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[Qemu-devel] [PATCH v4 24/26] qcow2: Invoke refcount order amendment fun
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH v4 24/26] qcow2: Invoke refcount order amendment function |
Date: |
Wed, 3 Dec 2014 14:37:44 +0100 |
Make use of qcow2_change_refcount_order() to support changing the
refcount order with qemu-img amend.
Signed-off-by: Max Reitz <address@hidden>
---
block/qcow2.c | 44 +++++++++++++++++++++++++++++++++++---------
1 file changed, 35 insertions(+), 9 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 6caac05..7df5af0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2606,13 +2606,7 @@ 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;
}
@@ -2660,6 +2654,7 @@ typedef enum Qcow2AmendOperation {
* invocation from an operation change */
QCOW2_NO_OPERATION = 0,
+ QCOW2_CHANGING_REFCOUNT_ORDER,
QCOW2_DOWNGRADING,
} Qcow2AmendOperation;
@@ -2735,6 +2730,7 @@ 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;
@@ -2785,8 +2781,16 @@ 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 */
@@ -2800,6 +2804,7 @@ 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) */
@@ -2812,6 +2817,27 @@ static int qcow2_amend_options(BlockDriverState *bs,
QemuOpts *opts,
}
}
+ if (s->refcount_bits != refcount_bits) {
+ int refcount_order = ffs(refcount_bits) - 1;
+ 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) {
+ qerror_report_err(local_error);
+ return ret;
+ }
+ }
+
if (backing_file || backing_format) {
ret = qcow2_change_backing_file(bs, backing_file ?: bs->backing_file,
backing_format ?: bs->backing_format);
--
1.9.3
- Re: [Qemu-devel] [PATCH v4 16/26] qcow2: Allow creation with refcount order != 4, (continued)
- [Qemu-devel] [PATCH v4 19/26] qcow2: Use error_report() in qcow2_amend_options(), Max Reitz, 2014/12/03
- [Qemu-devel] [PATCH v4 20/26] qcow2: Use abort() instead of assert(false), Max Reitz, 2014/12/03
- [Qemu-devel] [PATCH v4 21/26] qcow2: Split upgrade/downgrade paths for amend, Max Reitz, 2014/12/03
- [Qemu-devel] [PATCH v4 22/26] qcow2: Use intermediate helper CB for amend, Max Reitz, 2014/12/03
- [Qemu-devel] [PATCH v4 23/26] qcow2: Add function for refcount order amendment, Max Reitz, 2014/12/03
- [Qemu-devel] [PATCH v4 24/26] qcow2: Invoke refcount order amendment function,
Max Reitz <=
- [Qemu-devel] [PATCH v4 25/26] qcow2: Point to amend function in check, Max Reitz, 2014/12/03
- [Qemu-devel] [PATCH v4 26/26] iotests: Add test for different refcount widths, Max Reitz, 2014/12/03
[Qemu-devel] [PATCH v4 15/26] iotests: Prepare for refcount_bits option, Max Reitz, 2014/12/03