Receiving two REMOVE actions for the same USB drive

Tue Apr 29 01:09:16 UTC 2014

On Mon, Apr 28, 2014 at 06:03:01PM +0200, Mason wrote:
> Isaac Dunham wrote:
> 
> > Mason wrote:
> > 
> >> Ralf Friedl wrote:
> >> 
> >>> If you say that simple filtering of the events would be annoying, you 
> >>> don't want to change the kernel to avoid the double notification.
> >> 
> >> What do you mean by "you don't want to change the kernel" ?
> >> 
> >> I am /pretty sure/ that the vanilla kernel does not notify twice,
> >> and that this bug was introduced by one of the vendor's patches. 
> > 
> > A normal kernel will generate _tons_ of messages per USB device.
> 
> You are correct, of course.
> 
> This mdev is configured to filter out most of the kernel notifications,
> as we are only interested in block events.
> 
> # cat /etc/mdev.conf
> $SUBSYSTEM=block 0:0 660 ! */application/forward_events
> 
> When a block device is inserted, I receive
> - one "add" action for the block device itself
> - then one "add" action for each partition on the block device
> (e.g. MDEV=sda, MDEV=sda1, MDEV=sda2, etc)
> 
> when the device is removed, I should receive the "symmetric" events
> - one "remove" action for each partition
> - then one remove action for the block device itself
> 
> Do you disagree?
> 
> > Just tested with a random USB device, vanilla kernel 3.10.33;
> > I get 2x ACTION=add, 2x ACTION=remove
> 
> What SUBSYSTEM is it for?
> What are the values of MDEV each time?

That was SUBSYSTEM=usb, logged without mdev.
Here is inserting and removing U3 usb drive, likewise logged without mdev.
...
Looks like it's not duplicating remove events for the block subsystem.

If you have two "remove" actions when you pull out a "superfloppy" usb
drive, I'm curious how many you get with a single-partition usb drive.

(The thought is that it might be something about one for removal of the
device, one for removal of the partition...except that when the device
is the partition, it might be sending two events with the same devname
for that reason.)

HTH,
Isaac Dunham
-------------- next part --------------
___518___
___520___
___523___
___524___
DEVNAME=bus/usb/001/003
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1420
BUSNUM=001
MAJOR=189
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3
SUBSYSTEM=usb
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=2
TYPE=0/0/0
DEVNUM=003
PRODUCT=8ec/20/200
PWD=/
DEVTYPE=usb_device
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1421
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0
SUBSYSTEM=usb
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MODALIAS=usb:v08ECp0020d0200dc00dsc00dp00ic08isc06ip50in00
TYPE=0/0/0
INTERFACE=8/6/80
PRODUCT=8ec/20/200
PWD=/
DEVTYPE=usb_interface
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1423
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/scsi_host/host2
SUBSYSTEM=scsi_host
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1422
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
DEVTYPE=scsi_host
___529___
___530___
___532___
___534___
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1424
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
DEVTYPE=scsi_target
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1425
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MODALIAS=scsi:t-0x00
PWD=/
DEVTYPE=scsi_device
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1426
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/scsi_disk/2:0:0:0
SUBSYSTEM=scsi_disk
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
___536___
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1427
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/scsi_device/2:0:0:0
SUBSYSTEM=scsi_device
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
DEVNAME=sg1
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1428
MAJOR=21
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/scsi_generic/sg1
SUBSYSTEM=scsi_generic
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=1
PWD=/
___539___
___541___
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1429
DEVPATH=/devices/virtual/bdi/8:16
SUBSYSTEM=bdi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
___544___
DEVNAME=bsg/2:0:0:0
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1430
MAJOR=253
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/bsg/2:0:0:0
SUBSYSTEM=bsg
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=1
PWD=/
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1431
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MODALIAS=scsi:t-0x05
PWD=/
DEVTYPE=scsi_device
___547___
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1432
DEVPATH=/devices/virtual/bdi/11:0
SUBSYSTEM=bdi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
___548___
___550___
DEVNAME=sr0
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1433
MAJOR=11
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/block/sr0
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=0
PWD=/
DEVTYPE=disk
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1434
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/scsi_device/2:0:0:1
SUBSYSTEM=scsi_device
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
___552___
DEVNAME=sr0
ACTION=change
SHLVL=1
HOME=/
SEQNUM=1435
MAJOR=11
DISK_MEDIA_CHANGE=1
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/block/sr0
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=0
PWD=/
DEVTYPE=disk
___554___
DEVNAME=sg2
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1436
MAJOR=21
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/scsi_generic/sg2
SUBSYSTEM=scsi_generic
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=2
PWD=/
___556___
DEVNAME=sdb
___558___
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1437
MAJOR=8
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/block/sdb
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=16
PWD=/
DEVTYPE=disk
DEVNAME=bsg/2:0:0:1
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1438
MAJOR=253
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/bsg/2:0:0:1
SUBSYSTEM=bsg
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=2
PWD=/
___560___
___562___
DEVNAME=sdb2
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1440
MAJOR=8
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/block/sdb/sdb2
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=18
PWD=/
DEVTYPE=partition
DEVNAME=sdb1
ACTION=add
SHLVL=1
HOME=/
SEQNUM=1439
MAJOR=8
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/block/sdb/sdb1
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=17
PWD=/
DEVTYPE=partition
___572___
___574___
___573___
DEVNAME=bsg/2:0:0:0
___576___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1441
MAJOR=253
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/bsg/2:0:0:0
SUBSYSTEM=bsg
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=1
PWD=/
DEVNAME=sg1
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1442
MAJOR=21
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/scsi_generic/sg1
SUBSYSTEM=scsi_generic
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=1
PWD=/
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1443
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/scsi_device/2:0:0:0
SUBSYSTEM=scsi_device
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1444
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/scsi_disk/2:0:0:0
SUBSYSTEM=scsi_disk
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
___579___
___581___
DEVNAME=sdb2
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1445
MAJOR=8
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/block/sdb/sdb2
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=18
PWD=/
DEVTYPE=partition
DEVNAME=sdb1
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1446
MAJOR=8
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/block/sdb/sdb1
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=17
PWD=/
DEVTYPE=partition
___582___
___585___
___586___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1447
DEVPATH=/devices/virtual/bdi/8:16
SUBSYSTEM=bdi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
DEVNAME=sdb
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1448
MAJOR=8
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0/block/sdb
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=16
PWD=/
DEVTYPE=disk
___588___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1449
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:0
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MODALIAS=scsi:t-0x00
PWD=/
DEVTYPE=scsi_device
___591___
___593___
DEVNAME=bsg/2:0:0:1
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1450
MAJOR=253
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/bsg/2:0:0:1
SUBSYSTEM=bsg
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=2
PWD=/
DEVNAME=sg2
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1451
MAJOR=21
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/scsi_generic/sg2
SUBSYSTEM=scsi_generic
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=2
PWD=/
___595___
___597___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1452
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/scsi_device/2:0:0:1
SUBSYSTEM=scsi_device
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
ACTION=remove
___598___
SHLVL=1
HOME=/
SEQNUM=1453
DEVPATH=/devices/virtual/bdi/11:0
SUBSYSTEM=bdi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1455
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MODALIAS=scsi:t-0x05
PWD=/
DEVTYPE=scsi_device
___601___
DEVNAME=sr0
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1454
MAJOR=11
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0/2:0:0:1/block/sr0
SUBSYSTEM=block
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=0
PWD=/
DEVTYPE=disk
___603___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1456
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/target2:0:0
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
DEVTYPE=scsi_target
___604___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1457
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2/scsi_host/host2
SUBSYSTEM=scsi_host
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
___607___
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1458
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0/host2
SUBSYSTEM=scsi
PATH=/sbin:/bin:/usr/sbin:/usr/bin
PWD=/
DEVTYPE=scsi_host
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1459
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3/1-3:1.0
SUBSYSTEM=usb
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MODALIAS=usb:v08ECp0020d0200dc00dsc00dp00ic08isc06ip50in00
TYPE=0/0/0
INTERFACE=8/6/80
PRODUCT=8ec/20/200
PWD=/
DEVTYPE=usb_interface
___609___
DEVNAME=bus/usb/001/003
ACTION=remove
SHLVL=1
HOME=/
SEQNUM=1460
BUSNUM=001
MAJOR=189
DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-3
SUBSYSTEM=usb
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MINOR=2
TYPE=0/0/0
DEVNUM=003
PRODUCT=8ec/20/200
PWD=/
DEVTYPE=usb_device