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2024-02-09io_uring: add register/unregister napi functionStefan Roesch
This adds an api to register and unregister the napi for io-uring. If the arg value is specified when unregistering, the current napi setting for the busy poll timeout is copied into the user structure. If this is not required, NULL can be passed as the arg value. Signed-off-by: Stefan Roesch <shr@devkernel.io> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230608163839.2891748-7-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-09io-uring: add sqpoll support for napi busy pollStefan Roesch
This adds the sqpoll support to the io-uring napi. Signed-off-by: Stefan Roesch <shr@devkernel.io> Suggested-by: Olivier Langlois <olivier@trillion01.com> Link: https://lore.kernel.org/r/20230608163839.2891748-6-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-09io-uring: add napi busy poll supportStefan Roesch
This adds the napi busy polling support in io_uring.c. It adds a new napi_list to the io_ring_ctx structure. This list contains the list of napi_id's that are currently enabled for busy polling. The list is synchronized by the new napi_lock spin lock. The current default napi busy polling time is stored in napi_busy_poll_to. If napi busy polling is not enabled, the value is 0. In addition there is also a hash table. The hash table store the napi id and the pointer to the above list nodes. The hash table is used to speed up the lookup to the list elements. The hash table is synchronized with rcu. The NAPI_TIMEOUT is stored as a timeout to make sure that the time a napi entry is stored in the napi list is limited. The busy poll timeout is also stored as part of the io_wait_queue. This is necessary as for sq polling the poll interval needs to be adjusted and the napi callback allows only to pass in one value. This has been tested with two simple programs from the liburing library repository: the napi client and the napi server program. The client sends a request, which has a timestamp in its payload and the server replies with the same payload. The client calculates the roundtrip time and stores it to calculate the results. The client is running on host1 and the server is running on host 2 (in the same rack). The measured times below are roundtrip times. They are average times over 5 runs each. Each run measures 1 million roundtrips. no rx coal rx coal: frames=88,usecs=33 Default 57us 56us client_poll=100us 47us 46us server_poll=100us 51us 46us client_poll=100us+ 40us 40us server_poll=100us client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on client client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on server client_poll=100us+ 41us 39us server_poll=100us+ prefer napi busy poll on client + server Signed-off-by: Stefan Roesch <shr@devkernel.io> Suggested-by: Olivier Langlois <olivier@trillion01.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230608163839.2891748-5-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-09io-uring: move io_wait_queue definition to header fileStefan Roesch
This moves the definition of the io_wait_queue structure to the header file so it can be also used from other files. Signed-off-by: Stefan Roesch <shr@devkernel.io> Link: https://lore.kernel.org/r/20230608163839.2891748-4-shr@devkernel.io Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-09io_uring: add support for ftruncateTony Solomonik
Adds support for doing truncate through io_uring, eliminating the need for applications to roll their own thread pool or offload mechanism to be able to do non-blocking truncates. Signed-off-by: Tony Solomonik <tony.solomonik@gmail.com> Link: https://lore.kernel.org/r/20240202121724.17461-3-tony.solomonik@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: Simplify the allocation of slab cachesKunwu Chan
commit 0a31bd5f2bbb ("KMEM_CACHE(): simplify slab cache creation") introduces a new macro. Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Link: https://lore.kernel.org/r/20240130100247.81460-1-chentao@kylinos.cn Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring/sqpoll: manage task_work privatelyJens Axboe
Decouple from task_work running, and cap the number of entries we process at the time. If we exceed that number, push remaining entries to a retry list that we'll process first next time. We cap the number of entries to process at 8, which is fairly random. We just want to get enough per-ctx batching here, while not processing endlessly. Since we manually run PF_IO_WORKER related task_work anyway as the task never exits to userspace, with this we no longer need to add an actual task_work item to the per-process list. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: pass in counter to handle_tw_list() rather than return itJens Axboe
No functional changes in this patch, just in preparation for returning something other than count from this helper. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: cleanup handle_tw_list() calling conventionJens Axboe
Now that we don't loop around task_work anymore, there's no point in maintaining the ring and locked state outside of handle_tw_list(). Get rid of passing in those pointers (and pointers to pointers) and just do the management internally in handle_tw_list(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring/poll: improve readability of poll reference decrementingJens Axboe
This overly long line is hard to read. Break it up by AND'ing the ref mask first, then perform the atomic_sub_return() with the value itself. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove unconditional looping in local task_work handlingJens Axboe
If we have a ton of notifications coming in, we can be looping in here for a long time. This can be problematic for various reasons, mostly because we can starve userspace. If the application is waiting on N events, then only re-run if we need more events. Fixes: c0e0d6ba25f1 ("io_uring: add IORING_SETUP_DEFER_TASKRUN") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove next io_kiocb fetch in task_work runningJens Axboe
We just reversed the task_work list and that will have touched requests as well, just get rid of this optimization as it should not make a difference anymore. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: handle traditional task_work in FIFO orderJens Axboe
For local task_work, which is used if IORING_SETUP_DEFER_TASKRUN is set, we reverse the order of the lockless list before processing the work. This is done to process items in the order in which they were queued, as the llist always adds to the head. Do the same for traditional task_work, so we have the same behavior for both types. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove 'loops' argument from trace_io_uring_task_work_run()Jens Axboe
We no longer loop in task_work handling, hence delete the argument from the tracepoint as it's always 1 and hence not very informative. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: remove looping around handling traditional task_workJens Axboe
A previous commit added looping around handling traditional task_work as an optimization, and while that may seem like a good idea, it's also possible to run into application starvation doing so. If the task_work generation is bursty, we can get very deep task_work queues, and we can end up looping in here for a very long time. One immediately observable problem with that is handling network traffic using provided buffers, where flooding incoming traffic and looping task_work handling will very quickly lead to buffer starvation as we keep running task_work rather than returning to the application so it can handle the associated CQEs and also provide buffers back. Fixes: 3a0c037b0e16 ("io_uring: batch task_work") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring/kbuf: cleanup passing back cflagsJens Axboe
We have various functions calculating the CQE cflags we need to pass back, but it's all the same everywhere. Make a number of the putting functions void, and just have the two main helps for this, io_put_kbuf() and io_put_kbuf_comp() calculate the actual mask and pass it back. While at it, cleanup how we put REQ_F_BUFFER_RING buffers. Before this change, we would call into __io_put_kbuf() only to go right back in to the header defined functions. As clearing this type of buffer is just re-assigning the buf_index and incrementing the head, this is very wasteful. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring/rw: remove dead file == NULL checkJens Axboe
Any read/write opcode has needs_file == true, which means that we would've failed the request long before reaching the issue stage if we didn't successfully assign a file. This check has been dead forever, and is really a leftover from generic code. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: cleanup io_req_complete_post()Jens Axboe
Move the ctx declaration and assignment up to be generally available in the function, as we use req->ctx at the top anyway. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: mark the need to lock/unlock the ring as unlikelyJens Axboe
Any of the fast paths will already have this locked, this helper only exists to deal with io-wq invoking request issue where we do not have the ctx->uring_lock held already. This means that any common or fast path will already have this locked, mark it as such. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: add io_file_can_poll() helperJens Axboe
This adds a flag to avoid dipping dereferencing file and then f_op to figure out if the file has a poll handler defined or not. We generally call this at least twice for networked workloads, and if using ring provided buffers, we do it on every buffer selection. Particularly the latter is troublesome, as it's otherwise a very fast operation. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring/cancel: don't default to setting req->work.cancel_seqJens Axboe
Just leave it unset by default, avoiding dipping into the last cacheline (which is otherwise untouched) for the fast path of using poll to drive networked traffic. Add a flag that tells us if the sequence is valid or not, and then we can defer actually assigning the flag and sequence until someone runs cancelations. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08io_uring: expand main struct io_kiocb flags to 64-bitsJens Axboe
We're out of space here, and none of the flags are easily reclaimable. Bump it to 64-bits and re-arrange the struct a bit to avoid gaps. Add a specific bitwise type for the request flags, io_request_flags_t. This will help catch violations of casting this value to a smaller type on 32-bit archs, like unsigned int. This creates a hole in the io_kiocb, so move nr_tw up and rsrc_node down to retain needing only cacheline 0 and 1 for non-polled opcodes. No functional changes intended in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-06io_uring: use file_mnt_idmap helperAlexander Mikhalitsyn
Let's use file_mnt_idmap() as we do that across the tree. No functional impact. Cc: Christian Brauner <brauner@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: io-uring@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Link: https://lore.kernel.org/r/20240129180024.219766-2-aleksandr.mikhalitsyn@canonical.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-01io_uring/net: fix sr->len for IORING_OP_RECV with MSG_WAITALL and buffersJens Axboe
If we use IORING_OP_RECV with provided buffers and pass in '0' as the length of the request, the length is retrieved from the selected buffer. If MSG_WAITALL is also set and we get a short receive, then we may hit the retry path which decrements sr->len and increments the buffer for a retry. However, the length is still zero at this point, which means that sr->len now becomes huge and import_ubuf() will cap it to MAX_RW_COUNT and subsequently return -EFAULT for the range as a whole. Fix this by always assigning sr->len once the buffer has been selected. Cc: stable@vger.kernel.org Fixes: 7ba89d2af17a ("io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-29io_uring/net: limit inline multishot retriesJens Axboe
If we have multiple clients and some/all are flooding the receives to such an extent that we can retry a LOT handling multishot receives, then we can be starving some clients and hence serving traffic in an imbalanced fashion. Limit multishot retry attempts to some arbitrary value, whose only purpose serves to ensure that we don't keep serving a single connection for way too long. We default to 32 retries, which should be more than enough to provide fairness, yet not so small that we'll spend too much time requeuing rather than handling traffic. Cc: stable@vger.kernel.org Depends-on: 704ea888d646 ("io_uring/poll: add requeue return code from poll multishot handling") Depends-on: 1e5d765a82f ("io_uring/net: un-indent mshot retry path in io_recv_finish()") Depends-on: e84b01a880f6 ("io_uring/poll: move poll execution helpers higher up") Fixes: b3fdea6ecb55 ("io_uring: multishot recv") Fixes: 9bb66906f23e ("io_uring: support multishot in recvmsg") Link: https://github.com/axboe/liburing/issues/1043 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-29io_uring/poll: add requeue return code from poll multishot handlingJens Axboe
Since our poll handling is edge triggered, multishot handlers retry internally until they know that no more data is available. In preparation for limiting these retries, add an internal return code, IOU_REQUEUE, which can be used to inform the poll backend about the handler wanting to retry, but that this should happen through a normal task_work requeue rather than keep hammering on the issue side for this one request. No functional changes in this patch, nobody is using this return code just yet. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-29io_uring/net: un-indent mshot retry path in io_recv_finish()Jens Axboe
In preparation for putting some retry logic in there, have the done path just skip straight to the end rather than have too much nesting in here. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-29io_uring/poll: move poll execution helpers higher upJens Axboe
In preparation for calling __io_poll_execute() higher up, move the functions to avoid forward declarations. No functional changes in this patch. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-28io_uring/rw: ensure poll based multishot read retries appropriatelyJens Axboe
io_read_mshot() always relies on poll triggering retries, and this works fine as long as we do a retry per size of the buffer being read. The buffer size is given by the size of the buffer(s) in the given buffer group ID. But if we're reading less than what is available, then we don't always get to read everything that is available. For example, if the buffers available are 32 bytes and we have 64 bytes to read, then we'll correctly read the first 32 bytes and then wait for another poll trigger before we attempt the next read. This next poll trigger may never happen, in which case we just sit forever and never make progress, or it may trigger at some point in the future, and now we're just delivering the available data much later than we should have. io_read_mshot() could do retries itself, but that is wasteful as we'll be going through all of __io_read() again, and most likely in vain. Rather than do that, bump our poll reference count and have io_poll_check_events() do one more loop and check with vfs_poll() if we have more data to read. If we do, io_read_mshot() will get invoked again directly and we'll read the next chunk. io_poll_multishot_retry() must only get called from inside io_poll_issue(), which is our multishot retry handler, as we know we already "own" the request at this point. Cc: stable@vger.kernel.org Link: https://github.com/axboe/liburing/issues/1041 Fixes: fc68fcda0491 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-23io_uring: enable audit and restrict cred override for IORING_OP_FIXED_FD_INSTALLPaul Moore
We need to correct some aspects of the IORING_OP_FIXED_FD_INSTALL command to take into account the security implications of making an io_uring-private file descriptor generally accessible to a userspace task. The first change in this patch is to enable auditing of the FD_INSTALL operation as installing a file descriptor into a task's file descriptor table is a security relevant operation and something that admins/users may want to audit. The second change is to disable the io_uring credential override functionality, also known as io_uring "personalities", in the FD_INSTALL command. The credential override in FD_INSTALL is particularly problematic as it affects the credentials used in the security_file_receive() LSM hook. If a task were to request a credential override via REQ_F_CREDS on a FD_INSTALL operation, the LSM would incorrectly check to see if the overridden credentials of the io_uring were able to "receive" the file as opposed to the task's credentials. After discussions upstream, it's difficult to imagine a use case where we would want to allow a credential override on a FD_INSTALL operation so we are simply going to block REQ_F_CREDS on IORING_OP_FIXED_FD_INSTALL operations. Fixes: dc18b89ab113 ("io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL") Signed-off-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20240123215501.289566-2-paul@paul-moore.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-18Merge tag 'for-6.8/io_uring-2024-01-18' of git://git.kernel.dk/linuxLinus Torvalds
Pull io_uring fixes from Jens Axboe: "Nothing major in here, just a few fixes and cleanups that arrived after the initial merge window pull request got finalized, as well as a fix for a patch that got merged earlier" * tag 'for-6.8/io_uring-2024-01-18' of git://git.kernel.dk/linux: io_uring: combine cq_wait_nr checks io_uring: clean *local_work_add var naming io_uring: clean up local tw add-wait sync io_uring: adjust defer tw counting io_uring/register: guard compat syscall with CONFIG_COMPAT io_uring/rsrc: improve code generation for fixed file assignment io_uring/rw: cleanup io_rw_done()
2024-01-17Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "Generic: - Use memdup_array_user() to harden against overflow. - Unconditionally advertise KVM_CAP_DEVICE_CTRL for all architectures. - Clean up Kconfigs that all KVM architectures were selecting - New functionality around "guest_memfd", a new userspace API that creates an anonymous file and returns a file descriptor that refers to it. guest_memfd files are bound to their owning virtual machine, cannot be mapped, read, or written by userspace, and cannot be resized. guest_memfd files do however support PUNCH_HOLE, which can be used to switch a memory area between guest_memfd and regular anonymous memory. - New ioctl KVM_SET_MEMORY_ATTRIBUTES allowing userspace to specify per-page attributes for a given page of guest memory; right now the only attribute is whether the guest expects to access memory via guest_memfd or not, which in Confidential SVMs backed by SEV-SNP, TDX or ARM64 pKVM is checked by firmware or hypervisor that guarantees confidentiality (AMD PSP, Intel TDX module, or EL2 in the case of pKVM). x86: - Support for "software-protected VMs" that can use the new guest_memfd and page attributes infrastructure. This is mostly useful for testing, since there is no pKVM-like infrastructure to provide a meaningfully reduced TCB. - Fix a relatively benign off-by-one error when splitting huge pages during CLEAR_DIRTY_LOG. - Fix a bug where KVM could incorrectly test-and-clear dirty bits in non-leaf TDP MMU SPTEs if a racing thread replaces a huge SPTE with a non-huge SPTE. - Use more generic lockdep assertions in paths that don't actually care about whether the caller is a reader or a writer. - let Xen guests opt out of having PV clock reported as "based on a stable TSC", because some of them don't expect the "TSC stable" bit (added to the pvclock ABI by KVM, but never set by Xen) to be set. - Revert a bogus, made-up nested SVM consistency check for TLB_CONTROL. - Advertise flush-by-ASID support for nSVM unconditionally, as KVM always flushes on nested transitions, i.e. always satisfies flush requests. This allows running bleeding edge versions of VMware Workstation on top of KVM. - Sanity check that the CPU supports flush-by-ASID when enabling SEV support. - On AMD machines with vNMI, always rely on hardware instead of intercepting IRET in some cases to detect unmasking of NMIs - Support for virtualizing Linear Address Masking (LAM) - Fix a variety of vPMU bugs where KVM fail to stop/reset counters and other state prior to refreshing the vPMU model. - Fix a double-overflow PMU bug by tracking emulated counter events using a dedicated field instead of snapshotting the "previous" counter. If the hardware PMC count triggers overflow that is recognized in the same VM-Exit that KVM manually bumps an event count, KVM would pend PMIs for both the hardware-triggered overflow and for KVM-triggered overflow. - Turn off KVM_WERROR by default for all configs so that it's not inadvertantly enabled by non-KVM developers, which can be problematic for subsystems that require no regressions for W=1 builds. - Advertise all of the host-supported CPUID bits that enumerate IA32_SPEC_CTRL "features". - Don't force a masterclock update when a vCPU synchronizes to the current TSC generation, as updating the masterclock can cause kvmclock's time to "jump" unexpectedly, e.g. when userspace hotplugs a pre-created vCPU. - Use RIP-relative address to read kvm_rebooting in the VM-Enter fault paths, partly as a super minor optimization, but mostly to make KVM play nice with position independent executable builds. - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on CONFIG_HYPERV as a minor optimization, and to self-document the code. - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV "emulation" at build time. ARM64: - LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB base granule sizes. Branch shared with the arm64 tree. - Large Fine-Grained Trap rework, bringing some sanity to the feature, although there is more to come. This comes with a prefix branch shared with the arm64 tree. - Some additional Nested Virtualization groundwork, mostly introducing the NV2 VNCR support and retargetting the NV support to that version of the architecture. - A small set of vgic fixes and associated cleanups. Loongarch: - Optimization for memslot hugepage checking - Cleanup and fix some HW/SW timer issues - Add LSX/LASX (128bit/256bit SIMD) support RISC-V: - KVM_GET_REG_LIST improvement for vector registers - Generate ISA extension reg_list using macros in get-reg-list selftest - Support for reporting steal time along with selftest s390: - Bugfixes Selftests: - Fix an annoying goof where the NX hugepage test prints out garbage instead of the magic token needed to run the test. - Fix build errors when a header is delete/moved due to a missing flag in the Makefile. - Detect if KVM bugged/killed a selftest's VM and print out a helpful message instead of complaining that a random ioctl() failed. - Annotate the guest printf/assert helpers with __printf(), and fix the various bugs that were lurking due to lack of said annotation" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (185 commits) x86/kvm: Do not try to disable kvmclock if it was not enabled KVM: x86: add missing "depends on KVM" KVM: fix direction of dependency on MMU notifiers KVM: introduce CONFIG_KVM_COMMON KVM: arm64: Add missing memory barriers when switching to pKVM's hyp pgd KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache RISC-V: KVM: selftests: Add get-reg-list test for STA registers RISC-V: KVM: selftests: Add steal_time test support RISC-V: KVM: selftests: Add guest_sbi_probe_extension RISC-V: KVM: selftests: Move sbi_ecall to processor.c RISC-V: KVM: Implement SBI STA extension RISC-V: KVM: Add support for SBI STA registers RISC-V: KVM: Add support for SBI extension registers RISC-V: KVM: Add SBI STA info to vcpu_arch RISC-V: KVM: Add steal-update vcpu request RISC-V: KVM: Add SBI STA extension skeleton RISC-V: paravirt: Implement steal-time support RISC-V: Add SBI STA extension definitions RISC-V: paravirt: Add skeleton for pv-time support RISC-V: KVM: Fix indentation in kvm_riscv_vcpu_set_reg_csr() ...
2024-01-17io_uring: combine cq_wait_nr checksPavel Begunkov
Instead of explicitly checking ->cq_wait_nr for whether there are waiting, which is currently represented by 0, we can store there a large value and the nr_tw will automatically filter out those cases. Add a named constant for that and for the wake up bias value. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/38def30282654d980673976cd42fde9bab19b297.1705438669.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-17io_uring: clean *local_work_add var namingPavel Begunkov
if (!first) { ... } While it reads as do something if it's not the first entry, it does exactly the opposite because "first" here is a pointer to the first entry. Remove the confusion by renaming it into "head". Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3b8be483b52f58a524185bb88694b8a268e7e85d.1705438669.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-17io_uring: clean up local tw add-wait syncPavel Begunkov
Kill a smp_mb__after_atomic() right before wake_up, it's useless, and add a comment explaining implicit barriers from cmpxchg and synchronsation around ->cq_wait_nr with the waiter. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3007f3c2d53c72b61de56919ef56b53158b8276f.1705438669.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-17io_uring: adjust defer tw countingPavel Begunkov
The UINT_MAX work item counting bias in io_req_local_work_add() in case of !IOU_F_TWQ_LAZY_WAKE works in a sense that we will not miss a wake up, however it's still eerie. In particular, if we add a lazy work item after a non-lazy one, we'll increment it and get nr_tw==0, and subsequent adds may try to unnecessarily wake up the task, which is though not so likely to happen in real workloads. Half the bias, it's still large enough to be larger than any valid ->cq_wait_nr, which is limited by IORING_MAX_CQ_ENTRIES, but further have a good enough of space before it overflows. Fixes: 8751d15426a31 ("io_uring: reduce scheduling due to tw") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/108b971e958deaf7048342930c341ba90f75d806.1705438669.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-17io_uring/register: guard compat syscall with CONFIG_COMPATJens Axboe
Add compat.h include to avoid a potential build issue: io_uring/register.c:281:6: error: call to undeclared function 'in_compat_syscall'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration] if (in_compat_syscall()) { ^ 1 warning generated. io_uring/register.c:282:9: error: call to undeclared function 'compat_get_bitmap'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration] ret = compat_get_bitmap(cpumask_bits(new_mask), ^ Fixes: c43203154d8a ("io_uring/register: move io_uring_register(2) related code to register.c") Reported-by: Manu Bretelle <chantra@meta.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-11Merge tag 'for-6.8/io_uring-2024-01-08' of git://git.kernel.dk/linuxLinus Torvalds
Pull io_uring updates from Jens Axboe: "Mostly just come fixes and cleanups, but one feature as well. In detail: - Harden the check for handling IOPOLL based on return (Pavel) - Various minor optimizations (Pavel) - Drop remnants of SCM_RIGHTS fd passing support, now that it's no longer supported since 6.7 (me) - Fix for a case where bytes_done wasn't initialized properly on a failure condition for read/write requests (me) - Move the register related code to a separate file (me) - Add support for returning the provided ring buffer head (me) - Add support for adding a direct descriptor to the normal file table (me, Christian Brauner) - Fix for ensuring pending task_work for a ring with DEFER_TASKRUN is run even if we timeout waiting (me)" * tag 'for-6.8/io_uring-2024-01-08' of git://git.kernel.dk/linux: io_uring: ensure local task_work is run on wait timeout io_uring/kbuf: add method for returning provided buffer ring head io_uring/rw: ensure io->bytes_done is always initialized io_uring: drop any code related to SCM_RIGHTS io_uring/unix: drop usage of io_uring socket io_uring/register: move io_uring_register(2) related code to register.c io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL io_uring/cmd: inline io_uring_cmd_get_task io_uring/cmd: inline io_uring_cmd_do_in_task_lazy io_uring: split out cmd api into a separate header io_uring: optimise ltimeout for inline execution io_uring: don't check iopoll if request completes
2024-01-11Merge tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: "Pretty quiet round this time around. This contains: - NVMe updates via Keith: - nvme fabrics spec updates (Guixin, Max) - nvme target udpates (Guixin, Evan) - nvme attribute refactoring (Daniel) - nvme-fc numa fix (Keith) - MD updates via Song: - Fix/Cleanup RCU usage from conf->disks[i].rdev (Yu Kuai) - Fix raid5 hang issue (Junxiao Bi) - Add Yu Kuai as Reviewer of the md subsystem - Remove deprecated flavors (Song Liu) - raid1 read error check support (Li Nan) - Better handle events off-by-1 case (Alex Lyakas) - Efficiency improvements for passthrough (Kundan) - Support for mapping integrity data directly (Keith) - Zoned write fix (Damien) - rnbd fixes (Kees, Santosh, Supriti) - Default to a sane discard size granularity (Christoph) - Make the default max transfer size naming less confusing (Christoph) - Remove support for deprecated host aware zoned model (Christoph) - Misc fixes (me, Li, Matthew, Min, Ming, Randy, liyouhong, Daniel, Bart, Christoph)" * tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linux: (78 commits) block: Treat sequential write preferred zone type as invalid block: remove disk_clear_zoned sd: remove the !ZBC && blk_queue_is_zoned case in sd_read_block_characteristics drivers/block/xen-blkback/common.h: Fix spelling typo in comment blk-cgroup: fix rcu lockdep warning in blkg_lookup() blk-cgroup: don't use removal safe list iterators block: floor the discard granularity to the physical block size mtd_blkdevs: use the default discard granularity bcache: use the default discard granularity zram: use the default discard granularity null_blk: use the default discard granularity nbd: use the default discard granularity ubd: use the default discard granularity block: default the discard granularity to sector size bcache: discard_granularity should not be smaller than a sector block: remove two comments in bio_split_discard block: rename and document BLK_DEF_MAX_SECTORS loop: don't abuse BLK_DEF_MAX_SECTORS aoe: don't abuse BLK_DEF_MAX_SECTORS null_blk: don't cap max_hw_sectors to BLK_DEF_MAX_SECTORS ...
2024-01-11io_uring/rsrc: improve code generation for fixed file assignmentJens Axboe
For the normal read/write path, we have already locked the ring submission side when assigning the file. This causes branch mispredictions when we then check and try and lock again in io_req_set_rsrc_node(). As this is a very hot path, this matters. Add a basic helper that already assumes we already have it locked, and use that in io_file_get_fixed(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-10io_uring/rw: cleanup io_rw_done()Jens Axboe
This originally came from the aio side, and it's laid out rather oddly. The common case here is that we either get -EIOCBQUEUED from submitting an async request, or that we complete the request correctly with the given number of bytes. Handling the odd internal restart error codes is not a common operation. Lay it out a bit more optimally that better explains the normal flow, and switch to avoiding the indirect call completely as this is our kiocb and we know the completion handler can only be one of two possible variants. While at it, move it to where it belongs in the file, with fellow end IO helpers. Outside of being easier to read, this also reduces the text size of the function by 24 bytes for me on arm64. Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-09Merge tag 'mm-stable-2024-01-08-15-31' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...
2024-01-08Merge tag 'vfs-6.8.rw' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfsLinus Torvalds
Pull vfs rw updates from Christian Brauner: "This contains updates from Amir for read-write backing file helpers for stacking filesystems such as overlayfs: - Fanotify is currently in the process of introducing pre content events. Roughly, a new permission event will be added indicating that it is safe to write to the file being accessed. These events are used by hierarchical storage managers to e.g., fill the content of files on first access. During that work we noticed that our current permission checking is inconsistent in rw_verify_area() and remap_verify_area(). Especially in the splice code permission checking is done multiple times. For example, one time for the whole range and then again for partial ranges inside the iterator. In addition, we mostly do permission checking before we call file_start_write() except for a few places where we call it after. For pre-content events we need such permission checking to be done before file_start_write(). So this is a nice reason to clean this all up. After this series, all permission checking is done before file_start_write(). As part of this cleanup we also massaged the splice code a bit. We got rid of a few helpers because we are alredy drowning in special read-write helpers. We also cleaned up the return types for splice helpers. - Introduce generic read-write helpers for backing files. This lifts some overlayfs code to common code so it can be used by the FUSE passthrough work coming in over the next cycles. Make Amir and Miklos the maintainers for this new subsystem of the vfs" * tag 'vfs-6.8.rw' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (30 commits) fs: fix __sb_write_started() kerneldoc formatting fs: factor out backing_file_mmap() helper fs: factor out backing_file_splice_{read,write}() helpers fs: factor out backing_file_{read,write}_iter() helpers fs: prepare for stackable filesystems backing file helpers fsnotify: optionally pass access range in file permission hooks fsnotify: assert that file_start_write() is not held in permission hooks fsnotify: split fsnotify_perm() into two hooks fs: use splice_copy_file_range() inline helper splice: return type ssize_t from all helpers fs: use do_splice_direct() for nfsd/ksmbd server-side-copy fs: move file_start_write() into direct_splice_actor() fs: fork splice_file_range() from do_splice_direct() fs: create {sb,file}_write_not_started() helpers fs: create file_write_started() helper fs: create __sb_write_started() helper fs: move kiocb_start_write() into vfs_iocb_iter_write() fs: move permission hook out of do_iter_read() fs: move permission hook out of do_iter_write() fs: move file_start_write() into vfs_iter_write() ...
2024-01-08Merge tag 'vfs-6.8.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "This contains the usual miscellaneous features, cleanups, and fixes for vfs and individual fses. Features: - Add Jan Kara as VFS reviewer - Show correct device and inode numbers in proc/<pid>/maps for vma files on stacked filesystems. This is now easily doable thanks to the backing file work from the last cycles. This comes with selftests Cleanups: - Remove a redundant might_sleep() from wait_on_inode() - Initialize pointer with NULL, not 0 - Clarify comment on access_override_creds() - Rework and simplify eventfd_signal() and eventfd_signal_mask() helpers - Process aio completions in batches to avoid needless wakeups - Completely decouple struct mnt_idmap from namespaces. We now only keep the actual idmapping around and don't stash references to namespaces - Reformat maintainer entries to indicate that a given subsystem belongs to fs/ - Simplify fput() for files that were never opened - Get rid of various pointless file helpers - Rename various file helpers - Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from last cycle - Make relatime_need_update() return bool - Use GFP_KERNEL instead of GFP_USER when allocating superblocks - Replace deprecated ida_simple_*() calls with their current ida_*() counterparts Fixes: - Fix comments on user namespace id mapping helpers. They aren't kernel doc comments so they shouldn't be using /** - s/Retuns/Returns/g in various places - Add missing parameter documentation on can_move_mount_beneath() - Rename i_mapping->private_data to i_mapping->i_private_data - Fix a false-positive lockdep warning in pipe_write() for watch queues - Improve __fget_files_rcu() code generation to improve performance - Only notify writer that pipe resizing has finished after setting pipe->max_usage otherwise writers are never notified that the pipe has been resized and hang - Fix some kernel docs in hfsplus - s/passs/pass/g in various places - Fix kernel docs in ntfs - Fix kcalloc() arguments order reported by gcc 14 - Fix uninitialized value in reiserfs" * tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits) reiserfs: fix uninit-value in comp_keys watch_queue: fix kcalloc() arguments order ntfs: dir.c: fix kernel-doc function parameter warnings fs: fix doc comment typo fs tree wide selftests/overlayfs: verify device and inode numbers in /proc/pid/maps fs/proc: show correct device and inode numbers in /proc/pid/maps eventfd: Remove usage of the deprecated ida_simple_xx() API fs: super: use GFP_KERNEL instead of GFP_USER for super block allocation fs/hfsplus: wrapper.c: fix kernel-doc warnings fs: add Jan Kara as reviewer fs/inode: Make relatime_need_update return bool pipe: wakeup wr_wait after setting max_usage file: remove __receive_fd() file: stop exposing receive_fd_user() fs: replace f_rcuhead with f_task_work file: remove pointless wrapper file: s/close_fd_get_file()/file_close_fd()/g Improve __fget_files_rcu() code generation (and thus __fget_light()) file: massage cleanup of files that failed to open fs/pipe: Fix lockdep false-positive in watchqueue pipe_write() ...
2024-01-04io_uring: ensure local task_work is run on wait timeoutJens Axboe
A previous commit added an earlier break condition here, which is fine if we're using non-local task_work as it'll be run on return to userspace. However, if DEFER_TASKRUN is used, then we could be leaving local task_work that is ready to process in the ctx list until next time that we enter the kernel to wait for events. Move the break condition to _after_ we have run task_work. Cc: stable@vger.kernel.org Fixes: 846072f16eed ("io_uring: mimimise io_cqring_wait_schedule") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-02Merge tag 'loongarch-kvm-6.8' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.8 1. Optimization for memslot hugepage checking. 2. Cleanup and fix some HW/SW timer issues. 3. Add LSX/LASX (128bit/256bit SIMD) support.
2023-12-29io_uring: use mempool KASAN hookAndrey Konovalov
Use the proper kasan_mempool_unpoison_object hook for unpoisoning cached objects. A future change might also update io_uring to check the return value of kasan_mempool_poison_object to prevent double-free and invalid-free bugs. This proves to be non-trivial with the current way io_uring caches objects, so this is left out-of-scope of this series. Link: https://lkml.kernel.org/r/eca18d6cbf676ed784f1a1f209c386808a8087c5.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: rename kasan_slab_free_mempool to kasan_mempool_poison_objectAndrey Konovalov
Patch series "kasan: save mempool stack traces". This series updates KASAN to save alloc and free stack traces for secondary-level allocators that cache and reuse allocations internally instead of giving them back to the underlying allocator (e.g. mempool). As a part of this change, introduce and document a set of KASAN hooks: bool kasan_mempool_poison_pages(struct page *page, unsigned int order); void kasan_mempool_unpoison_pages(struct page *page, unsigned int order); bool kasan_mempool_poison_object(void *ptr); void kasan_mempool_unpoison_object(void *ptr, size_t size); and use them in the mempool code. Besides mempool, skbuff and io_uring also cache allocations and already use KASAN hooks to poison those. Their code is updated to use the new mempool hooks. The new hooks save alloc and free stack traces (for normal kmalloc and slab objects; stack traces for large kmalloc objects and page_alloc are not supported by KASAN yet), improve the readability of the users' code, and also allow the users to prevent double-free and invalid-free bugs; see the patches for the details. This patch (of 21): Rename kasan_slab_free_mempool to kasan_mempool_poison_object. kasan_slab_free_mempool is a slightly confusing name: it is unclear whether this function poisons the object when it is freed into mempool or does something when the object is freed from mempool to the underlying allocator. The new name also aligns with other mempool-related KASAN hooks added in the following patches in this series. Link: https://lkml.kernel.org/r/cover.1703024586.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/c5618685abb7cdbf9fb4897f565e7759f601da84.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-21io_uring/kbuf: add method for returning provided buffer ring headJens Axboe
The tail of the provided ring buffer is shared between the kernel and the application, but the head is private to the kernel as the application doesn't need to see it. However, this also prevents the application from knowing how many buffers the kernel has consumed. Usually this is fine, as the information is inherently racy in that the kernel could be consuming buffers continually, but for cleanup purposes it may be relevant to know how many buffers are still left in the ring. Add IORING_REGISTER_PBUF_STATUS which will return status for a given provided buffer ring. Right now it just returns the head, but space is reserved for more information later in, if needed. Link: https://github.com/axboe/liburing/discussions/1020 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-21io_uring/rw: ensure io->bytes_done is always initializedJens Axboe
If IOSQE_ASYNC is set and we fail importing an iovec for a readv or writev request, then we leave ->bytes_done uninitialized and hence the eventual failure CQE posted can potentially have a random res value rather than the expected -EINVAL. Setup ->bytes_done before potentially failing, so we have a consistent value if we fail the request early. Cc: stable@vger.kernel.org Reported-by: xingwei lee <xrivendell7@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>