Comment 0 for bug 1706132

#### This scenario is testing [iscsi <-> scsi <-> disk <-> xfs]

[ 551.125604] sd 2:0:0:1: rejecting I/O to offline device
[ 551.125615] sd 2:0:0:1: rejecting I/O to offline device
[ 551.125627] sd 2:0:0:1: rejecting I/O to offline device
[ 551.125639] sd 2:0:0:1: rejecting I/O to offline device

[ 551.135216] XFS (sda1): metadata I/O error: block 0xeffe01 ("xfs_trans_read_buf_map") error 5 numblks 1
[ 551.135274] XFS (sda1): page discard on page ffffea0002a89cc0, inode 0x83, offset 6442385408.

# when XFS shuts down because of an error (or offline disk, example):

[ 551.850498] XFS (sda1): xfs_do_force_shutdown(0x2) called from line 1197 of file /build/linux-lts-xenial-roXrYH/linux-lts-xenial-4.4.0/fs/xfs/xfs_log.c. Return address = 0xffffffffc0300388
[ 551.850568] XFS (sda1): Log I/O Error Detected. Shutting down filesystem

[ 551.850618] XFS (sda1): xfs_log_force: error -5 returned.

[ 551.850630] XFS (sda1): Failing async write on buffer block 0x77ff08. Retrying async write.
[ 551.850634] XFS (sda1): Failing async write on buffer block 0x77ff10. Retrying async write.
[ 551.850638] XFS (sda1): Failing async write on buffer block 0x77ff01. Retrying async write.
[ 551.853171] XFS (sda1): Please umount the filesystem and rectify the problem(s)

[ 551.874131] XFS (sda1): metadata I/O error: block 0x1dffc49 ("xlog_iodone") error 5 numblks 64
[ 551.877993] XFS (sda1): xfs_do_force_shutdown(0x2) called from line 1197 of file /build/linux-lts-xenial-roXrYH/linux-lts-xenial-4.4.0/fs/xfs/xfs_log.c. Return address = 0xffffffffc0300388

[ 551.899036] XFS (sda1): xfs_log_force: error -5 returned.
[ 569.323074] XFS (sda1): xfs_log_force: error -5 returned.
[ 599.403085] XFS (sda1): xfs_log_force: error -5 returned.
[ 629.483111] XFS (sda1): xfs_log_force: error -5 returned.
[ 659.563115] XFS (sda1): xfs_log_force: error -5 returned.
[ 689.643014] XFS (sda1): xfs_log_force: error -5 returned.

# when I execute:

# sudo umount /dev/sda1:

[81634.923043] XFS (sda1): xfs_log_force: error -5 returned.
[81640.739097] XFS (sda1): xfs_log_force: error -5 returned.
[81640.739137] XFS (sda1): Unmounting Filesystem
[81640.739463] XFS (sda1): xfs_log_force: error -5 returned.
[81640.739508] XFS (sda1): xfs_log_force: error -5 returned.
[81640.742741] sd 2:0:0:1: rejecting I/O to offline device
[81640.745576] blk_update_request: 25 callbacks suppressed
[81640.745601] blk_update_request: I/O error, dev sda, sector 0

# i was able to umount and then to remove iscsi disk.

# but if i try to unload the xfs module:

inaddy@(trustyiscsicli):~$ sudo rmmod xfs
[82211.059301] =============================================================================
[82211.063764] BUG xfs_log_ticket (Tainted: G OE ): Objects remaining in xfs_log_ticket on kmem_cache_close()
[82211.067450] -----------------------------------------------------------------------------
[82211.067450]
[82211.070580] INFO: Slab 0xffffea0002eb7640 objects=22 used=1 fp=0xffff8800badd9f18 flags=0xffffc000000080
[82211.074430] INFO: Object 0xffff8800badd9228 @offset=552
[82211.076133] kmem_cache_destroy xfs_log_ticket: Slab cache still has objects

AND

[82211.059301] =============================================================================
[82211.063764] BUG xfs_log_ticket (Tainted: G OE ): Objects remaining in xfs_log_ticket on kmem_cache_close()
[82211.067450] -----------------------------------------------------------------------------
[82211.067450]
[82211.070570] Disabling lock debugging due to kernel taint
[82211.070580] INFO: Slab 0xffffea0002eb7640 objects=22 used=1 fp=0xffff8800badd9f18 flags=0xffffc000000080
[82211.073964] CPU: 3 PID: 32230 Comm: rmmod Tainted: G B OE 4.4.0-74-generic #95~14.04.1-Ubuntu
[82211.073970] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[82211.073975] 0000000000000000 ffff8800baf53d28 ffffffff813dce3c ffffea0002eb7640
[82211.073984] ffff880036614300 ffff8800baf53e00 ffffffff811dc4b4 ffff880000000020
[82211.073991] ffff8800baf53e10 ffff8800baf53dc0 656a624f02e294c0 616d657220737463
[82211.074013] Call Trace:
[82211.074039] [<ffffffff813dce3c>] dump_stack+0x63/0x87
[82211.074066] [<ffffffff811dc4b4>] slab_err+0xb4/0xe0
[82211.074081] [<ffffffff8118cfd2>] ? __free_kmem_pages+0x22/0x40
[82211.074089] [<ffffffff811dcc6c>] ? __free_slab+0xcc/0x1a0
[82211.074097] [<ffffffff811df799>] ? __kmalloc+0x229/0x270
[82211.074106] [<ffffffff811e14b1>] ? __kmem_cache_shutdown+0x111/0x2b0
[82211.074127] [<ffffffff811e14d1>] __kmem_cache_shutdown+0x131/0x2b0
[82211.074157] [<ffffffff811a85ef>] kmem_cache_destroy+0x1bf/0x220
[82211.074289] [<ffffffffc031a368>] xfs_destroy_zones+0xeb/0x10a [xfs]
[82211.074382] [<ffffffffc031a3fc>] exit_xfs_fs+0x6f/0xc73 [xfs]
[82211.074395] [<ffffffff81101f3d>] SyS_delete_module+0x18d/0x220
[82211.074404] [<ffffffff8107986b>] ? exit_to_usermode_loop+0x78/0xa2
[82211.074416] [<ffffffff818066b6>] entry_SYSCALL_64_fastpath+0x16/0x75
[82211.074430] INFO: Object 0xffff8800badd9228 @offset=552
[82211.076133] kmem_cache_destroy xfs_log_ticket: Slab cache still has objects
[82211.078221] CPU: 3 PID: 32230 Comm: rmmod Tainted: G B OE 4.4.0-74-generic #95~14.04.1-Ubuntu
[82211.078226] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[82211.078230] 0000000000000000 ffff8800baf53e60 ffffffff813dce3c ffff880036614300
[82211.078238] ffff880036614300 ffff8800baf53ec8 ffffffff811a8648 0000000000000000
[82211.078245] 00ff8800baf53eb8 ffff8800baf53e80 ffff8800baf53e80 ffff8800baf53e90
[82211.078253] Call Trace:
[82211.078262] [<ffffffff813dce3c>] dump_stack+0x63/0x87
[82211.078271] [<ffffffff811a8648>] kmem_cache_destroy+0x218/0x220
[82211.078334] [<ffffffffc031a368>] xfs_destroy_zones+0xeb/0x10a [xfs]
[82211.078382] [<ffffffffc031a3fc>] exit_xfs_fs+0x6f/0xc73 [xfs]
[82211.078389] [<ffffffff81101f3d>] SyS_delete_module+0x18d/0x220
[82211.078395] [<ffffffff8107986b>] ? exit_to_usermode_loop+0x78/0xa2
[82211.078401] [<ffffffff818066b6>] entry_SYSCALL_64_fastpath+0x16/0x75
[82269.173849] SGI XFS with ACLs, security attributes, realtime, no debug enabled