We need to cleanup resources on the probe() callback registered
with __register_blkdev(), now that add_disk() error handling is
supported. Address this.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211103230437.1639990-13-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit bf9c0538e4 ("ataflop: use a separate gendisk for each media
format") introduced ataflop_probe_lock mutex, but forgot to unlock the
mutex when atari_floppy_init() (i.e. module loading) succeeded. This will
result in double lock deadlock if ataflop_probe() is called. Also,
unregister_blkdev() must not be called from atari_floppy_init() with
ataflop_probe_lock held when atari_floppy_init() failed, for
ataflop_probe() waits for ataflop_probe_lock with major_names_lock held
(i.e. AB-BA deadlock).
__register_blkdev() needs to be called last in order to avoid calling
ataflop_probe() when atari_floppy_init() is about to fail, for memory for
completing already-started ataflop_probe() safely will be released as soon
as atari_floppy_init() released ataflop_probe_lock mutex.
As with commit 8b52d8be86 ("loop: reorder loop_exit"),
unregister_blkdev() needs to be called first in order to avoid calling
ataflop_alloc_disk() from ataflop_probe() after del_gendisk() from
atari_floppy_exit().
By relocating __register_blkdev() / unregister_blkdev() as explained above,
we can remove ataflop_probe_lock mutex, for probe function and __exit
function are serialized by major_names_lock mutex.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: bf9c0538e4 ("ataflop: use a separate gendisk for each media format")
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Link: https://lore.kernel.org/r/20211103230437.1639990-11-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As it turns out, my earlier patch in commit 86d46fdaa1 (block:
ataflop: fix breakage introduced at blk-mq refactoring) was
incomplete. This patch fixes any remaining issues found during
more testing and code review.
Requests exceeding 4 k are handled in 4k segments but
__blk_mq_end_request() is never called on these (still
sectors outstanding on the request). With redo_fd_request()
removed, there is no provision to kick off processing of the
next segment, causing requests exceeding 4k to hang. (By
setting /sys/block/fd0/queue/max_sectors_k <= 4 as workaround,
this behaviour can be avoided).
Instead of reintroducing redo_fd_request(), requeue the remainder
of the request by calling blk_mq_requeue_request() on incomplete
requests (i.e. when blk_update_request() still returns true), and
rely on the block layer to queue the residual as new request.
Both error handling and formatting needs to release the
ST-DMA lock, so call finish_fdc() on these (this was previously
handled by redo_fd_request()). finish_fdc() may be called
legitimately without the ST-DMA lock held - make sure we only
release the lock if we actually held it. In a similar way,
early exit due to errors in ataflop_queue_rq() must release
the lock.
After minor errors, fd_error sets up to recalibrate the drive
but never re-runs the current operation (another task handled by
redo_fd_request() before). Call do_fd_action() to get the next
steps (seek, retry read/write) underway.
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Fixes: 6ec3938cff (ataflop: convert to blk-mq)
CC: linux-block@vger.kernel.org
Link: https://lore.kernel.org/r/20211024002013.9332-1-schmitzmic@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Refactoring of the Atari floppy driver when converting to blk-mq
has broken the state machine in not-so-subtle ways:
finish_fdc() must be called when operations on the floppy device
have completed. This is crucial in order to relase the ST-DMA
lock, which protects against concurrent access to the ST-DMA
controller by other drivers (some DMA related, most just related
to device register access - broken beyond compare, I know).
When rewriting the driver's old do_request() function, the fact
that finish_fdc() was called only when all queued requests had
completed appears to have been overlooked. Instead, the new
request function calls finish_fdc() immediately after the last
request has been queued. finish_fdc() executes a dummy seek after
most requests, and this overwrites the state machine's interrupt
hander that was set up to wait for completion of the read/write
request just prior. To make matters worse, finish_fdc() is called
before device interrupts are re-enabled, making certain that the
read/write interupt is missed.
Shifting the finish_fdc() call into the read/write request
completion handler ensures the driver waits for the request to
actually complete. With a queue depth of 2, we won't see long
request sequences, so calling finish_fdc() unconditionally just
adds a little overhead for the dummy seeks, and keeps the code
simple.
While we're at it, kill ataflop_commit_rqs() which does nothing
but run finish_fdc() unconditionally, again likely wiping out an
in-flight request.
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Fixes: 6ec3938cff ("ataflop: convert to blk-mq")
CC: linux-block@vger.kernel.org
CC: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Link: https://lore.kernel.org/r/20211019061321.26425-1-schmitzmic@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-15-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Instead of using two separate code paths for cleaning up an atari disk,
use one. We take the more careful approach to check for *all* disk
types, as is done on exit. The init path didn't have that check as
the alternative disk types are only probed for later, they are not
initialized by default.
Yes, there is a shared tag for all disks.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-14-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The ataflop assumes del_gendisk() is safe to call, this is only
true because add_disk() does not return a failure, but that will
change soon. And so, before we get to adding error handling for
that case, let's make sure we keep track of which disks actually
get registered. Then we use this to only call del_gendisk for them.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20210927220302.1073499-13-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Drop various include not actually used in genhd.h itself, and
move the remaning includes closer together.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-30-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Smatch complains that the "type > NUM_DISK_MINORS" should be >=
instead of >. We also need to subtract one from "type" at the start.
Fixes: bf9c0538e4 ("ataflop: use a separate gendisk for each media format")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The function uses "type" as an array index:
q = unit[drive].disk[type]->queue;
Unfortunately the bounds check on "type" isn't done until later in the
function. Fix this by moving the bounds check to the start.
Fixes: bf9c0538e4 ("ataflop: use a separate gendisk for each media format")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The Atari floppy driver usually autodetects the media when used with the
ormal /dev/fd? devices, which also are the only nodes created by udev.
But it also supports various aliases that force a given media format.
That is currently supported using the blk_register_region framework
which finds the floppy gendisk even for a 'mismatched' dev_t. The
problem with this (besides the code complexity) is that it creates
multiple struct block_device instances for the whole device of a
single gendisk, which can lead to interesting issues in code not
aware of that fact.
To fix this just create a separate gendisk for each of the aliases
if they are accessed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Switch to use bdev_check_media_change instead of check_disk_change and
call floppy_revalidate manually. Given that floppy_revalidate only
deals with media change events, the extra call into ->revalidate_disk
from bdev_disk_changed is not required either, so stop wiring up the
method.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning (Building: m68k):
drivers/block/ataflop.c: In function ‘fd_locked_ioctl’:
drivers/block/ataflop.c:1728:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
set_capacity(floppy->disk, MAX_DISK_SIZE * 2);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/block/ataflop.c:1729:2: note: here
case FDFMTEND:
^~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 9fd097b149.
Instead of leaving disk->events completely empty, we now export the
supported events again, and tell the block layer not to forward events to
user space by not setting DISK_EVENT_FLAG_UEVENT. This allows the block
layer to distinguish between devices that for which events should be
handled in kernel only, and devices which don't support any meda change
events at all.
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Smatch complains that there is an off by one if the allocation fails in:
DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
In that situation, "i" would be point to one element beyond the end of
the unit[] array.
There is a second bug because the error handling calls
blk_mq_free_tag_set(&unit[i].tag_set); regardless of whether
"disk->queue" is NULL or non-NULL. So if blk_mq_init_sq_queue() fails,
then that means unit[i].tag_set->tags is NULL and it leads to an Oops.
It's easiest to call put_disk() before the goto to clean up the partial
iteration. Then the earlier unit[] elements are fully allocated so we
can remove the checks whether "disk->queue" is NULL and the code is
simpler.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This driver is already pretty broken, in that it has two wait_events()
(one in stdma_lock()) in request_fn. Get rid of the first one by
freezing/quiescing the queue on format, and the second one by replacing
it with stdma_try_lock(). The rest is straightforward. Compile-tested
only and probably incorrect.
Cc: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Converted to blk_mq_init_sq_queue()
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move queue allocation next to disk allocation to fix a couple of issues:
- If add_disk() hasn't been called, we should clear disk->queue before
calling put_disk().
- If we fail to allocate a request queue, we still need to put all of
the disks, not just the ones that we allocated queues for.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
atafd.h and atafdreg.h are only used from ataflop.c, so merge them in
there.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rename get_disk() to get_disk_and_module() to make sure what the
function does. It's not a great name but at least it is now clear that
put_disk() is not it's counterpart.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This changes all DEFINE_TIMER() callbacks to use a struct timer_list
pointer instead of unsigned long. Since the data argument has already been
removed, none of these callbacks are using their argument currently, so
this renames the argument to "unused".
Done using the following semantic patch:
@match_define_timer@
declarer name DEFINE_TIMER;
identifier _timer, _callback;
@@
DEFINE_TIMER(_timer, _callback);
@change_callback depends on match_define_timer@
identifier match_define_timer._callback;
type _origtype;
identifier _origarg;
@@
void
-_callback(_origtype _origarg)
+_callback(struct timer_list *unused)
{ ... }
Signed-off-by: Kees Cook <keescook@chromium.org>
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings. This patch
instead introduces a new blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning. Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.
For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.
blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block core updates from Jens Axboe:
"It's a big(ish) round this time, lots of development effort has gone
into blk-mq in the last 3 months. Generally we're heading to where
3.16 will be a feature complete and performant blk-mq. scsi-mq is
progressing nicely and will hopefully be in 3.17. A nvme port is in
progress, and the Micron pci-e flash driver, mtip32xx, is converted
and will be sent in with the driver pull request for 3.16.
This pull request contains:
- Lots of prep and support patches for scsi-mq have been integrated.
All from Christoph.
- API and code cleanups for blk-mq from Christoph.
- Lots of good corner case and error handling cleanup fixes for
blk-mq from Ming Lei.
- A flew of blk-mq updates from me:
* Provide strict mappings so that the driver can rely on the CPU
to queue mapping. This enables optimizations in the driver.
* Provided a bitmap tagging instead of percpu_ida, which never
really worked well for blk-mq. percpu_ida relies on the fact
that we have a lot more tags available than we really need, it
fails miserably for cases where we exhaust (or are close to
exhausting) the tag space.
* Provide sane support for shared tag maps, as utilized by scsi-mq
* Various fixes for IO timeouts.
* API cleanups, and lots of perf tweaks and optimizations.
- Remove 'buffer' from struct request. This is ancient code, from
when requests were always virtually mapped. Kill it, to reclaim
some space in struct request. From me.
- Remove 'magic' from blk_plug. Since we store these on the stack
and since we've never caught any actual bugs with this, lets just
get rid of it. From me.
- Only call part_in_flight() once for IO completion, as includes two
atomic reads. Hopefully we'll get a better implementation soon, as
the part IO stats are now one of the more expensive parts of doing
IO on blk-mq. From me.
- File migration of block code from {mm,fs}/ to block/. This
includes bio.c, bio-integrity.c, bounce.c, and ioprio.c. From me,
from a discussion on lkml.
That should describe the meat of the pull request. Also has various
little fixes and cleanups from Dave Jones, Shaohua Li, Duan Jiong,
Fengguang Wu, Fabian Frederick, Randy Dunlap, Robert Elliott, and Sam
Bradshaw"
* 'for-3.16/core' of git://git.kernel.dk/linux-block: (100 commits)
blk-mq: push IPI or local end_io decision to __blk_mq_complete_request()
blk-mq: remember to start timeout handler for direct queue
block: ensure that the timer is always added
blk-mq: blk_mq_unregister_hctx() can be static
blk-mq: make the sysfs mq/ layout reflect current mappings
blk-mq: blk_mq_tag_to_rq should handle flush request
block: remove dead code in scsi_ioctl:blk_verify_command
blk-mq: request initialization optimizations
block: add queue flag for disabling SG merging
block: remove 'magic' from struct blk_plug
blk-mq: remove alloc_hctx and free_hctx methods
blk-mq: add file comments and update copyright notices
blk-mq: remove blk_mq_alloc_request_pinned
blk-mq: do not use blk_mq_alloc_request_pinned in blk_mq_map_request
blk-mq: remove blk_mq_wait_for_tags
blk-mq: initialize request in __blk_mq_alloc_request
blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
blk-mq: add helper to insert requests from irq context
blk-mq: remove stale comment for blk_mq_complete_request()
blk-mq: allow non-softirq completions
...
With the kernel running from FastRAM instead of ST-RAM, none of ST-RAM is
mapped by mem_init, and DMA-addressable buffer must be mapped by ioremap.
Use platform specific virt/phys translation helpers for this case.
Signed-off-by: Michael Schmitz <schmitz@debian.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.
Convert old style drivers to just use bio_data().
For the discard payload use case, just reference the page
in the bio.
Signed-off-by: Jens Axboe <axboe@fb.com>
sleep_on() is inherently racy, and has been deprecated for a long time.
This fixes two instances in the atari floppy driver:
* fdc_wait/fdc_busy becomes an open-coded mutex. We cannot use the
regular mutex since it gets released in interrupt context. The
open-coded version using wait_event() and cmpxchg() is equivalent
to the existing code but does the checks atomically, and we can
now safely check the condition with irqs enabled.
* format_wait becomes a completion, which is the natural structure
here. The format ioctl waits for the background task to either
complete or abort.
This does not attempt to fix the preexisting bug of calling schedule
with local interrupts disabled.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michael Schmitz <schmitz@biophys.uni-duesseldorf.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In-kernel disk event polling doesn't matter for legacy/fringe drivers
and may lead to infinite event loop if ->check_events() implementation
generates events on level condition instead of edge.
Now that block layer supports suppressing exporting unlisted events,
simply leaving disk->events cleared allows these drivers to keep the
internal revalidation behavior intact while avoiding weird
interactions with userland event handler.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Convert the floppy drivers from ->media_changed() to ->check_events().
Both floppy and ataflop buffer media changed state bit and clear them
on revalidation and will behave correctly with kernel event polling.
I can't tell how amiflop clears its event and it's possible that it
may generate spurious events when polled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Geert, my crosstool don't produce warning below. I guess this has to do
something with compiler version.
- Geert noticed following warning during compilation.
drivers/block/amiflop.c:1344: warning: ‘rq’ may be used uninitialized in
this function
drivers/block/ataflop.c:1402: warning: ‘rq’ may be used uninitialized in
this function
- Initialize rq to NULL to fix the warning. If we can't find a suitable request
to dispatch, this function should return NULL instead of a possibly garbage
pointer.
- Cross compile tested only. Don't have hardware to test it.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits)
cciss: fix PCI IDs for new Smart Array controllers
drbd: add race-breaker to drbd_go_diskless
drbd: use dynamic_dev_dbg to optionally log uuid changes
dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set
drbd: cleanup: change "<= 0" to "== 0"
drbd: relax the grace period of the md_sync timer again
drbd: add some more explicit drbd_md_sync
drbd: drop wrong debug asserts, fix recently introduced race
drbd: cleanup useless leftover warn/error printk's
drbd: add explicit drbd_md_sync to drbd_resync_finished
drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED
drbd: fix for possible deadlock on IO error during resync
drbd: fix unlikely access after free and list corruption
drbd: fix for spurious fullsync (uuids rotated too fast)
drbd: allow for explicit resync-finished notifications
drbd: preparation commit, using full state in receive_state()
drbd: drbd_send_ack_dp must not rely on header information
drbd: Fix regression in recv_bm_rle_bits (compressed bitmap)
drbd: Fixed a stupid copy and paste error
drbd: Allow larger values for c-fill-target.
...
Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal
The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.
This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.
file=$1
name=$2
if grep -q lock_kernel ${file} ; then
if grep -q 'include.*linux.mutex.h' ${file} ; then
sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
else
sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
fi
sed -i ${file} \
-e "/^#include.*linux.mutex.h/,$ {
1,/^\(static\|int\|long\)/ {
/^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);
} }" \
-e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
-e '/[ ]*cycle_kernel_lock();/d'
else
sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \
-e '/cycle_kernel_lock()/d'
fi
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
o Use one request queue per gendisk instead of sharing the queue.
o Don't have hardware. No compile testing or run time testing done. Completely
untested.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens 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: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens 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: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
There is a nice gem in drivers/block/ataflop.c::do_fd_request()
void do_fd_request(struct request_queue * q)
{
unsigned long flags;
DPRINT(("do_fd_request for pid %d\n",current->pid));
while( fdc_busy ) sleep_on( &fdc_wait );
fdc_busy = 1;
stdma_lock(floppy_irq, NULL);
atari_disable_irq( IRQ_MFP_FDC );
local_save_flags(flags); /* The request function is called with ints
local_irq_disable(); * disabled... so must save the IPL for later */
redo_fd_request();
local_irq_restore(flags);
atari_enable_irq( IRQ_MFP_FDC );
}
If you look at the code long enough, you will notioce that the
local_irq_disable() call is actually commented out. This has been
introduced back in 2002 in [1], but as you can see, the same bug has been
there even before, with the sti() call being commented out in the very
same way :)
I am not familiar with the code myself at all, but I guess that the whole
stuff can just be removed. Why do we need save_flags/restore_flags at all,
without actually disabling the local IRQs afterwards? The
redo_fd_request() doesn't seem to do anything that would mess with flags
inconsistently.
[1] http://lkml.org/lkml/2002/12/27/58
Jens:
That does look odd. The comment is correct that the function is entered
with interrupts disabled (and the queue lock held). So I'd say your
patch looks fine, the whole save/restore business looks meaningless.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Michael Schmitz <schmitz@biophys.uni-duesseldorf.de>
dtp is derefenced on the lines above the test !dtp, and so it cannot be
NULL at this point.
A simplified version of the semantic match that finds this problem is as
follows: (http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r@
expression x,E,E1;
identifier f,l;
position p1,p2;
@@
*x@p1->f = E1;
... when != x = E
when != goto l;
(
*x@p2 == NULL
|
*x@p2 != NULL
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Till now block layer allowed two separate modes of request execution.
A request is always acquired from the request queue via
elv_next_request(). After that, drivers are free to either dequeue it
or process it without dequeueing. Dequeue allows elv_next_request()
to return the next request so that multiple requests can be in flight.
Executing requests without dequeueing has its merits mostly in
allowing drivers for simpler devices which can't do sg to deal with
segments only without considering request boundary. However, the
benefit this brings is dubious and declining while the cost of the API
ambiguity is increasing. Segment based drivers are usually for very
old or limited devices and as converting to dequeueing model isn't
difficult, it doesn't justify the API overhead it puts on block layer
and its more modern users.
Previous patches converted all block low level drivers to dequeueing
model. This patch completes the API transition by...
* renaming elv_next_request() to blk_peek_request()
* renaming blkdev_dequeue_request() to blk_start_request()
* adding blk_fetch_request() which is combination of peek and start
* disallowing completion of queued (not started) requests
* applying new API to all LLDs
Renamings are for consistency and to break out of tree code so that
it's apparent that out of tree drivers need updating.
[ Impact: block request issue API cleanup, no functional change ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: unsik Kim <donari75@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Laurent Vivier <Laurent@lvivier.info>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
ataflop has single request in flight. Till now, whenever it needs to
access the in-flight request it called elv_next_request(). This patch
makes ataflop track the in-flight request directly and dequeue it when
processing starts. The added complexity is minimal and this will help
future block layer changes.
[ Impact: dequeue in-flight request, one elv_next_request() per request ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Geert Uytterhoeven