Hi all, I've hit the following bug while unmounting a xfs partition ----------- [cut here ] --------- [please bite here ] --------- Kernel BUG at drivers/md/md.c:5035 invalid opcode: 0000 [1] SMP CPU 0 Modules linked in: unionfs sbp2 ohci1394 ieee1394 raid456 xor w83627ehf i2c_isa i2c_core Pid: 1838, comm: umount Not tainted 2.6.18.6 #3 RIP: 0010:[<ffffffff8048ddc8>] [<ffffffff8048ddc8>] md_write_start+0x28/0x160 RSP: 0000:ffff81000d581b28 EFLAGS: 00010246 RAX: 0000000000000001 RBX: ffff8100184f3800 RCX: ffff8100184ea670 RDX: 0000000000000008 RSI: ffff810011ade140 RDI: ffff8100184f3800 RBP: ffff810011ade140 R08: 0000000000000000 R09: 00000000000000ff R10: ffff810011ade140 R11: ffffffff8038fbc0 R12: ffff810018094c00 R13: ffff810011ade140 R14: ffff810011ade140 R15: 0000000000000000 FS: 00002b7ce7f871f0(0000) GS:ffffffff807b9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00002b7ce7807471 CR3: 0000000016818000 CR4: 00000000000006e0 Process umount (pid: 1838, threadinfo ffff81000d580000, task ffff81001f5ff850) Stack: ffff810004b630d0 0000000000000000 0000000000001000 ffff81000d581c08 0000000000000001 ffffffff8028a355 0000000000000008 ffff810011ade140 ffff810018094c00 ffffffff8801dc51 0000000000000000 ffff8100075f5880 Call Trace: [<ffffffff8801dc51>] :raid456:make_request+0x51/0x540 [<ffffffff803ae472>] generic_make_request+0x152/0x170 [<ffffffff803b0fbd>] submit_bio+0xdd/0xf0 [<ffffffff8039ae36>] xfs_buf_iorequest+0x3c6/0x430 [<ffffffff8039fdc5>] xfs_bdstrat_cb+0x45/0x50 [<ffffffff8039743c>] xfs_bwrite+0x6c/0xf0 [<ffffffff8038fa1f>] xfs_syncsub+0x16f/0x2a0 [<ffffffff803a166f>] xfs_fs_sync_super+0x4f/0x130 [<ffffffff8028aab6>] __fsync_super+0x76/0xa0 [<ffffffff8028ab69>] fsync_super+0x9/0x20 [<ffffffff8028eb60>] generic_shutdown_super+0x40/0x150 [<ffffffff8028ec9d>] kill_block_super+0x2d/0x50 [<ffffffff8028ed6f>] deactivate_super+0x4f/0x80 [<ffffffff802a5100>] sys_umount+0x220/0x280 [<ffffffff80209daa>] system_call+0x7e/0x83 [<00002b7ce788c689>] Code: 0f 0b 68 ed d4 59 80 c2 ab 13 eb 21 83 f8 02 75 1c c7 47 2c RIP [<ffffffff8048ddc8>] md_write_start+0x28/0x160 RSP <ffff81000d581b28> Kernel : stock-kernel 2.6.18.6, x86_64 Setup : xfs on raid5, on 5 250Go ieee1394 drives Way to reproduce : 1. assemble the array 2. mount the xfs array 3. mark the array read-only (mdadm -o) 4. umount the xfs array... I guess the problem is hit in md.c: md_write_start(), at the BUG_ON(mddev->ro == 1). It is obvious that my mddev->ro is set to 1, because I set it read-only. Nowhere before md_write_start() the check on mddev->ro == 1 is done, so that the upper layer never sees that the underlying device is read-only. As a result, when xfs wishes to write to it, bad things happen. May it be possible to relax the BUG_ON() and be able to send to upper-layer a more gentle message ? Regards - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
