Published at LXer:

The question of if and when Reiser4 will be merged into the mainline Linux kernel has been an on-going debate for a couple of years [story]. The filesystem was described as being "fairly stable for average users" by Hans Reiser [interview] over two years ago, in March of 2004 [story]. It has been merged into Andrew Morton [interview]'s -mm kernel [story], though issues such as Reiser4 plugins [story] and coding style [story] caused lengthy discussions last year. Two recent threads on thelkml raised the question again, asking at a non-technical level why Reiser 4 has not been included in the Linux kernel. Some have offered theories that Reiser4 is being blocked for political reasons, others because of concerns that once Reiser4 is included Namesys might forget it and move onto another filesystem. Responses to these theories point out that in reality there are technical issues that must be resolved before the filesystem will be merged, and that much progress has been made toward this end. Additional discussion can be found on a relevant and recently createdkernel newbies wiki page.Hans Reiser posted a "short term task list for Reiser4" to address the remaining technical issues. The todo list included getting batch_write merged into the -mm kernel [story], getting read optimization code merged into the -mm kernel, documenting everything in theNamesys wiki, exploring and addressing reports of system pauses when using Reiser4, a complete review of the crypt-compress code, a large effort in optimizing fsync, a review of installation instructions, and a review of the kernel documentation. Hans explains, "unfortunately, our code stability is going to decrease for a bit due to all these changes to the read and write code --- no way to cure that but passage of time. On the other hand, our CPU usage went way down. Reiser4's only performance weakness now is fsync. Once the crypt-compress code is ready, we will release Reiser4.1-beta (with plugins, releasing a beta means telling users that if they mount -o reiser4.1-beta then cryptcompress will be their default plugin, and if they don't, then they are using Reiser4.0 still). Doubling our performance and halving our disk usage is going to be fun."

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