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2019-11-07blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTATTejun Heo
blkg_rwstat is now only used by bfq-iosched and blk-throtl when on cgroup1. Let's move it into its own files and gate it behind a config option. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07blk-cgroup: reimplement basic IO stats using cgroup rstatTejun Heo
blk-cgroup has been using blkg_rwstat to track basic IO stats. Unfortunately, reading recursive stats scales badly as itinvolves walking all descendants. On systems with a huge number of cgroups (dead or alive), this can lead to substantial CPU cost when reading IO stats. This patch reimplements basic IO stats using cgroup rstat which uses more memory but makes recursive stat reading O(# descendants which have been active since last reading) instead of O(# descendants). * blk-cgroup core no longer uses sync/async stats. Introduce new stat enums - BLKG_IOSTAT_{READ|WRITE|DISCARD}. * Add blkg_iostat[_set] which encapsulates byte and io stats, last values for propagation delta calculation and u64_stats_sync for correctness on 32bit archs. * Update the new percpu stat counters directly and implement blkcg_rstat_flush() to implement propagation. * blkg_print_stat() can now bring the stats up to date by calling cgroup_rstat_flush() and print them instead of directly summing up all descendants. * It now allocates 96 bytes per cpu. It used to be 40 bytes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Dan Schatzberg <dschatzberg@fb.com> Cc: Daniel Xu <dlxu@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07blk-cgroup: remove now unused blkg_print_stat_{bytes|ios}_recursive()Tejun Heo
These don't have users anymore. Remove them. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07blk-throtl: stop using blkg->stat_bytes and ->stat_iosTejun Heo
When used on cgroup1, blk-throtl uses the blkg->stat_bytes and ->stat_ios from blk-cgroup core to populate four stat knobs. blk-cgroup core is moving away from blkg_rwstat to improve scalability and won't be able to support this usage. It isn't like the sharing gains all that much. Let's break them out to dedicated rwstat counters which are updated when on cgroup1. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07bfq-iosched: stop using blkg->stat_bytes and ->stat_iosTejun Heo
When used on cgroup1, bfq uses the blkg->stat_bytes and ->stat_ios from blk-cgroup core to populate six stat knobs. blk-cgroup core is moving away from blkg_rwstat to improve scalability and won't be able to support this usage. It isn't like the sharing gains all that much. Let's break it out to dedicated rwstat counters which are updated when on cgroup1. This makes use of bfqg_*rwstat*() helpers outside of CONFIG_BFQ_CGROUP_DEBUG. Move them out. v2: Compile fix when !CONFIG_BFQ_CGROUP_DEBUG. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07bfq-iosched: relocate bfqg_*rwstat*() helpersTejun Heo
Collect them right under #ifdef CONFIG_BFQ_CGROUP_DEBUG. The next patch will use them from !DEBUG path and this makes it easy to move them out of the ifdef block. This is pure code reorganization. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07Merge branch 'for-linus' into for-5.5/blockJens Axboe
Pull on for-linus to resolve what otherwise would have been a conflict with the cgroups rstat patchset from Tejun. * for-linus: (942 commits) blkcg: make blkcg_print_stat() print stats only for online blkgs nvme: change nvme_passthru_cmd64 to explicitly mark rsvd nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths nvme-rdma: fix a segmentation fault during module unload iocost: don't nest spin_lock_irq in ioc_weight_write() io_uring: ensure we clear io_kiocb->result before each issue um-ubd: Entrust re-queue to the upper layers nvme-multipath: remove unused groups_only mode in ana log nvme-multipath: fix possible io hang after ctrl reconnect io_uring: don't touch ctx in setup after ring fd install io_uring: Fix leaked shadow_req Linux 5.4-rc5 riscv: cleanup do_trap_break nbd: verify socket is supported during setup ata: libahci_platform: Fix regulator_get_optional() misuse nbd: handle racing with error'ed out commands nbd: protect cmd->status with cmd->lock io_uring: fix bad inflight accounting for SETUP_IOPOLL|SETUP_SQTHREAD io_uring: used cached copies of sq->dropped and cq->overflow ARM: dts: stm32: relax qspi pins slew-rate for stm32mp157 ...
2019-11-07block: add zone open, close and finish ioctl supportAjay Joshi
Introduce three new ioctl commands BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE to allow applications to control the condition of zones on a zoned block device through the execution of the REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH operations. Contains contributions from Matias Bjorling, Hans Holmberg, Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig. Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com> Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07block: add zone open, close and finish operationsAjay Joshi
Zoned block devices (ZBC and ZAC devices) allow an explicit control over the condition (state) of zones. The operations allowed are: * Open a zone: Transition to open condition to indicate that a zone will actively be written * Close a zone: Transition to closed condition to release the drive resources used for writing to a zone * Finish a zone: Transition an open or closed zone to the full condition to prevent write operations To enable this control for in-kernel zoned block device users, define the new request operations REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH as well as the generic function blkdev_zone_mgmt() for submitting these operations on a range of zones. This results in blkdev_reset_zones() removal and replacement with this new zone magement function. Users of blkdev_reset_zones() (f2fs and dm-zoned) are updated accordingly. Contains contributions from Matias Bjorling, Hans Holmberg, Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig. Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com> Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07block: Simplify REQ_OP_ZONE_RESET_ALL handlingDamien Le Moal
There is no need for the function __blkdev_reset_all_zones() as REQ_OP_ZONE_RESET_ALL can be handled directly in blkdev_reset_zones() bio loop with an early break from the loop. This patch removes this function and modifies blkdev_reset_zones(), simplifying the code. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07block: Remove REQ_OP_ZONE_RESET pluggingDamien Le Moal
REQ_OP_ZONE_RESET operations cannot be merged as these bios and requests do not have a size and are never sequential due to the zone start sector position required for their execution. As a result, there is no point in using a plug around blkdev_reset_zones() bio issuing loop. This patch removes this unnecessary plugging. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-06blkcg: make blkcg_print_stat() print stats only for online blkgsTejun Heo
blkcg_print_stat() iterates blkgs under RCU and doesn't test whether the blkg is online. This can call into pd_stat_fn() on a pd which is still being initialized leading to an oops. The heaviest operation - recursively summing up rwstat counters - is already done while holding the queue_lock. Expand queue_lock to cover the other operations and skip the blkg if it isn't online yet. The online state is protected by both blkcg and queue locks, so this guarantees that only online blkgs are processed. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Roman Gushchin <guro@fb.com> Cc: Josef Bacik <jbacik@fb.com> Fixes: 903d23f0a354 ("blk-cgroup: allow controllers to output their own stats") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-06block: Warn if elevator= parameter is usedJan Kara
With transition to blk-mq, the elevator= kernel argument was removed as it makes less and less sense with the current variety of devices. Since this may surprise some users and there are advices on the Internet that still suggest to use it, let's at least warn if the parameter is used. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-04block: avoid blk_bio_segment_split for small I/O operationsChristoph Hellwig
__blk_queue_split() adds significant overhead for small I/O operations. Add a shortcut to avoid it for cases where we know we never need to split. Based on a patch from Ming Lei. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-04blk-mq: make sure that line break can be printedMing Lei
8962842ca5ab ("blk-mq: avoid sysfs buffer overflow with too many CPU cores") avoids sysfs buffer overflow, and reserves one character for line break. However, the last snprintf() doesn't get correct 'size' parameter passed in, so fixed it. Fixes: 8962842ca5ab ("blk-mq: avoid sysfs buffer overflow with too many CPU cores") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-04block: sed-opal: Introduce Opal Datastore UIDRevanth Rajashekar
This patch introduces Opal Datastore UID. The generic read/write table ioctl can use this UID to access the Opal Datastore. Reviewed-by: Scott Bauer <sbauer@plzdonthack.me> Reviewed-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-04block: sed-opal: Add support to read/write opal tables genericallyRevanth Rajashekar
This feature gives the user RW access to any opal table with admin1 authority. The flags described in the new structure determines if the user wants to read/write the data. Flags are checked for valid values in order to allow future features to be added to the ioctl. The user can provide the desired table's UID. Also, the ioctl provides a size and offset field and internally will loop data accesses to return the full data block. Read overrun is prevented by the initiator's sec_send_recv() backend. The ioctl provides a private field with the intention to accommodate any future expansions to the ioctl. Reviewed-by: Scott Bauer <sbauer@plzdonthack.me> Reviewed-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-04block: sed-opal: Generalizing write data to any opal tableRevanth Rajashekar
This patch refactors the existing "write_shadowmbr" func and creates a new generalized function "generic_table_write_data", to write data to any opal table. Also, a few cleanups are included in this patch. Reviewed-by: Scott Bauer <sbauer@plzdonthack.me> Reviewed-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-02blk-mq: avoid sysfs buffer overflow with too many CPU coresMing Lei
It is reported that sysfs buffer overflow can be triggered if the system has too many CPU cores(>841 on 4K PAGE_SIZE) when showing CPUs of hctx via /sys/block/$DEV/mq/$N/cpu_list. Use snprintf to avoid the potential buffer overflow. This version doesn't change the attribute format, and simply stops showing CPU numbers if the buffer is going to overflow. Cc: stable@vger.kernel.org Fixes: 676141e48af7("blk-mq: don't dump CPU -> hw queue map on driver load") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-01blk-mq: Make blk_mq_run_hw_queue() return voidJohn Garry
Since commit 97889f9ac24f ("blk-mq: remove synchronize_rcu() from blk_mq_del_queue_tag_set()"), the return value of blk_mq_run_hw_queue() is never checked, so make it return void, which very marginally simplifies the code. Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: John Garry <john.garry@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-31iocost: don't nest spin_lock_irq in ioc_weight_write()Dan Carpenter
This code causes a static analysis warning: block/blk-iocost.c:2113 ioc_weight_write() error: double lock 'irq' We disable IRQs in blkg_conf_prep() and re-enable them in blkg_conf_finish(). IRQ disable/enable should not be nested because that means the IRQs will be enabled at the first unlock instead of the second one. Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25blk-mq: remove needless goto from blk_mq_get_driver_tagAndré Almeida
The only usage of the label "done" is when (rq->tag != -1) at the beginning of the function. Rather than jumping to label, we can just remove this label and execute the code at the "if". Besides that, the code that would be executed after the label "done" is the return of the logical expression (rq->tag != -1) but since we are already inside the if, we now that this is true. Remove the label and replace the goto with the proper result of the label. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25block: Reduce the amount of memory used for tag setsBart Van Assche
Instead of allocating an array of size nr_cpu_ids for set->tags, allocate an array of size set->nr_hw_queues. This patch improves behavior that was introduced by commit 868f2f0b7206 ("blk-mq: dynamic h/w context count"). Reallocating tag sets from inside __blk_mq_update_nr_hw_queues() is safe because: - All request queues that share the tag sets are frozen before the tag sets are reallocated. - blk_mq_queue_tag_busy_iter() holds q->q_usage_counter while active and hence is serialized against __blk_mq_update_nr_hw_queues(). Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25block: Reduce the amount of memory required per request queueBart Van Assche
Instead of always allocating at least nr_cpu_ids hardware queues per request queue, reallocate q->queue_hw_ctx if it has to grow. This patch improves behavior that was introduced by commit 868f2f0b7206 ("blk-mq: dynamic h/w context count"). Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-25block: Remove the synchronize_rcu() call from __blk_mq_update_nr_hw_queues()Bart Van Assche
Since the blk_mq_{,un}freeze_queue() calls in __blk_mq_update_nr_hw_queues() already serialize __blk_mq_update_nr_hw_queues() against blk_mq_queue_tag_busy_iter(), the synchronize_rcu() call in __blk_mq_update_nr_hw_queues() is not necessary. Hence remove it. Note: the synchronize_rcu() call in __blk_mq_update_nr_hw_queues() was introduced by commit f5bbbbe4d635 ("blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter"). Commit 530ca2c9bd69 ("blk-mq: Allow blocking queue tag iter callbacks") removed the rcu_read_{,un}lock() calls that correspond to the synchronize_rcu() call in __blk_mq_update_nr_hw_queues(). Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-23compat_ioctl: reimplement SG_IO handlingArnd Bergmann
There are two code locations that implement the SG_IO ioctl: the old sg.c driver, and the generic scsi_ioctl helper that is in turn used by multiple drivers. To eradicate the old compat_ioctl conversion handler for the SG_IO command, I implement a readable pair of put_sg_io_hdr() /get_sg_io_hdr() helper functions that can be used for both compat and native mode, and then I call this from both drivers. For the iovec handling, there is already a compat_import_iovec() function that can simply be called in place of import_iovec(). To avoid having to pass the compat/native state through multiple indirections, I mark the SG_IO command itself as compatible in fs/compat_ioctl.c and use in_compat_syscall() to figure out where we are called from. As a side-effect of this, the sg.c driver now also accepts the 32-bit sg_io_hdr format in compat mode using the read/write interface, not just ioctl. This should improve compatiblity with old 32-bit binaries, but it would break if any application intentionally passes the 64-bit data structure in compat mode here. Steffen Maier helped debug an issue in an earlier version of this patch. Cc: Steffen Maier <maier@linux.ibm.com> Cc: linux-scsi@vger.kernel.org Cc: Doug Gilbert <dgilbert@interlog.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-15blk-rq-qos: fix first node deletion of rq_qos_del()Tejun Heo
rq_qos_del() incorrectly assigns the node being deleted to the head if it was the first on the list in the !prev path. Fix it by iterating with ** instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-15blkcg: Fix multiple bugs in blkcg_activate_policy()Tejun Heo
blkcg_activate_policy() has the following bugs. * cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") added @blkcg to ->pd_alloc_fn(); however, blkcg_activate_policy() ends up using pd's allocated for the root blkcg for all preallocations, so ->pd_init_fn() for non-root blkcgs can be passed in pd's which are allocated for the root blkcg. For blk-iocost, this means that ->pd_init_fn() can write beyond the end of the allocated object as it determines the length of the flex array at the end based on the blkcg's nesting level. * Each pd is initialized as they get allocated. If alloc fails, the policy will get freed with pd's initialized on it. * After the above partial failure, the partial pds are not freed. This patch fixes all the above issues by * Restructuring blkcg_activate_policy() so that alloc and init passes are separate. Init takes place only after all allocs succeeded and on failure all allocated pds are freed. * Unifying and fixing the cleanup of the remaining pd_prealloc. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-14block: Fix elv_support_iosched()Damien Le Moal
A BIO based request queue does not have a tag_set, which prevent testing for the flag BLK_MQ_F_NO_SCHED indicating that the queue does not require an elevator. This leads to an incorrect initialization of a default elevator in some cases such as BIO based null_blk (queue_mode == BIO) with zoned mode enabled as the default elevator in this case is mq-deadline instead of "none". Fix this by testing for a NULL queue mq_ops field which indicates that the queue is BIO based and should not have an elevator. Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-10block: account statistics for passthrough requestsLogan Gunthorpe
Presently, passthrough requests are not accounted for because blk_do_io_stat() expressly rejects them. Based on some digging in the history, this doesn't seem like a concious decision but one that evolved from the change from blk_fs_request() to blk_rq_is_passthrough(). To support this, call blk_account_io_start() in blk_execute_rq_nowait() and remove the passthrough check in blk_do_io_stat(). Link: https://lore.kernel.org/linux-block/20191010100526.GA27209@lst.de/ Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-stat: Optimise blk_stat_add()Pavel Begunkov
blk_stat_add() calls {get,put}_cpu_ptr() in a loop, which entails overhead of disabling/enabling preemption. The loop is under RCU (i.e.short) anyway, so do get_cpu() in advance. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-mq: Embed counters into struct mq_inflightPavel Begunkov
Store inflight counters immediately in struct mq_inflight. That's type-safer and removes extra indirection. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-mq: Reuse callback in blk_mq_in_flight*()Pavel Begunkov
Reuse a more generic callback in both blk_mq_in_flight() and blk_mq_in_flight_rw(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07blk-mq: Inline status checkersPavel Begunkov
blk_mq_request_completed() and blk_mq_request_started() are short, inline it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Reduce sysfs_lock locking inside blk_cleanup_queue()Bart Van Assche
Since blk_cleanup_queue() is called after blk_unregister_queue() and since that last function removes all sysfs attributes, serializing any code in blk_cleanup_queue() against sysfs callback methods nor against I/O scheduler changes is necessary. Hence remove the syfs_lock locking calls from the start of blk_cleanup_queue(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Remove "dying" checks from sysfs callbacksBart Van Assche
Block drivers must call del_gendisk() before blk_cleanup_queue(). del_gendisk() calls kobject_del() and kobject_del() waits until any ongoing sysfs callback functions have finished. In other words, the sysfs callback functions won't be called for a queue in the dying state. Hence remove the "dying" checks from the sysfs callback functions. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Remove request_queue.nr_queuesBart Van Assche
Commit 897bb0c7f1ea ("blk-mq: Use proper cpumask iterator"; v4.6) removed the last use of request_queue.nr_queues from outside blk_mq_init_allocate_queue(). Remove this member variable to make struct request_queue smaller. This patch does not change any functionality. Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07block: Fix three kernel-doc warningsBart Van Assche
Fix the following kernel-doc warnings: block/t10-pi.c:242: warning: Function parameter or member 'rq' not described in 't10_pi_type3_prepare' block/t10-pi.c:249: warning: Function parameter or member 'rq' not described in 't10_pi_type3_complete' block/t10-pi.c:249: warning: Function parameter or member 'nr_bytes' not described in 't10_pi_type3_complete' Cc: Max Gurtovoy <maxg@mellanox.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Fixes: 54d4e6ab91eb ("block: centralize PI remapping logic to the block layer") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-06blk-wbt: fix performance regression in wbt scale_up/scale_downHarshad Shirwadkar
scale_up wakes up waiters after scaling up. But after scaling max, it should not wake up more waiters as waiters will not have anything to do. This patch fixes this by making scale_up (and also scale_down) return when threshold is reached. This bug causes increased fdatasync latency when fdatasync and dd conv=sync are performed in parallel on 4.19 compared to 4.14. This bug was introduced during refactoring of blk-wbt code. Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Cc: stable@vger.kernel.org Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-03block: sed-opal: fix sparse warning: convert __be64 dataRandy Dunlap
sparse warns about incorrect type when using __be64 data. It is not being converted to CPU-endian but it should be. Fixes these sparse warnings: ../block/sed-opal.c:375:20: warning: incorrect type in assignment (different base types) ../block/sed-opal.c:375:20: expected unsigned long long [usertype] align ../block/sed-opal.c:375:20: got restricted __be64 const [usertype] alignment_granularity ../block/sed-opal.c:376:25: warning: incorrect type in assignment (different base types) ../block/sed-opal.c:376:25: expected unsigned long long [usertype] lowest_lba ../block/sed-opal.c:376:25: got restricted __be64 const [usertype] lowest_aligned_lba Fixes: 455a7b238cd6 ("block: Add Sed-opal library") Cc: Scott Bauer <scott.bauer@intel.com> Cc: Rafael Antognolli <rafael.antognolli@intel.com> Cc: linux-block@vger.kernel.org Reviewed-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-03block: sed-opal: fix sparse warning: obsolete array init.Randy Dunlap
Fix sparse warning: (missing '=') ../block/sed-opal.c:133:17: warning: obsolete array initializer, use C99 syntax Fixes: ff91064ea37c ("block: sed-opal: check size of shadow mbr") Cc: linux-block@vger.kernel.org Cc: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de> Cc: David Kozub <zub@linux.fjfi.cvut.cz> Reviewed-by: Scott Bauer <sbauer@plzdonthack.me> Reviewed-by: Revanth Rajashekar <revanth.rajashekar@intel.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27blk-mq: apply normal plugging for HDDMing Lei
Some HDD drive may expose multiple hardware queues, such as MegraRaid. Let's apply the normal plugging for such devices because sequential IO may benefit a lot from plug merging. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Dave Chinner <dchinner@redhat.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27blk-mq: honor IO scheduler for multiqueue devicesMing Lei
If a device is using multiple queues, the IO scheduler may be bypassed. This may hurt performance for some slow MQ devices, and it also breaks zoned devices which depend on mq-deadline for respecting the write order in one zone. Don't bypass io scheduler if we have one setup. This patch can double sequential write performance basically on MQ scsi_debug when mq-deadline is applied. Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Dave Chinner <dchinner@redhat.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27block: fix null pointer dereference in blk_mq_rq_timed_out()Yufen Yu
We got a null pointer deference BUG_ON in blk_mq_rq_timed_out() as following: [ 108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040 [ 108.827059] PGD 0 P4D 0 [ 108.827313] Oops: 0000 [#1] SMP PTI [ 108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431 [ 108.829503] Workqueue: kblockd blk_mq_timeout_work [ 108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330 [ 108.838191] Call Trace: [ 108.838406] bt_iter+0x74/0x80 [ 108.838665] blk_mq_queue_tag_busy_iter+0x204/0x450 [ 108.839074] ? __switch_to_asm+0x34/0x70 [ 108.839405] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.839823] ? blk_mq_stop_hw_queue+0x40/0x40 [ 108.840273] ? syscall_return_via_sysret+0xf/0x7f [ 108.840732] blk_mq_timeout_work+0x74/0x200 [ 108.841151] process_one_work+0x297/0x680 [ 108.841550] worker_thread+0x29c/0x6f0 [ 108.841926] ? rescuer_thread+0x580/0x580 [ 108.842344] kthread+0x16a/0x1a0 [ 108.842666] ? kthread_flush_work+0x170/0x170 [ 108.843100] ret_from_fork+0x35/0x40 The bug is caused by the race between timeout handle and completion for flush request. When timeout handle function blk_mq_rq_timed_out() try to read 'req->q->mq_ops', the 'req' have completed and reinitiated by next flush request, which would call blk_rq_init() to clear 'req' as 0. After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"), normal requests lifetime are protected by refcount. Until 'rq->ref' drop to zero, the request can really be free. Thus, these requests cannot been reused before timeout handle finish. However, flush request has defined .end_io and rq->end_io() is still called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq' can be reused by the next flush request handle, resulting in null pointer deference BUG ON. We fix this problem by covering flush request with 'rq->ref'. If the refcount is not zero, flush_end_io() return and wait the last holder recall it. To record the request status, we add a new entry 'rq_status', which will be used in flush_end_io(). Cc: Christoph Hellwig <hch@infradead.org> Cc: Keith Busch <keith.busch@intel.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: stable@vger.kernel.org # v4.18+ Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> ------- v2: - move rq_status from struct request to struct blk_flush_queue v3: - remove unnecessary '{}' pair. v4: - let spinlock to protect 'fq->rq_status' v5: - move rq_status after flush_running_idx member of struct blk_flush_queue Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-27rq-qos: get rid of redundant wbt_update_limits()Yufen Yu
We have updated limits after calling wbt_set_min_lat(). No need to update again. Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26iocost: bump up default latency targets for hard disksTejun Heo
The default hard disk param sets latency targets at 50ms. As the default target percentiles are zero, these don't directly regulate vrate; however, they're still used to calculate the period length - 100ms in this case. This is excessively low. A SATA drive with QD32 saturated with random IOs can easily reach avg completion latency of several hundred msecs. A period duration which is substantially lower than avg completion latency can lead to wildly fluctuating vrate. Let's bump up the default latency targets to 250ms so that the period duration is sufficiently long. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26iocost: improve nr_lagging handlingTejun Heo
Some IOs may span multiple periods. As latencies are collected on completion, the inbetween periods won't register them and may incorrectly decide to increase vrate. nr_lagging tracks these IOs to avoid those situations. Currently, whenever there are IOs which are spanning from the previous period, busy_level is reset to 0 if negative thus suppressing vrate increase. This has the following two problems. * When latency target percentiles aren't set, vrate adjustment should only be governed by queue depth depletion; however, the current code keeps nr_lagging active which pulls in latency results and can keep down vrate unexpectedly. * When lagging condition is detected, it resets the entire negative busy_level. This turned out to be way too aggressive on some devices which sometimes experience extended latencies on a small subset of commands. In addition, a lagging IO will be accounted as latency target miss on completion anyway and resetting busy_level amplifies its impact unnecessarily. This patch fixes the above two problems by disabling nr_lagging counting when latency target percentiles aren't set and blocking vrate increases when there are lagging IOs while leaving busy_level as-is. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26iocost: better trace vrate changesTejun Heo
vrate_adj tracepoint traces vrate changes; however, it does so only when busy_level is non-zero. busy_level turning to zero can sometimes be as interesting an event. This patch also enables vrate_adj tracepoint on other vrate related events - busy_level changes and non-zero nr_lagging. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26block: don't release queue's sysfs lock during switching elevatorMing Lei
cecf5d87ff20 ("block: split .sysfs_lock into two locks") starts to release & acquire sysfs_lock before registering/un-registering elevator queue during switching elevator for avoiding potential deadlock from showing & storing 'queue/iosched' attributes and removing elevator's kobject. Turns out there isn't such deadlock because 'q->sysfs_lock' isn't required in .show & .store of queue/iosched's attributes, and just elevator's sysfs lock is acquired in elv_iosched_store() and elv_iosched_show(). So it is safe to hold queue's sysfs lock when registering/un-registering elevator queue. The biggest issue is that commit cecf5d87ff20 assumes that concurrent write on 'queue/scheduler' can't happen. However, this assumption isn't true, because kernfs_fop_write() only guarantees that concurrent write aren't called on the same open file, but the write could be from different open on the file. So we can't release & re-acquire queue's sysfs lock during switching elevator, otherwise use-after-free on elevator could be triggered. Fixes the issue by not releasing queue's sysfs lock during switching elevator. Fixes: cecf5d87ff20 ("block: split .sysfs_lock into two locks") Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-26blk-mq: move lockdep_assert_held() into elevator_exitMing Lei
Commit c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq") removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with lockdep_assert_held() called in blk_mq_sched_free_requests() which is run in failure path of elevator_init_mq(). blk_mq_sched_free_requests() is called in the following 3 functions: elevator_init_mq() elevator_exit() blk_cleanup_queue() In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly by 'mutex_lock(&q->sysfs_lock)'. So moving the lockdep_assert_held() from blk_mq_sched_free_requests() into elevator_exit() for fixing the report by syzbot. Reported-by: syzbot+da3b7677bb913dc1b737@syzkaller.appspotmail.com Fixed: c48dac137a62 ("block: don't hold q->sysfs_lock in elevator_init_mq") Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>