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* dm: remove legacy request-based IO pathJens Axboe2018-10-111-290/+26
| | | | | | | | dm supports both, and since we're killing off the legacy path in general, get rid of it in dm. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: convert to bioset_init()/mempool_init()Kent Overstreet2018-05-301-1/+1
| | | | | | | | Convert dm to embedded bio sets. Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: consolidate struct request timestamp fieldsOmar Sandoval2018-05-091-1/+1
| | | | | | | | | | | | | | | | Currently, struct request has four timestamp fields: - A start time, set at get_request time, in jiffies, used for iostats - An I/O start time, set at start_request time, in ktime nanoseconds, used for blk-stats (i.e., wbt, kyber, hybrid polling) - Another start time and another I/O start time, used for cfq and bfq These can all be consolidated into one start time and one I/O start time, both in ktime nanoseconds, shaving off up to 16 bytes from struct request depending on the kernel config. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'for-linus-20180204' of git://git.kernel.dk/linux-blockLinus Torvalds2018-02-041-3/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull more block updates from Jens Axboe: "Most of this is fixes and not new code/features: - skd fix from Arnd, fixing a build error dependent on sla allocator type. - blk-mq scheduler discard merging fixes, one from me and one from Keith. This fixes a segment miscalculation for blk-mq-sched, where we mistakenly think two segments are physically contigious even though the request isn't carrying real data. Also fixes a bio-to-rq merge case. - Don't re-set a bit on the buffer_head flags, if it's already set. This can cause scalability concerns on bigger machines and workloads. From Kemi Wang. - Add BLK_STS_DEV_RESOURCE return value to blk-mq, allowing us to distuingish between a local (device related) resource starvation and a global one. The latter might happen without IO being in flight, so it has to be handled a bit differently. From Ming" * tag 'for-linus-20180204' of git://git.kernel.dk/linux-block: block: skd: fix incorrect linux/slab_def.h inclusion buffer: Avoid setting buffer bits that are already set blk-mq-sched: Enable merging discard bio into request blk-mq: fix discard merge with scheduler attached blk-mq: introduce BLK_STS_DEV_RESOURCE
| * blk-mq: introduce BLK_STS_DEV_RESOURCEMing Lei2018-01-301-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This status is returned from driver to block layer if device related resource is unavailable, but driver can guarantee that IO dispatch will be triggered in future when the resource is available. Convert some drivers to return BLK_STS_DEV_RESOURCE. Also, if driver returns BLK_STS_RESOURCE and SCHED_RESTART is set, rerun queue after a delay (BLK_MQ_DELAY_QUEUE) to avoid IO stalls. BLK_MQ_DELAY_QUEUE is 3 ms because both scsi-mq and nvmefc are using that magic value. If a driver can make sure there is in-flight IO, it is safe to return BLK_STS_DEV_RESOURCE because: 1) If all in-flight IOs complete before examining SCHED_RESTART in blk_mq_dispatch_rq_list(), SCHED_RESTART must be cleared, so queue is run immediately in this case by blk_mq_dispatch_rq_list(); 2) if there is any in-flight IO after/when examining SCHED_RESTART in blk_mq_dispatch_rq_list(): - if SCHED_RESTART isn't set, queue is run immediately as handled in 1) - otherwise, this request will be dispatched after any in-flight IO is completed via blk_mq_sched_restart() 3) if SCHED_RESTART is set concurently in context because of BLK_STS_RESOURCE, blk_mq_delay_run_hw_queue() will cover the above two cases and make sure IO hang can be avoided. One invariant is that queue will be rerun if SCHED_RESTART is set. Suggested-by: Jens Axboe <axboe@kernel.dk> Tested-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge tag 'for-4.16/dm-changes' of ↵Linus Torvalds2018-01-311-2/+4
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - DM core fixes to ensure that bio submission follows a depth-first tree walk; this is critical to allow forward progress without the need to use the bioset's BIOSET_NEED_RESCUER. - Remove DM core's BIOSET_NEED_RESCUER based dm_offload infrastructure. - DM core cleanups and improvements to make bio-based DM more efficient (e.g. reduced memory footprint as well leveraging per-bio-data more). - Introduce new bio-based mode (DM_TYPE_NVME_BIO_BASED) that leverages the more direct IO submission path in the block layer; this mode is used by DM multipath and also optimizes targets like DM thin-pool that stack directly on NVMe data device. - DM multipath improvements to factor out legacy SCSI-only (e.g. scsi_dh) code paths to allow for more optimized support for NVMe multipath. - A fix for DM multipath path selectors (service-time and queue-length) to select paths in a more balanced way; largely academic but doesn't hurt. - Numerous DM raid target fixes and improvements. - Add a new DM "unstriped" target that enables Intel to workaround firmware limitations in some NVMe drives that are striped internally (this target also works when stacked above the DM "striped" target). - Various Documentation fixes and improvements. - Misc cleanups and fixes across various DM infrastructure and targets (e.g. bufio, flakey, log-writes, snapshot). * tag 'for-4.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (69 commits) dm cache: Documentation: update default migration_throttling value dm mpath selector: more evenly distribute ties dm unstripe: fix target length versus number of stripes size check dm thin: fix trailing semicolon in __remap_and_issue_shared_cell dm table: fix NVMe bio-based dm_table_determine_type() validation dm: various cleanups to md->queue initialization code dm mpath: delay the retry of a request if the target responded as busy dm mpath: return DM_MAPIO_DELAY_REQUEUE if QUEUE_IO or PG_INIT_REQUIRED dm mpath: return DM_MAPIO_REQUEUE on blk-mq rq allocation failure dm log writes: fix max length used for kstrndup dm: backfill missing calls to mutex_destroy() dm snapshot: use mutex instead of rw_semaphore dm flakey: check for null arg_name in parse_features() dm thin: extend thinpool status format string with omitted fields dm thin: fixes in thin-provisioning.txt dm thin: document representation of <highest mapped sector> when there is none dm thin: fix documentation relative to low water mark threshold dm cache: be consistent in specifying sectors and SI units in cache.txt dm cache: delete obsoleted paragraph in cache.txt dm cache: fix grammar in cache-policies.txt ...
| * dm: various cleanups to md->queue initialization codeMike Snitzer2018-01-291-2/+0
| | | | | | | | | | | | Also, add dm_sysfs_init() error handling to dm_create(). Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: delay the retry of a request if the target responded as busyMike Snitzer2018-01-291-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add DM_ENDIO_DELAY_REQUEUE to allow request-based multipath's multipath_end_io() to instruct dm-rq.c:dm_done() to delay a requeue. This is beneficial to do if BLK_STS_RESOURCE is returned from the target (because target is busy). Relative to blk-mq: kick the hw queues via blk_mq_requeue_work(), indirectly from dm-rq.c:__dm_mq_kick_requeue_list(), after a delay. For old .request_fn: use blk_delay_queue(). bio-based multipath doesn't have feature parity with request-based for retryable error requeues; that is something that'll need fixing in the future. Suggested-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Bart Van Assche <bart.vanassche@wdc.com> [as interpreted from Bart's "... patch looks fine to me."]
* | blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedbackMing Lei2018-01-171-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_insert_cloned_request() is called in the fast path of a dm-rq driver (e.g. blk-mq request-based DM mpath). blk_insert_cloned_request() uses blk_mq_request_bypass_insert() to directly append the request to the blk-mq hctx->dispatch_list of the underlying queue. 1) This way isn't efficient enough because the hctx spinlock is always used. 2) With blk_insert_cloned_request(), we completely bypass underlying queue's elevator and depend on the upper-level dm-rq driver's elevator to schedule IO. But dm-rq currently can't get the underlying queue's dispatch feedback at all. Without knowing whether a request was issued or not (e.g. due to underlying queue being busy) the dm-rq elevator will not be able to provide effective IO merging (as a side-effect of dm-rq currently blindly destaging a request from its elevator only to requeue it after a delay, which kills any opportunity for merging). This obviously causes very bad sequential IO performance. Fix this by updating blk_insert_cloned_request() to use blk_mq_request_direct_issue(). blk_mq_request_direct_issue() allows a request to be issued directly to the underlying queue and returns the dispatch feedback (blk_status_t). If blk_mq_request_direct_issue() returns BLK_SYS_RESOURCE the dm-rq driver will now use DM_MAPIO_REQUEUE to _not_ destage the request. Whereby preserving the opportunity to merge IO. With this, request-based DM's blk-mq sequential IO performance is vastly improved (as much as 3X in mpath/virtio-scsi testing). Signed-off-by: Ming Lei <ming.lei@redhat.com> [blk-mq.c changes heavily influenced by Ming Lei's initial solution, but they were refactored to make them less fragile and easier to read/review] Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | dm: fix incomplete request_queue initializationMike Snitzer2018-01-151-9/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DM is no longer prone to having its request_queue be improperly initialized. Summary of changes: - defer DM's blk_register_queue() from add_disk()-time until dm_setup_md_queue() by using add_disk_no_queue_reg() in alloc_dev(). - dm_setup_md_queue() is updated to fully initialize DM's request_queue (_after_ all table loads have occurred and the request_queue's type, features and limits are known). A very welcome side-effect of these changes is DM no longer needs to: 1) backfill the "mq" sysfs entry (because historically DM didn't initialize the request_queue to use blk-mq until _after_ blk_register_queue() was called via add_disk()). 2) call elv_register_queue() to get .request_fn request-based DM device's "iosched" exposed in syfs. In addition, blk-mq debugfs support is now made available because request-based DM's blk-mq request_queue is now properly initialized before dm_setup_md_queue() calls blk_register_queue(). These changes also stave off the need to introduce new DM-specific workarounds in block core, e.g. this proposal: https://patchwork.kernel.org/patch/10067961/ In the end DM devices should be less unicorn in nature (relative to initialization and availability of block core infrastructure provided by the request_queue). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Tested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: remove QUEUE_FLAG_STACKABLEChristoph Hellwig2017-10-051-1/+1
| | | | | | | | | We already have a queue_is_rq_based helper to check if a request_queue is request based, so we can remove the flag for it. Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* dm rq: do not update rq partially in each ending bioMing Lei2017-08-281-11/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | We don't need to update the original dm request partially when ending each cloned bio: just update original dm request once when the whole cloned request is finished. This still allows full support for partial completion because a new 'completed' counter accounts for incremental progress as the clone bios complete. Partial request update can be a bit expensive, so we should try to avoid it, especially because it is run in softirq context. Avoiding all the partial request updates fixes both hard lockup and soft lockups that were easily reproduced while running Laurence's test[1] on IB/SRP. BTW, after d4acf3650c7c ("block: Make blk_mq_delay_kick_requeue_list() rerun the queue at a quiet time"), we need to make the test more aggressive for reproducing the lockup: 1) run hammer_write.sh 32 or 64 concurrently. 2) write 8M each time [1] https://marc.info/?l=linux-block&m=150220185510245&w=2 Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm rq: make dm-sq requeuing behavior consistent with dm-mq behaviorBart Van Assche2017-08-281-4/+5
| | | | | | | | | | DM_MAPIO_DELAY_REQUEUE causes dm-mq to requeue after a delay but causes dm-sq to requeue immediately. Make the behavior of dm-sq consistent with that of dm-mq. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* blk-mq: use the introduced blk_mq_unquiesce_queue()Ming Lei2017-06-181-1/+1
| | | | | | | | | | | | | | | | blk_mq_unquiesce_queue() is used for unquiescing the queue explicitly, so replace blk_mq_start_stopped_hw_queues() with it. For the scsi part, this patch takes Bart's suggestion to switch to block quiesce/unquiesce API completely. Cc: linux-nvme@lists.infradead.org Cc: linux-scsi@vger.kernel.org Cc: dm-devel@redhat.com Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: switch bios to blk_status_tChristoph Hellwig2017-06-091-1/+1
| | | | | | | | | | Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* blk-mq: switch ->queue_rq return value to blk_status_tChristoph Hellwig2017-06-091-4/+4
| | | | | | | | | Use the same values for use for request completion errors as the return value from ->queue_rq. BLK_STS_RESOURCE is special cased to cause a requeue, and all the others are completed as-is. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: introduce new block status code typeChristoph Hellwig2017-06-091-10/+10
| | | | | | | | | | | | | | | | | | | | | | | Currently we use nornal Linux errno values in the block layer, and while we accept any error a few have overloaded magic meanings. This patch instead introduces a new blk_status_t value that holds block layer specific status codes and explicitly explains their meaning. Helpers to convert from and to the previous special meanings are provided for now, but I suspect we want to get rid of them in the long run - those drivers that have a errno input (e.g. networking) usually get errnos that don't know about the special block layer overloads, and similarly returning them to userspace will usually return somethings that strictly speaking isn't correct for file system operations, but that's left as an exercise for later. For now the set of errors is a very limited set that closely corresponds to the previous overloaded errno values, but there is some low hanging fruite to improve it. blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse typechecking, so that we can easily catch places passing the wrong values. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* dm rq: add a missing break to map_requestChristoph Hellwig2017-05-151-0/+1
| | | | | | | | We don't want to bug when receiving a DM_MAPIO_KILL value.. Fixes: 412445ac ("dm: introduce a new DM_MAPIO_KILL return value") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2017-05-061-4/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes and updates from Jens Axboe: "Some fixes and followup features/changes that should go in, in this merge window. This contains: - Two fixes for lightnvm from Javier, fixing problems in the new code merge previously in this merge window. - A fix from Jan for the backing device changes, fixing an issue in NFS that causes a failure to mount on certain setups. - A change from Christoph, cleaning up the blk-mq init and exit request paths. - Remove elevator_change(), which is now unused. From Bart. - A fix for queue operation invocation on a dead queue, from Bart. - A series fixing up mtip32xx for blk-mq scheduling, removing a bandaid we previously had in place for this. From me. - A regression fix for this series, fixing a case where we wait on workqueue flushing from an invalid (non-blocking) context. From me. - A fix/optimization from Ming, ensuring that we don't both quiesce and freeze a queue at the same time. - A fix from Peter on lock ordering for CPU hotplug. Not a real problem right now, but will be once the CPU hotplug rework goes in. - A series from Omar, cleaning up out blk-mq debugfs support, and adding support for exporting info from schedulers in debugfs as well. This is really useful in debugging stalls or livelocks. From Omar" * 'for-linus' of git://git.kernel.dk/linux-block: (28 commits) mq-deadline: add debugfs attributes kyber: add debugfs attributes blk-mq-debugfs: allow schedulers to register debugfs attributes blk-mq: untangle debugfs and sysfs blk-mq: move debugfs declarations to a separate header file blk-mq: Do not invoke queue operations on a dead queue blk-mq-debugfs: get rid of a bunch of boilerplate blk-mq-debugfs: rename hw queue directories from <n> to hctx<n> blk-mq-debugfs: don't open code strstrip() blk-mq-debugfs: error on long write to queue "state" file blk-mq-debugfs: clean up flag definitions blk-mq-debugfs: separate flags with | nfs: Fix bdi handling for cloned superblocks block/mq: Cure cpu hotplug lock inversion lightnvm: fix bad back free on error path lightnvm: create cmd before allocating request blk-mq: don't use sync workqueue flushing from drivers mtip32xx: convert internal commands to regular block infrastructure mtip32xx: cleanup internal tag assumptions block: don't call blk_mq_quiesce_queue() after queue is frozen ...
| * blk-mq: update ->init_request and ->exit_request prototypesChristoph Hellwig2017-05-021-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | Remove the request_idx parameter, which can't be used safely now that we support I/O schedulers with blk-mq. Except for a superflous check in mtip32xx it was unused anyway. Also pass the tag_set instead of just the driver data - this allows drivers to avoid some code duplication in a follow on cleanup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | dm: introduce a new DM_MAPIO_KILL return valueChristoph Hellwig2017-05-011-7/+5
| | | | | | | | | | | | | | | | This untangles the DM_MAPIO_* values returned from ->clone_and_map_rq from the error codes used by the block layer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | dm rq: change ->rq_end_io calling conventionsChristoph Hellwig2017-05-011-7/+10
| | | | | | | | | | | | | | | | | | | | | | Instead of returning either a DM_ENDIO_* constant or an error code, add a new DM_ENDIO_DONE value that means keep errno as is. This allows us to easily keep the existing error code in case where we can't push back, and it also preparares for the new block level status codes with strict type checking. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | Merge branch 'dm-4.12' into dm-4.12-post-mergeMike Snitzer2017-05-011-2/+6
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| * dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue()Bart Van Assche2017-04-271-1/+5
| | | | | | | | | | | | | | | | | | | | | | Otherwise the request-based DM blk-mq request_queue will be put into service without being properly exported via sysfs. Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm mpath: requeue after a small delay if blk_get_request() failsBart Van Assche2017-04-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If blk_get_request() returns ENODEV then multipath_clone_and_map() causes a request to be requeued immediately. This can cause a kworker thread to spend 100% of the CPU time of a single core in __blk_mq_run_hw_queue() and also can cause device removal to never finish. Avoid this by only requeuing after a delay if blk_get_request() fails. Additionally, reduce the requeue delay. Cc: stable@vger.kernel.org # 4.9+ Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | blk-mq: remove the error argument to blk_mq_complete_requestChristoph Hellwig2017-04-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | Now that all drivers that call blk_mq_complete_requests have a ->complete callback we can remove the direct call to blk_mq_end_request, as well as the error argument to blk_mq_complete_request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | dm rq: don't pass irrelevant error code to blk_mq_complete_requestChristoph Hellwig2017-04-201-1/+1
| | | | | | | | | | | | | | | | | | | | dm never uses rq->errors, so there is no need to pass an error argument to blk_mq_complete_request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | dm: support REQ_OP_WRITE_ZEROESChristoph Hellwig2017-04-081-3/+8
| | | | | | | | | | | | | | | | Copy & paste from the REQ_OP_WRITE_SAME code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge branch 'for-linus' into for-4.12/blockJens Axboe2017-04-071-0/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | We've added a considerable amount of fixes for stalls and issues with the blk-mq scheduling in the 4.11 series since forking off the for-4.12/block branch. We need to do improvements on top of that for 4.12, so pull in the previous fixes to make our lives easier going forward. Signed-off-by: Jens Axboe <axboe@fb.com>
| * | dm rq: Avoid that request processing stalls sporadicallyBart Van Assche2017-04-071-0/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running the srp-test software I noticed that request processing stalls sporadically at the beginning of a test, namely when mkfs is run against a dm-mpath device. Every time when that happened the following command was sufficient to resume request processing: echo run >/sys/kernel/debug/block/dm-0/state This patch avoids that such request processing stalls occur. The test I ran is as follows: while srp-test/run_tests -d -r 30 -t 02-mq; do :; done Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Jens Axboe <axboe@fb.com>
* | blk-mq: constify struct blk_mq_opsEric Biggers2017-03-311-1/+1
|/ | | | | | | Constify all instances of blk_mq_ops, as they are never modified. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* dm-rq: don't dereference request payload after ending requestJens Axboe2017-02-241-2/+4
| | | | | | | | | | | | | Bart reported a case where dm would crash with use-after-free poison. This is due to dm_softirq_done() accessing memory associated with a request after calling end_request on it. This is most visible on !blk-mq, since we free the memory immediately for that case. Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes: eb8db831be80 ("dm: always defer request allocation to the owner of the request_queue") Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-4.11/next' into for-4.11/linus-mergeJens Axboe2017-02-171-211/+57
|\ | | | | | | Signed-off-by: Jens Axboe <axboe@fb.com>
| * dm: always defer request allocation to the owner of the request_queueChristoph Hellwig2017-01-271-195/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DM already calls blk_mq_alloc_request on the request_queue of the underlying device if it is a blk-mq device. But now that we allow drivers to allocate additional data and initialize it ahead of time we need to do the same for all drivers. Doing so and using the new cmd_size infrastructure in the block layer greatly simplifies the dm-rq and mpath code, and should also make arbitrary combinations of SQ and MQ devices with SQ or MQ device mapper tables easily possible as a further step. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * dm: remove incomplete BLOCK_PC supportChristoph Hellwig2017-01-271-16/+0
| | | | | | | | | | | | | | | | | | | | DM tries to copy a few fields around for BLOCK_PC requests, but given that no dm-target ever wires up scsi_cmd_ioctl BLOCK_PC can't actually be sent to dm. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: simplify blk_init_allocated_queueChristoph Hellwig2017-01-271-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Return an errno value instead of the passed in queue so that the callers don't have to keep track of two queues, and move the assignment of the request_fn and lock to the caller as passing them as argument doesn't simplify anything. While we're at it also remove two pointless NULL assignments, given that the request structure is zeroed on allocation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | dm rq: cope with DM device destruction while in dm_old_request_fn()Mike Snitzer2017-02-031-0/+4
|/ | | | | | | | | | Fixes a crash in dm_table_find_target() due to a NULL struct dm_table being passed from dm_old_request_fn() that races with DM device destruction. Reported-by: artem@flashgrid.io Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
* Merge tag 'dm-4.10-changes' of ↵Linus Torvalds2016-12-141-8/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - various fixes and improvements to request-based DM and DM multipath - some locking improvements in DM bufio - add Kconfig option to disable the DM block manager's extra locking which mainly serves as a developer tool - a few bug fixes to DM's persistent-data - a couple changes to prepare for multipage biovec support in the block layer - various improvements and cleanups in the DM core, DM cache, DM raid and DM crypt - add ability to have DM crypt use keys from the kernel key retention service - add a new "error_writes" feature to the DM flakey target, reads are left unchanged in this mode * tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (40 commits) dm flakey: introduce "error_writes" feature dm cache policy smq: use hash_32() instead of hash_32_generic() dm crypt: reject key strings containing whitespace chars dm space map: always set ev if sm_ll_mutate() succeeds dm space map metadata: skip useless memcpy in metadata_ll_init_index() dm space map metadata: fix 'struct sm_metadata' leak on failed create Documentation: dm raid: define data_offset status field dm raid: fix discard support regression dm raid: don't allow "write behind" with raid4/5/6 dm mpath: use hw_handler_params if attached hw_handler is same as requested dm crypt: add ability to use keys from the kernel key retention service dm array: remove a dead assignment in populate_ablock_with_values() dm ioctl: use offsetof() instead of open-coding it dm rq: simplify use_blk_mq initialization dm: use blk_set_queue_dying() in __dm_destroy() dm bufio: drop the lock when doing GFP_NOIO allocation dm bufio: don't take the lock in dm_bufio_shrink_count dm bufio: avoid sleeping while holding the dm_bufio lock dm table: simplify dm_table_determine_type() dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device ...
| * dm rq: simplify use_blk_mq initializationBart Van Assche2016-12-081-5/+1
| | | | | | | | | | | | | | | | Use a single statement to declare and initialize 'use_blk_mq' instead of two statements. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm rq: replace 'bio->bi_vcnt == 1' with !bio_multiple_segmentsMing Lei2016-11-211-1/+1
| | | | | | | | | | | | | | | | Avoid accessing .bi_vcnt directly, because the bio can be split from block layer and .bi_vcnt should never have been used here. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| * dm rq: fix a race condition in rq_completed()Bart Van Assche2016-11-141-2/+8
| | | | | | | | | | | | | | | | | | | | It is required to hold the queue lock when calling blk_run_queue_async() to avoid that a race between blk_run_queue_async() and blk_cleanup_queue() is triggered. Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-blockLinus Torvalds2016-12-131-42/+10
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block layer updates from Jens Axboe: "This is the main block pull request this series. Contrary to previous release, I've kept the core and driver changes in the same branch. We always ended up having dependencies between the two for obvious reasons, so makes more sense to keep them together. That said, I'll probably try and keep more topical branches going forward, especially for cycles that end up being as busy as this one. The major parts of this pull request is: - Improved support for O_DIRECT on block devices, with a small private implementation instead of using the pig that is fs/direct-io.c. From Christoph. - Request completion tracking in a scalable fashion. This is utilized by two components in this pull, the new hybrid polling and the writeback queue throttling code. - Improved support for polling with O_DIRECT, adding a hybrid mode that combines pure polling with an initial sleep. From me. - Support for automatic throttling of writeback queues on the block side. This uses feedback from the device completion latencies to scale the queue on the block side up or down. From me. - Support from SMR drives in the block layer and for SD. From Hannes and Shaun. - Multi-connection support for nbd. From Josef. - Cleanup of request and bio flags, so we have a clear split between which are bio (or rq) private, and which ones are shared. From Christoph. - A set of patches from Bart, that improve how we handle queue stopping and starting in blk-mq. - Support for WRITE_ZEROES from Chaitanya. - Lightnvm updates from Javier/Matias. - Supoort for FC for the nvme-over-fabrics code. From James Smart. - A bunch of fixes from a whole slew of people, too many to name here" * 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits) blk-stat: fix a few cases of missing batch flushing blk-flush: run the queue when inserting blk-mq flush elevator: make the rqhash helpers exported blk-mq: abstract out blk_mq_dispatch_rq_list() helper blk-mq: add blk_mq_start_stopped_hw_queue() block: improve handling of the magic discard payload blk-wbt: don't throttle discard or write zeroes nbd: use dev_err_ratelimited in io path nbd: reset the setup task for NBD_CLEAR_SOCK nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME nvme-fabrics: Add target support for FC transport nvme-fabrics: Add host support for FC transport nvme-fabrics: Add FC transport LLDD api definitions nvme-fabrics: Add FC transport FC-NVME definitions nvme-fabrics: Add FC transport error codes to nvme.h Add type 0x28 NVME type code to scsi fc headers nvme-fabrics: patch target code in prep for FC transport support nvme-fabrics: set sqe.command_id in core not transports parser: add u64 number parser nvme-rdma: align to generic ib_event logging helper ...
| * dm: Fix a race condition related to stopping and starting queuesBart Van Assche2016-11-021-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure that all ongoing dm_mq_queue_rq() and dm_mq_requeue_request() calls have stopped before setting the "queue stopped" flag. This allows to remove the "queue stopped" test from dm_mq_queue_rq() and dm_mq_requeue_request(). This patch fixes a race condition because dm_mq_queue_rq() is called without holding the queue lock and hence BLK_MQ_S_STOPPED can be set at any time while dm_mq_queue_rq() is in progress. This patch prevents that the following hang occurs sporadically when using dm-mq: INFO: task systemd-udevd:10111 blocked for more than 480 seconds. Call Trace: [<ffffffff8161f397>] schedule+0x37/0x90 [<ffffffff816239ef>] schedule_timeout+0x27f/0x470 [<ffffffff8161e76f>] io_schedule_timeout+0x9f/0x110 [<ffffffff8161fb36>] bit_wait_io+0x16/0x60 [<ffffffff8161f929>] __wait_on_bit_lock+0x49/0xa0 [<ffffffff8114fe69>] __lock_page+0xb9/0xc0 [<ffffffff81165d90>] truncate_inode_pages_range+0x3e0/0x760 [<ffffffff81166120>] truncate_inode_pages+0x10/0x20 [<ffffffff81212a20>] kill_bdev+0x30/0x40 [<ffffffff81213d41>] __blkdev_put+0x71/0x360 [<ffffffff81214079>] blkdev_put+0x49/0x170 [<ffffffff812141c0>] blkdev_close+0x20/0x30 [<ffffffff811d48e8>] __fput+0xe8/0x1f0 [<ffffffff811d4a29>] ____fput+0x9/0x10 [<ffffffff810842d3>] task_work_run+0x83/0xb0 [<ffffffff8106606e>] do_exit+0x3ee/0xc40 [<ffffffff8106694b>] do_group_exit+0x4b/0xc0 [<ffffffff81073d9a>] get_signal+0x2ca/0x940 [<ffffffff8101bf43>] do_signal+0x23/0x660 [<ffffffff810022b3>] exit_to_usermode_loop+0x73/0xb0 [<ffffffff81002cb0>] syscall_return_slowpath+0xb0/0xc0 [<ffffffff81624e33>] entry_SYSCALL_64_fastpath+0xa6/0xa8 Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * dm: Use BLK_MQ_S_STOPPED instead of QUEUE_FLAG_STOPPED in blk-mq codeBart Van Assche2016-11-021-15/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Instead of manipulating both QUEUE_FLAG_STOPPED and BLK_MQ_S_STOPPED in the dm start and stop queue functions, only manipulate the latter flag. Change blk_queue_stopped() tests into blk_mq_queue_stopped(). Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()Bart Van Assche2016-11-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls are followed by kicking the requeue list. Hence add an argument to these two functions that allows to kick the requeue list. This was proposed by Christoph Hellwig. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: Remove blk_mq_cancel_requeue_work()Bart Van Assche2016-11-021-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since blk_mq_requeue_work() no longer restarts stopped queues canceling requeue work is no longer needed to prevent that a stopped queue would be restarted. Hence remove this function. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: Avoid that requeueing starts stopped queuesBart Van Assche2016-11-021-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since blk_mq_requeue_work() starts stopped queues and since execution of this function can be scheduled after a queue has been stopped it is not possible to stop queues without using an additional state variable to track whether or not the queue has been stopped. Hence modify blk_mq_requeue_work() such that it does not start stopped queues. My conclusion after a review of the blk_mq_stop_hw_queues() and blk_mq_{delay_,}kick_requeue_list() callers is as follows: * In the dm driver starting and stopping queues should only happen if __dm_suspend() or __dm_resume() is called and not if the requeue list is processed. * In the SCSI core queue stopping and starting should only be performed by the scsi_internal_device_block() and scsi_internal_device_unblock() functions but not by any other function. Although the blk_mq_stop_hw_queue() call in scsi_queue_rq() may help to reduce CPU load if a LLD queue is full, figuring out whether or not a queue should be restarted when requeueing a command would require to introduce additional locking in scsi_mq_requeue_cmd() to avoid a race with scsi_internal_device_block(). Avoid this complexity by removing the blk_mq_stop_hw_queue() call from scsi_queue_rq(). * In the NVMe core only the functions that call blk_mq_start_stopped_hw_queues() explicitly should start stopped queues. * A blk_mq_start_stopped_hwqueues() call must be added in the xen-blkfront driver in its blkif_recover() function. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Roger Pau Monné <roger.pau@citrix.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: James Bottomley <jejb@linux.vnet.ibm.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: split out request-only flags into a new namespaceChristoph Hellwig2016-10-281-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A lot of the REQ_* flags are only used on struct requests, and only of use to the block layer and a few drivers that dig into struct request internals. This patch adds a new req_flags_t rq_flags field to struct request for them, and thus dramatically shrinks the number of common requests. It also removes the unfortunate situation where we have to fit the fields from the same enum into 32 bits for struct bio and 64 bits for struct request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge tag 'dm-4.9-fixes' of ↵Linus Torvalds2016-10-281-2/+5
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: - a couple DM raid and DM mirror fixes - a couple .request_fn request-based DM NULL pointer fixes - a fix for a DM target reference count leak, on target load error, that prevented associated DM target kernel module(s) from being removed * tag 'dm-4.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm table: fix missing dm_put_target_type() in dm_table_add_target() dm rq: clear kworker_task if kthread_run() returned an error dm: free io_barrier after blk_cleanup_queue call dm raid: fix activation of existing raid4/10 devices dm mirror: use all available legs on multiple failures dm mirror: fix read error on recovery after default leg failure dm raid: fix compat_features validation
| * dm rq: clear kworker_task if kthread_run() returned an errorMike Snitzer2016-10-181-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | cleanup_mapped_device() calls kthread_stop() if kworker_task is non-NULL. Currently the assigned value could be a valid task struct or an error code (e.g -ENOMEM). Reset md->kworker_task to NULL if kthread_run() returned an erorr. Fixes: 7193a9defc ("dm rq: check kthread_run return for .request_fn request-based DM") Cc: stable@vger.kernel.org # 4.8 Reported-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
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