From mboxrd@z Thu Jan  1 00:00:00 1970
From: rohan.puri15@gmail.com (rohan puri)
Date: Tue, 8 Nov 2011 17:29:59 +0530
Subject: Getting a block from a block device?
In-Reply-To: <CAAfuxnKP5aZ5vnro_zEGMW76JS3-QRCZmjseda7wgpX0ymQxmw@mail.gmail.com>
References: <CAAfuxnKBfMNusYQ4VDX=GNc5KcjgmE8Wk9Jk-NtiiaXycHhA3g@mail.gmail.com>
	<CACzurzsCpKN_9Ew+g-HLvH=GuPQU=Tzf8yrimf-zDOjPtFsF2w@mail.gmail.com>
	<CAAfuxnKP5aZ5vnro_zEGMW76JS3-QRCZmjseda7wgpX0ymQxmw@mail.gmail.com>
Message-ID: <CALJfu6MXDpv18sJs6TrvC5TTY8wRfrgHPsPOJQw_FjanuvvdEQ@mail.gmail.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

On Tue, Nov 8, 2011 at 5:26 PM, Dan Luedtke <maildanrl@googlemail.com>wrote:

> Hallo,
>
> On Tue, Nov 8, 2011 at 12:27 PM, Stephen Gream <poisonthemon@gmail.com>
> wrote:
> > Once you have the device registered (on /sys or /dev), register a read
> > callback on the file and use copy_to_user to output the data
>
> I read that article you referred to, but I don't think it addresses my
> problem, as I may have been more clear on what I want to achieve
> before. Sorry for that!
> I want to eventually implement a file system, and therefore I am
> studying the kernel sources to get an idea about all that.
>
> Here is my general understanding on how thinks may work :)
>
> virtual file system (VFS) <-[1]-> my file system implementation
> <-[2]-> a block device
>
> As I understood, all these subsystems are running in kernel mode.
>
> For [1] I read vfs.txt and learned about the VFS-API
> For [2] I have no idea where I can find the API documentation, however
> there were some hints on the book "Linux Driver Development" from
> O'Reilly in chapter "block devices". Nothing really helpful, as they
> were talking about registering new block devices. I want to use
> already present devices where I expect my filesystem to be present on.
> To check that, I have to read the first 512 bytes.
>
> The userspace implementation I was talking about previously is
> something like a mkfs.myfilesystem, that's why i referred to fopen()
> there.
>
> Thank you!
>
> Greetings,
>
> Dan
> --
> Dan Luedtke
> http://www.danrl.de
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
Dan,

You need to look at other block-based file systems in the kernel sources in
fs dir for examples and understand how they do it.

Regards,
Rohan Puri
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20111108/935dbce9/attachment.html