summaryrefslogtreecommitdiffstats
path: root/fs
diff options
context:
space:
mode:
authorBijan Mottahedeh <bijan.mottahedeh@oracle.com>2020-04-03 13:51:33 -0700
committerJens Axboe <axboe@kernel.dk>2020-04-03 14:55:39 -0600
commit581f981034890dfd27be7e98946e8f0461f3967a (patch)
tree6025e4ec59cc494b03333ab11c73224c6f26624f /fs
parentc336e992cb1cb1db9ee608dfb30342ae781057ab (diff)
downloadlinux-581f981034890dfd27be7e98946e8f0461f3967a.tar.gz
linux-581f981034890dfd27be7e98946e8f0461f3967a.tar.bz2
linux-581f981034890dfd27be7e98946e8f0461f3967a.zip
io_uring: process requests completed with -EAGAIN on poll list
A request that completes with an -EAGAIN result after it has been added to the poll list, will not be removed from that list in io_do_iopoll() because the f_op->iopoll() will not succeed for that request. Maintain a retryable local list similar to the done list, and explicity reissue requests with an -EAGAIN result. Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/io_uring.c29
1 files changed, 26 insertions, 3 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index ce76157c2f95..78ae8e8ed5bf 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1744,11 +1744,24 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
io_free_req_many(ctx, &rb);
}
+static void io_iopoll_queue(struct list_head *again)
+{
+ struct io_kiocb *req;
+
+ do {
+ req = list_first_entry(again, struct io_kiocb, list);
+ list_del(&req->list);
+ refcount_inc(&req->refs);
+ io_queue_async_work(req);
+ } while (!list_empty(again));
+}
+
static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
long min)
{
struct io_kiocb *req, *tmp;
LIST_HEAD(done);
+ LIST_HEAD(again);
bool spin;
int ret;
@@ -1763,9 +1776,9 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
struct kiocb *kiocb = &req->rw.kiocb;
/*
- * Move completed entries to our local list. If we find a
- * request that requires polling, break out and complete
- * the done list first, if we have entries there.
+ * Move completed and retryable entries to our local lists.
+ * If we find a request that requires polling, break out
+ * and complete those lists first, if we have entries there.
*/
if (req->flags & REQ_F_IOPOLL_COMPLETED) {
list_move_tail(&req->list, &done);
@@ -1774,6 +1787,13 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
if (!list_empty(&done))
break;
+ if (req->result == -EAGAIN) {
+ list_move_tail(&req->list, &again);
+ continue;
+ }
+ if (!list_empty(&again))
+ break;
+
ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
if (ret < 0)
break;
@@ -1786,6 +1806,9 @@ 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);
+ if (!list_empty(&again))
+ io_iopoll_queue(&again);
+
return ret;
}