lkml.org 
[lkml]   [2006]   [Jan]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Block device API
On Wed, Jan 25, 2006 at 08:17:02AM +0500, Fawad Lateef wrote:
> On 1/25/06, Joshua Hudson <joshudson@gmail.com> wrote:
> > I am working on a kernel filesystem driver. I have found plenty of
> > documentation on
> > how to communicate between the VFS and the filesystem driver, but nothing
> > on how to communicate between the block device and the filesystem driver.
> >
>
> AFAIK there isn't any documentation/article for block and filesystem
> layer interaction (or till now me also not able to find any) :)
>
> > I found sb_bread() but there is no corrisponding sb_bwrite().
> > I presume that if ((struct superblock *)s) -> bdev is the block
> > device handle, but I cannot find the read/write pair of functions.
> > -
>
> sb_bread is the function used for reading a block (especially
> superblock) from the storage. For reading/writing do look at

Does __bread() contribute to page cache? I think not. And we don't
care the work done by __bread().

> generic_file_read/write functions found in mm/filemap.c and when going
> through the code you will see its ends up in calling
> mappings->a_ops->readpage(s)/writepage(s) of filesystem in which
> normal filesystems (like ext2) just call function
> mpage_readpages/writepages found in fs/mpage.c which performs actual
> read/write on the block device.
--
Coywolf Qi Hunt
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-01-25 09:40    [W:0.036 / U:0.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site