debian/patches/extra/0011-block-Fix-locking-in-qmp_block_resize.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Kevin Wolf <kwolf@redhat.com>
   3 Date: Thu, 3 Dec 2020 18:23:10 +0100
   4 Subject: [PATCH] block: Fix locking in qmp_block_resize()
   5
   6 The drain functions assume that we hold the AioContext lock of the
   7 drained block node. Make sure to actually take the lock.
   8
   9 Cc: qemu-stable@nongnu.org
  10 Fixes: eb94b81a94bce112e6b206df846c1551aaf6cab6
  11 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
  12 Message-Id: <20201203172311.68232-3-kwolf@redhat.com>
  13 Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  14 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
  15 Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
  16 ---
  17  blockdev.c | 5 ++++-
  18  1 file changed, 4 insertions(+), 1 deletion(-)
  19
  20 diff --git a/blockdev.c b/blockdev.c
  21 index fe6fb5dc1d..9a86e9fb4b 100644
  22 --- a/blockdev.c
  23 +++ b/blockdev.c
  24 @@ -2481,14 +2481,17 @@ void coroutine_fn qmp_block_resize(bool has_device, const char *device,
  25          goto out;
  26      }
  27
  28 +    bdrv_co_lock(bs);
  29      bdrv_drained_begin(bs);
  30 +    bdrv_co_unlock(bs);
  31 +
  32      old_ctx = bdrv_co_enter(bs);
  33      blk_truncate(blk, size, false, PREALLOC_MODE_OFF, 0, errp);
  34      bdrv_co_leave(bs, old_ctx);
  35 -    bdrv_drained_end(bs);
  36
  37  out:
  38      bdrv_co_lock(bs);
  39 +    bdrv_drained_end(bs);
  40      blk_unref(blk);
  41      bdrv_co_unlock(bs);
  42  }