Fix http://bugzilla.kernel.org/show_bug.cgi?id=7667

This is because the packet driver tries to send down read/write BLOCK_PC
commands that don't use a bio and do not use sg lists.

The right fix is to replace all the packet_command stuff in the packet
driver by scsi_execute() which needs to be lifted from scsi code to
the block code for that.

Fix the bug for now.  It's not the full way to a generic execute block pc
infrastcuture but fixes the bug for the time being.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a sysfs and debugfs interface to the pktcdvd driver.

Look into the Documentation/ABI/testing/* files in the patch for more info.
Signed-off-by: NThomas Maier <balagi@justmail.de>
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds a bio write queue congestion control to the pktcdvd driver with
fixed on/off marks.  It prevents that the driver consumes a unlimited
amount of write requests.

[akpm@osdl.org: sync with congestion_wait() renaming]
Signed-off-by: NThomas Maier <balagi@justmail.de>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch makes some of the procfs functions reusable (for
coming sysfs patch e.g.):
pkt_setup_dev()
pkt_remove_dev()
...
Signed-off-by: NThomas Maier <balagi@justmail.de>
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: NNigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

pktcdvd: Rename a variable for better readability.
Signed-off-by: NThomas Maier <balagi@justmail.de>
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

pktcdvd: Replace pktcdvd strings with macro DRIVER_NAME.
Signed-off-by: NThomas Maier <balagi@justmail.de>
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACK
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: NJens Axboe <axboe@suse.de>

The pkt_*_dev functions operate on not-this-blockdevice, and that is
sufficiently checked at setup time.  As a result there is a natural
hierarchy, which needs nesting annotations
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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

Also fixes all drivers that set this field.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch changes several mempool users, all of which are basically just
wrappers around kmalloc(), to use the common mempool_kmalloc/kfree, rather
than their own wrapper function, removing a bunch of duplicated code.
Signed-off-by: NMatthew Dobson <colpatch@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Convert to use mutex from a semaphore
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When attempting to open the device for writing, only return -EROFS if the disc
appears to be readable but not writable.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the pkt_writable_track() function to make it work correctly for all types
of CD/DVD discs.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Writing the detected disc type in the kernel log is not useful during normal
use of the driver, so remove the printk statements.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Boolean functions should return non-zero when they mean "true", otherwise the
calling code looks weird.  (As suggested by Linus.)
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It looks like the code in pkt_generic_packet() worked by luck in the past, but
after commit 186d330e leaving rq->cmd_len
uninitialized doesn't work any more.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reduce stack usage in the pkt_start_write() function.  Even though it's not
currently a real problem, the pages and offsets arrays can be eliminated,
which saves approximately 1000 bytes of stack space.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Unlocking the door when the disc is in use is obviously not good, because then
it's possible to eject the disc at the wrong time and cause severe disc data
corruption.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If opening for write fails, the open method should return -EROFS.  This makes
"mount" try again with a read-only mount, instead of just giving up.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Change some messages that don't indicate an error so that they are only
printed when debugging is enabled.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Allocate memory for read-gathering at open time, when it is known just how
much memory is needed.  This avoids wasting kernel memory when the real packet
size is smaller than the maximum packet size supported by the driver.  This is
always the case when using DVD discs.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The version information is not useful for a driver that is maintained in
Linus' kernel tree.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The pktcdvd driver was using an 8 bit field to store the packet length
obtained from the disc track info.  This causes it to overflow packet length
values of 128KB or more.  I changed the field to 32 bits to fix this.

The pktcdvd driver defaulted to its maximum allowed packet length when it
detected a 0 in the track info field.  I changed this to fail the operation
and refuse to access the media.  This seems more sane than attempting to
access it with a value that almost certainly will not work.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Un-inline two functions in the pktcdvd driver.  This makes the compiled code
172 bytes smaller on my system.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use bd_claim() when opening the cdrom device to prevent user space programs
such as cdrecord, hald and kded from interfering with the burning process.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is an old bug in the pkt_count_states() function that causes stack
corruption.  When compiling with gcc 3.x or 2.x it is harmless, but gcc 4
allocates local variables differently, which makes the bug visible.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Found this on Coverty's linux bug database (http://linuxbugsdb.coverity.com).

The function pkt_iosched_process_queue makes a call to bdev_get_queue and
stores the result but never uses it, so it looks like it can be safely
removed.
Signed-off-by: NGabriel A. Devenyi <ace@staticwave.ca>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 - added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove some redundant BUG_ON() statements in pktcdvd and move one run-time
check to compile-time.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use kcalloc and kzalloc in pktcdvd.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the /proc statistics, only count writes that upper layers have requested.
Don't count additional writes created inside the packet driver to satisfy the
requirement to only write full packets.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update the "theory of operation" description.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the packet writing driver, if the drive reports a packet size larger than
the driver can handle, bail out safely instead of triggering a BUG_ON.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

1. Establish a simple API for process freezing defined in linux/include/sched.h:

   frozen(process)		Check for frozen process
   freezing(process)		Check if a process is being frozen
   freeze(process)		Tell a process to freeze (go to refrigerator)
   thaw_process(process)	Restart process
   frozen_process(process)	Process is frozen now

2. Remove all references to PF_FREEZE and PF_FROZEN from all
   kernel sources except sched.h

3. Fix numerous locations where try_to_freeze is manually done by a driver

4. Remove the argument that is no longer necessary from two function calls.

5. Some whitespace cleanup

6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
   cleared before setting PF_FROZEN, recalc_sigpending does not check
   PF_FROZEN).

This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!
Signed-off-by: NChristoph Lameter <christoph@lameter.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch improves write performance for the CD/DVD packet writing driver.
 The logic for switching between reading and writing has been changed so
that streaming writes are no longer interrupted by read requests.
Signed-off-by: NPeter Osterlund <petero2@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>