Monitoring Removable USB Drives
I've been looking into writing some media player software and one function I want is to be able to detect inserted drives and do things with them.
inotify
First I looked at using inotify and just monitoring /dev. This is quite simple; you get IN_CREATE and IN_DELETE events when the directories are created or otherwise, and then you can do what is necessary.
Then came the problem of the doing bit - well you want to mount drives. You can use usbmount or udevd but at this point I was trying for an in-memory solution and I couldn't work out how to find out when they were mounted without having another script run.
libblkid & mount(2)
blkid is used by the usbmount script to determine if the device is a mountable partition; so I looked into libblkdid to do the same from code. It's a bit of a quirky api, and is poorly documented but not terribly difficult to use for what I want. The api is designed for implementing glue between kernel and scripts. The variables you get are again, pretty much undocumented as far as i can gather so it's just a process of run it and see what looks useful.
But using it isn't hard. Basically when a /dev/sd* appears I perform a probe and if it has the right variables set I call mount. I only want read-only access so that simplifies the mount options considerably.
Here's a partial prototype example of the inotify handler and mounting process. This is basically what usbmount does but it ignores any options in fstab and so forth.
static int mount_add(const char *name, blkid_probe p) {
int idx = mount_alloc();
if (idx >= 0) {
int res;
const char *type;
size_t type_size;
printf("checking mount %s\n", name);
if (blkid_probe_lookup_value(p, "TYPE", &type, &type_size) == 0) {
char point[(strlen("/var/run/usb-00") + 1)];
sprintf(point, "/var/run/usb-%02d", idx);
res = mkdir(point, 0777);
res = mount(name, point, type, MS_NOEXEC | MS_RDONLY | MS_NOSUID, NULL);
if (res != 0) {
perror("mount");
return -1;
}
printf("mounted: %s <- %s\n", point, name);
mounted[idx].name = strdup(name);
mounted[idx].point = strdup(point);
if (blkid_probe_lookup_value(p, "UUID", &type, &type_size) == 0)
mounted[idx].uuid = strdup(type);
} else {
idx = -1;
}
}
return idx;
}
static int mount_remove(const char *name) {
int idx = mount_index(name);
if (idx >= 0) {
int res = umount2(mounted[idx].point, MNT_DETACH);
if (res != 0)
perror("umount2");
else
printf("unmounted: %s <- %s\n", mounted[idx].point, mounted[idx].name);
free(mounted[idx].name);
free(mounted[idx].point);
free(mounted[idx].uuid);
memset(&mounted[idx], 0, sizeof(struct mounted));
}
return idx;
}
static void
handle_events(int fd, int wd)
{
char buf[4096] __attribute__ ((aligned(__alignof__(struct inotify_event))));
int i;
ssize_t len;
char *ptr;
for (;;) {
len = read(fd, buf, sizeof buf);
if (len == -1 && errno != EAGAIN) {
perror("read");
exit(EXIT_FAILURE);
}
if (len <= 0)
break;
for (ptr = buf; ptr < buf + len;) {
const struct inotify_event *event;
event = (const struct inotify_event *) ptr;
if (event->len && strncmp(event->name, "sd", 2) == 0) {
char name[(event->len + 1 + strlen("/dev/"))];
sprintf(name, "/dev/%s", event->name);
if (event->mask & IN_CREATE) {
blkid_probe p = blkid_new_probe_from_filename(name);
int rc;
blkid_probe_enable_partitions(p, 0);
blkid_probe_enable_superblocks(p, 1);
rc = blkid_do_safeprobe(p);
int idx = mount_add(name, p);
if (idx >= 0) {
// do something with added mount
}
blkid_free_probe(p);
}
if (event->mask & IN_DELETE) {
int idx = mount_index(name);
if (idx >= 0) {
// do something with removed mount
}
}
}
ptr += sizeof(struct inotify_event) + event->len;
}
}
}
udevd, NETLINK_KOBJECT_UEVENT
But I was curious - just how are the dev entries created? I thought it must be udevd or something. The only articles or documentation I could find were unclear on the matter.
So first, NETLINK_KOBJECT_UEVENT, this unpleasantly named 'network' protocol is used these days to monitor kernel activities like usb hotplugging. So I took a small example and started dumping out what I got.
The documentation and examples talk about using a 'struct nmlsghdr' as the datagram payload, but this is in error. You just get the payload directly. And the payload appears to be list of NUL terminated strings; which surprise are just environment variable declarations (i'm noticing a trend here).
Anyway, here's a complete example which dumps out the messages.
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <linux/netlink.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
int main(int argc, char **argv) {
int s = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
struct sockaddr_nl addr = {
.nl_family = AF_NETLINK,
.nl_pid = getpid(),
.nl_groups = ~0
};
int res;
char data[8192];
struct msghdr msg;
struct iovec iov;
bind(s, (void *)&addr, sizeof(addr));
iov.iov_base = data;
iov.iov_len = 8192;
msg.msg_name = (void *)&(addr);
msg.msg_namelen = sizeof(addr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
while ((res = recvmsg(s, &msg, 0)) >= 0) {
if (strcmp(data, "libudev") != 0) {
unsigned char *x = data, *e = data+res;
while (x < e) {
printf(" %s\n", x);
x += strlen(x) + 1;
}
printf("\n");
} else {
for (int i=0;i<res;i+=16) {
for (int j=i;j < i+16;j++)
printf(j < res ? " %02x" : " ", data[j]);
printf(" ");
for (int j=i;j < i+16;j++)
putchar(j < res ? (isprint(data[j]) ? data[j] : '.') : ' ');
printf("\n");
}
printf("\n");
}
}
return 0;
}
The libudev test is because udevd repackages the requests and sends them out again in some proprietary binary format for some reason which is unclear to me at this time.
And this is the output when I plug in a usb drive.
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2
SUBSYSTEM=usb
MAJOR=189
MINOR=645
DEVNAME=bus/usb/006/006
DEVTYPE=usb_device
PRODUCT=90c/1000/1100
TYPE=0/0/0
BUSNUM=006
DEVNUM=006
SEQNUM=7439
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=90c/1000/1100
TYPE=0/0/0
INTERFACE=8/6/80
MODALIAS=usb:v090Cp1000d1100dc00dsc00dp00ic08isc06ip50in00
SEQNUM=7440
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6
SUBSYSTEM=scsi
DEVTYPE=scsi_host
SEQNUM=7441
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/scsi_host/host6
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/scsi_host/host6
SUBSYSTEM=scsi_host
SEQNUM=7442
bind@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0
ACTION=bind
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
DRIVER=usb-storage
PRODUCT=90c/1000/1100
TYPE=0/0/0
INTERFACE=8/6/80
MODALIAS=usb:v090Cp1000d1100dc00dsc00dp00ic08isc06ip50in00
SEQNUM=7443
bind@/devices/pci0000:00/0000:00:10.0/usb6/6-2
ACTION=bind
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2
SUBSYSTEM=usb
MAJOR=189
MINOR=645
DEVNAME=bus/usb/006/006
DEVTYPE=usb_device
DRIVER=usb
PRODUCT=90c/1000/1100
TYPE=0/0/0
BUSNUM=006
DEVNUM=006
SEQNUM=7444
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 89 02 00 00 05 77 c5 e5 27 f8 f5 0c (........w..'...
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 00 53 55 42 53 59 53 54 45 4d 3d 75 /6-2.SUBSYSTEM=u
73 62 00 44 45 56 4e 41 4d 45 3d 2f 64 65 76 2f sb.DEVNAME=/dev/
62 75 73 2f 75 73 62 2f 30 30 36 2f 30 30 36 00 bus/usb/006/006.
44 45 56 54 59 50 45 3d 75 73 62 5f 64 65 76 69 DEVTYPE=usb_devi
63 65 00 50 52 4f 44 55 43 54 3d 39 30 63 2f 31 ce.PRODUCT=90c/1
30 30 30 2f 31 31 30 30 00 54 59 50 45 3d 30 2f 000/1100.TYPE=0/
30 2f 30 00 42 55 53 4e 55 4d 3d 30 30 36 00 44 0/0.BUSNUM=006.D
45 56 4e 55 4d 3d 30 30 36 00 53 45 51 4e 55 4d EVNUM=006.SEQNUM
3d 37 34 33 39 00 4d 41 4a 4f 52 3d 31 38 39 00 =7439.MAJOR=189.
4d 49 4e 4f 52 3d 36 34 35 00 55 53 45 43 5f 49 MINOR=645.USEC_I
4e 49 54 49 41 4c 49 5a 45 44 3d 32 30 35 35 39 NITIALIZED=20559
39 39 33 30 37 35 34 35 00 49 44 5f 56 45 4e 44 99307545.ID_VEND
4f 52 3d 53 61 6d 73 75 6e 67 00 49 44 5f 56 45 OR=Samsung.ID_VE
4e 44 4f 52 5f 45 4e 43 3d 53 61 6d 73 75 6e 67 NDOR_ENC=Samsung
00 49 44 5f 56 45 4e 44 4f 52 5f 49 44 3d 30 39 .ID_VENDOR_ID=09
30 63 00 49 44 5f 4d 4f 44 45 4c 3d 46 6c 61 73 0c.ID_MODEL=Flas
68 5f 44 72 69 76 65 5f 44 55 4f 00 49 44 5f 4d h_Drive_DUO.ID_M
4f 44 45 4c 5f 45 4e 43 3d 46 6c 61 73 68 5c 78 ODEL_ENC=Flash\x
32 30 44 72 69 76 65 5c 78 32 30 44 55 4f 00 49 20Drive\x20DUO.I
44 5f 4d 4f 44 45 4c 5f 49 44 3d 31 30 30 30 00 D_MODEL_ID=1000.
49 44 5f 52 45 56 49 53 49 4f 4e 3d 31 31 30 30 ID_REVISION=1100
00 49 44 5f 53 45 52 49 41 4c 3d 53 61 6d 73 75 .ID_SERIAL=Samsu
6e 67 5f 46 6c 61 73 68 5f 44 72 69 76 65 5f 44 ng_Flash_Drive_D
55 4f 5f 30 33 33 31 35 31 36 30 37 30 30 31 38 UO_0331516070018
38 31 31 00 49 44 5f 53 45 52 49 41 4c 5f 53 48 811.ID_SERIAL_SH
4f 52 54 3d 30 33 33 31 35 31 36 30 37 30 30 31 ORT=033151607001
38 38 31 31 00 49 44 5f 42 55 53 3d 75 73 62 00 8811.ID_BUS=usb.
49 44 5f 55 53 42 5f 49 4e 54 45 52 46 41 43 45 ID_USB_INTERFACE
53 3d 3a 30 38 30 36 35 30 3a 00 49 44 5f 56 45 S=:080650:.ID_VE
4e 44 4f 52 5f 46 52 4f 4d 5f 44 41 54 41 42 41 NDOR_FROM_DATABA
53 45 3d 53 69 6c 69 63 6f 6e 20 4d 6f 74 69 6f SE=Silicon Motio
6e 2c 20 49 6e 63 2e 20 2d 20 54 61 69 77 61 6e n, Inc. - Taiwan
20 28 66 6f 72 6d 65 72 6c 79 20 46 65 69 79 61 (formerly Feiya
20 54 65 63 68 6e 6f 6c 6f 67 79 20 43 6f 72 70 Technology Corp
2e 29 00 49 44 5f 4d 4f 44 45 4c 5f 46 52 4f 4d .).ID_MODEL_FROM
5f 44 41 54 41 42 41 53 45 3d 46 6c 61 73 68 20 _DATABASE=Flash
44 72 69 76 65 00 44 52 49 56 45 52 3d 75 73 62 Drive.DRIVER=usb
00 .
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 8f 01 00 00 05 77 c5 e5 b1 02 47 65 (........w....Ge
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 00 53 55 42 /6-2/6-2:1.0.SUB
53 59 53 54 45 4d 3d 75 73 62 00 44 45 56 54 59 SYSTEM=usb.DEVTY
50 45 3d 75 73 62 5f 69 6e 74 65 72 66 61 63 65 PE=usb_interface
00 50 52 4f 44 55 43 54 3d 39 30 63 2f 31 30 30 .PRODUCT=90c/100
30 2f 31 31 30 30 00 54 59 50 45 3d 30 2f 30 2f 0/1100.TYPE=0/0/
30 00 49 4e 54 45 52 46 41 43 45 3d 38 2f 36 2f 0.INTERFACE=8/6/
38 30 00 4d 4f 44 41 4c 49 41 53 3d 75 73 62 3a 80.MODALIAS=usb:
76 30 39 30 43 70 31 30 30 30 64 31 31 30 30 64 v090Cp1000d1100d
63 30 30 64 73 63 30 30 64 70 30 30 69 63 30 38 c00dsc00dp00ic08
69 73 63 30 36 69 70 35 30 69 6e 30 30 00 53 45 isc06ip50in00.SE
51 4e 55 4d 3d 37 34 34 30 00 55 53 45 43 5f 49 QNUM=7440.USEC_I
4e 49 54 49 41 4c 49 5a 45 44 3d 32 30 35 35 39 NITIALIZED=20559
39 39 33 30 39 32 38 36 00 49 44 5f 56 45 4e 44 99309286.ID_VEND
4f 52 5f 46 52 4f 4d 5f 44 41 54 41 42 41 53 45 OR_FROM_DATABASE
3d 53 69 6c 69 63 6f 6e 20 4d 6f 74 69 6f 6e 2c =Silicon Motion,
20 49 6e 63 2e 20 2d 20 54 61 69 77 61 6e 20 28 Inc. - Taiwan (
66 6f 72 6d 65 72 6c 79 20 46 65 69 79 61 20 54 formerly Feiya T
65 63 68 6e 6f 6c 6f 67 79 20 43 6f 72 70 2e 29 echnology Corp.)
00 49 44 5f 4d 4f 44 45 4c 5f 46 52 4f 4d 5f 44 .ID_MODEL_FROM_D
41 54 41 42 41 53 45 3d 46 6c 61 73 68 20 44 72 ATABASE=Flash Dr
69 76 65 00 44 52 49 56 45 52 3d 75 73 62 2d 73 ive.DRIVER=usb-s
74 6f 72 61 67 65 00 torage.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 97 00 00 00 29 20 1a 28 a0 05 fb 58 (.......) .(...X
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 00 53 55 42 53 59 53 54 45 4d 3d 73 63 73 t6.SUBSYSTEM=scs
69 00 44 45 56 54 59 50 45 3d 73 63 73 69 5f 68 i.DEVTYPE=scsi_h
6f 73 74 00 53 45 51 4e 55 4d 3d 37 34 34 31 00 ost.SEQNUM=7441.
55 53 45 43 5f 49 4e 49 54 49 41 4c 49 5a 45 44 USEC_INITIALIZED
3d 32 30 35 35 39 39 39 33 31 30 38 39 37 00 =2055999310897.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 9a 00 00 00 a0 05 fb 58 00 00 00 00 (..........X....
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 73 63 73 69 5f 68 6f 73 74 2f 68 6f 73 t6/scsi_host/hos
74 36 00 53 55 42 53 59 53 54 45 4d 3d 73 63 73 t6.SUBSYSTEM=scs
69 5f 68 6f 73 74 00 53 45 51 4e 55 4d 3d 37 34 i_host.SEQNUM=74
34 32 00 55 53 45 43 5f 49 4e 49 54 49 41 4c 49 42.USEC_INITIALI
5a 45 44 3d 32 30 35 35 39 39 39 33 31 31 38 36 ZED=205599931186
31 00 1.
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0
SUBSYSTEM=scsi
DEVTYPE=scsi_target
SEQNUM=7445
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0
SUBSYSTEM=scsi
DEVTYPE=scsi_device
MODALIAS=scsi:t-0x00
SEQNUM=7446
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/scsi_disk/6:0:0:0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/scsi_disk/6:0:0:0
SUBSYSTEM=scsi_disk
SEQNUM=7447
bind@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0
ACTION=bind
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0
SUBSYSTEM=scsi
DEVTYPE=scsi_device
DRIVER=sd
MODALIAS=scsi:t-0x00
SEQNUM=7448
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/scsi_device/6:0:0:0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/scsi_device/6:0:0:0
SUBSYSTEM=scsi_device
SEQNUM=7449
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/scsi_generic/sg1
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/scsi_generic/sg1
SUBSYSTEM=scsi_generic
MAJOR=21
MINOR=1
DEVNAME=sg1
SEQNUM=7450
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/bsg/6:0:0:0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/bsg/6:0:0:0
SUBSYSTEM=bsg
MAJOR=246
MINOR=1
DEVNAME=bsg/6:0:0:0
SEQNUM=7451
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 a5 00 00 00 29 20 1a 28 f2 6a 9f 62 (.......) .(.j.b
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 00 53 t6/target6:0:0.S
55 42 53 59 53 54 45 4d 3d 73 63 73 69 00 44 45 UBSYSTEM=scsi.DE
56 54 59 50 45 3d 73 63 73 69 5f 74 61 72 67 65 VTYPE=scsi_targe
74 00 53 45 51 4e 55 4d 3d 37 34 34 35 00 55 53 t.SEQNUM=7445.US
45 43 5f 49 4e 49 54 49 41 4c 49 5a 45 44 3d 32 EC_INITIALIZED=2
30 35 36 30 30 30 36 35 39 36 37 32 00 056000659672.
add@/devices/virtual/bdi/8:16
ACTION=add
DEVPATH=/devices/virtual/bdi/8:16
SUBSYSTEM=bdi
SEQNUM=7452
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 cc 00 00 00 29 20 1a 28 7d b5 06 b5 (.......) .(}...
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 00 53 55 42 53 59 53 54 45 4d :0:0:0.SUBSYSTEM
3d 73 63 73 69 00 44 45 56 54 59 50 45 3d 73 63 =scsi.DEVTYPE=sc
73 69 5f 64 65 76 69 63 65 00 4d 4f 44 41 4c 49 si_device.MODALI
41 53 3d 73 63 73 69 3a 74 2d 30 78 30 30 00 53 AS=scsi:t-0x00.S
45 51 4e 55 4d 3d 37 34 34 36 00 55 53 45 43 5f EQNUM=7446.USEC_
49 4e 49 54 49 41 4c 49 5a 45 44 3d 32 30 35 36 INITIALIZED=2056
30 30 30 36 36 31 36 31 35 00 44 52 49 56 45 52 000661615.DRIVER
3d 73 64 00 =sd.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 66 00 00 00 2a 18 84 a1 00 00 00 00 (...f...*.......
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 76 69 72 74 75 61 6c 2f 62 64 69 2f ces/virtual/bdi/
38 3a 31 36 00 53 55 42 53 59 53 54 45 4d 3d 62 8:16.SUBSYSTEM=b
64 69 00 53 45 51 4e 55 4d 3d 37 34 35 32 00 55 di.SEQNUM=7452.U
53 45 43 5f 49 4e 49 54 49 41 4c 49 5a 45 44 3d SEC_INITIALIZED=
32 30 35 36 30 30 30 36 36 32 34 30 31 00 2056000662401.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 b4 00 00 00 7d b5 06 b5 00 00 00 00 (.......}.......
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 2f 73 63 73 69 5f 64 65 76 69 :0:0:0/scsi_devi
63 65 2f 36 3a 30 3a 30 3a 30 00 53 55 42 53 59 ce/6:0:0:0.SUBSY
53 54 45 4d 3d 73 63 73 69 5f 64 65 76 69 63 65 STEM=scsi_device
00 53 45 51 4e 55 4d 3d 37 34 34 39 00 55 53 45 .SEQNUM=7449.USE
43 5f 49 4e 49 54 49 41 4c 49 5a 45 44 3d 32 30 C_INITIALIZED=20
35 36 30 30 30 36 36 35 31 34 31 00 56000665141.
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/block/sdb
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/block/sdb
SUBSYSTEM=block
MAJOR=8
MINOR=16
DEVNAME=sdb
DEVTYPE=disk
SEQNUM=7453
add@/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/block/sdb/sdb1
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.0/usb6/6-2/6-2:1.0/host6/target6:0:0/6:0:0:0/block/sdb/sdb1
SUBSYSTEM=block
MAJOR=8
MINOR=17
DEVNAME=sdb1
DEVTYPE=partition
PARTN=1
SEQNUM=7454
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 b0 00 00 00 89 0e a9 0f 00 00 00 00 (...............
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 2f 73 63 73 69 5f 64 69 73 6b :0:0:0/scsi_disk
2f 36 3a 30 3a 30 3a 30 00 53 55 42 53 59 53 54 /6:0:0:0.SUBSYST
45 4d 3d 73 63 73 69 5f 64 69 73 6b 00 53 45 51 EM=scsi_disk.SEQ
4e 55 4d 3d 37 34 34 37 00 55 53 45 43 5f 49 4e NUM=7447.USEC_IN
49 54 49 41 4c 49 5a 45 44 3d 32 30 35 36 30 30 ITIALIZED=205600
30 36 36 36 30 33 30 00 0666030.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 d4 00 00 00 3c e8 b1 f8 00 00 00 00 (.......<.......
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 2f 73 63 73 69 5f 67 65 6e 65 :0:0:0/scsi_gene
72 69 63 2f 73 67 31 00 53 55 42 53 59 53 54 45 ric/sg1.SUBSYSTE
4d 3d 73 63 73 69 5f 67 65 6e 65 72 69 63 00 44 M=scsi_generic.D
45 56 4e 41 4d 45 3d 2f 64 65 76 2f 73 67 31 00 EVNAME=/dev/sg1.
53 45 51 4e 55 4d 3d 37 34 35 30 00 4d 41 4a 4f SEQNUM=7450.MAJO
52 3d 32 31 00 4d 49 4e 4f 52 3d 31 00 55 53 45 R=21.MINOR=1.USE
43 5f 49 4e 49 54 49 41 4c 49 5a 45 44 3d 32 30 C_INITIALIZED=20
35 36 30 30 30 36 36 36 35 39 35 00 56000666595.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 cf 00 00 00 0d df d8 a1 00 00 00 00 (...............
00 00 00 00 00 00 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 2f 62 73 67 2f 36 3a 30 3a 30 :0:0:0/bsg/6:0:0
3a 30 00 53 55 42 53 59 53 54 45 4d 3d 62 73 67 :0.SUBSYSTEM=bsg
00 44 45 56 4e 41 4d 45 3d 2f 64 65 76 2f 62 73 .DEVNAME=/dev/bs
67 2f 36 3a 30 3a 30 3a 30 00 53 45 51 4e 55 4d g/6:0:0:0.SEQNUM
3d 37 34 35 31 00 4d 41 4a 4f 52 3d 32 34 36 00 =7451.MAJOR=246.
4d 49 4e 4f 52 3d 31 00 55 53 45 43 5f 49 4e 49 MINOR=1.USEC_INI
54 49 41 4c 49 5a 45 44 3d 32 30 35 36 30 30 30 TIALIZED=2056000
36 36 37 30 34 32 00 667042.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 54 03 00 00 f0 03 1d b7 7b cb c5 ee (...T.......{...
02 00 04 00 10 80 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 2f 62 6c 6f 63 6b 2f 73 64 62 :0:0:0/block/sdb
00 53 55 42 53 59 53 54 45 4d 3d 62 6c 6f 63 6b .SUBSYSTEM=block
00 44 45 56 4e 41 4d 45 3d 2f 64 65 76 2f 73 64 .DEVNAME=/dev/sd
62 00 44 45 56 54 59 50 45 3d 64 69 73 6b 00 53 b.DEVTYPE=disk.S
45 51 4e 55 4d 3d 37 34 35 33 00 55 53 45 43 5f EQNUM=7453.USEC_
49 4e 49 54 49 41 4c 49 5a 45 44 3d 32 30 35 36 INITIALIZED=2056
30 30 30 37 33 36 33 35 39 00 4d 41 4a 4f 52 3d 000736359.MAJOR=
38 00 4d 49 4e 4f 52 3d 31 36 00 49 44 5f 56 45 8.MINOR=16.ID_VE
4e 44 4f 52 3d 53 61 6d 73 75 6e 67 00 49 44 5f NDOR=Samsung.ID_
56 45 4e 44 4f 52 5f 45 4e 43 3d 53 61 6d 73 75 VENDOR_ENC=Samsu
6e 67 5c 78 32 30 00 49 44 5f 56 45 4e 44 4f 52 ng\x20.ID_VENDOR
5f 49 44 3d 30 39 30 63 00 49 44 5f 4d 4f 44 45 _ID=090c.ID_MODE
4c 3d 46 6c 61 73 68 5f 44 72 69 76 65 5f 44 55 L=Flash_Drive_DU
4f 00 49 44 5f 4d 4f 44 45 4c 5f 45 4e 43 3d 46 O.ID_MODEL_ENC=F
6c 61 73 68 5c 78 32 30 44 72 69 76 65 5c 78 32 lash\x20Drive\x2
30 44 55 4f 5c 78 32 30 00 49 44 5f 4d 4f 44 45 0DUO\x20.ID_MODE
4c 5f 49 44 3d 31 30 30 30 00 49 44 5f 52 45 56 L_ID=1000.ID_REV
49 53 49 4f 4e 3d 31 31 30 30 00 49 44 5f 53 45 ISION=1100.ID_SE
52 49 41 4c 3d 53 61 6d 73 75 6e 67 5f 46 6c 61 RIAL=Samsung_Fla
73 68 5f 44 72 69 76 65 5f 44 55 4f 5f 30 33 33 sh_Drive_DUO_033
31 35 31 36 30 37 30 30 31 38 38 31 31 2d 30 3a 1516070018811-0:
30 00 49 44 5f 53 45 52 49 41 4c 5f 53 48 4f 52 0.ID_SERIAL_SHOR
54 3d 30 33 33 31 35 31 36 30 37 30 30 31 38 38 T=03315160700188
31 31 00 49 44 5f 54 59 50 45 3d 64 69 73 6b 00 11.ID_TYPE=disk.
49 44 5f 49 4e 53 54 41 4e 43 45 3d 30 3a 30 00 ID_INSTANCE=0:0.
49 44 5f 42 55 53 3d 75 73 62 00 49 44 5f 55 53 ID_BUS=usb.ID_US
42 5f 49 4e 54 45 52 46 41 43 45 53 3d 3a 30 38 B_INTERFACES=:08
30 36 35 30 3a 00 49 44 5f 55 53 42 5f 49 4e 54 0650:.ID_USB_INT
45 52 46 41 43 45 5f 4e 55 4d 3d 30 30 00 49 44 ERFACE_NUM=00.ID
5f 55 53 42 5f 44 52 49 56 45 52 3d 75 73 62 2d _USB_DRIVER=usb-
73 74 6f 72 61 67 65 00 44 45 56 4c 49 4e 4b 53 storage.DEVLINKS
3d 2f 64 65 76 2f 64 69 73 6b 2f 62 79 2d 69 64 =/dev/disk/by-id
2f 75 73 62 2d 53 61 6d 73 75 6e 67 5f 46 6c 61 /usb-Samsung_Fla
73 68 5f 44 72 69 76 65 5f 44 55 4f 5f 30 33 33 sh_Drive_DUO_033
31 35 31 36 30 37 30 30 31 38 38 31 31 2d 30 3a 1516070018811-0:
30 20 2f 64 65 76 2f 64 69 73 6b 2f 62 79 2d 70 0 /dev/disk/by-p
61 74 68 2f 70 63 69 2d 30 30 30 30 3a 30 30 3a ath/pci-0000:00:
31 30 2e 30 2d 75 73 62 2d 30 3a 32 3a 31 2e 30 10.0-usb-0:2:1.0
2d 73 63 73 69 2d 30 3a 30 3a 30 3a 30 00 49 44 -scsi-0:0:0:0.ID
5f 50 41 54 48 3d 70 63 69 2d 30 30 30 30 3a 30 _PATH=pci-0000:0
30 3a 31 30 2e 30 2d 75 73 62 2d 30 3a 32 3a 31 0:10.0-usb-0:2:1
2e 30 2d 73 63 73 69 2d 30 3a 30 3a 30 3a 30 00 .0-scsi-0:0:0:0.
49 44 5f 50 41 54 48 5f 54 41 47 3d 70 63 69 2d ID_PATH_TAG=pci-
30 30 30 30 5f 30 30 5f 31 30 5f 30 2d 75 73 62 0000_00_10_0-usb
2d 30 5f 32 5f 31 5f 30 2d 73 63 73 69 2d 30 5f -0_2_1_0-scsi-0_
30 5f 30 5f 30 00 49 44 5f 50 41 52 54 5f 54 41 0_0_0.ID_PART_TA
42 4c 45 5f 54 59 50 45 3d 64 6f 73 00 54 41 47 BLE_TYPE=dos.TAG
53 3d 3a 73 79 73 74 65 6d 64 3a 00 S=:systemd:.
6c 69 62 75 64 65 76 00 fe ed ca fe 28 00 00 00 libudev.....(...
28 00 00 00 e5 04 00 00 f0 03 1d b7 cb 23 44 89 (............#D.
02 00 04 00 10 80 00 00 41 43 54 49 4f 4e 3d 61 ........ACTION=a
64 64 00 44 45 56 50 41 54 48 3d 2f 64 65 76 69 dd.DEVPATH=/devi
63 65 73 2f 70 63 69 30 30 30 30 3a 30 30 2f 30 ces/pci0000:00/0
30 30 30 3a 30 30 3a 31 30 2e 30 2f 75 73 62 36 000:00:10.0/usb6
2f 36 2d 32 2f 36 2d 32 3a 31 2e 30 2f 68 6f 73 /6-2/6-2:1.0/hos
74 36 2f 74 61 72 67 65 74 36 3a 30 3a 30 2f 36 t6/target6:0:0/6
3a 30 3a 30 3a 30 2f 62 6c 6f 63 6b 2f 73 64 62 :0:0:0/block/sdb
2f 73 64 62 31 00 53 55 42 53 59 53 54 45 4d 3d /sdb1.SUBSYSTEM=
62 6c 6f 63 6b 00 44 45 56 4e 41 4d 45 3d 2f 64 block.DEVNAME=/d
65 76 2f 73 64 62 31 00 44 45 56 54 59 50 45 3d ev/sdb1.DEVTYPE=
70 61 72 74 69 74 69 6f 6e 00 50 41 52 54 4e 3d partition.PARTN=
31 00 53 45 51 4e 55 4d 3d 37 34 35 34 00 55 53 1.SEQNUM=7454.US
45 43 5f 49 4e 49 54 49 41 4c 49 5a 45 44 3d 32 EC_INITIALIZED=2
30 35 36 30 30 30 37 39 35 39 37 39 00 4d 41 4a 056000795979.MAJ
4f 52 3d 38 00 4d 49 4e 4f 52 3d 31 37 00 49 44 OR=8.MINOR=17.ID
5f 42 55 53 3d 75 73 62 00 49 44 5f 49 4e 53 54 _BUS=usb.ID_INST
41 4e 43 45 3d 30 3a 30 00 49 44 5f 4d 4f 44 45 ANCE=0:0.ID_MODE
4c 3d 46 6c 61 73 68 5f 44 72 69 76 65 5f 44 55 L=Flash_Drive_DU
4f 00 49 44 5f 4d 4f 44 45 4c 5f 45 4e 43 3d 46 O.ID_MODEL_ENC=F
6c 61 73 68 5c 78 32 30 44 72 69 76 65 5c 78 32 lash\x20Drive\x2
30 44 55 4f 5c 78 32 30 00 49 44 5f 4d 4f 44 45 0DUO\x20.ID_MODE
4c 5f 49 44 3d 31 30 30 30 00 49 44 5f 50 41 52 L_ID=1000.ID_PAR
54 5f 54 41 42 4c 45 5f 54 59 50 45 3d 64 6f 73 T_TABLE_TYPE=dos
00 49 44 5f 50 41 54 48 3d 70 63 69 2d 30 30 30 .ID_PATH=pci-000
30 3a 30 30 3a 31 30 2e 30 2d 75 73 62 2d 30 3a 0:00:10.0-usb-0:
32 3a 31 2e 30 2d 73 63 73 69 2d 30 3a 30 3a 30 2:1.0-scsi-0:0:0
3a 30 00 49 44 5f 50 41 54 48 5f 54 41 47 3d 70 :0.ID_PATH_TAG=p
63 69 2d 30 30 30 30 5f 30 30 5f 31 30 5f 30 2d ci-0000_00_10_0-
75 73 62 2d 30 5f 32 5f 31 5f 30 2d 73 63 73 69 usb-0_2_1_0-scsi
2d 30 5f 30 5f 30 5f 30 00 49 44 5f 52 45 56 49 -0_0_0_0.ID_REVI
53 49 4f 4e 3d 31 31 30 30 00 49 44 5f 53 45 52 SION=1100.ID_SER
49 41 4c 3d 53 61 6d 73 75 6e 67 5f 46 6c 61 73 IAL=Samsung_Flas
68 5f 44 72 69 76 65 5f 44 55 4f 5f 30 33 33 31 h_Drive_DUO_0331
35 31 36 30 37 30 30 31 38 38 31 31 2d 30 3a 30 516070018811-0:0
00 49 44 5f 53 45 52 49 41 4c 5f 53 48 4f 52 54 .ID_SERIAL_SHORT
3d 30 33 33 31 35 31 36 30 37 30 30 31 38 38 31 =033151607001881
31 00 49 44 5f 54 59 50 45 3d 64 69 73 6b 00 49 1.ID_TYPE=disk.I
44 5f 55 53 42 5f 44 52 49 56 45 52 3d 75 73 62 D_USB_DRIVER=usb
2d 73 74 6f 72 61 67 65 00 49 44 5f 55 53 42 5f -storage.ID_USB_
49 4e 54 45 52 46 41 43 45 53 3d 3a 30 38 30 36 INTERFACES=:0806
35 30 3a 00 49 44 5f 55 53 42 5f 49 4e 54 45 52 50:.ID_USB_INTER
46 41 43 45 5f 4e 55 4d 3d 30 30 00 49 44 5f 56 FACE_NUM=00.ID_V
45 4e 44 4f 52 3d 53 61 6d 73 75 6e 67 00 49 44 ENDOR=Samsung.ID
5f 56 45 4e 44 4f 52 5f 45 4e 43 3d 53 61 6d 73 _VENDOR_ENC=Sams
75 6e 67 5c 78 32 30 00 49 44 5f 56 45 4e 44 4f ung\x20.ID_VENDO
52 5f 49 44 3d 30 39 30 63 00 44 45 56 4c 49 4e R_ID=090c.DEVLIN
4b 53 3d 2f 64 65 76 2f 64 69 73 6b 2f 62 79 2d KS=/dev/disk/by-
6c 61 62 65 6c 2f 53 61 6d 73 75 6e 67 5c 78 32 label/Samsung\x2
30 55 53 42 20 2f 64 65 76 2f 64 69 73 6b 2f 62 0USB /dev/disk/b
79 2d 70 61 74 68 2f 70 63 69 2d 30 30 30 30 3a y-path/pci-0000:
30 30 3a 31 30 2e 30 2d 75 73 62 2d 30 3a 32 3a 00:10.0-usb-0:2:
31 2e 30 2d 73 63 73 69 2d 30 3a 30 3a 30 3a 30 1.0-scsi-0:0:0:0
2d 70 61 72 74 31 20 2f 64 65 76 2f 64 69 73 6b -part1 /dev/disk
2f 62 79 2d 69 64 2f 75 73 62 2d 53 61 6d 73 75 /by-id/usb-Samsu
6e 67 5f 46 6c 61 73 68 5f 44 72 69 76 65 5f 44 ng_Flash_Drive_D
55 4f 5f 30 33 33 31 35 31 36 30 37 30 30 31 38 UO_0331516070018
38 31 31 2d 30 3a 30 2d 70 61 72 74 31 20 2f 64 811-0:0-part1 /d
65 76 2f 64 69 73 6b 2f 62 79 2d 75 75 69 64 2f ev/disk/by-uuid/
45 35 34 31 2d 43 30 44 44 00 49 44 5f 46 53 5f E541-C0DD.ID_FS_
4c 41 42 45 4c 3d 53 61 6d 73 75 6e 67 5f 55 53 LABEL=Samsung_US
42 00 49 44 5f 46 53 5f 4c 41 42 45 4c 5f 45 4e B.ID_FS_LABEL_EN
43 3d 53 61 6d 73 75 6e 67 5c 78 32 30 55 53 42 C=Samsung\x20USB
00 49 44 5f 46 53 5f 55 55 49 44 3d 45 35 34 31 .ID_FS_UUID=E541
2d 43 30 44 44 00 49 44 5f 46 53 5f 55 55 49 44 -C0DD.ID_FS_UUID
5f 45 4e 43 3d 45 35 34 31 2d 43 30 44 44 00 49 _ENC=E541-C0DD.I
44 5f 46 53 5f 56 45 52 53 49 4f 4e 3d 46 41 54 D_FS_VERSION=FAT
33 32 00 49 44 5f 46 53 5f 54 59 50 45 3d 76 66 32.ID_FS_TYPE=vf
61 74 00 49 44 5f 46 53 5f 55 53 41 47 45 3d 66 at.ID_FS_USAGE=f
69 6c 65 73 79 73 74 65 6d 00 49 44 5f 50 41 52 ilesystem.ID_PAR
54 5f 45 4e 54 52 59 5f 53 43 48 45 4d 45 3d 64 T_ENTRY_SCHEME=d
6f 73 00 49 44 5f 50 41 52 54 5f 45 4e 54 52 59 os.ID_PART_ENTRY
5f 54 59 50 45 3d 30 78 63 00 49 44 5f 50 41 52 _TYPE=0xc.ID_PAR
54 5f 45 4e 54 52 59 5f 4e 55 4d 42 45 52 3d 31 T_ENTRY_NUMBER=1
00 49 44 5f 50 41 52 54 5f 45 4e 54 52 59 5f 4f .ID_PART_ENTRY_O
46 46 53 45 54 3d 36 34 00 49 44 5f 50 41 52 54 FFSET=64.ID_PART
5f 45 4e 54 52 59 5f 53 49 5a 45 3d 31 32 35 33 _ENTRY_SIZE=1253
30 34 37 36 38 00 49 44 5f 50 41 52 54 5f 45 4e 04768.ID_PART_EN
54 52 59 5f 44 49 53 4b 3d 38 3a 31 36 00 54 41 TRY_DISK=8:16.TA
47 53 3d 3a 73 79 73 74 65 6d 64 3a 00 GS=:systemd:.
Ignoring the libudev snot there's basically a flurry of events, a short pause, and then the last couple of interesting events where the device nodes become available.
AS FAR AS I CAN GATHER ... there appears to be no documentation regarding the format or order of these kernel messages; what variables will be included and what they mean. Well there's always the kernel source but I could find nothing in [kernel-source]/Documnetation nor anywhere else.
I suppose it is relatively straightforward to just 'suck it and see' but documentation would be nice all the same.
At this point I went down a rabbit hole of trying to work out who ACTUALLY creates the /dev entries; it turns out it's the kernel. So infact udevd isn't really doing anything particularly useful on my system. Probably just as well now that the systemd developers have started 'maintaining' it.
systemd
So anyway i've done a bit of prototyping and I'm sure I can get away without needing udevd at all, systemd is thankfully not anywhere near the mele already. Then I went down another rabbit hole of finding out the current status of systemd.
It's still not good. And i'm pretty sure it never will be. With any luck IBM will pull their finger out and realise what a huge risk and waste of money the project is to their new acquisition and throw it in the bin where it belongs. But of course i'm not holding my breath, it's been designed to be unremovable and was agressively promoted and pushed onto 3rd party projects for a reason. As an aside, hopefully IBM can make jfs a first-class filesystem citizen rather than the red-headed step-child it seems to be these days.
The blog fromthecodefront has a very clear analysis of the situation. Grating narcissitic and abusive personalities aside, this is the first time i've come across any sourcode. It is not pretty. It looks exactly like the code I write when i'm developing prototypes; lots of cut and paste, poor modularisation, meaningless function names, etc. Although I usually tend to use more comments, meaningful labels, and fewer weird-arsed macros to 'save typing' (infact i almost never use macros for that anymore; inline or plain functions can usually be used). And because it's all in C, there's quite an impedence mismatch when a scripting language would be the better choice. This is not the type of code I force onto others, and certainly not any system-critical components.
The developers seem to be out of their depth and absolute arseholes when called out on it. The passive-aggressive and other psychopathic behaviours are very troublesome; I dont deal with abusers like that and neither should you. Multiple commenters say that's just ad-hominem and not important: but it is important, and these guys are not nice people.
Fortunately I usually dont have bother with systemd much anyway - I have few services and they are running already. Shutdown and/or suspsend are sometimes broken but I can always just pull the power plug. Asking for passwords on encrypted disks is also pretty shit (console output overflows the prompts); it's just something else I have to workaround.
Actually I tried using it to stop udevd so I could determine what if anything it was doing on my system: and it refused to let me turn it off or disable it (or mask it, whatever they fuck they want call it). I stopped, disabled, and masked every 'service' or 'socket' with udev in the name, no asusage. I had to chmod the systemd-udevd binary to non-executable in the end.
The only saving grace is that systemd-udevd doesn't really do anything so it can't really fuck it up. Even systemd doesn't really do much apart from run a few scripts in some order.
Where's this going
Well i'm not really sure if i'll stick to a simple monolothic music service or go the whole hog and work on a modularised multi-process (and significnalty more secure) design. Simple is nice but the other approach has some relatively interesting things to play with.
But it's all very time-consuming and too sedentry. My body is falling apart.
I need to get out of the house more; every time i get stuck into a coding project (most recently for work) I seem to rapidly stack on weight. It's related to some (medicinal) drugs once taken and now stopped and obviously some over-consumption and it's fucking pissing me off. The weight is also completely fucking up my sleep and that's pissing me off even more. I'm pissed off a lot lately!