Re: root dir

[Alberich de megres <alberich2k5@gmail.com>]

thanks Dave :)

I didn't know about rkfs..

is there some other place that gives a deep loop to vfs?
and what about journaling?

:)


On Mon, Feb 9, 2009 at 11:05 PM, Dave Kleikamp
<shaggy@linux.vnet.ibm.com> wrote:
> On Mon, 2009-02-09 at 14:54 +0100, Alberich de megres wrote:
>> Hello,
>>
>> I'm making my firsts steps with vfs and filesystem playground.
>>
>> I created a very simple fs, for wich i have a rude mkfs and its
>> fill_super function on kernel side. fill_super finish ok, and loadas
>> the super block for my filesystem, but when i make mount -t testfs
>> /dev/sdb1 /mnt/tfs i got the following message: "mount: not a
>> directory"
>
> fill_super() needs to at least allocate an inode and dentry for the root
> inode and assign sb->s_root to point to the root dentry.
>
>> And here comes my question: what vfs is supposed to do since it loads
>> sb and tries to list dir content? and what functions vfs needs at
>> least to mount my fs? ( just load it, and display an empty dir with
>> ls, not creating files etc... )
>>
>
> The root inode needs to have file operations (i_fop) that include a
> readdir() method and probably one for llseek()  (generic_file_llseek
> should be sufficient).
>
> If you haven't already found it, you probably want to take a look at
> http://www.geocities.com/ravikiran_uvs/articles/rkfs.html
>
> Shaggy
> --
> David Kleikamp
> IBM Linux Technology Center
>
>