Commit Graph

277 Commits

Author SHA1 Message Date
Luis Chamberlain b5bd357cf8 block: add docs for gendisk / request_queue refcount helpers
This adds documentation for the gendisk / request_queue refcount
helpers.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:57 -06:00
Konstantin Khlebnikov 8ab1d40a64 block: remove rcu_read_lock() from part_stat_lock()
The RCU lock is required only in disk_map_sector_rcu() to lookup the
partition.  After that request holds reference to related hd_struct.

Replace get_cpu() with preempt_disable() - returned cpu index is unused.

[hch: rebased]

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig 58d4f14fc3 block: always use a percpu variable for disk stats
percpu variables have a perfectly fine working stub implementation
for UP kernels, so use that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27 05:21:23 -06:00
Christoph Hellwig 10ec5e86f9 block: merge part_{inc,dev}_in_flight into their only callers
part_inc_in_flight and part_dec_in_flight only have one caller each, and
those callers are purely for bio based drivers.  Merge each function into
the only caller, and remove the superflous blk-mq checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Christoph Hellwig b2f609e191 block: move the blk-mq calls out of part_in_flight{,_rw}
Don't bother to call part_in_flight / part_in_flight_rw on blk-mq
devices, just call the blk-mq versions directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19 09:35:24 -06:00
Ming Lei 27eb3af9a3 block: don't hold part0's refcount in IO path
gendisk can't be gone when there is IO activity, so not hold
part0's refcount in IO path.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:40 -06:00
Ming Lei 07c4e1e834 block: only define 'nr_sects_seq' in hd_part for 32bit SMP
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP,
so define it just for 32bit SMP.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:39 -06:00
Ming Lei b7d6c30333 block: fix use-after-free on cached last_lookup partition
delete_partition() clears the cached last_lookup partition. However the
.last_lookup cache may be overwritten by one IO path after it is cleared
from delete_partition(). Then another IO path may use the cached deleting
partition after hd_struct_free() is called, then use-after-free is triggered
on the cached partition.

Fixes the issue by the following approach:

1) always get the partition's refcount via hd_struct_try_get() before
setting .last_lookup

2) move clearing .last_lookup from delete_partition() to hd_struct_free()
which is the release handle of the partition's percpu-refcount, so that no
IO path can cache deleteing partition via .last_lookup.

It is one candidate approach of Yufen's patch[1] which adds overhead
in fast path by indirect lookup which may introduce one extra cacheline
in IO path. Also this patch relies on percpu-refcount's protection, and
it is easier to understand and verify.

[1] https://lore.kernel.org/linux-block/20200109013551.GB9655@ming.t460p/T/#t

Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12 20:31:39 -06:00
Christoph Hellwig 3c5d202b55 bdi: remove bdi_register_owner
Split out a new bdi_set_owner helper to set the owner, and move the policy
for creating the bdi name back into genhd.c, where it belongs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09 16:15:13 -06:00
Christoph Hellwig 9bc5c397d8 block: fold bdev_unhash_inode into invalidate_partition
invalidate_partition and bdev_unhash_inode are always paired, and
invalidate_partition already does an icache lookup for the block device
inode.  Piggy back on that to remove the inode from the hash.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:33:00 -06:00
Christoph Hellwig 02d33b6771 block: mark invalidate_partition static
invalidate_partition is only used in genhd.c, so mark it static.  Also
drop the return value given that is is always ignored.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Christoph Hellwig cddae808ae block: pass a hd_struct to delete_partition
All callers have the hd_struct at hand, so pass it instead of performing
another lookup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-20 11:32:59 -06:00
Linus Torvalds 10f36b1e80 for-5.7/block-2020-03-29
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Merge tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Online capacity resizing (Balbir)

 - Number of hardware queue change fixes (Bart)

 - null_blk fault injection addition (Bart)

 - Cleanup of queue allocation, unifying the node/no-node API
   (Christoph)

 - Cleanup of genhd, moving code to where it makes sense (Christoph)

 - Cleanup of the partition handling code (Christoph)

 - disk stat fixes/improvements (Konstantin)

 - BFQ improvements (Paolo)

 - Various fixes and improvements

* tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits)
  block: return NULL in blk_alloc_queue() on error
  block: move bio_map_* to blk-map.c
  Revert "blkdev: check for valid request queue before issuing flush"
  block: simplify queue allocation
  bcache: pass the make_request methods to blk_queue_make_request
  null_blk: use blk_mq_init_queue_data
  block: add a blk_mq_init_queue_data helper
  block: move the ->devnode callback to struct block_device_operations
  block: move the part_stat* helpers from genhd.h to a new header
  block: move block layer internals out of include/linux/genhd.h
  block: move guard_bio_eod to bio.c
  block: unexport get_gendisk
  block: unexport disk_map_sector_rcu
  block: unexport disk_get_part
  block: mark part_in_flight and part_in_flight_rw static
  block: mark block_depr static
  block: factor out requeue handling from dispatch code
  block/diskstats: replace time_in_queue with sum of request times
  block/diskstats: accumulate all per-cpu counters in one pass
  block/diskstats: more accurate approximation of io_ticks for slow disks
  ...
2020-03-30 11:20:13 -07:00
Christoph Hellwig 348e114bbd block: move the ->devnode callback to struct block_device_operations
There really isn't any good reason to stash a method directly into
struct gendisk.  Move it together with the other block device
operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-27 09:50:05 -06:00
Christoph Hellwig 1b4d4dbdae block: unexport get_gendisk
get_gendisk is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig a7818aedda block: unexport disk_map_sector_rcu
disk_map_sector_rcu is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig 572e7fc85b block: unexport disk_get_part
disk_get_part is not used by any modular code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig 6005771c17 block: mark part_in_flight and part_in_flight_rw static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Christoph Hellwig 31eb618679 block: mark block_depr static
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 09:50:08 -06:00
Konstantin Khlebnikov 8cd5b8fc00 block/diskstats: replace time_in_queue with sum of request times
Column "time_in_queue" in diskstats is supposed to show total waiting time
of all requests. I.e. value should be equal to the sum of times from other
columns. But this is not true, because column "time_in_queue" is counted
separately in jiffies rather than in nanoseconds as other times.

This patch removes redundant counter for "time_in_queue" and shows total
time of read, write, discard and flush requests.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:12 -06:00
Konstantin Khlebnikov ea18e0f0a6 block/diskstats: accumulate all per-cpu counters in one pass
Reading /proc/diskstats iterates over all cpus for summing each field.
It's faster to sum all fields in one pass.

Hammering /proc/diskstats with fio shows 2x performance improvement:

fio --name=test --numjobs=$JOBS --filename=/proc/diskstats \
    --size=1k --bs=1k --fallocate=none --create_on_open=1 \
    --time_based=1 --runtime=10 --invalidate=0 --group_report

	  JOBS=1	JOBS=10
Before:	  7k iops	64k iops
After:	 18k iops      120k iops

Also this way code is more compact:

add/remove: 1/0 grow/shrink: 0/2 up/down: 194/-1540 (-1346)
Function                                     old     new   delta
part_stat_read_all                             -     194    +194
diskstats_show                              1344     631    -713
part_stat_show                              1219     392    -827
Total: Before=14966947, After=14965601, chg -0.01%

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25 08:49:10 -06:00
Christoph Hellwig 3ad5cee5cd block: move sysfs methods shared by disks and partitions to genhd.c
Move the sysfs _show methods that are used both on the full disk and
partition nodes to genhd.c instead of hiding them in the partitioning
code.  Also move the declaration for these methods to block/blk.h so
that we don't expose them to drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Christoph Hellwig 5cbd28e3ce block: move disk_name and related helpers out of partition-generic.c
Thes functions aren't really related to partition support, so move them
to a more suitable place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Christoph Hellwig d2332c5c04 block: remove the blk_lookup_devt export
This function is only used by init/do_mounts.c, which can't be modular.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Balbir Singh e598a72fae block/genhd: Notify udev about capacity change
Allow block/genhd to notify user space (via udev) about disk size changes
using a new helper set_capacity_revalidate_and_notify(), which is a wrapper
on top of set_capacity(). set_capacity_revalidate_and_notify() will only
notify via udev if the current capacity or the target capacity is not zero
and iff the capacity changes.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Someswarudu Sangaraju <ssomesh@amazon.com>
Signed-off-by: Balbir Singh <sblbir@amazon.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-18 15:13:21 -06:00
Shin'ichiro Kawasaki b53df2e744 block: Fix partition support for host aware zoned block devices
Commit b72053072c ("block: allow partitions on host aware zone
devices") introduced the helper function disk_has_partitions() to check
if a given disk has valid partitions. However, since this function result
directly depends on the disk partition table length rather than the
actual existence of valid partitions in the table, it returns true even
after all partitions are removed from the disk. For host aware zoned
block devices, this results in zone management support to be kept
disabled even after removing all partitions.

Fix this by changing disk_has_partitions() to walk through the partition
table entries and return true if and only if a valid non-zero size
partition is found.

Fixes: b72053072c ("block: allow partitions on host aware zone devices")
Cc: stable@vger.kernel.org # 5.5
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12 07:54:39 -06:00
Konstantin Khlebnikov b686631865 block: add iostat counters for flush requests
Requests that triggers flushing volatile writeback cache to disk (barriers)
have significant effect to overall performance.

Block layer has sophisticated engine for combining several flush requests
into one. But there is no statistics for actual flushes executed by disk.
Requests which trigger flushes usually are barriers - zero-size writes.

This patch adds two iostat counters into /sys/class/block/$dev/stat and
/proc/diskstats - count of completed flush requests and their total time.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-21 09:06:47 -07:00
Damien Le Moal 737eb78e82 block: Delay default elevator initialization
When elevator_init_mq() is called from blk_mq_init_allocated_queue(),
the only information known about the device is the number of hardware
queues as the block device scan by the device driver is not completed
yet for most drivers. The device type and elevator required features
are not set yet, preventing to correctly select the default elevator
most suitable for the device.

This currently affects all multi-queue zoned block devices which default
to the "none" elevator instead of the required "mq-deadline" elevator.
These drives currently include host-managed SMR disks connected to a
smartpqi HBA and null_blk block devices with zoned mode enabled.
Upcoming NVMe Zoned Namespace devices will also be affected.

Fix this by adding the boolean elevator_init argument to
blk_mq_init_allocated_queue() to control the execution of
elevator_init_mq(). Two cases exist:
1) elevator_init = false is used for calls to
   blk_mq_init_allocated_queue() within blk_mq_init_queue(). In this
   case, a call to elevator_init_mq() is added to __device_add_disk(),
   resulting in the delayed initialization of the queue elevator
   after the device driver finished probing the device information. This
   effectively allows elevator_init_mq() access to more information
   about the device.
2) elevator_init = true preserves the current behavior of initializing
   the elevator directly from blk_mq_init_allocated_queue(). This case
   is used for the special request based DM devices where the device
   gendisk is created before the queue initialization and device
   information (e.g. queue limits) is already known when the queue
   initialization is executed.

Additionally, to make sure that the elevator initialization is never
done while requests are in-flight (there should be none when the device
driver calls device_add_disk()), freeze and quiesce the device request
queue before calling blk_mq_init_sched() in elevator_init_mq().

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-05 19:52:34 -06:00
Akinobu Mita 1624b0b200 block: fix sysfs module parameters directory path in comment
The runtime configurable module parameter files are located under
/sys/module/MODULENAME/parameters, not /sys/module/MODULENAME.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-16 10:16:33 -06:00
Gustavo A. R. Silva 78b90a2ce8 block: genhd: Use struct_size() helper
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace the following form:

sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0])

with:

struct_size(new_ptbl, part, target)

Also, notice that variable size is unnecessary, hence it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-15 01:46:09 -06:00
Bart Van Assche 33c826ef19 block: Convert blk_invalidate_devt() header into a non-kernel-doc header
This patch avoids that the kernel-doc tool warns about this function
header when building with W=1.

Reviewed-by: Chaitanya Kulkarni <chiatanya.kulkarni@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-31 15:12:34 -06:00
Christoph Hellwig 3dcf60bcb6 block: add SPDX tags to block layer files missing licensing information
Various block layer files do not have any licensing information at all.
Add SPDX tags for the default kernel GPLv2 license to those.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-30 16:12:03 -06:00
Yufen Yu 6fcc44d1d7 block: fix use-after-free on gendisk
commit 2da78092dd "block: Fix dev_t minor allocation lifetime"
specifically moved blk_free_devt(dev->devt) call to part_release()
to avoid reallocating device number before the device is fully
shutdown.

However, it can cause use-after-free on gendisk in get_gendisk().
We use md device as example to show the race scenes:

Process1		Worker			Process2
md_free
						blkdev_open
del_gendisk
  add delete_partition_work_fn() to wq
  						__blkdev_get
						get_gendisk
put_disk
  disk_release
    kfree(disk)
    						find part from ext_devt_idr
						get_disk_and_module(disk)
    					  	cause use after free

    			delete_partition_work_fn
			put_device(part)
    		  	part_release
		    	remove part from ext_devt_idr

Before <devt, hd_struct pointer> is removed from ext_devt_idr by
delete_partition_work_fn(), we can find the devt and then access
gendisk by hd_struct pointer. But, if we access the gendisk after
it have been freed, it can cause in use-after-freeon gendisk in
get_gendisk().

We fix this by adding a new helper blk_invalidate_devt() in
delete_partition() and del_gendisk(). It replaces hd_struct
pointer in idr with value 'NULL', and deletes the entry from
idr in part_release() as we do now.

Thanks to Jan Kara for providing the solution and more clear comments
for the code.

Fixes: 2da78092dd ("block: Fix dev_t minor allocation lifetime")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 09:48:12 -06:00
Martin Wilck cdf3e3deb7 block: check_events: don't bother with events if unsupported
Drivers now report to the block layer if they support media change
events. If this is not the case, there's no need to allocate the event
structure, and all event handling code can effectively be skipped. This
simplifies code flow in particular for non-removable sd devices.

This effectively reverts commit 75e3f3ee3c ("block: always allocate
genhd->ev if check_events is implemented").

The sysfs files for the events are kept in place even if no events are
supported, as user space may rely on them being present. The only
difference is that an error code is now returned if the user tries to
set poll_msecs.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 13:35:28 -06:00
Martin Wilck c92e2f04b3 block: disk_events: introduce event flags
Currently, an empty disk->events field tells the block layer not to
forward media change events to user space. This was done in commit
7c88a168da ("block: don't propagate unlisted DISK_EVENTs to userland")
in order to avoid events from "fringe" drivers to be forwarded to user
space. By doing so, the block layer lost the information which events
were supported by a particular block device, and most importantly,
whether or not a given device supports media change events at all.

Prepare for not interpreting the "events" field this way in the future
any more. This is done by adding an additional field "event_flags" to
struct gendisk, and two flag bits that can be set to have the device
treated like one that had the "events" field set to a non-zero value
before. This applies only to the sd and sr drivers, which are changed to
set the new flags.

The new flags are DISK_EVENT_FLAG_POLL to enforce polling of the device
for synchronous events, and DISK_EVENT_FLAG_UEVENT to tell the
blocklayer to generate udev events from kernel events.

In order to add the event_flags field to struct gendisk, the events
field is converted to an "unsigned short"; it doesn't need to hold
values bigger than 2 anyway.

This patch doesn't change behavior.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 13:35:24 -06:00
Martin Wilck 673387a930 block: genhd: remove async_events field
The async_events field, intended to be used for drivers that support
asynchronous notifications about disk events (aka media change events),
isn't currently used by any driver, and apparently that has been that
way for a long time (if not forever). Remove it.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-12 13:35:22 -06:00
Keyur Patel dfc76d11dd block: Replace function name in string with __func__
Replace hard coded function name register_blkdev with __func__, to
improve robustness and to conform to the Linux kernel coding
style. Issue found using checkpatch.

Signed-off-by: Keyur Patel <iamkeyur96@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:09:08 -07:00
zhengbin 4d7c1d3fd7 block: fix NULL pointer dereference in register_disk
If __device_add_disk-->bdi_register_owner-->bdi_register-->
bdi_register_va-->device_create_vargs fails, bdi->dev is still
NULL, __device_add_disk-->register_disk will visit bdi->dev->kobj.
This patch fixes that.

Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-28 14:01:36 -07:00
Mikulas Patocka e016b78201 block: return just one value from part_in_flight
The previous patches deleted all the code that needed the second value
returned from part_in_flight - now the kernel only uses the first value.

Consequently, part_in_flight (and blk_mq_in_flight) may be changed so that
it only returns one value.

This patch just refactors the code, there's no functional change.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:38 -07:00
Mikulas Patocka 1226b8dd0e block: switch to per-cpu in-flight counters
Now when part_round_stats is gone, we can switch to per-cpu in-flight
counters.

We use the local-atomic type local_t, so that if part_inc_in_flight or
part_dec_in_flight is reentrantly called from an interrupt, the value will
be correct.

The other counters could be corrupted due to reentrant interrupt, but the
corruption only results in slight counter skew - the in_flight counter
must be exact, so it needs local_t.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Mikulas Patocka 5b18b5a737 block: delete part_round_stats and switch to less precise counting
We want to convert to per-cpu in_flight counters.

The function part_round_stats needs the in_flight counter every jiffy, it
would be too costly to sum all the percpu variables every jiffy, so it
must be deleted. part_round_stats is used to calculate two counters -
time_in_queue and io_ticks.

time_in_queue can be calculated without part_round_stats, by adding the
duration of the I/O when the I/O ends (the value is almost as exact as the
previously calculated value, except that time for in-progress I/Os is not
counted).

io_ticks can be approximated by increasing the value when I/O is started
or ended and the jiffies value has changed. If the I/Os take less than a
jiffy, the value is as exact as the previously calculated value. If the
I/Os take more than a jiffy, io_ticks can drift behind the previously
calculated value.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Mike Snitzer 112f158f66 block: stop passing 'cpu' to all percpu stats methods
All of part_stat_* and related methods are used with preempt disabled,
so there is no need to pass cpu around to allow of them.  Just call
smp_processor_id() as needed.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10 08:30:37 -07:00
Jens Axboe 344e9ffcbd block: add queue_is_mq() helper
Various spots check for q->mq_ops being non-NULL, but provide
a helper to do this instead.

Where the ->mq_ops != NULL check is redundant, remove it.

Since mq == rq-based now that legacy is gone, get rid of the
queue_is_rq_based() and just use queue_is_mq() everywhere.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-16 08:34:06 -07:00
Jens Axboe c0aac682fa This is the 4.19-rc6 release
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Merge tag 'v4.19-rc6' into for-4.20/block

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-01 08:58:57 -06:00
Hannes Reinecke fef912bf86 block: genhd: add 'groups' argument to device_add_disk
Update device_add_disk() to take an 'groups' argument so that
individual drivers can register a device with additional sysfs
attributes.
This avoids race condition the driver would otherwise have if these
groups were to be created with sysfs_add_groups().

Signed-off-by: Martin Wilck <martin.wilck@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-28 08:30:28 -06:00
Omar Sandoval b57e99b4b8 block: use nanosecond resolution for iostat
Klaus Kusche reported that the I/O busy time in /proc/diskstats was not
updating properly on 4.18. This is because we started using ktime to
track elapsed time, and we convert nanoseconds to jiffies when we update
the partition counter. However, this gets rounded down, so any I/Os that
take less than a jiffy are not accounted for. Previously in this case,
the value of jiffies would sometimes increment while we were doing I/O,
so at least some I/Os were accounted for.

Let's convert the stats to use nanoseconds internally. We still report
milliseconds as before, now more accurately than ever. The value is
still truncated to 32 bits for backwards compatibility.

Fixes: 522a777566 ("block: consolidate struct request timestamp fields")
Cc: stable@vger.kernel.org
Reported-by: Klaus Kusche <klaus.kusche@computerix.info>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21 20:26:59 -06:00
Michael Callahan bdca3c87fb block: Track DISCARD statistics and output them in stat and diskstat
Add tracking of REQ_OP_DISCARD ios to the partition statistics and
append them to the various stat files in /sys as well as
/proc/diskstats.  These are tracked with the same four stats as reads
and writes:

Number of discard ios completed.
Number of discard ios merged
Number of discard sectors completed
Milliseconds spent on discard requests

This is done via adding a new STAT_DISCARD define to genhd.h and then
using it to index that stat field for discard requests.

tj: Refreshed on top of v4.17 and other previous updates.

Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18 08:44:22 -06:00
Michael Callahan dbae2c5513 block: Define and use STAT_READ and STAT_WRITE
Add defines for STAT_READ and STAT_WRITE for indexing the partition
stat entries. This clarifies some fs/ code which has hardcoded 1 for
STAT_WRITE and will make it easier to extend the stats with additional
fields.

tj: Refreshed on top of v4.17.

Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18 08:44:18 -06:00
Linus Torvalds cf626b0da7 Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull procfs updates from Al Viro:
 "Christoph's proc_create_... cleanups series"

* 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (44 commits)
  xfs, proc: hide unused xfs procfs helpers
  isdn/gigaset: add back gigaset_procinfo assignment
  proc: update SIZEOF_PDE_INLINE_NAME for the new pde fields
  tty: replace ->proc_fops with ->proc_show
  ide: replace ->proc_fops with ->proc_show
  ide: remove ide_driver_proc_write
  isdn: replace ->proc_fops with ->proc_show
  atm: switch to proc_create_seq_private
  atm: simplify procfs code
  bluetooth: switch to proc_create_seq_data
  netfilter/x_tables: switch to proc_create_seq_private
  netfilter/xt_hashlimit: switch to proc_create_{seq,single}_data
  neigh: switch to proc_create_seq_data
  hostap: switch to proc_create_{seq,single}_data
  bonding: switch to proc_create_seq_data
  rtc/proc: switch to proc_create_single_data
  drbd: switch to proc_create_single
  resource: switch to proc_create_seq_data
  staging/rtl8192u: simplify procfs code
  jfs: simplify procfs code
  ...
2018-06-04 10:00:01 -07:00
Joe Perches 5657a819a8 block drivers/block: Use octal not symbolic permissions
Convert the S_<FOO> symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...>

Miscellanea:

o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesis

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-24 13:38:59 -06:00