On Fri, Jun 24, 2022 at 02:58:28PM -0700, Nathan Chancellor wrote:
> Hi Matthew,
>
> I bisected a boot failure on one of my test machines to your commit
> c462f63731e0 ("mm: Add an assertion that PG_private and folio->private
> are in sync"), which landed in next-20220624. I didn't see this patch
> posted to any mailing list on lore, hence this separate thread;
> apologies if it was and I missed it. I didn't see this reported yet but
> I see the assertion triggered when systemd-zram-setup@zram0 runs:
urgh, sorry about that. i really need to wean zsmalloc off using struct
page. i'll drop this patch; feel free to just revert it, there's nothing
that will depend on it.
> zram0: detected capacity change from 0 to 16777216
> page:00000000fed1c582 refcount:1 mapcount:33 mapping:000000007b9116a6 index:0xfffffda990ac2640 pfn:0x20b5278
> aops:zsmalloc_aops ino:488c
> flags: 0x2ffff000000001(locked|node=0|zone=2|lastcpupid=0xffff)
> raw: 002ffff000000001 0000000000000000 dead000000000122 ffff6a6422c621fa
> raw: fffffda990ac2640 ffff6a642a1e5e40 0000000100000020 0000000000000000
> page dumped because: VM_BUG_ON_FOLIO(!folio_test_swapbacked(folio) && (folio_test_private(folio) == !folio_get_private(folio)))
> ------------[ cut here ]------------
> kernel BUG at mm/filemap.c:1560!
> Internal error: Oops - BUG: 0 [#1] SMP
> Modules linked in: zram xfs fsl_dpaa2_eth pcs_lynx phylink ahci_qoriq crct10dif_ce ghash_ce sbsa_gwdt fsl_mc_dpio nvme nvme_core xhci_plat_hcd lm90 rtc_fsl_ftm_alarm at803x xgmac_mdio ahci_platform i2c_imx ip6_tables ip_tables ipmi_devintf ipmi_msghandler fuse
> CPU: 0 PID: 813 Comm: mkswap Not tainted 5.19.0-rc3-00032-gc462f63731e0 #1
> Hardware name: SolidRun Ltd. SolidRun CEX7 Platform, BIOS EDK II Jun 21 2022
> pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : folio_unlock+0x98/0x9c
> lr : folio_unlock+0x98/0x9c
> sp : ffff8000095bb680
> x29: ffff8000095bb680 x28: 0000000000001000 x27: 0000000000000000
> x26: 0000000000001000 x25: ffff6a642ab48000 x24: 0000000000000001
> x23: 0020b59770000000 x22: ffff6a642a1e5e40 x21: 0000000000000001
> x20: ffff6a642a802000 x19: fffffda990d49e00 x18: 0000000000000020
> x17: 696c6f662864656b x16: 636162706177735f x15: 747365745f6f696c
> x14: 6f6621284f494c4f x13: 2929296f696c6f66 x12: 0000000000000018
> x11: 0000000000000000 x10: 0000000000000027 x9 : 0000000000000002
> x8 : 0000000100000002 x7 : 6163656220646570 x6 : 6d75642065676170
> x5 : ffffa31574652d6f x4 : 6f696c6f66286574 x3 : 65745f6f696c6f66
> x2 : 80000000ffffe314 x1 : ffffa31573961a43 x0 : 000000000000007f
> Call trace:
> folio_unlock+0x98/0x9c
> unlock_page+0x28/0x58
> SetZsPageMovable+0x74/0x100
> zs_malloc+0x218/0x234
> __zram_bvec_write+0x158/0x458 [zram]
> zram_bvec_rw+0x94/0x194 [zram]
> zram_submit_bio+0x1a4/0x240 [zram]
> __submit_bio+0x88/0x2f0
> submit_bio_noacct_nocheck+0xa4/0x1d8
> submit_bio_noacct+0x2e4/0x40c
> submit_bio+0x100/0x13c
> submit_bh_wbc+0x158/0x1a0
> __block_write_full_page+0x39c/0x700
> block_write_full_page+0x98/0xac
> blkdev_writepage+0x28/0x34
> __writepage+0x2c/0xbc
> write_cache_pages+0x1e4/0x44c
> generic_writepages+0x54/0x80
> blkdev_writepages+0x1c/0x28
> do_writepages+0xd8/0x1c8
> filemap_fdatawrite_wbc+0x80/0xa4
> file_write_and_wait_range+0x78/0xdc
> blkdev_fsync+0x24/0x48
> __arm64_sys_fsync+0x74/0xb0
> invoke_syscall+0x78/0x118
> el0_svc_common+0x94/0xfc
> do_el0_svc+0x38/0xc0
> el0_svc+0x34/0x110
> el0t_64_sync_handler+0x84/0xf0
> el0t_64_sync+0x190/0x194
> Code: 17fffff5 90009781 9137e021 9401212e (d4210000)
> ---[ end trace 0000000000000000 ]---
> note: mkswap[813] exited with preempt_count 3
> ------------[ cut here ]------------
>
> If there is any additional information I can provide or patches I can
> test, I am more than happy to do so.
>
> Cheers,
> Nathan
