n Wed, Jan 17, 2018 at 9:05 AM, inventsekar <inventse...@gmail.com> wrote: > Hi All, i have been reading > Unix filesystem - evolution, design and implementation by Steve D. Pate > > and it provides a simple file system source code for learning and playing > with. > On the header file, it defines the fs magic number as > #define UX_MAGIC 0x58494e55 > > 1. which means, will it assign this magic number to ALL files created on > this sample fs? That can't be so. Otherwise, why we need to define a magic > number?
There can be many different types of filesystems on a Linux computer; the magic number can be used to distinguish which type a particular filesystem is. If you look at usr/include/linux/magic.h you'll see, for example, #define EXT2_SUPER_MAGIC 0xEF53 and as an example of using that particular magic number, check out arch/blackfin/kernel/setup.c or fs/ext2/super.c. -- Jim _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
