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[Qemu-block] [PULL 66/85] qcow2: add bdrv_measure() support
From: |
Max Reitz |
Subject: |
[Qemu-block] [PULL 66/85] qcow2: add bdrv_measure() support |
Date: |
Tue, 11 Jul 2017 18:07:55 +0200 |
From: Stefan Hajnoczi <address@hidden>
Use qcow2_calc_prealloc_size() to get the required file size.
Signed-off-by: Stefan Hajnoczi <address@hidden>
Reviewed-by: Alberto Garcia <address@hidden>
Message-id: address@hidden
Signed-off-by: Max Reitz <address@hidden>
---
block/qcow2.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 137 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index db8d81f..52dc6bf 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3426,6 +3426,142 @@ static coroutine_fn int
qcow2_co_flush_to_os(BlockDriverState *bs)
return 0;
}
+static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
+ Error **errp)
+{
+ Error *local_err = NULL;
+ BlockMeasureInfo *info;
+ uint64_t required = 0; /* bytes that contribute to required size */
+ uint64_t virtual_size; /* disk size as seen by guest */
+ uint64_t refcount_bits;
+ uint64_t l2_tables;
+ size_t cluster_size;
+ int version;
+ char *optstr;
+ PreallocMode prealloc;
+ bool has_backing_file;
+
+ /* Parse image creation options */
+ cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
+ if (local_err) {
+ goto err;
+ }
+
+ version = qcow2_opt_get_version_del(opts, &local_err);
+ if (local_err) {
+ goto err;
+ }
+
+ refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
+ if (local_err) {
+ goto err;
+ }
+
+ optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
+ prealloc = qapi_enum_parse(PreallocMode_lookup, optstr,
+ PREALLOC_MODE__MAX, PREALLOC_MODE_OFF,
+ &local_err);
+ g_free(optstr);
+ if (local_err) {
+ goto err;
+ }
+
+ optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
+ has_backing_file = !!optstr;
+ g_free(optstr);
+
+ virtual_size = align_offset(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+ cluster_size);
+
+ /* Check that virtual disk size is valid */
+ l2_tables = DIV_ROUND_UP(virtual_size / cluster_size,
+ cluster_size / sizeof(uint64_t));
+ if (l2_tables * sizeof(uint64_t) > QCOW_MAX_L1_SIZE) {
+ error_setg(&local_err, "The image size is too large "
+ "(try using a larger cluster size)");
+ goto err;
+ }
+
+ /* Account for input image */
+ if (in_bs) {
+ int64_t ssize = bdrv_getlength(in_bs);
+ if (ssize < 0) {
+ error_setg_errno(&local_err, -ssize,
+ "Unable to get image virtual_size");
+ goto err;
+ }
+
+ virtual_size = align_offset(ssize, cluster_size);
+
+ if (has_backing_file) {
+ /* We don't how much of the backing chain is shared by the input
+ * image and the new image file. In the worst case the new image's
+ * backing file has nothing in common with the input image. Be
+ * conservative and assume all clusters need to be written.
+ */
+ required = virtual_size;
+ } else {
+ int cluster_sectors = cluster_size / BDRV_SECTOR_SIZE;
+ int64_t sector_num;
+ int pnum = 0;
+
+ for (sector_num = 0;
+ sector_num < ssize / BDRV_SECTOR_SIZE;
+ sector_num += pnum) {
+ int nb_sectors = MAX(ssize / BDRV_SECTOR_SIZE - sector_num,
+ INT_MAX);
+ BlockDriverState *file;
+ int64_t ret;
+
+ ret = bdrv_get_block_status_above(in_bs, NULL,
+ sector_num, nb_sectors,
+ &pnum, &file);
+ if (ret < 0) {
+ error_setg_errno(&local_err, -ret,
+ "Unable to get block status");
+ goto err;
+ }
+
+ if (ret & BDRV_BLOCK_ZERO) {
+ /* Skip zero regions (safe with no backing file) */
+ } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) ==
+ (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) {
+ /* Extend pnum to end of cluster for next iteration */
+ pnum = ROUND_UP(sector_num + pnum, cluster_sectors) -
+ sector_num;
+
+ /* Count clusters we've seen */
+ required += (sector_num % cluster_sectors + pnum) *
+ BDRV_SECTOR_SIZE;
+ }
+ }
+ }
+ }
+
+ /* Take into account preallocation. Nothing special is needed for
+ * PREALLOC_MODE_METADATA since metadata is always counted.
+ */
+ if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) {
+ required = virtual_size;
+ }
+
+ info = g_new(BlockMeasureInfo, 1);
+ info->fully_allocated =
+ qcow2_calc_prealloc_size(virtual_size, cluster_size,
+ ctz32(refcount_bits));
+
+ /* Remove data clusters that are not required. This overestimates the
+ * required size because metadata needed for the fully allocated file is
+ * still counted.
+ */
+ info->required = info->fully_allocated - virtual_size + required;
+ return info;
+
+err:
+ error_propagate(errp, local_err);
+ return NULL;
+}
+
static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BDRVQcow2State *s = bs->opaque;
@@ -4024,6 +4160,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_snapshot_delete = qcow2_snapshot_delete,
.bdrv_snapshot_list = qcow2_snapshot_list,
.bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
+ .bdrv_measure = qcow2_measure,
.bdrv_get_info = qcow2_get_info,
.bdrv_get_specific_info = qcow2_get_specific_info,
--
2.9.4
- [Qemu-block] [PULL 56/85] iotests: add more LUKS hash combination tests, (continued)
- [Qemu-block] [PULL 56/85] iotests: add more LUKS hash combination tests, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 58/85] iotests: Use absolute paths for executables, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 59/85] iotests: Add test for colon handling, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 60/85] tests: Avoid non-portable 'echo -ARG', Max Reitz, 2017/07/11
- [Qemu-block] [PULL 61/85] block: add bdrv_measure() API, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 62/85] raw-format: add bdrv_measure() support, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 57/85] iotests: chown LUKS device before qemu-io launches, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 63/85] qcow2: extract preallocation calculation function, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 64/85] qcow2: make refcount size calculation conservative, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 65/85] qcow2: extract image creation option parsing, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 66/85] qcow2: add bdrv_measure() support,
Max Reitz <=
- [Qemu-block] [PULL 68/85] qemu-iotests: support per-format golden output files, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 67/85] qemu-img: add measure subcommand, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 70/85] block: Add PreallocMode to BD.bdrv_truncate(), Max Reitz, 2017/07/11
- [Qemu-block] [PULL 69/85] iotests: add test 178 for qemu-img measure, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 71/85] block: Add PreallocMode to bdrv_truncate(), Max Reitz, 2017/07/11
- [Qemu-block] [PULL 72/85] block: Add PreallocMode to blk_truncate(), Max Reitz, 2017/07/11
- [Qemu-block] [PULL 73/85] qemu-img: Expose PreallocMode for resizing, Max Reitz, 2017/07/11
- [Qemu-block] [PULL 74/85] block/file-posix: Small fixes in raw_create(), Max Reitz, 2017/07/11
- [Qemu-block] [PULL 75/85] block/file-posix: Extract raw_regular_truncate(), Max Reitz, 2017/07/11
- [Qemu-block] [PULL 76/85] block/file-posix: Generalize raw_regular_truncate, Max Reitz, 2017/07/11