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2023-08-25io_uring: refactor __io_get_cqe()Pavel Begunkov2-20/+16
Make __io_get_cqe simpler by not grabbing the cqe from refilled cached, but letting io_get_cqe() do it for us. That's cleaner and removes some duplication. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/74dc8fdf2657e438b2e05e1d478a3596924604e9.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-25io_uring: simplify big_cqe handlingPavel Begunkov3-20/+8
Don't keep big_cqe bits of req in a union with hash_node, find a separate space for it. It's bit safer, but also if we keep it always initialised, we can get rid of ugly REQ_F_CQE32_INIT handling. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/447aa1b2968978c99e655ba88db536e903df0fe9.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-25io_uring: cqe init hardeningPavel Begunkov1-1/+1
io_kiocb::cqe stores the completion info which we'll memcpy to userspace, and we rely on callbacks and other later steps to populate it with right values. We have never had problems with that, but it would still be safer to zero it on allocation. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/b16a3b64dde678686460d3c3792c3ba6d3d1bc7a.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-25io_uring: improve cqe !tracing hot pathPavel Begunkov1-4/+5
While looking at io_fill_cqe_req()'s asm I stumbled on our trace points turning into the chunk below: trace_io_uring_complete(req->ctx, req, req->cqe.user_data, req->cqe.res, req->cqe.flags, req->extra1, req->extra2); io_uring/io_uring.c:898: trace_io_uring_complete(req->ctx, req, req->cqe.user_data, movq 232(%rbx), %rdi # req_44(D)->big_cqe.extra2, _5 movq 224(%rbx), %rdx # req_44(D)->big_cqe.extra1, _6 movl 84(%rbx), %r9d # req_44(D)->cqe.D.81184.flags, _7 movl 80(%rbx), %r8d # req_44(D)->cqe.res, _8 movq 72(%rbx), %rcx # req_44(D)->cqe.user_data, _9 movq 88(%rbx), %rsi # req_44(D)->ctx, _10 ./arch/x86/include/asm/jump_label.h:27: asm_volatile_goto("1:" 1:jmp .L1772 # objtool NOPs this # ... It does a jump_label for actual tracing, but those 6 moves will stay there in the hottest io_uring path. As an optimisation, add a trace_io_uring_complete_enabled() check, which is also uses jump_labels, it tricks the compiler into behaving. It removes the junk without changing anything else int the hot path. Note: apparently, it's not only me noticing it, and people are also working it around. We should remove the check when it's solved generically or rework tracing. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/555d8312644b3776f4be7e23f9b92943875c4bc7.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-22io_uring: stop calling free_compound_page()Matthew Wilcox (Oracle)2-10/+2
Patch series "Remove _folio_dtor and _folio_order", v2. This patch (of 13): folio_put() is the standard way to write this, and it's not appreciably slower. This is an enabling patch for removing free_compound_page() entirely. Link: https://lkml.kernel.org/r/20230816151201.3655946-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230816151201.3655946-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21io_uring: use kiocb_{start,end}_write() helpersAmir Goldstein1-19/+4
Use helpers instead of the open coded dance to silence lockdep warnings. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Message-Id: <20230817141337.1025891-5-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21io_uring: rename kiocb_end_write() local helperAmir Goldstein1-5/+5
This helper does not take a kiocb as input and we want to create a common helper by that name that takes a kiocb as input. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Message-Id: <20230817141337.1025891-2-amir73il@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-18io_uring/rsrc: Annotate struct io_mapped_ubuf with __counted_byKees Cook1-1/+1
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct io_mapped_ubuf. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Jens Axboe <axboe@kernel.dk> Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: io-uring@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20230817212146.never.853-kees@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-16io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is usedJens Axboe5-15/+41
If we setup the ring with SQPOLL, then that polling thread has its own io-wq setup. This means that if the application uses IORING_REGISTER_IOWQ_AFF to set the io-wq affinity, we should not be setting it for the invoking task, but rather the sqpoll task. Add an sqpoll helper that parks the thread and updates the affinity, and use that one if we're using SQPOLL. Fixes: fe76421d1da1 ("io_uring: allow user configurable IO thread CPU affinity") Cc: stable@vger.kernel.org # 5.10+ Link: https://github.com/axboe/liburing/discussions/884 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring: simplify io_run_task_work_sig returnPavel Begunkov1-2/+2
Nobody cares about io_run_task_work_sig returning 1, we only check for negative errors. Simplify by keeping to 0/-error returns. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3aec8a532c003d6e50739b969a82989402696170.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring/rsrc: keep one global dummy_ubufPavel Begunkov2-13/+10
We set empty registered buffers to dummy_ubuf as an optimisation. Currently, we allocate the dummy entry for each ring, whenever we can simply have one global instance. We're casting out const on assignment, it's fine as we're not going to change the content of the dummy, the constness gives us an extra layer of protection if sth ever goes wrong. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/e4a96dda35ab755914bc43f6781bba0df97ac489.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring: never overflow io_aux_cqePavel Begunkov5-14/+16
Now all callers of io_aux_cqe() set allow_overflow to false, remove the parameter and not allow overflowing auxilary multishot cqes. When CQ is full the function callers and all multishot requests in general are expected to complete the request. That prevents indefinite in-background grows of the overflow list and let's the userspace to handle the backlog at its own pace. Resubmitting a request should also be faster than accounting a bunch of overflows, so it should be better for perf when it happens, but a well behaving userspace should be trying to avoid overflows in any case. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/bb20d14d708ea174721e58bb53786b0521e4dd6d.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring: remove return from io_req_cqe_overflow()Pavel Begunkov2-5/+5
Nobody checks io_req_cqe_overflow()'s return, make it return void. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8f2029ad0c22f73451664172d834372608ee0a77.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring: open code io_fill_cqe_req()Pavel Begunkov3-14/+7
io_fill_cqe_req() is only called from one place, open code it, and rename __io_fill_cqe_req(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f432ce75bb1c94cadf0bd2add4d6aa510bd1fb36.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring/net: don't overflow multishot recvPavel Begunkov1-1/+1
Don't allow overflowing multishot recv CQEs, it might get out of hand, hurt performance, and in the worst case scenario OOM the task. Cc: stable@vger.kernel.org Fixes: b3fdea6ecb55c ("io_uring: multishot recv") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0b295634e8f1b71aa764c984608c22d85f88f75c.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring/net: don't overflow multishot acceptPavel Begunkov1-1/+1
Don't allow overflowing multishot accept CQEs, we want to limit the grows of the overflow list. Cc: stable@vger.kernel.org Fixes: 4e86a2c980137 ("io_uring: implement multishot mode for accept") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7d0d749649244873772623dd7747966f516fe6e2.1691757663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring/io-wq: don't gate worker wake up success on wake_up_process()Jens Axboe1-4/+7
All we really care about is finding a free worker. If said worker is already running, it's either starting new work already or it's just finishing up existing work. For the latter, we'll be finding this work item next anyway, and for the former, if the worker does go to sleep, it'll create a new worker anyway as we have pending items. This reduces try_to_wake_up() overhead considerably: 23.16% -10.46% [kernel.kallsyms] [k] try_to_wake_up Reviewed-by: Hao Xu <howeyxu@tencent.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring/io-wq: reduce frequency of acct->lock acquisitionsJens Axboe1-13/+34
When we check if we have work to run, we grab the acct lock, check, drop it, and then return the result. If we do have work to run, then running the work will again grab acct->lock and get the work item. This causes us to grab acct->lock more frequently than we need to. If we have work to do, have io_acct_run_queue() return with the acct lock still acquired. io_worker_handle_work() is then always invoked with the acct lock already held. In a simple test cases that stats files (IORING_OP_STATX always hits io-wq), we see a nice reduction in locking overhead with this change: 19.32% -12.55% [kernel.kallsyms] [k] __cmpwait_case_32 20.90% -12.07% [kernel.kallsyms] [k] queued_spin_lock_slowpath Reviewed-by: Hao Xu <howeyxu@tencent.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring/io-wq: don't grab wq->lock for worker activationJens Axboe1-3/+0
The worker free list is RCU protected, and checks for workers going away when iterating it. There's no need to hold the wq->lock around the lookup. Reviewed-by: Hao Xu <howeyxu@tencent.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-11io_uring: remove unnecessary forward declarationJens Axboe1-1/+0
We never use io_move_task_work_from_local() before it's defined in the file anyway, so kill the forward declaration. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10io_uring: have io_file_put() take an io_kiocb rather than the fileJens Axboe2-7/+5
No functional changes in this patch, just a prep patch for needing the request in io_file_put(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10io_uring/splice: use fput() directlyJens Axboe1-2/+2
No point in using io_file_put() here, as we need to check if it's a fixed file in the caller anyway. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10io_uring/fdinfo: get rid of ref trygetJens Axboe1-12/+6
The caller holds a reference to the ring itself, so by definition the ring cannot go away. There's no need to play games with tryget for the reference, as we don't need an extra reference at all. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring: cleanup 'ret' handling in io_iopoll_check()Jens Axboe1-7/+10
We return 0 for success, or -error when there's an error. Move the 'ret' variable into the loop where we are actually using it, to make it clearer that we don't carry this variable forward for return outside of the loop. While at it, also move the need_resched() break condition out of the while check itself, keeping it with the signal pending check. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring: break iopolling on signalPavel Begunkov1-0/+3
Don't keep spinning iopoll with a signal set. It'll eventually return back, e.g. by virtue of need_resched(), but it's not a nice user experience. Cc: stable@vger.kernel.org Fixes: def596e9557c9 ("io_uring: support for IO polling") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/eeba551e82cad12af30c3220125eb6cb244cc94c.1691594339.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring: fix false positive KASAN warningsPavel Begunkov2-2/+0
io_req_local_work_add() peeks into the work list, which can be executed in the meanwhile. It's completely fine without KASAN as we're in an RCU read section and it's SLAB_TYPESAFE_BY_RCU. With KASAN though it may trigger a false positive warning because internal io_uring caches are sanitised. Remove sanitisation from the io_uring request cache for now. Cc: stable@vger.kernel.org Fixes: 8751d15426a31 ("io_uring: reduce scheduling due to tw") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/c6fbf7a82a341e66a0007c76eefd9d57f2d3ba51.1691541473.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring: fix drain stalls by invalid SQEPavel Begunkov1-0/+2
cq_extra is protected by ->completion_lock, which io_get_sqe() misses. The bug is harmless as it doesn't happen in real life, requires invalid SQ index array and racing with submission, and only messes up the userspace, i.e. stall requests execution but will be cleaned up on ring destruction. Fixes: 15641e427070f ("io_uring: don't cache number of dropped SQEs") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/66096d54651b1a60534bb2023f2947f09f50ef73.1691538547.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring/rsrc: Remove unused declaration io_rsrc_put_tw()Yue Haibing1-1/+0
Commit 36b9818a5a84 ("io_uring/rsrc: don't offload node free") removed the implementation but leave declaration. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20230808151058.4572-1-yuehaibing@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring: annotate the struct io_kiocb slab for appropriate user copyJens Axboe1-2/+14
When compiling the kernel with clang and having HARDENED_USERCOPY enabled, the liburing openat2.t test case fails during request setup: usercopy: Kernel memory overwrite attempt detected to SLUB object 'io_kiocb' (offset 24, size 24)! ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:102! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 3 PID: 413 Comm: openat2.t Tainted: G N 6.4.3-g6995e2de6891-dirty #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 RIP: 0010:usercopy_abort+0x84/0x90 Code: ce 49 89 ce 48 c7 c3 68 48 98 82 48 0f 44 de 48 c7 c7 56 c6 94 82 4c 89 de 48 89 c1 41 52 41 56 53 e8 e0 51 c5 00 48 83 c4 18 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 41 57 41 56 RSP: 0018:ffffc900016b3da0 EFLAGS: 00010296 RAX: 0000000000000062 RBX: ffffffff82984868 RCX: 4e9b661ac6275b00 RDX: ffff8881b90ec580 RSI: ffffffff82949a64 RDI: 00000000ffffffff RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900016b3c88 R11: ffffc900016b3c30 R12: 00007ffe549659e0 R13: ffff888119014000 R14: 0000000000000018 R15: 0000000000000018 FS: 00007f862e3ca680(0000) GS:ffff8881b90c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005571483542a8 CR3: 0000000118c11000 CR4: 00000000003506e0 Call Trace: <TASK> ? __die_body+0x63/0xb0 ? die+0x9d/0xc0 ? do_trap+0xa7/0x180 ? usercopy_abort+0x84/0x90 ? do_error_trap+0xc6/0x110 ? usercopy_abort+0x84/0x90 ? handle_invalid_op+0x2c/0x40 ? usercopy_abort+0x84/0x90 ? exc_invalid_op+0x2f/0x40 ? asm_exc_invalid_op+0x16/0x20 ? usercopy_abort+0x84/0x90 __check_heap_object+0xe2/0x110 __check_object_size+0x142/0x3d0 io_openat2_prep+0x68/0x140 io_submit_sqes+0x28a/0x680 __se_sys_io_uring_enter+0x120/0x580 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x55714834de26 Code: ca 01 0f b6 82 d0 00 00 00 8b ba cc 00 00 00 45 31 c0 31 d2 41 b9 08 00 00 00 83 e0 01 c1 e0 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> 66 0f 1f 84 00 00 00 00 00 89 30 eb 89 0f 1f 40 00 8b 00 a8 06 RSP: 002b:00007ffe549659c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007ffe54965a50 RCX: 000055714834de26 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000008 R10: 0000000000000000 R11: 0000000000000246 R12: 000055714834f057 R13: 00007ffe54965a50 R14: 0000000000000001 R15: 0000557148351dd8 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- when it tries to copy struct open_how from userspace into the per-command space in the io_kiocb. There's nothing wrong with the copy, but we're missing the appropriate annotations for allowing user copies to/from the io_kiocb slab. Allow copies in the per-command area, which is from the 'file' pointer to when 'opcode' starts. We do have existing user copies there, but they are not all annotated like the one that openat2_prep() uses, copy_struct_from_user(). But in practice opcodes should be allowed to copy data into their per-command area in the io_kiocb. Reported-by: Breno Leitao <leitao@debian.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-09io_uring: Add io_uring command support for socketsBreno Leitao1-0/+28
Enable io_uring commands on network sockets. Create two new SOCKET_URING_OP commands that will operate on sockets. In order to call ioctl on sockets, use the file_operations->io_uring_cmd callbacks, and map it to a uring socket function, which handles the SOCKET_URING_OP accordingly, and calls socket ioctls. This patches was tested by creating a new test case in liburing. Link: https://github.com/leitao/liburing/tree/io_uring_cmd Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230627134424.2784797-1-leitao@debian.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-08io_uring/parisc: Adjust pgoff in io_uring mmap() for pariscHelge Deller1-0/+3
The changes from commit 32832a407a71 ("io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()") to the parisc implementation of get_unmapped_area() broke glibc's locale-gen executable when running on parisc. This patch reverts those architecture-specific changes, and instead adjusts in io_uring_mmu_get_unmapped_area() the pgoff offset which is then given to parisc's get_unmapped_area() function. This is much cleaner than the previous approach, and we still will get a coherent addresss. This patch has no effect on other architectures (SHM_COLOUR is only defined on parisc), and the liburing testcase stil passes on parisc. Cc: stable@vger.kernel.org # 6.4 Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Fixes: 32832a407a71 ("io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()") Fixes: d808459b2e31 ("io_uring: Adjust mapping wrt architecture aliasing requirements") Link: https://lore.kernel.org/r/ZNEyGV0jyI8kOOfz@p100 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-07io_uring: correct check for O_TMPFILEAleksa Sarai1-2/+4
O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old check for whether RESOLVE_CACHED can be used would incorrectly think that O_DIRECTORY could not be used with RESOLVE_CACHED. Cc: stable@vger.kernel.org # v5.12+ Fixes: 3a81fd02045c ("io_uring: enable LOOKUP_CACHED path resolution for filename lookups") Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Link: https://lore.kernel.org/r/20230807-resolve_cached-o_tmpfile-v3-1-e49323e1ef6f@cyphar.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-02Merge tag 'xfs-async-dio.6-2023-08-01' of git://git.kernel.dk/linux into ↵Darrick J. Wong1-3/+24
iomap-6.6-mergeA Improve iomap/xfs async dio write performance iomap always punts async dio write completions to a workqueue, which has a cost in terms of efficiency (now you need an unrelated worker to process it) and latency (now you're bouncing a completion through an async worker, which is a classic slowdown scenario). io_uring handles IRQ completions via task_work, and for writes that don't need to do extra IO at completion time, we can safely complete them inline from that. This patchset adds IOCB_DIO_CALLER_COMP, which an IO issuer can set to inform the completion side that any extra work that needs doing for that completion can be punted to a safe task context. The iomap dio completion will happen in hard/soft irq context, and we need a saner context to process these completions. IOCB_DIO_CALLER_COMP is added, which can be set in a struct kiocb->ki_flags by the issuer. If the completion side of the iocb handling understands this flag, it can choose to set a kiocb->dio_complete() handler and just call ki_complete from IRQ context. The issuer must then ensure that this callback is processed from a task. io_uring punts IRQ completions to task_work already, so it's trivial wire it up to run more of the completion before posting a CQE. This is good for up to a 37% improvement in throughput/latency for low queue depth IO, patch 5 has the details. If we need to do real work at completion time, iomap will clear the IOMAP_DIO_CALLER_COMP flag. This work came about when Andres tested low queue depth dio writes for postgres and compared it to doing sync dio writes, showing that the async processing slows us down a lot. * tag 'xfs-async-dio.6-2023-08-01' of git://git.kernel.dk/linux: iomap: support IOCB_DIO_CALLER_COMP io_uring/rw: add write support for IOCB_DIO_CALLER_COMP fs: add IOCB flags related to passing back dio completions iomap: add IOMAP_DIO_INLINE_COMP iomap: only set iocb->private for polled bio iomap: treat a write through cache the same as FUA iomap: use an unsigned type for IOMAP_DIO_* defines iomap: cleanup up iomap_dio_bio_end_io() Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-08-02io_uring/rw: add write support for IOCB_DIO_CALLER_COMPJens Axboe1-3/+24
If the filesystem dio handler understands IOCB_DIO_CALLER_COMP, we'll get a kiocb->ki_complete() callback with kiocb->dio_complete set. In that case, rather than complete the IO directly through task_work, queue up an intermediate task_work handler that first processes this callback and then immediately completes the request. For XFS, this avoids a punt through a workqueue, which is a lot less efficient and adds latency to lower queue depth (or sync) O_DIRECT writes. Only do this for non-polled IO, as polled IO doesn't need this kind of deferral as it always completes within the task itself. This then avoids a check for deferral in the polled IO completion handler. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-28Merge tag 'io_uring-6.5-2023-07-28' of git://git.kernel.dk/linuxLinus Torvalds1-6/+17
Pull io_uring fix from Jens Axboe: "Just a single tweak to a patch from last week, to avoid having idle cqring waits be attributed as iowait" * tag 'io_uring-6.5-2023-07-28' of git://git.kernel.dk/linux: io_uring: gate iowait schedule on having pending requests
2023-07-24io_uring: gate iowait schedule on having pending requestsJens Axboe1-6/+17
A previous commit made all cqring waits marked as iowait, as a way to improve performance for short schedules with pending IO. However, for use cases that have a special reaper thread that does nothing but wait on events on the ring, this causes a cosmetic issue where we know have one core marked as being "busy" with 100% iowait. While this isn't a grave issue, it is confusing to users. Rather than always mark us as being in iowait, gate setting of current->in_iowait to 1 by whether or not the waiting task has pending requests. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/io-uring/CAMEGJJ2RxopfNQ7GNLhr7X9=bHXKo+G5OOe0LUq=+UgLXsv1Xg@mail.gmail.com/ Link: https://bugzilla.kernel.org/show_bug.cgi?id=217699 Link: https://bugzilla.kernel.org/show_bug.cgi?id=217700 Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reported-by: Phil Elwell <phil@raspberrypi.com> Tested-by: Andres Freund <andres@anarazel.de> Fixes: 8a796565cec3 ("io_uring: Use io_schedule* in cqring wait") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-22Merge tag 'io_uring-6.5-2023-07-21' of git://git.kernel.dk/linuxLinus Torvalds1-26/+26
Pull io_uring fixes from Jens Axboe: - Fix for io-wq not always honoring REQ_F_NOWAIT, if it was set and punted directly (eg via DRAIN) (me) - Capability check fix (Ondrej) - Regression fix for the mmap changes that went into 6.4, which apparently broke IA64 (Helge) * tag 'io_uring-6.5-2023-07-21' of git://git.kernel.dk/linux: ia64: mmap: Consider pgoff when searching for free mapping io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area() io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq io_uring: don't audit the capability check in io_uring_create()
2023-07-21io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()Helge Deller1-25/+17
The io_uring testcase is broken on IA-64 since commit d808459b2e31 ("io_uring: Adjust mapping wrt architecture aliasing requirements"). The reason is, that this commit introduced an own architecture independend get_unmapped_area() search algorithm which finds on IA-64 a memory region which is outside of the regular memory region used for shared userspace mappings and which can't be used on that platform due to aliasing. To avoid similar problems on IA-64 and other platforms in the future, it's better to switch back to the architecture-provided get_unmapped_area() function and adjust the needed input parameters before the call. Beside fixing the issue, the function now becomes easier to understand and maintain. This patch has been successfully tested with the io_uring testcase on physical x86-64, ppc64le, IA-64 and PA-RISC machines. On PA-RISC the LTP mmmap testcases did not report any regressions. Cc: stable@vger.kernel.org # 6.4 Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: matoro <matoro_mailinglist_kernel@matoro.tk> Fixes: d808459b2e31 ("io_uring: Adjust mapping wrt architecture aliasing requirements") Link: https://lore.kernel.org/r/20230721152432.196382-2-deller@gmx.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-20io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wqJens Axboe1-0/+8
io-wq assumes that an issue is blocking, but it may not be if the request type has asked for a non-blocking attempt. If we get -EAGAIN for that case, then we need to treat it as a final result and not retry or arm poll for it. Cc: stable@vger.kernel.org # 5.10+ Link: https://github.com/axboe/liburing/issues/897 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-18io_uring: don't audit the capability check in io_uring_create()Ondrej Mosnacek1-1/+1
The check being unconditional may lead to unwanted denials reported by LSMs when a process has the capability granted by DAC, but denied by an LSM. In the case of SELinux such denials are a problem, since they can't be effectively filtered out via the policy and when not silenced, they produce noise that may hide a true problem or an attack. Since not having the capability merely means that the created io_uring context will be accounted against the current user's RLIMIT_MEMLOCK limit, we can disable auditing of denials for this check by using ns_capable_noaudit() instead of capable(). Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Link: https://bugzilla.redhat.com/show_bug.cgi?id=2193317 Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Link: https://lore.kernel.org/r/20230718115607.65652-1-omosnace@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/cancel: wire up IORING_ASYNC_CANCEL_OP for sync cancelJens Axboe1-3/+8
Allow usage of IORING_ASYNC_CANCEL_OP through the sync cancelation API as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/cancel: support opcode based lookup and cancelationJens Axboe3-5/+17
Add IORING_ASYNC_CANCEL_OP flag for cancelation, which allows the application to target cancelation based on the opcode of the original request. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/cancel: add IORING_ASYNC_CANCEL_USERDATAJens Axboe1-6/+12
Add a flag to explicitly match on user_data in the request for cancelation purposes. This is the default behavior if none of the other match flags are set, but if we ALSO want to match on user_data, then this flag can be set. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring: use cancelation match helper for poll and timeout requestsJens Axboe2-17/+7
Get rid of the request vs io_cancel_data checking and just use the exported helper for this. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/cancel: fix sequence matching for IORING_ASYNC_CANCEL_ANYJens Axboe1-2/+3
We always need to check/update the cancel sequence if IORING_ASYNC_CANCEL_ALL is set. Also kill the redundant check for IORING_ASYNC_CANCEL_ANY at the end, if we get here we know it's not set as we would've matched it higher up. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/cancel: abstract out request match helperJens Axboe2-4/+14
We have different match code in a variety of spots. Start the cleanup of this by abstracting out a helper that can be used to check if a given request matches the cancelation criteria outlined in io_cancel_data. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/timeout: always set 'ctx' in io_cancel_dataJens Axboe1-2/+2
In preparation for using a generic handler to match requests for cancelation purposes, ensure that ctx is set in io_cancel_data. The timeout handlers don't check for this as it'll always match, but we'll need it set going forward. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17io_uring/poll: always set 'ctx' in io_cancel_dataJens Axboe1-1/+1
This isn't strictly necessary for this callsite, as it uses it's internal lookup for this cancelation purpose. But let's be consistent with how it's used in general and set ctx as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-15Merge tag 'io_uring-6.5-2023-07-14' of git://git.kernel.dk/linuxLinus Torvalds1-2/+13
Pull io_uring fix from Jens Axboe: "Just a single tweak for the wait logic in io_uring" * tag 'io_uring-6.5-2023-07-14' of git://git.kernel.dk/linux: io_uring: Use io_schedule* in cqring wait
2023-07-07io_uring: Use io_schedule* in cqring waitAndres Freund1-2/+13
I observed poor performance of io_uring compared to synchronous IO. That turns out to be caused by deeper CPU idle states entered with io_uring, due to io_uring using plain schedule(), whereas synchronous IO uses io_schedule(). The losses due to this are substantial. On my cascade lake workstation, t/io_uring from the fio repository e.g. yields regressions between 20% and 40% with the following command: ./t/io_uring -r 5 -X0 -d 1 -s 1 -c 1 -p 0 -S$use_sync -R 0 /mnt/t2/fio/write.0.0 This is repeatable with different filesystems, using raw block devices and using different block devices. Use io_schedule_prepare() / io_schedule_finish() in io_cqring_wait_schedule() to address the difference. After that using io_uring is on par or surpassing synchronous IO (using registered files etc makes it reliably win, but arguably is a less fair comparison). There are other calls to schedule() in io_uring/, but none immediately jump out to be similarly situated, so I did not touch them. Similarly, it's possible that mutex_lock_io() should be used, but it's not clear if there are cases where that matters. Cc: stable@vger.kernel.org # 5.10+ Cc: Pavel Begunkov <asml.silence@gmail.com> Cc: io-uring@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Andres Freund <andres@anarazel.de> Link: https://lore.kernel.org/r/20230707162007.194068-1-andres@anarazel.de [axboe: minor style fixup] Signed-off-by: Jens Axboe <axboe@kernel.dk>
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