ufs2: Add st_nlink and st_blocks to stat()

Change-Id: I89279aa1b02c3814642f2e454408198b21cf7689
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6859
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

ufs2: Add access() support

Change-Id: I4c2fa12a623f0893c976430893f448f734794548
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6858
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

ufs2: Reading symbolic links

Symbolic links are now showing path and relative path can be tested.

Change-Id: I47820a475d78d8090c02564f698e72dd8fbaa3a1
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3171
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

ufs2: Implementing read function

Attempting to read data from direct blocks and single indirect
blocks even if the data stored is not in continous blocks and
DirectoryIterator now uses ReadAt to iterate through directories.

Change-Id: I8156aba53782da8c2bb4481db611ae26d8881b35
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3088
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

ufs2: implementing open_dir and read_dir function

Root directory is read sucessfully.

Change-Id: I8bdc8c1a52edb679a6cb4b5f70e7f42eb2b2c8f1
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2907
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

ufs2: Implementing read_stat function and fs_info

Change-Id: I337c53c017f00f480af7ac94a5774b39eb5255db
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2773
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

ufs2: Reading inodes of ufs2.

Now file system can be mounted sucessfully.

Adding documentation for using the code.

Change-Id: I2bd1b72e06ffc3b5f6306aaa69c59becf4cb882b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2696
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>