linux-toradex.git/include/linux/sysfs.h, branch v2.6.38.6

sysfs: Add sysfs_merge_group() and sysfs_unmerge_group()

2010-10-16T23:57:44+00:00

This patch (as1420) adds sysfs_merge_group() and sysfs_unmerge_group()
functions, allowing drivers easily to add and remove sets of
attributes to a pre-existing attribute group directory.

Signed-off-by: Alan Stern 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Rafael J. Wysocki

kobject: Break the kobject namespace defs into their own header

2010-08-24T01:12:46+00:00

Break the kobject namespace defs into their own header to avoid a header file
inclusion ordering problem between linux/sysfs.h and linux/kobject.h.

This fixes the build breakage on older versions of gcc.

Signed-off-by: David Howells 
Cc: Eric Biederman 
Signed-off-by: Greg Kroah-Hartman

sysfs: Remove owner field from sysfs struct attribute

2010-08-05T20:53:35+00:00

Signed-off-by: Guenter Roeck 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: sysfs_chmod_file's attr can be const

2010-08-05T20:53:34+00:00

sysfs_chmod_file doesn't change the attribute it operates on, so this
attribute can be marked const.

Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

sysfs: add struct file* to bin_attr callbacks

2010-05-21T16:37:31+00:00

This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.

Signed-off-by: Chris Wright 
Signed-off-by: Greg Kroah-Hartman

sysfs: Don't use enums in inline function declaration.

2010-05-21T16:37:31+00:00

It appears gcc can't cope with using an enum that is only declared in
an inline function declaration, that doesn't even use the variable
that is so declared.

Avoid the silliness and replace the enum with an int, and make gcc
happy.

Signed-off-by: Eric W. Biederman 
Acked-by: Randy Dunlap 
Signed-off-by: Greg Kroah-Hartman

sysfs: Comment sysfs directory tagging logic

2010-05-21T16:37:31+00:00

Add some in-line comments to explain the new infrastructure, which
was introduced to support sysfs directory tagging with namespaces.
I think an overall description someplace might be good too, but it
didn't really seem to fit into Documentation/filesystems/sysfs.txt,
which appears more geared toward users, rather than maintainers, of
sysfs.

(Tejun, please let me know if I can make anything clearer or failed
altogether to comment something that should be commented.)

Signed-off-by: Serge E. Hallyn 
Cc: Eric W. Biederman 
Cc: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: Implement sysfs_delete_link

2010-05-21T16:37:31+00:00

When removing a symlink sysfs_remove_link does not provide
enough information to figure out which tagged directory the symlink
falls in.  So I need sysfs_delete_link which is passed the target
of the symlink to delete.

sysfs_rename_link is updated to call sysfs_delete_link instead
of sysfs_remove_link as we have all of the information necessary
and the callers are interesting.

Both of these functions now have enough information to find a symlink
in a tagged directory.  The only restriction is that they must be called
before the target kobject is renamed or deleted.  If they are called
later I loose track of which tag the target kobject was marked with
and can no longer find the old symlink to remove it.

This patch was split from an earlier patch.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Benjamin Thery 
Signed-off-by: Daniel Lezcano 
Acked-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: Implement sysfs tagged directory support.

2010-05-21T16:37:31+00:00

The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Benjamin Thery 
Signed-off-by: Greg Kroah-Hartman

sysfs: fix for thinko with sysfs_bin_attr_init()

2010-03-08T01:04:52+00:00

After merging the final tree, today's linux-next build (powerpc
allyesconfig) failed like this:

drivers/pci/pci-sysfs.c: In function 'pci_create_legacy_files':
drivers/pci/pci-sysfs.c:645: error: lvalue required as unary '&' operand
drivers/pci/pci-sysfs.c:658: error: lvalue required as unary '&' operand

Caused by commit "sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on
dynamic attributes" interacting with commit "sysfs: Use one lockdep
class per sysfs attribute") both from the driver-core tree.

Signed-off-by: Stephen Rothwell 
Cc: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman