ffs details

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

ffs details

whistlez-ml
Hi, I need some details about ffs, I read the kernel source but my c
knowledge is very basic. I understood all about the superblock but my
problem is understand how the files are allocated on the disk.
Anyone could give me more details about files allocation ?
Thank you.

Reply | Threaded
Open this post in threaded view
|

Re: ffs details

Philip Guenther-2
On Tue, Feb 25, 2020 at 6:03 PM <[hidden email]> wrote:

> Hi, I need some details about ffs, I read the kernel source but my c
> knowledge is very basic. I understood all about the superblock but my
> problem is understand how the files are allocated on the disk.
> Anyone could give me more details about files allocation ?
>

You should start from the paper that described the design and
implementation:
    https://www.cs.berkeley.edu/~brewer/cs262/FFS.pdf

as linked to from https://en.wikipedia.org/wiki/Unix_File_System

Kirk McKusick has continued to revise and improve FFS; many of those
changes have been included in OpenBSD.  Check his biography and his
personal website for links to papers and presentations.


Philip Guenther
Reply | Threaded
Open this post in threaded view
|

Re: ffs details

Otto Moerbeek
In reply to this post by whistlez-ml
On Wed, Feb 26, 2020 at 03:02:02AM +0100, [hidden email] wrote:

> Hi, I need some details about ffs, I read the kernel source but my c
> knowledge is very basic. I understood all about the superblock but my
> problem is understand how the files are allocated on the disk.
> Anyone could give me more details about files allocation ?
> Thank you.
>

Did you read the ffs paper
https://people.eecs.berkeley.edu/~brewer/cs262/FFS.pdf

Some things have changes a bit (like rotational optimization) but the
general ideas hold.

        -Otto