xfs: make Directory Iterator class an abstract class

Directory Iterator class represents one instance which could be Short, Extent, Leaf, Node or B+Tree, a good case for making it an abstract class

Change-Id: I925255caf4c4f8bc01a975740ef2ebf0bb2e1b49
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5764
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

xfs: Node, B+Tree based directories and v5 files support

-Implemented node and B+Tree based directories support for xfs v5

-Implemented file read support for xfs v5

-Implemented common template function for all data headers check

This patch completes #17783 and #17703

Change-Id: Id4389168d07f31a97e8867e3cb3321b4523b13c0
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5483
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

xfs: B+Tree GetNext() works

The GetNext() works well for B+Trees and that wraps up the work needed
for all kinds of GetNext().
Change-Id: Ie965d3da273364f8fdbdb8faee5cb3c214881130
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3124
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: B+Tree ExtentMap reading

We can now read all the extent maps from the leaves. This will be needed
to implement the GetNext() functionality.

Change-Id: Ie10b453c33bec6e6d3109743d695f86a90de45cd
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3119
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: Reading Node Directories

Node directories can now be read. With this, extent directories are
complete.
Change-Id: Ic42c8464e810137cff4946e8c975edc121daaa4f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3045
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: Attempt at reading Leaf Directories

We can read leaf directories now but I've only checked for a single
block working right now. I might make a few more changes in an upcoming
patch.

Change-Id: I325de8a6fad4ef9298e7810256cba47a87c45187
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3027
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: Read Block directories

Block directories can now be read.
Change-Id: I9aa898638e6ac39cb903f2dd58cd184785e1a06b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2992
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: An attempt to read block directories

Map entries can be read, most structures are in place. Next is to
actually work with the directory block.

Change-Id: I700ee2e003bdef97838b1f06a95e53a5e4293658
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2981
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: Read Short Form Directories

We can now read short form directories.
Change-Id: I23eb6ef52e8bb07643213e603ed0185f536c649f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2952
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: An attempt at reading shortform dir

This patch gets read_dir, lookup and few others to work. Entries cannot
be listed yet except the root.

Change-Id: Ic4b7b61a794a1b75849e45777a383b3315b15aa8
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2915
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>