Re: Request for new block_device_operations function pointer

[Matt D. Robinson]

On Tue, 18 Sep 2001, Alexander Viro wrote:
|>On Tue, 18 Sep 2001, Matt D. Robinson wrote:
|>
|>> This would allow projects such as LKCD to use a specific dump
|>> device associated to a block device driver.  This dump driver
|>> writes data out directly to disk at a specific offset.  The
|>
|>... while submit_bh()... writes data out directly to disk at a specific
|>offset.  Amazing, isn't it?
|>
|>Notice that you _will_ need to deal with IO in driver's queue, no matter
|>how you implement the thing.  submit_bh() already does it.

... and deals with interrupt state, and any special device
requirements?  Actually, we don't want to deal with any
outstanding I/O.  You don't want to flush any outstanding
requests if you're crashing (which is what LKCD is for).
Sure, submit_bh() when things are running fine.  But not when
you're crashing.  And also, this is intended at some point in
the future to work to raw devices as well.

I don't want to deal with b_end_io(), blk_get_queue(),
generic_make_request() or any of that stuff.  This is
supposed to be raw data to the disk.

Again, the point here is to create a device operation that
allows the driver to enter a dumping state and write out
data raw to the device.  It's not intended for the normal
block operations path.

Thanks,

--Matt