Every user of the BKL in the sd driver is the
result of the pushdown from the block layer
into the open/close/ioctl functions.

The only place that used to rely on the BKL is
the sdkp->openers variable, which gets converted
into an atomic_t.

Nothing else seems to rely on the BKL, since the
functions do not touch global data without holding
another lock, and the open/close functions are
still protected from concurrent execution using
the bdev->bd_mutex.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

We leak a page allocated for discard on some error conditions
(e.g. scsi_prep_state_check returns BLKPREP_DEFER in
scsi_setup_blk_pc_cmnd).

We unprep on requests that weren't prepped in the error path of
scsi_init_io. It makes the error path to clean up scsi commands messy.

Let's strictly apply the rule that we can't unprep on a request that
wasn't prepped.

Calling just scsi_put_command() in the error path of scsi_init_io() is
enough. We don't set REQ_DONTPREP yet.

scsi_setup_discard_cmnd can safely free a page on the error case with
the above rule.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This is for block's for-2.6.36.

We need to reset q->unprep_rq_fn in sd_remove. Otherwise we hit kernel
oops if we access to a scsi disk device via sg after removing scsi
disk module.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This removes q->prepare_flush_fn completely (changes the
blk_queue_ordered API).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

scsi-ml builds flush requests via q->prepare_flush_fn(), however,
builds discard requests via q->prep_rq_fn.

Using two different mechnisms for the similar requests (building
commands in SCSI ULD) doesn't make sense.

Handing both via q->prep_rq_fn makes the code design simpler.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

- sd_done isn't called for pc request so we never call the code.
- we use sd_unprep to free discard page now.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

This fixes discard page leak by using q->unprep_rq_fn facility.

q->unprep_rq_fn is called when all the data buffer (req->bio and
scsi_data_buffer) in the request is freed.

sd_unprep() uses rq->buffer to free discard page allocated in
sd_prepare_discard().
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Reviewed-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Allocating a fixed payload for discard requests always was a horrible hack,
and it's not coming to byte us when adding support for discard in DM/MD.

So change the code to leave the allocation of a payload to the lowlevel
driver.  Unfortunately that means we'll need another hack, which allows
us to update the various block layer length fields indicating that we
have a payload.  Instead of hiding this in sd.c, which we already partially
do for UNMAP support add a documented helper in the core block layer for it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

We can safely remove ISA_DMA_THRESHOLD usage in aha1542. aha1542 uses
ISA_DMA_THRESHOLD to see if:

- the buffers in scatter/list are below 16MB.
- scsi_host is below 16MB.

Both checkings were added in the ancient times but aren't necessary
nowadays since we properly bounce the buffers and allocate scsi_host
below 16MB with non-zero unchecked_isa_dma.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>

A driver needs to be ready to take an interrupt as soon as it registers
an interrupt handler. I noticed the following oops when testing kdump:

ipr: IBM Power RAID SCSI Device Driver version: 2.5.0 (February 11, 2010)
ibmvscsi 30000002: SRP_VERSION: 16.a
ibmvscsi 30000002: SRP_VERSION: 16.a
Unable to handle kernel paging request for data at address 0x00000000
...
pc: c000000004085e34: .tasklet_action+0xf4/0x1dc
...
c000000004086fe4 .__do_softirq+0x16c/0x2c0
c00000000403138c .call_do_softirq+0x14/0x24
c00000000400ee14 .do_softirq+0xa0/0x104
c00000000408690c .irq_exit+0x70/0xd0
c00000000400f190 .do_IRQ+0x214/0x2a8
c000000004004804 hardware_interrupt_entry+0x1c/0x98
--- Exception: 501 (Hardware Interrupt) at c00000000400c544 .raw_local_irq_restore+0x48/0x54
c00000000465d2a8 ._raw_spin_unlock_irqrestore+0x74/0xa0
c0000000040e7f00 .__setup_irq+0x2ec/0x3f0
c0000000040e8198 .request_threaded_irq+0x194/0x22c
c00000000446d854 .rpavscsi_init_crq_queue+0x284/0x3f0
c00000000446c764 .ibmvscsi_probe+0x688/0x710
c00000000402903c .vio_bus_probe+0x37c/0x3e4
c000000004403f10 .driver_probe_device+0xec/0x1b8
c000000004404088 .__driver_attach+0xac/0xf4
c000000004403184 .bus_for_each_dev+0x98/0x104
c000000004403c98 .driver_attach+0x40/0x60
c0000000044026f0 .bus_add_driver+0x154/0x324
c0000000044045d0 .driver_register+0xe8/0x1ac
c00000000402b2a8 .vio_register_driver+0x54/0x74
c000000004933ea4 .ibmvscsi_module_init+0x80/0xc0
c000000004009834 .do_one_initcall+0x98/0x1d8
c0000000049005b4 .kernel_init+0x27c/0x33c
c000000004031550 .kernel_thread+0x54/0x70

srp_task needs to be setup before request_irq. The patch below fixes the oops.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Acked-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

It was possible to overflow the buffer used to print out the formatted
version of the resource path.  The fix is to limit the number of
bytes that get formatted.

This patch also updates the ipr_show_resource_path function to display the
resource address for devices that are attached to adapters that don't
support resource paths.
Signed-off-by: NWayne Boyer <wayneb@linux.vnet.ibm.com>
Acked-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Implement sd_unlock_native_capacity() method which calls into
hostt->unlock_native_capacity() if implemented.  This will be invoked
by block layer if partitions extend beyond the end of the device and
can be used to implement, for example, on-demand ATA host protected
area unlocking.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Grant patches added an of mach table to struct device_driver. However,
while he changed the macio device code to use that, he left the match
table pointer in struct macio_driver and didn't update drivers to use
the "new" one, thus breaking the probing.

This completes the change by moving all drivers to setup the "new"
one, removing all traces of the old one, and while at it (since it
changes the exact same locations), I also remove two other duplicates
from struct driver which are the name and owner fields.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

st_open() suggests that llseek() doesn't work: "We really want to do
nonseekable_open(inode, filp); here, but some versions of tar incorrectly
call lseek on tapes and bail out if that fails.  So we disallow pread()
and pwrite(), but permit lseeks."

Instead of using the fallback default_llseek() the driver should use
noop_llseek() which leaves the file->f_pos untouched but succeeds.
Signed-off-by: NJan Blunck <jblunck@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kai Makisara <Kai.Makisara@kolumbus.fi>
Cc: Willem Riede <osst@riede.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__os_scsi_tape_open() suggests that llseek() doesn't work: "We really want
to do nonseekable_open(inode, filp); here, but some versions of tar
incorrectly call lseek on tapes and bail out if that fails.  So we
disallow pread() and pwrite(), but permit lseeks."

Instead of using the fallback default_llseek() the driver should use
noop_llseek() which leaves the file->f_pos untouched but succeeds.
Signed-off-by: NJan Blunck <jblunck@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Willem Riede <osst@riede.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

osst_read()/osst_write() modify file->f_pos directly instead of the ppos
given to them.  The VFS later updates the file->f_pos and overwrites it
with the value of ppos.
Signed-off-by: NJan Blunck <jblunck@suse.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Willem Riede <osst@riede.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Kill the obsolete HOSTS_C define and the related double inclusion of mvme147.h
Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

This patch (as1357) fixes a race in SCSI target allocation and
release.  Putting a target in the STARGET_DEL state isn't protected by
the host lock, so an old target structure could be reused by a new
device even though it's about to be deleted.  The cure is to change
the state while still holding the host lock.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The debugging code using the freed structure is moved before the kfree.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@free@
expression E;
position p;
@@
kfree@p(E)

@@
expression free.E, subE<=free.E, E1;
position free.p;
@@

  kfree@p(E)
  ...
(
  subE = E1
|
* E
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

1. To support instantaneous report for SCSI device existing by periodic
   polling
2. In arcmsr_iop_xfer(), inform AP of F/W's deadlock state to prevent
   endless waiting
3. To block the coming SCSI command while the driver is handling bus reset
4. To support HW reset in bus reset error handler
Signed-off-by: NNick Cheng <nick.cheng@areca.com.tw>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>