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2021-03-21io_uring: call req_set_fail_links() on short send[msg]()/recv[msg]() with ↵Stefan Metzmacher1-4/+20
MSG_WAITALL Without that it's not safe to use them in a linked combination with others. Now combinations like IORING_OP_SENDMSG followed by IORING_OP_SPLICE should be possible. We already handle short reads and writes for the following opcodes: - IORING_OP_READV - IORING_OP_READ_FIXED - IORING_OP_READ - IORING_OP_WRITEV - IORING_OP_WRITE_FIXED - IORING_OP_WRITE - IORING_OP_SPLICE - IORING_OP_TEE Now we have it for these as well: - IORING_OP_SENDMSG - IORING_OP_SEND - IORING_OP_RECVMSG - IORING_OP_RECV For IORING_OP_RECVMSG we also check for the MSG_TRUNC and MSG_CTRUNC flags in order to call req_set_fail_links(). There might be applications arround depending on the behavior that even short send[msg]()/recv[msg]() retuns continue an IOSQE_IO_LINK chain. It's very unlikely that such applications pass in MSG_WAITALL, which is only defined in 'man 2 recvmsg', but not in 'man 2 sendmsg'. It's expected that the low level sock_sendmsg() call just ignores MSG_WAITALL, as MSG_ZEROCOPY is also ignored without explicitly set SO_ZEROCOPY. We also expect the caller to know about the implicit truncation to MAX_RW_COUNT, which we don't detect. cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/c4e1a4cc0d905314f4d5dc567e65a7b09621aab3.1615908477.git.metze@samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-18io_uring: don't leak creds on SQO attach errorPavel Begunkov1-11/+6
Attaching to already dead/dying SQPOLL task is disallowed in io_sq_offload_create(), but cleanup is hand coded by calling io_put_sq_data()/etc., that miss to put ctx->sq_creds. Defer everything to error-path io_sq_thread_finish(), adding ctx->sqd_list in the error case as well as finish will handle it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-18io_uring: use typesafe pointers in io_uring_taskStefan Metzmacher1-2/+2
Signed-off-by: Stefan Metzmacher <metze@samba.org> Link: https://lore.kernel.org/r/ce2a598e66e48347bb04afbaf2acc67c0cc7971a.1615809009.git.metze@samba.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-18io_uring: remove structures from include/linux/io_uring.hStefan Metzmacher1-0/+16
Link: https://lore.kernel.org/r/8c1d14f3748105f4caeda01716d47af2fa41d11c.1615809009.git.metze@samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-18io_uring: imply MSG_NOSIGNAL for send[msg]()/recv[msg]() callsStefan Metzmacher1-4/+4
We never want to generate any SIGPIPE, -EPIPE only is much better. Signed-off-by: Stefan Metzmacher <metze@samba.org> Link: https://lore.kernel.org/r/38961085c3ec49fd21550c7788f214d1ff02d2d4.1615908477.git.metze@samba.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: fix sqpoll cancellation via task_workPavel Begunkov1-1/+5
Running sqpoll cancellations via task_work_run() is a bad idea because it depends on other task works to be run, but those may be locked in currently running task_work_run() because of how it's (splicing the list in batches). Enqueue and run them through a separate callback head, namely struct io_sq_data::park_task_work. As a nice bonus we now precisely control where it's run, that's much safer than guessing where it can happen as it was before. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: add generic callback_head helpersPavel Begunkov1-26/+36
We already have helpers to run/add callback_head but taking ctx and working with ctx->exit_task_work. Extract generic versions of them implemented in terms of struct callback_head, it will be used later. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: fix concurrent parkingPavel Begunkov1-2/+11
If io_sq_thread_park() of one task got rescheduled right after set_bit(), before it gets back to mutex_lock() there can happen park()/unpark() by another task with SQPOLL locking again and continuing running never seeing that first set_bit(SHOULD_PARK), so won't even try to put the mutex down for parking. It will get parked eventually when SQPOLL drops the lock for reschedule, but may be problematic and will get in the way of further fixes. Account number of tasks waiting for parking with a new atomic variable park_pending and adjust SHOULD_PARK accordingly. It doesn't entirely replaces SHOULD_PARK bit with this atomic var because it's convenient to have it as a bit in the state and will help to do optimisations later. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: halt SQO submission on ctx exitPavel Begunkov1-0/+8
io_sq_thread_finish() is called in io_ring_ctx_free(), so SQPOLL task is potentially running submitting new requests. It's not a disaster because of using a "try" variant of percpu_ref_get, but is far from nice. Remove ctx from the sqd ctx list earlier, before cancellation loop, so SQPOLL can't find it and so won't submit new requests. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: replace sqd rw_semaphore with mutexPavel Begunkov1-22/+14
The only user of read-locking of sqd->rw_lock is sq_thread itself, which is by definition alone, so we don't really need rw_semaphore, but mutex will do. Replace it with a mutex, and kill read-to-write upgrading and extra task_work handling in io_sq_thread(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: fix complete_post use ctx after freePavel Begunkov1-6/+11
If io_req_complete_post() put not a final ref, we can't rely on the request's ctx ref, and so ctx may potentially be freed while complete_post() is in io_cqring_ev_posted()/etc. In that case get an additional ctx reference, and put it in the end, so protecting following io_cqring_ev_posted(). And also prolong ctx lifetime until spin_unlock happens, as we do with mutexes, so added percpu_ref_get() doesn't race with ctx free. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-15io_uring: fix ->flags races by linked timeoutsPavel Begunkov1-1/+0
It's racy to modify req->flags from a not owning context, e.g. linked timeout calling req_set_fail_links() for the master request might race with that request setting/clearing flags while being executed concurrently. Just remove req_set_fail_links(prev) from io_link_timeout_fn(), io_async_find_and_cancel() and functions down the line take care of setting the fail bit. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-14io_uring: convert io_buffer_idr to XArrayJens Axboe1-28/+15
Like we did for the personality idr, convert the IO buffer idr to use XArray. This avoids a use-after-free on removal of entries, since idr doesn't like doing so from inside an iterator, and it nicely reduces the amount of code we need to support this feature. Fixes: 5a2e745d4d43 ("io_uring: buffer registration infrastructure") Cc: stable@vger.kernel.org Cc: Matthew Wilcox <willy@infradead.org> Cc: yangerkun <yangerkun@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-13io_uring: allow IO worker threads to be frozenJens Axboe1-0/+1
With the freezer using the proper signaling to notify us of when it's time to freeze a thread, we can re-enable normal freezer usage for the IO threads. Ensure that SQPOLL, io-wq, and the io-wq manager call try_to_freeze() appropriately, and remove the default setting of PF_NOFREEZE from create_io_thread(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-12io_uring: fix OP_ASYNC_CANCEL across tasksPavel Begunkov1-1/+40
IORING_OP_ASYNC_CANCEL tries io-wq cancellation only for current task. If it fails go over tctx_list and try it out for every single tctx. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-12io_uring: cancel sqpoll via task_workPavel Begunkov1-80/+71
1) The first problem is io_uring_cancel_sqpoll() -> io_uring_cancel_task_requests() basically doing park(); park(); and so hanging. 2) Another one is more subtle, when the master task is doing cancellations, but SQPOLL task submits in-between the end of the cancellation but before finish() requests taking a ref to the ctx, and so eternally locking it up. 3) Yet another is a dying SQPOLL task doing io_uring_cancel_sqpoll() and same io_uring_cancel_sqpoll() from the owner task, they race for tctx->wait events. And there probably more of them. Instead do SQPOLL cancellations from within SQPOLL task context via task_work, see io_sqpoll_cancel_sync(). With that we don't need temporal park()/unpark() during cancellation, which is ugly, subtle and anyway doesn't allow to do io_run_task_work() properly. io_uring_cancel_sqpoll() is called only from SQPOLL task context and under sqd locking, so all parking is removed from there. And so, io_sq_thread_[un]park() and io_sq_thread_stop() are not used now by SQPOLL task, and that spare us from some headache. Also remove ctx->sqd_list early to avoid 2). And kill tctx->sqpoll, which is not used anymore. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-12io_uring: prevent racy sqd->thread checksPavel Begunkov1-6/+22
SQPOLL thread to which we're trying to attach may be going away, it's not nice but a more serious problem is if io_sq_offload_create() sees sqd->thread==NULL, and tries to init it with a new thread. There are tons of ways it can be exploited or fail. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-12io_uring: remove useless ->startup completionPavel Begunkov1-6/+0
We always do complete(&sqd->startup) almost right after sqd->thread creation, either in the success path or in io_sq_thread_finish(). It's specifically created not started for us to be able to set some stuff like sqd->thread and io_uring_alloc_task_context() before following right after wake_up_new_task(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-12io_uring: cancel deferred requests in try_cancelPavel Begunkov1-4/+6
As io_uring_cancel_files() and others let SQO to run between io_uring_try_cancel_requests(), SQO may generate new deferred requests, so it's safer to try to cancel them in it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-11io_uring: perform IOPOLL reaping if canceler is thread itselfJens Axboe1-1/+2
We bypass IOPOLL completion polling (and reaping) for the SQPOLL thread, but if it's the thread itself invoking cancelations, then we still need to perform it or no one will. Fixes: 9936c7c2bc76 ("io_uring: deduplicate core cancellations sequence") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-11io_uring: force creation of separate context for ATTACH_WQ and non-threadsJens Axboe1-2/+14
Earlier kernels had SQPOLL threads that could share across anything, as we grabbed the context we needed on a per-ring basis. This is no longer the case, so only allow attaching directly if we're in the same thread group. That is the common use case. For non-group tasks, just setup a new context and thread as we would've done if sharing wasn't set. This isn't 100% ideal in terms of CPU utilization for the forked and share case, but hopefully that isn't much of a concern. If it is, there are plans in motion for how to improve that. Most importantly, we want to avoid app side regressions where sharing worked before and now doesn't. With this patch, functionality is equivalent to previous kernels that supported IORING_SETUP_ATTACH_WQ with SQPOLL. Reported-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: remove indirect ctx into sqo injectionPavel Begunkov1-25/+3
We use ->ctx_new_list to notify sqo about new ctx pending, then sqo should stop and splice it to its sqd->ctx_list, paired with ->sq_thread_comp. The last one is broken because nobody reinitialises it, and trying to fix it would only add more complexity and bugs. And the first isn't really needed as is done under park(), that protects from races well. Add ctx into sqd->ctx_list directly (under park()), it's much simpler and allows to kill both, ctx_new_list and sq_thread_comp. note: apparently there is no real problem at the moment, because sq_thread_comp is used only by io_sq_thread_finish() followed by parking, where list_del(&ctx->sqd_list) removes it well regardless whether it's in the new or the active list. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: fix invalid ctx->sq_thread_idlePavel Begunkov1-4/+4
We have to set ctx->sq_thread_idle before adding a ring to an SQ task, otherwise sqd races for seeing zero and accounting it as such. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10kernel: make IO threads unfreezable by defaultJens Axboe1-1/+0
The io-wq threads were already marked as no-freeze, but the manager was not. On resume, we perpetually have signal_pending() being true, and hence the manager will loop and spin 100% of the time. Just mark the tasks created by create_io_thread() as PF_NOFREEZE by default, and remove any knowledge of it in io-wq and io_uring. Reported-by: Kevin Locke <kevin@kevinlocke.name> Tested-by: Kevin Locke <kevin@kevinlocke.name> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: always wait for sqd exited when stopping SQPOLL threadJens Axboe1-8/+8
We have a tiny race where io_put_sq_data() calls io_sq_thead_stop() and finds the thread gone, but the thread has indeed not fully exited or called complete() yet. Close it up by always having io_sq_thread_stop() wait on completion of the exit event. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: remove unneeded variable 'ret'Yang Li1-2/+1
Fix the following coccicheck warning: ./fs/io_uring.c:8984:5-8: Unneeded variable: "ret". Return "0" on line 8998 Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Link: https://lore.kernel.org/r/1615271441-33649-1-git-send-email-yang.lee@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: move all io_kiocb init early in io_init_req()Jens Axboe1-4/+3
If we hit an error path in the function, make sure that the io_kiocb is fully initialized at that point so that freeing the request always sees a valid state. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: fix complete_post races for linked reqPavel Begunkov1-7/+14
Calling io_queue_next() after spin_unlock in io_req_complete_post() races with the other side extracting and reusing this request. Hand coded parts of io_req_find_next() considering that io_disarm_next() and io_req_task_queue() have (and safe) to be called with completion_lock held. It already does io_commit_cqring() and io_cqring_ev_posted(), so just reuse it for post io_disarm_next(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/5672a62f3150ee7c55849f40c0037655c4f2840f.1615250156.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: add io_disarm_next() helperPavel Begunkov1-33/+35
A preparation patch placing all preparations before extracting a next request into a separate helper io_disarm_next(). Also, don't spuriously do ev_posted in a rare case where REQ_F_FAIL_LINK is set but there are no requests linked (i.e. after cancelling a linked timeout or setting IOSQE_IO_LINK on a last request of a submission batch). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/44ecff68d6b47e1c4e6b891bdde1ddc08cfc3590.1615250156.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: fix io_sq_offload_create error handlingPavel Begunkov1-3/+2
Don't set IO_SQ_THREAD_SHOULD_STOP when io_sq_offload_create() has failed on io_uring_alloc_task_context() but leave everything to io_sq_thread_finish(), because currently io_sq_thread_finish() hangs on trying to park it. That's great it stalls there, because otherwise the following io_sq_thread_stop() would be skipped on IO_SQ_THREAD_SHOULD_STOP check and the sqo would race for sqd with freeing ctx. A simple error injection gives something like this. [ 245.463955] INFO: task sqpoll-test-hang:523 blocked for more than 122 seconds. [ 245.463983] Call Trace: [ 245.463990] __schedule+0x36b/0x950 [ 245.464005] schedule+0x68/0xe0 [ 245.464013] schedule_timeout+0x209/0x2a0 [ 245.464032] wait_for_completion+0x8b/0xf0 [ 245.464043] io_sq_thread_finish+0x44/0x1a0 [ 245.464049] io_uring_setup+0x9ea/0xc80 [ 245.464058] __x64_sys_io_uring_setup+0x16/0x20 [ 245.464064] do_syscall_64+0x38/0x50 [ 245.464073] entry_SYSCALL_64_after_hwframe+0x44/0xae Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: Convert personality_idr to XArrayMatthew Wilcox (Oracle)1-23/+24
You can't call idr_remove() from within a idr_for_each() callback, but you can call xa_erase() from an xa_for_each() loop, so switch the entire personality_idr from the IDR to the XArray. This manifests as a use-after-free as idr_for_each() attempts to walk the rest of the node after removing the last entry from it. Fixes: 071698e13ac6 ("io_uring: allow registering credentials") Cc: stable@vger.kernel.org # 5.6+ Reported-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> [Pavel: rebased (creds load was moved into io_init_req())] Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7ccff36e1375f2b0ebf73d957f037b43becc0dde.1615212806.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: clean R_DISABLED startup messPavel Begunkov1-19/+6
There are enough of problems with IORING_SETUP_R_DISABLED, including the burden of checking and kicking off the SQO task all over the codebase -- for exit/cancel/etc. Rework it, always start the thread but don't do submit unless the flag is gone, that's much easier. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: fix unrelated ctx reqs cancellationPavel Begunkov1-6/+13
io-wq now is per-task, so cancellations now should match against request's ctx. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-10io_uring: SQPOLL parking fixesJens Axboe1-99/+34
We keep running into weird dependency issues between the sqd lock and the parking state. Disentangle the SQPOLL thread from the last bits of the kthread parking inheritance, and just replace the parking state, and two associated locks, with a single rw mutex. The SQPOLL thread keeps the mutex for read all the time, except if someone has marked us needing to park. Then we drop/re-acquire and try again. This greatly simplifies the parking state machine (by just getting rid of it), and makes it a lot more obvious how it works - if you need to modify the ctx list, then you simply park the thread which will grab the lock for writing. Fold in fix from Hillf Danton on not setting STOP on a fatal signal. Fixes: e54945ae947f ("io_uring: SQPOLL stop error handling fixes") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: kill io_sq_thread_fork() and return -EOWNERDEAD if the sq_thread ↵Stefan Metzmacher1-28/+3
is gone This brings the behavior back in line with what 5.11 and earlier did, and this is no longer needed with the improved handling of creds not needing to do unshare(). Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: run __io_sq_thread() with the initial creds from io_uring_setup()Stefan Metzmacher1-0/+10
With IORING_SETUP_ATTACH_WQ we should let __io_sq_thread() use the initial creds from each ctx. Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: cancel reqs of all iowq's on ring exitPavel Begunkov1-3/+39
io_ring_exit_work() have to cancel all requests, including those staying in io-wq, however it tries only cancellation of current tctx, which is NULL. If we've got task==NULL, use the ctx-to-tctx map to go over all tctx/io-wq and try cancellations on them. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: warn when ring exit takes too longPavel Begunkov1-0/+5
We use system_unbound_wq to run io_ring_exit_work(), so it's hard to monitor whether removal hang or not. Add WARN_ONCE to catch hangs. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: index io_uring->xa by ctx not filePavel Begunkov1-13/+11
We don't use task file notes anymore, and no need left in indexing task->io_uring->xa by file, and replace it with ctx. It's better design-wise, especially since we keep a dangling file, and so have to keep an eye on not dereferencing it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: don't take task ring-file notesPavel Begunkov1-3/+2
With ->flush() gone we're now leaving all uring file notes until the task dies/execs, so the ctx will not be freed until all tasks that have ever submit a request die. It was nicer with flush but not much, we could have locked as described ctx in many cases. Now we guarantee that ctx outlives all tctx in a sense that io_ring_exit_work() waits for all tctxs to drop their corresponding enties in ->xa, and ctx won't go away until then. Hence, additional io_uring file reference (a.k.a. task file notes) are not needed anymore. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: do ctx initiated file note removalPavel Begunkov1-2/+46
Another preparation patch. When full quiesce is done on ctx exit, use task_work infra to remove corresponding to the ctx io_uring->xa entries. For that we use the back tctx map. Also use ->in_idle to prevent removing it while we traversing ->xa on cancellation, just ignore it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: introduce ctx to tctx back mapPavel Begunkov1-14/+44
For each pair tcxt-ctx create an object and chain it into ctx, so we have a way to traverse all tctx that are using current ctx. Preparation patch, will be used later. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-08io_uring: make del_task_file more forgivingPavel Begunkov1-5/+8
Rework io_uring_del_task_file(), so it accepts an index to delete, and it's not necessarily have to be in the ->xa. Infer file from xa_erase() to maintain a single origin of truth. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-06io-wq: always track creds for async issueJens Axboe1-14/+19
If we go async with a request, grab the creds that the task currently has assigned and make sure that the async side switches to them. This is handled in the same way that we do for registered personalities. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-05io_uring: don't restrict issue_flags for io_openatPavel Begunkov1-1/+1
45d189c606292 ("io_uring: replace force_nonblock with flags") did something strange for io_openat() slicing all issue_flags but IO_URING_F_NONBLOCK. Not a bug for now, but better to just forward the flags. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-05io_uring: make SQPOLL thread parking sanerJens Axboe1-35/+30
We have this weird true/false return from parking, and then some of the callers decide to look at that. It can lead to unbalanced parks and sqd locking. Have the callers check the thread status once it's parked. We know we have the lock at that point, so it's either valid or it's NULL. Fix race with parking on thread exit. We need to be careful here with ordering of the sdq->lock and the IO_SQ_THREAD_SHOULD_PARK bit. Rename sqd->completion to sqd->parked to reflect that this is the only thing this completion event doesn. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-05io_uring: clear IOCB_WAITQ for non -EIOCBQUEUED returnJens Axboe1-0/+1
The callback can only be armed, if we get -EIOCBQUEUED returned. It's important that we clear the WAITQ bit for other cases, otherwise we can queue for async retry and filemap will assume that we're armed and return -EAGAIN instead of just blocking for the IO. Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-05io_uring: don't keep looping for more events if we can't flush overflowJens Axboe1-3/+12
It doesn't make sense to wait for more events to come in, if we can't even flush the overflow we already have to the ring. Return -EBUSY for that condition, just like we do for attempts to submit with overflow pending. Cc: stable@vger.kernel.org # 5.11 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-05io_uring: move to using create_io_thread()Jens Axboe1-19/+19
This allows us to do task creation and setup without needing to use completions to try and synchronize with the starting thread. Get rid of the old io_wq_fork_thread() wrapper, and the 'wq' and 'worker' startup completion events - we can now do setup before the task is running. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-05io_uring: reliably cancel linked timeoutsPavel Begunkov1-0/+1
Linked timeouts are fired asynchronously (i.e. soft-irq), and use generic cancellation paths to do its stuff, including poking into io-wq. The problem is that it's racy to access tctx->io_wq, as io_uring_task_cancel() and others may be happening at this exact moment. Mark linked timeouts with REQ_F_INLIFGHT for now, making sure there are no timeouts before io-wq destraction. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>