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2020-05-29blk-throttle: remove tg_drain_biosGuoqing Jiang
After blk_throtl_drain is removed, there is no caller of tg_drain_bios, so remove it as well. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-throttle: remove blk_throtl_drainGuoqing Jiang
After the commit 5addeae1bedc4 ("blk-cgroup: remove blkcg_drain_queue"), there is no caller of blk_throtl_drain, so let's remove it. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: drain I/O when all CPUs in a hctx are offlineMing Lei
Most of blk-mq drivers depend on managed IRQ's auto-affinity to setup up queue mapping. Thomas mentioned the following point[1]: "That was the constraint of managed interrupts from the very beginning: The driver/subsystem has to quiesce the interrupt line and the associated queue _before_ it gets shutdown in CPU unplug and not fiddle with it until it's restarted by the core when the CPU is plugged in again." However, current blk-mq implementation doesn't quiesce hw queue before the last CPU in the hctx is shutdown. Even worse, CPUHP_BLK_MQ_DEAD is a cpuhp state handled after the CPU is down, so there isn't any chance to quiesce the hctx before shutting down the CPU. Add new CPUHP_AP_BLK_MQ_ONLINE state to stop allocating from blk-mq hctxs where the last CPU goes away, and wait for completion of in-flight requests. This guarantees that there is no inflight I/O before shutting down the managed IRQ. Add a BLK_MQ_F_STACKING and set it for dm-rq and loop, so we don't need to wait for completion of in-flight requests from these drivers to avoid a potential dead-lock. It is safe to do this for stacking drivers as those do not use interrupts at all and their I/O completions are triggered by underlying devices I/O completion. [1] https://lore.kernel.org/linux-block/alpine.DEB.2.21.1904051331270.1802@nanos.tec.linutronix.de/ [hch: different retry mechanism, merged two patches, minor cleanups] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: add blk_mq_all_tag_iterMing Lei
Add a new blk_mq_all_tag_iter function to iterate over all allocated scheduler tags and driver tags. This is more flexible than the existing blk_mq_all_tag_busy_iter function as it allows the callers to do whatever they want on allocated request instead of being limited to started requests. It will be used to implement draining allocated requests on specified hctx in this patchset. [hch: switch from the two booleans to a more readable flags field and consolidate the tags iter functions] Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Bart van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctxChristoph Hellwig
blk_mq_alloc_request_hctx is only used for NVMeoF connect commands, so tailor it to the specific requirements, and don't bother the general fast path code with its special twinkles. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: use BLK_MQ_NO_TAG in more placesChristoph Hellwig
Replace various magic -1 constants for tags with BLK_MQ_NO_TAG. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAGChristoph Hellwig
To prepare for wider use of this constant give it a more applicable name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: move more request initialization to blk_mq_rq_ctx_initChristoph Hellwig
Don't split request initialization between __blk_mq_alloc_request and blk_mq_rq_ctx_init. Also remove the op argument as it can be derived from the blk_mq_alloc_data structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: simplify the blk_mq_get_request calling conventionChristoph Hellwig
The bio argument is entirely unused, and the request_queue can be passed through the alloc_data, given that it needs to be filled out for the low-level tag allocation anyway. Also rename the function to __blk_mq_alloc_request as the switch between get and alloc in the call chains is rather confusing. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: remove the bio argument to ->prepare_requestChristoph Hellwig
None of the I/O schedulers actually needs it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-29blk-mq: blk-mq: provide forced completion methodKeith Busch
Drivers may need to bypass error injection for error recovery. Rename __blk_mq_complete_request() to blk_mq_force_complete_rq() and export that function so drivers may skip potential fake timeouts after they've reclaimed lost requests. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-28Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"Jens Axboe
This reverts commit c58c1f83436b501d45d4050fd1296d71a9760bcb. io_uring does do the right thing for this case, and we're still returning -EAGAIN to userspace for the cases we don't support. Revert this change to avoid doing endless spins of resubmits. Cc: stable@vger.kernel.org # v5.6 Reported-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: blk-crypto-fallback: remove redundant initialization of variable errColin Ian King
The variable err is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Satya Tangirala <satyat@google.com> Addresses-Coverity: ("Unused value") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: reduce part_stat_lock() scopeChristoph Hellwig
We only need the stats lock (aka preempt_disable()) for updating the states, not for looking up or dropping the hd_struct reference. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: remove rcu_read_lock() from part_stat_lock()Konstantin Khlebnikov
The RCU lock is required only in disk_map_sector_rcu() to lookup the partition. After that request holds reference to related hd_struct. Replace get_cpu() with preempt_disable() - returned cpu index is unused. [hch: rebased] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: add a blk_account_io_merge_bio helperKonstantin Khlebnikov
Move the non-"new_io" branch of blk_account_io_start() into separate function. Fix merge accounting for discards (they were counted as write merges). The new blk_account_io_merge_bio() doesn't call update_io_ticks() unlike blk_account_io_start(), as there is no reason for that. [hch: rebased] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: account merge of two requestsKonstantin Khlebnikov
Also rename blk_account_io_merge() into blk_account_io_merge_request() to distinguish it from merging request and bio. [hch: rebased] Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: always use a percpu variable for disk statsChristoph Hellwig
percpu variables have a perfectly fine working stub implementation for UP kernels, so use that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: move update_io_ticks to blk-core.cChristoph Hellwig
All callers are in blk-core.c, so move update_io_ticks over. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: remove generic_{start,end}_io_acctChristoph Hellwig
Remove these now unused functions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-27block: add disk/bio-based accounting helpersChristoph Hellwig
Add two new helpers to simplify I/O accounting for bio based drivers. Currently these drivers use the generic_start_io_acct and generic_end_io_acct helpers which have very cumbersome calling conventions, don't actually return the time they started accounting, and try to deal with accounting for partitions, which can't happen for bio based drivers. The new helpers will be used to subsequently replace uses of the old helpers. The main API is the bio based wrappes in blkdev.h, but for zram which wants to account rw_page based I/O lower level routines are provided as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22block: remove the disk and queue NULL checks in blkdev_issue_flushChristoph Hellwig
Both of these never can be NULL for a live block device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-22block: remove the error_sector argument to blkdev_issue_flushChristoph Hellwig
The argument isn't used by any caller, and drivers don't fill out bi_sector for flush requests either. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-21s390/dasd: remove ioctl_by_bdev callsStefan Haberland
The IBM partition parser requires device type specific information only available to the DASD driver to correctly register partitions. The current approach of using ioctl_by_bdev with a fake user space pointer is discouraged. Fix this by replacing IOCTL calls with direct in-kernel function calls. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: Remove unused flush_queue_delayed in struct blk_flush_queueBaolin Wang
The flush_queue_delayed was introdued to hold queue if flush is running for non-queueable flush drive by commit 3ac0cc450870 ("hold queue if flush is running for non-queueable flush drive"), but the non mq parts of the flush code had been removed by commit 7e992f847a08 ("block: remove non mq parts from the flush code"), as well as removing the usage of the flush_queue_delayed flag. Thus remove the unused flush_queue_delayed flag. Signed-off-by: Baolin Wang <baolin.wang7@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: Fix type of first compat_put_{,u}long() argumentBart Van Assche
This patch fixes the following sparse warnings: block/ioctl.c:209:16: warning: incorrect type in argument 1 (different address spaces) block/ioctl.c:209:16: expected void const volatile [noderef] <asn:1> * block/ioctl.c:209:16: got signed int [usertype] *argp block/ioctl.c:214:16: warning: incorrect type in argument 1 (different address spaces) block/ioctl.c:214:16: expected void const volatile [noderef] <asn:1> * block/ioctl.c:214:16: got unsigned int [usertype] *argp block/ioctl.c:666:40: warning: incorrect type in argument 1 (different address spaces) block/ioctl.c:666:40: expected signed int [usertype] *argp block/ioctl.c:666:40: got void [noderef] <asn:1> *argp block/ioctl.c:672:41: warning: incorrect type in argument 1 (different address spaces) block/ioctl.c:672:41: expected unsigned int [usertype] *argp block/ioctl.c:672:41: got void [noderef] <asn:1> *argp Fixes: 9b81648cb5e3 ("compat_ioctl: simplify up block/ioctl.c") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: merge part_{inc,dev}_in_flight into their only callersChristoph Hellwig
part_inc_in_flight and part_dec_in_flight only have one caller each, and those callers are purely for bio based drivers. Merge each function into the only caller, and remove the superflous blk-mq checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: don't call part_{inc,dec}_in_flight for blk-mq devicesChristoph Hellwig
part_inc_in_flight and part_dec_in_flight are no-ops for blk-mq queues, so remove the calls in purely blk-mq callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: move the blk-mq calls out of part_in_flight{,_rw}Christoph Hellwig
Don't bother to call part_in_flight / part_in_flight_rw on blk-mq devices, just call the blk-mq versions directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19block: mark blk_account_io_completion staticChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: allow blk_mq_make_request to consume the q_usage_counter referenceChristoph Hellwig
blk_mq_make_request currently needs to grab an q_usage_counter reference when allocating a request. This is because the block layer grabs one before calling blk_mq_make_request, but also releases it as soon as blk_mq_make_request returns. Remove the blk_queue_exit call after blk_mq_make_request returns, and instead let it consume the reference. This works perfectly fine for the block layer caller, just device mapper needs an extra reference as the old problem still persists there. Open code blk_queue_enter_live in device mapper, as there should be no other callers and this allows better documenting why we do a non-try get. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: remove a pointless queue enter pair in blk_mq_alloc_request_hctxChristoph Hellwig
No need for two queue references. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: remove a pointless queue enter pair in blk_mq_alloc_requestChristoph Hellwig
No need for two queue references. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-19blk-mq: move the call to blk_queue_enter_live out of blk_mq_get_requestChristoph Hellwig
Move the blk_queue_enter_live calls into the callers, where they can successively be cleaned up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: blk-crypto-fallback for Inline EncryptionSatya Tangirala
Blk-crypto delegates crypto operations to inline encryption hardware when available. The separately configurable blk-crypto-fallback contains a software fallback to the kernel crypto API - when enabled, blk-crypto will use this fallback for en/decryption when inline encryption hardware is not available. This lets upper layers not have to worry about whether or not the underlying device has support for inline encryption before deciding to specify an encryption context for a bio. It also allows for testing without actual inline encryption hardware - in particular, it makes it possible to test the inline encryption code in ext4 and f2fs simply by running xfstests with the inlinecrypt mount option, which in turn allows for things like the regular upstream regression testing of ext4 to cover the inline encryption code paths. For more details, refer to Documentation/block/inline-encryption.rst. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: Make blk-integrity preclude hardware inline encryptionSatya Tangirala
Whenever a device supports blk-integrity, make the kernel pretend that the device doesn't support inline encryption (essentially by setting the keyslot manager in the request queue to NULL). There's no hardware currently that supports both integrity and inline encryption. However, it seems possible that there will be such hardware in the near future (like the NVMe key per I/O support that might support both inline encryption and PI). But properly integrating both features is not trivial, and without real hardware that implements both, it is difficult to tell if it will be done correctly by the majority of hardware that support both. So it seems best not to support both features together right now, and to decide what to do at probe time. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: Inline encryption support for blk-mqSatya Tangirala
We must have some way of letting a storage device driver know what encryption context it should use for en/decrypting a request. However, it's the upper layers (like the filesystem/fscrypt) that know about and manages encryption contexts. As such, when the upper layer submits a bio to the block layer, and this bio eventually reaches a device driver with support for inline encryption, the device driver will need to have been told the encryption context for that bio. We want to communicate the encryption context from the upper layer to the storage device along with the bio, when the bio is submitted to the block layer. To do this, we add a struct bio_crypt_ctx to struct bio, which can represent an encryption context (note that we can't use the bi_private field in struct bio to do this because that field does not function to pass information across layers in the storage stack). We also introduce various functions to manipulate the bio_crypt_ctx and make the bio/request merging logic aware of the bio_crypt_ctx. We also make changes to blk-mq to make it handle bios with encryption contexts. blk-mq can merge many bios into the same request. These bios need to have contiguous data unit numbers (the necessary changes to blk-merge are also made to ensure this) - as such, it suffices to keep the data unit number of just the first bio, since that's all a storage driver needs to infer the data unit number to use for each data block in each bio in a request. blk-mq keeps track of the encryption context to be used for all the bios in a request with the request's rq_crypt_ctx. When the first bio is added to an empty request, blk-mq will program the encryption context of that bio into the request_queue's keyslot manager, and store the returned keyslot in the request's rq_crypt_ctx. All the functions to operate on encryption contexts are in blk-crypto.c. Upper layers only need to call bio_crypt_set_ctx with the encryption key, algorithm and data_unit_num; they don't have to worry about getting a keyslot for each encryption context, as blk-mq/blk-crypto handles that. Blk-crypto also makes it possible for request-based layered devices like dm-rq to make use of inline encryption hardware by cloning the rq_crypt_ctx and programming a keyslot in the new request_queue when necessary. Note that any user of the block layer can submit bios with an encryption context, such as filesystems, device-mapper targets, etc. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: Keyslot Manager for Inline EncryptionSatya Tangirala
Inline Encryption hardware allows software to specify an encryption context (an encryption key, crypto algorithm, data unit num, data unit size) along with a data transfer request to a storage device, and the inline encryption hardware will use that context to en/decrypt the data. The inline encryption hardware is part of the storage device, and it conceptually sits on the data path between system memory and the storage device. Inline Encryption hardware implementations often function around the concept of "keyslots". These implementations often have a limited number of "keyslots", each of which can hold a key (we say that a key can be "programmed" into a keyslot). Requests made to the storage device may have a keyslot and a data unit number associated with them, and the inline encryption hardware will en/decrypt the data in the requests using the key programmed into that associated keyslot and the data unit number specified with the request. As keyslots are limited, and programming keys may be expensive in many implementations, and multiple requests may use exactly the same encryption contexts, we introduce a Keyslot Manager to efficiently manage keyslots. We also introduce a blk_crypto_key, which will represent the key that's programmed into keyslots managed by keyslot managers. The keyslot manager also functions as the interface that upper layers will use to program keys into inline encryption hardware. For more information on the Keyslot Manager, refer to documentation found in block/keyslot-manager.c and linux/keyslot-manager.h. Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14iocost: don't let vrate run wild while there's no saturation signalTejun Heo
When the QoS targets are met and nothing is being throttled, there's no way to tell how saturated the underlying device is - it could be almost entirely idle, at the cusp of saturation or anywhere inbetween. Given that there's no information, it's best to keep vrate as-is in this state. Before 7cd806a9a953 ("iocost: improve nr_lagging handling"), this was the case - if the device isn't missing QoS targets and nothing is being throttled, busy_level was reset to zero. While fixing nr_lagging handling, 7cd806a9a953 ("iocost: improve nr_lagging handling") broke this. Now, while the device is hitting QoS targets and nothing is being throttled, vrate keeps getting adjusted according to the existing busy_level. This led to vrate keeping climing till it hits max when there's an IO issuer with limited request concurrency if the vrate started low. vrate starts getting adjusted upwards until the issuer can issue IOs w/o being throttled. From then on, QoS targets keeps getting met and nothing on the system needs throttling and vrate keeps getting increased due to the existing busy_level. This patch makes the following changes to the busy_level logic. * Reset busy_level if nr_shortages is zero to avoid the above scenario. * Make non-zero nr_lagging block lowering nr_level but still clear positive busy_level if there's clear non-saturation signal - QoS targets are met and nr_shortages is non-zero. nr_lagging's role is preventing adjusting vrate upwards while there are long-running commands and it shouldn't keep busy_level positive while there's clear non-saturation signal. * Restructure code for clarity and add comments. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andy Newell <newella@fb.com> Fixes: 7cd806a9a953 ("iocost: improve nr_lagging handling") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: move blk_io_schedule() out of header fileMing Lei
blk_io_schedule() isn't called from performance sensitive code path, and it is easier to maintain by exporting it as symbol. Also blk_io_schedule() is only called by CONFIG_BLOCK code, so it is safe to do this way. Meantime fixes build failure when CONFIG_BLOCK is off. Cc: Christoph Hellwig <hch@infradead.org> Fixes: e6249cdd46e4 ("block: add blk_io_schedule() for avoiding task hung in sync dio") Reported-by: Satya Tangirala <satyat@google.com> Tested-by: Satya Tangirala <satyat@google.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: export bio_release_pages and bio_iov_iter_get_pagesJohannes Thumshirn
Export bio_release_pages and bio_iov_iter_get_pages, so they can be used from modular code. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: Modify revalidate zonesDamien Le Moal
Modify the interface of blk_revalidate_disk_zones() to add an optional driver callback function that a driver can use to extend processing done during zone revalidation. The callback, if defined, is executed with the device request queue frozen, after all zones have been inspected. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: introduce blk_req_zone_write_trylockJohannes Thumshirn
Introduce blk_req_zone_write_trylock(), which either grabs the write-lock for a sequential zone or returns false, if the zone is already locked. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: Introduce REQ_OP_ZONE_APPENDKeith Busch
Define REQ_OP_ZONE_APPEND to append-write sectors to a zone of a zoned block device. This is a no-merge write operation. A zone append write BIO must: * Target a zoned block device * Have a sector position indicating the start sector of the target zone * The target zone must be a sequential write zone * The BIO must not cross a zone boundary * The BIO size must not be split to ensure that a single range of LBAs is written with a single command. Implement these checks in generic_make_request_checks() using the helper function blk_check_zone_append(). To avoid write append BIO splitting, introduce the new max_zone_append_sectors queue limit attribute and ensure that a BIO size is always lower than this limit. Export this new limit through sysfs and check these limits in bio_full(). Also when a LLDD can't dispatch a request to a specific zone, it will return BLK_STS_ZONE_RESOURCE indicating this request needs to be delayed, e.g. because the zone it will be dispatched to is still write-locked. If this happens set the request aside in a local list to continue trying dispatching requests such as READ requests or a WRITE/ZONE_APPEND requests targetting other zones. This way we can still keep a high queue depth without starving other requests even if one request can't be served due to zone write-locking. Finally, make sure that the bio sector position indicates the actual write position as indicated by the device on completion. Signed-off-by: Keith Busch <kbusch@kernel.org> [ jth: added zone-append specific add_page and merge_page helpers ] Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: rename __bio_add_pc_page to bio_add_hw_pageChristoph Hellwig
Rename __bio_add_pc_page() to bio_add_hw_page() and explicitly pass in a max_sectors argument. This max_sectors argument can be used to specify constraints from the hardware. Signed-off-by: Christoph Hellwig <hch@lst.de> [ jth: rebased and made public for blk-map.c ] Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: don't hold part0's refcount in IO pathMing Lei
gendisk can't be gone when there is IO activity, so not hold part0's refcount in IO path. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Cc: Yufen Yu <yuyufen@huawei.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: only define 'nr_sects_seq' in hd_part for 32bit SMPMing Lei
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP, so define it just for 32bit SMP. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Cc: Yufen Yu <yuyufen@huawei.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: fix use-after-free on cached last_lookup partitionMing Lei
delete_partition() clears the cached last_lookup partition. However the .last_lookup cache may be overwritten by one IO path after it is cleared from delete_partition(). Then another IO path may use the cached deleting partition after hd_struct_free() is called, then use-after-free is triggered on the cached partition. Fixes the issue by the following approach: 1) always get the partition's refcount via hd_struct_try_get() before setting .last_lookup 2) move clearing .last_lookup from delete_partition() to hd_struct_free() which is the release handle of the partition's percpu-refcount, so that no IO path can cache deleteing partition via .last_lookup. It is one candidate approach of Yufen's patch[1] which adds overhead in fast path by indirect lookup which may introduce one extra cacheline in IO path. Also this patch relies on percpu-refcount's protection, and it is easier to understand and verify. [1] https://lore.kernel.org/linux-block/20200109013551.GB9655@ming.t460p/T/#t Reported-by: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hou Tao <houtao1@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-12block: reset mapping if failed to update hardware queue countWeiping Zhang
When we increase hardware queue count, blk_mq_update_queue_map will reset the mapping between cpu and hardware queue base on the hardware queue count(set->nr_hw_queues). The mapping cannot be reset if it encounters error in blk_mq_realloc_hw_ctxs, but the fallback flow will continue using it, then blk_mq_map_swqueue will touch a invalid memory, because the mapping points to a wrong hctx. blktest block/030: null_blk: module loaded Increasing nr_hw_queues to 8 fails, fallback to 1 ================================================================== BUG: KASAN: null-ptr-deref in blk_mq_map_swqueue+0x2f2/0x830 Read of size 8 at addr 0000000000000128 by task nproc/8541 CPU: 5 PID: 8541 Comm: nproc Not tainted 5.7.0-rc4-dbg+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack+0xa5/0xe6 __kasan_report.cold+0x65/0xbb kasan_report+0x45/0x60 check_memory_region+0x15e/0x1c0 __kasan_check_read+0x15/0x20 blk_mq_map_swqueue+0x2f2/0x830 __blk_mq_update_nr_hw_queues+0x3df/0x690 blk_mq_update_nr_hw_queues+0x32/0x50 nullb_device_submit_queues_store+0xde/0x160 [null_blk] configfs_write_file+0x1c4/0x250 [configfs] __vfs_write+0x4c/0x90 vfs_write+0x14b/0x2d0 ksys_write+0xdd/0x180 __x64_sys_write+0x47/0x50 do_syscall_64+0x6f/0x310 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Tested-by: Bart van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-09bdi: remove the name field in struct backing_dev_infoChristoph Hellwig
The name is only printed for a not registered bdi in writeback. Use the device name there as is more useful anyway for the unlike case that the warning triggers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>