ext4 has sparked good controversy on the LKML. Aside from the recent delayed alloc and fsync issues, the whole FS stack is getting some much needed attention. Indeed, Linux file systems are starting to feel like first class citizens again with ext4 and Btrfs (merged in 2.6.29 for testing!) and the surrounding infrastructure being worked on. A lot of long overdue problems are being mitigated. Jens Axboe claims 8% single drive and 25% array speedup with some recent pdflush patches. This is very good news for all users since disk I/O has had a fast growing gap with CPU and main memory bandwidth, even with SSDs. The fruits of this labor are quite visible with recent boot speedups in distros like the upcoming Fedora 11.