debian/patches/extra/0003-block-Do-not-unref-bs-file-on-error-in-BD-s-open.patch

   1 From 7abd8d3ceb29140469c3662fb53de6a4dfe4623e Mon Sep 17 00:00:00 2001
   2 From: Max Reitz <mreitz@redhat.com>
   3 Date: Thu, 13 Apr 2017 17:43:34 +0200
   4 Subject: [PATCH 03/15] block: Do not unref bs->file on error in BD's open
   5
   6 The block layer takes care of removing the bs->file child if the block
   7 driver's bdrv_open()/bdrv_file_open() implementation fails. The block
   8 driver therefore does not need to do so, and indeed should not unless it
   9 sets bs->file to NULL afterwards -- because if this is not done, the
  10 bdrv_unref_child() in bdrv_open_inherit() will dereference the freed
  11 memory block at bs->file afterwards, which is not good.
  12
  13 We can now decide whether to add a "bs->file = NULL;" after each of the
  14 offending bdrv_unref_child() invocations, or just drop them altogether.
  15 The latter is simpler, so let's do that.
  16
  17 Cc: qemu-stable <qemu-stable@nongnu.org>
  18 Signed-off-by: Max Reitz <mreitz@redhat.com>
  19 Reviewed-by: Eric Blake <eblake@redhat.com>
  20 Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
  21 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
  22 ---
  23  block/blkdebug.c  | 4 +---
  24  block/blkreplay.c | 3 ---
  25  block/blkverify.c | 3 ---
  26  3 files changed, 1 insertion(+), 9 deletions(-)
  27
  28 diff --git a/block/blkdebug.c b/block/blkdebug.c
  29 index 67e8024e36..cc4a146e84 100644
  30 --- a/block/blkdebug.c
  31 +++ b/block/blkdebug.c
  32 @@ -389,14 +389,12 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
  33      } else if (align) {
  34          error_setg(errp, "Invalid alignment");
  35          ret = -EINVAL;
  36 -        goto fail_unref;
  37 +        goto out;
  38      }
  39
  40      ret = 0;
  41      goto out;
  42
  43 -fail_unref:
  44 -    bdrv_unref_child(bs, bs->file);
  45  out:
  46      if (ret < 0) {
  47          g_free(s->config_file);
  48 diff --git a/block/blkreplay.c b/block/blkreplay.c
  49 index e1102119fb..6aa5fd4156 100755
  50 --- a/block/blkreplay.c
  51 +++ b/block/blkreplay.c
  52 @@ -37,9 +37,6 @@ static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
  53
  54      ret = 0;
  55  fail:
  56 -    if (ret < 0) {
  57 -        bdrv_unref_child(bs, bs->file);
  58 -    }
  59      return ret;
  60  }
  61
  62 diff --git a/block/blkverify.c b/block/blkverify.c
  63 index 9a1e21c6ad..af23281669 100644
  64 --- a/block/blkverify.c
  65 +++ b/block/blkverify.c
  66 @@ -142,9 +142,6 @@ static int blkverify_open(BlockDriverState *bs, QDict *options, int flags,
  67
  68      ret = 0;
  69  fail:
  70 -    if (ret < 0) {
  71 -        bdrv_unref_child(bs, bs->file);
  72 -    }
  73      qemu_opts_del(opts);
  74      return ret;
  75  }
  76 --
  77 2.11.0
  78