linux-kernel - Re: [PATCH] mtd: Allocate bdi objects dynamically

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Message-ID: <20161129081204.GA6617@mentor.com>
Date:   Tue, 29 Nov 2016 13:42:05 +0530
From:   Sandeep Jain <Sandeep_Jain@...tor.com>
To:     Marek Vasut <marek.vasut@...il.com>
CC:     Richard Weinberger <richard.weinberger@...il.com>,
        Steve Longerbeam <steve_longerbeam@...tor.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Jim Baxter <jim_baxter@...tor.com>,
        "linux-mtd@...ts.infradead.org" <linux-mtd@...ts.infradead.org>,
        Brian Norris <computersforpeace@...il.com>,
        David Woodhouse <dwmw2@...radead.org>
Subject: Re: [PATCH] mtd: Allocate bdi objects dynamically

Dear Maintainers,
   This patch is already reviewed twice with no issues.
Requesting your attention for patch merge.

Thanks & Regards,
Sandeep Jain

On Sat, Nov 05, 2016 at 08:22:31AM +0100, Marek Vasut wrote:
> On 11/03/2016 12:34 PM, Sandeep Jain wrote:
> > Dear Maintainers,
> >   This patch is reviewed by Richard.
> > Requesting for Maintainer's attention for patch merge.
> > 
> > Thanks & Regards,
> > Sandeep Jain
> > 
> > On Sat, Sep 17, 2016 at 04:41:47PM +0200, Richard Weinberger wrote:
> >> On Thu, Aug 4, 2016 at 4:01 PM, Sandeep Jain <Sandeep_Jain@...tor.com> wrote:
> >>> From: Steve Longerbeam <steve_longerbeam@...tor.com>
> >>>
> >>> The MTD backing dev info objects mtd_bdi was statically allocated.
> >>> So when MTD is built as a loadable module, this object fall in the
> >>> vmalloc address space.
> >>>
> >>> The problem with that, is that the BDI APIs use wake_up_bit(), which calls
> >>> virt_to_page() to retrieve the memory zone of the page containing the
> >>> wait_queue to wake up, and virt_to_page() is not valid for vmalloc or
> >>> highmem addresses.
> >>>
> >>> Fix this by allocating the BDI objects dynamically with kmalloc. The
> >>> objects now fall in the logical address space so that BDI APIs will
> >>> work in all cases (mtd builtin or module).
> >>>
> >>> Signed-off-by: Steve Longerbeam <steve_longerbeam@...tor.com>
> >>> Signed-off-by: Jim Baxter <jim_baxter@...tor.com>
> >>> Signed-off-by: Sandeep Jain <Sandeep_Jain@...tor.com>
> >>
> >> Reviewed-by: Richard Weinberger <richard@....at>
> 
> I don't see any obvious problem either:
> Reviewed-by: Marek Vasut <marek.vasut@...il.com>
> 
> -- 
> Best regards,
> Marek Vasut