Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Use pci_resource_start for getting start of regions and pci_iomap to not
doing this directly by using dev->resource... (Thanks to Rolf Eike Beer)

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Use kzalloc instad of kmalloc+memset(0).

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Spaces were used for indent, there was more than 80 columns per line. Get
rid of that stuff.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

The flash_info structure has a bunch of missing fields which causes problems
when actually tryin to use some ST parts as it gets detected incorrectly.

Signed-off-by: Aubrey L1 <aubreylee@gmail.com>
Signed-off-by: Josh Boyer <jwboyer@gmail.com>

Trying to pass kernel command line arguments to block2mtd at boot-time does
not work currently. block2mtd_setup() is called so early that kmalloc()
fails nevermind being able to do open_bdev_excl() (which requires rootfs to
be mounted. This patch only saves the option string at the early boot stage,
and parses them later when block2mtd_init() is called. If open_bdev_excl()
fails, open_by_devnum(name_to_dev_t()) is tried instead, which makes it
possible to initialize the driver before rootfs has been mounted. Also gets
rid of the superfluous parse_name() that only checks if name is longer than
80 chars and copies it to a string that is not kfreed.

With this patch, I can boot statically compiled block2mtd, and mount jffs2
as rootfs (without modules or initrd), with lilo config like this:

   root=/dev/mtdblock0
   append="rootfstype=jffs2 block2mtd.block2mtd=/dev/hdc2,65536"

(Note that rootfstype=jffs2 is required, since the kernel only tries
filesystems without "nodev" attribute by default, and jffs is "nodev").

Compared to first version of this patch, this one does not copy the
parameters to the global buffer if init has already been called, and the
global array is marked as __initdata.

Compared to the second version of this patch, module build is fixed.

Compared to the third version of this patch, statically compiled block2mtd
driver with no boot-time parameter no longer gives spurious error 'cannot
open device ""'

Signed-off-by: Ville Herva <vherva@vianova.fi>
Acked-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

PMC551 depends on PCI in Kconfig so there is no need to #error in code if PCI
is not set.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

* git://git.infradead.org/mtd-2.6:
  [JFFS2][XATTR] Fix memory leak in POSIX-ACL support
  fs/jffs2/: make 2 functions static
  [MTD] NAND: Fix broken sharpsl driver
  [JFFS2][XATTR] Fix xd->refcnt race condition
  MTD: kernel-doc fixes + additions
  MTD: fix all kernel-doc warnings
  [MTD] DOC: Fixup read functions and do a little cleanup

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>