linux-ext4 - Re: [PATCH 0/6 v3] dax: Page invalidation fixes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 19 Dec 2016 13:51:53 -0800
From:   Dan Williams <dan.j.williams@...el.com>
To:     Jan Kara <jack@...e.cz>
Cc:     linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        Ross Zwisler <ross.zwisler@...ux.intel.com>,
        Linux MM <linux-mm@...ck.org>,
        linux-ext4 <linux-ext4@...r.kernel.org>,
        Johannes Weiner <hannes@...xchg.org>,
        "linux-nvdimm@...ts.01.org" <linux-nvdimm@...ts.01.org>
Subject: Re: [PATCH 0/6 v3] dax: Page invalidation fixes

On Mon, Dec 19, 2016 at 1:56 AM, Jan Kara <jack@...e.cz> wrote:
> On Fri 16-12-16 17:35:35, Dan Williams wrote:
>> On Tue, Dec 13, 2016 at 10:57 AM, Dan Williams <dan.j.williams@...el.com> wrote:
>> > On Tue, Dec 13, 2016 at 3:52 AM, Jan Kara <jack@...e.cz> wrote:
>> >> On Mon 12-12-16 17:47:02, Jan Kara wrote:
>> >>> Hello,
>> >>>
>> >>> this is the third revision of my fixes of races when invalidating hole pages in
>> >>> DAX mappings. See changelogs for details. The series is based on my patches to
>> >>> write-protect DAX PTEs which are currently carried in mm tree. This is a hard
>> >>> dependency because we really need to closely track dirtiness (and cleanness!)
>> >>> of radix tree entries in DAX mappings in order to avoid discarding valid dirty
>> >>> bits leading to missed cache flushes on fsync(2).
>> >>>
>> >>> The tests have passed xfstests for xfs and ext4 in DAX and non-DAX mode.
>> >>>
>> >>> Johannes, are you OK with patch 2/6 in its current form? I'd like to push these
>> >>> patches to some tree once DAX write-protection patches are merged.  I'm hoping
>> >>> to get at least first three patches merged for 4.10-rc2... Thanks!
>> >>
>> >> OK, with the final ack from Johannes and since this is mostly DAX stuff,
>> >> can we take this through NVDIMM tree and push to Linus either late in the
>> >> merge window or for -rc2? These patches require my DAX patches sitting in mm
>> >> tree so they can be included in any git tree only once those patches land
>> >> in Linus' tree (which may happen only once Dave and Ted push out their
>> >> stuff - this is the most convoluted merge window I'd ever to deal with ;-)...
>> >> Dan?
>> >>
>> >
>> > I like the -rc2 plan better than sending a pull request based on some
>> > random point in the middle of the merge window. I can give Linus a
>> > heads up in my initial nvdimm pull request for -rc1 that for
>> > coordination purposes we'll be sending this set of follow-on DAX
>> > cleanups for -rc2.
>>
>> So what's still pending for -rc2? I want to be explicit about what I'm
>> requesting Linus be prepared to receive after -rc1. The libnvdimm pull
>> request is very light this time around since I ended up deferring the
>> device-dax-subdivision topic until 4.11 and sub-section memory hotplug
>> didn't make the cutoff for -mm. We can spend some of that goodwill on
>> your patches ;-).
>
> ;-) So I'd like all these 6 patches to go for rc2. The first three patches
> fix invalidation of exceptional DAX entries (a bug which is there for a
> long time) - without these patches data loss can occur on power failure
> even though user called fsync(2). The other three patches change locking of
> DAX faults so that ->iomap_begin() is called in a more relaxed locking
> context and we are safe to start a transaction there for ext4.
>
>> I can roll them into libnvdimm-for-next now for the integration
>> testing coverage, rebase to -rc1 when it's out, wait for your thumbs
>> up on the testing and send a pull request on the 23rd.
>
> Yup, all prerequisites are merged now so you can pick these patches up.
> Thanks! Note that I'll be on vacation on Dec 23 - Jan 1.

Sounds good, the contents are now out on libnvdimm-pending awaiting
0day-run before moving them over to libnvdimm-for-next, also it's down
to 5 patches since it seems that the "dax: Fix sleep in atomic contex
in grab_mapping_entry()" change went upstream already.
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html