TAKE - dmapi - use vfsmount ptr in dmapi_mount_event callout

[Dean Roehrich <roehrich@sgi.com>]

To fix dm_handle_to_path() I need to be able to open a file by its handle,
when I don't know which filesystem the handle belongs to--meaning, I don't
have an open filedescriptor that I could use in, say,
ioctl(XFS_IOC_OPEN_BY_HANDLE), which means I don't have access to a vfsmount
ptr, which means I can't fully populate a new "struct file", which means
I'm giving the user a new filedescriptor that isn't safe to use.

This mod allows DMAPI to keep a vfsmount pointer that was used during the
mount event, and in a followup mod I will use that pointer for an
open_by_handle operation.

Date:  Thu Mar 21 08:42:58 PST 2002
Workarea:  clink-eth.americas.sgi.com:/data/clink/a67/roehrich/2.4.x-xfs

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/slinx/2.4.x-xfs


Modid:  2.4.x-xfs:slinx:114620a
linux/include/linux/fs.h - 1.145
	- Change dmapi_mount_event in struct super_operations, to have vfsmount ptr
	  param instead of super_block param.

linux/fs/xfs/xfs_dmapi.h - 1.21
	- Change xfs_dm_mount() prototype for vfsmount ptr.

linux/fs/xfs/xfs_dmapi.c - 1.49
	- Change xfs_dm_mount() to accept vfsmount ptr, and to call dm_hookup_vfsmount.

linux/fs/xfs/linux/xfs_dmistubs.c - 1.14
	- fixup xfs_dm_mount() stub, for new vfsmount param.

linux/fs/xfs/linux/xfs_super.c - 1.164
	- Change linvfs_dmapi_mount to take vfsmount ptr rather than super_block.

linux/include/linux/dmapi_kern.h - 1.8
	- add prototype for dm_hookup_vfsmount.

linux/fs/xfs/linux/xfs_vfs.h - 1.10
	- Change vfs_dmapi_mount prototype and VFSOPS_DMAPI_MOUNT macro to send
	  vfsmount ptr.

linux/fs/namespace.c - 1.9
	- Put the vfsmount ptr into the dmapi_mount_event callout, rather than the 
	  superblock.  We can get the superblock later from the vfsmount.

linux/fs/xfs_dmapi/dmapi_register.c - 1.6
	- Add new function dm_hookup_vfsmount() to attach the vfsmount ptr to
	  the dm_fsreg_t.

linux/fs/xfs_dmapi/dmapi_private.h - 1.4
	- Add vfsmount ptr to dm_fsreg_t.