kernel WARNING "sysfs: cannot create duplicate filename /devices/virtual/bdi/vboxsf-$SHARENAME"

[Sam Morris]

The following kernel messages are regularly logged since upgrading to 4.0. They appear harmless.

Jun  6 20:00:41 wintermute kernel: [   18.074041] ------------[ cut here ]------------
Jun  6 20:00:41 wintermute kernel: [   18.074048] WARNING: at /build/buildd-linux-2.6_2.6.39-1+b1-amd64-h9EWBu
/linux-2.6-2.6.39/debian/build/source_amd64_none/fs/sysfs/dir.c:455 sysfs_add_one+0x86/0x98()
Jun  6 20:00:41 wintermute kernel: [   18.074051] Hardware name: VirtualBox
Jun  6 20:00:41 wintermute kernel: [   18.074052] sysfs: cannot create duplicate filename 
'/devices/virtual/bdi/vboxsf-vmshare'
Jun  6 20:00:41 wintermute kernel: [   18.074054] Modules linked in: bridge stp bnep rfcomm bluetooth rfkill binfmt_misc ppdev lp sha256_generic cryptd aes_x86_64 aes_generic 
cbc dm_crypt dm_mod joydev snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq snd_timer snd_seq_device 
pcspkr snd processor soundcore psmouse ac thermal_sys power_supply button serio_raw parport_pc parport 
snd_page_alloc evdev fuse vboxsf(O) vboxguest(O) loop autofs4 ext4 mbcache jbd2 crc16 nbd usbhid hid sg sd_mod 
sr_mod cdrom crc_t10dif ohci_hcd ahci libahci libata ehci_hcd virtio_net scsi_mod usbcore virtio_pci 
virtio_ring virtio [last unloaded: scsi_wait_scan]
Jun  6 20:00:41 wintermute kernel: [   18.074089] Pid: 1226, comm: mount.vboxsf Tainted: G           O 2.6.39-1-amd64 #1
Jun  6 20:00:41 wintermute kernel: [   18.074091] Call Trace:
Jun  6 20:00:41 wintermute kernel: [   18.074097]  [<ffffffff810458b4>] ? warn_slowpath_common+0x78/0x8c
Jun  6 20:00:41 wintermute kernel: [   18.074100]  [<ffffffff81045966>] ? warn_slowpath_fmt+0x45/0x4a
Jun  6 20:00:41 wintermute kernel: [   18.074102]  [<ffffffff8114f8aa>] ? sysfs_add_one+0x86/0x98
Jun  6 20:00:41 wintermute kernel: [   18.074105]  [<ffffffff811500cd>] ? create_dir+0x67/0x9f
Jun  6 20:00:41 wintermute kernel: [   18.074108]  [<ffffffff81150196>] ? sysfs_create_dir+0x91/0xa5
Jun  6 20:00:41 wintermute kernel: [   18.074112]  [<ffffffff811a34fc>] ? kobject_add_internal+0xc8/0x181
Jun  6 20:00:41 wintermute kernel: [   18.074114]  [<ffffffff811a3745>] ? kobject_add+0x66/0x6b
Jun  6 20:00:41 wintermute kernel: [   18.074118]  [<ffffffff81331dc0>] ? mutex_lock+0xd/0x33
Jun  6 20:00:41 wintermute kernel: [   18.074120]  [<ffffffff811a3376>] ? kobject_get+0x12/0x17
Jun  6 20:00:41 wintermute kernel: [   18.074124]  [<ffffffff81242cfa>] ? device_add+0xcf/0x5d7
Jun  6 20:00:41 wintermute kernel: [   18.074127]  [<ffffffff8124329f>] ? device_create_vargs+0x8b/0xbc
Jun  6 20:00:41 wintermute kernel: [   18.074131]  [<ffffffff810cbb0f>] ? bdi_register+0x5a/0x183
Jun  6 20:00:41 wintermute kernel: [   18.074133]  [<ffffffff810cb794>] ? bdi_init+0x12b/0x157
Jun  6 20:00:41 wintermute kernel: [   18.074137]  [<ffffffff8110d9c1>] ? inode_sb_list_add+0x10/0x4b
Jun  6 20:00:41 wintermute kernel: [   18.074141]  [<ffffffffa01914fc>] ? sf_read_super_26+0x44f/0x514 [vboxsf]
Jun  6 20:00:41 wintermute kernel: [   18.074144]  [<ffffffff811a2788>] ? ida_get_new_above+0x196/0x1b7
Jun  6 20:00:41 wintermute kernel: [   18.074147]  [<ffffffff811a2bb3>] ? idr_pre_get+0x57/0x6b
Jun  6 20:00:41 wintermute kernel: [   18.074151]  [<ffffffff810fd06a>] ? unlock_super+0x21/0x21
Jun  6 20:00:41 wintermute kernel: [   18.074154]  [<ffffffff810fd0b8>] ? set_anon_super+0x4e/0xe1
Jun  6 20:00:41 wintermute kernel: [   18.074157]  [<ffffffff810fdf6a>] ? sget+0x35d/0x372
Jun  6 20:00:41 wintermute kernel: [   18.074160]  [<ffffffffa01910ad>] ? sf_glob_free+0x2a/0x2a [vboxsf]
Jun  6 20:00:41 wintermute kernel: [   18.074163]  [<ffffffff810fe05c>] ? mount_nodev+0x45/0x79
Jun  6 20:00:41 wintermute kernel: [   18.074165]  [<ffffffff810fdb2f>] ? mount_fs+0x6c/0x14a
Jun  6 20:00:41 wintermute kernel: [   18.074168]  [<ffffffff81112ce9>] ? vfs_kern_mount+0x61/0x97
Jun  6 20:00:41 wintermute kernel: [   18.074171]  [<ffffffff81112d7e>] ? do_kern_mount+0x49/0xd6
Jun  6 20:00:41 wintermute kernel: [   18.074173]  [<ffffffff81113533>] ? do_mount+0x728/0x792
Jun  6 20:00:41 wintermute kernel: [   18.074176]  [<ffffffff810e6260>] ? alloc_pages_current+0xa7/0xca
Jun  6 20:00:41 wintermute kernel: [   18.074179]  [<ffffffff81113625>] ? sys_mount+0x88/0xc3
Jun  6 20:00:41 wintermute kernel: [   18.074182]  [<ffffffff81338c12>] ? system_call_fastpath+0x16/0x1b
Jun  6 20:00:41 wintermute kernel: [   18.074184] ---[ end trace 8683823577cfa94a ]---
Jun  6 20:00:41 wintermute kernel: [   18.074186] kobject_add_internal failed for vboxsf-vmshare with -EEXIST, don't try to register things with the same 
name in the same directory.

This may be a duplicate of #8056, but for me the shared folders work fine, whereas in that bug the user cannot mount them.

Guest is Linux 2.6.32 through 2.6.39.

[Sam Morris]

complete syslog output

[Frank Mehnert]

Please also attach a VBox.log file from such a VM session.

[Sam Morris]

virtualbox log

[Sam Morris]

NB, I'm still seeing this with 4.1.4

[Michael Thayer]

Sorry about this, but I have to ask - did you upgrade the Guest Additions in that guest? I thought I had fixed that problem.