From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 8 Sep 2020 14:25:36 +0000 (+0200)
Subject: 5.8-stable patches
X-Git-Tag: v4.14.197~13
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=258a735d18f15f246e484b5e9020bb802ae97797;p=thirdparty%2Fkernel%2Fstable-queue.git

5.8-stable patches

added patches:
	io_uring-no-read-write-retry-on-eagain-error-and-o_nonblock-marked-file.patch
---

diff --git a/queue-5.8/io_uring-no-read-write-retry-on-eagain-error-and-o_nonblock-marked-file.patch b/queue-5.8/io_uring-no-read-write-retry-on-eagain-error-and-o_nonblock-marked-file.patch
new file mode 100644
index 00000000000..f7f7dfa9631
--- /dev/null
+++ b/queue-5.8/io_uring-no-read-write-retry-on-eagain-error-and-o_nonblock-marked-file.patch
@@ -0,0 +1,59 @@
+From 355afaeb578abac907217c256a844cfafb0337b2 Mon Sep 17 00:00:00 2001
+From: Jens Axboe <axboe@kernel.dk>
+Date: Wed, 2 Sep 2020 09:30:31 -0600
+Subject: io_uring: no read/write-retry on -EAGAIN error and O_NONBLOCK marked file
+
+From: Jens Axboe <axboe@kernel.dk>
+
+commit 355afaeb578abac907217c256a844cfafb0337b2 upstream.
+
+Actually two things that need fixing up here:
+
+- The io_rw_reissue() -EAGAIN retry is explicit to block devices and
+  regular files, so don't ever attempt to do that on other types of
+  files.
+
+- If we hit -EAGAIN on a nonblock marked file, don't arm poll handler for
+  it. It should just complete with -EAGAIN.
+
+Cc: stable@vger.kernel.org
+Reported-by: Norman Maurer <norman.maurer@googlemail.com>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/io_uring.c |   13 +++++++++++++
+ 1 file changed, 13 insertions(+)
+
+--- a/fs/io_uring.c
++++ b/fs/io_uring.c
+@@ -2697,8 +2697,15 @@ static int io_read(struct io_kiocb *req,
+ 		else
+ 			ret2 = -EINVAL;
+ 
++		/* no retry on NONBLOCK marked file */
++		if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) {
++			ret = 0;
++			goto done;
++		}
++
+ 		/* Catch -EAGAIN return for forced non-blocking submission */
+ 		if (!force_nonblock || ret2 != -EAGAIN) {
++	done:
+ 			kiocb_done(kiocb, ret2);
+ 		} else {
+ copy_iov:
+@@ -2823,7 +2830,13 @@ static int io_write(struct io_kiocb *req
+ 		 */
+ 		if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
+ 			ret2 = -EAGAIN;
++		/* no retry on NONBLOCK marked file */
++		if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) {
++			ret = 0;
++			goto done;
++		}
+ 		if (!force_nonblock || ret2 != -EAGAIN) {
++done:
+ 			kiocb_done(kiocb, ret2);
+ 		} else {
+ copy_iov:
diff --git a/queue-5.8/series b/queue-5.8/series
index a3c67d9e3dd..855127a5dd9 100644
--- a/queue-5.8/series
+++ b/queue-5.8/series
@@ -173,3 +173,4 @@ mm-slub-fix-conversion-of-freelist_corrupted.patch
 mm-track-page-table-modifications-in-__apply_to_page_range.patch
 mm-madvise-fix-vma-user-after-free.patch
 mm-rmap-fixup-copying-of-soft-dirty-and-uffd-ptes.patch
+io_uring-no-read-write-retry-on-eagain-error-and-o_nonblock-marked-file.patch