On Tue, Aug 6, 2013 at 8:36 PM, Sankar P <sankar.curiosity@xxxxxxxxx> wrote: > 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 ? > Its upto you, but doing that before extents seems more towards basic tutorial steps for writing a filesystem. > 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
