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authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-24 13:03:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-24 13:03:40 -0700
commit0ee818c393dce98340bff2b08573d4d2d8650eb7 (patch)
tree9512ab02eba9e7341020a53f5c75b08be9999cbb /fs
parent4d4a60cede3604208c671f5a73a6edd094237b13 (diff)
parent991468dcf198bb87f24da330676724a704912b47 (diff)
Merge tag 'io_uring-5.14-2021-07-24' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe: - Fix a memory leak due to a race condition in io_init_wq_offload (Yang) - Poll error handling fixes (Pavel) - Fix early fdput() regression (me) - Don't reissue iopoll requests off release path (me) - Add a safety check for io-wq queue off wrong path (me) * tag 'io_uring-5.14-2021-07-24' of git://git.kernel.dk/linux-block: io_uring: explicitly catch any illegal async queue attempt io_uring: never attempt iopoll reissue from release path io_uring: fix early fdput() of file io_uring: fix memleak in io_init_wq_offload() io_uring: remove double poll entry on arm failure io_uring: explicitly count entries for poll reqs
Diffstat (limited to 'fs')
-rw-r--r--fs/io-wq.c7
-rw-r--r--fs/io_uring.c55
2 files changed, 45 insertions, 17 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 843d4a7bcd6e..cf086b01c6c6 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -731,7 +731,12 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
int work_flags;
unsigned long flags;
- if (test_bit(IO_WQ_BIT_EXIT, &wqe->wq->state)) {
+ /*
+ * If io-wq is exiting for this task, or if the request has explicitly
+ * been marked as one that should not get executed, cancel it here.
+ */
+ if (test_bit(IO_WQ_BIT_EXIT, &wqe->wq->state) ||
+ (work->flags & IO_WQ_WORK_CANCEL)) {
io_run_cancel(work, wqe);
return;
}
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0cac361bf6b8..5a0fd6bcd318 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1294,6 +1294,17 @@ static void io_queue_async_work(struct io_kiocb *req)
/* init ->work of the whole link before punting */
io_prep_async_link(req);
+
+ /*
+ * Not expected to happen, but if we do have a bug where this _can_
+ * happen, catch it here and ensure the request is marked as
+ * canceled. That will make io-wq go through the usual work cancel
+ * procedure rather than attempt to run this request (or create a new
+ * worker for it).
+ */
+ if (WARN_ON_ONCE(!same_thread_group(req->task, current)))
+ req->work.flags |= IO_WQ_WORK_CANCEL;
+
trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
&req->work, req->flags);
io_wq_enqueue(tctx->io_wq, &req->work);
@@ -2205,7 +2216,7 @@ static inline bool io_run_task_work(void)
* Find and free completed poll iocbs
*/
static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
- struct list_head *done)
+ struct list_head *done, bool resubmit)
{
struct req_batch rb;
struct io_kiocb *req;
@@ -2220,7 +2231,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
req = list_first_entry(done, struct io_kiocb, inflight_entry);
list_del(&req->inflight_entry);
- if (READ_ONCE(req->result) == -EAGAIN &&
+ if (READ_ONCE(req->result) == -EAGAIN && resubmit &&
!(req->flags & REQ_F_DONT_REISSUE)) {
req->iopoll_completed = 0;
req_ref_get(req);
@@ -2244,7 +2255,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
}
static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
- long min)
+ long min, bool resubmit)
{
struct io_kiocb *req, *tmp;
LIST_HEAD(done);
@@ -2287,7 +2298,7 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
}
if (!list_empty(&done))
- io_iopoll_complete(ctx, nr_events, &done);
+ io_iopoll_complete(ctx, nr_events, &done, resubmit);
return ret;
}
@@ -2305,7 +2316,7 @@ static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
while (!list_empty(&ctx->iopoll_list)) {
unsigned int nr_events = 0;
- io_do_iopoll(ctx, &nr_events, 0);
+ io_do_iopoll(ctx, &nr_events, 0, false);
/* let it sleep and repeat later if can't complete a request */
if (nr_events == 0)
@@ -2367,7 +2378,7 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
list_empty(&ctx->iopoll_list))
break;
}
- ret = io_do_iopoll(ctx, &nr_events, min);
+ ret = io_do_iopoll(ctx, &nr_events, min, true);
} while (!ret && nr_events < min && !need_resched());
out:
mutex_unlock(&ctx->uring_lock);
@@ -4802,6 +4813,7 @@ IO_NETOP_FN(recv);
struct io_poll_table {
struct poll_table_struct pt;
struct io_kiocb *req;
+ int nr_entries;
int error;
};
@@ -4995,11 +5007,11 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
struct io_kiocb *req = pt->req;
/*
- * If poll->head is already set, it's because the file being polled
- * uses multiple waitqueues for poll handling (eg one for read, one
- * for write). Setup a separate io_poll_iocb if this happens.
+ * The file being polled uses multiple waitqueues for poll handling
+ * (e.g. one for read, one for write). Setup a separate io_poll_iocb
+ * if this happens.
*/
- if (unlikely(poll->head)) {
+ if (unlikely(pt->nr_entries)) {
struct io_poll_iocb *poll_one = poll;
/* already have a 2nd entry, fail a third attempt */
@@ -5027,7 +5039,7 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
*poll_ptr = poll;
}
- pt->error = 0;
+ pt->nr_entries++;
poll->head = head;
if (poll->events & EPOLLEXCLUSIVE)
@@ -5104,11 +5116,16 @@ static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
ipt->pt._key = mask;
ipt->req = req;
- ipt->error = -EINVAL;
+ ipt->error = 0;
+ ipt->nr_entries = 0;
mask = vfs_poll(req->file, &ipt->pt) & poll->events;
+ if (unlikely(!ipt->nr_entries) && !ipt->error)
+ ipt->error = -EINVAL;
spin_lock_irq(&ctx->completion_lock);
+ if (ipt->error)
+ io_poll_remove_double(req);
if (likely(poll->head)) {
spin_lock(&poll->head->lock);
if (unlikely(list_empty(&poll->wait.entry))) {
@@ -6792,7 +6809,7 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
mutex_lock(&ctx->uring_lock);
if (!list_empty(&ctx->iopoll_list))
- io_do_iopoll(ctx, &nr_events, 0);
+ io_do_iopoll(ctx, &nr_events, 0, true);
/*
* Don't submit if refs are dying, good for io_uring_register(),
@@ -7899,15 +7916,19 @@ static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,
struct io_wq_data data;
unsigned int concurrency;
+ mutex_lock(&ctx->uring_lock);
hash = ctx->hash_map;
if (!hash) {
hash = kzalloc(sizeof(*hash), GFP_KERNEL);
- if (!hash)
+ if (!hash) {
+ mutex_unlock(&ctx->uring_lock);
return ERR_PTR(-ENOMEM);
+ }
refcount_set(&hash->refs, 1);
init_waitqueue_head(&hash->wait);
ctx->hash_map = hash;
}
+ mutex_unlock(&ctx->uring_lock);
data.hash = hash;
data.task = task;
@@ -7981,9 +8002,11 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx,
f = fdget(p->wq_fd);
if (!f.file)
return -ENXIO;
- fdput(f);
- if (f.file->f_op != &io_uring_fops)
+ if (f.file->f_op != &io_uring_fops) {
+ fdput(f);
return -EINVAL;
+ }
+ fdput(f);
}
if (ctx->flags & IORING_SETUP_SQPOLL) {
struct task_struct *tsk;