hi
if anyone knows what is this warning plz explain...!!!

WARNING: at block/genhd.c:126 unregister_blkdev+0x56/0x77()
Modules linked in: sample_app(-) sit tunnel4 vfat fat ipt_MASQUERADE iptable_nat nf_nat bridge stp bnep rfcomm l2cap bluetooth ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi scsi_transport_iscsi fuse sunrpc ipt_REJECT nf_conntrack_ipv4 iptable_filter ip_tables ip6t_REJECT xt_tcpudp nf_conntrack_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables x_tables cpufreq_ondemand acpi_cpufreq loop dm_multipath i915 drm ipv6 kvm snd_hda_intel tpm_infineon snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq tpm snd_seq_device snd_pcm_oss pata_jmicron button firewire_ohci i2c_i801 i2c_core snd_mixer_oss firewire_core ppdev parport_pc parport snd_pcm tpm_bios snd_timer snd_page_alloc snd_hwdep e1000e snd soundcore serio_raw pcspkr iTCO_wdt iTCO_vendor_support crc_itu_t sg dm_snapshot dm_zero dm_mirror dm_log dm_mod pata_acpi ata_piix ata_generic libata sd_mod scsi_mod ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last unloaded: sample_app]
Pid: 5039, comm: rmmod Tainted: G W 2.6.27.42 #1
[<c063a3fe>] ? printk+0xf/0x11
[<c042a920>] warn_on_slowpath+0x41/0x65
[<c04c34e5>] ? sysfs_addrm_finish+0x198/0x1ae
[<c04c3522>] ? remove_dir+0x27/0x2e
[<c0483d1c>] ? kfree+0x9a/0xb0
[<c04fab0e>] ? kobject_release+0x4b/0x50
[<c04fab0e>] ? kobject_release+0x4b/0x50
[<c04fab0e>] ? kobject_release+0x4b/0x50
[<c04faac3>] ? kobject_release+0x0/0x50
[<c04fb5ad>] ? kref_put+0x39/0x44
[<c04faa3e>] ? kobject_put+0x37/0x3c
[<c056fada>] ? bus_remove_driver+0x84/0x89
[<c04f3147>] unregister_blkdev+0x56/0x77
[<f8fca095>] test_exit+0x26/0x34 [sample_app]
[<c044a55c>] sys_delete_module+0x1b1/0x202
[<c04748d8>] ? remove_vma+0x55/0x5b
[<c0403a2f>] sysenter_do_call+0x12/0x2f
[<c0630000>] ? nv_msi_ht_cap_quirk+0xe/0xe5
=======================
---[ end trace 9e46b92cbd396d60 ]---

How about providing some actual details...like version/distro of Linux, and what you're doing to GET this error. Just posting an error message doesn't give us alot to go on.

And spell out your words...