[PATCH] configfs, a filesystem for userspace-driven kernel object configuration

Joel Becker
2005-04-03T19:58:02Z

Folks,
I humbly submit configfs. With configfs, a configfs
config_item is created via an explicit userspace operation: mkdir(2).
It is destroyed via rmdir(2). The attributes appear at mkdir(2) time,
and can be read or modified via read(2) and write(2). readdir(3)
queries the list of items and/or attributes.
The lifetime of the filesystem representation is completely
driven by userspace. The lifetime of the objects themselves are managed
by a kref, but at rmdir(2) time they disappear from the filesystem.
configfs is not intended to replace sysfs or procfs, merely to
coexist with them.
An interface in /proc where the API is:

# echo "create foo 1 3 0x00013" > /proc/mythingy

or an ioctl(2) interface where the API is:

struct mythingy_create {
char *name;
int index;
int count;
unsigned long address;
}

do_create {
mythingy_create = {"foo", 1, 3, 0x0013};
return ioctl(fd, MYTHINGY_CREATE, &mythingy_create);
}

becomes this in configfs:

# cd /config/mythingy
# mkdir foo
# echo 1 > foo/index
# echo 3 > foo/count
# echo 0x00013 > foo/address

Instead of a binary blob that's passed around or a cryptic
string that has to be formatted just so, configfs provides an interface
that's completely scriptable and navigable.
Patch is against 2.6.12-rc1-bk3.

http://oss.oracle.com/~jlbec/files/configfs/2.6.12-rc1-bk3/configfs-2.6.12-rc1-bk3-1.patch

Joel

--

"Not everything that can be counted counts, and not everything
that counts can be counted."
- Albert Einstein

Joel Becker
Senior Member of Technical Staff
Oracle
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127