[forwarding test case to fstests@vger] On Mon, Mar 23, 2020 at 9:50 AM Phasip <phasip@xxxxxxxxx> wrote: > > Hello! > > I have stumbled upon two ways of producing kernel warnings when using the overlayfs, both seem to be results of the same issue. > > The issue seems to be related to handling of hard links that are created directly in the upperdir. > Below is my system details and then two samples with a list of commands to reproduce and the corresponding kernel warning > > System details > ------------------- > My kernel version: Linux ubuntu 5.6.0-050600rc5-generic #202003082130 SMP Mon Mar 9 01:33:48 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux > > # modinfo overlay > filename: /lib/modules/5.6.0-050600rc5-generic/kernel/fs/overlayfs/overlay.ko > alias: fs-overlay > license: GPL > description: Overlay filesystem > author: Miklos Szeredi <miklos@xxxxxxxxxx> > srcversion: DF053786AE7737625051D8F > depends: > retpoline: Y > intree: Y > name: overlay > vermagic: 5.6.0-050600rc5-generic SMP mod_unload > parm: check_copy_up:Obsolete; does nothing > parm: redirect_max:Maximum length of absolute redirect xattr value (ushort) > parm: redirect_dir:Default to on or off for the redirect_dir feature (bool) > parm: redirect_always_follow:Follow redirects even if redirect_dir feature is turned off (bool) > parm: index:Default to on or off for the inodes index feature (bool) > parm: nfs_export:Default to on or off for the NFS export feature (bool) > parm: xino_auto:Auto enable xino feature (bool) > parm: metacopy:Default to on or off for the metadata only copy up feature (bool) > > > Sample 1 > ------------- > mkdir work lower upper final > sudo mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper,metacopy=on overlay final > touch final/h > ln upper/h upper/k > rm -rf final/k > rm -rf final/h > dmesg > > [ 5771.305217] ------------[ cut here ]------------ > [ 5771.305227] WARNING: CPU: 1 PID: 116244 at fs/inode.c:302 drop_nlink+0x28/0x40 > [ 5771.305228] Modules linked in: overlay intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul ghash_clmulni_intel vmw_balloon aesni_intel crypto_simd cryptd glue_helper intel_rapl_perf joydev input_leds serio_raw i2c_piix4 mac_hid vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock vmw_vmci parport_pc ppdev lp parport autofs4 vmw_pvscsi vmxnet3 hid_generic vmwgfx psmouse usbhid hid ttm drm_kms_helper ahci libahci e1000 mptspi syscopyarea mptscsih sysfillrect sysimgblt mptbase fb_sys_fops cec rc_core scsi_transport_spi drm pata_acpi [last unloaded: overlay] > [ 5771.305255] CPU: 1 PID: 116244 Comm: rm Tainted: G W 5.6.0-050600rc5-generic #202003082130 > [ 5771.305256] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/29/2019 > [ 5771.305258] RIP: 0010:drop_nlink+0x28/0x40 > [ 5771.305260] Code: 66 90 0f 1f 44 00 00 55 8b 47 48 48 89 e5 85 c0 74 18 8d 50 ff 89 57 48 85 d2 75 0c 48 8b 47 28 f0 48 ff 80 98 04 00 00 5d c3 <0f> 0b c7 47 48 ff ff ff ff 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 > [ 5771.305261] RSP: 0018:ffffb7c042bdbdd8 EFLAGS: 00010246 > [ 5771.305262] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000200000000 > [ 5771.305263] RDX: ffffa0ec6f512f80 RSI: 0000000100000000 RDI: ffffa0ec726a22a8 > [ 5771.305263] RBP: ffffb7c042bdbdd8 R08: 0000000000000002 R09: 0000000000000064 > [ 5771.305264] R10: ffffa0ec7271b300 R11: ffffa0eaf2158668 R12: ffffa0eaf400a480 > [ 5771.305264] R13: ffffb7c042bdbe08 R14: 0000000000000000 R15: 0000000000000000 > [ 5771.305266] FS: 00007f81856ac700(0000) GS:ffffa0ec75e40000(0000) knlGS:0000000000000000 > [ 5771.305266] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 5771.305267] CR2: 0000000001a2e000 CR3: 000000003466c004 CR4: 00000000003606e0 > [ 5771.305273] Call Trace: > [ 5771.305283] ovl_do_remove+0x348/0x4c0 [overlay] > [ 5771.305287] ovl_unlink+0x13/0x20 [overlay] > [ 5771.305289] vfs_unlink+0x114/0x200 > [ 5771.305290] do_unlinkat+0x19a/0x2d0 > [ 5771.305292] __x64_sys_unlinkat+0x38/0x60 > [ 5771.305318] do_syscall_64+0x57/0x1b0 > [ 5771.305322] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [ 5771.305323] RIP: 0033:0x7f81851cfac7 > [ 5771.305325] Code: 73 01 c3 48 8b 0d d1 b3 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 b3 2c 00 f7 d8 64 89 01 48 > [ 5771.305325] RSP: 002b:00007ffdfc056c58 EFLAGS: 00000202 ORIG_RAX: 0000000000000107 > [ 5771.305327] RAX: ffffffffffffffda RBX: 0000000001a2f230 RCX: 00007f81851cfac7 > [ 5771.305327] RDX: 0000000000000000 RSI: 0000000001a2e000 RDI: 00000000ffffff9c > [ 5771.305328] RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 > [ 5771.305328] R10: 000000000000015e R11: 0000000000000202 R12: 0000000001a2df70 > [ 5771.305329] R13: 00007ffdfc056d80 R14: 0000000000000000 R15: 0000000000000000 > [ 5771.305331] ---[ end trace 67e413528020d510 ]--- > > > Sample 2 > ------------- > mkdir work lower upper final > sudo mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper,metacopy=on overlay final > touch final/h > ln upper/h upper/k > rm -rf final/k > touch final/z > mv final/z final/h > dmesg > > [ 6633.944688] ------------[ cut here ]------------ > [ 6633.944700] WARNING: CPU: 0 PID: 47279 at fs/inode.c:302 drop_nlink+0x28/0x40 > [ 6633.944701] Modules linked in: overlay intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul ghash_clmulni_intel vmw_balloon aesni_intel crypto_simd cryptd glue_helper intel_rapl_perf joydev input_leds serio_raw i2c_piix4 mac_hid vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock vmw_vmci parport_pc ppdev lp parport autofs4 vmw_pvscsi vmxnet3 hid_generic vmwgfx psmouse usbhid hid ttm drm_kms_helper ahci libahci e1000 mptspi syscopyarea mptscsih sysfillrect sysimgblt mptbase fb_sys_fops cec rc_core scsi_transport_spi drm pata_acpi [last unloaded: overlay] > [ 6633.944732] CPU: 0 PID: 47279 Comm: mv Tainted: G W 5.6.0-050600rc5-generic #202003082130 > [ 6633.944733] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/29/2019 > [ 6633.944735] RIP: 0010:drop_nlink+0x28/0x40 > [ 6633.944736] Code: 66 90 0f 1f 44 00 00 55 8b 47 48 48 89 e5 85 c0 74 18 8d 50 ff 89 57 48 85 d2 75 0c 48 8b 47 28 f0 48 ff 80 98 04 00 00 5d c3 <0f> 0b c7 47 48 ff ff ff ff 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 > [ 6633.944737] RSP: 0018:ffffb7c045163cc8 EFLAGS: 00010246 > [ 6633.944738] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 > [ 6633.944739] RDX: 0000000000000000 RSI: 0000000000000800 RDI: ffffa0ec726a0020 > [ 6633.944739] RBP: ffffb7c045163cc8 R08: 0000000000000000 R09: 0000000000000000 > [ 6633.944740] R10: ffffa0eaf22cb500 R11: ffffa0eb93e20540 R12: ffffa0eaf22cb080 > [ 6633.944740] R13: ffffa0eb93e21440 R14: ffffb7c045163d40 R15: 0000000000000000 > [ 6633.944741] FS: 00007f866894e800(0000) GS:ffffa0ec75e00000(0000) knlGS:0000000000000000 > [ 6633.944742] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 6633.944743] CR2: 0000000001ba9808 CR3: 00000000af75c005 CR4: 00000000003606f0 > [ 6633.944753] Call Trace: > [ 6633.944767] ovl_rename+0x92f/0x940 [overlay] > [ 6633.944770] vfs_rename+0x3df/0x9b0 > [ 6633.944775] ? _cond_resched+0x19/0x30 > [ 6633.944779] ? security_path_rename+0x88/0xb0 > [ 6633.944780] do_renameat2+0x507/0x570 > [ 6633.944782] __x64_sys_rename+0x23/0x30 > [ 6633.944786] do_syscall_64+0x57/0x1b0 > [ 6633.944787] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [ 6633.944789] RIP: 0033:0x7f8667db9367 > [ 6633.944790] Code: 75 12 48 89 df e8 a9 d7 08 00 85 c0 0f 95 c0 0f b6 c0 f7 d8 5b c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 52 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 01 8b 35 00 f7 d8 64 89 01 48 > [ 6633.944790] RSP: 002b:00007ffc331da4a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000052 > [ 6633.944792] RAX: ffffffffffffffda RBX: 0000000000008000 RCX: 00007f8667db9367 > [ 6633.944792] RDX: 0000000000000000 RSI: 00007ffc331dc517 RDI: 00007ffc331dc50f > [ 6633.944793] RBP: 00007ffc331da870 R08: 0000000000000000 R09: 0000000000000000 > [ 6633.944793] R10: 0000000000000640 R11: 0000000000000202 R12: 00007ffc331da601 > [ 6633.944794] R13: 00007ffc331da960 R14: 00007ffc331dc50f R15: 0000000000000000 > [ 6633.944795] ---[ end trace 67e413528020d64a ]--- > > > Best Wishes > Pasi Saarinen >
