no longer working for some time.

A driver that had been marked as BROKEN for such a long time seems to be
unlikely to be revived in the forseeable future.

But if anyone wants to ever revive this driver, the code is still present in
the older kernel releases.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NAlan Cox <alan@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

This is a rewrite of the ramdisk block device driver.

The old one is really difficult because it effectively implements a block
device which serves data out of its own buffer cache.  It relies on the dirty
bit being set, to pin its backing store in cache, however there are non
trivial paths which can clear the dirty bit (eg.  try_to_free_buffers()),
which had recently lead to data corruption.  And in general it is completely
wrong for a block device driver to do this.

The new one is more like a regular block device driver.  It has no idea about
vm/vfs stuff.  It's backing store is similar to the buffer cache (a simple
radix-tree of pages), but it doesn't know anything about page cache (the pages
in the radix tree are not pagecache pages).

There is one slight downside -- direct block device access and filesystem
metadata access goes through an extra copy and gets stored in RAM twice.
However, this downside is only slight, because the real buffercache of the
device is now reclaimable (because we're not playing crazy games with it), so
under memory intensive situations, footprint should effectively be the same --
maybe even a slight advantage to the new driver because it can also reclaim
buffer heads.

The fact that it now goes through all the regular vm/fs paths makes it
much more useful for testing, too.

   text    data     bss     dec     hex filename
   2837     849     384    4070     fe6 drivers/block/rd.o
   3528     371      12    3911     f47 drivers/block/brd.o

Text is larger, but data and bss are smaller, making total size smaller.

A few other nice things about it:
- Similar structure and layout to the new loop device handlinag.
- Dynamic ramdisk creation.
- Runtime flexible buffer head size (because it is no longer part of the
  ramdisk code).
- Boot / load time flexible ramdisk size, which could easily be extended
  to a per-ramdisk runtime changeable size (eg. with an ioctl).
- Can use highmem for the backing store.

[akpm@linux-foundation.org: fix build]
[byron.bbradley@gmail.com: make rd_size non-static]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NByron Bradley <byron.bbradley@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This gets rid of the lguest bus, drivers and DMA mechanism, to make
way for a generic virtio mechanism.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The block driver uses scatter-gather lists with sg[0] being the
request information (struct virtio_blk_outhdr) with the type, sector
and inbuf id.  The next N sg entries are the bio itself, then the last
sg is the status byte.  Whether the N entries are in or out depends on
whether it's a read or a write.

We accept the normal (SCSI) ioctls: they get handed through to the other
side which can then handle it or reply that it's unsupported.  It's
not clear that this actually works in general, since I don't know
if blk_pc_request() requests have an accurate rq_data_dir().

Although we try to reply -ENOTTY on unsupported commands, ioctl(fd,
CDROMEJECT) returns success to userspace.  This needs a separate
patch.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <jens.axboe@oracle.com>

Gabriel C reports lguest doesn't compile with CONFIG_BLOCK=n.  Fix this
by introducing a config var for the block device, which depends on
LGUEST && BLOCK.  Do the same for the net driver, rather then depending
gratuitously on CONFIG_NET.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a Disk Storage Driver for the PS3:
  - Implemented as a block device driver with a dynamic major
  - Disk names (and partitions) are of the format ps3d%c(%u)
  - Uses software scatter-gather with a 64 KiB bounce buffer as the hypervisor
    doesn't support scatter-gather

Cc: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: NJens Axboe <jens.axboe@oracle.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Lguest block driver

A simple block driver for lguest.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The block device frontend driver allows the kernel to access block
devices exported exported by a virtual machine containing a physical
block device driver.
Signed-off-by: NIan Pratt <ian.pratt@xensource.com>
Signed-off-by: NChristian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Greg KH <greg@kroah.com>
Cc: Jens Axboe <axboe@kernel.dk>

Tested on Xilinx Virtex ppc405, Katmai 440SPe, and Microblaze
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NStefan Roese <sr@denx.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: John William <jwilliams@itee.uq.edu.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch removes some code that became dead code after the ATARI_ACSI
removal.

It also indirectly fixes the following bug introduced by
commit c2bcf3b8:

 config ATARI_SLM
        tristate "Atari SLM laser printer support"
-       depends on ATARI && ATARI_ACSI!=n
+       depends on ATARI
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Originally from Boaz Harrosh <bharrosh@panasas.com>

It hasn't been working in 2.5 or 2.6 ever, since it's still buffer_head
based.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

The BLK_DEV_SWIM_IOP driver has:
- already been marked as BROKEN in 2.6.0 three years ago and
- is still marked as BROKEN.

Drivers that had been marked as BROKEN for such a long time seem to be
unlikely to be revived in the forseeable future.

But if anyone wants to ever revive this driver, the code is still
present in the older kernel releases.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

floppy98 went out together with the rest of PC98 subarch.  Remove stale
Makefile entry that remained.
Signed-off-by: NArthur Othieno <apgo@patchbomb.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/block/ is right now a mix of core and driver parts. Lets move
the core parts to a new top level directory. Al will move the fs/
related block parts to block/ next.
Signed-off-by: NJens Axboe <axboe@suse.de>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!