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Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c86
1 files changed, 63 insertions, 23 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3790c7fe9fee..aae0ef2ec34d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1753,6 +1753,9 @@ static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb,
struct io_ring_ctx *ctx = req->ctx;
int ret, notify;
+ if (tsk->flags & PF_EXITING)
+ return -ESRCH;
+
/*
* SQPOLL kernel thread doesn't need notification, just a wakeup. For
* all other cases, use TWA_SIGNAL unconditionally to ensure we're
@@ -1787,8 +1790,10 @@ static void __io_req_task_cancel(struct io_kiocb *req, int error)
static void io_req_task_cancel(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
+ struct io_ring_ctx *ctx = req->ctx;
__io_req_task_cancel(req, -ECANCELED);
+ percpu_ref_put(&ctx->refs);
}
static void __io_req_task_submit(struct io_kiocb *req)
@@ -2010,6 +2015,12 @@ static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
static inline bool io_run_task_work(void)
{
+ /*
+ * Not safe to run on exiting task, and the task_work handling will
+ * not add work to such a task.
+ */
+ if (unlikely(current->flags & PF_EXITING))
+ return false;
if (current->task_works) {
__set_current_state(TASK_RUNNING);
task_work_run();
@@ -2283,13 +2294,17 @@ static bool io_resubmit_prep(struct io_kiocb *req, int error)
goto end_req;
}
- ret = io_import_iovec(rw, req, &iovec, &iter, false);
- if (ret < 0)
- goto end_req;
- ret = io_setup_async_rw(req, iovec, inline_vecs, &iter, false);
- if (!ret)
+ if (!req->io) {
+ ret = io_import_iovec(rw, req, &iovec, &iter, false);
+ if (ret < 0)
+ goto end_req;
+ ret = io_setup_async_rw(req, iovec, inline_vecs, &iter, false);
+ if (!ret)
+ return true;
+ kfree(iovec);
+ } else {
return true;
- kfree(iovec);
+ }
end_req:
req_set_fail_links(req);
io_req_complete(req, ret);
@@ -3034,6 +3049,7 @@ static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
if (!wake_page_match(wpq, key))
return 0;
+ req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
list_del_init(&wait->entry);
init_task_work(&req->task_work, io_req_task_submit);
@@ -3091,6 +3107,7 @@ static bool io_rw_should_retry(struct io_kiocb *req)
wait->wait.flags = 0;
INIT_LIST_HEAD(&wait->wait.entry);
kiocb->ki_flags |= IOCB_WAITQ;
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
kiocb->ki_waitq = wait;
io_get_req_task(req);
@@ -3115,6 +3132,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
struct iov_iter __iter, *iter = &__iter;
ssize_t io_size, ret, ret2;
size_t iov_count;
+ bool no_async;
if (req->io)
iter = &req->io->rw.iter;
@@ -3132,7 +3150,8 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
kiocb->ki_flags &= ~IOCB_NOWAIT;
/* If the file doesn't support async, just async punt */
- if (force_nonblock && !io_file_supports_async(req->file, READ))
+ no_async = force_nonblock && !io_file_supports_async(req->file, READ);
+ if (no_async)
goto copy_iov;
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), iov_count);
@@ -3155,10 +3174,8 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
goto done;
/* some cases will consume bytes even on error returns */
iov_iter_revert(iter, iov_count - iov_iter_count(iter));
- ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
- if (ret)
- goto out_free;
- return -EAGAIN;
+ ret = 0;
+ goto copy_iov;
} else if (ret < 0) {
/* make sure -ERESTARTSYS -> -EINTR is done */
goto done;
@@ -3176,6 +3193,8 @@ copy_iov:
ret = ret2;
goto out_free;
}
+ if (no_async)
+ return -EAGAIN;
/* it's copied and will be cleaned with ->io */
iovec = NULL;
/* now use our persistent iterator, if we aren't already */
@@ -3508,8 +3527,6 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
const char __user *fname;
int ret;
- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
- return -EINVAL;
if (unlikely(sqe->ioprio || sqe->buf_index))
return -EINVAL;
if (unlikely(req->flags & REQ_F_FIXED_FILE))
@@ -3536,6 +3553,8 @@ static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
u64 flags, mode;
+ if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
+ return -EINVAL;
if (req->flags & REQ_F_NEED_CLEANUP)
return 0;
mode = READ_ONCE(sqe->len);
@@ -3550,6 +3569,8 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
size_t len;
int ret;
+ if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
+ return -EINVAL;
if (req->flags & REQ_F_NEED_CLEANUP)
return 0;
how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
@@ -3767,7 +3788,7 @@ static int io_epoll_ctl_prep(struct io_kiocb *req,
#if defined(CONFIG_EPOLL)
if (sqe->ioprio || sqe->buf_index)
return -EINVAL;
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
return -EINVAL;
req->epoll.epfd = READ_ONCE(sqe->fd);
@@ -3882,7 +3903,7 @@ static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+ if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
return -EINVAL;
if (sqe->ioprio || sqe->buf_index)
return -EINVAL;
@@ -4724,6 +4745,8 @@ static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
if (mask && !(mask & poll->events))
return 0;
+ list_del_init(&wait->entry);
+
if (poll && poll->head) {
bool done;
@@ -5399,6 +5422,8 @@ static int io_async_cancel(struct io_kiocb *req)
static int io_files_update_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
+ if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL))
+ return -EINVAL;
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
return -EINVAL;
if (sqe->ioprio || sqe->rw_flags)
@@ -5449,6 +5474,8 @@ static int io_req_defer_prep(struct io_kiocb *req,
if (unlikely(ret))
return ret;
+ io_prep_async_work(req);
+
switch (req->opcode) {
case IORING_OP_NOP:
break;
@@ -5646,6 +5673,11 @@ static void __io_clean_op(struct io_kiocb *req)
io_put_file(req, req->splice.file_in,
(req->splice.flags & SPLICE_F_FD_IN_FIXED));
break;
+ case IORING_OP_OPENAT:
+ case IORING_OP_OPENAT2:
+ if (req->open.filename)
+ putname(req->open.filename);
+ break;
}
req->flags &= ~REQ_F_NEED_CLEANUP;
}
@@ -6323,9 +6355,6 @@ static void io_submit_state_start(struct io_submit_state *state,
struct io_ring_ctx *ctx, unsigned int max_ios)
{
blk_start_plug(&state->plug);
-#ifdef CONFIG_BLOCK
- state->plug.nowait = true;
-#endif
state->comp.nr = 0;
INIT_LIST_HEAD(&state->comp.list);
state->comp.ctx = ctx;
@@ -8180,6 +8209,8 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
/* cancel this request, or head link requests */
io_attempt_cancel(ctx, cancel_req);
io_put_req(cancel_req);
+ /* cancellations _may_ trigger task work */
+ io_run_task_work();
schedule();
finish_wait(&ctx->inflight_wait, &wait);
}
@@ -8385,11 +8416,19 @@ static int io_uring_show_cred(int id, void *p, void *data)
static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
{
+ bool has_lock;
int i;
- mutex_lock(&ctx->uring_lock);
+ /*
+ * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
+ * since fdinfo case grabs it in the opposite direction of normal use
+ * cases. If we fail to get the lock, we just don't iterate any
+ * structures that could be going away outside the io_uring mutex.
+ */
+ has_lock = mutex_trylock(&ctx->uring_lock);
+
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
- for (i = 0; i < ctx->nr_user_files; i++) {
+ for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
struct fixed_file_table *table;
struct file *f;
@@ -8401,13 +8440,13 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
seq_printf(m, "%5u: <none>\n", i);
}
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
- for (i = 0; i < ctx->nr_user_bufs; i++) {
+ for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
(unsigned int) buf->len);
}
- if (!idr_is_empty(&ctx->personality_idr)) {
+ if (has_lock && !idr_is_empty(&ctx->personality_idr)) {
seq_printf(m, "Personalities:\n");
idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
}
@@ -8422,7 +8461,8 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
req->task->task_works != NULL);
}
spin_unlock_irq(&ctx->completion_lock);
- mutex_unlock(&ctx->uring_lock);
+ if (has_lock)
+ mutex_unlock(&ctx->uring_lock);
}
static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.