From 61ce55fc02c57b5ec61e4b3a75dfab7ef6a92bd8 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 27 Jul 2015 17:51:38 +0200 Subject: qcow2: Invoke refcount order amendment function Make use of qcow2_change_refcount_order() to support changing the refcount order with qemu-img amend. Signed-off-by: Max Reitz Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block/qcow2.c | 44 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 9 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 851de25..0304de6 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2885,13 +2885,7 @@ static int qcow2_downgrade(BlockDriverState *bs, int target_version, } if (s->refcount_order != 4) { - /* we would have to convert the image to a refcount_order == 4 image - * here; however, since qemu (at the time of writing this) does not - * support anything different than 4 anyway, there is no point in doing - * so right now; however, we should error out (if qemu supports this in - * the future and this code has not been adapted) */ - error_report("qcow2_downgrade: Image refcount orders other than 4 are " - "currently not supported."); + error_report("compat=0.10 requires refcount_bits=16"); return -ENOTSUP; } @@ -2939,6 +2933,7 @@ typedef enum Qcow2AmendOperation { * invocation from an operation change */ QCOW2_NO_OPERATION = 0, + QCOW2_CHANGING_REFCOUNT_ORDER, QCOW2_DOWNGRADING, } Qcow2AmendOperation; @@ -3014,6 +3009,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, const char *compat = NULL; uint64_t cluster_size = s->cluster_size; bool encrypt; + int refcount_bits = s->refcount_bits; int ret; QemuOptDesc *desc = opts->list->desc; Qcow2AmendHelperCBInfo helper_cb_info; @@ -3065,8 +3061,16 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, lazy_refcounts); } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { - error_report("Cannot change refcount entry width"); - return -ENOTSUP; + refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, + refcount_bits); + + if (refcount_bits <= 0 || refcount_bits > 64 || + !is_power_of_2(refcount_bits)) + { + error_report("Refcount width must be a power of two and may " + "not exceed 64 bits"); + return -EINVAL; + } } else { /* if this point is reached, this probably means a new option was * added without having it covered here */ @@ -3080,6 +3084,7 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, .original_status_cb = status_cb, .original_cb_opaque = cb_opaque, .total_operations = (new_version < old_version) + + (s->refcount_bits != refcount_bits) }; /* Upgrade first (some features may require compat=1.1) */ @@ -3092,6 +3097,27 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, } } + if (s->refcount_bits != refcount_bits) { + int refcount_order = ctz32(refcount_bits); + Error *local_error = NULL; + + if (new_version < 3 && refcount_bits != 16) { + error_report("Different refcount widths than 16 bits require " + "compatibility level 1.1 or above (use compat=1.1 or " + "greater)"); + return -EINVAL; + } + + helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; + ret = qcow2_change_refcount_order(bs, refcount_order, + &qcow2_amend_helper_cb, + &helper_cb_info, &local_error); + if (ret < 0) { + error_report_err(local_error); + return ret; + } + } + if (backing_file || backing_format) { ret = qcow2_change_backing_file(bs, backing_file ?: s->image_backing_file, -- cgit v1.1