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block/rbd: workaround for ceph issue #53784

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librbd had a bug until early 2022 that affected all versions of ceph that
supported fast-diff. This bug results in reporting of incorrect offsets
if the offset parameter to rbd_diff_iterate2 is not object aligned.

This patch works around this bug for pre Quincy versions of librbd.

Fixes: 0347a8fd4c3faaedf119be04c197804be40a384b
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Message-Id: <20220113144426.4036493-3-pl@kamp.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Tested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Peter Lieven 2022-01-13 15:44:26 +01:00 committed by Kevin Wolf
parent 9e302f64bb
commit fc176116cd
1 changed files with 40 additions and 2 deletions
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42
block/rbd.c
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@ -1320,6 +1320,7 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
int status, r;
RBDDiffIterateReq req = { .offs = offset };
uint64_t features, flags;
uint64_t head = 0;
assert(offset + bytes <= s->image_size);
@ -1347,7 +1348,43 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
return status;
}
r = rbd_diff_iterate2(s->image, NULL, offset, bytes, true, true,
#if LIBRBD_VERSION_CODE < LIBRBD_VERSION(1, 17, 0)
/*
* librbd had a bug until early 2022 that affected all versions of ceph that
* supported fast-diff. This bug results in reporting of incorrect offsets
* if the offset parameter to rbd_diff_iterate2 is not object aligned.
* Work around this bug by rounding down the offset to object boundaries.
* This is OK because we call rbd_diff_iterate2 with whole_object = true.
* However, this workaround only works for non cloned images with default
* striping.
*
* See: https://tracker.ceph.com/issues/53784
*/
/* check if RBD image has non-default striping enabled */
if (features & RBD_FEATURE_STRIPINGV2) {
return status;
}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
/*
* check if RBD image is a clone (= has a parent).
*
* rbd_get_parent_info is deprecated from Nautilus onwards, but the
* replacement rbd_get_parent is not present in Luminous and Mimic.
*/
if (rbd_get_parent_info(s->image, NULL, 0, NULL, 0, NULL, 0) != -ENOENT) {
return status;
}
#pragma GCC diagnostic pop
head = req.offs & (s->object_size - 1);
req.offs -= head;
bytes += head;
#endif
r = rbd_diff_iterate2(s->image, NULL, req.offs, bytes, true, true,
qemu_rbd_diff_iterate_cb, &req);
if (r < 0 && r != QEMU_RBD_EXIT_DIFF_ITERATE2) {
return status;
@ -1366,7 +1403,8 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
status = BDRV_BLOCK_ZERO | BDRV_BLOCK_OFFSET_VALID;
}
*pnum = req.bytes;
assert(req.bytes > head);
*pnum = req.bytes - head;
return status;
}