cherry-pick upstream fixes for 7.0.0

[pve-qemu.git] / debian / patches / extra / 0004-linux-aio-fix-unbalanced-plugged-counter-in-laio_io_.patch

diff --git a/debian/patches/extra/0004-linux-aio-fix-unbalanced-plugged-counter-in-laio_io_.patch b/debian/patches/extra/0004-linux-aio-fix-unbalanced-plugged-counter-in-laio_io_.patch
new file mode 100644 (file)
index 0000000..cf130ac
--- /dev/null
+++ b/debian/patches/extra/0004-linux-aio-fix-unbalanced-plugged-counter-in-laio_io_.patch
@@ -0,0 +1,44 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Stefan Hajnoczi <stefanha@redhat.com>
+Date: Thu, 9 Jun 2022 17:47:11 +0100
+Subject: [PATCH] linux-aio: fix unbalanced plugged counter in laio_io_unplug()
+
+Every laio_io_plug() call has a matching laio_io_unplug() call. There is
+a plugged counter that tracks the number of levels of plugging and
+allows for nesting.
+
+The plugged counter must reflect the balance between laio_io_plug() and
+laio_io_unplug() calls accurately. Otherwise I/O stalls occur since
+io_submit(2) calls are skipped while plugged.
+
+Reported-by: Nikolay Tenev <nt@storpool.com>
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
+Message-id: 20220609164712.1539045-2-stefanha@redhat.com
+Cc: Stefano Garzarella <sgarzare@redhat.com>
+Fixes: 68d7946648 ("linux-aio: add `dev_max_batch` parameter to laio_io_unplug()")
+[Stefano Garzarella suggested adding a Fixes tag.
+--Stefan]
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+(cherry-picked from commit f387cac5af030a58ac5a0dacf64cab5e5a4fe5c7)
+Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
+---
+ block/linux-aio.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/block/linux-aio.c b/block/linux-aio.c
+index 4c423fcccf..6078da7e42 100644
+--- a/block/linux-aio.c
++++ b/block/linux-aio.c
+@@ -363,8 +363,10 @@ void laio_io_unplug(BlockDriverState *bs, LinuxAioState *s,
+                     uint64_t dev_max_batch)
+ {
+     assert(s->io_q.plugged);
++    s->io_q.plugged--;
++
+     if (s->io_q.in_queue >= laio_max_batch(s, dev_max_batch) ||
+-        (--s->io_q.plugged == 0 &&
++        (!s->io_q.plugged &&
+          !s->io_q.blocked && !QSIMPLEQ_EMPTY(&s->io_q.pending))) {
+         ioq_submit(s);
+     }