Clean up some of the problems with the rtas_flash driver:
(1) It shouldn't fiddle with the internals of the procfs filesystem (altering
pde->count).
(2) If pid namespaces are in effect, then you can get multiple inodes
connected to a single pde, thereby rendering the pde->count > 2 test
useless.
(3) The pde->count fudging doesn't work for forked, dup'd or cloned file
descriptors, so add static mutexes and use them to wrap access to the
driver through read, write and release methods.
(4) The driver can only handle one device, so allocate most of the data
previously attached to the pde->data as static variables instead (though
allocate the validation data buffer with kmalloc).
(5) We don't need to save the pde pointers as long as we have the filenames
available for removal.
(6) Don't try to multiplex what the update file read method does based on the
filename. Instead provide separate file ops and split the function.
Whilst we're at it, tabulate the procfile information and loop through it when
creating or destroying them rather than manually coding each one.
[Folded fixes from Vasant Hegde <hegdevasant@linux.vnet.ibm.com>]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cc: Paul Mackerras <paulus@samba.org>
cc: Anton Blanchard <anton@samba.org>
cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
e8eeded3c5