From: Fengguang Wu <fengguang.wu@intel.com>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: viro@zeniv.linux.org.uk, jack@suse.cz, hch@lst.de,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Fix queueing work if !bdi_cap_writeback_dirty()
Date: Thu, 13 Sep 2012 14:03:51 +0800 [thread overview]
Message-ID: <20120913060351.GA23682@localhost> (raw)
In-Reply-To: <87a9wueayc.fsf@devron.myhome.or.jp>
On Thu, Sep 13, 2012 at 02:41:31PM +0900, OGAWA Hirofumi wrote:
> Fengguang Wu <fengguang.wu@intel.com> writes:
>
> >> If used custom bdi with BDI_CAP_NO_WRITEBACK, wait_for_completion()
> >> (e.g. sync_inodes_sb()) will be blocked forever.
> >
> > The sync(2) block cannot be fixed by this patch?
>
> This patch fixes block problem too.
Ah OK, my sight was somehow limited by the screen size and only saw
the first chunk...
> >> I tested by custom bdi with BDI_CAP_NO_WRITEBACK - sync(2) blocked
> >> forever by this reason.
> >
> > What's your test script? How do you create/use that custom bdi?
>
> Ah, I wrote my kernel module to test. I guess there is no users in
> current kernel for now, because it doesn't work.
OK. Got it. So I'd suggest to change the first chunk to a VM_BUG_ON(),
which should be enough to catch new bad callers. The other two chunks
look fine.
Thanks,
Fengguang
next prev parent reply other threads:[~2012-09-13 6:03 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-11 18:28 [PATCH] Fix queueing work if !bdi_cap_writeback_dirty() OGAWA Hirofumi
2012-09-12 2:42 ` Fengguang Wu
2012-09-12 8:00 ` OGAWA Hirofumi
2012-09-13 0:33 ` Fengguang Wu
2012-09-13 5:41 ` OGAWA Hirofumi
2012-09-13 6:03 ` Fengguang Wu [this message]
2012-09-13 6:31 ` OGAWA Hirofumi
2012-09-13 6:39 ` Fengguang Wu
2012-09-13 7:53 ` OGAWA Hirofumi
2012-09-14 11:13 ` OGAWA Hirofumi
2012-09-14 11:18 ` Fengguang Wu
2012-09-14 11:14 ` Fengguang Wu
2012-09-14 12:12 ` OGAWA Hirofumi
2012-09-14 12:53 ` Fengguang Wu
2012-09-14 13:07 ` OGAWA Hirofumi
2012-09-14 13:33 ` Fengguang Wu
2012-09-14 13:49 ` OGAWA Hirofumi
2012-09-14 13:19 ` Jan Kara
2012-09-14 13:44 ` OGAWA Hirofumi
2012-09-14 14:45 ` Jan Kara
2012-09-14 15:10 ` OGAWA Hirofumi
2012-09-16 21:49 ` Jan Kara
2012-09-16 23:24 ` OGAWA Hirofumi
2012-09-17 8:48 ` Jan Kara
2012-09-17 9:39 ` OGAWA Hirofumi
2012-09-17 9:56 ` Jan Kara
2012-09-17 10:37 ` OGAWA Hirofumi
2012-09-17 15:54 ` Jan Kara
2012-09-17 16:55 ` OGAWA Hirofumi
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