From fc176116cdea816ceb8dd969080b2b95f58edbc0 Mon Sep 17 00:00:00 2001 From: Peter Lieven Date: Thu, 13 Jan 2022 15:44:26 +0100 Subject: block/rbd: workaround for ceph issue #53784 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 Message-Id: <20220113144426.4036493-3-pl@kamp.de> Reviewed-by: Ilya Dryomov Reviewed-by: Stefano Garzarella Tested-by: Stefano Garzarella Signed-off-by: Kevin Wolf --- block/rbd.c | 42 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 40 insertions(+), 2 deletions(-) (limited to 'block/rbd.c') diff --git a/block/rbd.c b/block/rbd.c index 20bb896c4a..8f183eba2a 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -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; } -- cgit v1.2.3