On 4/8/22 15:50, Bob Pearson wrote:
Actually it doesn't hang forever but I get the following
......
[ 107.579576] sd 4:0:0:0: [sdb] Synchronizing SCSI cache
[ 291.970133] sd 4:0:0:0: [sdb] Synchronize Cache(10) failed: Result: hostbyte=DID_TIME_OUT driverbyte=DRIVER_OK
[ 292.247547] rdma_rxe: unloaded
So it waits for about 3 minutes for something and then gives up.
(+Christoph)
Hi Bob,
I can reproduce this behavior with the Soft-iWARP driver by running the
following command:
cd blktests && use_siw=1 ./check -q srp/001
Christoph, the call stack involved in this issue is as follows:
__schedule+0x4c3/0xd20
schedule+0x82/0x110
schedule_timeout+0x122/0x200
io_schedule_timeout+0x7b/0xc0
__wait_for_common+0x2bc/0x380
wait_for_completion_io_timeout+0x1d/0x20
blk_execute_rq+0x1db/0x200
__scsi_execute+0x1fb/0x310
sd_sync_cache+0x155/0x2c0 [sd_mod]
sd_shutdown+0xbb/0x190 [sd_mod]
sd_remove+0x5b/0x80 [sd_mod]
device_remove+0x9a/0xb0
device_release_driver_internal+0x2c5/0x360
device_release_driver+0x12/0x20
bus_remove_device+0x1aa/0x270
device_del+0x2d4/0x640
__scsi_remove_device+0x168/0x1a0
scsi_forget_host+0xa8/0xb0
scsi_remove_host+0x9b/0x150
sdebug_driver_remove+0x3d/0x140 [scsi_debug]
device_remove+0x6f/0xb0
device_release_driver_internal+0x2c5/0x360
device_release_driver+0x12/0x20
bus_remove_device+0x1aa/0x270
device_del+0x2d4/0x640
device_unregister+0x18/0x70
sdebug_do_remove_host+0x138/0x180 [scsi_debug]
scsi_debug_exit+0x45/0xd5 [scsi_debug]
__do_sys_delete_module.constprop.0+0x210/0x320
__x64_sys_delete_module+0x1f/0x30
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
One of the functions in the above call stack is sd_remove(). sd_remove()
calls del_gendisk() just before calling sd_shutdown(). sd_shutdown()
submits the SYNCHRONIZE CACHE command. In del_gendisk() I found the
following comment: "Fail any new I/O". Do you agree that failing new I/O
before sd_shutdown() is called is wrong? Is there any other way to fix
this than moving the blk_queue_start_drain() etc. calls out of
del_gendisk() and into a new function?
Thanks,
Bart.
