From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com ([119.145.14.66]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bzMSf-0007g5-4r for linux-mtd@lists.infradead.org; Wed, 26 Oct 2016 11:33:39 +0000 Message-ID: <581093C5.7080105@huawei.com> Date: Wed, 26 Oct 2016 19:30:13 +0800 From: Sheng Yong MIME-Version: 1.0 To: Boris Brezillon , Dan Carpenter CC: , Richard Weinberger Subject: Re: [bug report] UBI: Fastmap: Do not add vol if it already exists References: <20161025204607.GA27826@elgon.mountain> <58100B0B.3030906@huawei.com> <20161026082536.GP4418@mwanda> <20161026112346.40588a81@bbrezillon> In-Reply-To: <20161026112346.40588a81@bbrezillon> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 10/26/2016 5:23 PM, Boris Brezillon wrote: > + Richard > > On Wed, 26 Oct 2016 11:25:36 +0300 > Dan Carpenter wrote: > >> On Wed, Oct 26, 2016 at 09:46:51AM +0800, Sheng Yong wrote: >>> Hi Dan, >>> >>> On 10/26/2016 4:46 AM, Dan Carpenter wrote: >>>> Hello shengyong, >>>> >>>> The patch e96a8a3bb671: "UBI: Fastmap: Do not add vol if it already >>>> exists" from May 26, 2015, leads to the following static checker >>>> warning: >>>> >>>> drivers/mtd/ubi/fastmap.c:712 ubi_attach_fastmap() >>>> warn: PTR_ERR(av) is never (-22) >>>> >>>> drivers/mtd/ubi/fastmap.c >>>> 703 >>>> 704 av = add_vol(ai, be32_to_cpu(fmvhdr->vol_id), >>>> 705 be32_to_cpu(fmvhdr->used_ebs), >>>> 706 be32_to_cpu(fmvhdr->data_pad), >>>> 707 fmvhdr->vol_type, >>>> 708 be32_to_cpu(fmvhdr->last_eb_bytes)); >>>> 709 >>>> 710 if (!av) >>>> 711 goto fail_bad; >>>> 712 if (PTR_ERR(av) == -EINVAL) { >>>> >>>> av is either -EEXIST or -ENOMEM. It's never -EINVAL. >>> The commit e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already exists") >>> adds a "return ERR_PTR(-EINVAL);" to add_vol(). So I think av could be -EINVAL. >>> You mean add_vol should return -EEXIST instead of -EINVAL? >>> >> >> Oh, ah. I'm on linux-next. Commit de4c455b3e9f ("UBI: factorize code >> used to manipulate volumes at attach time") removed the -EINVAL. >> >> It's really Boris to blame for this warning. I'm not sure what the fix >> is. > > Yes, sorry, I didn't notice the caller was explicitly testing for > -EINVAL. > > Here is a patch fixing the problem: > > --->8--- >>>From 66d46bb212a8fcdcdd54def051492abb1668f1b2 Mon Sep 17 00:00:00 2001 > From: Boris Brezillon > Date: Wed, 26 Oct 2016 11:17:03 +0200 > Subject: [PATCH] UBI: fastmap: Fix add_vol() return value test in > ubi_attach_fastmap() > > Commit e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already > exists") introduced a bug by changing the possible error codes returned > by add_vol(): > - this functions no longer returns NULL in case of allocation failure > but return ERR_PTR(-ENOMEM) > - when a duplicate entry in the volume RB tree is found it returns > ERR_PTR(-EEXIST) instead of ERR_PTR(-EINVAL) > > Fix the tests done of add_vol() return value accordingly. > > Fixes: e96a8a3bb671 ("UBI: Fastmap: Do not add vol if it already exists") > Signed-off-by: Boris Brezillon > --- > drivers/mtd/ubi/fastmap.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c > index d6384d965788..eb39c44726e3 100644 > --- a/drivers/mtd/ubi/fastmap.c > +++ b/drivers/mtd/ubi/fastmap.c > @@ -707,11 +707,11 @@ static int ubi_attach_fastmap(struct ubi_device *ubi, > fmvhdr->vol_type, > be32_to_cpu(fmvhdr->last_eb_bytes)); > > - if (!av) > - goto fail_bad; > - if (PTR_ERR(av) == -EINVAL) { > - ubi_err(ubi, "volume (ID %i) already exists", > - fmvhdr->vol_id); > + if (IS_ERR(av)) { > + if (PTR_ERR(av) == -EEXIST) > + ubi_err(ubi, "volume (ID %i) already exists", > + fmvhdr->vol_id); > + > goto fail_bad; > } > > . > Acked-by: Sheng Yong thanks, Sheng