On Thu, Feb 21, 2019 at 11:22:39AM +0100, Marek Szyprowski wrote: > Hi Ming, > > On 2019-02-21 11:16, Ming Lei wrote: > > On Thu, Feb 21, 2019 at 11:08:19AM +0100, Marek Szyprowski wrote: > >> On 2019-02-21 10:57, Ming Lei wrote: > >>> On Thu, Feb 21, 2019 at 09:42:59AM +0100, Marek Szyprowski wrote: > >>>> On 2019-02-15 12:13, Ming Lei wrote: > >>>>> This patch pulls the trigger for multi-page bvecs. > >>>>> > >>>>> Reviewed-by: Omar Sandoval <osandov@xxxxxx> > >>>>> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> > >>>> 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 > >> I've tested that patch, but it doesn't make any difference on the test > >> system. In the log I see no warning added by it. > > I guess it might be related with memory corruption, could you enable the > > following debug options and post the dmesg log? > > > > CONFIG_DEBUG_STACKOVERFLOW=y > > CONFIG_KASAN=y > > It won't be that easy as none of the above options is available on ARM > 32bit. I will try to apply some ARM KASAN patches floating on the net > and let you know the result. Hi Marek, Could you test the following patch? diff --git a/block/bounce.c b/block/bounce.c index add085e28b1d..0c618c0b3cf8 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -295,7 +295,6 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, bool bounce = false; int sectors = 0; bool passthrough = bio_is_passthrough(*bio_orig); - struct bvec_iter_all iter_all; bio_for_each_segment(from, *bio_orig, iter) { if (i++ < BIO_MAX_PAGES) @@ -315,7 +314,8 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, bio = bounce_clone_bio(*bio_orig, GFP_NOIO, passthrough ? NULL : &bounce_bio_set); - bio_for_each_segment_all(to, bio, i, iter_all) { + /* bio won't be multi-page bvec, so operate its bvec table directly */ + for (i = 0, to = bio->bi_io_vec; i < bio->bi_vcnt; to++, i++) { struct page *page = to->bv_page; if (page_to_pfn(page) <= q->limits.bounce_pfn) Thanks, Ming
