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2019-02-28block: implement bio helper to add iter bvec pages to bioJens Axboe
For an ITER_BVEC, we can just iterate the iov and add the pages to the bio directly. For now, we grab a reference to those pages, and release them normally on IO completion. This isn't really needed for the normal case of O_DIRECT from/to a file, but some of the more esoteric use cases (like splice(2)) will unconditionally put the pipe buffer pages when the buffers are released. Until we can manage that case properly, ITER_BVEC pages are treated like normal pages in terms of reference counting. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15block: enable multipage bvecsMing Lei
This patch pulls the trigger for multi-page bvecs. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15block: allow bio_for_each_segment_all() to iterate over multi-page bvecMing Lei
This patch introduces one extra iterator variable to bio_for_each_segment_all(), then we can allow bio_for_each_segment_all() to iterate over multi-page bvec. Given it is just one mechannical & simple change on all bio_for_each_segment_all() users, this patch does tree-wide change in one single patch, so that we can avoid to use a temporary helper for this conversion. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-02Merge tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull more block updates from Jens Axboe: - Dead code removal for loop/sunvdc (Chengguang) - Mark BIDI support for bsg as deprecated, logging a single dmesg warning if anyone is actually using it (Christoph) - blkcg cleanup, killing a dead function and making the tryget_closest variant easier to read (Dennis) - Floppy fixes, one fixing a regression in swim3 (Finn) - lightnvm use-after-free fix (Gustavo) - gdrom leak fix (Wenwen) - a set of drbd updates (Lars, Luc, Nathan, Roland) * tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block: (28 commits) block/swim3: Fix regression on PowerBook G3 block/swim3: Fix -EBUSY error when re-opening device after unmount block/swim3: Remove dead return statement block/amiflop: Don't log error message on invalid ioctl gdrom: fix a memory leak bug lightnvm: pblk: fix use-after-free bug block: sunvdc: remove redundant code block: loop: remove redundant code bsg: deprecate BIDI support in bsg blkcg: remove unused __blkg_release_rcu() blkcg: clean up blkg_tryget_closest() drbd: Change drbd_request_detach_interruptible's return type to int drbd: Avoid Clang warning about pointless switch statment drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire") drbd: skip spurious timeout (ping-timeo) when failing promote drbd: don't retry connection if peers do not agree on "authentication" settings drbd: fix print_st_err()'s prototype to match the definition drbd: avoid spurious self-outdating with concurrent disconnect / down drbd: do not block when adjusting "disk-options" while IO is frozen drbd: fix comment typos ...
2018-12-28Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "This is the main pull request for block/storage for 4.21. Larger than usual, it was a busy round with lots of goodies queued up. Most notable is the removal of the old IO stack, which has been a long time coming. No new features for a while, everything coming in this week has all been fixes for things that were previously merged. This contains: - Use atomic counters instead of semaphores for mtip32xx (Arnd) - Cleanup of the mtip32xx request setup (Christoph) - Fix for circular locking dependency in loop (Jan, Tetsuo) - bcache (Coly, Guoju, Shenghui) * Optimizations for writeback caching * Various fixes and improvements - nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith) * host and target support for NVMe over TCP * Error log page support * Support for separate read/write/poll queues * Much improved polling * discard OOM fallback * Tracepoint improvements - lightnvm (Hans, Hua, Igor, Matias, Javier) * Igor added packed metadata to pblk. Now drives without metadata per LBA can be used as well. * Fix from Geert on uninitialized value on chunk metadata reads. * Fixes from Hans and Javier to pblk recovery and write path. * Fix from Hua Su to fix a race condition in the pblk recovery code. * Scan optimization added to pblk recovery from Zhoujie. * Small geometry cleanup from me. - Conversion of the last few drivers that used the legacy path to blk-mq (me) - Removal of legacy IO path in SCSI (me, Christoph) - Removal of legacy IO stack and schedulers (me) - Support for much better polling, now without interrupts at all. blk-mq adds support for multiple queue maps, which enables us to have a map per type. This in turn enables nvme to have separate completion queues for polling, which can then be interrupt-less. Also means we're ready for async polled IO, which is hopefully coming in the next release. - Killing of (now) unused block exports (Christoph) - Unification of the blk-rq-qos and blk-wbt wait handling (Josef) - Support for zoned testing with null_blk (Masato) - sx8 conversion to per-host tag sets (Christoph) - IO priority improvements (Damien) - mq-deadline zoned fix (Damien) - Ref count blkcg series (Dennis) - Lots of blk-mq improvements and speedups (me) - sbitmap scalability improvements (me) - Make core inflight IO accounting per-cpu (Mikulas) - Export timeout setting in sysfs (Weiping) - Cleanup the direct issue path (Jianchao) - Export blk-wbt internals in block debugfs for easier debugging (Ming) - Lots of other fixes and improvements" * tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits) kyber: use sbitmap add_wait_queue/list_del wait helpers sbitmap: add helpers for add/del wait queue handling block: save irq state in blkg_lookup_create() dm: don't reuse bio for flushes nvme-pci: trace SQ status on completions nvme-rdma: implement polling queue map nvme-fabrics: allow user to pass in nr_poll_queues nvme-fabrics: allow nvmf_connect_io_queue to poll nvme-core: optionally poll sync commands block: make request_to_qc_t public nvme-tcp: fix spelling mistake "attepmpt" -> "attempt" nvme-tcp: fix endianess annotations nvmet-tcp: fix endianess annotations nvme-pci: refactor nvme_poll_irqdisable to make sparse happy nvme-pci: only set nr_maps to 2 if poll queues are supported nvmet: use a macro for default error location nvmet: fix comparison of a u16 with -1 blk-mq: enable IO poll if .nr_queues of type poll > 0 blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight() blk-mq: skip zero-queue maps in blk_mq_map_swqueue ...
2018-12-21blkcg: clean up blkg_tryget_closest()Dennis Zhou
The implementation of blkg_tryget_closest() wasn't super obvious and became a point of suspicion when debugging [1]. So let's clean it up so it's obviously not the problem. Also add missing RCU read locking to bio_clone_blkg_association(), which got exposed by adding the RCU read lock held check in blkg_tryget_closest(). [1] https://lore.kernel.org/linux-block/a7e97e4b-0dd8-3a54-23b7-a0f27b17fde8@kernel.dk/ Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the unused bio_set_pages_dirty and bio_check_pages_dirty exportsChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the unused bio_iov_iter_get_pages exportChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-14block: remove the bio_phys_segments exportChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block/bio: Do not zero user pagesKeith Busch
We don't need to zero fill the bio if not using kernel allocated pages. Fixes: f3587d76da05 ("block: Clear kernel memory before copying to user") # v4.20-rc2 Reported-by: Todd Aiken <taiken@mvtech.ca> Cc: Laurence Oberman <loberman@redhat.com> Cc: stable@vger.kernel.org Cc: Bart Van Assche <bvanassche@acm.org> Tested-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: delete part_round_stats and switch to less precise countingMikulas Patocka
We want to convert to per-cpu in_flight counters. The function part_round_stats needs the in_flight counter every jiffy, it would be too costly to sum all the percpu variables every jiffy, so it must be deleted. part_round_stats is used to calculate two counters - time_in_queue and io_ticks. time_in_queue can be calculated without part_round_stats, by adding the duration of the I/O when the I/O ends (the value is almost as exact as the previously calculated value, except that time for in-progress I/Os is not counted). io_ticks can be approximated by increasing the value when I/O is started or ended and the jiffies value has changed. If the I/Os take less than a jiffy, the value is as exact as the previously calculated value. If the I/Os take more than a jiffy, io_ticks can drift behind the previously calculated value. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-10block: stop passing 'cpu' to all percpu stats methodsMike Snitzer
All of part_stat_* and related methods are used with preempt disabled, so there is no need to pass cpu around to allow of them. Just call smp_processor_id() as needed. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: rename blkg_try_get() to blkg_tryget()Dennis Zhou
blkg reference counting now uses percpu_ref rather than atomic_t. Let's make this consistent with css_tryget. This renames blkg_try_get to blkg_tryget and now returns a bool rather than the blkg or %NULL. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: remove bio_disassociate_task()Dennis Zhou
Now that a bio only holds a blkg reference, so clean up is simply putting back that reference. Remove bio_disassociate_task() as it just calls bio_disassociate_blkg() and call the latter directly. Signed-off-by: Dennis Zhou <dennis@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: remove additional reference to the cssDennis Zhou
The previous patch in this series removed carrying around a pointer to the css in blkg. However, the blkg association logic still relied on taking a reference on the css to ensure we wouldn't fail in getting a reference for the blkg. Here the implicit dependency on the css is removed. The association continues to rely on the tryget logic walking up the blkg tree. This streamlines the three ways that association can happen: normal, swap, and writeback. Signed-off-by: Dennis Zhou <dennis@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: remove bio->bi_css and instead use bio->bi_blkgDennis Zhou
Prior patches ensured that any bio that interacts with a request_queue is properly associated with a blkg. This makes bio->bi_css unnecessary as blkg maintains a reference to blkcg already. This removes the bio field bi_css and transfers corresponding uses to access via bi_blkg. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: associate writeback bios with a blkgDennis Zhou
One of the goals of this series is to remove a separate reference to the css of the bio. This can and should be accessed via bio_blkcg(). In this patch, wbc_init_bio() now requires a bio to have a device associated with it. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: associate a blkg for pages being evicted by swapDennis Zhou
A prior patch in this series added blkg association to bios issued by cgroups. There are two other paths that we want to attribute work back to the appropriate cgroup: swap and writeback. Here we modify the way swap tags bios to include the blkg. Writeback will be tackle in the next patch. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: consolidate bio_issue_init() to be a part of coreDennis Zhou
bio_issue_init among other things initializes the timestamp for an IO. Rather than have this logic handled by policies, this consolidates it to be on the init paths (normal, clone, bounce clone). Signed-off-by: Dennis Zhou <dennis@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: associate blkg when associating a deviceDennis Zhou
Previously, blkg association was handled by controller specific code in blk-throttle and blk-iolatency. However, because a blkg represents a relationship between a blkcg and a request_queue, it makes sense to keep the blkg->q and bio->bi_disk->queue consistent. This patch moves association into the bio_set_dev macro(). This should cover the majority of cases where the device is set/changed keeping the two pointers consistent. Fallback code is added to blkcg_bio_issue_check() to catch any missing paths. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07dm: set the static flush bio device on demandDennis Zhou
The next patch changes the macro bio_set_dev() to associate a bio with a blkg based on the device set. However, dm creates a static bio to be used as the basis for cloning empty flush bios on creation. The bio_set_dev() call in alloc_dev() will cause problems with the next patch adding association to bio_set_dev() because the call is before the bdev is associated with a gendisk (bd_disk is %NULL). To get around this, set the device on the static bio every time and use that to clone to the other bios. Signed-off-by: Dennis Zhou <dennis@kernel.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: introduce common blkg association logicDennis Zhou
There are 3 ways blkg association can happen: association with the current css, with the page css (swap), or from the wbc css (writeback). This patch handles how association is done for the first case where we are associating bsaed on the current css. If there is already a blkg associated, the css will be reused and association will be redone as the request_queue may have changed. Signed-off-by: Dennis Zhou <dennis@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: convert blkg_lookup_create() to find closest blkgDennis Zhou
There are several scenarios where blkg_lookup_create() can fail such as the blkcg dying, request_queue is dying, or simply being OOM. Most handle this by simply falling back to the q->root_blkg and calling it a day. This patch implements the notion of closest blkg. During blkg_lookup_create(), if it fails to create, return the closest blkg found or the q->root_blkg. blkg_try_get_closest() is introduced and used during association so a bio is always attached to a blkg. Signed-off-by: Dennis Zhou <dennis@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-07blkcg: fix ref count issue with bio_blkcg() using task_cssDennis Zhou
The bio_blkcg() function turns out to be inconsistent and consequently dangerous to use. The first part returns a blkcg where a reference is owned by the bio meaning it does not need to be rcu protected. However, the third case, the last line, is problematic: return css_to_blkcg(task_css(current, io_cgrp_id)); This can race against task migration and the cgroup dying. It is also semantically different as it must be called rcu protected and is susceptible to failure when trying to get a reference to it. This patch adds association ahead of calling bio_blkcg() rather than after. This makes association a required and explicit step along the code paths for calling bio_blkcg(). In blk-iolatency, association is moved above the bio_blkcg() call to ensure it will not return %NULL. BFQ uses the old bio_blkcg() function, but I do not want to address it in this series due to the complexity. I have created a private version documenting the inconsistency and noting not to use it. Signed-off-by: Dennis Zhou <dennis@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19block: Remove bio->bi_iocDamien Le Moal
bio->bi_ioc is never set so always NULL. Remove references to it in bio_disassociate_task() and in rq_ioc() and delete this field from struct bio. With this change, rq_ioc() always returns current->io_context without the need for a bio argument. Further simplify the code and make it more readable by also removing this helper, which also allows to simplify blk_mq_sched_assign_ioc() by removing its bio argument. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-12block: copy ioprio in __bio_clone_fast() and bounceHannes Reinecke
We need to copy the io priority, too; otherwise the clone will run with a different priority than the original one. Fixes: 43b62ce3ff0a ("block: move bio io prio to a new field") Signed-off-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jean Delvare <jdelvare@suse.de> Fixed up subject, and ordered stores. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-09Merge tag 'for-linus-20181109' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer fixes from Jens Axboe: - Two fixes for an ubd regression, one for missing locking, and one for a missing initialization of a field. The latter was an old latent bug, but it's now visible and triggers (Me, Anton Ivanov) - Set of NVMe fixes via Christoph, but applied manually due to a git tree mixup (Christoph, Sagi) - Fix for a discard split regression, in three patches (Ming) - Update libata git trees (Geert) - SPDX identifier for sata_rcar (Kuninori Morimoto) - Virtual boundary merge fix (Johannes) - Preemptively clear memory we are going to pass to userspace, in case the driver does a short read (Keith) * tag 'for-linus-20181109' of git://git.kernel.dk/linux-block: block: make sure writesame bio is aligned with logical block size block: cleanup __blkdev_issue_discard() block: make sure discard bio is aligned with logical block size Revert "nvmet-rdma: use a private workqueue for delete" nvme: make sure ns head inherits underlying device limits nvmet: don't try to add ns to p2p map unless it actually uses it sata_rcar: convert to SPDX identifiers ubd: fix missing initialization of io_req block: Clear kernel memory before copying to user MAINTAINERS: Fix remaining pointers to obsolete libata.git ubd: fix missing lock around request issue block: respect virtual boundary mask in bvecs
2018-11-07block: Clear kernel memory before copying to userKeith Busch
If the kernel allocates a bounce buffer for user read data, this memory needs to be cleared before copying it to the user, otherwise it may leak kernel memory to user space. Laurence Oberman <loberman@redhat.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-02Merge tag 'for-linus-20181102' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer fixes from Jens Axboe: "The biggest part of this pull request is the revert of the blkcg cleanup series. It had one fix earlier for a stacked device issue, but another one was reported. Rather than play whack-a-mole with this, revert the entire series and try again for the next kernel release. Apart from that, only small fixes/changes. Summary: - Indentation fixup for mtip32xx (Colin Ian King) - The blkcg cleanup series revert (Dennis Zhou) - Two NVMe fixes. One fixing a regression in the nvme request initialization in this merge window, causing nvme-fc to not work. The other is a suspend/resume p2p resource issue (James, Keith) - Fix sg discard merge, allowing us to merge in cases where we didn't before (Jianchao Wang) - Call rq_qos_exit() after the queue is frozen, preventing a hang (Ming) - Fix brd queue setup, fixing an oops if we fail setting up all devices (Ming)" * tag 'for-linus-20181102' of git://git.kernel.dk/linux-block: nvme-pci: fix conflicting p2p resource adds nvme-fc: fix request private initialization blkcg: revert blkcg cleanups series block: brd: associate with queue until adding disk block: call rq_qos_exit() after queue is frozen mtip32xx: clean an indentation issue, remove extraneous tabs block: fix the DISCARD request merge
2018-11-01Merge branch 'work.afs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull AFS updates from Al Viro: "AFS series, with some iov_iter bits included" * 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits) missing bits of "iov_iter: Separate type from direction and use accessor functions" afs: Probe multiple fileservers simultaneously afs: Fix callback handling afs: Eliminate the address pointer from the address list cursor afs: Allow dumping of server cursor on operation failure afs: Implement YFS support in the fs client afs: Expand data structure fields to support YFS afs: Get the target vnode in afs_rmdir() and get a callback on it afs: Calc callback expiry in op reply delivery afs: Fix FS.FetchStatus delivery from updating wrong vnode afs: Implement the YFS cache manager service afs: Remove callback details from afs_callback_break struct afs: Commit the status on a new file/dir/symlink afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS afs: Don't invoke the server to read data beyond EOF afs: Add a couple of tracepoints to log I/O errors afs: Handle EIO from delivery function afs: Fix TTL on VL server and address lists afs: Implement VL server rotation afs: Improve FS server rotation error handling ...
2018-11-01blkcg: revert blkcg cleanups seriesDennis Zhou
This reverts a series committed earlier due to null pointer exception bug report in [1]. It seems there are edge case interactions that I did not consider and will need some time to understand what causes the adverse interactions. The original series can be found in [2] with a follow up series in [3]. [1] https://www.spinics.net/lists/cgroups/msg20719.html [2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/ This reverts the following commits: d459d853c2ed, b2c3fa546705, 101246ec02b5, b3b9f24f5fcc, e2b0989954ae, f0fcb3ec89f3, c839e7a03f92, bdc2491708c4, 74b7c02a9bc1, 5bf9a1f3b4ef, a7b39b4e961c, 07b05bcc3213, 49f4c2dc2b50, 27e6fa996c53 Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-24iov_iter: Use accessor functionDavid Howells
Use accessor functions to access an iterator's type and direction. This allows for the possibility of using some other method of determining the type of iterator than if-chains with bitwise-AND conditions. Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-20blkcg: reassociate bios when make_request() is called recursivelyDennis Zhou
When submitting a bio, multiple recursive calls to make_request() may occur. This causes the initial associate done in blkcg_bio_issue_check() to be incorrect and reference the prior request_queue. This introduces a helper to do reassociation when make_request() is recursively called. Fixes: a7b39b4e961c ("blkcg: always associate a bio with a blkg") Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Dennis Zhou <dennis@kernel.org> Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-01Merge tag 'v4.19-rc6' into for-4.20/blockJens Axboe
Merge -rc6 in, for two reasons: 1) Resolve a trivial conflict in the blk-mq-tag.c documentation 2) A few important regression fixes went into upstream directly, so they aren't in the 4.20 branch. Signed-off-by: Jens Axboe <axboe@kernel.dk> * tag 'v4.19-rc6': (780 commits) Linux 4.19-rc6 MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c cpufreq: qcom-kryo: Fix section annotations perf/core: Add sanity check to deal with pinned event failure xen/blkfront: correct purging of persistent grants Revert "xen/blkfront: When purging persistent grants, keep them in the buffer" selftests/powerpc: Fix Makefiles for headers_install change blk-mq: I/O and timer unplugs are inverted in blktrace dax: Fix deadlock in dax_lock_mapping_entry() x86/boot: Fix kexec booting failure in the SEV bit detection code bcache: add separate workqueue for journal_write to avoid deadlock drm/amd/display: Fix Edid emulation for linux drm/amd/display: Fix Vega10 lightup on S3 resume drm/amdgpu: Fix vce work queue was not cancelled when suspend Revert "drm/panel: Add device_link from panel device to DRM device" xen/blkfront: When purging persistent grants, keep them in the buffer clocksource/drivers/timer-atmel-pit: Properly handle error cases block: fix deadline elevator drain for zoned block devices ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set ... Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24block: merge BIOVEC_SEG_BOUNDARY into biovec_phys_mergeableChristoph Hellwig
These two checks should always be performed together, so merge them into a single helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24block: add a missing BIOVEC_SEG_BOUNDARY check in bio_add_pc_pageChristoph Hellwig
The actual recaculation of segments in __blk_recalc_rq_segments will do this check, so there is no point in forcing it if we know it won't succeed. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-24block: simplify BIOVEC_PHYS_MERGEABLEChristoph Hellwig
Turn the macro into an inline, move it to blk.h and simplify the arch hooks a bit. Also rename the function to biovec_phys_mergeable as there is no need to shout. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: rename blkg_try_get to blkg_trygetDennis Zhou (Facebook)
blkg reference counting now uses percpu_ref rather than atomic_t. Let's make this consistent with css_tryget. This renames blkg_try_get to blkg_tryget and now returns a bool rather than the blkg or NULL. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: remove additional reference to the cssDennis Zhou (Facebook)
The previous patch in this series removed carrying around a pointer to the css in blkg. However, the blkg association logic still relied on taking a reference on the css to ensure we wouldn't fail in getting a reference for the blkg. Here the implicit dependency on the css is removed. The association continues to rely on the tryget logic walking up the blkg tree. This streamlines the three ways that association can happen: normal, swap, and writeback. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: remove bio->bi_css and instead use bio->bi_blkgDennis Zhou (Facebook)
Prior patches ensured that all bios are now associated with some blkg. This now makes bio->bi_css unnecessary as blkg maintains a reference to the blkcg already. This patch removes the field bi_css and transfers corresponding uses to access via bi_blkg. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: associate a blkg for pages being evicted by swapDennis Zhou (Facebook)
A prior patch in this series added blkg association to bios issued by cgroups. There are two other paths that we want to attribute work back to the appropriate cgroup: swap and writeback. Here we modify the way swap tags bios to include the blkg. Writeback will be tackle in the next patch. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: consolidate bio_issue_init to be a part of coreDennis Zhou (Facebook)
bio_issue_init among other things initializes the timestamp for an IO. Rather than have this logic handled by policies, this consolidates it to be on the init paths (normal, clone, bounce clone). Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: always associate a bio with a blkgDennis Zhou (Facebook)
Previously, blkg's were only assigned as needed by blk-iolatency and blk-throttle. bio->css was also always being associated while blkg was being looked up and then thrown away in blkcg_bio_issue_check. This patch begins the cleanup of bio->css and bio->bi_blkg by always associating a blkg in blkcg_bio_issue_check. This tries to create the blkg, but if it is not possible, falls back to using the root_blkg of the request_queue. Therefore, a bio will always be associated with a blkg. The duplicate association logic is removed from blk-throttle and blk-iolatency. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: convert blkg_lookup_create to find closest blkgDennis Zhou (Facebook)
There are several scenarios where blkg_lookup_create can fail. Examples include the blkcg dying, request_queue is dying, or simply being OOM. At the end of the day, most handle this by simply falling back to the q->root_blkg and calling it a day. This patch implements the notion of closest blkg. During blkg_lookup_create, if it fails to create, return the closest blkg found or the q->root_blkg. blkg_try_get_closest is introduced and used during association so a bio is always attached to a blkg. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21blkcg: fix ref count issue with bio_blkcg using task_cssDennis Zhou (Facebook)
The accessor function bio_blkcg either returns the blkcg associated with the bio or finds one in the current context. This can cause an issue when trying to associate a bio with a blkcg. Particularly, it's the third case that is problematic: return css_to_blkcg(task_css(current, io_cgrp_id)); As the above may race against task migration and the cgroup exiting, it is not always ok to take a reference on the blkcg returned from bio_blkcg. This patch adds association ahead of calling bio_blkcg rather than after. This makes association a required and explicit step along the code paths for calling bio_blkcg. blk_get_rl is modified as well to get a reference to the blkcg it may use and blk_put_rl will always put the reference back. Association is also moved above the bio_blkcg call to ensure it will not return NULL in blk-iolatency. BFQ and CFQ utilize this flaw, but due to the complexity, I do not want to address this in this series. I've created a private version of the function with notes not to use it describing the flaw. Hopefully soon, that code can be cleaned up. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-21block: use nanosecond resolution for iostatOmar Sandoval
Klaus Kusche reported that the I/O busy time in /proc/diskstats was not updating properly on 4.18. This is because we started using ktime to track elapsed time, and we convert nanoseconds to jiffies when we update the partition counter. However, this gets rounded down, so any I/Os that take less than a jiffy are not accounted for. Previously in this case, the value of jiffies would sometimes increment while we were doing I/O, so at least some I/Os were accounted for. Let's convert the stats to use nanoseconds internally. We still report milliseconds as before, now more accurately than ever. The value is still truncated to 32 bits for backwards compatibility. Fixes: 522a777566f5 ("block: consolidate struct request timestamp fields") Cc: stable@vger.kernel.org Reported-by: Klaus Kusche <klaus.kusche@computerix.info> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-20block: use bio_add_page in bio_iov_iter_get_pagesChristoph Hellwig
Replace a nasty hack with a different nasty hack to prepare for multipage bio_vecs. By moving the temporary page array as far up as possible in the space allocated for the bio_vec array we can iterate forward over it and thus use bio_add_page. Using bio_add_page means we'll be able to merge physically contiguous pages once support for multipath bio_vecs is merged. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-06block: remove bio_rewind_iter()Ming Lei
It is pointed that bio_rewind_iter() is one very bad API[1]: 1) bio size may not be restored after rewinding 2) it causes some bogus change, such as 5151842b9d8732 (block: reset bi_iter.bi_done after splitting bio) 3) rewinding really makes things complicated wrt. bio splitting 4) unnecessary updating of .bi_done in fast path [1] https://marc.info/?t=153549924200005&r=1&w=2 So this patch takes Kent's suggestion to restore one bio into its original state via saving bio iterator(struct bvec_iter) in bio_integrity_prep(), given now bio_rewind_iter() is only used by bio integrity code. Cc: Dmitry Monakhov <dmonakhov@openvz.org> Cc: Hannes Reinecke <hare@suse.com> Suggested-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-31blkcg: use tryget logic when associating a blkg with a bioDennis Zhou (Facebook)
There is a very small change a bio gets caught up in a really unfortunate race between a task migration, cgroup exiting, and itself trying to associate with a blkg. This is due to css offlining being performed after the css->refcnt is killed which triggers removal of blkgs that reach their blkg->refcnt of 0. To avoid this, association with a blkg should use tryget and fallback to using the root_blkg. Fixes: 08e18eab0c579 ("block: add bi_blkg to the bio for cgroups") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Tejun Heo <tj@kernel.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-14Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "First pull request for this merge window, there will also be a followup request with some stragglers. This pull request contains: - Fix for a thundering heard issue in the wbt block code (Anchal Agarwal) - A few NVMe pull requests: * Improved tracepoints (Keith) * Larger inline data support for RDMA (Steve Wise) * RDMA setup/teardown fixes (Sagi) * Effects log suppor for NVMe target (Chaitanya Kulkarni) * Buffered IO suppor for NVMe target (Chaitanya Kulkarni) * TP4004 (ANA) support (Christoph) * Various NVMe fixes - Block io-latency controller support. Much needed support for properly containing block devices. (Josef) - Series improving how we handle sense information on the stack (Kees) - Lightnvm fixes and updates/improvements (Mathias/Javier et al) - Zoned device support for null_blk (Matias) - AIX partition fixes (Mauricio Faria de Oliveira) - DIF checksum code made generic (Max Gurtovoy) - Add support for discard in iostats (Michael Callahan / Tejun) - Set of updates for BFQ (Paolo) - Removal of async write support for bsg (Christoph) - Bio page dirtying and clone fixups (Christoph) - Set of bcache fix/changes (via Coly) - Series improving blk-mq queue setup/teardown speed (Ming) - Series improving merging performance on blk-mq (Ming) - Lots of other fixes and cleanups from a slew of folks" * tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits) blkcg: Make blkg_root_lookup() work for queues in bypass mode bcache: fix error setting writeback_rate through sysfs interface null_blk: add lock drop/acquire annotation Blk-throttle: reduce tail io latency when iops limit is enforced block: paride: pd: mark expected switch fall-throughs block: Ensure that a request queue is dissociated from the cgroup controller block: Introduce blk_exit_queue() blkcg: Introduce blkg_root_lookup() block: Remove two superfluous #include directives blk-mq: count the hctx as active before allocating tag block: bvec_nr_vecs() returns value for wrong slab bcache: trivial - remove tailing backslash in macro BTREE_FLAG bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section bcache: set max writeback rate when I/O request is idle bcache: add code comments for bset.c bcache: fix mistaken comments in request.c bcache: fix mistaken code comments in bcache.h bcache: add a comment in super.c bcache: avoid unncessary cache prefetch bch_btree_node_get() bcache: display rate debug parameters to 0 when writeback is not running ...