| File Descriptor File System (fdfs) is an improved version of the original |
| fdescfs(5) for FreeBSD kernel. |
| |
| fdescfs(5) presents only wrapper nodes in type of character device, therefore |
| doesn't reflect the real underlying file types. While this improved version |
| presents the file descriptor nodes in their original forms whenever possible. |
| For a file descriptor of directory or regular file, the original VFS node will |
| be provided, rather than a wrapper node. For a file descriptor of pipe or |
| socket, a wrapper node with the correct file type will be provided. |
| |
| However fdescfs(5) does guarantee the new file descriptor obtained by |
| open(2)ing a file descriptor node is same as the one a F_DUPFD operation would |
| return. fdfs on the other hand, presents the real VFS node when the file |
| descriptor is backed by one; therefore an open(2) call on such a node would be |
| equivalent to an open(2) call on the underlying VFS node directly. |
| |
| This implementation also enables creating additional hard link to a regular |
| file using an existing file descriptor. |
| |
| Usage: |
| mount -t fdfs fdfs /dev/fd/ |
| nmount fstype=fdfs fspath=/dev/fd/ |
| |