun 26 2012 at 11:51am -0400,
> Christoph Hellwig <hch at infradead.org> wrote:
> 
> > On Tue, Jun 26, 2012 at 11:27:25AM -0400, Mike Snitzer wrote:
> > > It is concerning that a FLUSH may fail but the blkdev_issue_flush
> > > callers assume it will always succeed.
> > > 
> > > Each blkdev_issue_flush caller should come to terms with the reality
> > > that a FLUSH may fail -- the file_operations' .fsync methods in
> > > particular.  nilfs2 is the only filesystem that checks
> > > blkdev_issue_flush's return.
> > 
> > Good spot, but it would be way better if you actually provided patches
> > to fix this instead of just adding more compiler warnings.
> 
> Alasdair pointed this issue out in response to me asserting that
> blkdev_issue_flush does return non-void.  But anyway, others knowing
> about this issue is half the battle. ;)
> 
> Most .fsync methods are straight-forward to convert but I'd prefer each
> filesystem maintainer actively audit all blkdev_issue_flush calls.

So send it out with maintainers on cc: and get Acks.  That way we have a
coherent patch series cleaning up the in-tree filesystems, rather than a
bunch of warnings for every compile until the maintainers notice.

Joel


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