[PATCH 0/3] Allow sysfs to be dynamically populated

[Matthew Wilcox <matthew@wil.cx>]

The first patch in this series is just a bugfix.

The second and third patches offer progressively more flexibility to
dynamically construct the contents of sysfs directories.  The second
patch delays the allocation of sysfs_dirents until the contents of
the directory is requested.  This functionality is only used by the
attribute_groups in that patch, but could (in principle) be extended to
other directory providers.

The third patch extends this to permit attribute groups to be dynamically
constructed before the directory they're in is populated.  I also add a
user for this; the much-requested ability to display the MSI-X vectors
in use by a device.

Both patches also deconstruct the directories / attribute groups when the
dentry of the directory goes out of cache.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."