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2019-11-21block: add iostat counters for flush requestsKonstantin Khlebnikov1-2/+6
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>
2019-09-05block: Delay default elevator initializationDamien Le Moal1-0/+9
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>
2019-07-16block: fix sysfs module parameters directory path in commentAkinobu Mita1-1/+1
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>
2019-06-15block: genhd: Use struct_size() helperGustavo A. R. Silva1-3/+2
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>
2019-05-31block: Convert blk_invalidate_devt() header into a non-kernel-doc headerBart Van Assche1-2/+2
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>
2019-04-30block: add SPDX tags to block layer files missing licensing informationChristoph Hellwig1-0/+1
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>
2019-04-22block: fix use-after-free on gendiskYufen Yu1-0/+19
commit 2da78092dda "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: 2da78092dda1 ("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>
2019-04-12block: check_events: don't bother with events if unsupportedMartin Wilck1-11/+16
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 75e3f3ee3c64 ("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>
2019-04-12block: disk_events: introduce event flagsMartin Wilck1-4/+9
Currently, an empty disk->events field tells the block layer not to forward media change events to user space. This was done in commit 7c88a168da80 ("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>
2019-04-12block: genhd: remove async_events fieldMartin Wilck1-6/+4
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>
2019-02-28block: Replace function name in string with __func__Keyur Patel1-4/+4
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>
2019-02-28block: fix NULL pointer dereference in register_diskzhengbin1-4/+6
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>
2018-12-10block: return just one value from part_in_flightMikulas Patocka1-22/+12
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>
2018-12-10block: switch to per-cpu in-flight countersMikulas Patocka1-10/+33
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>
2018-12-10block: delete part_round_stats and switch to less precise countingMikulas Patocka1-3/+0
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>
2018-12-10block: stop passing 'cpu' to all percpu stats methodsMike Snitzer1-3/+2
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>
2018-11-16block: add queue_is_mq() helperJens Axboe1-4/+4
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>
2018-10-01Merge tag 'v4.19-rc6' into for-4.20/blockJens Axboe1-3/+3
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>
2018-09-28block: genhd: add 'groups' argument to device_add_diskHannes Reinecke1-5/+14
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>
2018-09-21block: use nanosecond resolution for iostatOmar Sandoval1-3/+3
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: 522a777566f5 ("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>
2018-07-18block: Track DISCARD statistics and output them in stat and diskstatMichael Callahan1-3/+10
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>
2018-07-18block: Define and use STAT_READ and STAT_WRITEMichael Callahan1-8/+8
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>
2018-06-04Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-26/+2
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 ...
2018-05-24block drivers/block: Use octal not symbolic permissionsJoe Perches1-20/+17
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>
2018-05-16proc: introduce proc_create_seq{,_data}Christoph Hellwig1-26/+2
Variants of proc_create{,_data} that directly take a struct seq_operations argument and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-04-26blk-mq: fix sysfs inflight counterOmar Sandoval1-0/+12
When the blk-mq inflight implementation was added, /proc/diskstats was converted to use it, but /sys/block/$dev/inflight was not. Fix it by adding another helper to count in-flight requests by data direction. Fixes: f299b7c7a9de ("blk-mq: provide internal in-flight variant") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-15block, char_dev: Use correct format specifier for unsigned intsSrivatsa S. Bhat1-8/+11
register_blkdev() and __register_chrdev_region() treat the major number as an unsigned int. So print it the same way to avoid absurd error statements such as: "... major requested (-1) is greater than the maximum (511) ..." (and also fix off-by-one bugs in the error prints). While at it, also update the comment describing register_blkdev(). Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-26genhd: Fix BUG in blkdev_open()Jan Kara1-1/+20
When two blkdev_open() calls for a partition race with device removal and recreation, we can hit BUG_ON(!bd_may_claim(bdev, whole, holder)) in blkdev_open(). The race can happen as follows: CPU0 CPU1 CPU2 del_gendisk() bdev_unhash_inode(part1); blkdev_open(part1, O_EXCL) blkdev_open(part1, O_EXCL) bdev = bd_acquire() bdev = bd_acquire() blkdev_get(bdev) bd_start_claiming(bdev) - finds old inode 'whole' bd_prepare_to_claim() -> 0 bdev_unhash_inode(whole); <device removed> <new device under same number created> blkdev_get(bdev); bd_start_claiming(bdev) - finds new inode 'whole' bd_prepare_to_claim() - this also succeeds as we have different 'whole' here... - bad things happen now as we have two exclusive openers of the same bdev The problem here is that block device opens can see various intermediate states while gendisk is shutting down and then being recreated. We fix the problem by introducing new lookup_sem in gendisk that synchronizes gendisk deletion with get_gendisk() and furthermore by making sure that get_gendisk() does not return gendisk that is being (or has been) deleted. This makes sure that once we ever manage to look up newly created bdev inode, we are also guaranteed that following get_gendisk() will either return failure (and we fail open) or it returns gendisk for the new device and following bdget_disk() will return new bdev inode (i.e., blkdev_open() follows the path as if it is completely run after new device is created). Reported-and-analyzed-by: Hou Tao <houtao1@huawei.com> Tested-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Add helper put_disk_and_module()Jan Kara1-4/+16
Add a proper counterpart to get_disk_and_module() - put_disk_and_module(). Currently it is opencoded in several places. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Rename get_disk() to get_disk_and_module()Jan Kara1-6/+4
Rename get_disk() to get_disk_and_module() to make sure what the function does. It's not a great name but at least it is now clear that put_disk() is not it's counterpart. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Fix leaked module reference for NVME devicesJan Kara1-0/+3
Commit 8ddcd653257c "block: introduce GENHD_FL_HIDDEN" added handling of hidden devices to get_gendisk() but forgot to drop module reference which is also acquired by get_disk(). Drop the reference as necessary. Arguably the function naming here is misleading as put_disk() is *not* the counterpart of get_disk() but let's fix that in the follow up commit since that will be more intrusive. Fixes: 8ddcd653257c18a669fcb75ee42c37054908e0d6 CC: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-15block: allow gendisk's request_queue registration to be deferredMike Snitzer1-3/+17
Since I can remember DM has forced the block layer to allow the allocation and initialization of the request_queue to be distinct operations. Reason for this is block/genhd.c:add_disk() has requires that the request_queue (and associated bdi) be tied to the gendisk before add_disk() is called -- because add_disk() also deals with exposing the request_queue via blk_register_queue(). DM's dynamic creation of arbitrary device types (and associated request_queue types) requires the DM device's gendisk be available so that DM table loads can establish a master/slave relationship with subordinate devices that are referenced by loaded DM tables -- using bd_link_disk_holder(). But until these DM tables, and their associated subordinate devices, are known DM cannot know what type of request_queue it needs -- nor what its queue_limits should be. This chicken and egg scenario has created all manner of problems for DM and, at times, the block layer. Summary of changes: - Add device_add_disk_no_queue_reg() and add_disk_no_queue_reg() variant that drivers may use to add a disk without also calling blk_register_queue(). Driver must call blk_register_queue() once its request_queue is fully initialized. - Return early from blk_unregister_queue() if QUEUE_FLAG_REGISTERED is not set. It won't be set if driver used add_disk_no_queue_reg() but driver encounters an error and must del_gendisk() before calling blk_register_queue(). - Export blk_register_queue(). These changes allow DM to use add_disk_no_queue_reg() to anchor its gendisk as the "master" for master/slave relationships DM must establish with subordinate devices referenced in DM tables that get loaded. Once all "slave" devices for a DM device are known its request_queue can be properly initialized and then advertised via sysfs -- important improvement being that no request_queue resource initialization performed by blk_register_queue() is missed for DM devices anymore. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-15block: only bdi_unregister() in del_gendisk() if !GENHD_FL_HIDDENMike Snitzer1-1/+2
device_add_disk() will only call bdi_register_owner() if !GENHD_FL_HIDDEN, so it follows that del_gendisk() should only call bdi_unregister() if !GENHD_FL_HIDDEN. Found with code inspection. bdi_unregister() won't do any harm if bdi_register_owner() wasn't used but best to avoid the unnecessary call to bdi_unregister(). Fixes: 8ddcd65325 ("block: introduce GENHD_FL_HIDDEN") Signed-off-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-19block: genhd.c: fix message typoRandy Dunlap1-1/+1
Fix typo in error message. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-19block: add WARN_ON if bdi register failweiping zhang1-2/+5
device_add_disk need do more safety error handle, so this patch just add WARN_ON. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Adapted for current series by me. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-21/+49
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-10block: avoid null pointer dereference on null diskColin Ian King1-1/+1
It is possible that the pointer disk can be null and hence we can get a null pointer deference when accessing disk->flags. Add a null pointer check to avoid the dereference. Detected by CoverityScan, CID#1461133 ("Explicit null dereferenced") Fixes: 8ddcd653257c ("block: introduce GENHD_FL_HIDDEN") Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block: create 'slaves' and 'holders' entries for hidden gendisksHannes Reinecke1-7/+7
When creating nvme multipath devices we should populate the 'slaves' and 'holders' directorys properly to aid userspace topology detection. Signed-off-by: Hannes Reinecke <hare@suse.com> [hch: split from a larger patch] Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03block: introduce GENHD_FL_HIDDENChristoph Hellwig1-18/+50
With this flag a driver can create a gendisk that can be used for I/O submission inside the kernel, but which is not registered as user facing block device. This will be useful for the NVMe multipath implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03block: don't look at the struct device dev_t in disk_devtChristoph Hellwig1-4/+0
The hidden gendisks introduced in the next patch need to keep the dev field in their struct device empty so that udev won't try to create block device nodes for them. To support that rewrite disk_devt to look at the major and first_minor fields in the gendisk itself instead of looking into the struct device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-26block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion()Byungchul Park1-8/+2
Darrick posted the following warning and Dave Chinner analyzed it: > ====================================================== > WARNING: possible circular locking dependency detected > 4.14.0-rc1-fixes #1 Tainted: G W > ------------------------------------------------------ > loop0/31693 is trying to acquire lock: > (&(&ip->i_mmaplock)->mr_lock){++++}, at: [<ffffffffa00f1b0c>] xfs_ilock+0x23c/0x330 [xfs] > > but now in release context of a crosslock acquired at the following: > ((complete)&ret.event){+.+.}, at: [<ffffffff81326c1f>] submit_bio_wait+0x7f/0xb0 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #2 ((complete)&ret.event){+.+.}: > lock_acquire+0xab/0x200 > wait_for_completion_io+0x4e/0x1a0 > submit_bio_wait+0x7f/0xb0 > blkdev_issue_zeroout+0x71/0xa0 > xfs_bmapi_convert_unwritten+0x11f/0x1d0 [xfs] > xfs_bmapi_write+0x374/0x11f0 [xfs] > xfs_iomap_write_direct+0x2ac/0x430 [xfs] > xfs_file_iomap_begin+0x20d/0xd50 [xfs] > iomap_apply+0x43/0xe0 > dax_iomap_rw+0x89/0xf0 > xfs_file_dax_write+0xcc/0x220 [xfs] > xfs_file_write_iter+0xf0/0x130 [xfs] > __vfs_write+0xd9/0x150 > vfs_write+0xc8/0x1c0 > SyS_write+0x45/0xa0 > entry_SYSCALL_64_fastpath+0x1f/0xbe > > -> #1 (&xfs_nondir_ilock_class){++++}: > lock_acquire+0xab/0x200 > down_write_nested+0x4a/0xb0 > xfs_ilock+0x263/0x330 [xfs] > xfs_setattr_size+0x152/0x370 [xfs] > xfs_vn_setattr+0x6b/0x90 [xfs] > notify_change+0x27d/0x3f0 > do_truncate+0x5b/0x90 > path_openat+0x237/0xa90 > do_filp_open+0x8a/0xf0 > do_sys_open+0x11c/0x1f0 > entry_SYSCALL_64_fastpath+0x1f/0xbe > > -> #0 (&(&ip->i_mmaplock)->mr_lock){++++}: > up_write+0x1c/0x40 > xfs_iunlock+0x1d0/0x310 [xfs] > xfs_file_fallocate+0x8a/0x310 [xfs] > loop_queue_work+0xb7/0x8d0 > kthread_worker_fn+0xb9/0x1f0 > > Chain exists of: > &(&ip->i_mmaplock)->mr_lock --> &xfs_nondir_ilock_class --> (complete)&ret.event > > Possible unsafe locking scenario by crosslock: > > CPU0 CPU1 > ---- ---- > lock(&xfs_nondir_ilock_class); > lock((complete)&ret.event); > lock(&(&ip->i_mmaplock)->mr_lock); > unlock((complete)&ret.event); > > *** DEADLOCK *** The warning is a false positive, caused by the fact that all wait_for_completion()s in submit_bio_wait() are waiting with the same lock class. However, some bios have nothing to do with others, for example in the case of loop devices, there's no direct connection between the bios of an upper device and the bios of a lower device(=loop device). The safest way to assign different lock classes to different devices is to do it for each gendisk. In other words, this patch assigns a lockdep_map per gendisk and uses it when initializing completion in submit_bio_wait(). Analyzed-by: Dave Chinner <david@fromorbit.com> Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Byungchul Park <byungchul.park@lge.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-10-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-20/+71
Pull block layer updates from Jens Axboe: "This is the first pull request for 4.14, containing most of the code changes. It's a quiet series this round, which I think we needed after the churn of the last few series. This contains: - Fix for a registration race in loop, from Anton Volkov. - Overflow complaint fix from Arnd for DAC960. - Series of drbd changes from the usual suspects. - Conversion of the stec/skd driver to blk-mq. From Bart. - A few BFQ improvements/fixes from Paolo. - CFQ improvement from Ritesh, allowing idling for group idle. - A few fixes found by Dan's smatch, courtesy of Dan. - A warning fixup for a race between changing the IO scheduler and device remova. From David Jeffery. - A few nbd fixes from Josef. - Support for cgroup info in blktrace, from Shaohua. - Also from Shaohua, new features in the null_blk driver to allow it to actually hold data, among other things. - Various corner cases and error handling fixes from Weiping Zhang. - Improvements to the IO stats tracking for blk-mq from me. Can drastically improve performance for fast devices and/or big machines. - Series from Christoph removing bi_bdev as being needed for IO submission, in preparation for nvme multipathing code. - Series from Bart, including various cleanups and fixes for switch fall through case complaints" * 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits) kernfs: checking for IS_ERR() instead of NULL drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set drbd: Fix allyesconfig build, fix recent commit drbd: switch from kmalloc() to kmalloc_array() drbd: abort drbd_start_resync if there is no connection drbd: move global variables to drbd namespace and make some static drbd: rename "usermode_helper" to "drbd_usermode_helper" drbd: fix race between handshake and admin disconnect/down drbd: fix potential deadlock when trying to detach during handshake drbd: A single dot should be put into a sequence. drbd: fix rmmod cleanup, remove _all_ debugfs entries drbd: Use setup_timer() instead of init_timer() to simplify the code. drbd: fix potential get_ldev/put_ldev refcount imbalance during attach drbd: new disk-option disable-write-same drbd: Fix resource role for newly created resources in events2 drbd: mark symbols static where possible drbd: Send P_NEG_ACK upon write error in protocol != C drbd: add explicit plugging when submitting batches drbd: change list_for_each_safe to while(list_first_entry_or_null) drbd: introduce drbd_recv_header_maybe_unplug ...
2017-08-23block: add a __disk_get_part helperChristoph Hellwig1-13/+13
This helper allows looking up a partion under RCU protection without grabbing a reference to it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23block: reject attempts to allocate more than DISK_MAX_PARTS partitionsChristoph Hellwig1-0/+7
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18genhd: Annotate all part and part_tbl pointer dereferencesBart Van Assche1-5/+10
Annotate gendisk.part_tbl and disk_part_tbl.part dereferences with rcu_dereference_protected(). This patch does not change the behavior of the modified code but ensures that sparse does not complain about disk->part_tbl manipulations nor about part_tbl->part accesses. Additionally, improve documentation of the locking requirements of the modified functions. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09blk-mq: provide internal in-flight variantJens Axboe1-0/+37
We don't have to inc/dec some counter, since we can just iterate the tags. That makes inc/dec a noop, but means we have to iterate busy tags to get an in-flight count. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09block: make part_in_flight() take an array of two intsJens Axboe1-1/+3
Instead of returning the count that matches the partition, pass in an array of two ints. Index 0 will be filled with the inflight count for the partition in question, and index 1 will filled with the root inflight count, if the partition passed in is not the root. This is in preparation for being able to calculate both in one go. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09block: pass in queue to inflight accountingJens Axboe1-2/+2
No functional change in this patch, just in preparation for basing the inflight mechanism on the queue in question. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-17block: order /proc/devices by major numberLogan Gunthorpe1-5/+13
Presently, the order of the block devices listed in /proc/devices is not entirely sequential. If a block device has a major number greater than BLKDEV_MAJOR_HASH_SIZE (255), it will be ordered as if its major were module 255. For example, 511 appears after 1. This patch cleans that up and prints each major number in the correct order, regardless of where they are stored in the hash table. In order to do this, we introduce BLKDEV_MAJOR_MAX as an artificial limit (chosen to be 512). It will then print all devices in major order number from 0 to the maximum. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20block: Constify disk_typeBart Van Assche1-2/+2
The variable 'disk_type' is never modified so constify it. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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