Thank you everyone for the plenty of good pointers. I should be able to proceed from here :-) On Fri, Mar 29, 2013 at 7:31 PM, Tobias Boege <tobias@xxxxxxxxxxxxxx> wrote: > On Fri, 29 Mar 2013, Sankar P wrote: >> On Fri, Mar 29, 2013 at 3:28 PM, Tobias Boege <tobias@xxxxxxxxxxxxxx> wrote: >> > On Fri, 29 Mar 2013, Sankar P wrote: >> >> Hi, >> >> >> >> I am trying to write a simple filesystem to learn the basics of it. >> >> >> >> I have decided on a simple layout for my filesystem where the first >> >> block will be the super block and will contain the version >> >> information etc. The second block will contain the list of inodes. >> >> Third block onwards will be data blocks. Each file can grow only up to >> >> a single block size. Thrid block will represent the first file, fourth >> >> block for the second file and so on. Directories will not be >> >> supported. >> >> >> >> Now I want to create a mkfs for my filesystem as mentioned above. But >> >> I am not able to find out how to do the mkfs for my filesystem such >> >> that the generic mkfs utility will understand my filesystem. What APIs >> >> should I be using ? >> >> >> >> Any help is appreciated. Thanks. >> > >> > According to my copy of the mkfs sources, you just have to create a program >> > named "mkfs.ID" where ID identifies your filesystem. Then put that program >> > in a location that the generic mkfs can find, i.e. under $PATH (mkfs seems >> > to make some additions to PATH but you should figure this out yourself). >> > >> > Finally, calling "mkfs -t ID" makes mkfs search for a program named >> > "mkfs.ID" - simple concatenation. >> > >> >> oh okay. But how do I create the superblock ? What are the APIs >> available to do these block level operations from a user space >> application (my mkfs program ) ? >> > > Look at how other mkfs.* do it. In general, these programs seem to be fairly > complex. To interface with block devices from userspace: use the standard > system calls, open(), lseek(), write(), ... > > For an example, you can look at the e2fsprogs source code. If you get > through the jungle of indirections you will eventually find just a plain > write() call in lib/ext2fs/unix_io.c:raw_write_blk() which is used for data > transfer. > > Regards, > Tobi > > > _______________________________________________ > 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
