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

[Mike Snitzer]

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.