summaryrefslogtreecommitdiff
path: root/block/blk-mq.c
AgeCommit message (Collapse)AuthorFilesLines
2016-10-10Merge branch 'for-4.9/block-smp' of git://git.kernel.dk/linux-blockLinus Torvalds1-67/+56
Pull blk-mq CPU hotplug update from Jens Axboe: "This is the conversion of blk-mq to the new hotplug state machine" * 'for-4.9/block-smp' of git://git.kernel.dk/linux-block: blk-mq: fixup "Convert to new hotplug state machine" blk-mq: Convert to new hotplug state machine blk-mq/cpu-notif: Convert to new hotplug state machine
2016-10-10Merge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-blockLinus Torvalds1-46/+37
Pull blk-mq irq/cpu mapping updates from Jens Axboe: "This is the block-irq topic branch for 4.9-rc. It's mostly from Christoph, and it allows drivers to specify their own mappings, and more importantly, to share the blk-mq mappings with the IRQ affinity mappings. It's a good step towards making this work better out of the box" * 'for-4.9/block-irq' of git://git.kernel.dk/linux-block: blk_mq: linux/blk-mq.h does not include all the headers it depends on blk-mq: kill unused blk_mq_create_mq_map() blk-mq: get rid of the cpumask in struct blk_mq_tags nvme: remove the post_scan callout nvme: switch to use pci_alloc_irq_vectors blk-mq: provide a default queue mapping for PCI device blk-mq: allow the driver to pass in a queue mapping blk-mq: remove ->map_queue blk-mq: only allocate a single mq_map per tag_set blk-mq: don't redistribute hardware queues on a CPU hotplug event
2016-10-08Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-120/+63
Pull block layer updates from Jens Axboe: "This is the main pull request for block layer changes in 4.9. As mentioned at the last merge window, I've changed things up and now do just one branch for core block layer changes, and driver changes. This avoids dependencies between the two branches. Outside of this main pull request, there are two topical branches coming as well. This pull request contains: - A set of fixes, and a conversion to blk-mq, of nbd. From Josef. - Set of fixes and updates for lightnvm from Matias, Simon, and Arnd. Followup dependency fix from Geert. - General fixes from Bart, Baoyou, Guoqing, and Linus W. - CFQ async write starvation fix from Glauber. - Add supprot for delayed kick of the requeue list, from Mike. - Pull out the scalable bitmap code from blk-mq-tag.c and make it generally available under the name of sbitmap. Only blk-mq-tag uses it for now, but the blk-mq scheduling bits will use it as well. From Omar. - bdev thaw error progagation from Pierre. - Improve the blk polling statistics, and allow the user to clear them. From Stephen. - Set of minor cleanups from Christoph in block/blk-mq. - Set of cleanups and optimizations from me for block/blk-mq. - Various nvme/nvmet/nvmeof fixes from the various folks" * 'for-4.9/block' of git://git.kernel.dk/linux-block: (54 commits) fs/block_dev.c: return the right error in thaw_bdev() nvme: Pass pointers, not dma addresses, to nvme_get/set_features() nvme/scsi: Remove power management support nvmet: Make dsm number of ranges zero based nvmet: Use direct IO for writes admin-cmd: Added smart-log command support. nvme-fabrics: Add host_traddr options field to host infrastructure nvme-fabrics: revise host transport option descriptions nvme-fabrics: rework nvmf_get_address() for variable options nbd: use BLK_MQ_F_BLOCKING blkcg: Annotate blkg_hint correctly cfq: fix starvation of asynchronous writes blk-mq: add flag for drivers wanting blocking ->queue_rq() blk-mq: remove non-blocking pass in blk_mq_map_request blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue() block: export bio_free_pages to other modules lightnvm: propagate device_add() error code lightnvm: expose device geometry through sysfs lightnvm: control life of nvm_dev in driver blk-mq: register device instead of disk ...
2016-09-23blk-mq: skip unmapped queues in blk_mq_alloc_request_hctxChristoph Hellwig1-2/+14
This provides the caller a feedback that a given hctx is not mapped and thus no command can be sent on it. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-23blk-mq: fixup "Convert to new hotplug state machine"Sebastian Andrzej Siewior1-1/+1
The "blk_mq_queue_reinit_dead()" just cleared the cpumask instead doing a copy. Since we might never had an online callback we could end up with a ZERO mask which in turn leads to crash as test robot demonstarted. Fixes: 65d5291eee66 ("blk-mq: Convert to new hotplug state machine") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-22blk-mq: add flag for drivers wanting blocking ->queue_rq()Jens Axboe1-1/+1
If a driver sets BLK_MQ_F_BLOCKING, it is allowed to block in its ->queue_rq() handler. For that case, blk-mq ensures that we always calls it from a safe context. Signed-off-by: Jens Axboe <axboe@fb.com> Tested-by: Josef Bacik <jbacik@fb.com>
2016-09-22blk-mq: remove non-blocking pass in blk_mq_map_requestChristoph Hellwig1-13/+1
bt_get already does a non-blocking pass as well as running the queue when scheduling internally, no need to duplicate it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-22blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue()Jens Axboe1-14/+2
Two cases: 1) blk_mq_alloc_request() needlessly re-runs the queue, after calling into the tag allocation without NOWAIT set. We don't need to do that. 2) blk_mq_map_request() should just use blk_mq_run_hw_queue() with the async flag set to false. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-09-22blk-mq: Convert to new hotplug state machineSebastian Andrzej Siewior1-44/+43
Install the callbacks via the state machine so we can phase out the cpu hotplug notifiers mess. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-block@vger.kernel.org Cc: rt@linutronix.de Cc: Christoph Hellwing <hch@lst.de> Link: http://lkml.kernel.org/r/20160919212601.180033814@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-22blk-mq/cpu-notif: Convert to new hotplug state machineThomas Gleixner1-23/+13
Replace the block-mq notifier list management with the multi instance facility in the cpu hotplug state machine. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-block@vger.kernel.org Cc: rt@linutronix.de Cc: Christoph Hellwing <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-17sbitmap: push per-cpu last_tag into sbitmap_queueOmar Sandoval1-1/+1
Allocating your own per-cpu allocation hint separately makes for an awkward API. Instead, allocate the per-cpu hint as part of the struct sbitmap_queue. There's no point for a struct sbitmap_queue without the cache, but you can still use a bare struct sbitmap. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-17blk-mq: abstract tag allocation out into sbitmap libraryOmar Sandoval1-80/+32
This is a generally useful data structure, so make it available to anyone else who might want to use it. It's also a nice cleanup separating the allocation logic from the rest of the tag handling logic. The code is behind a new Kconfig option, CONFIG_SBITMAP, which is only selected by CONFIG_BLOCK for now. This should be a complete noop functionality-wise. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-16blk-mq: account higher order dispatchJens Axboe1-4/+9
We currently account a '0' dispatch, and anything above that still falls below the range set by BLK_MQ_MAX_DISPATCH_ORDER. If we dispatch more, we don't account it. Change the last bucket to be inclusive of anything above the range we track, and have the sysfs file reflect that by including a '+' in the output: $ cat /sys/block/nvme0n1/mq/0/dispatched 0 1006 1 20229 2 1 4 0 8 0 16 0 32+ 0 Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com>
2016-09-15blk-mq: kill unused blk_mq_create_mq_map()Jens Axboe1-24/+0
Fixes 1b157939f92a ("blk-mq: get rid of the cpumask in struct blk_mq_tags") Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: get rid of the cpumask in struct blk_mq_tagsChristoph Hellwig1-4/+21
Unused now that NVMe sets up irq affinity before calling into blk-mq. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: allow the driver to pass in a queue mappingChristoph Hellwig1-3/+15
This allows drivers specify their own queue mapping by overriding the setup-time function that builds the mq_map. This can be used for example to build the map based on the MSI-X vector mapping provided by the core interrupt layer for PCI devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: remove ->map_queueChristoph Hellwig1-29/+11
All drivers use the default, so provide an inline version of it. If we ever need other queue mapping we can add an optional method back, although supporting will also require major changes to the queue setup code. This provides better code generation, and better debugability as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: only allocate a single mq_map per tag_setChristoph Hellwig1-8/+14
The mapping is identical for all queues in a tag_set, so stop wasting memory for building multiple. Note that for now I've kept the mq_map pointer in the request_queue, but we'll need to investigate if we can remove it without suffering too much from the additional pointer chasing. The same would apply to the mq_ops pointer as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15blk-mq: don't redistribute hardware queues on a CPU hotplug eventChristoph Hellwig1-2/+0
Currently blk-mq will totally remap hardware context when a CPU hotplug even happened, which causes major havoc for drivers, as they are never told about this remapping. E.g. any carefully sorted out CPU affinity will just be completely messed up. The rebuild also doesn't really help for the common case of cpu hotplug, which is soft onlining / offlining of cpus - in this case we should just leave the queue and irq mapping as is. If it actually worked it would have helped in the case of physical cpu hotplug, although for that we'd need a way to actually notify the driver. Note that drivers may already be able to accommodate such a topology change on their own, e.g. using the reset_controller sysfs file in NVMe will cause the driver to get things right for this case. With the rebuild removed we will simplify retain the queue mapping for a soft offlined CPU that will work when it comes back online, and will map any newly onlined CPU to queue 0 until the driver initiates a rebuild of the queue map. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14blk-mq: introduce blk_mq_delay_kick_requeue_list()Mike Snitzer1-4/+12
blk_mq_delay_kick_requeue_list() provides the ability to kick the q->requeue_list after a specified time. To do this the request_queue's 'requeue_work' member was changed to a delayed_work. blk_mq_delay_kick_requeue_list() allows DM to defer processing requeued requests while it doesn't make sense to immediately requeue them (e.g. when all paths in a DM multipath have failed). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29blk-mq: prefetch request in blk_mq_tag_to_rq()Jens Axboe1-1/+4
When drivers or the core calls this function, they usually dereference the request shortly there after. Prefetch the first cache line. Profiling IO workloads shows that this is the most common cache miss on the block side of things. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29blk-mq: turn hctx->run_work into a regular work structJens Axboe1-5/+4
We don't need the larger delayed work struct, since we always run it immediately. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-25blk-mq: improve warning for running a queue on the wrong CPUJens Axboe1-2/+3
__blk_mq_run_hw_queue() currently warns if we are running the queue on a CPU that isn't set in its mask. However, this can happen if a CPU is being offlined, and the workqueue handling will place the work on CPU0 instead. Improve the warning so that it only triggers if the batch cpu in the hardware queue is currently online. If it triggers for that case, then it's indicative of a flow problem in blk-mq, so we want to retain it for that case. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-25blk-mq: don't overwrite rq->mq_ctxJens Axboe1-39/+16
We do this in a few places, if the CPU is offline. This isn't allowed, though, since on multi queue hardware, we can't just move a request from one software queue to another, if they map to different hardware queues. The request and tag isn't valid on another hardware queue. This can happen if plugging races with CPU offlining. But it does no harm, since it can only happen in the window where we are currently busy freezing the queue and flushing IO, in preparation for redoing the software <-> hardware queue mappings. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe1-5/+5
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04blk-mq: Allow timeouts to run while queue is freezingGabriel Krisman Bertazi1-1/+14
In case a submitted request gets stuck for some reason, the block layer can prevent the request starvation by starting the scheduled timeout work. If this stuck request occurs at the same time another thread has started a queue freeze, the blk_mq_timeout_work will not be able to acquire the queue reference and will return silently, thus not issuing the timeout. But since the request is already holding a q_usage_counter reference and is unable to complete, it will never release its reference, preventing the queue from completing the freeze started by first thread. This puts the request_queue in a hung state, forever waiting for the freeze completion. This was observed while running IO to a NVMe device at the same time we toggled the CPU hotplug code. Eventually, once a request got stuck requiring a timeout during a queue freeze, we saw the CPU Hotplug notification code get stuck inside blk_mq_freeze_queue_wait, as shown in the trace below. [c000000deaf13690] [c000000deaf13738] 0xc000000deaf13738 (unreliable) [c000000deaf13860] [c000000000015ce8] __switch_to+0x1f8/0x350 [c000000deaf138b0] [c000000000ade0e4] __schedule+0x314/0x990 [c000000deaf13940] [c000000000ade7a8] schedule+0x48/0xc0 [c000000deaf13970] [c0000000005492a4] blk_mq_freeze_queue_wait+0x74/0x110 [c000000deaf139e0] [c00000000054b6a8] blk_mq_queue_reinit_notify+0x1a8/0x2e0 [c000000deaf13a40] [c0000000000e7878] notifier_call_chain+0x98/0x100 [c000000deaf13a90] [c0000000000b8e08] cpu_notify_nofail+0x48/0xa0 [c000000deaf13ac0] [c0000000000b92f0] _cpu_down+0x2a0/0x400 [c000000deaf13b90] [c0000000000b94a8] cpu_down+0x58/0xa0 [c000000deaf13bc0] [c0000000006d5dcc] cpu_subsys_offline+0x2c/0x50 [c000000deaf13bf0] [c0000000006cd244] device_offline+0x104/0x140 [c000000deaf13c30] [c0000000006cd40c] online_store+0x6c/0xc0 [c000000deaf13c80] [c0000000006c8c78] dev_attr_store+0x68/0xa0 [c000000deaf13cc0] [c0000000003974d0] sysfs_kf_write+0x80/0xb0 [c000000deaf13d00] [c0000000003963e8] kernfs_fop_write+0x188/0x200 [c000000deaf13d50] [c0000000002e0f6c] __vfs_write+0x6c/0xe0 [c000000deaf13d90] [c0000000002e1ca0] vfs_write+0xc0/0x230 [c000000deaf13de0] [c0000000002e2cdc] SyS_write+0x6c/0x110 [c000000deaf13e30] [c000000000009204] system_call+0x38/0xb4 The fix is to allow the timeout work to execute in the window between dropping the initial refcount reference and the release of the last reference, which actually marks the freeze completion. This can be achieved with percpu_refcount_tryget, which does not require the counter to be alive. This way the timeout work can do it's job and terminate a stuck request even during a freeze, returning its reference and avoiding the deadlock. Allowing the timeout to run is just a part of the fix, since for some devices, we might get stuck again inside the device driver's timeout handler, should it attempt to allocate a new request in that path - which is a quite common action for Abort commands, which need to be sent after a timeout. In NVMe, for instance, we call blk_mq_alloc_request from inside the timeout handler, which will fail during a freeze, since it also tries to acquire a queue reference. I considered a similar change to blk_mq_alloc_request as a generic solution for further device driver hangs, but we can't do that, since it would allow new requests to disturb the freeze process. I thought about creating a new function in the block layer to support unfreezable requests for these occasions, but after working on it for a while, I feel like this should be handled in a per-driver basis. I'm now experimenting with changes to the NVMe timeout path, but I'm open to suggestions of ways to make this generic. Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Cc: Keith Busch <keith.busch@intel.com> Cc: linux-nvme@lists.infradead.org Cc: linux-block@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-27Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+43
Pull block driver updates from Jens Axboe: "This branch also contains core changes. I've come to the conclusion that from 4.9 and forward, I'll be doing just a single branch. We often have dependencies between core and drivers, and it's hard to always split them up appropriately without pulling core into drivers when that happens. That said, this contains: - separate secure erase type for the core block layer, from Christoph. - set of discard fixes, from Christoph. - bio shrinking fixes from Christoph, as a followup up to the op/flags change in the core branch. - map and append request fixes from Christoph. - NVMeF (NVMe over Fabrics) code from Christoph. This is pretty exciting! - nvme-loop fixes from Arnd. - removal of ->driverfs_dev from Dan, after providing a device_add_disk() helper. - bcache fixes from Bhaktipriya and Yijing. - cdrom subchannel read fix from Vchannaiah. - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier. - set of drbd updates and fixes from Fabian, Lars, and Philipp. - mg_disk error path fix from Bart. - user notification for failed device add for loop, from Minfei. - NVMe in general: + NVMe delay quirk from Guilherme. + SR-IOV support and command retry limits from Keith. + fix for memory-less NUMA node from Masayoshi. + use UINT_MAX for discard sectors, from Minfei. + cancel IO fixes from Ming. + don't allocate unused major, from Neil. + error code fixup from Dan. + use constants for PSDT/FUSE from James. + variable init fix from Jay. + fabrics fixes from Ming, Sagi, and Wei. + various fixes" * 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits) nvme/pci: Provide SR-IOV support nvme: initialize variable before logical OR'ing it block: unexport various bio mapping helpers scsi/osd: open code blk_make_request target: stop using blk_make_request block: simplify and export blk_rq_append_bio block: ensure bios return from blk_get_request are properly initialized virtio_blk: use blk_rq_map_kern memstick: don't allow REQ_TYPE_BLOCK_PC requests block: shrink bio size again block: simplify and cleanup bvec pool handling block: get rid of bio_rw and READA block: don't ignore -EOPNOTSUPP blkdev_issue_write_same block: introduce BLKDEV_DISCARD_ZERO to fix zeroout NVMe: don't allocate unused nvme_major nvme: avoid crashes when node 0 is memoryless node. nvme: Limit command retries loop: Make user notify for adding loop device failed nvme-loop: fix nvme-loop Kconfig dependencies nvmet: fix return value check in nvmet_subsys_alloc() ...
2016-07-27Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-20/+22
Pull core block updates from Jens Axboe: - the big change is the cleanup from Mike Christie, cleaning up our uses of command types and modified flags. This is what will throw some merge conflicts - regression fix for the above for btrfs, from Vincent - following up to the above, better packing of struct request from Christoph - a 2038 fix for blktrace from Arnd - a few trivial/spelling fixes from Bart Van Assche - a front merge check fix from Damien, which could cause issues on SMR drives - Atari partition fix from Gabriel - convert cfq to highres timers, since jiffies isn't granular enough for some devices these days. From Jan and Jeff - CFQ priority boost fix idle classes, from me - cleanup series from Ming, improving our bio/bvec iteration - a direct issue fix for blk-mq from Omar - fix for plug merging not involving the IO scheduler, like we do for other types of merges. From Tahsin - expose DAX type internally and through sysfs. From Toshi and Yigal * 'for-4.8/core' of git://git.kernel.dk/linux-block: (76 commits) block: Fix front merge check block: do not merge requests without consulting with io scheduler block: Fix spelling in a source code comment block: expose QUEUE_FLAG_DAX in sysfs block: add QUEUE_FLAG_DAX for devices to advertise their DAX support Btrfs: fix comparison in __btrfs_map_block() block: atari: Return early for unsupported sector size Doc: block: Fix a typo in queue-sysfs.txt cfq-iosched: Charge at least 1 jiffie instead of 1 ns cfq-iosched: Fix regression in bonnie++ rewrite performance cfq-iosched: Convert slice_resid from u64 to s64 block: Convert fifo_time from ulong to u64 blktrace: avoid using timespec block/blk-cgroup.c: Declare local symbols static block/bio-integrity.c: Add #include "blk.h" block/partition-generic.c: Remove a set-but-not-used variable block: bio: kill BIO_MAX_SIZE cfq-iosched: temporarily boost queue priority for idle classes block: drbd: avoid to use BIO_MAX_SIZE block: bio: remove BIO_MAX_SECTORS ...
2016-07-21block: ensure bios return from blk_get_request are properly initializedChristoph Hellwig1-0/+4
blk_get_request is used for BLOCK_PC and similar passthrough requests. Currently we always need to call blk_rq_set_block_pc or an open coded version of it to allow appending bios using the request mapping helpers later on, which is a somewhat awkward API. Instead move the initialization part of blk_rq_set_block_pc into blk_get_request, so that we always have a safe to use request. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05blk-mq: add blk_mq_alloc_request_hctxMing Lin1-0/+39
For some protocols like NVMe over Fabrics we need to be able to send initialization commands to a specific queue. Based on an earlier patch from Christoph Hellwig <hch@lst.de>. Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> [hch: disallow sleeping allocation, req_op fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-09blk-mq: actually hook up defer list when running requestsOmar Sandoval1-1/+1
If ->queue_rq() returns BLK_MQ_RQ_QUEUE_OK, we use continue and skip over the rest of the loop body. However, dptr is assigned later in the loop body, and the BLK_MQ_RQ_QUEUE_OK case is exactly the case that we'd want it for. NVMe isn't actually using BLK_MQ_F_DEFER_ISSUE yet, nor is any other in-tree driver, but if the code's going to be there, it might as well work. Fixes: 74c450521dd8 ("blk-mq: add a 'list' parameter to ->queue_rq()") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie1-2/+2
To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block: convert is_sync helpers to use REQ_OPs.Mike Christie1-4/+4
This patch converts the is_sync helpers to use separate variables for the operation and flags. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block: prepare mq request creation to use REQ_OPsMike Christie1-14/+16
This patch modifies the blk mq request creation code to use separate variables for the operation and flags, because in the the next patches the struct request users will be converted like was done for bios. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-02blk-mq: really fix plug list flushing for nomerge queuesOmar Sandoval1-9/+8
Commit 0809e3ac6231 ("block: fix plug list flushing for nomerge queues") updated blk_mq_make_request() to set request_count even when blk_queue_nomerges() returns true. However, blk_mq_make_request() only does limited plugging and doesn't use request_count; blk_sq_make_request() is the one that should have been fixed. Do that and get rid of the unnecessary work in the mq version. Fixes: 0809e3ac6231 ("block: fix plug list flushing for nomerge queues") Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-26blk-mq: clear q->mq_ops if init failMing Lin1-1/+3
blk_mq_init_queue() calls blk_mq_init_allocated_queue(), but q->mq_ops was not cleared when blk_mq_init_allocated_queue() fails. Then blk_cleanup_queue() calls blk_mq_free_queue() which will crash because: - q->all_q_node is not added to all_q_list yet - q->tag_set is NULL - hctx was not setup yet or already freed Fixed it by clearing q->mq_ops on error path. Signed-off-by: Ming Lin <ming.l@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-16blk-mq: fix undefined behaviour in order_to_size()Bartlomiej Zolnierkiewicz1-1/+1
When this_order variable in blk_mq_init_rq_map() becomes zero the code incorrectly decrements the variable and passes the result to order_to_size() helper causing undefined behaviour: UBSAN: Undefined behaviour in block/blk-mq.c:1459:27 shift exponent 4294967295 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc6-00072-g33656a1 #22 Fix the code by checking this_order variable for not having the zero value first. Reported-by: Meelis Roos <mroos@linux.ee> Fixes: 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism") Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-03block: Minor blk_account_io_start usage cleanupMichael Callahan1-2/+1
blk_account_io_start does not need to be wrapped with blk_do_io_stat ais it already checks for that condition. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-20blk-mq: Use proper cpumask iteratorThomas Gleixner1-1/+2
queue_for_each_ctx() iterates over per_cpu variables under the assumption that the possible cpu mask cannot have holes. That's wrong as all cpumasks can have holes. In case there are holes the iteration ends up accessing uninitialized memory and crashing as a result. Replace the macro by a proper for_each_possible_cpu() loop and drop the unused macro blk_ctx_sum() which references queue_for_each_ctx(). Reported-by: Xiong Zhou <jencce.kernel@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-19Merge branch 'for-4.6/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-71/+113
Pull core block updates from Jens Axboe: "Here are the core block changes for this merge window. Not a lot of exciting stuff going on in this round, most of the changes have been on the driver side of things. That pull request is coming next. This pull request contains: - A set of fixes for chained bio handling from Christoph. - A tag bounds check for blk-mq from Hannes, ensuring that we don't do something stupid if a device reports an invalid tag value. - A set of fixes/updates for the CFQ IO scheduler from Jan Kara. - A set of blk-mq fixes from Keith, adding support for dynamic hardware queues, and fixing init of max_dev_sectors for stacking devices. - A fix for the dynamic hw context from Ming. - Enabling of cgroup writeback support on a block device, from Shaohua" * 'for-4.6/core' of git://git.kernel.dk/linux-block: blk-mq: add bounds check on tag-to-rq conversion block: bio_remaining_done() isn't unlikely block: cleanup bio_endio block: factor out chained bio completion block: don't unecessarily clobber bi_error for chained bios block-dev: enable writeback cgroup support blk-mq: Fix NULL pointer updating nr_requests blk-mq: mark request queue as mq asap block: Initialize max_dev_sectors to 0 blk-mq: dynamic h/w context count cfq-iosched: Allow parent cgroup to preempt its child cfq-iosched: Allow sync noidle workloads to preempt each other cfq-iosched: Reorder checks in cfq_should_preempt() cfq-iosched: Don't group_idle if cfqq has big thinktime
2016-03-15blk-mq: add bounds check on tag-to-rq conversionHannes Reinecke1-1/+4
We need to check for a valid index before accessing the array element to avoid accessing invalid memory regions. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Modified by Jens to drop the unlikely(), and make the fall through path be having a valid tag. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-03-04blk-mq: Fix NULL pointer updating nr_requestsKeith Busch1-0/+2
A h/w context's tags are freed if it was not assigned a CPU. Check if the context has tags before updating the depth. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-15blk-mq: mark request queue as mq asapMing Lei1-1/+3
Currently q->mq_ops is used widely to decide if the queue is mq or not, so we should set the 'flag' asap so that both block core and drivers can get the correct mq info. For example, commit 868f2f0b720(blk-mq: dynamic h/w context count) moves the hctx's initialization before setting q->mq_ops in blk_mq_init_allocated_queue(), then cause blk_alloc_flush_queue() to think the queue is non-mq and don't allocate command size for the per-hctx flush rq. This patches should fix the problem reported by Sasha. Cc: Keith Busch <keith.busch@intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Fixes: 868f2f0b720 ("blk-mq: dynamic h/w context count") Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-11blk-mq: End unstarted requests on dying queueKeith Busch1-2/+4
Go directly to ending a request if it wasn't started. Previously, completing a request may invoke a driver callback for a request it didn't initialize. Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-09blk-mq: dynamic h/w context countKeith Busch1-69/+104
The hardware's provided queue count may change at runtime with resource provisioning. This patch allows a block driver to alter the number of h/w queues available when its resource count changes. The main part is a new blk-mq API to request a new number of h/w queues for a given live tag set. The new API freezes all queues using that set, then adjusts the allocated count prior to remapping these to CPUs. The bulk of the rest just shifts where h/w contexts and all their artifacts are allocated and freed. The number of max h/w contexts is capped to the number of possible cpus since there is no use for more than that. As such, all pre-allocated memory for pointers need to account for the max possible rather than the initial number of queues. A side effect of this is that the blk-mq will proceed successfully as long as it can allocate at least one h/w context. Previously it would fail request queue initialization if less than the requested number was allocated. Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-22Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+8
Pull NVMe updates from Jens Axboe: "Last branch for this series is the nvme changes. It's in a separate branch to avoid splitting too much between core and NVMe changes, since NVMe is still helping drive some blk-mq changes. That said, not a huge amount of core changes in here. The grunt of the work is the continued split of the code" * 'for-4.5/nvme' of git://git.kernel.dk/linux-block: (67 commits) uapi: update install list after nvme.h rename NVMe: Export NVMe attributes to sysfs group NVMe: Shutdown controller only for power-off NVMe: IO queue deletion re-write NVMe: Remove queue freezing on resets NVMe: Use a retryable error code on reset NVMe: Fix admin queue ring wrap nvme: make SG_IO support optional nvme: fixes for NVME_IOCTL_IO_CMD on the char device nvme: synchronize access to ctrl->namespaces nvme: Move nvme_freeze/unfreeze_queues to nvme core PCI/AER: include header file NVMe: Export namespace attributes to sysfs NVMe: Add pci error handlers block: remove REQ_NO_TIMEOUT flag nvme: merge iod and cmd_info nvme: meta_sg doesn't have to be an array nvme: properly free resources for cancelled command nvme: simplify completion handling nvme: special case AEN requests ...
2015-12-22block: remove REQ_NO_TIMEOUT flagChristoph Hellwig1-2/+0
This was added for the 'magic' AEN requests in the NVMe driver that never return. We now handle them purely inside the driver and don't need this core hack any more. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-22block: defer timeouts to a workqueueChristoph Hellwig1-3/+8
Timer context is not very useful for drivers to perform any meaningful abort action from. So instead of calling the driver from this useless context defer it to a workqueue as soon as possible. Note that while a delayed_work item would seem the right thing here I didn't dare to use it due to the magic in blk_add_timer that pokes deep into timer internals. But maybe this encourages Tejun to add a sensible API for that to the workqueue API and we'll all be fine in the end :) Contains a major update from Keith Bush: "This patch removes synchronizing the timeout work so that the timer can start a freeze on its own queue. The timer enters the queue, so timer context can only start a freeze, but not wait for frozen." Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03blk-mq: Avoid memoryless numa node encoded in hctx numa_nodeRaghavendra K T1-1/+1
In architecture like powerpc, we can have cpus without any local memory attached to it (a.k.a memoryless nodes). In such cases cpu to node mapping can result in memory allocation hints for block hctx->numa_node populated with node values which does not have real memory. Instead use local_memory_node(), which is guaranteed to have memory. local_memory_node is a noop in other architectures that does not support memoryless nodes. Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03blk-mq: Reuse hardware context cpumask for tagsRaghavendra K T1-8/+1
hctx->cpumask is already populated and let the tag cpumask follow that instead of going through a new for loop. Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>