add @uptodate argument to end_that_request_last() and @error
to rq_end_io_fn().  there's no generic way to pass error code
to request completion function, making generic error handling
of non-fs request difficult (rq->errors is driver-specific and
each driver uses it differently).  this patch adds @uptodate
to end_that_request_last() and @error to rq_end_io_fn().

for fs requests, this doesn't really matter, so just using the
same uptodate argument used in the last call to
end_that_request_first() should suffice.  imho, this can also
help the generic command-carrying request jens is working on.
Signed-off-by: Ntejun heo <htejun@gmail.com>
Signed-Off-By: NJens Axboe <axboe@suse.de>

Removed an unused variable
Signed-off-by: NDaniel Marjamaki <daniel.marjamaki@comhem.se>
Signed-off-by: NPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Rename misleading UB_MINORS_PER_MAJOR into UB_PARTS_PER_LUN.
Signed-off-by: NPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Implement command retries and resets in ub. It is advantageous for users
to know if their devices are getting bad. However, failing every I/O
is not practical if you have a external USB enclosure with a hard drive.
Signed-off-by: NPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

It is no longer needed, so let's remove it, saving a bit of memory.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds a shim driver libusual, which routes devices between
usb-storage and ub according to the common table, based on unusual_devs.h.
The help and example syntax is in Kconfig.
Signed-off-by: NPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

readpage(), prepare_write(), and commit_write() callers are updated to
understand the special return code AOP_TRUNCATED_PAGE in the style of
writepage() and WRITEPAGE_ACTIVATE.  AOP_TRUNCATED_PAGE tells the caller that
the callee has unlocked the page and that the operation should be tried again
with a new page.  OCFS2 uses this to detect and work around a lock inversion in
its aop methods.  There should be no change in behaviour for methods that don't
return AOP_TRUNCATED_PAGE.

WRITEPAGE_ACTIVATE is also prepended with AOP_ for consistency and they are
made enums so that kerneldoc can be used to document their semantics.
Signed-off-by: NZach Brown <zach.brown@oracle.com>

This patch adds setting our drv->queue = NULL back in deregister_disk.  The
drv->queue is part of our controller struct.  blk_cleanup_queue works only
on the queue in the gendisk struct.
Signed-off-by: NMike Miller <mike.miller@hp.com>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This undoes the put_disk patch I sent in before.

If I had been paying attention I would have seen that we call put_disk
from free_hba during driver unload.  That's the only time we want to
call it.  If it's called from deregister disk we may remove the
controller (cNd0) unintentionally.
Signed-off-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This fix causes problems on the very first floppy access - we haven't yet
talked to the FDC so we don't know which state the write-protect tab is in.

Revert for now.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Jeff Garzik pointed me to his code to see how to remove a disk from
the system _properly_. Well, here it is...
Every place we remove disks we are now testing before calling del_gendisk
or blk_cleanup_queue and then call put_disk.
Signed-off-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NJens Axboe <axboe@suse.de>

Applications using CCISS_BIG_PASSTHRU complained that the data written
was zeros. The problem is that the buffer is being cleared after the
user copy, unless the user copy has failed... Correct that logic.
Signed-off-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NJens Axboe <axboe@suse.de>

drivers/block/cciss_scsi.c:264: warning: `print_bytes' defined but not used
drivers/block/cciss_scsi.c:298: warning: `print_cmd' defined but not used
Signed-off-by: NGrant Coady <gcoady@gmail.com>
Acked-by: NMike Miller <mike.miller@hp.com>
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>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

A few more callers of permission() just want to check for a different access
pattern on an already open file.  This patch adds a wrapper for permission()
that takes a file in preparation of per-mount read-only support and to clean
up the callers a little.  The helper is not intended for new code, everything
without the interface set in stone should use vfs_permission()
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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>

This patch removes almost all inclusions of linux/version.h.  The 3
#defines are unused in most of the touched files.

A few drivers use the simple KERNEL_VERSION(a,b,c) macro, which is
unfortunatly in linux/version.h.

There are also lots of #ifdef for long obsolete kernels, this was not
touched.  In a few places, the linux/version.h include was move to where
the LINUX_VERSION_CODE was used.

quilt vi `find * -type f -name "*.[ch]"|xargs grep -El '(UTS_RELEASE|LINUX_VERSION_CODE|KERNEL_VERSION|linux/version.h)'|grep -Ev '(/(boot|coda|drm)/|~$)'`

search pattern:
/UTS_RELEASE\|LINUX_VERSION_CODE\|KERNEL_VERSION\|linux\/\(utsname\|version\).h
Signed-off-by: NOlaf Hering <olh@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Evgeny Stambulchik found that doing the following always worked:

# mount /dev/fd0 /mnt/floppy/
mount: block device /dev/fd0 is write-protected, mounting read-only
# mount -o remount,rw /mnt/floppy
# echo $?
0

This is the case because the block device /dev/fd0 is writeable but the
floppy disk is marked protected.  A fix is to simply have floppy_open mark
the underlying gendisk policy according to reality (since the VFS doesn't
provide a way for do_remount_sb to inquire as to the current device
status).
Signed-off-by: NJon Masters <jcm@jonmasters.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJames Nelson <james4765@gmail.com>
Signed-off-by: NDomen Puncer <domen@coderock.org>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NPaul Mackerras <paulus@samba.org>

This is the remaining misc drivers/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in misc files in
drivers/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NAristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
Acked-by: NRoland Dreier <rolandd@cisco.com>
Acked-by: NPierre Ossman <drzeus@drzeus.cx>
Acked-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NLen Brown <len.brown@intel.com>
Acked-by: N"Antonino A. Daplas" <adaplas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Convert to proper kernel-doc format.

Some have extra blank lines (not allowed immed.  after the function name)
or need blank lines (after all parameters).  Function summary must be only
one line.

Colon (":") in a function description does weird things (causes kernel-doc
to think that it's a new section head sadly).
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce the notion of cooperating processes (those that submit requests
close to one another), and use these statistics to make better choices about
whether or not to do anticipatory waiting.

Help and analysis from Seetharami Seelam <seelam@cs.utep.edu>

Performance testing from Seelam:

I set up my system and executed a couple of tests that I used for OLS.  I
tested with AS, cooperative process patch merged in -mm tree (which I called
Nick, below) and the cooperative patch with modifications to as_update_iohist
(which I called Seelam).

I used a dual-processor (2.28GHz Pentium 4 Xeon) system, with 1 GB main memory
and 1 MB L2 cache, running Linux 2.6.9.  Only a single processor is used for
the experiments.  I used 7.2K RPM Maxtor 10GB drive configured with ext2 file
system.

Experiment 1 (ex1) consists of reading  one Linux source trees using

  find . -type f -exec cat '{}' ';' > /dev/null.

Experiment 2 (ex2) consists of reading two disjoint Linux source trees
using

  find . -type f -exec cat '{}' ';' > /dev/null.

Experiment 3 (ex3) consists of streaming read of a 2GB file in the background
and 1 instance of the chunk reads in Experiment 1.

Timings for reading the Linux source are shown below:

             AS                     Nick          Seelam
ex1:      0m25.813s               0m27.859s      0m27.640s
ex2:      1m11.468s               1m13.918s      1m5.869s
ex3:      81m44.352s             10m38.572s      6m47.994s

The difference between the numbers in Experiment 3 must be due to the code in
as_update_iohist.  (akpm: that's not part of this patch.  So this patch is
"Nick").
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds SCSI error handling code to the SCSI portion
of the cciss driver.
Signed-off-by: NStephen M. Cameron <steve.cameron@hp.com>
Acked-by: NMike Miller <mike.miller@hp.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

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>

cfq's add_req_fn callback may invoke q->request_fn directly and
depending on low-level driver used and timing, a queued request may be
finished & deallocated before add_req_fn callback returns.  So,
__elv_add_request must not access rq after it's passed to add_req_fn
callback.

This patch moves rq_mergeable test above add_req_fn().  This may
result in q->last_merge pointing to REQ_NOMERGE request if add_req_fn
callback sets it but as RQ_NOMERGE is checked again when blk layer
actually tries to merge requests, this does not cause any problem.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NKelly Daly <kelly@au.ibm.com>

Signed-off-by: NKelly Daly <kelly@au.ibm.com>

Signed-off-by: NKelly Daly <kelly@au.ibm.com>

Signed-off-by: NKelly Daly <kelly@au.ibm.com>

Signed-off-by: NJens Axboe <axboe@suse.de>

Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).
Signed-off-by: NJens Axboe <axboe@suse.de>

Right now we do it at queueing time, which works alright for reads
(since they are usually sync), but not for async writes since we can
queue io a lot faster than we can complete it. This makes the vmstat
output look extremely bursty.
Signed-off-by: NJens Axboe <axboe@suse.de>

Tejun Heo notes:

   "I'm currently debugging this.  The problem is that we are using the
    generic dispatch queue directly in the noop sched and merging is NOT
    allowed on dispatch queues but generic handling of last_merge tries
    to merge requests.  I'm still trying to verify this, so I'll be back
    with results soon."

In the meantime, disable merging for noop by setting REQ_NOMERGE in
elevator_noop_add_request().

Eventually, we should add a noop_list and do the dispatching like in the
other io schedulers.  Merging is still beneficial for noop (and it has
always done it).
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Don't clear ->elevator_data on exit, if we are switching queues we are
overwriting the data of the new io scheduler.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.

In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch.  This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other.  So if any
hunk rejects or gets in the way of other patches, just drop it.  My scripts
will pick it up again in the next round.
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If the requested I/O scheduler is already in place, elevator_switch simply
leaves the queue alone, and returns.  However, it forgets to call
elevator_put, so

'echo [current_sched] > /sys/block/[dev]/queue/scheduler'

will leak a reference, causing the current_sched module to be permanently
pinned in memory.
Signed-off-by: NNate Diller <nate@namesys.com>
Acked-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a kconfig submenu to select the default I/O scheduler, in case
anticipatory is not compiled in or another default is preferred.  Also,
since no-op is always available, we should use it whenever the selected
default is not.
Signed-off-by: NNate Diller <nate@namesys.com>
Acked-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The last patch from Jens Axboe for drivers/block/paride/pf.c introduced
pf_end_request() which sets pf_req to NULL.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>