ExposeFS

Introduction

Say you have a bunch of files on a special filesystem that some giant corporation loves to use for completely insane reasons as well as maintain backwards compatibility with software that should have bit the dust ages ago.

Requirements

ExposeFS exposes itself as a POSIX compliant filesystem. That said it expects only one extension to what most would consider a standard POSIX file system which is hard links. The overlay filesystem will appear to have hard links for many nodes including the owner information nodes and acl information nodes.

Sparse Files

Work in progress

Caching
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Memory is used to create inode maps allowing multiple filesystems to be 
backed up at once while retaining the ability to use hard links for 
cached information as well as hard links per filesystem.  The mapping is 
simple and inode count starts at 1.  In memory the hard links are stored 
as an integer that relates to a set of two integers, one for the file 
system ID (0 is reserved for internal uses), and one for the actual 
inode.

Supported Underlaying Filesystems
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Common

This section covers all common information that all supported filesystems should have.

• */data (GET/SET) The actual file data
• */uid (GET/SET) POSIX UID Number
• */gid (GET/SET) POSIX GID ...
• */uidname (GET/SET) Resolved user name
• */gidname (GET/SET) Resolved group name
• */ctime (GET/SET) Creation Timestamp
• */atime (GET/SET) Access Timestamp
• */mtime (GET/SET) Modify Timestamp
• */mode (GET/SET) File mode

Supported Underlaying Filesystems (pending):

HFS+

The following are exposed for Mac OS X (tested) HFS+ filesystems.

  - */acl (GET/SET) ACL
  - */aclname (GET) Resolved ACL
  - */rsrc (GET/SET) Resource Fork

Contact
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hardwire on freenode