Re: [PATCH V15 14/18] block: enable multipage bvecs

From: Ming Lei <ming.lei@redhat.com>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, Theodore Ts'o <tytso@mit.edu>,
	Omar Sandoval <osandov@fb.com>, Sagi Grimberg <sagi@grimberg.me>,
	Dave Chinner <dchinner@redhat.com>,
	Kent Overstreet <kent.overstreet@gmail.com>,
	Mike Snitzer <snitzer@redhat.com>,
	dm-devel@redhat.com, Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org, linux-raid@vger.kernel.org,
	David Sterba <dsterba@suse.com>,
	linux-btrfs@vger.kernel.org,
	"Darrick J . Wong" <darrick.wong@oracle.com>,
	linux-xfs@vger.kernel.org, Gao Xiang <gaoxiang25@huawei.com>,
	Christoph Hellwig <hch@lst.de>,
	linux-ext4@vger.kernel.org, Coly Li <colyli@suse.de>,
	linux-bcache@vger.kernel.org, Boaz Harrosh <ooo@electrozaur.com>,
	Bob
Subject: Re: [PATCH V15 14/18] block: enable multipage bvecs
Date: Thu, 21 Feb 2019 17:57:34 +0800	[thread overview]
Message-ID: <20190221095733.GA12448@ming.t460p> (raw)
In-Reply-To: <6c9ae4de-c56f-a2b3-2542-da7d8b95601d@samsung.com>

On Thu, Feb 21, 2019 at 09:42:59AM +0100, Marek Szyprowski wrote:
> Dear All,
> 
> On 2019-02-15 12:13, Ming Lei wrote:
> > This patch pulls the trigger for multi-page bvecs.
> >
> > Reviewed-by: Omar Sandoval <osandov@fb.com>
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> 
> Since Linux next-20190218 I've observed problems with block layer on one
> of my test devices (Odroid U3 with EXT4 rootfs on SD card). Bisecting
> this issue led me to this change. This is also the first linux-next
> release with this change merged. The issue is fully reproducible and can
> be observed in the following kernel log:
> 
> sdhci: Secure Digital Host Controller Interface driver
> sdhci: Copyright(c) Pierre Ossman
> s3c-sdhci 12530000.sdhci: clock source 2: mmc_busclk.2 (100000000 Hz)
> s3c-sdhci 12530000.sdhci: Got CD GPIO
> mmc0: SDHCI controller on samsung-hsmmc [12530000.sdhci] using ADMA
> mmc0: new high speed SDHC card at address aaaa
> mmcblk0: mmc0:aaaa SL16G 14.8 GiB
> 
> ...
> 
> EXT4-fs (mmcblk0p2): INFO: recovery required on readonly filesystem
> EXT4-fs (mmcblk0p2): write access will be enabled during recovery
> EXT4-fs (mmcblk0p2): recovery complete
> EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
> VFS: Mounted root (ext4 filesystem) readonly on device 179:2.
> devtmpfs: mounted
> Freeing unused kernel memory: 1024K
> hub 1-3:1.0: USB hub found
> Run /sbin/init as init process
> hub 1-3:1.0: 3 ports detected
> *** stack smashing detected ***: <unknown> terminated
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
> CPU: 1 PID: 1 Comm: init Not tainted 5.0.0-rc6-next-20190218 #1546
> Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
> [<c01118d0>] (unwind_backtrace) from [<c010d794>] (show_stack+0x10/0x14)
> [<c010d794>] (show_stack) from [<c09ff8a4>] (dump_stack+0x90/0xc8)
> [<c09ff8a4>] (dump_stack) from [<c0125944>] (panic+0xfc/0x304)
> [<c0125944>] (panic) from [<c012bc98>] (do_exit+0xabc/0xc6c)
> [<c012bc98>] (do_exit) from [<c012c100>] (do_group_exit+0x3c/0xbc)
> [<c012c100>] (do_group_exit) from [<c0138908>] (get_signal+0x130/0xbf4)
> [<c0138908>] (get_signal) from [<c010c7a0>] (do_work_pending+0x130/0x618)
> [<c010c7a0>] (do_work_pending) from [<c0101034>]
> (slow_work_pending+0xc/0x20)
> Exception stack(0xe88c3fb0 to 0xe88c3ff8)
> 3fa0:                                     00000000 bea7787c 00000005
> b6e8d0b8
> 3fc0: bea77a18 b6f92010 b6e8d0b8 00000001 b6e8d0c8 00000001 b6e8c000
> bea77b60
> 3fe0: 00000020 bea77998 ffffffff b6d52368 60000050 ffffffff
> CPU3: stopping
> 
> I would like to help debugging and fixing this issue, but I don't really
> have idea where to start. Here are some more detailed information about
> my test system:
> 
> 1. Board: ARM 32bit Samsung Exynos4412-based Odroid U3 (device tree
> source: arch/arm/boot/dts/exynos4412-odroidu3.dts)
> 
> 2. Block device: MMC/SDHCI/SDHCI-S3C with SD card
> (drivers/mmc/host/sdhci-s3c.c driver, sdhci_2 device node in the device
> tree)
> 
> 3. Rootfs: Ext4
> 
> 4. Kernel config: arch/arm/configs/exynos_defconfig
> 
> I can gather more logs if needed, just let me which kernel option to
> enable. Reverting this commit on top of next-20190218 as well as current
> linux-next (tested with next-20190221) fixes this issue and makes the
> system bootable again.

Could you test the patch in following link and see if it can make a difference?

https://marc.info/?l=linux-aio&m=155070355614541&w=2

Thanks,
Ming