From: Alan Stern <stern@rowland.harvard.edu>
To: Piergiorgio Sartor <piergiorgio.sartor@nexgo.de>
Cc: Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
USB list <linux-usb@vger.kernel.org>,
<linux-block@vger.kernel.org>,
Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: reeze while write on external usb 3.0 hard disk [Bug 204095]
Date: Wed, 16 Oct 2019 13:01:20 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1910161258081.1304-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20191013181116.GA3858@lazy.lzy>
On Sun, 13 Oct 2019, Piergiorgio Sartor wrote:
> On Mon, Sep 30, 2019 at 08:25:01PM +0200, Piergiorgio Sartor wrote:
> > On Sun, Sep 29, 2019 at 09:01:48PM -0400, Alan Stern wrote:
> > > On Sun, 29 Sep 2019, Piergiorgio Sartor wrote:
> > >
> > > > On Wed, Sep 25, 2019 at 02:31:58PM -0400, Alan Stern wrote:
> > > > > On Wed, 25 Sep 2019, Piergiorgio Sartor wrote:
> > > > >
> > > > > > On Mon, Aug 26, 2019 at 07:38:33PM +0200, Piergiorgio Sartor wrote:
> > > > > > > On Tue, Aug 20, 2019 at 06:37:22PM +0200, Piergiorgio Sartor wrote:
> > > > > > > > On Tue, Aug 20, 2019 at 09:23:26AM +0200, Christoph Hellwig wrote:
> > > > > > > > > On Mon, Aug 19, 2019 at 10:14:25AM -0400, Alan Stern wrote:
> > > > > > > > > > Let's bring this to the attention of some more people.
> > > > > > > > > >
> > > > > > > > > > It looks like the bug that was supposed to be fixed by commit
> > > > > > > > > > d74ffae8b8dd ("usb-storage: Add a limitation for
> > > > > > > > > > blk_queue_max_hw_sectors()"), which is part of 5.2.5, but apparently
> > > > > > > > > > the bug still occurs.
> > > > > > > > >
> > > > > > > > > Piergiorgio,
> > > > > > > > >
> > > > > > > > > can you dump the content of max_hw_sectors_kb file for your USB storage
> > > > > > > > > device and send that to this thread?
> > > > > > > >
> > > > > > > > Hi all,
> > > > > > > >
> > > > > > > > for both kernels, 5.1.20 (working) and 5.2.8 (not working),
> > > > > > > > the content of /sys/dev/x:y/queue/max_hw_sectors_kb is 512
> > > > > > > > for USB storage devices (2.0 and 3.0).
> > > > > > > >
> > > > > > > > This is for the PC showing the issue.
> > > > > > > >
> > > > > > > > In an other PC, which does not show the issus at the moment,
> > > > > > > > the values are 120, for USB2.0, and 256, for USB3.0.
> > >
> > > > > One thing you can try is git bisect from 5.1.20 (or maybe just 5.1.0)
> > > > > to 5.2.8. If you can identify a particular commit which caused the
> > > > > problem to start, that would help.
> > > >
> > > > OK, I tried a bisect (2 days compilations...).
> > > > Assuming I've done everything correctly (how to
> > > > test this? How to remove the guilty patch?), this
> > > > was the result:
> > > >
> > > > 09324d32d2a0843e66652a087da6f77924358e62 is the first bad commit
> > > > commit 09324d32d2a0843e66652a087da6f77924358e62
> > > > Author: Christoph Hellwig <hch@lst.de>
> > > > Date: Tue May 21 09:01:41 2019 +0200
> > > >
> > > > block: force an unlimited segment size on queues with a virt boundary
> > > >
> > > > We currently fail to update the front/back segment size in the bio when
> > > > deciding to allow an otherwise gappy segement to a device with a
> > > > virt boundary. The reason why this did not cause problems is that
> > > > devices with a virt boundary fundamentally don't use segments as we
> > > > know it and thus don't care. Make that assumption formal by forcing
> > > > an unlimited segement size in this case.
> > > >
> > > > Fixes: f6970f83ef79 ("block: don't check if adjacent bvecs in one bio can be mergeable")
> > > > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > > > Reviewed-by: Ming Lei <ming.lei@redhat.com>
> > > > Reviewed-by: Hannes Reinecke <hare@suse.com>
> > > > Signed-off-by: Jens Axboe <axboe@kernel.dk>
> > > >
> > > > :040000 040000 57ba04a02f948022c0f6ba24bfa36f3b565b2440 8c925f71ce75042529c001bf244b30565d19ebf3 M block
> > > >
> > > > What to do now?
> > >
> > > Here's how to verify that the bisection got a correct result. First,
> > > do a git checkout of commit 09324d32d2a0, build the kernel, and make
> > > sure that it exhibits the problem.
> > >
> > > Next, have git write out the contents of that commit in the form of a
> > > patch (git show commit-id >patchfile), and revert it (git apply -R
> > > patchfile). Build the kernel from that tree, and make sure that it
> > > does not exhibit the problem. If it doesn't, you have definitely shown
> > > that this commit is the cause (or at least, is _one_ of the causes).
> >
> > I tried as suggested, i.e. jumping to commit
> > 09324d32d2a0843e66652a087da6f77924358e62, testing,
> > removing the patch, testing.
> > The result was as expected.
> > I was able to reproduce the issue with the commit,
> > I was not able to reproduce it without.
> > It seems this patch / commit is causing the problem.
> > Directly or indirectly.
> >
> > What are the next steps?
>
> Hi all,
>
> I tested kernel 5.3.5 (Fedora kernel-5.3.5-200.fc30.x86_64),
> with same problematic results.
>
> Again, what should be done now?
> Could you please revert the patch?
>
> Or is there something else to check?
Here is one more thing you can try. I have no idea whether it will
make any difference, but the Changelog entry for the patch you
identified suggests that it might help.
Alan Stern
Index: usb-devel/drivers/usb/storage/scsiglue.c
===================================================================
--- usb-devel.orig/drivers/usb/storage/scsiglue.c
+++ usb-devel/drivers/usb/storage/scsiglue.c
@@ -68,7 +68,6 @@ static const char* host_info(struct Scsi
static int slave_alloc (struct scsi_device *sdev)
{
struct us_data *us = host_to_us(sdev->host);
- int maxp;
/*
* Set the INQUIRY transfer length to 36. We don't use any of
@@ -78,15 +77,6 @@ static int slave_alloc (struct scsi_devi
sdev->inquiry_len = 36;
/*
- * USB has unusual scatter-gather requirements: the length of each
- * scatterlist element except the last must be divisible by the
- * Bulk maxpacket value. Fortunately this value is always a
- * power of 2. Inform the block layer about this requirement.
- */
- maxp = usb_maxpacket(us->pusb_dev, us->recv_bulk_pipe, 0);
- blk_queue_virt_boundary(sdev->request_queue, maxp - 1);
-
- /*
* Some host controllers may have alignment requirements.
* We'll play it safe by requiring 512-byte alignment always.
*/
next prev parent reply other threads:[~2019-10-16 17:01 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190817095422.GA4200@lazy.lzy>
2019-08-19 14:14 ` reeze while write on external usb 3.0 hard disk [Bug 204095] Alan Stern
2019-08-20 7:23 ` Christoph Hellwig
2019-08-20 16:37 ` Piergiorgio Sartor
2019-08-26 17:38 ` Piergiorgio Sartor
2019-08-29 14:08 ` Christoph Hellwig
2019-09-25 17:07 ` Piergiorgio Sartor
2019-09-25 18:31 ` Alan Stern
2019-09-27 9:04 ` Peter Chen
2019-09-29 20:13 ` Piergiorgio Sartor
2019-09-30 1:01 ` Alan Stern
2019-09-30 18:25 ` Piergiorgio Sartor
2019-10-13 18:11 ` Piergiorgio Sartor
2019-10-16 17:01 ` Alan Stern [this message]
2019-10-17 17:53 ` Piergiorgio Sartor
2019-10-17 19:23 ` Alan Stern
2019-11-08 23:05 ` Piergiorgio Sartor
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Pine.LNX.4.44L0.1910161258081.1304-100000@iolanthe.rowland.org \
--to=stern@rowland.harvard.edu \
--cc=axboe@kernel.dk \
--cc=hch@lst.de \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=piergiorgio.sartor@nexgo.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).