From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Kent Subject: Re: [PATCH] autofs: don't stuck in a loop if vfs_write returns an error Date: Fri, 10 Jun 2016 16:45:23 +0800 Message-ID: <1465548323.3174.2.camel@themaw.net> References: <1459487558-21258-1-git-send-email-avagin@gmail.com> <1459496266.2974.1.camel@themaw.net> <1464053664.3108.21.camel@themaw.net> <1464587527.3025.6.camel@themaw.net> <1465435406.3154.4.camel@themaw.net> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=themaw.net; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-sasl-enc :x-sasl-enc; s=mesmtp; bh=cQpBc2h91y2SFk1kObHzEKbEksM=; b=ML6iNh 2CZUpgk0hxKC5Oj0zZumFWuCRidPuPX+oUr/iTPCLQHORD6zVwGKcL3MyOsjainy VycaAV/ig2k7jY6tC0hKV4JHCc7Hcm1cQ2ZjNY0um6EwsqQaKsB7WqNTw+BlN86t m2l83XNPRAu1xjhqUpxUZdFfLbN1H99eWc534= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-sasl-enc:x-sasl-enc; s=smtpout; bh=cQpBc2h91y2SFk1 kObHzEKbEksM=; b=NkemAVinBHkv1cECF/T4JmFtC5KRD4vGIHPAjsnSMik2vWR bpmmVA/Jsu3P0WUfAVtNOLovPG5dVi5wihB7SCleqaVPOAbcUs0MJbD6Z8dc7bn/ DD8BLkLl2i9IV/IYP8WRU8rtVrEXkGCB8vO9/kE/kjjsln9PTe8AfiUkHuLY= In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrei Vagin Cc: autofs@vger.kernel.org, LKML , Andrew Morton On Thu, 2016-06-09 at 10:27 -0700, Andrei Vagin wrote: > On Wed, Jun 8, 2016 at 6:23 PM, Ian Kent wrote: > > On Mon, 2016-05-30 at 13:52 +0800, Ian Kent wrote: > > > On Tue, 2016-05-24 at 09:34 +0800, Ian Kent wrote: > > > > On Mon, 2016-05-23 at 14:50 -0700, Andrei Vagin wrote: > > > > > Hi Ian, > > > > > > > > > > When are you going to apply this patch? We can't test linux-next > > > > > without > > > > > it. > > > > > > > > I though I sent this with the last series but I can't see that I have. > > > > > > > > I have the rest of that series to send over to Andrew which I was > > > > planning > > > > to > > > > do > > > > after the current merge window closes (which is about now I guess). > > > > > > > > I'll include it in that series. > > > > Sorry for the hold up, ;) > > > > > > Some bad news I'm afraid. > > > > > > I was getting ready to send these over to Andrew and found that opendir(3) > > > is > > > failing on a number of tests (51 of 230, 9 fails are expected) with 4.6.0. > > > > > > It's not the patches, yours or mine and it doesn't happen with 4.4.x > > > kernels. > > > > > > Looks like I'm going to have to bisect to work out what's going on and > > > that > > > will > > > take a while. > > > > The regression has been fixed now. > > > > Al Viro sent a patch for it to Linus yesterday, it's commit e6ec03a25f1 in > > the > > Linux tree. > > It's good! > > > > > I can send my patches to Andrew (after re-testing) but any autofs related > > testing of linux.next will need the above commit. > > > > Andrew, surely this isn't the first time this type of problem has happened, > > how > > is it usually handled, what do I need to do to make this go smoothly? > > In linux-next we catch two sorts of bugs. > > 1. If bugs is triggered very often, we report it, when it isn't in > Linus' tree. And such bugs are fixed very fast. > 2. If bugs is triggered rarely. In this case we may detect this bug > too late, when it's in Linus' tree. In this case we may need to > workaraound it. > > Here the problem belongs to the second type. It is triggered only when > one or more tests failed and we try to kill all test processes. > Actually it doesn't affect regular runs of tests, but it's annoying > when we are investigating something. > > Ian, I don't think that you need to do anything special. Thank you for > handling this patch! LOL, it's good that it was my standard (relatively simple) testing that exposed it. I'll wait a little longer in case Andrew has anything to add then send the patch series to him. > > Thanks, > Andrew > > > > > > > > > > > > > > Ian > > > > > > > > > > > > > > Thanks, > > > > > Andrew > > > > > > > > > > > > > > > On Fri, Apr 1, 2016 at 12:37 AM, Ian Kent wrote: > > > > > > On Thu, 2016-03-31 at 22:12 -0700, Andrey Vagin wrote: > > > > > > > From: Andrey Vagin > > > > > > > > > > > > > > __vfs_write() returns a negative value in a error case. > > > > > > > > > > > > Ha, right, I'll send this along to Andrew with my next series which > > > > > > should be soon. > > > > > > > > > > > > > > > > > > > > Cc: Ian Kent > > > > > > > Signed-off-by: Andrey Vagin > > > > > > > --- > > > > > > > fs/autofs4/waitq.c | 7 ++++--- > > > > > > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > > > > > > > > > > > diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c > > > > > > > index 0146d91..631f155 100644 > > > > > > > --- a/fs/autofs4/waitq.c > > > > > > > +++ b/fs/autofs4/waitq.c > > > > > > > @@ -66,11 +66,12 @@ static int autofs4_write(struct autofs_sb_info > > > > > > > *sbi, > > > > > > > set_fs(KERNEL_DS); > > > > > > > > > > > > > > mutex_lock(&sbi->pipe_mutex); > > > > > > > - wr = __vfs_write(file, data, bytes, &file->f_pos); > > > > > > > - while (bytes && wr) { > > > > > > > + while (bytes) { > > > > > > > + wr = __vfs_write(file, data, bytes, &file->f_pos); > > > > > > > + if (wr <= 0) > > > > > > > + break; > > > > > > > data += wr; > > > > > > > bytes -= wr; > > > > > > > - wr = __vfs_write(file, data, bytes, &file->f_pos); > > > > > > > } > > > > > > > mutex_unlock(&sbi->pipe_mutex); > > > -- > > > To unsubscribe from this list: send the line "unsubscribe autofs" in