linux-toradex.git/fs/sysfs/group.c, branch v3.0.44

SYSFS: Fix erroneous comments for sysfs_update_group().

2011-05-10T21:22:00+00:00

Fix what is clearly a simple copy-and-paste error in commenting the
sysfs_update_group() routine.

Signed-off-by: Robert P. J. Day 
Signed-off-by: Greg Kroah-Hartman

sysfs: remove useless test from sysfs_merge_group

2010-11-29T19:59:53+00:00

Dan Carpenter pointed out that the new sysfs_merge_group() and
sysfs_unmerge_group() routines requires their grp argument to be
non-NULL, because they dereference grp to obtain the list of
attributes.  Hence it's pointless for the routines to include a test
and special-case handling for when grp is NULL.  This patch (as1433)
removes the unneeded tests.

Signed-off-by: Alan Stern 
CC: Dan Carpenter 
Signed-off-by: Greg Kroah-Hartman

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

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

Use WARN() in fs/sysfs

2008-07-26T19:00:07+00:00

Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes
part of the warning section for better reporting/collection.  Also, with this,
one fo the if() sections collapses entirely into the WARN().

Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[SCSI] sysfs: make group is_valid return a mode_t

2008-04-22T20:16:31+00:00

We have a problem in scsi_transport_spi in that we need to customise
not only the visibility of the attributes, but also their mode.  Fix
this by making the is_visible() callback return a mode, with 0
indicating is not visible.

Also add a sysfs_update_group() API to allow us to change either the
visibility or mode of the files at any time on the fly.

Acked-by: Kay Sievers 
Signed-off-by: James Bottomley

sysfs: remove BUG_ON() from sysfs_remove_group()

2008-02-07T19:31:46+00:00

It's possible that the caller of sysfs_remove_group messed up and passed in an attribute group that was not really registered to this kobject.  But don't panic for such a foolish error, spit out a warning about what happened, and continue on our way safely.

Cc: Roland Dreier 
Cc: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

[SCSI] sysfs: add filter function to groups

2008-01-23T17:29:18+00:00

This patch allows the various users of attribute_groups to selectively
allow the appearance of group attributes.  The primary consumer of
this will be the transport classes in which we currently have
elaborate attribute selection algorithms to do this same thing.

Acked-by: Greg KH 
Signed-off-by: James Bottomley

sysfs: Remove first pass at shadow directory support

2007-10-12T21:51:03+00:00

While shadow directories appear to be a good idea, the current scheme
of controlling their creation and destruction outside of sysfs appears
to be a locking and maintenance nightmare in the face of sysfs
directories dynamically coming and going.  Which can now occur for
directories containing network devices when CONFIG_SYSFS_DEPRECATED is
not set.

This patch removes everything from the initial shadow directory support
that allowed the shadow directory creation to be controlled at a higher
level.  So except for a few bits of sysfs_rename_dir everything from
commit b592fcfe7f06c15ec11774b5be7ce0de3aa86e73 is now gone.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: cleanup semaphore.h

2007-10-12T21:51:03+00:00

Cleanup semaphore.h

Signed-off-by: Dave Young 
Signed-off-by: Greg Kroah-Hartman