For sync IO, we'll often do them serialized. This means we'll be touching
the queue timer for every IO, as opposed to only occasionally like we
do for queued IO. Instead of deleting the timer when the last request
is removed, just let continue running. If a new request comes up soon
we then don't have to readd the timer again. If no new requests arrive,
the timer will expire without side effect later.
This improves high iops sync IO by ~1%.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Now the rq->deadline can't be zero if the request is in the
timeout_list, so there is no need to have next_set. There is no need to
access a request's deadline field if blk_rq_timed_out is called on it.
Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
cpu_coregroup_map returned a cpumask_t: it's going away.
(Note, the sched part of this patch won't apply meaningfully to the
sched tree, but I'm posting it to show the goal).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@redhat.com>
There's no point in having too short SG_IO timeouts, since if the
command does end up timing out, we'll end up through the reset sequence
that is several seconds long in order to abort the command that timed
out.
As a result, shorter timeouts than a few seconds simply do not make
sense, as the recovery would be longer than the timeout itself.
Add a BLK_MIN_SG_TIMEOUT to match the existign BLK_DEFAULT_SG_TIMEOUT.
Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update FMODE_NDELAY before each ioctl call so that we can kill the
magic FMODE_NDELAY_NOW. It would be even better to do this directly
in setfl(), but for that we'd need to have FMODE_NDELAY for all files,
not just block special files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 33c2dca495 (trim file propagation
in block/compat_ioctl.c) removed the handling of some ioctls from
compat_blkdev_driver_ioctl. That caused them to be rejected as unknown
by the compat layer.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix setting of max_segment_size and seg_boundary mask for stacked md/dm
devices.
When stacking devices (LVM over MD over SCSI) some of the request queue
parameters are not set up correctly in some cases by default, namely
max_segment_size and and seg_boundary mask.
If you create MD device over SCSI, these attributes are zeroed.
Problem become when there is over this mapping next device-mapper mapping
- queue attributes are set in DM this way:
request_queue max_segment_size seg_boundary_mask
SCSI 65536 0xffffffff
MD RAID1 0 0
LVM 65536 -1 (64bit)
Unfortunately bio_add_page (resp. bio_phys_segments) calculates number of
physical segments according to these parameters.
During the generic_make_request() is segment cout recalculated and can
increase bio->bi_phys_segments count over the allowed limit. (After
bio_clone() in stack operation.)
Thi is specially problem in CCISS driver, where it produce OOPS here
BUG_ON(creq->nr_phys_segments > MAXSGENTRIES);
(MAXSEGENTRIES is 31 by default.)
Sometimes even this command is enough to cause oops:
dd iflag=direct if=/dev/<vg>/<lv> of=/dev/null bs=128000 count=10
This command generates bios with 250 sectors, allocated in 32 4k-pages
(last page uses only 1024 bytes).
For LVM layer, it allocates bio with 31 segments (still OK for CCISS),
unfortunatelly on lower layer it is recalculated to 32 segments and this
violates CCISS restriction and triggers BUG_ON().
The patch tries to fix it by:
* initializing attributes above in queue request constructor
blk_queue_make_request()
* make sure that blk_queue_stack_limits() inherits setting
(DM uses its own function to set the limits because it
blk_queue_stack_limits() was introduced later. It should probably switch
to use generic stack limit function too.)
* sets the default seg_boundary value in one place (blkdev.h)
* use this mask as default in DM (instead of -1, which differs in 64bit)
Bugs related to this:
https://bugzilla.redhat.com/show_bug.cgi?id=471639http://bugzilla.kernel.org/show_bug.cgi?id=8672
Signed-off-by: Milan Broz <mbroz@redhat.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Miller <mike.miller@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
blkdev_dequeue_request() and elv_dequeue_request() are equivalent and
both start the timeout timer. Barrier code dequeues the original
barrier request but doesn't passes the request itself to lower level
driver, only broken down proxy requests; however, as the original
barrier code goes through the same dequeue path and timeout timer is
started on it. If barrier sequence takes long enough, this timer
expires but the low level driver has no idea about this request and
oops follows.
Timeout timer shouldn't have been started on the original barrier
request as it never goes through actual IO. This patch unexports
elv_dequeue_request(), which has no external user anyway, and makes it
operate on elevator proper w/o adding the timer and make
blkdev_dequeue_request() call elv_dequeue_request() and add timer.
Internal users which don't pass the request to driver - barrier code
and end_that_request_last() - are converted to use
elv_dequeue_request().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
disk->node_id will be refered in allocating in disk_expand_part_tbl, so we
should set it before disk->node_id is refered.
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
mapping. Which is good if pages were mapped - but if they were provided
by someone else and just copied then bad things happen - pages are
released once here, and once by caller, leading to user triggerable BUG
at include/linux/mm.h:246.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Port to the new tracepoints API: split DEFINE_TRACE() and DECLARE_TRACE()
sites. Spread them out to the usage sites, as suggested by
Mathieu Desnoyers.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
This was a forward port of work done by Mathieu Desnoyers, I changed it to
encode the 'what' parameter on the tracepoint name, so that one can register
interest in specific events and not on classes of events to then check the
'what' parameter.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If the size passed in is OK but we end up mapping too many segments,
we call the unmap path directly like from IO completion. But from IO
completion we have an extra reference to the bio, so this error case
goes OOPS when it attempts to free and already free bio.
Fix it by getting an extra reference to the bio before calling the
unmap failure case.
Reported-by: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We run into system boot failure with kernel 2.6.28-rc. We found it on a
couple of machines, including T61 notebook, nehalem machine, and another
HPC NX6325 notebook. All the machines use FedoraCore 8 or FedoraCore 9.
With kernel prior to 2.6.28-rc, system boot doesn't fail.
I debug it and locate the root cause. Pls. see
http://bugzilla.kernel.org/show_bug.cgi?id=11899https://bugzilla.redhat.com/show_bug.cgi?id=471517
As a matter of fact, there are 2 bugs.
1)root=/dev/sda1, system boot randomly fails. Mostly, boot for 5 times
and fails once. nash has a bug. Some of its functions misuse return
value 0. Sometimes, 0 means timeout and no uevent available. Sometimes,
0 means nash gets an uevent, but the uevent isn't block-related (for
exmaple, usb). If by coincidence, kernel tells nash that uevents are
available, but kernel also set timeout, nash might stops collecting
other uevents in queue if current uevent isn't block-related. I work
out a patch for nash to fix it.
http://bugzilla.kernel.org/attachment.cgi?id=18858
2) root=LABEL=/, system always can't boot. initrd init reports
switchroot fails. Here is an executation branch of nash when booting:
(1) nash read /sys/block/sda/dev; Assume major is 8 (on my desktop)
(2) nash query /proc/devices with the major number; It found line
"8 sd";
(3) nash use 'sd' to search its own probe table to find device (DISK)
type for the device and add it to its own list;
(4) Later on, it probes all devices in its list to get filesystem
labels; scsi register "8 sd" always.
When major is 259, nash fails to find the device(DISK) type. I enables
CONFIG_DEBUG_BLOCK_EXT_DEVT=y when compiling kernel, so 259 is picked up
for device /dev/sda1, which causes nash to fail to find device (DISK)
type.
To fixing issue 2), I create a patch for nash and another patch for
kernel.
http://bugzilla.kernel.org/attachment.cgi?id=18859http://bugzilla.kernel.org/attachment.cgi?id=18837
Below is the patch for kernel 2.6.28-rc4. It registers blkext, a new
block device in proc/devices.
With 2 patches on nash and 1 patch on kernel, I boot my machines for
dozens of times without failure.
Signed-off-by Zhang Yanmin <yanmin.zhang@linux.intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Make add_partition() return pointer to the new hd_struct on success
and ERR_PTR() value on failure. This change will be used to fix md
autodetection bug.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch (as1159b) changes the timeout routines in the block core to
use round_jiffies_up(). There's no point in rounding the timer
deadline down, since if it expires too early we will have to restart
it.
The patch also removes some unnecessary tests when a request is
removed from the queue's timer list.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Move the calling blk_delete_timer to later in end_that_request_last to
address an issue where blkdev_dequeue_request may have add a timer for the
request.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Block queue supports two usage models - one where block driver peeks
at the front of queue using elv_next_request(), processes it and
finishes it and the other where block driver peeks at the front of
queue, dequeue the request using blkdev_dequeue_request() and finishes
it. The latter is more flexible as it allows the driver to process
multiple commands concurrently.
These two inconsistent usage models affect the block layer
implementation confusing. For some, elv_next_request() is considered
the issue point while others consider blkdev_dequeue_request() the
issue point.
Till now the inconsistency mostly affect only accounting, so it didn't
really break anything seriously; however, with block layer timeout,
this inconsistency hits hard. Block layer considers
elv_next_request() the issue point and adds timer but SCSI layer
thinks it was just peeking and when the request can't process the
command right away, it's just left there without further processing.
This makes the request dangling on the timer list and, when the timer
goes off, the request which the SCSI layer and below think is still on
the block queue ends up in the EH queue, causing various problems - EH
hang (failed count goes over busy count and EH never wakes up),
WARN_ON() and oopses as low level driver trying to handle the unknown
command, etc. depending on the timing.
As SCSI midlayer is the only user of block layer timer at the moment,
moving blk_add_timer() to elv_dequeue_request() fixes the problem;
however, this two usage models definitely need to be cleaned up in the
future.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We need to do bd_claim() only if file hadn't been opened with O_EXCL
and then we have no need to use file itself as owner.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Most of that stuff doesn't need BKL at all; expand in the (only) caller,
merge the switch into one there and leave BKL only around the stuff that
might actually need it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both. That's this changeset.
2) for each driver convert to new methods. *ALL* drivers
are converted in this series.
3) kill the old (renamed) methods.
Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain. The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.
New methods:
open(bdev, mode)
release(disk, mode)
ioctl(bdev, mode, cmd, arg) /* Called without BKL */
compat_ioctl(bdev, mode, cmd, arg)
locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Analog of blkdev_driver_ioctl() with sane arguments. For
now uses fake struct file, by the end of the series it won't
and blkdev_driver_ioctl() will become a wrapper around it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: remove __generic_unplug_device() from exports
block: move q->unplug_work initialization
blktrace: pass zfcp driver data
blktrace: add support for driver data
block: fix current kernel-doc warnings
block: only call ->request_fn when the queue is not stopped
block: simplify string handling in elv_iosched_store()
block: fix kernel-doc for blk_alloc_devt()
block: fix nr_phys_segments miscalculation bug
block: add partition attribute for partition number
block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT
softirq: Add support for triggering softirq work on softirqs.
modprobe loop; rmmod loop effectively creates a blk_queue and destroys it
which results in q->unplug_work being canceled without it ever being
initialized.
Therefore, move the initialization of q->unplug_work from
blk_queue_make_request() to blk_alloc_queue*().
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Fix block kernel-doc warnings:
Warning(linux-2.6.27-git4//fs/block_dev.c:1272): No description found for parameter 'path'
Warning(linux-2.6.27-git4//block/blk-core.c:1021): No description found for parameter 'cpu'
Warning(linux-2.6.27-git4//block/blk-core.c:1021): No description found for parameter 'part'
Warning(/var/linsrc/linux-2.6.27-git4//block/genhd.c:544): No description found for parameter 'partno'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Callers should use either blk_run_queue/__blk_run_queue, or
blk_start_queueing() to invoke request handling instead of calling
->request_fn() directly as that does not take the queue stopped
flag into account.
Also add appropriate comments on the above functions to detail
their usage.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
strlcpy() guarantees the dest buffer is NULL teminated.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This fixes the bug reported by Nikanth Karthikesan <knikanth@suse.de>:
http://lkml.org/lkml/2008/10/2/203
The root cause of the bug is that blk_phys_contig_segment
miscalculates q->max_segment_size.
blk_phys_contig_segment checks:
req->biotail->bi_size + next_req->bio->bi_size > q->max_segment_size
But blk_recalc_rq_segments might expect that req->biotail and the
previous bio in the req are supposed be merged into one
segment. blk_recalc_rq_segments might also expect that next_req->bio
and the next bio in the next_req are supposed be merged into one
segment. In such case, we merge two requests that can't be merged
here. Later, blk_rq_map_sg gives more segments than it should.
We need to keep track of segment size in blk_recalc_rq_segments and
use it to see if two requests can be merged. This patch implements it
in the similar way that we used to do for hw merging (virtual
merging).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.
This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.
Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The DM and MD integrity support now depends on being able to use
gendisks instead of block_devices when comparing integrity profiles.
Change function parameters accordingly.
Also update comparison logic so that two NULL profiles are a valid
configuration.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
- kobject_del already puts the parent.
- Set integrity profile to NULL to prevent stale data.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch removes end_queued_request() and end_dequeued_request(),
which are no longer used.
As a results, users of __end_request() became only end_request().
So the actual code in __end_request() is moved to end_request()
and __end_request() is removed.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch converts elevator to use __blk_end_request() directly
so that end_{queued|dequeued}_request() can be removed.
Related 'uptodate' arguments is converted to 'error'.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Define as 32, which is is what BDEVNAME_SIZE is/was as well. This keeps
the user interface the same and gets rid of the difference between
kernel and user api here.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds an new interface, blk_lld_busy(), to check lld's
busy state from the block layer.
blk_lld_busy() calls down into low-level drivers for the checking
if the drivers set q->lld_busy_fn() using blk_queue_lld_busy().
This resolves a performance problem on request stacking devices below.
Some drivers like scsi mid layer stop dispatching request when
they detect busy state on its low-level device like host/target/device.
It allows other requests to stay in the I/O scheduler's queue
for a chance of merging.
Request stacking drivers like request-based dm should follow
the same logic.
However, there is no generic interface for the stacked device
to check if the underlying device(s) are busy.
If the request stacking driver dispatches and submits requests to
the busy underlying device, the requests will stay in
the underlying device's queue without a chance of merging.
This causes performance problem on burst I/O load.
With this patch, busy state of the underlying device is exported
via q->lld_busy_fn(). So the request stacking driver can check it
and stop dispatching requests if busy.
The underlying device driver must return the busy state appropriately:
1: when the device driver can't process requests immediately.
0: when the device driver can process requests immediately,
including abnormal situations where the device driver needs
to kill all requests.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
blk_start_queueing() should act like the generic queue unplugging
and kicking and ignore a stopped queue. Such a queue may not be
run until after a call to blk_start_queue().
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
By only allowing async IO to consume 3/4 ths of the tag depth, we
always have slots free to serve sync IO. This is important to avoid
having writes fill the entire tag queue, thus starving reads.
Original patch and idea from Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We really need to know about the hardware tagging support as well,
since if the SSD does not do tagging then we still want to idle.
Otherwise have the same dependent sync IO vs flooding async IO
problem as on rotational media.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We don't want to idle in AS/CFQ if the device doesn't have a seek
penalty. So add a QUEUE_FLAG_NONROT to indicate a non-rotational
device, low level drivers should set this flag upon discovery of
an SSD or similar device type.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds a queue flag to indicate the block device can be
used for request stacking.
Request stacking drivers need to stack their devices on top of
only devices of which q->request_fn is functional.
Since bio stacking drivers (e.g. md, loop) basically initialize
their queue using blk_alloc_queue() and don't set q->request_fn,
the check of (q->request_fn == NULL) looks enough for that purpose.
However, dm will become both types of stacking driver (bio-based and
request-based). And dm will always set q->request_fn even if the dm
device is bio-based of which q->request_fn is not functional actually.
So we need something else to distinguish the type of the device.
Adding a queue flag is a solution for that.
The reason why dm always sets q->request_fn is to keep
the compatibility of dm user-space tools.
Currently, all dm user-space tools are using bio-based dm without
specifying the type of the dm device they use.
To use request-based dm without changing such tools, the kernel
must decide the type of the dm device automatically.
The automatic type decision can't be done at the device creation time
and needs to be deferred until such tools load a mapping table,
since the actual type is decided by dm target type included in
the mapping table.
So a dm device has to be initialized using blk_init_queue()
so that we can load either type of table.
Then, all queue stuffs are set (e.g. q->request_fn) and we have
no element to distinguish that it is bio-based or request-based,
even after a table is loaded and the type of the device is decided.
By the way, some stuffs of the queue (e.g. request_list, elevator)
are needless when the dm device is used as bio-based.
But the memory size is not so large (about 20[KB] per queue on ia64),
so I hope the memory loss can be acceptable for bio-based dm users.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds blk_insert_cloned_request(), a generic request
submission interface for request stacking drivers.
Request-based dm will use it to submit their clones to underlying
devices.
blk_rq_check_limits() is also added because it is possible that
the lower queue has stronger limitations than the upper queue
if multiple drivers are stacking at request-level.
Not only for blk_insert_cloned_request()'s internal use, the function
will be used by request-based dm when the queue limitation is
modified (e.g. by replacing dm's table).
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds blk_update_request(), which updates struct request
with completing its data part, but doesn't complete the struct
request itself.
Though it looks like end_that_request_first() of older kernels,
blk_update_request() should be used only by request stacking drivers.
Request-based dm will use it in bio->bi_end_io callback to update
the original request when a data part of a cloned request completes.
Followings are additional background information of why request-based
dm needs this interface.
- Request stacking drivers can't use blk_end_request() directly from
the lower driver's completion context (bio->bi_end_io or rq->end_io),
because some device drivers (e.g. ide) may try to complete
their request with queue lock held, and it may cause deadlock.
See below for detailed description of possible deadlock:
<http://marc.info/?l=linux-kernel&m=120311479108569&w=2>
- To solve that, request-based dm offloads the completion of
cloned struct request to softirq context (i.e. using
blk_complete_request() from rq->end_io).
- Though it is possible to use the same solution from bio->bi_end_io,
it will delay the notification of bio completion to the original
submitter. Also, it will cause inefficient partial completion,
because the lower driver can't perform the cloned request anymore
and request-based dm needs to requeue and redispatch it to
the lower driver again later. That's not good.
- So request-based dm needs blk_update_request() to perform the bio
completion in the lower driver's completion context, which is more
efficient.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
When a driver calls blk_cleanup_queue(), the device should be fully idle.
However, the block layer may have pending plugging timers and the IO
schedulers may have pending work in the work queues. So quisce the device
by waiting for the timer and flushing the work queues.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We cannot abort a request if we raced with the timeout handler already,
or with the IO completion. So make blk_abort_request() mark the request
as complete, and only continue if we succeeded.
Found and suggested by Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Only works for the generic request timer handling. Allows one to
sporadically ignore request completions, thus exercising the timeout
handling.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Two mods to blkdev_issue_discard(), thinking ahead to its use on swap:
1. Add gfp_mask argument, so swap allocation can use it where GFP_KERNEL
might deadlock but GFP_NOIO is safe.
2. Enlarge nr_sects argument from unsigned to sector_t: unsigned long is
enough to cover a whole swap area, but sector_t suits any partition.
Change sb_issue_discard()'s nr_blocks to sector_t too; but no need seen
for a gfp_mask there, just pass GFP_KERNEL down to blkdev_issue_discard().
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.
Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
seqf can be started multiple times for a read and the header should be
printed only for the initial one. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch changes blk_rq_map_user to accept a NULL user-space buffer
with a READ command if rq_map_data is not NULL. Thus a caller can pass
page frames to lk_rq_map_user to just set up a request and bios with
page frames propely. bio_uncopy_user (called via blk_rq_unmap_user)
doesn't copy data to user space with such request.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
bdget_disk() and blk_lookup_devt() never cared whether the specified
partition (or disk) is zero sized or not. I got confused while
converting those not to depend on consecutive minor numbers in commit
5a6411b1178baf534aa9138052864dfa89d3eada and later when dev0 was added
it broke callers which expected to get valid return for zero sized
disk devices.
So, they never needed nr_sects checks in the first place. Kill them.
This problem was spotted and debugged by Bartlmoiej Zolnierkiewicz.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Noticed by sparse:
block/blk-softirq.c:156:12: warning: symbol 'blk_softirq_init' was not declared. Should it be static?
block/genhd.c:583:28: warning: function 'bdget_disk' with external linkage has definition
block/genhd.c:659:17: warning: incorrect type in argument 1 (different base types)
block/genhd.c:659:17: expected unsigned int [unsigned] [usertype] size
block/genhd.c:659:17: got restricted gfp_t
block/genhd.c:659:29: warning: incorrect type in argument 2 (different base types)
block/genhd.c:659:29: expected restricted gfp_t [usertype] flags
block/genhd.c:659:29: got unsigned int
block: kmalloc args reversed
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This adds blk_rq_aligned helper function to see if alignment and
padding requirement is satisfied for DMA transfer. This also converts
blk_rq_map_kern and __blk_rq_map_user to use the helper function.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch introduces struct rq_map_data to enable bio_copy_use_iov()
use reserved pages.
Currently, bio_copy_user_iov allocates bounce pages but
drivers/scsi/sg.c wants to allocate pages by itself and use
them. struct rq_map_data can be used to pass allocated pages to
bio_copy_user_iov.
The current users of bio_copy_user_iov simply passes NULL (they don't
want to use pre-allocated pages).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Douglas Gilbert <dougg@torque.net>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently, blk_rq_map_user and blk_rq_map_user_iov always do
GFP_KERNEL allocation.
This adds gfp_mask argument to blk_rq_map_user and blk_rq_map_user_iov
so sg can use it (sg always does GFP_ATOMIC allocation).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Douglas Gilbert <dougg@torque.net>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
CFQ's detection of queueing devices assumes a non-queuing device and detects
if the queue depth reaches a certain threshold. Under some workloads (e.g.
synchronous reads), CFQ effectively forces a unit queue depth, thus defeating
the detection logic. This leads to poor performance on queuing hardware,
since the idle window remains enabled.
This patch inverts the sense of the logic: assume a queuing-capable device,
and detect if the depth does not exceed the threshold.
Signed-off-by: Aaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We should just check for rq->bio, as that is really the information
we are looking for. Even if the bio attached doesn't carry data,
we still need to do IO post processing on it.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Somewhat incomplete, as we do allow merges of requests and bios
that have different completion CPUs given. This is done on the
assumption that a larger IO is still more beneficial than CPU
locality.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds support for controlling the IO completion CPU of
either all requests on a queue, or on a per-request basis. We export
a sysfs variable (rq_affinity) which, if set, migrates completions
of requests to the CPU that originally submitted it. A bio helper
(bio_set_completion_cpu()) is also added, so that queuers can ask
for completion on that specific CPU.
In testing, this has been show to cut the system time by as much
as 20-40% on synthetic workloads where CPU affinity is desired.
This requires a little help from the architecture, so it'll only
work as designed for archs that are using the new generic smp
helper infrastructure.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Now that disk and partition handlings are mostly unified, it's easy to
allow disk to have extended device number. This patch makes
add_disk() use extended device number if disk->minors is zero. Both
sd and ide-disk are updated to use this.
* sd_format_disk_name() is implemented which can generically determine
the drive name. This removes disk number restriction stemming from
limited device names.
* If sd index goes over SD_MAX_DISKS (which can be increased now BTW),
sd simply doesn't initialize minors letting block layer choose
extended device number.
* If CONFIG_DEBUG_EXT_DEVT is set, both sd and ide-disk always set
minors to 0 and use extended device numbers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
With previous changes, it's meaningless to limit the number of
partitions. Replace @ext_minors with GENHD_FL_EXT_DEVT such that
setting the flag allows the disk to have maximum number of allowed
partitions (only limited by the number of entries in parsed_partitions
as determined by MAX_PART constant).
This kills not-too-pretty alloc_disk_ext[_node]() functions and makes
@minors parameter to alloc_disk[_node]() unnecessary. The parameter
is left alone to avoid disturbing the users.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
disk->__part used to be statically allocated to the maximum possible
number of partitions. This patch makes partition array allocation
dynamic. The added overhead is minimal as only real change is one
memory dereference changed to RCU one. This saves both a bit of
memory and cpu cycles iterating through unoccupied slots and makes
increasing partition limit easier.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Move stats related fields - stamp, in_flight, dkstats - from disk to
part0 and unify stat handling such that...
* part_stat_*() now updates part0 together if the specified partition
is not part0. ie. part_stat_*() are now essentially all_stat_*().
* {disk|all}_stat_*() are gone.
* part_round_stats() is updated similary. It handles part0 stats
automatically and disk_round_stats() is killed.
* part_{inc|dec}_in_fligh() is implemented which automatically updates
part0 stats for parts other than part0.
* disk_map_sector_rcu() is updated to return part0 if no part matches.
Combined with the above changes, this makes NULL special case
handling in callers unnecessary.
* Separate stats show code paths for disk are collapsed into part
stats show code paths.
* Rename disk_stat_lock/unlock() to part_stat_lock/unlock()
While at it, reposition stat handling macros a bit and add missing
parentheses around macro parameters.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
GENHD_FL_FAIL for disk is what make_it_fail is for parts. Kill it and
use part0->make_it_fail. Sysfs node handling is unified too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Till now, bdev->bd_part is set only if the bdev was for parts other
than part0. This patch makes bdev->bd_part always set so that code
paths don't have to differenciate common handling.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Move disk->holder_dir to part0->holder_dir. Kill now mostly
superflous bdev_get_holder().
While at it, kill superflous kobject_get/put() around holder_dir,
slave_dir and cmd_filter creation and collapse
disk_sysfs_add_subdirs() into register_disk(). These serve no purpose
but obfuscating the code.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Now that capacity and __dev are moved to part0, part0 and others can
share the same method.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Move disk->__dev to part0->__dev. This simplifies bdget_disk() and
lookup_devt() and allows common sysfs attributes to be unified.
part_to_disk() is updated to handle part0 -> disk.
Updated to include a fix from Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
he writes:
"part0 is a "special" partition and doesn't need to have capacity set - this
fixes regression caused by "block: move __dev from disk to part0" commit."
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
genhd and partition code handled disk and partitions separately. All
information about the whole disk was in struct genhd and partitions in
struct hd_struct. However, the whole disk (part0) and other
partitions have a lot in common and the data structures end up having
good number of common fields and thus separate code paths doing the
same thing. Also, the partition array was indexed by partno - 1 which
gets pretty confusing at times.
This patch introduces partition 0 and makes the partition array
indexed by partno. Following patches will unify the handling of disk
and parts piece-by-piece.
This patch also implements disk_partitionable() which tests whether a
disk is partitionable. With coming dynamic partition array change,
the most common usage of disk_max_parts() will be testing whether a
disk is partitionable and the number of max partitions will become
much less important.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Implement {disk|part}_to_dev() and use them to access generic device
instead of directly dereferencing {disk|part}->dev. To make sure no
user is left behind, rename generic devices fields to __dev.
This is in preparation of unifying partition 0 handling with other
partitions.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Extended devt introduces non-contiguos device numbers. This patch
implements a debug option which forces most devt allocations to be
from the extended area and spreads them out. This is enabled by
default if DEBUG_KERNEL is set and achieves...
1. Detects code paths in kernel or userland which expect predetermined
consecutive device numbers.
2. When something goes wrong, avoid corruption as adding to the minor
of earlier partition won't lead to the wrong but valid device.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
With extended minors and the soon-to-follow debug feature, large minor
numbers for block devices will be common. This patch does the
followings to make printouts pretty.
* Adapt print formats such that large minors don't break the
formatting.
* For extended MAJ:MIN, %02x%02x for MAJ:MIN used in
printk_all_partitions() doesn't cut it anymore. Update it such that
%03x:%05x is used if either MAJ or MIN doesn't fit in %02x.
* Implement ext_range sysfs attribute which shows total minors the
device can use including both conventional minor space and the
extended one.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Implement extended device numbers. A block driver can tell block
layer that it wants to use extended device numbers. After the usual
minor space is used up, block layer automatically allocates devt's
from EXT_BLOCK_MAJOR.
Currently only one major number is allocated for this but as the
allocation is strictly on-demand, ~1mil minor space under it should
suffice unless the system actually has more than ~1mil partitions and
if that ever happens adding more majors to the extended devt area is
easy.
Due to internal implementation issues, the first partition can't be
allocated on the extended area. In other words, genhd->minors should
at least be 1. This limitation will be lifted by later changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
There are two variants of stat functions - ones prefixed with double
underbars which don't care about preemption and ones without which
disable preemption before manipulating per-cpu counters. It's unclear
whether the underbarred ones assume that preemtion is disabled on
entry as some callers don't do that.
This patch unifies diskstats access by implementing disk_stat_lock()
and disk_stat_unlock() which take care of both RCU (for partition
access) and preemption (for per-cpu counter access). diskstats access
should always be enclosed between the two functions. As such, there's
no need for the versions which disables preemption. They're removed
and double underbars ones are renamed to drop the underbars. As an
extra argument is added, there's no danger of using the old version
unconverted.
disk_stat_lock() uses get_cpu() and returns the cpu index and all
diskstat functions which access per-cpu counters now has @cpu
argument to help RT.
This change adds RCU or preemption operations at some places but also
collapses several preemption ops into one at others. Overall, the
performance difference should be negligible as all involved ops are
very lightweight per-cpu ones.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
disk->part[] is protected by its matching bdev's lock. However,
non-critical accesses like collecting stats and printing out sysfs and
proc information used to be performed without any locking. As
partitions can come and go dynamically, partitions can go away
underneath those non-critical accesses. As some of those accesses are
writes, this theoretically can lead to silent corruption.
This patch fixes the race by using RCU for the partition array and dev
reference counter to hold partitions.
* Rename disk->part[] to disk->__part[] to make sure no one outside
genhd layer proper accesses it directly.
* Use RCU for disk->__part[] dereferencing.
* Implement disk_{get|put}_part() which can be used to get and put
partitions from gendisk respectively.
* Iterators are implemented to help iterate through all partitions
safely.
* Functions which require RCU readlock are marked with _rcu suffix.
* Use disk_put_part() in __blkdev_put() instead of directly putting
the contained kobject.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Implement disk_devt() and part_devt() and use them to directly
access devt instead of computing it from ->major and ->first_minor.
Note that all references to ->major and ->first_minor outside of
block layer is used to determine devt of the disk (the part0) and as
->major and ->first_minor will continue to represent devt for the
disk, converting these users aren't strictly necessary. However,
convert them for consistency.
* Implement disk_max_parts() to avoid directly deferencing
genhd->minors.
* Update bdget_disk() such that it doesn't assume consecutive minor
space.
* Move devt computation from register_disk() to add_disk() and make it
the only one (all other usages use the initially determined value).
These changes clean up the code and will help disk->part dereference
fix and extended block device numbers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In hd_struct, @partno is used to denote partition number and a number
of other places use @part to denote hd_struct. Functions use @part
and @index instead. This causes confusion and makes it difficult to
use consistent variable names for hd_struct. Always use @partno if a
variable represents partition number.
Also, print out functions use @f or @part for seq_file argument. Use
@seqf uniformly instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch makes the following misc updates in preparation for
disk->part dereference fix and extended block devt support.
* implment part_to_disk()
* fix comment about gendisk->part indexing
* rename get_part() to disk_map_sector()
* don't use n which is always zero while printing disk information in
diskstats_show()
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
d805dda4 tried to fix error case handling in add_partition() but had a
few problems.
* disk->part[] entry is set early and left dangling if operation
fails.
* Once device initialized, the last put_device() is responsible for
freeing all the resources. The failure path freed part_stats and p
regardless of put_device() causing double free.
* holders subdir holds reference to the disk device, so failure path
should remove it to release resources properly which was missing.
This patch fixes the above problems and while at it move partition
slot busy check into add_partition() for completeness and inlines
holders subdirectory creation. Using separate function for it just
obfuscates the code.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Abdel Benamrouche <draconux@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
delete_partition() was noop for zero length partition. As the
addition code allows creating zero lenght partition and deletion is
assumed to always succeed, this causes memory leak for zero length
partitions. Allow zero length partitions to end their meaningless
lives.
While at it, allow deleting zero lenght partition via
BLKPG_DEL_PARTITION ioctl too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Recent block_class iteration updates 5c6f35c5..27f3025 converted all
class device iteration to class_for_each_device() and
class_find_device(), which are correct but pain in the ass to use.
This pach converts them to newly introduced class_dev_iterator so that
they can use more natural control structures instead of separate
callbacks and struct to pass parameters to them.
This results in smaller and easier code.
This patch also restores the original behavior of not printing header
in /proc/partitions if there's no partition to print. This is trivial
but still user-visible behavior.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block_class_lock protects major_names array and bdev_map and doesn't
have anything to do with block class devices. Don't grab them while
iterating over block class devices.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Recent block_class iteration updates 5c6f35c5..27f3025 broke partition
info printouts.
* printk_all_partitions(): Partition print out stops when it meets a
partition hole. Partition printing inner loop should continue
instead of exiting on empty partition slot.
* /proc/partitions and /proc/diskstats: If all information can't be
read in single read(), the information is truncated. This is
because find_start() doesn't actually update the counter containing
the initial seek. It runs to the end and ends up always reporting
EOF on the second read.
This patch fixes both problems.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Remove hw_segments field from struct bio and struct request. Without virtual
merge accounting they have no purpose.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Deadline currently only batches sector-contiguous requests, so except
for a few circumstances (e.g. requests in a single direction), it is
essentially first come first served. This is bad for throughput, so
change it to CSCAN, which means requests in a batch do not need to be
sequential and are issued in increasing sector order.
Signed-off-by: Aaron Carroll <aaronc@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
But blkdev_issue_discard() still emits requests which are interpreted as
soft barriers, because naïve callers might otherwise issue subsequent
writes to those same sectors, which might cross on the queue (if they're
reallocated quickly enough).
Callers still _can_ issue non-barrier discard requests, but they have to
take care of queue ordering for themselves.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We may well want mkfs tools to use this to mark the whole device as
unwanted before they format it, for example.
The ioctl takes a pair of uint64_ts, which are start offset and length
in _bytes_. Although at the moment it might make sense for them both to
be in 512-byte sectors, I don't want to limit the ABI to that.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Barriers should be submitted with the WRITE flag set.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Let the compiler see what's going on, and it can all get a lot simpler.
On PPC64 this reduces the size of the code calculating these bits by
about 60%. On x86_64 it's less of a win -- only 40%.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some block devices benefit from a hint that they can forget the contents
of certain sectors. Add basic support for this to the block core, along
with a 'blkdev_issue_discard()' helper function which issues such
requests.
The caller doesn't get to provide an end_io functio, since
blkdev_issue_discard() will automatically split the request up into
multiple bios if appropriate. Neither does the function wait for
completion -- it's expected that callers won't care about when, or even
_if_, the request completes. It's only a hint to the device anyway. By
definition, the file system doesn't _care_ about these sectors any more.
[With feedback from OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> and
Jens Axboe <jens.axboe@oracle.com]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
I have another request for the block filter SG_IO command whitelist,
specifically the MMC streaming command set SET READ AHEAD command.
The command applies only to MMC CDROM/DVDROM drives with the streaming
optional feature set. The command is useful to cdparanoia in that it
allows explicit cache control side effects that are, on many drives,
cdparanoia's most efficient way to flush/disable the media cache on
cdrom drives. I am aware of no reason why it should not be accessible
from usespace.
Also note that the command is already fully accessible through the
SCSI-native version of the SG_IO ioctl as well as the traditional SG
interface. The command is only being refused on block devices. That
means that on a typical stock distro, the command is available through
/dev/sg* but not /dev/scd* although both are typically available and
accessible. Filtering the command is not providing any protection,
only a confusing inconsistency.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We still have life time issues with the sysfs command filter kobject,
so disable it for 2.6.27 release. We can revisit this and make it work
properly for 2.6.28, for 2.6.27 release it's too risky.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
/proc/partitions didn't use to write out the header if there was no
partition. However, recent commit 66c64afe changed the behavior.
This is nothing major but there's no reason to change user visible
behavior without a good rationale. Restore the original behavior.
Note that 2.6.28 has clean up changes scheduled which will replace
this rather hacky implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch remove blk_register_filter and blk_unregister_filter in
gendisk, and adds them to sd.c, sr.c. and ide-cd.c
The commit abf5439370 moved cmdfilter
from gendisk to request_queue. It turned out that in some subsystems
multiple gendisks share a single request_queue. So we get:
Using physmap partition information
Creating 3 MTD partitions on "physmap-flash":
0x00000000-0x01c00000 : "User FS"
0x01c00000-0x01c40000 : "booter"
kobject (8511c410): tried to init an initialized object, something is seriously wrong.
Call Trace:
[<8036644c>] dump_stack+0x8/0x34
[<8021f050>] kobject_init+0x50/0xcc
[<8021fa18>] kobject_init_and_add+0x24/0x58
[<8021d20c>] blk_register_filter+0x4c/0x64
[<8021c194>] add_disk+0x78/0xe0
[<8027d14c>] add_mtd_blktrans_dev+0x254/0x278
[<8027c8f0>] blktrans_notify_add+0x40/0x78
[<80279c00>] add_mtd_device+0xd0/0x150
[<8027b090>] add_mtd_partitions+0x568/0x5d8
[<80285458>] physmap_flash_probe+0x2ac/0x334
[<802644f8>] driver_probe_device+0x12c/0x244
[<8026465c>] __driver_attach+0x4c/0x84
[<80263c64>] bus_for_each_dev+0x58/0xac
[<802633ec>] bus_add_driver+0xc4/0x24c
[<802648e0>] driver_register+0xcc/0x184
[<80100460>] _stext+0x60/0x1bc
In the long term, we need to fix such subsystems but we need a quick
fix now. This patch add the command filter support to only sd and sr
though it might be useful for other SG_IO users (such as cciss).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reported-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's not used for anything. On top of that, it's racy and can thus
trigger a faulty BUG_ON() in __blk_free_tags() on queue exit.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch changes the interface of the cmd filter to use a +/-
notation like:
echo -- +0x02 +0x03 -0x08
If neither + or - is given it defaults to + (allow command).
Note: The interface was added in 2.6.17-rc1 and is unused and
undocumented so far so it's safe to change it.
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: jens.axboe@oracle.com
Cc: James.Bottomley@hansenpartnership.com
Cc: dan.j.williams@intel.com
Cc: pjones@redhat.com
Cc: viro@zeniv.linux.org.uk
Cc: dougg@torque.net
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Technically, the cmd_filter would be applied to other protocols though
it's unlikely to happen. Putting SCSI stuff to request_queue is kinda
layer violation. So let's rename it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
cmd_filter works only for the block layer SG_IO with SCSI block
devices. It breaks scsi/sg.c, bsg, and the block layer SG_IO with SCSI
character devices (such as st). We hit a kernel crash with them.
The problem is that cmd_filter code accesses to gendisk (having struct
blk_scsi_cmd_filter) via inode->i_bdev->bd_disk. It works for only
SCSI block device files. With character device files, inode->i_bdev
leads you to struct cdev. inode->i_bdev->bd_disk->blk_scsi_cmd_filter
isn't safe.
SCSI ULDs don't expose gendisk; they keep it private. bsg needs to be
independent on any protocols. We shouldn't change ULDs to expose their
gendisk.
This patch moves struct blk_scsi_cmd_filter from gendisk to
request_queue, a common object, which eveyone can access to.
The user interface doesn't change; users can change the filters via
/sys/block/. gendisk has a pointer to request_queue so the cmd_filter
code accesses to struct blk_scsi_cmd_filter.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Otherwise we leak references, which is not a good thing to do.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The proc files get truncated if they do not fit into the buffer with
a single read(). We need to move the seq_file index from the callback
of class_find_device() to the caller of class_find_device(), to keep
its value across multiple invocations of the callback.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
blk_plug_device() must be called with the queue lock held, so callers
often just grab and release the lock for that purpose. Add a helper
that does just that.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It seems cdrwtool in the udftools has been unusable on "modern" kernels
for some time. A Google search reveals many people with the same issue
but no solution (cdrwtool fails to format the disk). After spending some
time tracking down the issue, it comes down to the following:
The udftools still use the older CDROM_SEND_PACKET interface to send
things like FORMAT_UNIT through to the drive. They should really be
updated, but that's another story. Since most distros are using libata
now, the cd or dvd burner appears as a SCSI device, and we wind up in
block/scsi_ioctl.c. Here, the code tries to take the "struct
cdrom_generic_command" and translate it and stuff it into a "struct
sg_io_hdr" structure so it can pass it to the modern sg_io() routine
instead. Unfortunately, there is one error, or rather an omission in the
translation. The timeout that is passed in in the "struct
cdrom_generic_command" is in HZ=100 units, and this is modified and
correctly converted to jiffies by use of clock_t_to_jiffies(). However,
a little further down, this cgc.timeout value in jiffies is simply
copied into the sg_io_hdr timeout, which should be in milliseconds.
Since most modern x86 kernels seems to be getting build with HZ=250, the
timeout that is passed to sg_io and eventually converted to the
timeout_per_command member of the scsi_cmnd structure is now four times
too small. Since cdrwtool tries to set the timeout to one hour for the
FORMAT_UNIT command, and it takes about 20 minutes to format a 4x CDRW,
the SCSI error-handler kicks in after the FORMAT_UNIT completes because
it took longer than the incorrectly-calculated timeout.
[jejb: fix up whitespace]
Signed-off-by: Tim Wright <timw@splhi.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the proper class iterator function instead of mucking around in the
internals of the class structures.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The seq_start call is the better place for the header for the file, that
way we don't have to be mucking in the class structure to try to figure
out if this is the first partition or not.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use the proper class iterator function instead of mucking around in the
internals of the class structures.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These functions are only needed if CONFIG_PROC_FS is enabled, so save
the space when it is not.
This also makes it easier for a patch later in this series to work
properly if CONFIG_PROC_FS is not enabled.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use the proper class iterator function instead of mucking around in the
internals of the class structures.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use the proper class iterator function instead of mucking around in the
internals of the class structures.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Warn if something really bad happens if we can't create this link.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Why?:
There are occasions where userspace would like to access sysfs
attributes for a device but it may not know how sysfs has named the
device or the path. For example what is the sysfs path for
/dev/disk/by-id/ata-ST3160827AS_5MT004CK? With this change a call to
stat(2) returns the major:minor then userspace can see that
/sys/dev/block/8:32 links to /sys/block/sdc.
What are the alternatives?:
1/ Add an ioctl to return the path: Doable, but sysfs is meant to reduce
the need to proliferate ioctl interfaces into the kernel, so this
seems counter productive.
2/ Use udev to create these symlinks: Also doable, but it adds a
udev dependency to utilities that might be running in a limited
environment like an initramfs.
3/ Do a full-tree search of sysfs.
[kay.sievers@vrfy.org: fix duplicate registrations]
[kay.sievers@vrfy.org: cleanup suggestions]
Cc: Neil Brown <neilb@suse.de>
Cc: Tejun Heo <htejun@gmail.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Reviewed-by: SL Baur <steve@xemacs.org>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Mark Lord <lkml@rtr.ca>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (102 commits)
[SCSI] scsi_dh: fix kconfig related build errors
[SCSI] sym53c8xx: Fix bogus sym_que_entry re-implementation of container_of
[SCSI] scsi_cmnd.h: remove double inclusion of linux/blkdev.h
[SCSI] make struct scsi_{host,target}_type static
[SCSI] fix locking in host use of blk_plug_device()
[SCSI] zfcp: Cleanup external header file
[SCSI] zfcp: Cleanup code in zfcp_erp.c
[SCSI] zfcp: zfcp_fsf cleanup.
[SCSI] zfcp: consolidate sysfs things into one file.
[SCSI] zfcp: Cleanup of code in zfcp_aux.c
[SCSI] zfcp: Cleanup of code in zfcp_scsi.c
[SCSI] zfcp: Move status accessors from zfcp to SCSI include file.
[SCSI] zfcp: Small QDIO cleanups
[SCSI] zfcp: Adapter reopen for large number of unsolicited status
[SCSI] zfcp: Fix error checking for ELS ADISC requests
[SCSI] zfcp: wait until adapter is finished with ERP during auto-port
[SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver
[SCSI] sg: Add target reset support
[SCSI] lib: Add support for the T10 (SCSI) Data Integrity Field CRC
[SCSI] sd: Move scsi_disk() accessor function to sd.h
...
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (80 commits)
ide-floppy: fix unfortunate function naming
ide-tape: unify idetape_create_read/write_cmd
ide: add ide_pc_intr() helper
ide-{floppy,scsi}: read Status Register before stopping DMA engine
ide-scsi: add more debugging to idescsi_pc_intr()
ide-scsi: use pc->callback
ide-floppy: add more debugging to idefloppy_pc_intr()
ide-tape: always log debug info in idetape_pc_intr() if debugging is enabled
ide-tape: add ide_tape_io_buffers() helper
ide-tape: factor out DSC handling from idetape_pc_intr()
ide-{floppy,tape}: move checking of ->failed_pc to ->callback
ide: add ide_issue_pc() helper
ide: add PC_FLAG_DRQ_INTERRUPT pc flag
ide-scsi: move idescsi_map_sg() call out from idescsi_issue_pc()
ide: add ide_transfer_pc() helper
ide-scsi: set drive->scsi flag for devices handled by the driver
ide-{cd,floppy,tape}: remove checking for drive->scsi
ide: add PC_FLAG_ZIP_DRIVE pc flag
ide-tape: factor out waiting for good ireason from idetape_transfer_pc()
ide-tape: set PC_FLAG_DMA_IN_PROGRESS flag in idetape_transfer_pc()
...
All the users of blk_end_sync_rq has gone (they are converted to use
blk_execute_rq). This unexports blk_end_sync_rq.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Some uses blk_put_request asymmetrically, that is, they uses it with
requests that not allocated by blk_get_request. As a result,
blk_put_request has a hack to catch a NULL request_queue. Now such
callers are fixed (they use blk_get_request properly). So we can
safely remove the hack in blk_put_request.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
For blk_pm_resume_request() requests (which are used only by IDE subsystem
currently) the queue is stopped so we need to call ->request_fn explicitly.
Thanks to:
- Rafael for reporting/bisecting the bug
- Borislav/Rafael for testing the fix
This is a preparation for converting IDE to use blk_execute_rq().
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* 'core/softirq' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
softirq: remove irqs_disabled warning from local_bh_enable
softirq: remove initialization of static per-cpu variable
Remove argument from open_softirq which is always NULL
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (37 commits)
splice: fix generic_file_splice_read() race with page invalidation
ramfs: enable splice write
drivers/block/pktcdvd.c: avoid useless memset
cdrom: revert commit 22a9189 (cdrom: use kmalloced buffers instead of buffers on stack)
scsi: sr avoids useless buffer allocation
block: blk_rq_map_kern uses the bounce buffers for stack buffers
block: add blk_queue_update_dma_pad
DAC960: push down BKL
pktcdvd: push BKL down into driver
paride: push ioctl down into driver
block: use get_unaligned_* helpers
block: extend queue_flag bitops
block: request_module(): use format string
Add bvec_merge_data to handle stacked devices and ->merge_bvec()
block: integrity flags can't use bit ops on unsigned short
cmdfilter: extend default read filter
sg: fix odd style (extra parenthesis) introduced by cmd filter patch
block: add bounce support to blk_rq_map_user_iov
cfq-iosched: get rid of enable_idle being unused warning
allow userspace to modify scsi command filter on per device basis
...
If you do a modremove of any sas driver, you run into an oops on
shutdown when the host is removed (coming from the host bsg device).
The root cause seems to be that there's a use after free of the
bsg_class_device: In bsg_kref_release_function, this is used (to do a
put_device(bcg->parent) after bcg->release has been called. In sas (and
possibly many other things) bcd->release frees the queue which contains
the bsg_class_device, so we get a put_device on unreferenced memory.
Fix this by taking a copy of the pointer to the parent before releasing
bsg.
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
We don't need to hold bsg_mutex during bsg_complete_all_commands(). It
leads to a problem that we block bsg_unregister_queue during
bsg_complete_all_commands (untill all the outstanding commands
complete).
Thanks to Pete Wyckoff for finding the bug and testing the patch.
The detailed bug report is:
http://marc.info/?l=linux-scsi&m=121182137132145&w=2
Tested-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
blk_rq_map_kern is used for kernel internal I/Os. Some callers use
this function with stack buffers but DMA to/from the stack buffers
leads to memory corruption on a non-coherent platform.
This patch make blk_rq_map_kern uses the bounce buffers if a caller
passes a stack buffer (on the all platforms for simplicity).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This adds blk_queue_update_dma_pad to prevent LLDs from overwriting
the dma pad mask wrongly (we added blk_queue_update_dma_alignment due
to the same reason).
This also converts libata to use blk_queue_update_dma_pad instead of
blk_queue_dma_pad.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Avoid bad things happening if the module has a printk control string in
its name.
Signed-off-by: maximilian attems <max@stro.at>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds the commands that the former sg filter allowed for read
access to the cmdfilter to keep userspace apps that rely on them working.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
blk_rq_map_user_iov can't handle the bounce buffer (it means that the
bio_map_user_iov path doesn't work with a LLD that needs GFP_DMA).
This patch fixes blk_rq_map_user_iov to support the bounce buffer.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.
Original patch from Peter Jones.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.
This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.
See Documentation/block/data-integrity.txt for more information.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This allows a user to annotate the blk trace stream: writing a suitable
message to {/sys/kernel/debug}/block/<dsf>/msg will have it propagated
into the trace stream.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Now that blktrace has the ability to carry arbitrary messages in
its stream, use that for some CFQ logging.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
If we have multiple tasks freeing io contexts when as-iosched
is being unloaded, we could complete() ioc_gone twice. Fix that by
protecting ioc_gone complete() and clearing with a spinlock for
just that purpose. Doesn't matter from a performance perspective,
since it'll only enter that path when ioc_gone != NULL (when as-iosched
is being rmmod'ed).
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
If we have multiple tasks freeing cfq_io_contexts when cfq-iosched
is being unloaded, we could complete() ioc_gone twice. Fix that by
protecting ioc_gone complete() and clearing with a spinlock for
just that purpose. Doesn't matter from a performance perspective,
since it'll only enter that path when ioc_gone != NULL (when cfq-iosched
is being rmmod'ed).
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
AS scheduler alternates between issuing read and write batches. It does
the batch switch only after all requests from the previous batch are
completed.
When switching to a write batch, if there is an on-going read request,
it waits for its completion and indicates its intention of switching by
setting ad->changed_batch and the new direction but does not update the
batch_expire_time for the new write batch which it does in the case of
no previous pending requests.
On completion of the read request, it sees that we were waiting for the
switch and schedules work for kblockd right away and resets the
ad->changed_data flag.
Now when kblockd enters dispatch_request where it is expected to pick
up a write request, it in turn ends the write batch because the
batch_expire_timer was not updated and shows the expire timestamp for
the previous batch.
This results in the write starvation for all the cases where there is
the intention for switching to a write batch, but there is a previous
in-flight read request and the batch gets reverted to a read_batch
right away.
This also holds true in the reverse case (switching from a write batch
to a read batch with an in-flight write request).
I've checked that this bug exists on 2.6.11, 2.6.18, 2.6.24 and
linux-2.6-block git HEAD. I've tested the fix on x86 platforms with
SCSI drives where the driver asks for the next request while a current
request is in-flight.
This patch is based off linux-2.6-block git HEAD.
Bug reproduction:
A simple scenario which reproduces this bug is:
- dd if=/dev/hda3 of=/dev/null &
- lilo
The lilo takes forever to complete.
This can also be reproduced fairly easily with the earlier dd and
another test
program doing msync().
The example test program below should print out a message after every
iteration
but it simply hangs forever. With this bugfix it makes forward progress.
====
Example test program using msync() (thanks to suleiman AT google DOT
com)
inline uint64_t
rdtsc(void)
{
int64_t tsc;
__asm __volatile("rdtsc" : "=A" (tsc));
return (tsc);
}
int
main(int argc, char **argv)
{
struct stat st;
uint64_t e, s, t;
char *p, q;
long i;
int fd;
if (argc < 2) {
printf("Usage: %s <file>\n", argv[0]);
return (1);
}
if ((fd = open(argv[1], O_RDWR | O_NOATIME)) < 0)
err(1, "open");
if (fstat(fd, &st) < 0)
err(1, "fstat");
p = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
t = 0;
for (i = 0; i < 1000; i++) {
*p = 0;
msync(p, 4096, MS_SYNC);
s = rdtsc();
*p = 0;
__asm __volatile(""::: "memory");
e = rdtsc();
if (argc > 2)
printf("%d: %lld cycles %jd %jd\n",
i, e - s, (intmax_t)s, (intmax_t)e);
t += e - s;
}
printf("average time: %lld cycles\n", t / 1000);
return (0);
}
Cc: <stable@kernel.org>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
As we may run relay_reserve from interrupt context we must always disable
IRQs. This is because a call to relay_reserve may expose previously written
data to use space.
Updated new message code and an old but related comment.
Signed-off-by: Carl Henrik Lunde <chlunde@ping.uio.no>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 30f2f0eb4b ("block: do_mounts -
accept root=<non-existant partition>") extended blk_lookup_devt() to be
able to look up partitions that had not yet been registered, but in the
process made the assumption that the '&block_class.devices' list only
contains disk devices and that you can do 'dev_to_disk(dev)' on them.
That isn't actually true. The block_class device list also contains the
partitions we've discovered so far, and you can't just do a
'dev_to_disk()' on those.
So make sure to only work on devices that block/genhd.c has registered
itself, something we can test by checking the 'dev->type' member. This
makes the loop in blk_lookup_devt() match the other such loops in this
file.
[ We may want to do an alternate version that knows to handle _either_
whole-disk devices or partitions, but for now this is the minimal fix
for a series of crashes reported by Mariusz Kozlowski in
http://lkml.org/lkml/2008/5/25/25
and Ingo in
http://lkml.org/lkml/2008/6/9/39 ]
Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Neil Brown <neilb@suse.de>
Cc: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cfq_cic_lookup() needs to properly protect ioc->ioc_data before
dereferencing it and also exclude updaters of ioc->ioc_data as well.
Also add a number of comments documenting why the existing RCU usage
is OK.
Thanks a lot to "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> for
review and comments!
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently it uses a single static char array, but that risks
being corrupted when multiple users issue message notes at the
same time. Make the buffers dynamically allocated when the trace
is setup and make them per-cpu instead.
The default max message size of 1k is also very large, the
interface is mainly for small text notes. So shrink it to 128 bytes.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Allows messages to be inserted into blktrace streams.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
saves 8 bytes of padding & increases objects/slab from 30 to 32 on my
AMD64 config
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In function get_request_wait, the second call to get_request could be
moved to the end of the while loop, because if the first call to
get_request fails, the second call will fail without sleep.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
As git-grep shows, open_softirq() is always called with the last argument
being NULL
block/blk-core.c: open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
kernel/hrtimer.c: open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
kernel/rcuclassic.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL);
kernel/rcupreempt.c: open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL);
kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL);
kernel/softirq.c: open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL);
kernel/softirq.c: open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL);
kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);
This observation has already been made by Matthew Wilcox in June 2002
(http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html)
"I notice that none of the current softirq routines use the data element
passed to them."
and the situation hasn't changed since them. So it appears we can safely
remove that extra argument to save 128 (54) bytes of kernel data (text).
Signed-off-by: Carlos R. Mafra <crmafra@ift.unesp.br>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
As setting and clearing queue flags now requires that we hold a spinlock
on the queue, and as blk_queue_stack_limits is called without that lock,
get the lock inside blk_queue_stack_limits.
For blk_queue_stack_limits to be able to find the right lock, each md
personality needs to set q->queue_lock to point to the appropriate lock.
Those personalities which didn't previously use a spin_lock, us
q->__queue_lock. So always initialise that lock when allocated.
With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no
longer cause warnings as it will be clear that the proper lock is held.
Thanks to Dan Williams for review and fixing the silly bugs.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Nick Piggin <npiggin@suse.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Jacek Luczak <difrost.kernel@gmail.com>
Cc: Prakash Punnoor <prakash@punnoor.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some devices, like md, may create partitions only at first access,
so allow root= to be set to a valid non-existant partition of an
existing disk. This applies only to non-initramfs root mounting.
This fixes a regression from 2.6.24 which did allow this to happen and
broke some users machines :(
Acked-by: Neil Brown <neilb@suse.de>
Tested-by: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Cc: stable <stable@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
bdevname() fills the buffer that it is given as a parameter, so calling
strcpy() or snprintf() on the returned value is redundant (and probably not
guaranteed to work - I don't think strcpy and snprintf support overlapping
buffers.)
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_part() is fairly expensive, as it O(N) loops over partitions
to find the right one. In lots of normal IO paths we end up looking
up the partition twice, to make matters even worse. Change the
stat add code to accept a passed in partition instead.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We currently set all processes to the best-effort scheduling class,
regardless of what CPU scheduling class they belong to. Improve that
so that we correctly track idle and rt scheduling classes as well.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Original patch from Mikulas Patocka <mpatocka@redhat.com>
Mike Anderson was doing an OLTP benchmark on a computer with 48 physical
disks mapped to one logical device via device mapper.
He found that there was a slowdown on request_queue->lock in function
generic_unplug_device. The slowdown is caused by the fact that when some
code calls unplug on the device mapper, device mapper calls unplug on all
physical disks. These unplug calls take the lock, find that the queue is
already unplugged, release the lock and exit.
With the below patch, performance of the benchmark was increased by 18%
(the whole OLTP application, not just block layer microbenchmarks).
So I'm submitting this patch for upstream. I think the patch is correct,
because when more threads call simultaneously plug and unplug, it is
unspecified, if the queue is or isn't plugged (so the patch can't make
this worse). And the caller that plugged the queue should unplug it
anyway. (if it doesn't, there's 3ms timeout).
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
put_io_context() drops the RCU read lock before calling into cfq_dtor(),
however we need to hold off freeing there before grabbing and
dereferencing the first object on the list.
So extend the rcu_read_lock() scope to cover the calling of cfq_dtor(),
and optimize cfq_free_io_context() to use a new variant for
call_for_each_cic() that assumes the RCU read lock is already held.
Hit in the wild by Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
For most initialization purposes, calling blk_queue_init_tags() without
the queue lock held is OK. Only if called for resizing an existing map
must the lock be held. Ditto for tag cleanup, the maps are reference
counted.
So switch the general queue flag setting to the unlocked variant, but
retain the locked variant for resizing.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Concurrency isn't a big deal here since we have requests in flight
at this point, but do the locked variant to set a better example.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6:
[SCSI] aic94xx: fix section mismatch
[SCSI] u14-34f: Fix 32bit only problem
[SCSI] dpt_i2o: sysfs code
[SCSI] dpt_i2o: 64 bit support
[SCSI] dpt_i2o: move from virt_to_bus/bus_to_virt to dma_alloc_coherent
[SCSI] dpt_i2o: use standard __init / __exit code
[SCSI] megaraid_sas: fix suspend/resume sections
[SCSI] aacraid: Add Power Management support
[SCSI] aacraid: Fix jbod operations scan issues
[SCSI] aacraid: Fix warning about macro side-effects
[SCSI] add support for variable length extended commands
[SCSI] Let scsi_cmnd->cmnd use request->cmd buffer
[SCSI] bsg: add large command support
[SCSI] aacraid: Fix down_interruptible() to check the return value correctly
[SCSI] megaraid_sas; Update the Version and Changelog
[SCSI] ibmvscsi: Handle non SCSI error status
[SCSI] bug fix for free list handling
[SCSI] ipr: Rename ipr's state scsi host attribute to prevent collisions
[SCSI] megaraid_mbox: fix Dell CERC firmware problem
Add support for variable-length, extended, and vendor specific
CDBs to scsi-ml. It is now possible for initiators and ULD's
to issue these types of commands. LLDs need not change much.
All they need is to raise the .max_cmd_len to the longest command
they support (see iscsi patch).
- clean-up some code paths that did not expect commands to be
larger than 16, and change cmd_len members' type to short as
char is not enough.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This enables bsg to handle the request length larger than BLK_MAX_CDB
(mainly for the variable length CDB format).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info object.
This allows us to see and set the various BDI specific variables.
In particular this properly exposes the read-ahead window for all relevant
users and /sys/block/<block>/queue/read_ahead_kb should be deprecated.
With patient help from Kay Sievers and Greg KH
[mszeredi@suse.cz]
- split off NFS and FUSE changes into separate patches
- document new sysfs attributes under Documentation/ABI
- do bdi_class_init as a core_initcall, otherwise the "default" BDI
won't be initialized
- remove bdi_init_fmt macro, it's not used very much
[akpm@linux-foundation.org: fix ia64 warning]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg KH <greg@kroah.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The block I/O + elevator + I/O scheduler code spend a lot of time trying
to merge I/Os -- rightfully so under "normal" circumstances. However,
if one were to know that the incoming I/O stream was /very/ random in
nature, the cycles are wasted.
This patch adds a per-request_queue tunable that (when set) disables
merge attempts (beyond the simple one-hit cache check), thus freeing up
a non-trivial amount of CPU cycles.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch changes rq->cmd from the static array to a pointer to
support large commands.
We rarely handle large commands. So for optimization, a struct request
still has a static array for a command. rq_init sets rq->cmd pointer
to the static array.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This is a preparation for changing rq->cmd from the static array to a
pointer.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This rename rq_init() blk_rq_init() and export it. Any path that hands
the request to the block layer needs to call it to initialize the
request.
This is a preparation for large command support, which needs to
initialize the request in a proper way (that is, just doing a memset()
will not work).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
blk_get_request initializes rq->cmd (rq_init does) so the users don't
need to do that.
The purpose of this patch is to remove sizeof(rq->cmd) and &rq->cmd,
as a preparation for large command support, which changes rq->cmd from
the static array to a pointer. sizeof(rq->cmd) will not make sense and
&rq->cmd won't work.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch fixes the following build error with UML and gcc 4.3:
<-- snip -->
...
CC block/blk-barrier.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/blk-barrier.c: In function ‘blk_do_ordered’:
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/blk-barrier.c:57: sorry, unimplemented: inlining failed in call to ‘blk_ordered_cur_seq’: function body not available
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/blk-barrier.c:252: sorry, unimplemented: called from here
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/blk-barrier.c:57: sorry, unimplemented: inlining failed in call to ‘blk_ordered_cur_seq’: function body not available
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/blk-barrier.c:253: sorry, unimplemented: called from here
make[2]: *** [block/blk-barrier.o] Error 1
<-- snip -->
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch fixes the following build error with UML and gcc 4.3:
<-- snip -->
...
CC block/elevator.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/elevator.c: In function ‘elv_merge’:
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/elevator.c:73: sorry, unimplemented: inlining failed in call to ‘elv_rq_merge_ok’: function body not available
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/elevator.c:103: sorry, unimplemented: called from here
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/elevator.c:73: sorry, unimplemented: inlining failed in call to ‘elv_rq_merge_ok’: function body not available
/home/bunk/linux/kernel-2.6/git/linux-2.6/block/elevator.c:495: sorry, unimplemented: called from here
make[2]: *** [block/elevator.o] Error 1
make[1]: *** [block] Error 2
<-- snip -->
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
We can save some atomic ops in the IO path, if we clearly define
the rules of how to modify the queue flags.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds bio_copy_kern similar to
bio_copy_user. blk_rq_map_kern uses bio_copy_kern instead of
bio_map_kern if necessary.
bio_copy_kern uses temporary pages and the bi_end_io callback frees
these pages. bio_copy_kern saves the original kernel buffer at
bio->bi_private it doesn't use something like struct bio_map_data to
store the information about the caller.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This requires moving rq_init() from get_request() to blk_alloc_request().
The upside is that we can now require an rq_init() from any path that
wishes to hand the request to the block layer.
rq_init() will be exported for the code that uses struct request
without blk_get_request.
This is a preparation for large command support, which needs to
initialize struct request in a proper way (that is, just doing a
memset() will not work).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds release callback support, which is called when a bsg
device goes away. bsg_register_queue() takes a pointer to a callback
function. This feature is useful for stuff like sas_host that can't
use the release callback in struct device.
If a caller doesn't need bsg's release callback, it can call
bsg_register_queue() with NULL pointer (e.g. scsi devices can use
release callback in struct device so they don't need bsg's callback).
With this patch, bsg uses kref for refcounts on bsg devices instead of
get/put_device in fops->open/release. bsg calls put_device and the
caller's release callback (if it was registered) in kref_put's
release.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block:
block: fix blk_register_queue() return value
block: fix memory hotplug and bouncing in block layer
block: replace remaining __FUNCTION__ occurrences
Kconfig: clean up block/Kconfig help descriptions
cciss: fix warning oops on rmmod of driver
cciss: Fix race between disk-adding code and interrupt handler
block: move the padding adjustment to blk_rq_map_sg
block: add bio_copy_user_iov support to blk_rq_map_user_iov
block: convert bio_copy_user to bio_copy_user_iov
loop: manage partitions in disk image
cdrom: use kmalloced buffers instead of buffers on stack
cdrom: make unregister_cdrom() return void
cdrom: use list_head for cdrom_device_info list
cdrom: protect cdrom_device_info list by mutex
cdrom: cleanup hardcoded error-code
cdrom: remove ifdef CONFIG_SYSCTL
blk_register_queue() returns -ENXIO when queue->request_fn is NULL. But there
are some block drivers that call blk_register_queue() via add_disk() with
queue->request_fn == NULL. (For example, brd, loop)
Although no one checks return value of blk_register_queue(), this patch makes
it return 0 instead of -ENXIO when queue->request_fn is NULL,
Also this patch adds warning when blk_register_queue() and
blk_unregister_queue() are called with queue == NULL rather than ignore
invalid usage silently.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Modify the help descriptions of block/Kconfig for clarity, accuracy and
consistency.
Refactor the BLOCK description a bit. The wording "This permits ... to be
removed" isn't quite right; the block layer is removed when the option is
disabled, whereas most descriptions talk about what happens when the option is
enabled. Reformat the list of what is affected by disabling the block layer.
Add more examples of large block devices to LBD and strive for technical
accuracy; block devices of size _exactly_ 2TB require CONFIG_LBD, not only
"bigger than 2TB". Also try to say (perhaps not very clearly) that the config
option is only needed when you want to have individual block devices of size
>= 2TB, for example if you had 3 x 1TB disks in your computer you'd have a
total storage size of 3TB but you wouldn't need the option unless you want to
aggregate those disks into a RAID or LVM.
Improve terminology and grammar on BLK_DEV_IO_TRACE.
I also added the boilerplate "If unsure, say N" to most options.
Precisely say "2TB and larger" for LSF.
Indent the help text for BLK_DEV_BSG by 2 spaces in accordance with the
standard.
Signed-off-by: Nick Andrew <nick@nick-andrew.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
blk_rq_map_user adjusts bi_size of the last bio. It breaks the rule
that req->data_len (the true data length) is equal to sum(bio). It
broke the scsi command completion code.
commit e97a294ef6 was introduced to fix
the above issue. However, the partial completion code doesn't work
with it. The commit is also a layer violation (scsi mid-layer should
not know about the block layer's padding).
This patch moves the padding adjustment to blk_rq_map_sg (suggested by
James). The padding works like the drain buffer. This patch breaks the
rule that req->data_len is equal to sum(sg), however, the drain buffer
already broke it. So this patch just restores the rule that
req->data_len is equal to sub(bio) without breaking anything new.
Now when a low level driver needs padding, blk_rq_map_user and
blk_rq_map_user_iov guarantee there's enough room for padding.
blk_rq_map_sg can safely extend the last entry of a scatter list.
blk_rq_map_sg must extend the last entry of a scatter list only for a
request that got through bio_copy_user_iov. This patches introduces
new REQ_COPY_USER flag.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
With this patch, blk_rq_map_user_iov uses bio_copy_user_iov when a low
level driver needs padding or a buffer in sg_iovec isn't aligned. That
is, it uses temporary kernel buffers instead of mapping user pages
directly.
When a LLD needs padding, later blk_rq_map_sg needs to extend the last
entry of a scatter list. bio_copy_user_iov guarantees that there is
enough space for padding by using temporary kernel buffers instead of
user pages.
blk_rq_map_user_iov needs buffers in sg_iovec to be aligned. The
comment in blk_rq_map_user_iov indicates that drivers/scsi/sg.c also
needs buffers in sg_iovec to be aligned. Actually, drivers/scsi/sg.c
works with unaligned buffers in sg_iovec (it always uses temporary
kernel buffers).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's big, but there doesn't seem to be a way to split it up smaller...
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (137 commits)
[SCSI] iscsi: bidi support for iscsi_tcp
[SCSI] iscsi: bidi support at the generic libiscsi level
[SCSI] iscsi: extended cdb support
[SCSI] zfcp: Fix error handling for blocked unit for send FCP command
[SCSI] zfcp: Remove zfcp_erp_wait from slave destory handler to fix deadlock
[SCSI] zfcp: fix 31 bit compile warnings
[SCSI] bsg: no need to set BSG_F_BLOCK bit in bsg_complete_all_commands
[SCSI] bsg: remove minor in struct bsg_device
[SCSI] bsg: use better helper list functions
[SCSI] bsg: replace kobject_get with blk_get_queue
[SCSI] bsg: takes a ref to struct device in fops->open
[SCSI] qla1280: remove version check
[SCSI] libsas: fix endianness bug in sas_ata
[SCSI] zfcp: fix compiler warning caused by poking inside new semaphore (linux-next)
[SCSI] aacraid: Do not describe check_reset parameter with its value
[SCSI] aacraid: Fix down_interruptible() to check the return value
[SCSI] sun3_scsi_vme: add MODULE_LICENSE
[SCSI] st: rename flush_write_buffer()
[SCSI] tgt: use KMEM_CACHE macro
[SCSI] initio: fix big endian problems for auto request sense
...
Before bsg_complete_all_commands is called, BSG_F_BLOCK bit is always
set.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
minor in struct bsg_device is used as identifier to find the
corresponding struct bsg_device_class. However, request_queuse can be
used as identifier for that and the minor in struct bsg_device is
unnecessary.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This replace hlist_for_each and list_entry with hlist_for_each_entry
and list_first_entry respectively.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Both takes a ref to a queue. But blk_get_queue checks QUEUE_FLAG_DEAD
and is more appropriate interface here.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
bsg_register_queue() takes a ref to struct device that a caller
passes. For example, bsg takes a ref to the sdev_gendev for scsi
devices. However, bsg doesn't inrease the refcount in fops->open. So
while an application opens a bsg device, the scsi device that the bsg
device holds can go away (bsg also takes a ref to a queue, but it
doesn't prevent the device from going away).
With this patch, bsg increases the refcount of struct device in
fops->open and decreases it in fops->release.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
hdparm explicitely marks HDIO_[UNREGISTER,SCAN]_HWIF ioctls as DANGEROUS
and given the number of bugs we can assume that there are no real users:
* DMA has no chance of working because DMA resources are released by
ide_unregister() and they are never allocated again.
* Since ide_init_hwif_ports() is used for ->io_ports[] setup the ioctls
don't work for almost all hosts with "non-standard" (== non ISA-like)
layout of IDE taskfile registers (there is a lot of such host drivers).
* ide_port_init_devices() is not called when probing IDE devices so:
- drive->autotune is never set and IDE host/devices are not programmed
for the correct PIO/DMA transfer modes (=> possible data corruption)
- host specific I/O 32-bit and IRQ unmasking settings are not applied
(=> possible data corruption)
- host specific ->port_init_devs method is not called (=> no luck with
ht6560b, qd65xx and opti621 host drivers)
* ->rw_disk method is not preserved (=> no HPT3xxN chipsets support).
* ->serialized flag is not preserved (=> possible data corruption when
using icside, aec62xx (ATP850UF chipset), cmd640, cs5530, hpt366
(HPT3xxN chipsets), rz1000, sc1200, dtc2278 and ht6560b host drivers).
* ->ack_intr method is not preserved (=> needed by ide-cris, buddha,
gayle and macide host drivers).
* ->sata_scr[] and sata_misc[] is cleared by ide_unregister() and it
isn't initialized again (SiI3112 support needs them).
* To issue an ioctl() there need to be at least one IDE device present
in the system.
* ->cable_detect method is not preserved + it is not called when probing
IDE devices so cable detection is broken (however since DMA support is
also broken it doesn't really matter ;-).
* Some objects which may have already been freed in ide_unregister()
are restored by ide_hwif_restore() (i.e. ->hwgroup).
* ide_register_hw() may unregister unrelated IDE ports if free ide_hwifs[]
slot cannot be found.
* When IDE host drivers are modular unregistered port may be re-used by
different host driver that owned it first causing subtle bugs.
Since we now have a proper warm-plug support remove these ioctls,
then remove no longer needed:
- ide_register_hw() and ide_hwif_restore() functions
- 'init_default' and 'restore' arguments of ide_unregister()
- zeroeing of hwif->{dma,extra}_* fields in ide_unregister()
As an added bonus IDE core code size shrinks by ~3kB (x86-32).
v2:
* fix ide_unregister() arguments in cleanup_module() (Andrew Morton).
v3:
* fix ide_unregister() arguments in palm_bk3710.c.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
When switching scheduler from cfq, cfq_exit_queue() does not clear
ioc->ioc_data, leaving a dangling pointer that can deceive the following
lookups when the iosched is switched back to cfq. The pattern that can
trigger that is the following:
- elevator switch from cfq to something else;
- module unloading, with elv_unregister() that calls cfq_free_io_context()
on ioc freeing the cic (via the .trim op);
- module gets reloaded and the elevator switches back to cfq;
- reallocation of a cic at the same address as before (with a valid key).
To fix it just assign NULL to ioc_data in __cfq_exit_single_io_context(),
that is called from the regular exit path and from the elevator switching
code. The only path that frees a cic and is not covered is the error handling
one, but cic's freed in this way are never cached in ioc_data.
Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
SLAB_DESTROY_BY_RCU is not a direct substitute for normal call_rcu()
freeing, since it'll page freeing but NOT object freeing. So change
cfq to do the freeing on its own.
Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Looking a bit closer into this regression the reason this can't be
right is that dma_addr common default is BLK_BOUNCE_HIGH and most
machines have less than 4G. So if you do:
if (b_pfn <= (min_t(u64, 0xffffffff, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
dma = 1
that will translate to:
if (BLK_BOUNCE_HIGH <= BLK_BOUNCE_HIGH)
dma = 1
So for 99% of hardware this will trigger unnecessary GFP_DMA
allocations and isa pooling operations.
Also note how the 32bit code still does b_pfn < blk_max_low_pfn.
I guess this is what you were looking after. I didn't verify but as
far as I can tell, this will stop the regression with isa dma
operations at boot for 99% of blkdev/memory combinations out there and
I guess this fixes the setups with >4G of ram and 32bit pci cards as
well (this also retains symmetry with the 32bit code).
Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Fixes:
block/genhd.c:361: warning: ignoring return value of ‘class_register’, declared with attribute warn_unused_result
Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is important to eg dm, that tries to decide whether to stop using
barriers or not.
Tested as working by Anders Henke <anders.henke@1und1.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Introduced between 2.6.25-rc2 and -rc3
block/blk-map.c:154:14: warning: symbol 'bio' shadows an earlier one
block/blk-map.c:110:13: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Intoduced between 2.6.25-rc2 and -rc3
block/blk-settings.c:319:12: warning: function 'blk_queue_dma_drain' with external linkage has definition
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch removes the unused export of blk_rq_map_user_iov.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch removes the unused exports of blk_{get,put}_queue.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch contains the following cleanups:
- make the needlessly global struct disk_type static
- #if 0 the unused genhd_media_change_notify()
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch adds a proper prototye for blk_dev_init() in block/blk.h
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Every file should include the headers containing the externs for its
global functions (in this case for __blk_queue_free_tags()).
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
For some non-x86 systems with 4GB or upper 4GB memory,
we need increase the range of addresses that can be
used for direct DMA in 64-bit kernel.
Signed-off-by: Yang Shi <yang.shi@windriver.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Block layer alignment was used for two different purposes - memory
alignment and padding. This causes problems in lower layers because
drivers which only require memory alignment ends up with adjusted
rq->data_len. Separate out padding such that padding occurs iff
driver explicitly requests it.
Tomo: restorethe code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbd
according to padding alignment.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The meaning of rq->data_len was changed to the length of an allocated
buffer from the true data length. It breaks SG_IO friends and
bsg. This patch restores the meaning of rq->data_len to the true data
length and adds rq->extra_len to store an extended length (due to
drain buffer and padding).
This patch also removes the code to update bio in blk_rq_map_user
introduced by the commit 40b01b9bbd.
The commit adjusts bio according to memory alignment
(queue_dma_alignment). However, memory alignment is NOT padding
alignment. This adjustment also breaks SG_IO friends and bsg. Padding
alignment needs to be fixed in a proper way (by a separate patch).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
Clear drain buffer before chaining if the command in question is a
write.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Draining shouldn't be done for commands where overflow may indicate
data integrity issues. Add dma_drain_needed callback to
request_queue. Drain buffer is appened iff this function returns
non-zero.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
With padding and draining moved into it, block layer now may extend
requests as directed by queue parameters, so now a request has two
sizes - the original request size and the extended size which matches
the size of area pointed to by bios and later by sgs. The latter size
is what lower layers are primarily interested in when allocating,
filling up DMA tables and setting up the controller.
Both padding and draining extend the data area to accomodate
controller characteristics. As any controller which speaks SCSI can
handle underflows, feeding larger data area is safe.
So, this patch makes the primary data length field, request->data_len,
indicate the size of full data area and add a separate length field,
request->raw_data_len, for the unmodified request size. The latter is
used to report to higher layer (userland) and where the original
request size should be fed to the controller or device.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
DMA start address and transfer size alignment for PC requests are
achieved using bio_copy_user() instead of bio_map_user(). This works
because bio_copy_user() always uses full pages and block DMA alignment
isn't allowed to go over PAGE_SIZE.
However, the implementation didn't update the last bio of the request
to make this padding visible to lower layers. This patch makes
blk_rq_map_user() extend the last bio such that it includes the
padding area and the size of area pointed to by the request is
properly aligned.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently we fail if someone requests a valid io scheduler, but it's
modular and not currently loaded. That can happen from a driver init
asking for a different scheduler, or online switching through sysfs
as requested by a user.
This patch makes elevator_get() request_module() to attempt to load
the appropriate module, instead of requiring that done manually.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
It's cumbersome to browse a radix tree from start to finish, especially
since we modify keys when a process exits. So add a hlist for the single
purpose of browsing over all known cfq_io_contexts, used for exit,
io prio change, etc.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=9948
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
