From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from a.ns.miles-group.at ([95.130.255.143] helo=radon.swed.at) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XxuMZ-0007mV-CJ for linux-mtd@lists.infradead.org; Mon, 08 Dec 2014 09:12:16 +0000 Message-ID: <54856B54.7020306@nod.at> Date: Mon, 08 Dec 2014 10:11:48 +0100 From: Richard Weinberger MIME-Version: 1.0 To: Tanya Brokhman , dedekind1@gmail.com Subject: Re: [PATCH 3/6] UBI: Fastmap: Notify user in case of an ubi_update_fastmap() failure References: <1417347340-6872-1-git-send-email-richard@nod.at> <1417347340-6872-4-git-send-email-richard@nod.at> <54845D53.1070903@codeaurora.org> <548462A8.2010107@nod.at> <54854C28.4050107@codeaurora.org> In-Reply-To: <54854C28.4050107@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi! Am 08.12.2014 um 07:58 schrieb Tanya Brokhman: > On 12/7/2014 4:22 PM, Richard Weinberger wrote: >> Am 07.12.2014 um 14:59 schrieb Tanya Brokhman: >>> Hi Richard, >>> >>> On 11/30/2014 1:35 PM, Richard Weinberger wrote: >>>> If ubi_update_fastmap() fails notify the user. >>>> This is not a hard error as ubi_update_fastmap() makes sure that upon failure >>>> the current on-flash fastmap will no be used upon next UBI attach. >>>> >>>> Signed-off-by: Richard Weinberger >>>> --- >>>> drivers/mtd/ubi/wl.c | 6 +++++- >>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c >>>> index 523d8a4..7821342 100644 >>>> --- a/drivers/mtd/ubi/wl.c >>>> +++ b/drivers/mtd/ubi/wl.c >>>> @@ -657,7 +657,11 @@ again: >>>> * refill the WL pool synchronous. */ >>>> if (pool->used == pool->size || wl_pool->used == wl_pool->size) { >>>> spin_unlock(&ubi->wl_lock); >>>> - ubi_update_fastmap(ubi); >>>> + ret = ubi_update_fastmap(ubi); >>>> + if (ret) { >>>> + ubi_msg(ubi, "Unable to write a new fastmap: %i", ret); >>>> + return -ENOSPC; >>> >>> Why do you fail the whole function (ubi_wl_get_peb) if fastmap update failed? Its possible that the fm_pools were refilled correctly, and the actual fastmap_write failed, so there >>> is nothing preventing the user to get peb allocated and continue working. You invalidate the fastmap, so if powercut occurs a full scan will be performed. So its possible to >>> allocate from fm_pools (although fastmap is not valid on disc) and try writing fastmap again when the pools filled up. >>> I'm for the ubi_msg but against "return -ENOSPC;" >> >> Maybe the case you've described is powercut safe, but there can be other unsafe cases. >> Let's stay on the safe side and be paranoid, it does not hurt. >> If fastmap has proven stable we can start with tricky optimizations. > > I'm sorry that I'm being petty here but the commit msg states that you "notify the user in case of update fastamap failure". It says nothing about you failing ubi_wl_get_peb as > well. And this is a major change. At least divide this into 2 patches (so I can disagree to the function failing and agree to the msg to user :) ) With user I meant users of that function. Thanks, //richard