AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/08/11 07:22	flow	patch-triage	1m Args: null Results: { "EnableConfigs": [ "IO_URING" ], "FocusSymbols": [ "io_wq_create", "io_wq_put_and_exit", "io_wq_enqueue", "io_wq_cancel_cb" ], "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.", "NeedsKMSAN": false, "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.", "WorthFuzzing": true }
1/1	2026/08/11 07:22	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 2ecaa2a619cf9c377d20a4f876432c84e3d16065\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Tue Aug 11 07:22:49 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/io_uring/io-wq.c b/io_uring/io-wq.c\nindex 2e14880eef92a..fa403ed245962 100644\n--- a/io_uring/io-wq.c\n+++ b/io_uring/io-wq.c\n@@ -211,9 +211,12 @@ static void io_worker_cancel_cb(struct io_worker worker)\n \tstruct io_wq wq = worker-\u003ewq;\n \n \tatomic_dec(\u0026acct-\u003enr_running);\n-\traw_spin_lock(\u0026acct-\u003eworkers_lock);\n-\tacct-\u003enr_workers--;\n-\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\n+\t/* create_worker_cb() has not reserved a worker slot yet. */\n+\tif (worker-\u003ecreate_work.func != create_worker_cb) {\n+\t\traw_spin_lock(\u0026acct-\u003eworkers_lock);\n+\t\tacct-\u003enr_workers--;\n+\t\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\n+\t}\n \tio_worker_ref_put(wq);\n \tclear_bit_unlock(0, \u0026worker-\u003ecreate_state);\n \tio_worker_release(worker);\n" }
2/1	2026/08/11 07:22	agent	patch-evaluator	1m Model: best-expensive Args: null Results: { "EnableConfigs": [ "IO_URING" ], "FocusSymbols": [ "io_wq_create", "io_wq_put_and_exit", "io_wq_enqueue", "io_wq_cancel_cb" ], "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.", "WorthFuzzing": true } Instruction: You are an expert Linux kernel maintainer. Your job is to review a provided patch series and determine if it makes functional changes to the kernel that should be fuzzed. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively use your code access tools to examine the actual source code and confirm any assumptions. Return WorthFuzzing=false if the patch only contains: - Modifications to Documentation/, Kconfig files, or code comments. - Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints. - Changes to numeric constants or macros that do not functionally alter execution flow. - Code paths that are impossible to reach in virtualized environments like GCE or QEMU, even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim). - Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU. - Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove) that are executed only during PCI hot-unplug or sysfs driver unbind operations. If it modifies reachable core kernel logic, drivers, or architectures, use your code search tools to verify the code can be executed, then return WorthFuzzing=true. When returning WorthFuzzing=true, you MUST ALSO: 1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols. Avoid listing generic hot-path functions to prevent skewed test distributions. Prefer non-static, non-inlined API entrypoint functions over internal static helper functions (which are inlined by the compiler and do not have distinct symbol addresses). 2. Identify any specific CONFIG_ options required to properly test this new/modified feature. Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions. Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4"). Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: For your convenience, here is the diff of the changes: commit 2ecaa2a619cf9c377d20a4f876432c84e3d16065 Author: syz-cluster <triage@syzkaller.com> Date: Tue Aug 11 07:22:49 2026 +0000 syz-cluster: applied patch under review diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c index 2e14880eef92a..fa403ed245962 100644 --- a/io_uring/io-wq.c +++ b/io_uring/io-wq.c @@ -211,9 +211,12 @@ static void io_worker_cancel_cb(struct io_worker worker) struct io_wq wq = worker->wq; atomic_dec(&acct->nr_running); - raw_spin_lock(&acct->workers_lock); - acct->nr_workers--; - raw_spin_unlock(&acct->workers_lock); + /* create_worker_cb() has not reserved a worker slot yet. */ + if (worker->create_work.func != create_worker_cb) { + raw_spin_lock(&acct->workers_lock); + acct->nr_workers--; + raw_spin_unlock(&acct->workers_lock); + } io_worker_ref_put(wq); clear_bit_unlock(0, &worker->create_state); io_worker_release(worker);
3/2	2026/08/11 07:22	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 2099 output: 36 thoughts: 158 Thoughts: Analyzing a Patch in io_uring/io-wq.c Okay, so I'm looking at this patch within `io_uring/io-wq.c`. It seems to be touching `io_worker_cancel_cb`. The key change is around this conditional: avoiding decrementing `acct->nr_workers` under certain circumstances. Let me see... the logic here is skipping the decrement when `worker->create_work.func` isn't `create_worker_cb`. Hmm, the comment says something about `create_worker_cb()` not reserving a worker slot yet. Right, so if it's not `create_worker_cb`, what is it? Is this related to `create_worker_cont`? I need to double-check the implementations of both `io_worker_cancel_cb` and `create_worker_cb` within this file. The dependency and how they relate is obviously the key to this patch. Let's dig in and see the flow.
4/2	2026/08/11 07:22	tool	grepper	0m Args: { "Expression": "io_worker_cancel_cb", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "io_uring/io-wq.c=198=bool io_wq_worker_stopped(void)\n--\nio_uring/io-wq.c-207-\nio_uring/io-wq.c:208:static void io_worker_cancel_cb(struct io_worker worker)\nio_uring/io-wq.c-209-{\n--\nio_uring/io-wq.c=235=static void io_worker_exit(struct io_worker worker)\n--\nio_uring/io-wq.c-245-\t\t\tbreak;\nio_uring/io-wq.c:246:\t\tio_worker_cancel_cb(worker);\nio_uring/io-wq.c-247-\t}\n--\nio_uring/io-wq.c=1324=static void io_wq_cancel_tw_create(struct io_wq wq)\n--\nio_uring/io-wq.c-1331-\t\tworker = container_of(cb, struct io_worker, create_work);\nio_uring/io-wq.c:1332:\t\tio_worker_cancel_cb(worker);\nio_uring/io-wq.c-1333-\t\t/\n" }
5/2	2026/08/11 07:22	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 2826 output: 34 thoughts: 30 Thoughts: Okay, let's dive into these callbacks: `io_worker_cancel_cb`, `create_worker_cb`, and `create_worker_cont`. My initial thought is to understand their relationship and how they contribute to the overall workflow. I need to figure out the orchestration here. Is `io_worker_cancel_cb` used to clean up or signal termination, and how does it interact with `create_worker_cb` which likely spawns new threads or processes? Is `create_worker_cont` related, perhaps a continuation or completion handler after worker creation? My immediate goal is to map out the control flow, identifying potential race conditions or synchronization issues between these callbacks. I'll need to consider how state is shared between them, especially if there's any shared data that requires careful locking or atomic operations. I'll also be looking for any hints about error handling: do these callbacks handle errors independently, or is there a centralized error-reporting mechanism? I need to analyze how cancellation is propagated through this chain, and look at the edge cases like the thread exiting while processing a request.
6/2	2026/08/11 07:22	tool	grepper	0m Args: { "Expression": "create_worker_cb", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "io_uring/io-wq.c=149=static bool io_acct_cancel_pending_work(struct io_wq wq,\n--\nio_uring/io-wq.c-151-\t\t\t\t\tstruct io_cb_cancel_data match);\nio_uring/io-wq.c:152:static void create_worker_cb(struct callback_head cb);\nio_uring/io-wq.c-153-static void io_wq_cancel_tw_create(struct io_wq wq);\n--\nio_uring/io-wq.c=208=static void io_worker_cancel_cb(struct io_worker worker)\n--\nio_uring/io-wq.c-213-\tatomic_dec(\u0026acct-\u003enr_running);\nio_uring/io-wq.c:214:\t/ create_worker_cb() has not reserved a worker slot yet. /\nio_uring/io-wq.c:215:\tif (worker-\u003ecreate_work.func != create_worker_cb) {\nio_uring/io-wq.c-216-\t\traw_spin_lock(\u0026acct-\u003eworkers_lock);\n--\nio_uring/io-wq.c=225=static bool io_task_worker_match(struct callback_head cb, void data)\n--\nio_uring/io-wq.c-228-\nio_uring/io-wq.c:229:\tif (cb-\u003efunc != create_worker_cb)\nio_uring/io-wq.c-230-\t\treturn false;\n--\nio_uring/io-wq.c=347=static void io_wq_inc_running(struct io_worker worker)\n--\nio_uring/io-wq.c-353-\nio_uring/io-wq.c:354:static void create_worker_cb(struct callback_head cb)\nio_uring/io-wq.c-355-{\n--\nio_uring/io-wq.c=459=static void io_wq_dec_running(struct io_worker worker)\n--\nio_uring/io-wq.c-480-\tatomic_inc(\u0026wq-\u003eworker_refs);\nio_uring/io-wq.c:481:\tio_queue_worker_create(worker, acct, create_worker_cb);\nio_uring/io-wq.c-482-}\n--\nio_uring/io-wq.c=1309=static bool io_task_work_match(struct callback_head cb, void data)\n--\nio_uring/io-wq.c-1312-\nio_uring/io-wq.c:1313:\tif (cb-\u003efunc != create_worker_cb \u0026\u0026 cb-\u003efunc != create_worker_cont)\nio_uring/io-wq.c-1314-\t\treturn false;\n" }
7/2	2026/08/11 07:22	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 3842 output: 34 thoughts: 227 Thoughts: Analyzing a Subtle io_uring Worker Fix Okay, so I'm looking at this patch for `io_uring/io-wq.c`, specifically how it handles `io_worker_cancel_cb`. The key change is this conditional logic: don't decrement `acct->nr_workers` if the worker's creation function isn't `create_worker_cb`. The code snippet really clarifies it: ```c /* create_worker_cb() has not reserved a worker slot yet. */ if (worker->create_work.func != create_worker_cb) { raw_spin_lock(&acct->workers_lock); acct->nr_workers--; raw_spin_unlock(&acct->workers_lock); } ``` My initial thought is, this is a functional modification; it's fixing a potential bug in how io_uring workers are managed during cancellation. That's a good candidate for fuzzing. I need to figure out which config options enable this functionality and identify the relevant symbols. The function `io_worker_cancel_cb` itself is static, so I'll need to look at what calls it to understand how the system uses it. A quick look shows that it's called by `io_worker_exit` and `io_wq_cancel_tw_create`, which should give me good entry points for fuzzing.
8/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_worker_exit", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "io_uring/io-wq.c=225=static bool io_task_worker_match(struct callback_head cb, void data)\n--\nio_uring/io-wq.c-234-\nio_uring/io-wq.c:235:static void io_worker_exit(struct io_worker worker)\nio_uring/io-wq.c-236-{\n--\nio_uring/io-wq.c=685=static int io_wq_worker(void data)\n--\nio_uring/io-wq.c-748-\nio_uring/io-wq.c:749:\tio_worker_exit(worker);\nio_uring/io-wq.c-750-\treturn 0;\n" }
9/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 4609 output: 38 thoughts: 38 Thoughts: Here's my understanding, as if these were my own thoughts: Dissecting the I/O Worker Threads Okay, so I'm looking at the core of the I/O worker thread mechanism. `io_wq_worker`... that's the primary thread function, the heart of the whole operation. That's the function where the actual work gets done. That's where the I/O processing is orchestrated. Then I see `io_wq_cancel_tw_create`, and that's called specifically from `io_wq_exit_workers`. So, when the system's shutting down the worker threads, this cancellation function is invoked. Makes perfect sense. It's a cleanup step, potentially to prevent any new thread creations from succeeding on shutdown. It's all about making the process as tidy as possible. I'll need to dig into `io_wq_cancel_tw_create` more to understand what resources it's cleaning up. The context is obviously about thread management and specifically the cleanup of thread creation related structures within the I/O worker context.
10/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_cancel_tw_create", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "io_uring/io-wq.c=152=static void create_worker_cb(struct callback_head cb);\nio_uring/io-wq.c:153:static void io_wq_cancel_tw_create(struct io_wq wq);\nio_uring/io-wq.c-154-\n--\nio_uring/io-wq.c=390=static bool io_queue_worker_create(struct io_worker worker,\n--\nio_uring/io-wq.c-420-\t\tif (test_bit(IO_WQ_BIT_EXIT, \u0026wq-\u003estate))\nio_uring/io-wq.c:421:\t\t\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-422-\t\tio_worker_ref_put(wq);\n--\nio_uring/io-wq.c=1319=void io_wq_exit_start(struct io_wq wq)\n--\nio_uring/io-wq.c-1323-\nio_uring/io-wq.c:1324:static void io_wq_cancel_tw_create(struct io_wq wq)\nio_uring/io-wq.c-1325-{\n--\nio_uring/io-wq.c=1342=static void io_wq_exit_workers(struct io_wq wq)\n--\nio_uring/io-wq.c-1348-\nio_uring/io-wq.c:1349:\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-1350-\n" }
11/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 5335 output: 36 thoughts: 47 Thoughts: Okay, here's my interpretation of those thoughts, presented as if they're my own: Analyzing io_wq Destruction Right, so I'm looking at `io_wq_exit_workers` and `io_wq_exit_start`. Those are definitely called during the destruction process of an `io_wq`, making them key to understanding how it all unravels. My primary goal here is to get a clearer picture of that process. I need to identify the pieces, from start to finish. Therefore, I need to see what other related functions might be useful to understand how the `io_wq` is created, and even more critically, torn down. I’ll focus on non-static functions, as they're the ones most likely to be part of the public API or at least interact with other parts of the system. I need to cast a wider net here and find anything involved in either creation or destruction that might be lurking around. This will give me a comprehensive view of how `io_wq` life cycle is handled.
12/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_exit_workers", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "io_uring/io-wq.c=390=static bool io_queue_worker_create(struct io_worker worker,\n--\nio_uring/io-wq.c-417-\t\t now set. wq exit does that too, but we can have added this\nio_uring/io-wq.c:418:\t\t * work item after we canceled in io_wq_exit_workers().\nio_uring/io-wq.c-419-\t\t /\n--\nio_uring/io-wq.c=1324=static void io_wq_cancel_tw_create(struct io_wq wq)\n--\nio_uring/io-wq.c-1341-\nio_uring/io-wq.c:1342:static void io_wq_exit_workers(struct io_wq wq)\nio_uring/io-wq.c-1343-{\n--\nio_uring/io-wq.c=1398=void io_wq_put_and_exit(struct io_wq wq)\n--\nio_uring/io-wq.c-1401-\nio_uring/io-wq.c:1402:\tio_wq_exit_workers(wq);\nio_uring/io-wq.c-1403-\tio_wq_destroy(wq);\n" }
13/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 5976 output: 34 thoughts: 30 Thoughts: Okay, here's my interpretation of those thoughts, tailored for an expert audience, presented in the first person: Investigating the `io_wq` Cleanup Procedure Alright, I'm thinking about `io_wq_put_and_exit`. The fact that it's not a static function immediately piques my interest. It implies it might be called from outside the module, which has implications for synchronization and potential race conditions, if not handled carefully. I need to understand the contexts in which it's being used beyond the immediate scope. To get a better understanding of how the `io_wq` structure is managed, I really need to trace its origins, the lifecycle of the object, and its finalization routine. So, I need to see where this function is being called from. Therefore, let's dive into the creation process. I'll take a look at `io_wq_create` next. This will likely shed some light on the expected usage and lifecycle of the `io_wq`.
14/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_create", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "io_uring/io-wq.c=295=static bool io_acct_activate_free_worker(struct io_wq_acct acct)\n--\nio_uring/io-wq.c-325- /\nio_uring/io-wq.c:326:static bool io_wq_create_worker(struct io_wq wq, struct io_wq_acct acct)\nio_uring/io-wq.c-327-{\n--\nio_uring/io-wq.c=1028=void io_wq_enqueue(struct io_wq wq, struct io_wq_work work)\n--\nio_uring/io-wq.c-1061-\nio_uring/io-wq.c:1062:\t\tdid_create = io_wq_create_worker(wq, acct);\nio_uring/io-wq.c-1063-\t\tif (likely(did_create))\n--\nio_uring/io-wq.c=1235=static int io_wq_hash_wake(struct wait_queue_entry wait, unsigned mode,\n--\nio_uring/io-wq.c-1253-\nio_uring/io-wq.c:1254:struct io_wq io_wq_create(unsigned bounded, struct io_wq_data *data)\nio_uring/io-wq.c-1255-{\n" }
15/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6615 output: 33 thoughts: 64 Thoughts: Okay, let's see. If I'm trying to zero in on the core of this I/O workqueue implementation, my initial instinct is to look at the primary entry and exit points, the creation and destruction, really. So, `io_wq_create` and `io_wq_put_and_exit` definitely jump out as important symbols to trace. They are the scaffolding, the building and dismantling, so to speak. Then, of course, the actual work enqueuing needs consideration: `io_wq_enqueue` is obviously a critical piece. That's where the actual I/O requests are getting submitted. Now, what about the worker itself? Ah, `io_wq_worker`... that one's static, isn't it? Hmm, static means internal to the file, and that might make it a less obvious target for someone trying to interface with it from another context. I need to be aware of what is exposed, and what is internal. I should also check to see if there are any other non-static functions related to the workqueue. They could be the key to integration.
16/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_", "PathPrefix": "io_uring/io-wq.c" } Results: { "Output": "\nFull output is too long, showing 500 out of 532 lines.\nUse more precise expression if possible.\n\nio_uring/io-wq.c=48=struct io_worker {\n--\nio_uring/io-wq.c-54-\tstruct io_wq wq;\nio_uring/io-wq.c:55:\tstruct io_wq_acct acct;\nio_uring/io-wq.c-56-\nio_uring/io-wq.c:57:\tstruct io_wq_work cur_work;\nio_uring/io-wq.c-58-\traw_spinlock_t lock;\n--\nio_uring/io-wq.c-79-\nio_uring/io-wq.c:80:struct io_wq_acct {\nio_uring/io-wq.c-81-\t/\n--\nio_uring/io-wq.c-102-\traw_spinlock_t lock;\nio_uring/io-wq.c:103:\tstruct io_wq_work_list work_list;\nio_uring/io-wq.c-104-\tunsigned long flags;\n--\nio_uring/io-wq.c=116=struct io_wq {\n--\nio_uring/io-wq.c-118-\nio_uring/io-wq.c:119:\tstruct io_wq_hash hash;\nio_uring/io-wq.c-120-\n--\nio_uring/io-wq.c-127-\nio_uring/io-wq.c:128:\tstruct io_wq_acct acct[IO_WQ_ACCT_NR];\nio_uring/io-wq.c-129-\n--\nio_uring/io-wq.c-131-\nio_uring/io-wq.c:132:\tstruct io_wq_work hash_tail[IO_WQ_NR_HASH_BUCKETS];\nio_uring/io-wq.c-133-\n--\nio_uring/io-wq.c-136-\nio_uring/io-wq.c:137:static enum cpuhp_state io_wq_online;\nio_uring/io-wq.c-138-\nio_uring/io-wq.c=139=struct io_cb_cancel_data {\n--\nio_uring/io-wq.c-146-\nio_uring/io-wq.c:147:static bool create_io_worker(struct io_wq wq, struct io_wq_acct acct);\nio_uring/io-wq.c:148:static void io_wq_dec_running(struct io_worker worker);\nio_uring/io-wq.c-149-static bool io_acct_cancel_pending_work(struct io_wq wq,\nio_uring/io-wq.c:150:\t\t\t\t\tstruct io_wq_acct acct,\nio_uring/io-wq.c-151-\t\t\t\t\tstruct io_cb_cancel_data match);\nio_uring/io-wq.c=152=static void create_worker_cb(struct callback_head cb);\nio_uring/io-wq.c:153:static void io_wq_cancel_tw_create(struct io_wq wq);\nio_uring/io-wq.c-154-\nio_uring/io-wq.c=155=static inline unsigned int __io_get_work_hash(unsigned int work_flags)\n--\nio_uring/io-wq.c-159-\nio_uring/io-wq.c:160:static inline unsigned int io_get_work_hash(struct io_wq_work work)\nio_uring/io-wq.c-161-{\n--\nio_uring/io-wq.c=170=static void io_worker_release(struct io_worker worker)\n--\nio_uring/io-wq.c-175-\nio_uring/io-wq.c:176:static inline struct io_wq_acct io_get_acct(struct io_wq wq, bool bound)\nio_uring/io-wq.c-177-{\n--\nio_uring/io-wq.c-180-\nio_uring/io-wq.c:181:static inline struct io_wq_acct io_work_get_acct(struct io_wq wq,\nio_uring/io-wq.c-182-\t\t\t\t\t\t unsigned int work_flags)\n--\nio_uring/io-wq.c-186-\nio_uring/io-wq.c:187:static inline struct io_wq_acct io_wq_get_acct(struct io_worker worker)\nio_uring/io-wq.c-188-{\n--\nio_uring/io-wq.c=192=static void io_worker_ref_put(struct io_wq wq)\n--\nio_uring/io-wq.c-197-\nio_uring/io-wq.c:198:bool io_wq_worker_stopped(void)\nio_uring/io-wq.c-199-{\n--\nio_uring/io-wq.c-201-\nio_uring/io-wq.c:202:\tif (WARN_ON_ONCE(!io_wq_current_is_worker()))\nio_uring/io-wq.c-203-\t\treturn true;\n--\nio_uring/io-wq.c=208=static void io_worker_cancel_cb(struct io_worker worker)\nio_uring/io-wq.c-209-{\nio_uring/io-wq.c:210:\tstruct io_wq_acct acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-211-\tstruct io_wq wq = worker-\u003ewq;\n--\nio_uring/io-wq.c=235=static void io_worker_exit(struct io_worker worker)\n--\nio_uring/io-wq.c-237-\tstruct io_wq wq = worker-\u003ewq;\nio_uring/io-wq.c:238:\tstruct io_wq_acct acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-239-\n--\nio_uring/io-wq.c-256-\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\nio_uring/io-wq.c:257:\tio_wq_dec_running(worker);\nio_uring/io-wq.c-258-\t/\n--\nio_uring/io-wq.c-269-\nio_uring/io-wq.c:270:static inline bool __io_acct_run_queue(struct io_wq_acct acct)\nio_uring/io-wq.c-271-{\n--\nio_uring/io-wq.c-279- /\nio_uring/io-wq.c:280:static inline bool io_acct_run_queue(struct io_wq_acct acct)\nio_uring/io-wq.c-281-\t__acquires(\u0026acct-\u003elock)\n--\nio_uring/io-wq.c-294- /\nio_uring/io-wq.c:295:static bool io_acct_activate_free_worker(struct io_wq_acct acct)\nio_uring/io-wq.c-296-\t__must_hold(RCU)\n--\nio_uring/io-wq.c-325- /\nio_uring/io-wq.c:326:static bool io_wq_create_worker(struct io_wq wq, struct io_wq_acct acct)\nio_uring/io-wq.c-327-{\n--\nio_uring/io-wq.c-346-\nio_uring/io-wq.c:347:static void io_wq_inc_running(struct io_worker worker)\nio_uring/io-wq.c-348-{\nio_uring/io-wq.c:349:\tstruct io_wq_acct acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-350-\n--\nio_uring/io-wq.c=354=static void create_worker_cb(struct callback_head cb)\n--\nio_uring/io-wq.c-358-\nio_uring/io-wq.c:359:\tstruct io_wq_acct acct;\nio_uring/io-wq.c-360-\tbool activated_free_worker, do_create = false;\n--\nio_uring/io-wq.c=390=static bool io_queue_worker_create(struct io_worker worker,\nio_uring/io-wq.c:391:\t\t\t\t struct io_wq_acct acct,\nio_uring/io-wq.c-392-\t\t\t\t task_work_func_t func)\n--\nio_uring/io-wq.c-417-\t\t now set. wq exit does that too, but we can have added this\nio_uring/io-wq.c:418:\t\t * work item after we canceled in io_wq_exit_workers().\nio_uring/io-wq.c-419-\t\t /\nio_uring/io-wq.c-420-\t\tif (test_bit(IO_WQ_BIT_EXIT, \u0026wq-\u003estate))\nio_uring/io-wq.c:421:\t\t\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-422-\t\tio_worker_ref_put(wq);\n--\nio_uring/io-wq.c-435-/ Defer if current and next work are both hashed to the same chain /\nio_uring/io-wq.c:436:static bool io_wq_hash_defer(struct io_wq_work work, struct io_wq_acct acct)\nio_uring/io-wq.c-437-{\nio_uring/io-wq.c-438-\tunsigned int hash, work_flags;\nio_uring/io-wq.c:439:\tstruct io_wq_work next;\nio_uring/io-wq.c-440-\n--\nio_uring/io-wq.c-443-\twork_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:444:\tif (!__io_wq_is_hashed(work_flags))\nio_uring/io-wq.c-445-\t\treturn false;\n--\nio_uring/io-wq.c-451-\thash = __io_get_work_hash(work_flags);\nio_uring/io-wq.c:452:\tnext = container_of(acct-\u003ework_list.first, struct io_wq_work, list);\nio_uring/io-wq.c-453-\twork_flags = atomic_read(\u0026next-\u003eflags);\nio_uring/io-wq.c:454:\tif (!__io_wq_is_hashed(work_flags))\nio_uring/io-wq.c-455-\t\treturn false;\n--\nio_uring/io-wq.c-458-\nio_uring/io-wq.c:459:static void io_wq_dec_running(struct io_worker worker)\nio_uring/io-wq.c-460-{\nio_uring/io-wq.c:461:\tstruct io_wq_acct acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-462-\tstruct io_wq wq = worker-\u003ewq;\n--\nio_uring/io-wq.c-472-\t\treturn;\nio_uring/io-wq.c:473:\tif (io_wq_hash_defer(worker-\u003ecur_work, acct)) {\nio_uring/io-wq.c-474-\t\traw_spin_unlock(\u0026acct-\u003elock);\n--\nio_uring/io-wq.c-487- /\nio_uring/io-wq.c:488:static void __io_worker_busy(struct io_wq_acct acct, struct io_worker worker)\nio_uring/io-wq.c-489-{\n--\nio_uring/io-wq.c-500- /\nio_uring/io-wq.c:501:static void __io_worker_idle(struct io_wq_acct acct, struct io_worker worker)\nio_uring/io-wq.c-502-\t__must_hold(acct-\u003eworkers_lock)\n--\nio_uring/io-wq.c=510=static bool io_wait_on_hash(struct io_wq wq, unsigned int hash)\n--\nio_uring/io-wq.c-526-\nio_uring/io-wq.c:527:static struct io_wq_work io_get_next_work(struct io_wq_acct acct,\nio_uring/io-wq.c-528-\t\t\t\t\t struct io_wq wq)\n--\nio_uring/io-wq.c-530-{\nio_uring/io-wq.c:531:\tstruct io_wq_work_node node, prev;\nio_uring/io-wq.c:532:\tstruct io_wq_work work, tail;\nio_uring/io-wq.c-533-\tunsigned int stall_hash = -1U;\n--\nio_uring/io-wq.c-538-\nio_uring/io-wq.c:539:\t\twork = container_of(node, struct io_wq_work, list);\nio_uring/io-wq.c-540-\n--\nio_uring/io-wq.c-542-\t\twork_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:543:\t\tif (!__io_wq_is_hashed(work_flags)) {\nio_uring/io-wq.c-544-\t\t\twq_list_del(\u0026acct-\u003ework_list, node, prev);\n--\nio_uring/io-wq.c=585=static void io_assign_current_work(struct io_worker worker,\nio_uring/io-wq.c:586:\t\t\t\t struct io_wq_work work)\nio_uring/io-wq.c-587-{\n--\nio_uring/io-wq.c-600- /\nio_uring/io-wq.c:601:static void io_worker_handle_work(struct io_wq_acct acct,\nio_uring/io-wq.c-602-\t\t\t\t struct io_worker worker)\n--\nio_uring/io-wq.c-607-\tdo {\nio_uring/io-wq.c:608:\t\tstruct io_wq_work work;\nio_uring/io-wq.c-609-\n--\nio_uring/io-wq.c-643-\t\t\tbool do_kill = test_bit(IO_WQ_BIT_EXIT, \u0026wq-\u003estate);\nio_uring/io-wq.c:644:\t\t\tstruct io_wq_work next_hashed, linked;\nio_uring/io-wq.c-645-\t\t\tunsigned int work_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:646:\t\t\tunsigned int hash = __io_wq_is_hashed(work_flags)\nio_uring/io-wq.c-647-\t\t\t\t? __io_get_work_hash(work_flags)\n--\nio_uring/io-wq.c-654-\t\t\t\tatomic_or(IO_WQ_WORK_CANCEL, \u0026work-\u003eflags);\nio_uring/io-wq.c:655:\t\t\tio_wq_submit_work(work);\nio_uring/io-wq.c-656-\t\t\tio_assign_current_work(worker, NULL);\nio_uring/io-wq.c-657-\nio_uring/io-wq.c:658:\t\t\tlinked = io_wq_free_work(work);\nio_uring/io-wq.c-659-\t\t\twork = next_hashed;\nio_uring/io-wq.c:660:\t\t\tif (!work \u0026\u0026 linked \u0026\u0026 !io_wq_is_hashed(linked)) {\nio_uring/io-wq.c-661-\t\t\t\twork = linked;\n--\nio_uring/io-wq.c-665-\t\t\tif (linked)\nio_uring/io-wq.c:666:\t\t\t\tio_wq_enqueue(wq, linked);\nio_uring/io-wq.c-667-\n--\nio_uring/io-wq.c-684-\nio_uring/io-wq.c:685:static int io_wq_worker(void data)\nio_uring/io-wq.c-686-{\nio_uring/io-wq.c-687-\tstruct io_worker worker = data;\nio_uring/io-wq.c:688:\tstruct io_wq_acct acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-689-\tstruct io_wq wq = worker-\u003ewq;\n--\nio_uring/io-wq.c-755- /\nio_uring/io-wq.c:756:void io_wq_worker_running(struct task_struct tsk)\nio_uring/io-wq.c-757-{\n--\nio_uring/io-wq.c-766-\tset_bit(IO_WORKER_F_RUNNING, \u0026worker-\u003eflags);\nio_uring/io-wq.c:767:\tio_wq_inc_running(worker);\nio_uring/io-wq.c-768-}\n--\nio_uring/io-wq.c-773- /\nio_uring/io-wq.c:774:void io_wq_worker_sleeping(struct task_struct tsk)\nio_uring/io-wq.c-775-{\n--\nio_uring/io-wq.c-785-\tclear_bit(IO_WORKER_F_RUNNING, \u0026worker-\u003eflags);\nio_uring/io-wq.c:786:\tio_wq_dec_running(worker);\nio_uring/io-wq.c-787-}\nio_uring/io-wq.c-788-\nio_uring/io-wq.c:789:static void io_init_new_worker(struct io_wq wq, struct io_wq_acct acct, struct io_worker worker,\nio_uring/io-wq.c-790-\t\t\t struct task_struct tsk)\n--\nio_uring/io-wq.c-803-\nio_uring/io-wq.c:804:static bool io_wq_work_match_all(struct io_wq_work work, void data)\nio_uring/io-wq.c-805-{\n--\nio_uring/io-wq.c=844=static void create_worker_cont(struct callback_head cb)\n--\nio_uring/io-wq.c-848-\tstruct io_wq wq;\nio_uring/io-wq.c:849:\tstruct io_wq_acct acct;\nio_uring/io-wq.c-850-\n--\nio_uring/io-wq.c-853-\twq = worker-\u003ewq;\nio_uring/io-wq.c:854:\tacct = io_wq_get_acct(worker);\nio_uring/io-wq.c:855:\ttsk = create_io_thread(io_wq_worker, worker, NUMA_NO_NODE);\nio_uring/io-wq.c-856-\tif (!IS_ERR(tsk)) {\n--\nio_uring/io-wq.c-865-\t\t\tstruct io_cb_cancel_data match = {\nio_uring/io-wq.c:866:\t\t\t\t.fn\t\t= io_wq_work_match_all,\nio_uring/io-wq.c-867-\t\t\t\t.cancel_all\t= true,\n--\nio_uring/io-wq.c=886=static void io_workqueue_create(struct work_struct work)\n--\nio_uring/io-wq.c-889-\t\t\t\t\t\twork.work);\nio_uring/io-wq.c:890:\tstruct io_wq_acct acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-891-\n--\nio_uring/io-wq.c-895-\nio_uring/io-wq.c:896:static bool create_io_worker(struct io_wq wq, struct io_wq_acct acct)\nio_uring/io-wq.c-897-{\n--\nio_uring/io-wq.c-919-\nio_uring/io-wq.c:920:\ttsk = create_io_thread(io_wq_worker, worker, NUMA_NO_NODE);\nio_uring/io-wq.c-921-\tif (!IS_ERR(tsk)) {\n--\nio_uring/io-wq.c-937- /\nio_uring/io-wq.c:938:static bool io_acct_for_each_worker(struct io_wq_acct acct,\nio_uring/io-wq.c-939-\t\t\t\t bool (func)(struct io_worker , void ),\n--\nio_uring/io-wq.c-958-\nio_uring/io-wq.c:959:static void io_wq_for_each_worker(struct io_wq wq,\nio_uring/io-wq.c-960-\t\t\t\t bool (func)(struct io_worker , void ),\n--\nio_uring/io-wq.c-967-\nio_uring/io-wq.c:968:static bool io_wq_worker_wake(struct io_worker worker, void data)\nio_uring/io-wq.c-969-{\n--\nio_uring/io-wq.c-974-\nio_uring/io-wq.c:975:void io_wq_set_exit_on_idle(struct io_wq wq, bool enable)\nio_uring/io-wq.c-976-{\n--\nio_uring/io-wq.c-988-\trcu_read_lock();\nio_uring/io-wq.c:989:\tio_wq_for_each_worker(wq, io_wq_worker_wake, NULL);\nio_uring/io-wq.c-990-\trcu_read_unlock();\n--\nio_uring/io-wq.c-992-\nio_uring/io-wq.c:993:static void io_run_cancel(struct io_wq_work work, struct io_wq wq)\nio_uring/io-wq.c-994-{\n--\nio_uring/io-wq.c-996-\t\tatomic_or(IO_WQ_WORK_CANCEL, \u0026work-\u003eflags);\nio_uring/io-wq.c:997:\t\tio_wq_submit_work(work);\nio_uring/io-wq.c:998:\t\twork = io_wq_free_work(work);\nio_uring/io-wq.c-999-\t} while (work);\n--\nio_uring/io-wq.c-1001-\nio_uring/io-wq.c:1002:static void io_wq_insert_work(struct io_wq wq, struct io_wq_acct acct,\nio_uring/io-wq.c:1003:\t\t\t struct io_wq_work work, unsigned int work_flags)\nio_uring/io-wq.c-1004-{\nio_uring/io-wq.c-1005-\tunsigned int hash;\nio_uring/io-wq.c:1006:\tstruct io_wq_work tail;\nio_uring/io-wq.c-1007-\nio_uring/io-wq.c:1008:\tif (!__io_wq_is_hashed(work_flags)) {\nio_uring/io-wq.c-1009-append:\n--\nio_uring/io-wq.c-1022-\nio_uring/io-wq.c:1023:static bool io_wq_work_match_item(struct io_wq_work work, void data)\nio_uring/io-wq.c-1024-{\n--\nio_uring/io-wq.c-1027-\nio_uring/io-wq.c:1028:void io_wq_enqueue(struct io_wq wq, struct io_wq_work work)\nio_uring/io-wq.c-1029-{\nio_uring/io-wq.c-1030-\tunsigned int work_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:1031:\tstruct io_wq_acct acct = io_work_get_acct(wq, work_flags);\nio_uring/io-wq.c-1032-\tstruct io_cb_cancel_data match = {\nio_uring/io-wq.c:1033:\t\t.fn\t\t= io_wq_work_match_item,\nio_uring/io-wq.c-1034-\t\t.data\t\t= work,\n--\nio_uring/io-wq.c-1049-\traw_spin_lock(\u0026acct-\u003elock);\nio_uring/io-wq.c:1050:\tio_wq_insert_work(wq, acct, work, work_flags);\nio_uring/io-wq.c-1051-\tclear_bit(IO_ACCT_STALLED_BIT, \u0026acct-\u003eflags);\n--\nio_uring/io-wq.c-1061-\nio_uring/io-wq.c:1062:\t\tdid_create = io_wq_create_worker(wq, acct);\nio_uring/io-wq.c-1063-\t\tif (likely(did_create))\n--\nio_uring/io-wq.c-1081- /\nio_uring/io-wq.c:1082:void io_wq_hash_work(struct io_wq_work work, void val)\nio_uring/io-wq.c-1083-{\n--\nio_uring/io-wq.c-1089-\nio_uring/io-wq.c:1090:static bool __io_wq_worker_cancel(struct io_worker worker,\nio_uring/io-wq.c-1091-\t\t\t\t struct io_cb_cancel_data match,\nio_uring/io-wq.c:1092:\t\t\t\t struct io_wq_work work)\nio_uring/io-wq.c-1093-{\n--\nio_uring/io-wq.c-1102-\nio_uring/io-wq.c:1103:static bool io_wq_worker_cancel(struct io_worker worker, void data)\nio_uring/io-wq.c-1104-{\n--\nio_uring/io-wq.c-1111-\traw_spin_lock(\u0026worker-\u003elock);\nio_uring/io-wq.c:1112:\tif (__io_wq_worker_cancel(worker, match, worker-\u003ecur_work))\nio_uring/io-wq.c-1113-\t\tmatch-\u003enr_running++;\n--\nio_uring/io-wq.c-1118-\nio_uring/io-wq.c:1119:static inline void io_wq_remove_pending(struct io_wq wq,\nio_uring/io-wq.c:1120:\t\t\t\t\tstruct io_wq_acct acct,\nio_uring/io-wq.c:1121:\t\t\t\t\t struct io_wq_work work,\nio_uring/io-wq.c:1122:\t\t\t\t\t struct io_wq_work_node prev)\nio_uring/io-wq.c-1123-{\nio_uring/io-wq.c-1124-\tunsigned int hash = io_get_work_hash(work);\nio_uring/io-wq.c:1125:\tstruct io_wq_work prev_work = NULL;\nio_uring/io-wq.c-1126-\nio_uring/io-wq.c:1127:\tif (io_wq_is_hashed(work) \u0026\u0026 work == wq-\u003ehash_tail[hash]) {\nio_uring/io-wq.c-1128-\t\tif (prev)\nio_uring/io-wq.c:1129:\t\t\tprev_work = container_of(prev, struct io_wq_work, list);\nio_uring/io-wq.c:1130:\t\tif (prev_work \u0026\u0026 io_wq_is_hashed(prev_work) \u0026\u0026\nio_uring/io-wq.c-1131-\t\t io_get_work_hash(prev_work) == hash)\n--\nio_uring/io-wq.c=1139=static bool io_acct_cancel_pending_work(struct io_wq wq,\nio_uring/io-wq.c:1140:\t\t\t\t\tstruct io_wq_acct acct,\nio_uring/io-wq.c-1141-\t\t\t\t\tstruct io_cb_cancel_data match)\nio_uring/io-wq.c-1142-{\nio_uring/io-wq.c:1143:\tstruct io_wq_work_node node, prev;\nio_uring/io-wq.c:1144:\tstruct io_wq_work work;\nio_uring/io-wq.c-1145-\n--\nio_uring/io-wq.c-1147-\twq_list_for_each(node, prev, \u0026acct-\u003ework_list) {\nio_uring/io-wq.c:1148:\t\twork = container_of(node, struct io_wq_work, list);\nio_uring/io-wq.c-1149-\t\tif (!match-\u003efn(work, match-\u003edata))\nio_uring/io-wq.c-1150-\t\t\tcontinue;\nio_uring/io-wq.c:1151:\t\tio_wq_remove_pending(wq, acct, work, prev);\nio_uring/io-wq.c-1152-\t\traw_spin_unlock(\u0026acct-\u003elock);\n--\nio_uring/io-wq.c-1162-\nio_uring/io-wq.c:1163:static void io_wq_cancel_pending_work(struct io_wq wq,\nio_uring/io-wq.c-1164-\t\t\t\t struct io_cb_cancel_data match)\n--\nio_uring/io-wq.c-1168-\tfor (i = 0; i \u003c IO_WQ_ACCT_NR; i++) {\nio_uring/io-wq.c:1169:\t\tstruct io_wq_acct acct = io_get_acct(wq, i == 0);\nio_uring/io-wq.c-1170-\n--\nio_uring/io-wq.c-1178-\nio_uring/io-wq.c:1179:static void io_acct_cancel_running_work(struct io_wq_acct acct,\nio_uring/io-wq.c-1180-\t\t\t\t\tstruct io_cb_cancel_data match)\n--\nio_uring/io-wq.c-1182-\traw_spin_lock(\u0026acct-\u003eworkers_lock);\nio_uring/io-wq.c:1183:\tio_acct_for_each_worker(acct, io_wq_worker_cancel, match);\nio_uring/io-wq.c-1184-\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\n--\nio_uring/io-wq.c-1186-\nio_uring/io-wq.c:1187:static void io_wq_cancel_running_work(struct io_wq wq,\nio_uring/io-wq.c-1188-\t\t\t\t struct io_cb_cancel_data match)\n--\nio_uring/io-wq.c-1197-\nio_uring/io-wq.c:1198:enum io_wq_cancel io_wq_cancel_cb(struct io_wq wq, work_cancel_fn cancel,\nio_uring/io-wq.c-1199-\t\t\t\t void data, bool cancel_all)\n--\nio_uring/io-wq.c-1219-\t /\nio_uring/io-wq.c:1220:\tio_wq_cancel_pending_work(wq, \u0026match);\nio_uring/io-wq.c-1221-\tif (match.nr_pending \u0026\u0026 !match.cancel_all)\n--\nio_uring/io-wq.c-1223-\nio_uring/io-wq.c:1224:\tio_wq_cancel_running_work(wq, \u0026match);\nio_uring/io-wq.c-1225-\tif (match.nr_running \u0026\u0026 !match.cancel_all)\n--\nio_uring/io-wq.c-1234-\nio_uring/io-wq.c:1235:static int io_wq_hash_wake(struct wait_queue_entry wait, unsigned mode,\nio_uring/io-wq.c-1236-\t\t\t int sync, void key)\n--\nio_uring/io-wq.c-1244-\tfor (i = 0; i \u003c IO_WQ_ACCT_NR; i++) {\nio_uring/io-wq.c:1245:\t\tstruct io_wq_acct acct = \u0026wq-\u003eacct[i];\nio_uring/io-wq.c-1246-\n--\nio_uring/io-wq.c-1253-\nio_uring/io-wq.c:1254:struct io_wq io_wq_create(unsigned bounded, struct io_wq_data data)\nio_uring/io-wq.c-1255-{\n--\nio_uring/io-wq.c-1277-\tINIT_LIST_HEAD(\u0026wq-\u003ewait.entry);\nio_uring/io-wq.c:1278:\twq-\u003ewait.func = io_wq_hash_wake;\nio_uring/io-wq.c-1279-\tfor (i = 0; i \u003c IO_WQ_ACCT_NR; i++) {\nio_uring/io-wq.c:1280:\t\tstruct io_wq_acct acct = \u0026wq-\u003eacct[i];\nio_uring/io-wq.c-1281-\n--\nio_uring/io-wq.c-1294-\tinit_completion(\u0026wq-\u003eworker_done);\nio_uring/io-wq.c:1295:\tret = cpuhp_state_add_instance_nocalls(io_wq_online, \u0026wq-\u003ecpuhp_node);\nio_uring/io-wq.c-1296-\tif (ret) {\n--\nio_uring/io-wq.c-1302-err:\nio_uring/io-wq.c:1303:\tio_wq_put_hash(data-\u003ehash);\nio_uring/io-wq.c-1304-\tfree_cpumask_var(wq-\u003ecpu_mask);\n--\nio_uring/io-wq.c=1309=static bool io_task_work_match(struct callback_head cb, void data)\n--\nio_uring/io-wq.c-1318-\nio_uring/io-wq.c:1319:void io_wq_exit_start(struct io_wq wq)\nio_uring/io-wq.c-1320-{\n--\nio_uring/io-wq.c-1323-\nio_uring/io-wq.c:1324:static void io_wq_cancel_tw_create(struct io_wq wq)\nio_uring/io-wq.c-1325-{\n--\nio_uring/io-wq.c-1341-\nio_uring/io-wq.c:1342:static void io_wq_exit_workers(struct io_wq wq)\nio_uring/io-wq.c-1343-{\n--\nio_uring/io-wq.c-1348-\nio_uring/io-wq.c:1349:\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-1350-\nio_uring/io-wq.c-1351-\trcu_read_lock();\nio_uring/io-wq.c:1352:\tio_wq_for_each_worker(wq, io_wq_worker_wake, NULL);\nio_uring/io-wq.c-1353-\trcu_read_unlock();\n--\nio_uring/io-wq.c-1383-\nio_uring/io-wq.c:1384:static void io_wq_destroy(struct io_wq wq)\nio_uring/io-wq.c-1385-{\nio_uring/io-wq.c-1386-\tstruct io_cb_cancel_data match = {\nio_uring/io-wq.c:1387:\t\t.fn\t\t= io_wq_work_match_all,\nio_uring/io-wq.c-1388-\t\t.cancel_all\t= true,\n--\nio_uring/io-wq.c-1390-\nio_uring/io-wq.c:1391:\tcpuhp_state_remove_instance_nocalls(io_wq_online, \u0026wq-\u003ecpuhp_node);\nio_uring/io-wq.c:1392:\tio_wq_cancel_pending_work(wq, \u0026match);\nio_uring/io-wq.c-1393-\tfree_cpumask_var(wq-\u003ecpu_mask);\nio_uring/io-wq.c:1394:\tio_wq_put_hash(wq-\u003ehash);\nio_uring/io-wq.c-1395-\tkfree(wq);\n--\nio_uring/io-wq.c-1397-\nio_uring/io-wq.c:1398:void io_wq_put_and_exit(struct io_wq wq)\nio_uring/io-wq.c-1399-{\n--\nio_uring/io-wq.c-1401-\nio_uring/io-wq.c:1402:\tio_wq_exit_workers(wq);\nio_uring/io-wq.c:1403:\tio_wq_destroy(wq);\nio_uring/io-wq.c-1404-}\n--\nio_uring/io-wq.c=1406=struct online_data {\n--\nio_uring/io-wq.c-1410-\nio_uring/io-wq.c:1411:static bool io_wq_worker_affinity(struct io_worker worker, void data)\nio_uring/io-wq.c-1412-{\n--\nio_uring/io-wq.c-1421-\nio_uring/io-wq.c:1422:static int __io_wq_cpu_online(struct io_wq wq, unsigned int cpu, bool online)\nio_uring/io-wq.c-1423-{\n--\nio_uring/io-wq.c-1429-\trcu_read_lock();\nio_uring/io-wq.c:1430:\tio_wq_for_each_worker(wq, io_wq_worker_affinity, \u0026od);\nio_uring/io-wq.c-1431-\trcu_read_unlock();\n--\nio_uring/io-wq.c-1434-\nio_uring/io-wq.c:1435:static int io_wq_cpu_online(unsigned int cpu, struct hlist_node node)\nio_uring/io-wq.c-1436-{\n--\n\n" }
17/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 17254 output: 28 thoughts: 97 Thoughts: Analyzing the IO-WQ Infrastructure Okay, let's dive into this `io_wq` business. My initial focus is on understanding the core lifecycle – specifically, `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, and `io_wq_cancel_cb`. I'm starting by zeroing in on `io_wq_cancel_cb`. The fact that it's not a static function is significant, immediately implying it's designed for external interaction or perhaps a module's use. Now, let's shift gears slightly and consider configuration. Are there any relevant config options impacting this? I need to know under what circumstances this code is even built. The filename `io_uring/io-wq.c` is suggestive – my immediate assumption is that it's compiled when `CONFIG_IO_URING` is set. To be certain, I'll quickly check the `io_uring/Makefile` to confirm that dependency. This information is key to understanding the scope of its use and its role within the larger IO_URING ecosystem.
18/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io-wq", "PathPrefix": "io_uring/Makefile" } Results: { "Output": "io_uring/Makefile=19=obj-$(CONFIG_IO_URING_ZCRX)\t+= zcrx.o\nio_uring/Makefile:20:obj-$(CONFIG_IO_WQ)\t\t+= io-wq.o\nio_uring/Makefile-21-obj-$(CONFIG_FUTEX)\t\t+= futex.o\n" }
19/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 17709 output: 24 thoughts: 39 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience: Investigating the IO Workqueue Configuration Right, let's see. My mental map immediately suggests that the key configuration option here is likely `CONFIG_IO_WQ`. Given what I'm dealing with, the context points towards something related to I/O workqueues, which is pretty self-explanatory. Now, I need to pinpoint the exact location for this configuration. Given the typical kernel build system structure, `init/Kconfig` is always a good starting point for general system options. However, since the prompt specified `IO_URING`, I would lean toward checking `io_uring/Kconfig` for the configuration option `CONFIG_IO_WQ`. The module structure should provide more detailed information on specific feature settings. The location of the configuration option will provide insight into the context and dependencies of the IO workqueue implementation. Time to dive into those Kconfig files and see what they reveal.
20/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "config IO_WQ", "PathPrefix": "" } Results: { "Output": "fs/Kconfig=421=source \"fs/unicode/Kconfig\"\nfs/Kconfig-422-\nfs/Kconfig:423:config IO_WQ\nfs/Kconfig-424-\tbool\n" }
21/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 18045 output: 24 thoughts: 17 Thoughts: Okay, here's my interpretation of that thought process, tailored for an expert audience, and presented as if it were my own internal monologue: Investigating the `IO_WQ` Boolean Alright, so `IO_WQ` is a boolean, and my immediate instinct is to figure out its selection criteria. What conditions or code paths actually set this flag? It's a key piece of state, so understanding its origins is critical for debugging or optimizing anything related to it. I need to trace back through the code and pinpoint precisely where this boolean is toggled. Are we dealing with a global flag, a per-object attribute, or something more context-dependent? The goal is to build a mental map of its lifecycle so I can anticipate how it behaves and why it might be in a particular state at any given point. Let's dig in and find those write operations.
22/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "select IO_WQ", "PathPrefix": "" } Results: { "Output": "init/Kconfig=1918=config IO_URING\ninit/Kconfig-1919-\tbool \"Enable IO uring support\" if EXPERT\ninit/Kconfig:1920:\tselect IO_WQ\ninit/Kconfig-1921-\tdefault y\n" }
23/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 18353 output: 28 thoughts: 35 Thoughts: Okay, here's my interpretation of those thoughts, crafted with the expectation that I'm discussing this with a fellow expert: IO_URING and IO_WQ: A Quick Scan Alright, the core concept I'm working with is `IO_URING` selecting `IO_WQ`. My immediate thought is, "Okay, let's get `IO_URING` activated, that's step one." But before I dive into the implementation, a good practice is to understand the surrounding ecosystem. I need to quickly identify any direct dependencies `IO_WQ` may have. Are there any prerequisites I need to handle first? Any potential conflicts to be aware of? Best to get that lay of the land now, before I waste time making a configuration and finding out later that I need to tweak it due to an unforeseen dependency issue.
24/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "config IO_WQ", "PathPrefix": "fs/Kconfig" } Results: { "Output": "fs/Kconfig=421=source \"fs/unicode/Kconfig\"\nfs/Kconfig-422-\nfs/Kconfig:423:config IO_WQ\nfs/Kconfig-424-\tbool\n" }
25/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 18658 output: 27 thoughts: 267 Thoughts: Debugging the IO_URING Boolean Okay, so it looks like we're dealing with a simple `bool` issue here, meaning `IO_URING` is the flag to focus on. I need to refresh my memory on the key symbols involved in this area. Let's see... I've got `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, and `io_wq_cancel_cb`. Aha! Now I remember, the bug must be lurking within `io_worker_cancel_cb`. This is called from `io_worker_exit` and `io_wq_cancel_tw_create`, right? And `io_wq_cancel_tw_create` in turn is called from `io_wq_exit_workers` and `io_queue_worker_create`. Okay, this is starting to make more sense. `io_queue_worker_create` gets called from both `io_wq_dec_running` and `io_wq_create_worker`, which in turn is called from `io_wq_enqueue`. And we're seeing that `io_wq_dec_running` is called from `io_worker_exit` and `io_wq_worker_sleeping`. Now I'm getting a little confused: `io_wq_worker_sleeping` is called from `io_wq_worker`? No, wait a minute... it looks like it's the scheduler that calls `io_wq_worker_sleeping`. I should double-check that part and start digging into the details of the call to `io_wq_worker_sleeping` to confirm the cause of the issue.
26/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_worker_sleeping", "PathPrefix": "" } Results: { "Output": "io_uring/io-wq.c=756=void io_wq_worker_running(struct task_struct tsk)\n--\nio_uring/io-wq.c-773- /\nio_uring/io-wq.c:774:void io_wq_worker_sleeping(struct task_struct tsk)\nio_uring/io-wq.c-775-{\n--\nio_uring/io-wq.h=66=enum io_wq_cancel io_wq_cancel_cb(struct io_wq wq, work_cancel_fn cancel,\n--\nio_uring/io-wq.h-69-#if defined(CONFIG_IO_WQ)\nio_uring/io-wq.h:70:extern void io_wq_worker_sleeping(struct task_struct );\nio_uring/io-wq.h-71-extern void io_wq_worker_running(struct task_struct );\nio_uring/io-wq.h-72-#else\nio_uring/io-wq.h:73:static inline void io_wq_worker_sleeping(struct task_struct tsk)\nio_uring/io-wq.h-74-{\n--\nkernel/sched/core.c=7260=static inline void sched_submit_work(struct task_struct *tsk)\n--\nkernel/sched/core.c-7278-\telse if (task_flags \u0026 PF_IO_WORKER)\nkernel/sched/core.c:7279:\t\tio_wq_worker_sleeping(tsk);\nkernel/sched/core.c-7280-\n" }
27/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 19713 output: 31 thoughts: 84 Thoughts: Okay, here's my take on those thoughts, framed as my own mental processing: Pinpointing the Key Players in I/O Workqueue Sleep/Wake-up Right, so `io_wq_worker_sleeping` is triggered by the scheduler itself. That's the crucial hint. This tells me that I need to zoom in on the functions that control workqueue creation, destruction, and task enqueueing and canceling. Let's see... the primary suspects are: `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, and `io_wq_cancel_cb`. Those seem like the logical places to start digging deeper to understand the sleep/wakeup mechanism from this vantage point. Now, is `io_wq_cancel_cb` really a useful focal point in this investigation? Gotta figure out if it's got a strong connection to the process- let's see.
28/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_cancel_cb", "PathPrefix": "io_uring/" } Results: { "Output": "io_uring/cancel.c=78=static int io_async_cancel_one(struct io_uring_task tctx,\n--\nio_uring/cancel.c-88-\tall = cd-\u003eflags \u0026 (IORING_ASYNC_CANCEL_ALL\|IORING_ASYNC_CANCEL_ANY);\nio_uring/cancel.c:89:\tcancel_ret = io_wq_cancel_cb(tctx-\u003eio_wq, io_cancel_cb, cd, all);\nio_uring/cancel.c-90-\tswitch (cancel_ret) {\n--\nio_uring/cancel.c=489=static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx ctx)\n--\nio_uring/cancel.c-505-\t\t\tcontinue;\nio_uring/cancel.c:506:\t\tcret = io_wq_cancel_cb(tctx-\u003eio_wq, io_cancel_ctx_cb, ctx, true);\nio_uring/cancel.c-507-\t\tret \|= (cret != IO_WQ_CANCEL_NOTFOUND);\n--\nio_uring/cancel.c=515=__cold bool io_uring_try_cancel_requests(struct io_ring_ctx ctx,\n--\nio_uring/cancel.c-539-\t\t /\nio_uring/cancel.c:540:\t\tcret = io_wq_cancel_cb(tctx-\u003eio_wq, io_cancel_task_cb,\nio_uring/cancel.c-541-\t\t\t\t \u0026cancel, true);\n--\nio_uring/io-wq.c=1187=static void io_wq_cancel_running_work(struct io_wq wq,\n--\nio_uring/io-wq.c-1197-\nio_uring/io-wq.c:1198:enum io_wq_cancel io_wq_cancel_cb(struct io_wq wq, work_cancel_fn cancel,\nio_uring/io-wq.c-1199-\t\t\t\t void data, bool cancel_all)\n--\nio_uring/io-wq.h=64=typedef bool (work_cancel_fn)(struct io_wq_work , void );\nio_uring/io-wq.h-65-\nio_uring/io-wq.h:66:enum io_wq_cancel io_wq_cancel_cb(struct io_wq wq, work_cancel_fn cancel,\nio_uring/io-wq.h-67-\t\t\t\t\tvoid data, bool cancel_all);\n--\nio_uring/io_uring.c=2318=static __cold void io_ring_exit_work(struct work_struct work)\n--\nio_uring/io_uring.c-2357-\t\t\tif (tsk \u0026\u0026 tsk-\u003eio_uring \u0026\u0026 tsk-\u003eio_uring-\u003eio_wq)\nio_uring/io_uring.c:2358:\t\t\t\tio_wq_cancel_cb(tsk-\u003eio_uring-\u003eio_wq,\nio_uring/io_uring.c-2359-\t\t\t\t\t\tio_cancel_ctx_cb, ctx, true);\n" }
29/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 20802 output: 29 thoughts: 66 Thoughts: Okay, let's see, my mental gears are turning... Tracking Down Callers and Understanding Control Flow Right, so `io_wq_cancel_cb`... I recall that this callback is definitely triggered from a few key places. It's called by `io_async_cancel_one`, which makes sense for handling asynchronous cancellation, and also by `io_uring_try_cancel_requests` which is related to I/O ring cancellation attempts, and finally by `io_ring_exit_work` which is part of the clean up process. That makes it a solid focus for my analysis. Those three paths make it fairly central to I/O management. Hmm, now let me consider... what about `io_wq_create`? Where does that fit in? I should probably review the places that call that function too...
30/2	2026/08/11 07:23	tool	grepper	0m Args: { "Expression": "io_wq_create", "PathPrefix": "io_uring/" } Results: { "Output": "io_uring/io-wq.c=295=static bool io_acct_activate_free_worker(struct io_wq_acct acct)\n--\nio_uring/io-wq.c-325- /\nio_uring/io-wq.c:326:static bool io_wq_create_worker(struct io_wq wq, struct io_wq_acct acct)\nio_uring/io-wq.c-327-{\n--\nio_uring/io-wq.c=1028=void io_wq_enqueue(struct io_wq wq, struct io_wq_work work)\n--\nio_uring/io-wq.c-1061-\nio_uring/io-wq.c:1062:\t\tdid_create = io_wq_create_worker(wq, acct);\nio_uring/io-wq.c-1063-\t\tif (likely(did_create))\n--\nio_uring/io-wq.c=1235=static int io_wq_hash_wake(struct wait_queue_entry wait, unsigned mode,\n--\nio_uring/io-wq.c-1253-\nio_uring/io-wq.c:1254:struct io_wq io_wq_create(unsigned bounded, struct io_wq_data data)\nio_uring/io-wq.c-1255-{\n--\nio_uring/io-wq.h=37=struct io_wq_data {\n--\nio_uring/io-wq.h-41-\nio_uring/io-wq.h:42:struct io_wq io_wq_create(unsigned bounded, struct io_wq_data data);\nio_uring/io-wq.h-43-void io_wq_exit_start(struct io_wq wq);\n--\nio_uring/tctx.c=16=static struct io_wq io_init_wq_offload(struct io_ring_ctx ctx,\n--\nio_uring/tctx.c-42-\nio_uring/tctx.c:43:\treturn io_wq_create(concurrency, \u0026data);\nio_uring/tctx.c-44-}\n" }
31/2	2026/08/11 07:23	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 21637 output: 33 thoughts: 61 Thoughts: Here's my take on the thought process, as requested: Diving into the IO_uring Workqueue Landscape Okay, so I'm digging into this `io_uring` code, and I need to pinpoint the critical areas, especially regarding the workqueues. `io_wq_create` is the function that jumps out. I see it's called directly from `io_init_wq_offload` within `io_uring/tctx.c`. That makes `io_wq_create` a good symbol to concentrate on first. Hmm, while I'm at it, I should consider the complementary function to `io_wq_create`. The name `io_wq_put_and_exit` catches my eye. Is it the key to cleanup and teardown? It's probably worth adding that to my mental map of the core workqueue operations.
32/2	2026/08/11 07:24	tool	grepper	0m Args: { "Expression": "io_wq_put_and_exit", "PathPrefix": "io_uring/" } Results: { "Output": "io_uring/io-wq.c=1384=static void io_wq_destroy(struct io_wq wq)\n--\nio_uring/io-wq.c-1397-\nio_uring/io-wq.c:1398:void io_wq_put_and_exit(struct io_wq wq)\nio_uring/io-wq.c-1399-{\n--\nio_uring/io-wq.h=43=void io_wq_exit_start(struct io_wq wq);\nio_uring/io-wq.h:44:void io_wq_put_and_exit(struct io_wq wq);\nio_uring/io-wq.h-45-void io_wq_set_exit_on_idle(struct io_wq wq, bool enable);\n--\nio_uring/tctx.c=145=int __io_uring_add_tctx_node(struct io_ring_ctx ctx)\n--\nio_uring/tctx.c-189-\t\t\tio_wq_exit_start(tctx-\u003eio_wq);\nio_uring/tctx.c:190:\t\t\tio_wq_put_and_exit(tctx-\u003eio_wq);\nio_uring/tctx.c-191-\t\t}\n--\nio_uring/tctx.c=243=__cold void io_uring_clean_tctx(struct io_uring_task tctx)\n--\nio_uring/tctx.c-257-\t\t /\nio_uring/tctx.c:258:\t\tio_wq_put_and_exit(wq);\nio_uring/tctx.c-259-\t\ttctx-\u003eio_wq = NULL;\n" }
33/2	2026/08/11 07:24	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 22357 output: 29 thoughts: 30 Thoughts: Okay, here's my take on those thoughts, framed as an expert's internal monologue: Focusing on IO Completion Queues Alright, yep, `io_wq_put_and_exit` seems like a solid candidate for my initial focus. It's a key point in the lifecycle, handling the "cleanup on exit" aspect which is always critical. I've got a decent understanding of how it fits in at the moment. Hmm, but what about `io_wq_enqueue`? Thinking about it a bit, I'm already aware that enqueueing is probably a relevant area to examine, because a bottleneck or issue there could ripple throughout the entire system. It’s where work gets injected, so any inefficiencies are going to propagate. Maybe I should consider that as well.
34/2	2026/08/11 07:24	tool	grepper	0m Args: { "Expression": "io_wq_enqueue", "PathPrefix": "io_uring/" } Results: { "Output": "io_uring/io-wq.c=601=static void io_worker_handle_work(struct io_wq_acct acct,\n--\nio_uring/io-wq.c-665-\t\t\tif (linked)\nio_uring/io-wq.c:666:\t\t\t\tio_wq_enqueue(wq, linked);\nio_uring/io-wq.c-667-\n--\nio_uring/io-wq.c=1023=static bool io_wq_work_match_item(struct io_wq_work work, void data)\n--\nio_uring/io-wq.c-1027-\nio_uring/io-wq.c:1028:void io_wq_enqueue(struct io_wq wq, struct io_wq_work work)\nio_uring/io-wq.c-1029-{\n--\nio_uring/io-wq.h=45=void io_wq_set_exit_on_idle(struct io_wq wq, bool enable);\nio_uring/io-wq.h-46-\nio_uring/io-wq.h:47:void io_wq_enqueue(struct io_wq wq, struct io_wq_work work);\nio_uring/io-wq.h-48-void io_wq_hash_work(struct io_wq_work work, void val);\n--\nio_uring/io_uring.c=408=static void io_queue_iowq(struct io_kiocb *req)\n--\nio_uring/io_uring.c-432-\ttrace_io_uring_queue_async_work(req, io_wq_is_hashed(\u0026req-\u003ework));\nio_uring/io_uring.c:433:\tio_wq_enqueue(tctx-\u003eio_wq, \u0026req-\u003ework);\nio_uring/io_uring.c-434-}\n" }
35/2	2026/08/11 07:24	llm	patch-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 23067 output: 164 thoughts: 295 Thoughts: My Analysis of the io_uring Worker Cancellation Patch Okay, after reviewing the patch and its context, I've zeroed in on `io_wq_enqueue` as a key symbol for focused fuzzing – seems like a good starting point. Expanding on that, the other functions to keep an eye on are `io_wq_create`, `io_wq_put_and_exit`, and `io_wq_cancel_cb`. Those, along with `io_wq_enqueue`, will give me a solid coverage of the relevant components. Now, let's confirm the configuration. It looks like the main configuration option controlling this area is `IO_URING`. Double-checking...yes, `CONFIG_IO_URING` is defined in `init/Kconfig`. Wait, hold on... it appears that `CONFIG_IO_WQ` is automatically selected by `CONFIG_IO_URING`. Excellent, that simplifies things – just `IO_URING` is sufficient to enable the code paths I need to target. I need to articulate the reasoning behind this selection, for my own record and to clarify the rationale for fuzzing. The patch is specifically modifying `io_worker_cancel_cb` within `io_uring/io-wq.c`. The change conditional decrements `acct->nr_workers` in the function only when a very specific condition is met, namely `worker->create_work.func != create_worker_cb`. This is fixing a bug related to io_uring worker cancellation, where the worker slot wasn't properly reserved. This is a functional change in the core io_uring logic. I think that it's worth fuzzing given that it's in a reachable code path. So, to summarize: * Focus Symbols: `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, `io_wq_cancel_cb` * Enable Configs: `IO_URING` I'm ready to proceed with setting up the fuzzing environment and targeting these components now.
36/2	2026/08/11 07:24	tool	set-results	0m Args: { "EnableConfigs": [ "IO_URING" ], "FocusSymbols": [ "io_wq_create", "io_wq_put_and_exit", "io_wq_enqueue", "io_wq_cancel_cb" ], "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "IO_URING" ], "FocusSymbols": [ "io_wq_create", "io_wq_put_and_exit", "io_wq_enqueue", "io_wq_cancel_cb" ], "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.", "WorthFuzzing": true }
37/1	2026/08/11 07:24	action	If	0m Args: { "WorthFuzzing": true } Results: null
38/2	2026/08/11 07:24	agent	kmsan-evaluator	0m Model: best-expensive Args: null Results: { "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.", "NeedsKMSAN": false } Instruction: You are an expert Linux kernel security engineer specializing in kernel memory error detectors (KASAN and KMSAN). Your job is to review the provided patch series and determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer) fuzzing session in addition to standard KASAN fuzzing. CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN: - Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable a comprehensive suite of debugging tools and sanitizers, including KASAN (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks. - KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap, or page allocations) and kernel-to-user memory info-leaks. Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN, LOCKDEP, OR OTHER STANDARD BUG DETECTORS. A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks that are detected ONLY by KMSAN. Look holistically at the patch series and surrounding code. Even if no direct uninitialized field accesses or new buffer allocations are added in the diff itself, a patch may alter control flow, bounds checking, or data length calculations in ways that change how the rest of the code operates on existing buffers (e.g. allowing uninitialized stack/heap memory to be read, copied to user space, or used in control flow). Do not hesitate to use your code access tools to inspect the surrounding code, called functions, and callers. Set NeedsKMSAN=true ONLY IF the patch introduces or modifies: 1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb attributes, ioctl output arguments, socket options, or BPF buffers) where fields or structure padding might not be fully initialized/zeroed. 2. Conditional logic or branching that depends on potentially uninitialized variables or struct fields. 3. Allocation or initialization of complex data structures where uninitialized fields could be read later in reachable code paths. 4. Bounds checks, lengths, or logic in a way that allows surrounding code to access uninitialized bytes of existing buffers. Set NeedsKMSAN=false IF: - The code changes primarily risk out-of-bounds access, array overflows, NULL pointer dereferences, locking deadlocks, or use-after-free bugs (these are already caught by KASAN, LOCKDEP, or standard bug detectors). - All stack/heap structures touched or introduced by the patch are fully zeroed or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied. - The patch does not introduce any risk of uninitialized memory usage or info-leaks. Use your code access tools to inspect the surrounding code if necessary, then provide detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch. Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: For your convenience, here is the diff of the changes: commit 2ecaa2a619cf9c377d20a4f876432c84e3d16065 Author: syz-cluster <triage@syzkaller.com> Date: Tue Aug 11 07:22:49 2026 +0000 syz-cluster: applied patch under review diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c index 2e14880eef92a..fa403ed245962 100644 --- a/io_uring/io-wq.c +++ b/io_uring/io-wq.c @@ -211,9 +211,12 @@ static void io_worker_cancel_cb(struct io_worker worker) struct io_wq wq = worker->wq; atomic_dec(&acct->nr_running); - raw_spin_lock(&acct->workers_lock); - acct->nr_workers--; - raw_spin_unlock(&acct->workers_lock); + /* create_worker_cb() has not reserved a worker slot yet. */ + if (worker->create_work.func != create_worker_cb) { + raw_spin_lock(&acct->workers_lock); + acct->nr_workers--; + raw_spin_unlock(&acct->workers_lock); + } io_worker_ref_put(wq); clear_bit_unlock(0, &worker->create_state); io_worker_release(worker);
39/3	2026/08/11 07:24	llm	kmsan-evaluator	0m Model: gemini-3.1-pro-preview Args: null Results: null Tokens: input: 2096 output: 108 thoughts: 499 Thoughts: Analyzing the io_uring Worker Accounting Patch Okay, so I'm looking at this patch for `io_uring/io-wq.c`, specifically the modification to `io_worker_cancel_cb`. It's a pretty straightforward fix, and thankfully, it doesn't involve any of the memory safety issues that keep me up at night! The crux of the change is this conditional check being added around the decrement of `acct->nr_workers`: ```c /* create_worker_cb() has not reserved a worker slot yet. / if (worker->create_work.func != create_worker_cb) { raw_spin_lock(&acct->workers_lock); acct->nr_workers--; raw_spin_unlock(&acct->workers_lock); } ``` Essentially, we're making sure we only decrement the worker count if `create_worker_cb` hasn't already reserved a slot. It's an accounting correction. Before this change, there was a bug where the worker count was being decremented prematurely in certain scenarios. This could lead to incorrect worker counts, possibly leading to subtle deadlocks, or resource leaks. Now, going through `io_worker_cancel_cb` again, it's clear this is just about keeping track of the workers, nothing else. ```c static void io_worker_cancel_cb(struct io_worker worker) { struct io_wq_acct acct = io_wq_get_acct(worker); struct io_wq wq = worker->wq; atomic_dec(&acct->nr_running); /* create_worker_cb() has not reserved a worker slot yet. */ if (worker->create_work.func != create_worker_cb) { raw_spin_lock(&acct->workers_lock); acct->nr_workers--; raw_spin_unlock(&acct->workers_lock); } io_worker_ref_put(wq); clear_bit_unlock(0, &worker->create_state); io_worker_release(worker); } ``` So, definitely no uninitialized memory shenanigans are at play here, which is a relief. I'm comfortable saying this doesn't need to be flagged for KMSAN, I'll set NeedsKMSAN to false. It's purely an accounting fix.
40/3	2026/08/11 07:24	tool	set-results	0m Args: { "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.", "NeedsKMSAN": false }

{
  "EnableConfigs": [
    "IO_URING"
  ],
  "FocusSymbols": [
    "io_wq_create",
    "io_wq_put_and_exit",
    "io_wq_enqueue",
    "io_wq_cancel_cb"
  ],
  "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.",
  "WorthFuzzing": true
}

{
  "PatchDiff": "commit 2ecaa2a619cf9c377d20a4f876432c84e3d16065\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Aug 11 07:22:49 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/io_uring/io-wq.c b/io_uring/io-wq.c\nindex 2e14880eef92a..fa403ed245962 100644\n--- a/io_uring/io-wq.c\n+++ b/io_uring/io-wq.c\n@@ -211,9 +211,12 @@ static void io_worker_cancel_cb(struct io_worker *worker)\n \tstruct io_wq *wq = worker-\u003ewq;\n \n \tatomic_dec(\u0026acct-\u003enr_running);\n-\traw_spin_lock(\u0026acct-\u003eworkers_lock);\n-\tacct-\u003enr_workers--;\n-\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\n+\t/* create_worker_cb() has not reserved a worker slot yet. */\n+\tif (worker-\u003ecreate_work.func != create_worker_cb) {\n+\t\traw_spin_lock(\u0026acct-\u003eworkers_lock);\n+\t\tacct-\u003enr_workers--;\n+\t\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\n+\t}\n \tio_worker_ref_put(wq);\n \tclear_bit_unlock(0, \u0026worker-\u003ecreate_state);\n \tio_worker_release(worker);\n"
}

{
  "EnableConfigs": [
    "IO_URING"
  ],
  "FocusSymbols": [
    "io_wq_create",
    "io_wq_put_and_exit",
    "io_wq_enqueue",
    "io_wq_cancel_cb"
  ],
  "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.",
  "WorthFuzzing": true
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
  even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).
- Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed,
  ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU.
- Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove)
  that are executed only during PCI hot-unplug or sysfs driver unbind operations.

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
   Prefer non-static, non-inlined API entrypoint functions over internal static helper functions
   (which are inlined by the compiler and do not have distinct symbol addresses).
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs
   needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs
   output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit 2ecaa2a619cf9c377d20a4f876432c84e3d16065
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Aug 11 07:22:49 2026 +0000

    syz-cluster: applied patch under review

diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index 2e14880eef92a..fa403ed245962 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -211,9 +211,12 @@ static void io_worker_cancel_cb(struct io_worker *worker)
 	struct io_wq *wq = worker->wq;
 
 	atomic_dec(&acct->nr_running);
-	raw_spin_lock(&acct->workers_lock);
-	acct->nr_workers--;
-	raw_spin_unlock(&acct->workers_lock);
+	/* create_worker_cb() has not reserved a worker slot yet. */
+	if (worker->create_work.func != create_worker_cb) {
+		raw_spin_lock(&acct->workers_lock);
+		acct->nr_workers--;
+		raw_spin_unlock(&acct->workers_lock);
+	}
 	io_worker_ref_put(wq);
 	clear_bit_unlock(0, &worker->create_state);
 	io_worker_release(worker);

gemini-3.1-pro-preview

							input: 2099
							output: 36
							thoughts: 158

**Analyzing a Patch in io_uring/io-wq.c**

Okay, so I'm looking at this patch within `io_uring/io-wq.c`. It seems to be touching `io_worker_cancel_cb`. The key change is around this conditional: avoiding decrementing `acct->nr_workers` under certain circumstances. Let me see... the logic here is skipping the decrement when `worker->create_work.func` isn't `create_worker_cb`. Hmm, the comment says something about `create_worker_cb()` not reserving a worker slot yet. Right, so if it's *not* `create_worker_cb`, what *is* it? Is this related to `create_worker_cont`? I need to double-check the implementations of both `io_worker_cancel_cb` and `create_worker_cb` within this file. The dependency and how they relate is obviously the key to this patch. Let's dig in and see the flow.

{
  "Expression": "io_worker_cancel_cb",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "io_uring/io-wq.c=198=bool io_wq_worker_stopped(void)\n--\nio_uring/io-wq.c-207-\nio_uring/io-wq.c:208:static void io_worker_cancel_cb(struct io_worker *worker)\nio_uring/io-wq.c-209-{\n--\nio_uring/io-wq.c=235=static void io_worker_exit(struct io_worker *worker)\n--\nio_uring/io-wq.c-245-\t\t\tbreak;\nio_uring/io-wq.c:246:\t\tio_worker_cancel_cb(worker);\nio_uring/io-wq.c-247-\t}\n--\nio_uring/io-wq.c=1324=static void io_wq_cancel_tw_create(struct io_wq *wq)\n--\nio_uring/io-wq.c-1331-\t\tworker = container_of(cb, struct io_worker, create_work);\nio_uring/io-wq.c:1332:\t\tio_worker_cancel_cb(worker);\nio_uring/io-wq.c-1333-\t\t/*\n"
}

gemini-3.1-pro-preview

							input: 2826
							output: 34
							thoughts: 30

Okay, let's dive into these callbacks: `io_worker_cancel_cb`, `create_worker_cb`, and `create_worker_cont`. My initial thought is to understand their relationship and how they contribute to the overall workflow. I need to figure out the orchestration here. Is `io_worker_cancel_cb` used to clean up or signal termination, and how does it interact with `create_worker_cb` which likely spawns new threads or processes? Is `create_worker_cont` related, perhaps a continuation or completion handler after worker creation? My immediate goal is to map out the control flow, identifying potential race conditions or synchronization issues between these callbacks. I'll need to consider how state is shared between them, especially if there's any shared data that requires careful locking or atomic operations. I'll also be looking for any hints about error handling: do these callbacks handle errors independently, or is there a centralized error-reporting mechanism? I need to analyze how cancellation is propagated through this chain, and look at the edge cases like the thread exiting while processing a request.

{
  "Expression": "create_worker_cb",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "io_uring/io-wq.c=149=static bool io_acct_cancel_pending_work(struct io_wq *wq,\n--\nio_uring/io-wq.c-151-\t\t\t\t\tstruct io_cb_cancel_data *match);\nio_uring/io-wq.c:152:static void create_worker_cb(struct callback_head *cb);\nio_uring/io-wq.c-153-static void io_wq_cancel_tw_create(struct io_wq *wq);\n--\nio_uring/io-wq.c=208=static void io_worker_cancel_cb(struct io_worker *worker)\n--\nio_uring/io-wq.c-213-\tatomic_dec(\u0026acct-\u003enr_running);\nio_uring/io-wq.c:214:\t/* create_worker_cb() has not reserved a worker slot yet. */\nio_uring/io-wq.c:215:\tif (worker-\u003ecreate_work.func != create_worker_cb) {\nio_uring/io-wq.c-216-\t\traw_spin_lock(\u0026acct-\u003eworkers_lock);\n--\nio_uring/io-wq.c=225=static bool io_task_worker_match(struct callback_head *cb, void *data)\n--\nio_uring/io-wq.c-228-\nio_uring/io-wq.c:229:\tif (cb-\u003efunc != create_worker_cb)\nio_uring/io-wq.c-230-\t\treturn false;\n--\nio_uring/io-wq.c=347=static void io_wq_inc_running(struct io_worker *worker)\n--\nio_uring/io-wq.c-353-\nio_uring/io-wq.c:354:static void create_worker_cb(struct callback_head *cb)\nio_uring/io-wq.c-355-{\n--\nio_uring/io-wq.c=459=static void io_wq_dec_running(struct io_worker *worker)\n--\nio_uring/io-wq.c-480-\tatomic_inc(\u0026wq-\u003eworker_refs);\nio_uring/io-wq.c:481:\tio_queue_worker_create(worker, acct, create_worker_cb);\nio_uring/io-wq.c-482-}\n--\nio_uring/io-wq.c=1309=static bool io_task_work_match(struct callback_head *cb, void *data)\n--\nio_uring/io-wq.c-1312-\nio_uring/io-wq.c:1313:\tif (cb-\u003efunc != create_worker_cb \u0026\u0026 cb-\u003efunc != create_worker_cont)\nio_uring/io-wq.c-1314-\t\treturn false;\n"
}

gemini-3.1-pro-preview

							input: 3842
							output: 34
							thoughts: 227

**Analyzing a Subtle io_uring Worker Fix**

Okay, so I'm looking at this patch for `io_uring/io-wq.c`, specifically how it handles `io_worker_cancel_cb`. The key change is this conditional logic: don't decrement `acct->nr_workers` if the worker's creation function isn't `create_worker_cb`. The code snippet really clarifies it:

```c
	/* create_worker_cb() has not reserved a worker slot yet. */
	if (worker->create_work.func != create_worker_cb) {
		raw_spin_lock(&acct->workers_lock);
		acct->nr_workers--;
		raw_spin_unlock(&acct->workers_lock);
	}
```

My initial thought is, this is a functional modification; it's fixing a potential bug in how io_uring workers are managed during cancellation. That's a good candidate for fuzzing. I need to figure out which config options enable this functionality and identify the relevant symbols. The function `io_worker_cancel_cb` itself is static, so I'll need to look at what calls it to understand how the system uses it. A quick look shows that it's called by `io_worker_exit` and `io_wq_cancel_tw_create`, which should give me good entry points for fuzzing.

{
  "Expression": "io_worker_exit",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "io_uring/io-wq.c=225=static bool io_task_worker_match(struct callback_head *cb, void *data)\n--\nio_uring/io-wq.c-234-\nio_uring/io-wq.c:235:static void io_worker_exit(struct io_worker *worker)\nio_uring/io-wq.c-236-{\n--\nio_uring/io-wq.c=685=static int io_wq_worker(void *data)\n--\nio_uring/io-wq.c-748-\nio_uring/io-wq.c:749:\tio_worker_exit(worker);\nio_uring/io-wq.c-750-\treturn 0;\n"
}

gemini-3.1-pro-preview

							input: 4609
							output: 38
							thoughts: 38

Here's my understanding, as if these were my own thoughts:

**Dissecting the I/O Worker Threads**

Okay, so I'm looking at the core of the I/O worker thread mechanism. `io_wq_worker`... that's the primary thread function, the heart of the whole operation. That's the function where the actual work gets done. That's where the I/O processing is orchestrated.

Then I see `io_wq_cancel_tw_create`, and that's called specifically from `io_wq_exit_workers`. So, when the system's shutting down the worker threads, this cancellation function is invoked. Makes perfect sense. It's a cleanup step, potentially to prevent any new thread creations from succeeding on shutdown. It's all about making the process as tidy as possible. I'll need to dig into `io_wq_cancel_tw_create` more to understand what resources it's cleaning up. The context is obviously about thread management and specifically the cleanup of thread creation related structures within the I/O worker context.

{
  "Expression": "io_wq_cancel_tw_create",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "io_uring/io-wq.c=152=static void create_worker_cb(struct callback_head *cb);\nio_uring/io-wq.c:153:static void io_wq_cancel_tw_create(struct io_wq *wq);\nio_uring/io-wq.c-154-\n--\nio_uring/io-wq.c=390=static bool io_queue_worker_create(struct io_worker *worker,\n--\nio_uring/io-wq.c-420-\t\tif (test_bit(IO_WQ_BIT_EXIT, \u0026wq-\u003estate))\nio_uring/io-wq.c:421:\t\t\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-422-\t\tio_worker_ref_put(wq);\n--\nio_uring/io-wq.c=1319=void io_wq_exit_start(struct io_wq *wq)\n--\nio_uring/io-wq.c-1323-\nio_uring/io-wq.c:1324:static void io_wq_cancel_tw_create(struct io_wq *wq)\nio_uring/io-wq.c-1325-{\n--\nio_uring/io-wq.c=1342=static void io_wq_exit_workers(struct io_wq *wq)\n--\nio_uring/io-wq.c-1348-\nio_uring/io-wq.c:1349:\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-1350-\n"
}

gemini-3.1-pro-preview

							input: 5335
							output: 36
							thoughts: 47

Okay, here's my interpretation of those thoughts, presented as if they're my own:

**Analyzing io_wq Destruction**

Right, so I'm looking at `io_wq_exit_workers` and `io_wq_exit_start`. Those are definitely called during the destruction process of an `io_wq`, making them key to understanding how it all unravels. My primary goal here is to get a clearer picture of that process. I need to identify the pieces, from start to finish.

Therefore, I need to see what other related functions might be useful to understand how the `io_wq` is created, and even more critically, torn down. I’ll focus on non-static functions, as they're the ones most likely to be part of the public API or at least interact with other parts of the system. I need to cast a wider net here and find anything involved in either creation or destruction that might be lurking around. This will give me a comprehensive view of how `io_wq` life cycle is handled.

{
  "Expression": "io_wq_exit_workers",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "io_uring/io-wq.c=390=static bool io_queue_worker_create(struct io_worker *worker,\n--\nio_uring/io-wq.c-417-\t\t * now set. wq exit does that too, but we can have added this\nio_uring/io-wq.c:418:\t\t * work item after we canceled in io_wq_exit_workers().\nio_uring/io-wq.c-419-\t\t */\n--\nio_uring/io-wq.c=1324=static void io_wq_cancel_tw_create(struct io_wq *wq)\n--\nio_uring/io-wq.c-1341-\nio_uring/io-wq.c:1342:static void io_wq_exit_workers(struct io_wq *wq)\nio_uring/io-wq.c-1343-{\n--\nio_uring/io-wq.c=1398=void io_wq_put_and_exit(struct io_wq *wq)\n--\nio_uring/io-wq.c-1401-\nio_uring/io-wq.c:1402:\tio_wq_exit_workers(wq);\nio_uring/io-wq.c-1403-\tio_wq_destroy(wq);\n"
}

gemini-3.1-pro-preview

							input: 5976
							output: 34
							thoughts: 30

Okay, here's my interpretation of those thoughts, tailored for an expert audience, presented in the first person:

**Investigating the `io_wq` Cleanup Procedure**

Alright, I'm thinking about `io_wq_put_and_exit`. The fact that it's *not* a static function immediately piques my interest. It implies it might be called from outside the module, which has implications for synchronization and potential race conditions, if not handled carefully. I need to understand the contexts in which it's being used beyond the immediate scope. To get a better understanding of how the `io_wq` structure is managed, I really need to trace its origins, the lifecycle of the object, and its finalization routine. So, I need to see *where* this function is being called from. Therefore, let's dive into the creation process. I'll take a look at `io_wq_create` next. This will likely shed some light on the expected usage and lifecycle of the `io_wq`.

{
  "Expression": "io_wq_create",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "io_uring/io-wq.c=295=static bool io_acct_activate_free_worker(struct io_wq_acct *acct)\n--\nio_uring/io-wq.c-325- */\nio_uring/io-wq.c:326:static bool io_wq_create_worker(struct io_wq *wq, struct io_wq_acct *acct)\nio_uring/io-wq.c-327-{\n--\nio_uring/io-wq.c=1028=void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)\n--\nio_uring/io-wq.c-1061-\nio_uring/io-wq.c:1062:\t\tdid_create = io_wq_create_worker(wq, acct);\nio_uring/io-wq.c-1063-\t\tif (likely(did_create))\n--\nio_uring/io-wq.c=1235=static int io_wq_hash_wake(struct wait_queue_entry *wait, unsigned mode,\n--\nio_uring/io-wq.c-1253-\nio_uring/io-wq.c:1254:struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)\nio_uring/io-wq.c-1255-{\n"
}

gemini-3.1-pro-preview

							input: 6615
							output: 33
							thoughts: 64

Okay, let's see. If I'm trying to zero in on the core of this I/O workqueue implementation, my initial instinct is to look at the primary entry and exit points, the creation and destruction, really. So, `io_wq_create` and `io_wq_put_and_exit` definitely jump out as important symbols to trace. They are the scaffolding, the building and dismantling, so to speak.

Then, of course, the actual work enqueuing needs consideration: `io_wq_enqueue` is obviously a critical piece. That's where the actual I/O requests are getting submitted.

Now, what about the worker itself? Ah, `io_wq_worker`... that one's static, isn't it? Hmm, static means internal to the file, and that might make it a less obvious target for someone trying to interface with it from another context. I need to be aware of what is exposed, and what is internal. I should also check to see if there are any other non-static functions related to the workqueue. They could be the key to integration.

{
  "Expression": "io_wq_",
  "PathPrefix": "io_uring/io-wq.c"
}

{
  "Output": "\nFull output is too long, showing 500 out of 532 lines.\nUse more precise expression if possible.\n\nio_uring/io-wq.c=48=struct io_worker {\n--\nio_uring/io-wq.c-54-\tstruct io_wq *wq;\nio_uring/io-wq.c:55:\tstruct io_wq_acct *acct;\nio_uring/io-wq.c-56-\nio_uring/io-wq.c:57:\tstruct io_wq_work *cur_work;\nio_uring/io-wq.c-58-\traw_spinlock_t lock;\n--\nio_uring/io-wq.c-79-\nio_uring/io-wq.c:80:struct io_wq_acct {\nio_uring/io-wq.c-81-\t/**\n--\nio_uring/io-wq.c-102-\traw_spinlock_t lock;\nio_uring/io-wq.c:103:\tstruct io_wq_work_list work_list;\nio_uring/io-wq.c-104-\tunsigned long flags;\n--\nio_uring/io-wq.c=116=struct io_wq {\n--\nio_uring/io-wq.c-118-\nio_uring/io-wq.c:119:\tstruct io_wq_hash *hash;\nio_uring/io-wq.c-120-\n--\nio_uring/io-wq.c-127-\nio_uring/io-wq.c:128:\tstruct io_wq_acct acct[IO_WQ_ACCT_NR];\nio_uring/io-wq.c-129-\n--\nio_uring/io-wq.c-131-\nio_uring/io-wq.c:132:\tstruct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS];\nio_uring/io-wq.c-133-\n--\nio_uring/io-wq.c-136-\nio_uring/io-wq.c:137:static enum cpuhp_state io_wq_online;\nio_uring/io-wq.c-138-\nio_uring/io-wq.c=139=struct io_cb_cancel_data {\n--\nio_uring/io-wq.c-146-\nio_uring/io-wq.c:147:static bool create_io_worker(struct io_wq *wq, struct io_wq_acct *acct);\nio_uring/io-wq.c:148:static void io_wq_dec_running(struct io_worker *worker);\nio_uring/io-wq.c-149-static bool io_acct_cancel_pending_work(struct io_wq *wq,\nio_uring/io-wq.c:150:\t\t\t\t\tstruct io_wq_acct *acct,\nio_uring/io-wq.c-151-\t\t\t\t\tstruct io_cb_cancel_data *match);\nio_uring/io-wq.c=152=static void create_worker_cb(struct callback_head *cb);\nio_uring/io-wq.c:153:static void io_wq_cancel_tw_create(struct io_wq *wq);\nio_uring/io-wq.c-154-\nio_uring/io-wq.c=155=static inline unsigned int __io_get_work_hash(unsigned int work_flags)\n--\nio_uring/io-wq.c-159-\nio_uring/io-wq.c:160:static inline unsigned int io_get_work_hash(struct io_wq_work *work)\nio_uring/io-wq.c-161-{\n--\nio_uring/io-wq.c=170=static void io_worker_release(struct io_worker *worker)\n--\nio_uring/io-wq.c-175-\nio_uring/io-wq.c:176:static inline struct io_wq_acct *io_get_acct(struct io_wq *wq, bool bound)\nio_uring/io-wq.c-177-{\n--\nio_uring/io-wq.c-180-\nio_uring/io-wq.c:181:static inline struct io_wq_acct *io_work_get_acct(struct io_wq *wq,\nio_uring/io-wq.c-182-\t\t\t\t\t\t  unsigned int work_flags)\n--\nio_uring/io-wq.c-186-\nio_uring/io-wq.c:187:static inline struct io_wq_acct *io_wq_get_acct(struct io_worker *worker)\nio_uring/io-wq.c-188-{\n--\nio_uring/io-wq.c=192=static void io_worker_ref_put(struct io_wq *wq)\n--\nio_uring/io-wq.c-197-\nio_uring/io-wq.c:198:bool io_wq_worker_stopped(void)\nio_uring/io-wq.c-199-{\n--\nio_uring/io-wq.c-201-\nio_uring/io-wq.c:202:\tif (WARN_ON_ONCE(!io_wq_current_is_worker()))\nio_uring/io-wq.c-203-\t\treturn true;\n--\nio_uring/io-wq.c=208=static void io_worker_cancel_cb(struct io_worker *worker)\nio_uring/io-wq.c-209-{\nio_uring/io-wq.c:210:\tstruct io_wq_acct *acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-211-\tstruct io_wq *wq = worker-\u003ewq;\n--\nio_uring/io-wq.c=235=static void io_worker_exit(struct io_worker *worker)\n--\nio_uring/io-wq.c-237-\tstruct io_wq *wq = worker-\u003ewq;\nio_uring/io-wq.c:238:\tstruct io_wq_acct *acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-239-\n--\nio_uring/io-wq.c-256-\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\nio_uring/io-wq.c:257:\tio_wq_dec_running(worker);\nio_uring/io-wq.c-258-\t/*\n--\nio_uring/io-wq.c-269-\nio_uring/io-wq.c:270:static inline bool __io_acct_run_queue(struct io_wq_acct *acct)\nio_uring/io-wq.c-271-{\n--\nio_uring/io-wq.c-279- */\nio_uring/io-wq.c:280:static inline bool io_acct_run_queue(struct io_wq_acct *acct)\nio_uring/io-wq.c-281-\t__acquires(\u0026acct-\u003elock)\n--\nio_uring/io-wq.c-294- */\nio_uring/io-wq.c:295:static bool io_acct_activate_free_worker(struct io_wq_acct *acct)\nio_uring/io-wq.c-296-\t__must_hold(RCU)\n--\nio_uring/io-wq.c-325- */\nio_uring/io-wq.c:326:static bool io_wq_create_worker(struct io_wq *wq, struct io_wq_acct *acct)\nio_uring/io-wq.c-327-{\n--\nio_uring/io-wq.c-346-\nio_uring/io-wq.c:347:static void io_wq_inc_running(struct io_worker *worker)\nio_uring/io-wq.c-348-{\nio_uring/io-wq.c:349:\tstruct io_wq_acct *acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-350-\n--\nio_uring/io-wq.c=354=static void create_worker_cb(struct callback_head *cb)\n--\nio_uring/io-wq.c-358-\nio_uring/io-wq.c:359:\tstruct io_wq_acct *acct;\nio_uring/io-wq.c-360-\tbool activated_free_worker, do_create = false;\n--\nio_uring/io-wq.c=390=static bool io_queue_worker_create(struct io_worker *worker,\nio_uring/io-wq.c:391:\t\t\t\t   struct io_wq_acct *acct,\nio_uring/io-wq.c-392-\t\t\t\t   task_work_func_t func)\n--\nio_uring/io-wq.c-417-\t\t * now set. wq exit does that too, but we can have added this\nio_uring/io-wq.c:418:\t\t * work item after we canceled in io_wq_exit_workers().\nio_uring/io-wq.c-419-\t\t */\nio_uring/io-wq.c-420-\t\tif (test_bit(IO_WQ_BIT_EXIT, \u0026wq-\u003estate))\nio_uring/io-wq.c:421:\t\t\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-422-\t\tio_worker_ref_put(wq);\n--\nio_uring/io-wq.c-435-/* Defer if current and next work are both hashed to the same chain */\nio_uring/io-wq.c:436:static bool io_wq_hash_defer(struct io_wq_work *work, struct io_wq_acct *acct)\nio_uring/io-wq.c-437-{\nio_uring/io-wq.c-438-\tunsigned int hash, work_flags;\nio_uring/io-wq.c:439:\tstruct io_wq_work *next;\nio_uring/io-wq.c-440-\n--\nio_uring/io-wq.c-443-\twork_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:444:\tif (!__io_wq_is_hashed(work_flags))\nio_uring/io-wq.c-445-\t\treturn false;\n--\nio_uring/io-wq.c-451-\thash = __io_get_work_hash(work_flags);\nio_uring/io-wq.c:452:\tnext = container_of(acct-\u003ework_list.first, struct io_wq_work, list);\nio_uring/io-wq.c-453-\twork_flags = atomic_read(\u0026next-\u003eflags);\nio_uring/io-wq.c:454:\tif (!__io_wq_is_hashed(work_flags))\nio_uring/io-wq.c-455-\t\treturn false;\n--\nio_uring/io-wq.c-458-\nio_uring/io-wq.c:459:static void io_wq_dec_running(struct io_worker *worker)\nio_uring/io-wq.c-460-{\nio_uring/io-wq.c:461:\tstruct io_wq_acct *acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-462-\tstruct io_wq *wq = worker-\u003ewq;\n--\nio_uring/io-wq.c-472-\t\treturn;\nio_uring/io-wq.c:473:\tif (io_wq_hash_defer(worker-\u003ecur_work, acct)) {\nio_uring/io-wq.c-474-\t\traw_spin_unlock(\u0026acct-\u003elock);\n--\nio_uring/io-wq.c-487- */\nio_uring/io-wq.c:488:static void __io_worker_busy(struct io_wq_acct *acct, struct io_worker *worker)\nio_uring/io-wq.c-489-{\n--\nio_uring/io-wq.c-500- */\nio_uring/io-wq.c:501:static void __io_worker_idle(struct io_wq_acct *acct, struct io_worker *worker)\nio_uring/io-wq.c-502-\t__must_hold(acct-\u003eworkers_lock)\n--\nio_uring/io-wq.c=510=static bool io_wait_on_hash(struct io_wq *wq, unsigned int hash)\n--\nio_uring/io-wq.c-526-\nio_uring/io-wq.c:527:static struct io_wq_work *io_get_next_work(struct io_wq_acct *acct,\nio_uring/io-wq.c-528-\t\t\t\t\t   struct io_wq *wq)\n--\nio_uring/io-wq.c-530-{\nio_uring/io-wq.c:531:\tstruct io_wq_work_node *node, *prev;\nio_uring/io-wq.c:532:\tstruct io_wq_work *work, *tail;\nio_uring/io-wq.c-533-\tunsigned int stall_hash = -1U;\n--\nio_uring/io-wq.c-538-\nio_uring/io-wq.c:539:\t\twork = container_of(node, struct io_wq_work, list);\nio_uring/io-wq.c-540-\n--\nio_uring/io-wq.c-542-\t\twork_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:543:\t\tif (!__io_wq_is_hashed(work_flags)) {\nio_uring/io-wq.c-544-\t\t\twq_list_del(\u0026acct-\u003ework_list, node, prev);\n--\nio_uring/io-wq.c=585=static void io_assign_current_work(struct io_worker *worker,\nio_uring/io-wq.c:586:\t\t\t\t   struct io_wq_work *work)\nio_uring/io-wq.c-587-{\n--\nio_uring/io-wq.c-600- */\nio_uring/io-wq.c:601:static void io_worker_handle_work(struct io_wq_acct *acct,\nio_uring/io-wq.c-602-\t\t\t\t  struct io_worker *worker)\n--\nio_uring/io-wq.c-607-\tdo {\nio_uring/io-wq.c:608:\t\tstruct io_wq_work *work;\nio_uring/io-wq.c-609-\n--\nio_uring/io-wq.c-643-\t\t\tbool do_kill = test_bit(IO_WQ_BIT_EXIT, \u0026wq-\u003estate);\nio_uring/io-wq.c:644:\t\t\tstruct io_wq_work *next_hashed, *linked;\nio_uring/io-wq.c-645-\t\t\tunsigned int work_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:646:\t\t\tunsigned int hash = __io_wq_is_hashed(work_flags)\nio_uring/io-wq.c-647-\t\t\t\t? __io_get_work_hash(work_flags)\n--\nio_uring/io-wq.c-654-\t\t\t\tatomic_or(IO_WQ_WORK_CANCEL, \u0026work-\u003eflags);\nio_uring/io-wq.c:655:\t\t\tio_wq_submit_work(work);\nio_uring/io-wq.c-656-\t\t\tio_assign_current_work(worker, NULL);\nio_uring/io-wq.c-657-\nio_uring/io-wq.c:658:\t\t\tlinked = io_wq_free_work(work);\nio_uring/io-wq.c-659-\t\t\twork = next_hashed;\nio_uring/io-wq.c:660:\t\t\tif (!work \u0026\u0026 linked \u0026\u0026 !io_wq_is_hashed(linked)) {\nio_uring/io-wq.c-661-\t\t\t\twork = linked;\n--\nio_uring/io-wq.c-665-\t\t\tif (linked)\nio_uring/io-wq.c:666:\t\t\t\tio_wq_enqueue(wq, linked);\nio_uring/io-wq.c-667-\n--\nio_uring/io-wq.c-684-\nio_uring/io-wq.c:685:static int io_wq_worker(void *data)\nio_uring/io-wq.c-686-{\nio_uring/io-wq.c-687-\tstruct io_worker *worker = data;\nio_uring/io-wq.c:688:\tstruct io_wq_acct *acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-689-\tstruct io_wq *wq = worker-\u003ewq;\n--\nio_uring/io-wq.c-755- */\nio_uring/io-wq.c:756:void io_wq_worker_running(struct task_struct *tsk)\nio_uring/io-wq.c-757-{\n--\nio_uring/io-wq.c-766-\tset_bit(IO_WORKER_F_RUNNING, \u0026worker-\u003eflags);\nio_uring/io-wq.c:767:\tio_wq_inc_running(worker);\nio_uring/io-wq.c-768-}\n--\nio_uring/io-wq.c-773- */\nio_uring/io-wq.c:774:void io_wq_worker_sleeping(struct task_struct *tsk)\nio_uring/io-wq.c-775-{\n--\nio_uring/io-wq.c-785-\tclear_bit(IO_WORKER_F_RUNNING, \u0026worker-\u003eflags);\nio_uring/io-wq.c:786:\tio_wq_dec_running(worker);\nio_uring/io-wq.c-787-}\nio_uring/io-wq.c-788-\nio_uring/io-wq.c:789:static void io_init_new_worker(struct io_wq *wq, struct io_wq_acct *acct, struct io_worker *worker,\nio_uring/io-wq.c-790-\t\t\t       struct task_struct *tsk)\n--\nio_uring/io-wq.c-803-\nio_uring/io-wq.c:804:static bool io_wq_work_match_all(struct io_wq_work *work, void *data)\nio_uring/io-wq.c-805-{\n--\nio_uring/io-wq.c=844=static void create_worker_cont(struct callback_head *cb)\n--\nio_uring/io-wq.c-848-\tstruct io_wq *wq;\nio_uring/io-wq.c:849:\tstruct io_wq_acct *acct;\nio_uring/io-wq.c-850-\n--\nio_uring/io-wq.c-853-\twq = worker-\u003ewq;\nio_uring/io-wq.c:854:\tacct = io_wq_get_acct(worker);\nio_uring/io-wq.c:855:\ttsk = create_io_thread(io_wq_worker, worker, NUMA_NO_NODE);\nio_uring/io-wq.c-856-\tif (!IS_ERR(tsk)) {\n--\nio_uring/io-wq.c-865-\t\t\tstruct io_cb_cancel_data match = {\nio_uring/io-wq.c:866:\t\t\t\t.fn\t\t= io_wq_work_match_all,\nio_uring/io-wq.c-867-\t\t\t\t.cancel_all\t= true,\n--\nio_uring/io-wq.c=886=static void io_workqueue_create(struct work_struct *work)\n--\nio_uring/io-wq.c-889-\t\t\t\t\t\twork.work);\nio_uring/io-wq.c:890:\tstruct io_wq_acct *acct = io_wq_get_acct(worker);\nio_uring/io-wq.c-891-\n--\nio_uring/io-wq.c-895-\nio_uring/io-wq.c:896:static bool create_io_worker(struct io_wq *wq, struct io_wq_acct *acct)\nio_uring/io-wq.c-897-{\n--\nio_uring/io-wq.c-919-\nio_uring/io-wq.c:920:\ttsk = create_io_thread(io_wq_worker, worker, NUMA_NO_NODE);\nio_uring/io-wq.c-921-\tif (!IS_ERR(tsk)) {\n--\nio_uring/io-wq.c-937- */\nio_uring/io-wq.c:938:static bool io_acct_for_each_worker(struct io_wq_acct *acct,\nio_uring/io-wq.c-939-\t\t\t\t    bool (*func)(struct io_worker *, void *),\n--\nio_uring/io-wq.c-958-\nio_uring/io-wq.c:959:static void io_wq_for_each_worker(struct io_wq *wq,\nio_uring/io-wq.c-960-\t\t\t\t  bool (*func)(struct io_worker *, void *),\n--\nio_uring/io-wq.c-967-\nio_uring/io-wq.c:968:static bool io_wq_worker_wake(struct io_worker *worker, void *data)\nio_uring/io-wq.c-969-{\n--\nio_uring/io-wq.c-974-\nio_uring/io-wq.c:975:void io_wq_set_exit_on_idle(struct io_wq *wq, bool enable)\nio_uring/io-wq.c-976-{\n--\nio_uring/io-wq.c-988-\trcu_read_lock();\nio_uring/io-wq.c:989:\tio_wq_for_each_worker(wq, io_wq_worker_wake, NULL);\nio_uring/io-wq.c-990-\trcu_read_unlock();\n--\nio_uring/io-wq.c-992-\nio_uring/io-wq.c:993:static void io_run_cancel(struct io_wq_work *work, struct io_wq *wq)\nio_uring/io-wq.c-994-{\n--\nio_uring/io-wq.c-996-\t\tatomic_or(IO_WQ_WORK_CANCEL, \u0026work-\u003eflags);\nio_uring/io-wq.c:997:\t\tio_wq_submit_work(work);\nio_uring/io-wq.c:998:\t\twork = io_wq_free_work(work);\nio_uring/io-wq.c-999-\t} while (work);\n--\nio_uring/io-wq.c-1001-\nio_uring/io-wq.c:1002:static void io_wq_insert_work(struct io_wq *wq, struct io_wq_acct *acct,\nio_uring/io-wq.c:1003:\t\t\t      struct io_wq_work *work, unsigned int work_flags)\nio_uring/io-wq.c-1004-{\nio_uring/io-wq.c-1005-\tunsigned int hash;\nio_uring/io-wq.c:1006:\tstruct io_wq_work *tail;\nio_uring/io-wq.c-1007-\nio_uring/io-wq.c:1008:\tif (!__io_wq_is_hashed(work_flags)) {\nio_uring/io-wq.c-1009-append:\n--\nio_uring/io-wq.c-1022-\nio_uring/io-wq.c:1023:static bool io_wq_work_match_item(struct io_wq_work *work, void *data)\nio_uring/io-wq.c-1024-{\n--\nio_uring/io-wq.c-1027-\nio_uring/io-wq.c:1028:void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)\nio_uring/io-wq.c-1029-{\nio_uring/io-wq.c-1030-\tunsigned int work_flags = atomic_read(\u0026work-\u003eflags);\nio_uring/io-wq.c:1031:\tstruct io_wq_acct *acct = io_work_get_acct(wq, work_flags);\nio_uring/io-wq.c-1032-\tstruct io_cb_cancel_data match = {\nio_uring/io-wq.c:1033:\t\t.fn\t\t= io_wq_work_match_item,\nio_uring/io-wq.c-1034-\t\t.data\t\t= work,\n--\nio_uring/io-wq.c-1049-\traw_spin_lock(\u0026acct-\u003elock);\nio_uring/io-wq.c:1050:\tio_wq_insert_work(wq, acct, work, work_flags);\nio_uring/io-wq.c-1051-\tclear_bit(IO_ACCT_STALLED_BIT, \u0026acct-\u003eflags);\n--\nio_uring/io-wq.c-1061-\nio_uring/io-wq.c:1062:\t\tdid_create = io_wq_create_worker(wq, acct);\nio_uring/io-wq.c-1063-\t\tif (likely(did_create))\n--\nio_uring/io-wq.c-1081- */\nio_uring/io-wq.c:1082:void io_wq_hash_work(struct io_wq_work *work, void *val)\nio_uring/io-wq.c-1083-{\n--\nio_uring/io-wq.c-1089-\nio_uring/io-wq.c:1090:static bool __io_wq_worker_cancel(struct io_worker *worker,\nio_uring/io-wq.c-1091-\t\t\t\t  struct io_cb_cancel_data *match,\nio_uring/io-wq.c:1092:\t\t\t\t  struct io_wq_work *work)\nio_uring/io-wq.c-1093-{\n--\nio_uring/io-wq.c-1102-\nio_uring/io-wq.c:1103:static bool io_wq_worker_cancel(struct io_worker *worker, void *data)\nio_uring/io-wq.c-1104-{\n--\nio_uring/io-wq.c-1111-\traw_spin_lock(\u0026worker-\u003elock);\nio_uring/io-wq.c:1112:\tif (__io_wq_worker_cancel(worker, match, worker-\u003ecur_work))\nio_uring/io-wq.c-1113-\t\tmatch-\u003enr_running++;\n--\nio_uring/io-wq.c-1118-\nio_uring/io-wq.c:1119:static inline void io_wq_remove_pending(struct io_wq *wq,\nio_uring/io-wq.c:1120:\t\t\t\t\tstruct io_wq_acct *acct,\nio_uring/io-wq.c:1121:\t\t\t\t\t struct io_wq_work *work,\nio_uring/io-wq.c:1122:\t\t\t\t\t struct io_wq_work_node *prev)\nio_uring/io-wq.c-1123-{\nio_uring/io-wq.c-1124-\tunsigned int hash = io_get_work_hash(work);\nio_uring/io-wq.c:1125:\tstruct io_wq_work *prev_work = NULL;\nio_uring/io-wq.c-1126-\nio_uring/io-wq.c:1127:\tif (io_wq_is_hashed(work) \u0026\u0026 work == wq-\u003ehash_tail[hash]) {\nio_uring/io-wq.c-1128-\t\tif (prev)\nio_uring/io-wq.c:1129:\t\t\tprev_work = container_of(prev, struct io_wq_work, list);\nio_uring/io-wq.c:1130:\t\tif (prev_work \u0026\u0026 io_wq_is_hashed(prev_work) \u0026\u0026\nio_uring/io-wq.c-1131-\t\t    io_get_work_hash(prev_work) == hash)\n--\nio_uring/io-wq.c=1139=static bool io_acct_cancel_pending_work(struct io_wq *wq,\nio_uring/io-wq.c:1140:\t\t\t\t\tstruct io_wq_acct *acct,\nio_uring/io-wq.c-1141-\t\t\t\t\tstruct io_cb_cancel_data *match)\nio_uring/io-wq.c-1142-{\nio_uring/io-wq.c:1143:\tstruct io_wq_work_node *node, *prev;\nio_uring/io-wq.c:1144:\tstruct io_wq_work *work;\nio_uring/io-wq.c-1145-\n--\nio_uring/io-wq.c-1147-\twq_list_for_each(node, prev, \u0026acct-\u003ework_list) {\nio_uring/io-wq.c:1148:\t\twork = container_of(node, struct io_wq_work, list);\nio_uring/io-wq.c-1149-\t\tif (!match-\u003efn(work, match-\u003edata))\nio_uring/io-wq.c-1150-\t\t\tcontinue;\nio_uring/io-wq.c:1151:\t\tio_wq_remove_pending(wq, acct, work, prev);\nio_uring/io-wq.c-1152-\t\traw_spin_unlock(\u0026acct-\u003elock);\n--\nio_uring/io-wq.c-1162-\nio_uring/io-wq.c:1163:static void io_wq_cancel_pending_work(struct io_wq *wq,\nio_uring/io-wq.c-1164-\t\t\t\t      struct io_cb_cancel_data *match)\n--\nio_uring/io-wq.c-1168-\tfor (i = 0; i \u003c IO_WQ_ACCT_NR; i++) {\nio_uring/io-wq.c:1169:\t\tstruct io_wq_acct *acct = io_get_acct(wq, i == 0);\nio_uring/io-wq.c-1170-\n--\nio_uring/io-wq.c-1178-\nio_uring/io-wq.c:1179:static void io_acct_cancel_running_work(struct io_wq_acct *acct,\nio_uring/io-wq.c-1180-\t\t\t\t\tstruct io_cb_cancel_data *match)\n--\nio_uring/io-wq.c-1182-\traw_spin_lock(\u0026acct-\u003eworkers_lock);\nio_uring/io-wq.c:1183:\tio_acct_for_each_worker(acct, io_wq_worker_cancel, match);\nio_uring/io-wq.c-1184-\traw_spin_unlock(\u0026acct-\u003eworkers_lock);\n--\nio_uring/io-wq.c-1186-\nio_uring/io-wq.c:1187:static void io_wq_cancel_running_work(struct io_wq *wq,\nio_uring/io-wq.c-1188-\t\t\t\t       struct io_cb_cancel_data *match)\n--\nio_uring/io-wq.c-1197-\nio_uring/io-wq.c:1198:enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,\nio_uring/io-wq.c-1199-\t\t\t\t  void *data, bool cancel_all)\n--\nio_uring/io-wq.c-1219-\t */\nio_uring/io-wq.c:1220:\tio_wq_cancel_pending_work(wq, \u0026match);\nio_uring/io-wq.c-1221-\tif (match.nr_pending \u0026\u0026 !match.cancel_all)\n--\nio_uring/io-wq.c-1223-\nio_uring/io-wq.c:1224:\tio_wq_cancel_running_work(wq, \u0026match);\nio_uring/io-wq.c-1225-\tif (match.nr_running \u0026\u0026 !match.cancel_all)\n--\nio_uring/io-wq.c-1234-\nio_uring/io-wq.c:1235:static int io_wq_hash_wake(struct wait_queue_entry *wait, unsigned mode,\nio_uring/io-wq.c-1236-\t\t\t    int sync, void *key)\n--\nio_uring/io-wq.c-1244-\tfor (i = 0; i \u003c IO_WQ_ACCT_NR; i++) {\nio_uring/io-wq.c:1245:\t\tstruct io_wq_acct *acct = \u0026wq-\u003eacct[i];\nio_uring/io-wq.c-1246-\n--\nio_uring/io-wq.c-1253-\nio_uring/io-wq.c:1254:struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)\nio_uring/io-wq.c-1255-{\n--\nio_uring/io-wq.c-1277-\tINIT_LIST_HEAD(\u0026wq-\u003ewait.entry);\nio_uring/io-wq.c:1278:\twq-\u003ewait.func = io_wq_hash_wake;\nio_uring/io-wq.c-1279-\tfor (i = 0; i \u003c IO_WQ_ACCT_NR; i++) {\nio_uring/io-wq.c:1280:\t\tstruct io_wq_acct *acct = \u0026wq-\u003eacct[i];\nio_uring/io-wq.c-1281-\n--\nio_uring/io-wq.c-1294-\tinit_completion(\u0026wq-\u003eworker_done);\nio_uring/io-wq.c:1295:\tret = cpuhp_state_add_instance_nocalls(io_wq_online, \u0026wq-\u003ecpuhp_node);\nio_uring/io-wq.c-1296-\tif (ret) {\n--\nio_uring/io-wq.c-1302-err:\nio_uring/io-wq.c:1303:\tio_wq_put_hash(data-\u003ehash);\nio_uring/io-wq.c-1304-\tfree_cpumask_var(wq-\u003ecpu_mask);\n--\nio_uring/io-wq.c=1309=static bool io_task_work_match(struct callback_head *cb, void *data)\n--\nio_uring/io-wq.c-1318-\nio_uring/io-wq.c:1319:void io_wq_exit_start(struct io_wq *wq)\nio_uring/io-wq.c-1320-{\n--\nio_uring/io-wq.c-1323-\nio_uring/io-wq.c:1324:static void io_wq_cancel_tw_create(struct io_wq *wq)\nio_uring/io-wq.c-1325-{\n--\nio_uring/io-wq.c-1341-\nio_uring/io-wq.c:1342:static void io_wq_exit_workers(struct io_wq *wq)\nio_uring/io-wq.c-1343-{\n--\nio_uring/io-wq.c-1348-\nio_uring/io-wq.c:1349:\tio_wq_cancel_tw_create(wq);\nio_uring/io-wq.c-1350-\nio_uring/io-wq.c-1351-\trcu_read_lock();\nio_uring/io-wq.c:1352:\tio_wq_for_each_worker(wq, io_wq_worker_wake, NULL);\nio_uring/io-wq.c-1353-\trcu_read_unlock();\n--\nio_uring/io-wq.c-1383-\nio_uring/io-wq.c:1384:static void io_wq_destroy(struct io_wq *wq)\nio_uring/io-wq.c-1385-{\nio_uring/io-wq.c-1386-\tstruct io_cb_cancel_data match = {\nio_uring/io-wq.c:1387:\t\t.fn\t\t= io_wq_work_match_all,\nio_uring/io-wq.c-1388-\t\t.cancel_all\t= true,\n--\nio_uring/io-wq.c-1390-\nio_uring/io-wq.c:1391:\tcpuhp_state_remove_instance_nocalls(io_wq_online, \u0026wq-\u003ecpuhp_node);\nio_uring/io-wq.c:1392:\tio_wq_cancel_pending_work(wq, \u0026match);\nio_uring/io-wq.c-1393-\tfree_cpumask_var(wq-\u003ecpu_mask);\nio_uring/io-wq.c:1394:\tio_wq_put_hash(wq-\u003ehash);\nio_uring/io-wq.c-1395-\tkfree(wq);\n--\nio_uring/io-wq.c-1397-\nio_uring/io-wq.c:1398:void io_wq_put_and_exit(struct io_wq *wq)\nio_uring/io-wq.c-1399-{\n--\nio_uring/io-wq.c-1401-\nio_uring/io-wq.c:1402:\tio_wq_exit_workers(wq);\nio_uring/io-wq.c:1403:\tio_wq_destroy(wq);\nio_uring/io-wq.c-1404-}\n--\nio_uring/io-wq.c=1406=struct online_data {\n--\nio_uring/io-wq.c-1410-\nio_uring/io-wq.c:1411:static bool io_wq_worker_affinity(struct io_worker *worker, void *data)\nio_uring/io-wq.c-1412-{\n--\nio_uring/io-wq.c-1421-\nio_uring/io-wq.c:1422:static int __io_wq_cpu_online(struct io_wq *wq, unsigned int cpu, bool online)\nio_uring/io-wq.c-1423-{\n--\nio_uring/io-wq.c-1429-\trcu_read_lock();\nio_uring/io-wq.c:1430:\tio_wq_for_each_worker(wq, io_wq_worker_affinity, \u0026od);\nio_uring/io-wq.c-1431-\trcu_read_unlock();\n--\nio_uring/io-wq.c-1434-\nio_uring/io-wq.c:1435:static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node)\nio_uring/io-wq.c-1436-{\n--\n\n"
}

gemini-3.1-pro-preview

							input: 17254
							output: 28
							thoughts: 97

**Analyzing the IO-WQ Infrastructure**

Okay, let's dive into this `io_wq` business. My initial focus is on understanding the core lifecycle – specifically, `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, and `io_wq_cancel_cb`. I'm starting by zeroing in on `io_wq_cancel_cb`. The fact that it's *not* a static function is significant, immediately implying it's designed for external interaction or perhaps a module's use.

Now, let's shift gears slightly and consider configuration. Are there any relevant config options impacting this? I need to know under what circumstances this code is even built. The filename `io_uring/io-wq.c` is suggestive – my immediate assumption is that it's compiled when `CONFIG_IO_URING` is set. To be certain, I'll quickly check the `io_uring/Makefile` to confirm that dependency. This information is key to understanding the scope of its use and its role within the larger IO_URING ecosystem.

{
  "Expression": "io-wq",
  "PathPrefix": "io_uring/Makefile"
}

{
  "Output": "io_uring/Makefile=19=obj-$(CONFIG_IO_URING_ZCRX)\t+= zcrx.o\nio_uring/Makefile:20:obj-$(CONFIG_IO_WQ)\t\t+= io-wq.o\nio_uring/Makefile-21-obj-$(CONFIG_FUTEX)\t\t+= futex.o\n"
}

gemini-3.1-pro-preview

							input: 17709
							output: 24
							thoughts: 39

Okay, here's my take on those thoughts, tailored for an expert audience:

**Investigating the IO Workqueue Configuration**

Right, let's see. My mental map immediately suggests that the key configuration option here is likely `CONFIG_IO_WQ`. Given what I'm dealing with, the context points towards something related to I/O workqueues, which is pretty self-explanatory. Now, I need to pinpoint the exact location for this configuration. Given the typical kernel build system structure, `init/Kconfig` is always a good starting point for general system options. However, since the prompt specified `IO_URING`, I would lean toward checking `io_uring/Kconfig` for the configuration option `CONFIG_IO_WQ`. The module structure should provide more detailed information on specific feature settings. The location of the configuration option will provide insight into the context and dependencies of the IO workqueue implementation. Time to dive into those Kconfig files and see what they reveal.

{
  "Expression": "config IO_WQ",
  "PathPrefix": ""
}

{
  "Output": "fs/Kconfig=421=source \"fs/unicode/Kconfig\"\nfs/Kconfig-422-\nfs/Kconfig:423:config IO_WQ\nfs/Kconfig-424-\tbool\n"
}

gemini-3.1-pro-preview

							input: 18045
							output: 24
							thoughts: 17

Okay, here's my interpretation of that thought process, tailored for an expert audience, and presented as if it were my own internal monologue:

**Investigating the `IO_WQ` Boolean**

Alright, so `IO_WQ` is a boolean, and my immediate instinct is to figure out its selection criteria. What conditions or code paths actually *set* this flag? It's a key piece of state, so understanding its origins is critical for debugging or optimizing anything related to it. I need to trace back through the code and pinpoint precisely *where* this boolean is toggled. Are we dealing with a global flag, a per-object attribute, or something more context-dependent? The goal is to build a mental map of its lifecycle so I can anticipate how it behaves and why it might be in a particular state at any given point. Let's dig in and find those write operations.

{
  "Expression": "select IO_WQ",
  "PathPrefix": ""
}

{
  "Output": "init/Kconfig=1918=config IO_URING\ninit/Kconfig-1919-\tbool \"Enable IO uring support\" if EXPERT\ninit/Kconfig:1920:\tselect IO_WQ\ninit/Kconfig-1921-\tdefault y\n"
}

gemini-3.1-pro-preview

							input: 18353
							output: 28
							thoughts: 35

Okay, here's my interpretation of those thoughts, crafted with the expectation that I'm discussing this with a fellow expert:

**IO_URING and IO_WQ: A Quick Scan**

Alright, the core concept I'm working with is `IO_URING` selecting `IO_WQ`. My immediate thought is, "Okay, let's get `IO_URING` activated, that's step one." But before I dive into the implementation, a good practice is to understand the surrounding ecosystem. I need to quickly identify any direct dependencies `IO_WQ` may have. Are there any prerequisites I need to handle first? Any potential conflicts to be aware of? Best to get that lay of the land now, before I waste time making a configuration and finding out later that I need to tweak it due to an unforeseen dependency issue.

{
  "Expression": "config IO_WQ",
  "PathPrefix": "fs/Kconfig"
}

{
  "Output": "fs/Kconfig=421=source \"fs/unicode/Kconfig\"\nfs/Kconfig-422-\nfs/Kconfig:423:config IO_WQ\nfs/Kconfig-424-\tbool\n"
}

gemini-3.1-pro-preview

							input: 18658
							output: 27
							thoughts: 267

**Debugging the IO_URING Boolean**

Okay, so it looks like we're dealing with a simple `bool` issue here, meaning `IO_URING` is the flag to focus on. I need to refresh my memory on the key symbols involved in this area. Let's see... I've got `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, and `io_wq_cancel_cb`.

Aha! Now I remember, the bug must be lurking within `io_worker_cancel_cb`. This is called from `io_worker_exit` and `io_wq_cancel_tw_create`, right? And `io_wq_cancel_tw_create` in turn is called from `io_wq_exit_workers` and `io_queue_worker_create`. Okay, this is starting to make more sense. `io_queue_worker_create` gets called from both `io_wq_dec_running` and `io_wq_create_worker`, which in turn is called from `io_wq_enqueue`. And we're seeing that `io_wq_dec_running` is called from `io_worker_exit` and `io_wq_worker_sleeping`. Now I'm getting a little confused: `io_wq_worker_sleeping` is called from `io_wq_worker`? No, wait a minute... it looks like it's the scheduler that calls `io_wq_worker_sleeping`. I should double-check that part and start digging into the details of the call to `io_wq_worker_sleeping` to confirm the cause of the issue.

{
  "Expression": "io_wq_worker_sleeping",
  "PathPrefix": ""
}

{
  "Output": "io_uring/io-wq.c=756=void io_wq_worker_running(struct task_struct *tsk)\n--\nio_uring/io-wq.c-773- */\nio_uring/io-wq.c:774:void io_wq_worker_sleeping(struct task_struct *tsk)\nio_uring/io-wq.c-775-{\n--\nio_uring/io-wq.h=66=enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,\n--\nio_uring/io-wq.h-69-#if defined(CONFIG_IO_WQ)\nio_uring/io-wq.h:70:extern void io_wq_worker_sleeping(struct task_struct *);\nio_uring/io-wq.h-71-extern void io_wq_worker_running(struct task_struct *);\nio_uring/io-wq.h-72-#else\nio_uring/io-wq.h:73:static inline void io_wq_worker_sleeping(struct task_struct *tsk)\nio_uring/io-wq.h-74-{\n--\nkernel/sched/core.c=7260=static inline void sched_submit_work(struct task_struct *tsk)\n--\nkernel/sched/core.c-7278-\telse if (task_flags \u0026 PF_IO_WORKER)\nkernel/sched/core.c:7279:\t\tio_wq_worker_sleeping(tsk);\nkernel/sched/core.c-7280-\n"
}

gemini-3.1-pro-preview

							input: 19713
							output: 31
							thoughts: 84

Okay, here's my take on those thoughts, framed as my own mental processing:

**Pinpointing the Key Players in I/O Workqueue Sleep/Wake-up**

Right, so `io_wq_worker_sleeping` is triggered by the scheduler itself. That's the crucial hint. This tells me that I need to zoom in on the functions that control workqueue creation, destruction, and task enqueueing and canceling. Let's see... the primary suspects are: `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, and `io_wq_cancel_cb`. Those seem like the logical places to start digging deeper to understand the sleep/wakeup mechanism from this vantage point. Now, is `io_wq_cancel_cb` really a useful focal point in this investigation? Gotta figure out if it's got a strong connection to the process- let's see.

{
  "Expression": "io_wq_cancel_cb",
  "PathPrefix": "io_uring/"
}

{
  "Output": "io_uring/cancel.c=78=static int io_async_cancel_one(struct io_uring_task *tctx,\n--\nio_uring/cancel.c-88-\tall = cd-\u003eflags \u0026 (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY);\nio_uring/cancel.c:89:\tcancel_ret = io_wq_cancel_cb(tctx-\u003eio_wq, io_cancel_cb, cd, all);\nio_uring/cancel.c-90-\tswitch (cancel_ret) {\n--\nio_uring/cancel.c=489=static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)\n--\nio_uring/cancel.c-505-\t\t\tcontinue;\nio_uring/cancel.c:506:\t\tcret = io_wq_cancel_cb(tctx-\u003eio_wq, io_cancel_ctx_cb, ctx, true);\nio_uring/cancel.c-507-\t\tret |= (cret != IO_WQ_CANCEL_NOTFOUND);\n--\nio_uring/cancel.c=515=__cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,\n--\nio_uring/cancel.c-539-\t\t */\nio_uring/cancel.c:540:\t\tcret = io_wq_cancel_cb(tctx-\u003eio_wq, io_cancel_task_cb,\nio_uring/cancel.c-541-\t\t\t\t       \u0026cancel, true);\n--\nio_uring/io-wq.c=1187=static void io_wq_cancel_running_work(struct io_wq *wq,\n--\nio_uring/io-wq.c-1197-\nio_uring/io-wq.c:1198:enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,\nio_uring/io-wq.c-1199-\t\t\t\t  void *data, bool cancel_all)\n--\nio_uring/io-wq.h=64=typedef bool (work_cancel_fn)(struct io_wq_work *, void *);\nio_uring/io-wq.h-65-\nio_uring/io-wq.h:66:enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,\nio_uring/io-wq.h-67-\t\t\t\t\tvoid *data, bool cancel_all);\n--\nio_uring/io_uring.c=2318=static __cold void io_ring_exit_work(struct work_struct *work)\n--\nio_uring/io_uring.c-2357-\t\t\tif (tsk \u0026\u0026 tsk-\u003eio_uring \u0026\u0026 tsk-\u003eio_uring-\u003eio_wq)\nio_uring/io_uring.c:2358:\t\t\t\tio_wq_cancel_cb(tsk-\u003eio_uring-\u003eio_wq,\nio_uring/io_uring.c-2359-\t\t\t\t\t\tio_cancel_ctx_cb, ctx, true);\n"
}

gemini-3.1-pro-preview

							input: 20802
							output: 29
							thoughts: 66

Okay, let's see, my mental gears are turning...

**Tracking Down Callers and Understanding Control Flow**

Right, so `io_wq_cancel_cb`... I recall that this callback is definitely triggered from a few key places. It's called by `io_async_cancel_one`, which makes sense for handling asynchronous cancellation, and also by `io_uring_try_cancel_requests` which is related to I/O ring cancellation attempts, and finally by `io_ring_exit_work` which is part of the clean up process. That makes it a solid focus for my analysis. Those three paths make it fairly central to I/O management.

Hmm, now let me consider... what about `io_wq_create`? Where does that fit in? I should probably review the places that call *that* function too...

{
  "Expression": "io_wq_create",
  "PathPrefix": "io_uring/"
}

{
  "Output": "io_uring/io-wq.c=295=static bool io_acct_activate_free_worker(struct io_wq_acct *acct)\n--\nio_uring/io-wq.c-325- */\nio_uring/io-wq.c:326:static bool io_wq_create_worker(struct io_wq *wq, struct io_wq_acct *acct)\nio_uring/io-wq.c-327-{\n--\nio_uring/io-wq.c=1028=void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)\n--\nio_uring/io-wq.c-1061-\nio_uring/io-wq.c:1062:\t\tdid_create = io_wq_create_worker(wq, acct);\nio_uring/io-wq.c-1063-\t\tif (likely(did_create))\n--\nio_uring/io-wq.c=1235=static int io_wq_hash_wake(struct wait_queue_entry *wait, unsigned mode,\n--\nio_uring/io-wq.c-1253-\nio_uring/io-wq.c:1254:struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)\nio_uring/io-wq.c-1255-{\n--\nio_uring/io-wq.h=37=struct io_wq_data {\n--\nio_uring/io-wq.h-41-\nio_uring/io-wq.h:42:struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);\nio_uring/io-wq.h-43-void io_wq_exit_start(struct io_wq *wq);\n--\nio_uring/tctx.c=16=static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,\n--\nio_uring/tctx.c-42-\nio_uring/tctx.c:43:\treturn io_wq_create(concurrency, \u0026data);\nio_uring/tctx.c-44-}\n"
}

gemini-3.1-pro-preview

							input: 21637
							output: 33
							thoughts: 61

Here's my take on the thought process, as requested:

**Diving into the IO_uring Workqueue Landscape**

Okay, so I'm digging into this `io_uring` code, and I need to pinpoint the critical areas, especially regarding the workqueues. `io_wq_create` is the function that jumps out. I see it's called directly from `io_init_wq_offload` within `io_uring/tctx.c`. That makes `io_wq_create` a good symbol to concentrate on first.

Hmm, while I'm at it, I should consider the complementary function to `io_wq_create`. The name `io_wq_put_and_exit` catches my eye. Is it the key to cleanup and teardown? It's probably worth adding that to my mental map of the core workqueue operations.

{
  "Expression": "io_wq_put_and_exit",
  "PathPrefix": "io_uring/"
}

{
  "Output": "io_uring/io-wq.c=1384=static void io_wq_destroy(struct io_wq *wq)\n--\nio_uring/io-wq.c-1397-\nio_uring/io-wq.c:1398:void io_wq_put_and_exit(struct io_wq *wq)\nio_uring/io-wq.c-1399-{\n--\nio_uring/io-wq.h=43=void io_wq_exit_start(struct io_wq *wq);\nio_uring/io-wq.h:44:void io_wq_put_and_exit(struct io_wq *wq);\nio_uring/io-wq.h-45-void io_wq_set_exit_on_idle(struct io_wq *wq, bool enable);\n--\nio_uring/tctx.c=145=int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)\n--\nio_uring/tctx.c-189-\t\t\tio_wq_exit_start(tctx-\u003eio_wq);\nio_uring/tctx.c:190:\t\t\tio_wq_put_and_exit(tctx-\u003eio_wq);\nio_uring/tctx.c-191-\t\t}\n--\nio_uring/tctx.c=243=__cold void io_uring_clean_tctx(struct io_uring_task *tctx)\n--\nio_uring/tctx.c-257-\t\t */\nio_uring/tctx.c:258:\t\tio_wq_put_and_exit(wq);\nio_uring/tctx.c-259-\t\ttctx-\u003eio_wq = NULL;\n"
}

gemini-3.1-pro-preview

							input: 22357
							output: 29
							thoughts: 30

Okay, here's my take on those thoughts, framed as an expert's internal monologue:

**Focusing on IO Completion Queues**

Alright, yep, `io_wq_put_and_exit` seems like a solid candidate for my initial focus. It's a key point in the lifecycle, handling the "cleanup on exit" aspect which is always critical. I've got a decent understanding of how it fits in at the moment.

Hmm, but what about `io_wq_enqueue`? Thinking about it a bit, I'm already aware that enqueueing is probably a relevant area to examine, because a bottleneck or issue there could ripple throughout the entire system. It’s where work gets injected, so any inefficiencies are going to propagate. Maybe I should consider that as well.

{
  "Expression": "io_wq_enqueue",
  "PathPrefix": "io_uring/"
}

{
  "Output": "io_uring/io-wq.c=601=static void io_worker_handle_work(struct io_wq_acct *acct,\n--\nio_uring/io-wq.c-665-\t\t\tif (linked)\nio_uring/io-wq.c:666:\t\t\t\tio_wq_enqueue(wq, linked);\nio_uring/io-wq.c-667-\n--\nio_uring/io-wq.c=1023=static bool io_wq_work_match_item(struct io_wq_work *work, void *data)\n--\nio_uring/io-wq.c-1027-\nio_uring/io-wq.c:1028:void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)\nio_uring/io-wq.c-1029-{\n--\nio_uring/io-wq.h=45=void io_wq_set_exit_on_idle(struct io_wq *wq, bool enable);\nio_uring/io-wq.h-46-\nio_uring/io-wq.h:47:void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);\nio_uring/io-wq.h-48-void io_wq_hash_work(struct io_wq_work *work, void *val);\n--\nio_uring/io_uring.c=408=static void io_queue_iowq(struct io_kiocb *req)\n--\nio_uring/io_uring.c-432-\ttrace_io_uring_queue_async_work(req, io_wq_is_hashed(\u0026req-\u003ework));\nio_uring/io_uring.c:433:\tio_wq_enqueue(tctx-\u003eio_wq, \u0026req-\u003ework);\nio_uring/io_uring.c-434-}\n"
}

gemini-3.1-pro-preview

							input: 23067
							output: 164
							thoughts: 295

**My Analysis of the io_uring Worker Cancellation Patch**

Okay, after reviewing the patch and its context, I've zeroed in on `io_wq_enqueue` as a key symbol for focused fuzzing – seems like a good starting point. Expanding on that, the other functions to keep an eye on are `io_wq_create`, `io_wq_put_and_exit`, and `io_wq_cancel_cb`. Those, along with `io_wq_enqueue`, will give me a solid coverage of the relevant components.

Now, let's confirm the configuration. It looks like the main configuration option controlling this area is `IO_URING`. Double-checking...yes, `CONFIG_IO_URING` is defined in `init/Kconfig`. Wait, hold on... it appears that `CONFIG_IO_WQ` is automatically selected by `CONFIG_IO_URING`. Excellent, that simplifies things – just `IO_URING` is sufficient to enable the code paths I need to target.

I need to articulate the reasoning behind this selection, for my own record and to clarify the rationale for fuzzing. The patch is specifically modifying `io_worker_cancel_cb` within `io_uring/io-wq.c`. The change conditional decrements `acct->nr_workers` in the function only when a very specific condition is met, namely `worker->create_work.func != create_worker_cb`. This is fixing a bug related to io_uring worker cancellation, where the worker slot wasn't properly reserved. This is a *functional* change in the core io_uring logic. I think that it's worth fuzzing given that it's in a reachable code path.

So, to summarize:

*   **Focus Symbols:** `io_wq_create`, `io_wq_put_and_exit`, `io_wq_enqueue`, `io_wq_cancel_cb`
*   **Enable Configs:** `IO_URING`

I'm ready to proceed with setting up the fuzzing environment and targeting these components now.

{
  "EnableConfigs": [
    "IO_URING"
  ],
  "FocusSymbols": [
    "io_wq_create",
    "io_wq_put_and_exit",
    "io_wq_enqueue",
    "io_wq_cancel_cb"
  ],
  "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "IO_URING"
  ],
  "FocusSymbols": [
    "io_wq_create",
    "io_wq_put_and_exit",
    "io_wq_enqueue",
    "io_wq_cancel_cb"
  ],
  "Reasoning": "The patch modifies `io_worker_cancel_cb` in `io_uring/io-wq.c` to conditionally decrement `acct-\u003enr_workers` only if `worker-\u003ecreate_work.func != create_worker_cb`. This fixes a bug in io_uring worker cancellation where the worker slot was not yet reserved. This is a functional change in the core io_uring logic that is reachable and worth fuzzing.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

{
  "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.",
  "NeedsKMSAN": false
}

You are an expert Linux kernel security engineer specializing in kernel memory
error detectors (KASAN and KMSAN). Your job is to review the provided patch series and
determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer)
fuzzing session in addition to standard KASAN fuzzing.

CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN:
- Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable
  a comprehensive suite of debugging tools and sanitizers, including KASAN
  (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP
  (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks.
- KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap,
  or page allocations) and kernel-to-user memory info-leaks.

Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN,
LOCKDEP, OR OTHER STANDARD BUG DETECTORS.
A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY
set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks
that are detected ONLY by KMSAN.

Look holistically at the patch series and surrounding code. Even if no direct
uninitialized field accesses or new buffer allocations are added in the diff itself,
a patch may alter control flow, bounds checking, or data length calculations in ways
that change how the rest of the code operates on existing buffers (e.g. allowing
uninitialized stack/heap memory to be read, copied to user space, or used in control
flow). Do not hesitate to use your code access tools to inspect the surrounding code,
called functions, and callers.

Set NeedsKMSAN=true ONLY IF the patch introduces or modifies:
1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb
   attributes, ioctl output arguments, socket options, or BPF buffers) where fields
   or structure padding might not be fully initialized/zeroed.
2. Conditional logic or branching that depends on potentially uninitialized variables
   or struct fields.
3. Allocation or initialization of complex data structures where uninitialized fields
   could be read later in reachable code paths.
4. Bounds checks, lengths, or logic in a way that allows surrounding code to access
   uninitialized bytes of existing buffers.

Set NeedsKMSAN=false IF:
- The code changes primarily risk out-of-bounds access, array overflows, NULL pointer
  dereferences, locking deadlocks, or use-after-free bugs (these are already caught
  by KASAN, LOCKDEP, or standard bug detectors).
- All stack/heap structures touched or introduced by the patch are fully zeroed
  or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied.
- The patch does not introduce any risk of uninitialized memory usage or info-leaks.

Use your code access tools to inspect the surrounding code if necessary, then provide
detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit 2ecaa2a619cf9c377d20a4f876432c84e3d16065
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Aug 11 07:22:49 2026 +0000

    syz-cluster: applied patch under review

diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index 2e14880eef92a..fa403ed245962 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -211,9 +211,12 @@ static void io_worker_cancel_cb(struct io_worker *worker)
 	struct io_wq *wq = worker->wq;
 
 	atomic_dec(&acct->nr_running);
-	raw_spin_lock(&acct->workers_lock);
-	acct->nr_workers--;
-	raw_spin_unlock(&acct->workers_lock);
+	/* create_worker_cb() has not reserved a worker slot yet. */
+	if (worker->create_work.func != create_worker_cb) {
+		raw_spin_lock(&acct->workers_lock);
+		acct->nr_workers--;
+		raw_spin_unlock(&acct->workers_lock);
+	}
 	io_worker_ref_put(wq);
 	clear_bit_unlock(0, &worker->create_state);
 	io_worker_release(worker);

gemini-3.1-pro-preview

							input: 2096
							output: 108
							thoughts: 499

**Analyzing the io_uring Worker Accounting Patch**

Okay, so I'm looking at this patch for `io_uring/io-wq.c`, specifically the modification to `io_worker_cancel_cb`. It's a pretty straightforward fix, and thankfully, it doesn't involve any of the memory safety issues that keep me up at night!

The crux of the change is this conditional check being added around the decrement of `acct->nr_workers`:

```c
	/* create_worker_cb() has not reserved a worker slot yet. */
	if (worker->create_work.func != create_worker_cb) {
		raw_spin_lock(&acct->workers_lock);
		acct->nr_workers--;
		raw_spin_unlock(&acct->workers_lock);
	}
```

Essentially, we're making sure we only decrement the worker count if `create_worker_cb` hasn't already reserved a slot. It's an accounting correction. Before this change, there was a bug where the worker count was being decremented prematurely in certain scenarios. This could lead to incorrect worker counts, possibly leading to subtle deadlocks, or resource leaks.

Now, going through `io_worker_cancel_cb` again, it's clear this is just about keeping track of the workers, nothing else.

```c
static void io_worker_cancel_cb(struct io_worker *worker)
{
	struct io_wq_acct *acct = io_wq_get_acct(worker);
	struct io_wq *wq = worker->wq;

	atomic_dec(&acct->nr_running);
	/* create_worker_cb() has not reserved a worker slot yet. */
	if (worker->create_work.func != create_worker_cb) {
		raw_spin_lock(&acct->workers_lock);
		acct->nr_workers--;
		raw_spin_unlock(&acct->workers_lock);
	}
	io_worker_ref_put(wq);
	clear_bit_unlock(0, &worker->create_state);
	io_worker_release(worker);
}
```

So, definitely no uninitialized memory shenanigans are at play here, which is a relief. I'm comfortable saying this doesn't need to be flagged for KMSAN, I'll set NeedsKMSAN to false. It's purely an accounting fix.

{
  "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch fixes an accounting bug in io_worker_cancel_cb() where acct-\u003enr_workers was decremented even if create_worker_cb() had not reserved a worker slot yet. This is a logic bug related to resource accounting and concurrency, which does not involve uninitialized memory reads, info-leaks, or uninitialized structure fields. Therefore, KMSAN is not applicable here.",
  "NeedsKMSAN": false
}

LLM Calls Summary:
Total Calls	Total Tokens	Avg Tokens	Total Duration (Seconds)	Avg Duration (Seconds)

Tool Calls Summary:
Total Calls	Total Duration (Seconds)	Avg Duration (Seconds)