- 26 Apr, 2021 4 commits
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Pavel Begunkov authored
All sqpoll rings (even sharing sqpoll task) are currently dead bound to the task that created them, iow when owner task dies it kills all its SQPOLL rings and their inflight requests via task_work infra. It's neither the nicist way nor the most convenient as adds extra locking/waiting and dependencies. Leave it alone and rely on SIGKILL being delivered on its thread group exit, so there are only two cases left: 1) thread group is dying, so sqpoll task gets a signal and exit itself cancelling all requests. 2) an sqpoll ring is dying. Because refs_kill() is called the sqpoll not going to submit any new request, and that's what we need. And io_ring_exit_work() will do all the cancellation itself before actually killing ctx, so sqpoll doesn't need to worry about it. Signed-off-by:
Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/3cd7f166b9c326a2c932b70e71a655b03257b366.1619389911.git.asml.silence@gmail.comSigned-off-by:
Jens Axboe <axboe@kernel.dk>
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Pavel Begunkov authored
After closing an SQPOLL ring, io_ring_exit_work() kicks in and starts doing cancellations via io_uring_try_cancel_requests(). It will go through io_uring_try_cancel_iowq(), which uses ctx->tctx_list, but as SQPOLL task don't have a ctx note, its io-wq won't be reachable and so is left not cancelled. It will eventually cancelled when one of the tasks dies, but if a thread group survives for long and changes rings, it will spawn lots of unreclaimed resources and live locked works. Cancel SQPOLL task's io-wq separately in io_ring_exit_work(). Cc: stable@vger.kernel.org Signed-off-by:
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Colin Ian King authored
The variable up.resv is not initialized and is being checking for a non-zero value in the call to _io_register_rsrc_update. Fix this by explicitly setting the variable to 0. Addresses-Coverity: ("Uninitialized scalar variable)" Fixes: c3bdad02 ("io_uring: add generic rsrc update with tags") Signed-off-by:Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20210426094735.8320-1-colin.king@canonical.comSigned-off-by:
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Pavel Begunkov authored
Now we allocate io_mapped_ubuf instead of bvec, so we clearly have to check its address after allocation. Fixes: 41edf1a5 ("io_uring: keep table of pointers to ubufs") Reported-by:
kernel test robot <lkp@intel.com> Signed-off-by:
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- 25 Apr, 2021 15 commits
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Stefan Metzmacher authored
This is done by create_io_thread() now. Signed-off-by:
Stefan Metzmacher <metze@samba.org> Signed-off-by:
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Stefan Metzmacher authored
Otherwise io_wq_worker_{running,sleeping}() may dereference an invalid pointer (in future). Currently all users of create_io_thread() are fine and get task->pf_io_worker = NULL implicitly from the wq_manager, which got it either from the userspace thread of the sq_thread, which explicitly reset it to NULL. I think it's safer to always reset it in order to avoid future problems. Fixes: 3bfe6106 ("io-wq: fork worker threads from original task") cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: -
Hao Xu authored
we shall update sq_thread_idle anytime we do ctx deletion from ctx_list Fixes:734551df ("io_uring: fix shared sqpoll cancellation hangs") Signed-off-by:
Hao Xu <haoxu@linux.alibaba.com> Link: https://lore.kernel.org/r/1619256380-236460-1-git-send-email-haoxu@linux.alibaba.comSigned-off-by:
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Pavel Begunkov authored
Hook buffers into all rsrc infrastructure, including tagging and updates. Suggested-by:
Bijan Mottahedeh <bijan.mottahedeh@oracle.com> Signed-off-by:
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Bijan Mottahedeh authored
Apply fixed_rsrc functionality for fixed buffers support. Signed-off-by:
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Pavel Begunkov authored
With dynamic buffer updates, registered buffers in the table may change at any moment. First of all we want to prevent future races between updating and importing (i.e. io_import_fixed()), where the latter one may happen without uring_lock held, e.g. from io-wq. Save the first loaded io_mapped_ubuf buffer and reuse. Signed-off-by:
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Pavel Begunkov authored
Instead of keeping a table of ubufs convert them into pointers to ubuf, so we can atomically read one pointer and be sure that the content of ubuf won't change. Because it was already dynamically allocating imu->bvec, throw both imu and bvec into a single structure so they can be allocated together. Signed-off-by:
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Pavel Begunkov authored
Add IORING_REGISTER_RSRC_UPDATE, which also supports passing in rsrc tags. Implement it for registered files. Signed-off-by:
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Pavel Begunkov authored
Add a new io_uring_register() opcode for rsrc registeration. Instead of accepting a pointer to resources, fds or iovecs, it @arg is now pointing to a struct io_uring_rsrc_register, and the second argument tells how large that struct is to make it easily extendible by adding new fields. All that is done mainly to be able to pass in a pointer with tags. Pass it in and enable CQE posting for file resources. Doesn't support setting tags on update yet. A design choice made here is to not post CQEs on rsrc de-registration, but only when we updated-removed it by rsrc dynamic update. Signed-off-by:
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Pavel Begunkov authored
As resources are getting more support and common parts, it'll be more convenient to index resources and use it for indexing. Signed-off-by:
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Pavel Begunkov authored
Extract some common parts for rsrc update, will be used reg buffers support dynamic (i.e. quiesce-lee) managing. Signed-off-by:
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Pavel Begunkov authored
We need a way to notify userspace when a lazily removed resource actually died out. This will be done by associating a tag, which is u64 exactly like req->user_data, with each rsrc (e.g. buffer of file). A CQE will be posted once a resource is actually put down. Tag 0 is a special value set by default, for whcih it don't generate an CQE, so providing the old behaviour. Don't expose it to the userspace yet, but prepare internally, allocate buffers, add all posting hooks, etc. Signed-off-by:
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Pavel Begunkov authored
Make __io_cqring_fill_event() agnostic of struct io_kiocb, pass all the data needed directly into it. Will be used to post rsrc removal completions, which don't have an associated request. Signed-off-by:
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Pavel Begunkov authored
Add io_rsrc_data_free() helper for destroying rsrc_data, easier for search and the function will get more stuff to destroy shortly. Signed-off-by:
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Pavel Begunkov authored
A preparation patch moving __io_sqe_files_unregister() definition closer to other "files" functions without any modification. Signed-off-by:
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- 23 Apr, 2021 1 commit
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Hao Xu authored
do this to avoid race below: userspace kernel | check sqring and iopoll_list submit sqe | check IORING_SQ_NEED_WAKEUP | (which is not set) | | | set IORING_SQ_NEED_WAKEUP wait cqe | schedule(never wakeup again) Signed-off-by:
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- 20 Apr, 2021 4 commits
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Pavel Begunkov authored
Just a bit of code tossing in io_sq_offload_create(), so it looks a bit better. No functional changes. Signed-off-by:
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Pavel Begunkov authored
Put sq_creds as a part of io_ring_ctx_free(), it's easy to miss doing it in io_sq_thread_finish(), especially considering past mistakes related to ring creation failures. Signed-off-by:
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Pavel Begunkov authored
REQ_F_INFLIGHT deaccounting doesn't do any spinlocking or resource freeing anymore, so it's safe to move it into the normal cleanup flow, i.e. into io_clean_op(), so making it cleaner. Also move io_req_needs_clean() to be first in io_dismantle_req() so it doesn't reload req->flags. Signed-off-by:
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Jens Axboe authored
A previous commit removed the need for this, but overlooked that we no longer use it at all. Get rid of it. Fixes: 685fe7fe ("io-wq: eliminate the need for a manager thread") Reported-by:
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- 19 Apr, 2021 2 commits
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Pavel Begunkov authored
[ 736.982891] INFO: task iou-sqp-4294:4295 blocked for more than 122 seconds. [ 736.982897] Call Trace: [ 736.982901] schedule+0x68/0xe0 [ 736.982903] io_uring_cancel_sqpoll+0xdb/0x110 [ 736.982908] io_sqpoll_cancel_cb+0x24/0x30 [ 736.982911] io_run_task_work_head+0x28/0x50 [ 736.982913] io_sq_thread+0x4e3/0x720 We call io_uring_cancel_sqpoll() one by one for each ctx either in sq_thread() itself or via task works, and it's intended to cancel all requests of a specified context. However the function uses per-task counters to track the number of inflight requests, so it counts more requests than available via currect io_uring ctx and goes to sleep for them to appear (e.g. from IRQ), that will never happen. Cancel a bit more than before, i.e. all ctxs that share sqpoll and continue to use shared counters. Don't forget that we should not remove ctx from the list before running that task_work sqpoll-cancel, otherwise the function wouldn't be able to find the context and will hang. Reported-by:
Joakim Hassila <joj@mac.com> Reported-by:
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Pavel Begunkov authored
SQPOLL task won't submit requests for a context that is currently dying, so no need to remove ctx from sqd_list prior the main loop of io_ring_exit_work(). Kill it, will be removed by io_sq_thread_finish() and only brings confusion and lockups. Cc: stable@vger.kernel.org Signed-off-by:
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- 18 Apr, 2021 3 commits
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Pavel Begunkov authored
Move restriction checks of __io_uring_register() before quiesce, saves from waiting for requests in fail case and simplifies the code a bit. Also add array_index_nospec() for safety Signed-off-by:
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Pavel Begunkov authored
Colin reported before possible overflow and sign extension problems in io_provide_buffers_prep(). As Linus pointed out previous attempt did nothing useful, see d81269fe ("io_uring: fix provide_buffers sign extension"). Do that with help of check_<op>_overflow helpers. And fix struct io_provide_buf::len type, as it doesn't make much sense to keep it signed. Reported-by:
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Pavel Begunkov authored
Don't fail submission attempts if there are CQEs in the overflow backlog, but give away the decision making to the userspace. It might be very inconvenient to the userspace, especially if submission and completion are done by different threads. We can remove it because of recent changes, where requests are now not locked by the backlog, backlog entries are allocated separately, so they take less space and cgroup accounted. Signed-off-by:
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- 16 Apr, 2021 4 commits
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Jens Axboe authored
A hand-edit while applying this patch on top of a new base resulted in a reverted check for re-issue, resulting in spurious -EAGAIN errors. Fixes: 8c130827 ("io_uring: don't alter iopoll reissue fail ret code") Signed-off-by:
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Jens Axboe authored
We manage these separately right now, just tie it to the request lifetime and make it be part of the usual REQ_F_NEED_CLEANUP logic. Signed-off-by: -
Jens Axboe authored
We have this in two spots right now, which is a bit fragile. In preparation for moving REQ_F_POLLED cleanup into the same spot, move the check into a separate helper so we only have it once. Signed-off-by: -
Jens Axboe authored
The re-add handling isn't correct for the multi wait case, so let's just disable it for now explicitly until we can get that sorted out. This just turns it into a one-shot request. Since we pass back whether or not a poll request terminates in multishot mode on completion, this should not break properly behaving applications that check for IORING_CQE_F_MORE on completion. Signed-off-by:
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- 14 Apr, 2021 4 commits
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Pavel Begunkov authored
Having poll update function as a part of IORING_OP_POLL_ADD is not great, we have to do hack around struct layouts and add some overhead in the way of more popular POLL_ADD. Even more serious drawback is that POLL_ADD requires file and always grabs it, and so poll update, which doesn't need it. Incorporate poll update into IORING_OP_POLL_REMOVE instead of IORING_OP_POLL_ADD. It also more consistent with timeout remove/update. Fixes: b69de288 ("io_uring: allow events and user_data update of running poll requests") Signed-off-by:
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Pavel Begunkov authored
Isolate poll mask SQE parsing and preparations into a new function, which will be reused shortly. Fixes: b69de288 ("io_uring: allow events and user_data update of running poll requests") Signed-off-by:
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Pavel Begunkov authored
Don't allow REQ_OP_POLL_REMOVE to kill apoll requests, users should not know about it. Also, remove weird -EACCESS in io_poll_update(), it shouldn't know anything about apoll, and have to work even if happened to have a poll and an async poll'ed request with same user_data. Fixes: b69de288 ("io_uring: allow events and user_data update of running poll requests") Signed-off-by:
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Pavel Begunkov authored
Don't reinit io_ring_exit_work()'s exit work/completions on each iteration, that's wasteful. Also add list_rotate_left(), so if we failed to complete the task job, we don't try it again and again but defer it until others are processed. Signed-off-by:
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- 13 Apr, 2021 3 commits
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Pavel Begunkov authored
io_iopoll_getevents() is of no use to us anymore, io_iopoll_check() handles all the cases. Signed-off-by:
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Pavel Begunkov authored
The only way to get out of io_iopoll_getevents() and continue iterating is to have empty iopoll_list, otherwise the main loop would just exit. So, instead of the unlock on 8th time heuristic, do that based on iopoll_list. Also, as no one can add new requests to iopoll_list while io_iopoll_check() hold uring_lock, it's useless to spin with the list empty, return in that case. Signed-off-by:
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Pavel Begunkov authored
As CQE overflows are now untied from requests and so don't hold any ref, we don't need to handle exiting/exec'ing cases there anymore. Moreover, it's much nicer in regards to userspace to save overflowed CQEs whenever possible, so remove failing on in_idle. Signed-off-by:
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