Redirecting FileSystem
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Pimp Your Filesystem


The RedirFS or redirecting file system is a new layer between virtual file system switch (VFS) and file system drivers. It is implemented as an out-of-kernel module for Linux 2.6 and it provides framework allowing modification of file system calls in the VFS layer. The RedirFS by itself does not provide any additional functionality and if it is loaded into the Linux kernel, it just occupies some memory space and it does practically nothing. Now you maybe ask yourself a question: "So what is it good for then?". The RedirFS is intended to be used by so-called filters. Filter is a linux kernel module (LKM) that uses the RedirFS framework. Each filter can add some useful functionality to the existing file systems like transparent compression, transparent encryption, merging contents of several directories into one, allowing writing to a read-only media and others. Filter can set pre and post callback functions for selected file system calls (e.g. read or open) and include or exclude directories or single files for which its callback functions will be called. Every filter has its priority - a unique number that defines in which order will the filters be called. The RedirFS manages all filters and calls their callback functions in order specified by their priorities. While the RedirFS is located in the VFS layer, filters can be used generally in all file systems (e.g. ext2, nfs, proc). In addition, the RedirFS allows filters to be on-the-fly registered and unregistered.

RedirFS Features

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News


2008-07-01
  • RedirFS 0.3-pre2 released.
    • fixed removing of rfs_file objects
    • added support for file systems which are adding dentry/inode objects during readdir (e.g. NFS)
  • DummyFlt 0.2-pre2 released.
    • proper unregistration after error in the init module function

2008-06-27
  • RedirFS 0.3-pre1 and DummyFlt 0.2-pre1 released. RedirFS Framework is completely rewritten and it has slightly different interface then 0.2 version. This means that all filters need to be adapted to this new interface. New DummyFlt 0.2-pre1 can be used as an example how to do it. For now RedirFS 0.3-pre1 also does not implement all features introduced in the 0.2 version like support for private data, address space operations and only several operations can be redirected. This version contains new path management which is not based on path names and it should safely handle renames.

2008-05-26
  • All services should work again. Sorry for all that troubles.

2008-05-24
  • It tooks one month to transfer .org domain from one holder to another (we need to transfer it from Grisoft to FUT VUT because of the hosting). Never ever...
  • now the nameservers for redirfs.org are directed correctly to FIT BUT, so web should work again. It will take another 2-3days before mail do.

2008-04-24
  • RedirFS server was moved to FIT BUT as previous hosting was not good enough. IP address of the server has changed with this.

2007-11-29
  • RedirFS server has new IP address 212.96.161.248

2007-11-23

2007-11-04
  • Presentation slides for the LinuxAlt conference are available at the documentation page.

2007-10-29

2007-10-22

2007-10-16
  • RedirFS 0.2 has been released. It is rewritten from scratch with focus on SMP safety and it has implemented almost all planned features. Please note that this version is intended for public testing and bug hunting. It is highly recommended to use it only on testing computer where system crash can not cause any harm. Bugs can be reported in the RedirFS's bugzilla.
  • DummyFlt 0.1 has been released. It is dummy testing filter and it can be used as an inspiration for your own filter.

2007-09-11
  • There is going to be a RedirFS presentation on Sunday 4th November 10:00 - 10:50 at Linuxalt 2007. Conference takes place in Brno, Czech Republic at FIT BUT. Note that the web pages and whole conference is Czech only.

2007-05-17

older news

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