There are have been attempts at "phase tree" filesystems with essentially transactional write semantics for data and metadata simultaneously. Tux2 was one such

There are have been attempts at "phase tree" filesystems with essentially transactional write semantics for data and metadata simultaneously. Tux2 was one such nascent attempt that ended (rightly or wrongly) due to patent conflict with Netapp's WAFL [1]. The interesting thing is, I just took a look at what I believe were the patents in conflict, and they appear to have expired in 2015 [2,3]. Combining the phase tree concept with, say, Merkle trees might open up very interesting possibilities for large-scale reliable file storage. [1] https://linux.slashdot.org/story/00/10/13/2117258/tux2-the-filesystem-that-would-be-king https://linux.slashdot.org/story/00/10/13/2117258/tux2-the-f... [2] https://patents.google.com/patent/US5819292 https://patents.google.com/patent/US5819292 [3] https://patents.google.com/patent/US5963962 https://patents.google.com/patent/US5963962