udev - create all partitions of blockdevice

Here is the first try to create all partitons of a blockdevice, since removable media devices may need to acces the expected partition to revalidate the media.

It uses the attribute syntax introduced with the last %s{file} patch. I'm using this with my multi-slot-flash-card-reader:

SYSFS{model}="USB Storage-SMC ", NAME{all_partitions}="smartmedia" SYSFS{model}="USB Storage-CFC ", NAME{all_partitions}="compactflash" SYSFS{model}="USB Storage-MSC ", NAME{all_partitions}="memorystick" SYSFS{model}="USB Storage-MMC ", NAME{all_partitions}="multimedia"

and I get:

tree /udev/
/udev/

  |-- memorystick
  |-- memorystick1
  |-- memorystick10
  |-- memorystick11
  |-- memorystick12
  |-- memorystick13
  |-- memorystick14
  |-- memorystick15
  |-- memorystick2
  |-- memorystick3
  |-- memorystick4
  |-- memorystick5
  |-- memorystick6
  |-- memorystick7
  |-- memorystick8
  |-- memorystick9
  |-- multimedia
  |-- multimedia1
  |-- multimedia10
  |-- multimedia11
  |-- multimedia12
  |-- multimedia13
  |-- multimedia14
  |-- multimedia15
  |-- multimedia2
  |-- multimedia3
  |-- multimedia4
  |-- multimedia5
  |-- multimedia6
  |-- multimedia7
  |-- multimedia8
  |-- multimedia9

...

If needed, we can make the number of partions to create adjustable with the attribute?

Quoted 7 lines · Kay Sievers

Here is the first try to create all partitons of a blockdevice, since removable media devices may need to acces the expected partition to revalidate the media.

It uses the attribute syntax introduced with the last %s{file} patch. I'm using this with my multi-slot-flash-card-reader:

Quoted 7 lines

SYSFS{model}="USB Storage-SMC ", NAME{all_partitions}="smartmedia" SYSFS{model}="USB Storage-CFC ", NAME{all_partitions}="compactflash" SYSFS{model}="USB Storage-MSC ", NAME{all_partitions}="memorystick" SYSFS{model}="USB Storage-MMC ", NAME{all_partitions}="multimedia"

If needed, we can make the number of partions to create adjustable with the attribute?

Nice, this is great. I don't think we need to change the number of partitions.

I've applied this, and checked in a fix for udev-add.c if 'fake' was true (which it is for udevtest). I'll go test this for my devices with partitions.

Quoted 19 lines · Greg KH

Quoted 7 lines · Kay Sievers

Here is the first try to create all partitons of a blockdevice, since removable media devices may need to acces the expected partition to revalidate the media.

It uses the attribute syntax introduced with the last %s{file} patch. I'm using this with my multi-slot-flash-card-reader:

Quoted 7 lines

SYSFS{model}="USB Storage-SMC ", NAME{all_partitions}="smartmedia" SYSFS{model}="USB Storage-CFC ", NAME{all_partitions}="compactflash" SYSFS{model}="USB Storage-MSC ", NAME{all_partitions}="memorystick" SYSFS{model}="USB Storage-MMC ", NAME{all_partitions}="multimedia"

If needed, we can make the number of partions to create adjustable with the attribute?

Nice, this is great. I don't think we need to change the number of partitions.

Quoted 3 lines

I've applied this, and checked in a fix for udev-add.c if 'fake' was true (which it is for udevtest). I'll go test this for my devices with partitions.

Should we export the scsi 'removable' flag via sysfs attribute for use with all_partitions? Kernel patch is a trivial:

So you could have rules such as:

KERNEL="sd*", BUS="scsi", SYSFS{removable}="1", NAME{all_partitions}="%k" KERNEL="sd*", BUS="scsi", SYSFS{removable}="0", NAME="%k"

AFAIUI CD-ROM never wants all_partitions even though they are marked removable. Tape is also removable. So, the KERNEL="sd*".

Though it won't help for non-scsi (implies non-usb mass storage) media.

A global rule affecting all partitions or naming would be nice, so you would not have to have a separate rule, but then like Kay's example rules above, if you are specifically naming a device, you already know it is removable, and can set all_partitions.

For example, you only need the first rule below, but if in some simliar case, you required two rules, that is ugly:

SYSFS{model}="USB Storage-SMC ", SYSFS{removable}="1", NAME{all_partitions}="smartmedia" SYSFS{model}="USB Storage-SMC ", SYSFS{removable}="0", NAME="smartmedia"

Quoted 2 lines · Patrick Mansfield

Should we export the scsi 'removable' flag via sysfs attribute for use with all_partitions? Kernel patch is a trivial:

<snip patch>

Yes, this is a good idea.

Then we can just trigger off of this, right? Will this flag always be correct, even for the very cheap flash readers on the market?

Quoted 7 lines

So you could have rules such as:

KERNEL="sd*", BUS="scsi", SYSFS{removable}="1", NAME{all_partitions}="%k" KERNEL="sd*", BUS="scsi", SYSFS{removable}="0", NAME="%k"

AFAIUI CD-ROM never wants all_partitions even though they are marked removable. Tape is also removable. So, the KERNEL="sd*".

Yeah, that would make sense.

Quoted 1 line

Though it won't help for non-scsi (implies non-usb mass storage) media.

Do you know of any? Old zip drives use scsi, right? What about floppy drives?

I ran with this patch:

diff -uprN -X /home/patman/dontdiff base-2.6/drivers/block/genhd.c blk-attr-2.6/drivers/block/genhd.c

drivers/block/genhd.c +11 -0

@@ -352,6 +352,12 @@ static ssize_t disk_range_read(struct ge
 {
 	return sprintf(page, "%d\n", disk->minors);
 }
+static ssize_t disk_removable_read(struct gendisk * disk, char *page)
+{
+	return sprintf(page, "%d\n",
+		       (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
+
+}
 static ssize_t disk_size_read(struct gendisk * disk, char *page)
 {
 	return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));

@@ -394,6 +400,10 @@ static struct disk_attribute disk_attr_r
 	.attr = {.name = "range", .mode = S_IRUGO },
 	.show	= disk_range_read
 };
+static struct disk_attribute disk_attr_removable = {
+	.attr = {.name = "removable", .mode = S_IRUGO },
+	.show	= disk_removable_read
+};
 static struct disk_attribute disk_attr_size = {
 	.attr = {.name = "size", .mode = S_IRUGO },
 	.show	= disk_size_read

@@ -406,6 +416,7 @@ static struct disk_attribute disk_attr_s
 static struct attribute * default_attrs[] = {
 	&disk_attr_dev.attr,
 	&disk_attr_range.attr,
+	&disk_attr_removable.attr,
 	&disk_attr_size.attr,
 	&disk_attr_stat.attr,
 	NULL,

And then I see:

[root@laptop root]# for i in /sys/block/*; do echo $i removable is $(cat $i/removable); done /sys/block/fd0 removable is 1
/sys/block/hda removable is 0
/sys/block/hdc removable is 1
/sys/block/sda removable is 1

hda is my boot/root disk. hdc my cd drive.

For sda, both my fairly cheap dazzle xd card reader and my olympus c750 give the same result.

(The ide floppy is the bay thing on my laptop, though it has a cd drive in it.)

Can we mark all sbp2 and usb-storage devices as removeable somehow? They can disappear at any time.