debian/patches/extra/0005-block-rbd-workaround-for-ceph-issue-53784.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Peter Lieven <pl@kamp.de>
   3 Date: Thu, 13 Jan 2022 15:44:26 +0100
   4 Subject: [PATCH] block/rbd: workaround for ceph issue #53784
   5
   6 librbd had a bug until early 2022 that affected all versions of ceph that
   7 supported fast-diff. This bug results in reporting of incorrect offsets
   8 if the offset parameter to rbd_diff_iterate2 is not object aligned.
   9
  10 This patch works around this bug for pre Quincy versions of librbd.
  11
  12 Fixes: 0347a8fd4c3faaedf119be04c197804be40a384b
  13 Cc: qemu-stable@nongnu.org
  14 Signed-off-by: Peter Lieven <pl@kamp.de>
  15 Message-Id: <20220113144426.4036493-3-pl@kamp.de>
  16 Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
  17 Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
  18 Tested-by: Stefano Garzarella <sgarzare@redhat.com>
  19 Signed-off-by: Kevin Wolf <kwolf@redhat.com>
  20 ---
  21  block/rbd.c | 42 ++++++++++++++++++++++++++++++++++++++++--
  22  1 file changed, 40 insertions(+), 2 deletions(-)
  23
  24 diff --git a/block/rbd.c b/block/rbd.c
  25 index 20bb896c4a..8f183eba2a 100644
  26 --- a/block/rbd.c
  27 +++ b/block/rbd.c
  28 @@ -1320,6 +1320,7 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
  29      int status, r;
  30      RBDDiffIterateReq req = { .offs = offset };
  31      uint64_t features, flags;
  32 +    uint64_t head = 0;
  33
  34      assert(offset + bytes <= s->image_size);
  35
  36 @@ -1347,7 +1348,43 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
  37          return status;
  38      }
  39
  40 -    r = rbd_diff_iterate2(s->image, NULL, offset, bytes, true, true,
  41 +#if LIBRBD_VERSION_CODE < LIBRBD_VERSION(1, 17, 0)
  42 +    /*
  43 +     * librbd had a bug until early 2022 that affected all versions of ceph that
  44 +     * supported fast-diff. This bug results in reporting of incorrect offsets
  45 +     * if the offset parameter to rbd_diff_iterate2 is not object aligned.
  46 +     * Work around this bug by rounding down the offset to object boundaries.
  47 +     * This is OK because we call rbd_diff_iterate2 with whole_object = true.
  48 +     * However, this workaround only works for non cloned images with default
  49 +     * striping.
  50 +     *
  51 +     * See: https://tracker.ceph.com/issues/53784
  52 +     */
  53 +
  54 +    /* check if RBD image has non-default striping enabled */
  55 +    if (features & RBD_FEATURE_STRIPINGV2) {
  56 +        return status;
  57 +    }
  58 +
  59 +#pragma GCC diagnostic push
  60 +#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  61 +    /*
  62 +     * check if RBD image is a clone (= has a parent).
  63 +     *
  64 +     * rbd_get_parent_info is deprecated from Nautilus onwards, but the
  65 +     * replacement rbd_get_parent is not present in Luminous and Mimic.
  66 +     */
  67 +    if (rbd_get_parent_info(s->image, NULL, 0, NULL, 0, NULL, 0) != -ENOENT) {
  68 +        return status;
  69 +    }
  70 +#pragma GCC diagnostic pop
  71 +
  72 +    head = req.offs & (s->object_size - 1);
  73 +    req.offs -= head;
  74 +    bytes += head;
  75 +#endif
  76 +
  77 +    r = rbd_diff_iterate2(s->image, NULL, req.offs, bytes, true, true,
  78                            qemu_rbd_diff_iterate_cb, &req);
  79      if (r < 0 && r != QEMU_RBD_EXIT_DIFF_ITERATE2) {
  80          return status;
  81 @@ -1366,7 +1403,8 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
  82          status = BDRV_BLOCK_ZERO | BDRV_BLOCK_OFFSET_VALID;
  83      }
  84
  85 -    *pnum = req.bytes;
  86 +    assert(req.bytes > head);
  87 +    *pnum = req.bytes - head;
  88      return status;
  89  }
  90