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    SubjectRe: [PATCH] mtd: partitions: Handle add_mtd_device() failures gracefully
    Hi Boris,

    On Thu, Apr 26, 2018 at 7:53 PM, Boris Brezillon
    <boris.brezillon@bootlin.com> wrote:
    > On Tue, 10 Apr 2018 15:26:20 +0200
    > Geert Uytterhoeven <geert@linux-m68k.org> wrote:
    >> On Mon, Apr 9, 2018 at 11:59 PM, Marek Vasut <marek.vasut@gmail.com> wrote:
    >> > On 04/09/2018 02:25 PM, Geert Uytterhoeven wrote:
    >> >> Currently add_mtd_device() failures are plainly ignored, which may lead
    >> >> to kernel crashes later.
    >>
    >> >> Fix this by ignoring and freeing partitions that failed to add in
    >> >> add_mtd_partitions(). The same issue is present in mtd_add_partition(),
    >> >> so fix that as well.
    >> >>
    >> >> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
    >> >> ---
    >> >> I don't know if it is worthwhile factoring out the common handling.
    >> >>
    >> >> Should allocate_partition() fail instead? There's a comment saying
    >> >> "let's register it anyway to preserve ordering".
    >>
    >> >> --- a/drivers/mtd/mtdpart.c
    >> >> +++ b/drivers/mtd/mtdpart.c
    >>
    >> >> @@ -746,7 +753,15 @@ int add_mtd_partitions(struct mtd_info *master,
    >> >> list_add(&slave->list, &mtd_partitions);
    >> >> mutex_unlock(&mtd_partitions_mutex);
    >> >>
    >> >> - add_mtd_device(&slave->mtd);
    >> >> + ret = add_mtd_device(&slave->mtd);
    >> >> + if (ret) {
    >> >> + mutex_lock(&mtd_partitions_mutex);
    >> >> + list_del(&slave->list);
    >> >> + mutex_unlock(&mtd_partitions_mutex);
    >> >> + free_partition(slave);
    >> >> + continue;
    >> >> + }
    >> >
    >> > Why is the partition even in the list in the first place ? Can we avoid
    >> > adding it rather than adding and removing it ?
    >>
    >> Hence my question "Should allocate_partition() fail instead?".
    >
    > I'd prefer this option too. Can you prepare a new version doing that?

    OK, then I have another question ;-)

    Should this be a special failure, so all other valid partitions on the
    same FLASH
    are still added, or should it be fatal, so no partitions are added at all?

    Gr{oetje,eeting}s,

    Geert

    --
    Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

    In personal conversations with technical people, I call myself a hacker. But
    when I'm talking to journalists I just say "programmer" or something like that.
    -- Linus Torvalds

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