- 25 Jul, 2022 40 commits
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Pavel Begunkov authored
Add internal part of send zerocopy notifications. There are two main structures, the first one is struct io_notif, which carries inside struct ubuf_info and maps 1:1 to it. io_uring will be binding a number of zerocopy send requests to it and ask to complete (aka flush) it. When flushed and all attached requests and skbs complete, it'll generate one and only one CQE. There are intended to be passed into the network layer as struct msghdr::msg_ubuf. The second concept is notification slots. The userspace will be able to register an array of slots and subsequently addressing them by the index in the array. Slots are independent of each other. Each slot can have only one notifier at a time (called active notifier) but many notifiers during the lifetime. When active, a notifier not going to post any completion but the userspace can attach requests to it by specifying the corresponding slot while issueing send zc requests. Eventually, the userspace will want to "flush" the notifier losing any way to attach new requests to it, however it can use the next atomatically added notifier of this slot or of any other slot. When the network layer is done with all enqueued skbs attached to a notifier and doesn't need the specified in them user data, the flushed notifier will post a CQE. Signed-off-by:
Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3ecf54c31a85762bf679b0a432c9f43ecf7e61cc.1657643355.git.asml.silence@gmail.comSigned-off-by:
Jens Axboe <axboe@kernel.dk>
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Pavel Begunkov authored
Make io_put_task() available to non-core parts of io_uring, we'll need it for notification infrastructure. Signed-off-by:
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Pavel Begunkov authored
Initialise newly added ->msg_ubuf in io_recv() and io_send(). Signed-off-by:
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Jens Axboe authored
* for-5.20/io_uring: (716 commits) io_uring: ensure REQ_F_ISREG is set async offload net: fix compat pointer in get_compat_msghdr() io_uring: Don't require reinitable percpu_ref io_uring: fix types in io_recvmsg_multishot_overflow io_uring: Use atomic_long_try_cmpxchg in __io_account_mem io_uring: support multishot in recvmsg net: copy from user before calling __get_compat_msghdr net: copy from user before calling __copy_msghdr io_uring: support 0 length iov in buffer select in compat io_uring: fix multishot ending when not polled io_uring: add netmsg cache io_uring: impose max limit on apoll cache io_uring: add abstraction around apoll cache io_uring: move apoll cache to poll.c io_uring: consolidate hash_locked io-wq handling io_uring: clear REQ_F_HASH_LOCKED on hash removal io_uring: don't race double poll setting REQ_F_ASYNC_DATA io_uring: don't miss setting REQ_F_DOUBLE_POLL io_uring: disable multishot recvmsg io_uring: only trace one of complete or overflow ... Signed-off-by: -
Jens Axboe authored
Merge branch 'io_uring-zerocopy-send' of git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux into for-5.20/io_uring-zerocopy-send Merge prep net series for io_uring tx zc from the Jakub's tree. * 'io_uring-zerocopy-send' of git://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux: net: fix uninitialised msghdr->sg_from_iter tcp: support externally provided ubufs ipv6/udp: support externally provided ubufs ipv4/udp: support externally provided ubufs net: introduce __skb_fill_page_desc_noacc net: introduce managed frags infrastructure net: Allow custom iter handler in msghdr skbuff: carry external ubuf_info in msghdr skbuff: add SKBFL_DONT_ORPHAN flag skbuff: don't mix ubuf_info from different sources ipv6: avoid partial copy for zc ipv4: avoid partial copy for zc
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Jens Axboe authored
If we're offloading requests directly to io-wq because IOSQE_ASYNC was set in the sqe, we can miss hashing writes appropriately because we haven't set REQ_F_ISREG yet. This can cause a performance regression with buffered writes, as io-wq then no longer correctly serializes writes to that file. Ensure that we set the flags in io_prep_async_work(), which will cause the io-wq work item to be hashed appropriately. Fixes: 584b0180 ("io_uring: move read/write file prep state into actual opcode handler") Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/Reported-by:
kernel test robot <oliver.sang@intel.com> Tested-by:
Yin Fengwei <fengwei.yin@intel.com> Signed-off-by:
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Jens Axboe authored
A previous change enabled external users to copy the data before calling __get_compat_msghdr(), but didn't modify get_compat_msghdr() or __io_compat_recvmsg_copy_hdr() to take that into account. They are both stil passing in the __user pointer rather than the copied version. Ensure we pass in the kernel struct, not the pointer to the user data. Link: https://lore.kernel.org/all/46439555-644d-08a1-7d66-16f8f9a320f0@samsung.com/ Fixes: 1a3e4e94a1b9 ("net: copy from user before calling __get_compat_msghdr") Reported-by:
Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by:
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Michal Koutný authored
The commit 8bb649ee ("io_uring: remove ring quiesce for io_uring_register") removed the worklow relying on reinit/resurrection of the percpu_ref, hence, initialization with that requested is a relic. This is based on code review, this causes no real bug (and theoretically can't). Technically it's a revert of commit 21482896 ("io_uring: initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since the flag omission is now justified, I'm not making this a revert. Fixes: 8bb649ee ("io_uring: remove ring quiesce for io_uring_register") Signed-off-by:
Michal Koutný <mkoutny@suse.com> Acked-by:
Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by:
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Dylan Yudaken authored
io_recvmsg_multishot_overflow had incorrect types on non x64 system. But also it had an unnecessary INT_MAX check, which could just be done by changing the type of the accumulator to int (also simplifying the casts). Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Fixes: a8b38c4ce724 ("io_uring: support multishot in recvmsg") Signed-off-by:
Dylan Yudaken <dylany@fb.com> Link: https://lore.kernel.org/r/20220715130252.610639-1-dylany@fb.comSigned-off-by:
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Uros Bizjak authored
Use atomic_long_try_cmpxchg instead of atomic_long_cmpxchg (*ptr, old, new) == old in __io_account_mem. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, atomic_long_try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg fails, enabling further code simplifications. No functional change intended. Signed-off-by:
Uros Bizjak <ubizjak@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by:
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Dylan Yudaken authored
Similar to multishot recv, this will require provided buffers to be used. However recvmsg is much more complex than recv as it has multiple outputs. Specifically flags, name, and control messages. Support this by introducing a new struct io_uring_recvmsg_out with 4 fields. namelen, controllen and flags match the similar out fields in msghdr from standard recvmsg(2), payloadlen is the length of the payload following the header. This struct is placed at the start of the returned buffer. Based on what the user specifies in struct msghdr, the next bytes of the buffer will be name (the next msg_namelen bytes), and then control (the next msg_controllen bytes). The payload will come at the end. The return value in the CQE is the total used size of the provided buffer. Signed-off-by:
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Dylan Yudaken authored
this is in preparation for multishot receive from io_uring, where it needs to have access to the original struct user_msghdr. functionally this should be a no-op. Acked-by:
Paolo Abeni <pabeni@redhat.com> Signed-off-by:
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Dylan Yudaken authored
this is in preparation for multishot receive from io_uring, where it needs to have access to the original struct user_msghdr. functionally this should be a no-op. Acked-by:
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Dylan Yudaken authored
Match up work done in "io_uring: allow iov_len = 0 for recvmsg and buffer select", but for compat code path. Fixes: a68caad69ce5 ("io_uring: allow iov_len = 0 for recvmsg and buffer select") Signed-off-by: -
Dylan Yudaken authored
If multishot is not actually polling then return IOU_OK rather than the result. If the result was > 0 this will confuse things further up the callstack which expect a return <= 0. Fixes: 1300ebb20286 ("io_uring: multishot recv") Signed-off-by: -
Jens Axboe authored
For recvmsg/sendmsg, if they don't complete inline, we currently need to allocate a struct io_async_msghdr for each request. This is a somewhat large struct. Hook up sendmsg/recvmsg to use the io_alloc_cache. This reduces the alloc + free overhead considerably, yielding 4-5% of extra performance running netbench. Signed-off-by: -
Jens Axboe authored
Caches like this tend to grow to the peak size, and then never get any smaller. Impose a max limit on the size, to prevent it from growing too big. A somewhat randomly chosen 512 is the max size we'll allow the cache to get. If a batch of frees come in and would bring it over that, we simply start kfree'ing the surplus. Signed-off-by: -
Jens Axboe authored
In preparation for adding limits, and one more user, abstract out the core bits of the allocation+free cache. Signed-off-by: -
Jens Axboe authored
This is where it's used, move the flush handler in there. Signed-off-by: -
Pavel Begunkov authored
Don't duplicate code disabling REQ_F_HASH_LOCKED for IO_URING_F_UNLOCKED (i.e. io-wq), move the handling into __io_arm_poll_handler(). Signed-off-by:
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Pavel Begunkov authored
Instead of clearing REQ_F_HASH_LOCKED while arming a poll, unset the bit when we're removing the entry from the table in io_poll_tw_hash_eject(). Signed-off-by:
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Pavel Begunkov authored
Just as with io_poll_double_prepare() setting REQ_F_DOUBLE_POLL, we can race with the first poll entry when setting REQ_F_ASYNC_DATA. Move it under io_poll_double_prepare(). Fixes: a18427bb2d9b ("io_uring: optimise submission side poll_refs") Signed-off-by: -
Pavel Begunkov authored
When adding a second poll entry we should set REQ_F_DOUBLE_POLL unconditionally. We might race with the first entry removal but that doesn't change the rule. Fixes: a18427bb2d9b ("io_uring: optimise submission side poll_refs") Reported-and-tested-by: syzbot+49950ba66096b1f0209b@syzkaller.appspotmail.com Signed-off-by: -
Dylan Yudaken authored
recvmsg has semantics that do not make it trivial to extend to multishot. Specifically it has user pointers and returns data in the original parameter. In order to make this API useful these will need to be somehow included with the provided buffers. For now remove multishot for recvmsg as it is not useful. Signed-off-by:
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Dylan Yudaken authored
In overflow we see a duplcate line in the trace, and in some cases 3 lines (if initial io_post_aux_cqe fails). Instead just trace once for each CQE Signed-off-by:
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Dylan Yudaken authored
Make the trace format consistent with io_uring_complete for cflags Signed-off-by:
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Dylan Yudaken authored
Support multishot receive for io_uring. Typical server applications will run a loop where for each recv CQE it requeues another recv/recvmsg. This can be simplified by using the existing multishot functionality combined with io_uring's provided buffers. The API is to add the IORING_RECV_MULTISHOT flag to the SQE. CQEs will then be posted (with IORING_CQE_F_MORE flag set) when data is available and is read. Once an error occurs or the socket ends, the multishot will be removed and a completion without IORING_CQE_F_MORE will be posted. The benefit to this is that the recv is much more performant. * Subsequent receives are queued up straight away without requiring the application to finish a processing loop. * If there are more data in the socket (sat the provided buffer size is smaller than the socket buffer) then the data is immediately returned, improving batching. * Poll is only armed once and reused, saving CPU cycles Signed-off-by:
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Dylan Yudaken authored
Similar to multishot poll, drop multishot accept when CQE overflow occurs. Signed-off-by:
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Dylan Yudaken authored
On overflow, multishot poll can still complete with the IORING_CQE_F_MORE flag set. If in the meantime the user clears a CQE and a the poll was cancelled then the poll will post a CQE without the IORING_CQE_F_MORE (and likely result -ECANCELED). However when processing the application will encounter the non-overflow CQE which indicates that there will be no more events posted. Typical userspace applications would free memory associated with the poll in this case. It will then subsequently receive the earlier CQE which has overflowed, which breaks the contract given by the IORING_CQE_F_MORE flag. Signed-off-by:
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Dylan Yudaken authored
Some use cases of io_post_aux_cqe would not want to overflow as is, but might want to change the flags/result. For example multishot receive requires in order CQE, and so if there is an overflow it would need to stop receiving until the overflow is taken care of. Signed-off-by:
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Dylan Yudaken authored
For multishot we want a way to signal the caller that multishot has ended but also this might not be an error return. For example sockets return 0 when closed, which should end a multishot recv, but still have a CQE with result 0 Introduce IOU_STOP_MULTISHOT which does this and indicates that the return code is stored inside req->cqe Signed-off-by:
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Dylan Yudaken authored
The values returned are a bit confusing, where 0 and 1 have implied meaning, so add some definitions for them. Signed-off-by:
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Dylan Yudaken authored
Rather than passing an error back to the user with a buffer attached, recycle the buffer immediately. Signed-off-by:
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Dylan Yudaken authored
When using BUFFER_SELECT there is no technical requirement that the user actually provides iov, and this removes one copy_from_user call. So allow iov_len to be 0. Signed-off-by:
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Dylan Yudaken authored
Attempt to restore bgid. This is needed when recycling unused buffers as the next time around it will want the correct bgid. Signed-off-by:
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Dylan Yudaken authored
If user gives 0 for length, we can set it from the available buffer size. Signed-off-by:
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Pavel Begunkov authored
From recently io_uring provides an option to allocate a file index for operation registering fixed files. However, it's utterly unusable with mixed approaches when for a part of files the userspace knows better where to place it, as it may race and users don't have any sane way to pick a slot and hoping it will not be taken. Let the userspace to register a range of fixed file slots in which the auto-allocation happens. The use case is splittting the fixed table in two parts, where on of them is used for auto-allocation and another for slot-specified operations. Signed-off-by:
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Jens Axboe authored
With IORING_OP_MSG_RING, one ring can send a message to another ring. Extend that support to also allow sending a fixed file descriptor to that ring, enabling one ring to pass a registered descriptor to another one. Arguments are extended to pass in: sqe->addr3 fixed file slot in source ring sqe->file_index fixed file slot in destination ring IORING_OP_MSG_RING is extended to take a command argument in sqe->addr. If set to zero (or IORING_MSG_DATA), it sends just a message like before. If set to IORING_MSG_SEND_FD, a fixed file descriptor is sent according to the above arguments. Two common use cases for this are: 1) Server needs to be shutdown or restarted, pass file descriptors to another onei 2) Backend is split, and one accepts connections, while others then get the fd passed and handle the actual connection. Both of those are classic SCM_RIGHTS use cases, and it's not possible to support them with direct descriptors today. By default, this will post a CQE to the target ring, similarly to how IORING_MSG_DATA does it. If IORING_MSG_RING_CQE_SKIP is set, no message is posted to the target ring. The issuer is expected to notify the receiver side separately. Signed-off-by: -
Jens Axboe authored
Put it with the filetable code, which is where it belongs. While doing so, have the helpers take a ctx rather than an io_kiocb. It doesn't make sense to use a request, as it's not an operation on the request itself. It applies to the ring itself. Signed-off-by: -
Gustavo A. R. Silva authored
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/78Signed-off-by:
Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by:
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