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Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c241
1 files changed, 217 insertions, 24 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index f83de4c6a826..dd094b387cab 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -200,6 +200,7 @@ struct io_ring_ctx {
struct io_uring_sqe *sq_sqes;
struct list_head defer_list;
+ struct list_head timeout_list;
} ____cacheline_aligned_in_smp;
/* IO offload */
@@ -216,6 +217,7 @@ struct io_ring_ctx {
struct wait_queue_head cq_wait;
struct fasync_struct *cq_fasync;
struct eventfd_ctx *cq_ev_fd;
+ atomic_t cq_timeouts;
} ____cacheline_aligned_in_smp;
struct io_rings *rings;
@@ -283,6 +285,11 @@ struct io_poll_iocb {
struct wait_queue_entry wait;
};
+struct io_timeout {
+ struct file *file;
+ struct hrtimer timer;
+};
+
/*
* NOTE! Each of the iocb union members has the file pointer
* as the first entry in their struct definition. So you can
@@ -294,6 +301,7 @@ struct io_kiocb {
struct file *file;
struct kiocb rw;
struct io_poll_iocb poll;
+ struct io_timeout timeout;
};
struct sqe_submit submit;
@@ -313,6 +321,7 @@ struct io_kiocb {
#define REQ_F_LINK_DONE 128 /* linked sqes done */
#define REQ_F_FAIL_LINK 256 /* fail rest of links */
#define REQ_F_SHADOW_DRAIN 512 /* link-drain shadow req */
+#define REQ_F_TIMEOUT 1024 /* timeout request */
u64 user_data;
u32 result;
u32 sequence;
@@ -344,6 +353,8 @@ struct io_submit_state {
};
static void io_sq_wq_submit_work(struct work_struct *work);
+static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data,
+ long res);
static void __io_free_req(struct io_kiocb *req);
static struct kmem_cache *req_cachep;
@@ -400,26 +411,30 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
INIT_LIST_HEAD(&ctx->poll_list);
INIT_LIST_HEAD(&ctx->cancel_list);
INIT_LIST_HEAD(&ctx->defer_list);
+ INIT_LIST_HEAD(&ctx->timeout_list);
return ctx;
}
static inline bool io_sequence_defer(struct io_ring_ctx *ctx,
struct io_kiocb *req)
{
- if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN)
+ /* timeout requests always honor sequence */
+ if (!(req->flags & REQ_F_TIMEOUT) &&
+ (req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN)
return false;
return req->sequence != ctx->cached_cq_tail + ctx->rings->sq_dropped;
}
-static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
+static struct io_kiocb *__io_get_deferred_req(struct io_ring_ctx *ctx,
+ struct list_head *list)
{
struct io_kiocb *req;
- if (list_empty(&ctx->defer_list))
+ if (list_empty(list))
return NULL;
- req = list_first_entry(&ctx->defer_list, struct io_kiocb, list);
+ req = list_first_entry(list, struct io_kiocb, list);
if (!io_sequence_defer(ctx, req)) {
list_del_init(&req->list);
return req;
@@ -428,6 +443,16 @@ static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
return NULL;
}
+static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
+{
+ return __io_get_deferred_req(ctx, &ctx->defer_list);
+}
+
+static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx)
+{
+ return __io_get_deferred_req(ctx, &ctx->timeout_list);
+}
+
static void __io_commit_cqring(struct io_ring_ctx *ctx)
{
struct io_rings *rings = ctx->rings;
@@ -446,25 +471,50 @@ static void __io_commit_cqring(struct io_ring_ctx *ctx)
static inline void io_queue_async_work(struct io_ring_ctx *ctx,
struct io_kiocb *req)
{
- int rw;
+ int rw = 0;
- switch (req->submit.sqe->opcode) {
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- rw = !(req->rw.ki_flags & IOCB_DIRECT);
- break;
- default:
- rw = 0;
- break;
+ if (req->submit.sqe) {
+ switch (req->submit.sqe->opcode) {
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ rw = !(req->rw.ki_flags & IOCB_DIRECT);
+ break;
+ }
}
queue_work(ctx->sqo_wq[rw], &req->work);
}
+static void io_kill_timeout(struct io_kiocb *req)
+{
+ int ret;
+
+ ret = hrtimer_try_to_cancel(&req->timeout.timer);
+ if (ret != -1) {
+ atomic_inc(&req->ctx->cq_timeouts);
+ list_del(&req->list);
+ io_cqring_fill_event(req->ctx, req->user_data, 0);
+ __io_free_req(req);
+ }
+}
+
+static void io_kill_timeouts(struct io_ring_ctx *ctx)
+{
+ struct io_kiocb *req, *tmp;
+
+ spin_lock_irq(&ctx->completion_lock);
+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, list)
+ io_kill_timeout(req);
+ spin_unlock_irq(&ctx->completion_lock);
+}
+
static void io_commit_cqring(struct io_ring_ctx *ctx)
{
struct io_kiocb *req;
+ while ((req = io_get_timeout_req(ctx)) != NULL)
+ io_kill_timeout(req);
+
__io_commit_cqring(ctx);
while ((req = io_get_deferred_req(ctx)) != NULL) {
@@ -1248,6 +1298,51 @@ static void io_async_list_note(int rw, struct io_kiocb *req, size_t len)
}
}
+/*
+ * For files that don't have ->read_iter() and ->write_iter(), handle them
+ * by looping over ->read() or ->write() manually.
+ */
+static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb,
+ struct iov_iter *iter)
+{
+ ssize_t ret = 0;
+
+ /*
+ * Don't support polled IO through this interface, and we can't
+ * support non-blocking either. For the latter, this just causes
+ * the kiocb to be handled from an async context.
+ */
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EOPNOTSUPP;
+ if (kiocb->ki_flags & IOCB_NOWAIT)
+ return -EAGAIN;
+
+ while (iov_iter_count(iter)) {
+ struct iovec iovec = iov_iter_iovec(iter);
+ ssize_t nr;
+
+ if (rw == READ) {
+ nr = file->f_op->read(file, iovec.iov_base,
+ iovec.iov_len, &kiocb->ki_pos);
+ } else {
+ nr = file->f_op->write(file, iovec.iov_base,
+ iovec.iov_len, &kiocb->ki_pos);
+ }
+
+ if (nr < 0) {
+ if (!ret)
+ ret = nr;
+ break;
+ }
+ ret += nr;
+ if (nr != iovec.iov_len)
+ break;
+ iov_iter_advance(iter, nr);
+ }
+
+ return ret;
+}
+
static int io_read(struct io_kiocb *req, const struct sqe_submit *s,
bool force_nonblock)
{
@@ -1265,8 +1360,6 @@ static int io_read(struct io_kiocb *req, const struct sqe_submit *s,
if (unlikely(!(file->f_mode & FMODE_READ)))
return -EBADF;
- if (unlikely(!file->f_op->read_iter))
- return -EINVAL;
ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter);
if (ret < 0)
@@ -1281,7 +1374,11 @@ static int io_read(struct io_kiocb *req, const struct sqe_submit *s,
if (!ret) {
ssize_t ret2;
- ret2 = call_read_iter(file, kiocb, &iter);
+ if (file->f_op->read_iter)
+ ret2 = call_read_iter(file, kiocb, &iter);
+ else
+ ret2 = loop_rw_iter(READ, file, kiocb, &iter);
+
/*
* In case of a short read, punt to async. This can happen
* if we have data partially cached. Alternatively we can
@@ -1326,8 +1423,6 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s,
file = kiocb->ki_filp;
if (unlikely(!(file->f_mode & FMODE_WRITE)))
return -EBADF;
- if (unlikely(!file->f_op->write_iter))
- return -EINVAL;
ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter);
if (ret < 0)
@@ -1365,7 +1460,10 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s,
}
kiocb->ki_flags |= IOCB_WRITE;
- ret2 = call_write_iter(file, kiocb, &iter);
+ if (file->f_op->write_iter)
+ ret2 = call_write_iter(file, kiocb, &iter);
+ else
+ ret2 = loop_rw_iter(WRITE, file, kiocb, &iter);
if (!force_nonblock || ret2 != -EAGAIN) {
io_rw_done(kiocb, ret2);
} else {
@@ -1714,6 +1812,7 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe)
if (!poll->file)
return -EBADF;
+ req->submit.sqe = NULL;
INIT_WORK(&req->work, io_poll_complete_work);
events = READ_ONCE(sqe->poll_events);
poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP;
@@ -1765,6 +1864,81 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return ipt.error;
}
+static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
+{
+ struct io_ring_ctx *ctx;
+ struct io_kiocb *req;
+ unsigned long flags;
+
+ req = container_of(timer, struct io_kiocb, timeout.timer);
+ ctx = req->ctx;
+ atomic_inc(&ctx->cq_timeouts);
+
+ spin_lock_irqsave(&ctx->completion_lock, flags);
+ list_del(&req->list);
+
+ io_cqring_fill_event(ctx, req->user_data, -ETIME);
+ io_commit_cqring(ctx);
+ spin_unlock_irqrestore(&ctx->completion_lock, flags);
+
+ io_cqring_ev_posted(ctx);
+
+ io_put_req(req);
+ return HRTIMER_NORESTART;
+}
+
+static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ unsigned count, req_dist, tail_index;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct list_head *entry;
+ struct timespec ts;
+
+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
+ return -EINVAL;
+ if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->timeout_flags ||
+ sqe->len != 1)
+ return -EINVAL;
+ if (copy_from_user(&ts, (void __user *) (unsigned long) sqe->addr,
+ sizeof(ts)))
+ return -EFAULT;
+
+ /*
+ * sqe->off holds how many events that need to occur for this
+ * timeout event to be satisfied.
+ */
+ count = READ_ONCE(sqe->off);
+ if (!count)
+ count = 1;
+
+ req->sequence = ctx->cached_sq_head + count - 1;
+ req->flags |= REQ_F_TIMEOUT;
+
+ /*
+ * Insertion sort, ensuring the first entry in the list is always
+ * the one we need first.
+ */
+ tail_index = ctx->cached_cq_tail - ctx->rings->sq_dropped;
+ req_dist = req->sequence - tail_index;
+ spin_lock_irq(&ctx->completion_lock);
+ list_for_each_prev(entry, &ctx->timeout_list) {
+ struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, list);
+ unsigned dist;
+
+ dist = nxt->sequence - tail_index;
+ if (req_dist >= dist)
+ break;
+ }
+ list_add(&req->list, entry);
+ spin_unlock_irq(&ctx->completion_lock);
+
+ hrtimer_init(&req->timeout.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ req->timeout.timer.function = io_timeout_fn;
+ hrtimer_start(&req->timeout.timer, timespec_to_ktime(ts),
+ HRTIMER_MODE_REL);
+ return 0;
+}
+
static int io_req_defer(struct io_ring_ctx *ctx, struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
@@ -1842,6 +2016,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
case IORING_OP_RECVMSG:
ret = io_recvmsg(req, s->sqe, force_nonblock);
break;
+ case IORING_OP_TIMEOUT:
+ ret = io_timeout(req, s->sqe);
+ break;
default:
ret = -EINVAL;
break;
@@ -2098,13 +2275,11 @@ static int __io_queue_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
struct io_uring_sqe *sqe_copy;
- sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL);
+ sqe_copy = kmemdup(s->sqe, sizeof(*sqe_copy), GFP_KERNEL);
if (sqe_copy) {
struct async_list *list;
- memcpy(sqe_copy, s->sqe, sizeof(*sqe_copy));
s->sqe = sqe_copy;
-
memcpy(&req->submit, s, sizeof(*s));
list = io_async_list_from_sqe(ctx, s->sqe);
if (!io_add_to_prev_work(list, req)) {
@@ -2359,18 +2534,22 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes,
io_queue_link_head(ctx, link, &link->submit, shadow_req,
true);
link = NULL;
+ shadow_req = NULL;
}
prev_was_link = (sqes[i].sqe->flags & IOSQE_IO_LINK) != 0;
if (link && (sqes[i].sqe->flags & IOSQE_IO_DRAIN)) {
if (!shadow_req) {
shadow_req = io_get_req(ctx, NULL);
+ if (unlikely(!shadow_req))
+ goto out;
shadow_req->flags |= (REQ_F_IO_DRAIN | REQ_F_SHADOW_DRAIN);
refcount_dec(&shadow_req->refs);
}
shadow_req->sequence = sqes[i].sequence;
}
+out:
if (unlikely(mm_fault)) {
io_cqring_add_event(ctx, sqes[i].sqe->user_data,
-EFAULT);
@@ -2436,7 +2615,7 @@ static int io_sq_thread(void *data)
* to sleep.
*/
if (inflight || !time_after(jiffies, timeout)) {
- cpu_relax();
+ cond_resched();
continue;
}
@@ -2545,18 +2724,22 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit,
io_queue_link_head(ctx, link, &link->submit, shadow_req,
force_nonblock);
link = NULL;
+ shadow_req = NULL;
}
prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0;
if (link && (s.sqe->flags & IOSQE_IO_DRAIN)) {
if (!shadow_req) {
shadow_req = io_get_req(ctx, NULL);
+ if (unlikely(!shadow_req))
+ goto out;
shadow_req->flags |= (REQ_F_IO_DRAIN | REQ_F_SHADOW_DRAIN);
refcount_dec(&shadow_req->refs);
}
shadow_req->sequence = s.sequence;
}
+out:
s.has_user = true;
s.needs_lock = false;
s.needs_fixed_file = false;
@@ -2593,6 +2776,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
const sigset_t __user *sig, size_t sigsz)
{
struct io_rings *rings = ctx->rings;
+ unsigned nr_timeouts;
int ret;
if (io_cqring_events(rings) >= min_events)
@@ -2611,7 +2795,15 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
return ret;
}
- ret = wait_event_interruptible(ctx->wait, io_cqring_events(rings) >= min_events);
+ nr_timeouts = atomic_read(&ctx->cq_timeouts);
+ /*
+ * Return if we have enough events, or if a timeout occured since
+ * we started waiting. For timeouts, we always want to return to
+ * userspace.
+ */
+ ret = wait_event_interruptible(ctx->wait,
+ io_cqring_events(rings) >= min_events ||
+ atomic_read(&ctx->cq_timeouts) != nr_timeouts);
restore_saved_sigmask_unless(ret == -ERESTARTSYS);
if (ret == -ERESTARTSYS)
ret = -EINTR;
@@ -3282,6 +3474,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
percpu_ref_kill(&ctx->refs);
mutex_unlock(&ctx->uring_lock);
+ io_kill_timeouts(ctx);
io_poll_remove_all(ctx);
io_iopoll_reap_events(ctx);
wait_for_completion(&ctx->ctx_done);