With this commit, extent tree operations are divorced from inodes and
rely on ocfs2_caching_info.  Phew!
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We only allow unwritten extents on data, so the toplevel
ocfs2_mark_extent_written() can use an inode all it wants.  But the
subfunction isn't even using the inode argument.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Don't use a struct inode anymore.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It already has an extent_tree.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

One more generic btree function that is isolated from struct inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

One more function that doesn't need a struct inode to pass to its
children.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

One more function down, no inode in the entire insert-extent chain.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2_insert_extent() wants to insert a record into the extent map if
it's an inode data extent.  But since many btrees can call that
function, let's make it an op on ocfs2_extent_tree.  Other tree types
can leave it empty.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It's not using it, so remove it from the parameter list.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It already has an ocfs2_extent_tree and doesn't need the inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We don't want struct inode in generic btree operations.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Don't pass the inode in.  We don't want it around for generic btree
operations.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

They aren't using it, so remove it from their parameter lists.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Another on the way to generic btree functions.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Give it an ocfs2_extent_tree and it is happy.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2_remove_extent() wants to truncate the extent map if it's
truncating an inode data extent.  But since many btrees can call that
function, let's make it an op on ocfs2_extent_tree.  Other tree types
can leave it empty.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It's not using it anymore.  Remove it from the parameter list.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2_grow_branch() not really using it other than to pass it to the
subfunctions ocfs2_shift_tree_depth(), ocfs2_find_branch_target(), and
ocfs2_add_branch().  The first two weren't it either, so they drop the
argument.  ocfs2_add_branch() only passed it to
ocfs2_adjust_rightmost_branch(), which drops the inode argument and uses
the ocfs2_extent_tree as well.

ocfs2_append_rec_to_path() can be take an ocfs2_extent_tree instead of
the inode.  The function ocfs2_adjust_rightmost_records() goes along for
the ride.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It's not using it, so remove it from the parameter list.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Drop it from the parameters - they already have ocfs2_extent_list.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It already gets ocfs2_extent_tree, so we can just use that.  This chains
to the same modification for ocfs2_remove_rightmost_path() and
ocfs2_rotate_rightmost_leaf_left().
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It already has struct ocfs2_extent_tree, which has the caching info.  So
we don't need to pass it struct inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

It already has struct ocfs2_extent_tree, which has the caching info.  So
we don't need to pass it struct inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Pass in the extent tree, which is all we need.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We don't need struct inode in ocfs2_rotate_tree_right() anymore.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We can get to the inode from the caching information.  Other parent
types don't need it.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Get rid of the inode argument.  Use extent_tree instead.  This means a
few more functions have to pass an extent_tree around.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Pass the ocfs2_extent_list down through ocfs2_rotate_tree_right() and
get rid of struct inode in ocfs2_rotate_subtree_root_right().
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Completely unused argument.  Get rid of it.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2_unlink_path() doesn't need struct inode, so let's pass it struct
ocfs2_extent_tree.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Pass struct ocfs2_extent_tree into ocfs2_create_new_meta_bhs().  It no
longer needs struct inode or ocfs2_super.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

ocfs2_find_path and ocfs2_find_leaf() walk our btrees, reading extent
blocks.  They need struct ocfs2_caching_info for that, but not struct
inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

extent blocks belong to btrees on more than just inodes, so we want to
pass the ocfs2_caching_info structure directly to
ocfs2_read_extent_block().  A number of places in alloc.c can now drop
struct inode from their argument list.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

What do we cache?  Metadata blocks.  What are most of our non-inode metadata
blocks?  Extent blocks for our btrees.  struct ocfs2_extent_tree is the
main structure for managing those.  So let's store the associated
ocfs2_caching_info there.

This means that ocfs2_et_root_journal_access() doesn't need struct inode
anymore, and any place that has an et can refer to et->et_ci instead of
INODE_CACHE(inode).
Signed-off-by: Joel Becker <joel.becker@oracle.com>

The next step in divorcing metadata I/O management from struct inode is
to pass struct ocfs2_caching_info to the journal functions.  Thus the
journal locks a metadata cache with the cache io_lock function.  It also
can compare ci_last_trans and ci_created_trans directly.

This is a large patch because of all the places we change
ocfs2_journal_access..(handle, inode, ...) to
ocfs2_journal_access..(handle, INODE_CACHE(inode), ...).
Signed-off-by: Joel Becker <joel.becker@oracle.com>

Similar ip_last_trans, ip_created_trans tracks the creation of a journal
managed inode.  This specifically tracks what transaction created the
inode.  This is so the code can know if the inode has ever been written
to disk.

This behavior is desirable for any journal managed object.  We move it
to struct ocfs2_caching_info as ci_created_trans so that any object
using ocfs2_caching_info can rely on this behavior.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We have the read side of metadata caching isolated to struct
ocfs2_caching_info, now we need the write side.  This means the journal
functions.  The journal only does a couple of things with struct inode.

This change moves the ip_last_trans field onto struct
ocfs2_caching_info as ci_last_trans.  This field tells the journal
whether a pending journal flush is required.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We are really passing the inode into the ocfs2_read/write_blocks()
functions to get at the metadata cache.  This commit passes the cache
directly into the metadata block functions, divorcing them from the
inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We don't really want to cart around too many new fields on the
ocfs2_caching_info structure.  So let's wrap all our access of the
parent object in a set of operations.  One pointer on caching_info, and
more flexibility to boot.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

We want to use the ocfs2_caching_info structure in places that are not
inodes.  To do that, it can no longer rely on referencing the inode
directly.

This patch moves the flags to ocfs2_caching_info->ci_flags, stores
pointers to the parent's locks on the ocfs2_caching_info, and renames
the constants and flags to reflect its independant state.
Signed-off-by: Joel Becker <joel.becker@oracle.com>