On Tue, Aug 6, 2013 at 10:10 AM, Rajat Sharma <fs.rajat@xxxxxxxxx> wrote: > Hey buddy, its a good work. You never know how many people you end up > helping with this code. I would definitely recommend this as a > starter. > Thank you so much :) It feels so nice to hear this from you :) > One recommendation: add support for page-cache. Start with read-cache > only, and then mmap support, you need that to allow binary execution. > oh okay. You suggest that I should do this before I start implementing the support for extents ? Sankar > -Rajat > > On Tue, Aug 6, 2013 at 12:27 AM, Sankar P <sankar.curiosity@xxxxxxxxx> wrote: >> Hi, >> >> For learning purposes, I thought I would implement a filesystem from >> the scratch. It has reached a state where I can do a 1.0 release. >> >> The sources are at: https://github.com/psankar/simplefs >> >> The layout is simple. The first (zeroth) block is the superblock and >> contains information like fs magic, number of inodes, freeblock map >> etc. The next block is the inode store. Creation of files and >> directories is supported. Nested directories are supported. A file can >> grow up to one block only. The data blocks for a directory contain the >> filename and inode number of its children. For files, it will >> obviously contain the actual data of the file. There are three >> rudimentary locks to make sure the accesses are thread safe. >> >> The 1.0 version is filled with a lot of TODOs and memory leaks. Also >> while implementing this, I realized that it is a bad idea to maintain >> the superblock and the freeblock store together in a block. So I am >> planning to change the on-disk layout in the next version. >> >> Apart from moving the super block to minimize locks, I am planning to >> implement support for extents in the next version, and journalling in >> the next-to-next version. The next version will take some time to >> come, though. But if someone wants to try filesystems from the >> scratch, I thought it may be useful if I share the link now itself. >> >> Also, I take this moment to thank the kernelnewbies list, especially >> the regular people like Mulyadi Santosa, Valdis Kletnieks, Rajat >> Sharma, Greg Freemyer etc. Also I would like to thank Neha Naik, >> Manish Katiyar who helped me with some queries during this particular >> implementation. I saw that Manish Katiyar has also done a similar >> from-the-scratch implementation and it motivated me to pursue further. >> >> Any feedback on the code is welcome. Although, I want to inform that I >> plan to change the locking until after I decide on a good on-disk >> layout for the next version, which will by-design minimize the locking >> needs, by splitting out freestore from superblock, keep track of >> children inode in a better way etc. Also I have been resisting the >> urge to look at ext or any other filesystem's design so as to not skew >> my thoughts and go with a fresh state of mind and get my own design :) >> >> Thanks. >> >> -- >> Sankar P >> http://psankar.blogspot.com >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies@xxxxxxxxxxxxxxxxx >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- Sankar P http://psankar.blogspot.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
