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* Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-blockLinus Torvalds2016-12-1331-388/+2004
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * elevator: make the rqhash helpers exportedJens Axboe2016-12-091-0/+5
| | | | | | | | | | Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Hannes Reinecke <hare@suse.com>
| * blk-mq: add blk_mq_start_stopped_hw_queue()Jens Axboe2016-12-091-0/+1
| | | | | | | | | | | | | | | | We have a variant for all hardware queues, but not one for a single hardware queue. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Hannes Reinecke <hare@suse.com>
| * block: improve handling of the magic discard payloadChristoph Hellwig2016-12-092-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of allocating a single unused biovec for discard requests, send them down without any payload. Instead we allow the driver to add a "special" payload using a biovec embedded into struct request (unioned over other fields never used while in the driver), and overloading the number of segments for this case. This has a couple of advantages: - we don't have to allocate the bio_vec - the amount of special casing for discard requests in the block layer is significantly reduced - using this same scheme for other request types is trivial, which will be important for implementing the new WRITE_ZEROES op on devices where it actually requires a payload (e.g. SCSI) - we can get rid of playing games with the request length, as we'll never touch it and completions will work just fine - it will allow us to support ranged discard operations in the future by merging non-contiguous discard bios into a single request - last but not least it removes a lot of code This patch is the common base for my WIP series for ranges discards and to remove discard_zeroes_data in favor of always using REQ_OP_WRITE_ZEROES, so it would be good to get it in quickly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * nvme-fabrics: Add FC transport LLDD api definitionsJames Smart2016-12-061-0/+851
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Host: - LLDD registration with the host transport - registering host ports (local ports) and target ports seen on fabric (remote ports) - Data structures and call points for FC-4 LS's and FCP IO requests Target: - LLDD registration with the target transport - registering nvme subsystem ports (target ports) - Data structures and call points for reception of FC-4 LS's and FCP IO requests, and callbacks to perform data and rsp transfers for the io. Add to MAINTAINERS file Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * nvme-fabrics: Add FC transport FC-NVME definitionsJames Smart2016-12-061-0/+268
| | | | | | | | | | | | | | | | | | | | | | | | - Formats for Cmd, Data, Rsp IUs - Formats FC-4 LS definitions - Add to MAINTAINERS file Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * nvme-fabrics: Add FC transport error codes to nvme.hJames Smart2016-12-061-0/+13
| | | | | | | | | | | | | | | | Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * Add type 0x28 NVME type code to scsi fc headersJames Smart2016-12-061-0/+2
| | | | | | | | | | | | | | Signed-off-by: James Smart <james.smart@broadcom.com> Acked-by: Johannes Thumshirn <jth@kernel.org> Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * parser: add u64 number parserJames Smart2016-12-061-0/+1
| | | | | | | | | | | | | | Will be used by the nvme-fabrics FC transport in parsing options Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
| * nvme.h: add Write Zeroes definitionsChaitanya Kulkarni2016-12-011-0/+20
| | | | | | | | | | | | | | | | | | Add the command structure, optional command set support (ONCS) bit and a new error code for the Write Zeroes command. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: add support for REQ_OP_WRITE_ZEROESChaitanya Kulkarni2016-12-013-11/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a new block layer operation to zero out a range of LBAs. This allows to implement zeroing for devices that don't use either discard with a predictable zero pattern or WRITE SAME of zeroes. The prominent example of that is NVMe with the Write Zeroes command, but in the future, this should also help with improving the way zeroing discards work. For this operation, suitable entry is exported in sysfs which indicate the number of maximum bytes allowed in one write zeroes operation by the device. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: add async variant of blkdev_issue_zerooutChaitanya Kulkarni2016-12-011-0/+3
| | | | | | | | | | | | | | | | | | | | Similar to __blkdev_issue_discard this variant allows submitting the final bio asynchronously and chaining multiple ranges into a single completion. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: transform target get/set bad blockJavier González2016-11-291-3/+12
| | | | | | | | | | | | | | | | | | | | Since targets are given a virtual target device, it is necessary to translate all communication between targets and the backend device. Implement the translation layer for get/set bad block table. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: use target nvm on target-specific ops.Javier González2016-11-291-3/+3
| | | | | | | | | | | | | | | | | | On target-specific operations pass on nvm_tgt_dev instead of the generic nvm device. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: introduce max_phys_sects helper functionJavier González2016-11-291-0/+1
| | | | | | | | | | | | | | | | | | | | Target devices do not have access to the device driver operations. Introduce a helper function that exposes the max. number of physical sectors supported by the underlying device. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: introduce helpers for generic ops in rrpcJavier González2016-11-291-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Avoid calling media manager and device-specific operations directly from rrpc. Create helper functions on lightnvm's core instead. Signed-off-by: Javier González <javier@cnexlabs.com> Made it work with null_blk as well. Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: eliminate nvm_lun abstraction in mmJavier González2016-11-291-19/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to naturally support multi-target instances on an Open-Channel SSD, targets should own the LUNs they get blocks from and manage provisioning internally. This is done in several steps. Since targets own the LUNs the are instantiated on top of and manage the free block list internally, there is no need for a LUN abstraction in the media manager. LUNs are intrinsically managed as in the physical layout (ch:0,lun:0, ..., ch:0,lun:n, ch:1,lun:0, ch:1,lun:n, ..., ch:m,lun:0, ch:m,lun:n) and given to the targets based on the target creation ioctl. This simplifies LUN management and clears the path for a partition manager to sit directly underneath LightNVM targets. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: eliminate nvm_block abstraction on mmJavier González2016-11-291-46/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to naturally support multi-target instances on an Open-Channel SSD, targets should own the LUNs they get blocks from and manage provisioning internally. This is done in several steps. A part of this transformation is that targets manage their blocks internally. This patch eliminates the nvm_block abstraction and moves block management to the target logic. The rrpc target is transformed. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: remove debug lun statistics from gennvmJavier González2016-11-291-5/+0
| | | | | | | | | | | | | | | | | | | | | | Since LUNs are managed internally on targets, the media manager has no access to the free LUN lists. Thus, debug functions that show LUN information on the device should not be implemented on the media manager, but rather on the target in itself. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: remove get_lun operation on gennvmJavier González2016-11-291-6/+2
| | | | | | | | | | | | | | | | | | Since LUNs are managed internally on the target, there is no need for the media manager to implement a get_lun operation. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: move block provisioning to targetsJavier González2016-11-291-61/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | In order to naturally support multi-target instances on an Open-Channel SSD, targets should own the LUNs they get blocks from and manage provisioning internally. This is done in several steps. This patch moves the block provisioning inside of the target and removes the get/put block interface from the media manager. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: manage lun partitions internally in mmJavier González2016-11-291-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LUNs are exclusively owned by targets implementing a block device FTL. Doing this reservation requires at the moment a 2-way callback gennvm <-> target. The reason behind this is that LUNs were not assumed to always be exclusively owned by targets. However, this design decision goes against I/O determinism QoS (two targets would mix I/O on the same parallel unit in the device). This patch makes LUN reservation as part of the target creation on the media manager. This makes that LUNs are always exclusively owned by the target instantiated on top of them. LUN stripping and/or sharing should be implemented on the target itself or the layers on top. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: remove gen_lun abstractionJavier González2016-11-291-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | The gen_lun abstraction in the generic media manager was conceived on the assumption that a single target would instantiated on top of it. This has complicated target design to implement multi-instances. Remove this abstraction and move its logic to nvm_lun, which manages physical lun geometry and operations. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: make address conversion functions globalJavier González2016-11-291-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Targets are assumed to used the same generic ppa format, where the address is partitioned on ch:lun:block:pg:pl:sec. Thus, make the function in charge of transforming the ppa address from a linear format to the generic one available to all targets. This function will be needed by the media manager in order to do target mapping translations when targets are divided on different physical partitions. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: cleanup unused target operationsJavier González2016-11-291-6/+0
| | | | | | | | | | | | | | | | Cleanup definition leftovers from old gennvm interface Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: add ECC error codesJavier González2016-11-291-0/+2
| | | | | | | | | | | | | | | | Add ECC error codes to enable the appropriate handling in the target. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: export set bad block tableJavier González2016-11-291-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bad blocks should be managed by block owners. This would be either targets for data blocks or sysblk for system blocks. In order to support this, export two functions: One to mark a block as an specific type (e.g., bad block) and another to update the bad block table on the device. Move bad block management to rrpc. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * lightnvm: enable to send hint to erase commandJavier González2016-11-291-4/+3
| | | | | | | | | | | | | | | | | | | | Erases might be subject to host hints. An example is multi-plane programming to erase blocks in parallel. Enable targets to specify this hint. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * nvme: lightnvm: attach lightnvm sysfs to nvme block deviceMatias Bjørling2016-11-291-2/+0
| | | | | | | | | | | | | | | | | | Previously, LBA read and write were not supported in the lightnvm specification. Now that it supports it, lets use the traditional NVMe gendisk, and attach the lightnvm sysfs geometry export. Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
| * nbd: move multi-connection bit to unused valueJens Axboe2016-11-221-1/+1
| | | | | | | | | | | | | | | | Bit #7 is already used, move to bit #8 which is the first unused one. Fixes: 9561a7ade0c2 ("nbd: add multi-connection support") Signed-off-by: Jens Axboe <axboe@fb.com>
| * nbd: add multi-connection supportJosef Bacik2016-11-221-4/+5
| | | | | | | | | | | | | | | | | | | | | | NBD can become contended on its single connection. We have to serialize all writes and we can only process one read response at a time. Fix this by allowing userspace to provide multiple connections to a single nbd device. This coupled with block-mq drastically increases performance in multi-process cases. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: bio: pass bvec table to bio_init()Ming Lei2016-11-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some drivers often use external bvec table, so introduce this helper for this case. It is always safe to access the bio->bi_io_vec in this way for this case. After converting to this usage, it will becomes a bit easier to evaluate the remaining direct access to bio->bi_io_vec, so it can help to prepare for the following multipage bvec support. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixed up the new O_DIRECT cases. Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: clear all of bi_opf in bio_set_op_attrsChristoph Hellwig2016-11-211-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 87374179 ("block: add a proper block layer data direction encoding") we only or the new op and flags into bi_opf in bio_set_op_attrs instead of clearing the old value. I've not seen any breakage with the new behavior, but it seems dangerous. Also convert it to an inline function to make the argument passing safer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: Change extern inline to static inlineTobias Klauser2016-11-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With compilers which follow the C99 standard (like modern versions of gcc and clang), "extern inline" does the opposite thing from older versions of gcc (emits code for an externally linkable version of the inline function). "static inline" does the intended behavior in all cases instead. Description taken from commit 6d91857d4826 ("staging, rtl8192e, LLVMLinux: Change extern inline to static inline"). This also fixes the following GCC warning when building with CONFIG_PM disabled: ./include/linux/blkdev.h:1143:20: warning: no previous prototype for 'blk_set_runtime_active' [-Wmissing-prototypes] Fixes: d07ab6d11477 ("block: Add blk_set_runtime_active()") Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: make the polling code adaptiveJens Axboe2016-11-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous commit introduced the hybrid sleep/poll mode. Take that one step further, and use the completion latencies to automatically sleep for half the mean completion time. This is a good approximation. This changes the 'io_poll_delay' sysfs file a bit to expose the various options. Depending on the value, the polling code will behave differently: -1 Never enter hybrid sleep mode 0 Use half of the completion mean for the sleep delay >0 Use this specific value as the sleep delay Signed-off-by: Jens Axboe <axboe@fb.com> Tested-By: Stephen Bates <sbates@raithlin.com> Reviewed-By: Stephen Bates <sbates@raithlin.com>
| * blk-mq: implement hybrid poll mode for sync O_DIRECTJens Axboe2016-11-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables a hybrid polling mode. Instead of polling after IO submission, we can induce an artificial delay, and then poll after that. For example, if the IO is presumed to complete in 8 usecs from now, we can sleep for 4 usecs, wake up, and then do our polling. This still puts a sleep/wakeup cycle in the IO path, but instead of the wakeup happening after the IO has completed, it'll happen before. With this hybrid scheme, we can achieve big latency reductions while still using the same (or less) amount of CPU. Signed-off-by: Jens Axboe <axboe@fb.com> Tested-By: Stephen Bates <sbates@raithlin.com> Reviewed-By: Stephen Bates <sbates@raithlin.com>
| * block: move poll code to blk-mqJens Axboe2016-11-111-1/+1
| | | | | | | | | | | | | | | | The poll code is blk-mq specific, let's move it to blk-mq.c. This is a prep patch for improving the polling code. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
| * block: hook up writeback throttlingJens Axboe2016-11-101-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable throttling of buffered writeback to make it a lot more smooth, and has way less impact on other system activity. Background writeback should be, by definition, background activity. The fact that we flush huge bundles of it at the time means that it potentially has heavy impacts on foreground workloads, which isn't ideal. We can't easily limit the sizes of writes that we do, since that would impact file system layout in the presence of delayed allocation. So just throttle back buffered writeback, unless someone is waiting for it. The algorithm for when to throttle takes its inspiration in the CoDel networking scheduling algorithm. Like CoDel, blk-wb monitors the minimum latencies of requests over a window of time. In that window of time, if the minimum latency of any request exceeds a given target, then a scale count is incremented and the queue depth is shrunk. The next monitoring window is shrunk accordingly. Unlike CoDel, if we hit a window that exhibits good behavior, then we simply increment the scale count and re-calculate the limits for that scale value. This prevents us from oscillating between a close-to-ideal value and max all the time, instead remaining in the windows where we get good behavior. Unlike CoDel, blk-wb allows the scale count to to negative. This happens if we primarily have writes going on. Unlike positive scale counts, this doesn't change the size of the monitoring window. When the heavy writers finish, blk-bw quickly snaps back to it's stable state of a zero scale count. The patch registers a sysfs entry, 'wb_lat_usec'. This sets the latency target to me met. It defaults to 2 msec for non-rotational storage, and 75 msec for rotational storage. Setting this value to '0' disables blk-wb. Generally, a user would not have to touch this setting. We don't enable WBT on devices that are managed with CFQ, and have a non-root block cgroup attached. If we have a proportional share setup on this particular disk, then the wbt throttling will interfere with that. We don't have a strong need for wbt for that case, since we will rely on CFQ doing that for us. Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-wbt: add general throttling mechanismJens Axboe2016-11-101-0/+153
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can hook this up to the block layer, to help throttle buffered writes. wbt registers a few trace points that can be used to track what is happening in the system: wbt_lat: 259:0: latency 2446318 wbt_stat: 259:0: rmean=2446318, rmin=2446318, rmax=2446318, rsamples=1, wmean=518866, wmin=15522, wmax=5330353, wsamples=57 wbt_step: 259:0: step down: step=1, window=72727272, background=8, normal=16, max=32 This shows a sync issue event (wbt_lat) that exceeded it's time. wbt_stat dumps the current read/write stats for that window, and wbt_step shows a step down event where we now scale back writes. Each trace includes the device, 259:0 in this case. Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: add scalable completion tracking of requestsJens Axboe2016-11-102-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For legacy block, we simply track them in the request queue. For blk-mq, we track them on a per-sw queue basis, which we can then sum up through the hardware queues and finally to a per device state. The stats are tracked in, roughly, 0.1s interval windows. Add sysfs files to display the stats. The feature is off by default, to avoid any extra overhead. In-kernel users of it can turn it on by setting QUEUE_FLAG_STATS in the queue flags. We currently don't turn it on if someone just reads any of the stats files, that is something we could add as well. Signed-off-by: Jens Axboe <axboe@fb.com>
| * nvme: introduce struct nvme_requestChristoph Hellwig2016-11-101-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a shared per-request structure for all NVMe I/O. This structure is embedded as the first member in all NVMe transport drivers request private data and allows to implement common functionality between the drivers. The first use is to replace the current abuse of the SCSI command passthrough fields in struct request for the NVMe command passthrough, but it will grow a field more fields to allow implementing things like common abort handlers in the future. The passthrough commands are handled by having a pointer to the SQE (struct nvme_command) in struct nvme_request, and the union of the possible result fields, which had to be turned from an anonymous into a named union for that purpose. This avoids having to pass a reference to a full CQE around and thus makes checking the result a lot more lightweight. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * writeback: track if we're sleeping on progress in balance_dirty_pages()Jens Axboe2016-11-081-0/+2
| | | | | | | | | | | | | | | | | | Note in the bdi_writeback structure whenever a task ends up sleeping waiting for progress. We can use that information in the lower layers to increase the priority of writes. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Jan Kara <jack@suse.cz>
| * block: add code to track actual device queue depthJens Axboe2016-11-061-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For blk-mq, ->nr_requests does track queue depth, at least at init time. But for the older queue paths, it's simply a soft setting. On top of that, it's generally larger than the hardware setting on purpose, to allow backup of requests for merging. Fill a hole in struct request with a 'queue_depth' member, that drivers can call to more closely inform the block layer of the real queue depth. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Jan Kara <jack@suse.cz>
| * block: immediately dispatch big size requestShaohua Li2016-11-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently block plug holds up to 16 non-mergeable requests. This makes sense if the request size is small, eg, reduce lock contention. But if request size is big enough, we don't need to worry about lock contention. Holding such request makes no sense and it lows the disk utilization. In practice, this improves 10% throughput for my raid5 sequential write workload. The size (128k) is arbitrary right now, but it makes sure lock contention is small. This probably could be more intelligent, eg, check average request size holded. Since this is mainly for sequential IO, probably not worthy. V2: check the last request instead of the first request, so as long as there is one big size request we flush the plug. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()Bart Van Assche2016-11-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Introduce blk_mq_quiesce_queue()Bart Van Assche2016-11-022-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_mq_quiesce_queue() waits until ongoing .queue_rq() invocations have finished. This function does *not* wait until all outstanding requests have finished (this means invocation of request.end_io()). The algorithm used by blk_mq_quiesce_queue() is as follows: * Hold either an RCU read lock or an SRCU read lock around .queue_rq() calls. The former is used if .queue_rq() does not block and the latter if .queue_rq() may block. * blk_mq_quiesce_queue() first calls blk_mq_stop_hw_queues() followed by synchronize_srcu() or synchronize_rcu(). The latter call waits for .queue_rq() invocations that started before blk_mq_quiesce_queue() was called. * The blk_mq_hctx_stopped() calls that control whether or not .queue_rq() will be called are called with the (S)RCU read lock held. This is necessary to avoid race conditions against blk_mq_quiesce_queue(). Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: Remove blk_mq_cancel_requeue_work()Bart Van Assche2016-11-021-1/+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: Introduce blk_mq_queue_stopped()Bart Van Assche2016-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The function blk_queue_stopped() allows to test whether or not a traditional request queue has been stopped. Introduce a helper function that allows block drivers to query easily whether or not one or more hardware contexts of a blk-mq queue have been stopped. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: 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>
| * block: add bio_iov_iter_get_pages()Kent Overstreet2016-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a helper that pins down a range from an iov_iter and adds it to a bio without requiring a separate memory allocation for the page array. It will be used for upcoming direct I/O implementations for block devices and iomap based file systems. Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [hch: ported to the iov_iter interface, renamed and added comments. All blame should be directed to me and all fame should go to Kent after this!] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * writeback: mark background writeback as suchJens Axboe2016-11-021-0/+2
| | | | | | | | | | | | | | | | If we're doing background type writes, then use the appropriate background write flags for that. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>