Re: [1/4] DST: Distributed storage documentation.

On Mon, Dec 10, 2007 at 01:51:43PM +0100, Kay Sievers (kay.sievers@vrfy.org) wrote:

On Dec 10, 2007 12:47 PM, Evgeniy Polyakov [off-list ref] wrote:

quoted

diff --git a/Documentation/dst/sysfs.txt b/Documentation/dst/sysfs.txt
new file mode 100644
index 0000000..79d79dc
--- /dev/null
+++ b/Documentation/dst/sysfs.txt

@@ -0,0 +1,30 @@
+This file describes sysfs files created for each storage.
+
+1. Per-storage files.
+Each storage has its own dir /sysfs/devices/$storage_name,

It's always /sys/devices/.

I meant that for each new device, it will be placed into
/sys/devices/its_name, but it can also be accessed via
/sys/bus/dst/devices/

quoted

+which contains following files:
+
+alg - contains name of the algorithm used to created given storage
+name - name of the storage
+nodes - map of the storage (list of nodes and their sizes and starts)
+remove_all_nodes - writable file which allows to remove all nodes from given
+       storage
+n-$start-$cookie - per node directory, where
+       $start - start of the given node in sectors,
+       $cookie - unique node's id used by DST
+
+2. Per-node files.
+Node's files are located in /sysfs/devices/$storage_name/n-$start-$cookie
+directory, described above.

To which class or bus do the devices you create belong? Care to show a
"tree" or "ls -la" of the device?

It is 'dst' bus.

uganda:~/codes# ls -la /sys/devices/staorge/
total 0
drwxr-xr-x 4 root root    0 2007-12-10 11:46 .
drwxr-xr-x 9 root root    0 2007-12-10 11:46 ..
-r--r--r-- 1 root root 4096 2007-12-10 11:46 alg
lrwxrwxrwx 1 root root    0 2007-12-10 11:46 bus -> ../../bus/dst
drwxr-xr-x 3 root root    0 2007-12-10 11:46 n-0-ffff81003e24117
-r--r--r-- 1 root root 4096 2007-12-10 11:46 name
-r--r--r-- 1 root root 4096 2007-12-10 11:46 nodes
drwxr-xr-x 2 root root    0 2007-12-10 11:46 power
-rw-r--r-- 1 root root 4096 2007-12-10 11:46 remove_all_nodes
lrwxrwxrwx 1 root root    0 2007-12-10 11:46 subsystem -> ../../bus/dst
-rw-r--r-- 1 root root 4096 2007-12-10 11:46 uevent
uganda:~/codes# ls -l /sys/bus/dst/
total 0
drwxr-xr-x 2 root root    0 2007-12-10 09:52 devices
drwxr-xr-x 2 root root    0 2007-12-10 09:52 drivers
-rw-r--r-- 1 root root 4096 2007-12-10 11:46 drivers_autoprobe
--w------- 1 root root 4096 2007-12-10 11:46 drivers_probe

Kay

-- 
	Evgeniy Polyakov