On Wed, Apr 24, 2024 at 12:26:26PM +0200, Geert Uytterhoeven wrote:
> Hi Ming,
>
> On Sun, 7 Apr 2024, Ming Lei wrote:
> > When one stacking device is over one device with virt_boundary_mask and
> > another one with max segment size, the stacking device have both limits
> > set. This way is allowed before d690cb8ae14b ("block: add an API to
> > atomically update queue limits").
> >
> > Relax the limit so that we won't break such kind of stacking setting.
> >
> > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218687
> > Reported-by: janpieter.sollie@xxxxxxxxx
> > Fixes: d690cb8ae14b ("block: add an API to atomically update queue limits")
> > Link: https://lore.kernel.org/linux-block/ZfGl8HzUpiOxCLm3@fedora/
> > Cc: Christoph Hellwig <hch@xxxxxx>
> > Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
> > Cc: dm-devel@xxxxxxxxxxxxxxx
> > Cc: Song Liu <song@xxxxxxxxxx>
> > Cc: linux-raid@xxxxxxxxxxxxxxx
> > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
>
> Thanks for your patch, which is now commit b561ea56a26415bf ("block:
> allow device to have both virt_boundary_mask and max segment size") in
> v6.9-rc4.
>
> With CONFIG_DMA_API_DEBUG_SG=y and IOMMU support enabled, this causes a
> warning on R-Car Gen3/Gen4 platforms:
>
> DMA-API: renesas_sdhi_internal_dmac ee160000.mmc: mapping sg segment longer than device claims to support [len=86016] [max=65536]
> WARNING: CPU: 1 PID: 281 at kernel/dma/debug.c:1178 debug_dma_map_sg+0x2ac/0x330
> Modules linked in:
> CPU: 1 PID: 281 Comm: systemd-udevd Tainted: G W 6.9.0-rc2-ebisu-00012-gb561ea56a264 #596
> Hardware name: Renesas Ebisu board based on r8a77990 (DT)
> pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : debug_dma_map_sg+0x2ac/0x330
> lr : debug_dma_map_sg+0x2ac/0x330
> sp : ffffffc083643470
> x29: ffffffc083643470 x28: 0000000000000080 x27: 0000000000010000
> x26: 0000000000000000 x25: 0000000000000001 x24: ffffffc0810afc30
> x23: ffffffffffffffff x22: ffffffc080c8366f x21: ffffff8008849f80
> x20: ffffff800cd24000 x19: ffffff80099a2810 x18: 0000000000000000
> x17: ffffff800801a000 x16: ffffffc080453f00 x15: ffffffc0836430f0
> x14: ffffffc08099fb50 x13: 0000000000000007 x12: 0000000000000000
> x11: 0000000000000202 x10: ffffffc0810d99d0 x9 : ffffffc081189bb0
> x8 : ffffffc083643178 x7 : ffffffc083643180 x6 : 00000000ffffdfff
> x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffff800ebad280
> Call trace:
> debug_dma_map_sg+0x2ac/0x330
> __dma_map_sg_attrs+0xcc/0xd0
> dma_map_sg_attrs+0xc/0x1c
> renesas_sdhi_internal_dmac_map+0x64/0x94
> renesas_sdhi_internal_dmac_pre_req+0x20/0x2c
> mmc_blk_mq_issue_rq+0x62c/0x6c8
> mmc_mq_queue_rq+0x194/0x218
> blk_mq_dispatch_rq_list+0x36c/0x4d4
> __blk_mq_sched_dispatch_requests+0x344/0x4e0
> blk_mq_sched_dispatch_requests+0x28/0x5c
> blk_mq_run_hw_queue+0x1a4/0x218
> blk_mq_flush_plug_list+0x2fc/0x4a0
> __blk_flush_plug+0x70/0x134
> blk_finish_plug+0x24/0x34
> read_pages+0x60/0x158
> page_cache_ra_unbounded+0x98/0x184
> do_page_cache_ra+0x44/0x50
> force_page_cache_ra+0x98/0x9c
> page_cache_sync_ra+0x30/0x54
> filemap_get_pages+0xfc/0x4f8
> filemap_read+0xe8/0x2b8
> blkdev_read_iter+0x12c/0x144
> vfs_read+0x104/0x150
> ksys_read+0x6c/0xd4
> __arm64_sys_read+0x14/0x1c
> invoke_syscall+0x70/0xf4
> el0_svc_common.constprop.0+0xb0/0xcc
> do_el0_svc+0x1c/0x24
> el0_svc+0x34/0x8c
> el0t_64_sync_handler+0x88/0x124
> el0t_64_sync+0x150/0x154
> irq event stamp: 0
> hardirqs last enabled at (0): [<0000000000000000>] 0x0
> hardirqs last disabled at (0): [<ffffffc08007efa4>] copy_process+0x6ac/0x18d4
> softirqs last enabled at (0): [<ffffffc08007efa4>] copy_process+0x6ac/0x18d4
> softirqs last disabled at (0): [<0000000000000000>] 0x0
>
> Reverting this commit, or disabling IOMMU support fixes the issue.
Hello Geert,
Can you test the following patch?
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 8e1d7ed52fef..ebba05a2bc7f 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -188,7 +188,10 @@ static int blk_validate_limits(struct queue_limits *lim)
* bvec and lower layer bio splitting is supposed to handle the two
* correctly.
*/
- if (!lim->virt_boundary_mask) {
+ if (lim->virt_boundary_mask) {
+ if (!lim->max_segment_size)
+ lim->max_segment_size = UINT_MAX;
+ } else {
/*
* The maximum segment size has an odd historic 64k default that
* drivers probably should override. Just like the I/O size we
thanks
Ming
