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2021-08-23io_uring: move req_ref_get() and friendsPavel Begunkov
Move all request refcount helpers to avoid forward declarations in the future. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/89fd36f6f3fe5b733dfe4546c24725eee40df605.1628705069.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: remove IRQ aspect of io_ring_ctx completion lockJens Axboe
We have no hard/soft IRQ users of this lock left, remove any IRQ disabling/saving and restoring when grabbing this lock. This is straight forward with no users entering with IRQs disabled anymore, the only thing to look out for is the waitqueue poll head lock which nests inside the completion lock. That needs IRQs disabled, and hence we have to do that now instead of relying on the outer lock doing so. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: run regular file completions from task_workJens Axboe
This is in preparation to making the completion lock work outside of hard/soft IRQ context. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: run linked timeouts from task_workJens Axboe
This is in preparation to making the completion lock work outside of hard/soft IRQ context. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: run timeouts from task_workJens Axboe
This is in preparation to making the completion lock work outside of hard/soft IRQ context. Add a timeout_lock to handle the ordering of timeout completions or cancelations with the timeouts actually triggering. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: remove file batch-get optimisationPavel Begunkov
For requests with non-fixed files, instead of grabbing just one reference, we get by the number of left requests, so the following requests using the same file can take it without atomics. However, it's not all win. If there is one request in the middle not using files or having a fixed file, we'll need to put back the left references. Even worse if an application submits requests dealing with different files, it will do a put for each new request, so doubling the number of atomics needed. Also, even if not used, it's still takes some cycles in the submission path. If a file used many times, it rather makes sense to pre-register it, if not, we may fall in the described pitfall. So, this optimisation is a matter of use case. Go with the simpliest code-wise way, remove it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: clean up tctx_task_work()Pavel Begunkov
After recent fixes, tctx_task_work() always does proper spinlocking before looking into ->task_list, so now we don't need atomics for ->task_state, replace it with non-atomic task_running using the critical section. Tide it up, combine two separate block with spinlocking, and always try to splice in there, so we do less locking when new requests are arriving during the function execution. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> [axboe: fix missing ->task_running reset on task_work_add() failure] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: inline io_poll_remove_waitqsPavel Begunkov
Inline io_poll_remove_waitqs() into its only user and clean it up. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/2f1a91a19ffcd591531dc4c61e2f11c64a2d6a6d.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: remove extra argument for overflow flushPavel Begunkov
Unlike __io_cqring_overflow_flush(), nobody does forced flushing with io_cqring_overflow_flush(), so removed the argument from it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/7594f869ca41b7cfb5a35a3c7c2d402242834e9e.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: inline struct io_comp_statePavel Begunkov
Inline struct io_comp_state into struct io_submit_state. They are already coupled tightly, together with mixed responsibilities it only brings confusion having them separately. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/e55bba77426b399e3a2e54e3c6c267c6a0fc4b57.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: use inflight_entry instead of compl.listPavel Begunkov
req->compl.list is used to cache freed requests, and so can't overlap in time with req->inflight_entry. So, use inflight_entry to link requests and remove compl.list. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/e430e79d22d70a190d718831bda7bfed1daf8976.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: remove redundant args from cache_freePavel Begunkov
We don't use @tsk argument of io_req_cache_free(), remove it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6a28b4a58ee0aaf0db98e2179b9c9f06f9b0cca1.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: cache __io_free_req()'d requestsPavel Begunkov
Don't kfree requests in __io_free_req() but put them back into the internal request cache. That makes allocations more sustainable and will be used for refcounting optimisations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9f4950fbe7771c8d41799366d0a3a08ac3040236.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: move io_fallback_req_func()Pavel Begunkov
Move io_fallback_req_func() to kill yet another forward declaration. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/d0a8f9d9a0057ed761d6237167d51c9378798d2d.1628536684.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: optimise putting task structPavel Begunkov
We cache all the reference to task + tctx, so if io_put_task() is called by the corresponding task itself, we can save on atomics and return the refs right back into the cache. It's beneficial for all inline completions, and also iopolling, when polling and submissions are done by the same task, including SQPOLL|IOPOLL. Note: io_uring_cancel_generic() can return refs to the cache as well, so those should be flushed in the loop for tctx_inflight() to work right. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6fe9646b3cb70e46aca1f58426776e368c8926b3.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: drop exec checks from io_req_task_submitPavel Begunkov
In case of on-exec io_uring cancellations, tasks already wait for all submitted requests to get completed/cancelled, so we don't need to check for ->in_execve separately. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/be8707049f10df9d20ca03dc4ca3316239b5e8e0.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: kill unused IO_IOPOLL_BATCHPavel Begunkov
IO_IOPOLL_BATCH is not used, delete it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/b2bdf19dbee2c9fc8865bbab9412135a14e24a64.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: improve ctx hang handlingPavel Begunkov
If io_ring_exit_work() can't get it done in 5 minutes, something is going very wrong, don't keep spinning at HZ / 20 rate, it doesn't help and it may take much of CPU time if there is a lot of workers stuck as such. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9e2d1ca81d569f6bc628af1a42ff6663bff7ce9c.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: deduplicate open iopoll checkPavel Begunkov
Move IORING_SETUP_IOPOLL check into __io_openat_prep(), so both openat and openat2 reuse it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9a73ce83e4ee60d011180ef177eecef8e87ff2a2.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: inline io_free_req_deferredPavel Begunkov
Inline io_free_req_deferred(), there is no reason to keep it separated. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/ce04b7180d4eac0d69dd00677b227eefe80c2cc5.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: move io_rsrc_node_alloc() definitionPavel Begunkov
Move the function together with io_rsrc_node_ref_zero() in the source file as it is to get rid of forward declarations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4d81f6f833e7d017860b24463a9a68b14a8a5ed2.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: move io_put_task() definitionPavel Begunkov
Move the function in the source file as it is to get rid of forward declarations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/33d917d69e4206557c75a5b98fe22bcdf77ce47d.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: extract a helper for ctx quiescePavel Begunkov
Refactor __io_uring_register() by extracting a helper responsible for ctx queisce. Looks better and will make it easier to add more optimisations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0339e0027504176be09237eefa7945bf9a6f153d.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: optimise io_cqring_wait() hot pathPavel Begunkov
Turns out we always init struct io_wait_queue in io_cqring_wait(), even if it's not used after, i.e. there are already enough of CQEs. And often it's exactly what happens, for instance, requests may have been completed inline, or in case of io_uring_enter(submit=N, wait=1). It shows up in my profiler, so optimise it by delaying the struct init. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/6f1b81c60b947d165583dc333947869c3d85d037.1628471125.git.asml.silence@gmail.com [axboe: fixed up for new cqring wait] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: add more locking annotations for submitPavel Begunkov
Add more annotations for submission path functions holding ->uring_lock. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/128ec4185e26fbd661dd3a424aa66108ee8ff951.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: don't halt iopoll too earlyPavel Begunkov
IOPOLL users should care more about getting completions for requests they submitted, but not in "device did/completed something". Currently, io_do_iopoll() may return a positive number, which will instruct io_iopoll_check() to break the loop and end the syscall, even if there is not enough CQEs or none at all. Don't return positive numbers, so io_iopoll_check() exits only when it gets an actual error, need reschedule or got enough CQEs. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/641a88f751623b6758303b3171f0a4141f06726e.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: refactor io_alloc_reqPavel Begunkov
Replace the main if of io_flush_cached_reqs() with inverted condition + goto, so all the cases are handled in the same way. And also extract io_preinit_req() to make it cleaner and easier to refer to. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1abcba1f7b55dc53bf1dbe95036e345ffb1d5b01.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io-wq: improve wq_list_add_tail()Pavel Begunkov
Prepare nodes that we're going to add before actually linking them, it's always safer and costs us nothing. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/f7e53f0c84c02ed6748c488ed0789b98f8cc6185.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: remove unnecessary PF_EXITING checkPavel Begunkov
We prefer nornal task_works even if it would fail requests inside. Kill a PF_EXITING check in io_req_task_work_add(), task_work_add() handles well dying tasks, i.e. return error when can't enqueue due to late stages of do_exit(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/fc14297e8441cd8f5d1743a2488cf0df09bf48ac.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: clean io-wq callbacksPavel Begunkov
Move io-wq callbacks closer to each other, so it's easier to work with them, and rename io_free_work() into io_wq_free_work() for consistency. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/851bbc7f0f86f206d8c1333efee8bcb9c26e419f.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: avoid touching inode in rw prepPavel Begunkov
If we use fixed files, we can be sure (almost) that REQ_F_ISREG is set. However, for non-reg files io_prep_rw() still will look into inode to double check, and that's expensive and can be avoided. The only caveat is that it only currently works with 64+ bit architectures, see FFS_ISREG, so we should consider that. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0a62780c491ca2522cd52db4ae3f16e03aafed0f.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: rename io_file_supports_async()Pavel Begunkov
io_file_supports_async() checks whether a file supports nowait operations, so "async" in the name is misleading. Rename it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/33d55b5ce43aa1884c637c1957f1e30d30dc3bec.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: inline fixed part of io_file_get()Pavel Begunkov
Optimise io_file_get() with registered files, which is in a hot path, by inlining parts of the function. Saves a function call, and inefficiencies of passing arguments, e.g. evaluating (sqe_flags & IOSQE_FIXED_FILE). It couldn't have been done before as compilers were refusing to inline it because of the function size. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/52115cd6ce28f33bd0923149c0e6cb611084a0b1.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: use kvmalloc for fixed filesPavel Begunkov
Instead of hand-coded two-level tables for registered files, allocate them with kvmalloc(). In many cases small enough tables are enough, and so can be kmalloc()'ed removing an extra memory load and a bunch of bit logic instructions from the hot path. If the table is larger, we trade off all the pros with a TLB-assisted memory lookup. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/280421d3b48775dabab773006bb5588c7b2dabc0.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io_uring: be smarter about waking multiple CQ ring waitersJens Axboe
Currently we only wake the first waiter, even if we have enough entries posted to satisfy multiple waiters. Improve that situation so that every waiter knows how much the CQ tail has to advance before they can be safely woken up. With this change, if we have N waiters each asking for 1 event and we get 4 completions, then we wake up 4 waiters. If we have N waiters asking for 2 completions and we get 4 completions, then we wake up the first two. Previously, only the first waiter would've been woken up. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23io-wq: remove GFP_ATOMIC allocation off schedule out pathJens Axboe
Daniel reports that the v5.14-rc4-rt4 kernel throws a BUG when running stress-ng: | [ 90.202543] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:35 | [ 90.202549] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2047, name: iou-wrk-2041 | [ 90.202555] CPU: 5 PID: 2047 Comm: iou-wrk-2041 Tainted: G W 5.14.0-rc4-rt4+ #89 | [ 90.202559] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 | [ 90.202561] Call Trace: | [ 90.202577] dump_stack_lvl+0x34/0x44 | [ 90.202584] ___might_sleep.cold+0x87/0x94 | [ 90.202588] rt_spin_lock+0x19/0x70 | [ 90.202593] ___slab_alloc+0xcb/0x7d0 | [ 90.202598] ? newidle_balance.constprop.0+0xf5/0x3b0 | [ 90.202603] ? dequeue_entity+0xc3/0x290 | [ 90.202605] ? io_wqe_dec_running.isra.0+0x98/0xe0 | [ 90.202610] ? pick_next_task_fair+0xb9/0x330 | [ 90.202612] ? __schedule+0x670/0x1410 | [ 90.202615] ? io_wqe_dec_running.isra.0+0x98/0xe0 | [ 90.202618] kmem_cache_alloc_trace+0x79/0x1f0 | [ 90.202621] io_wqe_dec_running.isra.0+0x98/0xe0 | [ 90.202625] io_wq_worker_sleeping+0x37/0x50 | [ 90.202628] schedule+0x30/0xd0 | [ 90.202630] schedule_timeout+0x8f/0x1a0 | [ 90.202634] ? __bpf_trace_tick_stop+0x10/0x10 | [ 90.202637] io_wqe_worker+0xfd/0x320 | [ 90.202641] ? finish_task_switch.isra.0+0xd3/0x290 | [ 90.202644] ? io_worker_handle_work+0x670/0x670 | [ 90.202646] ? io_worker_handle_work+0x670/0x670 | [ 90.202649] ret_from_fork+0x22/0x30 which is due to the RT kernel not liking a GFP_ATOMIC allocation inside a raw spinlock. Besides that not working on RT, doing any kind of allocation from inside schedule() is kind of nasty and should be avoided if at all possible. This particular path happens when an io-wq worker goes to sleep, and we need a new worker to handle pending work. We currently allocate a small data item to hold the information we need to create a new worker, but we can instead include this data in the io_worker struct itself and just protect it with a single bit lock. We only really need one per worker anyway, as we will have run pending work between to sleep cycles. https://lore.kernel.org/lkml/20210804082418.fbibprcwtzyt5qax@beryllium.lan/ Reported-by: Daniel Wagner <dwagner@suse.de> Tested-by: Daniel Wagner <dwagner@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23null_blk: add error handling support for add_disk()Luis Chamberlain
We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. The actual cleanup in case of error is already handled by the caller of null_gendisk_register(). Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23virtio_blk: add error handling support for add_disk()Luis Chamberlain
We never checked for errors on add_disk() as this function returned void. Now that this is fixed, use the shiny new error handling. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-11-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: add error handling for device_add_disk / add_diskLuis Chamberlain
Properly unwind on errors in device_add_disk. This is the initial work as drivers are not converted yet, which will follow in separate patches. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> [hch: major rebase. All bugs are probably mine] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: return errors from disk_alloc_eventsLuis Chamberlain
Prepare for proper error handling in add_disk. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> [hch: split from a larger patch] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: return errors from blk_integrity_addLuis Chamberlain
Prepare for proper error handling in add_disk. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> [hch: split from a larger patch] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: call blk_register_queue earlier in device_add_diskChristoph Hellwig
Ensure that all the sysfs bits are set up before bdev_add is called, as that will make the upcomding error handling much easier. However this means the call to disk_update_readahead has to be split as that requires a bdi. Also remove various sanity checks that don't make sense now that blk_register_queue only has a single caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210818144542.19305-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: call blk_integrity_add earlier in device_add_diskChristoph Hellwig
Doing all the sysfs file creation before adding the bdev and thus allowing it to be opened will simplify the about to be added error handling. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: create the bdi link earlier in device_add_diskChristoph Hellwig
This will simplify error handling going forward. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: call bdev_add later in device_add_diskChristoph Hellwig
Once bdev_add is called userspace can open the block device. Ensure that the struct device, which is used for refcounting of the disk besides various other things, is fully setup at that point. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: fold register_disk into device_add_diskChristoph Hellwig
There is no real reason these should be separate. Also simplify the groups assignment a bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210818144542.19305-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: add a sanity check for a live disk in del_gendiskChristoph Hellwig
Add a sanity check to del_gendisk to do nothing when the disk wasn't successfully added. This papers over the complete lack of add_disk error handling, which is about to get fixed gradually. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20210818144542.19305-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: add an explicit ->disk backpointer to the request_queueChristoph Hellwig
Replace the magic lookup through the kobject tree with an explicit backpointer, given that the device model links are set up and torn down at times when I/O is still possible, leading to potential NULL or invalid pointer dereferences. Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk") Reported-by: syzbot <syzbot+aa0801b6b32dca9dda82@syzkaller.appspotmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Sven Schnelle <svens@linux.ibm.com> Link: https://lore.kernel.org/r/20210816134624.GA24234@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: hold a request_queue reference for the lifetime of struct gendiskChristoph Hellwig
Acquire the queue ref dropped in disk_release in __blk_alloc_disk so any allocate gendisk always has a queue reference. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210816131910.615153-9-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-23block: pass a request_queue to __blk_alloc_diskChristoph Hellwig
Pass in a request_queue and assign disk->queue in __blk_alloc_disk to ensure struct gendisk always has a valid ->queue pointer. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210816131910.615153-8-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>