0114d3cd02
Linux SCSI can throw spurious -EAGAIN in some corner cases in its completion path, which will end up being the result in the completed io_uring request. Resubmitting such requests should allow block jobs to complete, even if such spurious errors are encountered. Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
50 lines
1.9 KiB
Diff
50 lines
1.9 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
|
|
From: Fabian Ebner <f.ebner@proxmox.com>
|
|
Date: Fri, 23 Jul 2021 12:42:23 +0200
|
|
Subject: [PATCH] block/io_uring: resubmit when result is -EAGAIN
|
|
|
|
Linux SCSI can throw spurious -EAGAIN in some corner cases in its
|
|
completion path, which will end up being the result in the completed
|
|
io_uring request.
|
|
|
|
Resubmitting such requests should allow block jobs to complete, even
|
|
if such spurious errors are encountered.
|
|
|
|
Co-authored-by: Stefan Hajnoczi <stefanha@gmail.com>
|
|
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
|
|
Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
|
|
---
|
|
block/io_uring.c | 16 +++++++++++++++-
|
|
1 file changed, 15 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/block/io_uring.c b/block/io_uring.c
|
|
index 00a3ee9fb8..dfa475cc87 100644
|
|
--- a/block/io_uring.c
|
|
+++ b/block/io_uring.c
|
|
@@ -165,7 +165,21 @@ static void luring_process_completions(LuringState *s)
|
|
total_bytes = ret + luringcb->total_read;
|
|
|
|
if (ret < 0) {
|
|
- if (ret == -EINTR) {
|
|
+ /*
|
|
+ * Only writev/readv/fsync requests on regular files or host block
|
|
+ * devices are submitted. Therefore -EAGAIN is not expected but it's
|
|
+ * known to happen sometimes with Linux SCSI. Submit again and hope
|
|
+ * the request completes successfully.
|
|
+ *
|
|
+ * For more information, see:
|
|
+ * https://lore.kernel.org/io-uring/20210727165811.284510-3-axboe@kernel.dk/T/#u
|
|
+ *
|
|
+ * If the code is changed to submit other types of requests in the
|
|
+ * future, then this workaround may need to be extended to deal with
|
|
+ * genuine -EAGAIN results that should not be resubmitted
|
|
+ * immediately.
|
|
+ */
|
|
+ if (ret == -EINTR || ret == -EAGAIN) {
|
|
luring_resubmit(s, luringcb);
|
|
continue;
|
|
}
|
|
--
|
|
2.30.2
|
|
|