From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.tricorecenter.de ([217.6.246.34] helo=root.phytec.de) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bHRoz-0007uR-KR for barebox@lists.infradead.org; Mon, 27 Jun 2016 08:23:11 +0000 Message-ID: <1467015758.3805.4.camel@lws-tremmet.phytec.de> From: Teresa Remmet Date: Mon, 27 Jun 2016 10:22:38 +0200 In-Reply-To: <20160624112043.GA20656@pengutronix.de> References: <1466586117-14464-1-git-send-email-t.remmet@phytec.de> <20160624112043.GA20656@pengutronix.de> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] mtd: ubi: Fix endless loop when moving PEB To: Sascha Hauer Cc: barebox@lists.infradead.org Hello Sascha, Am Freitag, den 24.06.2016, 13:20 +0200 schrieb Sascha Hauer: > Hi Teresa, > > On Wed, Jun 22, 2016 at 11:01:57AM +0200, Teresa Remmet wrote: > > When moving a PEB the leb_write_trylock() function is called. > > As the function never returns 0 UBI will end up in an endless > > loop. > > > > Noticed the issue when fastmap has been enabled and data is beeing copied > > several times to a UBI volume. When UBI tries to move the anchor PEB, > > the issue comes up. > > > > The leb_write_trylock() is now equal to the leb_write_lock(). > > But kept it for easier maintaince in future when syncing with > > kernel. > > > > Signed-off-by: Teresa Remmet > > --- > > drivers/mtd/ubi/eba.c | 11 +---------- > > 1 file changed, 1 insertion(+), 10 deletions(-) > > > > diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c > > index a7af247..31dbcd2 100644 > > --- a/drivers/mtd/ubi/eba.c > > +++ b/drivers/mtd/ubi/eba.c > > @@ -257,16 +257,7 @@ static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum) > > le = ltree_add_entry(ubi, vol_id, lnum); > > if (IS_ERR(le)) > > return PTR_ERR(le); > > - > > - /* Contention, cancel */ > > - le->users -= 1; > > - ubi_assert(le->users >= 0); > > - if (le->users == 0) { > > - rb_erase(&le->rb, &ubi->ltree); > > - kfree(le); > > - } > > - > > - return 1; > > + return 0; > > } > > This seems to be the missing link to make the following patch work. I > have tried this several times but so far never found this bug. Could you > give it a try? With this patch it should be now possible to ubiformat a > device with an image and to generate a fastmap when the device is > detached first. I tested it, and it is working. Ubi now successfully writes an anchor PEB. Teresa > > Sascha > > ------------------------8<--------------------------------- > > From 94cea61ade69f712383e282d6aa573d3a12f11d0 Mon Sep 17 00:00:00 2001 > From: Sascha Hauer > Date: Fri, 24 Jun 2016 11:38:24 +0200 > Subject: [PATCH] mtd: ubi: actually do work in wear leveling code > > The actual work in the wear leveling code is done in a separate thread. > Since we do not have threading so far we did not do any of the queued > work. Change this by calling the worker function synchronously. > > With this barebox now can write a fastmap on a freshly ubiformated > device. > > Signed-off-by: Sascha Hauer > --- > drivers/mtd/ubi/wl.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c > index 4535f2d..f24c219 100644 > --- a/drivers/mtd/ubi/wl.c > +++ b/drivers/mtd/ubi/wl.c > @@ -183,7 +183,6 @@ static void wl_entry_destroy(struct ubi_device *ubi, struct ubi_wl_entry *e) > kfree(e); > } > > -#ifndef CONFIG_MTD_UBI_FASTMAP > /** > * do_work - do one pending work. > * @ubi: UBI device description object > @@ -221,7 +220,6 @@ static int do_work(struct ubi_device *ubi) > > return err; > } > -#endif > > /** > * in_wl_tree - check if wear-leveling entry is present in a WL RB-tree. > @@ -523,8 +521,9 @@ static void __schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk) > list_add_tail(&wrk->list, &ubi->works); > ubi_assert(ubi->works_count >= 0); > ubi->works_count += 1; > - if (ubi->thread_enabled && !ubi_dbg_is_bgt_disabled(ubi)) > - wake_up_process(ubi->bgt_thread); > + > + /* No threading in barebox, so do work synchronously */ > + do_work(ubi); > } > > /** > -- > 2.8.1 > > > _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox