Background: incoming/ was mounted via nfs. An ISO on that directory was mounted via loopback to incoming/en. Then on the nfs server various things happened that broke the nfs mount to incoming; specifically, incoming/iso was created on the server (so that from the client's view there is the server-side incoming/iso dir, and that directory is also the loopback mount point for a file on the same nfs mount. Now when trying to unmount the incoming dir, it says busy, since an iso was mounted from that dir. Trying to unmount the iso was unsuccessful, presumably since that file doesn't exist. Now it just dies peacefully: # umount /mrtwig/incoming/iso umount: /mrtwig/incoming/7.0-i386-disc1.iso: block devices not permitted on fs but during the first unmount, the kernel was a bit more upset: # ls -l incoming incoming/iso /usr/bin/ls: incoming: Permission denied /usr/bin/ls: incoming/iso: Permission denied # umount incoming/iso kernel BUG at /usr/src/linux/include/linux/nfs_fs.h:164! invalid operand: 0000 CPU: 0 EIP: 0010:[<d090e555>] EFLAGS: 00010282 eax: 00000039 ebx: cece5c20 ecx: cfefd4e0 edx: 00000004 esi: cec7ace0 edi: ce0be6a0 ebp: ccd58120 esp: ca24df30 ds: 0018 es: 0018 ss: 0018 Process umount (pid: 20796, stackpage=ca24d000) Stack: d0915165 d0915300 000000a4 cd259b00 cd82ad60 c012c7a0 ce0be6a0 cd259b00 cd676000 00000700 ccd58120 ffffffe7 d5924b8d cd676000 00000000 00004c01 d5924fcb cd676000 00000700 c665fec0 00000000 00004c01 c0132c1c c7738e20 Call Trace: [<d0915165>] [<d0915300>] [<c012c7a0>] [<d5924b8d>] [<d5924fcb>] [<c0132c1c>] [<c0138e97>] [<c010a32f>] Code: 0f 0b 83 c4 0c 8d b6 00 00 00 00 85 db 74 0a 53 56 e8 1d 88 zsh: 20796 segmentation fault umount incoming/iso d0915140 __insmod_nfs_S.rodata_L12759 [nfs] d0918320 __insmod_nfs_S.data_L1324 [nfs] d0918908 __insmod_nfs_S.bss_L4 [nfs] d5925170 loop_register_transfer_Rd5e1e654 [loop] d5925198 loop_unregister_transfer_Rbfee3ad5 [loop] d5924000 __insmod_loop_O/lib/modules/2.4.0-test9/kernel/drivers/block/loop.o_M39D308D3_V132096 [loop] d5924060 __insmod_loop_S.text_L5286 [loop] d5925540 __insmod_loop_S.rodata_L1507 [loop] d5925ca0 __insmod_loop_S.data_L164 [loop] d5925d44 __insmod_loop_S.bss_L12 [loop] justin - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/