This adds a MOVE_SELF event to inotify.  It is sent whenever the inode
you are watching is moved.  We need this event so that we can catch
something like this:

 - app1:
	watch /etc/mtab

 - app2:
	cp /etc/mtab /tmp/mtab-work
	mv /etc/mtab /etc/mtab~
	mv /tmp/mtab-work /etc/mtab

app1 still thinks it's watching /etc/mtab but it's actually watching
/etc/mtab~.
Signed-off-by: NJohn McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: NRobert Love <rml@novell.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This removes the now unused fsnotify_unlink & fsnotify_rmdir code.
Compile tested.
Signed-off-by: NJohn McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The patch below unhooks fsnotify from vfs_unlink & vfs_rmdir.  It
introduces two new fsnotify calls, that are hooked in at the dcache
level.  This not only more closely matches how the VFS layer works, it
also avoids the problem with locking and inode lifetimes.

The two functions are

 - fsnotify_nameremove -- called when a directory entry is going away.
   It notifies the PARENT of the deletion.  This is called from
   d_delete().

 - inoderemove -- called when the files inode itself is going away.  It
   notifies the inode that is being deleted.  This is called from
   dentry_iput().
Signed-off-by: NJohn McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This avoids the whole #ifdef mess by just getting a copy of
dentry->d_inode before d_delete is called - that makes the codepaths the
same for the INOTIFY/DNOTIFY cases as for the regular no-notify case.
I've been running this under a Gnome session for the last 10 minutes.
Inotify is being used extensively.
Signed-off-by: NJohn McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When a file is moved over an existing file that you are watching,
inotify won't send you a DELETE_SELF event and it won't unref the inode
until the inotify instance is closed by the application.
Signed-off-by: NJohn McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: NRobert Love <rml@novell.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This rearranges the event ordering for "open" to be consistent with the
ordering of the other events.
Signed-off-by: NRobert Love <rml@novell.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:

        * dnotify requires the opening of one fd per each directory
          that you intend to watch. This quickly results in too many
          open files and pins removable media, preventing unmount.
        * dnotify is directory-based. You only learn about changes to
          directories. Sure, a change to a file in a directory affects
          the directory, but you are then forced to keep a cache of
          stat structures.
        * dnotify's interface to user-space is awful.  Signals?

inotify provides a more usable, simple, powerful solution to file change
notification:

        * inotify's interface is a system call that returns a fd, not SIGIO.
	  You get a single fd, which is select()-able.
        * inotify has an event that says "the filesystem that the item
          you were watching is on was unmounted."
        * inotify can watch directories or files.

Inotify is currently used by Beagle (a desktop search infrastructure),
Gamin (a FAM replacement), and other projects.

See Documentation/filesystems/inotify.txt.
Signed-off-by: NRobert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>