Messages in this thread | | | Date | Wed, 25 Jan 2006 08:17:02 +0500 | From | Fawad Lateef <> | Subject | Re: Block device API |
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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 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.
I hope this helps !
-- Fawad Lateef - 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/
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